U.S. patent number 10,478,449 [Application Number 15/782,048] was granted by the patent office on 2019-11-19 for 2'-methoxy substituted oligomeric compounds and compositions for use in gene modulations.
This patent grant is currently assigned to Ionis Pharmaceuticals, Inc.. The grantee listed for this patent is Ionis Pharmaceuticals, Inc.. Invention is credited to Stanley T. Crooke.
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United States Patent |
10,478,449 |
Crooke |
November 19, 2019 |
2'-methoxy substituted oligomeric compounds and compositions for
use in gene modulations
Abstract
Compositions comprising first and second oligomers are provided
wherein at least a portion of the first oligomer is capable of
hybridizing with at least a portion of the second oligomer, at
least a portion of the first oligomer is complementary to and
capable of hybridizing to a selected target nucleic acid, and at
least one of the first or second oligomers includes a modified
sugar and/or backbone modification. In some embodiments the
modification is a 2'-OCH.sub.3 substituent group on a sugar moiety.
Oligomer/protein compositions are also provided comprising an
oligomer complementary to and capable of hybridizing to a selected
target nucleic acid and at least one protein comprising at least a
portion of an RNA-induced silencing complex (RISC), wherein at
least one nucleotide of the oligomer has a modified sugar and/or
backbone modification.
Inventors: |
Crooke; Stanley T. (Carlsbad,
CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
Ionis Pharmaceuticals, Inc. |
Carlsbad |
CA |
US |
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Assignee: |
Ionis Pharmaceuticals, Inc.
(Carlsbad, CA)
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Family
ID: |
54868670 |
Appl.
No.: |
15/782,048 |
Filed: |
October 12, 2017 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20180028555 A1 |
Feb 1, 2018 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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14690120 |
Apr 17, 2015 |
9827263 |
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10701264 |
Nov 4, 2003 |
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60503521 |
Sep 16, 2003 |
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60423760 |
Nov 5, 2002 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C12N
15/111 (20130101); A61K 31/713 (20130101); C12N
2310/315 (20130101); C12N 2310/342 (20130101); C12N
2310/14 (20130101); C12N 2310/344 (20130101); C12N
2310/321 (20130101); C12N 2310/3521 (20130101); C12N
2310/322 (20130101); C12N 2310/3533 (20130101) |
Current International
Class: |
C12N
15/113 (20100101); A61K 31/713 (20060101); C12N
15/11 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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WO 1995/013834 |
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May 1995 |
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WO |
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WO 2002/081494 |
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Oct 2002 |
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WO |
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WO 2003/070895 |
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Aug 2003 |
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WO |
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WO-03070918 |
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Aug 2003 |
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WO |
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WO 2003/074654 |
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Sep 2003 |
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WO |
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WO 2003/106477 |
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Dec 2003 |
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WO |
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WO 2004/044141 |
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May 2004 |
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WO |
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WO 2004/080406 |
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Sep 2004 |
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WO |
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Other References
Duroux et al., "Rational design of point mutation-selective
antisense DNA targeted to codon 12 of Ha-ras mRNA in human cells"
Nucleic Acids Research (1995) 23(17):3411-3418. cited by applicant
.
Giles et al., "Increased specificity for antisense
oligodeoxynucleotide targeting of RNA cleavage of Rnase H using
chimeric methylphosphonodiester/phosphodiester structures" Nucleic
Acids Research (1992) 20(4):763-770. cited by applicant .
Gray et al., "Antisense DNA Inhibition of Tumor Growth Induced by
c-HA-ras-Oncogene in Nude Mice" Cancer Research (1993) 53:577-580.
cited by applicant .
Guo et al., "Direct fluorescence analysis of genetic polymorphisms
by hybridization with oligonucleotide arrays on glass supports"
Nucl. Acds Res. (1994) 22:5456-5465. cited by applicant .
Harborth et al., "Sequence, Chemical and Structural Variation of
Small Interfering RNAa and Shoart Hairpin RNAs and the Effect on
Mammalian Gene Silencing" Antisense & Nucleic Acid Drug
Development, Mary Ann Liebert, NY, US, Apr. 1, 2003, 13(2), 83-105.
cited by applicant .
Nestle et al., "Cationic Lipid is not Required for Uptake and
Selective Inhibitory Activity of ICAM-1 Phosphorothioate Antisense
Oligonucleotides in Keratinocytes" J. Invest. Dermatol. (1994)
103:569-575. cited by applicant .
U.S. Appl. No. 60/358,580, filed Feb. 20, 2002, Beigelman et al.
cited by applicant .
U.S. Appl. No. 60/402,541, filed Aug. 12, 2002, Kaufmann et al.
cited by applicant .
U.S. Appl. No. 60/503,271, filed Sep. 15, 2003, Crooke et al. cited
by applicant .
Hesson et al., "Probing the Relationship between RNA-Stimulated
ATPase and Helicase Activities of HCV NS3 Using 2'-O-Methyl RNA
Substrates" Biochemistry (2000) 39: 2619-2625. cited by
applicant.
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Primary Examiner: Vivlemore; Tracy
Attorney, Agent or Firm: McNeill Baur PLLC
Claims
What is claimed is:
1. A composition comprising a first oligomer and a second oligomer,
wherein: at least a portion of said first oligomer is capable of
hybridizing with at least a portion of said second oligomer, at
least a portion of said first oligomer is complementary to and
capable of hybridizing with a selected target nucleic acid, each of
said first and second oligomers are chimeric oligomers, wherein the
second oligomer has an internal segment comprising at least five
consecutive nucleosides having a 2'-OCH.sub.3 substituent group,
and wherein the chimeric oligomers are not gapmers.
2. The composition of claim 1 wherein each of said first and second
oligomers comprise from about 18 to about 30 linked
nucleosides.
3. The composition of claim 1 wherein each of said first and second
oligomers comprise from about 21 to about 24 linked
nucleosides.
4. The composition of claim 1 wherein each of said first and second
oligomers comprise 21 linked nucleosides.
5. The composition of claim 1 wherein each of said first and second
oligomers comprise nucleosides selected from
.beta.-D-ribonucleosides, 2'-OCH.sub.3 modified nucleosides and
2'-deoxythymidine nucleosides.
6. The composition of claim 1 wherein said first oligomer is an
antisense oligomer and the second oligomer is a sense oligomer.
7. The composition of claim 1 wherein said first and said second
oligomers are a complementary pair of siRNA oligomers.
8. The composition of claim 1 wherein each internucleoside linkage
is, independently, a phosphodiester or phosphorothioate
internucleoside linkage.
9. The composition of claim 1 wherein each internucleoside linkage
is a phosphodiester internucleoside linkage.
10. The composition of claim 1 wherein the 5'-terminal nucleoside
of said first oligomer has a 5'-phosphate group.
11. The composition of claim 1 wherein at least one of said first
and second oligomers comprises a nucleoside with a 2'-F substituent
group.
12. The composition of claim 1 wherein said first and second
oligomers form a blunt ended duplex.
13. The composition of claim 1 wherein at least one of said first
or second oligomers has an overhang.
14. The composition of claim 1 wherein each of said first and
second oligomers independently comprises a 3'-overhang consisting
of two deoxythymidine nucleosides.
15. The composition of claim 1 wherein at least one of said first
and second oligomers comprises a blockmer.
16. The composition of claim 15 wherein the blockmer comprises an
oligonucleoside having at least two consecutive nucleosides of a
first type located immediately adjacent to at least one nucleoside
of a second type and wherein said nucleosides of said first type
are different from said nucleosides of said second type.
17. The composition of claim 16 wherein each of said nucleosides of
said first type includes a 2'-OCH.sub.3 substituent group.
18. The composition of claim 16 wherein the blockmer comprises an
oligonucleoside having at least three consecutive nucleosides of
said first type.
19. The composition of claim 16 wherein the blockmer comprises an
oligonucleoside having at least five consecutive nucleosides of
said first type.
Description
SEQUENCE LISTING
The present application is being filed along with a Sequence
Listing in electronic format. The Sequence Listing is provided as a
file entitled ISIS5314C2SEQ_ST25.txt created Oct. 11, 2017, which
is 8 Kb in size. The information in the electronic format of the
sequence listing is incorporated herein by reference in its
entirety.
FIELD OF THE INVENTION
The present invention provides modified oligomers that modulate
gene expression via a RNA interference pathway. The oligomers of
the invention include one or more modifications thereon resulting
in differences in various physical properties and attributes
compared to wild type nucleic acids. The modified oligomers are
used alone or in compositions to modulate the targeted nucleic
acids. In preferred embodiments of the invention, the modifications
include a 2' substituent group on at least one sugar moiety of the
oligomer.
BACKGROUND OF THE INVENTION
In many species, introduction of double-stranded RNA (dsRNA)
induces potent and specific gene silencing. This phenomenon occurs
in both plants and animals and has roles in viral defense and
transposon silencing mechanisms. This phenomenon was originally
described more than a decade ago by researchers working with the
petunia flower. While trying to deepen the purple color of these
flowers, Jorgensen et al. introduced a pigment-producing gene under
the control of a powerful promoter. Instead of the expected deep
purple color, many of the flowers appeared variegated or even
white. Jorgensen named the observed phenomenon "cosuppression",
since the expression of both the introduced gene and the homologous
endogenous gene was suppressed (Napoli et al., Plant Cell, 1990, 2,
279-289; Jorgensen et al., Plant Mol. Biol., 1996, 31,
957-973).
Cosuppression has since been found to occur in many species of
plants, fungi, and has been particularly well characterized in
Neurospora crassa, where it is known as "quelling" (Cogoni and
Macino, Genes Dev. 2000, 10, 638-643; Guru, Nature, 2000, 404,
804-808).
The first evidence that dsRNA could lead to gene silencing in
animals came from work in the nematode, Caenorhabditis elegans. In
1995, researchers Guo and Kemphues were attempting to use antisense
RNA to shut down expression of the par-1 gene in order to assess
its function. As expected, injection of the antisense RNA disrupted
expression of par-1, but quizzically, injection of the sense-strand
control also disrupted expression (Guo and Kempheus, Cell, 1995,
81, 611-620).
This result was a puzzle until Fire et al. injected dsRNA (a
mixture of both sense and antisense strands) into C. elegans. This
injection resulted in much more efficient silencing than injection
of either the sense or the antisense strands alone. Injection of
just a few molecules of dsRNA per cell was sufficient to completely
silence the homologous gene's expression. Furthermore, injection of
dsRNA into the gut of the worm caused gene silencing not only
throughout the worm, but also in first generation offspring (Fire
et al., Nature, 1998, 391, 806-811).
The potency of this phenomenon led Timmons and Fire to explore the
limits of the dsRNA effects by feeding nematodes bacteria that had
been engineered to express dsRNA homologous to the C. elegans
unc-22 gene. Surprisingly, these worms developed an unc-22
null-like phenotype (Timmons and Fire, Nature 1998, 395, 854;
Timmons et al., Gene, 2001, 263, 103-112). Further work showed that
soaking worms in dsRNA was also able to induce silencing (Tabara et
al., Science, 1998, 282, 430-431). PCT publication WO 01/48183
discloses methods of inhibiting expression of a target gene in a
nematode worm involving feeding to the worm a food organism which
is capable of producing a double-stranded RNA structure having a
nucleotide sequence substantially identical to a portion of the
target gene following ingestion of the food organism by the
nematode, or by introducing a DNA capable of producing the
double-stranded RNA structure (Bogaert et al., 2001).
The posttranscriptional gene silencing defined in Caenorhabditis
elegans resulting from exposure to double-stranded RNA (dsRNA) has
since been designated as RNA interference (RNAi). This term has
come to generalize all forms of gene silencing involving dsRNA
leading to the sequence-specific reduction of endogenous targeted
mRNA levels; unlike co-suppression, in which transgenic DNA leads
to silencing of both the transgene and the endogenous gene.
Introduction of exogenous double-stranded RNA (dsRNA) into
Caenorhabditis elegans has been shown to specifically and potently
disrupt the activity of genes containing homologous sequences.
Montgomery et al. suggests that the primary interference affects of
dsRNA are post-transcriptional. This conclusion being derived from
examination of the primary DNA sequence after dsRNA-mediated
interference and a finding of no evidence of alterations, followed
by studies involving alteration of an upstream operon having no
effect on the activity of its downstream gene. These results argue
against an effect on initiation or elongation of transcription.
Finally using in situ hybridization they observed that
dsRNA-mediated interference produced a substantial, although not
complete, reduction in accumulation of nascent transcripts in the
nucleus, while cytoplasmic accumulation of transcripts was
virtually eliminated. These results indicate that the endogenous
mRNA is the primary target for interference and suggest a mechanism
that degrades the targeted mRNA before translation can occur. It
was also found that this mechanism is not dependent on the SMG
system, an mRNA surveillance system in C. elegans responsible for
targeting and destroying aberrant messages. The authors further
suggest a model of how dsRNA might function as a catalytic
mechanism to target homologous mRNAs for degradation. (Montgomery
et al., Proc. Natl. Acad. Sci. USA, 1998, 95, 15502-15507).
Recently, the development of a cell-free system from syncytial
blastoderm Drosophila embryos, which recapitulates many of the
features of RNAi, has been reported. The interference observed in
this reaction is sequence specific, is promoted by dsRNA but not
single-stranded RNA, functions by specific mRNA degradation, and
requires a minimum length of dsRNA. Furthermore, preincubation of
dsRNA potentiates its activity demonstrating that RNAi can be
mediated by sequence-specific processes in soluble reactions
(Tuschl et al., Genes Dev., 1999, 13, 3191-3197).
In subsequent experiments, Tuschl et al, using the Drosophila in
vitro system, demonstrated that 21- and 22-nt RNA fragments are the
sequence-specific mediators of RNAi. These fragments, which they
termed short interfering RNAs (siRNAs), were shown to be generated
by an RNase III-like processing reaction from long dsRNA. They also
showed that chemically synthesized siRNA duplexes with overhanging
3' ends mediate efficient target RNA cleavage in the Drosophila
lysate, and that the cleavage site is located near the center of
the region spanned by the guiding siRNA. In addition, they suggest
that the direction of dsRNA processing determines whether sense or
antisense target RNA can be cleaved by the siRNA-protein complex
(Elbashir et al., Genes Dev., 2001, 15, 188-200). Further
characterization of the suppression of expression of endogenous and
heterologous genes caused by the 21-23 nucleotide siRNAs have been
investigated in several mammalian cell lines, including human
embryonic kidney (293) and HeLa cells (Elbashir et al., Nature,
2001, 411, 494-498).
The Drosophila embryo extract system has been exploited, using
green fluorescent protein and luciferase tagged siRNAs, to
demonstrate that siRNAs can serve as primers to transform the
target mRNA into dsRNA. The nascent dsRNA is degraded to eliminate
the incorporated target mRNA while generating new siRNAs in a cycle
of dsRNA synthesis and degradation. Evidence is also presented that
mRNA-dependent siRNA incorporation to form dsRNA is carried out by
an RNA-dependent RNA polymerase activity (RdRP) (Lipardi et al.,
Cell, 2001, 107, 297-307).
The involvement of an RNA-directed RNA polymerase and siRNA primers
as reported by Lipardi et al. (Lipardi et al., Cell, 2001, 107,
297-307) is one of the many intriguing features of gene silencing
by RNA interference. This suggests an apparent catalytic nature to
the phenomenon. New biochemical and genetic evidence reported by
Nishikura et al. also shows that an RNA-directed RNA polymerase
chain reaction, primed by siRNA, amplifies the interference caused
by a small amount of "trigger" dsRNA (Nishikura, Cell, 2001, 107,
415-418).
Investigating the role of "trigger" RNA amplification during RNA
interference (RNAi) in Caenorhabditis elegans, Sijen et al revealed
a substantial fraction of siRNAs that cannot derive directly from
input dsRNA. Instead, a population of siRNAs (termed secondary
siRNAs) appeared to derive from the action of the previously
reported cellular RNA-directed RNA polymerase (RdRP) on mRNAs that
are being targeted by the RNAi mechanism. The distribution of
secondary siRNAs exhibited a distinct polarity (5'-3'; on the
antisense strand), suggesting a cyclic amplification process in
which RdRP is primed by existing siRNAs. This amplification
mechanism substantially augmented the potency of RNAi-based
surveillance, while ensuring that the RNAi machinery will focus on
expressed mRNAs (Sijen et al., Cell, 2001, 107, 465-476).
Most recently, Tijsterman et al. have shown that, in fact,
single-stranded RNA oligomers of antisense polarity can be potent
inducers of gene silencing. As is the case for co-suppression, they
showed that antisense RNAs act independently of the RNAi genes
rde-1 and rde-4 but require the mutator/RNAi gene mut-7 and a
putative DEAD box RNA helicase, mut-14. According to the authors,
their data favor the hypothesis that gene silencing is accomplished
by RNA primer extension using the mRNA as template, leading to
dsRNA that is subsequently degraded suggesting that single-stranded
RNA oligomers are ultimately responsible for the RNAi phenomenon
(Tijsterman et al., Science, 2002, 295, 694-697).
Several recent publications have described the structural
requirements for the dsRNA trigger required for RNAi activity.
Recent reports have indicated that ideal dsRNA sequences are 21 nt
in length containing 2 nt 3'-end overhangs (Elbashir et al, EMBO
(2001), 20, 6877-6887, Sabine Brantl, Biochimica et Biophysica
Acta, 2002, 1575, 15-25.) In this system, substitution of the 4
nucleosides from the 3'-end with 2'-deoxynucleosides has been
demonstrated to not affect activity. On the other hand,
substitution with 2'-deoxynucleosides or 2'-OCH.sub.3-nucleosides
throughout the sequence (sense or antisense) was shown to be
deleterious to RNAi activity.
Investigation of the structural requirements for RNA silencing in
C. elegans has demonstrated modification of the internucleotide
linkage (phosphorothioate) to not interfere with activity (Parrish
et al., Molecular Cell, 2000, 6, 1077-1087.) It was also shown by
Parrish et al., that chemical modification like 2'-amino or
5-iodouridine are well tolerated in the sense strand but not the
antisense strand of the dsRNA suggesting differing roles for the 2
strands in RNAi. Base modification such as guanine to inosine
(where one hydrogen bond is lost) has been demonstrated to decrease
RNAi activity independently of the position of the modification
(sense or antisense). Some "position independent" loss of activity
has been observed following the introduction of mismatches in the
dsRNA trigger. Some types of modifications, for example
introduction of sterically demanding bases such as 5-iodoU, have
been shown to be deleterious to RNAi activity when positioned in
the antisense strand, whereas modifications positioned in the sense
strand were shown to be less detrimental to RNAi activity. As was
the case for the 21 nt dsRNA sequences, RNA-DNA heteroduplexes did
not serve as triggers for RNAi. However, dsRNA containing
2'-F-2'-deoxynucleosides appeared to be efficient in triggering
RNAi response independent of the position (sense or antisense) of
the 2'-F-2'-deoxynucleosides.
In one study the reduction of gene expression was studied using
electroporated dsRNA and a 25mer morpholino oligomer in post
implantation mouse embryos (Mellitzer et al., Mechanisms of
Development, 2002, 118, 57-63). The morpholino oligomer did show
activity but was not as effective as the dsRNA.
A number of PCT applications have recently been published that
relate to the RNAi phenomenon. These include: PCT publication WO
00/44895; PCT publication WO 00/49035; PCT publication WO 00/63364;
PCT publication WO 01/36641; PCT publication WO 01/36646; PCT
publication WO 99/32619; PCT publication WO 00/44914; PCT
publication WO 01/29058; and PCT publication WO 01/75164.
U.S. Pat. Nos. 5,898,031 and 6,107,094, each of which is commonly
owned with this application and each of which is herein
incorporated by reference, describe certain oligonucleotide having
RNA like properties. When hybridized with RNA, these
oligonucleotides serve as substrates for a dsRNase enzyme with
resultant cleavage of the RNA by the enzyme.
In another recently published paper (Martinez et al., Cell, 2002,
110, 563-574) it was shown that single stranded as well as double
stranded siRNA resides in the RNA-induced silencing complex (RISC)
together with elF2C1 and elf2C2 (human GERp950) Argonaute proteins.
The activity of 5'-phosphorylated single stranded siRNA was
comparable to the double stranded siRNA in the system studied. In a
related study, the inclusion of a 5'-phosphate moiety was shown to
enhance activity of siRNA's in vivo in Drosophilia embryos (Boutla,
et al., Curr. Biol., 2001, 11, 1776-1780). In another study, it was
reported that the 5'-phosphate was required for siRNA function in
human HeLa cells (Schwarz et al., Molecular Cell, 2002, 10,
537-548).
In yet another recently published paper (Chiu et al., Molecular
Cell, 2002, 10, 549-561) it was shown that the 5'-hydroxyl group of
the siRNA is essential as it is phosphorylated for activity while
the 3'-hydroxyl group is not essential and tolerates substitute
groups such as biotin. It was further shown that bulge structures
in one or both of the sense or antisense strands either abolished
or severely lowered the activity relative to the unmodified siRNA
duplex. Also shown was severe lowering of activity when psoralen
was used to cross link an siRNA duplex.
Like the RNAse H pathway, the RNA interference pathway for
modulation of gene expression is an effective means for modulating
the levels of specific gene products and, thus, would be useful in
a number of therapeutic, diagnostic, and research applications
involving gene silencing. The present invention therefore provides
oligomeric compounds useful for modulating gene expression
pathways, including those relying on mechanisms of action such as
RNA interference and dsRNA enzymes, as well as antisense and
non-antisense mechanisms. One having skill in the art, once armed
with this disclosure will be able, without undue experimentation,
to identify preferred oligonucleotide compounds for these uses.
SUMMARY OF THE INVENTION
In certain aspects, the invention relates to compositions
comprising a first oligomer and a second oligomer, each having
linked nucleosidic bases. At least a portion of the first oligomer
is capable of hybridizing with at least a portion of the second
oligomer, at least a portion of the first oligomer is complementary
to and capable of hybridizing to a selected target nucleic acid,
and at least one of the first and second oligomers includes at
least one sugar moiety having a 2'-OCH.sub.3 substituent group.
In some embodiments, the first and second oligomers are a
complementary pair of siRNA oligomers. In certain embodiments, the
first and second oligomers are an antisense/sense pair of
oligomers. In some compositions, each of the first and second
oligomers has about 0 to about 40 linked nucleosides. In other
compositions, each of the first and second oligomers has about 18
to about 30 linked nucleosides. In yet other compositions, each of
the first and second oligomers has about 21 to about 24 linked
nucleosides.
In certain aspects, the first oligomer is an antisense oligomer. In
other aspects, the second oligomer comprises a sense oligomer. In
some embodiments, the second oligomer has a plurality of ribose
nucleoside units. In still other embodiments, the first oligomer
includes said 2'-OCH.sub.3 substituent group.
In some preferred embodiments, the first oligomer comprises a 3'
terminus and a 5' terminus, said 5' terminus comprising a hydroxy
terminal group. In other preferred embodiments, the 2'-OCH.sub.3
substitutent group extend from the 3' terminus of the first
oligomer through the fourth, third, or penultimate nucleoside from
the 5' terminus.
In certain preferred embodiments, the first oligomer comprises a 3'
terminus and a 5' terminus, wherein the nucleoside at the 5'
terminus comprises a 2'-OCH.sub.3 substitutent group. In some of
these compositions, the 5' terminus comprises a 3'-phosphate
terminal group.
In some aspects, the first oligomer is a chimeric oligomeric
compound. Certain chimeric compositions are a gapmer, an inverted
gapmer, a 3'-hemimer, a 5'-hemimer or a blockmer. In some aspects,
the chimeric oligomeric compound comprises two terminal RNA
segments having nucleosides of a first type and an internal RNA
segment having nucleosides of a second type and where said
nucleosides of said first type are different from said nucleosides
of said second type. In certain preferred embodiments, the
nucleosides of said first type includes a 2'-OCH.sub.3 substitutent
group.
In other embodiments, the invention is directed to
oligonucleomer/protein compositions comprising an oligomer
complementary to and capable of hybridizing to a selected target
nucleic acid, and at least one protein comprising at least a
portion of a RNA-induced silencing complex (RISC). The oligomer
includes at least one nucleoside having a 2'-OCH.sub.3 substituent
group on the sugar moiety.
Also provided by the present invention are pharmaceutical
compositions comprising any of the above compositions or oligomeric
compounds and a pharmaceutically acceptable carrier.
Methods for modulating the expression of a target nucleic acid in a
cell are also provided, wherein the methods comprise contacting the
cell with any of the above compositions or oligomeric
compounds.
Methods of treating or preventing a disease or condition associated
with a target nucleic acid are also provided, wherein the methods
comprise administering to a patient having or predisposed to the
disease or condition a therapeutically effective amount of any of
the above compositions or oligomeric compounds.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides oligomeric compounds useful in the
modulation of gene expression. Although not intending to be bound
by theory, oligomeric compounds of the invention modulate gene
expression by hybridizing to a nucleic acid target resulting in
loss of normal function of the target nucleic acid. As used herein,
the term "target nucleic acid" or "nucleic acid target" is used for
convenience to encompass any nucleic acid capable of being targeted
including without limitation DNA, RNA (including pre-mRNA and mRNA
or portions thereof) transcribed from such DNA, and also cDNA
derived from such RNA. In a preferred embodiment of this invention
modulation of gene expression is effected via modulation of a RNA
associated with the particular gene RNA.
The invention provides for modulation of a target nucleic acid that
is a messenger RNA. The messenger RNA is degraded by the RNA
interference mechanism as well as other mechanisms in which double
stranded RNA/RNA structures are recognized and degraded, cleaved or
otherwise rendered inoperable.
The functions of RNA to be interfered with can include replication
and transcription. Replication and transcription, for example, can
be from an endogenous cellular template, a vector, a plasmid
construct or otherwise. The functions of RNA to be interfered with
can include functions such as translocation of the RNA to a site of
protein translation, translocation of the RNA to sites within the
cell which are distant from the site of RNA synthesis, translation
of protein from the RNA, splicing of the RNA to yield one or more
RNA species, and catalytic activity or complex formation involving
the RNA which may be engaged in or facilitated by the RNA. In the
context of the present invention, "modulation" and "modulation of
expression" mean either an increase (stimulation) or a decrease
(inhibition) in the amount or levels of a nucleic acid molecule
encoding the gene, e.g., DNA or RNA. Inhibition is often the
preferred form of modulation of expression and mRNA is often a
preferred target nucleic acid.
Compounds of the Invention
The compounds of the invention include oligomeric compounds that
comprise at least one monomeric unit that has a 2'-OCH.sub.3
substituent group on the sugar moiety. 2'-Sugar substituents are
described in more detail in U.S. Pat. Nos. 5,670,633, 5,914,396,
6,005,087, 6,222,025, 6,307,040, 6,531,584 and in U.S. patent
application Ser. No. 10/444,628. The disclosure of each of these
patents and applications is incorporated herein by reference in its
entirety.
In some compositions, one or more sugars may conatain a
2'-subsititutent other than 2'-OCH.sub.3. In certain embodiments,
these substituent group may be halogen, amino, trifluoroalkyl,
trifluoroalkoxy, azido, aminooxy, alkyl, alkenyl, alkynyl, O-, S-,
or N(R*)-alkyl; O-, S-, or N(R*)-alkenyl; O-, S- or N(R*)-alkynyl;
O-, S- or N-aryl, O-, S-, or N(R*)-aralkyl; wherein said alkyl,
alkenyl, alkynyl, aryl and aralkyl may be substituted or
unsubstituted C.sub.1 to C.sub.10 alkyl, C.sub.2 to C.sub.10
alkenyl, C.sub.2 to C.sub.10 alkynyl, C.sub.5-C.sub.20 aryl or
C.sub.6-C.sub.20 aralkyl; and said substituted C.sub.1 to C.sub.10
alkyl, C.sub.2 to C.sub.10 alkenyl, C.sub.2 to C.sub.10 alkynyl,
C.sub.5-C.sub.20 aryl or C.sub.6-C.sub.20 aralkyl comprising
substitution with hydroxy, alkoxy, thioalkoxy, phthalimido,
halogen, amino, keto, carboxyl, nitro, nitroso, cyano, aryl,
haloalkyl, haloalkoxy, imidazole, azido, hydrazino, aminooxy,
isocyanato, sulfoxide, sulfone, disulfide, silyl, heterocycle,
carbocycle, an intercalator, a reporter group, a conjugate, a
polyamine, a polyamide, a polyalkylene glycol, or a polyether of
the formula (--O-alkyl).sub.m, where m is 1 to about 10; and R* is
hydrogen, or a protecting group.
As discussed above, the 2' substituent may be a halogen. In some
preferred embodiments the halogen is F. Certain oligonucleosides
that are N3'->P5' phosphoramidates having 2' fluoro substituents
have been shown to have superior acid stability. These compositions
can be made by procedures taught is U.S. Pat. No. 5,684,143, the
disclosure of which is incorporated herein in its entirety.
Some preferred substituents are 2'-O-alkyl substituents. These
alkyl groups include lower alkyl groups having from about 1 to
about 6 carbon atoms. In some preferred embodiments, the alkyl is a
C.sub.2-C.sub.6 group. Other 2' substituent groups include
2'-methoxyethoxy (MOE, 2'-OCH.sub.2CH.sub.2OCH.sub.3) and
2'-O-[2-(2-N,N-dimethylaminoethyl)oxyethyl]. These substituents are
described in U.S. Pat. Nos. 6,043,352 and 6,005,094, the
disclosures of which are incorporated herein by reference in their
entirety.
In other embodiments, the 2' substituent is
--O--R.sup.26-thio-R.sup.26 or --C--R.sup.26-thio-R.sup.26, wherein
said R.sup.26 is independently a compound selected from a group
consisting of alkyl, allyl, alkenyl, alkynyl, aryl, alkylaryl,
carbocyclic aryl, heterocyclic aryl, amide and ester. In some
embodiments, R.sup.26 is alkyl, allyl, alkenyl, alkynyl, aryl,
alkylaryl, carbocyclic aryl, or heterocyclic aryl. In certain
embodiments, the 2' substituent is 2'-O-methylthiomethyl. In other
embodiments, the 2' substituent is 2'-O-methylthioethyl. These
substituents are described in U.S. Pat. Nos. 5,716,824, 5,840,876
and 6,239,272, the disclosures of which are incorporated by
reference herein in their entirety.
In certain embodiments, the 2' substituent is cyano, fluoromethyl,
thioalkoxyl, fluoroalkoxyl, alkylsulfinyl, alkylsulfonyl, allyloxy
or alkeneoxy. In other embodiments, the 2'-substituent is
2'-alkylsulfinyl or alkylsulfonyl. In other preferred embodiments,
the 2'-substituent is 2'-thioalkoxyl, preferably, a
2'-S--(C.sub.1-C.sub.20 alkyl) substituent. These substituents are
described in U.S. Pat. No. 5,859,221, the disclosure of which is
incorporated herein by reference.
Some 2' substituents useful in the invention are of the formula
--X--Y. X is O, S, NR.sup.27, or CR.sup.27.sub.2 wherein each R is
independently H or C.sub.1-6 alkyl. Y is a linker moiety, a drug
residue optionally attached through a linker moiety, a label
optionally attached through a linker moiety, or a
property-affecting group optionally attached through a linker
moiety. In some embodiments, Y is a drug moiety. In certain
embodiments, the drug moiety is selected from the group consisting
of netropsin, anthramycin, quinoxaline antibiotics, actinomycin,
and pyrrolo (1-4) benzodiazepine. In other embodiments, Y is
substituted or unsubstituted alkyl (C.sub.2-20), substituted or
unsubstituted alkenyl (C.sub.2-20), substituted or unsubstituted
aryl (C.sub.6-20), wherein the substituents are selected from the
group consisting of a hydroxyl, an amino, a mercaptyl, a carboxy or
a keto moiety, --CH.sub.2COOH, --CH.sub.2COONH.sub.2,
--CH.sub.2COOEt, --CH.sub.2CONHCH.sub.2CH.sub.2NH.sub.2 and
SiR.sup.28.sub.3 wherein R.sup.28 is alkyl (C.sub.2-6). In certain
preferred embodiments, X is O or S. These substituents are
described in U.S. Pat. Nos. 5,466,786 and 5,792,847, the
disclosures of which are incorporated herein by reference in their
entirety.
Certain 2' substituents are of the formula:
-G1-G2-G3 where G1 is a bivalent linker, G2 is an aryl or
heteroaryl or aryl or heteroaryl containing group and G3 is an RNA
cleaving moiety having, for example, general acid/base properties.
In certain further preferred embodiments of the inventions, G3
further includes an electrophilic catalyst.
The bivalent liker may be a mono- or polyatomic linker. In some
embodiments, the bivalent linker is of the formula
-G.sup.11-G.sup.12. G.sup.11 contains a heteroatom and G.sup.12
contains an alkyl, alkenyl or alkynyl group. Preferred heteroatoms
include O, S, and N--H or N-alkyl. In some embodiments, the linker
may be methylene groups--i.e., --(CH.sub.2).sub.n-- or may include
heteroatoms and functional groups, e.g.,
--CH.sub.2OCH.sub.2CH.sub.2O-- or --CH.sub.2O--CH.sub.2CH.sub.2NH--
or --COOCH.sub.2CH.sub.2O--. In certain embodiments of the
invention, G1 connects to the internucleoside linkage, i.e. the
sugar linking group.
G2 preferably is a polycyclic moiety having from 2 to 6 rings, at
least 2 of said rings being joined to form an electronically
conjugated system. Representative G2 groups include naphthalene,
anthracene, phenanthrene, benzonaphthalene, fluorene, carbazole,
pyrido[4,3-b]carbazole, acridine, pyrene, anthraquinone, quinoline,
phenylquinoline, xanthene or 2,7-diazaanthracene groups.
Structures of this type preferably act as intercalators. Other
intercalators believed to be useful are described by Denny,
Anti-Cancer Drug Design 1989, 4, 241.
RNA-cleaving group G3 can be a functionality that has both general
acid and general base characteristics. It also can possess
electrophilic catalytic characteristics. It can further possess
metal ion coordinating characteristics. Such substituents are
described in U.S. Pat. No. 6,358,931, whose disclosure is
incorporated by reference herein in its entirety.
The 2' substituent may be of the formula --O-G1-G2-G3 where G1 is
alkyl, alkenyl, or alkynyl; G2 is an aryl; and G3 includes at least
one imidazole. In some preferred embodiments, G3 is an imidazole or
a bis-imidazole moiety. In other embodiments, G1-G2-G3 is an
alkynyl moiety. These substituents are described in U.S. Pat. No.
5,514,786, whose disclosure is incorporated herein by reference in
its entirety.
Some useful 2' substituents are of the formula
--C(X)--N(R.sup.29)(R.sup.30) where:
R.sup.29 and R.sup.30, independently, are H, R.sup.33, R.sup.34, an
amine protecting group or have formula
R.sup.33--N(R.sup.31)(R.sup.32), C(X)--R.sup.33, C(X)
R.sup.34--R.sup.33, C(X)-Q-R.sup.34--R.sup.33, or
C(X)-Q-R.sup.33;
R.sup.31 and R.sup.32, independently, are H, R.sup.33, R.sup.34, an
amine protecting group or have formula C(X)--R.sup.33,
C(X)--R.sup.34--R.sup.33, C(X)-Q-R.sup.34--R.sup.33, or
C(X)-Q-R.sup.33;
R.sub.33 is a steroid molecule, biotin, dinitrophenyl, a
fluorescein dye, a lipophilic molecule, a reporter enzyme, a
peptide, a protein, includes folic acid, or has formula
-Q-(CH.sub.2CH.sub.2-Q-).sub.x-R.sup.35;
R.sup.34 is alkyl having from 1 to about 10 carbon atoms;
X is O or S;
each Q is, independently, is NH, O, or S;
R.sup.35 is H, R.sup.34, C(O)OH, C(O)OR.sup.34, C(O)R.sup.41,
R.sup.34--N.sub.3, or R.sup.34--NH.sub.2;
R.sup.41 is Cl, Br, I, SO.sub.2R.sup.42 or has structure:
##STR00001## m is 2 or 7; and R.sup.42 alkyl having 1 to about 10
carbon atoms.
In some embodiments, R.sup.34 is alkyl having 1 to about 10 carbon
atoms, preferably having 6 carbon atoms. In other embodiments,
R.sup.29 is H and R.sup.30 is R.sup.33. Some compounds are such
that R.sup.29 is H and R.sup.30 is alkyl having 1 to about 10
carbon atoms, preferably 1 or 2 carbon atoms. In certain
embodiments, R.sup.29 and R.sup.30, together, are phthalimido. In
other embodiments, R.sup.29 is H and R.sup.30 is
R.sup.34--N(R.sup.31)(R.sup.32). These compounds are described in
U.S. Pat. No. 6,111,085, whose disclosure is incorporated herein by
reference in its entirety.
The sugar substituent may be a 2'-aminoalkoxy or a
2'-imidazolylalkoxy substituent, wherein the alkoxy moiety of said
substituent is C.sub.1-C.sub.20. In some embodiments the
substituent is 2'-O-(aminoprop-3-yl) or 2'-O-(aminobut-4-yl). In
other embodiments, the substituent is 2'-O->(imidazol-1-yl)
prop-3-yl or 2'-O->(imidazol-1-yl) but-4-yl. See, for example,
U.S. Pat. No. 5,872,232, which is incorporated herein by reference
in its entirety.
Certain 2' modifications are groups of the formula:
##STR00002## where m is from 0 to 10; y is from 1 to 10; x is 1; E
is N(R.sup.37)(R.sup.38) or N.dbd.C(R.sup.37)(R.sup.38); and each
of R.sup.36, R.sup.37 and R.sup.38 is, independently, H,
C.sub.1-C.sub.10 alkyl, and an amino protecting group, or R.sup.37
and R.sup.38 together, are an amino protecting group or wherein
R.sup.37 and R.sup.38 are joined in a C.sub.4-C.sub.10 ring
structure that can include at least one heteroatom selected from N
and O. In certain embodiments, R.sup.37 and R.sup.38 are
independently H or C.sub.1-C.sub.10 alkyl. In other embodiments
R.sup.37 and R.sup.38 are joined in a C.sub.4-C.sub.10 ring
structure that optionally includes one or more heteroatoms selected
from N and O. Some compounds of the invention comprise a ring
structure that is an imidazolyl ring, a piperidinyl ring, a
morpholinyl ring or a substituted piperazinyl ring. Certain
piperazine may be optionally substituted with a C.sub.1-C.sub.12
alkyl. These substituent groups may be produced by methods taught
by U.S. Pat. Nos. 6,127,533 and 6,172,209 the disclosures of which
are incorporated by reference herein in their entirety.
In certain embodiments, the 2' substituent is of the formula:
##STR00003## where R.sup.39 is alkyl having from 1 to about 10
carbon atoms or (CH.sub.2--CH.sub.2-Q).sub.x; R.sup.40 is alkenyl
having 2 to about 10 carbon atoms; R.sup.29 and R.sup.30,
independently, are H, R.sup.33, R.sup.39, an amine protecting group
or have formula R.sup.39--N(R.sup.31)(R.sup.32), C(X)--R.sup.33,
C(X)--R.sup.39--R.sup.33, C(X)-Q-R.sup.39--R.sup.33, or
C(X)-Q-R.sup.33; R.sup.31 and R.sup.32, independently, are H,
R.sup.33, R.sup.39, an amine protecting group or have formula
C(X)--R.sup.33, C(X)--R.sup.39--R.sup.33,
C(X)-Q-R.sup.39--R.sup.33, or C(X)-Q-R.sup.33; R.sup.33 is a
steroid molecule, a reporter molecule, a lipophilic molecule, a
reporter enzyme, a peptide, a protein, includes folic acid, or has
formula -Q-(CH.sub.2CH.sub.2-Q-).sub.x-R.sup.35; X is O or S; each
Q is, independently, is NH, O, or S; x is 1 to about 200; R.sup.35
is H, R.sup.39, C(O)OH, C(O)OR.sup.39, C(O)R.sup.41,
R.sup.39--N.sub.3, or R.sup.39--NH.sub.2; R.sup.41 is Cl, Br, I,
SO.sub.2R.sup.42 or has structure:
##STR00004## m is 2 or 7; and R.sub.42 is an alkyl having 1 to
about 10 carbon atoms. In some embodiments, R.sup.39 is alkyl
having 6 carbon atoms. In certain embodiments, R.sup.40 is
2-propenyl. In other embodiments, R.sup.29 is H and R.sup.30 is H.
In yet other embodiments, R.sup.29 is H and R.sup.30 is R.sup.33.
In some compositions, R.sup.29 is H and R.sup.30 is alkyl having 1
to about 10 carbon atoms. In certain embodiments, R.sup.29 and
R.sup.30, together, are phthalimido. In other embodiments, R.sup.29
is H and R.sup.30 is R.sup.39--N(R.sup.31)(R.sup.32). In certain
compositions of the invention, R.sup.31 is H and R.sup.32 is
R.sup.33. In other compositions, R.sup.31 is H and R.sup.32 is
alkyl having 1 to about 10 carbon atoms. In yet other compositions,
R.sup.30 is H and R.sup.32 is an alkyl having 1 or 2 carbon atoms.
In yet other compositions, R.sup.31 and R.sup.32, together, are
phthalimido. These substituents may be synthesized by methods
taught by U.S. Pat. No. 6,166,188, the disclosure of which is
incorporated herein by reference in its entirety.
Some 2' substituents are of the formula:
##STR00005## wherein each E.sub.1 and E.sub.2 is, independently, H,
C.sub.1-C.sub.10 alkyl, C.sub.2-C.sub.10 alkenyl, C.sub.2-C.sub.10
alkynyl, C.sub.6-C.sub.14 aryl, (CH.sub.2).sub.m--S--R.sup.43 where
m is from 1 to 10,
--{(CH.sub.2).sub.nn--N(H)}.sub.nnn--(CH.sub.2).sub.nnNH.sub.2
where each nn is an integer from 2 to 4 and nnn is an integer from
2 to 10, a polypeptide having from 2 to 10 peptide linked amino
acids, a folic acid moiety optionally bearing a linking group
attaching said folic acid moiety from the .alpha. or .gamma.
carboxyl group to the 2'-substituent wherein said linking group is
--N(H)--(CH.sub.2).sub.6--, or a cholesterol moiety optionally
bearing a linking group attaching said cholesterol moiety from the
hydroxyl group to the 2'-substituent, wherein said linking group is
--C(.dbd.O)--N(H)--(CH.sub.2).sub.6--; and R.sup.43 is H,
C.sub.1-C.sub.10 alkyl, C.sub.2-C.sub.10 alkenyl, C.sub.2-C.sub.10
alkynyl, C.sub.6-C.sub.14 aryl or a thio protecting group. In some
embodiments, each E.sub.1 and E.sub.2 is independently
C.sub.1-C.sub.10 alkyl.
In some embodiments, each E.sub.1 and E.sub.2 is, independently,
C.sub.1-C.sub.10 alkyl, or one of E.sub.1 and E.sub.2 is H and the
other of E.sub.1 and E.sub.2 is --CH.sub.3;
or each E.sub.1 and E.sub.2 is, independently, H,
--(CH.sub.2).sub.m--S--R.sup.43 where m is from 1 to 10,
--{(CH.sub.2).sub.nn--N(H)}.sub.nnn--(CH.sub.2).sub.nnNH.sub.2
where each nn is from 2 to 4 and nnn is from 2 to 10, a polypeptide
having from 2 to 10 peptide linked amino acids, a folic acid moiety
optionally bearing a linking group attaching said folic acid moiety
from the .alpha. or .gamma. carboxyl group to the 2'-substituent
wherein said linking group is --N(H)--(CH.sub.2).sub.6--, or a
cholesterol moiety optionally bearing a linking group attaching
said cholesterol moiety from the hydroxyl group to the
2'-substituent, wherein said linking group is
--C(.dbd.O)--N(H)--(CH.sub.2).sub.6--, provided that only one of
E.sub.1 and E.sub.2 is H; and R.sup.43 is H, C.sub.1-C.sub.10
alkyl, C.sub.2-C.sub.10 alkenyl, C.sub.2-C.sub.10 alkynyl,
C.sub.6-C.sub.14 aryl or a thio protecting group.
In certain embodiments, E.sub.1 is H and E.sub.2 is
--(CH.sub.2).sub.m--S--R.sup.43. In other embodiments, R.sup.43 is
C.sub.1-C.sub.10alkyl. Further embodiments are those where R.sup.43
is methyl. In yet other embodiments, E.sub.2 is
{(CH.sub.2).sub.nn--N(H)}.sub.nnn(CH.sub.2).sub.nnNH.sub.2 where
each nn is from 2 to 4 and nnn is from 2 to 10. In some
compositions, E.sub.2 is
--(CH.sub.2).sub.3--N(H)--(CH.sub.2).sub.4--N(H)--(CH.sub.2).sub.3--NH.su-
b.2 or --(CH.sub.2).sub.4--N(H)--(CH.sub.2).sub.3--NH.sub.2. In
certain embodiments, E.sub.2 is said polypeptide. In some
embodiments, the polypeptide is Lys-Tyr-Lys, Lys-Trp-Lys or
Lys-Lys-Lys-Lys. In yet other embodiments, E.sub.2 is a linked
folic acid or 5-methyl-tetrahydrofolic acid moiety. In further
embodiments, E.sub.2 is a cholesterol moiety. These substituents
may be made may methods disclosed in U.S. Pat. No. 6,147,200, whose
disclosure is incorporated by reference herein in its entirety.
Other 2' substituent groups of the invention are of the formula:
--X--(CR.sup.71R.sup.72).sub.n--O--SO.sub.2--O.sup.-Y.sup.+ where X
is a O, S, or N; R.sup.71 and R.sup.72 are independently H, alkyl,
aryl, O-alkyl, O-aryl, carboxylic acid, amide, ester, halogen,
trifluoromethyl, or amine; n is an integer from about 2 to about
10; and, Y is H, Li, Na, K, Cs or an amine. The synthesis of
compounds with these substituent groups is described in U.S. Pat.
No. 6,227,982, the disclosure of which is incorporated herein in
its entirety.
Some 2' substituents are of the formula:
##STR00006## where: each Z is, independently, a single bond, O, N
or S; each R.sup.46, R.sup.47, R.sup.48, and R.sup.49 is,
independently, hydrogen, C(O)R.sup.50, substituted or unsubstituted
C.sub.1-C.sub.10 alkyl, substituted or unsubstituted
C.sub.2-C.sub.10 alkenyl, substituted or unsubstituted
C.sub.2-C.sub.10 alkynyl, alkylsulfonyl, arylsulfonyl, a chemical
functional group or a conjugate group, wherein the substituent
groups are selected from hydroxyl, amino, alkoxy, carboxy, benzyl,
phenyl, nitro, thiol, thioalkoxy, halogen, alkyl, aryl, alkenyl and
alkynyl; or R.sup.46 and R.sup.47, together, are R.sup.51; each
R.sup.50 is, independently, substituted or unsubstituted
C.sub.1-C.sub.10 alkyl, trifluoromethyl, cyanoethyloxy, methoxy,
ethoxy, t-butoxy, allyloxy, 9-fluorenylmethoxy,
2-(trimethylsilyl)-ethoxy, 2,2,2-trichloroethoxy, benzyloxy,
butyryl, iso-butyryl, phenyl or aryl; each R.sup.51 is,
independently, hydrogen or forms a phthalimide moiety with the
nitrogen atom to which it is attached; each m is, independently,
zero or 1; and each n is, independently, an integer from 1 to about
6. These substituents may be synthesized by methods taught in U.S.
Pat. No. 6,534,639, whose disclosure is incorporated herein by
reference in its entirety.
In certain embodiments, the 2' modification is of the formula
--OR.sup.52 where R.sup.52 is
##STR00007## where R.sup.53 is hydrogen, C.sub.1-C.sub.21 alkyl,
C.sub.2-C.sub.21 alkenyl, C.sub.2-C.sub.21 alkynyl or
--C(.dbd.O)-alkyl; R.sup.54 is hydrogen, C.sub.1-C.sub.10alkyl,
--CH.sub.2--O--R.sup.55 or a radical of formula Ib; R.sup.55 is
hydrogen, C.sub.1-C.sub.22 alkyl, C.sub.3-C.sub.21 alkenyl, or
partially or completely fluorine-substituted C.sub.1-C.sub.10alkyl
or --[(CH.sub.2).sub.2--O].sub.m--R.sup.56; R.sup.56 is hydrogen or
C.sub.1-C.sub.21 alkyl; Z is --(CH.sub.2).sub.p-- or
--(CH.sub.2--CH.sub.2--O).sub.q--CH.sub.2CH.sub.2--, it being
possible for Z in the case of --CH.sub.2-- to be unsubstituted or
substituted by one or more identical or different substituents
selected from C.sub.1-C.sub.10 alkyl, C.sub.5-C.sub.6 cycloalkyl
and unsubstituted or C.sub.1-C.sub.4 alkyl-substituted phenyl; n is
an integer from 1 to 12; m is an integer from 1 to 4; p is an
integer from 1 to 10; and q is an integer from 1 to 4. Such
substituents are described in U.S. Pat. No. 5,969,116, the
disclosure of which is incorporated herein by reference in its
entirety.
Some 2' substituents may be cyclic compositions of the formula:
##STR00008## where L.sub.1, L.sub.2 and L.sub.3 form a ring system
having from about 4 to about 7 carbon atoms or having from about 3
to about 6 carbon atoms and 1 or 2 hetero atoms wherein said hetero
atoms are oxygen, nitrogen or sulfur and wherein said ring system
is aliphatic, unsaturated aliphatic, aromatic or heterocyclic; R is
OX, SX, N(H)X or NX.sub.2; X is H, C.sub.1-C.sub.8 alkyl,
C.sub.1-C.sub.8 haloalkyl, C(.dbd.NH)N(H)Z, C(.dbd.O)N(H)Z and
OC(.dbd.O)N(H)Z; Y is alkyl or haloalkyl having 1 to about 10
carbon atoms, alkenyl having 2 to about 10 carbon atoms, alkynyl
having 2 to about 10 carbon atoms, aryl having 6 to about 14 carbon
atoms, N(H)X, NX.sub.2, OX, halo, SX or CN; n is 0, 1 or 2; and Z
is H or C.sub.1-C.sub.8 alkyl.
In certain embodiments, the ring system is phenyl, pyridyl,
cyclopentyl, cyclobutyl, cyclohexyl, cycloheptyl, morpholino,
piperidyl or piperazinyl with the proviso that the elected ring
system is mono-, di-, or tri-substituted. In other embodiments, R
is OH, SH, OCH.sub.3, N(H)C(.dbd.NH)NH.sub.2,
N(H)C(.dbd.O)NH.sub.2, NH.sub.2, or OC(.dbd.O)NH.sub.2. In some
embodiments, L.sub.1 and L.sub.2 are each carbon atoms. In yet
other embodiments, L.sub.1 and L.sub.2 are carbon atoms and the
other of L.sub.1 and L.sub.2 is a heteroatom selected from O, S and
N. These ligands may be made by methods taught by U.S. Pat. No.
6,271,358, whose disclosure is incorporated herein by reference in
its entirety.
In some embodiments, the 2' position of the sugar ring can have two
substituents, Y1 and Y2; provided that both Y1 and Y2 are not H and
that when one of Y1 and Y2 is H and the other of Y1 and Y2 is OH,
the sugar ring is other than a ribose sugar. In certain
embodiments, Y1 and Y2 are each independently hydrogen; hydroxyl;
halogen; C.sub.2-4 alkenyl, C.sub.2-4 alkynyl, or C.sub.1-4 alkyl
optionally substituted with amino, hydroxy, or 1 to 3 fluorine
atoms; C.sub.1-10 alkoxy, optionally substituted with C.sub.1-3
alkoxy, C.sub.1-3 thioalkoxy or 1 to 3 fluorine atoms; C.sub.2-6
alkenyloxy; C.sub.1-4 alkylthio; C.sub.1-8 alkylcarbonyloxy;
aryloxycarbonyl; azido; amino; C.sub.1-4 alkylamino; di(C.sub.1-4
alkyl)amino; or Y.sup.3. Y.sup.3 is a conjugate molecule or a
reporter molecule. These substituents are described in more detail
in commonly owned U.S. patent application Ser. No. 10/444,628, the
disclosure of which is incorporated by reference in its entirety.
In some preferred embodiments Y1 is C.sub.2-4 alkenyl, C.sub.2-4
alkynyl, or C.sub.1-4 alkyl, wherein the alkyl is unsubstituted or
substituted with hydroxy, amino, C.sub.1-4 alkoxy, C.sub.1-4
alkylthio, or one to three fluorine atoms and Y2 is hydrogen,
fluorine, hydroxy, C.sub.1-10 alkoxy, or C.sub.1-10 alkyl. In other
preferred embodiments, Y1 is alkyl unsubstituted or substituted
with hydroxy, amino, C.sub.1-4 alkoxy, C.sub.1-4 alkylthio, or one
to three fluorine atoms, particularly where Y1 is methyl or
trifluoromethyl. In yet other preferred compounds, Y2 is hydrogen
or hydroxyl. These substituents are described in commonly owned
U.S. patent application Ser. No. 10/444,298, the disclosure of
which is incorporated herein by reference in its entirety.
Hybridization
In the context of this invention, "hybridization" means the pairing
of complementary strands of oligomeric compounds. In the present
invention, the preferred mechanism of pairing involves hydrogen
bonding, which may be Watson-Crick, Hoogsteen or reversed Hoogsteen
hydrogen bonding, between complementary nucleoside or nucleotide
bases (nucleobases) of the strands of oligomeric compounds. For
example, adenine and thymine are complementary nucleobases that
pair through the formation of hydrogen bonds. Hybridization can
occur under varying circumstances.
An oligomeric compound of the invention is believed to specifically
hybridize to the target nucleic acid and interfere with its normal
function to cause a loss of activity. There is preferably a
sufficient degree of complementarity to avoid non-specific binding
of the oligomeric compound to non-target nucleic acid sequences
under conditions in which specific binding is desired, i.e., under
physiological conditions in the case of in vivo assays or
therapeutic treatment, and under conditions in which assays are
performed in the case of in vitro assays.
In the context of the present invention the phrase "stringent
hybridization conditions" or "stringent conditions" refers to
conditions under which an oligomeric compound of the invention will
hybridize to its target sequence, but to a minimal number of other
sequences. Stringent conditions are sequence-dependent and will
vary with different circumstances and in the context of this
invention; "stringent conditions" under which oligomeric compounds
hybridize to a target sequence are determined by the nature and
composition of the oligomeric compounds and the assays in which
they are being investigated.
"Complementary," as used herein, refers to the capacity for precise
pairing of two nucleobases regardless of where the two are located.
For example, if a nucleobase at a certain position of an oligomeric
compound is capable of hydrogen bonding with a nucleobase at a
certain position of a target nucleic acid, then the position of
hydrogen bonding between the oligomer and the target nucleic acid
is considered to be a complementary position. The oligomeric
compound and the target nucleic acid are complementary to each
other when a sufficient number of complementary positions in each
molecule are occupied by nucleobases that can hydrogen bond with
each other. Thus, "specifically hybridizable" and "complementary"
are terms which are used to indicate a sufficient degree of precise
pairing or complementarity over a sufficient number of nucleobases
such that stable and specific binding occurs between the oligomer
and a target nucleic acid.
It is understood in the art that the sequence of the oligomeric
compound need not be 100% complementary to that of its target
nucleic acid to be specifically hybridizable. Moreover, an
oligomeric compound may hybridize over one or more segments such
that intervening or adjacent segments are not involved in the
hybridization event (e.g., a loop structure or hairpin structure).
It is preferred that the oligomeric compounds of the present
invention comprise at least 70% sequence complementarity to a
target region within the target nucleic acid, more preferably that
they comprise 90% sequence complementarity and even more preferably
comprise 95% sequence complementarity to the target region within
the target nucleic acid sequence to which they are targeted. For
example, an oligomeric compound in which 18 of 20 nucleobases of
the oligomeric compound are complementary to a target region, and
would therefore specifically hybridize, would represent 90 percent
complementarity. In this example, the remaining noncomplementary
nucleobases may be clustered or interspersed with complementary
nucleobases and need not be contiguous to each other or to
complementary nucleobases. As such, an oligomeric compound which is
18 nucleobases in length having 4 (four) noncomplementary
nucleobases which are flanked by two regions of complete
complementarity with the target nucleic acid would have 77.8%
overall complementarity with the target nucleic acid and would thus
fall within the scope of the present invention. Percent
complementarity of an oligomeric compound with a region of a target
nucleic acid can be determined routinely using BLAST programs
(basic local alignment search tools) and PowerBLAST programs known
in the art (Altschul et al., J. Mol. Biol., 1990, 215, 403-410;
Zhang and Madden, Genome Res., 1997, 7, 649-656).
Targets of the Invention
"Targeting" an oligomeric compound to a particular nucleic acid
molecule, in the context of this invention, can be a multistep
process. The process usually begins with the identification of a
target nucleic acid whose function is to be modulated. This target
nucleic acid may be, for example, a mRNA transcribed from a
cellular gene whose expression is associated with a particular
disorder or disease state, or a nucleic acid molecule from an
infectious agent.
The targeting process usually also includes determination of at
least one target region, segment, or site within the target nucleic
acid for the interaction to occur such that the desired effect,
e.g., modulation of expression, will result. Within the context of
the present invention, the term "region" is defined as a portion of
the target nucleic acid having at least one identifiable structure,
function, or characteristic. Within regions of target nucleic acids
are segments. "Segments" are defined as smaller or sub-portions of
regions within a target nucleic acid. "Sites," as used in the
present invention, are defined as positions within a target nucleic
acid. The terms region, segment, and site can also be used to
describe an oligomeric compound of the invention such as for
example a gapped oligomeric compound having 3 separate
segments.
Since, as is known in the art, the translation initiation codon is
typically 5'-AUG (in transcribed mRNA molecules; 5'-ATG in the
corresponding DNA molecule), the translation initiation codon is
also referred to as the "AUG codon," the "start codon" or the "AUG
start codon". A minority of genes have a translation initiation
codon having the RNA sequence 5'-GUG, 5'-UUG or 5'-CUG, and 5'-AUA,
5'-ACG and 5'-CUG have been shown to function in vivo. Thus, the
terms "translation initiation codon" and "start codon" can
encompass many codon sequences, even though the initiator amino
acid in each instance is typically methionine (in eukaryotes) or
formylmethionine (in prokaryotes). It is also known in the art that
eukaryotic and prokaryotic genes may have two or more alternative
start codons, any one of which may be preferentially utilized for
translation initiation in a particular cell type or tissue, or
under a particular set of conditions. In the context of the
invention, "start codon" and "translation initiation codon" refer
to the codon or codons that are used in vivo to initiate
translation of an mRNA transcribed from a gene encoding a nucleic
acid target, regardless of the sequence(s) of such codons. It is
also known in the art that a translation termination codon (or
"stop codon") of a gene may have one of three sequences, i.e.,
5'-UAA, 5'-UAG and 5'-UGA (the corresponding DNA sequences are
5'-TAA, 5'-TAG and 5'-TGA, respectively).
The terms "start codon region" and "translation initiation codon
region" refer to a portion of such an mRNA or gene that encompasses
from about 25 to about 50 contiguous nucleotides in either
direction (i.e., 5' or 3') from a translation initiation codon.
Similarly, the terms "stop codon region" and "translation
termination codon region" refer to a portion of such an mRNA or
gene that encompasses from about 25 to about 50 contiguous
nucleotides in either direction (i.e., 5' or 3') from a translation
termination codon. Consequently, the "start codon region" (or
"translation initiation codon region") and the "stop codon region"
(or "translation termination codon region") are all regions which
may be targeted effectively with the antisense oligomeric compounds
of the present invention.
The open reading frame (ORF) or "coding region," which is known in
the art to refer to the region between the translation initiation
codon and the translation termination codon, is also a region which
may be targeted effectively. Within the context of the present
invention, a preferred region is the intragenic region encompassing
the translation initiation or termination codon of the open reading
frame (ORF) of a gene.
Other target regions include the 5' untranslated region (5'UTR),
known in the art to refer to the portion of an mRNA in the 5'
direction from the translation initiation codon, and thus including
nucleotides between the 5' cap site and the translation initiation
codon of an mRNA (or corresponding nucleotides on the gene), and
the 3' untranslated region (3'UTR), known in the art to refer to
the portion of an mRNA in the 3' direction from the translation
termination codon, and thus including nucleotides between the
translation termination codon and 3' end of an mRNA (or
corresponding nucleotides on the gene). The 5' cap site of an mRNA
comprises an N7-methylated guanosine residue joined to the 5'-most
residue of the mRNA via a 5'-5' triphosphate linkage. The 5' cap
region of an mRNA is considered to include the 5' cap structure
itself as well as the first 50 nucleotides adjacent to the cap
site. It is also preferred to target the 5' cap region.
Although some eukaryotic mRNA transcripts are directly translated,
many contain one or more regions, known as "introns," which are
excised from a transcript before it is translated. The remaining
(and therefore translated) regions are known as "exons" and are
spliced together to form a continuous mRNA sequence. Targeting
splice sites, i.e., intron-exon junctions or exon-intron junctions,
may also be particularly useful in situations where aberrant
splicing is implicated in disease, or where an overproduction of a
particular splice product is implicated in disease. Aberrant fusion
junctions due to rearrangements or deletions are also preferred
target sites. mRNA transcripts produced via the process of splicing
of two (or more) mRNAs from different gene sources are known as
"fusion transcripts". It is also known that introns can be
effectively targeted using oligomeric compounds targeted to, for
example, pre-mRNA.
It is also known in the art that alternative RNA transcripts can be
produced from the same genomic region of DNA. These alternative
transcripts are generally known as "variants". More specifically,
"pre-mRNA variants" are transcripts produced from the same genomic
DNA that differ from other transcripts produced from the same
genomic DNA in either their start or stop position and contain both
intronic and exonic sequences.
Upon excision of one or more exon or intron regions, or portions
thereof during splicing, pre-mRNA variants produce smaller "mRNA
variants". Consequently, mRNA variants are processed pre-mRNA
variants and each unique pre-mRNA variant must always produce a
unique mRNA variant as a result of splicing. These mRNA variants
are also known as "alternative splice variants". If no splicing of
the pre-mRNA variant occurs then the pre-mRNA variant is identical
to the mRNA variant.
It is also known in the art that variants can be produced through
the use of alternative signals to start or stop transcription and
that pre-mRNAs and mRNAs can possess more that one start codon or
stop codon. Variants that originate from a pre-mRNA or mRNA that
use alternative start codons are known as "alternative start
variants" of that pre-mRNA or mRNA. Those transcripts that use an
alternative stop codon are known as "alternative stop variants" of
that pre-mRNA or mRNA. One specific type of alternative stop
variant is the "polyA variant" in which the multiple transcripts
produced result from the alternative selection of one of the "polyA
stop signals" by the transcription machinery, thereby producing
transcripts that terminate at unique polyA sites. Within the
context of the invention, the types of variants described herein
are also preferred target nucleic acids.
The locations on the target nucleic acid to which preferred
compounds and compositions of the invention hybridize are herein
below referred to as "preferred target segments." As used herein
the term "preferred target segment" is defined as at least an
8-nucleobase portion of a target region to which an active
antisense oligomeric compound is targeted. While not wishing to be
bound by theory, it is presently believed that these target
segments represent portions of the target nucleic acid that are
accessible for hybridization.
Once one or more target regions, segments or sites have been
identified, oligomeric compounds are chosen which are sufficiently
complementary to the target, i.e., hybridize sufficiently well and
with sufficient specificity, to give the desired effect.
In accordance with an embodiment of the this invention, a series of
nucleic acid duplexes comprising the antisense strand oligomeric
compounds of the present invention and their respective complement
sense strand compounds can be designed for a specific target or
targets. The ends of the strands may be modified by the addition of
one or more natural or modified nucleobases to form an overhang.
The sense strand of the duplex is designed and synthesized as the
complement of the antisense strand and may also contain
modifications or additions to either terminus. For example, in one
embodiment, both strands of the duplex would be complementary over
the central nucleobases, each having overhangs at one or both
termini.
For the purposes of describing an embodiment of this invention, the
combination of an antisense strand and a sense strand, each of can
be of a specified length, for example from 18 to 29 nucleotides
long, is identified as a complementary pair of siRNA oligomers.
This complementary pair of siRNA oligomers can include additional
nucleotides on either of their 5' or 3' ends. Further they can
include other molecules or molecular structures on their 3' or 5'
ends such as a phosphate group on the 5' end. A preferred group of
compounds of the invention include a phosphate group on the 5' end
of the antisense strand compound. Other preferred compounds also
include a phosphate group on the 5' end of the sense strand
compound. An even further preferred compounds would include
additional nucleotides such as a two base overhang on the 3'
end.
For example, a preferred siRNA complementary pair of oligomers
comprise an antisense strand oligomeric compound having the
sequence CGAGAGGCGGACGGGACCG (SEQ ID NO: 1) and having a
two-nucleobase overhang of deoxythymidine(dT) and its complement
sense strand. These oligomers would have the following
structure:
TABLE-US-00001 5' cgagaggcggacgggaccgTT 3' Antisense Strand
||||||||||||||||||| (SEQ ID NO: 2) 3' TTgctctccgcctgccctggc 5'
Complement Strand (SEQ ID NO: 3)
In an additional embodiment of the invention, a single oligomer
having both the antisense portion as a first region in the oligomer
and the sense portion as a second region in the oligomer is
selected. The first and second regions are linked together by
either a nucleotide linker (a string of one or more nucleotides
that are linked together in a sequence) or by a non-nucleotide
linker region or by a combination of both a nucleotide and
non-nucleotide structure. In each of these structures, the
oligomer, when folded back on itself, would be complementary at
least between the first region, the antisense portion, and the
second region, the sense portion. Thus the oligomer would have a
palindrome within it structure wherein the first region, the
antisense portion in the 5' to 3' direction, is complementary to
the second region, the sense portion in the 3' to 5' direction.
In a further embodiment, the invention includes oligomer/protein
compositions. Such compositions have both an oligomer component and
a protein component. The oligomer component comprises at least one
oligomer, either the antisense or the sense oligomer but preferably
the antisense oligomer (the oligomer that is antisense to the
target nucleic acid). The oligomer component can also comprise both
the antisense and the sense strand oligomers. The protein component
of the composition comprises at least one protein that forms a
portion of the RNA-induced silencing complex, i.e., the RISC
complex.
RISC is a ribonucleoprotein complex that contains an oligomer
component and proteins of the Argonaute family of proteins, among
others. While we do not wish to be bound by theory, the Argonaute
proteins make up a highly conserved family whose members have been
implicated in RNA interference and the regulation of related
phenomena. Members of this family have been shown to possess the
canonical PAZ and Piwi domains, thought to be a region of
protein-protein interaction. Other proteins containing these
domains have been shown to effect target cleavage, including the
RNAse, Dicer. The Argonaute family of proteins includes, but
depending on species, are not necessary limited to, elF2C1 and
elF2C2. elF2C2 is also known as human GERp95. While we do not wish
to be bound by theory, at least the antisense oligomer strand is
bound to the protein component of the RISC complex. Additional, the
complex might also include the sense strand oligomer. Carmell et
al, Genes and Development 2002, 16, 2733-2742.
Also while we do not wish to be bound by theory, it is further
believed that the RISC complex may interact with one or more of the
translation machinery components. Translation machinery components
include but are not limited to proteins that effect or aid in the
translation of an RNA into protein including the ribosomes or
polyribosome complex. Therefore, in a further embodiment of the
invention, the oligomer component of the invention is associated
with a RISC protein component and further associates with the
translation machinery of a cell. Such interaction with the
translation machinery of the cell would include interaction with
structural and enzymatic proteins of the translation machinery
including but not limited to the polyribosome and ribosomal
subunits.
In a further embodiment of the invention, the oligomer of the
invention is associated with cellular factors such as transporters
or chaperones. These cellular factors can be protein, lipid or
carbohydrate based and can have structural or enzymatic functions
that may or may not require the complexation of one or more metal
ions.
Furthermore, the oligomer of the invention itself may have one or
more moieties which are bound to the oligomer which facilitate the
active or passive transport, localization or compartmentalization
of the oligomer. Cellular localization includes, but is not limited
to, localization to within the nucleus, the nucleolus or the
cytoplasm. Compartmentalization includes, but is not limited to,
any directed movement of the oligomers of the invention to a
cellular compartment including the nucleus, nucleolus,
mitochondrion, or imbedding into a cellular membrane surrounding a
compartment or the cell itself.
In a further embodiment of the invention, the oligomer of the
invention is associated with cellular factors that affect gene
expression, more specifically those involved in RNA modifications.
These modifications include, but are not limited to
posttrascriptional modifications such as methylation. Furthermore,
the oligomer of the invention itself may have one or more moieties
which are bound to the oligomer which facilitate the
posttranscriptional modification.
The oligomeric compounds of the invention may be used in the form
of single-stranded, double-stranded, circular or hairpin oligomeric
compounds and may contain structural elements such as internal or
terminal bulges or loops. Once introduced to a system, the
oligomeric compounds of the invention may interact with or elicit
the action of one or more enzymes or may interact with one or more
structural proteins to effect modification of the target nucleic
acid.
One non-limiting example of such an interaction is the RISC
complex. Use of the RISC complex to effect cleavage of RNA targets
thereby greatly enhances the efficiency of oligomer-mediated
inhibition of gene expression. Similar roles have been postulated
for other ribonucleases such as those in the RNase III and
ribonuclease L family of enzymes.
Preferred forms of oligomeric compound of the invention include a
single-stranded antisense oligomer that binds in a RISC complex, a
double stranded antisense/sense pair of oligomer or a single strand
oligomer that includes both an antisense portion and a sense
portion. Each of these compounds or compositions is used to induce
potent and specific modulation of gene function. Such specific
modulation of gene function has been shown in many species by the
introduction of double-stranded structures, such as double-stranded
RNA (dsRNA) molecules and has been shown to induce potent and
specific antisense-mediated reduction of the function of a gene or
its associated gene products. This phenomenon occurs in both plants
and animals and is believed to have an evolutionary connection to
viral defense and transposon silencing.
The compounds and compositions of the invention are used to
modulate the expression of a target nucleic acid. "Modulators" are
those oligomeric compounds that decrease or increase the expression
of a nucleic acid molecule encoding a target and which comprise at
least an 8-nucleobase portion that is complementary to a preferred
target segment. The screening method comprises the steps of
contacting a preferred target segment of a nucleic acid molecule
encoding a target with one or more candidate modulators, and
selecting for one or more candidate modulators which decrease or
increase the expression of a nucleic acid molecule encoding a
target. Once it is shown that the candidate modulator or modulators
are capable of modulating (e.g. either decreasing or increasing)
the expression of a nucleic acid molecule encoding a target, the
modulator may then be employed in further investigative studies of
the function of a target, or for use as a research, diagnostic, or
therapeutic agent in accordance with the present invention.
Oligomeric Compounds
In the context of the present invention, the term "oligomeric
compound" refers to a polymeric structure capable of hybridizing a
region of a nucleic acid molecule. This term includes
oligonucleotides, oligonucleosides, oligonucleotide analogs,
oligonucleotide mimetics and combinations of these. Oligomeric
compounds routinely prepared linearly but can be joined or
otherwise prepared to be circular and may also include branching.
Oligomeric compounds can hybridized to form double stranded
compounds that can be blunt ended or may include overhangs. In
general an oligomeric compound comprises a backbone of linked
momeric subunits where each linked momeric subunit is directly or
indirectly attached to a heterocyclic base moiety. The linkages
joining the monomeric subunits, the sugar moieties or surrogates
and the heterocyclic base moieties can be independently modified
giving rise to a plurality of motifs for the resulting oligomeric
compounds including hemimers, gapmers and chimeras.
As is known in the art, a nucleoside is a base-sugar combination.
The base portion of the nucleoside is normally a heterocyclic base
moiety. The two most common classes of such heterocyclic bases are
purines and pyrimidines. Nucleotides are nucleosides that further
include a phosphate group covalently linked to the sugar portion of
the nucleoside. For those nucleosides that include a pentofuranosyl
sugar, the phosphate group can be linked to either the 2', 3' or 5'
hydroxyl moiety of the sugar. In forming oligomers, the phosphate
groups covalently link adjacent nucleosides to one another to form
a linear polymeric compound. The respective ends of this linear
polymeric structure can be joined to form a circular structure by
hybridization or by formation of a covalent bond, however, open
linear structures are generally preferred. Within the oligomer
structure, the phosphate groups are commonly referred to as forming
the internucleoside linkages of the oligomer. The normal
internucleoside linkage of RNA and DNA is a 3' to 5' phosphodiester
linkage.
In the context of this invention, the term "oligonucleotide" refers
to an oligomer or polymer of ribonucleic acid (RNA) or
deoxyribonucleic acid (DNA). This term includes oligonucleotides
composed of naturally-occurring nucleobases, sugars and covalent
internucleoside linkages. The term "oligonucleotide analog" refers
to oligonucleotides that have one or more non-naturally occurring
portions which function in a similar manner to oligonulceotides.
Such non-naturally occurring oligonucleotides are often preferred
the naturally occurring forms because of desirable properties such
as, for example, enhanced cellular uptake, enhanced affinity for
nucleic acid target and increased stability in the presence of
nucleases.
In the context of this invention, the term "oligonucleoside" refers
to nucleosides that are joined by internucleoside linkages that do
not have phosphorus atoms. Internucleoside linkages of this type
include short chain alkyl, cycloalkyl, mixed heteroatom alkyl,
mixed heteroatom cycloalkyl, one or more short chain heteroatomic
and one or more short chain heterocyclic. These internucleoside
linkages include but are not limited to siloxane, sulfide,
sulfoxide, sulfone, acetal, formacetal, thioformacetal, methylene
formacetal, thioformacetal, alkeneyl, sulfamate; methyleneimino,
methylenehydrazino, sulfonate, sulfonamide, amide and others having
mixed N, O, S and CH.sub.2 component parts.
In addition to the modifications described above, the nucleosides
of the oligomeric compounds of the invention can have a variety of
other modification so long as these other modifications either
alone or in combination with other nucleosides enhance one or more
of the desired properties described above. Thus, for nucleotides
that are incorporated into oligomers of the invention, these
nucleotides can have sugar portions that correspond to
naturally-occurring sugars or modified sugars. Representative
modified sugars include carbocyclic or acyclic sugars, sugars
having substituent groups at one or more of their 2', 3' or 4'
positions and sugars having substituents in place of one or more
hydrogen atoms of the sugar. Additional nucleosides amenable to the
present invention having altered base moieties and or altered sugar
moieties are disclosed in U.S. Pat. No. 3,687,808 and PCT
application PCT/US89/02323.
Altered base moieties or altered sugar moieties also include other
modifications consistent with the spirit of this invention. Such
oligomers are best described as being structurally distinguishable
from, yet functionally interchangeable with, naturally occurring or
synthetic wild type oligonucleotides. All such oligomers are
comprehended by this invention so long as they function effectively
to mimic the structure of a desired RNA or DNA strand. A class of
representative base modifications include tricyclic cytosine
analog, termed "G clamp" (Lin, et al., J. Am. Chem. Soc. 1998, 120,
8531). This analog makes four hydrogen bonds to a complementary
guanine (G) within a helix by simultaneously recognizing the
Watson-Crick and Hoogsteen faces of the targeted G. This G clamp
modification when incorporated into phosphorothioate oligomers,
dramatically enhances antisense potencies in cell culture. The
oligomers of the invention also can include phenoxazine-substituted
bases of the type disclosed by Flanagan, et al., Nat. Biotechnol.
1999, 17(1), 48-52.
The oligomeric compounds in accordance with this invention
preferably comprise from about 8 to about 80 nucleobases (i.e. from
about 8 to about 80 linked nucleosides). One of ordinary skill in
the art will appreciate that the invention embodies oligomeric
compounds of 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55,
56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72,
73, 74, 75, 76, 77, 78, 79, or 80 nucleobases in length.
In one preferred embodiment, the oligomeric compounds of the
invention are 12 to 50 nucleobases in length. One having ordinary
skill in the art will appreciate that this embodies oligomeric
compounds of 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41,
42, 43, 44, 45, 46, 47, 48, 49, or 50 nucleobases in length.
In another preferred embodiment, the oligomeric compounds of the
invention are 15 to 30 nucleobases in length. One having ordinary
skill in the art will appreciate that this embodies oligomeric
compounds of 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,
28, 29, or 30 nucleobases in length.
Particularly preferred oligomeric compounds are oligomers from
about 12 to about 50 nucleobases, even more preferably those
comprising from about 15 to about 30 nucleobases.
General Oligomer Synthesis
Oligomerization of modified and unmodified nucleosides is performed
according to literature procedures for DNA like compounds
(Protocols for Oligonucleotides and Analogs, Ed. Agrawal (1993),
Humana Press) and/or RNA like compounds (Scaringe, Methods (2001),
23, 206-217. Gait et al., Applications of Chemically synthesized
RNA in RNA:Protein Interactions, Ed. Smith (1998), 1-36. Gallo et
al., Tetrahedron (2001), 57, 5707-5713) synthesis as appropriate.
In addition specific protocols for the synthesis of oligomeric
compounds of the invention are illustrated in the examples
below.
RNA oligomers can be synthesized by methods disclosed herein or
purchased from various RNA synthesis companies such as for example
Dharmacon Research Inc., (Lafayette, Colo.).
Irrespective of the particular protocol used, the oligomeric
compounds used in accordance with this invention may be
conveniently and routinely made through the well-known technique of
solid phase synthesis. Equipment for such synthesis is sold by
several vendors including, for example, Applied Biosystems (Foster
City, Calif.). Any other means for such synthesis known in the art
may additionally or alternatively be employed.
For double stranded structures of the invention, once synthesized,
the complementary strands preferably are annealed. The single
strands are aliquoted and diluted to a concentration of 50 uM. Once
diluted, 30 uL of each strand is combined with 15 uL of a 5.times.
solution of annealing buffer. The final concentration of the buffer
is 100 mM potassium acetate, 30 mM HEPES-KOH pH 7.4, and 2 mM
magnesium acetate. The final volume is 75 uL. This solution is
incubated for 1 minute at 90.degree. C. and then centrifuged for 15
seconds. The tube is allowed to sit for 1 hour at 37.degree. C. at
which time the dsRNA duplexes are used in experimentation. The
final concentration of the dsRNA compound is 20 uM. This solution
can be stored frozen (-20.degree. C.) and freeze-thawed up to 5
times.
Once prepared, the desired synthetic duplexes are evaluated for
their ability to modulate target expression. When cells reach 80%
confluency, they are treated with synthetic duplexes comprising at
least one oligomeric compound of the invention. For cells grown in
96-well plates, wells are washed once with 200 .mu.L OPTI-MEM-1
reduced-serum medium (Gibco BRL) and then treated with 130 .mu.L of
OPTI-MEM-1 containing 12 .mu.g/mL LIPOFECTIN (Gibco BRL) and the
desired dsRNA compound at a final concentration of 200 nM. After 5
hours of treatment, the medium is replaced with fresh medium. Cells
are harvested 16 hours after treatment, at which time RNA is
isolated and target reduction measured by RT-PCR.
Oligomer and Monomer Modifications
As is known in the art, a nucleoside is a base-sugar combination.
The base portion of the nucleoside is normally a heterocyclic base.
The two most common classes of such heterocyclic bases are the
purines and the pyrimidines. Nucleotides are nucleosides that
further include a phosphate group covalently linked to the sugar
portion of the nucleoside. For those nucleosides that include a
pentofuranosyl sugar, the phosphate group can be linked to either
the 2', 3' or 5' hydroxyl moiety of the sugar. In forming
oligomers, the phosphate groups covalently link adjacent
nucleosides to one another to form a linear polymeric compound. In
turn, the respective ends of this linear polymeric compound can be
further joined to form a circular compound, however, linear
compounds are generally preferred. In addition, linear compounds
may have internal nucleobase complementarity and may therefore fold
in a manner as to produce a fully or partially double-stranded
compound. Within oligomers, the phosphate groups are commonly
referred to as forming the internucleoside linkage or in
conjunction with the sugar ring the backbone of the oligomer. The
normal internucleoside linkage that makes up the backbone of RNA
and DNA is a 3' to 5' phosphodiester linkage.
Modified Internucleoside Linkages
Specific examples of preferred antisense oligomeric compounds
useful in this invention include oligomers containing modified e.g.
non-naturally occurring internucleoside linkages. As defined in
this specification, oligomers having modified internucleoside
linkages include internucleoside linkages that retain a phosphorus
atom and internucleoside linkages that do not have a phosphorus
atom. For the purposes of this specification, and as sometimes
referenced in the art, modified oligomers that do not have a
phosphorus atom in their internucleoside backbone can also be
considered to be oligonucleosides.
In the C. elegans system, modification of the internucleotide
linkage (phosphorothioate) did not significantly interfere with
RNAi activity. Based on this observation, it is suggested that
certain preferred oligomeric compounds of the invention can also
have one or more modified internucleoside linkages. A preferred
phosphorus containing modified internucleoside linkage is the
phosphorothioate internucleoside linkage.
Preferred modified oligomer backbones containing a phosphorus atom
therein include, for example, phosphorothioates, chiral
phosphorothioates, phosphorodithioates, phosphotriesters,
aminoalkylphosphotriesters, methyl and other alkyl phosphonates
including 3'-alkylene phosphonates, 5'-alkylene phosphonates and
chiral phosphonates, phosphinates, phosphoramidates including
3'-amino phosphoramidate and aminoalkylphosphoramidates,
thionophosphoramidates, thionoalkylphosphonates,
thionoalkylphosphotriesters, selenophosphates and boranophosphates
having normal 3'-5' linkages, 2'-5' linked analogs of these, and
those having inverted polarity wherein one or more internucleotide
linkages is a 3' to 3', 5' to 5' or 2' to 2' linkage. Preferred
oligomers having inverted polarity comprise a single 3' to 3'
linkage at the 3'-most internucleotide linkage i.e. a single
inverted nucleoside residue which may be abasic (the nucleobase is
missing or has a hydroxyl group in place thereof). Various salts,
mixed salts and free acid forms are also included.
Representative United States patents that teach the preparation of
the above phosphorus-containing linkages include, but are not
limited to, U.S. Pat. Nos.: 3,687,808; 4,469,863; 4,476,301;
5,023,243; 5,177,196; 5,188,897; 5,264,423; 5,276,019; 5,278,302;
5,286,717; 5,321,131; 5,399,676; 5,405,939; 5,453,496; 5,455,233;
5,466,677; 5,476,925; 5,519,126; 5,536,821; 5,541,306; 5,550,111;
5,563,253; 5,571,799; 5,587,361; 5,194,599; 5,565,555; 5,527,899;
5,721,218; 5,672,697 and 5,625,050, certain of which are commonly
owned with this application, and each of which is herein
incorporated by reference.
In more preferred embodiments of the invention, oligomeric
compounds have one or more phosphorothioate and/or heteroatom
internucleoside linkages, in particular
--CH.sub.2--NH--O--CH.sub.2--,
--CH.sub.2--N(CH.sub.3)--O--CH.sub.2-- [known as a methylene
(methylimino) or MMI backbone],
--CH.sub.2--O--N(CH.sub.3)--CH.sub.2--,
--CH.sub.2--N(CH.sub.3)--N(CH.sub.3)--CH.sub.2-- and
--O--N(CH.sub.3)--CH.sub.2--CH.sub.2-- [wherein the native
phosphodiester internucleotide linkage is represented as
--O--P(.dbd.O)(OH)--O--CH.sub.2--]. The MMI type internucleoside
linkages are disclosed in the above referenced U.S. Pat. No.
5,489,677. Preferred amide internucleoside linkages are disclosed
in the above referenced U.S. Pat. No. 5,602,240.
Preferred modified oligomer backbones that do not include a
phosphorus atom therein have backbones that are formed by short
chain alkyl or cycloalkyl internucleoside linkages, mixed
heteroatom and alkyl or cycloalkyl internucleoside linkages, or one
or more short chain heteroatomic or heterocyclic internucleoside
linkages. These include those having morpholino linkages (formed in
part from the sugar portion of a nucleoside); siloxane backbones;
sulfide, sulfoxide and sulfone backbones; formacetal and
thioformacetal backbones; methylene formacetal and thioformacetal
backbones; riboacetal backbones; alkene containing backbones;
sulfamate backbones; methyleneimino and methylenehydrazino
backbones; sulfonate and sulfonamide backbones; amide backbones;
and others having mixed N, O, S and CH.sub.2 component parts.
Representative United States patents that teach the preparation of
the above oligonucleosides include, but are not limited to, U.S.
Pat. Nos.: 5,034,506; 5,166,315; 5,185,444; 5,214,134; 5,216,141;
5,235,033; 5,264,562; 5,264,564; 5,405,938; 5,434,257; 5,466,677;
5,470,967; 5,489,677; 5,541,307; 5,561,225; 5,596,086; 5,602,240;
5,610,289; 5,602,240; 5,608,046; 5,610,289; 5,618,704; 5,623,070;
5,663,312; 5,633,360; 5,677,437; 5,792,608; 5,646,269 and
5,677,439, certain of which are commonly owned with this
application, and each of which is herein incorporated by
reference.
Oligomer Mimetics
Another preferred group of oligomeric compounds amenable to the
present invention includes oligonucleotide mimetics. The term
mimetic as it is applied to oligonucleotides is intended to include
oligomeric compounds wherein only the furanose ring or both the
furanose ring and the internucleotide linkage are replaced with
novel groups, replacement of only the furanose ring is also
referred to in the art as being a sugar surrogate. The heterocyclic
base moiety or a modified heterocyclic base moiety is maintained
for hybridization with an appropriate target nucleic acid.
One such oligomeric compound, an oligonucleotide mimetic that has
been shown to have excellent hybridization properties, is referred
to as a peptide nucleic acid (PNA). In PNA oligomeric compounds,
the sugar-backbone of an oligonucleotide is replaced with an amide
containing backbone, in particular an aminoethylglycine backbone.
The nucleobases are retained and are bound directly or indirectly
to aza nitrogen atoms of the amide portion of the backbone.
Representative United States patents that teach the preparation of
PNA oligomeric compounds include, but are not limited to, U.S. Pat.
Nos.: 5,539,082; 5,714,331; and 5,719,262, each of which is herein
incorporated by reference. Further teaching of PNA oligomeric
compounds can be found in Nielsen et al., Science, 1991, 254,
1497-1500.
One oligonucleotide mimetic that has been reported to have
excellent hybridization properties is peptide nucleic acids (PNA).
The backbone in PNA compounds is two or more linked
aminoethylglycine units which gives PNA an amide containing
backbone. The heterocyclic base moieties are bound directly or
indirectly to aza nitrogen atoms of the amide portion of the
backbone.
Representative United States patents that teach the preparation of
PNA compounds include, but are not limited to, U.S. Pat. Nos.:
5,539,082; 5,714,331; and 5,719,262, each of which is herein
incorporated by reference. Further teaching of PNA compounds can be
found in Nielsen et al., Science, 1991, 254, 1497-1500.
PNA has been modified to incorporate numerous modifications since
the basic PNA structure was first prepared. The basic structure is
shown below:
##STR00009## wherein
Bx is a heterocyclic base moiety;
T.sub.4 is hydrogen, an amino protecting group, --C(O)R.sub.5,
substituted or unsubstituted C.sub.1-C.sub.10alkyl, substituted or
unsubstituted C.sub.2-C.sub.10 alkenyl, substituted or
unsubstituted C.sub.2-C.sub.10 alkynyl, alkylsulfonyl,
arylsulfonyl, a chemical functional group, a reporter group, a
conjugate group, a D or L .alpha.-amino acid linked via the
.alpha.-carboxyl group or optionally through the .omega.-carboxyl
group when the amino acid is aspartic acid or glutamic acid or a
peptide derived from D, L or mixed D and L amino acids linked
through a carboxyl group, wherein the substituent groups are
selected from hydroxyl, amino, alkoxy, carboxy, benzyl, phenyl,
nitro, thiol, thioalkoxy, halogen, alkyl, aryl, alkenyl and
alkynyl;
T.sub.5 is --OH, --N(Z.sub.1)Z.sub.2, R.sub.5, D or L .alpha.-amino
acid linked via the .alpha.-amino group or optionally through the
.omega.-amino group when the amino acid is lysine or ornithine or a
peptide derived from D, L or mixed D and L amino acids linked
through an amino group, a chemical functional group, a reporter
group or a conjugate group;
Z.sub.1 is hydrogen, C.sub.1-C.sub.6 alkyl, or an amino protecting
group;
Z.sub.2 is hydrogen, C.sub.1-C.sub.6 alkyl, an amino protecting
group, --C(.dbd.O)--(CH.sub.2).sub.n-J-Z.sub.3, a D or L
.alpha.-amino acid linked via the .alpha.-carboxyl group or
optionally through the co-carboxyl group when the amino acid is
aspartic acid or glutamic acid or a peptide derived from D, L or
mixed D and L amino acids linked through a carboxyl group;
Z.sub.3 is hydrogen, an amino protecting group, --C.sub.1-C.sub.6
alkyl, --C(.dbd.O)--CH.sub.3, benzyl, benzoyl, or
--(CH.sub.2).sub.n--N(H)Z.sub.1;
each J is O, S or NH;
R.sub.5 is a carbonyl protecting group; and
n is from 2 to about 50.
Another class of oligonucleotide mimetic that has been studied is
based on linked morpholino units (morpholino nucleic acid) having
heterocyclic bases attached to the morpholino ring. A number of
linking groups have been reported that link the morpholino
monomeric units in a morpholino nucleic acid. A preferred class of
linking groups have been selected to give a non-ionic oligomeric
compound. The non-ionic morpholino-based oligomeric compounds are
less likely to have undesired interactions with cellular proteins.
Morpholino-based oligomeric compounds are non-ionic mimics of
oligonucleotides which are less likely to form undesired
interactions with cellular proteins (Dwaine A. Braasch and David R.
Corey, Biochemistry, 2002, 41(14), 4503-4510). Morpholino-based
oligomeric compounds are disclosed in U.S. Pat. No. 5,034,506,
issued Jul. 23, 1991. The morpholino class of oligomeric compounds
have been prepared having a variety of different linking groups
joining the monomeric subunits.
Morpholino nucleic acids have been prepared having a variety of
different linking groups (L.sub.2) joining the monomeric subunits.
The basic formula is shown below:
##STR00010## wherein
T.sub.1 is hydroxyl or a protected hydroxyl;
T.sub.5 is hydrogen or a phosphate or phosphate derivative;
L.sub.2 is a linking group; and
n is from 2 to about 50.
A further class of oligonucleotide mimetic is referred to as
cyclohexenyl nucleic acids (CeNA). The furanose ring normally
present in an DNA/RNA molecule is replaced with a cyclohenyl ring.
CeNA DMT protected phosphoramidite monomers have been prepared and
used for oligomeric compound synthesis following classical
phosphoramidite chemistry. Fully modified CeNA oligomeric compounds
and oligomers having specific positions modified with CeNA have
been prepared and studied (see Wang et al., J. Am. Chem. Soc.,
2000, 122, 8595-8602). In general the incorporation of CeNA
monomers into a DNA chain increases its stability of a DNA/RNA
hybrid. CeNA oligoadenylates formed complexes with RNA and DNA
complements with similar stability to the native complexes. The
study of incorporating CeNA structures into natural nucleic acid
structures was shown by NMR and circular dichroism to proceed with
easy conformational adaptation. Furthermore the incorporation of
CeNA into a sequence targeting RNA was stable to serum and able to
activate E. Coli RNase resulting in cleavage of the target RNA
strand.
The general formula of CeNA is shown below:
##STR00011## wherein
each Bx is a heterocyclic base moiety;
T.sub.1 is hydroxyl or a protected hydroxyl; and
T2 is hydroxyl or a protected hydroxyl.
Another preferred group of oligomeric compounds amenable to the
present invention includes oligonucleotide mimetics. The term
mimetic as it is applied to oligomers is intended to include
oligomeric compounds wherein only the furanose ring or both the
furanose ring and the internucleotide linkage are replaced with
novel groups, replacement of only the furanose ring is also
referred to in the art as being a sugar surrogate. The heterocyclic
base moiety or a modified heterocyclic base moiety is maintained
for hybridization with an appropriate target nucleic acid.
Another class of oligonucleotide mimetic (anhydrohexitol nucleic
acid) can be prepared from one or more anhydrohexitol nucleosides
(see, Wouters and Herdewijn, Bioorg. Med. Chem. Lett., 1999, 9,
1563-1566) and would have the general formula:
##STR00012##
A further preferred modification includes Locked Nucleic Acids
(LNAs) in which the 2'-hydroxyl group is linked to the 4' carbon
atom of the sugar ring thereby forming a 2'-C,4'-C-oxymethylene
linkage thereby forming a bicyclic sugar moiety. The linkage is
preferably a methylene (--CH.sub.2--).sub.n group bridging the 2'
oxygen atom and the 4' carbon atom wherein n is 1 or 2 (Singh et
al., Chem. Commun., 1998, 4, 455-456). LNA and LNA analogs display
very high duplex thermal stabilities with complementary DNA and RNA
(Tm=+3 to +10 C), stability towards 3'-exonucleolytic degradation
and good solubility properties. The basic structure of LNA showing
the bicyclic ring system is shown below:
##STR00013##
The conformations of LNAs determined by 2D NMR spectroscopy have
shown that the locked orientation of the LNA nucleotides, both in
single-stranded LNA and in duplexes, constrains the phosphate
backbone in such a way as to introduce a higher population of the
N-type conformation (Petersen et al., J. Mol. Recognit., 2000, 13,
44-53). These conformations are associated with improved stacking
of the nucleobases (Wengel et al., Nucleosides Nucleotides, 1999,
18, 1365-1370).
LNA has been shown to form exceedingly stable LNA:LNA duplexes
(Koshkin et al., J. Am. Chem. Soc., 1998, 120, 13252-13253).
LNA:LNA hybridization was shown to be the most thermally stable
nucleic acid type duplex system, and the RNA-mimicking character of
LNA was established at the duplex level. Introduction of 3 LNA
monomers (T or A) significantly increased melting points
(Tm=+15/+11) toward DNA complements. The universality of
LNA-mediated hybridization has been stressed by the formation of
exceedingly stable LNA:LNA duplexes. The RNA-mimicking of LNA was
reflected with regard to the N-type conformational restriction of
the monomers and to the secondary structure of the LNA:RNA
duplex.
LNAs also form duplexes with complementary DNA, RNA or LNA with
high thermal affinities. Circular dichroism (CD) spectra show that
duplexes involving fully modified LNA (esp. LNA:RNA) structurally
resemble an A-form RNA:RNA duplex. Nuclear magnetic resonance (NMR)
examination of an LNA:DNA duplex confirmed the 3'-endo conformation
of an LNA monomer. Recognition of double-stranded DNA has also been
demonstrated suggesting strand invasion by LNA. Studies of
mismatched sequences show that LNAs obey the Watson-Crick base
pairing rules with generally improved selectivity compared to the
corresponding unmodified reference strands.
Novel types of LNA-oligomeric compounds, as well as the LNAs, are
useful in a wide range of diagnostic and therapeutic applications.
Among these are antisense applications, PCR applications,
strand-displacement oligomers, substrates for nucleic acid
polymerases and generally as nucleotide based drugs.
Potent and nontoxic antisense oligomers containing LNAs have been
described (Wahlestedt et al., Proc. Natl. Acad. Sci. U.S.A, 2000,
97, 5633-5638.) The authors have demonstrated that LNAs confer
several desired properties to antisense agents. LNA/DNA copolymers
were not degraded readily in blood serum and cell extracts. LNA/DNA
copolymers exhibited potent antisense activity in assay systems as
disparate as G-protein-coupled receptor signaling in living rat
brain and detection of reporter genes in Escherichia coli.
Lipofectin-mediated efficient delivery of LNA into living human
breast cancer cells has also been accomplished.
The synthesis and preparation of the LNA monomers adenine,
cytosine, guanine, 5-methyl-cytosine, thymine and uracil, along
with their oligomerization, and nucleic acid recognition properties
have been described (Koshkin et al., Tetrahedron, 1998, 54,
3607-3630). LNAs and preparation thereof are also described in WO
98/39352 and WO 99/14226.
The first analogs of LNA, phosphorothioate-LNA and 2'-thio-LNAs,
have also been prepared (Kumar et al., Bioorg. Med. Chem. Lett.,
1998, 8, 2219-2222). Preparation of locked nucleoside analogs
containing oligodeoxyribonucleotide duplexes as substrates for
nucleic acid polymerases has also been described (Wengel et al.,
PCT International Application WO 98-DK393 19980914).
Furthermore, synthesis of 2'-amino-LNA, a novel conformationally
restricted high-affinity oligonucleotide analog with a handle has
been described in the art (Singh et al., J. Org. Chem., 1998, 63,
10035-10039). In addition, 2'-Amino- and 2'-methylamino-LNA's have
been prepared and the thermal stability of their duplexes with
complementary RNA and DNA strands has been previously reported.
Further oligonucleotide mimetics have been prepared to include
bicyclic and tricyclic nucleoside analogs having the formulas
(amidite monomers shown):
##STR00014## (see Steffens et al., Helv. Chim. Acta, 1997, 80,
2426-2439; Steffens et al., J. Am. Chem. Soc., 1999, 121,
3249-3255; and Renneberg et al., J. Am. Chem. Soc., 2002, 124,
5993-6002). These modified nucleoside analogs have been
oligomerized using the phosphoramidite approach and the resulting
oligomeric compounds containing tricyclic nucleoside analogs have
shown increased thermal stabilities (Tm's) when hybridized to DNA,
RNA and itself. Oligomeric compounds containing bicyclic nucleoside
analogs have shown thermal stabilities approaching that of DNA
duplexes.
Another class of oligonucleotide mimetic is referred to as
phosphonomonoester nucleic acids incorporate a phosphorus group in
a backbone the backbone. This class of olignucleotide mimetic is
reported to have useful physical and biological and pharmacological
properties in the areas of inhibiting gene expression (antisense
oligonucleotides, ribozymes, sense oligonucleotides and
triplex-forming oligonucleotides), as probes for the detection of
nucleic acids and as auxiliaries for use in molecular biology.
The general formula (for definitions of variables see: U.S. Pat.
Nos. 5,874,553 and 6,127,346 herein incorporated by reference in
their entirety) is shown below.
##STR00015##
Another oligonucleotide mimetic has been reported wherein the
furanosyl ring has been replaced by a cyclobutyl moiety.
Modified Nucleobases/Naturally Occurring Nucleobases
Oligomeric compounds may also include nucleobase (often referred to
in the art simply as "base" or "heterocyclic base moiety")
modifications or substitutions. As used herein, "unmodified" or
"natural" nucleobases include the purine bases adenine (A) and
guanine (G), and the pyrimidine bases thymine (T), cytosine (C) and
uracil (U). Modified nucleobases also referred herein as
heterocyclic base moieties include other synthetic and natural
nucleobases such as 5-methylcytosine (5-me-C), 5-hydroxymethyl
cytosine, xanthine, hypoxanthine, 2-aminoadenine, 6-methyl and
other alkyl derivatives of adenine and guanine, 2-propyl and other
alkyl derivatives of adenine and guanine, 2-thiouracil,
2-thiothymine and 2-thiocytosine, 5-halouracil and cytosine,
5-propynyl (--C.ident.C--CH.sub.3) uracil and cytosine and other
alkynyl derivatives of pyrimidine bases, 6-azo uracil, cytosine and
thymine, 5-uracil (pseudouracil), 4-thiouracil, 8-halo, 8-amino,
8-thiol, 8-thioalkyl, 8-hydroxyl and other 8-substituted adenines
and guanines, 5-halo particularly 5-bromo, 5-trifluoromethyl and
other 5-substituted uracils and cytosines, 7-methylguanine and
7-methyladenine, 2-F-adenine, 2-amino-adenine, 8-azaguanine and
8-azaadenine, 7-deazaguanine and 7-deazaadenine and 3-deazaguanine
and 3-deazaadenine.
Heterocyclic base moieties may also include those in which the
purine or pyrimidine base is replaced with other heterocycles, for
example 7-deaza-adenine, 7-deazaguanosine, 2-aminopyridine and
2-pyridone. Further nucleobases include those disclosed in U.S.
Pat. No. 3,687,808, those disclosed in The Concise Encyclopedia Of
Polymer Science And Engineering, pages 858-859, Kroschwitz, J. I.,
ed. John Wiley & Sons, 1990, those disclosed by Englisch et
al., Angewandte Chemie, International Edition, 1991, 30, 613, and
those disclosed by Sanghvi, Y. S., Chapter 15, Antisense Research
and Applications, pages 289-302, Crooke, S. T. and Lebleu, B., ed.,
CRC Press, 1993. Certain of these nucleobases are particularly
useful for increasing the binding affinity of the oligomeric
compounds of the invention. These include 5-substituted
pyrimidines, 6-azapyrimidines and N-2, N-6 and O-6 substituted
purines, including 2-aminopropyladenine, 5-propynyluracil and
5-propynylcytosine. 5-methylcytosine substitutions have been shown
to increase nucleic acid duplex stability by 0.6-1.2.degree. C.
(Sanghvi, Y. S., Crooke, S. T. and Lebleu, B., eds., Antisense
Research and Applications, CRC Press, Boca Raton, 1993, pp.
276-278) and are presently preferred base substitutions, even more
particularly when combined with 2'-O-methoxyethyl sugar
modifications.
In one aspect of the present invention oligomeric compounds are
prepared having polycyclic heterocyclic compounds in place of one
or more heterocyclic base moieties. A number of tricyclic
heterocyclic compounds have been previously reported. These
compounds are routinely used in antisense applications to increase
the binding properties of the modified strand to a target strand.
The most studied modifications are targeted to guanosines hence
they have been termed G-clamps or cytidine analogs. Many of these
polycyclic heterocyclic compounds have the general formula:
##STR00016##
Representative cytosine analogs that make 3 hydrogen bonds with a
guanosine in a second strand include 1,3-diazaphenoxazine-2-one
(R.sub.10.dbd.O, R.sub.11--R.sub.14.dbd.H) [Kurchavov, et al.,
Nucleosides and Nucleotides, 1997, 16, 1837-1846],
1,3-diazaphenothiazine-2-one (R.sub.10.dbd.S,
R.sub.11--R.sub.14.dbd.H), [Lin, K.-Y.; Jones, R. J.; Matteucci, M.
J. Am. Chem. Soc. 1995, 117, 3873-3874] and
6,7,8,9-tetrafluoro-1,3-diazaphenoxazine-2-one (R.sub.10.dbd.O,
R.sub.11--R.sub.14.dbd.F) [Wang, J.; Lin, K.-Y., Matteucci, M.
Tetrahedron Lett. 1998, 39, 8385-8388]. Incorporated into
oligonucleotides these base modifications were shown to hybridize
with complementary guanine and the latter was also shown to
hybridize with adenine and to enhance helical thermal stability by
extended stacking interactions (also see U.S. patent application
entitled "Modified Peptide Nucleic Acids" filed May 24, 2002, Ser.
No. 10/155,920; and U.S. patent application entitled "Nuclease
Resistant Chimeric Oligonucleotides" filed May 24, 2002, Ser. No.
10/013,295, both of which are commonly owned with this application
and are herein incorporated by reference in their entirety).
Further helix-stabilizing properties have been observed when a
cytosine analog/substitute has an aminoethoxy moiety attached to
the rigid 1,3-diazaphenoxazine-2-one scaffold (R.sub.10.dbd.O,
R.sub.11.dbd.--O--(CH.sub.2).sub.2--NH.sub.2, R.sub.12-14.dbd.H)
[Lin, K.-Y.; Matteucci, M. J. Am. Chem. Soc. 1998, 120, 8531-8532].
Binding studies demonstrated that a single incorporation could
enhance the binding affinity of a model oligonucleotide to its
complementary target DNA or RNA with a .DELTA.T.sub.m of up to
18.degree. relative to 5-methyl cytosine (dC5.sup.me), which is the
highest known affinity enhancement for a single modification, yet.
On the other hand, the gain in helical stability does not
compromise the specificity of the oligomers. The Tm data indicate
an even greater discrimination between the perfect match and
mismatched sequences compared to dC5.sup.me. It was suggested that
the tethered amino group serves as an additional hydrogen bond
donor to interact with the Hoogsteen face, namely the O6, of a
complementary guanine thereby forming 4 hydrogen bonds. This means
that the increased affinity of G-clamp is mediated by the
combination of extended base stacking and additional specific
hydrogen bonding.
Further tricyclic heterocyclic compounds and methods of using them
that are amenable to the present invention are disclosed in U.S.
Pat. No. 6,028,183, which issued on May 22, 2000, and U.S. Pat. No.
6,007,992, which issued on Dec. 28, 1999, the contents of both are
commonly assigned with this application and are incorporated herein
in their entirety.
The enhanced binding affinity of the phenoxazine derivatives
together with their uncompromised sequence specificity make them
valuable nucleobase analogs for the development of more potent
antisense-based drugs. In fact, promising data have been derived
from in vitro experiments demonstrating that heptanucleotides
containing phenoxazine substitutions are capable to activate
RNaseH, enhance cellular uptake and exhibit an increased antisense
activity [Lin, K-Y; Matteucci, M. J. Am. Chem. Soc. 1998, 120,
8531-8532]. The activity enhancement was even more pronounced in
case of G-clamp, as a single substitution was shown to
significantly improve the in vitro potency of a 20mer
2'-deoxyphosphorothioate oligonucleotides [Flanagan, W. M.; Wolf,
J. J.; Olson, P.; Grant, D.; Lin, K.-Y.; Wagner, R. W.; Matteucci,
M. Proc. Natl. Acad. Sci. USA, 1999, 96, 3513-3518]. Nevertheless,
to optimize oligomer design and to better understand the impact of
these heterocyclic modifications on the biological activity, it is
important to evaluate their effect on the nuclease stability of the
oligomers.
Further modified polycyclic heterocyclic compounds useful as
heterocyclcic bases are disclosed in but not limited to, the above
noted U.S. Pat. No. 3,687,808, as well as U.S. Pat. Nos.:
4,845,205; 5,130,302; 5,134,066; 5,175,273; 5,367,066; 5,432,272;
5,434,257; 5,457,187; 5,459,255; 5,484,908; 5,502,177; 5,525,711;
5,552,540; 5,587,469; 5,594,121, 5,596,091; 5,614,617; 5,645,985;
5,646,269; 5,750,692; 5,830,653; 5,763,588; 6,005,096; and
5,681,941, and U.S. patent application Ser. No. 09/996,292 filed
Nov. 28, 2001, certain of which are commonly owned with the instant
application, and each of which is herein incorporated by
reference.
Conjugates
A further preferred substitution that can be appended to the
oligomeric compounds of the invention involves the linkage of one
or more moieties or conjugates which enhance the activity, cellular
distribution or cellular uptake of the resulting oligomeric
compounds. In one embodiment such modified oligomeric compounds are
prepared by covalently attaching conjugate groups to functional
groups such as hydroxyl or amino groups. Conjugate groups of the
invention include intercalators, reporter molecules, polyamines,
polyamides, polyethylene glycols, polyethers, groups that enhance
the pharmacodynamic properties of oligomers, and groups that
enhance the pharmacokinetic properties of oligomers. Typical
conjugates groups include cholesterols, lipids, phospho-lipids,
biotin, phenazine, folate, phenanthridine, anthraquinone, acridine,
fluoresceins, rhodamines, coumarins, and dyes. Groups that enhance
the pharmacodynamic properties, in the context of this invention,
include groups that improve oligomer uptake, enhance oligomer
resistance to degradation, and/or strengthen sequence-specific
hybridization with RNA. Groups that enhance the pharmacokinetic
properties, in the context of this invention, include groups that
improve oligomer uptake, distribution, metabolism or excretion.
Representative conjugate groups are disclosed in International
Patent Application PCT/US92/09196, filed Oct. 23, 1992 the entire
disclosure of which is incorporated herein by reference.
Conjugate moieties include but are not limited to lipid moieties
such as a cholesterol moiety (Letsinger et al., Proc. Natl. Acad.
Sci. USA, 1989, 86, 6553-6556), cholic acid (Manoharan et al.,
Bioorg. Med. Chem. Let., 1994, 4, 1053-1060), a thioether, e.g.,
hexyl-S-tritylthiol (Manoharan et al., Ann. N.Y. Acad. Sci., 1992,
660, 306-309; Manoharan et al., Bioorg. Med. Chem. Let., 1993, 3,
2765-2770), a thiocholesterol (Oberhauser et al., Nucl. Acids Res.,
1992, 20, 533-538), an aliphatic chain, e.g., dodecandiol or
undecyl residues (Saison-Behmoaras et al., EMBO J., 1991, 10,
1111-1118; Kabanov et al., FEBS Lett., 1990, 259, 327-330;
Svinarchuk et al., Biochimie, 1993, 75, 49-54), a phospholipid,
e.g., di-hexadecyl-rac-glycerol or triethylammonium
1,2-di-O-hexadecyl-rac-glycero-3-H-phosphonate (Manoharan et al.,
Tetrahedron Lett., 1995, 36, 3651-3654; Shea et al., Nucl. Acids
Res., 1990, 18, 3777-3783), a polyamine or a polyethylene glycol
chain (Manoharan et al., Nucleosides & Nucleotides, 1995, 14,
969-973), or adamantane acetic acid (Manoharan et al., Tetrahedron
Lett., 1995, 36, 3651-3654), a palmityl moiety (Mishra et al.,
Biochim. Biophys. Acta, 1995, 1264, 229-237), or an octadecylamine
or hexylamino-carbonyl-oxycholesterol moiety (Crooke et al., J.
Pharmacol. Exp. Ther., 1996, 277, 923-937.
The oligomeric compounds of the invention may also be conjugated to
active drug substances, for example, aspirin, warfarin,
phenylbutazone, ibuprofen, suprofen, fenbufen, ketoprofen,
(S)-(+)-pranoprofen, carprofen, dansylsarcosine,
2,3,5-triiodobenzoic acid, flufenamic acid, folinic acid, a
benzothiadiazide, chlorothiazide, a diazepine, indomethicin, a
barbiturate, a cephalosporin, a sulfa drug, an antidiabetic, an
antibacterial or an antibiotic. Oligonucleotide-drug conjugates and
their preparation are described in U.S. patent application Ser. No.
09/334,130 (filed Jun. 15, 1999) which is incorporated herein by
reference in its entirety.
Representative United States patents that teach the preparation of
such oligomer conjugates include, but are not limited to, U.S. Pat.
Nos.: 4,828,979; 4,948,882; 5,218,105; 5,525,465; 5,541,313;
5,545,730; 5,552,538; 5,578,717, 5,580,731; 5,580,731; 5,591,584;
5,109,124; 5,118,802; 5,138,045; 5,414,077; 5,486,603; 5,512,439;
5,578,718; 5,608,046; 4,587,044; 4,605,735; 4,667,025; 4,762,779;
4,789,737; 4,824,941; 4,835,263; 4,876,335; 4,904,582; 4,958,013;
5,082,830; 5,112,963; 5,214,136; 5,082,830; 5,112,963; 5,214,136;
5,245,022; 5,254,469; 5,258,506; 5,262,536; 5,272,250; 5,292,873;
5,317,098; 5,371,241, 5,391,723; 5,416,203, 5,451,463; 5,510,475;
5,512,667; 5,514,785; 5,565,552; 5,567,810; 5,574,142; 5,585,481;
5,587,371; 5,595,726; 5,597,696; 5,599,923; 5,599,928 and
5,688,941, certain of which are commonly owned with the instant
application, and each of which is herein incorporated by
reference.
Chimeric Oligomeric Compounds
It is not necessary for all positions in an oligomeric compound to
be uniformly modified, and in fact more than one of the
aforementioned modifications may be incorporated in a single
oligomeric compound or even at a single monomeric subunit such as a
nucleoside within a oligomeric compound. The present invention also
includes oligomeric compounds which are chimeric oligomeric
compounds. "Chimeric" oligomeric compounds or "chimeras," in the
context of this invention, are oligomeric compounds that contain
two or more chemically distinct regions, each made up of at least
one monomer unit, i.e., a nucleotide in the case of a nucleic acid
based oligomer.
Chimeric oligomeric compounds typically contain at least one region
modified so as to confer increased resistance to nuclease
degradation, increased cellular uptake, and/or increased binding
affinity for the target nucleic acid. An additional region of the
oligomeric compound may serve as a substrate for enzymes capable of
cleaving RNA:DNA or RNA:RNA hybrids. By way of example, RNase H is
a cellular endonuclease which cleaves the RNA strand of an RNA:DNA
duplex. Activation of RNase H, therefore, results in cleavage of
the RNA target, thereby greatly enhancing the efficiency of
inhibition of gene expression. Consequently, comparable results can
often be obtained with shorter oligomeric compounds when chimeras
are used, compared to for example phosphorothioate
deoxyoligonucleotides hybridizing to the same target region.
Cleavage of the RNA target can be routinely detected by gel
electrophoresis and, if necessary, associated nucleic acid
hybridization techniques known in the art.
Chimeric oligomeric compounds of the invention may be formed as
composite structures of two or more oligonucleotides,
oligonucleotide analogs, oligonucleosides and/or oligonucleotide
mimetics as described above. Such oligomeric compounds have also
been referred to in the art as hybrids hemimers, gapmers or
inverted gapmers. Representative United States patents that teach
the preparation of such hybrid structures include, but are not
limited to, U.S. Pat. Nos.: 5,013,830; 5,149,797; 5,220,007;
5,256,775; 5,366,878; 5,403,711; 5,491,133; 5,565,350; 5,623,065;
5,652,355; 5,652,356; and 5,700,922, certain of which are commonly
owned with the instant application, and each of which is herein
incorporated by reference in its entirety.
3'-Endo Modifications
In one aspect of the present invention oligomeric compounds include
nucleosides synthetically modified to induce a 3'-endo sugar
conformation. A nucleoside can incorporate synthetic modifications
of the heterocyclic base, the sugar moiety or both to induce a
desired 3'-endo sugar conformation. These modified nucleosides are
used to mimic RNA like nucleosides so that particular properties of
an oligomeric compound can be enhanced while maintaining the
desirable 3'-endo conformational geometry. There is an apparent
preference for an RNA type duplex (A form helix, predominantly
3'-endo) as a requirement (e.g. trigger) of RNA interference which
is supported in part by the fact that duplexes composed of
2'-deoxy-2'-F-nucleosides appears efficient in triggering RNAi
response in the C. elegans system. Properties that are enhanced by
using more stable 3'-endo nucleosides include but aren't limited to
modulation of pharmacokinetic properties through modification of
protein binding, protein off-rate, absorption and clearance;
modulation of nuclease stability as well as chemical stability;
modulation of the binding affinity and specificity of the oligomer
(affinity and specificity for enzymes as well as for complementary
sequences); and increasing efficacy of RNA cleavage. The present
invention provides oligomeric triggers of RNAi having one or more
nucleosides modified in such a way as to favor a C3'-endo type
conformation.
##STR00017##
Nucleoside conformation is influenced by various factors including
substitution at the 2', 3' or 4'-positions of the pentofuranosyl
sugar. Electronegative substituents generally prefer the axial
positions, while sterically demanding substituents generally prefer
the equatorial positions (Principles of Nucleic Acid Structure,
Wolfgang Sanger, 1984, Springer-Verlag.) Modification of the 2'
position to favor the 3'-endo conformation can be achieved while
maintaining the 2'-OH as a recognition element, as illustrated in
FIG. 2, below (Gallo et al., Tetrahedron (2001), 57, 5707-5713.
Harry-O'kuru et al., J. Org. Chem., (1997), 62(6), 1754-1759 and
Tang et al., J. Org. Chem. (1999), 64, 747-754.) Alternatively,
preference for the 3'-endo conformation can be achieved by deletion
of the 2'-OH as exemplified by 2'deoxy-2'F-nucleosides (Kawasaki et
al., J. Med. Chem. (1993), 36, 831-841), which adopts the 3'-endo
conformation positioning the electronegative fluorine atom in the
axial position. Other modifications of the ribose ring, for example
substitution at the 4'-position to give 4'-F modified nucleosides
(Guillerm et al., Bioorganic and Medicinal Chemistry Letters
(1995), 5, 1455-1460 and Owen et al., J. Org. Chem. (1976), 41,
3010-3017), or for example modification to yield methanocarba
nucleoside analogs (Jacobson et al., J. Med. Chem. Lett. (2000),
43, 2196-2203 and Lee et al., Bioorganic and Medicinal Chemistry
Letters (2001), 11, 1333-1337) also induce preference for the
3'-endo conformation. Along similar lines, oligomeric triggers of
RNAi response might be composed of one or more nucleosides modified
in such a way that conformation is locked into a C3'-endo type
conformation, i.e. Locked Nucleic Acid (LNA, Singh et al, Chem.
Commun. (1998), 4, 455-456), and ethylene bridged Nucleic Acids
(ENA, Morita et al, Bioorganic & Medicinal Chemistry Letters
(2002), 12, 73-76.) Examples of modified nucleosides amenable to
the present invention are shown below in Table I. These examples
are meant to be representative and not exhaustive.
TABLE-US-00002 TABLE I ##STR00018## ##STR00019## ##STR00020##
##STR00021## ##STR00022## ##STR00023## ##STR00024## ##STR00025##
##STR00026## ##STR00027## ##STR00028## ##STR00029## ##STR00030##
##STR00031## ##STR00032## ##STR00033## ##STR00034## ##STR00035##
##STR00036##
The preferred conformation of modified nucleosides and their
oligomers can be estimated by various methods such as molecular
dynamics calculations, nuclear magnetic resonance spectroscopy and
CD measurements. Hence, modifications predicted to induce RNA like
conformations, A-form duplex geometry in an oligomeric context, are
selected for use in the modified oligomers of the present
invention. The synthesis of numerous of the modified nucleosides
amenable to the present invention are known in the art (see for
example, Chemistry of Nucleosides and Nucleotides Vol 1-3, ed.
Leroy B. Townsend, 1988, Plenum press., and the examples section
below.) Nucleosides known to be inhibitors/substrates for RNA
dependent RNA polymerases (for example HCV NS5B
In one aspect, the present invention is directed to oligomers that
are prepared having enhanced properties compared to native RNA
against nucleic acid targets. A target is identified and an
oligomer is selected having an effective length and sequence that
is complementary to a portion of the target sequence. Each
nucleoside of the selected sequence is scrutinized for possible
enhancing modifications. A preferred modification would be the
replacement of one or more RNA nucleosides with nucleosides that
have the same 3'-endo conformational geometry. Such modifications
can enhance chemical and nuclease stability relative to native RNA
while at the same time being much cheaper and easier to synthesize
and/or incorporate into an oligomer. The selected sequence can be
further divided into regions and the nucleosides of each region
evaluated for enhancing modifications that can be the result of a
chimeric configuration. Consideration is also given to the 5' and
3'-termini as there are often advantageous modifications that can
be made to one or more of the terminal nucleosides. The oligomeric
compounds of the present invention include at least one 5'-modified
phosphate group on a single strand or on at least one 5'-position
of a double stranded sequence or sequences. Further modifications
are also considered such as internucleoside linkages, conjugate
groups, substitute sugars or bases, substitution of one or more
nucleosides with nucleoside mimetics and any other modification
that can enhance the selected sequence for its intended target.
The terms used to describe the conformational geometry of
homoduplex nucleic acids are "A Form" for RNA and "B Form" for DNA.
The respective conformational geometry for RNA and DNA duplexes was
determined from X-ray diffraction analysis of nucleic acid fibers
(Arnott and Hukins, Biochem. Biophys. Res. Comm., 1970, 47, 1504.)
In general, RNA:RNA duplexes are more stable and have higher
melting temperatures (Tm's) than DNA:DNA duplexes (Sanger et al.,
Principles of Nucleic Acid Structure, 1984, Springer-Verlag; New
York, N.Y.; Lesnik et al., Biochemistry, 1995, 34, 10807-10815;
Conte et al., Nucleic Acids Res., 1997, 25, 2627-2634). The
increased stability of RNA has been attributed to several
structural features, most notably the improved base stacking
interactions that result from an A-form geometry (Searle et al.,
Nucleic Acids Res., 1993, 21, 2051-2056). The presence of the 2'
hydroxyl in RNA biases the sugar toward a C3' endo pucker, i.e.,
also designated as Northern pucker, which causes the duplex to
favor the A-form geometry. In addition, the 2' hydroxyl groups of
RNA can form a network of water mediated hydrogen bonds that help
stabilize the RNA duplex (Egli et al., Biochemistry, 1996, 35,
8489-8494). On the other hand, deoxy nucleic acids prefer a C2'
endo sugar pucker, i.e., also known as Southern pucker, which is
thought to impart a less stable B-form geometry (Sanger, W. (1984)
Principles of Nucleic Acid Structure, Springer-Verlag, New York,
N.Y.). As used herein, B-form geometry is inclusive of both
C2'-endo pucker and O4'-endo pucker. This is consistent with
Berger, et. al., Nucleic Acids Research, 1998, 26, 2473-2480, who
pointed out that in considering the furanose conformations which
give rise to B-form duplexes consideration should also be given to
a O4'-endo pucker contribution.
DNA:RNA hybrid duplexes, however, are usually less stable than pure
RNA:RNA duplexes, and depending on their sequence may be either
more or less stable than DNA:DNA duplexes (Searle et al., Nucleic
Acids Res., 1993, 21, 2051-2056). The structure of a hybrid duplex
is intermediate between A- and B-form geometries, which may result
in poor stacking interactions (Lane et al., Eur. J. Biochem., 1993,
215, 297-306; Fedoroff et al., J. Mol. Biol., 1993, 233, 509-523;
Gonzalez et al., Biochemistry, 1995, 34, 4969-4982; Horton et al.,
J. Mol. Biol., 1996, 264, 521-533). The stability of the duplex
formed between a target RNA and a synthetic sequence is central to
therapies such as but not limited to antisense and RNA interference
as these mechanisms require the binding of a synthetic oligomer
strand to an RNA target strand. In the case of antisense, effective
inhibition of the mRNA requires that the antisense DNA have a very
high binding affinity with the mRNA. Otherwise the desired
interaction between the synthetic oligomer strand and target mRNA
strand will occur infrequently, resulting in decreased
efficacy.
One routinely used method of modifying the sugar puckering is the
substitution of the sugar at the 2'-position with a substituent
group that influences the sugar geometry. The influence on ring
conformation is dependant on the nature of the substituent at the
2'-position. A number of different substituents have been studied
to determine their sugar puckering effect. For example, 2'-halogens
have been studied showing that the 2'-fluoro derivative exhibits
the largest population (65%) of the C3'-endo form, and the 2'-iodo
exhibits the lowest population (7%). The populations of adenosine
(2'-OH) versus deoxyadenosine (2'-H) are 36% and 19%, respectively.
Furthermore, the effect of the 2'-fluoro group of adenosine dimers
(2'-deoxy-2'-fluoroadenosine-2'-deoxy-2'-fluoro-adenosine) is
further correlated to the stabilization of the stacked
conformation.
As expected, the relative duplex stability can be enhanced by
replacement of 2'-OH groups with 2'-F groups thereby increasing the
C3'-endo population. It is assumed that the highly polar nature of
the 2'-F bond and the extreme preference for C3'-endo puckering may
stabilize the stacked conformation in an A-form duplex. Data from
UV hypochromicity, circular dichroism, and .sup.1H NMR also
indicate that the degree of stacking decreases as the
electronegativity of the halo substituent decreases. Furthermore,
steric bulk at the 2'-position of the sugar moiety is better
accommodated in an A-form duplex than a B-form duplex. Thus, a
2'-substituent on the 3'-terminus of a dinucleoside monophosphate
is thought to exert a number of effects on the stacking
conformation: steric repulsion, furanose puckering preference,
electrostatic repulsion, hydrophobic attraction, and hydrogen
bonding capabilities. These substituent effects are thought to be
determined by the molecular size, electronegativity, and
hydrophobicity of the substituent. Melting temperatures of
complementary strands is also increased with the 2'-substituted
adenosine diphosphates. It is not clear whether the 3'-endo
preference of the conformation or the presence of the substituent
is responsible for the increased binding. However, greater overlap
of adjacent bases (stacking) can be achieved with the 3'-endo
conformation.
One synthetic 2'-modification that imparts increased nuclease
resistance and a very high binding affinity to nucleotides is the
2-methoxyethoxy (2'-MOE, 2'-OCH.sub.2CH.sub.2OCH.sub.3) side chain
(Baker et al., J. Biol. Chem., 1997, 272, 11944-12000). One of the
immediate advantages of the 2'-MOE substitution is the improvement
in binding affinity, which is greater than many similar 2'
modifications such as O-methyl, O-propyl, and O-aminopropyl.
Oligonucleotides having the 2'-O-methoxyethyl substituent also have
been shown to be antisense inhibitors of gene expression with
promising features for in vivo use (Martin, P., Helv. Chim. Acta,
1995, 78, 486-504; Altmann et al., Chimia, 1996, 50, 168-176;
Altmann et al., Biochem. Soc. Trans., 1996, 24, 630-637; and
Altmann et al., Nucleosides Nucleotides, 1997, 16, 917-926).
Relative to DNA, the oligomers having the 2'-MOE modification
displayed improved RNA affinity and higher nuclease resistance.
Chimeric oligomers having 2'-MOE substituents in the wing
nucleosides and an internal region of deoxy-phosphorothioate
nucleotides (also termed a gapped oligomer or gapmer) have shown
effective reduction in the growth of tumors in animal models at low
doses. 2'-MOE substituted oligomers have also shown outstanding
promise as antisense agents in several disease states. One such MOE
substituted oligomer is presently being investigated in clinical
trials for the treatment of CMV retinitis.
Chemistries Defined
Unless otherwise defined herein, alkyl means C.sub.1-C.sub.12,
preferably C.sub.1-C.sub.8, and more preferably C.sub.1-C.sub.6,
straight or (where possible) branched chain aliphatic
hydrocarbyl.
Unless otherwise defined herein, heteroalkyl means
C.sub.1-C.sub.12, preferably C.sub.1-C.sub.8, and more preferably
C.sub.1-C.sub.6, straight or (where possible) branched chain
aliphatic hydrocarbyl containing at least one, and preferably about
1 to about 3, hetero atoms in the chain, including the terminal
portion of the chain. Preferred heteroatoms include N, O and S.
Unless otherwise defined herein, cycloalkyl means C.sub.3-C.sub.12,
preferably C.sub.3-C.sub.8, and more preferably C.sub.3-C.sub.6,
aliphatic hydrocarbyl ring.
Unless otherwise defined herein, alkenyl means C.sub.2-C.sub.12,
preferably C.sub.2-C.sub.8, and more preferably C.sub.2-C.sub.6
alkenyl, which may be straight or (where possible) branched
hydrocarbyl moiety, which contains at least one carbon-carbon
double bond.
Unless otherwise defined herein, alkynyl means C.sub.2-C.sub.12,
preferably C.sub.2-C.sub.8, and more preferably C.sub.2-C.sub.6
alkynyl, which may be straight or (where possible) branched
hydrocarbyl moiety, which contains at least one carbon-carbon
triple bond.
Unless otherwise defined herein, heterocycloalkyl means a ring
moiety containing at least three ring members, at least one of
which is carbon, and of which 1, 2 or three ring members are other
than carbon. Preferably the number of carbon atoms varies from 1 to
about 12, preferably 1 to about 6, and the total number of ring
members varies from three to about 15, preferably from about 3 to
about 8. Preferred ring heteroatoms are N, O and S. Preferred
heterocycloalkyl groups include morpholino, thiomorpholino,
piperidinyl, piperazinyl, homopiperidinyl, homopiperazinyl,
homomorpholino, homothiomorpholino, pyrrolodinyl,
tetrahydrooxazolyl, tetrahydroimidazolyl, tetrahydrothiazolyl,
tetrahydroisoxazolyl, tetrahydropyrrazolyl, furanyl, pyranyl, and
tetrahydroisothiazolyl.
Unless otherwise defined herein, aryl means any hydrocarbon ring
structure containing at least one aryl ring. Preferred aryl rings
have about 6 to about 20 ring carbons. Especially preferred aryl
rings include phenyl, napthyl, anthracenyl, and phenanthrenyl.
Unless otherwise defined herein, hetaryl means a ring moiety
containing at least one fully unsaturated ring, the ring consisting
of carbon and non-carbon atoms. Preferably the ring system contains
about 1 to about 4 rings. Preferably the number of carbon atoms
varies from 1 to about 12, preferably 1 to about 6, and the total
number of ring members varies from three to about 15, preferably
from about 3 to about 8. Preferred ring heteroatoms are N, O and S.
Preferred hetaryl moieties include pyrazolyl, thiophenyl, pyridyl,
imidazolyl, tetrazolyl, pyridyl, pyrimidinyl, purinyl,
quinazolinyl, quinoxalinyl, benzimidazolyl, benzothiophenyl,
etc.
The term haloalkyl is defined as an alkyl containing one or more
halogen atoms. In some embodiments, the alkyl is fully halogenated.
For example, the haloalkyl may be trifluoromethyl. Similarly, the
term haloalkoxy is defined as an alkoxy group where the alkyl group
is a haloalkyl. For example, the haloalkoxy may be
trifluoroalkoxy.
Unless otherwise defined herein, where a moiety is defined as a
compound moiety, such as hetarylalkyl (hetaryl and alkyl), aralkyl
(aryl and alkyl), etc., each of the sub-moieties is as defined
herein.
Unless otherwise defined herein, an electron withdrawing group is a
group, such as the cyano or isocyanato group that draws electronic
charge away from the carbon to which it is attached. Other electron
withdrawing groups of note include those whose electronegativities
exceed that of carbon, for example halogen, nitro, or phenyl
substituted in the ortho- or para-position with one or more cyano,
isothiocyanato, nitro or halo groups.
Unless otherwise defined herein, the terms halogen and halo have
their ordinary meanings. Preferred halo (halogen) substituents are
Cl, Br, and I. The aforementioned optional substituents are, unless
otherwise herein defined, suitable substituents depending upon
desired properties. Included are halogens (Cl, Br, I), alkyl,
alkenyl, and alkynyl moieties, NO.sub.2, NH.sub.3 (substituted and
unsubstituted), acid moieties (e.g. --CO.sub.2H,
--OSO.sub.3H.sub.2, etc.), heterocycloalkyl moieties, hetaryl
moieties, aryl moieties, etc.
In all the preceding formulae, the squiggle (.about.) indicates a
bond to an oxygen or sulfur of the 5'-phosphate.
Phosphate protecting groups include those described in U.S. Pat.
Nos. 5,760,209, 5,614,621, 6,051,699, 6,020,475, 6,326,478,
6,169,177, 6,121,437, 6,465,628 each of which is expressly
incorporated herein by reference in its entirety.
Phosphotioate groups include those described in U.S. Pat. Nos.
3,687,808, 5,188,897, 5,278,302, 5,286,717, 5,405,939, 5,453,496,
and 5,587,361.
Alkylphosphoroamidate groups include those described in U.S. Pat.
Nos. 5,536,821 and 5,541,306,
Unless otherwise defined herein, alkoxy is defined as --O-alkyl
where alkyl is as defined above.
Unless otherwise defined herein, alkylthio is defined as --S-alkyl
where alkyl is as defined above.
As used herein, the terms alkyl, heteroalkyl, cycloalkyl, alkenyl,
alkynyl, heterocycloalkyl, aryl, and hetaryl include moieties that
are optionally substituted. Sitable substituents are well known to
those skilled in the art. These substituents include
C.sub.1-C.sub.20 alkyl, C.sub.2-C.sub.20 alkenyl, C.sub.2-C.sub.20
alkynyl, C.sub.5-C.sub.20 aryl, --O-alkyl, --O-alkenyl,
--O-alkynyl, --O-alkylamino, --O-alkylalkoxy, --O--
alkylaminoalkyl, --O-alkyl imidazole, --OH, --SH, --S-alkyl,
--S-alkenyl, --S-alkynyl, --N(H)-alkyl, --N(H)-alkenyl,
--N(H)-alkynyl, --N(alkyl).sub.2, --O-aryl, --S-aryl, --NH-aryl,
--ONO.sub.2, --O-aralkyl, --S-aralkyl, --N(H)-aralkyl, phthalimido
(attached at N), halogen, amino, keto (--C(.dbd.O)--R), carboxyl
(--C(.dbd.O)OH), nitro (--NO.sub.2), nitroso (--N.dbd.O), cyano
(--CN), trifluoromethyl (--CF.sub.3), trifluoromethoxy
(--O--CF.sub.3), imidazole, azido (--N.sub.3), hydrazino
(--N(H)--NH.sub.2), aminooxy (--O--NH.sub.2), isocyanato
(--N.dbd.C.dbd.O), sulfoxide (--S(.dbd.O)--R), sulfone
(--S(.dbd.O).sub.2--R), disulfide (--S--S--R), silyl, heterocycle,
carbocycle, intercalator, reporter group, conjugate, polyamine,
polyamide, polyalkylene glycol, and polyethers of the formula
(--O-alkyl).sub.m, where m is 1 to about 10; wherein each R is,
independently, hydrogen, a protecting group alkyl, alkenyl, or
alkynyl.
The terms blockmer, 3'-hemimer, 5'-hemimer, gapmer and inverted
gapmer are used in this specification to identify certain motifs or
positional placement of types or segments of nucleotides in an
oligomer. Depending on the number of nucleotide or nucleoside
subunits and their position in the oligomer, one or more than one
of these terms might apply to a particular construction and could
be used for identification purposes. A blockmer has at least one
block or segment of at least two consecutively located nucleotide
or nucleoside subunits of a first type positioned adjacent to at
least one nucleotide or nucleoside of a second type. Thus for
instances if the nucleotides or nucleosides of the first type are
represented by "X" and those of the second type are represented by
"Y"and if " . . . " represent nucleotides or nucleosides other that
the X or Y type nucleotides or the absence of any nucleotides then
the following structures . . . XXY . . . ; . . . XXYXX . . . ; . .
. XXYXXY . . . ; . . . XXYXXYXX . . . on so on for higher homologs
are possible where each X containing segment includes two members
and each Y containing segment includes only one member. If each X
containing segment includes two members and each Y subunit also
includes two members other representational blockmers include . . .
XXYY . . . ; . . . XXYYXX . . . ; . . . XXYYXXYY . . . ; . . .
XXYYXXYYXX . . . and so on for high homologs. These can be extended
to other representative structures having more X and/or Y members
in the blocks or segments, as for instances the structures
YXXXXYYYXXXXY; YYXXXYYXXXXYY; and YYYYXXXXYYYYXXXX.
If a block or segment of the first type of nucleotides or
nucleoside resides at the 5' or the 3' terminus and all of the
remaining nucleotides or nucleosides of the oligomer are of the
second type, then that blockmer is also a hemimer. Using the same X
and Y representation and selecting five members for each segment
and basing the hemimer designation on the X members then the
representations XXXXXYYYYY and YYYYYXXXX represent, respectively,
5' and 3' hemimers.
In gapmers, a block or segment of one type of nucleotides or
nucleosides is interspaced between first and second blocks of the
second type. As before if the designation is based on the X members
then XXXXYYYYXXXX represents a gapmer and YYYYXXXXYYYY represents
an invertered gapmer.
Screening, Target Validation and Drug Discovery
For use in screening and target validation, the compounds and
compositions of the invention are used to modulate the expression
of a selected protein. "Modulators" are those oligomeric compounds
and compositions that decrease or increase the expression of a
nucleic acid molecule encoding a protein and which comprise at
least an 8-nucleobase portion which is complementary to a preferred
target segment. The screening method comprises the steps of
contacting a preferred target segment of a nucleic acid molecule
encoding a protein with one or more candidate modulators, and
selecting for one or more candidate modulators which decrease or
increase the expression of a nucleic acid molecule encoding a
protein. Once it is shown that the candidate modulator or
modulators are capable of modulating (e.g. either decreasing or
increasing) the expression of a nucleic acid molecule encoding a
peptide, the modulator may then be employed in further
investigative studies of the function of the peptide, or for use as
a research, diagnostic, or therapeutic agent in accordance with the
present invention.
The conduction such screening and target validation studies,
oligomeric compounds of invention can be used combined with their
respective complementary strand oligomeric compound to form
stabilized double-stranded (duplexed) oligomers. Double stranded
oligomer moieties have been shown to modulate target expression and
regulate translation as well as RNA processing via an antisense
mechanism. Moreover, the double-stranded moieties may be subject to
chemical modifications (Fire et al., Nature, 1998, 391, 806-811;
Timmons and Fire, Nature 1998, 395, 854; Timmons et al., Gene,
2001, 263, 103-112; Tabara et al., Science, 1998, 282, 430-431;
Montgomery et al., Proc. Natl. Acad. Sci. USA, 1998, 95,
15502-15507; Tuschl et al., Genes Dev., 1999, 13, 3191-3197;
Elbashir et al., Nature, 2001, 411, 494-498; Elbashir et al., Genes
Dev. 2001, 15, 188-200; Nishikura et al., Cell (2001), 107,
415-416; and Bass et al., Cell (2000), 101, 235-238.) For example,
such double-stranded moieties have been shown to inhibit the target
by the classical hybridization of antisense strand of the duplex to
the target, thereby triggering enzymatic degradation of the target
(Tijsterman et al., Science, 2002, 295, 694-697).
For use in drug discovery and target validation, oligomeric
compounds of the present invention are used to elucidate
relationships that exist between proteins and a disease state,
phenotype, or condition. These methods include detecting or
modulating a target peptide comprising contacting a sample, tissue,
cell, or organism with the oligomeric compounds and compositions of
the present invention, measuring the nucleic acid or protein level
of the target and/or a related phenotypic or chemical endpoint at
some time after treatment, and optionally comparing the measured
value to a non-treated sample or sample treated with a further
oligomeric compound of the invention. These methods can also be
performed in parallel or in combination with other experiments to
determine the function of unknown genes for the process of target
validation or to determine the validity of a particular gene
product as a target for treatment or prevention of a disease or
disorder.
Kits, Research Reagents, Diagnostics, and Therapeutics
The oligomeric compounds and compositions of the present invention
can additionally be utilized for diagnostics, therapeutics,
prophylaxis and as research reagents and kits. Such uses allows for
those of ordinary skill to elucidate the function of particular
genes or to distinguish between functions of various members of a
biological pathway.
For use in kits and diagnostics, the oligomeric compounds and
compositions of the present invention, either alone or in
combination with other compounds or therapeutics, can be used as
tools in differential and/or combinatorial analyses to elucidate
expression patterns of a portion or the entire complement of genes
expressed within cells and tissues.
As one non-limiting example, expression patterns within cells or
tissues treated with one or more compounds or compositions of the
invention are compared to control cells or tissues not treated with
the compounds or compositions and the patterns produced are
analyzed for differential levels of gene expression as they
pertain, for example, to disease association, signaling pathway,
cellular localization, expression level, size, structure or
function of the genes examined. These analyses can be performed on
stimulated or unstimulated cells and in the presence or absence of
other compounds that affect expression patterns.
Examples of methods of gene expression analysis known in the art
include DNA arrays or microarrays (Brazma and Vilo, FEBS Lett.,
2000, 480, 17-24; Celis, et al., FEBS Lett., 2000, 480, 2-16), SAGE
(serial analysis of gene expression)(Madden, et al., Drug Discov.
Today, 2000, 5, 415-425), READS (restriction enzyme amplification
of digested cDNAs) (Prashar and Weissman, Methods Enzymol., 1999,
303, 258-72), TOGA (total gene expression analysis) (Sutcliffe, et
al., Proc. Natl. Acad. Sci. U.S.A, 2000, 97, 1976-81), protein
arrays and proteomics (Celis, et al., FEBS Lett., 2000, 480, 2-16;
Jungblut, et al., Electrophoresis, 1999, 20, 2100-10), expressed
sequence tag (EST) sequencing (Celis, et al., FEBS Lett., 2000,
480, 2-16; Larsson, et al., J. Biotechnol., 2000, 80, 143-57),
subtractive RNA fingerprinting (SuRF) (Fuchs, et al., Anal.
Biochem., 2000, 286, 91-98; Larson, et al., Cytometry, 2000, 41,
203-208), subtractive cloning, differential display (DD) (Jurecic
and Belmont, Curr. Opin. Microbiol., 2000, 3, 316-21), comparative
genomic hybridization (Carulli, et al., J. Cell Biochem. Suppl.,
1998, 31, 286-96), FISH (fluorescent in situ hybridization)
techniques (Going and Gusterson, Eur. J. Cancer, 1999, 35,
1895-904) and mass spectrometry methods (To, Comb. Chem. High
Throughput Screen, 2000, 3, 235-41).
The compounds and compositions of the invention are useful for
research and diagnostics, because these compounds and compositions
hybridize to nucleic acids encoding proteins. Hybridization of the
compounds and compositions of the invention with a nucleic acid can
be detected by means known in the art. Such means may include
conjugation of an enzyme to the compound or composition,
radiolabelling or any other suitable detection means. Kits using
such detection means for detecting the level of selected proteins
in a sample may also be prepared.
The specificity and sensitivity of compounds and compositions can
also be harnessed by those of skill in the art for therapeutic
uses. Antisense oligomeric compounds have been employed as
therapeutic moieties in the treatment of disease states in animals,
including humans. Antisense oligomer drugs, including ribozymes,
have been safely and effectively administered to humans and
numerous clinical trials are presently underway. It is thus
established that oligomeric compounds can be useful therapeutic
modalities that can be configured to be useful in treatment regimes
for the treatment of cells, tissues and animals, especially
humans.
For therapeutics, an animal, preferably a human, suspected of
having a disease or disorder that can be treated by modulating the
expression of a selected protein is treated by administering the
compounds and compositions. For example, in one non-limiting
embodiment, the methods comprise the step of administering to the
animal in need of treatment, a therapeutically effective amount of
a protein inhibitor. The protein inhibitors of the present
invention effectively inhibit the activity of the protein or
inhibit the expression of the protein. In one embodiment, the
activity or expression of a protein in an animal is inhibited by
about 10%. Preferably, the activity or expression of a protein in
an animal is inhibited by about 30%. More preferably, the activity
or expression of a protein in an animal is inhibited by 50% or
more.
For example, the reduction of the expression of a protein may be
measured in serum, adipose tissue, liver or any other body fluid,
tissue or organ of the animal. Preferably, the cells contained
within the fluids, tissues or organs being analyzed contain a
nucleic acid molecule encoding a protein and/or the protein
itself.
The compounds and compositions of the invention can be utilized in
pharmaceutical compositions by adding an effective amount of the
compound or composition to a suitable pharmaceutically acceptable
diluent or carrier. Use of the oligomeric compounds and methods of
the invention may also be useful prophylactically.
Formulations
The compounds and compositions of the invention may also be
admixed, encapsulated, conjugated or otherwise associated with
other molecules, molecule structures or mixtures of compounds, as
for example, liposomes, receptor-targeted molecules, oral, rectal,
topical or other formulations, for assisting in uptake,
distribution and/or absorption. Representative United States
patents that teach the preparation of such uptake, distribution
and/or absorption-assisting formulations include, but are not
limited to, U.S. Pat. Nos.: 5,108,921; 5,354,844; 5,416,016;
5,459,127; 5,521,291; 5,543,158; 5,547,932; 5,583,020; 5,591,721;
4,426,330; 4,534,899; 5,013,556; 5,108,921; 5,213,804; 5,227,170;
5,264,221; 5,356,633; 5,395,619; 5,416,016; 5,417,978; 5,462,854;
5,469,854; 5,512,295; 5,527,528; 5,534,259; 5,543,152; 5,556,948;
5,580,575; and 5,595,756, each of which is herein incorporated by
reference.
The compounds and compositions of the invention encompass any
pharmaceutically acceptable salts, esters, or salts of such esters,
or any other compound which, upon administration to an animal,
including a human, is capable of providing (directly or indirectly)
the biologically active metabolite or residue thereof. Accordingly,
for example, the disclosure is also drawn to prodrugs and
pharmaceutically acceptable salts of the oligomeric compounds of
the invention, pharmaceutically acceptable salts of such prodrugs,
and other bioequivalents.
The term "prodrug" indicates a therapeutic agent that is prepared
in an inactive form that is converted to an active form (i.e.,
drug) within the body or cells thereof by the action of endogenous
enzymes or other chemicals and/or conditions. In particular,
prodrug versions of the oligomers of the invention are prepared as
SATE [(S-acetyl-2-thioethyl) phosphate] derivatives according to
the methods disclosed in WO 93/24510 to Gosselin et al., published
Dec. 9, 1993 or in WO 94/26764 and U.S. Pat. No. 5,770,713 to
Imbach et al.
The term "pharmaceutically acceptable salts" refers to
physiologically and pharmaceutically acceptable salts of the
compounds and compositions of the invention: i.e., salts that
retain the desired biological activity of the parent compound and
do not impart undesired toxicological effects thereto. For
oligomers, preferred examples of pharmaceutically acceptable salts
and their uses are further described in U.S. Pat. No. 6,287,860,
which is incorporated herein in its entirety.
The present invention also includes pharmaceutical compositions and
formulations that include the compounds and compositions of the
invention. The pharmaceutical compositions of the present invention
may be administered in a number of ways depending upon whether
local or systemic treatment is desired and upon the area to be
treated. Administration may be topical (including ophthalmic and to
mucous membranes including vaginal and rectal delivery), pulmonary,
e.g., by inhalation or insufflation of powders or aerosols,
including by nebulizer; intratracheal, intranasal, epidermal and
transdermal), oral or parenteral. Parenteral administration
includes intravenous, intraarterial, subcutaneous, intraperitoneal
or intramuscular injection or infusion; or intracranial, e.g.,
intrathecal or intraventricular, administration. Pharmaceutical
compositions and formulations for topical administration may
include transdermal patches, ointments, lotions, creams, gels,
drops, suppositories, sprays, liquids and powders. Conventional
pharmaceutical carriers, aqueous, powder or oily bases, thickeners
and the like may be necessary or desirable. Coated condoms, gloves
and the like may also be useful.
The pharmaceutical formulations of the present invention, which may
conveniently be presented in unit dosage form, may be prepared
according to conventional techniques well known in the
pharmaceutical industry. Such techniques include the step of
bringing into association the active ingredients with the
pharmaceutical carrier(s) or excipient(s). In general, the
formulations are prepared by uniformly and intimately bringing into
association the active ingredients with liquid carriers or finely
divided solid carriers or both, and then, if necessary, shaping the
product.
The compounds and compositions of the present invention may be
formulated into any of many possible dosage forms such as, but not
limited to, tablets, capsules, gel capsules, liquid syrups, soft
gels, suppositories, and enemas. The compositions of the present
invention may also be formulated as suspensions in aqueous,
non-aqueous or mixed media. Aqueous suspensions may further contain
substances which increase the viscosity of the suspension
including, for example, sodium carboxymethylcellulose, sorbitol
and/or dextran. The suspension may also contain stabilizers.
Pharmaceutical compositions of the present invention include, but
are not limited to, solutions, emulsions, foams and
liposome-containing formulations. The pharmaceutical compositions
and formulations of the present invention may comprise one or more
penetration enhancers, carriers, excipients or other active or
inactive ingredients.
Emulsions are typically heterogenous systems of one liquid
dispersed in another in the form of droplets usually exceeding 0.1
.mu.m in diameter. Emulsions may contain additional components in
addition to the dispersed phases, and the active drug that may be
present as a solution in either the aqueous phase, oily phase or
itself as a separate phase. Microemulsions are included as an
embodiment of the present invention. Emulsions and their uses are
well known in the art and are further described in U.S. Pat. No.
6,287,860, which is incorporated herein in its entirety.
Formulations of the present invention include liposomal
formulations. As used in the present invention, the term "liposome"
means a vesicle composed of amphiphilic lipids arranged in a
spherical bilayer or bilayers. Liposomes are unilamellar or
multilamellar vesicles which have a membrane formed from a
lipophilic material and an aqueous interior that contains the
composition to be delivered. Cationic liposomes are positively
charged liposomes which are believed to interact with negatively
charged DNA molecules to form a stable complex. Liposomes that are
pH-sensitive or negatively-charged are believed to entrap DNA
rather than complex with it. Both cationic and noncationic
liposomes have been used to deliver DNA to cells.
Liposomes also include "sterically stabilized" liposomes, a term
which, as used herein, refers to liposomes comprising one or more
specialized lipids that, when incorporated into liposomes, result
in enhanced circulation lifetimes relative to liposomes lacking
such specialized lipids. Examples of sterically stabilized
liposomes are those in which part of the vesicle-forming lipid
portion of the liposome comprises one or more glycolipids or is
derivatized with one or more hydrophilic polymers, such as a
polyethylene glycol (PEG) moiety. Liposomes and their uses are
further described in U.S. Pat. No. 6,287,860, which is incorporated
herein in its entirety.
The pharmaceutical formulations and compositions of the present
invention may also include surfactants. The use of surfactants in
drug products, formulations and in emulsions is well known in the
art. Surfactants and their uses are further described in U.S. Pat.
No. 6,287,860, which is incorporated herein in its entirety.
In one embodiment, the present invention employs various
penetration enhancers to effect the efficient delivery of nucleic
acids, particularly oligomers. In addition to aiding the diffusion
of non-lipophilic drugs across cell membranes, penetration
enhancers also enhance the permeability of lipophilic drugs.
Penetration enhancers may be classified as belonging to one of five
broad categories, i.e., surfactants, fatty acids, bile salts,
chelating agents, and non-chelating non-surfactants. Penetration
enhancers and their uses are further described in U.S. Pat. No.
6,287,860, which is incorporated herein in its entirety.
One of skill in the art will recognize that formulations are
routinely designed according to their intended use, i.e. route of
administration.
Preferred formulations for topical administration include those in
which the oligomers of the invention are in admixture with a
topical delivery agent such as lipids, liposomes, fatty acids,
fatty acid esters, steroids, chelating agents and surfactants.
Preferred lipids and liposomes include neutral (e.g.
dioleoylphosphatidyl DOPE ethanolamine, dimyristoylphosphatidyl
choline DMPC, distearolyphosphatidyl choline) negative (e.g.
dimyristoylphosphatidyl glycerol DMPG) and cationic (e.g.
dioleoyltetramethylaminopropyl DOTAP and dioleoylphosphatidyl
ethanolamine DOTMA).
For topical or other administration, compounds and compositions of
the invention may be encapsulated within liposomes or may form
complexes thereto, in particular to cationic liposomes.
Alternatively, they may be complexed to lipids, in particular to
cationic lipids. Preferred fatty acids and esters, pharmaceutically
acceptable salts thereof, and their uses are further described in
U.S. Pat. No. 6,287,860, which is incorporated herein in its
entirety. Topical formulations are described in detail in U.S.
patent application Ser. No. 09/315,298 filed on May 20, 1999, which
is incorporated herein by reference in its entirety.
Compositions and formulations for oral administration include
powders or granules, microparticulates, nanoparticulates,
suspensions or solutions in water or non-aqueous media, capsules,
gel capsules, sachets, tablets or minitablets. Thickeners,
flavoring agents, diluents, emulsifiers, dispersing aids or binders
may be desirable. Preferred oral formulations are those in which
oligomers of the invention are administered in conjunction with one
or more penetration enhancers surfactants and chelators. Preferred
surfactants include fatty acids and/or esters or salts thereof,
bile acids and/or salts thereof. Preferred bile acids/salts and
fatty acids and their uses are further described in U.S. Pat. No.
6,287,860, which is incorporated herein in its entirety. Also
preferred are combinations of penetration enhancers, for example,
fatty acids/salts in combination with bile acids/salts. A
particularly preferred combination is the sodium salt of lauric
acid, capric acid and UDCA. Further penetration enhancers include
polyoxyethylene-9-lauryl ether, polyoxyethylene-20-cetyl ether.
Compounds and compositions of the invention may be delivered
orally, in granular form including sprayed dried particles, or
complexed to form micro or nanoparticles. Complexing agents and
their uses are further described in U.S. Pat. No. 6,287,860, which
is incorporated herein in its entirety. Certain oral formulations
for oligomers and their preparation are described in detail in U.S.
application Ser. No. 09/108,673 (filed Jul. 1, 1998), Ser. No.
09/315,298 (filed May 20, 1999) and Ser. No. 10/071,822, filed Feb.
8, 2002, each of which is incorporated herein by reference in their
entirety.
Compositions and formulations for parenteral, intrathecal or
intraventricular administration may include sterile aqueous
solutions that may also contain buffers, diluents and other
suitable additives such as, but not limited to, penetration
enhancers, carrier compounds and other pharmaceutically acceptable
carriers or excipients.
Certain embodiments of the invention provide pharmaceutical
compositions containing one or more of the compounds and
compositions of the invention and one or more other
chemotherapeutic agents that function by a non-antisense mechanism.
Examples of such chemo-therapeutic agents include but are not
limited to cancer chemotherapeutic drugs such as daunorubicin,
daunomycin, dactinomycin, doxorubicin, epirubicin, idarubicin,
esorubicin, bleomycin, mafosfamide, ifosfamide, cytosine
arabinoside, bis-chloroethylnitrosurea, busulfan, mitomycin C,
actinomycin D, mithramycin, prednisone, hydroxyprogesterone,
testosterone, tamoxifen, dacarbazine, procarbazine,
hexamethylmelamine, pentamethylmelamine, mitoxantrone, amsacrine,
chlorambucil, methylcyclohexylnitrosurea, nitrogen mustards,
melphalan, cyclophosphamide, 6-mercaptopurine, 6-thioguanine,
cytarabine, 5-azacytidine, hydroxyurea, deoxycoformycin,
4-hydroxyperoxycyclophosphoramide, 5-fluorouracil (5-FU),
5-fluorodeoxyuridine (5-FUdR), methotrexate (MTX), colchicine,
taxol, vincristine, vinblastine, etoposide (VP-16), trimetrexate,
irinotecan, topotecan, gemcitabine, teniposide, cisplatin and
diethylstilbestrol (DES). When used with the oligomeric compounds
of the invention, such chemo-therapeutic agents may be used
individually (e.g., 5-FU and oligomer), sequentially (e.g., 5-FU
and oligomer for a period of time followed by MTX and oligomer), or
in combination with one or more other such chemotherapeutic agents
(e.g., 5-FU, MTX and oligomer, or 5-FU, radiotherapy and oligomer).
Anti-inflammatory drugs, including but not limited to nonsteroidal
anti-inflammatory drugs and corticosteroids, and antiviral drugs,
including but not limited to ribivirin, vidarabine, acyclovir and
ganciclovir, may also be combined in compositions of the invention.
Combinations of compounds and compositions of the invention and
other drugs are also within the scope of this invention. Two or
more combined compounds such as two oligomeric compounds or one
oligomeric compound combined with further compounds may be used
together or sequentially.
In another related embodiment, compositions of the invention may
contain one or more of the compounds and compositions of the
invention targeted to a first nucleic acid and one or more
additional compounds such as antisense oligomeric compounds
targeted to a second nucleic acid target. Numerous examples of
antisense oligomeric compounds are known in the art. Alternatively,
compositions of the invention may contain two or more oligomeric
compounds and compositions targeted to different regions of the
same nucleic acid target. Two or more combined compounds may be
used together or sequentially
Dosing
The formulation of therapeutic compounds and compositions of the
invention and their subsequent administration (dosing) is believed
to be within the skill of those in the art. Dosing is dependent on
severity and responsiveness of the disease state to be treated,
with the course of treatment lasting from several days to several
months, or until a cure is effected or a diminution of the disease
state is achieved. Optimal dosing schedules can be calculated from
measurements of drug accumulation in the body of the patient.
Persons of ordinary skill can easily determine optimum dosages,
dosing methodologies and repetition rates. Optimum dosages may vary
depending on the relative potency of individual oligomers, and can
generally be estimated based on EC.sub.50s found to be effective in
in vitro and in vivo animal models. In general, dosage is from 0.01
ug to 100 g per kg of body weight, and may be given once or more
daily, weekly, monthly or yearly, or even once every 2 to 20 years.
Persons of ordinary skill in the art can easily estimate repetition
rates for dosing based on measured residence times and
concentrations of the drug in bodily fluids or tissues. Following
successful treatment, it may be desirable to have the patient
undergo maintenance therapy to prevent the recurrence of the
disease state, wherein the oligomer is administered in maintenance
doses, ranging from 0.01 ug to 100 g per kg of body weight, once or
more daily, to once every 20 years.
While the present invention has been described with specificity in
accordance with certain of its preferred embodiments, the following
examples serve only to illustrate the invention and are not
intended to limit the same.
The entire disclosure of each patent, patent application, and
publication cited or described in this document is hereby
incorporated by reference.
EXAMPLE 1
Synthesis of Nucleoside Phosphoramidites
The following compounds, including amidites and their intermediates
were prepared as described in U.S. Pat. No. 6,426,220 and published
PCT WO 02/36743; 5'-O-Dimethoxytrityl-thymidine intermediate for
5-methyl dC amidite, 5'-O-Dimethoxytrityl-2'-deoxy-5-methylcytidine
intermediate for 5-methyl-dC amidite,
5'-O-Dimethoxytrityl-2'-deoxy-N4-benzoyl-5-methylcytidine
penultimate intermediate for 5-methyl dC amidite,
[5'-O-(4,4'-Dimethoxytriphenylmethyl)-2'-deoxy-N.sup.4-benzoyl-5-methylcy-
tidin-3'-O-yl]-2-cyanoethyl-N,N-diisopropylphosphoramidite
(5-methyl dC amidite), 2'-Fluorodeoxyadenosine,
2'-Fluorodeoxyguanosine, 2'-Fluorouridine, 2'-Fluorodeoxycytidine,
2'-O-(2-Methoxyethyl) modified amidites,
2'-O-(2-methoxyethyl)-5-methyluridine intermediate,
5'-O-DMT-2'-O-(2-methoxyethyl)-5-methyluridine penultimate
intermediate,
[5'-O-(4,4'-Dimethoxytriphenylmethyl)-2'-O-(2-methoxyethyl)-5-methyluridi-
n-3'-O-yl]-2-cyanoethyl-N,N-diisopropylphosphoramidite (MOE T
amidite),
5'-O-Dimethoxytrityl-2'-O-(2-methoxyethyl)-5-methylcytidine
intermediate,
5'-O-dimethoxytrityl-2'-O-(2-methoxyethyl)-N.sup.4-benzoyl-5-methyl-cytid-
ine penultimate intermediate,
[5'-O-(4,4'-Dimethoxytriphenylmethyl)-2'-O-(2-methoxyethyl)-N.sup.4-benzo-
yl-5-methylcytidin-3'-O-yl]-2-cyanoethyl-N,N-diisopropylphosphoramidite
(MOE 5-Me-C amidite),
[5'-O-(4,4'-Dimethoxytriphenylmethyl)-2'-O-(2-methoxyethyl)-N.sup.6-benzo-
yladenosin-3'-O-yl]-2-cyanoethyl-N,N-diisopropylphosphoramidite
(MOE A amdite),
[5'-O-(4,4'-Dimethoxytriphenylmethyl)-2'-O-(2-methoxyethyl)-N.su-
p.4-isobutyrylguanosin-3'-O-yl]-2-cyanoethyl-N,N-diisopropylphosphoramidit-
e (MOE G amidite), 2'-O-(Aminooxyethyl) nucleoside amidites and
2'-O-(dimethylaminooxyethyl) nucleoside amidites,
2'-(Dimethylaminooxyethoxy) nucleoside amidites,
5'-O-tert-Butyldiphenylsilyl-O.sup.2-2'-anhydro-5-methyluridine,
5'-O-tert-Butyldiphenyl
silyl-2'-O-(2-hydroxyethyl)-5-methyluridine,
2'-O-([2-phthalimidoxy)ethyl]-5'-t-butyldiphenylsilyl-5-methyluridine,
5'-O-tert-butyldiphenylsilyl-2'-O-[(2-formadoximinooxy)ethyl]-5-methyluri-
dine, 5'-O-tert-Butyldiphenylsilyl-2'-O--[N,N
dimethylaminooxyethyl]-5-methyluridine,
2'-O-(dimethylaminooxyethyl)-5-methyluridine,
5'-O-DMT-2'-O-(dimethylaminooxyethyl)-5-methyluridine,
5'-O-DMT-2'-O-(2-N,N-dimethylaminooxyethyl)-5-methyluridine-3'-[(2-cyanoe-
thyl)-N,N-diisopropylphosphoramidite], 2'-(Aminooxyethoxy)
nucleoside amidites,
N2-isobutyryl-6-O-diphenylcarbamoyl-2'-O-(2-ethylacetyl)-5'-O-(-
4,4'-dimethoxytrityl)guanosine-3'-[(2-cyanoethyl)-N,N-diisopropylphosphora-
midite], 2'-dimethylaminoethoxyethoxy (2'-DMAEOE) nucleoside
amidites, 2'-O-[2(2-N,N-dimethylaminoethoxy)ethyl]-5-methyl
uridine,
5'-O-dimethoxytrityl-2'-O-[2(2-N,N-dimethylaminoethoxy)-ethyl)]-5-methyl
uridine and
5'-O-Dimethoxytrityl-2'-O-[2(2-N,N-dimethylaminoethoxy)-ethyl)]-5-methyl
uridine-3'-O-(cyanoethyl-N,N-diisopropyl)phosphoramidite.
EXAMPLE 2
Oligonucleotide and Oligonucleoside Synthesis
Oligonucleotides: Unsubstituted and substituted phosphodiester
(P.dbd.O) oligonucleotides are synthesized on an automated DNA
synthesizer (Applied Biosystems model 394) using standard
phosphoramidite chemistry with oxidation by iodine.
Phosphorothioates (P.dbd.S) are synthesized similar to
phosphodiester oligonucleotides with the following exceptions:
thiation was effected by utilizing a 10% w/v solution of
3,H-1,2-benzodithiole-3-one 1,1-dioxide in acetonitrile for the
oxidation of the phosphite linkages. The thiation reaction step
time was increased to 180 sec and preceded by the normal capping
step. After cleavage from the CPG column and deblocking in
concentrated ammonium hydroxide at 55.degree. C. (12-16 hr), the
oligonucleotides were recovered by precipitating with >3 volumes
of ethanol from a 1 M NH.sub.4OAc solution. Phosphinate
oligonucleotides are prepared as described in U.S. Pat. No.
5,508,270, herein incorporated by reference.
Alkyl phosphonate oligonucleotides are prepared as described in
U.S. Pat. No. 4,469,863, herein incorporated by reference.
3'-Deoxy-3'-methylene phosphonate oligonucleotides are prepared as
described in U.S. Pat. No. 5,610,289 or 5,625,050, herein
incorporated by reference.
Phosphoramidite oligonucleotides are prepared as described in U.S.
Pat. No. 5,256,775 or U.S. Pat. No. 5,366,878, herein incorporated
by reference.
Alkylphosphonothioate oligonucleotides are prepared as described in
published PCT applications PCT/US94/00902 and PCT/US93/06976
(published as WO 94/17093 and WO 94/02499, respectively), herein
incorporated by reference.
3'-Deoxy-3'-amino phosphoramidate oligonucleotides are prepared as
described in U.S. Pat. No. 5,476,925, herein incorporated by
reference.
Phosphotriester oligonucleotides are prepared as described in U.S.
Pat. No. 5,023,243, herein incorporated by reference.
Borano phosphate oligonucleotides are prepared as described in U.S.
Pat. Nos. 5,130,302 and 5,177,198, both herein incorporated by
reference.
Oligonucleosides: Methylenemethylimino linked oligonucleosides,
also identified as MMI linked oligonucleosides,
methylenedimethylhydrazo linked oligonucleosides, also identified
as MDH linked oligonucleosides, and methylenecarbonylamino linked
oligonucleosides, also identified as amide-3 linked
oligonucleosides, and methyleneaminocarbonyl linked
oligonucleosides, also identified as amide-4 linked
oligonucleosides, as well as mixed backbone oligomeric compounds
having, for instance, alternating MMI and P.dbd.O or P.dbd.S
linkages are prepared as described in U.S. Pat. Nos. 5,378,825,
5,386,023, 5,489,677, 5,602,240 and 5,610,289, all of which are
herein incorporated by reference.
Formacetal and thioformacetal linked oligonucleosides are prepared
as described in U.S. Pat. Nos. 5,264,562 and 5,264,564, herein
incorporated by reference.
Ethylene oxide linked oligonucleosides are prepared as described in
U.S. Pat. No. 5,223,618, herein incorporated by reference.
EXAMPLE 3
RNA Synthesis
In general, RNA synthesis chemistry is based on the selective
incorporation of various protecting groups at strategic
intermediary reactions. Although one of ordinary skill in the art
will understand the use of protecting groups in organic synthesis,
a useful class of protecting groups includes silyl ethers. In
particular bulky silyl ethers are used to protect the 5'-hydroxyl
in combination with an acid-labile orthoester protecting group on
the 2'-hydroxyl. This set of protecting groups is then used with
standard solid-phase synthesis technology. It is important to
lastly remove the acid labile orthoester protecting group after all
other synthetic steps. Moreover, the early use of the silyl
protecting groups during synthesis ensures facile removal when
desired, without undesired deprotection of 2' hydroxyl.
Following this procedure for the sequential protection of the
5'-hydroxyl in combination with protection of the 2'-hydroxyl by
protecting groups that are differentially removed and are
differentially chemically labile, RNA oligonucleotides were
synthesized.
RNA oligonucleotides are synthesized in a stepwise fashion. Each
nucleotide is added sequentially (3'- to 5'-direction) to a solid
support-bound oligonucleotide. The first nucleoside at the 3'-end
of the chain is covalently attached to a solid support. The
nucleotide precursor, a ribonucleoside phosphoramidite, and
activator are added, coupling the second base onto the 5'-end of
the first nucleoside. The support is washed and any unreacted
5'-hydroxyl groups are capped with acetic anhydride to yield
5'-acetyl moieties. The linkage is then oxidized to the more stable
and ultimately desired P(V) linkage. At the end of the nucleotide
addition cycle, the 5'-silyl group is cleaved with fluoride. The
cycle is repeated for each subsequent nucleotide.
Following synthesis, the methyl protecting groups on the phosphates
are cleaved in 30 minutes utilizing 1 M
disodium-2-carbamoyl-2-cyanoethylene-1,1-dithiolate trihydrate
(S.sub.2Na.sub.2) in DMF. The deprotection solution is washed from
the solid support-bound oligonucleotide using water. The support is
then treated with 40% methylamine in water for 10 minutes at
55.degree. C. This releases the RNA oligonucleotides into solution,
deprotects the exocyclic amines, and modifies the 2'-groups. The
oligonucleotides can be analyzed by anion exchange HPLC at this
stage.
The 2'-orthoester groups are the last protecting groups to be
removed. The ethylene glycol monoacetate orthoester protecting
group developed by Dharmacon Research, Inc. (Lafayette, Colo.), is
one example of a useful orthoester protecting group which, has the
following important properties. It is stable to the conditions of
nucleoside phosphoramidite synthesis and oligonucleotide synthesis.
However, after oligonucleotide synthesis the oligonucleotide is
treated with methylamine which not only cleaves the oligonucleotide
from the solid support but also removes the acetyl groups from the
orthoesters. The resulting 2-ethyl-hydroxyl substituents on the
orthoester are less electron withdrawing than the acetylated
precursor. As a result, the modified orthoester becomes more labile
to acid-catalyzed hydrolysis. Specifically, the rate of cleavage is
approximately 10 times faster after the acetyl groups are removed.
Therefore, this orthoester possesses sufficient stability in order
to be compatible with oligonucleotide synthesis and yet, when
subsequently modified, permits deprotection to be carried out under
relatively mild aqueous conditions compatible with the final RNA
oligonucleotide product.
Additionally, methods of RNA synthesis are well known in the art
(Scaringe, S. A. Ph.D. Thesis, University of Colorado, 1996;
Scaringe, S. A., et al., J. Am. Chem. Soc., 1998, 120, 11820-11821;
Matteucci, M. D. and Caruthers, M. H. J. Am. Chem. Soc., 1981, 103,
3185-3191; Beaucage, S. L. and Caruthers, M. H. Tetrahedron Lett.,
1981, 22, 1859-1862; Dahl, B. J., et al., Acta Chem. Scand, 1990,
44, 639-641; Reddy, M. P., et al., Tetrahedrom Lett., 1994, 25,
4311-4314; Wincott, F. et al., Nucleic Acids Res., 1995, 23,
2677-2684; Griffin, B. E., et al., Tetrahedron, 1967, 23,
2301-2313; Griffin, B. E., et al., Tetrahedron, 1967, 23,
2315-2331).
EXAMPLE 4
Synthesis of Chimeric Oligonucleotides
Chimeric oligonucleotides, oligonucleosides or mixed
oligonucleotides/oligonucleosides of the invention can be of
several different types. These include a first type wherein the
"gap" segment of linked nucleosides is positioned between 5' and 3'
"wing" segments of linked nucleosides and a second "open end" type
wherein the "gap" segment is located at either the 3' or the 5'
terminus of the oligomeric compound. Oligonucleotides of the first
type are also known in the art as "gapmers" or gapped
oligonucleotides. Oligonucleotides of the second type are also
known in the art as "hemimers" or "wingmers".
[2'-O-Me]-[2'-deoxy]-[2'-O-Me] Chimeric Phosphorothioate
Oligonucleotides
Chimeric oligonucleotides having 2'-O-alkyl phosphorothioate and
2'-deoxy phosphorothioate oligonucleotide segments are synthesized
using an Applied Biosystems automated DNA synthesizer Model 394, as
above. Oligonucleotides are synthesized using the automated
synthesizer and 2'-deoxy-5'-dimethoxytrityl-3'-O-phosphoramidite
for the DNA portion and
5'-dimethoxytrityl-2'-O-methyl-3'-O-phosphoramidite for 5' and 3'
wings. The standard synthesis cycle is modified by incorporating
coupling steps with increased reaction times for the
5'-dimethoxytrityl-2'-O-methyl-3'-O-phosphoramidite. The fully
protected oligonucleotide is cleaved from the support and
deprotected in concentrated ammonia (NH.sub.4OH) for 12-16 hr at
55.degree. C. The deprotected oligo is then recovered by an
appropriate method (precipitation, column chromatography, volume
reduced in vacuo and analyzed spetrophotometrically for yield and
for purity by capillary electrophoresis and by mass
spectrometry.
[2'-O-(2-Methoxyethyl)]-[2'-deoxy]-[2'-O-(Methoxyethyl)] Chimeric
Phosphorothioate Oligonucleotides
[2'-O-(2-methoxyethyl)]-[2'-deoxy]-[-2'-O-(methoxyethyl)] chimeric
phosphorothioate oligonucleotides were prepared as per the
procedure above for the 2'-O-methyl chimeric oligonucleotide, with
the substitution of 2'-O-(methoxyethyl) amidites for the
2'-O-methyl amidites.
[2'-O-(2-Methoxyethyl)Phosphodiester]-[2'-deoxy
Phosphorothioate]-[2'-O-(2-Methoxyethyl) Phosphodiester] Chimeric
Oligonucleotides
[2'-O-(2-methoxyethyl phosphodiester]-[2'-deoxy
phosphorothioate]-[2'-O-(methoxyethyl) phosphodiester] chimeric
oligonucleotides are prepared as per the above procedure for the
2'-O-methyl chimeric oligonucleotide with the substitution of
2'-O-(methoxyethyl) amidites for the 2'-O-methyl amidites,
oxidation with iodine to generate the phosphodiester
internucleotide linkages within the wing portions of the chimeric
structures and sulfurization utilizing 3,H-1,2 benzodithiole-3-one
1,1 dioxide (Beaucage Reagent) to generate the phosphorothioate
internucleotide linkages for the center gap.
Other chimeric oligonucleotides, chimeric oligonucleosides and
mixed chimeric oligonucleotides/oligonucleosides are synthesized
according to U.S. Pat. No. 5,623,065, herein incorporated by
reference.
EXAMPLE 5
Synthesis of 2'-Deoxy-2'-fluoro Modified Oligonucleotides
2'-Deoxy-2'-fluoro modified oligonucleotides may be prepared by
methods taught in U.S. Pat. No. 6,531,584.
EXAMPLE 6
Synthesis of 2'-Deoxy-2'-O-alkyl Modified Oligonucleotides
2'-Deoxy-2'-O-alkyl modified oligonucleotides may be prepared by
methods taught in U.S. Pat. No. 6,531,584.
EXAMPLE 7
Synthesis of 2'-O-[2(2-N,N-dimethylaminoethoxy)ethyl]-5-methyl
Uridine
2'-O-[2(2-N,N-dimethylaminoethoxy)ethyl]-5-methyl uridine may be
prepared by methods taught in U.S. Pat. No. 6,043,352.
EXAMPLE 8
Synthesis of
5'-O-Dimethoxytrityl-2'-O-methyl-3'-O--(N,N-diisopropylamino-O-.beta.-cya-
no ethylphosphine)-N-benzoyladenosine
5'-O-Dimethoxytrityl-2'-O-methyl-3'-O--(N,N-diisopropylamino-O-.beta.-cya-
no ethylphosphine)-N-benzoyladenosinemay be prepared by methods
taught in U.S. Pat. No. 6,005,094.
EXAMPLE 9
Synthesis of
5'-O-Dimethoxytrityl-2'-O-Methylthiomethyl-Nucleotides
5'-O-Dimethoxytrityl-2'-O-methylthiomethyl-nucleotides may be
prepared by methods taught in U.S. Pat. No. 6,239,272.
EXAMPLE 10
Synthesis of 2'-Deoxy-2'-(vinyloxy) Modified Oligonucleotides
2'-Deoxy-2'-(vinyloxy) modified oligonucleotides may be prepared by
methods taught in U.S. Pat. No. 5,859,221.
EXAMPLE 11
Synthesis of 2'-Deoxy-2'-(methylthio), (methylsulfinyl) and
(methylsulfonyl) Modified Oligonucleotides
2'-Deoxy-2'-(methylthio), (methylsulfinyl) and (methylsulfonyl)
modified oligonucleotides may be prepared by methods taught in U.S.
Pat. No. 5,859,221.
EXAMPLE 12
Synthesis of Oligonucleotides Bearing 2'-OCH.sub.2COOEt
Substituents
2'-OCH.sub.2COOEt modified oligonucleotides may be prepared by
methods taught in U.S. Pat. No. 5,792,847.
EXAMPLE 13
Synthesis of 9-(2-(O-2-Propynyloxy)-.beta.-D-ribofuranosyl)
Adenine
9-(2-(O-2-Propynyloxy)-3-D-ribofuranosyl) adenine may be prepared
by methods taught in U.S. Pat. No. 5,514,786.
EXAMPLE 14
Synthesis of
3'-O--(N-Allyloxycarbonyl-6-aminohexyl)-5'-O-dimethoxytrityl-uridine
3'-O--(N-Allyloxycarbonyl-6-aminohexyl)-5'-O-dimethoxytrityl-uridine
may be prepared by methods taught in U.S. Pat. No. 6,111,085.
EXAMPLE 15
Synthesis of 2'-O--(N-phthalimido) prop-3-yl adenosine
2'-O--(N-phthalimido) prop-3-yl adenosine may be prepared by
methods taught in U.S. Pat. No. 5,872,232.
EXAMPLE 16
Synthesis of
2'-O-(2-Phthalimido-N-hydroxyethyl)-3',5'-O-(1,1,3,3-tetraisopropyldisilo-
xane-1,3-diyl)adenosine
2'-O-(2-Phthalimido-N-hydroxyethyl)-3',5'-O-(1,1,3,3-tetraisopropyldisilo-
xane-1,3-diyl)adenosine may be prepared by methods taught in U.S.
Pat. No. 6,172,209.
EXAMPLE 17
Synthesis of 5'-O-Dimethoxytrityl-2'-O-(carbonylaminohexyl
aminocarbonyloxy cholesteryl)-N4-benzolyl chloride
5'-O-Dimethoxytrityl-2'-O-(carbonylaminohexyl aminocarbonyloxy
cholesteryl)-N4-benzolyl chloride may be prepared by methods taught
in U.S. Pat. No. 6,166,188.
EXAMPLE 18
Synthesis of
5'-O-[(2,2-dimethyl-1,1-diphenyl-1-silapropoxy)methyl]-2'-O--((N,N-dimeth-
ylaminoethyleneamino)carbonylmethylene)adenosine
5'-O-[(2,2-dimethyl-1,1-diphenyl-1-silapropoxy)methyl]-2'-O--((N,N-dimeth-
ylaminoethyleneamino)carbonylmethylene)adenosine may be prepared by
methods taught in U.S. Pat. No. 6,147,200.
EXAMPLE 19
Synthesis of 2'-O-(Propylsulfonic acid) Sodium Salt-N-3-(Benzyloxy)
Methyl-5-Methyluridine
2'-O-(Propylsulfonic acid) sodium salt-N-3-(benzyloxy)
methyl-5-methyluridine may be prepared by methods taught in U.S.
Pat. No. 6,277,982.
EXAMPLE 20
Synthesis of
##STR00037##
Modified Oligonucleotides
These oligonucleotides may be prepared by methods taught in U.S.
Pat. No. 5,969,116.
EXAMPLE 21
Synthesis of
5'-Dimethoxytrityl-2'-O-(trans-2-methoxycyclohexyl)-5-methyl
Uridine
5'-Dimethoxytrityl-2'-O-(trans-2-methoxycyclohexyl)-5-methyl
uridine may be prepared by methods taught in U.S. Pat. No.
6,277,982.
EXAMPLE 22
Synthesis of 2'-OH, 2'-Me Modified Compounds
##STR00038##
The above compound was prepared following the methods described in
J. Med. Chem. 41: 1708 (1998).
EXAMPLE 23
4-Amino-7-(2-C-methyl-.beta.-D-arabinofuranosyl)-7H-pyrrolo[2,3-d]pyrimidi-
ne
##STR00039##
To CrO.sub.3 (1.57 g, 1.57 mmol) in dichloromethane (DCM) (10 mL)
at 0.degree. C. was added acetic anhydride (145 mg, 1.41 mmol) and
then pyridine (245 mg, 3.10 mmol). The mixture was stirred for 15
min, then a solution of
7-[3,5-O-[1,1,3,3-tetrakis(1-methylethyl)-1,3-disiloxanediyl]-.beta.-D-ri-
bofuranosyl]-7H-pyrrolo[2,3-d]pyrimidin-4-amine [for preparation,
see J. Am. Chem. Soc. 105: 4059 (1983)] (508 mg, 1.00 mmol) in DCM
(3 mL) was added. The resulting solution was stirred for 2 h and
then poured into ethyl acetate (10 mL), and subsequently filtered
through silica gel using ethyl acetate as the eluent. The combined
filtrates were evaporated in vacuo, taken up in diethyl ether/THF
(1:1) (20 mL), cooled to -78.degree. C. and methylmagnesium bromide
(3M, in THF) (3.30 mL, 10 mmol) was added dropwise. The mixture was
stirred at -78.degree. C. for 10 min, then allowed to come to room
temperature (rt) and quenched by addition of saturated aqueous
ammonium chloride (10 mL) and extracted with DCM (20 mL). The
organic phase was evaporated in vacuo and the crude product
purified on silica gel using 5% methanol in dichloromethane as
eluent. Fractions containing the product were pooled and evaporated
in vacuo. The resulting oil was taken up in THF (5 mL) and
tetrabutylammonium fluoride (TBAF) on silica (1.1 mmol/g on silica)
(156 mg) was added. The mixture was stirred at rt for 30 min,
filtered, and evaporated in vacuo. The crude product was purified
on silica gel using 10% methanol in dichloromethane as eluent.
Fractions containing the product were pooled and evaporated in
vacuo to give the desired compound (49 mg) as a colorless
solid.
.sup.1H NMR (DMSO-d.sub.6): .delta. 1.08 (s, 3H), 3.67 (m, 2H),
3.74 (m, 1H), 3.83 (m, 1H), 5.19 (m, 1H), 5.23 (m, 1H), 5.48 (m,
1H), 6.08 (1H, s), 6.50 (m, 1H), 6.93 (bs, 2H), 7.33 (m, 1H), 8.02
(s, 1H).
EXAMPLE 24
Design and Screening of Duplexed Oligomeric Compounds Targeting a
Target
In accordance with the present invention, a series of nucleic acid
duplexes comprising the antisense oligomeric compounds of the
present invention and their complements can be designed to target a
target. The ends of the strands may be modified by the addition of
one or more natural or modified nucleobases to form an overhang.
The sense strand of the dsRNA is then designed and synthesized as
the complement of the antisense strand and may also contain
modifications or additions to either terminus. For example, in one
embodiment, both strands of the dsRNA duplex would be complementary
over the central nucleobases, each having overhangs at one or both
termini.
For example, a duplex comprising an antisense strand having the
sequence CGAGAGGCGGACGGGACCG (SEQ ID NO: 1) and having a
two-nucleobase overhang of deoxythymidine(dT) would have the
following structure:
TABLE-US-00003 5' cgagaggcggacgggaccgTT 3' Antisense Strand
||||||||||||||||||| (SEQ ID NO: 2) 3' TTgctctccgcctgccctggc 5'
Complement Strand (SEQ ID NO: 3)
RNA strands of the duplex can be synthesized by methods disclosed
herein or purchased from Dharmacon Research Inc., (Lafayette,
Colo.). Once synthesized, the complementary strands are annealed.
The single strands are aliquoted and diluted to a concentration of
50 uM. Once diluted, 30 uL of each strand is combined with 15 uL of
a 5.times. solution of annealing buffer. The final concentration of
said buffer is 100 mM potassium acetate, 30 mM HEPES-KOH pH 7.4,
and 2 mM magnesium acetate. The final volume is 75 uL. This
solution is incubated for 1 minute at 90.degree. C. and then
centrifuged for 15 seconds. The tube is allowed to sit for 1 hour
at 37.degree. C. at which time the dsRNA duplexes are used in
experimentation. The final concentration of the dsRNA duplex is 20
uM. This solution can be stored frozen (-20.degree. C.) and
freeze-thawed up to 5 times.
Once prepared, the duplexed antisense oligomeric compounds are
evaluated for their ability to modulate a target expression.
When cells reached 80% confluency, they are treated with duplexed
antisense oligomeric compounds of the invention. For cells grown in
96-well plates, wells are washed once with 200 .mu.L OPTI-MEM-1
reduced-serum medium (Gibco BRL) and then treated with 130 .mu.L of
OPTI-MEM-1 containing 12 .mu.g/mL LIPOFECTIN (Gibco BRL) and the
desired duplex antisense oligomeric compound at a final
concentration of 200 nM. After 5 hours of treatment, the medium is
replaced with fresh medium. Cells are harvested 16 hours after
treatment, at which time RNA is isolated and target reduction
measured by RT-PCR.
EXAMPLE 25
Oligonucleotide Isolation
After cleavage from the controlled pore glass solid support and
deblocking in concentrated ammonium hydroxide at 55.degree. C. for
12-16 hours, the oligonucleotides or oligonucleosides are recovered
by precipitation out of 1 M NH.sub.4OAc with >3 volumes of
ethanol. Synthesized oligonucleotides were analyzed by electrospray
mass spectroscopy (molecular weight determination) and by capillary
gel electrophoresis and judged to be at least 70% full length
material. The relative amounts of phosphorothioate and
phosphodiester linkages obtained in the synthesis was determined by
the ratio of correct molecular weight relative to the -16 amu
product (+/-32+/-48). For some studies oligonucleotides were
purified by HPLC, as described by Chiang et al., J. Biol. Chem.
1991, 266, 18162-18171. Results obtained with HPLC-purified
material were similar to those obtained with non-HPLC purified
material.
EXAMPLE 26
Oligonucleotide Synthesis--96 Well Plate Format
Oligonucleotides were synthesized via solid phase P(III)
phosphoramidite chemistry on an automated synthesizer capable of
assembling 96 sequences simultaneously in a 96-well format.
Phosphodiester internucleotide linkages were afforded by oxidation
with aqueous iodine. Phosphorothioate internucleotide linkages were
generated by sulfurization utilizing 3,H-1,2 benzodithiole-3-one
1,1 dioxide (Beaucage Reagent) in anhydrous acetonitrile. Standard
base-protected beta-cyanoethyl-diiso-propyl phosphoramidites were
purchased from commercial vendors (e.g. PE-Applied Biosystems,
Foster City, Calif., or Pharmacia, Piscataway, N.J.). Non-standard
nucleosides are synthesized as per standard or patented methods.
They are utilized as base protected beta-cyanoethyldiisopropyl
phosphoramidites.
Oligonucleotides were cleaved from support and deprotected with
concentrated NH.sub.4OH at elevated temperature (55-60.degree. C.)
for 12-16 hours and the released product then dried in vacuo. The
dried product was then re-suspended in sterile water to afford a
master plate from which all analytical and test plate samples are
then diluted utilizing robotic pipettors.
EXAMPLE 27
Oligonucleotide Analysis--96-Well Plate Format
The concentration of oligonucleotide in each well was assessed by
dilution of samples and UV absorption spectroscopy. The full-length
integrity of the individual products was evaluated by capillary
electrophoresis (CE) in either the 96-well format (Beckman
P/ACE.TM. MDQ) or, for individually prepared samples, on a
commercial CE apparatus (e.g., Beckman P/ACE.TM. 5000, ABI 270).
Base and backbone composition was confirmed by mass analysis of the
oligomeric compounds utilizing electrospray-mass spectroscopy. All
assay test plates were diluted from the master plate using single
and multi-channel robotic pipettors. Plates were judged to be
acceptable if at least 85% of the oligomeric compounds on the plate
were at least 85% full length.
EXAMPLE 28
Cell Culture and Oligonucleotide Treatment
The effect of oligomeric compounds on target nucleic acid
expression can be tested in any of a variety of cell types provided
that the target nucleic acid is present at measurable levels. This
can be routinely determined using, for example, PCR or Northern
blot analysis. The following cell types are provided for
illustrative purposes, but other cell types can be routinely used,
provided that the target is expressed in the cell type chosen. This
can be readily determined by methods routine in the art, for
example Northern blot analysis, ribonuclease protection assays, or
RT-PCR. T-24 cells:
The human transitional cell bladder carcinoma cell line T-24 was
obtained from the American Type Culture Collection (ATCC)
(Manassas, Va.). T-24 cells were routinely cultured in complete
McCoy's 5 A basal media (Invitrogen Corporation, Carlsbad, Calif.)
supplemented with 10% fetal calf serum (Invitrogen Corporation,
Carlsbad, Calif.), penicillin 100 units per mL, and streptomycin
100 micrograms per mL (Invitrogen Corporation, Carlsbad, Calif.).
Cells were routinely passaged by trypsinization and dilution when
they reached 90% confluence. Cells were seeded into 96-well plates
(Falcon-Primaria #353872) at a density of 7000 cells/well for use
in RT-PCR analysis.
For Northern blotting or other analysis, cells may be seeded onto
100 mm or other standard tissue culture plates and treated
similarly, using appropriate volumes of medium and
oligonucleotide.
A549 Cells:
The human lung carcinoma cell line A549 was obtained from the
American Type Culture Collection (ATCC) (Manassas, Va.). A549 cells
were routinely cultured in DMEM basal media (Invitrogen
Corporation, Carlsbad, Calif.) supplemented with 10% fetal calf
serum (Invitrogen Corporation, Carlsbad, Calif.), penicillin 100
units per mL, and streptomycin 100 micrograms per mL (Invitrogen
Corporation, Carlsbad, Calif.). Cells were routinely passaged by
trypsinization and dilution when they reached 90% confluence.
NHDF Cells:
Human neonatal dermal fibroblast (NHDF) were obtained from the
Clonetics Corporation (Walkersville, Md.). NHDFs were routinely
maintained in Fibroblast Growth Medium (Clonetics Corporation,
Walkersville, Md.) supplemented as recommended by the supplier.
Cells were maintained for up to 10 passages as recommended by the
supplier.
HEK Cells:
Human embryonic keratinocytes (HEK) were obtained from the
Clonetics Corporation (Walkersville, Md.). HEKs were routinely
maintained in Keratinocyte Growth Medium (Clonetics Corporation,
Walkersville, Md.) formulated as recommended by the supplier. Cells
were routinely maintained for up to 10 passages as recommended by
the supplier.
Treatment with Antisense Oligomeric Compounds:
When cells reached 65-75% confluency, they were treated with
oligonucleotide. For cells grown in 96-well plates, wells were
washed once with 100 .mu.L OPTI-MEM.TM.-1 reduced-serum medium
(Invitrogen Corporation, Carlsbad, Calif.) and then treated with
130 .mu.L of OPTI-MEM.TM.-1 containing 3.75 .mu.g/mL LIPOFECTIN.TM.
(Invitrogen Corporation, Carlsbad, Calif.) and the desired
concentration of oligonucleotide. Cells are treated and data are
obtained in triplicate. After 4-7 hours of treatment at 37.degree.
C., the medium was replaced with fresh medium. Cells were harvested
16-24 hours after oligonucleotide treatment.
The concentration of oligonucleotide used varies from cell line to
cell line. To determine the optimal oligonucleotide concentration
for a particular cell line, the cells are treated with a positive
control oligonucleotide at a range of concentrations. For human
cells the positive control oligonucleotide is selected from either
ISIS 13920 (TCCGTCATCGCTCCTCAGGG, SEQ ID NO: 4) which is targeted
to human H-ras, or ISIS 18078, (GTGCGCGCGAGCCCGAAATC, SEQ ID NO: 5)
which is targeted to human Jun-N-terminal kinase-2 (JNK2). Both
controls are 2'-O-methoxyethyl gapmers (2'-O-methoxyethyls shown in
bold) with a phosphorothioate backbone. For mouse or rat cells the
positive control oligonucleotide is ISIS 15770,
ATGCATTCTGCCCCCAAGGA, SEQ ID NO: 6, a 2'-O-methoxyethyl gapmer
(2'-O-methoxyethyls shown in bold) with a phosphorothioate backbone
which is targeted to both mouse and rat c-raf. The concentration of
positive control oligonucleotide that results in 80% inhibition of
c-H-ras (for ISIS 13920), JNK2 (for ISIS 18078) or c-raf (for ISIS
15770) mRNA is then utilized as the screening concentration for new
oligonucleotides in subsequent experiments for that cell line. If
80% inhibition is not achieved, the lowest concentration of
positive control oligonucleotide that results in 60% inhibition of
c-H-ras, JNK2 or c-raf mRNA is then utilized as the oligonucleotide
screening concentration in subsequent experiments for that cell
line. If 60% inhibition is not achieved, that particular cell line
is deemed as unsuitable for oligonucleotide transfection
experiments. The concentrations of antisense oligonucleotides used
herein are from 50 nM to 300 nM.
EXAMPLE 29
Analysis of Oligonucleotide Inhibition of a Target Expression
Modulation of a target expression can be assayed in a variety of
ways known in the art. For example, a target mRNA levels can be
quantitated by, e.g., Northern blot analysis, competitive
polymerase chain reaction (PCR), or real-time PCR (RT-PCR).
Real-time quantitative PCR is presently preferred. RNA analysis can
be performed on total cellular RNA or poly(A)+mRNA. The preferred
method of RNA analysis of the present invention is the use of total
cellular RNA as described in other examples herein. Methods of RNA
isolation are well known in the art. Northern blot analysis is also
routine in the art. Real-time quantitative (PCR) can be
conveniently accomplished using the commercially available ABI
PRISM.TM. 7600, 7700, or 7900 Sequence Detection System, available
from PE-Applied Biosystems, Foster City, Calif. and used according
to manufacturer's instructions.
Protein levels of a target can be quantitated in a variety of ways
well known in the art, such as immunoprecipitation, Western blot
analysis (immunoblotting), enzyme-linked immunosorbent assay
(ELISA) or fluorescence-activated cell sorting (FACS). Antibodies
directed to a target can be identified and obtained from a variety
of sources, such as the MSRS catalog of antibodies (Aerie
Corporation, Birmingham, Mich.), or can be prepared via
conventional monoclonal or polyclonal antibody generation methods
well known in the art.
EXAMPLE 30
Design of Phenotypic Assays and In Vivo Studies for the Use of a
Target Inhibitors
Phenotypic Assays
Once a target inhibitors have been identified by the methods
disclosed herein, the oligomeric compounds are further investigated
in one or more phenotypic assays, each having measurable endpoints
predictive of efficacy in the treatment of a particular disease
state or condition.
Phenotypic assays, kits and reagents for their use are well known
to those skilled in the art and are herein used to investigate the
role and/or association of a target in health and disease.
Representative phenotypic assays, which can be purchased from any
one of several commercial vendors, include those for determining
cell viability, cytotoxicity, proliferation or cell survival
(Molecular Probes, Eugene, Oreg.; PerkinElmer, Boston, Mass.),
protein-based assays including enzymatic assays (Panvera, LLC,
Madison, Wis.; BD Biosciences, Franklin Lakes, N.J.; Oncogene
Research Products, San Diego, Calif.), cell regulation, signal
transduction, inflammation, oxidative processes and apoptosis
(Assay Designs Inc., Ann Arbor, Mich.), triglyceride accumulation
(Sigma-Aldrich, St. Louis, Mo.), angiogenesis assays, tube
formation assays, cytokine and hormone assays and metabolic assays
(Chemicon International Inc., Temecula, Calif.; Amersham
Biosciences, Piscataway, N.J.).
In one non-limiting example, cells determined to be appropriate for
a particular phenotypic assay (i.e., MCF-7 cells selected for
breast cancer studies; adipocytes for obesity studies) are treated
with a target inhibitors identified from the in vitro studies as
well as control compounds at optimal concentrations which are
determined by the methods described above. At the end of the
treatment period, treated and untreated cells are analyzed by one
or more methods specific for the assay to determine phenotypic
outcomes and endpoints.
Phenotypic endpoints include changes in cell morphology over time
or treatment dose as well as changes in levels of cellular
components such as proteins, lipids, nucleic acids, hormones,
saccharides or metals. Measurements of cellular status which
include pH, stage of the cell cycle, intake or excretion of
biological indicators by the cell, are also endpoints of
interest.
Analysis of the geneotype of the cell (measurement of the
expression of one or more of the genes of the cell) after treatment
is also used as an indicator of the efficacy or potency of the
target inhibitors. Hallmark genes, or those genes suspected to be
associated with a specific disease state, condition, or phenotype,
are measured in both treated and untreated cells.
In Vivo Studies
The individual subjects of the in vivo studies described herein are
warm-blooded vertebrate animals, which includes humans.
The clinical trial is subjected to rigorous controls to ensure that
individuals are not unnecessarily put at risk and that they are
fully informed about their role in the study.
To account for the psychological effects of receiving treatments,
volunteers are randomly given placebo or a target inhibitor.
Furthermore, to prevent the doctors from being biased in
treatments, they are not informed as to whether the medication they
are administering is a a target inhibitor or a placebo. Using this
randomization approach, each volunteer has the same chance of being
given either the new treatment or the placebo.
Volunteers receive either the a target inhibitor or placebo for
eight week period with biological parameters associated with the
indicated disease state or condition being measured at the
beginning (baseline measurements before any treatment), end (after
the final treatment), and at regular intervals during the study
period. Such measurements include the levels of nucleic acid
molecules encoding a target or a target protein levels in body
fluids, tissues or organs compared to pre-treatment levels. Other
measurements include, but are not limited to, indices of the
disease state or condition being treated, body weight, blood
pressure, serum titers of pharmacologic indicators of disease or
toxicity as well as ADME (absorption, distribution, metabolism and
excretion) measurements.
Information recorded for each patient includes age (years), gender,
height (cm), family history of disease state or condition (yes/no),
motivation rating (some/moderate/great) and number and type of
previous treatment regimens for the indicated disease or
condition.
Volunteers taking part in this study are healthy adults (age 18 to
65 years) and roughly an equal number of males and females
participate in the study. Volunteers with certain characteristics
are equally distributed for placebo and a target inhibitor
treatment. In general, the volunteers treated with placebo have
little or no response to treatment, whereas the volunteers treated
with the target inhibitor show positive trends in their disease
state or condition index at the conclusion of the study.
EXAMPLE 31
RNA Isolation
Poly(A)+mRNA Isolation
Poly(A)+mRNA was isolated according to Miura et al., (Clin. Chem.,
1996, 42, 1758-1764). Other methods for poly(A)+mRNA isolation are
routine in the art. Briefly, for cells grown on 96-well plates,
growth medium was removed from the cells and each well was washed
with 200 .mu.L cold PBS. 60 .mu.L lysis buffer (10 mM Tris-HCl, pH
7.6, 1 mM EDTA, 0.5 M NaCl, 0.5% NP-40, 20 mM
vanadyl-ribonucleoside complex) was added to each well, the plate
was gently agitated and then incubated at room temperature for five
minutes. 55 .mu.L of lysate was transferred to Oligo d(T) coated
96-well plates (AGCT Inc., Irvine Calif.). Plates were incubated
for 60 minutes at room temperature, washed 3 times with 200 .mu.L
of wash buffer (10 mM Tris-HCl pH 7.6, 1 mM EDTA, 0.3 M NaCl).
After the final wash, the plate was blotted on paper towels to
remove excess wash buffer and then air-dried for 5 minutes. 60
.mu.L of elution buffer (5 mM Tris-HCl pH 7.6), preheated to
70.degree. C., was added to each well, the plate was incubated on a
90.degree. C. hot plate for 5 minutes, and the eluate was then
transferred to a fresh 96-well plate.
Cells grown on 100 mm or other standard plates may be treated
similarly, using appropriate volumes of all solutions.
Total RNA Isolation
Total RNA was isolated using an RNEASY 96.TM. kit and buffers
purchased from Qiagen Inc. (Valencia, Calif.) following the
manufacturer's recommended procedures. Briefly, for cells grown on
96-well plates, growth medium was removed from the cells and each
well was washed with 200 .mu.L cold PBS. 150 .mu.L Buffer RLT was
added to each well and the plate vigorously agitated for 20
seconds. 150 .mu.L of 70% ethanol was then added to each well and
the contents mixed by pipetting three times up and down. The
samples were then transferred to the RNEASY 96.TM. well plate
attached to a QIAVAC.TM. manifold fitted with a waste collection
tray and attached to a vacuum source. Vacuum was applied for 1
minute. 500 .mu.L of Buffer RW1 was added to each well of the
RNEASY 96.TM. plate and incubated for 15 minutes and the vacuum was
again applied for 1 minute. An additional 500 .mu.L of Buffer RW1
was added to each well of the RNEASY 96.TM. plate and the vacuum
was applied for 2 minutes. 1 mL of Buffer RPE was then added to
each well of the RNEASY 96.TM. plate and the vacuum applied for a
period of 90 seconds. The Buffer RPE wash was then repeated and the
vacuum was applied for an additional 3 minutes. The plate was then
removed from the QIAVAC.TM. manifold and blotted dry on paper
towels. The plate was then re-attached to the QIAVAC.TM. manifold
fitted with a collection tube rack containing 1.2 mL collection
tubes. RNA was then eluted by pipetting 140 .mu.L of RNAse free
water into each well, incubating 1 minute, and then applying the
vacuum for 3 minutes.
The repetitive pipetting and elution steps may be automated using a
QIAGEN Bio-Robot 9604 (Qiagen, Inc., Valencia Calif.). Essentially,
after lysing of the cells on the culture plate, the plate is
transferred to the robot deck where the pipetting, DNase treatment
and elution steps are carried out.
EXAMPLE 32
Real-time Quantitative PCR Analysis of a Target mRNA Levels
Quantitation of a target mRNA levels was accomplished by real-time
quantitative PCR using the ABI PRISM.TM. 7600, 7700, or 7900
Sequence Detection System (PE-Applied Biosystems, Foster City,
Calif.) according to manufacturer's instructions. This is a
closed-tube, non-gel-based, fluorescence detection system which
allows high-throughput quantitation of polymerase chain reaction
(PCR) products in real-time. As opposed to standard PCR in which
amplification products are quantitated after the PCR is completed,
products in real-time quantitative PCR are quantitated as they
accumulate. This is accomplished by including in the PCR reaction
an oligonucleotide probe that anneals specifically between the
forward and reverse PCR primers, and contains two fluorescent dyes.
A reporter dye (e.g., FAM or JOE, obtained from either PE-Applied
Biosystems, Foster City, Calif., Operon Technologies Inc., Alameda,
Calif. or Integrated DNA Technologies Inc., Coralville, Iowa) is
attached to the 5' end of the probe and a quencher dye (e.g.,
TAMRA, obtained from either PE-Applied Biosystems, Foster City,
Calif., Operon Technologies Inc., Alameda, Calif. or Integrated DNA
Technologies Inc., Coralville, Iowa) is attached to the 3' end of
the probe. When the probe and dyes are intact, reporter dye
emission is quenched by the proximity of the 3' quencher dye.
During amplification, annealing of the probe to the target sequence
creates a substrate that can be cleaved by the 5'-exonuclease
activity of Taq polymerase. During the extension phase of the PCR
amplification cycle, cleavage of the probe by Taq polymerase
releases the reporter dye from the remainder of the probe (and
hence from the quencher moiety) and a sequence-specific fluorescent
signal is generated. With each cycle, additional reporter dye
molecules are cleaved from their respective probes, and the
fluorescence intensity is monitored at regular intervals by laser
optics built into the ABI PRISM.TM. Sequence Detection System. In
each assay, a series of parallel reactions containing serial
dilutions of mRNA from untreated control samples generates a
standard curve that is used to quantitate the percent inhibition
after antisense oligonucleotide treatment of test samples.
Prior to quantitative PCR analysis, primer-probe sets specific to
the target gene being measured are evaluated for their ability to
be "multiplexed" with a GAPDH amplification reaction. In
multiplexing, both the target gene and the internal standard gene
GAPDH are amplified concurrently in a single sample. In this
analysis, mRNA isolated from untreated cells is serially diluted.
Each dilution is amplified in the presence of primer-probe sets
specific for GAPDH only, target gene only ("single-plexing"), or
both (multiplexing). Following PCR amplification, standard curves
of GAPDH and target mRNA signal as a function of dilution are
generated from both the single-plexed and multiplexed samples. If
both the slope and correlation coefficient of the GAPDH and target
signals generated from the multiplexed samples fall within 10% of
their corresponding values generated from the single-plexed
samples, the primer-probe set specific for that target is deemed
multiplexable. Other methods of PCR are also known in the art.
PCR reagents were obtained from Invitrogen Corporation, (Carlsbad,
Calif.). RT-PCR reactions were carried out by adding 20 .mu.L PCR
cocktail (2.5.times.PCR buffer minus MgCl.sub.2, 6.6 mM MgCl.sub.2,
375 .mu.M each of dATP, dCTP, dCTP and dGTP, 375 nM each of forward
primer and reverse primer, 125 nM of probe, 4 Units RNAse
inhibitor, 1.25 Units PLATINUM.RTM. Taq, 5 Units MuLV reverse
transcriptase, and 2.5.times.ROX dye) to 96-well plates containing
30 .mu.L total RNA solution (20-200 ng). The RT reaction was
carried out by incubation for 30 minutes at 48.degree. C. Following
a 10 minute incubation at 95.degree. C. to activate the
PLATINUM.RTM. Taq, 40 cycles of a two-step PCR protocol were
carried out: 95.degree. C. for 15 seconds (denaturation) followed
by 60.degree. C. for 1.5 minutes (annealing/extension).
Gene target quantities obtained by real time RT-PCR are normalized
using either the expression level of GAPDH, a gene whose expression
is constant, or by quantifying total RNA using RiboGreen.TM.
(Molecular Probes, Inc. Eugene, Oreg.). GAPDH expression is
quantified by real time RT-PCR, by being run simultaneously with
the target, multiplexing, or separately. Total RNA is quantified
using RiboGreen.TM. RNA quantification reagent (Molecular Probes,
Inc. Eugene, Oreg.). Methods of RNA quantification by RiboGreen.TM.
are taught in Jones, L. J., et al, (Analytical Biochemistry, 1998,
265, 368-374).
In this assay, 170 .mu.L of RiboGreen.TM. working reagent
(RiboGreen.TM. reagent diluted 1:350 in 10 mM Tris-HCl, 1 mM EDTA,
pH 7.5) is pipetted into a 96-well plate containing 30 .mu.L
purified, cellular RNA. The plate is read in a CytoFluor 4000 (PE
Applied Biosystems) with excitation at 485 nm and emission at 530
nm.
Probes and primers are designed to hybridize to a human a target
sequence, using published sequence information.
EXAMPLE 33
Northern Blot Analysis of a Target mRNA Levels
Eighteen hours after treatment, cell monolayers were washed twice
with cold PBS and lysed in 1 mL RNAZOL.TM. (TEL-TEST "B" Inc.,
Friendswood, Tex.). Total RNA was prepared following manufacturer's
recommended protocols. Twenty micrograms of total RNA was
fractionated by electrophoresis through 1.2% agarose gels
containing 1.1% formaldehyde using a MOPS buffer system (AMRESCO,
Inc. Solon, Ohio). RNA was transferred from the gel to
HYBOND.TM.-N+nylon membranes (Amersham Pharmacia Biotech,
Piscataway, N.J.) by overnight capillary transfer using a
Northern/Southern Transfer buffer system (TEL-TEST "B" Inc.,
Friendswood, Tex.). RNA transfer was confirmed by UV visualization.
Membranes were fixed by UV cross-linking using a STRATALINKER.TM.
UV Crosslinker 2400 (Stratagene, Inc, La Jolla, Calif.) and then
probed using QUICKHYB.TM. hybridization solution (Stratagene, La
Jolla, Calif.) using manufacturer's recommendations for stringent
conditions.
To detect human a target, a human a target specific primer probe
set is prepared by PCR To normalize for variations in loading and
transfer efficiency membranes are stripped and probed for human
glyceraldehyde-3-phosphate dehydrogenase (GAPDH) RNA (Clontech,
Palo Alto, Calif.).
Hybridized membranes were visualized and quantitated using a
PHOSPHORIMAGER.TM. and IMAGEQUANT.TM. Software V3.3 (Molecular
Dynamics, Sunnyvale, Calif.). Data was normalized to GAPDH levels
in untreated controls.
EXAMPLE 34
Inhibition of Human a Target Expression by Oligonucleotides
In accordance with the present invention, a series of oligomeric
compounds are designed to target different regions of the human
target RNA. The oligomeric compounds are analyzed for their effect
on human target mRNA levels by quantitative real-time PCR as
described in other examples herein. Data are averages from three
experiments. The target regions to which these preferred sequences
are complementary are herein referred to as "preferred target
segments" and are therefore preferred for targeting by oligomeric
compounds of the present invention. The sequences represent the
reverse complement of the preferred antisense oligomeric
compounds.
As these "preferred target segments" have been found by
experimentation to be open to, and accessible for, hybridization
with the antisense oligomeric compounds of the present invention,
one of skill in the art will recognize or be able to ascertain,
using no more than routine experimentation, further embodiments of
the invention that encompass other oligomeric compounds that
specifically hybridize to these preferred target segments and
consequently inhibit the expression of a target.
According to the present invention, antisense oligomeric compounds
include antisense oligomeric compounds, antisense oligonucleotides,
ribozymes, external guide sequence (EGS) oligonucleotides,
alternate splicers, primers, probes, and other short oligomeric
compounds that hybridize to at least a portion of the target
nucleic acid.
EXAMPLE 35
Western Blot Analysis of a Target Protein Levels
Western blot analysis (immunoblot analysis) is carried out using
standard methods. Cells are harvested 16-20 h after oligonucleotide
treatment, washed once with PBS, suspended in Laemmli buffer (100
ul/well), boiled for 5 minutes and loaded on a 16% SDS-PAGE gel.
Gels are run for 1.5 hours at 150 V, and transferred to membrane
for western blotting. Appropriate primary antibody directed to a
target is used, with a radiolabeled or fluorescently labeled
secondary antibody directed against the primary antibody species.
Bands are visualized using a PHOSPHORIMAGER.TM. (Molecular
Dynamics, Sunnyvale Calif.).
EXAMPLE 36
Blockmer Walk of 5 2'-O-Methy Modified Nucleosides in the Antisense
Strand of siRNA's Assayed for PTEN mRNA Levels Against Untreated
Control
The antisense (AS) strands listed below having SEQ ID NO: 8 were
individually duplexed with the sense (S) strand having SEQ ID NO: 7
and the activity was measured to determine the relative positional
effect of the 5 modifications.
TABLE-US-00004 SEQ ID NO:/ISIS NO Sequence 7/271790 (S)
5'-CAAAUCCAGAGGCUAGCAG-dTdT-3' 8/271071 (AS)
3'-dTdT-GUUUAGGUCUCCGAUCGUC-5' 8/271072 (AS)
3'-dTdT-GUUUAGGUCUCCGAUCGUC-5' 8/271073 (AS)
3'-dTdT-GUUUAGGUCUCCGAUCGUC-5' 8/271074 (AS)
3'-dTdT-GUUUAGGUCUCCGAUCGUC-5' 8/271075 (AS)
3'-dTdT-GUUUAGGUCUCCGAUCGUC-5'
Underlined nucleosides are 2'-O-methyl modified nucleosides, dT's
are deoxy thymidines, all other nucleosides are ribonucleosides and
all internucleoside linkages are phosphodiester.
The siRNA's having 5, 2'-O-methyl groups at least 2 positions
removed from the 5'-end of the antisense strand reduced PTEN mRNA
levels to from 25 to 35% of untreated control. The remaining 2
constructs increased PTEN mRNA levels above untreated control.
EXAMPLE 37
Solid Block of 2'-O-Methyl Modified Nucleosides in the Antisense
Strand of siRNA's Assayed for PTEN mRNA Levels Against Untreated
Control
The antisense strands listed below having SEQ ID NO:9 were
individually duplexed with the sense strand having SEQ ID NO:7 and
the activity was measured to determine the relative effect of
adding either 9 or 14, 2'-O-methyl modified nucleosides at the
3'-end of the resulting siRNA's.
TABLE-US-00005 SEQ ID NO:/ISIS NO Sequence 7/271790 (S)
5'-CAAAUCCAGAGGCUAGCAG-dTdT-3' 9/271079 (AS)
3'-UUGUUUAGGUCUCCGAUCGUC-5' 9/271081 (AS)
3'-UUGUUUAGGUCUCCGAUCGUC-5'
Underlined nucleosides are 2'-O-methyl modified nucleosides, dT's
are deoxy thymidines, all other nucleosides are ribonucleosides and
all internucleoside linkages are phosphodiester.
TABLE-US-00006 SEQ ID NO: Sequence (5'-3') 9
CUGCUAGCCUCUGGAUUUGUU
The siRNA having 9, 2'-O-methyl nucleosides reduced PTEN mRNA
levels to about 40% of untreated control whereas the construct
having 14, 2'-O-methyl nucleosides only reduced PTEN mRNA levels to
about 98% of control.
EXAMPLE 38
2'-O-Methy Blockmers (siRNA Vs asRNA)
A series of blockmers were prepared as duplexed siRNA's and also as
single strand asRNA's. The antisense strands were identical for the
siRNA's and the asRNA's.
TABLE-US-00007 SEQ ID NO:/ ISIS NO Sequence 5'-3' 10/308746 (S)
5'-AAGUAAGGACCAGAGACAAA-3' (PO) 11/303912 (AS)
3'-UUCAUUCCUGGUCUCUGUUU-P 5' (PS) 11/316449 (AS)
3'-UUCAUUCCUGGUCUCUGUUU-P 5' (PS) 11/335223 (AS)
3'-UUCAUUCCUGGUCUCUGUUU-P 5' (PS) 11/335224 (AS)
3'-UUCAUUCCUGGUCUCUGUUU-P 5' (PS) 11/335225 (AS)
3'-UUCAUUCCUGGUCUCUGUUU-P 5' (PS) 11/335226 (AS)
3'-UUCAUUCCUGGUCUCUGUUU-P 5' (PS) 11/335227 (AS)
3'-UUCAUUCCUGGUCUCUGUUU-P 5' (PS) 11/335228 (AS)
3'-UUCAUUCCUGGUCUCUGUUU-P 5' (PS)
Underlined nucleosides are 2'-O-methyl modified nucleosides, all
other nucleosides are ribonucleosides and all internucleoside
linkages for the AS strands are phosphorothioate and the
internucleoside linkages for the S strand are phosphodiester.
TABLE-US-00008 SEQ ID NO: Sequence (5'-3') 10 AAGUAAGGACCAGAGACAAA
11 UUUGUCUCUGGUCCUUACUU
The constructs were assayed for activity for measuring the levels
of PTEN mRNA in T24 cells against untreated control levels. All of
the asRNA's and siRNA's showed activity with the asRNA's having the
best activity in each case. A clear dose response was seen for all
the siRNA constructs (20, 40, 80 and 150 nm doses). There was a
good dose response for the asRNA's for 50, 100 and 200 nm doses. In
general the siRNA's were more active in this system at lower doses
than the asRNA's and at the 150 nm dose was able to reduce PTEN
mRNA levels to from 15 to 40% of untreated control. The unmodified
siRNA 303912 reduced PTEN mRNA levels to about 19% of the untreated
control.
EXAMPLE 39
3'-Hemimer 2'-O-Methyl siRNA Constructs
Blunt and overhanging siRNA constructs were prepared having a block
of 5, 2'-O-methyl nucleosides at the 3'-terminus.
TABLE-US-00009 SEQ ID NO:/ISIS NO Sequence (overhangs) 7/271790 (S)
5'-CAAAUCCAGAGGCUAGCAG-dTdT-3' 9/xxxxxx (AS)
3'-UUGUUUAGGUCUCCGAUCGUC-5' SEQ ID NO:/ISIS NO Sequence (blunt)
12/xxxxx (S) 5'-GUCAAAUCCAGAGGCUAGCAG-3' 13/xxxxxx (AS)
3'-CAGUUUAGGUCUCCGAUCGUC-5'
Underlined nucleosides are 2'-O-methyl modified nucleosides, all
other nucleosides are ribonucleosides and all internucleoside
linkages for the AS strands are phosphorothioate and the
internucleoside linkages for the S strand are phosphodiester.
TABLE-US-00010 SEQ ID NO: Sequence (5'-3') 12 GUCAAAUCCAGAGGCUAGCAG
13 CUGCUAGCCUCUGGAUUUGAC
The construct having overhangs was able to reduce PTEN mRNA levels
to about 36% of untreated control whereas the blunt ended construct
was able to reduce the PTEN mRNA levels to about 27% of untreated
control.
EXAMPLE 40
siRNA Hemimer Constructs
Three siRNA hemimer constructs were prepared and examined in a PTEN
assay. The hemimer constructs had 7, 2'-O-methyl nucleosides at the
3'-end. The hemimer was put in the sense strand only, the antisense
strand only and in both strands to compare the effects.
TABLE-US-00011 SEQ ID NO:/ISIS NO Constructs (overhangs) 14/271068
(S) 5'-CAAAUCCAGAGGCUAGCAGUU-3' 9/(AS) 3'-UUGUUUAGGUCUCCGAUCGUC-5'
14/271068 (S) 5'-CAAAUCCAGAGGCUAGCAGUU-3' 9/(AS)
3'-UUGUUUAGGUCUCCGAUCGUC-5' 14/(S) 5'-CAAAUCCAGAGGCUAGCAGUU-3'
9/(AS) 3'-UUGUUUAGGUCUCCGAUCGUC-5'
Underlined nucleosides are 2'-O-methyl modified nucleosides, all
other nucleosides are ribonucleosides and all internucleoside
linkages for the AS strands are phosphorothioate and the
internucleoside linkages for the S strand are phosphodiester.
TABLE-US-00012 SEQ ID NO: Sequence (5'-3') 14
CAAAUCCAGAGGCUAGCAGUU
The construct having the 7, 2'-O-methyl nucleosides only in the
antisense strand reduced PTEN mRNA levels to about 23% of untreated
control. The construct having the 7, 2'-O-methyl nucleosides in
both strands reduced the PTEN mRNA levels to about 25% of untreated
control. When the 7, 2'-O-methyl nucleosides were only in the sense
strand PTEN mRNA levels were reduced to about 31% of untreated
control.
EXAMPLE 41
siRNA Vs asRNA Hemimers
Four hemimers were prepared and assayed as the asRNA's and also as
the siRNA's in a PTEN assay. The unmodified sequence was also
tested as the asRNA and as the siRNA.
TABLE-US-00013 SEQ ID NO:/ISIS NO Constructs (overhangs) 10/308746
(S) 5'-AAGUAAGGACCAGAGACAAA-3' 11/303912 (AS)
3'-UUCAUUCCUGGUCUCUGUUU-P 5' 11/316449 (AS)
3'-UUCAUUCCUGGUCUCUGUUU-P 5' 11/319013 (AS)
3'-UUCAUUCCUGGUCUCUGUUU-P 5' 11/319014 (AS)
3'-UUCAUUCCUGGUCUCUGUUU-P 5' 11/319015 (AS)
3'-UUCAUUCCUGGUCUCUGUUU-P 5'
Underlined nucleosides are 2'-O-methyl modified nucleosides, all
other nucleosides are ribonucleosides and all internucleoside
linkages for the AS strands are phosphorothioate and the
internucleoside linkages for the S strand are phosphodiester.
TABLE-US-00014 Construct siRNA (% mRNA) asRNA (% mRNA) 11/303912 21
32 11/316449 17 26 11/319013 34 32 11/319014 54 42 11/319015 51
42
Percent mRNA is relative to untreated control in PTEN assay.
EXAMPLE 42
Representative siRNA's Prepared Having 2'O-Me Gapmers
The following antisense strands of siRNA's were hybridized to the
complementary full phosphodiester sense strand. Bolded monomers are
2'-OCH.sub.3 (also referred to as 2'-OMe) containing monomers.
Underlined monomers have PS linkages. Monomers without underlines
have PO linkages.
TABLE-US-00015 SEQ ID NO/ ISIS NO 15/300852 5'-OH-CUG CUA GCC UCU
GGA UUU GA (OMe/PO) 15/300853 5'-P-CUG CUA GCC UCU GGA UUU GA
(OMe/PO) 15/300854 5'-OH-CUG CUA GCC UCU GGA UUU GA (OMe/PO)
15/300855 5'-P-CUG CUA GCC UCU GGA UUU GA (OMe/PO/ PS) 16/300856
5'OH-CUA GCC UCU GGA UUU GA (OMe/PO/ PS) 15/300858 5'-OH-CUG CUA
GCC UCU GGA UUU GA (OMe/PS) 15/300859 5'-P-CUG CUA GCC UCU GGA UUU
GA (OMe/PS) 16/300860 5'-OH-CUA GCC UCU GGA UUU GA (OMe/PS)
17/303913 5'-OH-GUC UCU GGU CCU UAC UU (OMe/PS) 18/303915 5'-OH-UUU
UGU CUC UGG UCC UU (OMe/PS) 19/303917 5'-OH-CUG GUC CUU ACU UCC CC
(OMe/PS) 20/308743 5'P-UUU GUC UCU GGU CCU UAC UU (OMe/PS)
21/308744 5'-P-UCU CUG GUC CUU ACU UCC CC (OMe/PS) 22/328795
5'-P-UUU GUC UCU GGU CCU UAC UU (OMe/PS)
Example 43
Representative siRNA's Prepared Having 2'-O-Methyl Modified
Nucleosides
The following antisense strands of siRNA's were hybridized to the
complementary full phosphodiester sense strand. Where the antisense
strand has a TT 3'-terminus the corresponding sense strand also has
a 3'-TT (deoxyT's)
TABLE-US-00016 SEQ ID NO./ ISIS NO. 23/271065 CUG CUA GCC UCU GGA
UUU GTT PO 24/271067 CUG CUA GCC UCU GGA UUU GUU PO 25/271069 CUG
CUA GCC UCU GGA UUU GUT PO 23/271071 CUG CUA GCC UCU GGA UUU GTT PO
23/271072 CUG CUA GCC UCU GGA UUU GTT PO 23/271073 CUG CUA GCC UCU
GGA UUU GTT PO 23/271074 CUG CUA GCC UCU GGA UUU GTT PO 23/271075
CUG CUA GCC UCU GGA UUU GTT PO 23/271076 CUG CUA GCC UCU GGA UUU
GTT PO 23/271077 CUG CUA GCC UCU GGA UUU GTT PO 23/271078 CUG CUA
GCC UCU GGA UUU GTT PO 24/271079 CUG CUA GCC UCU GGA UUU GUU PO
25/271081 CUG CUA GCC TCT GGA TTT GUU PO 26/271082 CUG CUA GCC UCU
GGA UUU GAC PO/PS 25/271083 CUG CUA GCC UCU GGA UUU GUU PO/PS
23/271084 CUG CUA GCC UCU GGA UUU GTT PO 23/283547 CUG CUA GCC UCU
GGA UUU GTT PO 23/293999 CUG CUA GCC UCU GGA UUU GTT PO 23/294000
CUG CUA GCC UCU GGA UUU GTT PO 23/290223 CUG CUA GCC UCU GGA UUU
GTT PO
EXAMPLE 44
Representative siRNA's Prepared Having 2'-F and 2'-OCH.sub.3
Monomers
The following antisense strands of siRNA's were hybridized to the
complementary full phosphodiester sense strand. Where the antisense
strand has a TT 3'-terminus the corresponding sense strand also has
a 3'-TT (deoxyT's). Bolded monomers are 2'-F containing monomers.
Underlined monomers are 2'-OCH.sub.3. Monomers that are not bolded
or underlined do not contain a sugar surrogate. Linkages are shown
in the parenthesis after the sequence.
TABLE-US-00017 SEQ ID NO./ISIS NO. Composition (5' 3') Features
27/283546 CUG CUA GCC UCU GGA UUU GU.dT-3' (OMe/F/PO) 28/336240 UUU
GUC UCU GGU CCU UAC UU (OMe/F/PS)
SEQUENCE LISTINGS
1
28119DNAArtificial sequenceSynthetic oligonucleotide 1cgagaggcgg
acgggaccg 19221DNAArtificial sequenceSynthetic oligonucleotide
2cgagaggcgg acgggaccgt t 21321DNAArtificial sequenceSynthetic
oligonucleotide 3cggtcccgtc cgcctctcgt t 21420DNAArtificial
sequenceSynthetic oligonucleotide 4tccgtcatcg ctcctcaggg
20520DNAArtificial sequenceSynthetic oligonucleotide 5gtgcgcgcga
gcccgaaatc 20620DNAArtificial sequenceSynthetic oligonucleotide
6atgcattctg cccccaagga 20721DNAArtificial sequenceSynthetic
oligonucleotidemisc_feature(1)..(19)bases at these positions are
RNA 7caaauccaga ggcuagcagt t 21821DNAArtificial sequenceSynthetic
oligonucleotidemisc_feature(1)..(19)bases at these positions are
RNA 8cugcuagccu cuggauuugt t 21921RNAArtificial sequenceSynthetic
oligonucleotide 9cugcuagccu cuggauuugu u 211020RNAArtificial
sequenceSynthetic oligonucleotide 10aaguaaggac cagagacaaa
201120RNAArtificial sequenceSynthetic oligonucleotide 11uuugucucug
guccuuacuu 201221RNAArtificial sequenceSynthetic oligonucleotide
12gucaaaucca gaggcuagca g 211321RNAArtificial sequenceSynthetic
oligonucleotide 13cugcuagccu cuggauuuga c 211421RNAArtificial
sequenceSynthetic oligonucleotide 14caaauccaga ggcuagcagu u
211520RNAArtificial sequenceSynthetic oligonucleotide 15cugcuagccu
cuggauuuga 201617RNAArtificial sequenceSynthetic oligonucleotide
16cuagccucug gauuuga 171717RNAArtificial sequenceSynthetic
oligonucleotide 17gucucugguc cuuacuu 171817RNAArtificial
sequenceSynthetic oligonucleotide 18uuuugucucu gguccuu
171917RNAArtificial sequenceSynthetic oligonucleotide 19cugguccuua
cuucccc 172020RNAArtificial sequenceSynthetic oligonucleotide
20uuugucucug guccuuacuu 202120RNAArtificial sequenceSynthetic
oligonucleotide 21ucucuggucc uuacuucccc 202220RNAArtificial
sequenceSynthetic oligonucleotide 22uuugucucug guccuuacuu
202321DNAArtificial sequenceSynthetic
oligonucleotidemisc_feature(1)..(19)bases at these positions are
RNA 23cugcuagccu cuggauuugt t 212421RNAArtificial sequenceSynthetic
oligonucleotide 24cugcuagccu cuggauuugu u 212521DNAArtificial
sequenceSynthetic oligonucleotidemisc_feature(1)..(20)bases at
these positions are RNA 25cugcuagccu cuggauuugu t
212621RNAArtificial sequenceSynthetic oligonucleotide 26cugcuagccu
cuggauuuga c 212721DNAArtificial sequenceSynthetic
oligonucleotidemisc_feature(1)..(20)bases at these positions are
RNA 27cugcuagccu cuggauuugu t 212820RNAArtificial sequenceSynthetic
oligonucleotide 28uuugucucug guccuuacuu 20
* * * * *