The effects of estradiol and selective estrogen receptor modulators on gene expression and messenger RNA stability in immortalized sheep endometrial stromal cells and human endometrial adenocarcinoma cells

Expression profile analysis of LncRNAs and mRNAs in pre-receptive endometrium of women with polycystic ovary syndrome undergoing in vitro fertilization-embryo transfer

BACKGROUND

To compare the expression levels of long non-coding RNA (lncRNA) and messenger RNA (mRNA) in pre-receptive endometrium between patients with Polycystic Ovary Syndrome (PCOS)and normal ovulation undergoing in vitro fertilization-embryo transfer (IVF-ET).

METHODS

Endometrial tissues were collected with endometrial vacuum curette in pre-receptive phase (3 days after oocytes retrieval) from PCOS and control groups. LncRNAs and mRNAs of endometrium were identified via RNA sequencing and alignments. A subset of 9 differentially expressed lncRNAs and 11 mRNAs were validated by quantitative reverse transcription polymerase chain reaction(qRT-PCR)in 22 PCOS patients and 18 ovulation patients. The function of mRNAs with differential expression patterns were explored using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG).

RESULTS

We found out 687 up-regulated and 680 down-regulated mRNAs, as well as 345 up-regulated and 63 down-regulated lncRNAs in the PCOS patients in contrast to normal ovulation patients. qRT-PCR was used to detect the expression of 11 mRNAs, and validated that the expression of these 6 mRNAs CXCR4, RABL6, OPN3, SYBU, IDH1, NOP10 were significantly elevated among PCOS patients, and the expression of ZEB1 was significantly decreased. qRT-PCR was performed to detect the expression of 9 lncRNAs, and validated that the expression of these 7 lncRNAs IDH1-AS1, PCAT14, FTX, DANCR, PRKCQ-AS1, SNHG8, TPT1-AS1 were significantly enhanced among PCOS patients. Bioinformatics analysis showed that differentially expressed genes (DEGs) involved KEGG pathway were tyrosine metabolism, PI3K-Akt pathway, metabolic pathway, Jak-STAT pathway, pyruvate metabolism, protein processing in endoplasmic reticulum, oxidative phosphorylation and proteasome. The up-regulation of GO classification was involved in ATP metabolic process, oxidative phosphorylation, RNA catabolic process, and down-regulation of GO classification was response to corticosteroid, steroid hormone, and T cell activation.

CONCLUSION

Our results determined the characteristics and expression profile of endometrial lncRNAs and mRNAs in PCOS patients in pre-receptive phase, which is the day 3 after oocytes retrival. The possible pathways and related genes of endometrial receptivity disorders were found, and those lncRNAs may be developed as a predictive biomarker of endometrium in pre-receptive phase.

Metformin Regulates TET2 Expression to Inhibit Endometrial Carcinoma Proliferation: A New Mechanism

Objectives

To investigate the relationship between TET2 expression and endometrial cancer’s clinicopathological features and prognosis, and the effect of metformin on TET2 and 5hmC levels in endometrial cancer cells.

Methods

The clinical significance of TET2 expression in endometrial carcinoma was analyzed from TCGA public database. Eighty-eight patients with endometrial cancer and 20 patients with normal proliferative endometrium were enrolled in this study. TET2 and 5hmC were respectively detected by Immunohistochemistry and ELISA in endometrial tissues. Kaplan-Meier and Cox proportional hazard regression models were used to analyze relationships between TET2 and 5hmC and the overall survival of EC patients. Endometrial cell proliferation was assessed after TET2 gene knockdown. Western blotting and real-time PCR were used to detect the effect of metformin on TET2 expression and to explore whether AMPK is involved in metformin-mediated TET2 regulation.

Results

The clinical significance of expression of TET2 in endometrial cancer from TCGA public database confirmed that TET2 expression was significantly down-regulated in cancer samples and TET2 expression was also significantly different among different histopathological samples and TET2 is down-regulated in advanced, high-grade, and relapsed endometrial carcinoma tissues(P<0.05). Immunohistochemical analysis showed that TET2 and 5hmC levels were significantly lower in endometrial adenocarcinoma(P<0.05). TET2 expression was correlated with the degree of EC differentiation (P < 0.05). 5hmC levels were associated with clinical stage, differentiation, the depth of myometrial invasion, and lymph node metastasis (P < 0.05). The mean survival time of patients with negative staining for TET2 and 5hmC was shorter than that of patients with positive staining for both markers (P<0.05). Multivariate Cox regression analysis showed that TET2 expression was an independent risk factor for prognosis in patients with endometrial adenocarcinoma (HR = 14.520, 95% CI was 1.From 060 to 198.843, P = 0.045). siRNA-mediated TET2 knockdown increased the proliferation of EC cells. Metformin increased the levels of TET2 and 5hmC in EC cells. AMPK was involved in the regulation of TET2 by metformin.

Conclusions

TET2 may play an important role in EC development and may be a prognostic marker. Moreover, TET2 may be involved in a novel mechanism by which metformin inhibits EC cell proliferation.

Anandamide targets aromatase: A breakthrough on human decidualization

In each menstrual cycle endometrial stromal cells (hESC) proliferate and differentiate into specialized decidual cells, a process termed decidualization, which regulates endometrial receptivity. Decidualization is mainly controlled by sex ovarian hormones, estradiol (E₂) and progesterone. E₂ plays an important role in the expression of the progesterone receptor and promotes the endometrial stromal cells differentiation. Our group previously reported that anandamide (AEA) impairs decidualization through cannabinoid receptor 1 (CB1). In this study, we hypothesized whether AEA inhibitory effect on cell decidualization could be mediated through interaction with aromatase and consequent interference in estradiol production/signaling. We used an immortalized human endometrial stromal cell line (St-T1b) and human decidual fibroblasts (HdF) derived from human term placenta. In cells exposed to a differentiation stimulus, AEA-treatment prevents the increase of the expression of CYP19A1 gene encoding aromatase, E₂ levels and of estradiol receptor expression, that are observed in differentiating cells. Regarding CYP19A1 mRNA levels, the effect was partially reverted by a CB1 receptor antagonist and by a COX2 inhibitor. In addition, we report that AEA presents anti-aromatase activity in placental microsomes, the nature of the inhibition being the uncommon mixed type as revealed by the kinetic studies. Structural analysis of the AEA-Aromatase complexes determined that AEA may bind to the active site pocket of the enzyme. In overall we report that AEA inhibits aromatase activity and may affect E₂ signaling crucial for the decidualization process, indicating that a deregulation of the endocannabinoid system may be implicated in endometrial dysfunction and in fertility/infertility disorders.

Inhibition of CRM1 activity sensitizes endometrial and ovarian cell lines to TRAIL-induced cell death

BACKGROUND

CRM1 enrichment has been shown to be indicative of invasive as well as chemoresistant tumors. On the other hand, TRAIL, a powerful and specific anti-tumoral agent, has yet to be used effectively to treat gynecological tumors in patients. In the present study, we examined if CRM1, a nuclear exporter capable of mediating protein transport, could be a relevant target to restore chemosensitivity in chemoresistant cells. We thus explored the hypothesis that CRM1-driven nuclear exclusion of tumor suppressors could lead to chemoresistance and that CRM1 inhibitors could present a novel therapeutic approach, allowing sensitization to chemotherapeutic agents.

METHODS

Ovarian cancer cell lines, as well as endometrial cancer cell lines, were treated with leptomycin B (LMB), cisplatin and TRAIL, either singly or in combination, in order to induce apoptosis. Western blot and flow cytometry analysis were used to quantify caspases activation and apoptosis induction. Immunofluorescence was used to determine nuclear localization of p53. Colony formation assays were performed to determine therapeutic effectiveness; p53 siRNA were used to establish p53 role in sensitization. Additional information from GEO database and Prognoscan allowed us to contextualise the obtained results. Finally, qRT-PCR was performed to measure apoptotic regulators expression.

RESULTS

TRAIL and LMB combination therapy lead to cleavage of caspase-3 as well as the appearance of cleaved-PARP, and thus, apoptosis. Further experiments suggested that sensitization was achieved through the synergistic downregulation of multiple inhibitor of apoptosis, as well as the activation of apoptotic pathways. p53 was enriched in the nucleus following LMB treatments, but did not seem to be required for sensitization; additional experiments suggested that p53 opposed the apoptotic effects of LMB and TRAIL. Results obtained from public data repositories suggested that CRM1 was a driver of chemoresistance and poor prognostic; DR5, on the other hand, acted as as a marker of positive prognostic.

CONCLUSIONS

Taken together, our results suggest that the use of CRM1 inhibitors, in combination to chemotherapeutic compounds, could be highly effective in the treatment of gynecological malignancies.

Risk factors for ovarian involvement in young and premenopausal endometrioid endometrial cancer patients

OBJECTIVE

This study aimed to investigate the incidence of ovarian malignant involvement in young and premenopausal endometrioid endometrial cancer and study the possible risk factors.

METHODS

Premenopausal patients 45 years of age or younger with endometrioid endometrial cancer treated at the OB/GYN Hospital of Fudan University between 2009 and 2013 were identified. The incidence of ovarian malignant involvement in young and premenopausal endometrioid endometrial cancer patients were calculated and the possible risk factors were investigated.

RESULTS

A total of 144 younger (age ≤ 45, premenopausal) patients with endometrioid endometrial cancer were identified and coexisting malignant ovarian neoplasms were detected in 6 patients. Univariate analysis revealed that deeper myometrial invasion, positive lymphonode metastasis, positive LVSI, and high histologic grade (G2-G3) were associated with ovarian involvement in younger endometrial cancer patients. However, multivariate analysis revealed that only deep myometrial invasion was an independent risk factors for ovarian involvement (OR = 12.81, P = 0.046).

CONCLUSION

In conclusions, the incidence of coexisting ovarian malignant neoplasms in young and premenopausal patients with endometrioid endometrial cancer is low, and these findings may facilitate preoperative counseling of patients and decision making at the time of surgery.

Role of metformin in inhibiting estrogen-induced proliferation and regulating ERα and ERβ expression in human endometrial cancer cells

Diabetes mellitus (DM) is an important factor that contributes to the development of type I endometrial cancer (EC). Previous studies have demonstrated that metformin decreases mortality and risk of neoplasms in patients with DM. Since estrogen and estrogen receptor (ER) expression has been associated with the development of EC, the present study aimed to investigate the effects of metformin on cell proliferation and ER expression in EC cell lines that are sensitive to estrogen. The viability and proliferation of Ishikawa and HEC-1-A cells were measured following treatment with metformin and/or a 5' AMP-activated protein kinase (AMPK) inhibitor (compound C) with or without treatment with estradiol (E2). In addition, the levels of ERα, ERβ, AMPK, ribosomal protein S6 kinase β-1 (p70S6K), myc proto-oncogene protein (c-myc) and proto-oncogene c-fos (c-fos) were measured following treatment. Metformin significantly decreased E2-stimulated cell proliferation; an effect that was rescued in the presence of compound C. Metformin treatment markedly increased the phosphorylation of AMPK while decreasing p70S6K phosphorylation, indicating that metformin exerts its effects through stimulation of AMPK and subsequent inhibition of the mammalian target of rapamycin (mTOR) signaling pathway. In addition, metformin significantly inhibited ERα expression while increasing ERβ expression, whereas treatment with compound C reversed these effects. Reverse transcription-quantitative polymerase chain reaction analysis demonstrated that c-fos and c-myc expression were attenuated by metformin, an effect that was rescued in the presence of compound C. Therefore, metformin regulates the expression of ERs, and inhibits estrogen-mediated proliferation of human EC cells through the activation of AMPK and subsequent inhibition of the mTOR signaling pathway.

The role of fulvestrant in endometrial cancer

INTRODUCTION

Endometrial cancer is the most common malignancy of the female genital tract in industrialized countries. The traditional treatment of endometrial cancer is based on a surgical approach. In recent years, systemic endocrine therapy has demonstrated good efficacy in recurrent or metastatic setting, delaying progression, ameliorating quality of life and palliating symptoms. Areas covered: Phase I and II studies on selective estrogen receptor down-regulators used for the treatment of endometrial cancer treatment have been reviewed. The pharmacokinetic and pharmacodynamic features of selective receptor down-regulators have been also investigated. Expert opinion: Selective estrogen receptor down-regulators may exhibit clinical efficacy in the treatment of gynecological malignancies due to their pure estrogen receptor antagonist properties. However, up to now data are still limited and some unsolved questions remain. Fulvestrant has poor oral bioavailability and low pharmacodynamic characteristics. Further trials are required to examine new selective estrogen receptor down-regulator agents with better pharmacodynamic and pharmacokinetic profiles.

SUMO-1 Promotes Ishikawa Cell Proliferation and Apoptosis in Endometrial Cancer by Increasing Sumoylation of Histone H4

OBJECTIVES

To investigate the functional role of SUMO-1 on cell proliferation and apoptosis in endometrial cancer cells (Ishikawa line) and to explore the underlying regulatory mechanisms.

METHODS

Different concentrations of estradiol (E2) and small interfering RNA (siRNA) targeting the SUMO-1 (siCo) were treated in Ishikawa cells, and then quantitative polymerase chain reaction was used to examine the expression of progesterone receptor (PR) expression in Ishikawa cells. Western blots were applied to validate histone H4 sumoylation. CCK8 assay and flow cytometry were performed to investigate cell proliferation and apoptosis in Ishikawa cells.

RESULTS

Estradiol up-regulated the expression of PR messenger RNA, most obviously at 100 nM. SUMO-1 siRNA decreased the PR expression. Estradiol up-regulated H4 sumoylation and caused the increase of Ishikawa cell proliferation, whereas SUMO-1 siRNA down-regulated H4 sumoylation, inhibited the cell proliferation, and induced apoptosis. Furthermore, SUMO-1 siRNA-transfected cells were arrested in the S and G2/M phases and E2 increased the S and G2/M phases of Ishikawa cells.

CONCLUSION

SUMO-1 regulates the Ishikawa cell proliferation and apoptosis by the sumoylation of histone H4.

Developmental programming: postnatal estradiol modulation of prenatally organized reproductive neuroendocrine function in sheep

Gestational testosterone (TS) excess, acting via both the androgenic and estrogenic pathways, advances puberty and disrupts the neuroendocrine estradiol (E2) feedback and periovulatory hormonal dynamics in female sheep. These prenatally programmed defects may be subject to postnatal modifications by continued organizational and/or activational effects of steroids. This study investigated (1) the organizational contribution of prenatal estrogen excess and (2) the impact of postnatal exposure to E2 in modulating the effects of prenatal androgen excess (TS and dihydrotestosterone (DHT)) on puberty, neuroendocrine feedback mechanisms, and periovulatory hormonal dynamics in sheep. Pregnant Suffolk sheep were treated with TS, DHT, E2, or E2 plus DHT (ED) from days 30 to 90 of gestation. A subset of the control (C), TS, and DHT female offspring received a constant-release E2 implant postnatally. Findings revealed that (1) prenatal E2-treatment failed to reproduce the neuroendocrine disruptions predicted to be programmed by the estrogenic pathway and (2) prenatal E2D-treatment did not adequately replicate the reproductive neuroendocrine defects induced by prenatal TS excess. More importantly, continuous postnatal E2-treatment, while delaying the onset of puberty and reducing the inhibitory effects of E2 on tonic luteinizing hormone (LH) release, failed to amplify the E2-positive feedback and periovulatory defects induced by prenatal TS-treatment. Our results indicate that disruptions in E2-positive feedback mechanisms and periovulatory gonadotropin secretion induced by prenatal TS-treatment are programmed predominantly during the prenatal life with postnatal exposure to E2 excess not contributing further to these disruptions.

Survival Impact of Ovarian Preservation on Women With Early-Stage Endometrial Cancer: A Systematic Review and Meta-analysis

Objective

The aim of this article was to investigate the survival impact of ovarian preservation in surgically treated patients with early-stage endometrial cancer using a meta-analysis.

Methods

Major online databases, including PubMed, EMBASE, Web of Science, the Cochrane Library, as well as Grey Literature database, were searched to collect studies on the effects of ovarian preservation compared with bilateral salpingo-oophorectomy (BSO) for surgical treatment in endometrial cancer patients. The literature search was performed up to April 2016. The results were analyzed using RevMan 5.0 software and Stata/SE 12.0 software.

Results

Totally, 7 retrospective cohort studies including 1419 patients in ovarian preservation group and 15,826 patients in BSO group were enrolled. Meta-analysis showed that there was no significant difference in overall survival between the patients treated with ovarian preservation and BSO (hazards ratio [HR], 1.00; 95% confidence interval [CI], 0.72–1.39; P = 1.00). Similar result was achieved in the young and premenopausal women (HR, 0.99; 95% CI, 0.70–1.39; P = 0.39). Furthermore, the disease-free survival of patients whose ovaries were preserved was slightly compromised but with no statistical significance (HR, 1.49; 95% CI, 0.56–3.93; P = 0.42).

Conclusions

Ovarian preservation may be safe in patients with early-stage endometrial cancer, and it could be cautiously considered in treating young and premenopausal women because it is not associated with an adverse impact on the patients’ survival. Given the inherent limitations of the included studies, further well-designed randomized controlled trial are needed to confirm and update this analysis.

Treating gynecologic malignancies with selective estrogen receptor downregulators (SERDs): promise and challenges

Endometrial and ovarian cancers are estrogen-dependent gynecologic malignancies. Although many are estrogen receptor (ER) positive, treatment with the selective estrogen receptor modulator (SERM) tamoxifen, a tissue selective partial-agonist, has demonstrated only modest clinical benefit. Selective estrogen receptor downregulators (SERDs) are pure ER antagonists showing a benefit for advanced ER positive breast cancer, which has bolstered their potential use for ER positive gynecologic malignancies. We summarize these preclinical and clinical data, suggesting that a subpopulation of patients with endometrial or ovarian cancer exists in which treatment with SERDs results in improved outcome. However, the full potential of SERDs for a gynecologic malignancies will be realized only when the appropriate predictive biomarkers are identified. Additionally, a further understanding ER signaling in the context of ovarian and endometrial tissues that appear to involve c-Src and other kinase pathways is needed to successfully address the emergence of resistance with rationally designed combination therapies.

How do Japanese gynecologists view hormone replacement therapy for survivors of endometrial cancer? Japanese Gynecologic Oncology Group (JGOG) survey

BACKGROUND

This survey sought to determine Japanese gynecologists' attitudes concerning administering hormone replacement therapy (HRT) for patients after surgery for endometrial cancer (EC).

METHODS

Eight hundred and eighty-eight members of the Japanese Gynecologic Oncology Group (JGOG) were asked to respond to an anonymous questionnaire on the JGOG website. The survey asked whether or not HRT was to be administered when surgery was performed (including a hysterectomy and bilateral oophorectomy) to treat EC before or after menopause. If HRT was not to be administered, respondents were asked the reason why. Respondents were presented with the same hypothetical patients that were featured in a previous survey in Germany, and differences in the mindsets of Japanese and German physicians were compared.

RESULTS

Responses from 363 individuals (response rate 40.9 %) were analyzed. Seventy-eight percent of physicians considered HRT for patients undergoing surgery before menopause. The most prevalent reason of refusal to prescribe HRT was the risk of EC recurrence. Forty-eight percent of physicians considered HRT for patients undergoing surgery after menopause. The most prevalent reasons of refusal of HRT were its limited benefit and the availability of alternative therapies. Sixty-five percent of Japanese physicians responded that they would administer HRT to patients with low risk of recurrence vs. 46 % of physicians in Germany (P < 0.0002). Forty-nine percent of Japanese physicians approved of prescribing HRT for patients with high risk of recurrence vs. 25 % of physicians in Germany (P < 0.0001).

CONCLUSION

Many Japanese gynecologists have a favorable attitude toward prescribing HRT after treatment of EC.

Estradiol regulation of nucleotidases in female reproductive tract epithelial cells and fibroblasts

The use of topical and oral adenosine derivatives in HIV prevention that need to be maintained in tissues and cells at effective levels to prevent transmission prompted us to ask whether estradiol could influence the regulation of catabolic nucleotidase enzymes in epithelial cells and fibroblasts from the upper and lower female reproductive tract (FRT) as these might affect cellular TFV-DP levels. Epithelial cells and fibroblasts were isolated from endometrium (EM), endocervix (CX) and ectocervix (ECX) tissues from hysterectomy patients, grown to confluence and treated with or without estradiol prior to RNA isolation. The expression of nucleotidase (NT) genes was measurable by RT-PCR in epithelial cells and fibroblasts from all FRT tissues. To determine if sex hormones have the potential to regulate NT, we evaluated NT gene expression and NT biological activity in FRT cells following hormone treatment. Estradiol increased expression of Cytosolic 5′-nucleotidase after 2 or 4 h in endometrial epithelial cells but not epithelial cells or fibroblasts from other sites. In studies using a modified 5′-Nucleotidase biological assay for nucleotidases, estradiol increased NT activity in epithelial cells and fibroblasts from the EM, CX and ECX at 24 and 48 h. In related studies, HUVEC primary cells and a HUVEC cell line were unresponsive to estradiol in terms of nucleotidase expression or biological activity. Our findings of an increase in nucleotidase expression and biological activity induced by estradiol do not directly assess changes in microbicide metabolism. However, they do suggest that when estradiol levels are elevated during the menstrual cycle, FRT epithelial cells and fibroblasts from the EM, CX and ECX have the potential to influence microbicide levels that could enhance protection of HIV-target cells (CD4+T cells, macrophages and dendritic cells) throughout the FRT.

Uterine epithelial cells specifically induce interferon-stimulated genes in response to polyinosinic-polycytidylic acid independently of estradiol

Interferon β (IFNβ) is an antiviral cytokine secreted in response to pathogenic exposure that creates a restrictive intracellular environment through the action of downstream interferon-stimulated genes (ISG). The objective of this study was to examine the expression of IFNβ and ISG in both human uterine epithelial cells (UEC) and the ECC-1 uterine epithelial cell line and determine if expression changes with TLR stimulation and hormone exposure. Stimulation of primary uterine epithelial cells and ECC-1 cells with the TLR3 agonist poly (I:C) induced the mRNA expression of IFNβ, MxA, OAS2 and PKR. Other TLR agonists including imiquimod and CpG had no effect on either IFNβ or ISG expression. In contrast to ECC-1 cell responses which were slower, maximal IFNβ upregulation in UEC occurred 3 hours post-stimulation and preceded the ISG response which peaked approximately 12 hours after poly (I:C) exposure. Unexpectedly, estradiol, either alone or prior to treatment with poly (I:C), had no effect on IFNβ or ISG expression. Blockade of the IFN receptor abrogated the upregulation of MxA, OAS2 and PKR. Furthermore, neutralizing antibodies against IFNβ partially inhibited the upregulation of all three ISG. Estradiol, directly and in the presence of poly (I:C) had no effect on IFNβ and ISG expression. These results indicate that uterine epithelial cells are important sentinels of the innate immune system and demonstrate that uterine epithelial cells are capable of mounting a rapid IFN-mediated antiviral response that is independent of estradiol and is therefore potentially sustained throughout the menstrual cycle to aid in the defense of the uterus against potential pathogens.

Estrogen regulates endometrial cell cytoskeletal remodeling and motility via focal adhesion kinase

OBJECTIVE

To explore the effects of 17β-estradiol (E(2)) on cytoskeletal remodeling and motility of endometrial stromal cells (ESC) and Ishikawa cells and to characterize the role of focal adhesion kinase (FAK) in these processes.

DESIGN

In vitro study of cytoskeletal remodeling and cellular morphology and motility in ESC or Ishikawa cells.

SETTING

University research center.

PATIENT(S)

Endometrial samples obtained from women requiring endometrial biopsies.

INTERVENTION(S)

Treatments with E(2) and multiple inhibitors of signaling pathways.

MAIN OUTCOME MEASURE(S)

Activation of FAK, actin remodeling, membrane morphology, cell motility, and invasion.

RESULT(S)

Estrogen induces a rapid and concentration-related FAK phosphorylation in ESC and Ishikawa cells. In this time frame, FAK localizes to the plasma membrane at sites of focal adhesion complexes formation, as shown by immunofluorescence. Phosphorylation of FAK in the presence of estrogen depends on the recruitment of both estrogen receptor α and estrogen receptor β and of a rapid G protein-dependent signaling to c-Src and phosphatidylinositol 3-OH kinase. Activation of FAK in ESC and Ishikawa cells is required for estrogen-induced horizontal migration and invasion of three-dimensional matrices of endometrial cells.

CONCLUSION(S)

Estrogen enhances cytoskeletal and membrane remodeling in ESC and Ishikawa cells by controlling FAK, thus resulting in enhanced cell motility and invasion. These findings may have clinical relevance for the development of new therapeutic strategies for the prevention or control of endometrial diseases.

Controversies in the management of endometrial carcinoma

Endometrial carcinoma is the most common type of female genital tract malignancy. Although endometrial carcinoma is a low grade curable malignancy, the condition of the disease can range from excellent prognosis with high curability to aggressive disease with poor outcome. During the last 10 years many researches have provided some new valuable data of optimal treatments for endometrial carcinoma. Progression in diagnostic imaging, radiation delivery systems, and systemic therapies potentially can improve outcomes while minimizing morbidity. Firstly, total hysterectomy and bilateral salphingo-oophorectomy is the primary operative procedure. Pelvic lymhadenectomy is performed in most centers on therapeutic and prognostic grounds and to individualize adjuvant treatment. Women with endometrial carcinoma can be readily segregated intraoperatively into “low-risk” and “high-risk” groups to better identify those women who will most likely benefit from thorough lymphadenectomy. Secondly, adjuvant therapies have been proposed for women with endometrial carcinoma postoperatively. Postoperative irradiation is used to reduce pelvic and vaginal recurrences in high risk cases. Chemotherapy is emerging as an important treatment modality in advanced endometrial carcinoma. Meanwhile the availability of new hormonal and biological agents presents new opportunities for therapy.

Safety of Ovarian Preservation in Premenopausal Women With Endometrial Cancer

Purpose

Oophorectomy is commonly performed in premenopausal women with endometrial cancer who undergo hysterectomy. The benefits of oophorectomy in this setting are unknown, and the procedure subjects women to the long-term sequelae of estrogen deprivation. We examined the safety of ovarian preservation in young women with endometrial cancer who underwent hysterectomy.

Patients and Methods

Women ≤ 45 years of age with stage I endometrial cancer recorded from 1988 to 2004 in the Surveillance, Epidemiology, and End Results Database were examined. We developed Cox proportional hazards models and Kaplan-Meier curves to compare women who underwent oophorectomy with those who had ovarian preservation.

Results

A total of 3,269 women, including 402 patients (12%) who had ovarian preservation, were identified. Younger age (P < .0001), later year of diagnosis (P = .04), residence in the eastern United States (P = .02), and low tumor grade (P < .0001) were associated with ovarian preservation. In a multivariate Cox model, ovarian preservation had no effect on either cancer-specific (hazard ratio [HR] = 0.58; 95% CI, 0.14 to 2.44) or overall (HR = 0.68; 95% CI, 0.34 to 1.35) survival. The findings were unchanged when women who received pelvic radiotherapy were excluded.

Conclusion

Ovarian preservation in premenopausal women with early-stage endometrial cancer may be safe and not associated with an increase in cancer-related mortality.

Racial disparities in recurrence among patients with early-stage endometrial cancer: is recurrence increased in black patients who receive estrogen replacement therapy?

BACKGROUND

Population-based studies suggest that, because of inequalities in treatment, black women with localized endometrial cancer have shorter survival compared with white women. The objective of the current investigation was to determine whether there is a racial disparity in outcome between black patients and white patients with early-stage endometrial cancer treated similarly in a clinical trial setting.

METHODS

A retrospective review of 110 black patients and 1,049 white patients with stage I and II endometrial cancer (graded according to the International Federation of Gynecology and Obstetrics grading system) was performed using data from a randomized, placebo-controlled trial performed by the Gynecologic Oncology Group that evaluated postoperative estrogen replacement therapy (ERT) and the risk of cancer recurrence. Demographic, pathologic, treatment, and outcome-related data were collected and analyzed using regression and survival analysis.

RESULTS

Estimates of recurrence-free survival suggested that black patients may be more likely to have disease recurrence, particularly those receiving ERT. Within a median follow-up of 3 years, 5 of 56 black patients with endometrial cancer in the ERT group were identified with recurrent disease compared with only 8 of 521 white patients. Adjusted for age, body mass index, and tumor grade, the relative risk of recurrence among blacks in the ERT group was 11.2 (95% confidence interval, 2.86-43.59; P = .0005).

CONCLUSIONS

The findings of the current study suggested that recurrence-free survival may be shorter among black women with stage I endometrial cancer, even in a clinical trials setting in which patients receive similar treatment and follow-up. This increased risk of recurrence appeared to be most evident in black women with endometrial cancer who maintained ERT after primary treatment.

Developmental reprogramming of IGF signaling and susceptibility to endometrial hyperplasia in the rat

In rodents, a brief neonatal exposure of the developing reproductive tract to the xenoestrogen, diethylstilbestrol (DES) reprograms developing tissues to increase susceptibility to tumorigenesis in adult animals, including uterine adenocarcinoma. Progression from a normal endometrium to carcinoma occurs via the intermediate stage of endometrial hyperplasia. We previously reported that endometrial hyperplasia in postmenopausal women is linked to abnormal insulin-like growth factor-I (IGF-I) signaling. To identify early events involved in the development of hyperplasia in the endometrium, we examined expression and activation of IGF-I pathway components in endometrium of rats exposed to DES. By 5 months of age, 36/60 (60%) of rats exposed to DES on days 3-5 after birth developed endometrial hyperplasia compared to 0% of vehicle-treated controls. Consistent with activation of a mitogenic signaling pathway, Ki67-positive cells increased in DES-exposed endometrium despite compromised ovarian function and hypoestrogenic milieu characteristic of DES-exposed animals. The endometrium of DES-exposed rats overexpressed IGF-II and insulin receptor substrate-1 (IRS-1) and exhibited elevated Akt expression and activation (as judged by phosphorylation) and mTOR signaling (phosphorylation of S6) compared to vehicle-treated endometrium. In contrast to vehicle-treated endometrium, in which negative feedback to IRS-1 was observed (phosphorylation of S636/639), negative feedback to IRS-1 was absent in DES-exposed endometrium. These data support a central role for IGF-I signaling in the development of both human and rodent endometrial hyperplasia. Furthermore, both global activation of IGF-IR signaling and abrogation of negative feedback to IRS-1 appear to be reprogrammed by DES in endometrial hyperplasia, implicating for the first time loss of negative feedback to IRS-1 in development of a preneoplastic lesion.

Development and validation of endogenous reference genes for expression profiling of medaka (Oryzias latipes) exposed to endocrine disrupting chemicals by quantitative real-time RT-PCR

The quantitative real-time reverse transcription polymerase chain reaction (Q-RT-PCR) technique has been increasingly used in endocrine disrupting chemicals (EDCs) research. Usually, an appropriate endogenous control gene is critical for Q-RT-PCR to normalize the errors and sample-to-sample variations that occur in the course of tissue collection, RNA isolation, and RT-PCR. In this study, we cloned ribosomal protein L7 (RPL-7) from medaka (Oryzias latipes), and then used Q-RT-PCR to study its transcription characteristics and those of glyceraldehyde-3-phosphate dehydrogenase, beta-actin, mitochondrial 16S ribosomal RNA (16S rRNA), and 18S rRNA. Of the five genes, RPL-7 and 18S rRNA were expressed with the less variance among the same tissue samples, in different tissues, and stages of development and were unaffected by EDCs exposure. The expression levels of RPL-7 among different tissues were between 9.76 x 10(6) +/- 9.49 x 10(5) and 1.39 x 10(7) +/- 1.69 x 10(6) copies/microg RNA but those of 18S rRNA were as high as 4.48 x 10(11) +/- 5.95 x 10(10) to 5.90 x 10(11) +/- 1.21 x 10(10) copies/microg RNA, which is above the usual detection scope of Q-RT-PCR if no complementary DNA reaction dilution is performed. As a result, RPL-7 is the single suitable endogenous control gene for expression profiling in future studies, especially in studies on the EDCs issue using medaka.

The hair follicle as an estrogen target and source

For many decades, androgens have dominated endocrine research in hair growth control. Androgen metabolism and the androgen receptor currently are the key targets for systemic, pharmacological hair growth control in clinical medicine. However, it has long been known that estrogens also profoundly alter hair follicle growth and cycling by binding to locally expressed high-affinity estrogen receptors (ERs). Besides altering the transcription of genes with estrogen-responsive elements, 17beta-estradiol (E2) also modifies androgen metabolism within distinct subunits of the pilosebaceous unit (i.e., hair follicle and sebaceous gland). The latter displays prominent aromatase activity, the key enzyme for androgen conversion to E2, and is both an estrogen source and target. Here, we chart the recent renaissance of estrogen research in hair research; explain why the hair follicle offers an ideal, clinically relevant test system for studying the role of sex steroids, their receptors, and interactions in neuroectodermal-mesodermal interaction systems in general; and illustrate how it can be exploited to identify novel functions and signaling cross talks of ER-mediated signaling. Emphasizing the long-underestimated complexity and species-, gender-, and site-dependence of E2-induced biological effects on the hair follicle, we explore targets for pharmacological intervention in clinically relevant hair cycle manipulation, ranging from androgenetic alopecia and hirsutism via telogen effluvium to chemotherapy-induced alopecia. While defining major open questions, unsolved clinical challenges, and particularly promising research avenues in this area, we argue that the time has come to pay estrogen-mediated signaling the full attention it deserves in future endocrinological therapy of common hair growth disorders.

17 beta-estradiol activates PI3K/Akt signaling pathway by estrogen receptor (ER)-dependent and ER-independent mechanisms in endometrial cancer cells

Cellular response to estrogen is mediated both by estrogen receptor (ER) binding to estrogen response element (ERE) and by non-nuclear actions like activation of signal transducing pathways. The main aims are to study if PI3K/Akt signaling pathway can be activated by 17beta-estradiol (E2) via non-nuclear action and to investigate the relationship of the action of E2 and ER in endometrial cancer cells expressing with different status of ER. The levels of phosphorylated Akt (Ser473) (P-Akt) and total Akt were examined by western blot and Akt kinase activity was measured in cells after stimulation with 1 microM E2 at different time points. Inhibitory role of LY294002 on activation of Akt induced by E2 and its estrogen antagonist, ICI182780 were also tested. P-Akt/Akt was used as a measure of activation of Akt. We found that maximum P-Akt/Akt and Akt kinase activity took place at 30 min in Ishikawa cells and 15 min in HEC-1A cells and the activation persisted for at least 2 h after stimulation with 1 microM E2. The activation of Akt elicited gradually with increasing doses of E2. PI3K inhibitor, LY294002, stopped the activating Akt in a dose-dependent manner and 50 microM LY294002 completely blocked the activation of Akt induced by E2. ICI182780 could block the activation of PI3K/Akt in ER-positive Ishikawa cells but not in HEC-1A cells with poor-expressed ER. This study demonstrated that E2 is able to promptly activate PI3K/Akt signal pathway in Ishikawa cells in an ER-dependent manner and ER-independent in HEC-1A cells. Blockage of PI3K/Akt cascade may become a potential and effective way to control endometrial carcinoma, especially in ER-negative cancers, which show no response to endocrinal therapy.

Randomized double-blind trial of estrogen replacement therapy versus placebo in stage I or II endometrial cancer: a Gynecologic Oncology Group Study

PURPOSE

To determine the effect of estrogen replacement therapy (ERT) on recurrence rate and survival in women who have undergone surgery for stage I or II endometrial cancer.

PATIENTS AND METHODS

After surgery, eligible patients were allocated to therapy with ERT or placebo after undergoing hysterectomy with or without pelvic and aortic nodal sampling. Planned duration of hormonal versus placebo treatment was 3 years, with an additional 2 years of follow-up.

RESULTS

The median follow-up time for all 1,236 eligible and assessable patients was 35.7 months. Stage, grade, histologic subtype, and percentage of patients receiving adjuvant therapy were similarly distributed between the groups. The median age at diagnosis for the 618 patients randomly assigned to ERT was 57 years (range, 26 to 91 years). Two hundred fifty-one patients (41.1%) were compliant with ERT for the entire treatment period. Disease recurrence was experienced in 14 patients (2.3%). Eight patients (1.3%) developed a new malignancy. There were 26 deaths (4.2%), and five deaths (0.8%) were a result of endometrial cancer. The median age at diagnosis for the 618 patients in the placebo group was 57 years (range, 30 to 88 years). Twelve patients (1.9%) experienced disease recurrence. Ten patients (1.6%) developed a new malignancy. There were 9 deaths (3.1%) in the placebo group, and four deaths (0.6%) were a result of endometrial cancer.

CONCLUSION

Although this incomplete study cannot conclusively refute or support the safety of exogenous estrogen with regard to risk of endometrial recurrence, it is noteworthy that the absolute recurrence rate (2.1%) and the incidence of new malignancy were low.

Hypomethylation-linked activation of PAX2 mediates tamoxifen-stimulated endometrial carcinogenesis

Tamoxifen, a selective oestrogen receptor modulator, has been used in the treatment of all stages of hormone-responsive breast cancer. However, tamoxifen shows partial oestrogenic activity in the uterus and its use has been associated with an increased incidence of endometrial cancer. The molecular explanation for these observations is not known. Here we show that tamoxifen and oestrogen have distinct but overlapping target gene profiles. Among the overlapping target genes, we identify a paired-box gene, PAX2, that is crucially involved in cell proliferation and carcinogenesis in the endometrium. Our experiments show that PAX2 is activated by oestrogen and tamoxifen in endometrial carcinomas but not in normal endometrium, and that this activation is associated with cancer-linked hypomethylation of the PAX2 promoter.

The effects of the selective estrogen receptor modulators, methyl-piperidino-pyrazole (MPP), and raloxifene in normal and cancerous endometrial cell lines and in the murine uterus

Since estrogens have vital functions in the uterus but might also contribute to endometrial cancer, we sought to determine the in vitro effects of methyl-piperidino-pyrazole (MPP), raloxifene, and beta-estradiol on Ishikawa and RL-95 endometrial cancer, and ovine luminal endometrial (oLE) cell lines and the in vivo effects of these compounds in the rodent uterus. MPP and raloxifene (1 nM) induced significant apoptosis in the endometrial cancer and oLE cell lines compared to beta-estradiol treated and control cells (P <or= 0.0001-0.001). To determine the in vivo uterine effects of these compounds, ovariectomized wild-type (WT) and estrogen receptor-beta knockout (ERbetaKO) mice were treated with 25, 50, 100, or 150 microg of each compound. Although raloxifene caused no significant increase in uterine weight, the presumptive ERalpha antagonist, MPP (25-150 microg) increased uterine weight, and cell proliferation significantly relative to vehicle control in WT and ERbetaKO mice (P <or= 0.001). However, MPP did not increase uterine wet weight as effectively as beta-estradiol (P <or= 0.0001), and administration of either 50 microg of MPP or raloxifene effectively reversed the positive effects of 50 and 100 microg beta-estradiol. Unexpectedly, in view of the in vitro studies, MPP and raloxifene treatment of ovariectomized mice did not induce apoptosis of the luminal epithelial cells but rather these compounds induced apoptosis of the underlying uterine stromal cells. These results demonstrate that MPP and raloxifene can exert apparently contrasting in vitro versus in vivo effects, and that they have mixed agonist/antagonist action on murine uterine ERalpha in vivo.

IL-1β-Mediated Proinflammatory Responses Are Inhibited by Estradiol via Down-Regulation of IL-1 Receptor Type I in Uterine Epithelial Cells

The objective of this study was to examine the effects of sex hormones on IL-1beta-mediated responses by uterine epithelial cells. The mRNA expression and secretion of human beta-defensin-2 and CXCL8 by uterine epithelial cells was examined following stimulation with IL-1beta in the presence of estradiol or progesterone. Estradiol inhibited the IL-1beta-mediated mRNA expression and secretion of human beta-defensin-2 and CXCL8 by uterine epithelial cells while progesterone had no effect. Inhibition of the IL-1beta-mediated response by estradiol was dose dependent, with maximal inhibition observed using 10(-7) to 10(-10) M, and was shown to be mediated through the estrogen receptor because addition of a pure estrogen receptor antagonist abrogated this effect. The mechanism by which estradiol inhibits IL-1beta-mediated responses by uterine epithelial cells appears to be the down-modulation of the IL-1R type I, thereby reducing the uterine epithelial cell's ability to respond to IL-1beta. These results suggest that the inhibitory effect of estradiol on IL-1beta-mediated inflammatory responses by uterine epithelial cells indicates a link between the endocrine and immune systems and may be crucial for dampening proinflammatory responses during the time of ovulation or pregnancy.

Estrogen-induced smooth muscle cell growth is regulated by tuberin and associated with altered activation of platelet-derived growth factor receptor-beta and ERK-1/2

The mechanisms that regulate the diverse responses to estrogen (E2) are unknown. Loss of function of the tuberous sclerosis 2 gene (TSC2), a tumor suppressor gene, has been associated with a growth-promoting effect of E2. We hypothesized that tuberin, the protein product of TSC2, binds to estrogen receptors (ER) and regulates the growth effect of E2. An in vivo association between full-length tuberin and ERalpha was observed in HEK 293 cells and ELT-3 smooth muscle cells. In contrast, poor association was observed between tuberin and ERbeta. Complex formation with ERalpha and the C-terminal end of tuberin was also observed in vivo and in vitro, indicating that binding between ERalpha and tuberin occurs at the C-terminal end of the tuberin molecule. We examined the effect of tuberin expression in ELT-3 smooth muscle cells on the growth response to E2. The growth-promoting effect of E2 in tuberin-null ELT-3 smooth muscle cells was ERalpha-specific, associated with up-regulation and activation of platelet-derived growth factor receptor-beta (PDGFRbeta) and activation of the signaling intermediate, extracellular signal-regulated kinase-1/-2 (ERK-1/2). In contrast, the expression of tuberin in ELT-3 smooth muscle cells resulted in significant abrogation of E2-stimulated growth. In parallel with this observation, the expression of tuberin in ELT-3 cells also resulted in significant inhibition of PDGFRbeta and ERK-1/2 activation in response to E2. These results demonstrate that tuberin binds specifically to ERalpha and inhibits E2-induced proliferation of ELT-3 cells. Furthermore, the opposing effects of tuberin on estrogen-induced activation of PDGFRbeta and ERK-1/-2 suggest a pivotal role for tuberin in directing the signaling events that dictate the growth response to E2.