U.S. patent application number 14/801155 was filed with the patent office on 2016-06-16 for assay methods for the determination of fkbpl expression level in the context of breast cancer.
This patent application is currently assigned to THE QUEEN'S UNIVERSITY OF BELFAST. The applicant listed for this patent is THE QUEEN'S UNIVERSITY OF BELFAST. Invention is credited to Christopher Byrne, David Hirst, Hayley McKeen, Tracy ROBSON.
Application Number | 20160169897 14/801155 |
Document ID | / |
Family ID | 40834224 |
Filed Date | 2016-06-16 |
United States Patent
Application |
20160169897 |
Kind Code |
A1 |
ROBSON; Tracy ; et
al. |
June 16, 2016 |
ASSAY METHODS FOR THE DETERMINATION OF FKBPL EXPRESSION LEVEL IN
THE CONTEXT OF BREAST CANCER
Abstract
Disclosed are methods that employ FKBPL as a marker for a
subject's sensitivity to endocrine therapies in the treatment of
cancers, and as a predictive marker of cancer progression and
disease free survival in relation to hormone responsive
cancers.
Inventors: |
ROBSON; Tracy; (Belfast,
GB) ; Hirst; David; (Belfast, GB) ; McKeen;
Hayley; (Carrickfergus, GB) ; Byrne; Christopher;
(Lifford, IE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
THE QUEEN'S UNIVERSITY OF BELFAST |
Belfast |
|
GB |
|
|
Assignee: |
THE QUEEN'S UNIVERSITY OF
BELFAST
Belfast
GB
|
Family ID: |
40834224 |
Appl. No.: |
14/801155 |
Filed: |
July 16, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13265223 |
Nov 30, 2011 |
9110063 |
|
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PCT/GB2010/050819 |
May 19, 2010 |
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14801155 |
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Current U.S.
Class: |
506/9 ; 435/6.11;
435/6.12; 435/6.14; 435/7.1; 435/7.92 |
Current CPC
Class: |
G01N 33/573 20130101;
A61P 35/00 20180101; C12Q 2600/118 20130101; C12Q 2600/136
20130101; C12Q 1/6886 20130101; G01N 33/57415 20130101; C12Q
2600/158 20130101; G01N 2333/99 20130101; C12Q 2600/106
20130101 |
International
Class: |
G01N 33/574 20060101
G01N033/574; C12Q 1/68 20060101 C12Q001/68 |
Foreign Application Data
Date |
Code |
Application Number |
May 19, 2009 |
GB |
0908589.5 |
Claims
1. A method of characterising a cancer tissue comprising
determining in a test biological sample an expression level of at
least one of FKBPL, a FKBPL variant, and a fragment FKBPL or an
FKBPL variant; comparing the determined level of FKBPL to a control
standard or the expression of FKBPL, or a FKBPL variant or a
fragment thereof in a control sample; determining whether there is
a differential expression of FKBPL in the sample as compared to the
control standard or the expression of FKBPL in a control sample;
and characterising the cancer tissue, wherein characterising the
cancer tissue is the determination as to whether an agent, which
selectively modulates an oestrogen receptor present in a cancer
tissue or lowers the circulating levels of oestrogen in a cancer
tissue will decrease the progression of the cancer, or the
likelihood of the subject including the cancer tissue to have
cancer disease free survival.
2. The method as claimed in any of claim 1 wherein determining the
expression level of FKBPL comprises measuring the level of an
expression product of a FKBPL encoding gene.
3. The method of claim 2 wherein the expression product is mRNA or
a protein.
Description
FIELD OF INVENTION
[0001] The present invention relates to the use of FKBPL as a
biomarker for making cancer treatment decisions and also as a
predictive marker of cancer progression and disease free survival
in relation to hormone responsive cancers, for example ovarian
cancer, endometrial cancer, breast cancer and prostate cancer.
BACKGROUND OF THE INVENTION
[0002] Breast cancer is by far the most common cancer among women
with around 1 million women worldwide being diagnosed with the
disease each year. In the UK alone around 45,500 women are
diagnosed with breast cancer annually.
[0003] Currently all breast cancer patients are assessed for
oestrogen receptor (ER) and progesterone receptor (PR) status to
determine the suitability of respective patients for endocrine or
hormonal therapy. Endocrine or hormonal therapies are agents used
to treat women with breast cancer who have hormone receptors on
their breast cancer cells which allow the binding of hormone and
include anti-oestrogens, for example tamoxifen and fulvestrant, and
aromatase inhibitors which act to reduce the level of female
hormones in the body.
[0004] Tamoxifen is typically provided to all oestrogen receptor
positive (ER+) patients. However, only around 60% of these patients
show a response to tamoxifen, with up to 40% of ER+ tumours failing
to respond to or developing resistance to tamoxifen (non-responder
subjects).
[0005] As tamoxifen is known to increase the risk of endometrial
cancer, the provision of tamoxifen to subjects with non-responding
tumours (non-responder subjects) needlessly increases the risk of
these subjects to the risk of developing endometrial cancer.
[0006] Presently, a number of gene array panels are used to try and
predict the probability of disease recurrence and determine the
most suitable treatment for patients. One such gene panel is known
as Oncotype DX. This gene panel cannot be used to select women for
tamoxifen therapy. It only predicts recurrence in patients treated
with tamoxifen and whether they would be likely to benefit from
adjuvant chemotherapy. The assay requires formalin-fixed paraffin
embedded (FFPE) tissue. A further panel known as the MammaPrint
measures breast cancer recurrence independent of treatment. This
panel requires fresh tissue composed of a minimum of 30% malignant
cells.
[0007] Oncotype DX measures RNA levels of 21 genes (16 cancer genes
and 5 reference genes) which demonstrate a consistent statistical
link to distant breast cancer recurrence, as well as robust
predictive power regarding chemotherapy benefit. MammaPrint
measures RNA levels of 70 genes that are considered most
informative regarding likelihood of tumour recurrence. Both these
assays require expensive, sophisticated equipment.
[0008] Accurate prediction of a subject's response to endocrine
therapy, would prevent potential non responders being treated with
potentially harmful drugs when these may not provide a therapeutic
benefit. In addition the determination of those cancer patients
which would benefit from endocrine therapy, such as tamoxifen
therapy, would allow targetting of such drug regimens and thus may
provide for a reduction of healthcare budgets.
[0009] Furthermore, the ability to make predictions about cancer
progression/disease free survival would enable the design of
specific treatment strategies to prevent for example, metastasis
following surgery and chemotherapy/endocrine therapy.
SUMMARY OF INVENTION
[0010] The present inventors have determined that FKBPL can provide
an indication of patient response to endocrine therapies in
addition to being a predictive marker of cancer progression and
disease free survival.
[0011] FKBPL is an immunophilin-like protein that plays a role in
the cellular stress response and includes three tetratricolpeptide
repeat (TPR) motifs which are homologous to the Hsp90 interaction
sites of other immunophilins that have roles in steroid hormone
receptor signalling.
[0012] Accordingly, a first aspect of the present invention
provides a method of characterising a cancer tissue,
comprising:
[0013] determining in a test tissue sample an expression level of
at least FKBPL, a variant of FKBPL, or a fragment of FKBPL or a
variant of FKBPL, comparing the determined level with a control
standard or the expression of FKBPL in a control sample;
[0014] wherein differential expression of FKBPL, in the test tissue
sample, as compared to the control standard or the expression of
FKBPL in a control sample, is indicative of the character of the
cancer tissue.
[0015] Preferably, the gene encoding FKBPL (FK506 binding protein
like) is FK506 protein like, as defined by Genbank Accession number
AF139374, and Genbank Accession number AF139374.1 as disclosed by
Robson et al. (1997) Gene regulation by low dose ionizing radiation
in a normal human lung epithelial cell line, Biochem. Soc. Trans.
25(1), 335-342.
[0016] Optionally, the method may further comprise obtaining a
biological sample from a subject.
[0017] FKBPL can be encoded by the nucleotide sequence
[0018] Accesion number NM_022110
TABLE-US-00001 (SEQ ID NO 1) atggagacgc caccagtcaa
tacaattggagaaaaggaca cctctcagcc gcaacaagag tgggaaaaga accttcggga
gaaccttgattcagttattc agattaggca gcagccccga gaccctccta ccgaaacgct
tgagctggaagtaagcccag atccagccag ccaaattcta gagcatactc aaggagctga
aaaactggttgctgaacttg aaggagactc tcataagtct catggatcaa ccagtcagat
gccagaggcccttcaagctt ctgatctctg gtactgcccc gatgggagct ttgtcaagaa
gatcgtaatccgtggccatg gcttggacaa acccaaacta ggctcctgct gccgggtact
ggctttggggtttcctttcg gatcagggcc gccagagggc tggacagagc taactatggg
cgtagggccatggagggagg aaacttgggg ggagctcata gagaaatgct tggagtccat
gtgtcaaggtgaggaagcag agcttcagct gcctgggcac tctggacctc ctgtcaggct
cacactggcatccttcactc aaggccgaga ctcctgggag ctggagacta gcgagaagga
agccctggccagggaagaac gtgcaagggg cacagaacta tttcgagctg ggaaccctga
aggagctgcccgatgctatg gacgggctct tcggctgctc ctgactttac ccccacctgg
ccctccagaacgaactgtcc ttcatgccaa tctggctgcc tgtcagttgt tgctagggca
gcctcagttggcagcccaga gctgtgaccg ggtgttggag cgggagcctg gccatttaaa
ggccttataccgaagggggg ttgcccaggc tgcccttggg aacctggaaa aagcaactgc
tgacctcaagaaggtgctgg cgatagatcc caaaaaccgg gcagcccagg aggaactggg
gaaggtggtcattcagggga agaaccagga tgcagggctg gctcagggtc tgcgcaagat
gtttggctgattaaaagtta aaccttaaaa gagaaaaaaa aaaaaaa,
[0019] and can have the amino acid sequence
TABLE-US-00002 (SEQ ID NO 2)
METPPVNTIGEKDTSQPQQEWEKNLRENLDSVIQIRQQPRDPPTETLELE
VSPDPASQILEHTQGAEKLVAELEGDSHKSHGSTSQMPEALQASDLWYCP
DGSFVKKIVIRGHGLDKPKLGSCCRVLALGFPFGSGPPEGWTELTMGVGP
WREETWGELIEKCLESMCQGEEAELQLPGHSGPPVRLTLASFTQGRDSWE
LETSEKEALAREERARGTELFRAGNPEGAARCYGRALRLLLTLPPPGPPE
RTVLHANLAACQLLLGQPQLAAQSCDRVLEREPGHLKALYRRGVAQAALG
NLEKATADLKKVLAIDPKNRAAQEELGKWIQGKNQDAGLAQGLRKMFG or be a variant or
fragment thereof.
[0020] A FKBPL variant may be encoded by a nucleic acid seqence
comprising
TABLE-US-00003 (SEQ ID No 3) atggagacgc caccagtcaa
tacaattggagaaaaggaca cctctcagcc gcaacaagag tgggaaaaga accttcggga
gaaccttgattcagttattc agattaggca gcagccccga gaccctccta ccgaaacgct
tgagctggaagtaagcccag atccagccag ccaaattcta gagcatactc aaggagctga
aaaactggttgctgaacttg aaggagactc tcataagtct catggatcaa ccagtcagat
gccagaggcccttcaagctt ctgatctctg gtactgcccc gatgggagct ttgtcaagaa
gatcgtaatccgtggccatg gcttggacaa acccaaacta ggctcctgct gccgggtact
ggctttggggtttcctttcg gatcagggcc gccagagggc tggacagagc taactatggg
cgtagggccatggagggagg aaacttgggg ggagctcata gagaaatgct tggagtccat
gtgtcaaggtgaggaagcag agcttcagct gcctgggcac actggacctc ctgtcgggct
cacactggcatccttcactc aaggccgaga ctcctgggag ctggagacta gcgagaagga
agccctggccagggaagaac gtgcaagggg cacagaacta tttcgagctg ggaaccctga
aggagctgcccgatgctatg gacgggctct tcggctgctc ctgactttac ccccacctgg
ccctccagaacgaactgtcc ttcatgccaa tctggctgcc tgtcagttgt tgctagggca
gcctcagttggcagcccaga gctgtgaccg ggtgttggag cgggagcctg gccatttaaa
ggccttataccgaagggggg ttgcccaggc tgcccttggg aacctggaaa aagcaactgc
tgacctcaagaaggtgctgg cgatagatcc caaaaaccgg gcagcccagg aggaactggg
gaaggtggtcattcagggga agaaccagga tgcagggctg gctcagggtc tgcgcaagat
gtttggctgattaaaagtta aaccttaaaa gagaaaaaaa aaaaaaa
[0021] and have the amino acid sequence
TABLE-US-00004 (SEQ ID No 4)
METPPVNTIGEKDTSQPQQEWEKNLRENLDSVIQIRQQPRDPPTETLEL
EVSPDPASQILEHTQGAEKLVAELEGDSHKSHGSTSQMPEALQASDLWY
CPDGSFVKKIVIRGHGLDKPKLGSCCRVLALGFPFGSGPPEGWTELTMG
VGPWREETWGELIEKCLESMCQGEEAELQLPGHTGPPVGLTLASFTQGR
DSWELETSEKEALAREERARGTELFRAGNPEGAARCYGRALRLLLTLPP
PGPPERTVLHANLAACQLLLGQPQLAAQSCDRVLEREPGHLKALYRRGV
AQAALGNLEKATADLKKVLAIDPKNRAAQEELGKVVIQGKNQDAGLAQG LRKMFG.
[0022] In particular, the present inventors have determined that
oestrogen receptor positive (ER+) tumour cells or cancers which
stably express FKBPL have the character that they are highly
sensitive to anti-oestrogen agents, for example tamoxifen and
fulvestrant. In support of this work, the inventors have determined
that siRNA knock-down of FKBPL dramatically increased the
resistance of ER+ cells to tamoxifen and suggests that FKBPL level
could predict cancer progression and disease free survival.
[0023] By differential expression it is meant that following
detection of FKBPL in the test tissue sample and the control
sample, the level of FKBPL in a sample can be scored for example 0
(no detectable FKBPL), 1 (low detectable level of FKBPL), 2 (medium
detectable level of FKBPL), 3 (High detectable level of FKBPL) and
then the level detected between the test sample and the control
sample compared. Detection may be by, for example, staining
following suitable immunohistochemistry for FKBPL. Alternatively,
detection may allow quantitative measurement of FKBPL in a test
sample and a control sample. In embodiments, FKBPL levels could be
assessed before treatment with any agent and the levels of FKBPL at
that point scored as either 0, 1, 2, 3. These values could then be
used to predict response to either ER modulating drugs,
chemotherapy/radiation or new drugs. In embodiments it would not be
required to re-evaluate FKBPL levels after each treatment to
determine whether a patient would respond.
[0024] By highly sensitive is meant a tumour cell which is greater
than 80%, more preferably greater than 85%, more preferably greater
than 90%, more preferably greater than 95%, even more preferably
greater than 99% more likely to be inhibited from proliferating
(responsive to treatment) following treatment of the tumour cell
with a hormonal or anti-oestrogen agent than a tumour cell which
expresses reduced levels of FKBPL. With respect to cancer, cancer
which is highly sensitive is meant a cancer is greater than 80%,
preferably greater than 85% preferably greater than 90%, more
preferably greater than 98% and even more preferably greater that
99% more likely to be inhibited following treatment of the cancer
subject than a cancer subject with a cancer which exhibits reduced
levels of FKBPL. Cancer is inhibited if at least one symptom of the
cancer is alleviated, terminated, slowed down or prevented. As used
herein, cancer is also inhibited if recurrence or metastasis of the
cancer is reduced, slowed, delayed or prevented.
[0025] In embodiments of the invention, anti-oestrogen agents can
be selected from selective oestrogen receptor modulators, selective
oestrogen receptor downregulators or aromatase inhibitors. Examples
of such inhibitors are provided at Table 1. ER+ cells will
typically respond to tamoxifen, but the presence of increased FKBPL
levels in comparison to a control in combination with ER+ causes a
dramatic additional increase in the sensitivity of the tumour cell
or cancer to such endocrine drugs. Examples of endocrine drugs
which can be provided in table 1.
TABLE-US-00005 TABLE 1 Examples of Drug Types Class of Drug
Mechanism of Action (Commercial Name) Selective Estrogen Binds ER
to prevent Tamoxifen (Nolvadex) Receptor Modulator oestrogen
binding its Raloxifene (Evista) (SERM) receptor thereby inhibiting
Toremifene (Fareston) ER signalling Selective Estrogen Binds ER to
prevent Fulvestrant (Faslodex) Receptor oestrogen binding its
Downregulator receptor thereby inhibiting (SERD). ER signalling.
Degrades ER Aromatase Inhibits synthesis of Anastrozole Inhibitors
oestrogen by blocking (Arimidex) action of aromatase enzyme
Exemestane which normally converts (Aromasin) androgen to oestrogen
Letrozole (Femara)
[0026] In embodiments, the cancer tissue may be characterised by
considering the expression level of FKBPL in combination with the
expression level of at least one additional biomarker, for example
oestrogen receptor. In embodiments of the method, FKBPL, as a
predictor of anti-oestrogen response, in particular tamoxifen
response or cancer progression/disease free survival can be used
along with other standard biomarkers. The markers may be selected
such that the positive predictive value of the methods of the
invention are at least about 10%, preferably about 25% more
preferably about 50% and most preferably 90%. Accordingly, in
embodiments of the method there is provided a method of determining
the level of expression of FKBPL in a tumour sample and
determination of a level of expression of at least one of oestrogen
receptor (ER) and progesterone receptor (PR).
[0027] Suitable biomarkers for use in addition to FKBPL are;
breast-associated mucin CA15-3, CA 27.29, oestrogen receptor
.alpha. and .beta., progesterone receptor, Human Epidermal growth
factor Receptor 2 (HER2), urokinase Plasminogen Activator (uPA) and
Plasminogen Activator Inhibitor-1 (PAI-1), cathepsin D, cyclin
dependent kinase inhibitor (p21), S118ER, S167ER, ADAM
metallopeptidase domain 9 (ADAMS), BCL-2, MYC, TP53, BAG-1, HOXB13,
IL17BR, the ER coactivators, SRC-1 and SRC-3 (AIB1) or the ER
corepressor, NCoR1, AKT and pAKT or XAP3. Furthermore, FKBPL could
be used in combination with some or all of the markers in the
Oncotype Dx or MammaPrint arrays. In embodiments 50 markers or less
can be used in combination with FKBPL. In alternative embodiments,
20 markers or less can be used in combination with FKBPL, in
further embodiments 10 markers or less, or 5 markers or less can be
used in combination with FKBPL.
[0028] Measuring FKBPL expression levels in combination with the
p21 and/or cathepsin D may be advantageous to increase the
specificity of any diagnostic or prognostic test of the
invention.
[0029] The inventors have determined that FKBPL increases the
phosphorylation of ER. Phosphorylation status of ER could be used
in combination with the determination of the expression level of
FKBPL to increase the specificity of a test of the invention.
[0030] In embodiments of the invention when the method is as an
indicator for disease free survival and to provide a basis for
treatment decisions, the cancer tissue can be cancer tissue from
subjects with a hormone responsive cancer, for example ovarian,
endometrial, prostate or breast cancer. In preferred embodiments
the cancer tissue can be breast cancer tissue.
[0031] In embodiments of the invention, characterising a cancer
tissue can comprise determining a prognosis of a subject with the
cancer wherein a reduced expression of FKBPL, for example a reduced
mRNA level of FKBPL, predicts for a worse outcome and
prognosis.
[0032] In another embodiment of the invention, the method of
characterising the cancer tissue sample can include a step of
predicting the ability of an agent to inhibit or decrease the
progression of the cancer. For example a cancer tissue could be
tested to determine whether an agent which selectively modulates an
oestrogen receptor present in a cancer tissue or lowers the
circulating levels of oestrogen in a cancer tissue, is able to
inhibit the cancer in a subject from which the cancer tissue being
tested.
[0033] In embodiments of the invention determining the expression
level of FKBPL comprises measuring the level of an expression
product of the FKBPL encoding gene. In embodiments of the invention
determining the expression of level of an expresssion product can
include determining the activity and/or the location of FKBPL.
Determination of the activity of FKBPL may be performed by any
means known in the art. Determining the location of FKBPL may be
performed using any means known in the art, for example tagging
FKBPL with a detectable marker and analoging the cell. As will be
understood in the art, gene expression, for example of FKBPL, is a
multistep process in which genetic information of a cell encoded in
the genome is transcribed to produce RNA, for example mRNA and the
mRNA transcript is translated to produce corresponding protein. An
increased or decreased level of FKBPL can be detected by an
increase or decrease in any expression product, for example mRNA or
protein. The expression product, such as mRNA or a protein, may be
suitably determined using, for example, an antibody or binding
fragment thereof with binding specificity to FKBPL. In embodiments
the level of expression of protein product can be determined using
an immunohistochemical (IHC) or ELISA based assay. Alternatively
mRNA levels of FKBPL can be detected using microarray analysis or
Real-time PCR. A simple IHC or ELISA test for FKBPL requiring only
formalin fixed paraffin-embedded (FFPE) tissue would be
advantageous as it could be used on its own or in combination with
an ER/PR test, making it inexpensive, and easy to integrate into
the current NHS screening system. An embodiment of the invention
can be an IHC or ELISA test for FKBPL alone to test biological
samples or tissue samples.
[0034] As FKBPL is a secreted protein, it may therefore be detected
in biological fluids.
[0035] An increase or decrease in an expression product, for
example an mRNA transcript or an FKBPL protein may be at least
about 1%, at least about 2%, at least about 5%, at least about 10%,
at least about 20%, at least about 25%, at least about 30%, at
least about 50%, at least about 75%, at least about 100% or more,
higher or lower than a control. Alternatively, the expression
product may be increased or decreased at least about 2 fold, at
least about 3 fold, at least about 5 fold, at least about 8 fold,
at least about 10 fold, at least about 20 fold, at least about 100
fold from the control. In embodiments where protein expression is
detemined by immunohistochemistry, the expression product may be
measured semi-quantitatively, for example with protein expression
levels being noted 0, 1, 2 and 3 with 0 being no detectable
increase in expression from control and 3 being the highest
detected protein expression.
[0036] In embodiments, when FKBPL is detected in a tumour cell at
an increased level relative to a control, the tumour cell can be
more sensitive to an agent which selectively modulates an oestrogen
receptor present in a cancer tissue or lowers the circulating
levels of oestrogen in a cancer tissue, for example hormonal
treatments including tamoxifen, fulvestrant and aromatase
inhibitors. In embodiments, when FKBPL is detected in a tumour cell
at an increased level relative to a control, this can be indicative
of disease free survival of a subject.
[0037] In other embodiments, FKBPL localisation i.e. within the
cytoplasm rather than the nucleus or vice versa may also affect
response to endocrine therapies and therefore effect disease free
survival. The methods of the invention may be used in predictive
medicine, to provide a diagnostic assay, prognostic assay, or a
predicitive assay to monitor neoplastic disease, in particular
hormone responsive cancer, such as, but not limited to ovarian
cancer, endometrial cancer, breast cancer and prostate cancer.
[0038] Typically in such methods a biological sample can be a blood
sample, a serum sample, or cells or tissue isolated from a subject
using standard procedures, for example a needle biopsy. Early
diagnosis allows the provision of suitable therapy to a subject and
may thus enhance the success of a therapy. A cancer cell, including
a tumour cell refers to a cell that divide at an abnormal
(increased) rate.
[0039] Further, the assay may allow determination of the likely
success of a therapy, for example as a prognostic assay to
determine the positive or negative likelihood of disease free
survival, following medical intervention or lack of intervention.
For example the method may be provided to determine the most
effective treatment or combination of treatments, for example small
molecules, agonists, antagonists, proteins and peptides, antibodies
and antibody fragments, peptidomimetics, nucleic acids,
radiotherapy, chemotherapy and the like.
[0040] According to a second aspect of the present invention there
is provided a kit for predicting the sensitivity of a tumour cell
to an agent which selectively modulates an oestrogen receptor
present in a cancer tissue or lowers the circulating levels of
oestrogen in a cancer tissue, (for example an agent may be
tamoxifen, fulvestrant or an aromatase inhibitor), the kit
comprising means for detecting in a biological sample FKBPL
expression, or expression of an FKBPL variant, or expression of a
transcript or protein of a fragment thereof.
[0041] In embodiments, the kit can be suitable for indicating
disease for survival of a subject.
[0042] A kit is any manufacture (for example a package or
container) comprising at least one reagent, for example a probe,
for example primers, or antibodies, specifically for detecting
FKBPL. The manufacture may be promoted, distributed, or sold as
units for performing the present invention. Such kits can be
conveniently used in clinical settings.
[0043] Tumour cells with an increased sensitivity to an agent which
selectively modulates an oestrogen receptor present in a cancer
tissue or lowers the circulating levels of oestrogen in a cancer
tissue reduces the ability of the cancer to progress, for example
the tumour cell to proliferate.
[0044] In embodiments of the invention, the means for detecting in
a biological sample can be an antibody with binding specificity for
FKBPL or a fragment thereof. In alternative embodiments, the means
for detecting in a biological sample can be a nucleic acid probe
with binding specificity for FKBPL. In embodiments, a nucleic acid
probe may be specific for a FKBPL gene, a FKBPL mRNA transcript, or
may be a pair of primers for amplification of a FKBPL gene or a
portion thereof.
[0045] In specific embodiments, FKBPL protein can be detected using
a first antibody with binding specificity to FKBPL. In such
embodiments, a second antibody with binding specificity to the
first antibody can be provided wherein the second antibody can be
conjugated to a detectable label, for example, an enzyme such as
horseradish peroxidase, alkaline phosphatase, and other enzymes
commonly known in the art, a fluorescent label or fluorophore,
chromophore or a radioactive label. The term antibody refers to an
immunoglobulin molecule or combinations thereof that specifically
binds to or is immunologically reactive with a particular antigen
and includes polyclonal, monoclonal, genetically engineered and
otherwise modified forms of antibodies, not limited to chimeric
antibodies, humanised antibodies, heteroconjugate antibodies (for
example bispecific antibodies, diabodies, triabodies, and
tetrabodies), single chain Fv antibodies (scFv), or polypeptides
that contain at least a portion of immunoglobulin that is
sufficient to confer specific antigen binding to the polypeptide.
Antibody fragments include proteolytic antibody fragments such as
F(ab')2 fragments, Fab' fragments, Fab'-SH fragments, Fab
fragments, FV, rIgG, recombinant antibody fragments such as sFv
fragments, dsFv fragments, bispecific sFv fragments, bispecific
dsFv fragments, complementarity determining region (CDR) fragments,
camelid antibodies and antibodies produced by cartilaginous and
bony fishes and isolated binding domains thereof. A Fab fragment is
a monvalent fragment consisting of the VL, VH, CL and CH1 domains;
a F(ab')2 fragment is a bivalent fragment comprising two Fab
fragments linked by a disulphide bridge at the hinge region, an Fd
fragment consists of the VH and CH1 domains; an FV fragment
consists of the VL and VH domains of a single arm of an antibody;
and a dAb fragment consists of a VH domain. A single chain antibody
(scFv) is an antibody in which a VL and VH region are paired to
form a monovalent molecule via a synthetic linker that enables them
to be made as a single protein chain. Diabodies are bivalent,
bispecific antibodies in which the VH and VL domains are expressed
on a single polypeptide chain, but using a linker that is too short
to allow for pairing between the two domains on the same chain,
thereby forcing the domains to pair with complementary domains of
another chain and creating two antigen binding sites. A chimeric
antibody is an antibody that contains one or more regions from one
antibody and one or more regions from one or more other antibodies.
An antibody may have one or more binding sites. If there is more
than one binding site, the binding sites may be identical to one
another or may be different. For instance, a naturally occuring
immunoglobulin has two identical binding sites, a single chain
antibody or Fab fragment has one binding site, while a bispecific
or bifunctional antibody has two different binding sites.
[0046] In embodiments, the kit can include a control sample, such
as a cell line or tissue sample known not to express FKBPL or to
express FKBPL at a certain level, in particular breast cancer cell
lines or tissues for which the expression level of FKBPL has been
previously determined. In embodiments, a suitable control cell line
can be MCF7 or T47D where the expression level of FKBPL is
known.
[0047] In some embodiments, a kit includes instructional material
disclosing, for example, means of use of a probe or an antibody
that specifically binds an FKBPL expression product, for example
mRNA transcript or protein. The instructional materials can be in
written or provided in an electronic form.
[0048] In a specific embodiment, an antibody provided in the kit or
used in the methods of the invention can be FKBPL rabbit polyclonal
primary antibody (ProteinTech, IL, USA, Cat no. 10060-1-AP)
(primary antibody). In such an embodiment anti-rabbit IgG
HRP-linked whole antibody secondary (GE Healthcare, Cat no.
NA934V), can be used to detect the primary antibody.
[0049] According to a third aspect of the present invention, there
is provided a method of treating a subject with cancer comprising
the steps: [0050] determining in a test sample an expression level
of at least FKBPL, a variant of FKBPL or a fragment of FKBPL or an
FKBPL variant, [0051] comparing this expression level of FKBPL, a
variant of FKBPL or a fragment of FKBPL or FKBPL variant to that
determined in a control standard or the expression of FKBPL, a
variant of FKBPL or a fragment of FKBPL or FKBPL variant in a
control sample,
[0052] wherein, when the expression level of FKBPL in the test
sample is increased relative to the control standard or the
expression of FKBPL in a control sample, the subject is provided
with an agent which selectively reduces the level of oestrogen
receptor present in a cancer tissue or lowers the circulating
levels of oestrogen in a cancer tissue of the subject.
[0053] According to a fourth aspect of the present invention there
is provided a method of monitoring the treatment of a subject with
cancer, comprising the steps: [0054] determining in a test sample
an expression level of at least FKBPL, or a variant thereof, or a
fragment of FKBPL or variant of FKBPL. [0055] comparing the
detected level to the expression of FKBPL in a control cancer
sample; [0056] wherein when the expression level of FKBPL is
decreased in the test sample relative to the control sample, it is
indicative that the cancer is less sensitive to an agent which
selectively modulates oestrogen receptor present in the cancer
tissues or lowers the circulating levels of oestrogen in the cancer
tissue than in the control sample.
[0057] In embodiments of a method of the invention the control
sample can be obtained from a subject prior to the onset of cancer.
In alternative embodiments the control sample can be obtained from
a subject prior to the start of a treatment regimen for the cancer.
In a further embodiment, the control sample can be provided at a
first period in time prior to the provision of the test sample at a
second period of time. The difference between the first period of
time and the second period of time can be 1 day, 2, 3, 4, 5 or 6
days, 1 week, or 2, 3, 4 weeks, at least 1 month, 2, 3, 4, 5 or at
least 6 months. Suitably a cancer treatment regimen can be a first,
second, third or more cancer treatment regimen provided to a
subject.
[0058] When the level of FKBPL is increased in the test sample from
the level detected in a control sample, it is indicative that the
tumour is more sensitive to anti-oestrogen therapy, for example a
selective estrogen receptor modulator (tamoxifen), a selective
estrogen receptor downregulator (fluvestrant), or an aromatase
inhibitor, at the second period of time and thus provision of such
a therapy to a subject may increase disease free survival.
[0059] When the level of FKBPL is decreased in the test example
from the level detected in the control sample, it is indicative
that the tumour is less sensitive to anti-oestrogen therapy and
there is a greater likelihood of disease progression.
[0060] In embodiments of the invention, diagnosis, monitoring or
prognostication a cancerous or malignant condition in a subject can
be provided by: [0061] (i) providing a test sample from the
subject, [0062] (ii) determining in the sample an expression level
of at least one of FKBPL, a variant of FKBPL, a fragment of FKBPL
or an FKBPL variant, [0063] (iii) comparing the determined level to
the expression of FKBPL in the test sample to that in a control
sample; [0064] wherein when the expression level of FKBPL is
decreased in the test sample relative to the control sample, it is
indicative that the cancer is less sensitive to an agent which
selectively modulates oestrogen receptor present in the cancer
tissue or lowers the circulating levels of oestrogen in the cancer
tissue.
[0065] In an another embodiment, the invention provides for
optimizing an existing therapeutic agent against cancer, the
invention comprising the steps: [0066] (i) providing a first test
sample from a subject with cancer, [0067] (ii) providing a second
test sample from the subject with cancer after administration of a
therapeutic agent to the subject, [0068] (iii) determining the
expression level of FKBPL or a variant of FKBPL, or a fragment
thereof in the first and second samples, and [0069] (iv) comparing
the expression level of FKBPL or a variant of FKBPL or a fragment
thereof in the first and second samples wherein when the level of
FKBPL is increased it is indicative the subject will have an
increased liklihood of disease survival.
[0070] Optimisation may be to determine the optimal therapeutic
agent to use or to determine the concentrations or treatment
regimens which should be used.
[0071] In yet another embodiment there is provided a method of
testing a therapy or a new therapeutic agent for treating cancer
the method comprising: [0072] (i) providing a first sample, [0073]
(ii) providing a second sample wherein the second sample has been
exposed to a new therapy or therapeutic agent, [0074] (iii)
determining the expression level of FKBPL or a variant of FKBPL or
a fragment thereof in the first and second samples, and [0075] (iv)
comparing the expression level of FKBPL or a variant of FKBPL or a
fragment thereof in the first and second samples, wherein
[0076] when the level of FKBPL is increased, this is indicative
that the new therapy or therapeutic agent will increase the
liklihood of disease free survival of a subject with cancer if
provided with the new therapy or therapeutic agent.
[0077] As will be appreciated, the methods of the present invention
can be applied to cancer including, for example, breast cancer,
ovarian cancer, endometrial cancer and prostate cancer.
[0078] Biological samples for use in the present invention may
include tissue samples (such as breast tissue biopsies, or breast
cancer cell samples) or biological fluids. Suitably a sample may be
a body fluid or body tissue from a subject with cancer. The sample
may be for example, whole serum, blood plasma, urine, seminal
fluid, or seminal plasma. The particular type of body fluid or body
tissue depends on the type of cancer and the subject. In some
embodiments, samples of body fluid or tissue can be obtained from
tumour cells. Samples may be fresh or processed, for example fixed.
In particular embodiments, a sample may be provided to a solid
support, for example a microscope slide, a tissue culture dish, a
multi-well plate or membrane, BIACORE.TM. or protein or nucleic
acid chip. Typically the sample can be formalin fixed paraffin
embedded tissue or freshly frozen tissue or blood, or a sample
provided using any other methods for tumour preservation and
storage.
[0079] The sample may be suitably obtained from the subject before
or after administration of a therapeutic agent. As will be
appreciated, if a method to treat or optimise treatment of a
subject's cancer is being used, the preferred sample is a sample of
the subject's cancer. Alternatively, a cancer cell line similar to
the type of cancer being treated can be assayed. If the method is
being used to identify a new therapy or therapeutic agent, any
appropriate cell line may be used.
[0080] Determining Gene Expression Level
[0081] Gene expression levels may be determined using any technique
known in the art, for example methods based on hybridisation of
polynucleotides (mRNA transcripts), methods based on sequencing
polynucleotides or amplifying polynucleotides.
[0082] Quantification of mRNA gene transcript in a sample may be
performed using, without limitation, northern blotting, in situ
hybridisation, RNAse protease assays, PCR based methods such as
reverse transcription polymerase chain reaction (RT-PCR) and real
time quantitative PCT qRT-PCR. Alternatively, antibodies with
binding specificity to nucleic acid duplexes may be used to
determine mRNA levels. Microarray techniques using specific binding
members for RNAs of interest, for example cDNA or oligonucleotide
probes specific for RNAs of interest or antibodies specific for
mRNA of interest wherein the specific binding members are plated or
arrayed on a substrate, for example a glass slide or a microchip
substrate can be used. The specific binding members may be provided
on the substrate at an addressable location and the number of
addressable locations can vary from, for example at least three, at
least 10, at least 50, at least 100, at least 1000 or at least
10,000 or more. In embodiments the number of addressable locations
can vary from less than 1000, less than 100, less than 50, less
than 10, or less than 5. In such embodiments the sample is
contacted with the array and the arrayed specific binding members
can form detectable interactions with targets in the sample. The
interactions may be detected using suitable labels. Where
oligonucleotide probes are utilised, under appropriate conditions
the oligonucleotide probes can "hybridise" to a target nucleic acid
sequence to form base-paired duplexes with nucleic acid molecules
that have a complementary base sequence. Hybridisation conditions
resulting in particular degrees of stringency will vary depending
on the nature of the hybridisation method and the composition and
length of the hybridising nucleic acid sequences.
[0083] Stringent hybridisation occurs when a nucleic acid binds a
target nucleic acid with minimal background. Typically, to achieve
stringent hybridisation, temperatures of around 1.degree. C. to
about 20.degree. C., more preferably 5.degree. C. to about
20.degree. C. below the Tm (melting temperature at which half the
molecules dissociate from their partner) are used. However, it is
further defined by ionic strength and pH of the solution. Suitable
hybridisation conditions would be known to those of skill in the
art, and exemplary hybridisation conditions are:
[0084] Very high stringency (detects sequences that share at least
90% identity)--hybridisation 5.times.SSC at 65.degree. C. for about
16 hours,
[0085] High stringency (detects sequences that share at least 80%
identity)--hybridisation 5.times.-6.times.SSC at 65.degree. C. for
16 hours, and
[0086] Low stringency (detects sequences that share at least 50%
identity)--hybridisation 6.times.SSC at room temperature to
55.degree. C. for 20 to 30 minutes.
[0087] An example of a highly stringent wash condition is 0.15 M
NaCl at 72.degree. C. for about 15 minutes. An example of a
stringent wash condition is 0.2.times. sodium chloride and sodium
citrate (SSC) wash at 65.degree. C. for 15 minutes (see, Sambrook
and Russell, infra, for a description of SSC buffer for example
20.times.SSC made by dissolving 175.3 g of NaCl and 88.9 g of
sodium citrate in 800 ml distilled water. Adjusting pH to pH7.0
with HCl (IM) and adjusting volume to IL with distilled water).
Often, a high stringency wash is preceded by a low stringency wash
to remove background probe signal. An example of a medium
stringency wash for a duplex of, for example, more than 100
nucleotides, is 1.times.SSC at 45.degree. C. for 15 minutes. An
example of a low stringency wash for a duplex of, for example more
than 100 nucleotides, is 4-6.times.SSC at 40.degree. C. for 15
minutes. For short probes (for example about 10 to 50 nucleotides),
stringent conditions typically involve salt concentrations of less
than about 1.5 M, more preferably about 0.01 to 1.0 M, Na ion
concentration (or other salts) at pH 7.0 to 8.3, and the
temperature is typically at least about 30.degree. C. and at least
about 60.degree. C. for long probes (for example, >50
nucleotides).
[0088] The methodology used in PCR methods for example RT-PCR and
PCT and RT-PCR will be well known to those skilled in the art.
[0089] Some methods may require the isolation of RNA from a sample.
Such isolation techniques are known in the art and may utilise
commercially available RNA isolation kits from manufacturers such
as Qiagen.
[0090] Determination of Protein Expression
[0091] Immunohistochemistry (IHC) and ELISA are techniques useful
for detecting protein expression. Antibodies or binding fragments
of antibodies (monoclonal or polyclonal) may be used in the
disclosed methods and kits. Antibodies can be detected by direct
labelling of the antibodies or by using a second antibody which is
specific for the primary antibody which has binding specificity for
the target. The second antibody can be labelled with a detectable
moiety or can be conjugated to a hapten (such as a biotin or the
like) wherein the hapten is detectable by a detectably labelled
cognate hapten binding molecule, for example streptavidin
horseradish peroxidise.
[0092] The binding specificity of FKBPL antibodies (antibodies with
binding specificity to FKBPL) can be established using Western
blotting, in parallel with immunohistochemical analysis of
formalin-fixed, paraffin-embedded cell lines mimicking the handling
of the primary tumours (as described by O'Brien et al., 2007,
International Journal of Cancer, 120:1434-1443). In brief, a
parental MCF-7 breast cancer cell line+/-FKBPL targeted siRNA,
together with FKBPL overexpressing stable clones may be used to
optimize anti-FKBPL antibodies. Cell lines may be fixed in PFA for
30 min and resuspended in 70% ethanol overnight before being
embedded in paraffin and arrayed using a tissue arrayer.
Immunocytochemically stained cell pellet arrays may then be
compared with Western blot data to check the specificity and
suitability of the antibodies and the significance of correlations
determined using Spearman's rank test. The antibody displaying the
most comparable expression levels between the two assays may be
used for screening.
[0093] Alternatively, proteins may be detected using aptamers (for
example a single stranded nucleic acid molecule (such as, DNA or
RNA) that assumes a specific, sequence dependent shape and binds to
FKBPL protein with high affinity and specificity), mirror image
aptamers (SPIEGELMER.TM.), engineered nonimmunuoglobulin binding
proteins, for example nonimmunoglobulin binding proteins based on
scaffolds including fibronectin (ADNECTINS.TM.), CTLA-1
(EVIBODIES.TM.), lipocalins (ANTICALINS.TM.), protein A domain
(AFFIBODIES.TM.) or the like. In embodiments, an aptamer may
comprise less than 100 nucleotides, less than 75 nucleotides, less
than 50 nucleotides, for example 25 to 50 nucleotides, 10 to 50
nucleotides, 10 to 100 nucleotides.
[0094] In particular embodiments, an array may be provided
comprising protein sequences, including FKBPL or fragments of FKBPL
or antibodies with binding specificity to FKBPL or fragments
thereof. These protein sequences or antibodies can be conjoined to
a substrate. Changes in protein expression can be detected by, for
example, measuring the level of FKBPL in a sample which binds to
antibodies with binding specificity to FKBPL when the sample to be
tested is brought into contact with the array.
[0095] Suitable substrates for use in an array and array formats
would be known to those of skill in the art.
[0096] In particular embodiments IHC samples can be analysed using
an automated image analysis system, so as to provide a blinded
analysis. For this, whole-slide digital images can be first
captured at 20.times. using a ScanScope XT Slide Scanner (Aperio
Technologies). Secondly, a positive pixel count algorithm (Aperio
Technologies) can be used to develop a quantitative scoring model
for FKBPL expression. Statistical analysis of tissue
microarray-derived data can be carried out using the v2 test for
trend, Fisher's exact and Mann-Whitney tests for comparison of
FKBPL expression between tamoxifen responding and non-responding
tumours and Kaplan-Meier plots can be used for survival analysis
and the curves compared using the log-rank test. Cox proportional
hazards regression can be used to estimate proportional hazard
ratios and conduct multivariate analyses as described previously.
All calculations can be performed with SPSS v11.0 (SPSS, IL). In
addition, to facilitate generation of discrete multi-marker test,
fluorescently-tagged antibodies (carrying non-overlapping
fluorophores) against FKBPL, ER and PR (in the first instance) then
additional relevant biomarkers can be used simultaneously.
Advantageously a recently developed fluorescent scanning system
from Aperio, for example, the ScanScope FL system could be used.
This assay method would provide a further layer of sophistication
by providing more quantitative analysis than that afforded by
conventional brightfield imaging.
[0097] As will be appreciated, the methods of detecting the
expression of FKBPL, the location of FKBPL in a cell or the
activity of FKBPL may be applicable in relation to any of the
methods of the invention described herein or claimed.
[0098] Preferred features and embodiments of each aspect of the
invention are as for each of the other aspects mutatis mutandis
unless context demands otherwise.
DEFINITIONS
[0099] Cancer is a malignant neoplasm, for example one that has
undergone characteristic anaplasia with loss of differentiation,
increased rate of growth, invasion of surrounding tissue and is
capable of metastasis.
[0100] A nucleic acid molecule is said to be complementary with
another nucleic acid molecule if the two molecules share a
significant number of complementary nucleotides to form a stable
duplex or triplex when the strands bind (hybridise) to each other,
for example by forming Watson-Crick base pairs. Complementarity can
be described as a percentage of the proportion of base pairs
between two nucleic acid molecules within a specific region of two
molecules.
[0101] By contact is meant to bring an agent into close proximity
with another agent such that both agents can interact with each
other. For example an antibody or other binding member may be
brought into close proximity with a protein in a sample and where
the antibody has binding specificity for the protein the antibody
will bind the protein. Alternatively, a first nucleic acid may be
brought into close proximity with a second complementary nucleic
acid (a primer with a target sequence) and can be incubated such
that binding may be detected or amplification of the target
sequence may occur.
[0102] By detect is meant determining if an interaction between two
agents for example two proteins or two nucleic acids is present or
absent. This may include quantification. Detection may include the
use of an agent which is capable of detection (a label) using for
example spectrophotometry, flow cytometry, or microscopy. Exemplary
labels include radioactive isotopes (such as .sup.3H, .sup.14C,
.sup.15N, .sup.35S, .sup.90V, .sup.99TC, .sup.111Ln, .sup.125I, or
.sup.131I) fluorophores (such as fluorescein, fluorescein
isothiocyanate, rhodamine or the like), chromophores, ligands,
chemiluminescent agents, bioluminescent agents (such as luciferase,
green fluorescent protein (GFP) or yellow fluorescent protein),
enzymes that can produce a detectable reaction product (such as
horseradish peroxidise, luciferase, alkaline phosphatase,
beta-galactosidase) and combinations thereof.
[0103] By specific binding is meant a particular interaction
between one binding partner and another binding partner, for
example a primer and a target sequence or a protein specific
antibody and a protein. Interactions between one binding partner
and another binding partner may be mediated by one or more,
typically more than one, non-covalent bonds. An exemplary way of
characterising specific binding is by a specific binding curve.
[0104] Unless otherwise explained, all technical and scientific
terms used herein have the same meaning as commonly understood by
one of ordinary skill in the art to which a disclosed invention
belongs. The singular terms "a", "an", and "the" include plural
references unless the context clearly indicates otherwise.
[0105] As used herein a "subject" may be an animal, in particular a
mammal. For example, the subject may be a human. In alternative
embodiments, the subject can be male or female. In certain
embodiments, the subject can be a patient under medical care, or
actively seeking medical care for cancer.
[0106] An FKBPL variant may be a protein of SEQ ID No 2 wherein 25
or fewer, more preferably 15 or fewer, even more preferably of 10
or fewer, 2 or fewer amino acids are inserted, deleted or
substituted, whilst providing a protein with FKBPL activity.
[0107] A fragment of FKBPL or an FKBPL variant may comprise a
stretch of amino acid residues of at least 5 to 7 contiguous amino
acids, often at least 7 to 9 contiguous amino acids, typically 9 to
13 contiguous amino acids, more preferably at least 20 to 30 or
more contiguous amino acids, most preferably at least 30 to 40 or
more consecutive amino acids.
[0108] Throughout the specification, unless the context demands
otherwise, the terms `comprise` or `include`, or variations such as
`comprises` or `comprising`, `includes` or `including` will be
understood to imply the method or kit includes a stated integer or
group of integers, but not the exclusion of any other integer or
group of integers.
[0109] Each document, reference, patent application or patent cited
in this text is expressly incorporated herein in their entirety by
reference, which means it should be read and considered by the
reader as part of this text. That the document, reference, patent
application or patent cited in the text is not repeated in this
text is merely for reasons of conciseness. Reference to cited
material or information contained in the text should not be
understood as a concession that the material or information was
part of the common general knowledge or was known in any
country.
[0110] Embodiments of the present invention are now described with
reference to the following figures in which
[0111] FIG. 1 shows positive interaction exists between Hsp90,
FKBPL and oestrogen receptor in MCF-7 cells (using
co-immunoprecipitation) and that FKBPL co localises with
tubulin;
[0112] FIG. 2 illustrates FKBPL interaction with the
ubiquitin-related proteins, XAP3 and USP19 in yeast cells;
[0113] FIG. 3 illustrates FKBPL and XAP3 interact within ER complex
and overexpression of these proteins affects ER transactivity and
coactivator binding;
[0114] FIG. 4 shows FKBPL overexpression inhibits the clonogenic
potential of ER+ve MCF-7 cells following oestrogen deprivation and
slows growth of breast cancer cells;
[0115] FIG. 5A shows dependence on oestrogen renders
FKBPL-overexpressing cells more sensitive to tamoxifen; FIG. 5B
shows that FKBPL overexpresseion sensititzes MCF-7 cells to
fulvestrant; FIG. 5C shows correlation between tamoxifen IC5O and
FKBPL protein expression in breast cancer cell lines and; FIG. 5D
shows FKBPL knockdown by SiRNA confers resistance to tamoxifen and
fulvestrant in MCF-7;
[0116] FIG. 6A shows (SEQ ID No 5) FKBPL has putative oestrogen
responsive elements within its promoter (underlined and bold) and
FIG. 6B that FKBPL is upregulated in response to oestrogen;
[0117] FIGS. 7A and B show FKBPL over-expressing cells exhibit
decreased levels of oestrogen receptor and cathepsin D while FKBPL
knockdown causes increased expression of oestrogen receptor and
cathepsin D, FIG. 7C shows FKBPL repression in MCF7 cells increases
levels of ER and the ER-responsive gene, cathepsin D;
[0118] FIG. 8 shows that oestrogen receptor phosphorylation is
increased in FKBPL knock down cells and decreased in FKBPL
over-expressing cells;
[0119] FIG. 9 illustrates microarray analysis of FKBPL levels in
ER+VC versus ER-ve breast tissue and cell lines wherein Study 1 is:
Ivshina Breast Experiment Type: mRNA Analysis: Breast
Carcinoma--Estrogen Receptor Status; Class 1: Negative (34); Class
2: Positive (211); T-test: P-value: 0.008; Study 2 is Bittner
Breast Experiment Type: mRNA Analysis: Breast Carcinoma--Estrogen
Receptor Status, Class 1: Negative (78); Class 2: Positive (154);
T-test: P-value 0.009; Study 3 is Neve CellLine Experiment type:
mRNA Analysis: Breast Cell Line--Estrogen Receptor Status, Class 1:
Negative (32), Class 2: Positive (18); T-test: 2919 P-value: 0.006;
Study 4 is Miller Breast Experiment Type: mRNA Analysis: Breast
Carcinoma--Estrogen Receptor Status, Class 1: Negative (34); Class
2: Positive (213); T-test: P-value: 0.01; and
[0120] FIG. 10 illustrates that FKBPL levels fall as tumours
progress or when compared to normal tissue, wherein Study 1 is
Bredel Brain 2 Experiment Type: mRNA Analysis: Brain--Type, Class
1: Normal Brain (4); Class 2: Oligodendroglioma (8); T-test: 8.859
P-value: 6.9E-6; Study 2 is Bredel Brain 2 Experiment Type: mRNA
Analysis: Brain Type, Class 1: Normal Brain (4); Class 2:
Glioblastoma (31); T-test: 13.175 P-value: 1.4E-5; Study 3 is Liang
Brain Experiment Type: mRNA Analysis: Brain-Type, Class 1: Normal
Brain (3); Class 2: Glioblastoma Multiforme (30); T-Test: 7.464
P-value: 1.8E-5; Study 4 is Bredel Brain 2 Experiment Type: mRNA
Analysis: Brain-Type, Class 1: Normal Brain (4); Class 2:
Astrocytic Tumor (5); T-test: 9.627 P-value: 3.3E-S.
[0121] FKBPL was determined as part of the steroid receptor
molecular complex along with oestrogen receptor and Hsp90 (FIGS. 1a
& b). Furthermore, FKBPL was determined to co-localise with
tubulin, strongly supporting the role of FKBPL in retrograde
transport of hormone receptor complexes along microtubules (FIG.
1c). XAP3 and USP19 have been identified and confirmed as proteins
which also interact with FKBPL (FIG. 2a-d). Moreover, XAP3
interacts in a complex with ER and FKBPL (FIG. 3a) and XAP3
overexpression affects ER transactivity and coactivator binding
(FIG. 3b & c). ER+ve MCF-7 breast cancer cells, stably
overexpressing FKBPL, become dependent on oestrogen for their
growth, and even in the presence of oestrogen, FKBPL overexpression
inhibits the clonogenic potential of ER+ve MCF-7 cells (FIG. 4a
& b). This is indicative that breast tumours overexpressing
FKBPL would be highly sensitive to aromatase inhibitors, which act
by lowering circulating levels of estrogen.
[0122] Dependence on oestrogen renders FKBPL-overexpressing cells
up to 90% more sensitive to tamoxifen and up to 99% more sensitive
to fulvestrant (FIG. 5a & b). These responses are not clonal,
as several independent FKBPL overexpressing clones displayed the
same phenotype.
[0123] A preliminary study using cell lines of differing tamoxifen
sensitivity indicates a correlation with FKBPL levels (FIG. 5c).
Knock-down of FKBPL in wild-type MCF-7 cells, using a targeted
siRNA approach, dramatically increased the resistance of these
cells to tamoxifen (FIG. 5d), supporting a role for FKBPL as a
determinant of response to endocrine therapies.
[0124] The inventors have shown that FKBPL has putative oestrogen
responsive elements within its promoter and is upregulated in
response to oestrogen (FIG. 6--promoter sequences with oestrogen
receptor binding sites are marked thereon.). This suggests that
FKBPL itself is an oestrogen responsive gene.
[0125] Further, the inventors have determined that as FKBPL levels
increase in response to oestrogen, ER levels fall. This implicates
FKBPL in the stabilisation of ER.
[0126] The inventors have demonstrated that FKBPL over-expressing
cells exhibit decreased levels of ER suggesting that FKBPL affects
ER stability (FIG. 7a). This is supported by a decrease in the
levels of cathepsin D, an oestrogen-responsive gene critical to
breast cancer growth, survival and invasion (FIG. 7b).
[0127] Cathepsin D down-regulation might explain the decreased cell
growth observed in the FKBPL stably overexpressing cells.
Furthermore, knockdown of FKBPL using an siRNA approach increased
ER and cathepsin D levels (FIG. 7c). These data strongly support a
role for FKBPL protein in controlling the stabilty of ER protein,
as mRNA levels were not affected.
[0128] Without wishing to be bound by theory, the inventors propose
that in addition to FKBPL's role in stabilising ER levels, FKBPL
over-expression also has an impact on other pathways affecting
tamoxifen sensitivity, including the stabilisation (together with
Hps90) of the cyclin dependent kinase inhibitor, p21 (Jascur et
al., 2006). In support of the present invention, the inventors have
determined a dramatic fall in p21 levels when FKBPL is knocked down
with a targeted siRNA (see FIG. 8a).
[0129] A loss of p21's cyclin dependent kinase inhibitory property
resulted in hyperphosphorylation of ER at S118, with subsequent
increased expression of oestrogen receptor-regulated genes.
[0130] The inventors have shown that ER phosphorylation is
increased in FKBPL knock down cells and decreased in FKBPL
over-expressing cells (FIGS. 8 a & b). Together, these data
support a model in which low levels of FKBPL leads to low levels of
p21, hyperphosphorylation of ER and a growth-inducing
phenotype.
[0131] This is supported by the inventors data shown in FIGS. 5d
and 8a. By contrast, high levels of FKBPL stabilises p21, reducing
ER phosphorylation, abrogating tamoxifen-induced agonist potency
and so increase sensitivity to the drug (see data in FIGS. 5a and
8b).
[0132] Using a DNA microarray-based transcriptomic approach, the
inventors have determined differentially expressed genes within the
ligand-independent ER signalling pathway and in addition, ADAMS, a
gene previously shown to predict for sensitivity to tamoxifen,
independently of ER status is potentially up-regulated by FKBPL
(Sieuwerts et al, 2005).
[0133] Finally, analysis by the inventors has revealed that FKBPL
levels fall as tumours progress or when compared to normal tissue
(FIGS. 9 and 10).
EXAMPLES
Example 1
FKBPL Interacts with the Hsp90/ER Molecular Chaperone Complex
[0134] Since FKBPL contains TPR (tetratricopeptide repeat) domains
in its C-terminus and these domains are known to bind the molecular
steroid chaperone, Hsp90, this experiment assessed if FKBPL could
bind Hsp90 and the steroid receptor, ER, along with other
components of this complex.
[0135] To assess endogenous interactions between FKBPL and the
Hsp90/ER complex using coimmunoprecipitation, parental and
FKBPL-overexpressing stable MCF7 (ER+) cells were plated into T75
flasks and incubated for 24 h. Cells were lysed in 500 .mu.l lysis
buffer (20 mM Tris HCl pH 7.4, 1% Igepal, 12 mM sodium
deoxycholate, 0.1% SDS, 10 mM sodium Molybdate, 1 complete
EDTA--Free tablet-protease inhibitor). Pre-cleared lysates were
incubated with antibody bound Protein G-Sepharose beads (Cancer
Research, UK) at 4.degree. C. overnight. The beads were washed 5
times in lysis buffer, suspended in 50 .mu.l 2.times. Laemmli
buffer and heated at 100.degree. C. for 10 mins. Samples were
subjected to SDS-PAGE electrophoresis using the XCell Surelock
Mini-cell system (Invitrogen), transferred onto nitrocellulose
membranes, blocked for 1 h at room temperature with 1% skim milk
blocking solution and probed with anti-FKBPL rabbit polyclonal
(ProteinTech, Cat no. 10060-1-AP) at a dilution of 1:2000, anti-ER
alpha rabbit monoclonal (Millipore, Cat no. 07-662) at a dilution
of 1:1000 and GAPDH rabbit monoclonal (Sigma, Cat no. G9545) at a
dilution of 1:5000. The blot was then probed with anti-rabbit IgG
HRP-linked whole secondary antibody (GE Healthcare, Cat no. NA934V)
at a dilution of 1:10000. Antibody binding was detected using
Supersignal West Pico Chemiluminescent Substrate (Pierce, Cat no.
34080). DU145 cells were plated on chamber slides, fixed in 4%
paraformaldehyde for 20 min at room temperature, washed with
ice-cold PBS and permeabilized with 2% Bovine Serum Albumin (BSA)
containing 0.1% Triton-X 100 for 20 min at room temperature. FKBPL
was visualized with an anti-FKBPL rabbit polyclonal IgG (dilution
1:50) (ProteinTech, Cat no. 10060-1-AP) with Alexa Fluor.RTM. goat
anti-rabbit (GAR) 488 (Invitrogen, Cat no. A-11008) was used as
secondary antibody; tubulin was visualized with an
anti-.alpha.-Tubulin mouse monoclonal (1:500) (Sigma, Cat no.
T6074) and Alexa Fluor.RTM. donkey anti-mouse (DAM) 594
(Invitrogen, Cat no. A-21203) was used as a secondary antibody
(dilution 1:250). Negative controls were also analysed, to ensure
that the secondary antibodies did not bind non-specifically. Slides
were visualised using a Leica Confocal System TCS Sp2, (Leica,
Germany). A .times.40 magnification oil immersion Plan Apochromatic
objective was employed.
[0136] The results of the experiments are shown in FIG. 1. FKBPL,
Hsp90 and ER are present in the whole cell lysate of MCF7 cells.
Both Hsp90 and ER can be immunoprecipitated from MCF7 cells using
the FKBPL antibody therefore demonstrating that these proteins
interact in breast cancer cells.
Example 2
FKBPL Interacts with the Ubiquitin-Related Proteins, XAP3 and USP19
in Yeast and Mammalian Cells
[0137] To determine other FKBPL interacting proteins, the inventors
used the ProQuest Yeast Two-Hybrid System (Invitrogen, Cat no.
10835-015) to screen a human fetal brain pPC86/cDNA library. FKBPL
was cloned into the pDBLeu plasmid `in-frame` with the GAL4 binding
domain according to manufacturer's instructions. MaV203 yeast cells
were aliquoted into two 250 .mu.l volumes and to each tube 20 .mu.g
of pDBLeu/FKBPL and 20 .mu.g pPC86/cDNA library plasmids were added
and mixed well by swirling tubes. To each tube, 1.5 ml PEG/LiAc was
added and mixed well by swirling. Tubes were incubated for 30
minutes in a 30.degree. C. waterbath, swirling tubes every 10
minutes. To each tube, 88 .mu.l of fresh DMSO was added and mixed
by swirling. Cells were heat shocked for 20 minutes in a 42.degree.
C. waterbath, swirling tubes occasionally. Tubes were centrifuged
at 1800 rpm for 5 minutes and the supernatant discarded. Each
pellet was resuspended in 8 ml 0.9% NaCl, then combined into one
tube. To enable estimation of the total number of transformants,
100 .mu.l was removed and diluted 1:10, 1:100 and 1:1000 in 0.9%
NaCl. 100 .mu.l of each dilution was plated onto a 10 cm SC-Leu-Trp
plate then incubated at 30.degree. C. for 72 hours. The remaining
transformation mixture was plated in 400 .mu.l aliquots onto forty
15 cm SC-Leu-Trp-His+10 mM 3AT plates and incubated at 30.degree.
C. for 6 days. Any colonies that grew were streaked onto a 10 cm
SC-Leu-Trp plate and incubated for 2-3 days at 30.degree. C.
Following incubation, this master plate was replica plated onto
selection plates in the following order--1. YPAD containing a
nitrocellulose membrane, 2. SC-Leu-Trp-Ura, 3. SC-Leu-Trp-His+10 mM
3AT (immediately replica clean) then 4. SC-Leu-Trp+0.2% 5FOA
(immediately replica clean). All plates were incubated for 24 hours
at 30.degree. C. After 24 hours the YPAD plate was removed and the
X-Gal assay was performed. All other plates were replica cleaned
and incubated at 30.degree. C. for a further 48 hours. The growth
of interacting proteins were compared with the known controls
present on each plate but generally a positive interaction was
assessed using the following criteria--blue colonies with X-Gal
assay, colony growth on SC-Leu-Trp-Ura and SC-Leu-Trp-His+10 mM 3AT
plates and no growth on SC-Leu-Trp+0.2% 5FOA. The plasmid DNA was
extracted from yeast cells by alkaline lysis and electroporated
into ELECTROMAX DH10B E. coli cells using a Gene Pulser Cuvette
(0.1 cm electrode) (BioRad) voltage (2.5 kV), capacitance (25
.mu.F) and resistance (100.OMEGA.). To selectively isolate
pPC86/potential positive clones, cells were plated onto LB plates
containing 50 .mu.g/ml ampicillin and incubated for 16 hours at
37.degree. C. Plasmid DNA was then isolated using standard alkaline
lysis method.
[0138] Results are shown in FIGS. 2 A & B. Sequencing using
plasmid specific primers and BLAST sequence alignments
(www.ncbi.nlm.nih.gov) identified these interacting proteins as
XAP3 and USP19. XAP3 produced blue colonies with X-Gal assay,
minimal colony growth on SC-Leu-Trp-Ura, good colony growth on
SC-Leu-Trp-His+10 mM 3AT plates and no growth on SC-Leu-Trp+0.2%
5FOA, identifying this protein as strong interactor. USP19 produced
pale blue colonies with X-Gal assay, no colony growth on
SC-Leu-Trp-Ura, good colony growth on SC-Leu-Trp-His+10 mM 3AT
plates and slight growth on SC-Leu-Trp+0.2% 5FOA, identifying this
protein as weak interactor.
[0139] In order to confirm the interactions detected using the
yeast two-hybrid system and determine that the interaction can take
place in a biologically relevant model, the Checkmate Mammalian
Two-Hybrid System (Promega, Cat no. E2440) was used. Full length
FKBPL and a variety of FKBPL mutants were cloned `in-frame` into
pBIND plasmid according to manufacturer's instructions. XAP3 and
USP19 were cloned `in-frame` into pACT plasmid according to
manufacturer's instructions. 2.times.10.sup.4 L132 cells were
plated in triplicate into a 96 well plate for each transfection
condition and incubated overnight at 37.degree. C. with MEM
containing 10% FCS. FKBPL, XAP3 and USP19 plasmids were transfected
into cells using Lipofectamine Plus (Invitrogen, Cat no.) and
incubated at 37.degree. C. for 24 h. The plate was allowed to
equilibrate to room temperature then 75 .mu.l room temperature
Dual-Glo Luciferase Reagent (Promega, Cat no. E2920) was added to
each well, mixed thoroughly and wrapped in tinfoil. After 15
minutes incubation at room temperature, the Firefly luminescence
was measured using a GENios platereader (Tecan). 75 .mu.l room
temperature Dual-Glo Stop & Glo Reagent (Promega, Cat no.
E2920) was added to each well, mixed thoroughly and wrapped in
tinfoil. After 15 minutes incubation at room temperature, the
Renilla luminescence was measured.
[0140] Results are shown in FIGS. 2 C & D. Renilla luminescence
was used to correct for plasmid transfection efficiency. Following
correction, increased firefly luminescence over self-activations
controls indicated a positive interaction between the proteins.
Both XAP3 and USP19 were confirmed as true FKBPL interactors with a
20-fold and 10-fold induction of firefly luminescence,
respectively. Deletion mapping demonstrated that the interaction
between FKBPL and XAP3 was abrogated in FKBPL.DELTA.287 mutant
constructed so that FKBPL contained a single point mutation in a
conserved, positively charged amino acid (carboxylate clamp) known
to be essential for TPR interactions. Furthermore, removal of 149
amino acids from the end of FKBPL ie FKBPL.DELTA.200 also abrogated
any interaction with XAP3. These results identify that the region
of FKBPL from 200-349 amino acids is essential for interaction with
XAP3. Deletion mapping also identified the region spanning amino
acids 1-200 as essential for binding of FKBPL to USP19.
Example 3
FKBPL and XAP3 Interact within the ER Complex and Overexpression of
these Proteins Affects ER Transactivity and Coactivator Binding
[0141] To assess whether XAP3 was also present in the
FKBPL/Hsp90/ER complex, FKBPL stable 3.1 D2 cells transiently
transfected with pcDNA3.1-Myc/XAP3 were grown to 75% confluency in
two T175 flasks. Spent media was removed and cells washed twice
with ice-cold PBS. To each plate 500 .mu.l RIPA lysis buffer was
added and incubated for 1 h at 4.degree. C. with rotation before
being pelleted by centrifugation for 10 min at 4.degree. C. 80
.mu.l of the supernatant was removed and placed in a clean
eppendorf together with 20 .mu.l 5.times. Reducing lane marker
sample buffer (Pierce, Cat no. 39000), boiled for 10 m and stored
at -20.degree. C. to be used as a positive control. 100 .mu.l of
Protein G-sepharose beads (Cancer Research, UK) were placed in an
eppendorf, centrifuged at 2500 rpm for 1 min, and supernatant
removed. The beads were then washed three times with 300 .mu.l of
lysis buffer and centrifuged at 2500 rpm for 1 min. The supernatant
was added to pre-washed beads and incubated at 4.degree. C. with
rotation overnight to pre-clear the lysate. Simultaneously, the
beads-antibody matrices were set up. Each antibody was diluted in
500 .mu.l of PBS and 100 .mu.l of pre-washed Protein G-sepharose
beads and incubated at 4.degree. C. with rotation overnight.
Following incubation, the beads-antibody matrices were centrifuged
at 2500 rpm for 1 min, the supernatant discarded and beads washed
twice with ice-cold lysis buffer. The lysate was centrifuged at
2500 rpm for 20 min and the supernatant divided equally between the
IP beads-antibody matrices and incubated at 4.degree. C. with
rotation overnight. Following incubation the IPs were centrifuged
at 2500 rpm for 1 min, the supernatant discarded and washed three
times with 500 .mu.l of ice-cold lysis buffer, and twice with ice
cold PBS, centrifuging each time as before and discarding the
supernatant. The final supernatant was aspirated off with a fine
needle. The samples were resuspended in 50 .mu.l 5.times. Reducing
lane marker sample buffer diluted 1:5 with lysis buffer, heated at
100.degree. C. for 5 min and centrifuged. The membrane was
immunoblotted for the following proteins; anti-FKBPL rabbit
polyclonal (ProteinTech, Cat no. 10060-1-AP) at a dilution of
1:1000, anti-ER alpha rabbit monoclonal (Millipore, Cat no. 07-662)
at a dilution of 1:1000, anti-Hsp90 mouse monoclonal (BD
biosciences, Cat no. 610419) at a dilution of 1:1000 and anti-Myc
mouse monoclonal (Invitrogen, Cat no. R95025) at a dilution of
1:5000. The blot was then probed with anti-rabbit IgG HRP-linked
whole secondary antibody (GE Healthcare, Cat no. NA934V) or
anti-mouse IgG HRP-linked whole antibody secondary (GE Healthcare,
Cat no. NA931V) at a dilution of 1:10000. Antibody binding was
detected using Supersignal West Pico Chemiluminescent Substrate
(Pierce, Cat no. 34080).
[0142] To assess the ability of FKBPL and XAP3 to affect binding of
ER to oestrogen response elements and therefore transactivation of
ER responsive genes, 2.times.10.sup.4 cells/well (96-well plate)
parental MCF7 and FKBPL stable cells (3.1 D2) were plated in
triplicate for all conditions in phenol red-free DMEM containing
10% charcoal stripped fetal calf serum and incubated at 37.degree.
C. for 24 hours. Medium was carefully removed and 50 .mu.l phenol
red-free DMEM (serum free) added to each well (70 .mu.l to
non-transfected controls). Cells were transfected with an
ERE-luciferase reporter plasmid (pGL2-ERE-TATA-LUC)+/-XAP3 plasmid
using Lipofectamine Plus (Invitrogen, Cat no. P/N50470 and
10964-021) and optimized conditions (0.06 .mu.g DNA, 0.2 .mu.l Plus
reagent, 0.3 .mu.l lipofectamine per well), 20 .mu.l of
transfection mix was added to each well and incubated for 5 h.
Following incubation, transfection mix was replaced with 50 .mu.l
phenol red-free DMEM containing 10% charcoal stripped fetal calf
serum containing 10.sup.-8M E2 or 0.1% (v/v) DMSO and incubated for
24 h. 50 .mu.l Dual-Glo Luciferase reagent (Promega, Cat no. E2920)
was added and mixed gently by pipetting up and down. The plate was
covered with tinfoil and incubated at room temperature for 15 mins
then firefly luminescence was measured using the GENios platereader
(Tecan). 50 .mu.l Stop and Glo reagent (Promega, Cat no. E2920) was
added and mixed gently by pipetting up and down, covered with
tinfoil and incubated at room temperature for 15 mins then Renilla
luminescence was measured as before.
[0143] To determine whether FKBPL and XAP3 can affect the ability
of ER to bind its coactivators, the NR Peptide ERalpha ELISA
(Active Motif, Cat no. 49096) was used. This assay allows the
specific capture of ligand-activated ER alpha and evaluates the
agonist/antagonist effects of compounds on the activation of ER
alpha. A 96-well plate is coated with a sequence optimized peptide
containing the consensus binding motif (LXXLL) of ER alpha
co-activators. 50 .mu.g nuclear lysates from parental or stable
MCF7 cells were added to a well along with the test compound (25
.mu.M 17-.beta.-estradiol or 25 .mu.M tamoxifen). The plate was
sealed with adhesive cover and incubated at room temperature for 1
h on a rocking platform (100 rpm). Wells were washed 3 times with
200 .mu.l 1.times. Wash Buffer. 50 .mu.l of diluted ER primary was
added to all wells. Samples were incubated and washed as in
previous step. 50 .mu.l of diluted secondary antibody was added to
all wells and incubated as before. Wells were washed 4 times with
200 .mu.l 1.times. Wash Buffer. 100 .mu.l Developing Solution was
added and incubated for 2-5 minutes at room temp wrapped in
tinfoil. 100 .mu.l Stop Solution was added (blue colour should turn
yellow). Absorbance was read on a spectrophotometer within 5
minutes at 450 nm.
[0144] Coimmunoprecipitations determined that XAP3 does interact in
a complex with FKBPL/Hsp90/ER. Results shown in FIG. 3A. This is
the first description of an interaction between these proteins.
Furthermore, in both oestrogen-depleted (DMSO) and
oestrogen-supplemented (E2) medium, overexpression of FKBPL
enhanced ER.alpha. mediated transcription of the oestrogen response
element-driven luciferase reporter and the presence of XAP3 further
increased this effect. Results are shown in FIG. 3B. Furthermore,
FKBPL overexpression significantly enhanced the ability of ER to
bind the LXXLL coactivator sequence (p=0.0127). However,
overexpression of XAP3 inhibited this effect. These results suggest
that XAP3 itself may act as an ER coactivator and therefore
increased presence of XAP3 may block coactivator binding sites on
ER and prevent binding to coactivator sites on the ELISA plate.
Results are shown in FIG. 3C. Together these data suggest that XAP3
may co-operate with FKBPL in the modulation of ER signalling.
Example 4
FKBPL Overexpression Sensitizes MCF7 Cells to Oestrogen Deprivation
and Slows the Growth of Breast Cancer Cells
[0145] In order to determine the cellular affects of FKBPL
overexpression on breast cancer cells, MCF7 cells were engineered
to constitutively overexpress FKBPL (3.1D2, 3.1D3 and 3.1D9) and
assays performed to assess their clonogenic potential and cell
growth under various culture conditions; MCF7 cells served as
parental controls.
[0146] For oestrogen deprivation studies, 3.1 D2 and parental
control cells were plated at a density of 500 and 1000 cells/well
in a 6-well plate containing phenol red-free DMEM+10%
charcoal-stripped FCS and incubated at 37.degree. C. for 24 h. The
medium was replaced with phenol red-free DMEM+10% charcoal-stripped
FCS containing DMSO as vehicle control or 10.sup.-8M
17-.beta.-estradiol (Sigma, Cat no. E2758) and incubated under
normal conditions for 16 days. For growth assays, 2.times.10.sup.5
MCF7 parental or FKBPL stable cells were seeded into 35 mm dishes
with complete DMEM and incubated at 37.degree. C. for 24 h. Cell
growth was monitored at 24 h intervals using the trypan blue
exclusion assay.
[0147] MCF-7 breast cancer cells, stably overexpressing FKBPL (3.1
D2), become dependent on oestrogen for their growth, and even in
the presence of oestrogen, FKBPL overexpression inhibits the
clonogenic potential of MCF-7 cells (FIG. 4A). Furthermore, three
independent FKBPL overexpressing MCF7 clones (3.1 D2, 3.1 D3 and
3.1 D9) all demonstrate growth inhibition compared to parental
controls over a 5 day timecourse (FIG. 4B).
Example 5
FKBPL Overexpression Sensitizes MCF7 Breast Cancer Cells to SERM
and SERD Endocrine Therapies
[0148] Cells were plated at a density of 500 and 1000 cells/well in
a 6-well plate containing DMEM+10% FCS and incubated at 37.degree.
C. for 24 h. The medium was replaced with DMEM+10% FCS containing 1
.mu.M tamoxifen (Sigma, Cat no. T5648) or 2.5 nM fulvestrant
(Sigma, Cat no. 14409) and incubated under normal conditions for 16
days. In both experiments, colonies were fixed and stained with
0.4% Crystal Violet/70% methanol then counted.
[0149] FKBPL overexpression renders cells up to 90% more sensitive
to the SERM (selective oestrogen receptor modulator), tamoxifen;
these responses are not clonal, as several independent FKBPL
overexpressing clones displayed the same phenotype (FIG. 5A).
Furthermore, the amount of FKBPL protein overexpression in each
clone correlated with the increased sensitivity to tamoxifen
(R.sup.2=0.88). In response to the SERD (selective oestrogen
receptor down regulator), fulvestrant, overexpressing clones were
up to 99% more sensitive than parental controls and again this
response was not clonal (FIG. 5B). Correlation between FKBPL levels
and sensitivity to fulvestrant was also identified
(R.sup.2=0.81).
Example 6
Endogenous FKBPL Protein Expression Correlates with Tamoxifen
Sensitivity in Breast Cancer Cell Lines
[0150] Protein lysates were isolated from MCF7 (ER+), MDA-MB-231
(ER-), T47D (ER+) and FKBPL overexpressing MCF7 cell lines, 3.1 D2
and 3.1 D9. The IC.sub.50 of each cell line was determined as
follows: cells were plated at a density of 500 and 1000 cells/well
in a 6-well plate containing DMEM+10% FCS and incubated at
37.degree. C. for 24 h. The medium was replaced with DMEM+10% FCS
containing 0, 0.1, 0.25, 0.5, 1, 2.5, 5, 7.5, 10 .mu.M tamoxifen
(Sigma, Cat no. T5648) and incubated under normal conditions for 16
days. Colonies were fixed and stained with 0.4% Crystal Violet/70%
methanol then counted.
[0151] The IC50 of each cell line was determined as the dose of
tamoxifen required to inhibit clonogenic potential of cells by 50%.
This in vitro study of breast cancer cell lines further expanded
the evidence that higher endogenous FKBPL levels in breast cancer
cell lines; T47D (FKBPL++), MCF7 (FKBPL+), MDA-MB-231 (FKBPL+/-)
and FKBPL stable cell lines, 3.1 D2 (FKBPL+++) and 3.1D9 (FKBPL+)
correlated with increased sensitivity to tamoxifen (R.sup.2=0.93)
(FIG. 5C).
Example 7
Knockdown of FKBPL in MCF7 Cells Via a siRNA Targeted Approach
Confers Resistance to Endocrine Therapies
[0152] MCF7 cells were transfected with siControl non-targeting
siRNA #1 (Dharmacon, Cat no. D-001210-01-20) or FKBPL targeted
siRNA (Ambion, Cat no. 16104). Briefly, 1.times.10.sup.5 MCF7 cells
were seeded into 35 mm dishes and incubated at 37.degree. C. for 24
h. To transfect, in one tube 6.4 .mu.l of either siControl
non-targeting siRNA or FKBPL targeted siRNA (2 .mu.M) was added to
160 .mu.l OptiMEM (Invitrogen) and in another tube 4 .mu.l
Oligofectamine (Invitrogen, Cat no. 12252-011) was added to 30
.mu.l OptiMEM. Both tubes were incubated at room temperature for 5
min. Both tube contents were mixed and incubated at room
temperature for 20 min. During incubation, 800 .mu.l prewarmed
complete DMEM was added to the cells then 200 .mu.l transfection
mix was added dropwise and the dishes incubated at 37.degree. C.
for 72 h. Cells were then plated at a density of 1000 and 2000
cells/well in a 6-well plate containing DMEM+10% FCS and incubated
at 37.degree. C. for 24 h. The medium was replaced with DMEM+10%
FCS containing 1 .mu.M tamoxifen (Sigma, Cat no. T5648) or 2.5 nM
fulvestrant (Sigma, Cat no. 14409) and incubated under normal
conditions for 16 days. In both experiments, colonies were fixed
and stained with 0.4% Crystal Violet/70% methanol then counted.
[0153] Knock-down of FKBPL in wild-type MCF-7 cells, using a
targeted siRNA approach, dramatically increased the resistance of
these cells to tamoxifen and fulvestrant compared to the
non-targeting controls (FIG. 5D). This further supports a role for
FKBPL as a determinant of response to endocrine therapies.
Example 8
FKBPL is an Oestrogen Responsive Gene
[0154] To identify regions of the FKBPL promoter which ER may bind
to and therefore regulate FKBPL expression, 2206 bp upstream from
the transcription start site of FKBPL were selected and the WWW
ProScan Program was used to predict possible binding sites for
ER-.alpha..
[0155] To determine whether FKBPL itself could be regulated by
oestrogen, 2.times.10.sup.5 MCF7 parental cells were seeded into 35
mm dishes with phenol red-free DMEM+10% charcoal stripped FCS and
incubated at 37.degree. C. for 24 h. The medium was replaced with
phenol red-free DMEM+10% charcoal-stripped FCS containing DMSO as
vehicle control or 10.sup.-8M 17-.beta.-estradiol (Sigma, Cat no.
E2758) and incubated for 24 h. Cells were lysed in 250 .mu.l
2.times. laemmli buffer (Sigma) and subjected to SDS-PAGE
electrophoresis using the XCell Surelock Mini-cell system
(Invitrogen), transferred onto nitrocellulose membranes, blocked
for 1 h at room temperature with 1% skim milk blocking solution and
probed with FKBPL rabbit polyclonal (ProteinTech, Cat no.
10060-1-AP) at a dilution of 1:2000, ER rabbit monoclonal
(Millipore, Cat no. 07-662) at a dilution of 1:1000 and GAPDH
rabbit monoclonal (Sigma, Cat no. G9545) at a dilution of 1:5000.
The blot was then probed with corresponding anti-rabbit IgG
HRP-linked whole antibody secondary (GE Healthcare, Cat no. NA934V)
or anti-mouse IgG HRP-linked whole antibody secondary (GE
Healthcare, Cat no. NA931V) at a dilution of 1:10000. Antibody
binding was detected using Supersignal West Pico Chemiluminescent
Substrate (Pierce, Cat no. 34080).
[0156] Using ProScan, several Sp1 and ERE sites were identified in
the promoter region of FKBPL suggesting that ER could bind these
regions directly via ERE sites or indirectly using other
transcription factors via Sp1 sites. FKBPL protein expression is
upregulated by administration of 10.sup.-8M 17-.beta.-estradiol
suggesting that FKBPL is an oestrogen responsive gene. Furthermore,
as FKBPL levels increase, ER levels decrease implicating FKBPL in
the stabilisation of ER. Results are shown in FIG. 6.
Example 9
FKBPL Overexpression in MCF7 Cells Decreases Levels of ER and the
ER-Responsive Gene, Cathepsin D
[0157] In order to determine how FKBPL overexpression sensitizes
breast cancer cells to endocrine therapies, protein expression of
ER and ER-responsive genes were analysed.
[0158] Briefly, 2.times.10.sup.5 MCF7 parental or FKBPL stable
cells were seeded into 35 mm dishes with complete DMEM and
incubated at 37.degree. C. for 24 h. Cells were then lysed in 250
.mu.l 2.times. laemmli buffer (Sigma). Samples were subjected to
SDS-PAGE electrophoresis using the XCell Surelock Mini-cell system
(Invitrogen), transferred onto nitrocellulose membranes, blocked
for 1 h at room temperature with 1% skim milk blocking solution and
probed with FKBPL rabbit polyclonal (ProteinTech, Cat no.
10060-1-AP) at a dilution of 1:2000, ER rabbit monoclonal
(Millipore, Cat no. 07-662) at a dilution of 1:1000, cathepsin D
mouse monoclonal (Abcam, Cat no. ab6313) at a dilution of 1:1000
and GAPDH rabbit monoclonal (Sigma, Cat no. G9545) at a dilution of
1:5000. The blot was then probed with corresponding anti-rabbit IgG
HRP-linked whole antibody secondary (GE Healthcare, Cat no. NA934V)
or anti-mouse IgG HRP-linked whole antibody secondary (GE
Healthcare, Cat no. NA931V) at a dilution of 1:10000. Antibody
binding was detected using Supersignal West Pico Chemiluminescent
Substrate (Pierce, Cat no. 34080).
[0159] Compared to parental controls, FKBPL over-expressing cells
exhibit decreased levels of ER and cathepsin D, an
oestrogen-responsive gene critical to breast cancer growth,
survival and invasion (FIG. 7a & b).
Example 10
Knockdown of FKBPL in MCF7 Cells Via a siRNA Targeted Approach
Causes an Increase in ER and Cathepsin D Levels
[0160] MCF7 cells were transfected for 72 h with siControl
non-targeting siRNA #1 (Dharmacon, Cat no. D-001210-01-20) of FKBPL
targeted siRNA (Ambion, Cat no. 16104). Briefly, 1.times.10.sup.5
MCF7 cells were seeded into 35 mm dishes and incubated at
37.degree. C. for 24 h. To transfect, in one tube 6.4 .mu.l of
either siControl non-targeting siRNA or FKBPL targeted siRNA (2
.mu.M) was added to 160 .mu.l OptiMEM (Invitrogen) and in another
tube 4 .mu.l Oligofectamine (Invitrogen, Cat no. 12252-011) was
added to 30 .mu.l OptiMEM. Both tubes were incubated at room
temperature for 5 min. Both tube contents were mixed and incubated
at room temperature for 20 min. During incubation, 800 .mu.l
prewarmed complete DMEM was added to the cells then 200 .mu.l
transfection mix was added dropwise and the dishes incubated at
37.degree. C. for 72 h. Cells were then lysed in 250 .mu.l 2.times.
laemmli buffer (Sigma). Samples were subjected to SDS-PAGE
electrophoresis using the XCell Surelock Mini-cell system
(Invitrogen), transferred onto nitrocellulose membranes, blocked
for 1 h at room temperature with 1% skim milk blocking solution and
probed with FKBPL rabbit polyclonal (ProteinTech, Cat no.
10060-1-AP) at a dilution of 1:2000, ER rabbit monoclonal
(Millipore, Cat no. 07-662) at a dilution of 1:1000, cathepsin D
mouse monoclonal (Abcam, Cat no. ab6313) at a dilution of 1:1000,
and GAPDH rabbit monoclonal (Sigma, Cat no. G9545) at a dilution of
1:5000. The blot was then probed with corresponding anti-rabbit IgG
HRP-linked whole antibody secondary (GE Healthcare, Cat no. NA934V)
or anti-mouse IgG HRP-linked whole antibody secondary (GE
Healthcare, Cat no. NA931V) at a dilution of 1:10000. Antibody
binding was detected using Supersignal West Pico Chemiluminescent
Substrate (Pierce, Cat no. 34080).
[0161] Knockdown of FKBPL using an siRNA targeted approach
increased ER and cathepsin D levels further supporting a role for
FKBPL in controlling stability of ER signalling pathway proteins
(FIG. 7C).
Example 11
Phosphorylation Status of ER is Altered Following FKBPL Knockdown
and Overexpression
[0162] To study the effect of FKBPL overexpression on ER.alpha.
phosphorylation, 5.times.10.sup.4 MCF7 cells and 3.1 D2 were plated
in a 24 well dish with 500 .mu.l complete DMEM. After 12 h the
medium was aspirated and replaced with 500 .mu.l phenol red-free
DMEM supplemented with 10% charcoal stripped FCS. After 72 h serum
starvation, 10.sup.-8M 17-.beta. estradiol or 1 .mu.M tamoxifen was
added. The vehicle control for the addition of estradiol was DMSO
and for tamoxifen was fresh media. For studies on effect of FKBPL
knockdown on ER.alpha. phosphorylation, siRNA transfection was
carried out as outlined in Example 10 with the exception that
phenol red-free DMEM+10% charcoal stripped FCS medium was used
instead of complete DMEM. Cell lysates were assayed 15 min
post-addition of ligand and subjected to SDS-PAGE electrophoresis
using the XCell Surelock Mini-cell system (Invitrogen), transferred
onto nitrocellulose membranes, blocked for 1 h at room temperature
with 1% skim milk blocking solution and probed with FKBPL rabbit
polyclonal (ProteinTech, Cat no. 10060-1-AP) at a dilution of
1:2000, ER rabbit monoclonal (Millipore, Cat no. 07-662) at a
dilution of 1:1000, phospho-ER.alpha. (Ser118) mouse antibody (Cell
Signalling Technologies, Cat no. 9924) at a dilution of 1:1000, p21
mouse monoclonal (Upstate, Cat no. 05-345) at a dilution of 1:1000
and GAPDH rabbit monoclonal (Sigma, Cat no. G9545) at a dilution of
1:5000. The blot was then probed with corresponding anti-rabbit IgG
HRP-linked whole antibody secondary (GE Healthcare, Cat no. NA934V)
or anti-mouse IgG HRP-linked whole antibody secondary (GE
Healthcare, Cat no. NA931V) at a dilution of 1:10000. Antibody
binding was detected using Supersignal West Pico Chemiluminescent
Substrate (Pierce, Cat no. 34080).
[0163] Results demonstrate that ER phosphorylation is increased in
FKBPL knockdown cells and decreased in FKBPL over-expressing cells
(FIGS. 8A & B). Furthermore, p21 levels are decreased compared
to controls following FKBPL knockdown and increased in FKBPL stable
cell line compared to controls
Example 12
Genes Regulated by FKBPL Peptide Associated with ER Signalling in
MDA-MB-231 Cells
[0164] MDA-MB-231 cells were seeded onto chamber slides and
incubated at 37.degree. C. for 24 h. Treatment with 24mer FKBPL
peptide was carried out for 18 h then cells were harvested in 1 ml
RNA-STAT-60 (AMS Biotechnology, Cat no. CS-111) to enable total RNA
isolation according to manufacturer's instructions. These RNA
samples were analysed using Affymetrix Human Genome U133 Plus 2.0
arrays (Almac Diagnostics UK).
[0165] Briefly, 50 ng of total RNA was amplified using the
NuGEN.TM. Ovation.TM. RNA Amplification System V2. First-strand
synthesis of cDNA was conducted using a unique first-strand DNA/RNA
chimeric primer mix, resulting in cDNA/mRNA hybrid molecules.
Following fragmentation of the mRNA component of the cDNA/mRNA
molecules, second-strand synthesis was conducted and
double-stranded cDNA generated using a unique DNA/RNA heteroduplex
at one end. In the final amplification step, RNA within the
heteroduplex was degraded using RNaseH, and replication of the
resultant single-stranded cDNA was achieved through DNA/RNA
chimeric primer binding and DNA polymerase enzymatic activity. The
amplified single-stranded cDNA was purified using the Zymo Research
Clean and Concentrator.TM.-25 kit to allow for accurate
quantitation of the cDNA and to ensure optimal performance during
the fragmentation and labelling process. The single-stranded cDNA
was assessed using a spectrophotometer in combination with the
Agilent Bioanalyzer to ensure all samples were comparable. 3.75
.mu.g of amplified single-stranded cDNA was fragmented and labelled
using the FL-Ovation.TM. cDNA Biotin Module V2. The enzymatically
and chemically fragmented product (50-100 nt) was labelled via the
attachment of biotinylated nucleotides onto the 3'-end of the
fragmented cDNA. This cDNA was added to the hybridisation cocktail
in accordance with the NuGEN.TM. guidelines for hybridisation onto
Affymetrix GeneChip.RTM. arrays. Following hybridisation for 18
hours at 45.degree. C., the array was washed and stained on a
GeneChip.RTM. Fluidics Station 450 using the appropriate fluidics
script, before being inserted into the Affymetrix autoloader
carousel and scanned using the GeneChip.RTM. Scanner 3000. The
image files were assessed for proper grid alignment and image
artefacts and the data was also assessed using Affymetrix QC
measures. Background intensity, RawQ (Scanner Noise), and scaling
factor were assessed for comparability between samples. Process
control spike in probes (PolyA) and hybridisation control spike-in
probes were assessed to ensure no problems with sample processing
or hybridisation, and % Present calls were assessed to ensure
adequate levels of expression data and ensure no potential outlying
replicate chips. Hierarchical Clustering, Principal Components
Analysis (PCA) and Multidimensional Scaling was then carried out to
assess the suitability of data for further analysis (Almac
Diagnostics). Following this analysis, samples were subjected to
Gene Ontology Analysis, Upstream Sequence Analysis, Metacore
Pathway Analysis to elucidate mechanisms.
[0166] Genes involved in ligand-independent ER signalling pathways
were modulated following treatment with 24mer (Table 2). ADAM 9 was
upregulated and has been shown to predict tamoxifen sensitivity
independently of ER. This data implies that high levels of FKBPL
regulate ER signalling.
TABLE-US-00006 TABLE 2 Genes differentially expressed following
treatment with FKBPL 24mer peptide Gene Name Fold Increase (+),
Fold Decrease (-) ADAM 9 +1.84 CREBBP -1.68 EGFR -1.78 HRAS +1.98
PDPK1 +1.96 PIK3R1 +1.68 SOS1 -1.79 RAF1 -1.4
[0167] Although the invention has been shown and described with
reference to particular examples, it will be understood by those
skilled in the art that various changes in the form and details may
be made therein without departing from the scope of the present
invention.
Sequence CWU 1
1
511087DNAHomo sapiens 1atggagacgc caccagtcaa tacaattgga gaaaaggaca
cctctcagcc gcaacaagag 60tgggaaaaga accttcggga gaaccttgat tcagttattc
agattaggca gcagccccga 120gaccctccta ccgaaacgct tgagctggaa
gtaagcccag atccagccag ccaaattcta 180gagcatactc aaggagctga
aaaactggtt gctgaacttg aaggagactc tcataagtct 240catggatcaa
ccagtcagat gccagaggcc cttcaagctt ctgatctctg gtactgcccc
300gatgggagct ttgtcaagaa gatcgtaatc cgtggccatg gcttggacaa
acccaaacta 360ggctcctgct gccgggtact ggctttgggg tttcctttcg
gatcagggcc gccagagggc 420tggacagagc taactatggg cgtagggcca
tggagggagg aaacttgggg ggagctcata 480gagaaatgct tggagtccat
gtgtcaaggt gaggaagcag agcttcagct gcctgggcac 540tctggacctc
ctgtcaggct cacactggca tccttcactc aaggccgaga ctcctgggag
600ctggagacta gcgagaagga agccctggcc agggaagaac gtgcaagggg
cacagaacta 660tttcgagctg ggaaccctga aggagctgcc cgatgctatg
gacgggctct tcggctgctc 720ctgactttac ccccacctgg ccctccagaa
cgaactgtcc ttcatgccaa tctggctgcc 780tgtcagttgt tgctagggca
gcctcagttg gcagcccaga gctgtgaccg ggtgttggag 840cgggagcctg
gccatttaaa ggccttatac cgaagggggg ttgcccaggc tgcccttggg
900aacctggaaa aagcaactgc tgacctcaag aaggtgctgg cgatagatcc
caaaaaccgg 960gcagcccagg aggaactggg gaaggtggtc attcagggga
agaaccagga tgcagggctg 1020gctcagggtc tgcgcaagat gtttggctga
ttaaaagtta aaccttaaaa gagaaaaaaa 1080aaaaaaa 10872349PRTHomo
sapiens 2Met Glu Thr Pro Pro Val Asn Thr Ile Gly Glu Lys Asp Thr
Ser Gln 1 5 10 15 Pro Gln Gln Glu Trp Glu Lys Asn Leu Arg Glu Asn
Leu Asp Ser Val 20 25 30 Ile Gln Ile Arg Gln Gln Pro Arg Asp Pro
Pro Thr Glu Thr Leu Glu 35 40 45 Leu Glu Val Ser Pro Asp Pro Ala
Ser Gln Ile Leu Glu His Thr Gln 50 55 60 Gly Ala Glu Lys Leu Val
Ala Glu Leu Glu Gly Asp Ser His Lys Ser 65 70 75 80 His Gly Ser Thr
Ser Gln Met Pro Glu Ala Leu Gln Ala Ser Asp Leu 85 90 95 Trp Tyr
Cys Pro Asp Gly Ser Phe Val Lys Lys Ile Val Ile Arg Gly 100 105 110
His Gly Leu Asp Lys Pro Lys Leu Gly Ser Cys Cys Arg Val Leu Ala 115
120 125 Leu Gly Phe Pro Phe Gly Ser Gly Pro Pro Glu Gly Trp Thr Glu
Leu 130 135 140 Thr Met Gly Val Gly Pro Trp Arg Glu Glu Thr Trp Gly
Glu Leu Ile 145 150 155 160 Glu Lys Cys Leu Glu Ser Met Cys Gln Gly
Glu Glu Ala Glu Leu Gln 165 170 175 Leu Pro Gly His Ser Gly Pro Pro
Val Arg Leu Thr Leu Ala Ser Phe 180 185 190 Thr Gln Gly Arg Asp Ser
Trp Glu Leu Glu Thr Ser Glu Lys Glu Ala 195 200 205 Leu Ala Arg Glu
Glu Arg Ala Arg Gly Thr Glu Leu Phe Arg Ala Gly 210 215 220 Asn Pro
Glu Gly Ala Ala Arg Cys Tyr Gly Arg Ala Leu Arg Leu Leu 225 230 235
240 Leu Thr Leu Pro Pro Pro Gly Pro Pro Glu Arg Thr Val Leu His Ala
245 250 255 Asn Leu Ala Ala Cys Gln Leu Leu Leu Gly Gln Pro Gln Leu
Ala Ala 260 265 270 Gln Ser Cys Asp Arg Val Leu Glu Arg Glu Pro Gly
His Leu Lys Ala 275 280 285 Leu Tyr Arg Arg Gly Val Ala Gln Ala Ala
Leu Gly Asn Leu Glu Lys 290 295 300 Ala Thr Ala Asp Leu Lys Lys Val
Leu Ala Ile Asp Pro Lys Asn Arg 305 310 315 320 Ala Ala Gln Glu Glu
Leu Gly Lys Val Val Ile Gln Gly Lys Asn Gln 325 330 335 Asp Ala Gly
Leu Ala Gln Gly Leu Arg Lys Met Phe Gly 340 345 31087DNAHomo
sapiens 3atggagacgc caccagtcaa tacaattgga gaaaaggaca cctctcagcc
gcaacaagag 60tgggaaaaga accttcggga gaaccttgat tcagttattc agattaggca
gcagccccga 120gaccctccta ccgaaacgct tgagctggaa gtaagcccag
atccagccag ccaaattcta 180gagcatactc aaggagctga aaaactggtt
gctgaacttg aaggagactc tcataagtct 240catggatcaa ccagtcagat
gccagaggcc cttcaagctt ctgatctctg gtactgcccc 300gatgggagct
ttgtcaagaa gatcgtaatc cgtggccatg gcttggacaa acccaaacta
360ggctcctgct gccgggtact ggctttgggg tttcctttcg gatcagggcc
gccagagggc 420tggacagagc taactatggg cgtagggcca tggagggagg
aaacttgggg ggagctcata 480gagaaatgct tggagtccat gtgtcaaggt
gaggaagcag agcttcagct gcctgggcac 540actggacctc ctgtcgggct
cacactggca tccttcactc aaggccgaga ctcctgggag 600ctggagacta
gcgagaagga agccctggcc agggaagaac gtgcaagggg cacagaacta
660tttcgagctg ggaaccctga aggagctgcc cgatgctatg gacgggctct
tcggctgctc 720ctgactttac ccccacctgg ccctccagaa cgaactgtcc
ttcatgccaa tctggctgcc 780tgtcagttgt tgctagggca gcctcagttg
gcagcccaga gctgtgaccg ggtgttggag 840cgggagcctg gccatttaaa
ggccttatac cgaagggggg ttgcccaggc tgcccttggg 900aacctggaaa
aagcaactgc tgacctcaag aaggtgctgg cgatagatcc caaaaaccgg
960gcagcccagg aggaactggg gaaggtggtc attcagggga agaaccagga
tgcagggctg 1020gctcagggtc tgcgcaagat gtttggctga ttaaaagtta
aaccttaaaa gagaaaaaaa 1080aaaaaaa 10874349PRTHomo sapiens 4Met Glu
Thr Pro Pro Val Asn Thr Ile Gly Glu Lys Asp Thr Ser Gln 1 5 10 15
Pro Gln Gln Glu Trp Glu Lys Asn Leu Arg Glu Asn Leu Asp Ser Val 20
25 30 Ile Gln Ile Arg Gln Gln Pro Arg Asp Pro Pro Thr Glu Thr Leu
Glu 35 40 45 Leu Glu Val Ser Pro Asp Pro Ala Ser Gln Ile Leu Glu
His Thr Gln 50 55 60 Gly Ala Glu Lys Leu Val Ala Glu Leu Glu Gly
Asp Ser His Lys Ser 65 70 75 80 His Gly Ser Thr Ser Gln Met Pro Glu
Ala Leu Gln Ala Ser Asp Leu 85 90 95 Trp Tyr Cys Pro Asp Gly Ser
Phe Val Lys Lys Ile Val Ile Arg Gly 100 105 110 His Gly Leu Asp Lys
Pro Lys Leu Gly Ser Cys Cys Arg Val Leu Ala 115 120 125 Leu Gly Phe
Pro Phe Gly Ser Gly Pro Pro Glu Gly Trp Thr Glu Leu 130 135 140 Thr
Met Gly Val Gly Pro Trp Arg Glu Glu Thr Trp Gly Glu Leu Ile 145 150
155 160 Glu Lys Cys Leu Glu Ser Met Cys Gln Gly Glu Glu Ala Glu Leu
Gln 165 170 175 Leu Pro Gly His Thr Gly Pro Pro Val Gly Leu Thr Leu
Ala Ser Phe 180 185 190 Thr Gln Gly Arg Asp Ser Trp Glu Leu Glu Thr
Ser Glu Lys Glu Ala 195 200 205 Leu Ala Arg Glu Glu Arg Ala Arg Gly
Thr Glu Leu Phe Arg Ala Gly 210 215 220 Asn Pro Glu Gly Ala Ala Arg
Cys Tyr Gly Arg Ala Leu Arg Leu Leu 225 230 235 240 Leu Thr Leu Pro
Pro Pro Gly Pro Pro Glu Arg Thr Val Leu His Ala 245 250 255 Asn Leu
Ala Ala Cys Gln Leu Leu Leu Gly Gln Pro Gln Leu Ala Ala 260 265 270
Gln Ser Cys Asp Arg Val Leu Glu Arg Glu Pro Gly His Leu Lys Ala 275
280 285 Leu Tyr Arg Arg Gly Val Ala Gln Ala Ala Leu Gly Asn Leu Glu
Lys 290 295 300 Ala Thr Ala Asp Leu Lys Lys Val Leu Ala Ile Asp Pro
Lys Asn Arg 305 310 315 320 Ala Ala Gln Glu Glu Leu Gly Lys Val Val
Ile Gln Gly Lys Asn Gln 325 330 335 Asp Ala Gly Leu Ala Gln Gly Leu
Arg Lys Met Phe Gly 340 345 52281DNAHomo sapiens 5tttcttgatg
aaggaggact tgaaaggcaa tgatggatgt gaaaggaaag gtaaagagaa 60gcctcaggta
gtcacccaag ggacagggcc ggttggagag agagtcccga ggttttatcc
120tggagaacac cctgtactga atgagctctg aacataaaga tagttagcat
aggagggcct 180gaagtctcca gataaaaggc tgctgccact atcatttacc
acgacctctg ccattctcca 240ctctattgtc atccgccccc agtctccatt
ccaggacttc tctacacttt gactttttgt 300ttgtttgttt gtttgtttga
gacggagtct tgcgctgtcg cccaggctgg agcgcagtgg 360cacgatcttg
gctcaccgca agctccgcct tccgggttca tgccattctc ctgcctcagc
420ctcccgggta gctgggacta taggtgcccg ccaccacgcc cagctaattt
tttgtatttt 480tagtagagac ggggtttcac catgttgtcc aggctggtct
cgaacccctg acctcaagtg 540atccccccgc cgccccgccc cctccccccg
ccccgccccc ccccgccgcc tcggcctccc 600aaattgctgg gattacaggc
gtgcgcgatg cccggctttt tatttattta tttatttatt 660tttgaggcgg
gaatcttgct ctgtcgccag gctggattgc agtggcacca tctcggctca
720ctgcaacctc cgactccctg gttcaagcga ttctcccacc tcagcctccc
aagtagctgg 780gattacaggc acacgccacc atgcccagct aactttttgt
atttttagta gagacgagat 840ttcaccatgt tgccaggatg gtctcgatca
cctgacctcg tgatccgccc acctcagcct 900cccagagtct cagttgccaa
agctggagtg caatggcgcg atctcggctc actgcaacct 960ccgcttccca
ggtaagccat tctcctgcct cagcctcctg ggtagctggg atataggcgc
1020ccgccatcac gccgagctat ttttgcattt ttagtagaga cggggtttca
ccatgttggc 1080caggctggtc ttgaactcct gacctcaacc tcccaaagtg
ctgggattac aggcgtgagc 1140caccgcgccc ggcccacctt tttttttttt
tttttttttt ttttttgttt gagacggagt 1200ctctagtctc gctctgtcgc
ccaggctgga gtgcaatggt gtgatctcgg ctcactgcaa 1260cgtctgtctc
ccgggttcaa gcgattctcc tgtttcagcc ttccgagtag ttgggattac
1320aggcgcgcgc caccatgacc tactaatttt tgtattttta gtagagacag
ggtctcacca 1380tgttggccca ctttgactct tgagcagcct ggccagcccg
accgcgccaa attctgttcg 1440attctgccta gttcggttgc tctggcctag
ttcagttgct aaggcctgga gcttcatggt 1500tgcggaggaa atgatgtcac
gttcaatagg cgggctaacc agattcctcc cttctcccga 1560ttggctgcca
ggaatttgac tagattcgga gtctcgcggg ctccagggtt agttgtcagt
1620atctttccca gttgttccgc cccctacccc cttggctgcc aggaatttga
ctagattcgg 1680agtctcgcgg gctccagggt tagttgtcag tatctttccc
agttgttccg ccccctaccc 1740ccgcctcccg caccgcgccc ctctccggct
gccctctccg cgtggggcaa ggctccgagg 1800gcagcattca gtagccattt
agctttggaa ggagaggtga ttcgaatggc ccggctcctc 1860ctgtcaccat
gctaggcact ttggccgcgc aggtacttat tgacccgacc gggtgtccgt
1920agttggcgcg gctaccttaa ccgcagggaa ttgtggaatt tatagttcta
aattatatgt 1980gggtggaacg gggaagctgg agcagatttt tggaggaaag
caaaactggg gactttcagg 2040actaggggcc tgggtctcag aagaatggga
aaggacgaga aaggagtcta aataagaacc 2100ctgctattag cattgtttgg
ttttcttttc aggtgctgac ctgaacctgg ttcatccctt 2160tctgaccaaa
actgttcact caccgtggaa gggactaagc atccatatgg agacgccacc
2220agtcaataca attggagaaa aggacacctc tcagccgcaa caagagtggg
aaaagaacct 2280t 2281
* * * * *