Interferon Signaling in Estrogen Receptor-positive Breast Cancer: A Revitalized Topic

Cancer immunology is the most rapidly expanding field in cancer research, with the importance of immunity in cancer pathogenesis now well accepted including in the endocrine-related cancers. The immune system plays an essential role in the development of ductal and luminal epithelial differentiation in the mammary gland. Originally identified as evolutionarily conserved antipathogen cytokines, interferons (IFNs) have shown important immune-modulatory and antineoplastic properties when administered to patients with various types of cancer, including breast cancer. Recent studies have drawn attention to the role of tumor- and stromal-infiltrating lymphocytes in dictating therapy response and outcome of breast cancer patients, which, however, is highly dependent on the breast cancer subtype. The emerging role of tumor cell-inherent IFN signaling in the subtype-defined tumor microenvironment could influence therapy response with protumor activities in breast cancer. Here we review evidence with new insights into tumor cell-intrinsic and tumor microenvironment-derived IFN signaling, and the crosstalk of IFN signaling with key signaling pathways in estrogen receptor-positive (ER+) breast cancer. We also discuss clinical implications and opportunities exploiting IFN signaling to treat advanced ER+ breast cancer.

Virtual screening of the multi-gene regulatory molecular mechanism of Si-Wu-tang against non-triple-negative breast cancer based on network pharmacology combined with experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Si-Wu-Tang (SWT), a prestigious herbal formula from China, has been extensively used for centuries for female-related diseases. It has been documented that SWT has a significant inhibitory effect on non-triple-negative breast cancer (non-TNBC) cells. However, there has been limited comprehensive analysis of the targeted effects of the anticancer components of SWT and its exact biological mechanism.

AIM OF THE STUDY

This study aims to uncover the mechanism by which SWT treats non-TNBC by applying a network pharmacological method combined with experimental validation.

MATERIALS AND METHODS

First, SWT compounds were collected from the Traditional Chinese Medicines Systems Pharmacology database (TCMSP) and The Encyclopedia of Traditional Chinese Medicine (ETCM), and then the targets related to SWT were obtained from the TCMSP and SwissTarget databases. Second, a target data set of non-TNBC proteins was established by using the Online Mendelian Inheritance in Man (OMIM), GeneCards and Gene Expression Omnibus (GEO) databases. Third, based on the overlap of targets between SWT and non-TNBC, a protein-protein interaction (PPI) network was built to analyse the interactions among these targets, which focused on screening for hub targets by topology. On these hub genes, we conducted a meta-analysis and survival analysis to screen the best match targets, ESR1, PPARG, CAT, and PTGS2, which had a strong correlation with the ingredients of SWT in our verification by molecular docking. In vitro experiments further proved the reliability of the network pharmacology findings. Finally, FunRich software and the ClusterProfiler package were utilized for the enrichment analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) data.

RESULTS

A total of 141 active ingredients and 116 targets of SWT were selected. GO enrichment analysis showed that the biological processes through which SWT acted against non-TNBC (FDR<0.01) mainly involved modulating energy metabolism and apoptosis. According to RT-qPCR and Western blotting, the mRNA and protein expression of ESR1, PPARG and PTGS2 were upregulated (P < 0.01), and the mRNA and protein levels of CAT were downregulated (P < 0.01), suggesting a multi-gene regulatory molecular mechanism of SWT against non-triple-negative breast cancer.

CONCLUSIONS

This research explored the multi-gene pharmacological mechanism of action of SWT against non-TNBC through network pharmacology and in vitro experiments. The findings provide new ideas for research on the mechanism of action of Chinese medicine against breast cancer.

Expression of Estrogen Receptor-alpha in Nasal Polyps and the Effects of Dexamethasone on Estrogen Receptor-alpha Expression in RPMI 2650 Cells

BACKGROUND

Studies have reported that epithelial cell proliferation may be involved in the pathogenesis of nasal polyps (NPs). Estrogen receptor (ER)-α, one type of ER, is related to anti-inflammatory action and cell survival in certain tissues. In this study, we examined the presence or absence of ER-α in NPs and healthy inferior turbinate mucosae. We also investigated the effect of dexamethasone on ER-α expression, cell viability, and apoptosis in RPMI 2650 cells.

METHODS

Immunohistochemical staining and Western blot analysis were conducted to determine the expression of ER-α in 15 NPs and 15 healthy inferior turbinate mucosae. After treating RPMI 2650 cells with dexamethasone, ER-α expression was analyzed using Western blot analysis and cell viability was determined using the MTT assay. Western blot analysis and annexin V-phycoerythrin (PE) staining were used to examine apoptotic cell death.

RESULTS

Western blot analysis showed that ER-α expression was upregulated in 13 of the 15 NP tissues. Immunohistochemical staining for ER-α confirmed the results of the Western blot analysis. When RPMI 2650 cells were treated with dexamethasone, both ER-α expression and cell viability were decreased. Furthermore, the treatment of RPMI 2650 cells with dexamethasone increased apoptotic cell death, as shown by increased levels of BAX and cleaved caspase-3, decreased levels of Bcl-2, and an increased percentage of positive annexin V-PE stained cells.

CONCLUSION

ER-α expression was higher in NPs than in healthy inferior turbinate mucosae. When RPMI 2650 cells were treated with dexamethasone, ER-α expression was downregulated, cell viability decreased, and apoptosis increased. The decreased cell viability may be related, at least in part, to the decreased ER-α protein levels, which likely contributed to the induction of apoptotic cell death in RPMI 2650 cells.

Expression of oestrogen-α receptor in papillary thyroid carcinoma and its association with metastasis

INTRODUCTION

Papillary thyroid carcinoma (PTC) is the ninth most common malignancy among women. Although the disease prognosis is good, less favourable outcomes are predicted in those with higher disease stages and nodal metastasis. Oestrogen- α (ER-α) expression has been associated with aggressive presentation and greater disease progression and has been proposed as a predictor for lymph node metastases. The objective of this study was to evaluate the association between ER expression and clinicopathological features i.e. lymph node metastasis, tumour size, extrathyroidal extension, histological variants of PTC , age groups , ethnic and gender.

METHODS

We studied ER-α expression in 84 cases of PTC obtained within an eight-year period (2011-2018) by immunohistochemical technique (IHC). Associations between ER-α expression and clinicopathological features were evaluated using Fisher's exact test. The statistical significance was set at p < 0.05.

RESULTS

ER-α was expressed in 13.1% of all the PTC cases examined (n=11/84). There were no associations observed between ER-α expression and lymph node metastasis (p=1.000), tumour size (p=0.970), extrathyroidal extension (p=0.677), variants of PTC (p=1.000), age groups (p=0.188), gender (p=0.725) or race (p=0.920).

CONCLUSION

There was no evidence in this study to support the application of ER-α as prediction marker for lymph node metastasis or disease aggressiveness in PTC. Given that the scope of this study was limited to the protein expression of ER- α, we also propose the inclusion of molecular analysis of ESR1 gene expression, as well as inclusion of detailed clinical and radiological findings in future research investigating the role of ER-α in prognostication of PTC.

IFI27/ISG12 Downregulates Estrogen Receptor α Transactivation by Facilitating Its Interaction With CRM1/XPO1 in Breast Cancer Cells

The estrogen receptor alpha (ERα) is a ligand-activated transcription factor whose activity is modulated by its interaction with multiple protein complexes. In this work, we have identified the protein interferon alpha inducible protein 27 (IFI27/ISG12) as a novel ERα-associated protein. IFI27/ISG12 transcription is regulated by interferon and estradiol and its overexpression is associated to reduced overall survival in ER+ breast cancer patients but its function in mammary gland tissue remains elusive. In this study we showed that overexpression of IFI27/ISG12 in breast cancer cells attenuates ERα transactivation activity and the expression of ERα-dependent genes. Our results demonstrated that IFI27/ISG12 overexpression in MCF-7 cells reduced their proliferation rate in 2-D and 3-D cell culture assays and impaired their ability to migrate in a wound-healing assay. We show that IFI27/ISG12 downregulation of ERα transactivation activity is mediated by its ability to facilitate the interaction between ERα and CRM1/XPO1 that mediates the nuclear export of large macromolecules to the cytoplasm. IFI27/ISG12 overexpression was shown to impair the estradiol-dependent proliferation and tamoxifen-induced apoptosis in breast cancer cells. Our results suggest that IFI27/ISG12 may be an important factor in regulating ERα activity in breast cancer cells by modifying its nuclear versus cytoplasmic protein levels. We propose that IFI27/ISG12 may be a potential target of future strategies to control the growth and proliferation of ERα-positive breast cancer tumors.

The ancient Chinese formula Longdan Xiegan Tang improves antipsychotic-induced hyperprolactinemia by repairing the hypothalamic and pituitary TGF-β1 signaling in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Antipsychotics often induce hyperprolactinemia. The transforming growth factor (TGF)-beta1 signaling in the pituitary and hypothalamus inhibits prolactin synthesis and secretion, and its impairment is implicated in neuropsychiatric disorders. Longdan Xiegan Tang (LXT) alone or together with antipsychotics have been used to treat various neuropsychiatric diseases and hyperprolactinemia-associated disorders.

AIM OF THE STUDY

To investigate the effect of LXT on hyperprolactinemia and involvement of the TGF-beta1 signaling.

MATERIALS AND METHODS

Male rats were co-administered with olanzapine (5 mg/kg) and LXT extract (50 and 500 mg/kg) (p.o., × 8 weeks). Plasma concentrations of prolactin and TGF-beta1 were determined by ELISA. Protein expression was analyzed by Western blot.

RESULTS

Treatment of rats with LXT extract suppressed olanzapine-induced increase in plasma prolactin concentration and overexpression of pituitary and hypothalamic prolactin protein. Importantly, LXT restored olanzapine-induced decrease in protein expression of the key components of the TGF-beta1 signaling, TGF-beta1, type II TGF-beta receptor, type I TGF-beta receptor and phosphorylated SMAD3 in the pituitary and hypothalamus. Further, it antagonized downregulation of pituitary and hypothalamic dopamine D2 receptor (D2R) protein level, and inhibited pituitary estrogen receptor (ER) alpha and ERbeta protein expression.

CONCLUSIONS

The present results suggest that LXT ameliorates antipsychotic-induced hyperprolactinemia in rats by repairing the pituitary and hypothalamic TGF-beta1 signaling possibly via D2R, ERs or/and other pathways. Our findings may also provide scientific elucidation for use of the ancient Chinese formula to treat the impaired TGF-beta1 signaling-associated neuropsychiatric disorders.

A Systematic Study of the Impact of Estrogens and Selective Estrogen Receptor Modulators on Prostate Cancer Cell Proliferation

The estrogen signaling pathway has been reported to modulate prostate cancer (PCa) progression through the activity of estrogen receptors α and β (ERα and ERβ). Given that selective estrogen receptor modulators (SERMs) are used to treat breast cancer, ERs have been proposed as attractive therapeutic targets in PCa. However, many inconsistencies regarding the expression of ERs and the efficacy of SERMs for PCa treatment exist, notably due to the use of ERβ antibodies lacking specificity and treatments with high SERM concentrations leading to off-target effects. To end this confusion, our objective was to study the impact of estrogenic and anti-estrogenic ligands in well-studied in vitro PCa models with appropriate controls, dosages, and ER subtype-specific antibodies. When using physiologically relevant concentrations of nine estrogenic/anti-estrogenic compounds, including five SERMs, we observed no significant modulation of PCa cell proliferation. Using RNA-seq and validated antibodies, we demonstrate that these PCa models do not express ERs. In contrast, RNA-seq from PCa samples from patients have detectable expression of ERα. Overall, our study reveals that commonly used PCa models are inappropriate to study ERs and indicate that usage of alternative models is essential to properly assess the roles of the estrogen signaling pathway in PCa.

The prognostic values of estrogen receptor alpha and beta in patients with gastroesophageal cancer: A meta-analysis

BACKGROUND

Published studies have investigated the prognostic roles of estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) in gastroesophageal cancer patients with the controversial results. The aim of the study was to systematically evaluate the impacts of ERα and ERβ on the overall survival (OS) in patients.

METHOD

Relevant eligible studies were extracted from PubMed, Embase, Web of Science, CNKI and Wanfang databases (from the start date to November 2018) following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. HR (hazard ratio) with 95% confidence intervals (CIs) were used to assess the prognostic values of ERα and ERβ for OS in patients.

RESULTS

High ERα expression was associated with poor OS (HR = 1.58, 95% CI = 1.29-1.94, P < .001) and ERβ with better OS (HR = 0.56, 95% CI = 0.37-0.83, P = .004) in gastroesophageal cancer. Furthermore, unfavorable OS was found in Chinese gastroesophageal patients with higher ERα expression (HR = 1.57, 95% CI = 1.25-1.96, P < .001) and better OS with higher ERβ expression (HR = 0.51, 95% CI = 0.31-0.83, P < .01) in our subgroup analysis. Meanwhile, worse OS was found in esophageal squamous cell carcinoma (ESCC) patients with high ERα expression (HR = 1.74, 95% CI = 1.33-2.26, P < .001), and favorable OS in ESCC with ERβ overexpression (HR = 0.40, 95% CI = 0.31-0.52, P < .001). Besides, high ERα expression was associated with lower tumor differentiation in ESCC (OR = 1.64; 95% CI = 1.02-2.64, P = .04) and ERβ was linked with better tumor differentiation in gastric adenocarcinoma (GCA) (OR = 0.49; 95% CI = 0.26-0.94, P = .03).

CONCLUSIONS

ERα and ERβ might serve as potential prognostic biomarkers for gastroesophageal cancer patients. ERα overexpression predicted poor OS and lower tumor differentiation, and ERβ suggested favorable OS and better tumor differentiation. Further related studies should be performed to test these results.

Idiopathic prepubertal unilateral gynecomastia: Case report and literature review

RATIONALE

Prepubertal unilateral gynecomastia is extremely rare, whose etiology and management strategy are not familiar. We would like to present a case and a literature review of unilateral prepubertal gynecomastia.

PATIENT CONCERNS

A 11-year old male patient with complaints of unilateral enlargement of breast tissue presented in our clinic, whose physical examination, biochemical, hormonal and oncologic findings were normal.

DIAGNOSES

This patient was diagnosed as idiopathic unilateral prepubertal gynecomastia (IUPG) and self-abasement, social isolation and sensitive of interpersonal relationship.

INTERVENTIONS

The patient received subcutaneous mastectomy. Histopathological examinations showed idiopathic gynecomastia of ductal epithelial hyperplasia and active interstitial fibrous hyperplasia, with no evidence of any pathological finding. Immunohistochemical examination showed estrogen receptor (ER)-α positive (70%), epidermal growth factor receptor (EGFR) positive, Her-2 positive (1+), Progesterone Receptor (PR) positive (80%).

OUTCOMES

A remarkable improvement was observed both in the physical and mental conditions at the post-surgical 6-month follow-up visit, showing no evidence of recurrence.

LESSONS

Further investigation is needed to clarify the pathogenesis of IUPG. All patients with IUPG should have a full endocrine and oncologic evaluation, and surgical excision may be the individually designed for each patient with the help of MRI of breast.

Therapeutic strategies to induce ERα in luminal breast cancer to enhance tamoxifen efficacy

Breast cancer is the most prevalent malignancy and second leading cause of death in women worldwide, with hormone receptor-positive luminal breast cancers being the most widespread subtype. While these tumors are generally amenable to endocrine therapy, cellular heterogeneity and acquired ability of tumor cells to undergo cell state switching makes these populations difficult to be fully targeted and eradicated through conventional methods. We have leveraged a quality-by-design (QbD) approach that integrates biological responses with predictive mathematical modeling to identify key combinations of commercially available drugs to induce estrogen receptor expression for therapeutic targeting. This technology utilizes a high level of automation through a custom-built platform to reduce bias as well as design-of-experiments methodology to minimize the experimental iterations required. Utilizing this approach, we identified a combination of clinical compounds, each at concentrations well below their efficacious dose, able to induce the expression of estrogen receptor alpha (ESR1) in hormone-positive breast cancer cells. Induction of ESR1 in luminal cells leads to chemosensitization. These findings provide proof of concept for the utility of the QbD strategy and identify a unique drug cocktail able to sensitize breast cancer cells to tamoxifen.

The effects of bisphenol A, benzyl butyl phthalate, and di(2-ethylhexyl) phthalate on estrogen receptor alpha in estrogen receptor-positive cells under hypoxia

Endocrine-disrupting chemicals (EDCs) are widely used in various consumer goods. Consequently, humans are constantly exposed to EDCs, which is associated with a variety of endocrine-related diseases. In this study, we demonstrated the effects of bisphenol A (BPA), benzyl butyl phthalate (BBP), and di(2-ethylhexyl) phthalate (DEHP) on estrogen receptor alpha (ERα) expression under normoxia and hypoxia. First, we confirmed the effects of EDCs on ER activity using OECD Test Guideline 455. Compared to the 100% activity induced by 1 nM 17-β-estradiol (positive control), BPA and BBP exhibited 50% ERα activation at concentrations of 1.31 μM and 4.8 μM, respectively. In contrast, and consistent with previous reports, DEHP did not activate ERα. ERα is activated and degraded by hypoxia in breast cancer cells. BPA, BBP, and DEHP enhanced ERα-mediated transcriptional activity under hypoxia. All three EDCs decreased ERα protein levels under hypoxia in MCF-7 cells. The transcriptional activity of hypoxia-inducible factor-1 was decreased and secretion of vascular endothelial growth factor (VEGF) was increased by BPA and BBP under hypoxia in MCF-7 cells, but not by DEHP. All three EDCs decreased the ERα protein expression level in Ishikawa human endometrial adenocarcinoma cells, and DEHP caused a weak decrease in VEGF secretion under hypoxia. These results demonstrate down-regulation of ERα by EDCs may influence the pathological state associated with hypoxia.

Association of anti-inflammatory and antiangiogenic therapies negatively influences prostate cancer progression in TRAMP mice

BACKGROUND

Chronic inflammation has been implicated in cancer etiology and angiogenesis is stimulated in this disease. In prostate, the crosstalk between malignant epithelial cells and their microenvironment is an essential step of tumorigenesis during which glandular stroma undergo changes designated as reactive stroma. Thus, the aim herewith was to evaluate the effects of associating anti-inflammatory and antiangiogenic therapies on cancer progression, correlating them with steroid hormone receptor (AR and ERα), reactive stroma (vimentin, αSMA, and TGF-β), and cell proliferation (PCNA) markers expression in the Transgenic Adenocarcinoma of Mouse Prostate (TRAMP) model.

METHODS

TRAMP mice (12-week old) were divided into the groups: Control (TRCON): received the vehicles used for drug dilution; Celecoxib (TRCEL): received oral doses of the anti-inflammatory drug celecoxib (15 mg/kg) twice daily; Nintedanib (TRNTB): received oral doses of the antiangiogenic drug nintedanib (10 mg/kg) daily; Nintedanib+Celecoxib (TRNTCEL): received the combination of drugs. After 6 weeks, mice were euthanized and ventral prostate samples were harvested for morphological, immunohistochemical, and Western blotting analyses.

RESULTS

While celecoxib led to fibromuscular hypertrophy attenuation, nintedanib significantly reduced the incidence of well-differentiated adenocarcinoma (WDAC) foci in relation to controls, both when administered per se or in association to celecoxib. Furthermore, drug combination was associated with unique effects, including lower incidence of HGPIN lesions; lower AR stromal distribution; changes in ERα localization from epithelial nuclei to stroma as well as significant decrease of TGF-β levels and associated angiogenesis. In parallel, all treatments applied resulted in reduced inflammatory marker and vimentin (VIM) expression.

CONCLUSIONS

Celecoxib plus nintedanib is an effective antitumor combination against prostate cancer progression in TRAMP mice, showing remarkable efficacy in relation to isolated therapies. Importantly, this efficacy might be due to drug association effect on driving AR and mainly ERα distribution in the prostatic tissue towards benign patterns. In addition, celecoxib and nintedanib impaired the development of a stromal reaction by reducing the recruitment of reactive stroma cells and maintaining a normal smooth muscle cell-rich prostate stroma in TRAMP mice. Collectively, these findings pointed to the beneficial effects of combining anti-inflammatory and antiangiogenic strategies to prevent or delay prostatic tumorigenesis.

Estrogen receptor-alpha isoforms are the main estrogen receptors expressed in non-small cell lung carcinoma

The expression profile of estrogen receptors (ER) in Non-Small Cell Lung Carcinoma (NSCLC) remains contradictory. Here we investigated protein and transcriptome expression of ERα wild type and variants. Tissue Micro-Arrays of 200 cases of NSCLC (paired tumor/non-tumor) were assayed by immunohistochemistry using a panel of ERα antibodies targeting different epitopes (HC20, 6F11, 1D5, ERα36 and ERα17p). ERβ epitopes were also examined for comparison. In parallel we conducted a probe-set mapping (Affymetrix HGU133 plus 2 chip) meta-analysis of 12 NSCLC tumor public transcriptomic studies (1418 cases) and 39 NSCLC cell lines. Finally, we have investigated early transcriptional effects of 17β-estradiol, 17β-estradiol-BSA, tamoxifen and their combination in two NSCLC cell lines (A549, H520). ERα transcript and protein detection in NSCLC specimens and cell lines suggests that extranuclear ERα variants, like ERα36, prevail, while wild-type ERα66 is minimally expressed. In non-tumor lung, the wild-type ERα66 is quasi-absent. The combined evaluation of ERα isoform staining intensity and subcellular localization with sex, can discriminate NSCLC subtypes and normal lung. Overall ERα transcription decreases in NSCLC. ERα expression is sex-related in non-tumor tissue, but in NSCLC it is exclusively correlating with tumor histologic subtype. ERα isoform protein expression is higher than ERβ. ERα isoforms are functional and display specific early transcriptional effects following steroid treatment. In conclusion, our data show a wide extranuclear ERα-variant expression in normal lung and NSCLC that is not reported by routine pathology ER evaluation criteria, limited in the nuclear wild type receptor.

Neurons expressing estrogen receptor α differentially innervate the periaqueductal gray matter of female rats

The periaqueductal gray matter (PAG) is a brainstem site involved in distinct autonomic and behavioral responses. Among them, the motor control of female sexual behavior, including lordosis, is well described. Lordosis reflex is highly dependent on increasing levels of estradiol that occur in the afternoon of the proestrus day in normally cycling females. This effect is thought to be mediated primarily via actions in the ventromedial nucleus of the hypothalamus (VMH). By binding to estrogen receptor α (ERα), estradiol changes the activity of VMH neurons that project to the PAG. Evidence also exists for the coordination of PAG outputs by estradiol-responsive neurons outside the VMH. However, a comprehensive analysis of these circuitries is not available. Using stereotaxic injection of the retrograde tracer Fluorogold in distinct columns of the PAG we performed a systematic mapping of neurons innervating the PAG and those coexpressing ERα immunoreactivity. We found that the forebrain projections to PAG columns are largely segregated and that most of the ERα expressing neurons preferentially target the lateral and the ventrolateral columns. Dual labeled neurons were mostly found in the intermediate subdivision of the lateral septal nucleus, the posterior aspect of the medial bed nucleus of the stria terminalis, the medial preoptic nucleus, the striohypothalamic nucleus and the ventrolateral VMH. Few dual labeled neurons were also observed in the arcuate nucleus, in the posterodorsal subdivision of the medial nucleus of the amygdala and in the ventral premammillary nucleus. Our findings indicate that ERα modulates sexual behavior in female rats via an integrated neural network that differentially innervate the columns of the PAG.

Role of estrogen receptors α and β in the development of allergic airway inflammation in mice: A possible involvement of interleukin 33 and eosinophils

Recent studies have shown that the estrogen receptor α (ERα), but not ERβ, is involved in the proinflammatory and propruritic responses in cutaneous allergy. In addition, results from our recent study showed that while oral administration of the rather ERβ-selective agonist bisphenol A exacerbated the respiratory allergic inflammation, the potential inflammatory reaction in the skin was decreased after administration of bisphenol A. This study aimed to elucidate whether ERα and ERβ are involved in the progression of an allergic airway inflammation. We performed an in vivo experiment using an animal model of allergic airway inflammation using male BALB/c mice to confirm an increase in the proinflammatory response induced by propylpyrazoletriol (PPT), an ERα agonist, and diarylpropionitrile (DPN), an ERβ agonist. Oral administration of PPT or DPN showed a significant increase in the inflammation of the lung and infiltration of eosinophils. While the expression of Th2 cytokines such as interleukin 4 (IL-4) and IL-13 was not affected by exposure to PPT or DPN, administration of these agonists significantly increased the expression of IL-33. The mechanism underlying the development of such allergic inflammatory responses was determined by an in vitro study using the human bronchial epithelial cell line (BEAS-2B) and the human eosinophilic leukemia cell line (EoL-1). Activated cells were exposed to PPT or DPN for 24 h, and the cytokine levels were measured. The IL-33 levels in BEAS-2B cells increased significantly after exposure to PPT or DPN. In addition, pretreatment with PPT or DPN increased the expression of IL-8 in activated EoL-1 cells. Our findings indicate that ERα and ERβ are involved in the proinflammatory response in respiratory allergy, and their effects may be mediated by an increase in the expression of IL-33 and infiltration of eosinophils.

Menopausal Hormone Therapy use and breast cancer risk by receptor subtypes: Results from the New South Wales Cancer Lifestyle and EvaluAtion of Risk (CLEAR) study

Breast cancer risk is increased with current Menopausal Hormone Therapy (MHT) use, with higher risks reported for ER+ (Estrogen Receptor positive), and ER+/PR+ (Estrogen and Progesterone Receptor positive) breast cancers than those of ER- and ER-/PR- status, respectively. There is limited evidence to suggest MHT use is associated with the specific subtype characterised as ER+/PR+/HER2- (Estrogen and Progesterone Receptor positive and Human Epidermal growth factor Receptor2 negative) status. This study aims to investigate the MHT-breast cancer relationship for breast cancer tumor receptor subtypes defined by ER expression alone, by ER and PR expression only and by joint expression of ER, PR, and HER2. Analyses compared 399 cancer registry-verified breast cancer cases with receptor status information and 324 cancer-free controls. We used multinomial logistic regression to estimate adjusted odds ratios (aORs) and 95% Confidence Intervals (CI) for current and past versus never MHT use, for subgroups defined by tumor receptor expression. Current, but not past, use of MHT was associated with an elevated risk of ER+ breast cancer (aOR = 2.04, 95%CI: 1.28-3.24) and ER+/PR+ breast cancer (aOR = 2.29, 1.41-3.72). Current MHT use was also associated with an elevated risk of the ER+/PR+/HER2- subtype (aOR = 2.30, 1.42-3.73). None of the other subtypes based on ER, ER/PR or ER/PR/HER2 expression were significantly associated with current MHT use in this analysis. Current, but not past, use of MHT increases the risk of breast cancer, with consistently higher risks reported for ER+ and ER+/PR+ subtypes and mounting evidence regarding the specific ER+/PR+/HER2- subtype. Our findings contribute to quantification of the effects of MHT, and support efforts to articulate the receptor-mediated mechanisms by which MHT increases the risk of breast cancer.

Uridine derivatives from the seeds of Lepidium apetalum Willd. and their estrogenic effects

Ten uridine derivatives (lepidiumuridine B-K) were isolated from the seeds of Lepidium apetalum Willd. Lepidiumuridine B-J were previously undescribed compounds, and were structurally characterized using analysis of their NMR and MS data. Lepidiumuridine C, D, I, and J increased cell proliferation and expression of ERα in the MCF-7 cell line. In addition, blockage of ERα completely abolished cell proliferation and expression of ERα in MCF-7 cells, suggesting that the proliferation effects of lepidiumuridine C, D, I, and J were ERα-mediated. The uridine derivatives might belong to undescribed phytoestrogens.

Esr1+ cells in the ventromedial hypothalamus control female aggression

As an essential means of resolving conflicts, aggression is expressed by both sexes but often at a higher level in males than in females. Recent studies suggest that cells in the ventrolateral part of the ventromedial hypothalamus (VMHvl) that express estrogen receptor-α (Esr1) and progesterone receptor are essential for male but not female mouse aggression. In contrast, here we show that VMHvl^Esr1+ cells are indispensable for female aggression. This population was active when females attacked naturally. Inactivation of these cells reduced female aggression whereas their activation elicited attack. Additionally, we found that female VMHvl contains two anatomically distinguishable subdivisions that showed differential gene expression, projection and activation patterns after mating and fighting. These results support an essential role of the VMHvl in both male and female aggression and reveal the existence of two previously unappreciated subdivisions in the female VMHvl that are involved in distinct social behaviors.

Further evidence to support bimodality of oestrogen receptor expression in breast cancer

AIMS

Although oestrogen receptor (ER)-negative breast cancers (BCs) do not respond to hormone therapy, the response of ER-positive BCs is reported to be variable, which may suggest a dose-dependent effect. The aim of this study was to assess the pattern of ER expression in BCs at the protein (immunohistochemistry) and transcriptome (microarray-based gene expression) levels.

METHODS AND RESULTS

ER immunohistochemical (IHC) expression was assessed in a large series of BCs, including 3649 core biopsies and 1892 cases prepared as tissue microarrays (TMAs) stained with specific antibodies. ESR1 mRNA expression was assessed in the METABRIC study (1980 cases), by the use of the Linear Models for Microarray Data (limma) software, and the results were compared with protein levels. IHC data confirmed the bimodality of ER expression, with 92.2% and 89.2% of the cases showing completely negative (<1%) or highly positive (≥70%) expression on the cores and TMAs, respectively. Weakly positive cases (1-10%) and intermediately positive (11-69%) cases were infrequent (2.7% and 5.1%, and 1.6% and 9.2%, in cores and TMAs, respectively), and did not show survival difference from ER-negative tumours. When full-face sections of the corresponding excision specimens were immunostained, 47% of the ER-low/intermediate group were deemed to be ER-negative. Transcriptomic data not only showed a significant correlation between ESR1 mRNA and protein expression levels, but also confirmed the bimodality of ER expression at the mRNA level.

CONCLUSIONS

Our study provides further evidence that ER expression is bimodal, and that it is observed at both the mRNA and protein levels. The reported poor survival of BC patients with low ER expression in the early clinical trials may be related to the inclusion of ER-negative cases.

Tissue-selective expression of a conditionally-active ROCK2-estrogen receptor fusion protein

The serine/threonine kinases ROCK1 and ROCK2 are central mediators of actomyosin contractile force generation that act downstream of the RhoA small GTP-binding protein. As a result, they have key roles in regulating cell morphology and proliferation, and have been implicated in numerous pathological conditions and diseases including hypertension and cancer. Here we describe the generation of a gene-targeted mouse line that enables CRE-inducible expression of a conditionally-active fusion between the ROCK2 kinase domain and the hormone-binding domain of a mutated estrogen receptor (ROCK2:ER). This two-stage system of regulation allows for tissue-selective expression of the ROCK2:ER fusion protein, which then requires administration of estrogen analogues such as tamoxifen or 4-hydroxytamoxifen to elicit kinase activity. This conditional gain-of-function system was validated in multiple tissues by crossing with mice expressing CRE recombinase under the transcriptional control of cytokeratin14 (K14), murine mammary tumor virus (MMTV) or cytochrome P450 Cyp1A1 (Ah) promoters, driving appropriate expression in the epidermis, mammary or intestinal epithelia respectively. Given the interest in ROCK signaling in normal physiology and disease, this mouse line will facilitate research into the consequences of ROCK activation that could be used to complement conditional knockout models. Birth Defects Research (Part A) 106:636-646, 2016. © 2016 Wiley Periodicals, Inc.

A New Role for ERα: Silencing via DNA Methylation of Basal, Stem Cell, and EMT Genes

Resistance to hormonal therapies is a major clinical problem in the treatment of estrogen receptor α-positive (ERα⁺) breast cancers. Epigenetic marks, namely DNA methylation of cytosine at specific CpG sites (5mCpG), are frequently associated with ERα⁺ status in human breast cancers. Therefore, ERα may regulate gene expression in part via DNA methylation. This hypothesis was evaluated using a panel of breast cancer cell line models of antiestrogen resistance. Microarray gene expression profiling was used to identify genes normally silenced in ERα⁺ cells but derepressed upon exposure to the demethylating agent decitabine, derepressed upon long-term loss of ERα expression, and resuppressed by gain of ERα activity/expression. ERα-dependent DNA methylation targets (n = 39) were enriched for ERα-binding sites, basal-up/luminal-down markers, cancer stem cell, epithelial-mesenchymal transition, and inflammatory and tumor suppressor genes. Kaplan-Meier survival curve and Cox proportional hazards regression analyses indicated that these targets predicted poor distant metastasis-free survival among a large cohort of breast cancer patients. The basal breast cancer subtype markers LCN2 and IFI27 showed the greatest inverse relationship with ERα expression/activity and contain ERα-binding sites. Thus, genes that are methylated in an ERα-dependent manner may serve as predictive biomarkers in breast cancer.

IMPLICATIONS

ERα directs DNA methylation-mediated silencing of specific genes that have biomarker potential in breast cancer subtypes. Mol Cancer Res; 15(2); 152-64. ©2016 AACR.

Improved Risk Stratification for Breast Cancer Samples Based on the Expression Ratio of the Estrogen and Progesterone Receptor

BACKGROUND

The receptors for estrogen (ESR1) and progesterone (PGR) are both part of the same signaling pathway and routinely used for breast cancer stratification. We tested the hypothesis if a coordinated analysis could add extra information for prognostic stratification.

MATERIALS AND METHODS

ESR1 and PGR gene expression was first investigated by quantitative reverse transcription polymerase chain reaction in fresh-frozen invasive ductal breast cancer samples (Hamburg collective, case-control, n=317). Our results were then tested using two datasets generated by different technical approaches: i) a public DNA-chip data set (GSE3494, n=251) and ii) semiquantitative protein expression data based on immunohistochemistry (Stuttgart collective, n=18,528).

RESULTS

The PGR/ESR1 gene-expression ratio was a prognostic indicator in those with ESR1/PGR-positive breast cancer (Hamburg collective), with a high PGR/ESR1 expression ratio indicating a favorable outcome. In all three collectives, the PGR/ESR1 mRNA ratio or its protein equivalent was a univariate prognostic factor and also a multivariate prognostic factor in the Hamburg and Stuttgart collectives.

CONCLUSION

Calculation of the PGR/ESR1 gene-expression ratio and its immunohistochemical surrogate could be a useful and simple addition to routine breast cancer diagnostics. A high PGR/ESR1 ratio could be indicative of a favorable clinical outcome.

Impact of Apparent Antagonism of Estrogen Receptor β by Fulvestrant on Anticancer Activity of 2-Methoxyestradiol

Osteosarcoma is one of the most malignant bone tumors of childhood and adolescence. Interestingly, the presence of estrogen receptors α and β has been reported in human bone cells, including osteosarcoma. Thus, inhibitors of estrogens such as fulvestrant, are considered candidates for novel endocrine therapy in treatment of osteosarcoma. Another anticancer agent that seems to be very effective in treatment of osteosarcoma is a derivative of 17β-estradiol, 2-methoxyestradiol. The aim of this study was to determine the anticancer activities of pure anti-estrogen, fulvestrant and combined treatment of fulvestrant and 2-methoxyestradiol towards highly metastatic osteosarcoma 143B cells. 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay was used in order to determine the antiproliferative potential of the compounds, and western blotting for estrogen receptors α and β. Flow cytometry was used in order to determine induction of cell death, cell-cycle arrest, mitochondrial depolarization, and DNA damage. Herein, we showed that fulvestrant has anticancer activity only at high concentrations. We were able to find and expression of estrogen receptor β, while we did not detect estrogen receptor α in osteosarcoma 143B cells. Moreover, fulvestrant down-regulated the expression of estrogen receptor β, and this effect was reversed by 2-methoxyestradiol. Thus, the obtained data suggest that 2-methoxyestradiol may exert part of its anticancer activity through modulation of expression of estrogen receptor β.

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 ERβ) 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 ERβ (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 ERβ may promote the unrestrained growth of HGEC. Androgen receptor may therefore be a clinically relevant prognostic indicator and a potential therapeutic target in EC.

Expression and regulation of the estrogen receptors in PC-3 human prostate cancer cells

The aim of this study was to identify the expression, cellular localization and regulation of classic estrogen receptors ERα and ERβ, ER-α36 isoform and GPER in the androgen-independent prostate cancer cell line PC-3. In addition, we evaluated the relative contribution of these receptors to the activation of the ERK1/2 (extracellular signal-regulated protein kinases) signaling pathway. These four estrogen receptors were detected by Western blot assays and were shown by immunofluorescence assays to localize preferentially in extranuclear regions of PC-3 cells. In addition, treatment with 17β-estradiol (E2) (1 μM) for 24 h led to down-regulation of the classic estrogen receptors, whereas E2 at physiological concentration (0.1 nM) for 24h tended to increase the levels of ERα and ERβ. Furthermore, the ERα-selective agonist PPT selectively increased the expression of ERβ and the ERβ-selective agonist DPN increased ERα levels. None of these treatments affected expression of the ER-α36 isoform. The unusual cytoplasmic localization of the classic estrogen receptors in these cells differs from the nuclear localization in the majority of estrogen target cells and suggests that rapid signaling pathways may be preferentially activated. In fact, treatment with selective agonists of ERα, ERβ and GPER induced ERK1/2 phosphorylation that was blocked by the respective antagonists. On the other hand, activation of ERK1/2 induced by E2 may involve additional mechanisms because it was not blocked by the three antagonists. Taken together, the results indicate that there is a crosstalk between ERα and ERβ to regulate the expression of each other, and suggest the involvement of other receptors, such as ER-α36, in the rapid ERK1/2 activation by E2. The identification of new isoforms of ERs, regulation of the receptors and signaling pathways is important to develop new therapeutic strategies for the castration-resistant prostate cancer.

Activation of classical estrogen receptor subtypes reduces tight junction disruption of brain endothelial cells under ischemia/reperfusion injury

Ischemic stroke, which induces oxidative stress in the brain, disrupts tight junctions (TJs) between brain endothelial cells, resulting in blood-brain barrier (BBB) breakdown and brain edema. Estrogen reduces oxidative stress and protects brain endothelial cells from ischemic insult. The aim of this study was to determine the protective effects of estrogen on TJ disruption and to examine the roles of classical estrogen receptor (ER) subtypes, ERα- and ERβ, in estrogen effects in brain endothelial cells (bEnd.3) exposed to oxygen-glucose deprivation/reperfusion (OGD/R) injury. Estrogen pretreatment prevented OGD/R-induced decreases in cell viability and TJ protein levels. ERα- and ERβ-specific agonists also reduced TJ disruption. Knockdown of ERα or ERβ expression partially inhibited the effects of estrogen, but completely reversed the effects of corresponding ER subtype-specific agonists on the outcomes of OGD/R. During the early reperfusion period, activation of extracellular signal-regulated kinase1/2 and hypoxia-inducible factor 1α/vascular endothelial growth factor was associated with decreased expression of occludin and claudin-5, respectively, and these changes in TJ protein levels were differentially regulated by ER subtype-specific agonists. Our results suggest that ERα and ERβ activation reduce TJ disruption via inhibition of signaling molecules after ischemic injury and that targeting each ER subtype can be a useful strategy for protecting the BBB from ischemic stroke in postmenopausal women.

Endometrial Expression of Estrogen Receptors and the Androgen Receptor in Women With Polycystic Ovary Syndrome: A Lifestyle Intervention Study

CONTEXT

Polycystic ovary syndrome (PCOS) is a common cause of anovulation. It may also negatively affect the endometrium, which could lead to implantation failure and proliferative aberrations.

OBJECTIVE

Our objective was to study sex hormone receptors in the endometrium of women with PCOS.

DESIGN

This is a cross-sectional study and lifestyle intervention.

SETTING

Clinical and laboratory research unit was undertaken at a university hospital.

PARTICIPANTS

Twenty overweight/obese women fulfilling all three PCOS criteria (anovulation, hyperandrogenism, and polycystic ovaries), 10 body mass index-matched regularly menstruating controls, 11 normal-weight women with PCOS, and 11 normal-weight controls.

INTERVENTION

Intervention for this study included dietary management and physical exercise.

MAIN OUTCOME MEASURES

mRNA levels and immunostaining of estrogen receptor α (ERα) and β (ERβ), nongenomic estrogen receptor α36 (ERα36), and G-protein-coupled estrogen receptor-1 (GPER), and the androgen receptor (AR) on cycle days 6-8 and cycle days 21-23.

RESULTS

Before intervention, mRNA levels of ERα, ERα36, and the ERα/ERβ mRNA ratio were lower in proliferative endometrium of overweight/obese PCOS women compared with controls (P < .05). After intervention, ERα protein and the ERα/ERβ protein ratio in proliferative endometrium increased and were higher in PCOS women with improved menstrual function than in those without improvement (P < .05). In the subgroup of PCOS women with restored ovulation, only higher protein levels of GPER were found in secretory endometrium (P < .01). However, PCOS women who remained anovulatory had higher protein levels of ERα, GPER, and AR on cycle days 21-23 than controls (P < .05).

CONCLUSIONS

Lifestyle intervention alters, but does not fully restore, ER and AR expression in proliferative and secretory endometrium of obese women with PCOS.

[High expression of cyclin D1 is correlated with the expression of estrogen receptor and good prognosis in breast cancer]

OBJECTIVE

To explore the expression levels and clinical significance of cyclin D1 and estrogen receptor (ER) in breast cancer.

METHODS

Immunohistochemical staining was performed to detect the expression levels of cyclin D1 and ER in 102 breast cancers and 60 normal breast tissue specimens. Referring to clinicopathological parameters and 5-year follow-up data, we analyzed the correlations between cyclin D1, ER and their prognosis.

RESULTS

The expression levels of both cyclin D1 and ER were significantly different between breast cancer and normal breast tissues. Cyclin D1 expression was related to tumor histological grade, TNM stage and ER levels. Spearman correlation analysis showed that cyclin D1 and ER were positively related. Moreover, Kaplan-Meier analysis showed that patients who expressed high levels of cyclin D1 had a longer overall survival compared with those with low expressions. Cyclin D1, ER, and TNM stage were independent prognosis factors according to Cox analysis.

CONCLUSION

Cyclin D1 has a higher expression in breast cancer, positively correlated with ER and better prognosis.

[INFLUENCE OF PROGESTERONE DERIVATIVES ON THE VIABILITY AND EXPRESSION OF ESTROGEN RECEPTOR-ALPHA MRNA IN HELA CELLS.]

We have studied the effect of new ligands of progesterone receptors, including pregna-D'-pentaran 6-methoxyimino-16a,17a-cyclohexanopregn-4-en-3,20-dio-ne (K1047), 17a-acetoxy-3b-butanoyloxy-6-methylpregna-4,6-dien-20-one (buterol), progesterone (P4), and medroxyprogesterone acetate on the viability of HeLa cells and expression of estrogen receptor-alpha (Era) mRNA gene in these cells. K1I047 and buterol exhibited high cytostatic activity, which exceeded the activity of reference compounds on the average by 15% (p < 0.05). Both buterol and K-1047 (at 10(-6)M) effectively suppressed ERa mRNA gene expression in HeLa cell culture by 83.4 - 9 8.6%.

Application of a Patient Derived Xenograft Model for Predicative Study of Uterine Fibroid Disease

Human uterine fibroids, benign tumors derived from the smooth muscle layers of the uterus, impose a major health burden to up to 50% of premenopausal women in their daily life. To improve our understanding of this disease, we developed and characterized a patient-derived xenograft model by subcutaneous transplantation of pieces of human uterine fibroid tissue into three different strains of severe combined immunodeficient mice. Engrafted uterine fibroid tissue preserved the classical morphology with interwoven bundles of smooth muscle cells and an abundant deposition of collagenous matrix, similar to uterine fibroids in situ. The grafts expressed both estrogen receptor 1 and progesterone receptor. Additionally, both receptors were up-regulated by estrogen treatment. Growth of the fibroid grafts was dependent on 17β-estradiol and progesterone supplementation at levels similar to women with the disease and was studied for up to 60 days at maximum. Co-treatment with the antiprogestin mifepristone reduced graft growth (four independent donors, p<0.0001 two-sided t-test), as did treatment with the mTOR inhibitor rapamycin (three independent donors, p<0.0001 two-sided t-test). This in vivo animal model preserves the main histological and functional characteristics of human uterine fibroids, is amenable to intervention by pharmacological treatment, and can thus serve as an adequate model for the development of novel therapies.

[Cytoprotective Effects of Phytoestrogen Genistein against Cancer Cells]

In this paper we study the effect of synthetic isoflavonoid genistein against cancer HeLa cells, which contain estrogen receptors alpha but not beta, with the aim to determine the cytotoxic or cytoprotective effect of genistein. It is shown that the half maximal inhibitory concentration (IC50) value of genistein (0.2 mM) for the growth inhibition of HeLa cells is at least ten times higher than that one of tamoxifen and cisplatin--drugs, used in cervical cancer treatment. In micromolar concentrations (0.1-10 μM) genistein decreased the cytotoxic effects of cisplatin and tamoxifen. The decreased Bax mRNA expression and increased Bcl-2 mRNA expression after incubation .of the cells with genistein also demonstrate the cytoprotective, anti-apoptotic effect of genistein. Genistein, even in high concentrations, had no effect on membrane potential and calcium capacity of isolated mitochondria, without activating the opening of Ca(2+)-induced mitochondrial pore. Thus, these data demonstrate a cytoprotective effect of isoflavonoid genistein against this type of cancer cells.

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 17β-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 ERβ 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.

Upregulation of cell surface estrogen receptor alpha is associated with the mitogen-activated protein kinase/extracellular signal-regulated kinase activity and promotes autophagy maturation

Recently, accumulating evidence has implicated the dysregulation of autophagy as underlying the pathophysiology of several neurodegenerative diseases. The human neuronal cell line SH-SY5Y was exposed to 1-Methyl-4-phenylpyridinium (MPP(+)). The mechanism is that the sustained activation of the MAPK/ERK pathway by MPP(+) alters autophagy selectively at the maturation step, significant increasing in autophagy formation and delaying in autophagy degradation in SHSY5Y cells. In this study, we provided evidences that estrogen was capable of promoting SHSY5Y cells survival in MPP(+)-treated group. In particular, the up-regulation of mERα, but not mERβ, was associated with a rapid and transient activation of ERK phosphorylation compatible with promoting autophagy maturation. The up-regulation of mERα changed the sustained activation of ERK phosphorylation in MPP(+)-treated group into a temporary activation. Taken together, these findings strongly support that the expression of mERα promotes the maturation of autophagosomes into functional autolysosomes by regulating ERK, determining SHSY5Y cells survival.

CORRELATION BETWEEN CLINICAL PATHOLOGY OF LUMINAL B BREAST CANCER AND DETERMINATION OF ESTROGEN RECEPTOR, PROGESTERONE RECEPTOR AND HER2 EXPRESSION COMBINED WITH NUCLEAR MORPHOLOGY

Breast cancer, one of the most common malignant tumors in females, draws little attention because of its untypical symptoms and signs, so the disease is usually confirmed too late, in an advanced stage. Based on the detection of nuclear morphology parameters of luminal B breast cancer, this study explored how pathological features relate to estrogen receptor (ER) and progesterone receptor (PR) expression of human epidermal growth factor receptor-2 (HER2). A quantity of 354 breast cancer specimens with follow-up records from the department of pathology in the First People’s Hospital of Nantong and the Tumor Hospital of Nantong were selected as research subjects. Nuclear parameters of specimens stained by hematoxylin and eosin were measured by imaging analysis software. It was found that breast cancer can be divided into four types, luminal B, luminal A, HER2 over-expression and basal-like type based on immunohistochemical results of three antibodies, i.e, ER, PR and HER2. A total of 113 patients (31.8%) were confirmed with luminal B breast cancer, mostly in histological stage II; the difference of nuclear morphology was of statistical significance between ER+/PR+ and ER-/PR- (P<0.05), and most ER-/PR- was histologically confirmed as stage III, with lower survival rate than ER+/PR+ (P<0.05). Among these four subtypes of breast cancer, luminal B had the lowest brain metastasis rate, while HER2 over-expression subtype was found with the highest rate of lung and pleura metastasis. Besides, luminal B possessed longer disease-free survival (DFS) than basal-like (P<0.05) and longer total survival (OS) than HER2 over-expression (P<0.05) and basal-like subtypes (P<0.05). It can be concluded that detection of ER, PR and HER2 in combination with nuclear morphology is beneficial to evaluate treatment and prognosis of breast cancer.

Impact of estrogen and progesterone receptor expression on the clinical and molecular features of papillary thyroid cancer

BACKGROUND

Thyroid cancer is highly prevalent in women during the fertile age, which suggests a possible impact of hormonal and reproductive factors.

METHODS

We studied the expression of estrogen receptor α (ERα or ESR1) and progesterone receptor (PR or PGR) in 182 female and male patients with papillary thyroid cancer and correlated it to clinical and molecular features.

RESULTS

ERα and PR expression was found in 66.5 and 75.8% of patients respectively and was significantly correlated with larger tumor size and with a non-incidental diagnosis. Moreover, a trend toward a higher prevalence of local metastases was observed in ER- and PR-expressing tumors, which possibly indicates a more aggressive behavior. Interestingly, the occurrence of the 'receptor conversion' phenomenon, which has already been reported to have a negative prognostic effect in breast cancer, was demonstrated for the first time in thyroid tumors. Indeed, almost all of the ERα-positive primary tumors analyzed had ERα-negative metastatic lymph nodes. At the genetic analyses, BRAF(V600E) mutation was detected in 23.2% of the tumors and had a higher prevalence in larger tumors and in those with a stronger ERα or PR staining.

CONCLUSIONS

The whole of the findings reported in the present study argue for an association between ERα and PR sex hormone receptor expression and a more aggressive presentation. Although no impact on outcome was found, the evaluation of ERα and PR receptor expression could add insights into the biological behavior of tumors and could modify the follow-up, particularly in fertile women affected with persistent disease.

Immunohistochemical evaluation of pulmonary lymphangioleiomyomatosis

BACKGROUND

Lymphangioleiomyomatosis (LAM) is a rare interstitial lung disease characterized by abnormal smooth muscle-like cell (LAM cell) proliferation in the lung stroma. The origin of LAM cells is still unknown. The gold-standard immunohistochemical diagnostic for LAM is an immunopositive reaction to the HMB-45 antibody.

MATERIALS AND METHODS

We aimed to evaluate 15 diagnostic open-lung biopsy specimens of pulmonary LAM. Based on the LAM histologic score (LHS), we distinguished two groups of histological severity: early- and advanced-stage LAM. The expression of HMB-45, estrogen receptor (ER), progesterone receptor (PR), β-catenin, E-cadherin, podoplanin (D2-40), mini-chromosome maintenance protein 3 (MCM3), and epidermal growth factor receptor (EGFR) was evaluated immunohistochemically. Fluorescence in situ hybridization (FISH) was performed in order to investigate amplification of the EGFR gene in LAM cells.

RESULTS

The expression of ER and EGFR was significantly higher in advanced than in early-stage LAM. Amplification of the EGFR gene was not detected in any of the 15 studied cases. There was a strong-positive correlation between the expression of PR, ER, β-catenin, E-cadherin, and the standard marker of LAM, HMB45.

CONCLUSION

We conclude that together with LHS, ER may be considered a useful tool for evaluating the progression of LAM. β-Catenin and E-cadherin seem to be new potential specific markers of LAM cells. The increased expression of EGFR in LAM cells is not associated with EGFR gene amplification, although it may be a marker of disease progression; the role of this receptor in LAM pathogenesis should be further investigated. Positive reaction of LAM cells with podoplain demonstrates the existence of an additional lymphatic endothelial lineage in LAM cells.

Membrane estrogen receptor alpha is an important modulator of bone marrow C-Kit+ cells mediated cardiac repair after myocardial infarction

It has been validated that c-kit positive (c-kit+) cells in infarcted myocardium are from bone marrow (BM). Given the recent study that in the heart, estrogen receptor alpha (ERα) is involved in adaptive mechanisms by supporting cardiomyocytes survival via post-infarct cardiac c-kit+ cells, we tested a novel hypothesis that membrane ERα (mERа) supports survival of BM c-kit+ cells and enhance protective paracrine function for cardiac repair. Our data showed that myocardial infarction (MI) leads to an increase in c-kit+ first in bone marrow and then specifically within the infarcted myocardium. Also up-regulated mERа in post-infarct BM c-kit+ cells was found in day 3 post MI. In vitro co-culture system, mERа+ enhances the beneficial effects of BM c-kit+ cells by increasing their viability and reducing apoptosis. Post-infarct c-kit+ mERа+ cells population expresses predominant ERα and holds self-renewal as well as cardiac differentiation potentials after MI. In vivo, BM c-kit+ cells reduced infarct size, fibrosis and improved cardiac function. In conclusion, BM c-kit+ mERа+ exerted significantly cardiac protection after MI. A potential important implication of this study is that the manipulation of BM c-kit+ stem cells with ERа-dependent fashion may be helpful in recovering functional performance after cardiac tissue injury.

MEL-18 loss mediates estrogen receptor-α downregulation and hormone independence

The polycomb protein MEL-18 has been proposed as a tumor suppressor in breast cancer; however, its functional relevance to the hormonal regulation of breast cancer remains unknown. Here, we demonstrated that MEL-18 loss contributes to the hormone-independent phenotype of breast cancer by modulating hormone receptor expression. In multiple breast cancer cohorts, MEL-18 was markedly downregulated in triple-negative breast cancer (TNBC). MEL-18 expression positively correlated with the expression of luminal markers, including estrogen receptor-α (ER-α, encoded by ESR1). MEL-18 loss was also associated with poor response to antihormonal therapy in ER-α-positive breast cancer. Furthermore, whereas MEL-18 loss in luminal breast cancer cells resulted in the downregulation of expression and activity of ER-α and the progesterone receptor (PR), MEL-18 overexpression restored ER-α expression in TNBC. Consistently, in vivo xenograft experiments demonstrated that MEL-18 loss induces estrogen-independent growth and tamoxifen resistance in luminal breast cancer, and that MEL-18 overexpression confers tamoxifen sensitivity in TNBC. MEL-18 suppressed SUMOylation of the ESR1 transactivators p53 and SP1, thereby driving ESR1 transcription. MEL-18 facilitated the deSUMOylation process by inhibiting BMI-1/RING1B-mediated ubiquitin-proteasomal degradation of SUMO1/sentrin-specific protease 1 (SENP1). These findings demonstrate that MEL-18 is a SUMO-dependent regulator of hormone receptors and suggest MEL-18 expression as a marker for determining the antihormonal therapy response in patients with breast cancer.

Synergistic effect between celecoxib and luteolin is dependent on estrogen receptor in human breast cancer cells

The anti-cancer effects of celecoxib and luteolin are well known. Although our previous study demonstrated that the combination of celecoxib and luteolin synergistically inhibits breast tumor growth compared with each of the treatments alone, we did not uncover the molecular mechanisms of these effects. The aims of our present study were to compare the effects of a celecoxib and luteolin combination treatment in four different human breast cell lines and to determine the mechanisms of action in vitro and in vivo. The synergistic effects of a celecoxib and luteolin combination treatment yielded significantly greater cell growth inhibition in all four breast cancer cell lines compared with the single agents alone. In particular, combined celecoxib and luteolin treatment significantly decreased the growth of MDA-MB-231 cancer cells in vivo compared with either agent alone. The celecoxib and luteolin combination treatment induced synergistic effects via Akt inactivation and extracellular signal-regulated kinase (ERK) signaling inhibition in MCF-7 and MCF7/HER18 cells and via Akt inactivation and ERK signaling activation in MDA-MB-231 and SkBr3 cells. These results demonstrate the synergistic anti-tumor effect of the celecoxib and luteolin combination treatment in different four breast cancer cell lines, thus introducing the possibility of this combination as a new treatment modality.

1,25-dihydroxyvitamin D3 regulates expression of sex steroid receptors in human uterine fibroid cells

CONTEXT

Uterine fibroids (UFs) are the most common benign tumors in premenopausal women. In this study, we evaluated the effects of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] for the treatment of UFs.

OBJECTIVE

To determine the role of 1,25(OH)2D3 on the expression of sex steroid receptors in human UF cells.

DESIGN

Human UFs and their adjacent myometrium were analyzed for expression of estrogen receptor (ER)-α, progesterone receptor (PR)-A, and PR-B, as well as members of the steroid receptor coactivator (SRC) family. Immortalized human uterine fibroid (human uterine leiomyoma [HuLM]) cells were treated with 1,25(OH)2D3 and assayed for the expression and localization of the aforementioned receptors and SRCs using Western blot, immunohistochemistry, immunofluorescence, and immunoprecipitation assays.

MAIN OUTCOME MEASURES

We discovered a correlation between reduced levels of vitamin D receptor (VDR) and increased levels of ER-α, PR-A, and PR-B in these tissues. We evaluated the effects of 1,25(OH)2D3 on the regulation of the aforementioned sex steroid receptors.

RESULTS

We observed an inverse correlation between the up-regulated ER-α, PR-A, and PR-B and expression of VDR in UFs. Treatment with 1,25(OH)2D3 significantly decreased levels of ER-α, PR-A, and PR-B, as well as SRCs in HuLM cells (P < .05). In contrast, 1,25(OH)2D3 self-induced its own VDR, which resulted in an induction of VDR-retinoid X receptor-α complex in HuLM cells. Together, these results suggest that 1,25(OH)2D3 functions as an antagonist of sex steroid hormone receptors in HuLM cells.

CONCLUSIONS

1,25(OH)2D3 functions as a potent antiestrogenic/antiprogesteronic agent that may have utility as a novel therapeutic option for UF.

Cohesin modulates transcription of estrogen-responsive genes

The cohesin complex has essential roles in cell division, DNA damage repair and gene transcription. The transcriptional function of cohesin is thought to derive from its ability to connect distant regulatory elements with gene promoters. Genome-wide binding of cohesin in breast cancer cells frequently coincides with estrogen receptor alpha (ER), leading to the hypothesis that cohesin facilitates estrogen-dependent gene transcription. We found that cohesin modulates the expression of only a subset of genes in the ER transcription program, either activating or repressing transcription depending on the gene target. Estrogen-responsive genes most significantly influenced by cohesin were enriched in pathways associated with breast cancer progression such as PI3K and ErbB1. In MCF7 breast cancer cells, cohesin depletion enhanced transcription of TFF1 and TFF2, and was associated with increased ER binding and increased interaction between TFF1 and its distal enhancer situated within TMPRSS3. In contrast, cohesin depletion reduced c-MYC mRNA and was accompanied by reduced interaction between a distal enhancer of c-MYC and its promoters. Our data indicates that cohesin is not a universal facilitator of ER-induced transcription and can even restrict enhancer-promoter communication. We propose that cohesin modulates transcription of estrogen-dependent genes to achieve appropriate directionality and amplitude of expression.

Reprogramming of the ERRα and ERα target gene landscape triggers tamoxifen resistance in breast cancer

Endocrine treatment regimens for breast cancer that target the estrogen receptor-α (ERα) are effective, but acquired resistance remains a limiting drawback. One mechanism of acquired resistance that has been hypothesized is functional substitution of the orphan receptor estrogen-related receptor-α (ERRα) for ERα. To examine this hypothesis, we analyzed ERRα and ERα in recurrent tamoxifen-resistant breast tumors and conducted a genome-wide target gene profiling analysis of MCF-7 breast cancer cell populations that were sensitive or resistant to tamoxifen treatment. This analysis uncovered a global redirection in the target genes controlled by ERα, ERRα, and their coactivator AIB1, defining a novel set of target genes in tamoxifen-resistant cells. Beyond differences in the ERα and ERRα target gene repertoires, both factors were engaged in similar pathobiologic processes relevant to acquired resistance. Functional analyses confirmed a requirement for ERRα in tamoxifen- and fulvestrant-resistant MCF-7 cells, with pharmacologic inhibition of ERRα sufficient to partly restore sensitivity to antiestrogens. In clinical specimens (n = 1041), increased expression of ERRα was associated with enhanced proliferation and aggressive disease parameters, including increased levels of p53 in ERα-positive cases. In addition, increased ERRα expression was linked to reduced overall survival in independent tamoxifen-treated patient cohorts. Taken together, our results suggest that ERα and ERRα cooperate to promote endocrine resistance, and they provide a rationale for the exploration of ERRα as a candidate drug target to treat endocrine-resistant breast cancer.

Kinome-wide functional screen identifies role of PLK1 in hormone-independent, ER-positive breast cancer

Estrogen receptor (ER) α-positive breast cancers initially respond to antiestrogens but eventually become estrogen independent and recur. ER(+) breast cancer cells resistant to long-term estrogen deprivation (LTED) exhibit hormone-independent ER transcriptional activity and growth. A kinome-wide siRNA screen using a library targeting 720 kinases identified Polo-like kinase 1 (PLK1) as one of the top genes whose downregulation resulted in inhibition of estrogen-independent ER transcriptional activity and growth of LTED cells. High PLK1 mRNA and protein correlated with a high Ki-67 score in primary ER(+) breast cancers after treatment with the aromatase inhibitor letrozole. RNAi-mediated knockdown of PLK1 inhibited ER expression, estrogen-independent growth, and ER transcription in MCF7 and HCC1428 LTED cells. Pharmacologic inhibition of PLK1 with volasertib, a small-molecule ATP-competitive PLK1 inhibitor, decreased LTED cell growth, ER transcriptional activity, and ER expression. Volasertib in combination with the ER antagonist, fulvestrant, decreased MCF7 xenograft growth in ovariectomized mice more potently than each drug alone. JUNB, a component of the AP-1 complex, was expressed 16-fold higher in MCF7/LTED compared with parental MCF7 cells. Furthermore, JUNB and BCL2L1 (which encodes antiapoptotic BCL-xL) mRNA levels were markedly reduced upon volasertib treatment in MCF7/LTED cells, while they were increased in parental MCF7 cells. Finally, JUNB knockdown decreased ER expression and transcriptional activity in MCF7/LTED cells, suggesting that PLK1 drives ER expression and estrogen-independent growth via JUNB. These data support a critical role of PLK1 in acquired hormone-independent growth of ER(+) human breast cancer and is therefore a promising target in tumors that have escaped estrogen deprivation therapy.

Reproductive senescence blunts response of estrogen receptor-α expression to estrogen treatment in rat post-ischemic cerebral microvessels

BACKGROUND

Several studies demonstrate that estrogen treatment improves cerebral blood flow in ischemic brain regions of young ovariectomized (OVX) rats. Estrogen receptor-α (ER-α) may mediate estrogen's beneficial actions via its effects on the cerebral microvasculature. However, estrogen-derived benefit may be attenuated in aged, reproductively senescent (RS) rats. Our goal was to determine the effects of aging, estrogen deprivation and estrogen repletion with oral conjugated estrogens (CE) on postischemic cerebral microvascular protein expression of ER-α and ER-β.

METHODS

Fisher-344 (n = 37) female rats were randomly divided into the following groups: OVX, OVX CE-treated, RS untreated, and RS CE-treated. After 30 days pretreatment with CE (0.01 mg/kg) rats were subjected to 15 min. transient global cerebral ischemia. Non-ischemic naïve, OVX and RS rats were used as controls. Expression of ER-α and ER-β in isolated cortical cerebral microvessels (20 to 100 µm in diameter) was assessed using Western blot and immunohistochemistry techniques.

RESULTS

Age and reproductive status blunted nonischemic ER-α expression in microvessels of OVX rats (0.31 ± 0.05) and RS rats (0.33 ± 0.06) compared to naïve rats (0.45 ± 0.02). Postischemic microvascular expression of ER-α in OVX rats (0.01 ± 0.0) was increased by CE treatment (0.04 ± 0.01). Expression of ER-α in microvessels of RS rats (0.03 ± 0.02) was unaffected by CE treatment (0.01 ± 0.02). Western blot data are presented as a ratio of ER-α or ER-β proteins to β-actin and. Oral CE treatment had no effect on ER-β expression in postischemic microvessels of OVX and RS rats. Statistical analysis was performed by One-Way ANOVA and a Newman-Keuls or Student's post-hoc test.

CONCLUSION

Chronic treatment with CE increases ER-α but not ER-β expression in cerebral microvessels of OVX rats. Aging appears to reduce the normal ability of estrogen to increase ER-α expression in postischemic cerebral microvessels.

An epigenomic approach to therapy for tamoxifen-resistant breast cancer

Tamoxifen has been a frontline treatment for estrogen receptor alpha (ERα)-positive breast tumors in premenopausal women. However, resistance to tamoxifen occurs in many patients. ER still plays a critical role in the growth of breast cancer cells with acquired tamoxifen resistance, suggesting that ERα remains a valid target for treatment of tamoxifen-resistant (Tam-R) breast cancer. In an effort to identify novel regulators of ERα signaling, through a small-scale siRNA screen against histone methyl modifiers, we found WHSC1, a histone H3K36 methyltransferase, as a positive regulator of ERα signaling in breast cancer cells. We demonstrated that WHSC1 is recruited to the ERα gene by the BET protein BRD3/4, and facilitates ERα gene expression. The small-molecule BET protein inhibitor JQ1 potently suppressed the classic ERα signaling pathway and the growth of Tam-R breast cancer cells in culture. Using a Tam-R breast cancer xenograft mouse model, we demonstrated in vivo anti-breast cancer activity by JQ1 and a strong long-lasting effect of combination therapy with JQ1 and the ER degrader fulvestrant. Taken together, we provide evidence that the epigenomic proteins BRD3/4 and WHSC1 are essential regulators of estrogen receptor signaling and are novel therapeutic targets for treatment of Tam-R breast cancer.

Sex differences in expression of oestrogen receptor α but not androgen receptor mRNAs in the foetal lamb brain

Gonadal steroid hormones play important roles during critical periods of development to organise brain structures that control sexually dimorphic neuroendocrine responses and behaviours. Specific receptors for androgens and oestrogens must be expressed at appropriate times during development to mediate these processes. The present study was performed to test for sex differences in the relative expression of oestrogen receptor (ER)α and androgen receptor (AR) mRNA during the window of time in gestation that is critical for behavioural masculinisation and differentiation of the ovine sexually dimorphic nucleus (oSDN) in the sheep. In addition, we examined whether ERα and AR mRNA expression is localised within the nascent oSDN and could be involved in its development. Using the quantitative real-time polymerase chain reaction, we found that females expressed more ERα mRNA than males in medial preoptic area and medial basal hypothalamus during the mid-gestational critical period for brain sexual differentiation. No sex differences were found for AR mRNA in any tissue examined or for ERα in amygdala and frontal cortex. Using radioactive in situ hybridisation, we found that the distributions of ERα and AR mRNA overlapped with aromatase mRNA, which delineates the boundaries of the developing oSDN and identifies this nucleus as a target for both androgens and oestrogens. These data demonstrate that the transcriptional machinery for synthesising gonadal steroid receptors is functional in the foetal lamb brain during the critical period for sexual differentiation and suggest that possible mechanisms for establishing dimorphisms controlled by gonadal steroids may exist at the level of steroid hormone receptor expression.

[Expression and significance of ERalpha mRNA of residents exposed to arsenic via drinking water]

OBJECTIVE

To detect ERbeta mRNA expression of subjects exposed to different arsenic drinking water, and to analyze the potential relationship between their abnormal expression and heart injury caused by arsenic in order to study the endocrine disturbing effect of arsenic.

METHODS

Molecular epidemiological method was used. The study subjects included a total of 273 residents exposed to arsenic via drinking water,and they were divided into four groups according to arsenic concentration, and their blood ERbeta mRNA expression was detected by real-time RT-PCR.

RESULTS

The level of ERbeta mRNA expression rose with increasing of water As and urine As (r = 0.159, 0.21, P < 0.05). The prevalence of Q-Tc interval prolongation aggravated with increasing of water As(chi2 = 4.35, P = 0.037), while according with the variation of ERbeta mRNA expression. Tp-Te interval prolonged with increasing of water As (r = 0.199, P = 0.023), as well prolonged with increasing of ERbeta mRNA expression (r = 0.205, P = 0.019). The prevalence of arrhythmia was almost according with the variation of ERbeta mRNA expression.

CONCLUSION

chronic arsenic exposure can potentially disturb ERbeta mRNA expression, as well as there are possible relationship between ERbeta mRNA abnormal expression and Q-Tc interval prolongation and Tp-Te interval prolonged caused by arsenic.

Heterogeneity in the expression of receptors in the human breast cancer metastasized to the brain

Assessment of the human epidermal growth factor receptor-2 (Her2/ErbB2) and estrogen receptor (ER) and progesterone receptor (PR) expression in breast cancer has been an accepted standard to predict clinical outcome. Expression of these receptors in primary breast cancer has also been an important predictor of visceral organ metastasis. Many studies of breast cancer have reported risk factors for brain metastasis that include Her2/ErbB2 positivity, ER negativity, and negativity for all the above three receptors. However, it is not clear whether expression of these receptors would persist subsequent to brain metastasis. To address this possibility, we analyzed different breast cancer brain metastases (BCBM) for the expression of Her2/ErbB2, ER, and PR by immunohistochemistry procedure. The results showed that BCBM are heterogeneous in the receptor expression: Five BCBMs were Her2/ErbB2-positive and one negative; four BCBMs were ER-positive, and two were negative; five BCBMs were PR-positive and one negative. However, expression of these receptors in their combination is also heterogeneous: Four BCBMs were positive for all of the Her2/ErbB2, ER, and PR; one BCBM was positive for Her2/ErbB2 and PR but negative for ER; one BCBM was positive for PR but negative for Her2/ErbB2/ER. Similar heterogeneity in the expression of these receptors was also observed in primary tumors. Importantly, BCBM tumors that were assigned as ER- and PR-positive contained tumor cells that lacked expression of these receptors in other regions of the biopsies. Taken together, our findings indicate that the BCBM exhibit heterogeneity in the expression amounts of Her2/ErbB2, ER, and PR, which could be a result of the influence of tumor microenvironment in the brain or different tumor cells populating the metastatic region.

Dysregulated estrogen receptor signaling in the hypothalamic-pituitary-ovarian axis leads to ovarian epithelial tumorigenesis in mice

The etiology of ovarian epithelial cancer is poorly understood, mainly due to the lack of an appropriate experimental model for studying the onset and progression of this disease. We have created a mutant mouse model in which aberrant estrogen receptor alpha (ERα) signaling in the hypothalamic-pituitary-ovarian axis leads to ovarian epithelial tumorigenesis. In these mice, termed ERα^d/d, the ERα gene was conditionally deleted in the anterior pituitary, but remained intact in the hypothalamus and the ovary. The loss of negative-feedback regulation by estrogen (E) at the level of the pituitary led to increased production of luteinizing hormone (LH) by this tissue. Hyperstimulation of the ovarian cells by LH resulted in elevated steroidogenesis, producing high circulating levels of steroid hormones, including E. The ERα^d/d mice exhibited formation of palpable ovarian epithelial tumors starting at 5 months of age with 100% penetrance. By 15 months of age, 80% of ERα^d/d mice die. Besides proliferating epithelial cells, these tumors also contained an expanded population of luteinized stromal cells, which acquire the ability to express P450 aromatase and synthesize E locally. In response to the elevated levels of E, the ERα signaling was accentuated in the ovarian epithelial cells of ERα^d/d mice, triggering increased ERα-dependent gene expression, abnormal cell proliferation, and tumorigenesis. Consistent with these findings, treatment of ERα^d/d mice with letrozole, an aromatase inhibitor, markedly reduced circulating E and ovarian tumor volume. We have, therefore, developed a unique animal model, which serves as a useful tool for exploring the involvement of E-dependent signaling pathways in ovarian epithelial tumorigenesis.

Ovarian cancer is currently the most lethal gynecological cancer in the United States. Multiple epidemiological studies indicate that women who take hormone replacement therapy, estrogen or estrogen with progesterone, peri- or postmenopause will have an increased chance of developing ovarian cancer. Unfortunately, the five-year survival rate after diagnosis is very low indicating that better tools are needed to diagnose and treat ovarian cancer. The models that would allow investigation of this disease are severely limited. In this article we introduce a mouse model that develops epithelial ovarian tumors, and by employing inhibitors of estrogen synthesis, we show that ovarian tumorigenesis in this model is dependent on estrogen production within the ovarian tumor. These studies suggest that estrogen may play a role in promoting ovarian tumor growth.

New vitamin D less-calcemic analog affect human bone cell line and cultured vascular smooth muscle cells similar to other less-calcemic analogs

Primary cultures of human bone and vascular cells respond to vitamin D treatment by modulation of cell proliferation measured by DNA synthesis (DNA) and energy metabolism measured by creatine kinase specific activity (CK) via binding to vitamin D receptors (VDR) which are expressed in these cells. Vitamin D compounds also modulate the response to estradiol-17β (E₂) and the expression mRNAs of estrogen receptors (ERα and ERβ), VDR, 25-hydroxy vitamin D₃ 1-α hydroxylase (1OHase) and lipoxygenases (12LO and 15LO). We now compared our newly synthesized analog: 1α,25-dihydroxy-9-methylene-19-norvitamin D₃ JK152 (JK), on bone and vascular cells compared to other analogs. Human bone cell line SaOS₂ respond to JK by increased DNA and stimulated CK dose-dependently, similar to the less-calcemic analogs CB 1093 (CB) and EB 1089 (EB). JK also up-regulated the response to E₂ in terms of DNA and CK. JK inhibited DNA synthesis and increased CK in primary human vascular smooth muscle cells (VSMC) dose-dependently similar to EB and CB. JK up regulated the response to E₂ in terms of CK with no effect on DNA. JK similar to CB and EB stimulated mRNA expression of VDR and ERα, 12LO and 15LO, with no effect on ERβ and 1OHase mRNA expression in SaOS₂ measured by real time PCR. Similar treatments of VSMC with JK, CB and EB stimulated 12LO and 15LO, VDR and ERα mRNA expression with no effect on ERβ and 1OHase mRNA expression. The results presented here demonstrate that the new vitamin D less-calcemic analog JK is similar to other analogs in its effects on human cultured cells and therefore may be used in combined hormone replacement treatment (HRT) both in vitro and in vivo.