Altered Expression of ESR1, ESR2, PELP1 and c-SRC Genes Is Associated with Ovarian Cancer Manifestation.

Ovarian cancer remains the leading cause of death due to gynecologic malignancy. Estrogen-related pathways genes, such as estrogen receptors (ESR1 and ESR2) and their coregulators, proline-, glutamic acid-, and leucine-rich protein 1 (PELP1), and proto-oncogene tyrosine-protein kinase c-Src (SRC) are involved in ovarian cancer induction and development, still they require in-depth study. In our study, tissue samples were obtained from 52 females of Caucasian descent (control group without cancerous evidence (n = 27), including noncancerous benign changes (n = 15), and the ovarian carcinoma (n = 25)). Using quantitative analyses, we investigated ESRs, PELP1, and SRC mRNA expression association with ovarian tumorigenesis. Proteins' presence and their location were determined by Western blot and immunohistochemistry. Results showed that PELP1 and SRC expression levels were found to differ in tissues of different sample types. The expression patterns were complex and differed in the case of ovarian cancer patients compared to controls. The most robust protein immunoreactivity was observed for PELP1 and the weakest for ESR1. The expression patterns of analyzed genes represent a potentially interesting target in ovarian cancer biology, especially PELP1. This study suggests that specific estrogen-mediated functions in the ovary and ovary-derived cancer might result from different local interactions of estrogen with their receptors and coregulators.

αMß2 Is Antiatherogenic in Female but Not Male Mice.

Atherosclerosis is a complex inflammatory process characterized by monocyte recruitment into the arterial wall, their differentiation into macrophages, and lipid accumulation. Because integrin αMß2 (CD11b/CD18) mediates multiple diverse functions of leukocytes, we examined its role in atherogenesis. αM-/-/ApoE-/- and ApoE-/- mice were fed a control or high fat diet for 3 or 16 wk to induce atherogenesis. Unexpectedly, αM deficiency accelerated development of atherosclerosis in female but not in male mice. The size of aortic root lesions was 3-4.5-fold larger in female αM-/-/ApoE-/- than in ApoE-/- mice. Monocyte and macrophage content within the lesions was increased 2.5-fold in female αM-/-/ApoE-/- mice due to enhanced proliferation. αMß2 elimination promoted gender-dependent foam cell formation due to enhanced uptake of cholesterol by αM-/-/ApoE-/- macrophages. This difference was attributed to enhanced expression of lipid uptake receptors, CD36 and scavenger receptor A1 (SR-A1), in female mice. Macrophages from female αM-/-/ApoE-/- mice showed dramatically reduced expression of FoxM1 transcription factor and estrogen receptors (ER) α and ß. As their antagonists inhibited the effect of 17ß-estradiol (E2), E2 decreased CD36, SR-A1, and foam cell formation in ApoE-/- macrophages in an ERα- and ERß-dependent manner. However, female αM-/-/ApoE-/- macrophages failed to respond to E2 and maintained elevated CD36, SR-A1, and lipid accumulation. FoxM1 inhibition in ApoE-/- macrophages reduced ERs and enhanced CD36 and SR-A1 expression, whereas FoxM1 overexpression in αM-/-/ApoE-/- macrophages reversed their proatherogenic phenotype. We demonstrate a new, surprising atheroprotective role of αMß2 in female ApoE-/- mice. αMß2 maintains ER expression in macrophages and E2-dependent inhibition of foam cell formation.

Choriogenin transcription in medaka embryos and larvae as an alternative model for screening estrogenic endocrine-disrupting chemicals.

This study assessed the transcription levels of estrogen-responsive genes, such as vitellogenins (Vtg1 and Vtg2), choriogenins (ChgL, ChgH, and ChgHm), cytochrome P450 aromatase (CYP19a1b), and ER subtypes (ERα, ERß1, and ERß2), in 7 days-post-fertilization (dpf) embryos and 9 and 12 dpf larvae of medaka (Oryzias latipes) exposed to estrogenic endocrine-disrupting chemicals (EDCs). The <5 h-post-fertilization embryos were exposed to EDCs such as 17ß-estradiol (E2), p-n-nonylphenol (NP), and bisphenol A (BPA). In E2 (0.10-222 nM)-treated 7 dpf embryos and 9 or 12 dpf larvae, ChgL, ChgH, and ChgHm expression was up-regulated in a concentration-dependent manner. By contrast, interestingly, Vtg1 and Vtg2 expression was not induced in E2-treated 7 dpf embryos but was significantly induced in 9 and 12 dpf larvae, suggesting a developmental-stage-specific regulatory mechanism underlying Vtg expression. The maximum concentrations of NP (0.09-1.5 µM) and BPA (1.8-30 µM) up-regulated Chg expression in 9 or 12 dpf larvae, and the relative estrogenic potencies (REPs) of E2, NP, and BPA were 1, 2.1 × 10-4, and 1.0 × 10-5, respectively. Chg messenger RNA (mRNA) in medaka embryos and larvae can be used as a sensitive biomarker for screening potential estrogenic EDCs. Our assay system using embryos and larvae can be used as an in vivo alternative model because independent feeding stages (e.g., embryonic and early larval stages) are suitable alternatives.

The androgen receptor antagonist enzalutamide induces apoptosis, dysregulates the heat shock protein system, and diminishes the androgen receptor and estrogen receptor ß1 expression in prostate cancer cells.

Enzalutamide's accepted mode of action is by targeting the androgen receptor's (AR) activity. In clinical practice, enzalutamide demonstrates a good benefit-risk profile for the treatment of advanced prostate cancer (PC), even after poor response to standard antihormonal treatment. However, since both, well-established antiandrogens and enzalutamide, target AR functionality, we hypothesized that additional unknown mechanisms might be responsible for enzalutamide's superior anticancer activity. In the current study, PC cells were incubated with enzalutamide and enzalutamide-dependent modulation of apoptotic mechanisms were assessed via Western blot analysis, TDT-mediated dUTP-biotin nick end-labeling assay, and nuclear morphology assay. Alterations of heat shock protein (HSP), AR, and estrogen receptor (ER) expression were examined by Western blot analysis. Enzalutamide attenuated the proliferation of PC cells in a time- and dose-dependent manner. In the presence of enzalutamide, apoptosis occurred which was shown by increased BAX expression, decreased Bcl-2 expression, nuclear pyknosis, and genomic DNA fragmentation. Moreover, enzalutamide inhibited the expression of HSPs primarily involved in steroid receptor stabilization and suppressed AR and ERß1 expression. This study demonstrates for the first time that enzalutamide treatment of PC cells triggers varying molecular mechanisms resulting in antiproliferative effects of the drug. In addition to the well-characterized antagonistic inhibition of AR functionality, we have shown that enzalutamide also affects the intracellular synthesis of steroid receptor-associated HSPs, thereby diminishing the expression of AR and ERß1 proteins and inducing apoptotic pathways. According to an indirect attenuation of HSP-associated factors such as steroid receptors, endometrial carcinoma, uterine leiomyosarcoma, and mamma carcinoma cells also demonstrated inhibited cell growth in the presence of enzalutamide. Our data, therefore, suggest that enzalutamide's high efficacy is at least partially independent of AR and p53 protein expression, which are frequently lost in advanced PC.

Pregnenolone as a potential candidate for hormone therapy for female reproductive disorders targeting ERß.

Many steroid hormones such as estrogen (E2) bind to their receptors for the regulation of biological processes. Pregnenolone (P5) is the precursor form of almost all steroid hormones and is often used to treat skin disorders and neurological complications. However, the mechanism and physiological function of P5 in reproductive organs are not well established. In this study, we investigated the effects of P5 on activation and expression of E2 receptor (ER) in the uteri and ovaries. To study the mechanism of P5 directly, Ishikawa cells were transfected with E2 response element (ERE)-luciferase plasmid and isoforms of ER. ERE-luciferase activity induced by P5 was similar to that induced by E2, and P5 showed high activity for ERß without any relevance to P5-metabolizing hormones such as progesterone (P4) and E2. In an animal study, immature female rats treated with P5 showed upregulation of ERα and downregulation of ERß in the uteri, which is the main organ expressing ERα. In ERß-expressing organ ovaries, estrogen receptor 1, estrogen receptor 2, and P4 receptor were all downregulated by P5 and E2. Also, a decrease of ovarian cell proliferation and viability was observed in response to P5 relative to the control, suggesting that P5 may be a candidate for antiproliferative hormone of ovarian cancer. These findings suggest that P5 stimulates ERE promoter by ERß-mediated signaling in the uteri and ovaries. Activation of ERß by P5 may help in understanding the mechanism of ER-related female reproductive diseases such as endometriosis and ovarian cancer.

Estrogen receptor beta expression correlates with proliferation in desmoid tumors.

BACKGROUND AND OBJECTIVES: Estrogen receptor signaling and cyclin D1 have a major role in tumor cell proliferation in breast cancer. Desmoid tumors are rare neoplasms that may respond to endocrine treatment. The present study aimed to investigate the expression levels and the clinical relevance of estrogen receptor beta (ERß) and cyclin D1 in desmoid tumors. METHODS: This study consists of 83 patients with a surgically treated desmoid tumor. ERß and cyclin D1 expression was examined by immunohistochemistry in tissue microarrays. Cyclin A and Ki67 were studied in our previous work. RESULTS: Median ERß expression was 10.8%. ERß expression correlated with expression of the proliferation antigens Ki67 (rp = 0.35, P = 0.003), cyclin D1 (rp = 0.34, P = 0.004), and cyclin A (rp = 0.34, P = 0.004). ERß immunoexpression showed a trend towards predictive impact for recurrence as a continuous variable. Further explorative analysis indicated that very high ERß expression was related to high risk of relapse (hazard ratio [HR] 2.6; P = 0.02). Median cyclin D1 expression was 15.6%. High cyclin D1 expression was associated with high Ki67 and cyclin A expression. Cyclin D1 was not associated with time to recurrence. CONCLUSIONS: ERß and cyclin D1 immunopositivity correlated with high proliferation in desmoid tumors. High ERß expression might be predictive for postoperative recurrence.

Applicability of Anti-Human Estrogen Receptor ß Antibody PPZ0506 for the Immunodetection of Rodent Estrogen Receptor ß Proteins.

Several lines of controversial evidence concerning estrogen receptor ß (ERß) remain to be solved because of the unavailability of specific antibodies against ERß. The recent validation analysis identified a monoclonal antibody (PPZ0506) with sufficient specificity against human ERß. However, the specificity and cross-reactivity of PPZ0506 antibody against ERß proteins from laboratory animals have not been confirmed. In the present study, we aimed to validate the applicability of PPZ0506 to rodent studies. The antibody exhibited specific cross-reactivity against mouse and rat ERß proteins in immunoblot and immunocytochemical experiments using transfected cells. In immunohistochemistry for rat tissue sections, PPZ0506 showed immunoreactive signals in the ovary, prostate, and brain. These immunohistochemical profiles of rat ERß proteins in rat tissues accord well with its mRNA expression patterns. Although the antibody was reported to show the moderate signals in human testis, no immunoreactive signals were observed in rat testis. Subsequent RT-PCR analysis revealed that this species difference in ERß expression resulted from different expression profiles related to the alternative promoter usage between humans and rats. In conclusion, we confirmed applicability of PPZ0506 for rodent ERß studies, and our results provide a fundamental basis for further examination of ERß functions.

Neurochemical Characterization of Neurons Expressing Estrogen Receptor ß in the Hypothalamic Nuclei of Rats Using in Situ Hybridization and Immunofluorescence.

Estrogens play an essential role in multiple physiological functions in the brain, including reproductive neuroendocrine, learning and memory, and anxiety-related behaviors. To determine these estrogen functions, many studies have tried to characterize neurons expressing estrogen receptors known as ERα and ERß. However, the characteristics of ERß-expressing neurons in the rat brain still remain poorly understood compared to that of ERα-expressing neurons. The main aim of this study is to determine the neurochemical characteristics of ERß-expressing neurons in the rat hypothalamus using RNAscope in situ hybridization (ISH) combined with immunofluorescence. Strong Esr2 signals were observed especially in the anteroventral periventricular nucleus (AVPV), bed nucleus of stria terminalis, hypothalamic paraventricular nucleus (PVN), supraoptic nucleus, and medial amygdala, as previously reported. RNAscope ISH with immunofluorescence revealed that more than half of kisspeptin neurons in female AVPV expressed Esr2, whereas few kisspeptin neurons were found to co-express Esr2 in the arcuate nucleus. In the PVN, we observed a high ratio of Esr2 co-expression in arginine-vasopressin neurons and a low ratio in oxytocin and corticotropin-releasing factor neurons. The detailed neurochemical characteristics of ERß-expressing neurons identified in the current study can be very essential to understand the estrogen signaling via ERß.

Estrogen receptor ß is associated with expression of cancer associated genes and survival in ovarian cancer.

BACKGROUND: In ovarian cancer, the role of estrogen receptors (ERs), particularly of ERß, being suggested as tumor suppressor in breast and prostate cancer, remains unclear. We examined the expression of nuclear and cytoplasmic ERß in ovarian cancer and correlated it with expression of ovarian cancer markers CA125, CEA and CA72-4, steroid hormone receptors ERα and PR, cancer-associated genes EGFR, p53, HER2 and proliferation marker Ki-67. Additionally we examined to what extent expression of ERß and the other proteins affects survival of ovarian cancer patients. METHODS: We established a tissue microarray from 171 ovarian cancer patients and performed immunohistochemical analyses of the mentioned proteins. RESULTS: Nuclear ERß was detected in 47.31% of the ovarian cancer tissues and cytoplasmic expression of this receptor was observed in 23.08%. Nuclear expression of ERß was significantly decreased in the G3 subgroup compared to better differentiated cancers (p <  0.01) and correlated with ovarian cancer markers CEA (95% CI 0.1598-0.4465; p <  0.0001) and CA72-4 (95% CI 0.05953-0.3616; p <  0.01). Cytoplasmic ERß expression correlated with EGFR levels (95% CI 0.1059-0.4049; p <  0.001). ERα expression was associated with expression of CA125 and PR. Overall survival of patients with tumors expressing cytoplasmic ERß was significant longer compared to those with ERß-negative ovarian cancer (chi-square statistic of the log-rank, p < 0.05). Progression-free survival was dependent on expression of PR (chi-square statistic of the log-rank, p < 0.05) and Ki-67 (p = 0.05). CONCLUSIONS: Our data suggest an important, but distinct role of nuclear and cytoplasmic ERß expression in ovarian cancer and encourage further studies on its role in this cancer entity.

Female Sex Hormone Receptor Profiling in Uterine Adenosarcomas.

OBJECTIVE: This study aimed to identify the hormonal receptor status in uterine adenosarcoma (AS) and uterine AS with sarcomatous overgrowth (AS + SO), including those with high-grade histologic features (nuclear pleomorphism, atypical mitoses, necrosis), with or without heterologous elements. Estrogen receptor (ER) status, including estrogen receptor α (ERα), estrogen receptor ß (ERß), and G protein-coupled estrogen receptor (GPER), and progesterone receptor (PgR) status were examined. METHODS: From August 2001 to November 2013, 11 patients with histologic diagnosis of uterine AS were identified. Tumor tissue sections were stained for ERα, ERß, GPER, and PgR and examined both for percentage of overall cells stained and for intensity of staining. Descriptive statistics were calculated using clinicopathologic data abstracted from the medical record. RESULTS: Eight cases of AS and 3 cases of AS with high-grade features were identified. Seven of 8 tumor samples of AS showed strong or moderate intensity immunostaining for ERα; all AS + SO tumor samples showed minimal to no immunoreactivity for ERα. There was a significant decrease in ERα H scores in high-grade tumors when compared with AS (P = 0.01). Lower PgR H scores were observed in high-grade tumors compared with those in AS (P = 0.04). Estrogen receptor ß immunostaining was variable, and GPER immunostaining was absent in the majority of tumor samples. CONCLUSIONS: Higher expression of ERα and PgR was observed in AS when compared with those with AS + SO and high-grade features. Both tumor subtypes showed similar levels of ERß and GPER expression, although significant differences in ERß and GPER expression were not detected. In contrast to our previous findings in uterine carcinosarcoma, ERs ERß and GPER do not seem to play a significant role in AS in this study.

Hormone receptor expression profile of low-grade serous ovarian cancers.

OBJECTIVE: Low-grade serous ovarian carcinomas (LGSOCs) are a histological subtype of epithelial ovarian tumors, accounting for fewer than 5% of all cases of ovarian carcinoma. Due to the chemoresistant nature of this subtype a search for more effective systemic therapies is actively ongoing, hormonal therapy showing some degree of activity in this clinical setting. The present study ought to investigate the hormone receptor status of LGSOCs, as a strategy to provide molecular support for patient-tailored hormonal treatments. METHODS: Estrogen receptor α (ERα), ERß isoforms (i.e. ERß1, ERß2 and ERß5), progesterone and androgen receptor (PR, AR) expression was evaluated by immunohistochemistry in 25 untreated LGSOC primary tumors, 6 matched metastases and 6 micropapillary variant of serous borderline tumors (micropapillary SBOTs). In vitro cellular models were used to provide insights into clinical observations. RESULTS: Our results showed prominent expression of nuclear ERα, ERß2, ERß5 and PR in LGSOC primary tissues, while metastatic lesions also exhibit considerable cytoplasmic ERß2 levels. Notably, a higher expression of ERß1 protein was determined in micropapillary SBOTs compared to LGSOCs. In vitro experiments on LGSOC cell lines (i.e. HOC-7 and VOA-1056) revealed low/absent ERα, PR and AR protein expression, whereas the three ERß isoforms were all present. Proliferation of HOC-7 and VOA-1056 was not modulated by either the endogenous or the selective synthetic ligands. CONCLUSIONS: These novel findings highlight the need of assessing relative levels of ERα and ERß isoforms in the total receptor pool in future clinical studies investigating molecular predictors of response to hormonal therapy in LGSOC.

Generation of an estrogen receptor beta-iCre knock-in mouse.

A novel knock-in mouse that expresses codon-improved Cre recombinase (iCre) under regulation of the estrogen receptor beta (Esr2) promoter was developed for conditional deletion of genes and for the spatial and/or temporal localization of Esr2 expression. ESR2 is one of two classical nuclear estrogen receptors and displays a spatiotemporal expression pattern and functions that are different from the other estrogen receptor, ESR1. A cassette was constructed that contained iCre, a polyadenylation sequence, and a neomycin selection marker. This construct was used to insert iCre in front of the endogenous start codon of the Esr2 gene of a C57BL/6J embryonic stem cell line via homologous recombination. Resulting Esr2-iCre mice were bred with ROSA26-lacZ and Ai9-RFP reporter mice to visualize cells of functional iCre expression. Strong expression was observed in the ovary, the pituitary, the interstitium of the testes, the head and tail but not body of the epididymis, skeletal muscle, the coagulation gland (anterior prostate), the lung, and the preputial gland. Additional diffuse or patchy expression was observed in the cerebrum, the hypothalamus, the heart, the adrenal gland, the colon, the bladder, and the pads of the paws. Overall, Esr2-iCre mice will serve as a novel line for conditionally ablating genes in Esr2-expressing tissues, identifying novel Esr2-expressing cells, and differentiating the functions of ESR2 and ESR1.

Expression of estrogen and progesterone receptors across human malignancies: new therapeutic opportunities.

Estrogen and progesterone receptors (ERs and PRs) are known for their prognostic as well as treatment predictive value in breast cancer. Although these receptors are differentially expressed in some other malignancies, and likely participate in the biology of those cancer types, the relevance to outcome and therapy is not well established. The use of ER as a highly effective therapeutic target in oncology was pioneered in breast cancer, and the lessons learned from its success could potentially benefit patients with several other malignancies in which hormone receptors are highly expressed. Indeed, there are several potent drugs available that target hormone receptors. These agents show incontrovertible evidence of benefit in patients with hormone receptor-positive breast cancer. It is conceivable that these drugs may have salutary effects in a variety of cancers other than those originating in the breast, based on the overexpression of hormone receptors in some patients, and the preclinical and clinical reports showing responses to these drugs in diverse cancers, albeit in small series or anecdotally. We therefore undertook a literature review in order to summarize the current data regarding the biologic and clinical implications of expression of estrogen and progesterone receptors in various malignancies and the possibilities for deployment of hormone manipulation beyond breast cancer.

Androgen receptors are acquired by healthy postmenopausal endometrial epithelium and their subsequent loss in endometrial cancer is associated with poor survival.

BACKGROUND: Endometrial cancer (EC) is a hormone-driven disease, and androgen receptor (AR) expression in high-grade EC (HGEC) and metastatic EC has not yet been described. METHODS: The expression pattern and prognostic value of AR in relation to oestrogen (ERα and ERß) and progesterone (PR) receptors, and the proliferation marker Ki67 in all EC subtypes (n = 85) were compared with that of healthy and hyperplastic endometrium, using immunohistochemisty and qPCR. RESULTS: Compared with proliferative endometrium, postmenopausal endometrtial epithelium showed significantly higher expression of AR (P < 0.001) and ERα (P = 0.035), which persisted in hyperplastic epithelium and in low-grade EC (LGEC). High-grade EC showed a significant loss of AR (P < 0.0001), PR (P < 0.0001) and ERß (P < 0.035) compared with LGEC, whilst maintaining weak to moderate ERα. Unlike PR, AR expression in metastatic lesions was significantly (P = 0.039) higher than that in primary tumours. Androgen receptor expression correlated with favourable clinicopathological features and a lower proliferation index. Loss of AR, with/without the loss of PR was associated with a significantly lower disease-free survival (P < 0.0001, P < 0.0001, respectively). CONCLUSIONS: Postmenopausal endometrial epithelium acquires AR whilst preserving other steroid hormone receptors. Loss of AR, PR with retention of ERα and ERß may promote the unrestrained growth of HGEC. Androgen receptor may therefore be a clinically relevant prognostic indicator and a potential therapeutic target in EC.

c-Met and ERß expression differences in basal-like and non-basal-like triple-negative breast cancer.

Basal-like breast cancer (BLBC) and triple-negative breast cancer (TNBC) are two entities of breast cancer that share similar poor prognosis. Even though both cancers have overlaps, there are still some differences between those two types. It has been reported that the c-Met high expression was associated with poor prognosis not only in breast cancer but also in many other cancers. The role of ERß in pathogenesis and treatment of breast cancer has remained controversial. In this study, we firstly distinguished basal-like from nonbasal-like cancer patients in TNBC patients using CK5/6 and EGFR as markers and next determined the relationship of basal-like breast cancer with c-Met or ERß expression levels and prognosis in TNBC patients. One hundred twenty-seven patients who had been diagnosed with TNBC were enrolled. The clinical and pathological characteristics of the patients were recorded. The expression of EGFR, CK5/6, ERß, and c-Met were evaluated with immunohistochemical methods using paraffin blocks. The median age of patients was 50.7 years. CK5/6 immunopositivity was 31.5 % (40/127), and EGFR was 40.2 % (51/127). Of the TNBC cases, 55.1 % (71/127) were positive for either CK5/6 or EGFR and were thus classified as basal-like breast cancer. C-Met (P < 0.001) and ERß (P = 0.002) overexpression, small tumor sizes, a ductal subtype, and high-grade tumor were significantly correlated with BLBC. High c-Met expression was detected in 43.3 % patients. Metastatic lymph nodes and tumor size (>5 cm), which were both important prognostic predictors, were significantly associated with recurrence and mortality. BLBC typically demonstrates a unique profile. CK5/6 and EGFR expression combination indicates a higher basal-like phenotype possibility. The expression of c-Met and ERß were significantly related to the basal-like phenotype. The classical markers, lymph node metastasis, and tumor size were found to have important prognostic value. However, high c-Met expression and basal-like phenotypes did not show a direct correlation with poor prognosis.

Expression and significance of ERß and TrkB in endometriosis.

OBJECTIVES: To study the potential pathogenesis of endometriosis (EMs) in an area of estrogen receptors (ERs) and tyrosine kinase receptor type B (TrkB) expressions in tissues from patients with EMs. STUDY DESIGN: The authors examined the expressions of ERα, ERß, TrkB, brain-derived neurotrophic factor (BDNF), and SGPL1 in tissues with EMs, using real-time PCR, western blot, and immunohistochemistry. RESULTS: ERα and SGPL1 were mainly expressed in eutopic endometrium than that in ectopic endometrium of patients with ovarian endometriosis (p < 0.05), while ERß, BDNF, and TrkB were adverse, mainly detected in ectopic endometrium of the same patients with EMs (p < 0.01 and p < 0.05 ) by real-time PCR and western blot. ERß, ERα, TrkB, and SGPL1 proteins were mainly expressed in eutopic endometrium of proliferative phase with EMs than that in eutopic endometrium of secretory phase (p < 0.05 ). TrkB, BDNF, and SGPL1 were not found in endometrium of proliferative or secretory phase in control group. CONCLUSIONS: ERß expressed in cytoplasm may mediate pathogenesis of EMs.

Estradiol mediates vasculoprotection via ERRα-dependent regulation of lipid and ROS metabolism in the endothelium.

The estrogen-mediated vasculoprotective effect has been widely reported in many animal studies, although the clinical trials are controversial and the detailed mechanisms remain unclear. In this study, we focused on the molecular mechanism and consequence of 17ß-estradiol (E2)-induced ERRα (estrogen-related receptor alpha) expression in endothelium and its potential beneficial effects on vascular function. The human aorta endothelial cells were used to identify the detailed molecular mechanism and consequences for E2-induced ERRα expression through estrogen receptors (ER), where ERα responses E2-induced ERRα activation, and ERß responses basal ERRα expression. E2-induced ERRα expression increases fatty acid uptake/oxidation with increased mitochondrial replication, ATP generation and attenuated reactive oxygen species (ROS) formation. We have obtained further in vivo proof from high-fat diet mice that the lentivirus-carried endothelium-specific delivery of ERRα expression on the vascular wall normalizes E2 deficiency-induced increased plasma lipids with ameliorated vascular damage. ERRα knockdown worsens the problem, and the E2 could only partly restore this effect. This is the first time we report the detailed mechanism with direct evidence that E2-induced ERRα expression modulates the fatty acid metabolism and reduces the circulating lipids through endothelium. We conclude that E2-induced ERRα expression in endothelium plays an important role for the E2-induced vasculoprotective effect.

Hyperoxia-induced changes in estradiol metabolism in postnatal airway smooth muscle.

Supplemental oxygen, used to treat hypoxia in preterm and term neonates, increases the risk of neonatal lung diseases, such as bronchopulmonary dysplasia (BPD) and asthma. There is a known sex predilection for BPD, but the underlying mechanisms are not clear. We tested the hypothesis that altered, local estradiol following hyperoxia contributes to pathophysiological changes observed in immature lung. In human fetal airway smooth muscle (fASM) cells exposed to normoxia or hyperoxia, we measured the expression of proteins involved in estrogen metabolism and cell proliferation responses to estradiol. In fASM cells, CYP1a1 expression was increased by hyperoxia, whereas hyperoxia-induced enhancement of cell proliferation was blunted by estradiol. Pharmacological studies indicated that these effects were attributable to upregulation of CYP1a1 and subsequent increased metabolism of estradiol to a downstream intermediate 2-methoxyestradiol. Microarray analysis of mouse lung exposed to 14 days of hyperoxia showed the most significant alteration in CYP1a1 expression, with minimal changes in expression of five other genes related to estrogen receptors, synthesis, and metabolism. Our novel results on estradiol metabolism in fetal and early postnatal lung in the context of hyperoxia indicate CYP1a1 as a potential mechanism for the protective effect of estradiol in hyperoxia-exposed immature lung, which may help explain the sex difference in neonatal lung diseases.

Prognostic and predictive value of ERß1 and ERß2 in the Intergroup Exemestane Study (IES)-first results from PathIES†.

BACKGROUND: Intergroup Exemestane Study (IES) was a randomised study that showed a survival benefit of switching adjuvant endocrine therapy after 2-3 years from tamoxifen to exemestane. PathIES aimed to assess the potential prognostic and predictive value of ERß1 and ERß2 expression in primary tumours in order to determine benefit in the two treatment arms. PATIENTS AND METHODS: Primary tumour samples were available for 1256 patients (27% IES population). ERß1 and ERß2 expression was dichotomised at the median IHC score (high if ERß1 ≥ 191, ERß2 ≥ 164). Hazard ratios (HRs) were estimated by multivariable Cox proportional hazards models adjusting for clinicopathological factors. Treatment effects with biomarker expressions were determined by interaction tests. Analysis explored effects of markers both as a continuous variable and with dichotomised cut-offs. RESULTS: Neither ERß1 nor ERß2 were associated with disease-free survival (DFS) or overall survival (OS) in the whole cohort. In patients treated with continued tamoxifen, high ERß1 expression compared with low was associated with better DFS [HR = 0.38:95% confidence interval (CI) 0.21-0.68, P = 0.001]. DFS benefit of exemestane over tamoxifen (HR = 0.40:95% CI 0.22-0.70) was found in the low ERß1 subgroup (interaction P = 0.01). No significant difference with treatment was observed for ERß2 expression in either DFS or OS. CONCLUSION: In the PathIES population, exemestane appeared to be superior to tamoxifen among patients with low ERß1 expression but not in those with high ERß1 expression. This is the first trial of its kind to report a parameter potentially predicting benefit of an aromatase inhibitor when compared with tamoxifen and an independent validation is warranted.

HDAC inhibition does not induce estrogen receptor in human triple-negative breast cancer cell lines and patient-derived xenografts.

Several publications have suggested that histone deacetylase inhibitors (HDACis) could reverse the repression of estrogen receptor alpha (ERα) in triple-negative breast cancer (TNBC) cell lines, leading to the induction of a functional protein. Using different HDACis, vorinostat, panobinostat, and abexinostat, we therefore investigated this hypothesis in various human TNBC cell lines and patient-derived xenografts (PDXs). We used three human TNBC cell lines and three PDXs. We analyzed the in vitro toxicity of the compounds, their effects on the hormone receptors and hormone-related genes and protein expression both in vitro and in vivo models. We then explored intra-tumor histone H3 acetylation under abexinostat in xenograft models. Despite major cytotoxicity of all tested HDAC inhibitors and repression of deactylation-dependent CCND1 gene, neither ERα nor ERß, ESR1 or ESR2 genes respectively, were re-expressed in vitro. In vivo, after administration of abexinostat for three consecutive days, we did not observe any induction of ESR1 or ESR1-related genes and ERα protein expression by RT-qPCR and immunohistochemical methods in PDXs. This observation was concomitant to the fact that in vivo administration of abexinostat increased intra-tumor histone H3 acetylation. These observations do not allow us to confirm previous studies which suggested that HDACis are able to convert ER-negative (ER-) tumors to ER-positive (ER+) tumors, and that a combination of HDAC inhibitors and hormone therapy could be proposed in the management of TNBC patients.