| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Endocrinology |
1 Unité INSERM 540, Montpellier, France; 2 Laboratoire de Biologie Cellulaire et Hormonale, Hôpital Arnaud de Villeneuve, Montpellier, France; and the 3 Department of Obstetrics and Gynecology, University of Turin, Turin, Italy
 |
ABSTRACT |
|---|
 Top ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
and ERß levels in 58 ovarian cancer patients, that ERß expression decreased in cysts and ovarian carcinomas as compared with normal ovaries and that this decrease is attributable only to a selective loss in ERß expression during cancer progression. To address the question of a possible involvement of ERß in ovarian cancers, we restored ER and ERß expression in two human ovarian cancer cell lines PEO14 (ER-negative) and BG1 (ER-positive) using adenoviral delivery. ER, but not ERß, could induce progesterone receptor and fibulin-1C. Moreover, ER and ERß had opposite actions on cyclin D1 gene regulation, because ERß down-regulated cyclin D1 gene expression, whereas ER increased cyclin D1 levels. Interestingly, ERß expression strongly inhibited PEO14 and BG1 cell proliferation and cell motility in a ligand-independent manner, whereas ER had no marked effect. Induction of apoptosis by ERß also contributed to the decreased proliferation of ovarian cancer cells, as shown by Annexin V staining. This study shows that ERß is an important regulator of proliferation and motility of ovarian cancer and provides the first evidence for a proapoptotic role of ERß. The loss of ERß expression may thus be an important event leading to the development of ovarian cancer. |
INTRODUCTION |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
(2
, 3)
, only a minor proportion of patients (ranging from 7–18%) respond clinically to anti-estrogen treatment (4
, 5)
. The role of estrogens has been recently highlighted by the results of three large prospective studies showing that estradiol uptake in postmenopausal stage increased the risk of ovarian cancer incidence and mortality in women who used long-term estrogen replacement therapy (4
, 6, 7, 8)
. Estrogen effects are mediated by two estrogen receptors, ER (NR3A1) and ERß (NR3A2), which belong to a large family of nuclear receptors (9
, 10)
. The generation of the different estrogen receptor knockout (ERKO) mice provides ideal models to analyze the distinct roles of both estrogen receptors in various tissues (11
, 12)
. The ovarian phenotype of ERKO female mice is distinct from that of ERßKO mice. ERKO females are infertile whereas ERßKO females exhibit inefficient ovarian function and subfertility. Interestingly, double knockout mice (ERßKO) exhibit phenotypes that most heavily resemble those of the ERKO, with the exception of the ovarian phenotype, characterized by progressive germ cell loss accompanied by re-differentiation of the surrounding somatic cells, suggesting an important role for both ER forms in this tissue (13)
.
In the uterus, ERßKO mice show increased cell proliferation and an exaggerated response to 17ß-estradiol (E2; ref. 14
). Moreover, at least in the prostate, ERß is involved in the regulation of epithelial growth, and its absence results in hyperplasia of the prostatic epithelium (15)
. In the rodent mammary gland, 90% of ERß-bearing cells do not proliferate (16)
, confirming the involvement of ERß in the control of the proliferation in vivo. Several in vitro studies also show some evidence that ERß may negatively regulate cellular proliferation and have a protective role in normal breast and prostate (17, 18, 19)
. A loss of ERß expression or a decreased in ERß/ER ratio in epithelial ovarian cancer as compared with normal tissues has been reported consistently by several groups (20, 21, 22)
. This loss of ERß could thus constitute a crucial step in ovarian carcinogenesis and hormone unresponsiveness.
In this study we compared ER and ERß expression in different ovarian samples and showed that the increase in the ER/ERß mRNA ratio observed earlier in ovarian carcinomas (20, 21, 22)
was attributable to a selective decrease in ERß mRNA expression without significant variations in ER levels. To analyze ERß role, we engineered ER-positive and ER-negative ovarian cancer cell lines to express functional ERß. Interestingly, ERß expression had major effects on proliferation, motility, and apoptosis of ovarian cancer cells. All these results suggest that ERß could exert a protective role against ovarian cancer development.
|
MATERIALS AND METHODS |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
.
|
, ERß, and ribosomal 18S RNA levels in ovarian tissues, using ABI Prism 7700 Sequence Detector System (PE Applied Biosystems, Foster City, CA). The primers used for ERs and 18S are described in Table 2
. The thermal PCR conditions comprised an initial step at 95°C for 15 minutes and a two-step PCR for 45 cycles (20 seconds at 94°C followed by 20 seconds at 68°C and 15 seconds at 94°C followed by 20 seconds at 65°C for ER and ERß, respectively) or 35 cycles (15 seconds at 94°C followed by 15 seconds at 67°C for 18S). To create a standard curve for each gene, RNAs were produced by in vitro transcription from linearized templates corresponding to ER, ERß, and 18S cDNA constructs using T7 or T3 polymerases and reverse transcribed to cDNA.
|
-positive cells) were used in this study. PEO14 (obtained from Dr. Langdon, Hospital of Edinburg, United Kingdom) cells were cultured in RPMI 1640 (Life Technologies, Inc., Eraguy, France) supplemented with 10% FCS and gentamicin in the presence of 5% CO2. BG1 cells (ref. 24
; obtained from Dr. C. E. Welander, Emory University, Atlanta, GA) were cultured in Mc Coy’s medium (Life Technologies, Inc., Eraguy, France) containing 10% FCS. The human breast cancer cell line MCF-7 was cultured in DMEM-F12 medium supplemented with 10% FCS. To wean the cells off steroids, they were cultured in phenol red-free RPMI (PEO14 cells for 2 days) or in phenol red-free DMEM-F12 (BG1 and MCF-7 cells for 5 days) supplemented with 10% charcoal dextran-treated FCS (CDFCS).
Recombinant Adenovirus Construction, Propagation, and Infection.
The adenoviruses Ad5, Ad-ER and Ad-ERß used in this study have been described previously (17)
. PEO14 and BG1 cells were infected overnight with the different viruses. Ethanol control vehicle or E2 treatment (10–8 mol/L) began 18 hours after infection. The optimal infection conditions were determined for both cell lines using a ß-galactosidase encoding virus to determine the optimal multiplicity of infection (MOI). We observed a very efficient infection of cells when increasing the MOI from 0 to 100, leading to an infection of about 90% of the cells at MOI 100 for PEO14 cells and MOI 25 for BG1 cells (data not shown).
Plasmids.
The luciferase reporter plasmid ERE2-TK-LUC contains two copies of the consensus estrogen-responsive element (ERE) cloned upstream of the minimal herpes simplex virus thymidine kinase promoter. Cytomegalovirus (CMV)-ER and CMV-ERß correspond to the wild-type human ER and ERß cDNAs cloned into CMV5 plasmid under the control of the CMV promoter and were a kind gift of Dr. B. S. Katzenellenbogen. A CMV-Gal reporter was used as an internal control and corresponds to the ß-galactosidase gene cloned in CMV5.
Transient Transfection and Reporter Assays.
Approximately 3 x 105 PEO14 cells were seeded in 6-well plates 48 hours before transfection in phenol red-free RPMI 1640 supplemented with 10% CDFCS. Transfections were performed overnight with Lipofectamin 2000 (Invitrogen) according to the manufacturer’s protocols, using 2 µg of luciferase-reporter construct, 0.5 µg of the internal reference CMV-GAL, and 0.15 µg of CMV-ER expression vectors or recombinant viruses per well at MOI 100. Cells were then treated with 10–8 mol/L E2 or with ethanol vehicle. Cells were harvested 48 hours after E2-treatment and cell extracts prepared. The cells were lysed directly in the plates with 200 µl of cell culture lysis reagent (Promega). ß-Galactosidase and luciferase were determined as described previously (17)
.
Detection of ER and ERß Protein by Immunohistochemistry.
PEO14 cells were seeded in 10% CDFCS DMEM-F12 on sterile coverslips in 6-well plates and infected with Ad5, Ad-ER, or Ad-ERß at MOI 50. Two days after infection, the cells were fixed (4% formaldehyde 12 minutes/methanol 5 minutes/acetone 2 minutes) and washed with PBS. The coverslips were incubated for 30 minutes with PBS containing non-immune rabbit serum (1:40). Then the cells were incubated with the primary antibody (ER SRA-1000 1:2000, Stressgen; ERß 503 immunoglobulin Y 1:2500; ref. 16
) in PBS for 60 minutes at room temperature. The cells were then incubated with the secondary antibody (antimouse or antichicken peroxidase conjugate, 1:3000, Sigma, St. Louis, MO) in PBS-bovine 
globulin for 30 minutes at room temperature. Finally, the cells were incubated with a diaminobenzidine chromogen solution [0.66 mg/ml in PBS +0.08% H2O2 (30 vol)] for 10 minutes at room temperature. The cells were counterstained with hematoxylin.
RNA Isolation and Reverse Transcription PCR.
Total RNA was isolated using RNeasy mini kit (Qiagen) according to protocols provided by the manufacturer. Five micrograms of total RNA were subjected to a reverse transcription step using the M-MuLV Reverse Transcriptase RNase H- and random-hexamer primers (Amersham Biosciences) in a 20-µl reaction volume. PCR co-amplification was performed using 1:20 reverse transcription reaction using DyNAzyme EXT DNA polymerase and with different primers in the same reactions. Cycles of 30 seconds at 94°C, 1 minute at 60°C, and 1 minute at 72°C were done 29 times. One-tenth of each PCR was run on 1.5 to 2% agarose gel with ethidium bromide. Primers used were described previously for ER (25)
, ERß (26)
, and hypoxanthine phosphoribosyl transferase (27)
.
Northen Blot Analysis.
Twenty micrograms of total RNA were loaded on a 1% agarose-formaldehyde gel. RNA was then transferred to nylon membranes. Membranes were then hybridized with the different probes at 42°C in hybridization solution (ULTRAhyb, Ambion). The probes were 32P-labeled by multiprime DNA synthesis. The washes were performed as described previously (28)
. When required, the membranes were stripped of probe by boiling in 0.5% SDS solution and rehybridized. A probe for human 18S was used to confirm equal loading of RNA in all of the wells. Signals were quantified using PC BAS 1000 reader (Fujix).
Cell Proliferation Studies.
PEO14 and BG1 cells were maintained respectively for 48 hours and for 5 days in 10% Charcoal Dextran (CD)-FCS phenol red-free medium and then seeded at 20,000 cells/well in 24-well dishes. Cells were infected overnight with the different viruses. The next morning, the medium was removed and replaced with fresh 10% CDFCS medium. Treatment with E2 or ICI 182,780 began at the same time. After 2, 4, and 6 days of treatment, the total cell DNA was quantified by 3,5-diaminobenzoic acid assay as described previously (17)
.
Wound-Healing Assay.
Cells were plated in 6-well dishes in RPMI 1640 containing 10% CDFCS. Cells were infected with the different viruses overnight. The next morning, ethanol or E2 treatment began. After 24 hours of treatment, wound-induced migration was triggered by scraping the cells at day 1 with a blue tip, and the wound was pictured immediately (t = 0 hours). Twenty-four hours later the cells were pictured again. The percentage of wound filling was calculated by measuring the remaining gap space on the pictures.
Apoptosis Detection by Staining with Annexin V.
Apoptosis was assessed by staining DNA with Hoechst 33258 and by cell surface binding of Annexin V. The Annexin-V-Alexa 568 (Roche Diagnostic, Meylan, France) was used to detect apoptosis by fluorescence microscopy. PEO14 and BG1 cells were weaned off steroids for 4 days and then seeded in 12-well dishes. Cells were infected overnight with the different viruses. The next day, cells were treated with control vehicle ethanol or E2. After 48 hours of treatment, the cells were harvested, washed twice in PBS, and then resuspended in a binding buffer [HEPES, 10 mM (pH 7.4), 140 mM NaCl, 5 mM Nacl2], before staining with Annexin-V-Alexa 568 incubation reagent and Hoechst. Cells were then incubated in the dark for 15 minutes at room temperature. Cells were washed twice in PBS and immediately laid down on microscope slides with subsequent mounting in the anti-fading agent Mowiol. The scoring of apoptotic cells (%) was calculated by dividing the number of apoptotic cells (Annexin V) by the total of cells counted per cross-section (Hoechst). Counting by slide was performed, and this was repeated in three different experiments.
Statistics.
Data indicated in the text represent mean ± SD. Statistical differences within the populations were determined by Kruskal-Wallis nonparametric tests for quantitative parameters. P < 0.05 was considered as significant.
|
RESULTS |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
ER and ERß mRNA Expression in Ovarian Tissues.
We first analyzed by quantitative reverse transcription (RT)-PCR ER and ERß RNA expression in normal ovaries, ovarian cysts, and ovarian carcinomas (Fig. 1)
. All ovarian tissues analyzed expressed detectable levels of ER mRNA, and there was no significant difference in ER levels mRNA among the group of normal ovaries and the groups of ovarian cysts and ovarian carcinomas (P = 0.45; Fig. 1
). In contrast, ERß mRNA expression varied among the three groups of ovarian tissues. ERß was detectable in most normal ovaries (ERß+: 16 of 22, 72.7%), whereas ERß levels decreased in ovarian cysts (ERß+: 4 of 7, 57.1%) and in ovarian carcinomas (ERß+: 9 of 29, 31%). Statistical analysis showed a significant difference between the three groups (Kruskal-Wallis test, P = 0.001), with a marked decrease in ERß mRNA levels in ovarian cancers as compared with normal ovaries (P = 0.0003), suggesting that the loss of ERß expression may be an important early step of ovarian tumor progression.
|
and ERß. and ERß expression in ovarian cancer cells lines using adenoviruses encoding hER or hERß (Ad-ER and Ad-ERß). The expression of ER and ERß in Ad-ER- and Ad-ERß-infected PEO14 cells was checked by RT-PCR (Fig. 2A)
. We were not able not detect the expression of ER and ERß RNAs in PEO14 cells non-infected or infected with the nonrecombinant virus Ad5. After infection with Ad-ER or Ad-ERß, a high expression of corresponding ER and ERß mRNA could be observed. Immunohistochemistry experiments using ER- and ERß-specific antibodies show that ER and ERß proteins were not detected in Ad5-infected cells (Fig. 2B, c and d)
, whereas ER- and ERß-infected cells displayed a nuclear staining (respectively, Fig. 2B, a and b
).
|
encoding virus and plasmid in the presence of E2 (Fig. 2C)
. ERß encoding virus and plasmid were able to activate the transcription in the presence of E2, but the stimulation was half of that obtained with ER. The pure anti-estrogen ICI 182,780 did not stimulate ER or ERß activity but completely abolished E2-induced activities of ER and ERß (Fig. 2C)
.
ER and ERß Effects on Endogenous Target Genes.
As another control of the functionality of ERß in this system, we next determined whether the expression of endogenous genes known to be regulated by E2 in ovarian or breast ER-positive cells could also be modulated by ER or ERß in infected PEO14 cells (Fig. 3, A and B)
. ER was able to activate the expression of fibulin 1C and progesterone receptor (PR) in the presence of E2, whereas ERß had no effect. pS2 mRNA could not be detected in ovarian cancer cells infected with ER or ERß viruses. pS2 gene is likely to be altered in ovarian cancers. Indeed, although some ovarian tumors are producing pS2, pS2 is not regulated by estrogens (29
, 30)
. The mechanisms underlying this unresponsiveness remain to be determined. The pure anti-estrogen ICI 182,780 was not able to modify the levels of fibulin-1C and PR expression. Interestingly, ER and ERß also had an opposite effect on expression of cyclin D1 mRNA levels. Indeed, ER induced cyclin D1 in the presence of E2, whereas ERß inhibited cyclin D1 expression in a ligand-independent manner. Moreover, treatment of the cells with ICI 182,780 was not able to alleviate this inhibition. We have also analyzed the expression fibulin-1C and cdki p21WAF-1 genes in ER-positive BG-1 cells infected with Ad-ERß virus (Fig. 3, C and D)
. Northern blot experiments show that fibulin-1C RNA levels were increased after E2-treatment in non-infected or Ad5-infected BG-1 cells. Introduction of ERß in these cells did not alter this regulation. p21WAF-1 RNA was down-regulated by E2 in control cells, suggesting that the cells were proliferating more rapidly in the presence of E2. On the other hand, ERß was able to increase by about 2-fold p21WAF-1 levels in a ligand-independent manner. Interestingly, neither E2 nor ICI was able to modulate these effects.
|
. Control cells presented a similar growth pattern in the absence or in the presence of E2 (Fig. 4A
, left panel). When PEO14 cells were infected with Ad-ER virus, a moderate ligand-independent inhibition of proliferation occurred (Fig. 4A
, middle panel). Conversely, ERß strongly inhibited the proliferation in a ligand-independent manner (Fig. 4A
, right panel). The pure anti-estrogen ICI 182,780 had no effect by itself on the proliferation of naive cells and could not modulate the proliferation rate of ER- or ERß-expressing cells (Fig. 4B)
. These results confirm that inhibition of the proliferation by ERß (or ER) are ligand-independent, when their expression is restored in ER-negative ovarian cancer cells. We next determined whether this inhibitory effect of ERß could be obtained in ER-positive BG1 cell line (Fig. 4, C and D)
. The proliferation of these cells is increased by estrogens (30
, 31)
as shown in control cells (non-infected or infected with the nonrecombinant virus Ad5; Fig. 4, C and D
). When BG1 cells were infected with Ad-ERß virus, the proliferation was inhibited by 60%. This inhibition appears to be E2-independent, as suggested by the lack of effect of ICI 182,780 on the proliferation rate, and to involve an increase in p21WAF-1 expression as shown above.
|
. After 24 hours of migration, Ad5-infected PEO14 cells had filled 75% of the wound (Fig. 5B)
. ER-infected cells had filled about 65% of the wound in the absence or the presence of E2. However, ERß expressing cells had a very slow migration ability as they filled only 20 to 30% of the gap.
|
virus, about 8% of cells were in early apoptosis (Fig. 6, A and C)
, whereas 20% of ERß-infected cells were undergoing apoptosis. E2 treatment of PEO14 infected with Ad-ER increased by 2-fold the percentage of apoptotic cells, whereas E2 had no effect on ERß-induced apoptosis. Introduction of ERß in BG1 cells led to a 2-fold increase of apoptosis in the absence of E2 (Fig. 6, B and D)
. In BG1 cells, E2 had antiapoptotic properties as shown in non-infected, Ad5-infected, but also ERß-expressing cells, suggesting that the reduction of apoptosis may be attributable to the presence of endogenous ER.
|
|
DISCUSSION |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
At the clinical level, we found by quantitative PCR, using samples from 58 patients, that ERß RNA levels are reduced during ovarian tumor progression. By contrast, similar expression of ER mRNA was observed in normal ovaries and ovarian carcinomas. Numerous breast cancer studies suggest that ERß expression declines when cells turn cancerous (32, 33, 34, 35)
, whereas ERß expression in ovarian cancers is less documented, because studies have only used a limited sample number (21
, 22) . The fact that such decrease is observed not only in ovarian but also in breast, colon, and prostate cancers (32, 33, 34, 35, 36, 37)
suggests that the loss of ERß expression could be an important event in the pathogenesis of cancers and may reflect a general cellular mechanism contributing to the carcinogenesis of estrogen-dependent tissues.
On the basis of the decreased expression of ERß in ovarian cancer, our goal was to determine the possible protective effect of ERß against abnormal proliferation. To investigate this hypothesis, we introduced ERß in ovarian cancer cells and studied its effects on cell growth. Our work shows that ERß is involved in the regulation of proliferation of ovarian cancer cells, because ERß inhibits their proliferation. In breast and prostate cancers, exogenous ERß expression also reduces cell proliferation (17
, 19)
, suggesting that this is a general mechanism in ER-negative cancer cells. In ER-positive BG-1 cells, we also observed a decreased proliferation when ERß was expressed in these cells. These findings are in agreement with the results of Omoto et al. (18)
who showed that MCF-7 cells expressing stably ERß1 (ERßwt) or ERß2 (ERßcx) display a reduced cell growth and colony formation in an anchorage-independent situation. Recently, two studies showed that the expression of ERß in ER-positive breast cancer cells inhibits their growth (38
, 39) . Interestingly, ERß knockout analysis show that in prostate ERß controls, the regulation of epithelial growth and its absence results in hyperplasia of the prostatic epithelium (15)
. All together, these data clearly demonstrate that ERß is an inhibitor of proliferation, not only in ER-negative but also in ER-positive breast and ovarian cancer cells, supporting a general antiproliferative role for this receptor. The decreased proliferation that we observed in ovarian cancer cells could be the result at least in part of the inhibition of cyclin D1 expression by ERß. This down-regulation of cyclin D1 expression confirms findings that showed how ERß completely inhibits cyclin D1 gene expression in HeLa cells, whereas ER activates cyclin D1 mRNA levels (40)
. Two other studies also suggest that ERß might reduce cell proliferation by inhibiting cyclin D1 gene expression in breast (38
, 39)
. Several results raise the possibility that overexpression of cyclin D1 may contribute to the pathogenesis of epithelial ovarian cancers (41
, 42)
. On the other hand, p21WAF-1 up-regulation by ERß could also account for the decreased proliferation triggered by ERß. Several groups have also reported such regulation when ERß is expressed in breast cancer cells (17
, 38
, 39)
.
In addition to cyclin D1 regulation, we show that in the presence of E2, ER induced the expression of PR, fibulin-1C in PEO14-infected cells, whereas ERß has no effect on these genes. Very little is known about potential estrogen-regulated genes in ovarian tissue. This holds true for ERß target genes. To our knowledge, our work is the first evidence that expression of ERß in ovarian cancer cells can regulate endogenous gene levels. To date, most of the studies performed in different cell types have shown that ERß was generally less active than ER (43)
. Moreover, except for a few cases (44)
, all genes that are regulated by ERß are also regulated by ER in breast cancer cells (17
, 18)
. On the other hand, in bone, most of the genes that are regulated by estrogens in wild-type mice are also regulated in the same manner in ERßKO mice, suggesting that ER is the main ER transactivator in bone (45)
. More recently, an extensive search of ERß target genes in osteosarcoma cells has revealed that most of ERß target genes were also ER-regulated genes (46)
. All together, these data suggest that despite regulating a small set of specific genes, ERß may have major effects on tumor proliferation, survival, and invasion.
Ovarian cancer cells are characterized by their ability to invade freely the peritoneal cavity, which also accounts for their high aggressiveness and high morbidity (31) . We investigated the potential modulation of motility by ERß, as another key event occurring during tumor development. We indeed observed that ERß drastically inhibits motility of ER-negative ovarian cancer cell line as observed previously in breast and prostate cancer models exogenously expressing ERß (17 , 19) .
It was also of great interest to analyze the effects of ERß on apoptosis, because cell growth results from the balance of both cell cycle events and apoptosis regulation. Indeed, ovarian physiology involves apoptosis, because during the repair process of the ovarian surface epithelial cells after incessant ovulation, ovarian surface epithelium that are sequestered in inclusion cysts are normally eliminated by apoptosis, thereby removing potential sites of ovarian tumorigenesis (47) . Ghahremani et al. (47) proposed that the etiology of ovarian cancer stems from the loss of the apoptotic pathways that normally eliminate ovarian surface epithelium in inclusion cysts. Therefore, malignant transformation occurs when there is a disruption of the normal balance between cellular proliferation and apoptosis. We thus hypothesized that the loss of ERß and its potential proapoptotic function could represent an early process in ovarian transformation. And in fact, the introduction of ERß in ovarian cancer cells led to increased apoptosis as shown by Annexin V staining. This is the first observation that ERß controls apoptosis of ovarian cancer cells. Recent work has also suggested that in normal ovary, ERß could up-regulate FasL, a major apoptotic protein ligand (48) . In addition, we have shown recently that exogenous expression of ERß in prostate cancer cells leads also to apoptosis (19) . The precise mechanisms underlying apoptosis control by ERß will need to be investigated in the future.
In summary, our data show that ERß appears to be a key regulator of ovarian carcinogenesis. The loss of ERß expression during ovarian carcinogenesis may be a crucial and early step leading to dysregulated growth. Moreover, introduction of ERß in ovarian cancer cells has allowed us to show for the first time that this receptor exhibits protective properties against cancer development by increasing apoptosis and decreasing proliferation and motility. This suggests that ERß could act as a tumor suppressor in the ovary. The identification of ERß-regulated specific genes involved in epithelial proliferation and apoptosis may thus be a clue for understanding the progression of ovarian cancer and for the design of new target therapies.
|
ACKNOWLEDGMENTS |
|---|
and ERß cDNAs; J. P. Daures for statistical analysis; and the Vector Core of the University Hospital of Nantes, supported by the Association Française contre les Myopathies, for the production of adenovirus. |
FOOTNOTES |
|---|
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
Requests for reprints: INSERM U540, Molecular and Cellular Endocrinology of Cancers, 60 rue de Navacelles, 34090 Montpellier, France. Phone: 33-4-67-04-30-84; Fax: 33-4-67-04-30-84; E-mail: lazennec{at}montp.inserm.fr
Received 2/17/04. Revised 5/27/04. Accepted 6/22/04.
|
REFERENCES |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
This article has been cited by other articles:
|
|
 |
|
  L. Albanito, A. Madeo, R. Lappano, A. Vivacqua, V. Rago, A. Carpino, T. I. Oprea, E. R. Prossnitz, A. M. Musti, S. Ando, et al. G Protein-Coupled Receptor 30 (GPR30) Mediates Gene Expression Changes and Growth Response to 17{beta}-Estradiol and Selective GPR30 Ligand G-1 in Ovarian Cancer Cells Cancer Res., February 15, 2007; 67(4): 1859 - 1866. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Alvaro, B. Barbaro, A. Franchitto, P. Onori, S. S. Glaser, G. Alpini, H. Francis, L. Marucci, P. Sterpetti, S. Ginanni-Corradini, et al. Estrogens and Insulin-Like Growth Factor 1 Modulate Neoplastic Cell Growth in Human Cholangiocarcinoma Am. J. Pathol., September 1, 2006; 169(3): 877 - 888. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. J M O'Donnell, K. G Macleod, D. J Burns, J. F Smyth, and S. P Langdon Estrogen receptor-{alpha} mediates gene expression changes and growth response in ovarian cancer cells exposed to estrogen Endocr. Relat. Cancer, December 1, 2005; 12(4): 851 - 866. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Lazennec Retraction: Article on Estrogen Receptor {beta} in Ovarian Carcinogenesis Cancer Res., June 15, 2005; 65(12): 5480 - 5480. [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Cancer Research | Clinical Cancer Research |
| Cancer Epidemiology Biomarkers & Prevention | Molecular Cancer Therapeutics |
| Molecular Cancer Research | Cancer Prevention Research |
| Cancer Prevention Journals Portal | Cancer Reviews Online |
