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Sample records for estrogen receptor expression

  1. Sinonasal Leiomyoma With Estrogen Receptor Expression.

    PubMed

    Kim, Jong Seung; Shin, Jin Yong; Kwon, Sam Hyun

    2015-09-01

    Leiomyoma is an extremely rare tumor in sinonasal area. The reason for this is due to minimal amount of the smooth muscle in the area. The origin of this tumor is not clear and its etiology has not been proven in the literature. A 58-year-old woman who experienced nasal obstruction and epiphora visited our clinic. A huge mass was noted in right nasal cavity originating from the lacrimal bone area. The authors conducted endoscopic sinus surgery and obtained the specimen. Immunochemistry showed leiomyoma in the nasal cavity, which expressed estrogen receptor. There was no progesterone receptor expressed. The authors describe a sinonasal leiomyoma with estrogen receptors, not ever reported in previous article. PMID:26355987

  2. Estrogen and Progesterone hormone receptor expression in oral cavity cancer

    PubMed Central

    Biegner, Thorsten; Teriete, Peter; Hoefert, Sebastian; Krimmel, Michael; Munz, Adelheid; Reinert, Siegmar

    2016-01-01

    Background Recent studies have shown an increase in the incidence of oral squamous cell carcinoma (OSCC) in younger patients. The hypothesis that tumors could be hormonally induced during pregnancy or in young female patients without the well-known risk factors alcohol or tobacco abuse seems to be plausible. Material and Methods Estrogen Receptor alpha (ERα) and Progesterone Receptor (PR) expression were analyzed in normal oral mucosa (n=5), oral precursor lesions (simple hyperplasia, n=11; squamous intraepithelial neoplasia, SIN I-III, n=35), and OSCC specimen. OSCCs were stratified in a young female (n=7) study cohort and older patients (n=46). In the young female study cohort three patients (n=3/7) developed OSCC during or shortly after pregnancy. Breast cancer tissues were used as positive control for ERα and PR expression. Results ERα expression was found in four oral precursor lesions (squamous intraepithelial neoplasia, SIN I-III, n=4/35, 11%) and in five OSCC specimen (n=5/46, 11%). The five ERα positive OSCC samples were older male patients. All patients within the young female study cohort were negatively stained for both ERα and PR. Conclusions ER expression could be regarded as a seldom risk factor for OSCC. PR expression seems to be not relevant for the development of OSCC. Key words:Oral squamous cell carcinoma, estrogen receptor, progesterone receptor, hormone receptor. PMID:27475696

  3. Expression of Estrogen Receptor α in the Mouse Cerebral Cortex

    PubMed Central

    Dietrich, Alicia K.; Humphreys, Gwendolyn I.; Nardulli, Ann M.

    2015-01-01

    Although estrogen receptor alpha (ERα) and 17β-estradiol play critical roles in protecting the cerebral cortex from ischemia-induced damage, there has been some controversy about the expression of ERα in this region of the brain. We have examined ERα mRNA and protein levels in the cerebral cortices of female mice at postnatal days 5 and 17 and at 4, 13, and 18 months of age. We found that although ERα transcript levels declined from postnatal day 5 through 18 months of age, ERα protein levels remained stable. Importantly, expression of the E2-regulated progesterone receptor gene was sustained in younger and in older females suggesting that age-related changes in estrogen responsiveness in the cerebral cortex are not due to the absence of ERα protein. PMID:25700604

  4. Molecular Background of Estrogen Receptor Gene Expression in Endometriotic Cells.

    PubMed

    Izawa, Masao; Taniguchi, Fuminori; Harada, Tasuku

    2016-07-01

    The molecular background of estrogen receptor (ER) expression is important to understand the pathophysiology of the high estrogen environment in endometriosis. However, the molecular details have not been fully understood. The objective of this study is to evaluate the molecular background of ERα and ERβ messenger RNA (mRNA) expression in endometriotic cells. The following summarizes our observations: (1) ERα mRNA expression in endometriotic cells was estimated to be approximately one-tenth of that in endometrial cells. (2) Three mRNAs, which include 3 different 5'-untranslated exons tagged to an open reading frame of wild-type ERα, were detected. (3) Expression of ERβ mRNA depends mostly on 0N promoter and includes 2 open reading frames: one for a wild-type ERβ1 and another for a splice variant ERβ2. (4) Expression of ERβ1 mRNA was approximately 40-fold higher than that in endometrial cells. (5) Expression of ERβ2 mRNA was almost at a comparable level of the ERβ1. 9 (6) ERα and ERβ mRNAs are equivalently expressed in endometriotic cells. These observations show the molecular background of ER mRNA expression in endometriotic cells and provide a clue to further understanding the estrogen-dependent pathophysiology leading to clinical application in endometriosis. PMID:26704524

  5. Expression of estrogen and progesterone receptors in astrocytomas: a literature review.

    PubMed

    Tavares, Cléciton Braga; Gomes-Braga, Francisca das Chagas Sheyla Almeida; Costa-Silva, Danylo Rafhael; Escórcio-Dourado, Carla Solange; Borges, Umbelina Soares; Conde-Junior, Airton Mendes; Barros-Oliveira, Maria da Conceição; Sousa, Emerson Brandão; Barros, Lorena da Rocha; Martins, Luana Mota; Facina, Gil; da-Silva, Benedito Borges

    2016-08-01

    Gliomas are the most common type of primary central nervous system neoplasm. Astrocytomas are the most prevalent type of glioma and these tumors may be influenced by sex steroid hormones. A literature review for the presence of estrogen and progesterone receptors in astrocytomas was conducted in the PubMed database using the following MeSH terms: "estrogen receptor beta" OR "estrogen receptor alpha" OR "estrogen receptor antagonists" OR "progesterone receptors" OR "astrocytoma" OR "glioma" OR "glioblastoma". Among the 111 articles identified, 13 studies met our inclusion criteria. The majority of reports showed the presence of estrogen and progesterone receptors in astrocytomas. Overall, higher tumor grades were associated with decreased estrogen receptor expression and increased progesterone receptor expression. PMID:27626480

  6. Expression of Estrogen Receptor Alpha and Beta is Decreased in Hypospadias

    PubMed Central

    Qiao, Liang; Rodriguez, Esequiel; Weiss, Dana A.; Ferretti, Max; Risbridger, Gail; Cunha, Gerald R.; Baskin, Laurence S.

    2012-01-01

    Purpose Estrogenic endocrine disruptors acting via estrogen receptors α and β have been implicated in the etiology of hypospadias. However, the expression and distribution of estrogen receptors α and β in normal and hypospadiac human foreskins is unknown. We characterized the location and expression of estrogen receptors α and β in normal and hypospadiac foreskins. Materials and Methods We prospectively collected excess foreskin from 35 patients undergoing hypospadias repair and 15 patients undergoing elective circumcision. Hypospadias was classified as severe in 18 patients and mild in 17 based on the ectopic position of the meatus. mRNA expression levels in estrogen receptors α and β were quantified using reverse transcriptase polymerase chain reaction. Receptor location was characterized by immunohistochemical analysis. Additionally immunohistochemical analysis was performed in 4 archived human fetal penises. Results Mean ± SD ages were similar for the circumcision (9.5 ± 3 months) and hypospadias repair groups (9 ± 3 months, p = 0.75). mRNA expression levels in estrogen receptors α and β were significantly decreased in hypospadiac foreskin cases compared to controls (p <0.001), while no statistically significant differences were seen between foreskins with severe and mild hypospadias. Estrogen receptor β immunostaining was strong in normal foreskin but weak in hypospadiac foreskin. Estrogen receptor β immunoreactivity was most intense in the stratum basale and stratum spinosum. Estrogen receptor α immunostaining was weak in normal and mild hypospadias foreskin, and undetectable in severe hypospadias. Fetal penises expressed strong estrogen receptor β immunopositivity in the urethral plate epithelium, corpus spongiosum, corpora cavernosa and penile skin, while estrogen receptor α immunostaining was not detected. Conclusions These data demonstrate a difference in estrogen receptor α and β expression and location in the foreskin of patients

  7. Estrogen, SNP-Dependent Chemokine Expression and Selective Estrogen Receptor Modulator Regulation.

    PubMed

    Ho, Ming-Fen; Bongartz, Tim; Liu, Mohan; Kalari, Krishna R; Goss, Paul E; Shepherd, Lois E; Goetz, Matthew P; Kubo, Michiaki; Ingle, James N; Wang, Liewei; Weinshilboum, Richard M

    2016-03-01

    We previously reported, on the basis of a genome-wide association study for aromatase inhibitor-induced musculoskeletal symptoms, that single-nucleotide polymorphisms (SNPs) near the T-cell leukemia/lymphoma 1A (TCL1A) gene were associated with aromatase inhibitor-induced musculoskeletal pain and with estradiol (E2)-induced TCL1A expression. Furthermore, variation in TCL1A expression influenced the downstream expression of proinflammatory cytokines and cytokine receptors. Specifically, the top hit genome-wide association study SNP, rs11849538, created a functional estrogen response element (ERE) that displayed estrogen receptor (ER) binding and increased E2 induction of TCL1A expression only for the variant SNP genotype. In the present study, we pursued mechanisms underlying the E2-SNP-dependent regulation of TCL1A expression and, in parallel, our subsequent observations that SNPs at a distance from EREs can regulate ERα binding and that ER antagonists can reverse phenotypes associated with those SNPs. Specifically, we performed a series of functional genomic studies using a large panel of lymphoblastoid cell lines with dense genomic data that demonstrated that TCL1A SNPs at a distance from EREs can modulate ERα binding and expression of TCL1A as well as the expression of downstream immune mediators. Furthermore, 4-hydroxytamoxifen or fulvestrant could reverse these SNP-genotype effects. Similar results were found for SNPs in the IL17A cytokine and CCR6 chemokine receptor genes. These observations greatly expand our previous results and support the existence of a novel molecular mechanism that contributes to the complex interplay between estrogens and immune systems. They also raise the possibility of the pharmacological manipulation of the expression of proinflammatory cytokines and chemokines in a SNP genotype-dependent fashion. PMID:26866883

  8. Expression of estrogen and progesterone receptors in astrocytomas: a literature review

    PubMed Central

    Tavares, Cléciton Braga; Gomes-Braga, Francisca das Chagas Sheyla Almeida; Costa-Silva, Danylo Rafhael; Escórcio-Dourado, Carla Solange; Borges, Umbelina Soares; Conde, Airton Mendes; da Conceição Barros-Oliveira, Maria; Sousa, Emerson Brandão; da Rocha Barros, Lorena; Martins, Luana Mota; Facina, Gil; da-Silva, Benedito Borges

    2016-01-01

    Gliomas are the most common type of primary central nervous system neoplasm. Astrocytomas are the most prevalent type of glioma and these tumors may be influenced by sex steroid hormones. A literature review for the presence of estrogen and progesterone receptors in astrocytomas was conducted in the PubMed database using the following MeSH terms: “estrogen receptor beta” OR “estrogen receptor alpha” OR “estrogen receptor antagonists” OR “progesterone receptors” OR “astrocytoma” OR “glioma” OR “glioblastoma”. Among the 111 articles identified, 13 studies met our inclusion criteria. The majority of reports showed the presence of estrogen and progesterone receptors in astrocytomas. Overall, higher tumor grades were associated with decreased estrogen receptor expression and increased progesterone receptor expression.

  9. Linking estrogen receptor β expression with inflammatory bowel disease activity

    PubMed Central

    Pierdominici, Marina; Maselli, Angela; Varano, Barbara; Barbati, Cristiana; Cesaro, Paola; Spada, Cristiano; Zullo, Angelo; Lorenzetti, Roberto; Rosati, Marco; Rainaldi, Gabriella; Limiti, Maria Rosaria; Guidi, Luisa

    2015-01-01

    Crohn disease (CD) and ulcerative colitis (UC) are chronic forms of inflammatory bowel disease (IBD) whose pathogenesis is only poorly understood. Estrogens have a complex role in inflammation and growing evidence suggests that these hormones may impact IBD pathogenesis. Here, we demonstrated a significant reduction (p < 0.05) of estrogen receptor (ER)β expression in peripheral blood T lymphocytes from CD/UC patients with active disease (n = 27) as compared to those in remission (n = 21) and healthy controls (n = 29). Accordingly, in a subgroup of CD/UC patients undergoing to anti-TNF-α therapy and responsive to treatment, ERβ expression was higher (p < 0.01) than that observed in not responsive patients and comparable to that of control subjects. Notably, ERβ expression was markedly decreased in colonic mucosa of CD/UC patients with active disease, reflecting the alterations observed in peripheral blood T cells. ERβ expression inversely correlated with interleukin (IL)-6 serum levels and exogenous exposure of both T lymphocytes and intestinal epithelial cells to this cytokine resulted in ERβ downregulation. These results demonstrate that the ER profile is altered in active IBD patients at both mucosal and systemic levels, at least in part due to IL-6 dysregulation, and highlight the potential exploitation of T cell-associated ERβ as a biomarker of endoscopic disease activity. PMID:26497217

  10. Channel catfish (Ictalurus punctatus) leukocytes express estrogen receptor isoforms ERα and ERβ2 and are functionally modulated by estrogens

    USGS Publications Warehouse

    Iwanowicz, Luke R.; Stafford, James L.; Patiño, Reynaldo; Bengten, Eva; Miller, Norman W.; Blazer, Vicki

    2014-01-01

    Estrogens are recognized as modulators of immune responses in mammals and teleosts. While it is known that the effects of estrogens are mediated via leukocyte-specific estrogen receptors (ERs) in humans and mice, leucocyte-specific estrogen receptor expression and the effects of estrogens on this cell population is less explored and poorly understood in teleosts. Here in, we verify that channel catfish (Ictalurus punctaus) leukocytes express ERα and ERβ2. Transcripts of these isoforms were detected in tissue-associated leukocyte populations by PCR, but ERβ2 was rarely detected in PBLs. Expression of these receptors was temporally regulated in PBLs following polyclonal activation by concanavalin A, lipopolysaccharide or alloantigen based on evaluation by quantitative and end-point PCR. Examination of long-term leukocyte cell lines demonstrated that these receptors are differentially expressed depending on leukocyte lineage and phenotype. Expression of ERs was also temporally dynamic in some leukocyte lineages and may reflect stage of cell maturity. Estrogens affect the responsiveness of channel catfish peripheral blood leukocytes (PBLs) to mitogens in vitro. Similarly, bactericidal activity and phorbol 12-myristate 13-acetate induced respiratory burst was modulated by 17β-estradiol. These actions were blocked by the pure ER antagonist ICI 182780 indicating that response is, in part, mediated via ERα. In summary, estrogen receptors are expressed in channel catfish leukocytes and participate in the regulation of the immune response. This is the first time leukocyte lineage expression has been reported in teleost cell lines.

  11. Expression of estrogen-related receptor gamma (ERRgamma) in human skin.

    PubMed

    Krahn-Bertil, Elodie; Bolzinger, Marie-Alexandrine; Andre, Valérie; Orly, Isabelle; Kanitakis, Jean; Rousselle, Patricia; Damour, Odile

    2008-01-01

    Skin is a non-classical target for estrogens. Despite evidence showing that estrogen receptors (ER) are expressed in skin, there are still extensive gaps in our understanding of how estrogens exert their action in non-reproductive tissues. Estrogen-related receptor gamma (ERRgamma), an orphan member of the nuclear receptor superfamily, shows a strong sequence homology with estrogen receptor alpha but it does not bind estradiol. Here, for the first time, we demonstrate the expression of ERRgamma in adult human skin. ERRgamma mRNA was detected in the keratinocytes and fibroblasts of 8 female donor skins using RT-PCR. The presence of the protein was confirmed using immunohistochemistry on 11 adult human skins and Western Blotting on monolayer-cultures of fibroblasts and keratinocytes from respectively 4 and 2 donors. This study shows that ERRgamma is expressed in human skin and could intervene in a potentially new estrogen signaling pathway in the skin. PMID:18573717

  12. Expression and functional study of estrogen receptor-related receptors in human prostatic cells and tissues.

    PubMed

    Cheung, C P; Yu, Shan; Wong, K B; Chan, L W; Lai, Fernand M M; Wang, Xianghong; Suetsugi, Masatomo; Chen, Shiuan; Chan, Franky L

    2005-03-01

    Estrogen receptor-related receptors (ERRs; alpha, beta, gamma) are orphan nuclear receptors and constitutively active without binding to estrogen. Like estrogen receptors (ERs), ERRs bind to estrogen receptor elements and estrogen receptor element-related repeats. Growing evidence suggests that ERRs can cross-talk with ERs in different cell types via competition for DNA sites and coactivators. We hypothesize that ERRs might play regulatory roles in normal and neoplastic prostatic cells by sharing similar ER-mediated pathways or acting independently. In this study, we investigated mRNA and protein expression patterns of three ERR members in normal human prostate epithelial cells, established cell lines, cancer xenografts, and prostatic tissues. Additionally, effects of transient transfection of ERRs on prostatic cell proliferation and ER expression were also examined. RT-PCR showed that ERRalpha and ERRgamma transcripts were detected in most cell lines and xenografts, whereas ERRbeta was detected in normal epithelial cells and few immortalized cell lines but not in most cancer lines. Similar results were demonstrated in clinical prostatic specimens. Western blottings and immunohistochemistry confirmed similar expression patterns that ERR proteins were detected as nuclear proteins in epithelial cells, whereas their expressions became reduced or undetected in neoplastic prostatic cells. Transient transfection confirmed that ERRs were expressed in prostatic cells as nuclear proteins and transcriptionally active in the absence of estradiol. Transfection results showed that overexpression of ERRs inhibited cell proliferation and repressed ERalpha transcription in PC-3 cells. Our study shows that ERRs, which are coexpressed with ERs in prostatic cells, could regulate cell growth and modulate ER-mediated pathways via interference on ERalpha transcription in prostatic cells. PMID:15598686

  13. Expression and function of a novel variant of estrogen receptor-α36 in murine airways.

    PubMed

    Jia, Shuping; Zhang, Xintian; He, David Z Z; Segal, Manav; Berro, Abdo; Gerson, Trevor; Wang, Zhaoyi; Casale, Thomas B

    2011-11-01

    Evidence suggests that estrogen signaling is involved in sex differences in the prevalence rates and control of asthma, but the expression patterns of estrogen receptor variants and estrogen function in the lung are not well established. We investigated the expression of major estrogen receptor variants occurring naturally and after the development of allergen-induced airway hyperreactivity in a murine model of allergic asthma, along with the role of estrogen signaling in small-airway ciliary motion and smooth muscle contraction. Female BALB/c mice were sensitized with ovalbumin, and estrogen receptor expression patterns were examined by immunofluorescence and Western blot analysis. Time-lapse video and photodiode-based displacement measurement systems were used to assess the effects of estrogen signaling on airway ciliary beat frequency and smooth muscle contraction. We found that a novel variant of estrogen receptor (ER)-α, ER-α36, is expressed in airway epithelial and smooth muscle cells. ER-α36 was predominately localized on the plasma membranes of airway cells. After sensitization to allergen, the expression levels of ER-α36 increased significantly (P < 0.01), whereas the expression of ER-β and ER-α66 did not significantly change. Estrogen treatment in vitro resulted in a rapid increase in airway cilia motion in a dose-dependent fashion, but did not exert any effect on airway smooth muscle contraction. We speculate that the up-regulation of estrogen receptor expression associated with allergen-induced airway hyperresponsiveness may constitute a protective mechanism to facilitate the clearance of mucus. The identification and localization of specific estrogen receptor subtypes in the lung could lead to newer therapeutic avenues aimed at addressing sex differences of asthma susceptibility. PMID:21642591

  14. Regulation of the intronic promoter of rat estrogen receptor alpha gene, responsible for truncated estrogen receptor product-1 expression.

    PubMed

    Schausi, Diane; Tiffoche, Christophe; Thieulant, Marie-Lise

    2003-07-01

    We have characterized the intronic promoter of the rat estrogen receptor (ER) alpha gene, responsible for the lactotrope-specific truncated ER product (TERP)-1 isoform expression. Transcriptional regulation was investigated by transient transfections using 5'-deletion constructs. TERP promoter constructs were highly active in MMQ cells, a pure lactotrope cell line, whereas a low basal activity was detected in alphaT3-1 gonadotrope cells or in COS-7 monkey kidney cells. Serial deletion analysis revealed that 1) a minimal -693-bp region encompassing the TATA box is sufficient to allow lactotrope-specific expression; 2) the promoter contains strong positive cis-acting elements both in the distal and proximal regions, and 3) the region spanning the -1698/-1194 region includes repressor elements. Transient transfection studies, EMSAs, and gel shifts demonstrated that estrogen activates the TERP promoter via an estrogen-responsive element (ERE1) located within the proximal region. Mutation of ERE1 site completely abolishes the estradiol-dependent transcription, indicating that ERE1 site is sufficient to confer estrogen responsiveness to TERP promoter. In addition, ERalpha action was synergized by transfection of the pituitary-specific factor Pit-1. EMSAs showed that a single Pit-1 DNA binding element in the vicinity of the TATA box is sufficient to confer response by the TERP promoter. In conclusion, we demonstrated, for the first time, that TERP promoter regulation involves ERE and Pit-1 cis-elements and corresponding trans-acting factors, which could play a role in the physiological changes that occur in TERP-1 transcription in lactotrope cells. PMID:12810539

  15. Differential expression of estrogen receptor α and progesterone receptor in the normal and cryptorchid testis of a dog.

    PubMed

    Jung, Hyo Young; Yoo, Dae Young; Jo, Young Kwang; Kim, Geon A; Chung, Jin Young; Choi, Jung Hoon; Jang, Goo; Hwang, In Koo

    2016-06-01

    Descending of the testes is an important process for spermatogenesis and cryptorchidism is one of the most relevant genital defects in dogs. In a previous study, we observed abnormal morphology and proliferation of Sertoli cells in a cryptorchid testis. In the present study, we investigated the expression of estrogen and progesterone receptors in the normal and cryptorchid testis of a dog. Elective orchidectomy was performed on the dog's abdominal right testis (undescended, cryptorchid) and scrotal left testis (descended, normal). In the normal testis, estrogen receptor α immunoreactivity was detected in Leydig cells alone, while estrogen receptor α immunoreactivity in the cryptorchid testis was significantly prominent in the Sertoli cells as well. In addition, progesterone receptor immunoreactivity in the control testis was detected in the spermatids, but was not detected in the cryptorchid testis. This result suggests that unilateral cryptorchidism causes increases of estrogen receptor α expression in Sertoli cells. PMID:27382382

  16. Differential expression of estrogen receptor α and progesterone receptor in the normal and cryptorchid testis of a dog

    PubMed Central

    Jung, Hyo Young; Yoo, Dae Young; Jo, Young Kwang; Kim, Geon A; Chung, Jin Young; Choi, Jung Hoon

    2016-01-01

    Descending of the testes is an important process for spermatogenesis and cryptorchidism is one of the most relevant genital defects in dogs. In a previous study, we observed abnormal morphology and proliferation of Sertoli cells in a cryptorchid testis. In the present study, we investigated the expression of estrogen and progesterone receptors in the normal and cryptorchid testis of a dog. Elective orchidectomy was performed on the dog's abdominal right testis (undescended, cryptorchid) and scrotal left testis (descended, normal). In the normal testis, estrogen receptor α immunoreactivity was detected in Leydig cells alone, while estrogen receptor α immunoreactivity in the cryptorchid testis was significantly prominent in the Sertoli cells as well. In addition, progesterone receptor immunoreactivity in the control testis was detected in the spermatids, but was not detected in the cryptorchid testis. This result suggests that unilateral cryptorchidism causes increases of estrogen receptor α expression in Sertoli cells. PMID:27382382

  17. Corncob bedding alters the effects of estrogens on aggressive behavior and reduces estrogen receptorexpression in the brain.

    PubMed

    Villalon Landeros, Rosalina; Morisseau, Christophe; Yoo, Hyun Ju; Fu, Samuel H; Hammock, Bruce D; Trainor, Brian C

    2012-02-01

    There is growing appreciation that estrogen signaling pathways can be modulated by naturally occurring environmental compounds such as phytoestrogens and the more recently discovered xenoestrogens. Many researchers studying the effects of estrogens on brain function or behavior in animal models choose to use phytoestrogen-free food for this reason. Corncob bedding is commonly used in animal facilities across the United States and has been shown to inhibit estrogen-dependent reproductive behavior in rats. The mechanism for this effect was unclear, because the components of corncob bedding mediating this effect did not bind estrogen receptors. Here, we show in the California mouse (Peromyscus californicus) that estrogens decrease aggression when cardboard-based bedding is used but that this effect is absent when corncob bedding is used. California mice housed on corncob bedding also had fewer estrogen receptor-α-positive cells in the bed nucleus of the stria terminalis and ventromedial hypothalamus compared with mice housed on cardboard-based bedding. In addition, corncob bedding suppressed the expression of phosphorylated ERK in these brain regions as well as in the medial amygdala and medial preoptic area. Previous reports of the effects of corncob bedding on reproductive behavior are not widely appreciated. Our observations on the effects of corncob bedding on behavior and brain function should draw attention to the importance that cage bedding can exert on neuroendocrine research. PMID:22186416

  18. Immunohistochemical Expression of Estrogen and Progesterone Receptors Identifies a Subset of NSCLCs and Correlates with EGFR Mutation

    PubMed Central

    Raso, Maria G.; Behrens, Carmen; Herynk, Matthew H.; Liu, Suyu; Prudkin, Ludmila; Ozburn, Natalie C.; Woods, Denise M.; Tang, Ximing; Mehran, Reza J.; Moran, Cesar; Lee, J. Jack; Wistuba, Ignacio I.

    2010-01-01

    Purpose To determine the frequency of estrogen receptor α and β and progesterone receptor protein immunohistochemical expression in a large set of non–small cell lungcarcinoma (NSCLC) specimens and to compare our results with those for some of the same antibodies that have provided inconsistent results in previously published reports. Experimental Design Using multiple antibodies, we investigated the immunohistochemical expression of estrogen receptors α and β and progesterone receptor in 317 NSCLCs placed in tissue microarrays and correlated their expression with patients’ clinicopathologic characteristics and in adenocarcinomas with EGFR mutation status. Results Estrogen receptors α and β were detected in the nucleus and cytoplasm of NSCLC cells; however, the frequency of expression (nucleus, 5-36% for α and 42-56% for β; cytoplasm: <1-42% for α and 20-98% for β) varied among the different antibodies tested. Progesterone receptor was expressed in the nuclei of malignant cells in 63% of the tumors. Estrogen receptor α nuclear expression significantly correlated with adenocarcinoma histology, female gender, and history of never smoking (P = 0.0048 to <0.0001). In NSCLC, higher cytoplasmic estrogen receptor α expression significantly correlated with worse recurrence-free survival (hazard ratio, 1.77; 95% confidence interval, 1.12, 2.82; P = 0.015) in multivariate analysis. In adenocarcinomas, estrogen receptor α expression correlated with EGFR mutation (P = 0.0029 to <0.0001). Estrogen receptor β and progesterone receptor but not estrogen receptor α expressed in the normal epithelium adjacent to lung adenocarcinomas. Conclusions Estrogen receptor α and β expression distinguishes a subset of NSCLC that has defined clinicopathologic and genetic features. In lung adenocarcinoma, estrogen receptor α expression correlates with EGFR mutations. PMID:19706809

  19. Icariin exerts estrogen-like activity in ameliorating EAE via mediating estrogen receptor β, modulating HPA function and glucocorticoid receptor expression

    PubMed Central

    Wei, Zhisheng; Wang, Mengxia; Hong, Mingfan; Diao, Shengpeng; Liu, Aiqun; Huang, Yeqing; Yu, Qingyun; Peng, Zhongxing

    2016-01-01

    Background: Estrogen exerts neuroprotective and anti-inflammatory effects in EAE and multiple sclerosis (MS), but its clinical application is hindered due to side effects and risk of tumor. Phytoestrogen structurally or functionally mimics estrogen with fewer side effects than endogenous estrogen. Icariin (ICA), an active component of Epimedium extracts, demonstrates estrogen-like neuroprotective effects. However, it is unclear whether ICA is effective in EAE and what are the underlying mechanisms. Objective: To determine the therapeutic effects of ICA in EAE and explore the possible mechanisms. Methods: C57BL/6 EAE mice were treated with Diethylstilbestrol, different dose of ICA and mid-dose ICA combined with ICI 182780. The clinical scores and serum Interleukin-17 (IL-17), Corticosterone (CORT) concentrations were then analyzed. Western blot were performed to investigate the expressions of glucocorticoid receptor (GR), estrogen receptor alpha (ERα) and ERβ in the cerebral white matter of EAE mice. Results: High dose ICA is equally effective in ameliorating neurological signs of EAE as estrogen. Estrogen and ICA has no effects on serum concentrations of IL-17 in EAE. While the CORT levels were decreased by ICA at mid or high doses, the expressions of GR, ERα and ERβ were up-regulated by estrogen or different doses of ICA in a dosedependent manner. Estrogen induced the elevation of ERα more markedly than ICA. In contrast, ICA at mid and high doses promoted ERβ more significantly than estrogen. Conclusion: ICA exerts estrogen-like activity in ameliorating EAE via mediating ERβ, modulating HPA function and up-regulating the expression of GR in cerebral white matter. ICA may be a promising therapeutic option for MS. PMID:27186315

  20. Aromatase and estrogen receptor alpha mRNA expression as prognostic biomarkers in patients with astrocytomas.

    PubMed

    Dueñas Jiménez, J M; Candanedo Arellano, A; Santerre, A; Orozco Suárez, S; Sandoval Sánchez, H; Feria Romero, I; López-Elizalde, R; Alonso Venegas, M; Netel, B; de la Torre Valdovinos, B; Dueñas Jiménez, S H

    2014-09-01

    Estrogens are oncogenic hormones at a high level in breast, prostate, endometrial and lung cancer. Estrogens are synthesized by aromatase which has been used as a biomarker both in breast and lung cancer. Estrogen biological activities are executed by their classic receptors (ERα and ERβ). ERα has been described as a cancer promoter and ERβ, as a possible tumor suppressor. Both receptors are present at low levels in primary multiforme glioblastoma (GBM). The GBM frequency is 50 % higher in men than in women. The GBM patient survival period ranges from 7 to 18 months. The purpose of this pilot study was to evaluate aromatase and estrogen receptor expression, as well as 17ß-estradiol concentration in astrocytoma patients biopsies to obtain a prognosis biomarker for these patients. We analyzed 36 biopsies of astrocytoma patients with a different grade (I-IV) of malignity. Aromatase and estrogen receptor mRNA expression were analyzed by semiquantitative RT-PCR, and the E2 levels, by ELISA. E2 concentration was higher in GBM, compared to grade II or III astrocytomas. The number of cells immunoreactive to aromatase and estrogen receptors decreased as the grade of tumor malignity increased. Aromatase mRNA expression was present in all biopsies, regardless of malignity grade or patient age or gender. The highest expression of aromatase mRNA in GBM patients was associated to the worst survival prognostic (6.28 months). In contrast lowest expression of ERα mRNA in astrocytoma patients had a worst prognosis. In conclusion, aromatase and ERα expression could be used as prognosis biomarkers for astrocytoma patients. PMID:25005528

  1. Evidence for estrogen receptor expression in germ cell and somatic cell subpopulations in the ovary of the newly hatched chicken.

    PubMed

    Méndez, M C; Chávez, B; Echeverría, O; Vilchis, F; Vázquez Nin, G H; Pedernera, E

    1999-10-01

    Estrogens are involved in the gonadal morphogenesis of vertebrates, and almost all hormonal effects of 17beta-estradiol are mediated through specific receptors. At the time of sexual differentiation in the chicken, or even before, there is evidence of the presence of estrogen receptors and the secretion of 17beta-estradiol. However, no information is available regarding the cellular types that express the estrogen receptor in the immature chick ovary. The present study analyzes estrogen receptor expression in germ and somatic cells of the ovary in the newly hatched chicken. Highly purified cell subpopulations of germ and somatic cells were evaluated for specific 17beta-estradiol nuclear binding. In addition, the estrogen receptor was localized at the ultrastructural level by the immunogold technique. Finally, reverse transcription and polymerase chain reaction procedures detected a steady-state level of mRNA for the estrogen receptor. Somatic cells including typical steroidogenic cells showed specific 17beta-estradiol nuclear binding, displayed the estrogen receptor, and possessed estrogen receptor transcripts. The same result was observed in primary oocytes, together with the ultrastructural localization of estrogen receptor in extended chromatin filaments. Our experimental data support the hypothesis that estrogens are involved in the function of somatic and germ cells subpopulations in the immature chicken ovary. PMID:10555548

  2. Treatment of BG-1 Ovarian Cancer Cells Expressing Estrogen Receptors with Lambda-cyhalothrin and Cypermethrin Caused a Partial Estrogenicity Via an Estrogen Receptor-dependent Pathway

    PubMed Central

    Kim, Cho-Won; Go, Ryeo-Eun

    2015-01-01

    Synthetic pyrethroids (SPs) are the most common pesticides which are recently used for indoor pest control. The widespread use of SPs has resulted in the increased exposure to wild animals and humans. Recently, some SPs are suspected as endocrine disrupting chemicals (EDCs) and have been assessed for their potential estrogenicity by adopting various analyzing assays. In this study, we examined the estrogenic effects of lambda-cyhalothrin (LC) and cypermethrin (CP), the most commonly used pesticides in Korea, using BG-1 ovarian cancer cells expressing estrogen receptors (ERs). To evaluate the estrogenic activities of two SPs, LC and CP, we employed MTT assay and reverse-transcription polymerase chain reaction (RT-PCR) in LC or CP treated BG-1 ovarian cancer cells. In MTT assay, LC (10−6 M) and CP (10−5 M) significantly induced the growth of BG-1 cancer cells. LC or CP-induced cell growth was antagonized by addition of ICI 182,720 (10−8 M), an ER antagonist, suggesting that this effect appears to be mediated by an ER-dependent manner. Moreover, RT-PCR results showed that transcriptional level of cyclin D1, a cell cycle-regulating gene, was significantly up-regulated by LC and CP, while these effects were reversed by co-treatment of ICI 182,780. However, p21, a cyclin D-ckd-4 inhibitor gene, was not altered by LC or CP. Moreover, ERα expression was not significantly changed by LC and CP, while downregulated by E2. Finally, in xenografted mouse model transplanted with human BG-1 ovarian cancer cells, E2 significantly increased the tumor volume compare to a negative control, but LC did not. Taken together, these results suggest that LC and CP may possess estrogenic potentials by stimulating the growth of BG-1 ovarian cancer cells via partially ER signaling pathway associated with cell cycle as did E2, but this estrogenic effect was not found in in vivo mouse model. PMID:26877835

  3. Elevated Resistin Gene Expression in African American Estrogen and Progesterone Receptor Negative Breast Cancer

    PubMed Central

    Vallega, Karin A.; Liu, NingNing; Myers, Jennifer S.; Yu, Kaixian; Sang, Qing-Xiang Amy

    2016-01-01

    Introduction African American (AA) women diagnosed with breast cancer are more likely to have aggressive subtypes. Investigating differentially expressed genes between patient populations may help explain racial health disparities. Resistin, one such gene, is linked to inflammation, obesity, and breast cancer risk. Previous studies indicated that resistin expression is higher in serum and tissue of AA breast cancer patients compared to Caucasian American (CA) patients. However, resistin expression levels have not been compared between AA and CA patients in a stage- and subtype-specific context. Breast cancer prognosis and treatments vary by subtype. This work investigates differential resistin gene expression in human breast cancer tissues of specific stages, receptor subtypes, and menopause statuses in AA and CA women. Methods Differential gene expression analysis was performed using human breast cancer gene expression data from The Cancer Genome Atlas. We performed inter-race resistin gene expression level comparisons looking at receptor status and stage-specific data between AA and CA samples. DESeq was run to test for differentially expressed resistin values. Results Resistin RNA was higher in AA women overall, with highest values in receptor negative subtypes. Estrogen-, progesterone-, and human epidermal growth factor receptor 2- negative groups showed statistically significant elevated resistin levels in Stage I and II AA women compared to CA women. In inter-racial comparisons, AA women had significantly higher levels of resistin regardless of menopause status. In whole population comparisons, resistin expression was higher among Stage I and III estrogen receptor negative cases. In comparisons of molecular subtypes, resistin levels were significant higher in triple negative than in luminal A breast cancer. Conclusion Resistin gene expression levels were significantly higher in receptor negative subtypes, especially estrogen receptor negative cases in AA

  4. Expression and functional roles of estrogen receptor GPR30 in human intervertebral disc.

    PubMed

    Wei, Aiqun; Shen, Bojiang; Williams, Lisa A; Bhargav, Divya; Yan, Feng; Chong, Beng H; Diwan, Ashish D

    2016-04-01

    Estrogen withdrawal, a characteristic of female aging, is associated with age-related intervertebral disc (IVD) degeneration. The function of estrogen is mediated by two classic nuclear receptors, estrogen receptor (ER)-α and -β, and a membrane bound G-protein-coupled receptor 30 (GPR30). To date, the expression and function of GPR30 in human spine is poorly understood. This study aimed to evaluate GPR30 expression in IVD, and its role in estrogen-related regulation of proliferation and apoptosis of disc nucleus pulposus (NP) cells. GPR30 expression was examined in 30 human adult NP and 9 fetal IVD. Results showed that GPR30 was expressed in NP cells at both mRNA and protein levels. In human fetal IVD, GPR30 protein was expressed in the NP at 12-14 weeks gestation, but was undetectable at 8-11 weeks. The effect of 17β-estradiol (E2) on GPR30-mediated proliferation and interleukin-1β (IL-1β)-induced apoptosis of NP cells was investigated. Cultured NP cells were treated with or without E2, GPR30 antagonist G36, and ER antagonist ICI 182,780. NP cell viability was tested by MTS assay. Apoptosis was determined by flow cytometry using fluorescence labeled annexin-V, TUNEL assay and immumnocytochemical staining of activated caspase-3. E2 enhanced cell proliferation and prevented IL-1β-induced cell death, but the effect was partially blocked by G36 and completely abrogated by a combination of ICI 182,780 and G36. This study demonstrates that GPR30 is expressed in human IVD to transmit signals triggering E2-induced NP cell proliferation and protecting against IL-1β-induced apoptosis. The effects of E2 on NP cells require both GPR30 and classic estrogen receptors. PMID:26815911

  5. Differential expression of estrogen receptor α and β isoforms in multiple and solitary leiomyomas.

    PubMed

    Shao, Ruyue; Fang, Liaoqiong; Xing, Ruoxi; Xiong, Yu; Fang, Liaoqiong; Wang, Zhibiao

    Uterine leiomyomas are benign myometrial neoplasms that function as one of the common indications for hysterectomy. Clinical and biological evidences indicate that uterine leiomyomas are estrogen-dependent. Estrogen stimulates cell proliferation through binding to the estrogen receptor (ER), of which both subtypes α and β are present in leiomyomas. Clinically, leiomyomas may be singular or multiple, where the first one is rarely recurring if removed and the latter associated to a relatively young age or genetic predisposition. These markedly different clinical phenotypes indicate that there may different mechanism causing a similar smooth muscle response. To investigate the relative expression of ERα and ERβ in multiple and solitary uterine leiomyomas, we collected samples from 35 Chinese women (multiple leiomyomas n = 20, solitary leiomyoma n = 15) undergoing surgery to remove uterine leiomyomas. ELISA assay was performed to detect estrogen(E2) concentration. Quantitative real-time PCR analysis was performed to detect ERα and ERβ mRNA expression. Western blot and immunohistochemical analysis were performed to detect ERα and ERβ protein expression. We found that ERα mRNA and protein levels of in multiple leiomyomas were significantly lower than those of solitary leiomyomas, whereas ERβ mRNA and protein levels in multiple leiomyomas were significantly higher than those in solitary leiomyomas, irrespectively of the menstrual cycle stage. In both multiple and solitary leiomyomas, ERα expression was higher than that of ERβ. E2 concentration in multiple and solitary leiomyomas correlated with that of ERα expression. ERα was present in nuclus and cytoplasma while estrogen receptor β localized only in nuclei in both multiple and solitary leiomyomas. Our findings suggest that the difference of ERα and ERβ expression between multiple and solitary leiomyomas may be responsible for the course of the disease subtypes. PMID:26529545

  6. Estrogen Receptor Beta Expression in the Mouse Forebrain: Age and Sex Differences

    PubMed Central

    Zuloaga, Damian G.; Zuloaga, Kristen L.; Hinds, Laura R.; Carbone, David L.; Handa, Robert J.

    2016-01-01

    Estrogen receptors regulate multiple brain functions including stress, sexual, and memory associated behaviors as well as control of neuroendocrine and autonomic function. During development, estrogen signaling is involved in programming adult sex differences in physiology and behavior. Expression of estrogen receptor alpha changes across development in a region specific fashion. By contrast, estrogen receptor beta (ERβ) is expressed in many brain regions, yet few studies have explored sex and developmental differences in its expression largely due to the absence of selective reagents for anatomical localization of the protein. In this study, we utilized bacterial artificial chromosome transgenic mice expressing ERβ identified by enhanced green fluorescent protein (EGFP) to compare expression levels and distribution of ERβ in the male and female mouse forebrain on the day of birth (P0), postnatal day 4 (P4) and P21. Using qualitative analysis, we mapped the distribution of ERβ–EGFP and found developmental alterations in ERβ expression within the cortex, hippocampus, and hypothalamic regions including the arcuate, ventromedial, and paraventricular nuclei. We also report a sex difference in ERβ in the bed nucleus of the stria terminalis with males showing greater expression at P4 and P21. Another sex difference was found in the anteroventral periventricular nucleus of P21, but not P0 or P4 mice, where ERβ-EGFP-ir cells were densely clustered near the 3rd ventricle in females but not males. These developmental changes and sex differences in ERβ indicate a mechanism through which estrogens may differentially affect brain functions or program adult physiology at select times during development. PMID:23818057

  7. Estrogen receptor signaling during vertebrate development

    PubMed Central

    Bondesson, Maria; Hao, Ruixin; Lin, Chin-Yo; Williams, Cecilia; Gustafsson, Jan-Åke

    2014-01-01

    Estrogen receptors are expressed and their cognate ligands produced in all vertebrates, indicative of important and conserved functions. Through evolution estrogen has been involved in controlling reproduction, affecting both the development of reproductive organs and reproductive behavior. This review broadly describes the synthesis of estrogens and the expression patterns of aromatase and the estrogen receptors, in relation to estrogen functions in the developing fetus and child. We focus on the role of estrogens for development of reproductive tissues, as well as non-reproductive effects on the developing brain. We collate data from human, rodent, bird and fish studies and highlight common and species-specific effects of estrogen signaling on fetal development. Morphological malformations originating from perturbed estrogen signaling in estrogen receptor and aromatase knockout mice are discussed, as well as the clinical manifestations of rare estrogen receptor alpha and aromatase gene mutations in humans. PMID:24954179

  8. Opposing action of estrogen receptors alpha and beta on cyclin D1 gene expression.

    PubMed

    Liu, Meng-Min; Albanese, Chris; Anderson, Carol M; Hilty, Kristin; Webb, Paul; Uht, Rosalie M; Price, Richard H; Pestell, Richard G; Kushner, Peter J

    2002-07-01

    Induction of cyclin D1 gene transcription by estrogen receptor alpha (ERalpha) plays an important role in estrogen-mediated proliferation. There is no classical estrogen response element in the cyclin D1 promoter, and induction by ERalpha has been mapped to an alternative response element, a cyclic AMP-response element at -57, with possible participation of an activating protein-1 site at -954. The action of ERbeta at the cyclin D1 promoter is unknown, although evidence suggests that ERbeta may inhibit the proliferative action of ERalpha. We examined the response of cyclin D1 promoter constructs by luciferase assay and the response of the endogenous protein by Western blot in HeLa cells transiently expressing ERalpha, ERalphaK206A (a derivative that is superactive at alternative response elements), or ERbeta. In each case, ER activation at the cyclin D1 promoter is mediated by both the cyclic AMP-response element and the activating protein-1 site, which play partly redundant roles. The activation by ERbeta occurs only with antiestrogens. Estrogens, which activate cyclin D1 gene expression with ERalpha, inhibit expression with ERbeta. Strikingly, the presence of ERbeta completely inhibits cyclin D1 gene activation by estrogen and ERalpha or even by estrogen and the superactive ERalphaK206A. The observation of the opposing action and dominance of ERbeta over ERalpha in activation of cyclin D1 gene expression has implications for the postulated role of ERbeta as a modulator of the proliferative effects of estrogen. PMID:11986316

  9. Aromatase Expression Increases the Survival and Malignancy of Estrogen Receptor Positive Breast Cancer Cells

    PubMed Central

    Bandyopadhyay, Abhik; Kirma, Nameer B.; Tekmal, Rajeshwar R.; Wang, Shui; Sun, Lu-Zhe

    2015-01-01

    In postmenopausal women, local estrogen produced by adipose stromal cells in the breast is believed to support estrogen receptor alpha (ERα) positive breast cancer cell survival and growth. This raises the question of how the ERα positive metastatic breast cancer cells survive after they enter blood and lymph circulation, where estrogen level is very low in postmenopausal women. In this study, we show that the aromatase expression increased when ERα positive breast cancer cells were cultured in suspension. Furthermore, treatment with the aromatase substrate, testosterone, inhibited suspension culture-induced apoptosis whereas an aromatase inhibitor attenuated the effect of testosterone suggesting that suspended circulating ERα positive breast cancer cells may up-regulate intracrine estrogen activity for survival. Consistent with this notion, a moderate level of ectopic aromatase expression rendered a non-tumorigenic ERα positive breast cancer cell line not only tumorigenic but also metastatic in female nude mice without exogenous estrogen supplementation. The increased malignant phenotype was confirmed to be due to aromatase expression as the growth of orthotopic tumors regressed with systemic administration of an aromatase inhibitor. Thus, our study provides experimental evidence that aromatase plays an important role in the survival of metastatic ERα breast cancer cells by suppressing anoikis. PMID:25837259

  10. Conditional expression of constitutively active estrogen receptor {alpha} in chondrocytes impairs longitudinal bone growth in mice

    SciTech Connect

    Ikeda, Kazuhiro; Tsukui, Tohru; Imazawa, Yukiko; Horie-Inoue, Kuniko; Inoue, Satoshi

    2012-09-07

    Highlights: Black-Right-Pointing-Pointer Conditional transgenic mice expressing constitutively active estrogen receptor {alpha} (caER{alpha}) in chondrocytes were developed. Black-Right-Pointing-Pointer Expression of caER{alpha} in chondrocytes impaired longitudinal bone growth in mice. Black-Right-Pointing-Pointer caER{alpha} affects chondrocyte proliferation and differentiation. Black-Right-Pointing-Pointer This mouse model is useful for understanding the physiological role of ER{alpha}in vivo. -- Abstract: Estrogen plays important roles in the regulation of chondrocyte proliferation and differentiation, which are essential steps for longitudinal bone growth; however, the mechanisms of estrogen action on chondrocytes have not been fully elucidated. In the present study, we generated conditional transgenic mice, designated as caER{alpha}{sup ColII}, expressing constitutively active mutant estrogen receptor (ER) {alpha} in chondrocytes, using the chondrocyte-specific type II collagen promoter-driven Cre transgenic mice. caER{alpha}{sup ColII} mice showed retardation in longitudinal growth, with short bone lengths. BrdU labeling showed reduced proliferation of hypertrophic chondrocytes in the proliferating layer of the growth plate of tibia in caER{alpha}{sup ColII} mice. In situ hybridization analysis of type X collagen revealed that the maturation of hypertrophic chondrocytes was impaired in caER{alpha}{sup ColII} mice. These results suggest that ER{alpha} is a critical regulator of chondrocyte proliferation and maturation during skeletal development, mediating longitudinal bone growth in vivo.

  11. Differential expression of genes for aromatase and estrogen receptor during the gonadal development in chicken embryos.

    PubMed

    Nakabayashi, O; Kikuchi, H; Kikuchi, T; Mizuno, S

    1998-04-01

    In birds, differentiation of embryonic gonads is not as strictly determined by the genetic sex as it is in mammals, and can be influenced by early manipulation with a sex steroid hormone. Thus administration of an aromatase inhibitor induces testis development in the genetic female, and administration of estrogen induces a left ovotestis in the genetic male embryo. Another feature of avian gonadogenesis is that only the left ovary develops in most species. Molecular mechanisms underlying these features at the level of gene expression have not been elucidated. In this paper, we present evidence that a gene for aromatase cytochrome P-450, an enzyme required for the last step in the synthesis of estradiol-17beta, is expressed in medullae of the left and right gonads of a female chicken embryo, but not in those of a male chicken embryo, and that an estrogen receptor gene is expressed only in epithelium (and cortex later, in the female) of the left, not the right, gonad of both sexes, but the expression in the male left gonad is temporary and restricted to an early stage of development. Differential expression of these two genes serves well to explain the above features of gonadal development in birds. Furthermore, in ovo administration of estradiol-17beta from the 5th to the 14th day of incubation does not cause expression of the estrogen receptor gene in the right gonad of chicken embryos of either sex, suggesting that the absence of expression of the estrogen receptor gene in the right gonad is not the result of down-regulation, but may be regarded as an important cause of the unilateral ovarian development. PMID:9584834

  12. Chicken ovalbumin upstream promoter-transcription factor interacts with estrogen receptor, binds to estrogen response elements and half-sites, and inhibits estrogen-induced gene expression.

    PubMed

    Klinge, C M; Silver, B F; Driscoll, M D; Sathya, G; Bambara, R A; Hilf, R

    1997-12-12

    Chicken ovalbumin upstream promoter-transcription factor (COUP-TF) was identified as a low abundance protein in bovine uterus that co-purified with estrogen receptor (ER) in a ligand-independent manner and was separated from the ER by its lower retention on estrogen response element (ERE)-Sepharose. In gel mobility shift assays, COUP-TF bound as an apparent dimer to ERE and ERE half-sites. COUP-TF bound to an ERE half-site with high affinity, Kd = 1.24 nM. In contrast, ER did not bind a single ERE half-site. None of the class II nuclear receptors analyzed, i.e. retinoic acid receptor, retinoid X receptor, thyroid receptor, peroxisome proliferator-activated receptor, or vitamin D receptor, were constituents of the COUP-TF.DNA binding complex detected in gel mobility shift assays. Direct interaction of COUP-TF with ER was indicated by GST "pull-down" and co-immunoprecipitation assays. The nature of the ER ligand influenced COUP-TF-ERE half-site binding. When ER was liganded by the antiestrogen 4-hydroxytamoxifen (4-OHT), COUP-TF-half-site interaction decreased. Conversely, COUP-TF transcribed and translated in vitro enhanced the ERE binding of purified estradiol (E2)-liganded ER but not 4-OHT-liganded ER. Co-transfection of ER-expressing MCF-7 human breast cancer cells with an expression vector for COUP-TFI resulted in a dose-dependent inhibition of E2-induced expression of a luciferase reporter gene under the control of three tandem copies of EREc38. The ability of COUP-TF to bind specifically to EREs and half-sites, to interact with ER, and to inhibit E2-induced gene expression suggests COUP-TF regulates ER action by both direct DNA binding competition and through protein-protein interactions. PMID:9395481

  13. Expression of Genomic Functional Estrogen Receptor 1 in Mouse Sertoli Cells

    PubMed Central

    Lin, Jing; Zhu, Jia; Li, Xian; Li, Shengqiang; Lan, Zijian; Ko, Jay

    2014-01-01

    There is no consensus whether Sertoli cells express estrogen receptor 1 (Esr1). Reverse transcription-polymerase chain reaction, Western blot, and immunofluorescence demonstrated that mouse Sertoli cell lines, TM4, MSC-1, and 15P-1, and purified primary mouse Sertoli cells (PSCs) contained Esr1 messenger RNA and proteins. Incubation of Sertoli cells with 17β-estradiol (E2) or ESR1 agonist stimulated the expression of an estrogen responsive gene Greb1, which was prevented by ESR inhibitor or ESR1 antagonist. Overexpression of Esr1 in MSC-1 enhanced E2-induced Greb1 expression, while knockdown of Esr1 by small interfering RNA in TM4 attenuated the response. Furthermore, E2-induced Greb1 expression was abolished in the PSCs isolated from Amh-Cre/Esr1-floxed mice in which Esr1 in Sertoli cells were selectively deleted. Chromatin immunoprecipitation assays indicated that E2-induced Greb1 expression in Sertoli cells was mediated by binding of ESR1 to estrogen responsive elements. In summary, ligand-dependent nuclear ESR1 was present in mouse Sertoli cells and mediates a classical genomic action of estrogens. PMID:24615934

  14. Estrogen receptors and endothelium.

    PubMed

    Arnal, Jean-François; Fontaine, Coralie; Billon-Galés, Audrey; Favre, Julie; Laurell, Henrik; Lenfant, Françoise; Gourdy, Pierre

    2010-08-01

    Estrogens, and in particular 17beta-estradiol (E2), play a pivotal role in sexual development and reproduction and are also implicated in a large number of physiological processes, including the cardiovascular system. Both acetylcholine-induced and flow-dependent vasodilation are preserved or potentiated by estrogen treatment in both animal models and humans. Indeed, E2 increases the endothelial production of nitric oxide and prostacyclin and prevents early atheroma through endothelial-mediated mechanisms. Furthermore, whereas it prevents endothelial activation, E2 potentiates the ability of several subpopulations of the circulating or resident immune cells to produce proinflammatory cytokines. The balance between these 2 actions could determine the final effect in a given pathophysiological process. E2 also promotes endothelial healing, as well as angiogenesis. Estrogen actions are essentially mediated by 2 molecular targets: estrogen receptor-alpha (ERalpha) and ERbeta. The analysis of mouse models targeted for ERalpha or ERbeta demonstrated a prominent role of ERalpha in vascular biology. ERalpha directly modulates transcription of target genes through 2 activation functions (AFs), AF-1 and AF-2. Interestingly, an AF-1-deficient ERalpha isoform can be physiologically expressed in the endothelium and appears sufficient to mediate most of the vasculoprotective actions of E2. In contrast, AF-1 is necessary for the E2 actions in reproductive targets. Thus, it appears conceivable to uncouple the vasculoprotective and sexual actions with appropriate selective ER modulators. PMID:20631350

  15. Estrogen receptor α can selectively repress dioxin receptor-mediated gene expression by targeting DNA methylation.

    PubMed

    Marques, Maud; Laflamme, Liette; Gaudreau, Luc

    2013-09-01

    Selective inhibitory crosstalk has been known to occur within the signaling pathways of the dioxin (AhR) and estrogen (ERα) receptors. More specifically, ERα represses a cytochrome P450-encoding gene (CYP1A1) that converts cellular estradiol into a metabolite that inhibits the cell cycle, while it has no effect on a P450-encoding gene (CYP1B1) that converts estrodiol into a genotoxic product. Here we show that ERα represses CYP1A1 by targeting the Dnmt3B DNA methyltransferase and concomitant DNA methylation of the promoter. We also find that histone H2A.Z can positively contribute to CYP1A1 gene expression, and its presence at that gene is inversely correlated with DNA methylation. Taken together, our results provide a framework for how ERα can repress transcription, and how that impinges on the production of an enzyme that generates genotoxic estradiol metabolites, and potential breast cancer progression. Finally, our results reveal a new mechanism for how H2A.Z can positively influence gene expression, which is by potentially competing with DNA methylation events in breast cancer cells. PMID:23828038

  16. Estrogen receptor α can selectively repress dioxin receptor-mediated gene expression by targeting DNA methylation

    PubMed Central

    Marques, Maud; Laflamme, Liette; Gaudreau, Luc

    2013-01-01

    Selective inhibitory crosstalk has been known to occur within the signaling pathways of the dioxin (AhR) and estrogen (ERα) receptors. More specifically, ERα represses a cytochrome P450-encoding gene (CYP1A1) that converts cellular estradiol into a metabolite that inhibits the cell cycle, while it has no effect on a P450-encoding gene (CYP1B1) that converts estrodiol into a genotoxic product. Here we show that ERα represses CYP1A1 by targeting the Dnmt3B DNA methyltransferase and concomitant DNA methylation of the promoter. We also find that histone H2A.Z can positively contribute to CYP1A1 gene expression, and its presence at that gene is inversely correlated with DNA methylation. Taken together, our results provide a framework for how ERα can repress transcription, and how that impinges on the production of an enzyme that generates genotoxic estradiol metabolites, and potential breast cancer progression. Finally, our results reveal a new mechanism for how H2A.Z can positively influence gene expression, which is by potentially competing with DNA methylation events in breast cancer cells. PMID:23828038

  17. Identification, cloning, and expression of human estrogen receptor-{alpha}36, a novel variant of human estrogen receptor-{alpha}66

    SciTech Connect

    Wang Zhaoyi; Zhang Xintian; Shen Peng; Loggie, Brian W.; Chang Yunchao; Deuel, Thomas F. . E-mail: tfdeuel@scripps.edu

    2005-11-04

    The identification and subsequent cloning of the 66-kDa human estrogen receptor (here termed hER-{alpha}66), its 46-kDa splice variant hER-{alpha}46, and the closely related hER-{beta} have had a profound impact on the generation of new understanding of estrogen-mediated functions and led to progress in diagnosis and treatment of human breast cancer. However, a persistent problem has been that not all findings previously reported in estrogen-stimulated cell proliferation can be explained through the known properties of the different estrogen receptors described. As the consequence of a search for alternative mechanisms to account for these different findings, we have now identified, cloned, and expressed in HEK 293 cells a previously unrecognized 36-kDa variant of hER-{alpha}66, termed hER-{alpha}36. hER-{alpha}36 differs from hER-{alpha}66 since it lacks both transcriptional activation domains (AF-1 and AF-2) but it retains the DNA-binding domain, and partial dimerization and ligand-binding domains of hER-{alpha}66. It also contains three myristoylation sites postulated to direct ER-{alpha}36 to the plasma membrane. It is concluded that ER-{alpha}36 is a unique variant of ER-{alpha}66; ER-{alpha}36 is predicted to function as a dominant-negative effector of hER-{alpha}66-mediated estrogen-responsive gene pathways and has the potential to trigger membrane-initiated mitogenic estrogen signaling.

  18. Female predominance in meningiomas can not be explained by differences in progesterone, estrogen, or androgen receptor expression.

    PubMed

    Korhonen, Katariina; Salminen, Tiina; Raitanen, Jani; Auvinen, Anssi; Isola, Jorma; Haapasalo, Hannu

    2006-10-01

    The female predominance in meningioma incidence and association between meningioma and breast cancer suggest that growth of meningiomas is hormone-dependent. There are several discrepancies in literature about the proliferative effect of sex hormones on meningiomas. This study aims to evaluate the hormone receptor status of meningiomas and assess its relation to age, sex, histological grade, recurrence, and proliferation activity. The material was based on consecutive patients operated for meningioma at Tampere University Hospital in 1989-1999. The occurrence of progesterone, estrogen and androgen receptor in patients with primary and recurrent meningiomas was studied immunohistochemically by using specific monoclonal antibodies. Hormonal status was determined in 510 tumor samples. 443 samples were from primary meningiomas and 67 from recurrent tumors. Of the samples, 455 were benign (WHO grade I), 49 atypical (grade II), and 6 malignant (grade III). Of the primary tumor samples, 88% were progesterone receptor positive, 40% were positive for estrogen and 39% for androgen receptors. Grade I meningiomas had significantly higher incidence for estrogen and androgen receptors than higher grade meningiomas. Estrogen positive tumor samples had significantly higher proliferation index than estrogen negative samples. No difference in expression of sex hormone receptors was observed by sexes or age group. Estrogen and androgen receptors may have more influence on the pathogenesis of meningiomas than earlier thought. The higher incidence of meningiomas in women can not be explained by differences of sex hormone receptor expression. PMID:16703453

  19. Progesterone and estrogen receptor expression and activity in human non-small cell lung cancer

    PubMed Central

    Marquez-Garban, Diana C.; Mah, Vei; Alavi, Mohammad; Maresh, Erin L.; Chen, Hsiao-Wang; Bagryanova, Lora; Horvath, Steve; Chia, David; Garon, Edward; Goodglick, Lee; Pietras, Richard J.

    2011-01-01

    Lung cancer is the most common cause of cancer mortality in male and female patients in the US. Although it is clear that tobacco smoking is a major cause of lung cancer, about half of all women with lung cancer worldwide are never-smokers. Despite a declining smoking population, the incidence of non-small cell lung cancer (NSCLC), the predominant form of lung cancer, has reached epidemic proportions particularly in women. Emerging data suggest that factors other than tobacco, namely endogenous and exogenous female sex hormones, have a role in stimulating NSCLC progression. Aromatase, a key enzyme for estrogen biosynthesis, is expressed in NSCLC. Clinical data show that women with high levels of tumor aromatase (and high intratumoral estrogen) have worse survival than those with low aromatase. The present and previous studies also reveal significant expression and activity of estrogen receptors (ERα, ERβ) in both extranuclear and nuclear sites in most NSCLC. We now report further on the expression of progesterone receptor (PR) transcripts and protein in NSCLC. PR transcripts were significantly lower in cancerous as compared to non-malignant tissue. Using immunohistochemistry, expression of PR was observed in the nucleus and/or extranuclear compartments in the majority of human tumor specimens examined. Combinations of estrogen and progestins administered in vitro cooperate in promoting tumor secretion of vascular endothelial growth factor and, consequently, support tumor-associated angiogenesis. Further, dual treatment with estradiol and progestin increased the numbers of putative tumor stem/progenitor cells. Thus, ER- and/or PR-targeted therapies may offer new approaches to manage NSCLC. PMID:21600232

  20. Estrogen Receptor (ER) β Regulates ERα Expression in Stromal Cells Derived from Ovarian Endometriosis

    PubMed Central

    Trukhacheva, Elena; Lin, Zhihong; Reierstad, Scott; Cheng, You-Hong; Milad, Magdy; Bulun, Serdar E.

    2009-01-01

    Context: Estradiol and its nuclear receptors, estrogen receptor (ER) α and ERβ, play critical roles in endometrium and endometriosis. Levels of ERβ, due to pathological hypomethylation of its promoter, are significantly higher in endometriotic vs. endometrial tissue and stromal cells, whereas ERα levels are lower in endometriosis. Estradiol regulates ERα gene expression via its alternatively used promoters A, B, and C. Objective: The aim of the study was to determine whether high levels of ERβ in endometriotic stromal cells from ovarian endometriomas regulate ERα gene expression. Results: ERβ knockdown significantly increased ERα mRNA and protein levels in endometriotic stromal cells. Conversely, ERβ overexpression in endometrial stromal cells decreased ERα mRNA and protein levels. ERβ knockdown significantly decreased proliferation of endometriotic stromal cells. Chromatin immunoprecipitation assays demonstrated that estradiol enhanced ERβ binding to nonclassical activator protein 1 and specificity protein 1 motifs in the ERα gene promoters A and C and a classic estrogen response element in promoter B in endometriotic stromal cells. Conclusions: High levels of ERβ suppress ERα expression and response to estradiol in endometrial and endometriotic stromal cells via binding to classic and nonclassic DNA motifs in alternatively used ERα promoters. ERβ also regulates cell cycle progression and might contribute to proliferation of endometriotic stromal cells. We speculate that a significantly increased ratio of ERβ:ERα in endometriotic tissues may also suppress progesterone receptor expression and contribute to progesterone resistance. Thus, ERβ may serve as a significant therapeutic target for endometriosis. PMID:19001520

  1. Chick oviduct differentiation. The effect of estrogen and progesterone on the expression of progesterone receptor.

    PubMed

    Joensuu, T K

    1990-06-01

    Progesterone receptor (PR) is a marker of estrogen action. Its cellular appearance during estrogen (20 mg/kg i.m.)-induced differentiation of the immature chick oviduct was therefore studied by immunohistochemistry. PR was located in the epithelial, mesothelial, submucosal stromal and smooth muscle cells. Progesterone (20 mg/kg i.m.) caused an obvious decrease in PR immunoreactivity without inducing synthesis of progesterone-dependent avidin. Thus mere receptor occupation by ligand is not sufficient for this induction. This paper reports that the expression of PR in the mucosal stromal cell differs from that in other cell types. In the mucosal stromal cell PR was inducible, i.e., not shown without the action of estrogen. The formation of tubular glands did not commence before mucosal stromal cells expressed PR. It would seem that the mucosal stromal cells have a crucial role in mediating epithelial differentiation. The onset of differentiation was preceded by vascularization and invasion of mononuclear cells in the submucosa. It was conspicuous that the smooth muscle cells of arteries also contained PR. PMID:2207839

  2. The Estrogen ReceptorExpression in De Quervain’s Disease

    PubMed Central

    Shen, Po-Chuan; Wang, Ping-Hui; Wu, Po-Ting; Wu, Kuo-Chen; Hsieh, Jeng-Long; Jou, I-Ming

    2015-01-01

    Stenosing tenosynovitis of the first dorsal compartment of the wrist (a.k.a. de Quervain’s disease) is common but how estrogen is involved is still unknown. We previously reported that inflammation was involved in the pathogenesis of this ailment. In the present study, we extended our investigation of estrogen receptor (ER)-β expression to determine whether estrogen is involved in the pathogenesis of de Quervain’s. Intraoperative retinaculum samples were collected from 16 patients with the ailment. Specimens were histologically graded by collagen structure and immunohistochemically evaluated by quantifying the expression of ER-β, interleukin (IL)-1β and IL-6 (inflammatory cytokines), cyclooxygenase (COX)-2 (an inflammatory enzyme), and vascular endothelial growth factor (VEGF), and Von Willebrand’s factor (vWF). De Quervain’s occurs primarily in women. The female:male ratio in our study was 7:1. We found that ER-β expression in the retinaculum was positively correlated with disease grade and patient age. Additionally, disease severity was associated with inflammatory factors—IL-1β and IL-6, COX-2, and VEGF and vWF in tenosynovial tissue. The greater the levels of ER-β expression, tissue inflammation, and angiogenesis are, the more severe de Quervain’s disease is. ER-β might be a useful target for novel de Quervain’s disease therapy. PMID:26556342

  3. Differential expression of androgen, estrogen, and progesterone receptors in benign prostatic hyperplasia

    PubMed Central

    Song, Lingmin; Shen, Wenhao; Zhang, Heng; Wang, Qiwu; Wang, Yongquan; Zhou, Zhansong

    2016-01-01

    This study aimed to identify the differential expression levels of androgen receptor (AR), estrogen receptors (ERα, ERβ), and progesterone receptor (PGR) between normal prostate and benign prostatic hyperplasia (BPH). The combination of immunohistochemistry, quantitative real-time reverse transcription polymerase chain reaction, and Western blotting assay was used to identify the distribution and differential expression of these receptors at the immunoactive biomarker, transcriptional, and protein levels between 5 normal human prostate tissues and 40 BPH tissues. The results were then validated in a rat model of BPH induced by testosterone propionate and estradiol benzoate. In both human and rat prostate tissues, AR was localized mainly to epithelial and stromal cell nuclei; ERα was distributed mainly to stromal cells, but not exclusively; ERβ was interspersed in the basal layer of epithelium, but sporadically in epithelial and stromal cells; PGR was expressed abundantly in cytoplasm of epithelial and stromal cells. There were decreased expression of ERα and increased expression of PGR, but no difference in the expression of ERβ in the BPH compared to the normal prostate of both human and rat. Increased expression of AR in the BPH compared to the normal prostate of human was observed, however, the expression of AR in the rat prostate tissue was decreased. This study identified the activation of AR and PGR and repression of ERα in BPH, which indicate a promoting role of AR and PGR and an inhibitory role of ERα in the pathogenesis of BPH.

  4. Enhanced expression of G-protein coupled estrogen receptor (GPER/GPR30) in lung cancer

    PubMed Central

    2012-01-01

    Background G-protein-coupled estrogen receptor (GPER/GPR30) was reported to bind 17β-estradiol (E2), tamoxifen, and ICI 182,780 (fulvestrant) and promotes activation of epidermal growth factor receptor (EGFR)-mediated signaling in breast, endometrial and thyroid cancer cells. Although lung adenocarcinomas express estrogen receptors α and β (ERα and ERβ), the expression of GPER in lung cancer has not been investigated. The purpose of this study was to examine the expression of GPER in lung cancer. Methods The expression patterns of GPER in various lung cancer lines and lung tumors were investigated using standard quantitative real time PCR (at mRNA levels), Western blot and immunohistochemistry (IHC) methods (at protein levels). The expression of GPER was scored and the pairwise comparisons (cancer vs adjacent tissues as well as cancer vs normal lung tissues) were performed. Results Analysis by real-time PCR and Western blotting revealed a significantly higher expression of GPER at both mRNA and protein levels in human non small cell lung cancer cell (NSCLC) lines relative to immortalized normal lung bronchial epithelial cells (HBECs). The virally immortalized human small airway epithelial cell line HPL1D showed higher expression than HBECs and similar expression to NSCLC cells. Immunohistochemical analysis of tissue sections of murine lung adenomas as well as human lung adenocarcinomas, squamous cell carcinomas and non-small cell lung carcinomas showed consistently higher expression of GPER in the tumor relative to the surrounding non-tumor tissue. Conclusion The results from this study demonstrate increased GPER expression in lung cancer cells and tumors compared to normal lung. Further evaluation of the function and regulation of GPER will be necessary to determine if GPER is a marker of lung cancer progression. PMID:23273253

  5. Gene expression of estrogen and oxytocin receptors in the uterus of pregnant and parturient bitches.

    PubMed

    Veiga, G A L; Milazzotto, M P; Nichi, M; Lúcio, C F; Silva, L C G; Angrimani, D S R; Vannucchi, C I

    2015-04-01

    In the canine species, the precise mechanisms of pregnancy maintenance and the initiation of parturition are not completely understood. The expression of genes encoding the receptors for estrogen (ERα mRNA) and oxytocin (OTR mRNA) was studied in the endometrium and myometrium during pregnancy and parturition in dogs. Real-time PCR was performed to quantify the levels of ERα mRNA and OTR mRNA in the uterus of bitches during early (up to 20 days of gestation), mid (20 to 40 days) and late pregnancy (41 to 60 days), and parturition (first stage of labor). All tissues expressed ERα and OTR mRNA, and are thus possibly able to respond to eventual estrogen and oxytocin hormonal stimuli. No statistically significant differences in the expression of ERα mRNA were verified in the endometrium and myometrium throughout pregnancy and parturition, but expression of OTR mRNA increased at both parturition and late pregnancy. We concluded that the increase of endometrial and myometrial OTR mRNA expression in dogs is not an event dependent on estrogenic stimulation. Moreover, the contractility response of the canine uterus to oxytocin begins during pregnancy and maintains myometrial activity. The expression of OTR mRNA in canine uterine tissues varied over time, which supports an interpretation that the sensitivity and response to hormone therapy varies during the course of pregnancy and labor. Further studies are needed to elucidate the factors underlying the synthesis of uterine oxytocin receptors and the possible role of ERβ rather than ERα in the uterine tissues during pregnancy and parturition in dogs. PMID:25714892

  6. Gene Alterations of Ovarian Cancer Cells Expressing Estrogen Receptors by Estrogen and Bisphenol A Using Microarray Analysis

    PubMed Central

    Hwang, Kyung-A; Park, Se-Hyung; Yi, Bo-Rim

    2011-01-01

    Since endocrine disrupting chemicals (EDCs) may interfere with the endocrine system(s) of our body and have an estrogenicity, we evaluated the effect(s) of bisphenol A (BPA) on the transcriptional levels of altered genes in estrogen receptor (ER)-positive BG-1 ovarian cancer cells by microarray and real-time polymerase-chain reaction. In this study, treatment with 17β-estradiol (E2) or BPA increased mRNA levels of E2-responsive genes related to apoptosis, cancer and cell cycle, signal transduction and nucleic acid binding etc. In parallel with their microarray data, the mRNA levels of some altered genes including RAB31_MEMBER RAS ONCOGENE FAMILY (U59877), CYCLIN D1 (X59798), CYCLIN-DEPENDENT KINASE 4 (U37022), IGF-BINDING PROTEIN 4 (U20982), and ANTI-MULLERIAN HORMONE (NM_000479) were significantly induced by E2 or BPA in this cell model. These results indicate that BPA in parallel with E2 induced the transcriptional levels of E2-responsive genes in an estrogen receptor (ER)-positive BG-1 cells. In conclusion, these microarray and real-time polymerase-chain reaction results indicate that BPA, a potential weak estrogen, may have estrogenic effect by regulating E2-responsive genes in ER-positive BG-1 cells and BG-1 cells would be the best in vitro model to detect these estrogenic EDCs. PMID:21826169

  7. Spatiotemporal dynamics of the expression of estrogen receptors in the postnatal mouse brain.

    PubMed

    Sugiyama, N; Andersson, S; Lathe, R; Fan, X; Alonso-Magdalena, P; Schwend, T; Nalvarte, I; Warner, M; Gustafsson, J-A

    2009-02-01

    This study reports on the spatiotemporal dynamics of the expression of estrogen receptors (ERs) in the mouse central nervous system (CNS) during the early postnatal and the peripubertal period. At postnatal day 7 (P7), neurons with strong nuclear immunostaining for both ERalpha and ERbeta1 were widely distributed throughout the brain. Sucrose density gradient sedimentation followed by western blotting supported the histochemical evidence for high levels of both ERs at P7. Over the following 2 days, there was a rapid downregulation of ERs. At P9, ERalpha expression was visible only in the hypothalamic area. Decline in ERbeta1 expression was slower than that of ERalpha, and ERalpha-negative, ERbeta1-positive cells were observed in the dentate gyrus and walls of third ventricle. Between P14 and P35, ERs were undetectable except for the hypothalamic area. As before P7, the ovary does not produce estrogen but does produce 5alpha-androstane-3beta, 17beta-diol (3betaAdiol), an estrogenic metabolite of dihydrotestosterone, we examined the effects of high levels of 3betaAdiol in the postnatal period. We used CYP7B1 knockout mice which cannot hydroxylate and inactivate 3betaAdiol. The brains of these mice are abnormally large with reduced apoptosis. In the early postnatal period, there was 1-week delay in the timing of the reduction in ER expression in the brain. These data reveal that the time when ERs might be activated in the brain is limited to the first 8 postnatal days. In addition, the importance of aromatase has to be reconsidered as the alternative estrogen, 3betaAdiol, is important in neuronal function in the postnatal brain. PMID:18982005

  8. Distinct effects of 4-nonylphenol and estrogen-17β on expression of estrogen receptor α gene in smolting sockeye salmon

    USGS Publications Warehouse

    Luo, Qiong; Ban, Massatoshi; Ando, Hironori; Kitahashi, Takashi; Bhandari, Ramji K.; McCormick, Stephen D.; Urano, Akihisa

    2005-01-01

    Xenoestrogens such as 4-nonylphenol (4-NP) have been shown to affect the parr–smolt transformation, but their mechanisms of action are not known. We therefore examined effects of 4-NP and estradiol-17β (E2) on expression of estrogen receptor (ER) α gene in the liver, gill, pituitary and brain of sockeye salmon to elucidate molecular mechanisms of 4-NP and E2 and developmental differences in response during smolting. Fish were treated twice within a week with 4-NP (15 and 150 mg/kg BW), E2 (2 mg/kg BW) or only vehicle at three stages of smolting, pre-smolting in March, early smolting in April and late smolting in May. The absolute amounts of ERα mRNA were determined by real-time PCR. The basal amounts of ERα mRNA peaked in April in the liver, gill and pituitary. In March, E2 extensively increased the amounts in the liver, while 4-NP had no effects at this stage. In contrast, 4-NP (but not E2) decreased liver ERα mRNA in April. 4-NP also decreased the amount of ERα mRNA in the gill in April. In the pituitary, 4-NP increased ERα mRNA in March but decreased it in May. There were no significant effects in the brain. Changes in basal ERα mRNA observed in this study indicate that estrogen responsiveness of tissues may change during salmon smolting. Furthermore, 4-NP and E2 have different effects on expression of ERα gene in the liver and gill during smolting, and the response is dependent on smolt stage.

  9. Temporal expression of hepatic estrogen receptor 1, vitellogenin1 and vitellogenin2 in European silver eels.

    PubMed

    Palstra, Arjan P; Schnabel, Denhi; Nieveen, Maaike C; Spaink, Herman P; van den Thillart, Guido E E J M

    2010-03-01

    Because European silver eels have never been caught during or after their 6000-km reproductive migration to the Sargasso Sea, all existing knowledge on their sexual maturation comes from hormonal stimulation. Silver eels that start their oceanic migration are still immature with pre-vitellogenic oocytes. Hence we assumed that vitellogenesis should start with the expression of the estrogen receptor in the liver before the circulating 17beta-estradiol (E2) can have any effect. In this study we followed the hepatic vitellogenesis upon 4 weekly injections with carp pituitary extracts (CPE). New molecular primers for the expression of the estrogen receptor 1 (esr1), vitellogenin1 (vtg1) and vitellogenin2 (vtg2) in the liver were developed. Sequences of vtg2 and esr1 were not previously described in Anguilla anguilla. All eels showed weekly increase of the eye size and pectoral fin length, which are signs of early maturation. The same occurred with the gonadosomatic index, the oocyte stage and diameter, and number of deposited fat droplets. Early vitellogenesis appeared as a 3-step process (1) E2-levels and esr1 expression were significantly increased already after one injection, (2) vtg1 and vtg2 expression were significantly increased after one and two injections, respectively, and (3) vtg1 and vtg2 expression increased further after three and four injections. Then also plasma calcium (corresponds with plasma vitellogenin) increased and yolk globuli appeared in the oocytes. These results show that esr1 is the first of the three genes examined that is expressed during the onset of hepatic vitellogenesis. Furthermore, ovarian vitellogenesis (appearance of yolk globuli in oocytes) occurs 1-2 weeks later than the onset of hepatic vitellogenesis. PMID:19766647

  10. Parkin degrades estrogen-related receptors to limit the expression of monoamine oxidases.

    PubMed

    Ren, Yong; Jiang, Houbo; Ma, Dingyuan; Nakaso, Kazuhiro; Feng, Jian

    2011-03-15

    Parkin, whose mutations cause Parkinson disease (PD), controls oxidative stress by limiting the expression of monoamine oxidases (MAO)--mitochondrial enzymes responsible for the oxidative de-amination of dopamine. Here, we show that parkin performed this function by increasing the ubiquitination and degradation of estrogen-related receptors (ERR), orphan nuclear receptors that play critical roles in the transcription regulation of many nuclear-encoded mitochondrial proteins. All three ERRs (α, β and γ) increased the transcription of MAOs A and B; the effects were abolished by parkin, but not by its PD-linked mutants. Parkin bound to ERRs and increased their ubiquitination and degradation. In fibroblasts from PD patients with parkin mutations or brain slices from parkin knockout mice, degradation of ERRs was significantly attenuated. The results reveal the molecular mechanism by which parkin suppresses the transcription of MAOs to control oxidative stress induced by dopamine oxidation. PMID:21177257

  11. Parkin degrades estrogen-related receptors to limit the expression of monoamine oxidases

    PubMed Central

    Ren, Yong; Jiang, Houbo; Ma, Dingyuan; Nakaso, Kazuhiro; Feng, Jian

    2011-01-01

    Parkin, whose mutations cause Parkinson disease (PD), controls oxidative stress by limiting the expression of monoamine oxidases (MAO)—mitochondrial enzymes responsible for the oxidative de-amination of dopamine. Here, we show that parkin performed this function by increasing the ubiquitination and degradation of estrogen-related receptors (ERR), orphan nuclear receptors that play critical roles in the transcription regulation of many nuclear-encoded mitochondrial proteins. All three ERRs (α, β and γ) increased the transcription of MAOs A and B; the effects were abolished by parkin, but not by its PD-linked mutants. Parkin bound to ERRs and increased their ubiquitination and degradation. In fibroblasts from PD patients with parkin mutations or brain slices from parkin knockout mice, degradation of ERRs was significantly attenuated. The results reveal the molecular mechanism by which parkin suppresses the transcription of MAOs to control oxidative stress induced by dopamine oxidation. PMID:21177257

  12. Expression of Androgen Receptor in Estrogen Receptor–positive Breast Cancer

    PubMed Central

    Ziolkowski, Piotr; Grzebieniak, Zygmunt; Jelen, Michal; Bobinski, Piotr; Agrawal, Siddarth

    2016-01-01

    Objectives: The aim of the study was to estimate the implications of androgen receptor (AR) expression in estrogen receptor (ER)-positive subset of invasive breast carcinoma patients. Patients and Methods: We assessed the AR expression in a subset of 96 predominantly ER-positive invasive breast carcinomas and correlated this expression pattern with several clinical and pathologic parameters: histologic type and grade, tumor size, lymph node status, progesterone receptor (PgR) status, and human epidermal growth factor receptor type 2 (HER2) overexpression and evaluated the association of these parameters with 10-year survival using univariate and multivariate analyses. Data used for analysis were derived from medical records. Immunohistochemical analysis for AR, ER, PgR, and HER2 were carried out and semiquantitative evaluation of stainings was performed. Results: AR expression was demonstrated in 43.7% of patients. AR was significantly related to well-differentiated tumors and positive PgR/HER2 status. No statistical difference was demonstrated in AR expression in relation to tumor size, lymph node status, menopausal status, and tumor histologic type. AR expression was not an independent prognostic factor related to 10-year survival in ER-positive cancers. In multivariate analyses, older age at diagnosis, larger tumor size, and positive lymph node status were significantly associated with poorer 10-year survival. Conclusions: AR expression is significantly associated with ER/PgR/HER2 status and positively related to well-differentiated tumors. Although AR status in ER-positive cancers is not an independent prognostic factor, it might provide important additional information on prognosis and become a promising object for targeted therapy. PMID:26230371

  13. Comparison of estrogen and progesterone receptor expression in normal and tumor mammary tissues from dogs.

    PubMed

    Donnay, I; Rauïs, J; Devleeschouwer, N; Wouters-Ballman, P; Leclercq, G; Verstegen, J

    1995-09-01

    Concentrations of estrogen (ER) and progesterone (PR) receptors were measured by radioreceptor assay in tumor (n = 319) and normal (n = 166) mammary tissue from 248 bitches. Correlations between ER and PR and between receptor expression in tumor and normal mammary tissue from the same bitches were evaluated. The influence of tumor, clinical, or hormonal variables on receptor expression also was studied. Approximately 80% of tumor and 95% of normal mammary tissue expressed detectable concentrations of ER, PR, or both. Direct correlation was found between ER and PR concentrations in normal and tumor tissues. Median ER concentrations were significantly higher (46 +/- 47 fmol/mg of cytosolic protein vs 27 +/- 24 fmol/mg of cytosolic protein; P = 0.0002) in normal than in tumor tissue. On the other hand, PR concentrations were significantly higher (57 +/- 52 fmol/mg vs 77 +/- 99 fmol/mg; P = 0.03) in tumors (especially benign tumors) than in normal tissue. Poorly differentiated malignant tumors expressed lower concentrations of receptors than did benign or well differentiated malignant tumors. The ER and PR concentrations decreased with increasing size of the lesion. Hormonal status of the bitch significantly (P < 0.05) influenced receptor expression in normal tissue: bitches in the luteal phase of the estrous cycle had higher concentrations of ER (69 +/- 62 fmol/mg) than did ovariectomized bitches (24 +/- 19 fmol/mg) or bitches in anestrus (38 +/- 45 fmol/mg) or the follicular phase (13 +/- 7 fmol/mg).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7486397

  14. [Estrogens and pharmacological modulation of estrogen receptors].

    PubMed

    Sanidize, T V; Ratiani, L R; Gabuniia, L Iu; Tortladze, M L; Kuridze, N N

    2009-02-01

    Estrogens belong to more or less frequently prescribed preparations. Main fields of application of these preparations (as in monotherapy as well as in combination) are contraception and hormone replacement therapy during menopause. More uncommon indications of estrogens are growth inhibition and hypogonadism (in this case they are prescribed along with gonadotropic hormones). Synthesis and metabolism of estrogens, as well as their intracellular receptors are well studied these days, which allow us to understand physiology and pharmacology of these hormones. In pharmacology the main stage is detection of estrogen receptors inside of cells of targets. There are two types of estrogen receptors alpha- and beta- coded by different genes. A number of steroid and non-steroid compounds have characteristics of estrogens. Likely in the future their popularity will increase, as by the aging of population number of those women, who receive replacement therapy, will increase. Investigations to find an ideal elective modulator of estrogen receptors, that will possess anti-estrogenic activity in connection with mammal gland and develop indifference in connection with endometrium and at the same time will display ability to reduce hot flushes, bone resorption, atrophy of mucous membranes of vagina and urinary bladder, as well as it will favorably effect on metabolism of lipoproteins are carried out. PMID:19276483

  15. Effect of benzophenone-1 and octylphenol on the regulation of epithelial-mesenchymal transition via an estrogen receptor-dependent pathway in estrogen receptor expressing ovarian cancer cells.

    PubMed

    Shin, Sam; Go, Ryeo-Eun; Kim, Cho-Won; Hwang, Kyung-A; Nam, Ki-Hoan; Choi, Kyung-Chul

    2016-07-01

    Epithelial-mesenchymal transition (EMT) is an important process in embryonic development and cancer progression and metastasis. EMT is influenced by 17β-estradiol (E2), an endogenous estrogen. Benzophenone-1 (2,4-dihydroxybenzophenone, BP-1) and 4-tert-octylphenol (OP) are suspected endocrine disrupting chemicals (EDCs) because they can exhibit estrogenic properties. In this study, we examined whether BP-1 and OP can lead to EMT of BG-1 ovarian cancer cells expressing estrogen receptors (ERs). A wound healing assay and western blot assay were conducted to show the effect of BP-1 and OP on the migration of BG-1 cells and protein expression of EMT-related genes. BP-1 (10(-6) M) and OP (10(-6) M) significantly enhanced the migration capability of BG-1 cells by reducing the wounded area in the cell monolayer relative to the control, similar to E2 (10(-9) M). However, when BG-1 cells were co-treated with ICI 182,780, an ER antagonist, the uncovered area was maintained at the level of the control. N-cadherin, snail, and slug were increased by BP-1 and OP while E-cadherin was reduced compared to the control. However, this effect was also restored by co-treatment with ICI 182,780. Taken together, these results indicate that BP-1 and OP, the potential EDCs, may have the ability to induce ovarian cancer metastasis via regulation of the expression of EMT markers and migration of ER-expressing BG-1 ovarian cancer cells. PMID:27145024

  16. Heterogeneous estrogen receptor expression in circulating tumor cells suggests diverse mechanisms of fulvestrant resistance.

    PubMed

    Paoletti, Costanza; Larios, Jose M; Muñiz, Maria C; Aung, Kimberly; Cannell, Emily M; Darga, Elizabeth P; Kidwell, Kelley M; Thomas, Dafydd G; Tokudome, Nahomi; Brown, Martha E; Connelly, Mark C; Chianese, David A; Schott, Anne F; Henry, N Lynn; Rae, James M; Hayes, Daniel F

    2016-08-01

    Fulvestrant is a dose dependent selective estrogen receptor (ER) down-regulator (SERD) used in ER-positive metastatic breast cancer (MBC). Nearly all patients develop resistance. We performed molecular analysis of circulating tumor cells (CTC) to gain insight into fulvestrant resistance. Preclinical studies were performed with cultured breast cancer cells spiked into human blood and analyzed on the CellSearch(®) system. Clinical data are limited to a subset of patients with ER-positive MBC from a previously reported pilot trial whose disease was progressing on fulvestrant (N = 7) or aromatase inhibitors (AIs) (N = 10). CTCs were enumerated and phenotyped for ER and B-cell lymphoma (BCL2) using the CellSearch(®) CXC kit. In preclinical modeling, tamoxifen and AIs resulted in stabilized ER expression, whereas fulvestrant eliminated it. Five of seven patients progressing on fulvestrant had ≥5CTC/7.5 ml WB. Two of these five, treated with 500 mg/month fulvestrant, had no detectable CTC-expression of ER and BCL2 (an ER regulated gene). Three patients had heterogeneous CTC-ER and BCL2 expression indicating incomplete degradation of the ER target by fulvestrant. Two of these patients received 250 mg/month whereas the third patient received 500 mg/month fulvestrant. Her cancer harbored a mutation (Y537S) in the estrogen receptor alpha gene (ESR1). All seven ER positive patients progressing on AIs had heterogeneous CTC-ER expression. These results suggest heterogeneous mechanisms of resistance to fulvestrant, including insufficient dosage, ESR1 mutation, or conversion to dependence on non-ER pathways. CTC enumeration, phenotyping, and genotyping might identify patients who would benefit from fulvestrant dose escalation versus switching to alternative therapies. PMID:27178224

  17. Changes in estrogen receptor ERalpha and ERbeta expression in chicken (Gallus domesticus) adrenal gland during short-fasting and refeeding.

    PubMed

    Błachuta, Małgorzata; Wrońska-Fortuna, Danuta

    2012-01-01

    Estrogen receptors have been found in the adrenal gland of rodents, monkeys, mares and sheep, indicating a connection between sex steroids and the activity of the adrenal gland. In the present study, the expression of estrogen receptors alpha (ERalpha) and beta (ERbeta) in the chicken adrenal gland during stress induced by 24 h fasting and after refeeding was determined using reverse transcription and the polymerase chain reaction (RT-PCR). The presence of both ER mRNAs in the adrenal gland of all examined groups was found. The relative expression of ERalpha mRNA was higher than ERbeta mRNA. There were no significant differences in ERalpha mRNA expression among the examined groups. On the contrary, we observed changes in ERbeta expression during stress conditions. These findings indicate different pathways of estrogen action in the avian adrenal gland. Furthermore, changes in ERbeta level suggest that this form of estrogen receptor plays a predominant role for estrogen action in the chicken adrenal gland during stress. PMID:23342917

  18. Nutritional and exercise interventions variably affect estrogen receptor expression in the adipose tissue of male rats.

    PubMed

    Metz, Lore; Gerbaix, Maude; Masgrau, Aurélie; Guillet, Christelle; Walrand, Stéphane; Boisseau, Nathalie; Boirie, Yves; Courteix, Daniel

    2016-03-01

    Energy-dense food consumption and lack of physical activity are implicated in the development of the current obesity epidemic. The role of estrogen in adiposity and fuel partitioning is mediated mainly though the estrogen receptor α (ERα) isoform. We hypothesized that nutritional adaptation and exercise training, either individually or combined, could impact ERα expression in adipose tissue relative to glucose tolerance. Seventy-two Wistar rats were submitted to a high-fat, high-sucrose (HF-HS) diet for 16weeks. The first phase of our study was to investigate the effect of an HF-HS diet on whole-body glucose tolerance, as well as on body composition and ERα expression in different adipose tissues. Second, we investigated the effect of switching to a well-balanced diet, with or without exercise training for 8 weeks, on those same parameters. After the first part of this study, HF-HS-fed rats were fatter (8%) than control rats. Despite a decrease in glucose tolerance, ERα expression in adipose tissues was not significantly altered by an HF-HS diet. The return to a well-balanced diet significantly increased ERα expression in perirenal and epididymal adipose tissue, but there was no effect of diet or exercise training on whole-body glucose tolerance. The present findings suggest that diet is a powerful modulator of ERα expression in adipose tissue, as nutritional modulation after an HF-HS diet strongly affects ERα expression, particularly in perirenal and epididymal adipose tissue. However, ERα expression in adipose tissue does not appear to be associated with whole-body glucose tolerance. PMID:26923515

  19. The progesterone and estrogen modify the uterine prolactin and prolactin receptor expression of hyperprolactinemic mice.

    PubMed

    do Amaral, Vinícius Cestari; Carvalho, Kátia Candido; Maciel, Gustavo Arantes Rosa; Simoncini, Tommaso; da Silva, Priscilla Ludovico; Marcondes, Rodrigo Rodrigues; Soares, José Maria; Baracat, Edmund Chada

    2015-02-01

    The aim of this study was to evaluate the effects of metoclopramide-induced hyperprolactinemia on the prolactin (PRL) and PRL receptor's expression in the uterus of mice. For this purpose, 49 Swiss mice were divided into the following groups: GrSS (non-ovariectomized mice given vehicle); GrMET (non-ovariectomized mice treated with metoclopramide); OvSS (ovariectomized mice given vehicle); OvMET (ovariectomized mice treated with metoclopramide); OvMET+17βE (ovariectomized mice treated with metoclopramide and 17β estradiol); OvMET+MP (ovariectomized mice treated with metoclopramide and micronized progesterone); OvMET+17βE+MP (ovariectomized mice treated with metoclopramide and a solution of 17β estradiol and micronized progesterone). Immunohistochemical analyzes were evaluated semi-quantitatively. Our results showed that GrMET, OvMET+MP, and OvMET+17βE+MP presented strong PRL expression. OvMET and OvMET+17βE presented mild reaction, while GrSS and OvSS presented weak reaction. Concerning PRL receptor, OvMET+MP and OvMET+17βE+MP showed strong reaction; GrMET, OvSS, and OvMET+17βE showed mild reaction; and GrSS and OvMET showed weak reaction. These findings suggest that progesterone alone or in combination with estrogen may increase the expression of uterine PRL and PRL receptor. PMID:25299230

  20. Hormone-regulated v-rel estrogen receptor fusion protein: reversible induction of cell transformation and cellular gene expression.

    PubMed

    Boehmelt, G; Walker, A; Kabrun, N; Mellitzer, G; Beug, H; Zenke, M; Enrietto, P J

    1992-12-01

    We describe the construction of a v-rel estrogen receptor fusion protein (v-relER) which allows the regulation of v-rel oncoprotein activity by hormone. In the presence of estrogen, v-relER readily transformed primary chicken fibroblasts and bone marrow cells in vitro. In both cell types, v-rel-specific transformation was critically dependent on the presence of estrogen or the estrogen agonist 4-hydroxytamoxifen (OHT). Withdrawal of estrogen or application of an estrogen antagonist, ICI164,384 (ICI) caused a reversal of the transformed phenotype. We also demonstrate that the v-relER protein binds to NF-kappa B sites in an estrogen-dependent manner, thereby showing that sequence-specific DNA binding of v-relER is critical for the activation of its transforming capacity. In transient transfection experiments, we failed to demonstrate a clear repressor or activator function of the v-rel moiety in v-relER. However, in v-relER-transformed bone marrow cells, estrogen and OHT induced elevated mRNA levels of two cellular genes whose expression is constitutive and high in v-rel-transformed cells. These results suggest that v-rel might exert part of its activity as an activator of rel-responsive genes. PMID:1425595

  1. Estrogen-related receptor β deletion modulates whole-body energy balance via estrogen-related receptor γ and attenuates neuropeptide Y gene expression.

    PubMed

    Byerly, Mardi S; Al Salayta, Muhannad; Swanson, Roy D; Kwon, Kiwook; Peterson, Jonathan M; Wei, Zhikui; Aja, Susan; Moran, Timothy H; Blackshaw, Seth; Wong, G William

    2013-04-01

    Estrogen-related receptors (ERRs) α, β and γ are orphan nuclear hormone receptors with no known ligands. Little is known concerning the role of ERRβ in energy homeostasis, as complete ERRβ-null mice die mid-gestation. We generated two viable conditional ERRβ-null mouse models to address its metabolic function. Whole-body deletion of ERRβ in Sox2-Cre:ERRβ(lox/lox) mice resulted in major alterations in body composition, metabolic rate, meal patterns and voluntary physical activity levels. Nestin-Cre:ERRβ(lox/lox) mice exhibited decreased expression of ERRβ in hindbrain neurons, the predominant site of expression, decreased neuropeptide Y (NPY) gene expression in the hindbrain, increased lean body mass, insulin sensitivity, increased energy expenditure, decreased satiety and decreased time between meals. In the absence of ERRβ, increased ERRγ signaling decreased satiety and the duration of time between meals, similar to meal patterns observed for both the Sox2-Cre:ERRβ(lox/lox) and Nestin-Cre:ERRβ(lox/lox) strains of mice. Central and/or peripheral ERRγ signaling may modulate these phenotypes by decreasing NPY gene expression. Overall, the relative expression ratio between ERRβ and ERRγ may be important in modulating ingestive behavior, specifically satiety, gene expression, as well as whole-body energy balance. PMID:23360481

  2. DDT and its metabolites alter gene expression in human uterine cell lines through estrogen receptor-independent mechanisms.

    PubMed Central

    Frigo, Daniel E; Burow, Matthew E; Mitchell, Kamron A; Chiang, Tung-Chin; McLachlan, John A

    2002-01-01

    Endocrine-disrupting organochlorines, such as the pesticide dichlorodiphenyltrichloroethane (DDT), bind to and activate estrogen receptors (ERs), thereby eliciting estrogen-like effects. Although ERs function predominantly through activation of transcription via estrogen-responsive elements, both ERs, alpha and ss, can interact with various transcription factors such as activator protein-1 (AP-1). Additionally, estrogens may regulate early signaling events, suggesting that the biological effects of environmental estrogens may not be mediated through classic ER (alpha and ss) activity alone. We hypothesized that known environmental estrogens, such as DDT and its metabolites, activate AP-1-mediated gene transactivation through both ER-dependent and ER-independent means. Using two Ishikawa human endometrial adenocarcinoma cell line variants that we confirmed to be estrogen responsive [Ishikawa(+)] and estrogen unresponsive [Ishikawa(-)], we generated stably transfected AP-1 luciferase cell lines to identify the role of an estrogen-responsive mechanism in AP-1-mediated gene expression by various stimuli. Our results demonstrate that DDT and dichlorodiphenyldichloroethane (DDD) were the most potent activators of AP-1 activity; 2,2-bis(p-chlorophenyl) acetic acid failed to activate. Although stimulated in both Ishikawa(+) and Ishikawa(-) cells by DDT and its congeners, AP-1 activation was more pronounced in the estrogen-unresponsive Ishikawa(-) cells. In addition, DDT, DDD, and dichlorodiphenyldichloroethylene (DDE) could also stimulate AP-1 activity in the estrogen-unresponsive human embryonic kidney 293 cells using a different promoter context. Thus, our data demonstrate that DDT and its metabolites activate the AP-1 transcription factor independent of ER (alpha or ss) status. PMID:12460804

  3. Changes in estrogen receptor expression in the chick thymus during late embryonic development.

    PubMed

    Katayama, Masafumi; Fukuda, Tomokazu; Hatabu, Toshimitsu; Narabara, Kiyoaki; Abe, Asaki; Kondo, Yasuhiro

    2014-03-01

    In chickens, although estrogen receptors (ER) are reported to be associated with the immunological processes, detailed information about the differences in ER expression in the tissues related to the development of lymphocytes is not fully known, especially during the developmental stage. To learn more about this immunological relationship, we used semi-quantitative polymerase chain reaction method to detect the ER expression levels in the thymus tissues of chicks during the developmental stage. Furthermore, ER-expressing cells were detected by immunohistochemistry. The results of this study show that the expression level of ER increased on embryonic day 16 and decreased on day 20. Furthermore, ER expression was significantly higher in male than in female chickens at day 16. The increased expression on day 16 and decreased level on day 20 were also reproduced in the incidence of immunoreactive cells, although there was a 1-day delay in the elevated incidence of the cells. This study revealed the changes in ER expression and the incidence of ER-positive cells in the thymus of chickens during the developmental stage. PMID:24000785

  4. Expression of estrogen receptor subtypes in rat pituitary gland during pregnancy and lactation.

    PubMed

    Vaillant, Colette; Chesnel, Franck; Schausi, Diane; Tiffoche, Christophe; Thieulant, Marie-Lise

    2002-11-01

    The aim of this study was to examine whether the expression levels of mRNA of the three estrogen receptor (ER) subtypes, ERalpha, ERbeta, and truncated ER product-1 (TERP-1) found in the rat pituitary gland were modified during gestation, lactation, and postlactation periods. By using relative quantitative RT-PCR, we found that ERalpha mRNA significantly peaked in midpregnancy. However, the ERalpha protein level remained constant. ERbeta gene expression did not change throughout pregnancy, suggesting that it was not related to estradiol levels during this reproductive period. In contrast, both TERP-1 mRNA and protein levels dramatically increased throughout the second half of gestation, being faintly detectable in early pregnancy. TERP-1 expression was rapidly reversed by lactation, whereas neither pituitary ERalpha nor ERbeta relative levels were significantly altered. In addition, pup removal for 24-96 h on d 9 postpartum significantly reduced the expression of both ERalpha and ERbeta mRNA compared with that in lactating animals, but the expression of TERP-1 mRNA was no longer detected. Collectively, our data indicate that 1) TERP-1, ERalpha, and ERbeta expression levels are differentially regulated in the pituitary; 2) TERP-1 is variably expressed depending on the hormonal environment related to the estrous cycle, pregnancy, and lactation; and 3) TERP-1/ERalpha ratios dramatically change depending on reproductive periods, suggesting a critical role for TERP-1 in reproductive events. PMID:12399419

  5. Estrogen receptor-mediated miR-486-5p regulation of OLFM4 expression in ovarian cancer

    PubMed Central

    Liu, Xubin; Shen, Hongwei; Xia, Meng; Liu, Xingyang; Zhang, Wenhui; Wang, Liantang; Chen, Shangwu; Yu, Li

    2016-01-01

    Estrogen signaling influences the development and progression of ovarian tumors, but the underlying mechanisms are not well understood. In a previous study we demonstrated that impairment of estrogen receptor alpha (ERα)-mediated olfactomedin 4 (OLFM4) expression promotes the malignant progression of endometrioid adenocarcinoma, and we identified OLFM4 as a potential target of miR-486-5p. In this study we investigated the role of OLFM4 in ovarian serous adenocarcinoma. Ovarian serous adenocarcinoma tissues had reduced OLFM4 expression. Expression of OLFM4 was positively correlated with ERα expression, and estrogen (E2) treatment in ovarian cancer cells induced OLFM4 expression in an ERα-dependent manner. In contrast to ERα, miR-486-5p levels were inversely correlated with OLFM4 expression in ovarian serous adenocarcinoma. Ovarian cancer cells transfected with miR-486-5p mimics showed decreased OLFM4 mRNA expression, and ovarian cancer cells treated with E2 showed reduced cellular miR-486-5p levels. OLFM4 knockdown enhanced proliferation, migration, and invasion by ovarian cancer cells. Low expression of OLFM4 was also associated with high tumor FIGO stage and poor tumor differentiation. These results suggest OLFM4 is downregulated by miR-486-5p, which contributes to ovarian cancer tumorigenesis. Conversely, estrogen receptor signaling downregulates miR-486-5p and upregulates OLFM4 expression, slowing the development and progression of ovarian cancer. PMID:26871282

  6. Visualizing estrogen receptor-a-expressing neurons using a new ERa-ZsGreen reporter mouse line

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A variety of biological functions of estrogens, including regulation of energy metabolism, are mediated by neurons expressingestrogen receptor-a (ERa) in the brain. However, complex intracellular processes in these ERa-expressing neurons are difficult to unravel, due to the lack of strategy to visua...

  7. Increased expression of estrogen-related receptor β during adaptation of adult cardiomyocytes to sustained hypoxia

    PubMed Central

    Cunningham, Kathryn F; Beeson, Gyda C; Beeson, Craig C; McDermott, Paul J

    2016-01-01

    Estrogen-related Receptors (ERR) are members of the steroid hormone receptor superfamily of transcription factors that regulate expression of genes required for energy metabolism including mitochondrial biogenesis, fatty acid oxidation and oxidative phosphorylation. While ERRα and EPPγ isoforms are known to share a wide array of target genes in the adult myocardium, the function of ERRβ has not been characterized in cardiomyocytes. The purpose of this study was to determine the role of ERRβ in regulating energy metabolism in adult cardiomyocytes in primary culture. Adult feline cardiomyocytes were electrically stimulated to contract in either hypoxia (0.5% O2) or normoxia (21% O2). As compared to baseline values measured in normoxia, ERRβ mRNA levels increased significantly after 8 hours of hypoxia and remained elevated over 24 h. Conversely, ERRβ mRNA decreased to normoxic levels after 4 hours of reoxygenation. Hypoxia increased expression of the α and β isoforms of Peroxisome Proliferator-Activated Receptor γ Coactivator-1 (PGC-1) mRNA by 6-fold and 3-fold, respectively. Knockdown of ERRβ expression via adenoviral-mediated delivery of ERRβ shRNA blocked hypoxia-induced increases in PGC-1β mRNA, but not PGC-1α mRNA. Loss of ERRβ had no effect on mtDNA content as measured after 24 h of hypoxia. To determine whether loss of ERRβ affected mitochondrial function, oxygen consumption rates (OCR) were measured in contracting versus quiescent cardiomyocytes in normoxia. OCR was significantly lower in contracting cardiomyocytes expressing ERRβ shRNA than scrambled shRNA controls. Maximal OCR also was reduced by ERRβ knockdown. In conclusion: 1) hypoxia increases in ERRβ mRNA expression in contracting cardiomyocytes; 2) ERRβ is required for induction of the PGC-1β isoform in response to hypoxia; 3) ERRβ expression is required to sustain OCR in normoxic conditions. PMID:27335690

  8. Modulation of adipogenesis-related gene expression by estrogen-related receptor gamma during adipocytic differentiation.

    PubMed

    Kubo, Mayumi; Ijichi, Nobuhiro; Ikeda, Kazuhiro; Horie-Inoue, Kuniko; Takeda, Satoru; Inoue, Satoshi

    2009-02-01

    Estrogen-related receptor gamma (ERRgamma) is an orphan nuclear receptor that regulates cellular energy metabolism by modulating gene expression involved in oxidative metabolism and mitochondrial biogenesis in brown adipose tissue and heart. However, the physiological role of ERRgamma in adipogenesis and the development of white adipose tissue has not been well studied. Here we show that ERRgamma was up-regulated in murine mesenchyme-derived cells, especially in ST2 and C3H10T1/2 cells, at mRNA levels under the adipogenic differentiation condition including the inducer of cAMP, glucocorticoid, and insulin. The up-regulation of ERRgamma mRNA was also observed in inguinal white adipose and brown adipose tissues of mice fed a high-fat diet. Gene knockdown by ERRgamma-specific siRNA results in mRNA down-regulation of adipogenic marker genes including fatty acid binding protein 4, PPARgamma, and PGC-1beta in a preadipocyte cell line 3T3-L1 preadipocytes and mesenchymal ST2 and C3H10T1/2 cells in the adipogenesis medium. In contrast, stable expression of ERRgamma in 3T3-L1 cells resulted in up-regulation of these adipogenic marker genes under the adipogenic condition. These results suggest that ERRgamma positively regulate the adipocyte differentiation with modulating the expression of various adipogenesis-related genes. PMID:18809516

  9. Estrogen Receptor Agonists and Antagonists in the Yeast Estrogen Bioassay.

    PubMed

    Wang, Si; Bovee, Toine F H

    2016-01-01

    Cell-based bioassays can be used to predict the eventual biological activity of a substance on a living organism. In vitro reporter gene bioassays are based on recombinant vertebrate cell lines or yeast strains and especially the latter are easy-to-handle, cheap, and fast. Moreover, yeast cells do not express estrogen, androgen, progesterone or glucocorticoid receptors, and are thus powerful tools in the development of specific reporter gene systems that are devoid of crosstalk from other hormone pathways. This chapter describes our experience with an in-house developed RIKILT yeast estrogen bioassay for testing estrogen receptor agonists and antagonists, focusing on the applicability of the latter. PMID:26585147

  10. TOP2A RNA Expression and Recurrence in Estrogen Receptor-Positive Breast Cancer

    PubMed Central

    Sparano, Joseph A.; Goldstein, Lori J.; Davidson, Nancy E.; Sledge, George W.; Gray, Robert

    2016-01-01

    The purpose of this study is to evaluate the relationship between TOP2A RNA expression and recurrence in patients with operable estrogen receptor (ER) positive breast cancer. We evaluated TOP2A expression in a pooled analysis of 4 independent data sets with gene expression data including 752 patients with early stage, ER-positive, HER2-negative breast cancer, most of whom received either no adjuvant therapy or endocrine therapy without chemotherapy. We also used an algorithm to simulate the Oncotype DX Recurrence Score (simRS) and the proliferation component of the Recurrence Score (simPS). Results are expressed as the hazard ratio (HR) for estimates of the effect of a one standard deviation increase in the value of the log gene expression (x + 1SD vs. x) as a continuous function. TOP2A expression was significantly associated with recurrence (HR 1.56, p<0.0001), and after adjustment for simRS (HR 1.26, p=0.003). TOP2A correlated somewhat with simRS (0.45), but more strongly with simPS (0.69). For those with an intermediate simRS, high TOP2A expression (above the median) was associated with significantly higher relapse rates at five years (HR 1.82, p=0.007). TOP2A expression provides prognostic information in patients with ER-positive, HER2-negative breast cancer, a population known to have low incidence of TOP2A gene alterations. These findings confirm prior reports indicating that TOP2A expression provides prognostic information in ER-positive breast cancer. TOP2A expression may also be useful for identifying those with an intermediate RS who are more likely to relapse, although additional validation in datasets including measured rather than simulated RS will be required. PMID:22706628

  11. Estrogen-related receptor {alpha} modulates the expression of adipogenesis-related genes during adipocyte differentiation

    SciTech Connect

    Ijichi, Nobuhiro; Ikeda, Kazuhiro; Horie-Inoue, Kuniko; Yagi, Ken; Okazaki, Yasushi; Inoue, Satoshi . E-mail: INOUE-GER@h.u-tokyo.ac.jp

    2007-07-06

    Estrogen-related receptor {alpha} (ERR{alpha}) is an orphan nuclear receptor that regulates cellular energy metabolism by modulating gene expression involved in fatty acid oxidation and mitochondrial biogenesis in brown adipose tissue. However, the physiological role of ERR{alpha} in adipogenesis and white adipose tissue development has not been well studied. Here, we show that ERR{alpha} and ERR{alpha}-related transcriptional coactivators, peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) coactivator-1{alpha} (PGC-1{alpha}) and PGC-1{beta}, can be up-regulated in 3T3-L1 preadipocytes at mRNA levels under the adipogenic differentiation condition including the inducer of cAMP, glucocorticoid, and insulin. Gene knockdown by ERR{alpha}-specific siRNA results in mRNA down-regulation of fatty acid binding protein 4, PPAR{gamma}, and PGC-1{alpha} in 3T3-L1 cells in the adipogenesis medium. ERR{alpha} and PGC-1{beta} mRNA expression can be also up-regulated in another preadipocyte lineage DFAT-D1 cells and a pluripotent mesenchymal cell line C3H10T1/2 under the differentiation condition. Furthermore, stable expression of ERR{alpha} in 3T3-L1 cells up-regulates adipogenic marker genes and promotes triglyceride accumulation during 3T3-L1 differentiation. These results suggest that ERR{alpha} may play a critical role in adipocyte differentiation by modulating the expression of various adipogenesis-related genes.

  12. Tissue-specific regulation of porcine prolactin receptor expression by estrogen, progesterone, and prolactin.

    PubMed

    Trott, Josephine F; Horigan, Katherine C; Gloviczki, Julia M; Costa, Kristen M; Freking, Bradley A; Farmer, Chantal; Hayashi, Kanako; Spencer, Thomas; Morabito, Joseph E; Hovey, Russell C

    2009-07-01

    Prolactin (PRL) acts through its receptor (PRLR) via both endocrine and local paracrine/autocrine pathways to regulate biological processes including reproduction and lactation. We analyzed the tissue- and stage of gestation-specific regulation of PRL and PRLR expression in various tissues of pigs. Abundance of pPRLR-long form (LF) mRNA increased in the mammary gland and endometrium during gestation while in other tissues it remained constant. There was a parallel increase in the abundance of the pPRLR-LF protein in the mammary gland and endometrium during gestation. We determined the hormonal regulation of pPRLR-LF mRNA expression in various tissues from ovariectomized, hypoprolactinemic gilts given combinations of the replacement hormones estrogen (E(2)), progestin (P), and/or haloperidol-induced PRL. Abundance of pPRLR-LF mRNA in kidney and liver was unaffected by hormone treatments. Expression of uterine pPRLR-LF mRNA was induced by E(2) whereas the effect of E(2) was abolished by co-administering P. The expression of pPRLR-LF mRNA in the mammary gland stroma was induced by PRL, whereas E(2) induced its expression in the epithelium. In contrast to these changes in pPRLR expression, pPRL expression was relatively constant and low during gestation in all tissues except the pituitary. Taken together, these data reveal that specific combinations of E(2), P, and PRL differentially regulate pPRLR-LF expression in the endometrium and mammary glands, and that the action of PRL on its target tissues is dependent upon pPRLR-LF abundance more so than the local PRL expression. PMID:19401343

  13. Estrogen Receptor Alpha Distribution and Expression in the Social Neural Network of Monogamous and Polygynous Peromyscus

    PubMed Central

    Cushing, Bruce S.

    2016-01-01

    In microtine and dwarf hamsters low levels of estrogen receptor alpha (ERα) in the bed nucleus of the stria terminalis (BST) and medial amygdala (MeA) play a critical role in the expression of social monogamy in males, which is characterized by high levels of affiliation and low levels of aggression. In contrast, monogamous Peromyscus males display high levels of aggression and affiliative behavior with high levels of testosterone and aromatase activity. Suggesting the hypothesis that in Peromyscus ERα expression will be positively correlated with high levels of male prosocial behavior and aggression. ERα expression was compared within the social neural network, including the posterior medial BST, MeA posterodorsal, medial preoptic area (MPOA), ventromedial hypothalamus (VMH), and arcuate nucleus in two monogamous species, P. californicus and P. polionotus, and two polygynous species, P. leucopus and P. maniculatus. The results supported the prediction, with male P. polionotus and P. californicus expressing higher levels of ERα in the BST than their polygynous counter parts, and ERα expression was sexually dimorphic in the polygynous species, with females expressing significantly more than males in the BST in both polygynous species and in the MeA in P. leucopus. Peromyscus ERα expression also differed from rats, mice and microtines as in neither the MPOA nor the VMH was ERα sexually dimorphic. The results supported the hypothesis that higher levels of ERα are associated with monogamy in Peromyscus and that differential expression of ERα occurs in the same regions of the brains regardless of whether high or low expression is associated with social monogamy. Also discussed are possible mechanisms regulating this differential relationship. PMID:26959827

  14. [Cloning of gene fragment of estrogen receptor-beta and its expression in mouse embryo].

    PubMed

    Zhang, Zi-Feng; Fan, Shao-Hua; Lu, Jun; Wu, Dong-Mei; Shan, Qun; Hu, Bin; Li, Fei; Zheng, Yuan-Lin

    2008-03-01

    In order to study the expression and regulation effects of estrogen receptor-beta (ERbeta) in the development of mouse embryo, the primer of ERbeta was designed, the ERbeta fragment was first obtained by RT-PCR and subcloned into plasmids pGEM- 3Z, then the recombinant plasmids were linearized with the restriction enzymes of EcoRand Hind. Using Sp6 and T7 RNA polymerase, the digoxigenin(dig) labeled sense and anti-sense probes were transcriped in vitro, respectively. Then the expression of ERbeta in mouse embryo was examined with the probes by whole-mount in situ hybridization. The results indicated that ERbeta is expressed in the brain, spinal neural tube, genital ridge, pericardium, limb bud and mandibular arch of 10.5 dpc embryo, and is also expressed in the telencephalon, mesencephalon, medulla oblongata, spinal cord and limb bud of 13.5 dpc embryo. These results suggest that ERbeta maybe play a role of regulation in sexual differentiation, primal differentiation of neural tube, further differentiation of three primary cerebral vesicles and spinal cord, generation and differentiation of bone and cartilage of limb bud, development of pericardium and configuration differentiation of mandibular in mouse embryo. PMID:18332005

  15. Estrogen receptor scintigraphy.

    PubMed

    Scheidhauer, K; Scharl, A; Schicha, H

    1998-03-01

    Radio-labeled estrogen receptor ligands are tracers that can be used for functional receptor diagnosis. Their specificity towards receptors, together with the fact that only 50-70% of mammary carcinomas are receptor positive, renders them unsuitable for detection of primary tumors or metastases, and this means that estrogen receptor scintigraphy can be used neither for tumor screening nor for staging. However, both 18F-labeled and 123I-labeled estradiol derivatives are suitable for in vivo imaging of estrogen receptors. Their high specificity, established in animal experiments and in vitro studies has been reproduced in in vivo applications in humans. Tracers with positron radiation emitters are, however, hardly suitable for broad application owing to the short half-life of 18F, which would mean that users would need to be situated close to a cyclotron and a correspondingly equipped radiochemical laboratory. The number of available PET scanners, on the other hand, has increased over the last few years, especially in Germany, so that this, at least, does not present a limiting factor. All the same, 123I-labeled estradiol derivatives will find more widespread application, since the number of gamma-cameras incorporating modern multi-head systems is several times greater. The results of studies with 123I-E2-scintigraphy published to date are very promising, even given the initial technical problems mentioned above. As a method of examination, it could be optimised by using improved tracers with a higher tumor contrast and less disturbance from overlapping in diagnostically relevant locations, for instance, by selecting tracers with higher activities whose excretion is more renal than hepatobiliary. The use of modern multi-head camera systems can also be expected to improve the photon yield. PMID:9646642

  16. The Selective Estrogen Receptor Modulator Raloxifene Regulates Arginine-Vasopressin Gene Expression in Human Female Neuroblastoma Cells Through G Protein-Coupled Estrogen Receptor and ERK Signaling.

    PubMed

    Grassi, Daniela; Ghorbanpoor, Samar; Acaz-Fonseca, Estefania; Ruiz-Palmero, Isabel; Garcia-Segura, Luis M

    2015-10-01

    The selective estrogen receptor modulator raloxifene reduces blood pressure in hypertensive postmenopausal women. In the present study we have explored whether raloxifene regulates gene expression of arginine vasopressin (AVP), which is involved in the pathogenesis of hypertension. The effect of raloxifene was assessed in human female SH-SY5Y neuroblastoma cells, which have been recently identified as a suitable cellular model to study the estrogenic regulation of AVP. Raloxifene, within a concentration ranging from 10(-10) M to 10(-6) M, decreased the mRNA levels of AVP in SH-SY5Y cells with maximal effect at 10(-7) M. This effect of raloxifene was imitated by an agonist (±)-1-[(3aR*,4S*,9bS*)-4-(6-bromo-1,3-benzodioxol-5-yl)-3a,4,5,9b-tetrahydro-3H-cyclopenta[c]quinolin-8-yl]-ethanone of G protein-coupled estrogen receptor-1 (GPER) and blocked by an antagonist (3aS*,4R*,9bR*)-4-(6-bromo-1,3-benzodioxol-5-yl)-3a,4,5,9b-3H-cyclopenta[c]quinoline of GPER and by GPER silencing. Raloxifene induced a time-dependent increase in the level of phosphorylated ERK1 and ERK2, by a mechanism blocked by the GPER antagonist. The treatment of SH-SY5Y cells with either a MAPK/ERK kinase 1/2-specific inhibitor (1,4-diamino-2, 3-dicyano-1,4-bis(2-aminophenylthio)butadine) or a protein kinase C inhibitor (sotrastaurin) blocked the effects of raloxifene on the phosphorylation of ERK1/2 and the regulation of AVP mRNA levels. These results reveal a mechanism mediating the regulation of AVP expression by raloxifene, involving the activation of GPER, which in turn activates protein kinase C, MAPK/ERK kinase, and ERK. The regulation of AVP by raloxifene and GPER may have implications for the treatment of blood hypertension(.). PMID:26200092

  17. Three nuclear and two membrane estrogen receptors in basal teleosts, Anguilla sp.: Identification, evolutionary history and differential expression regulation.

    PubMed

    Lafont, Anne-Gaëlle; Rousseau, Karine; Tomkiewicz, Jonna; Dufour, Sylvie

    2016-09-01

    Estrogens interact with classical intracellular nuclear receptors (ESR), and with G-coupled membrane receptors (GPER). In the eel, we identified three nuclear (ESR1, ESR2a, ESR2b) and two membrane (GPERa, GPERb) estrogen receptors. Duplicated ESR2 and GPER were also retrieved in most extant teleosts. Phylogeny and synteny analyses suggest that they result from teleost whole genome duplication (3R). In contrast to conserved 3R-duplicated ESR2 and GPER, one of 3R-duplicated ESR1 has been lost shortly after teleost emergence. Quantitative PCRs revealed that the five receptors are all widely expressed in the eel, but with differential patterns of tissue expression and regulation. ESR1 only is consistently up-regulated in vivo in female eel BPG-liver axis during induced sexual maturation, and also up-regulated in vitro by estradiol in eel hepatocyte primary cultures. This first comparative study of the five teleost estradiol receptors provides bases for future investigations on differential roles that may have contributed to the conservation of multiple estrogen receptors. PMID:26654744

  18. Phylogenetic sequence analysis, recombinant expression, and tissue distribution of a channel catfish estrogen receptor beta

    USGS Publications Warehouse

    Xia, Zhenfang; Gale, William L.; Chang, Xiaotian; Langenau, David; Patino, Reynaldo; Maule, Alec G.; Densmore, Llewellyn D.

    2000-01-01

    An estrogen receptor β (ERβ) cDNA fragment was amplified by RT-PCR of total RNAextracted from liver and ovary of immature channel catfish. This cDNA fragment was used to screen an ovarian cDNA library made from an immature female fish. A clone was obtained that contained an open reading frame encoding a 575-amino-acid protein with a deduced molecular weight of 63.9 kDa. Maximum parsimony and Neighbor Joining analyses were used to generate a phylogenetic classification of channel catfish ERβ on the basis of 25 full-length teleost and tetrapod ER sequences. The consensus tree obtained indicated the existence of two major vertebrate ER subtypes, α and β. Within each subtype, and in accordance with established phylogenetic relationships, teleost and tetrapod ER were monophyletic confirming the results of a previous analysis (Z. Xiaet al., 1999, Gen. Comp. Endocrinol. 113, 360–368). Extracts of COS-7 cells transfectedwith channel catfish ERβ cDNA bound estrogen with high affinity (Kd = 0.21 nM) and specificity. The affinity of channel catfish ERβ for estrogen was higher than previously reported for channel catfish ERα. As determined by qualitative RT-PCR, the tissue distributions of ERα and ERβ were similar but not identical. Both ER subtypes were present in ovary and testis. ERα was found in all other tissues examined from juvenile and mature fish of both sexes. ERβ was also found in most tissues except, in most cases, whole blood and head kidney. Interestingly, the pattern of expression of ER subtypes in head kidney always corresponded to the pattern in whole blood. In conclusion, we isolated a channel catfish ERβ with ligand-binding affinity and tissue expression patterns different from ERα. Also, we confirmed the validity of our previously proposed general classification scheme for vertebrate ER into α and β subtypes and within each subtype, into teleost and tetrapod clades.

  19. Molecular characterization and expression profile of the estrogen receptor α gene during different reproductive phases in Monopterus albus

    PubMed Central

    Ding, Weidong; Cao, Liping; Cao, Zheming; Bing, Xuwen; Zhao, Fazhen

    2016-01-01

    To understand the molecular mechanism of estrogen and to evaluate the role of the estrogen receptor in mediating estrogen action, the full-length cDNA of estrogen receptor α (ERα) was cloned from Monopterus albus, and its expression pattern and distribution were investigated. The ERα cDNA of M. albus includes an open reading frame of 1863 bp, a 140-bp 5’-untranslated region and a 797-bp 3’-untranslated region. Amino acid sequence homology analysis showed that the Monopterus albus ERα has a moderate degree of similarity with Sebastes schlegelii, Zoarces viviparus and Haplochromis burtoni (81.1%, 80.7% and 80.4%, respectively). Quantitative PCR results showed that the highest level of ERα expression was in the liver; the next highest level of expression was observed in the gonads, where it was expressed at high levels particularly in the ovary in developmental stages IV and V and in the testis in developmental stage II/III. Immunohistochemistry analysis showed that ERα was present as slender particles distributed mainly in the membranes of spermatocytes and oocytes in the testis and ovary, whereas no positive signal was observed in the cytoplasm of sperm cells. This report describes the first molecular characterization of full-length ERα and its tissue-specific distribution in M. albus. PMID:27295422

  20. Molecular characterization and expression profile of the estrogen receptor α gene during different reproductive phases in Monopterus albus.

    PubMed

    Ding, Weidong; Cao, Liping; Cao, Zheming; Bing, Xuwen; Zhao, Fazhen

    2016-01-01

    To understand the molecular mechanism of estrogen and to evaluate the role of the estrogen receptor in mediating estrogen action, the full-length cDNA of estrogen receptor α (ERα) was cloned from Monopterus albus, and its expression pattern and distribution were investigated. The ERα cDNA of M. albus includes an open reading frame of 1863 bp, a 140-bp 5'-untranslated region and a 797-bp 3'-untranslated region. Amino acid sequence homology analysis showed that the Monopterus albus ERα has a moderate degree of similarity with Sebastes schlegelii, Zoarces viviparus and Haplochromis burtoni (81.1%, 80.7% and 80.4%, respectively). Quantitative PCR results showed that the highest level of ERα expression was in the liver; the next highest level of expression was observed in the gonads, where it was expressed at high levels particularly in the ovary in developmental stages IV and V and in the testis in developmental stage II/III. Immunohistochemistry analysis showed that ERα was present as slender particles distributed mainly in the membranes of spermatocytes and oocytes in the testis and ovary, whereas no positive signal was observed in the cytoplasm of sperm cells. This report describes the first molecular characterization of full-length ERα and its tissue-specific distribution in M. albus. PMID:27295422

  1. Thioredoxin and thioredoxin reductase influence estrogen receptor alpha-mediated gene expression in human breast cancer cells.

    PubMed

    Rao, Abhi K; Ziegler, Yvonne S; McLeod, Ian X; Yates, John R; Nardulli, Ann M

    2009-12-01

    Accumulation of reactive oxygen species (ROS) in cells damages resident proteins, lipids, and DNA. In order to overcome the oxidative stress that occurs with ROS accumulation, cells must balance free radical production with an increase in the level of antioxidant enzymes that convert free radicals to less harmful species. We identified two antioxidant enzymes, thioredoxin (Trx) and Trx reductase (TrxR), in a complex associated with the DNA-bound estrogen receptor alpha (ERalpha). Western analysis and immunocytochemistry were used to demonstrate that Trx and TrxR are expressed in the cytoplasm and in the nuclei of MCF-7 human breast cancer cells. More importantly, endogenously expressed ERalpha, Trx, and TrxR interact and ERalpha and TrxR associate with the native, estrogen-responsive pS2 and progesterone receptor genes in MCF-7 cells. RNA interference assays demonstrated that Trx and TrxR differentially influence estrogen-responsive gene expression and that together, 17beta-estradiol, Trx, and TrxR alter hydrogen peroxide (H(2)O(2)) levels in MCF-7 cells. Our findings suggest that Trx and TrxR are multifunctional proteins that, in addition to modulating H(2)O(2) levels and transcription factor activity, aid ERalpha in regulating the expression of estrogen-responsive genes in target cells. PMID:19620238

  2. Estrogen receptor alpha (ESR1)-signaling regulates the expression of the taxane-response biomarker PRP4K.

    PubMed

    Lahsaee, Sara; Corkery, Dale P; Anthes, Livia E; Holly, Alice; Dellaire, Graham

    2016-01-01

    The pre-mRNA splicing factor 4 kinase PRP4K (PRPF4B), is an essential kinase that is a component of the U5 snRNP and functions in spliceosome assembly. We demonstrated that PRP4K is a novel biological marker for taxane response in ovarian cancer patients and reduced levels of PRP4K correlate with intrinsic and acquired taxane resistance in both breast and ovarian cancer. Breast cancer treatments are chosen based on hormone and growth factor receptor status, with HER2 (ERBB2) positive breast cancer patients receiving anti-HER2 agents and taxanes and estrogen receptor alpha (ESR1) positive (ER+) breast cancer patients receiving anti-estrogen therapies such as tamoxifen. Here we demonstrate that PRP4K is expressed in the normal mammary duct epithelial cells of the mouse, and that estrogen induces PRP4K gene and protein expression in ER+ human MCF7 breast cancer cells. Estrogen acts through ESR1 to regulate PRP4K expression, as over-expression of ESR1 in the ER-negative MDA-MB-231 breast cancer cell line increased the expression of this kinase, and knock-down of ESR1 in ER+ T47D breast cancer cells reduced PRP4K levels. Furthermore, treatment with 4-hydroxytamoxifen (4-OHT) resulted in a dose-dependent decrease in PRP4K protein expression in MCF7 cells. Consistent with our previous studies identifying PRP4K as a taxane-response biomarker, reduced PRP4K expression in 4-OHT-treated cells correlated with reduced sensitivity to paclitaxel. Thus, PRP4K is novel estrogen regulated kinase, and its levels can be reduced by 4-OHT in ER+ breast cancer cells altering their response to taxanes. PMID:26712520

  3. Expression of estrogen and progesterone receptors in angioleiomyoma of the nasal cavity of six patients

    PubMed Central

    ZHU, GUOCHEN; XIAO, DAJIANG; SUN, PING

    2016-01-01

    Angioleiomyoma of the nasal cavity is extremely rare. There are only a small number of studies in the literature that demonstrate that the estrogen receptor (ER) and progesterone receptor (PR) are expressed in angioleiomyoma, and the results from these studies are inconsistent. The present study identified 6 patients with nasal angioleiomyoma that were treated between 2004 and 2013. All patients underwent endoscopic surgery and were followed-up for 1–10 years. Resected tumors were investigated for the presence of ER and PR using immunoperoxidase staining. Of the 6 patients, 4 were men and 2 were woman. The mean age of the patients was 60.5 years. The tumors of the 6 patients were identified in the nasal septum, middle turbinate, inferior turbinate, lateral wall of the nasal cavity and nasal vestibule. The clinical manifestations reported by the patients consisted of a painless mass, recurrent epistaxis and nasal obstruction. There were no specific features observed in any of the patients using computed tomography or magnetic resonance imaging. All the patients underwent tumor dissection visualized with a nasal endoscope and recovered without recurrence or malignancy of the tumor post-surgery. Hematoxylin and eosin and immunoperoxidase staining confirmed the diagnosis of angioleiomyoma in all patients. In 5 patients the nuclei of the smooth muscle tumor cells markedly expressed ER and PR. To the best of our knowledge, the present study is the first to demonstrate that ER and PR are clearly expressed in nasal angioleiomyoma. The present study suggests that the sex hormones are possibly associated with the growth of angioleiomyoma. PMID:27073480

  4. Cloning, Characterization, and Expression Profile of Estrogen Receptor in Common Chinese Cuttlefish, Sepiella japonica.

    PubMed

    Lü, Zhen-Ming; Liu, Wan; Liu, Li-Qin; Wang, Tian-Ming; Shi, Hui-Lai; Ping, Hong-Ling; Chi, Chang-Feng; Yang, Jing-Wen; Wu, Chang-Wen

    2016-03-01

    Sex steroid hormones are widely detected in molluscs and play important roles in sex determination, gonadal tissue maturation, and gametogenesis. Nevertheless, the signaling pathways of sex steroids in cephalopod have not yet been clearly elucidated. In the present study, a full-length sequence encoding the estrogen receptor (ER) was isolated from common Chinese cuttlefish, Sepiella japonica. The sjER cDNA clone was found to contain 1,788 nucleotides including a 1,470 bp open reading frame encoding 489 amino acid (aa) residues. The deduced ER protein consisted of six nuclear receptor characteristic domains. Based on a phylogenetic analysis, the ER DNA-binding domain and ligand-binding domain are highly conserved compared to other mollusc ERs. Highest aa identities were found for sjER with common octopus (Octopus vulgaris) ER (89%) and pacific oyster (Crassostrea gigas) ER (61%). Tissue expression analysis confirmed that sjER was widely distributed among tissues and predominantly expressed in the brain, liver, gonad (testis and ovary), and other accessory sexual gland (nidamental gland). The ER expression was temporally upregulated in the brain, liver, and ovary during the early sexual maturation period in S. japonica, which is coincident with the fluctuation of ovary estradiol content. These suggest that sjER may be involved in regulating the reproductive cycle of S. japonica. A fusion protein transient transfections assay showed that sjER was mainly located in the nucleus, suggesting a possible orthodox working mechanism of S. japonica ER in the nucleus through a ligand-dependent activation of specific gene transcription. PMID:27076436

  5. Regulation of Estrogen Receptor α Expression in the Hypothalamus by Sex Steroids: Implication in the Regulation of Energy Homeostasis

    PubMed Central

    Liu, Xian; Shi, Haifei

    2015-01-01

    Sex differences exist in the complex regulation of energy homeostasis that utilizes central and peripheral systems. It is widely accepted that sex steroids, especially estrogens, are important physiological and pathological components in this sex-specific regulation. Estrogens exert their biological functions via estrogen receptors (ERs). ERα, a classic nuclear receptor, contributes to metabolic regulation and sexual behavior more than other ER subtypes. Physiological and molecular studies have identified multiple ERα-rich nuclei in the hypothalamus of the central nervous system (CNS) as sites of actions that mediate effects of estrogens. Much of our understanding of ERα regulation has been obtained using transgenic models such as ERα global or nuclei-specific knockout mice. A fundamental question concerning how ERα is regulated in wild-type animals, including humans, in response to alterations in steroid hormone levels, due to experimental manipulation (i.e., castration and hormone replacement) or physiological stages (i.e., puberty, pregnancy, and menopause), lacks consistent answers. This review discusses how different sex hormones affect ERα expression in the hypothalamus. This information will contribute to the knowledge of estrogen action in the CNS, further our understanding of discrepancies in correlation of altered sex hormone levels with metabolic disturbances when comparing both sexes, and improve health issues in postmenopausal women. PMID:26491443

  6. NHE-RF, a Merlin-Interacting Protein, Is Primarily Expressed in Luminal Epithelia, Proliferative Endometrium, and Estrogen Receptor-Positive Breast Carcinomas

    PubMed Central

    Stemmer-Rachamimov, Anat O.; Wiederhold, Thorsten; Nielsen, G. Petur; James, Marianne; Pinney-Michalowski, Denise; Roy, Jennifer E.; Cohen, Wendy A.; Ramesh, Vijaya; Louis, David N.

    2001-01-01

    NHE-RF, a regulatory cofactor for NHE (Na+-H+ exchanger) type 3, interacts with ion transporters and receptors through its PDZ domains and with the MERM proteins (merlin, ezrin, radixin and moesin) via its carboxyl terminus. Thus, NHE-RF may act as a multifunctional adaptor protein and play a role in the assembly of signal transduction complexes, linking ion channels and receptors to the actin cytoskeleton. NHE-RF expression is up-regulated in response to estrogen in estrogen receptor-positive breast carcinoma cell lines, suggesting that it may be involved in estrogen signaling. To further understand NHE-RF function and its possible role in estrogen signaling, we analyzed NHE-RF expression in normal human tissues, including cycling endometrium, and in breast carcinomas, tissues in which estrogen plays an important role in regulating cell growth and proliferation. NHE-RF is expressed in many epithelia, especially in cells specialized in ion transport or absorption, and is often localized to apical (luminal) membranes. NHE-RF expression varies markedly in proliferative versus secretory endometrium, with high expression in proliferative (estrogen-stimulated) endometrium. Furthermore, estrogen receptor status and NHE-RF expression correlate closely in breast carcinoma specimens. These findings support a role for NHE-RF in estrogen signaling. PMID:11141479

  7. Estrogen receptors in the medial amygdala inhibit the expression of male prosocial behavior

    PubMed Central

    Cushing, Bruce S.; Perry, Adam; Musatov, Sergei; Ogawa, Sonoko; Papademetriou, Eros

    2008-01-01

    Studies using estrogen receptor alpha (ERα) knockout mice indicate that ERα masculinizes male behavior. Recent studies of ERα and male prosocial behavior have shown an inverse relationship between ERα expression in regions of the brain that regulate social behavior, including the medial amygdala (MeA), and the expression of male prosocial behavior. These studies have lead to the hypothesis that low levels of ERα are necessary to “permit” the expression of high levels of male prosocial behavior. To test this, viral vectors were used to enhance ERα in male prairie voles (Microtus ochrogaster), which display high levels of prosocial behavior and low levels of MeA ERα. Adult male prairie voles were transfected with ERα in the MeA or the caudate putamen (ERα control) or luciferase (MeA - site-specific control), and three weeks later tested for spontaneous alloparental behavior and partner preference. Enhancing ERα in the MeA altered/reduced male prosocial behavior. Only a third of ERα-MeA males, compared to all control males, were alloparental. ERα-MeA males also displayed a significant a preference for a novel female. This is a critical finding as the manipulations of neuropeptides, oxytocin and vasopressin, can inhibit the formation of a partner preference, but do not lead to the formation of a preference for a novel female. The results support the hypothesis that low levels of ERα are necessary for high levels of male prosocial behavior, and provide the first direct evidence that site-specific ERα expression plays a critical role in the expression of male prosocial behavior. PMID:18842899

  8. Dual effects of daidzein on chicken hepatic vitellogenin II expression and estrogen receptor-mediated transactivation in vitro.

    PubMed

    Ni, Ying-Dong; Hong, Wen-Jie; Zhou, Yu-Chuan; Grossmann, Roland; Zhao, Ru-Qian

    2010-03-01

    Two in vitro systems were employed to delineate the estrogenic activity of daidzein (Da), alone or in combination with high or low concentrations of estrogen in two cell types possessing different estrogen-receptor (ER) isoforms, ERalpha and/or ERbeta: (1) vitellogenin II (VTG), the egg yolk precursor protein and the endpoint biomarker for estrogenicity, in chicken primary hepatocytes, and (2) CHO-K1 cells transiently co-transfected with ERalpha or ERbeta and estrogen-response elements (ERE) linked to a luciferase reporter gene. Da (100 microM) alone induced VTG mRNA expression in chicken hepatocytes, albeit with much less potency compared to estradiol (E(2)). Da exhibited different effects in the presence of 1 microM and 10 microM E(2). At a concentration of 100 microM, Da enhanced 1 microM E(2)-induced VTG transcription by 2.4-fold, but significantly inhibited 10 microM E(2)-induced VTG mRNA expression in a dose-dependent fashion from 1 to 100 microM. Tamoxifen completely blocked the estrogenic effect of daidzein, alone or in combination with 1 microM of E(2), but did not influence its anti-estrogenic effect on 10 microM E(2)-induced VTG mRNA expression. Furthermore, neither E(2) nor daidzein, alone or in combination, affected ERalpha mRNA expression, yet all the treatments significantly up-regulated ERbeta mRNA expression in chicken hepatocytes. E(2) effectively triggered estrogen-response elements (ERE)-driven reporter gene transactivation in CHO-K1 cells expressing ERalpha or ERbeta and showed much greater potency with ERalpha than with ERbeta. In contrast, daidzein was 1000 times more powerful in stimulating ERbeta- over ERalpha-mediated transactivation. Daidzein, in concentrations ranging from 5 nM to 50 microM, did not affect ERbeta-mediated transactivation induced by 1 nM E(2), but it significantly inhibited ERbeta-mediated transactivation induced by 10 nM E(2) at 500 nM. Despite the tremendous difference in sensitivity between the two in vitro systems

  9. Maternal care associated with methylation of the estrogen receptor-alpha1b promoter and estrogen receptor-alpha expression in the medial preoptic area of female offspring.

    PubMed

    Champagne, Frances A; Weaver, Ian C G; Diorio, Josie; Dymov, Sergiy; Szyf, Moshe; Meaney, Michael J

    2006-06-01

    Variations in maternal behavior are associated with differences in estrogen receptor (ER)-alpha expression in the medial preoptic area (MPOA) and are transmitted across generations such that, as adults, the female offspring of mothers that exhibit increased pup licking/grooming (LG) over the first week postpartum (i.e. high LG mothers) show increased ERalpha expression in the MPOA and are themselves high LG mothers. In the present studies, cross-fostering confirmed an association between maternal care and ERalpha expression in the MPOA; the biological offspring of low LG mothers fostered at birth to high LG dams show increased ERalpha expression in the MPOA. Cross-fostering the biological offspring of high LG mothers to low LG dams produces the opposite effect. We examined whether the maternal programing of ERalpha expression is associated with differences in methylation of the relevant ERalpha promoter. Levels of cytosine methylation across the ERalpha1b promoter were significantly elevated in the adult offspring of low, compared with high, LG mothers. Differentially methylated regions included a signal transducer and activator of transcription (Stat)5 binding site and the results of chromatin immunoprecipitation assays revealed decreased Stat5b binding to the ERalpha1b promoter in the adult offspring of low, compared with high, LG mothers. Finally, we found increased Stat5b levels in the MPOA of neonates reared by high, compared with low, LG mothers. These findings suggest that maternal care is associated with cytosine methylation of the ERalpha1b promoter, providing a potential mechanism for the programming of individual differences in ERalpha expression and maternal behavior in the female offspring. PMID:16513834

  10. Arsenic Induces Functional Re-Expression of Estrogen Receptor α by Demethylation of DNA in Estrogen Receptor-Negative Human Breast Cancer

    PubMed Central

    Liu, Hongxia; Jiang, Fei; Wang, Yubang; Hu, Chunyan; Qi, Hong; Zhong, Caiyun; Wang, Xinru; Li, Zhong

    2012-01-01

    Estrogen receptor α (ERα) is a marker predictive for response of breast cancers to endocrine therapy. About 30% of breast cancers, however, are hormone- independent because of lack of ERα expression. New strategies are needed for re-expression of ERα and sensitization of ER-negative breast cancer cells to selective ER modulators. The present report shows that arsenic trioxide induces reactivated ERα, providing a target for therapy with ER antagonists. Exposure of ER-negative breast cancer cells to arsenic trioxide leads to re-expression of ERα mRNA and functional ERα protein in in vitro and in vivo. Luciferase reporter gene assays and 3-(4,5-dimethylthiazol-2-yl)- 5-(3-carboxymethoxyphenyl)- 2-(4-sulfophenyl)- 2H-tetrazolium (MTS) assays show that, upon exposure to arsenic trioxide, formerly unresponsive, ER-negative MDA-MB-231 breast cancer cells become responsive to ER antagonists, 4-hydroxytamoxifen and ICI 182,780. Furthermore, methylation- specific PCR and bisulfite-sequencing PCR assays show that arsenic trioxide induces partial demethylation of the ERα promoter. A methyl donor, S-adenosylmethionine (SAM), reduces the degree of arsenic trioxide-induced re-expression of ERα and demethylation. Moreover, Western blot and ChIP assays show that arsenic trioxide represses expression of DNMT1 and DNMT3a along with partial dissociation of DNMT1 from the ERα promoter. Thus, arsenic trioxide exhibits a previously undefined function which induces re-expression ERα in ER-negative breast cancer cells through demethylation of the ERα promoter. These findings could provide important information regarding the application of therapeutic agents targeting epigenetic changes in breast cancers and potential implication of arsenic trioxide as a new drug for the treatment of ER–negative human breast cancer. PMID:22558281

  11. The Expression of the Androgen Receptor and Estrogen Receptor 1 is Related to Sex Dimorphism in the Gerbil Prostate Development.

    PubMed

    Sanches, Bruno D A; Maldarine, Juliana S; Zani, Bruno C; Biancardi, Manoel F; Santos, Fernanda C A; Góes, Rejane M; Vilamaior, Patricia S L; Taboga, Sebastião R

    2016-08-01

    The development of the prostate gland in females has not yet been clearly elucidated, and the sexual dimorphism associated with such gland development in general is far from being understood. In the present study, we used tridimensional (3D) reconstructions and histochemical and immunohistochemical techniques to describe the sexual dimorphism and its causes in the early postnatal development of the prostate in male and female Mongolian gerbils (Meriones unguiculatus). We observed that the female prostate was smaller, had fewer branches throughout the development, and underwent differentiation earlier than that in males. Also, the expression of the estrogen receptor 1 (ESR1 or ER-alpha) and fibroblast growth factor 10 (FGF10) was decreased in the periductal region, and the expression of the androgen receptor (AR) was increased in the epithelium. All together, these changes decreased proliferation and branching and led to an earlier prematuration of the female prostate. These new data shed light on the underlying mechanisms involved with the sexual dimorphism in the development of the prostate. Anat Rec, 299:1130-1139, 2016. © 2016 Wiley Periodicals, Inc. PMID:27184581

  12. Estrogenic status modulates aryl hydrocarbon receptor - mediated hepatic gene expression and carcinogenicity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Estrogenic status is thought to influence the cancer risk in women and has been reported to affect toxicity of carcinogenic polycyclic aromatic hydrocarbons (PAHs) in animals. The objective of this study was to examine the influence of estradiol (E2) on hepatic gene expression changes mediated by 7,...

  13. MOLECULAR CLONING OF PORCINE ESTROGEN RECEPTOR-BETA COMPLEMENTARY DNAS AND DEVELOPMENTAL EXPRESSION I PERIIMPLANTATION EMBRYOS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the pig, estrogens transiently produced by embryos and progestins of maternal origin target the uterine endometrium, causing alterations in gene expression and secretory activity, both of which are important for the initiation of embryo attachment. The potential direct embryotrophic roles of estr...

  14. Obesity Suppresses Estrogen Receptor Beta Expression in Breast Cancer Cells via a HER2-Mediated Pathway.

    PubMed

    Bowers, Laura W; Wiese, Megan; Brenner, Andrew J; Rossi, Emily L; Tekmal, Rajeshwar R; Hursting, Stephen D; deGraffenried, Linda A

    2015-01-01

    Obesity is associated with a worse breast cancer prognosis, while greater breast tumor estrogen receptor beta (ERβ) expression is correlated with improved therapy response and survival. The objective of this study was to determine the impact of obesity on breast cancer cell ERβ expression, which is currently unknown. We utilized an in vitro model of obesity in which breast cancer cells were exposed to patient serum pooled by body mass index category (obese (OB): ≥30 kg/m2; normal weight (N): 18.5-24.9 kg/m2). Four human mammary tumor cell lines representing the major breast cancer subtypes (SKBR3, MCF-7, ZR75, MDA-MB-231) and mammary tumor cells from MMTV-neu mice were used. ERβ expression, assessed by qPCR and western blotting, was suppressed in the two HER2-overexpressing cell lines (SKBR3, MMTV-neu) following OB versus N sera exposure, but did not vary in the other cell lines. Expression of Bcl-2 and cyclin D1, two genes negatively regulated by ERβ, was elevated in SKBR3 cells following exposure to OB versus N sera, but this difference was eliminated when the ERβ gene was silenced with siRNA. Herceptin, a HER2 antagonist, and siRNA to HER2 were used to evaluate the role of HER2 in sera-induced ERβ modulation. SKBR3 cell treatment with OB sera plus Herceptin increased ERβ expression three-fold. Similar results were obtained when HER2 expression was silenced with siRNA. OB sera also promoted greater SKBR3 cell viability and growth, but this variance was not present when ERβ was silenced or the cells were modified to overexpress ERβ. Based on this data, we conclude that obesity-associated systemic factors suppress ERβ expression in breast cancer cells via a HER2-mediated pathway, leading to greater cell viability and growth. Elucidation of the mechanism(s) mediating this effect could provide important insights into how ERβ expression is regulated as well as how obesity promotes a more aggressive disease. PMID:26709918

  15. Estrogen Regulates Angiotensin II Receptor Expression Patterns and Protects the Heart from Ischemic Injury in Female Rats.

    PubMed

    Xue, Qin; Xiao, Daliao; Zhang, Lubo

    2015-07-01

    Previous studies have shown that female offspring are resistant to fetal stress-induced programming of ischemic-sensitive phenotype in the heart; however, the mechanisms responsible remain unclear. The present study tested the hypothesis that estrogen plays a role in protecting females in fetal programming of increased heart vulnerability. Pregnant rats were divided into normoxic and hypoxic (10.5% O2 from Day 15 to 21 of gestation) groups. Ovariectomy (OVX) and estrogen (E2) replacement were performed in 8-wk-old female offspring. Hearts of 4-mo-old females were subjected to ischemia and reperfusion injury in a Langendorff preparation. OVX significantly decreased postischemic recovery of left ventricular function and increased myocardial infarction, and no difference was observed between normoxic and hypoxic groups. The effect of OVX was rescued by E2 replacement. OVX decreased the binding of glucocorticoid receptor (GR) to glucocorticoid response elements at angiotensin II type 1 (Agtr1) and type 2 (Agtr2) receptor promoters, resulting in a decrease in Agtr1 and an increase in Agtr2 in the heart. Additionally, OVX decreased estrogen receptor (ER) expression in the heart and inhibited ER/GR interaction in binding to glucocorticoid response elements at the promoters. Consistent with the changes in Agtrs, OVX significantly decreased Prkce abundance in the heart. These OVX-induced changes were abrogated by E2 replacement. The results indicate that estrogen is not directly responsible for the sex dimorphism in fetal programming of heart ischemic vulnerability but suggest a novel mechanism of estrogen in regulating cardiac Agtr1/Agtr2 expression patterns and protecting female hearts against ischemia and reperfusion injury. PMID:25972014

  16. Estrogen Regulates Angiotensin II Receptor Expression Patterns and Protects the Heart from Ischemic Injury in Female Rats1

    PubMed Central

    Xue, Qin; Xiao, Daliao; Zhang, Lubo

    2015-01-01

    Previous studies have shown that female offspring are resistant to fetal stress-induced programming of ischemic-sensitive phenotype in the heart; however, the mechanisms responsible remain unclear. The present study tested the hypothesis that estrogen plays a role in protecting females in fetal programming of increased heart vulnerability. Pregnant rats were divided into normoxic and hypoxic (10.5% O2 from Day 15 to 21 of gestation) groups. Ovariectomy (OVX) and estrogen (E2) replacement were performed in 8-wk-old female offspring. Hearts of 4-mo-old females were subjected to ischemia and reperfusion injury in a Langendorff preparation. OVX significantly decreased postischemic recovery of left ventricular function and increased myocardial infarction, and no difference was observed between normoxic and hypoxic groups. The effect of OVX was rescued by E2 replacement. OVX decreased the binding of glucocorticoid receptor (GR) to glucocorticoid response elements at angiotensin II type 1 (Agtr1) and type 2 (Agtr2) receptor promoters, resulting in a decrease in Agtr1 and an increase in Agtr2 in the heart. Additionally, OVX decreased estrogen receptor (ER) expression in the heart and inhibited ER/GR interaction in binding to glucocorticoid response elements at the promoters. Consistent with the changes in Agtrs, OVX significantly decreased Prkce abundance in the heart. These OVX-induced changes were abrogated by E2 replacement. The results indicate that estrogen is not directly responsible for the sex dimorphism in fetal programming of heart ischemic vulnerability but suggest a novel mechanism of estrogen in regulating cardiac Agtr1/Agtr2 expression patterns and protecting female hearts against ischemia and reperfusion injury. PMID:25972014

  17. CLONING, EXPRESSION AND CHARACTERIZATION OF THE ANDROGEN RECEPTOR AND ISOLATION OF ESTROGEN RECEPTOR ALPHA FROM THE FATHEAD MINNOW (PIMEPHALES PROMELAS)

    EPA Science Inventory

    In vitro screening assays designed to identify hormone mimics or antagonists, including those recommended for use in the EPA's Tier 1 screening battery, typically use mammalian estrogen (ER) and androgen receptors (AR) such as rat or human. Although we know that the amino acid s...

  18. Gender difference in the activity but not expression of estrogen receptors α and β in human lung adenocarcinoma cells

    PubMed Central

    Dougherty, Susan M; Mazhawidza, Williard; Bohn, Aimee R; Robinson, Krista A; Mattingly, Kathleen A; Blankenship, Kristy A; Huff, Mary O; McGregor, William G; Klinge, Carolyn M

    2006-01-01

    The higher frequency of lung adenocarcinoma in women smokers than in men smokers suggests a role for gender-dependent factors in the etiology of lung cancer. We evaluated estrogen receptor (ER) α and β expression and activity in human lung adenocarcinoma cell lines and normal lung fibroblasts. Full-length ERα and ERβ proteins were expressed in all cell lines with higher ERβ than ERα. Although estradiol (E2) binding was similar, E2 stimulated proliferation only in cells from females, and this response was inhibited by anti-estrogens 4-hydroxytamoxifen (4-OHT) and ICI 182,780. In contrast, E2 did not stimulate replication of lung adenocarcinoma cells from males and 4-OHT or ICI did not block cell proliferation. Similarly, transcription of an estrogen response element-driven reporter gene was stimulated by E2 in lung adenocarcinoma cells from females, but not males. Progesterone receptor (PR) expression was increased by E2 in two out of five adenocarcinoma cell lines from females, but none from males. E2 decreased E-cadherin protein expression in some of the cell lines from females, as it did in MCF-7 breast cancer cells, but not in the cell lines from males. Thus, ERα and ERβ expression does not correlate with the effect of ER ligands on cellular activities in lung adenocarcinoma cells. On the other hand, coactivator DRIP205 expression was higher in lung adenocarcinoma cells from females versus males and higher in adenocarcinoma cells than in normal human bronchial epithelial cells. DRIP205 and other ER coregulators may contribute to differences in estrogen responsiveness between lung adenocarcinoma cells in females and males. PMID:16601283

  19. Biochanin A affects steroidogenesis and estrogen receptorexpression in porcine granulosa cells.

    PubMed

    Nynca, Anna; Swigonska, Sylwia; Piasecka, Joanna; Kolomycka, Agnieszka; Kaminska, Barbara; Radziewicz-Pigiel, Marta; Gut-Nagel, Marta; Ciereszko, Renata E

    2013-10-15

    Biochanin A, similar to other isoflavones, is present in soy and soy-based food, but predominantly in red clover. Red clover extract and biochanin A were reported to affect reproductive processes as well as to demonstrate menopause relief and anticancerogenic properties. Because porcine granulosa cells provide a suitable in vitro model for studying the intracellular mechanism of phytoestrogen action in the ovary, the objective of the study was to evaluate the in vitro effects of biochanin A on the following: (1) progesterone (P4) and estradiol (E2) secretion by granulosa cells, (2) viability of the granulosa cells, and (3) mRNA and protein expression of estrogen receptors α (ERα) and β (ERβ) in the granulosa cells harvested from both medium (3-6 mm) and large (≥8 mm) porcine ovarian follicles. RIA, alamarBlue assay, reverse transcriptase-polymerase chain reaction, and immunocytochemistry were used in the study to address the objectives. Biochanin A significantly inhibited P4 and did not affect E2 secretion by porcine granulosa cells regardless of the size of follicles that served as the source of the cells. Cell viability was not affected by the treatment. Biochanin A did not alter ERα and ERβ mRNA levels in the cultured porcine granulosa cells. In contrast, this isoflavone increased (P < 0.05) the immunoexpression of ERβ in the cells from both follicle types. In summary, biochanin A, similar to genistein and daidzein, affects follicular steroidogenesis and ER expression. Its effect on ERβ protein was more intense compared with other previously examined phytoestrogens. PMID:23953692

  20. Association of estrogen receptor-α and progesterone receptor A expression with hormonal mammary carcinogenesis: role of the host microenvironment

    PubMed Central

    Montero Girard, Guadalupe; Vanzulli, Silvia I; Cerliani, Juan Pablo; Bottino, María Cecilia; Bolado, Julieta; Vela, Jorge; Becu-Villalobos, Damasia; Benavides, Fernando; Gutkind, Silvio; Patel, Vyomesh; Molinolo, Alfredo; Lanari, Claudia

    2007-01-01

    Introduction Medroxyprogesterone acetate (MPA) induces estrogen receptor (ER)-positive and progesterone receptor (PR)-positive ductal invasive mammary carcinomas in BALB/c mice. We sought to reproduce this MPA cancer model in C57BL/6 mice because of their widespread use in genetic engineering. Within this experimental setting, we studied the carcinogenic effects of MPA, the morphologic changes in mammary glands that are induced by MPA and progesterone, and the levels of ER and PR expression in MPA-treated and progesterone-treated mammary glands. Finally, we evaluated whether the differences found between BALB/c and C57BL/6 mouse strains were due to intrinsic differences in epithelial cells. Methods The carcinogenic effect of MPA was evaluated in C57BL/6 mice using protocols proven to be carcinogenic in BALB/c mice. In addition, BALB/c and C57BL/6 females were treated with progesterone or MPA for 1 or 2 months, and mammary glands were excised for histologic studies and for immunohistochemical and Western blot evaluation of ER and PR. Hormone levels were determined by radioimmunoassay. Isolated mammary epithelial cells were transplanted into cleared fat pads of 21-day-old female Swiss nu/nu mice or control congenic animals. Results MPA failed to induce mammary carcinomas or significant morphologic changes in the mammary glands of C57BL/6 mice. The expression of ER-α and PR isoform A in virgin mice was surprisingly much higher in BALB/c than in C57BL/6 mammary glands, and both receptors were downregulated in progestin-treated BALB/c mice (P < 0.05). PR isoform B levels were low in virgin control mice and increased after progestin treatment in both strains. ER-β expression followed a similar trend. No differences in hormone levels were found between strains. Surprisingly, the transplantation of the epithelial mammary gland cells of both strains into the cleared fat pads of Swiss (nu/nu) mice abolished the mammary gland morphologic differences and the ER and PR

  1. Selective Estrogen Receptor Modulators

    PubMed Central

    2016-01-01

    Selective estrogen receptor modulators (SERMs) are now being used as a treatment for breast cancer, osteoporosis and postmenopausal symptoms, as these drugs have features that can act as an estrogen agonist and an antagonist, depending on the target tissue. After tamoxifen, raloxifene, lasofoxifene and bazedoxifene SERMs have been developed and used for treatment. The clinically decisive difference among these drugs (i.e., the key difference) is their endometrial safety. Compared to bisphosphonate drug formulations for osteoporosis, SERMs are to be used primarily in postmenopausal women of younger age and are particularly recommended if there is a family history of invasive breast cancer, as their use greatly reduces the incidence of this type of cancer in women. Among the above mentioned SERMs, raloxifene has been widely used in prevention and treatment of postmenopausal osteoporosis and vertebral compression fractures, and clinical studies are now underway to test the comparative advantages of raloxifene with those of bazedoxifene, a more recently developed SERM. Research on a number of adverse side effects of SERM agents is being performed to determine the long-term safety of this class of compouds for treatment of osteoporosis. PMID:27559463

  2. Estrogen and androgen receptor expression in surface epithelium and inclusion cyst in the ovary of premenopausal and postmenopausal women

    PubMed Central

    2013-01-01

    Background The importance of surface epithelium and epithelial inclusion cysts in the ovary arises from studies demonstrating that these structures are susceptible to epithelial ovarian cancer development. The expression of estrogen receptor alpha (ER alpha), androgen receptor (AR), in epithelial cells of the ovary from premenopausal and postmenopausal women is interesting because sexual steroid hormones are involved in cell growth and differentiation. Methods The presence of ER alpha, AR, and the orphan G protein-coupled receptor 30 (GPR30) was demonstrated by immunofluorescence in ovaries obtained from 79 pre and postmenopausal patients, undergoing histero-salpingo-oophorectomy for proliferative gynecological diseases. The proportion of patients that displayed positive reaction for estrogen and androgen receptors in epithelial cells of the ovary was evaluated according to menopausal status and associated pathology. Results The proportion of patients that displayed a positive receptor expression in the epithelial cells of the ovarian surface and cortical inclusion cysts shows that ER alpha is present in 20 of 79 patients (0.25), AR in 33 of 79 (0.42) and GPR30 in 38 of 55 (0.69). There are no differences in ER alpha, AR, and GPR30 expression between pre and postmenopausal patients and considering the associated pathology, proportions for ER alpha and GPR30 are similar. The patients with cervical cancer show a higher proportion of AR expression in epithelial cells of the ovary, which is statistically significant (P < 0.01) compared with patients with other proliferative diseases. Conclusions The presence of ER alpha, AR, and GPR30 in the surface epithelial ovarian cells and its derivatives are observed with a proportion that is specific for each receptor. The proportion of expression for these receptors in the epithelial cells of the ovary does not change after menopause. The proportion of ovaries with AR positive epithelial cells in patients with cervical

  3. The temporal expression of estrogen receptor alpha-36 and runx2 in human bone marrow derived stromal cells during osteogenesis

    SciTech Connect

    Francis, W.R.; Owens, S.E.; Wilde, C.; Pallister, I.; Kanamarlapudi, V.; Zou, W.; Xia, Z.

    2014-10-24

    Highlights: • ERα36 is the predominant ERα isoform involved in bone regulation in human BMSC. • ERα36 mRNA is significantly upregulated during the process of osteogenesis. • The pattern of ERα36 and runx2 mRNA expression is similar during osteogenesis. • ERα36 appears to be co-localised with runx2 during osteogenesis. - Abstract: During bone maintenance in vivo, estrogen signals through estrogen receptor (ER)-α. The objectives of this study were to investigate the temporal expression of ERα36 and ascertain its functional relevance during osteogenesis in human bone marrow derived stromal cells (BMSC). This was assessed in relation to runt-related transcription factor-2 (runx2), a main modulatory protein involved in bone formation. ERα36 and runx2 subcellular localisation was assessed using immunocytochemistry, and their mRNA expression levels by real time PCR throughout the process of osteogenesis. The osteogenically induced BMSCs demonstrated a rise in ERα36 mRNA during proliferation followed by a decline in expression at day 10, which represents a change in dynamics within the culture between the proliferative stage and the differentiative stage. The mRNA expression profile of runx2 mirrored that of ERα36 and showed a degree subcellular co-localisation with ERα36. This study suggests that ERα36 is involved in the process of osteogenesis in BMSCs, which has implications in estrogen deficient environments.

  4. Aptamer-Assisted Detection of the Altered Expression of Estrogen Receptor Alpha in Human Breast Cancer

    PubMed Central

    Ahirwar, Rajesh; Vellarikkal, Shamsudheen Karuthedath; Sett, Arghya; Sivasubbu, Sridhar; Scaria, Vinod; Bora, Utpal; Borthakur, Bibhuti Bhusan; Kataki, Amal Chandra; Sharma, Jagannath Dev; Nahar, Pradip

    2016-01-01

    An increase in the expression of estrogen receptors (ER) and the expanded population of ER-positive cells are two common phenotypes of breast cancer. Detection of the aberrantly expressed ERα in breast cancer is carried out using ERα-antibodies and radiolabelled ligands to make decisions about cancer treatment and targeted therapy. Capitalizing on the beneficial advantages of aptamer over the conventional antibody or radiolabelled ligand, we have identified a DNA aptamer that selectively binds and facilitates the detection of ERα in human breast cancer tissue sections. The aptamer is identified using the high throughput sequencing assisted SELEX screening. Biophysical characterization confirms the binding and formation of a thermodynamically stable complex between the identified DNA aptamer (ERaptD4) and ERα (Ka = 1.55±0.298×108 M-1; ΔH = 4.32×104±801.1 cal/mol; ΔS = -108 cal/mol/deg). Interestingly, the specificity measurements suggest that the ERaptD4 internalizes into ERα-positive breast cancer cells in a target-selective manner and localizes specifically in the nuclear region. To harness these characteristics of ERaptD4 for detection of ERα expression in breast cancer samples, we performed the aptamer-assisted histochemical analysis of ERα in tissue samples from breast cancer patients. The results were validated by performing the immunohistochemistry on same samples with an ERα-antibody. We found that the two methods agree strongly in assay output (kappa value = 0.930, p-value <0.05 for strong ERα positive and the ERα negative samples; kappa value = 0.823, p-value <0.05 for the weak/moderate ER+ve samples, n = 20). Further, the aptamer stain the ERα-positive cells in breast tissues without cross-reacting to ERα-deficient fibroblasts, adipocytes, or the inflammatory cells. Our results demonstrate a significant consistency in the aptamer-assisted detection of ERα in strong ERα positive, moderate ERα positive and ERα negative breast cancer

  5. Uterine gland development begins postnatally and is accompanied by estrogen and progesterone receptor expression in the dog.

    PubMed

    Cooke, P S; Borsdorf, D C; Ekman, G C; Doty, K F; Clark, S G; Dziuk, P J; Bartol, F F

    2012-11-01

    During neonatal and juvenile life, mammalian uteri undergo extensive structural and functional changes, including uterine gland differentiation and development. In sheep and mice, inhibition of neonatal uterine gland development induced by progestin treatment led to a permanent aglandular uterine phenotype and adult infertility, suggesting that this strategy might be useful for sterilizing dogs and other companion animals. The goal of this study was to define temporal patterns of adenogenesis (gland development), cell proliferation, and progesterone and estrogen receptor expression in uteri of neonatal and juvenile dogs as a first step toward determining whether neonatal progestin treatments might be a feasible contraceptive approach in this species. Uteri obtained from puppies at postnatal wk 1, 2, 4, 6, or 8 were evaluated histologically and immunostained for MKI67, a marker of cell proliferation, estrogen receptor-1, and progesterone receptor. Adenogenesis was under way at 1 wk of age, as indicated by the presence of nascent glands beginning to bud from the luminal epithelium, and rapid proliferation of both luminal epithelial and stromal cells. By Week 2, glands were clearly identifiable and proliferation of luminal, glandular, and stromal cells was pronounced. At Week 4, increased numbers of endometrial glands were evident penetrating uterine stroma, even as proliferative activity decreased in all cell compartments as compared with Week 2. Whereas gland development was most advanced at Weeks 6 to 8, luminal, glandular, and stromal proliferation was minimal, indicating that the uterus was nearly mitotically quiescent at this age. Both estrogen receptor-1 and progesterone receptor were expressed consistently in uterine stromal and epithelial cells at all ages examined. In summary, canine uterine adenogenesis was underway by 1 wk of age and prepubertal glandular proliferation was essentially complete by Week 6. These results provided information necessary to

  6. Differential expression of estrogen receptor alpha (ERalpha) protein in MCF-7 breast cancer cells chronically exposed to TCDD.

    PubMed

    Marquez-Bravo, Lydia G; Gierthy, John F

    2008-02-01

    Estrogens play a key role in the development and evolution of breast cancer tumors. Estrogen receptor alpha (ERalpha) mediates many of the biological activities of estrogens, and its expression is associated with low invasiveness and good prognosis. Recent epidemiological reports suggest that long-term exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is implicated in the increased incidence of breast cancer in exposed women. TCDD interferes with the expression of some ERalpha-dependent genes and inhibits estradiol (E2)- dependent growth of breast cancer cells in vitro. However, E2-dependent xenographs of MCF-7 human breast cancer cells resumed growth after a 2-week exposure to TCDD. The mechanisms involved in the resumption of cell growth are not completely understood. In this study, we show that short term-exposure (16 days) to 1 nM TCDD results in the suppression of ERalpha protein expression, while chronic exposure for more than 1 year (LTDX cells) results in the partial re-expression of the receptor. Immunocytochemistry studies showed that re-expression of ERalpha in LTDX cells occurred in some of the cells. Analysis by Western immunoblots indicated that four out of five LTDX clones expressed ERalpha at levels comparable to those in unexposed MCF-7 cells. Removal of TCDD treatment for 16 days restored the expression of ERalpha in the ERalpha-negative clonal cells. These results suggest that MCF-7 cells chronically exposed to TCDD contain at least two cell subpopulations that may respond differently to the ERalpha-mediated effects of TCDD. PMID:17960587

  7. The Effects of Phytoestrogen Genistein on Steroidogenesis and Estrogen Receptor Expression in Porcine Granulosa Cells of Large Follicles.

    PubMed

    Nynca, Anna; Sadowska, Agnieszka; Orlowska, Karina; Jablonska, Monika; Ciereszko, Renata E

    2015-01-01

    Genistein is a biologically active isoflavone with estrogenic or antiestrogenic activity which can be found in a variety of soy products. Since in pigs' diet soy is the main source of protein, genistein may affect the reproductive/endocrine systems in these animals. Genistein has been shown to alter porcine ovarian and adrenal steroidogenesis but the mechanism of this action is still not clear. It is known that genistein binds to both estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ), although it has a higher affinity to ERβ. Moreover, this phytoestrogen was demonstrated to posses the activity of protein tyrosine kinase (PTK) inhibitor. The aim of the study was to examine the in vitro effects of genistein on: (1) progesterone (P4) and estradiol (E2) secretion by porcine luteinized granulosa cells harvested from large follicles, and (2) the mRNA and protein expression of ERa and ERβ in these cells. In addition, to verify the role of PTK-dependent mechanisms possibly involved in genistein biological action, we tested the effects of lavendustin C, the nonsteroidal PTK inhibitor, on granulosa cell steroidogenesis. Genistein significantly inhibited P4 and did not affect E2 secretion by porcine luteinized granulosa cells isolated from large follicles. Lavendustin C did not affect basal steroids secretion by examined cells. Genistein did not alter ERa but increased ERβ mRNA levels in the cultured porcine granulosa cells. In contrast to medium follicles, the expression of ERβ protein was unaffected by genistein in granulosa cells of large follicles. To conclude, the soy phytoestrogen genistein acts directly on the porcine ovary to decrease progesterone production and to increase the expression of ERβ mRNA. Moreover, genistein-induced changes in follicular steroidogenesis and granulosal sensitivity to estrogens in pigs may depend on maturity of the follicles. PMID:26255463

  8. Effect of Monochromatic Light on Expression of Estrogen Receptor (ER) and Progesterone Receptor (PR) in Ovarian Follicles of Chicken.

    PubMed

    Liu, Lingbin; Li, Diyan; Gilbert, Elizabeth R; Xiao, Qihai; Zhao, Xiaoling; Wang, Yan; Yin, Huadong; Zhu, Qing

    2015-01-01

    Artificial illumination is widely used in modern poultry houses and different wavelengths of light affect poultry production and behaviour. In this study, we measure mRNA and protein abundance of estrogen receptors (ERs) and progesterone receptors (PRs) in order to investigate the effect of monochromatic light on egg production traits and gonadal hormone function in chicken ovarian follicles. Five hundred and fifty-two 19-wk-old laying hens were exposed to three monochromatic lights: red (RL; 660 nm), green (GL; 560 nm), blue (BL; 480 nm) and control cool white (400-760 nm) light with an LED (light-emitting diode). There were 4 identical light-controlled rooms (n = 138) each containing 3 replicate pens (46 birds per pen). Water was supplied ad libitum and daily rations were determined according to the nutrient suggestions for poultry. Results showed that under BL conditions there was an increase in the total number of eggs at 300 days of age and egg-laying rate during the peak laying period. The BL and GL extended the duration of the peak laying period. Plasma melatonin was lowest in birds reared under BL. Plasma estradiol was elevated in the GL-exposed laying hens, and GL and BL increased progesterone at 28 wk of age. In the granulosa layers of the fifth largest preovulatory follicle (F5), the third largest preovulatory follicle (F3) and the largest preovulatory follicle (F1), ERα mRNA was increased by BL and GL. Treatment with BL increased ERβ mRNA in granulosa layers of F5, F3 and F1, while GL increased ERβ mRNA in F5 and F3. There was a corresponding increase in abundance of the proteins in the granulosa layers of F5, with an increase in PR-B, generated via an alternative splice site, relative to PR-A. Treatment with BL also increased expression of PR mRNA in all of the granulosa layers of follicles, while treatment with GL increased expression of PR mRNA in granulosa layers of SYF(small yellow follicle), F5 and F1. These results indicate that blue and green

  9. Effect of Monochromatic Light on Expression of Estrogen Receptor (ER) and Progesterone Receptor (PR) in Ovarian Follicles of Chicken

    PubMed Central

    Gilbert, Elizabeth R.; Xiao, Qihai; Zhao, Xiaoling; Wang, Yan; Yin, Huadong; Zhu, Qing

    2015-01-01

    Artificial illumination is widely used in modern poultry houses and different wavelengths of light affect poultry production and behaviour. In this study, we measure mRNA and protein abundance of estrogen receptors (ERs) and progesterone receptors (PRs) in order to investigate the effect of monochromatic light on egg production traits and gonadal hormone function in chicken ovarian follicles. Five hundred and fifty-two 19-wk-old laying hens were exposed to three monochromatic lights: red (RL; 660 nm), green (GL; 560 nm), blue (BL; 480 nm) and control cool white (400–760 nm) light with an LED (light-emitting diode). There were 4 identical light-controlled rooms (n = 138) each containing 3 replicate pens (46 birds per pen). Water was supplied ad libitum and daily rations were determined according to the nutrient suggestions for poultry. Results showed that under BL conditions there was an increase in the total number of eggs at 300 days of age and egg-laying rate during the peak laying period. The BL and GL extended the duration of the peak laying period. Plasma melatonin was lowest in birds reared under BL. Plasma estradiol was elevated in the GL-exposed laying hens, and GL and BL increased progesterone at 28 wk of age. In the granulosa layers of the fifth largest preovulatory follicle (F5), the third largest preovulatory follicle (F3) and the largest preovulatory follicle (F1), ERα mRNA was increased by BL and GL. Treatment with BL increased ERβ mRNA in granulosa layers of F5, F3 and F1, while GL increased ERβ mRNA in F5 and F3. There was a corresponding increase in abundance of the proteins in the granulosa layers of F5, with an increase in PR-B, generated via an alternative splice site, relative to PR-A. Treatment with BL also increased expression of PR mRNA in all of the granulosa layers of follicles, while treatment with GL increased expression of PR mRNA in granulosa layers of SYF(small yellow follicle), F5 and F1. These results indicate that blue and

  10. The 5p12 breast cancer susceptibility locus affects MRPS30 expression in estrogen-receptor positive tumors

    PubMed Central

    Quigley, David A.; Fiorito, Elisa; Nord, Silje; Van Loo, Peter; Alnæs, Grethe Grenaker; Fleischer, Thomas; Tost, Jorg; Vollan, Hans Kristian Moen; Tramm, Trine; Overgaard, Jens; Bukholm, Ida R; Hurtado, Antoni; Balmain, Allan; Børresen-Dale, Anne-Lise; Kristensen, Vessela

    2014-01-01

    Genome-wide association studies have identified numerous loci linked to breast cancer susceptibility, but the mechanism by which variations at these loci influence susceptibility is usually unknown. Some variants are only associated with particular clinical subtypes of breast cancer. Understanding how and why these variants influence subtype-specific cancer risk contributes to our understanding of cancer etiology. We conducted a genome-wide expression Quantitative Trait Locus (eQTL) study in a discovery set of 287 breast tumors and 97 normal mammary tissue samples and a replication set of 235 breast tumors. We found that the risk-associated allele of rs7716600 in the 5p12 estrogen receptor-positive (ER-positive) susceptibility locus was associated with elevated expression of the nearby gene MRPS30 exclusively in ER-positive tumors. We replicated this finding in 235 independent tumors. Further, we showed the rs7716600 risk genotype was associated with decreased MRPS30 promoter methylation exclusively in ER-positive breast tumors. In vitro studies in MCF-7 cells carrying the protective genotype showed that estrogen stimulation decreased MRPS30 promoter chromatin availability and mRNA levels. In contrast, in 600MPE cells carrying the risk genotype, estrogen increased MRPS30 expression and did not affect promoter availability. Our data suggest the 5p12 risk allele affects MRPS30 expression in estrogen-responsive tumor cells after tumor initiation by a mechanism affecting chromatin availability. These studies emphasize that the genetic architecture of breast cancer is context-specific, and integrated analysis of gene expression and chromatin remodeling in normal and tumor tissues will be required to explain the mechanisms of risk alleles. PMID:24388359

  11. Expression levels of estrogen receptor α mRNA in peripheral blood cells are an independent biomarker for postmenopausal osteoporosis☆

    PubMed Central

    Chou, Chi-Wen; Chiang, Tsay-I; Chang, I-Chang; Huang, Chung-Hung; Cheng, Ya-Wen

    2016-01-01

    Background The up- and down-regulation of the osteoclastogenesis response depends on the estrogen/estrogen receptor (ER) signaling pathway. Previous reports have shown that the promoter hypermethylation and gene polymorphism of ERα are risks for menopausal osteoporosis. No previous study has evaluated the expression levels of ERα mRNA in menopausal osteoporosis using human subjects. We hypothesized that ERα mRNA expression may show less resistance to postmenopausal osteoporosis. Methods In this study, we enrolled 107 women older than 45 years without menstruation and classified them into control, osteopenia, and osteoporosis groups depending on their T-scores. The ERα mRNA levels in peripheral blood cells (PBCs) were analyzed via quantitative real-time reverse-transcription polymerase chain reaction (QRT-PCR), and estrogen in the serum was detected via ELISA. Results ERα mRNA levels in PBCs had a negative correlation with age and a positive correlation with estrogen and BAP in the osteopenia and osteoporosis groups, but not in the control group. Additionally, multivariate analysis showed that older age (> 55 years), and low ERα mRNA levels in PBLs (≦ 250.39 copies/μg DNA) were associated with an approximately 9.188-, and 31.25-fold risk of osteoporosis. Conclusion We conclude that ERα mRNA levels in PBLs could be used as an independent risk factor for postmenopausal osteoporosis. General significance Our findings suggested that ERα mRNA levels in PBLs may be more important than age and serum estrogen levels. PMID:27051599

  12. Expression of the chicken progesterone receptor forms A and B is differentially regulated by estrogen in vivo.

    PubMed

    Syvälä, H; Vienonen, A; Ylikomi, T; Bläuer, M; Zhuang, Y H; Tuohimaa, P

    1997-02-24

    The chicken progesterone receptor (cPR), like its human counterpart (hPR), exists as two isoforms, PR-A and PR-B, displaying different biological activities depending upon cellular and promoter contexts. Here we show that the ratio of PR isoforms observed in the immature chicken oviduct is changed during estrogen-induced differentiation from PR-B dominancy to that of PR-A. This is the first report describing that the expression ratio of PR isoforms is altered by upregulation of PR-A by estrogen action in vivo. This result provides a plausible explanation to the differences in oviduct's response to progesterone depending on hormonal and developmental status of the animal. PMID:9070848

  13. Molecular Characterization and Sex-Specific Tissue Expression of Estrogen Receptor Alpha (esr1), Estrogen Receptor Beta-a (esr2a) and Ovarian Aromatase (cyp19a1a) in Yellow Perch (Perca flavescens)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yellow perch (Perca flavescens) exhibit an estrogen-stimulated sexual size dimorphism (SSD) wherein females grow faster and larger than males. To aid in the examination of this phenomenon, the cDNA sequences encoding estrogen receptor-alpha (esr1), estrogen receptor-beta-a (esr2a) and ovarian aroma...

  14. Estrogen Receptor Expression Is Associated with DNA Repair Capacity in Breast Cancer

    PubMed Central

    Matta, Jaime; Morales, Luisa; Ortiz, Carmen; Adams, Damian; Vargas, Wanda; Casbas, Patricia; Dutil, Julie; Echenique, Miguel; Suárez, Erick

    2016-01-01

    Estrogen-receptor-positive (ER+) tumors employ complex signaling that engages in crosstalk with multiple pathways through genomic and non-genomic regulation. A greater understanding of these pathways is important for developing improved biomarkers that can better determine treatment choices, risk of recurrence and cancer progression. Deficiencies in DNA repair capacity (DRC) is a hallmark of breast cancer (BC); therefore, in this work we tested whether ER signaling influences DRC. We analyzed the association between ER positivity (% receptor activation) and DRC in 270 BC patients, then further stratified our analysis by HER2 receptor status. Our results show that among HER2 negative, the likelihood of having low DRC values among ER- women is 1.92 (95% CI: 1.03, 3.57) times the likelihood of having low DRC values among ER+ women, even adjusting for different potential confounders (p<0.05); however, a contrary pattern was observed among HER2 positives women. In conclusion, there is an association between DRC levels and ER status, and this association is modified by HER2 receptor status. Adding a DNA repair capacity test to hormone receptor testing may provide new information on defective DNA repair phenotypes, which could better stratify BC patients who have ER+ tumors. ER+/HER2- tumors are heterogeneous, incompletely defined, and clinically challenging to treat; the addition of a DRC test could better characterize and classify these patients as well as help clinicians select optimal therapies, which could improve outcomes and reduce recurrences. PMID:27032101

  15. G Protein-Coupled Receptor 30 Expression Is Required for Estrogen Stimulation of Primordial Follicle Formation in the Hamster Ovary

    PubMed Central

    Wang, Cheng; Prossnitz, Eric R.; Roy, Shyamal K.

    2008-01-01

    Estradiol-17β (E2) plays an important role in the formation and development of primordial follicles, but the mechanisms remain unclear. G protein-coupled receptor 30 (GPR30) can mediate a rapid and transcription-independent E2 signaling in various cells. The objectives of this study were to examine whether GPR30 was expressed in the neonatal hamster ovary and whether it could mediate estrogen action during the formation of primordial follicles. GPR30 mRNA levels decreased from the 13th day of gestation (E13) through the second day of postnatal (P2) life, followed by steady increases from P3 through P6. Consistent with the changes in mRNA levels, GPR30 protein expression decreased from E13 to P2 followed by a significant increase by P7, the day before the first appearance of primordial follicles in the hamster ovary. GPR30 was expressed both in the oocytes and somatic cells, although the expression in the oocytes was low. GPR30 protein was located primarily in the perinuclear endoplasmic reticulum, which was also the site of E2-BSA-FITC (E2-BSA-fluorescein isothiocyanate) binding. E2 or E2-BSA increased intracellular calcium in neonatal hamster ovary cells in vitro. Exposure to GPR30 small interfering RNA in vitro significantly reduced GPR30 mRNA and protein levels in cultured hamster ovaries, attenuated E-BSA binding to cultured P6 ovarian cells, and markedly suppressed estrogen-stimulated primordial follicle formation. These results suggest that a membrane estrogen receptor, GPR30, is expressed in the ovary during perinatal development and mediates E2 action on primordial follicle formation. PMID:18499747

  16. Molecular cloning, expression, and stress response of the estrogen-related receptor gene (AccERR) from Apis cerana cerana

    NASA Astrophysics Data System (ADS)

    Zhang, Weixing; Zhu, Ming; Zhang, Ge; Liu, Feng; Wang, Hongfang; Guo, Xingqi; Xu, Baohua

    2016-04-01

    Estrogen-related receptor (ERR), which belongs to the nuclear receptor superfamily, has been implicated in diverse physiological processes involving the estrogen signaling pathway. However, little information is available on ERR in Apis cerana cerana. In this report, we isolated the ERR gene and investigated its involvement in antioxidant defense. Quantitative real-time polymerase chain reaction (qPCR) revealed that the highest mRNA expression occurred in eggs during different developmental stages. The expression levels of AccERR were highest in the muscle, followed by the rectum. The predicted transcription factor binding sites in the promoter of AccERR suggested that AccERR potentially functions in early development and in environmental stress responses. The expression of AccERR was induced by cold (4 °C), heat (42 °C), ultraviolet light (UV), HgCl2, and various types of pesticides (phoxim, deltamethrin, triadimefon, and cyhalothrin). Western blot was used to measure the expression levels of AccERR protein. These data suggested that AccERR might play a vital role in abiotic stress responses.

  17. Molecular cloning, expression, and stress response of the estrogen-related receptor gene (AccERR) from Apis cerana cerana.

    PubMed

    Zhang, Weixing; Zhu, Ming; Zhang, Ge; Liu, Feng; Wang, Hongfang; Guo, Xingqi; Xu, Baohua

    2016-04-01

    Estrogen-related receptor (ERR), which belongs to the nuclear receptor superfamily, has been implicated in diverse physiological processes involving the estrogen signaling pathway. However, little information is available on ERR in Apis cerana cerana. In this report, we isolated the ERR gene and investigated its involvement in antioxidant defense. Quantitative real-time polymerase chain reaction (qPCR) revealed that the highest mRNA expression occurred in eggs during different developmental stages. The expression levels of AccERR were highest in the muscle, followed by the rectum. The predicted transcription factor binding sites in the promoter of AccERR suggested that AccERR potentially functions in early development and in environmental stress responses. The expression of AccERR was induced by cold (4 °C), heat (42 °C), ultraviolet light (UV), HgCl2, and various types of pesticides (phoxim, deltamethrin, triadimefon, and cyhalothrin). Western blot was used to measure the expression levels of AccERR protein. These data suggested that AccERR might play a vital role in abiotic stress responses. PMID:26922780

  18. Calmodulin enhances the stability of the estrogen receptor.

    PubMed

    Li, Z; Joyal, J L; Sacks, D B

    2001-05-18

    The estrogen receptor mediates breast cell proliferation and is the principal target for chemotherapy of breast carcinoma. Previous studies have demonstrated that the estrogen receptor binds to calmodulin-Sepharose in vitro. However, the association of endogenous calmodulin with endogenous estrogen receptors in intact cells has not been reported, and the function of the interaction is obscure. Here we demonstrate by co-immunoprecipitation from MCF-7 human breast epithelial cells that endogenous estrogen receptors bind to endogenous calmodulin. Estradiol treatment of the cells had no significant effect on the interaction. However, incubation of the cells with tamoxifen enhanced by 5-10-fold the association of calmodulin with the estrogen receptor and increased the total cellular content of estrogen receptors by 1.5-2-fold. In contrast, the structurally distinct calmodulin antagonists trifluoperazine and CGS9343B attenuated the interaction between calmodulin and the estrogen receptor and dramatically reduced the number of estrogen receptors in the cell. Neither of these agents altered the amount of estrogen receptor mRNA, suggesting that calmodulin stabilizes the protein. This hypothesis is supported by the observation that, in the presence of Ca2+, calmodulin protected estrogen receptors from in vitro proteolysis by trypsin. Furthermore, overexpression of wild type calmodulin, but not a mutant calmodulin incapable of binding Ca2+, increased the concentration of estrogen receptors in MCF-7 cells, whereas transient expression of a calmodulin inhibitor peptide reduced the estrogen receptor concentration. These data demonstrate that calmodulin binds to the estrogen receptor in intact cells in a Ca2+-dependent, but estradiol-independent, manner, thereby modulating the stability and the steady state level of estrogen receptors. PMID:11278648

  19. Estrogen-related receptor {alpha} is essential for the expression of antioxidant protection genes and mitochondrial function

    SciTech Connect

    Rangwala, Shamina M. . E-mail: shamina.rangwala@novartis.com; Li, Xiaoyan; Lindsley, Loren; Wang, Xiaomei; Shaughnessy, Stacey; Daniels, Thomas G.; Szustakowski, Joseph; Nirmala, N.R.; Wu, Zhidan; Stevenson, Susan C.

    2007-05-25

    Estrogen-related receptor {alpha} (ERR{alpha}) is an important mediator of mitochondrial biogenesis and function. To investigate the transcriptional network controlling these phenomena, we investigated mitochondrial gene expression in embryonic fibroblasts isolated from ERR{alpha} null mice. Peroxisome proliferator-activated receptor {gamma} coactivator-1{alpha} (PGC-1{alpha}) stimulated mitochondrial gene expression program in control cells, but not in the ERR{alpha} null cells. Interestingly, the induction of levels of mitochondrial oxidative stress protection genes in response to increased PGC-1{alpha} levels was dependent on ERR{alpha}. Furthermore, we found that the PGC-1{alpha}-mediated induction of estrogen-related receptor {gamma} and nuclear respiratory factor 2 (NRF-2), was dependent on the presence of ERR{alpha}. Basal levels of NRF-2 were decreased in the absence of ERR{alpha}. The absence of ERR{alpha} resulted in a decrease in citrate synthase enzyme activity in response to PGC-1{alpha} overexpression. Our results indicate an essential role for ERR{alpha} as a key regulator of oxidative metabolism.

  20. Identification of an estrogenic hormone receptor in Caenorhabditis elegans

    SciTech Connect

    Mimoto, Ai; Fujii, Madoka; Usami, Makoto; Shimamura, Maki; Hirabayashi, Naoko; Kaneko, Takako; Sasagawa, Noboru; Ishiura, Shoichi

    2007-12-28

    Changes in both behavior and gene expression occur in Caenorhabditis elegans following exposure to sex hormones such as estrogen and progesterone, and to bisphenol A (BPA), an estrogenic endocrine-disrupting compound. However, only one steroid hormone receptor has been identified. Of the 284 known nuclear hormone receptors (NHRs) in C. elegans, we selected nhr-14, nhr-69, and nhr-121 for analysis as potential estrogenic hormone receptors, because they share sequence similarity with the human estrogen receptor. First, the genes were cloned and expressed in Escherichia coli, and then the affinity of each protein for estrogen was determined using a surface plasmon resonance (SPR) biosensor. All three NHRs bound estrogen in a dose-dependent fashion. To evaluate the specificity of the binding, we performed a solution competition assay using an SPR biosensor. According to our results, only NHR-14 was able to interact with estrogen. Therefore, we next examined whether nhr-14 regulates estrogen signaling in vivo. To investigate whether these interactions actually control the response of C. elegans to hormones, we investigated the expression of vitellogenin, an estrogen responsive gene, in an nhr-14 mutant. Semi-quantitative RT-PCR showed that vitellogenin expression was significantly reduced in the mutant. This suggests that NHR-14 is a C. elegans estrogenic hormone receptor and that it controls gene expression in response to estrogen.

  1. MNU-induced rat mammary carcinomas: immunohistology and estrogen receptor expression.

    PubMed

    Soares-Maia, R; Faustino-Rocha, A; Teixeira-Guedes, C; Pinho-Oliveira, J; Talhada, D; Rema, A; Faria, F; Ginja, M; Ferreira, R; da Costa, R; Oliveira, Paula A; Lopes, C

    2013-01-01

    Environmental exposure to nitrosamines is associated with the development of cancer in a variety of target organs. One such carcinogen, N-methyl-N-nitrosurea (MNU), has long been used to induce mammary tumors in rats, which provide a useful model to study mammary carcinogenesis. However, some poorly clarified issues remain, such as the lack of a clear description of morphological patterns of tumors and the distribution and role of estrogen receptors (ERs) during tumor progression, as tumors overexpressing ERs show a paradoxical tendency to recur after ovariectomy. Mammary carcinomas were induced in Sprague-Dawley rats using MNU. The tumors were studied histologically and distribution of smooth muscle actin and ERs was studied immunohistochemically. All tumors presented both an epithelial and a myoepithelial component, demonstrated by immunohistochemical detection of smooth muscle actin. Tumors showed distinct histological patterns: well-differentiated papillary and adenoid areas and poorly differentiated solid and spindle-cell foci. Overexpression of ERs (>75% of labelled cells vs. 0-75% in control tissue) occurred in papillary and adenoid areas but not in solid and spindle-cell foci. Poorly differentiated tumor foci are likely to represent a more advanced, estrogen-independent phase in cancer progression and constitute the basis for tumor recurrence after ovariectomy. PMID:24099429

  2. Ability of structurally diverse natural products and synthetic chemicals to induce gene expression mediated by estrogen receptors from various species.

    PubMed

    Matthews, J B; Fertuck, K C; Celius, T; Huang, Y-W; Fong, C J; Zacharewski, T R

    2002-10-01

    The ability of 14 structurally diverse estrogenic compounds to induce reporter gene expression mediated by estrogen receptors (ERs) from different species was examined. MCF-7 cells were transiently transfected with a Gal4-regulated luciferase reporter gene (17m5-G-Luc) and Gal4-ER chimeric receptors containing the D, E and F domains of the human alpha (Gal4-hERalphadef), mouse alpha (Gal4-mERalphadef), mouse beta (Gal4-mERbetadef), chicken (Gal4-cERalphadef), green anole (Gal4-aERalphadef), Xenopus (Gal4-xERdef) or rainbow trout alpha ERs (Gal4-rtERalphadef). The efficacy of 17beta-estradiol (E2) in inducing reporter gene expression was similar among the different constructs overall, with EC(50) values ranging from 0.05 to 0.7nM. However, Gal4-rtERalphadef had an EC(50) value at 37 degrees C of 28nM, though at 20 degrees C an EC(50) value of 1nM was observed. Despite a similar response to E2 treatment among the ERs, many differences were observed in the magnitude of the response to other structurally diverse chemicals. For example, coumestrol induced Gal4-mERbetadef- and Gal4-aERdef-mediated reporter gene expression 164- and 8-fold greater, respectively, than mediated with the other Gal4-ERs. As well, in contrast to results with other Gal4-ERs, alpha-zearalenol consistently induced Gal4-rtERalphadef-mediated reporter gene activity at lower concentrations than did E2. Overall, the results demonstrate that selected estrogenic compounds exhibit a differential ability to induce reporter gene activity mediated by ERs from different vertebrate species. These data also highlight the importance of incubation temperature when examining rtERalpha-mediated activity. PMID:12477484

  3. Prognostic relevance of estrogen receptor α, β and aromatase expression in non-small cell lung cancer.

    PubMed

    Skjefstad, Kaja; Grindstad, Thea; Khanehkenari, Mehrdad Rakaee; Richardsen, Elin; Donnem, Tom; Kilvaer, Thomas; Andersen, Sigve; Bremnes, Roy M; Busund, Lill-Tove; Al-Saad, Samer

    2016-09-01

    Sex steroids and their receptors are important in the fetal development of normal lung tissue. In addition emerging evidence reveals their significance in lung cancer pathogenesis. This encourages the exploitation of hormone receptors as treatment targets in lung cancer, as it has been successfully used in breast cancer. This study investigates the prognostic impact of estrogen receptor (ER) α and β and the aromatase (AR) enzyme in non-small cell lung cancer (NSCLC) patients. Tumor tissue from 335 NSCLC patients was collected and tissue microarrays (TMAs) were constructed. Immunohistochemical analyses were performed to evaluate the expression of ERα, ERβ and AR in the cytoplasme and nuclei of cells in the tumor epithelial and stromal compartment. By use of survival statistics we investigated the markers impact on disease-specific survival (DSS). Nuclear ERβ expression in tumor epithelial cells in female patients (HR 3.03; 95% CI 1.39-6.61) and tumor cell AR expression in all patients (HR 1.55; 95% CI 1.08-2.23) were significant negative prognostic markers of disease-specific survival in our cohort. High ERβ expression correlates with worse outcome in female patients. Further, patients with high AR expression had an unfavorable prognostic outcome compared with patients expressing low AR levels. These results emphasize the importance of sex steroids role in NSCLC, and, as anti-hormonal drugs are widely available, could lead to the development of novel palliative or even adjuvant treatment strategies in this patient population. PMID:27234503

  4. Cloning, in Vitro expression, and novel phylogenetic classification of a channel catfish estrogen receptor

    USGS Publications Warehouse

    Xia, Z.; Patino, R.; Gale, W.L.; Maule, A.G.; Densmore, L.D.

    1999-01-01

    We obtained two channel catfish estrogen receptor (ccER) cDNA from liver of female fish using RT–PCR. The two fragments were identical in sequence except that the smaller one had an out-of-frame deletion in the E domain, suggesting the existence of ccER splice variants. The larger fragment was used to screen a cDNA library from liver of a prepubescent female. A cDNA was obtained that encoded a 581-amino-acid ER with a deduced molecular weight of 63.8 kDa. Extracts of COS-7 cells transfected with ccER cDNA bound estrogen with high affinity (Kd = 4.7 nM) and specificity. Maximum parsimony and Neighbor Joining analyses were used to generate a phylogenetic classification of ccER on the basis of 18 full-length ER sequences. The tree suggested the existence of two major ER branches. One branch contained two clearly divergent clades which included all piscine ER (except Japanese eel ER) and all tetrapod ERα, respectively. The second major branch contained the eel ER and the mammalian ERβ. The high degree of divergence between the eel ER and mammalian ERβ suggested that they also represent distinct piscine and tetrapod ER. These data suggest that ERα and ERβ are present throughout vertebrates and that these two major ER types evolved by duplication of an ancestral ER gene. Sequence alignments with other members of the nuclear hormone receptor superfamily indicated the presence of 8 amino acids in the E domain that align exclusively among ER. Four of these amino acids have not received prior research attention and their function is unknown. The novel finding of putative ER splice variants in a nonmammalian vertebrate and the novel phylogenetic classification of ER offer new perspectives in understanding the diversification and function of ER.

  5. Selective Estrogen Receptor Modulators and Pharmacogenomic Variation in ZNF423 Regulation of BRCA1 Expression: Individualized Breast Cancer Prevention

    PubMed Central

    Ingle, James N.; Liu, Mohan; Wickerham, D. Lawrence; Schaid, Daniel J.; Wang, Liewei; Mushiroda, Taisei; Kubo, Michiaki; Costantino, Joseph P.; Vogel, Victor G.; Paik, Soonmyung; Goetz, Matthew P.; Ames, Matthew M.; Jenkins, Gregory D.; Batzler, Anthony; Carlson, Erin E.; Flockhart, David A.; Wolmark, Norman; Nakamura, Yusuke; Weinshilboum, Richard M.

    2013-01-01

    The selective estrogen receptor modulators (SERMs) tamoxifen and raloxifene can reduce the occurrence of breast cancer in high risk women by 50%, but this FDA-approved prevention therapy is not often used. We attempted to identify genetic factors that contribute to variation in SERM breast cancer prevention using DNA from the NSABP P-1 and P-2 breast cancer prevention trials. An initial discovery genome-wide association study identified common single nucleotide polymorphisms (SNPs) in or near the ZNF423 and CTSO genes that were associated with breast cancer risk during SERM therapy. We then showed that both ZNF423 and CTSO participated in the estrogen-dependent induction of BRCA1 expression, in both cases with SNP-dependent variation in induction. ZNF423 appeared to be an estrogen-inducible BRCA1 transcription factor. The odds ratio for differences in breast cancer risk during SERM therapy for subjects homozygous for both protective or both risk alleles for ZNF423 and CTSO was 5.71. PMID:23764426

  6. Polo-like kinase 2 gene expression is regulated by the orphan nuclear receptor estrogen receptor-related receptor gamma (ERRgamma).

    PubMed

    Park, Yun-Yong; Kim, Seok-Ho; Kim, Yong Joo; Kim, Sun Yee; Lee, Tae-Hoon; Lee, In-Kyu; Park, Seung Bum; Choi, Hueng-Sik

    2007-10-12

    Estrogen receptor-related receptor gamma (ERRgamma) is a member of the nuclear receptor family of transcriptional activators. To date, the target genes and physiological functions of ERRgamma are not well understood. In the current study, we identify that Plk2 is a novel target of ERRgamma. Northern blot analysis showed that overexpression of ERRgamma induced Plk2 expression in cancer cell lines. ERRgamma activated the Plk2 gene promoter, and deletion and mutational analysis of the Plk2 promoter revealed that the ERRgamma-response region is located between nucleotides (nt) -2327 and -2229 and -441 and -432 (relative to the transcriptional start site at +1). Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) analysis demonstrated that ERRgamma binds directly to the Plk2 promoter. Overexpression of ERRgamma in the presence of the mitotic inhibitor nocodazole significantly decreased apoptosis, and induced S-phase cell cycle progression through the induction of Plk2 expression. Taken together, these results demonstrated that Plk2 is a novel target of ERRgamma, and suggest that this interaction is crucial for cancer cell proliferation. PMID:17706602

  7. Expression of estrogen receptors alpha and beta in the corpus luteum and uterus from non-pregnant and pregnant llamas.

    PubMed

    Powell, Susan A; Smith, Bradford B; Timm, Karen I; Menino, Alfred R

    2007-08-01

    Because estrogen may be involved in maternal recognition of pregnancy and embryonic migration in llamas, expression of estrogen receptor subtypes alpha (ERalpha) and beta (ERbeta) was evaluated in corpus luteum (CL), endometrium, and uterus using relative RT-PCR. Tissues were recovered from sterile-mated (SM) and pregnant (PG) females during Days 7-11 and 7-13 (Day 0 = day of mating), respectively, and follicular phase and juvenile females. Luteal expression of ERalpha and beta was similar (P > 0.10) in SM and PG females and within Days 7-11, however, expression of ERalpha in ovarian tissue from follicular phase females was greater (P < 0.05) than Days 7 and 9 CL. Uterus expressed less ERalpha and beta compared to endometrium (P = 0.07 and P < 0.01, respectively). Expression of ERalpha was greater (P < 0.05) in Day 7 and follicular phase uteri than Days 9 and 11, Day 13 PG and juvenile uteri. Uterine ERbeta expression was greater (P = 0.09) in PG versus SM females and in mated compared to follicular phase females (P < 0.05). Endometrial expression of ERalpha and beta did not differ (P > 0.10) between SM and PG females or by day. The presence of luteal ER during this period may mean a role for estradiol in maternal recognition of pregnancy. Observed increases in uterine ER expression with no changes in endometrium suggest expression increased in myometrium and/or perimetrium. Upregulation of myometrial ERbeta in PG females may be involved in supporting uterine migration of the embryo. PMID:17219432

  8. Seasonal changes of androgen receptor, estrogen receptors and aromatase expression in the medial preoptic area of the wild male ground squirrels (Citellus dauricus Brandt).

    PubMed

    Zhang, F; Wang, J; Jiao, Y; Zhang, L; Zhang, H; Sheng, X; Han, Y; Yuan, Z; Weng, Q

    2016-01-01

    The wild ground squirrel is a typical seasonal breeder. In this study, using RT-PCR, western blot and immunohistochemistry, we investigated the mRNA and protein expressions of androgen receptor (AR), estrogen receptors α and β (ERα and ERβ) and aromatase cytochrome P450 (P450arom) in the medial preoptic area (MPOA) of hypothalamus of the wild male ground squirrel during the breeding season (April), the non-breeding season (June) and pre-hibernation (September). AR, ERα, ERβ and P450arom protein/mRNA were present in the MPOA of all seasons detected. The immunostaining of AR and ERα showed no significant changes in different periods, whereas ERβ and P450arom had higher immunoreactivities during the breeding season and pre-hibernation when compared to those of the non-breeding season. Consistently, both the protein and mRNA levels of P450arom and ERβ were higher in the MPOA of pre-hibernation and the breeding season than in the non-breeding season, whereas no significant difference amongst the three periods was observed for AR and ERα levels. These findings suggested that the MPOA of hypothalamus may be a direct target of androgen and estrogen. Androgen may play important regulatory roles through its receptor and/or the aromatized estrogen in the MPOA of hypothalamus of the wild male ground squirrels. PMID:27349316

  9. Seasonal Changes of Androgen Receptor, Estrogen Receptors and Aromatase Expression in the Medial Preoptic Area of the Wild Male Ground Squirrels (Citellus Dauricus Brandt)

    PubMed Central

    Zhang, F.; Wang, J.; Jiao, Y.; Zhang, L.; Zhang, H.; Sheng, X.; Han, Y.; Yuan, Z.; Weng, Q.

    2016-01-01

    The wild ground squirrel is a typical seasonal breeder. In this study, using RT-PCR, western blot and immunohistochemistry, we investigated the mRNA and protein expressions of androgen receptor (AR), estrogen receptors a and β (ERα and ERβ) and aromatase cytochrome P450 (P450arom) in the medial preoptic area (MPOA) of hypothalamus of the wild male ground squirrel during the breeding season (April), the non-breeding season (June) and pre-hibernation (September). AR, ERα, ERβ and P450arom protein/mRNA were present in the MPOA of all seasons detected. The immunostaining of AR and ERα showed no significant changes in different periods, whereas ERβ and P450arom had higher immunoreactivities during the breeding season and pre-hibernation when compared to those of the non-breeding season. Consistently, both the protein and mRNA levels of P450arom and ERβ were higher in the MPOA of pre-hibernation and the breeding season than in the non-breeding season, whereas no significant difference amongst the three periods was observed for AR and ERα levels. These findings suggested that the MPOA of hypothalamus may be a direct target of androgen and estrogen. Androgen may play important regulatory roles through its receptor and/or the aromatized estrogen in the MPOA of hypothalamus of the wild male ground squirrels. PMID:27349316

  10. Estrogen-related receptor alpha induces the expression of vascular endothelial growth factor in breast cancer cells

    PubMed Central

    Stein, Rebecca A.; Gaillard, Stéphanie; McDonnell, Donald P.

    2009-01-01

    Estrogen-related receptor alpha (ERRα) is an orphan member of the nuclear receptor family of transcription factors. In addition to its function as a metabolic regulator, ERRα has been implicated in the growth and progression of several malignancies. In the setting of breast cancer, not only is ERRα a putative negative prognostic factor, but we have recently found that knockdown of its expression retards tumor growth in a xenograft model of this disease. The specific aspects of ERRα function that are responsible for its actions in breast cancer, however, remain unclear. Using the coactivator PGC-1α as a protein ligand to regulate ERRα activity, we analyzed the effects of this receptor on gene expression in the ERα-positive MCF-7 cell line. This analysis led to the identification of a large number of potential ERRα target genes, many of which were subsequently validated in other breast cancer cell lines. Importantly, we demonstrate in this study that activation of ERRα in several different breast cancer cell lines leads to a significant increase in VEGF mRNA expression, an activity that translates into an increase in VEGF protein secretion. The induction of VEGF results from the interaction of ERRα with specific ERR-responsive elements within the VEGF promoter. These findings suggest that ERRα-dependent induction of VEGF may contribute to the overall negative phenotype observed in tumors in which ERRα is expressed and provide validation for its use as a therapeutic target in cancer. PMID:19429439

  11. Hypothalamic expression of genes for appetite regulators and estrogen α, estrogen β and leptin receptors in obese dams and their fetuses.

    PubMed

    Breton, A B; Cockrum, R R; Austin, K J; Cammack, K M; Ford, S P; Hess, B W; Moss, G E; Nathanielsz, P W; Alexander, B M

    2011-12-01

    Under- and over-nutrition during gestation may influence fetal hypothalamic development resulting in individuals predisposed to adverse health effects. This study examined fetuses from obese and control ewes to determine whether dam obesity alters hypothalamic expression of fetal appetite regulatory genes. A second objective was to contrast the expression of appetite regulatory genes in ewes that become the most obese to those that remained in moderate body condition on the same energy-rich diet. Multiparous, western white-faced ewes were weighed and individually fed 100% (control) or 150% (obese) of National Research Council requirements from day 60 before mating until day 75 of gestation. At day 75 of gestation, fetuses were collected and weighed. Hypothalamic tissue from fetal lambs and dams was collected and frozen for mRNA extraction. Dam obesity (P ≥ 0.16), fetal sex (P ≥ 0.44) or their interaction (P ≥ 0.42) did not affect the relative expression of fetal hypothalamic regulators of appetite, including neuropeptide Y, agouti-related protein, pro-opiomelanocortin, cocaine- and amphetamine-regulated transcript and receptors for leptin. Maternal obesity at day 75 of gestation in ewes did not affect developmental mechanisms responsible for the expression of fetal appetite regulatory genes and would not be expected to predispose offspring to adult-onset obesity through disrupted appetite regulation at this developmental time point. In the ewe, appetite regulatory genes did not differ (P > 0.20) with ewe adiposity; however, expression of estrogen receptor α, but not β (P = 0.37), in the medial basal hypothalamus was greater (P = 0.04) in obese than in control ewes. PMID:22440471

  12. Loading-related regulation of gene expression in bone in the contexts of estrogen deficiency, lack of estrogen receptor α and disuse

    PubMed Central

    Zaman, Gul; Saxon, Leanne K.; Sunters, Andrew; Hilton, Helen; Underhill, Peter; Williams, Debbie; Price, Joanna S.; Lanyon, Lance E.

    2010-01-01

    Loading-related changes in gene expression in resident cells in the tibia of female mice in the contexts of normality (WT), estrogen deficiency (WT-OVX), absence of estrogen receptor α (ERα−/−) and disuse due to sciatic neurectomy (WT-SN) were established by microarray. Total RNA was extracted from loaded and contra-lateral non-loaded tibiae at selected time points after a single, short period of dynamic loading sufficient to engender an osteogenic response. There were marked changes in the expression of many genes according to context as well as in response to loading within those contexts. In WT mice at 3, 8, 12 and 24 h after loading the expression of 642, 341, 171 and 24 genes, respectively, were differentially regulated compared with contra-lateral bones which were not loaded. Only a few of the genes differentially regulated by loading in the tibiae of WT mice have recognized roles in bone metabolism or have been linked previously to osteogenesis (Opn, Sost, Esr1, Tgfb1, Lrp1, Ostn, Timp, Mmp, Ctgf, Postn and Irs1, BMP and DLX5). The canonical pathways showing the greatest loading-related regulation were those involving pyruvate metabolism, mitochondrial dysfunction, calcium-induced apoptosis, glycolysis/gluconeogenesis, aryl hydrocarbon receptor and oxidative phosphorylation. In the tibiae from WT-OVX, ERα−/− and WT-SN mice, 440, 439 and 987 genes respectively were differentially regulated by context alone compared to WT. The early response to loading in tibiae of WT-OVX mice involved differential regulation compared to their contra-lateral non-loaded pair of fewer genes than in WT, more down-regulation than up-regulation and a later response. This was shared by WT-SN. In tibiae of ERα−/− mice, the number of genes differentially regulated by loading was markedly reduced at all time points. These data indicate that in resident bone cells, both basal and loading-related gene expression is substantially modified by context. Many of the genes

  13. Prenatal Bisphenol A Exposure Alters Sex-Specific Estrogen Receptor Expression in the Neonatal Rat Hypothalamus and Amygdala

    PubMed Central

    Patisaul, Heather B.

    2013-01-01

    Bisphenol A (BPA) exposure is ubiquitous, and in laboratory animals, early-life BPA exposure has been shown to alter sex-specific neural organization, neuroendocrine physiology, and behavior. The specific mechanisms underlying these brain-related outcomes, however, remain largely unknown, constraining the capacity to ascertain the potential human relevance of neural effects observed in animal models. In the perinatal rat brain, estrogen is masculinizing, suggesting that BPA-induced perturbation of estrogen receptor (ESR) expression may underpin later in-life neuroendocrine effects. We hypothesized that prenatal BPA exposure alters sex-specific ESR1 (ERα) and ESR2 (ERβ) expression in postnatal limbic nuclei. Sprague Dawley rats were mated and gavaged on gestational days (GDs) 6–21 with vehicle, 2.5 or 25 μg/kg bw/day BPA, or 5 or 10 μg/kg bw/day ethinyl estradiol. An additional group was restrained but not gavaged (naïve control). Offspring were sacrificed the day after birth to quantify ESR gene expression throughout the hypothalamus and amygdala by in situ hybridization. Relative to the vehicle group, significant effects of BPA were observed on ESR1 and ESR2 expression throughout the mediobasal hypothalamus and amygdala in both sexes. Significant differences in ESR expression were also observed in the mediobasal hypothalamus and amygdala of the naïve control group compared with the vehicle group, highlighting the potential for gavage to influence gene expression in the developing brain. These results indicate that ESR expression in the neonatal brain of both sexes can be altered by low-dose prenatal BPA exposure. PMID:23457122

  14. Tissue-specific Regulation of Porcine Prolactin Receptor Expression by Estrogen, Progesterone and Prolactin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prolactin (PRL) acts through its receptor (PRLR) via both endocrine and local paracrine/autocrine pathways to regulate biological processes including reproduction and lactation. We analyzed the tissue and stage of gestation-specific regulation of PRL and PRLR expression in various tissues of pigs. ...

  15. Expression of P450arom and Estrogen Receptor Alpha in the Oviduct of Chinese Brown Frog (Rana dybowskii) during Prehibernation.

    PubMed

    Weng, Ji; Liu, Yuning; Xu, Ying; Hu, Ruiqi; Zhang, Haolin; Sheng, Xia; Watanabe, Gen; Taya, Kazuyoshi; Weng, Qiang; Xu, Meiyu

    2015-01-01

    One specific physiological phenomenon of Chinese brown frog (Rana dybowskii) is that its oviduct expands prior to hibernation instead of expanding during the breeding period. In this study, we investigated the expression of P450arom and estrogen receptors α and β (ERα and ERβ) in the oviduct of Rana dybowskii during the breeding period and prehibernation. The results of the present study showed that there were significant differences in both oviductal weight and size with values markedly higher in prehibernation than in the breeding period. P450arom was observed in stromal tissue in both the breeding period and prehibernation. ERα was expressed in stromal tissue and epithelial cells in both periods, whereas ERβ could not be detected. The mean protein and mRNA levels of P450arom and ERα were significantly higher in prehibernation as compared to the breeding period. Besides, oviductal content of 17β-estradiol was also higher in prehibernation than in the breeding period. These results suggested that estrogen may play autocrine/paracrine roles mediated by ERα in regulating the oviductal hypertrophy during prehibernation. PMID:25802518

  16. Human myeloblastic leukemia cells (HL-60) express a membrane receptor for estrogen that signals and modulates retinoic acid-induced cell differentiation

    SciTech Connect

    Kauss, M. Ariel; Reiterer, Gudrun; Bunaciu, Rodica P.; Yen, Andrew

    2008-10-01

    Estrogen receptors are historically perceived as nuclear ligand activated transcription factors. An estrogen receptor has now been found localized to the plasma membrane of human myeloblastic leukemia cells (HL-60). Its expression occurs throughout the cell cycle, progressively increasing as cells mature from G{sub 1} to S to G{sub 2}/M. To ascertain that the receptor functioned, the effect of ligands, including a non-internalizable estradiol-BSA conjugate and tamoxifen, an antagonist of nuclear estrogen receptor function, were tested. The ligands caused activation of the ERK MAPK pathway. They also modulated the effect of retinoic acid, an inducer of MAPK dependent terminal differentiation along the myeloid lineage in these cells. In particular the ligands inhibited retinoic acid-induced inducible oxidative metabolism, a functional marker of terminal myeloid cell differentiation. To a lesser degree they also diminished retinoic acid-induced earlier markers of cell differentiation, namely CD38 and CD11b. However, they did not regulate retinoic acid-induced G{sub 0} cell cycle arrest. There is thus a membrane localized estrogen receptor in HL-60 myeloblastic leukemia cells that can cause ERK activation and modulates the response of these cells to retinoic acid, indicating crosstalk between the membrane estrogen and retinoic acid evoked pathways relevant to propulsion of cell differentiation.

  17. Human myeloblastic leukemia cells (HL-60) express a membrane receptor for estrogen that signals and modulates retinoic acid-induced cell differentiation.

    PubMed

    Kauss, M Ariel; Reiterer, Gudrun; Bunaciu, Rodica P; Yen, Andrew

    2008-10-01

    Estrogen receptors are historically perceived as nuclear ligand activated transcription factors. An estrogen receptor has now been found localized to the plasma membrane of human myeloblastic leukemia cells (HL-60). Its expression occurs throughout the cell cycle, progressively increasing as cells mature from G(1) to S to G(2)/M. To ascertain that the receptor functioned, the effect of ligands, including a non-internalizable estradiol-BSA conjugate and tamoxifen, an antagonist of nuclear estrogen receptor function, were tested. The ligands caused activation of the ERK MAPK pathway. They also modulated the effect of retinoic acid, an inducer of MAPK dependent terminal differentiation along the myeloid lineage in these cells. In particular the ligands inhibited retinoic acid-induced inducible oxidative metabolism, a functional marker of terminal myeloid cell differentiation. To a lesser degree they also diminished retinoic acid-induced earlier markers of cell differentiation, namely CD38 and CD11b. However, they did not regulate retinoic acid-induced G(0) cell cycle arrest. There is thus a membrane localized estrogen receptor in HL-60 myeloblastic leukemia cells that can cause ERK activation and modulates the response of these cells to retinoic acid, indicating crosstalk between the membrane estrogen and retinoic acid evoked pathways relevant to propulsion of cell differentiation. PMID:18692045

  18. Cartilage development requires the function of Estrogen-related receptor alpha that directly regulates sox9 expression in zebrafish

    PubMed Central

    Kim, Yong-Il; No Lee, Joon; Bhandari, Sushil; Nam, In-Koo; Yoo, Kyeong-Won; Kim, Se-Jin; Oh, Gi-Su; Kim, Hyung-Jin; So, Hong-Seob; Choe, Seong-Kyu; Park, Raekil

    2015-01-01

    Estrogen-related receptor alpha (ESRRa) regulates a number of cellular processes including development of bone and muscles. However, direct evidence regarding its involvement in cartilage development remains elusive. In this report, we establish an in vivo role of Esrra in cartilage development during embryogenesis in zebrafish. Gene expression analysis indicates that esrra is expressed in developing pharyngeal arches where genes necessary for cartilage development are also expressed. Loss of function analysis shows that knockdown of esrra impairs expression of genes including sox9, col2a1, sox5, sox6, runx2 and col10a1 thus induces abnormally formed cartilage in pharyngeal arches. Importantly, we identify putative ESRRa binding elements in upstream regions of sox9 to which ESRRa can directly bind, indicating that Esrra may directly regulate sox9 expression. Accordingly, ectopic expression of sox9 rescues defective formation of cartilage induced by the knockdown of esrra. Taken together, our results indicate for the first time that ESRRa is essential for cartilage development by regulating sox9 expression during vertebrate development. PMID:26657540

  19. Nonmonotonic response of vitellogenin and estrogen receptor α gene expression after octylphenol exposure of Cichlasoma dimerus (Perciformes, Cichlidae).

    PubMed

    Genovese, G; Regueira, M; Da Cuña, R H; Ferreira, M F; Varela, M L; Lo Nostro, F L

    2014-11-01

    In oviparous vertebrates, vitellogenin (VTG) is mainly produced by the liver in response to estrogen (E2) and its synthesis is traditionally coupled to estrogen receptor alpha induction. Even though VTG is a female-specific protein, chemicals that mimic natural estrogens, known as xenoestrogens, can activate its expression in males causing endocrine disruption to wildlife and humans. Alkylphenols such as nonylphenol (NP) and octylphenol (OP) are industrial additives used in the manufacture of a wide variety of plastics and detergents, and can disrupt endocrine functions in exposed animals. For more than a decade, the freshwater cichlid fish Cichlasoma dimerus has been used for ecotoxicological studies in our laboratory. We recently found an up-regulation of VTG gene expression in livers of male fish exposed to OP, from a silent state to values similar to those of E2-induced fish. To better understand the underlying mechanisms behind the action of xenoestrogens, the aim of this study was to analyze the dose-response relationship of C. dimerus VTG and estrogen receptors (ERs) gene expression after waterborne exposure to 0.15, 1.5, 15, and 150μg/L OP for up to 1 month (0, 1, 3, 7, 14, 21, and 28 days). At the end of the experiment, histological features of exposed fish included active hepatocytes with basophilic cytoplasm and high eosinophilic content in their vascular system due to augmented expression of VTG. In testis, high preponderance of sperm was found in fish exposed to 150μg/L OP. A classic dose-response down-regulation of the expression of Na(+)/K(+)-ATPase, a "non-gender specific gene" used for comparison, was found with increasing OP concentrations. No VTG and very low levels of ERα were detected in control male livers, but an up-regulation of both genes was found in males exposed to 0.15 or 150μg/L OP. Moreover, VTG transcripts were significant as early as day 3 or day 1 of exposure to these OP concentrations, respectively. Nearly no response was

  20. STANDARDIZATION AND VALIDATION OF PROPOSED PROTOCOLS FOR IN VITRO SCREENING ASSAYS AND QSAR FOR ESTROGEN RECEPTOR AND ANDROGEN RECEPTOR

    EPA Science Inventory

    Screening EDCs for androgenic and antiandrogenic activities was recommended by the EDSTAC Committee in it Final Report. This research will develop in vitro approaches to assess estrogen receptor binding, develop cell lines that stably express estrogen receptor for screening EDC...

  1. Estradiol concentration and the expression of estrogen receptors in the testes of the domestic goose (Anser anser f. domestica) during the annual reproductive cycle.

    PubMed

    Leska, A; Kiezun, J; Kaminska, B; Dusza, L

    2015-04-01

    Seasonal fluctuations in the activity of bird testes are regulated by a complex mechanism where androgens play a key role. Until recently, the role played by estrogens in males has been significantly underestimated. However, there is growing evidence that the proper functioning of the testes is associated with optimal estradiol (E2) concentration in both the plasma and testes of many mammalian species. Estrogens are gradually emerging as very important players in hormonal regulation of reproductive processes in male mammals. Despite the previously mentioned, it should be noted that estrogenic action is limited by the availability of specific receptors--estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ). Interestingly, there is a general scarcity of information concerning the estrogen responsive system in the testes of male birds, which is of particular interest in exploring the phenomenon of seasonality of reproduction. To address this question, we have investigated for the first time the simultaneous expression of testicular ERα and ERβ genes and proteins with the accompanying plasma and testicular E2 concentrations during the annual reproductive cycle of male bird. The research model was the domestic goose (Anser anser f. domestica), a species whose annual reproductive cycle can be divided into 3 distinct phases characterized by changes in testicular activity. It has been revealed that the stable plasma E2 profile did not correspond to changing intratesticular E2 profile throughout the experiment. The expression of ERα and ERβ genes and proteins was detected in gander testes and it fluctuated on a seasonal basis with lower level in breeding and sexual reactivation stages and higher level during the nonbreeding stage. Our results demonstrated changes in testicular sensitivity to estrogens in male domestic goose during the annual reproductive cycle. The seasonal pattern of estrogen receptors (ERs) expression was analyzed against the hormonal

  2. Sex Specific Expression of Estrogen Receptors α and β and Kiss1 in the Postnatal Rat Amygdala

    PubMed Central

    Cao, Jinyan; Patisaul, Heather B.

    2012-01-01

    The rodent amygdaloid complex is composed of numerous subnuclei important for the sex specific regulation of sociosexual behavior. Although estrogen receptors (ERs) are critical for organizing functional and cytoarchitectural sex differences in these subnuclei, a detailed developmental profile of ER expression in the amygdaloid complex is not available. Moreover, the kisspeptin gene (Kiss1) was recently identified in the adult amygdala, but it remains unknown if it is expressed during development. To fill these data gaps, rat brains (5–7/group) were assessed on postnatal days (PNDs) 0, 2, 4, 7 and 19 for ER alpha (ERα; Esr1), beta (ERβ; Esr2) and Kiss1 expression using in situ hybridization. Expression was quantified in the posterodorsal portion of the medial amygdala MePD, lateral (PLCo) and medial (PMCo) components of the posterior cortical nucleus, and the amygdalohippocampal area (AHi). ERα expression was high throughout the amygdala at birth, but sexually dimorphic only in the AHi. ERα expression in the MePD and the PLCo showed a U-shaped expression pattern over time. In the PMCo, ERα expression decreased from PND 2 and remained low through PND 19. Sexually dimorphic expression of ERβ in the MePD was observed on PND 0, with higher levels in females, but reversed by PND 4 due to declining levels in females. No Kiss1 signal was observed in the postnatal amygdala, suggesting that expression arises after puberty. These data reveal that ER expression is region specific within the neonatal amygdala. These differences likely contribute to sex differences in sociosexual behavior across the lifespan. PMID:22791648

  3. Evidence of a correlation of estrogen receptor level and avian osteoclast estrogen responsiveness.

    PubMed

    Pederson, L; Kremer, M; Foged, N T; Winding, B; Ritchie, C; Fitzpatrick, L A; Oursler, M J

    1997-05-01

    Isolated osteoclasts from 5-week-old chickens respond to estradiol treatment in vitro with decreased resorption activity, increased nuclear proto-oncogene expression, and decreased lysosomal enzyme secretion. This study examines osteoclasts from embryonic chickens and egg-laying hens for evidence of estrogen responsiveness. Although osteoclasts from both of these sources express estrogen receptor mRNA and protein, estradiol treatment had no effect on resorption activity. In contrast to the lack of effect on resorption, estradiol treatment for 30 minutes resulted in steady-state mRNA levels of c-fos and c-jun increasing in osteoclasts from embryonic chickens and decreasing in osteoclasts from egg-laying hens. These data suggest that a nuclear proto-oncogene response may not be involved in estradiol-mediated decreased osteoclast resorption activity. To examine the influence of circulating estrogen on osteoclast estrogen responsiveness, 5-week-old chickens were injected with estrogen for 4 days prior to sacrifice. Estradiol treatment of osteoclasts from these chickens did not decrease resorption activity in vitro. Transfection of an estrogen receptor expression vector into osteoclasts from the estradiol-injected chickens and egg-laying hens restored estrogen responsiveness. Osteoclasts from 5-week-old chickens and estradiol treated 5-week-old chickens transfected with the estrogen receptor expression vector contained significantly higher levels of estrogen receptor protein and responded to estradiol treatment by decreasing secretion of cathepsins B and L and tartrate-resistant acid phosphatase. In contrast, osteoclasts from embryonic chickens, egg-laying hens, and estradiol-treated 5-week-old chickens either untransfected or transfected with an empty expression vector did not respond similarly. These data suggest that modulation of osteoclast estrogen responsiveness may be controlled by changes in the osteoclast estrogen receptor levels. PMID:9144340

  4. Prognostic significance of full-length estrogen receptor beta expression in stage I-III triple negative breast cancer

    PubMed Central

    Shanle, Erin K; Onitilo, Adedayo A; Huang, Wei; Kim, KyungMann; Zang, Chong; Engel, Jessica M; Xu, Wei; Wisinski, Kari B

    2015-01-01

    Triple negative breast cancer (TNBC) is an aggressive breast cancer subtype for which there is a need to identify new therapeutic targets. Full-length estrogen receptor beta (ERβ1) may be a possible target given its antiproliferative effects on breast cancer cells. The prognostic significance of ERβ in breast cancer subtypes has remained elusive, and disparate results observed across previously published reports might be due to the detection of multiple ERβ isoforms, the lack of specific antibodies and the use of different cutoffs to define ERβpositivity. The objective of this retrospective study was to determine the association between ERβ1 expression and disease-free and overall survival, as well as Ki67 expression, in non-metastatic TNBC. Immunohistochemical protocols were optimized using xenograft tissues obtained from a breast cancer cell line with inducible ERβ1 expression. ERβ1 localization and expression were assessed in two cohorts of TNBC using the VECTRATM platform. There was a close relationship between nuclear and cytoplasmic ERβ1 expression. ERβ1 was expressed in a subset of TNBCs, but its expression was significantly associated with Ki67 in only one of the cohorts. There was no significant association between ERβ1 expression and disease-free and overall survival in either cohort. Although these results suggest that ERβ1 expression alone may not be informative in TNBCs, this study provides a new strategy for optimizing and objectively measuring ERβ1 expression in tissues, which may provide a standard for ERβ1 immunohistochemistry in future large-scale clinical studies aimed at better understanding the role of ERβ1 in breast cancer. PMID:26328009

  5. A Role for the Orphan Nuclear Receptor Estrogen-Related Receptor α in Endometrial Stromal Cell Decidualization and Expression of Genes Implicated in Energy Metabolism

    PubMed Central

    Bombail, Vincent; Gibson, Douglas A.; Collins, Frances; MacPherson, Sheila; Critchley, Hilary O. D.; Saunders, Philippa T. K.

    2010-01-01

    Context: Differentiation (decidualization) of endometrial stromal cells (ESC) is an essential prerequisite for successful implantation and establishment of pregnancy. Objective: The aim was to determine whether the orphan nuclear receptor estrogen-related receptor α (ERRα, NR3B1), and its target genes, medium chain specific acyl-CoA dehydrogenase (MCAD, ACADM), pyruvate dehydrogenase kinase 4 (PDK4), and phosphoenolpyruvate carboxykinase 2 (PEPCK, PCK2), play a role in the decidualization process. Setting: We conducted the study at a University Research Institute. Patients and Methods: Endometrial tissues were collected from women with regular menstrual cycles; tissues were used for recovery of primary ESC or RNA extraction or were fixed for immunohistochemistry. Primary ESC were decidualized in vitro; some cells were treated with XCT790 (ERRα inverse agonist). Results: Decidualization of ESC in vitro was associated with a significant increase in expression of transcripts encoding ERRα and its coactivator peroxisome proliferator-activated receptor γ coactivator-1 α. Expression of ERRα target genes was altered with increased expression of MCAD and PDK4 and reduced expression of PEPCK. Incubation of decidualized ESC with XCT790 reduced expression of ERRα and markers of decidualization such as IGFBP-1. Conclusion: Increased expression of ERRα may play a role in altering the bioenergetics of decidualized ESC in preparation for implantation of the embryo and successful establishment of early pregnancy. PMID:20668045

  6. Estrogen receptor alpha mediates epithelial to mesenchymal transition, expression of specific matrix effectors and functional properties of breast cancer cells.

    PubMed

    Bouris, Panagiotis; Skandalis, Spyros S; Piperigkou, Zoi; Afratis, Nikos; Karamanou, Konstantina; Aletras, Alexios J; Moustakas, Aristidis; Theocharis, Achilleas D; Karamanos, Nikos K

    2015-04-01

    The 17β-estradiol (E2)/estrogen receptor alpha (ERα) signaling pathway is one of the most important pathways in hormone-dependent breast cancer. E2 plays pivotal roles in cancer cell growth, survival, and architecture as well as in gene expression regulatory mechanisms. In this study, we established stably transfected MCF-7 cells by knocking down the ERα gene (designated as MCF-7/SP10+ cells), using specific shRNA lentiviral particles, and compared them with the control cells (MCF-7/c). Interestingly, ERα silencing in MCF-7 cells strongly induced cellular phenotypic changes accompanied by significant changes in gene and protein expression of several markers typical of epithelial to mesenchymal transition (EMT). Notably, these cells exhibited enhanced cell proliferation, migration and invasion. Moreover, ERα suppression strongly affected the gene and protein expression of EGFR and HER2 receptor tyrosine kinases, and various extracellular matrix (ECM) effectors, including matrix metalloproteinases and their endogenous inhibitors (MMPs/TIMPs) and components of the plasminogen activation system. The action caused by E2 in MCF-7/c cells in the expression of HER2, MT1-MMP, MMP1, MMP9, uPA, tPA, and PAI-1 was abolished in MCF-7/SP10+ cells lacking ERα. These data suggested a regulatory role for the E2/ERα pathway in respect to the composition and activity of the extracellular proteolytic molecular network. Notably, loss of ERα promoted breast cancer cell migration and invasion by inducing changes in the expression levels of certain matrix macromolecules (especially uPA, tPA, PAI-1) through the EGFR-ERK signaling pathway. In conclusion, loss of ERα in breast cancer cells results in a potent EMT characterized by striking changes in the expression profile of specific matrix macromolecules highlighting the potential nodal role of matrix effectors in breast cancer endocrine resistance. PMID:25728938

  7. DEVELOPMENT AND CHARACTERIZATION OF A CELL LINE THAT STABLY EXPRESSES AN ESTROGEN-RESPONSIVE LUCIFERASE REPORTER FOR THE DETECTION OF ESTROGEN RECEPTOR AGONIST AND ANTAGONISTS

    EPA Science Inventory

    Screening for endocrine disrupting chemicals (EDCs) that act as estrogens or antiestrogens relies on the use of in vitro binding and gene expression assays coupled with short-term diagnostic in vivo assays. Although binding assays are useful to identify chemicals that are competi...

  8. Role of ornithine decarboxylase in regulation of estrogen receptor alpha expression and growth in human breast cancer cells.

    PubMed

    Zhu, Qingsong; Jin, Lihua; Casero, Robert A; Davidson, Nancy E; Huang, Yi

    2012-11-01

    Our previous studies demonstrated that specific polyamine analogues, oligoamines, down-regulated the activity of a key polyamine biosynthesis enzyme, ornithine decarboxylase (ODC), and suppressed expression of estrogen receptor alpha (ERα) in human breast cancer cells. However, the mechanism underlying the potential regulation of ERα expression by polyamine metabolism has not been explored. Here, we demonstrated that RNAi-mediated knockdown of ODC (ODC KD) down-regulated the polyamine pool, and hindered growth in ERα-positive MCF7 and T47D and ERα-negative MDA-MB-231 breast cancer cells. ODC KD significantly induced the expression and activity of the key polyamine catabolism enzymes, spermine oxidase (SMO) and spermidine/spermine N (1)-acetyltransferase (SSAT). However, ODC KD-induced growth inhibition could not be reversed by exogenous spermidine or overexpression of antizyme inhibitor (AZI), suggesting that regulation of ODC on cell proliferation may involve the signaling pathways independent of polyamine metabolism. In MCF7 and T47D cells, ODC KD, but not DFMO treatment, diminished the mRNA and protein expression of ERα. Overexpression of antizyme (AZ), an ODC inhibitory protein, suppressed ERα expression, suggesting that ODC plays an important role in regulation of ERα expression. Decrease of ERα expression by ODC siRNA altered the mRNA expression of a subset of ERα response genes. Our previous analysis showed that oligoamines disrupt the binding of Sp1 family members to an ERα minimal promoter element containing GC/CA-rich boxes. By using DNA affinity precipitation and mass spectrometry analysis, we identified ZBTB7A, MeCP2, PARP-1, AP2, and MAZ as co-factors of Sp1 family members that are associated with the ERα minimal promoter element. Taken together, these data provide insight into a novel antiestrogenic mechanism for polyamine biosynthesis enzymes in breast cancer. PMID:22976807

  9. Identification of four novel phosphorylation sites in estrogen receptor α: impact on receptor-dependent gene expression and phosphorylation by protein kinase CK2

    PubMed Central

    2009-01-01

    Background Estrogen receptor α (ERα) phosphorylation is important for estrogen-dependent transcription of ER-dependent genes, ligand-independent receptor activation and endocrine therapy response in breast cancer. However ERα phosphorylation at the previously identified sites does not fully account for these receptor functions. To determine if additional ERα phosphorylation sites exist, COS-1 cells expressing human ERα were labeled with [32P]H3PO4 in vivo and ERα tryptic phosphopeptides were isolated to identify phosphorylation sites. Results Previously uncharacterized phosphorylation sites at serines 46/47, 282, 294, and 559 were identified by manual Edman degradation and phosphoamino acid analysis and confirmed by mutagenesis and phospho-specific antibodies. Antibodies detected phosphorylation of endogenous ERα in MCF-7, MCF-7-LCC2, and Ishikawa cancer cell lines by immunoblot. Mutation of Ser-282 and Ser-559 to alanine (S282A, S559A) resulted in ligand independent activation of ERα as determined by both ERE-driven reporter gene assays and endogenous pS2 gene expression in transiently transfected HeLa cells. Mutation of Ser-46/47 or Ser-294 to alanine markedly reduced estradiol dependent reporter activation. Additionally protein kinase CK2 was identified as a kinase that phosphorylated ERα at S282 and S559 using motif analysis, in vitro kinase assays, and incubation of cells with CK2 kinase inhibitor. Conclusion These novel ERα phosphorylation sites represent new means for modulation of ERα activity. S559 represents the first phosphorylation site identified in the extreme C-terminus (F domain) of a steroid receptor. PMID:20043841

  10. Dynamics of Protein Expression Reveals Primary Targets and Secondary Messengers of Estrogen Receptor Alpha Signaling in MCF-7 Breast Cancer Cells.

    PubMed

    Drabovich, Andrei P; Pavlou, Maria P; Schiza, Christina; Diamandis, Eleftherios P

    2016-06-01

    Estrogen receptor alpha (ERα)-mediated proliferation of breast cancer cells is facilitated through expression of multiple primary target genes, products of which induce a secondary response to stimulation. To differentiate between the primary and secondary target proteins of ERα signaling, we measured dynamics of protein expression induced by 17β-estradiol in MCF-7 breast cancer cells. Measurement of the global proteomic effects of estradiol by stable isotope labeling by amino acids in cell culture (SILAC) resulted in identification of 103 estrogen-regulated proteins, with only 40 of the corresponding genes having estrogen response elements. Selected reaction monitoring (SRM) assays were used to validate the differential expression of 19 proteins and measure the dynamics of their expression within 72 h after estradiol stimulation, and in the absence or presence of 4-hydroxytamoxifen, to confirm ERα-mediated signaling. Dynamics of protein expression unambiguously revealed early and delayed response proteins and well correlated with presence or absence of estrogen response elements in the corresponding genes. Finally, we quantified dynamics of protein expression in a rarely studied network of transcription factors with a negative feedback loop (ERα-EGR3-NAB2). Because NAB2 protein is a repressor of EGR3-induced transcription, siRNA-mediated silencing of NAB2 resulted in the enhanced expression of the EGR3-induced protein ITGA2. To conclude, we provided a high-quality proteomic resource to supplement genomic and transcriptomic studies of ERα signaling. PMID:27067054

  11. Estrogen Regulation of MicroRNA Expression

    PubMed Central

    Klinge, Carolyn M

    2009-01-01

    Women outlive men, but life expectancy is not influenced by hormone replacement (estrogen + progestin) therapy. Estrogens appear to protect brain, cardiovascular tissues, and bone from aging. Estrogens regulate genes directly through binding to estrogen receptors alpha and beta (ERα and ERβ) that are ligand-activated transcription factors and indirectly by activating plasma membrane-associated ER which, in turns, activates intracellular signaling cascades leading to altered gene expression. MicroRNAs (miRNAs) are short (19-25 nucleotides), naturally-occurring, non-coding RNA molecules that base-pair with the 3’ untranslated region of target mRNAs. This interaction either blocks translation of the mRNA or targets the mRNA transcript to be degraded. The human genome contains ~ 700-1,200 miRNAs. Aberrant patterns of miRNA expression are implicated in human diseases including breast cancer. Recent studies have identified miRNAs regulated by estrogens in human breast cancer cells, human endometrial stromal and myometrial smooth muscle cells, rat mammary gland, and mouse uterus. The decline of estradiol levels in postmenopausal women has been implicated in various age-associated disorders. The role of estrogen-regulated miRNA expression, the target genes of these miRNAs, and the role of miRNAs in aging has yet to be explored. PMID:19881910

  12. Molecular characterization of an estrogen receptor and estrogen-related receptor and their autoregulatory capabilities in two Mytilus species.

    PubMed

    Nagasawa, Kazue; Treen, Nicholas; Kondo, Reki; Otoki, Yurika; Itoh, Naoki; Rotchell, Jeanette M; Osada, Makoto

    2015-06-15

    Vertebrate-like sex steroid hormones have been widely detected in mollusks, and numerous experiments have shown the importance of steroids in gonad development. Nevertheless, their signaling pathways in invertebrates have not been uncovered yet. Steroid receptors are an ancient class of transcription factors with multiple roles in not only vertebrates but also invertebrates. Estrogen signaling is thought to have major roles in mollusk physiology, but the full repertoire of estrogen receptors is unknown. We presented the successful cloning of two novel forms of estrogen receptor-like genes. These receptors are present in two closely related species of Mytilus: Mytilus edulis and Mytilus galloprovincialis, commonly known and widely distributed sentinel species. Our phylogenetic analysis revealed that one of these receptors is an estrogen receptor (ER) and the other one is an estrogen-related receptor (ERR). Studies of expression analysis showed that both receptor mRNAs were localized in the oocytes and follicle cells in contact with developing oocytes in the ovary and Sertoli cells in the testis, and in the ciliated cells of the gill. In addition, we have evidence that one (ER) of these may have a capacity to autoregulate its own expression in the gonadal cells by estrogen (E2) and that this gene is responsive to estrogenic compounds. PMID:25862924

  13. The effects of exogenous melatonin and melatonin receptor blockade on aggression and estrogen-dependent gene expression in male California mice (Peromyscus californicus)

    PubMed Central

    Laredo, Sarah A.; Orr, Veronica; McMackin, Marissa Z.; Trainor, Brian C.

    2014-01-01

    Photoperiodic regulation of aggression has been well established in several vertebrate species, with rodents demonstrating increased aggression in short day photoperiods as compared to long day photoperiods. Previous work suggests that estrogens regulate aggression via rapid nongenomic pathways in short days and act more slowly in long days, most likely via genomic pathways. The current study therefore examines the role of melatonin in mediating aggression and estrogen-dependent gene transcription. In Experiment 1, male California mice were housed under long day photoperiods and were treated with either 0.3 ug/g of melatonin, 40 mg/kg of the melatonin receptor antagonist luzindole, or vehicle for 10 days. We found that melatonin administration significantly increased aggression as compared to mice receiving vehicle, but this phenotype was not completely ameliorated by luzindole. In Experiment 2, male California mice were injected with either 1 mg/kg of the aromatase inhibitor letrozole or vehicle, and oxytocin receptor (OTR), estrogen receptor alpha (ERα), and c-fos gene expression was examined in the bed nucleus of the stria terminalis (BNST) and medial preoptic area (MPOA). In the BNST, but not MPOA, OTR mRNA was significantly downregulated following letrozole administration, indicating that OTR is an estrogen-dependent gene in the BNST. In contrast, ERα was not estrogen dependent in either brain region. In the MPOA, OTR mRNA was inhibited by melatonin, and luzindole suppressed this effect. C-fos and ERα did not differ between treatments in any brain region examined. These results suggest that it is unlikely that melatonin facilitates aggression via broad spectrum regulation of estrogen-dependent gene expression. Instead melatonin may act via regulation of other transcription factors such as extracellular signal regulated kinase. PMID:24518867

  14. Seasonal expression of androgen receptor, aromatase, and estrogen receptor alpha and beta in the testis of the wild ground squirrel (Citellus dauricus Brandt).

    PubMed

    Li, Q; Zhang, F; Zhang, S; Sheng, X; Han, X; Weng, Q; Yuan, Z

    2015-01-01

    The aim of this study was to investigate the seasonal expression of androgen receptor (AR), estrogen receptors α and β (ERα and ERβ) and aromatase cytochrome P450 (P450arom) mRNA and protein by real-time PCR and immunohistochemistry in the wild ground squirrel (WGS) testes. Histologically, all types of spermatogenic cells including mature spermatozoa were identified in the breeding season (April), while spermatogonia and primary spermatocytes were observed in the nonbreeding season (June), and spermatogonia, primary spermatocytes and secondary spermatocytes were found in pre-hibernation (September). AR was present in Leydig cells, peritubular myoid cells and Sertoli cells in the breeding season and pre-hibernation with more intense staining in the breeding season, whereas AR was only found in Leydig cells in the nonbreeding season; P450arom was expressed in Leydig cells, Sertoli cells and germ cells during the breeding season, whereas P450arom was found in Leydig cells and Sertoli cells during pre-hibernation, but P450arom was not present in the nonbreeding season; stronger immunohistochemical signal for ERα was present in Sertoli cells and Leydig cells during the breeding season; ERβ was only expressed in Leydig cells of the breeding season. Consistent with the immunohistochemical results, the mean mRNA level of AR, P450arom, ERα and ERβ were higher in the testes of the breeding season when compared to pre-hibernation and the nonbreeding season. These results suggested that the seasonal changes in spermatogenesis and testicular recrudescence and regression process in WGSs might be correlated with expression levels of AR, P450arom and ERs, and that estrogen and androgen may play an important autocrine/paracrine role to regulate seasonal testicular function. PMID:25820559

  15. Estrogen-related receptor γ modulates cell proliferation and estrogen signaling in breast cancer.

    PubMed

    Ijichi, Nobuhiro; Shigekawa, Takashi; Ikeda, Kazuhiro; Horie-Inoue, Kuniko; Fujimura, Tetsuya; Tsuda, Hitoshi; Osaki, Akihiko; Saeki, Toshiaki; Inoue, Satoshi

    2011-01-01

    Breast cancer is primarily a hormone-dependent tumor that can be regulated by status of steroid hormones including estrogen and progesterone. Estrogen-related receptors (ERRs) are orphan nuclear receptors most closely related to estrogen receptor (ER) and much attention has been recently paid to the functions of ERRs in breast cancer in terms of the interactions with ER. In the present study, we investigated the expression of ERRγ in human invasive breast cancers by immunohistochemical analysis (n=110) obtained by radical mastectomy. Nuclear immunoreactivity of ERRγ was detected in 87 cases (79%) and tended to correlate with the lymph node status. No significant associations were observed with other clinicopathological characteristics, including the expression levels of both estrogen and progesterone receptors. In MCF-7 breast cancer cells, we demonstrated that ERRγ mRNA was up-regulated dose-dependently by estrogen, and that this up-regulation of ERRγ mRNA by estrogen was abolished by ICI 182,780 treatment. We also demonstrated that exogenously transfected ERRγ increased MCF-7 cell proliferation. Furthermore, ERRγ enhanced estrogen response element (ERE)-driven transcription in MCF-7 cells. In 293T cells, ERRγ could also stimulate ERE-mediated transcription with or without ERα. These results suggest that ERRγ plays an important role as a modulator of estrogen signaling in breast cancer cells. PMID:20883782

  16. Estrogen and progesterone receptor expression of decidual endometrium in a postmenopausal woman treated with tamoxifen and megestrol acetate.

    PubMed

    Cohen, I; Shulman, A; Altaras, M; Tepper, R; Cordoba, M; Beyth, Y

    1994-01-01

    To the best of our knowledge, this is the first report of in vivo endometrial estrogen and progesterone receptor induction as a result of tamoxifen exposure in a postmenopausal breast cancer patient. The following observations, that the postmenopausal endometrium is sensitive to tamoxifen, that this agent can act as an estrogen-like substance, and that it may cause proliferation of the endometrium in the absence of progestin, may explain the endometrial decidual changes described herein as a protective mechanism against possible neoplastic endometrial changes. PMID:7959340

  17. Expression of gene, protein and immunohistochemical localization of the estrogen receptor isoform ERα1 in male rainbow trout lymphoid organs; indication of the role of estrogens in the regulation of immune mechanisms.

    PubMed

    Massart, Sophie; Milla, Sylvain; Kestemont, Patrick

    2014-08-01

    In vertebrates, estrogens act on the reproductive system but also affect the functioning of non-reproductive tissues such as the immune system. In teleost fish, effects of estrogens and xenoestrogens have been reported extensively, but the available information on targeted tissues and cells is still scarce. Moreover, a better knowledge of the distinct ER subtypes is required to find out the mechanistic pathways by which estrogen compounds are able to disrupt endogenous estrogen signaling in fish immunity. The present study aimed at characterizing, in male rainbow trout juveniles, multi-tissue gene expression pattern of one isoform of estrogen receptor (ER), ERα1, at the mRNA and protein levels. The mRNA levels for ERα1 were measured in various lymphoid organs by real-time RT-PCR and ERα1 protein level by Western blot. Furthermore, this protein was located by immunohistochemistry in the same organs. The transcripts were ubiquitously expressed, but at a higher level in testis and liver, while the protein was more abundant in testis and skin. Moreover, the ERα1 was detected in endothelial, Kupffer, mucous and chloride cells, hematopoietic tissues, proximal tubule, epithelia of the skin and intestine, in the lamina propria and in the stratum granulosum. This distribution backs the idea that, in male rainbow trout, estrogeno-mimetic compounds could be involved in different immune mechanisms such as inflammatory response, transport of Ig, mucus production, regulation of cellular immunity and development and maturation of lymphoid and myeloid cells. PMID:24937418

  18. Loss of estrogen receptor beta expression in malignant human prostate cells in primary cultures and in prostate cancer tissues.

    PubMed

    Pasquali, D; Rossi, V; Esposito, D; Abbondanza, C; Puca, G A; Bellastella, A; Sinisi, A A

    2001-05-01

    The aim of this study was to investigate the expression of estrogen receptor (ER) beta and alpha genes in normal (N) and malignant (C) primary cultures of human prostate epithelial cells (PEC) and fibroblasts (PFC) and in the prostate tissue donors. Both ERbeta and ERalpha messenger ribonucleic acids were found by RT-PCR analysis in six NPECs and normal prostate tissues and in only one of six CPECs and in the respective cancer tissue donor. The other five CPECs and related cancer tissue donors and all normal and cancer PFCs expressed ERalpha messenger ribonucleic acid alone. Immunoblot analysis, using a polyclonal anti-ERbeta (C-terminal) antibody, demonstrated ERbeta protein in all NPEC lysates and in one of the six CPECS: ERalpha protein was expressed in both NPECs and CPECs when a polyclonal antibody directed against the ERalpha N-terminal domain was used. In contrast, ERalpha protein was not detected in two of the six CPEC lysates when ERalpha C-terminal monoclonal antibodies were used. Using a set of primers designed to amplify the region from exons 6-8, RT-PCR analysis demonstrated the absence of the expected transcript in these cells. The present study shows that the ERbeta gene is expressed together with ERalpha in normal prostates and NPECs, whereas it is barely detectable in prostate cancer and CPECS: Moreover, in some CPECs, the ERalpha gene may be transcribed in a changed protein, resulting from the expression of a deletion variant. Together, these data suggest that prostate malignancy is associated with a potential disorder of ER-mediated pathways. PMID:11344205

  19. Estradiol regulates AQP2 expression in the collecting duct: a novel inhibitory role for estrogen receptor α.

    PubMed

    Cheema, Muhammad Umar; Irsik, Debra L; Wang, Yan; Miller-Little, William; Hyndman, Kelly A; Marks, Eileen S; Frøkiær, Jørgen; Boesen, Erika I; Norregaard, Rikke

    2015-08-15

    While there is evidence that sex hormones influence multiple systems involved in salt and water homeostasis, the question of whether sex hormones regulate aquaporin-2 (AQP2) and thus water handling by the collecting duct has been largely ignored. Accordingly, the present study investigated AQP2 expression, localization and renal water handling in intact and ovariectomized (OVX) female rats, with and without estradiol or progesterone replacement. OVX resulted in a significant increase in urine osmolality and increase in p256-AQP2 in the renal cortex at 7 days post-OVX, as well as induced body weight changes. Relative to OVX alone, estradiol repletion produced a significant increase in urine output, normalized urinary osmolality and reduced both total AQP2 (protein and mRNA) and p256-AQP2 expression, whereas progesterone repletion had little effect. Direct effects of estradiol on AQP2 mRNA and protein levels were further tested in vitro using the mpkCCD principal cell line. Estradiol treatment of mpkCCD cells reduced AQP2 at both the mRNA and protein level in the absence of deamino-8-d-AVP (dDAVP) and significantly blunted the dDAVP-induced increase in AQP2 at the protein level only. We determined that mpkCCD and native mouse collecting ducts express both estrogen receptor (ER)α and ERβ and that female mice lacking ERα displayed significant increases in AQP2 protein compared with wild-type littermates, implicating ERα in mediating the inhibitory effect of estradiol on AQP2 expression. These findings suggest that changes in estradiol levels, such as during menopause or following reproductive surgeries, may contribute to dysregulation of water homeostasis in women. PMID:26062878

  20. CLONING AND IN VITRO EXPRESSION AND CHARACTERIZATION OF THE ANDROGEN RECEPTOR AND ISOLATION OF ESTROGEN RECEPTOR α FROM THE FATHEAD MINNOW (PIMEPHALES PROMELAS)

    EPA Science Inventory

    In vitro screening assays designed to identify hormone mimics or antagonists typically use mammalian (rat, human) estrogen (ER) and androgen receptors (AR). Although we know that the amino acid sequences of steroid receptors in nonmammalian vertebrates are not identical to the ma...

  1. ESR1 gene promoter region methylation in free circulating DNA and its correlation with estrogen receptor protein expression in tumor tissue in breast cancer patients

    PubMed Central

    2014-01-01

    Background Tumor expression of estrogen receptor (ER) is an important marker of prognosis, and is predictive of response to endocrine therapy in breast cancer. Several studies have observed that epigenetic events, such methylation of cytosines and deacetylation of histones, are involved in the complex mechanisms that regulate promoter transcription. However, the exact interplay of these factors in transcription activity is not well understood. In this study, we explored the relationship between ER expression status in tumor tissue samples and the methylation of the 5′ CpG promoter region of the estrogen receptor gene (ESR1) isolated from free circulating DNA (fcDNA) in plasma samples from breast cancer patients. Methods Patients (n = 110) with non-metastatic breast cancer had analyses performed of ER expression (luminal phenotype in tumor tissue, by immunohistochemistry method), and the ESR1-DNA methylation status (fcDNA in plasma, by quantitative methylation specific PCR technique). Results Our results showed a significant association between presence of methylated ESR1 in patients with breast cancer and ER negative status in the tumor tissue (p = 0.0179). There was a trend towards a higher probability of ESR1-methylation in those phenotypes with poor prognosis i.e. 80% of triple negative patients, 60% of HER2 patients, compared to 28% and 5.9% of patients with better prognosis such as luminal A and luminal B, respectively. Conclusion Silencing, by methylation, of the promoter region of the ESR1 affects the expression of the estrogen receptor protein in tumors of breast cancer patients; high methylation of ESR1-DNA is associated with estrogen receptor negative status which, in turn, may be implicated in the patient’s resistance to hormonal treatment in breast cancer. As such, epigenetic markers in plasma may be of interest as new targets for anticancer therapy, especially with respect to endocrine treatment. PMID:24495356

  2. Expression of estrogen receptor α in human breast cancer cells regulates mitochondrial oxidative stress under simulated microgravity

    NASA Astrophysics Data System (ADS)

    Zheng, Hong-xia; Tian, Wei-ming; Yan, Hong-ji; Jiang, Hua-dong; Liu, Shan-shan; Yue, Lei; Han, Fang; Wei, Li-jun; Chen, Xiong-biao; Li, Yu

    2012-05-01

    This study investigated intracellular oxidative stress and its underlying mechanisms in a rotary cell culture system used to achieve a simulated microgravity (SMG) environment. Experiments were conducted with human breast cancer cell lines MCF-7 (an estrogen receptor (ER) α positive cell line) and MDA-MB-231 (an ERα negative cell line) encapsulated in alginate/collagen carriers. After 48 h, SMG led to oxidative stress and DNA damage in the MDA-MB-231 cells but a significant increase in mitochondrial activity and minimal DNA damage in the MCF-7 cells. The activity of superoxide dismutase (SOD) significantly increased in the MCF-7 cells and decreased in MDA-MB-231 cells in the SMG environment compared with a standard gravity control. Moreover, SMG promoted expression of ERα and protein kinase C (PKC) epsilon in MCF-7 cells treated with PKC inhibitor Gö6983. Overall, exposure to SMG increased mitochondrial activity in ERα positive cells but induced cellular oxidative damage in ERα negative cells. Thus, ERα may play an important role in protecting cells from oxidative stress damage under simulated microgravity.

  3. Differential expression of estrogen receptor alpha in the embryonic adrenal-kidney-gonadal complex of the oviparous lizard, Calotes versicolor (Daud.).

    PubMed

    Inamdar, L S; Khodnapur, B S; Nindi, R S; Dasari, S; Seshagiri, P B

    2015-09-01

    Estrogen signalling is critical for ovarian differentiation in reptiles with temperature-dependent sex determination (TSD). To elucidate the involvement of estrogen in this process, adrenal-kidney-gonadal (AKG) expression of estrogen receptor (ERα) was studied at female-producing temperature (FPT) in the developing embryos of the lizard, Calotes versicolor which exhibits a distinct pattern of TSD. The eggs of this lizard were incubated at 31.5±0.5°C (100% FPT). The torso of embryos containing adrenal-kidney-gonadal complex (AKG) was collected during different stages of development and subjected to Western blotting and immunohistochemistry analysis. The ERα antibody recognized two protein bands with apparent molecular weight ∼55 and ∼45kDa in the total protein extracts of embryonic AKG complex of C. versicolor. The observed results suggest the occurrence of isoforms of ERα. The differential expression of two different protein isoforms may reveal their distinct role in cell proliferation during gonadal differentiation. This is the first report to reveal two isoforms of the ERα in a reptile during development. Immunohistochemical studies reveal a weak, but specific, cytoplasmic ERα immunostaining exclusively in the AKG during late thermo-sensitive period suggesting the responsiveness of AKG to estrogens before gonadal differentiation at FPT. Further, cytoplasmic as well as nuclear expression of ERα in the medulla and in oogonia of the cortex (faint activity) at gonadal differentiation stage suggests that the onset of gonadal estrogen activity coincides with sexual differentiation of gonad. Intensity and pattern of the immunoreactions of ERα in the medullary region at FPT suggest endogenous production of estrogen which may act in a paracrine fashion to induce neighboring cells into ovarian differentiation pathway. PMID:25127850

  4. Krüppel-like factor 9 regulates cell proliferation and compartmental expression of estrogen and progesterone receptors in the mouse uterine endometrium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The uterine endometrium undergoes dynamic changes in proliferation and differentiation in response to estrogen (E) and progesterone (P) during the estrous cycle and pregnancy. E and P exert their functions through their respective nuclear receptors, estrogen receptor (ESR) and progesterone receptor ...

  5. Gene expression profiling reveals novel regulation by bisphenol-A in estrogen receptor-{alpha}-positive human cells

    SciTech Connect

    Singleton, David W.; Feng, Yuxin; Yang, Jun; Puga, Alvaro; Lee, Adrian V.; Khan, Sohaib A. . E-mail: sohaib.khan@uc.edu

    2006-01-15

    Bisphenol-A (BPA) shows proliferative actions in uterus and mammary glands and may influence the development of male and female reproductive tracts in utero or during early postnatal life. Because of its ability to function as an estrogen receptor (ER) agonist, BPA has the potential to disrupt normal endocrine signaling through regulation of ER target genes. Some genes are regulated by both estradiol (E2) and BPA, but those exclusive to either agent have not been described. Using a yeast strain incorporating a vitellogenin A2 ERE-LacZ reporter gene into the genome, we found that BPA induced expression of the reporter in colonies transformed with the ER{alpha} expression plasmid, illustrating BPA-mediated regulation within a chromatin context. Additionally, a reporter gene transiently transfected into the endometrial cancer (Ishikawa) cell line also showed BPA activity, although at 100-fold less potency than E2. To compare global gene expression in response to BPA and E2, we used a variant of the MCF-7 breast cancer cell line stably expressing HA-tagged ER{alpha}. Cultures were treated for 3 h with an ethanol vehicle, E2 (10{sup -8} M), or BPA (10{sup -6} M), followed by isolation of RNA and microarray analysis with the human U95A probe array (Affymetrix, Santa Clara, CA, USA). More than 300 genes were changed 2-fold or more by either or both agents, with roughly half being up-regulated and half down-regulated. A number of growth- and development-related genes, such as HOXC1 and C6, Wnt5A, Frizzled, TGF{beta}-2, and STAT inhibitor 2, were found to be affected exclusively by BPA. We used quantitative real-time PCR to verify regulation of the HOXC6 gene, which showed decreased expression of approximately 2.5-fold by BPA. These results reveal novel effects by BPA and E2, raising interesting possibilities regarding the role of endocrine disruptors in sexual development.

  6. Cardiac lipin 1 expression is regulated by the peroxisome proliferator activated receptor γ coactivator 1α/estrogen related receptor axis.

    PubMed

    Mitra, Mayurranjan S; Schilling, Joel D; Wang, Xiaowei; Jay, Patrick Y; Huss, Janice M; Su, Xiong; Finck, Brian N

    2011-07-01

    Lipin family proteins (lipin 1, 2, and 3) are bifunctional intracellular proteins that regulate metabolism by acting as coregulators of DNA-bound transcription factors and also dephosphorylate phosphatidate to form diacylglycerol [phosphatidate phosphohydrolase activity] in the triglyceride synthesis pathway. Herein, we report that lipin 1 is enriched in heart and that hearts of mice lacking lipin 1 (fld mice) exhibit accumulation of phosphatidate. We also demonstrate that the expression of the gene encoding lipin 1 (Lpin1) is under the control of the estrogen-related receptors (ERRs) and their coactivator the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α). PGC-1α, ERRα, or ERRγ overexpression increased Lpin1 transcription in cultured ventricular myocytes and the ERRs were associated with response elements in the first intron of the Lpin1 gene. Concomitant RNAi-mediated knockdown of ERRα and ERRγ abrogated the induction of lipin 1 expression by PGC-1α overexpression. Consistent with these data, 3-fold overexpression of PGC-1α in intact myocardium of transgenic mice increased cardiac lipin 1 and ERRα/γ expression. Similarly, injection of the β2-adrenergic agonist clenbuterol induced PGC-1α and lipin 1 expression, and the induction in lipin 1 after clenbuterol occurred in a PGC-1α-dependent manner. In contrast, expression of PGC-1α, ERRα, ERRγ, and lipin 1 was down-regulated in failing heart. Cardiac phosphatidic acid phosphohydrolase activity was also diminished, while cardiac phosphatidate content was increased, in failing heart. Collectively, these data suggest that lipin 1 is the principal lipin protein in the myocardium and is regulated in response to physiologic and pathologic stimuli that impact cardiac metabolism. PMID:21549711

  7. Cardiac lipin 1 expression is regulated by the peroxisome proliferator activated receptor γ coactivator 1α/estrogen related receptor axis

    PubMed Central

    Mitra, Mayurranjan S.; Schilling, Joel D.; Wang, Xiaowei; Jay, Patrick Y.; Huss, Janice M.; Su, Xiong; Finck, Brian N.

    2011-01-01

    Lipin family proteins (lipin 1, 2, and 3) are bifunctional intracellular proteins that regulate metabolism by acting as coregulators of DNA-bound transcription factors and also dephosphorylate phosphatidate to form diacylglycerol [phosphatidate phosphohydrolase activity] in the triglyceride synthesis pathway. Herein, we report that lipin 1 is enriched in heart and that hearts of mice lacking lipin 1 (fld mice) exhibit accumulation of phosphatidate. We also demonstrate that the expression of the gene encoding lipin 1 (Lpin1) is under the control of the estrogen-related receptors (ERRs) and their coactivator the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α). PGC-1α, ERRα, or ERRγ overexpression increased Lpin1 transcription in cultured ventricular myocytes and the ERRs were associated with response elements in the first intron of the Lpin1 gene. Concomitant RNAi-mediated knockdown of ERRα and ERRγ abrogated the induction of lipin 1 expression by PGC-1α overexpression. Consistent with these data, 3-fold overexpression of PGC-1α in intact myocardium of transgenic mice increased cardiac lipin 1 and ERRα/γ expression. Similarly, injection of the β2-adrenergic agonist clenbuterol induced PGC-1α and lipin 1 expression, and the induction in lipin 1 after clenbuterol occurred in a PGC-1α-dependent manner. In contrast, expression of PGC-1α, ERRα, ERRγ, and lipin 1 was down-regulated in failing heart. Cardiac phosphatidic acid phosphohydrolase activity was also diminished, while cardiac phosphatidate content was increased, in failing heart. Collectively, these data suggest that lipin 1 is the principal lipin protein in the myocardium and is regulated in response to physiologic and pathologic stimuli that impact cardiac metabolism. PMID:21549711

  8. Visualization of Estrogen Receptor Transcriptional Activation in Zebrafish

    PubMed Central

    Halpern, Marnie E.

    2011-01-01

    Estrogens regulate a diverse range of physiological processes and affect multiple tissues. Estrogen receptors (ERs) regulate transcription by binding to DNA at conserved estrogen response elements, and such elements have been used to report ER activity in cultured cells and in transgenic mice. We generated stable, transgenic zebrafish containing five consecutive elements upstream of a c-fos minimal promoter and green fluorescent protein (GFP) to visualize and quantify transcriptional activation in live larvae. Transgenic larvae show robust, dose-dependent estrogen-dependent fluorescent labeling in the liver, consistent with er gene expression, whereas ER antagonists inhibit GFP expression. The nonestrogenic steroids dexamethasone and progesterone fail to activate GFP, confirming ER selectivity. Natural and synthetic estrogens activated the transgene with varying potency, and two chemicals, genistein and bisphenol A, preferentially induce GFP expression in the heart. In adult fish, fluorescence was observed in estrogenic tissues such as the liver, ovary, pituitary gland, and brain. Individual estrogen-responsive neurons and their projections were visualized in the adult brain, and GFP-positive neurons increased in number after 17β-estradiol exposure. The transgenic estrogen-responsive zebrafish allow ER signaling to be monitored visually and serve as in vivo sentinels for detection of estrogenic compounds. PMID:21540282

  9. [Estrogen receptor alpha in obesity and diabetes].

    PubMed

    Cahua-Pablo, José Ángel; Flores-Alfaro, Eugenia; Cruz, Miguel

    2016-01-01

    Estradiol (E2) is an important hormone in reproductive physiology, cardiovascular, skeletal and in the central nervous system (CNS). In human and rodents, E2 and its receptors are involved in the control of energy and glucose metabolism in health and metabolic diseases. The estrogen receptor (ER) belongs to the superfamily of nuclear receptors (NR), which are transcription factors that regulate gene expression. Three ER, ER-alpha, ER-beta and the G protein-coupled ER (GPER; also called GPR30) in tissues are involved in glucose and lipid homeostasis. Also, it may have important implications for risk factors associated with metabolic syndrome (MS), insulin resistance (IR), obesity and type 2 diabetes (T2D). PMID:27197110

  10. Localization of estrogen receptor in the central lymphoid organs of chickens during the late stage of embryogenesis.

    PubMed

    Katayama, Masafumi; Fukuda, Tomokazu; Narabara, Kiyoaki; Abe, Asaki; Kondo, Yasuhiro

    2012-01-01

    Immunological function in chicks is greatly affected by estrogen treatment during embryogenesis, but the mechanism of the estrogen effect is not fully understood. To elucidate the effect of estrogen on immune function, we observed estrogen receptor expression in the thymus and bursa of chick embryos by immunohistochemistry. We compared the distribution of estrogen receptor-positive cells with that of keratin-positive epithelial cells. Intense expression of estrogen receptors was detected in thymic and bursal lymphocytes. In peripheral lymphocytes, ER mRNA was detected by RT-PCR analysis. The results of fluorescence-activated cell sorting analysis indicated that the estrogen receptor was expressed in the cytoplasm of the lymphocytes. Furthermore, intense expression of the estrogen receptor was also confirmed in thymic Hassall's corpuscles, bursal follicle-associated epithelial cells, and the bursal interfollicular epithelium. Our results indicate that estrogen affects the differentiation of thymic and bursal lymphocytes, suggesting that the underlying role for estrogen in immune function. PMID:23132558

  11. Development of a quantitative diagnostic method of estrogen receptor expression levels by immunohistochemistry using organic fluorescent material-assembled nanoparticles

    SciTech Connect

    Gonda, Kohsuke; Miyashita, Minoru; Watanabe, Mika; Takahashi, Yayoi; Goda, Hideki; Okada, Hisatake; Nakano, Yasushi; Tada, Hiroshi; Amari, Masakazu; Ohuchi, Noriaki

    2012-09-28

    Highlights: Black-Right-Pointing-Pointer Organic fluorescent material-assembled nanoparticles for IHC were prepared. Black-Right-Pointing-Pointer New nanoparticle fluorescent intensity was 10.2-fold greater than Qdot655. Black-Right-Pointing-Pointer Nanoparticle staining analyzed a wide range of ER expression levels in tissue. Black-Right-Pointing-Pointer Nanoparticle staining enhanced the quantitative sensitivity for ER diagnosis. -- Abstract: The detection of estrogen receptors (ERs) by immunohistochemistry (IHC) using 3,3 Prime -diaminobenzidine (DAB) is slightly weak as a prognostic marker, but it is essential to the application of endocrine therapy, such as antiestrogen tamoxifen-based therapy. IHC using DAB is a poor quantitative method because horseradish peroxidase (HRP) activity depends on reaction time, temperature and substrate concentration. However, IHC using fluorescent material provides an effective method to quantitatively use IHC because the signal intensity is proportional to the intensity of the photon excitation energy. However, the high level of autofluorescence has impeded the development of quantitative IHC using fluorescence. We developed organic fluorescent material (tetramethylrhodamine)-assembled nanoparticles for IHC. Tissue autofluorescence is comparable to the fluorescence intensity of quantum dots, which are the most representative fluorescent nanoparticles. The fluorescent intensity of our novel nanoparticles was 10.2-fold greater than quantum dots, and they did not bind non-specifically to breast cancer tissues due to the polyethylene glycol chain that coated their surfaces. Therefore, the fluorescent intensity of our nanoparticles significantly exceeded autofluorescence, which produced a significantly higher signal-to-noise ratio on IHC-imaged cancer tissues than previous methods. Moreover, immunostaining data from our nanoparticle fluorescent IHC and IHC with DAB were compared in the same region of adjacent tissues sections to

  12. Temporal Heterogeneity of Estrogen Receptor Expression in Bone-Dominant Breast Cancer: 18F-Fluoroestradiol PET Imaging Shows Return of ER Expression

    PubMed Central

    Currin, Erin; Peterson, Lanell M.; Schubert, Erin K.; Link, Jeanne M.; Krohn, Kenneth A.; Livingston, Robert B.; Mankoff, David A.; Linden, Hannah M.

    2016-01-01

    Changes in estrogen receptor (ER) expression over the course of therapy may affect response to endocrine therapy. However, measuring temporal changes in ER expression requires serial biopsies, which are impractical and poorly tolerated by most patients. Functional ER imaging using 18F-fluoroestradiol (FES)-PET provides a noninvasive measure of regional ER expression and is ideally suited to serial studies. Additionally, lack of measurable FES uptake in metastatic sites of disease predict tumor progression in patients with ER-positive primary tumors treated with endocrine therapy. This report presents a case of restored sensitivity to endocrine therapy in a patient with bone-dominant breast cancer who underwent serial observational FES-PET imaging over the course of several treatments at our center, demonstrating the temporal heterogeneity of regional ER expression. Although loss and restoration of endocrine sensitivity in patients who have undergone prior hormonal and cytotoxic treatments has been reported, this is, to our knowledge, the first time the accompanying changes in ER expression have been documented by molecular imaging. PMID:26850484

  13. The Involvement of Angiotensin Type 1 and Type 2 Receptors in Estrogen-Induced Cell Proliferation and Vascular Endothelial Growth Factor Expression in the Rat Anterior Pituitary

    PubMed Central

    Lawnicka, Hanna; Ptasinska-Wnuk, Dorota; Mucha, Slawomir; Kunert-Radek, Jolanta; Pawlikowski, Marek; Stepien, Henryk

    2012-01-01

    The aim of our study was to examine the involvement of renin-angiotensin system (RAS) in estrogen-induced lactotropes proliferation and vascular endothelial growth factor (VEGF) expression in rat pituitary. The study was performed on Fisher 344 rats underwent 8-day treatment with diethylstilboestrol (DES). The proliferation index (PCNA) and VEGF expression in pituitary sections were estimated using immunohistochemical methods. Treatment with DES increased the number of PCNA-positive cells, VEGF-positive cells, and VEGF-positive blood vessels in pituitary. Stimulatory effect of estrogen on cell proliferation and VEGF expression in blood vessels was attenuated by losartan, PD123319, and captopril. VEGF immunoreactivity in pituitary cells of DES-treated rats was decreased by AT1 antagonist and not changed by AT2 blocker and ACE inhibitor. Our findings suggest the involvement of RAS in DES-induced cell proliferation and VEGF expression in pituitary. Both the AT1 and AT2 receptors appear to mediate the estrogen-dependent mitogenic and proangiogenic effects in rat pituitary. PMID:22645419

  14. 17β-Estradiol Induces Sulfotransferase 2A1 Expression through Estrogen Receptor α

    PubMed Central

    Li, Wei; Ning, Miaoran; Koh, Kwi Hye; Kim, Heesue

    2014-01-01

    Sulfotransferase (SULT) 2A1 catalyzes sulfonation of drugs and endogenous compounds and plays an important role in xenobiotic metabolism as well as in the maintenance of steroid and lipid homeostasis. A recent study showed that 17β-estradiol (E2) increases the mRNA levels of SULT2A1 in human hepatocytes. Here we report the underlying molecular mechanisms. E2 enhanced SULT2A1 expression in human hepatocytes and HepG2-ER cells (HepG2 stably expressing ERα). SULT2A1 induction by E2 was abrogated by antiestrogen ICI 182,780, indicating a key role of ERα in the induction. Results from deletion and mutation assays of SULT2A1 promoter revealed three cis-elements located within –257/+140 region of SULT2A1 that are potentially responsible for the induction. Chromatin immunoprecipitation assay verified the recruitment of ERα to the promoter region. Electrophoretic mobility shift assays revealed that AP-1 proteins bind to one of the cis-elements. Interestingly, SULT2A1 promoter assays using ERα mutants revealed that the DNA-binding domain of ERα is indispensable for SULT2A1 induction by E2, suggesting that direct ERα binding to the SULT2A1 promoter is also necessary for the induction. Taken together, our results indicate that E2 enhances SULT2A1 expression by both the classical and nonclassical mechanisms of ERα action. PMID:24492894

  15. Stress induced hippocampal mineralocorticoid and estrogen receptor β gene expression and long-term potentiation in male adult rats is sensitive to early-life stress experience.

    PubMed

    Wang, Han; Meyer, Katrin; Korz, Volker

    2013-02-01

    Glucocorticoid hormones and their receptors have been identified to be involved in emotional and cognitive disorders in early stressed subjects during adulthood. However, the impact of other steroid hormones and receptors has been considered less. Especially, functional roles of estrogen and estrogen receptors in male subjects are largely unknown. Therefore, we measured hippocampal concentrations of 17β-estradiol, corticosterone and testosterone, as well as the gene expression of estrogen receptor α and β (ERα, β), androgen receptor (AR), glucocorticoid (GR) and mineralocorticoid (MR) receptors after stress in adulthood in maternally separated (MS+; at postnatal days 14-16 for 6h each day) and control (MS-) male rats. In vivo hippocampal long-term potentiation (LTP) serves as a cellular model of learning and memory formation. Population spike- (PSA) and the fEPSP-LTP within the dentate gyrus (DG) were reinforced by elevated-platform-stress (EP-stress) in MS- but not in MS+ rats. MR- and ERβ-mRNA were upregulated 1h after EP-stress in MS- but not in MS+ rats as compared to non-stressed littermates. Infusion of an MR antagonist before LTP induction blocked early- and late-PSA- and -fEPSP-LTP, whereas blockade of ERβ impaired only the late PSA-LTP. Application of a DNA methyltransferase (DNMT) inhibitor partly restored the LTP-reinforcement in MS+ rats, accompanied by a retrieval of ERβ- but not MR-mRNA upregulation. Basal ERβ gene promoter methylation was similar between groups, whereas MS+ and MS- rats showed different methylation patterns across CpG sites after EP-stress. These findings indicate a key role of ERβ in early-stress mediated emotionality and emotion-induced late-LTP in adult male rats via DNA methylation mechanisms. PMID:22776422

  16. Comparison of estrogen receptor-α, progesterone receptor and calponin expression in gonadotrophin-releasing hormone agonist-sensitive and -resistant uterine fibroids

    PubMed Central

    Kim, Eun Hee; Kim, Joo Young; Lee, Yoon Hee; Chong, Gun Oh; Park, Ji Young

    2014-01-01

    Objective This study was aimed to compare immunohistochemical expression of estrogen receptor (ER)-α, progesterone receptor (PR), and calponin in gonadotrophin-releasing hormone agonist (GnRH-a)-sensitive and -resistant uterine fibroids. Methods We collected data retrospectively. The sensitive group consisted of women who had reduction in uterine volume greater than 40% following GnRH-a treatment. Uterine volume was either reduced by less than 10%, or was increased in the resistant group. A tissue microarray was constructed using formalin-fixed, paraffin-embedded tissues, 31 and 26 patients for the sensitive and resistant groups, respectively. Tissue sections were immunostained with antibodies against ER-α, PR, and calponin. The intensity and area of the immunohistochemical reactions were evaluated using a semi-quantitative scoring system. The Mann-Whitney U-test, Fisher's exact test, and Spearman's rank correlation test were used for analysis of data. Results PR (P = 0.04) and calponin (P = 0.03) showed a significantly higher staining intensity in the resistant group than in the sensitive group. Both groups showed comparable expression of ER-α (P = 0.23). In correlation analysis between changes in uterine volume after GnRH-a therapy and clinicopathological factors, the immunohistochemical intensity of PR (P = 0.04) and calponin (P = 0.03) was significantly correlated with changes in uterine volume. Conclusion This study shows that GnRH-a resistance of uterine fibroids is not related to ER-α content, but the expression of PR and calponin is related with GnRH-a resistance. PMID:24678488

  17. Nuclear Receptor Coregulators Krüppel-like Factor 9 and Prohibitin 2 Expression in Estrogen-Stimulated Proliferation of Mouse Uterine Endometrial Cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Estrogen receptor-alpha (ER alpha) influences many physiological processes by binding to its ligand estrogen (E2) and interacting with nuclear receptor coactivator and corepressor proteins to regulate transcription in target tissues. In the uterus, dysregulated ER-alpha activity leads to aberrant ce...

  18. Nuclear receptor co-regulator Kruppel-like factor 9 and prohibitin 2 expression in estrogen-induced epithelial cell proliferation in the mouse uterus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Estrogen, acting through its cognate receptor estrogen receptor-' (ESR1), is a critical regulator of uterine endometrial epithelial proliferation. Although the dynamic communication between endometrial stromal (ST) and epithelial cells is considered to be an important component in this process, key ...

  19. Novel Promising Estrogenic Receptor Modulators: Cytotoxic and Estrogenic Activity of Benzanilides and Dithiobenzanilides

    PubMed Central

    Kucinska, Malgorzata; Giron, Maria-Dolores; Piotrowska, Hanna; Lisiak, Natalia; Granig, Walter H.; Lopez-Jaramillo, Francisco-Javier; Salto, Rafael; Murias, Marek; Erker, Thomas

    2016-01-01

    The cytotoxicity of 27 benzanilides and dithiobenzanilides built on a stilbene scaffold and possessing various functional groups in aromatic rings previously described for their spasmolytic properties was assayed on three human cancer cell lines (A549 –lung adenocarcinoma, MCF-7 estrogen dependent breast adenocarcinoma and MDA-MB-231 estrogen independent breast adenocarcinoma) and 2 non-tumorigenic cell lines (CCD39Lu–lung fibroblasts, MCF-12A - breast epithelial). Three compounds (6, 15 and 18) showed selective antiproliferative activity against estrogen dependent MCF-7 cancer cells and their estrogenic activity was further confirmed in MCF-7 transfected with an estrogen receptor reporter plasmid and in HEK239 cells over-expressing the estrogen receptor alpha (ERα). Compound 18 is especially interesting as a potential candidate for therapy since it is highly toxic and selective towards estrogen dependent MCF7 cell lines (IC50 = 5.07 μM versus more than 100 μM for MDA-MB-231) and almost innocuous for normal breast cells (IC50 = 91.46 μM for MCF-12A). Docking studies have shown that compound 18 interacts with the receptor in the same cavity as estradiol although the extra aromatic ring is involved in additional binding interactions with residue W383. The role of W383 and the extended binding mode were confirmed by site-directed mutagenesis. PMID:26730945

  20. Targeted Radiotherapy of Estrogen Receptor Positive Tumors

    SciTech Connect

    Raghavan Rajagopalan

    2006-08-31

    The overall objectives of the proposal were to develop estrogen receptor (ER) binding small molecule radiopharmaceuticals for targeted radiotherapy of ER positive (ER+) tumors. In particular, this proposal focused on embedding a {sup 186,188}Re or a {sup 32}P radionuclide into an estrogen steroidal framework by isosteric substitution such that the resulting structure is topologically similar to the estrogen (estrogen mimic). The estrogen mimic molecules expected to bind to the ER and exhibit biodistribution akin to that of native estrogen due to structural mimicry. It is anticipated that the {sup 186,188}Re- or a {sup 32}P-containing estrogen mimics will be useful for targeted molecular radiotherapy of ER+ tumors. It is well established that the in vivo target tissue uptake of estrogen like steroidal molecules is related to the binding of the steroids to sex hormone binding globulin (SHBG). SHBG is important in the uptake of estrogens and testosterone in target tissues by SHBG receptors on the cell surface. However, hitherto the design of estrogen like small molecule radiopharmaceuticals was focused on optimizing ER binding characteristics without emphasis on SHBG binding properties. Consequently, even the molecules with good ER affinity in vitro, performed poorly in biodistribution studies. Based on molecular modeling studies the proposal focused on developing estrogen mimics 1-3 which were topologically similar to native estrogens, and form hydrogen bonds in ER and SHBG in the same manner as those of native estrogens. To this end the technical objectives of the proposal focused on synthesizing the rhenium-estrone and estradiol mimics 1 and 2 respectively, and phosphorous estradiol mimic 3 and to assess their stability and in vitro binding characteristics to ER and SHBG.

  1. Antiproliferative effect of the Ginkgo biloba extract is associated with the enhancement of cytochrome P450 1B1 expression in estrogen receptor-negative breast cancer cells

    PubMed Central

    ZHAO, XIAO-DAN; DONG, NI; MAN, HONG-TAO; FU, ZHONG-LIN; ZHANG, MEI-HONG; KOU, SHUANG; MA, SHI-LIANG

    2013-01-01

    Ginkgo biloba is a dioecious tree and its extract is a complex mixture that has been used for thousands of years to treat a variety of ailments in traditional Chinese medicine. The aim of this study was to present our observations on the inhibitory effects of different Ginkgo biloba extracts on human breast cancer cell proliferation and growth. Our results demonstrated that treatment of MCF-7 and MDA-MB-231 human breast cancer cells with Ginkgo biloba leaves and ginkgo fruit extract inhibited cell proliferation. It was also observed that this inhibition was accompanied by the enhancement of cytochrome P450 (CYP) 1B1 expression in MDA-MB-231 cells. In addition, treatment with ginkgo fruit extract resulted in a higher CYP1B1 expression in MDA-MB-231 cells compared to treatment with the Ginkgo biloba leaves extract. Our results suggested that the inhibitory effects of the Ginkgo biloba extract on estrogen receptor-negative breast cancer proliferation and the induction of CYP1B1 expression may be exerted through an alternative pathway, independent of the estrogen receptor or the aryl hydrocarbon receptor pathway. PMID:24649031

  2. Effects of pinostrobin on estrogen metabolism and estrogen receptor transactivation.

    PubMed

    Le Bail, J C; Aubourg, L; Habrioux, G

    2000-08-01

    The interaction between the estrogen receptor and 5-hydroxy-7-methoxyflavanone (pinostrobin) was studied in the presence or absence of estradiol or dehydroepiandrosterone sulfate (DHEAS), respectively, using a stably transfected human breast cancer cell line (MVLN). We also evaluated its action on the proliferation in estrogen-dependent (MCF-7) human breast cancer cells in the same conditions than the estrogen receptor assay. On the other hand pinostrobin was evaluated for their effects on the human placental aromatase, 3beta-hydroxysteroid dehydrogenase Delta(4)/Delta(5) isomerase and 17beta-hydroxysteroid dehydrogenase activities. Pinostrobin did not possess antiestrogenic activity but presented anti-aromatase activity and decreased the growth of MCF-7 cells induced by DHEAS and E(2). This study provides particularly evidence of the potential biological interest of pinostrobin among the flavonoids. PMID:10840157

  3. Molecular cloning, characterization, tissue distribution and mRNA expression changes during the hibernation and reproductive periods of estrogen receptor alpha (ESR1) in Chinese alligator, Alligator sinensis.

    PubMed

    Zhang, Ruidong; Hu, Yuehong; Wang, Huan; Yan, Peng; Zhou, Yongkang; Wu, Rong; Wu, Xiaobing

    2016-10-01

    Chinese alligator, Alligator sinensis, is a critically endangered reptile species unique to China. Little is known about the mechanism of growth- and reproduction-related hormones gene expression in Chinese alligator. Estrogens play important roles in regulating multiple reproduction- and non-reproduction-related functions by binding to their corresponding receptors. Here, the full-length cDNA of estrogen receptor alpha (ERα/ESR1) was cloned and sequenced from Chinese alligator for the first time, which comprises 1764bp nucleotides and encodes a predicted protein of 587 amino acids. Phylogenetic analysis of ESR1 showed that crocodilians and turtles were the sister-group of birds. The results of real-time quantitative PCR indicated that the ESR1 mRNA was widely expressed in the brain and peripheral tissues. In the brain and pituitary gland, ESR1 was most highly transcribed in the cerebellum. But in other peripheral tissues, ESR1 mRNA expression level was the highest in the ovary. Compared with hibernation period, ESR1 mRNA expression levels were increased significantly in the reproductive period (P<0.05) in cerebellum, pituitary gland, liver, spleen, lung, kidney and ovary, while no significant change in other examined tissues (P>0.05). The ESR1 mRNA expression levels changes during the two periods of different tissues suggested that ESR1 might play an important role in mediation of estrogenic multiple reproductive effects in Chinese alligator. Furthermore, it was the first time to quantify ESR1 mRNA level in the brain of crocodilians, and the distribution and expression of ESR1 mRNA in the midbrain, cerebellum and medulla oblongata was also reported for the first time in reptiles. PMID:27212643

  4. Adaptive increases in expression and vasodilator activity of estrogen receptor subtypes in a blood vessel-specific pattern during pregnancy.

    PubMed

    Mata, Karina M; Li, Wei; Reslan, Ossama M; Siddiqui, Waleed T; Opsasnick, Lauren A; Khalil, Raouf A

    2015-11-15

    Normal pregnancy is associated with adaptive hemodynamic, hormonal, and vascular changes, and estrogen (E2) may promote vasodilation during pregnancy; however, the specific E2 receptor (ER) subtype, post-ER signaling mechanism, and vascular bed involved are unclear. We tested whether pregnancy-associated vascular adaptations involve changes in the expression/distribution/activity of distinct ER subtypes in a blood vessel-specific manner. Blood pressure (BP) and plasma E2 were measured in virgin and pregnant (day 19) rats, and the thoracic aorta, carotid artery, mesenteric artery, and renal artery were isolated for measurements of ERα, ERβ, and G protein-coupled receptor 30 [G protein-coupled ER (GPER)] expression and tissue distribution in parallel with relaxation responses to E2 (all ERs) and the specific ER agonist 4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl)-tris-phenol (PPT; ERα), diarylpropionitrile (DPN; ERβ), and G1 (GPER). BP was slightly lower and plasma E2 was higher in pregnant versus virgin rats. Western blots revealed increased ERα and ERβ in the aorta and mesenteric artery and GPER in the aorta of pregnant versus virgin rats. Immunohistochemistry revealed that the increases in ERs were mainly in the intima and media. In phenylephrine-precontracted vessels, E2 and PPT caused relaxation that was greater in the aorta and mesenteric artery but similar in the carotid and renal artery of pregnant versus virgin rats. DPN- and G1-induced relaxation was greater in the mesenteric and renal artery than in the aorta and carotid artery, and aortic relaxation to G1 was greater in pregnant versus virgin rats. The nitric oxide synthase inhibitor N(ω)-nitro-l-arginine methyl ester with or without the cyclooxygenase inhibitor indomethacin with or without the EDHF blocker tetraethylammonium or endothelium removal reduced E2, PPT, and G1-induced relaxation in the aorta of pregnant rats, suggesting an endothelium-dependent mechanism, but did not affect E2-, PPT

  5. Estrogen Sensitivity of Target Genes and Expression of Nuclear Receptor Co-Regulators in Rat Prostate after Pre- and Postnatal Exposure to the Ultraviolet Filter 4-Methylbenzylidene Camphor

    PubMed Central

    Durrer, Stefan; Ehnes, Colin; Fuetsch, Michaela; Maerkel, Kirsten; Schlumpf, Margret; Lichtensteiger, Walter

    2007-01-01

    Background and objectives In previous studies, we found that the ultraviolet filter 4-methyl-benzylidene camphor (4-MBC) exhibits estrogenic activity, is a preferential estrogen receptor (ER)-β ligand, and interferes with development of female reproductive organs and brain of both sexes in rats. Here, we report effects on male development. Methods 4-MBC (0.7, 7, 24, 47 mg/kg/day) was administered in chow to the parent generation before mating, during gestation and lactation, and to offspring until adulthood. mRNA was determined in prostate lobes by real-time reverse transcription–polymerase chain reaction and protein was determined by Western blot analysis. Results 4-MBC delayed male puberty, decreased adult prostate weight, and slightly increased testis weight. Androgen receptor (AR), insulin-like growth factor-1 (IGF-1), ER-α, and ER-β expression in prostate were altered at mRNA and protein levels, with stronger effects in dorsolateral than ventral prostate. To assess sensitivity of target genes to estrogens, offspring were castrated on postnatal day 70, injected with 17β-estradiol (E2; 10 or 50 μg/kg, sc) or vehicle on postnatal day 84, and sacrificed 6 hr later. Acute repression of AR and IGF-1 mRNAs by E2, studied in ventral prostate, was reduced by 4-MBC exposure. This was accompanied by reduced co-repressor N-CoR (nuclear receptor co-repressor) protein in ventral and dorsolateral prostate, whereas steroid receptor coactivator-1 (SRC-1) protein levels were unaffected. Conclusions Our data indicate that 4-MBC affects development of male reproductive functions and organs, with a lowest observed adverse effect level of 0.7 mg/kg. Nuclear receptor coregulators were revealed as targets for endocrine disruptors, as shown for N-CoR in prostate and SRC-1 in uterus. This may have widespread effects on gene regulation. PMID:18174949

  6. Gene expression profiling in hearts of diabetic mice uncovers a potential role of estrogen-related receptor γ in diabetic cardiomyopathy.

    PubMed

    Lasheras, Jaime; Vilà, Maria; Zamora, Mònica; Riu, Efrén; Pardo, Rosario; Poncelas, Marcos; Cases, Ildefonso; Ruiz-Meana, Marisol; Hernández, Cristina; Feliu, Juan E; Simó, Rafael; García-Dorado, David; Villena, Josep A

    2016-07-15

    Diabetic cardiomyopathy is characterized by an abnormal oxidative metabolism, but the underlying mechanisms remain to be defined. To uncover potential mechanisms involved in the pathophysiology of diabetic cardiomyopathy, we performed a gene expression profiling study in hearts of diabetic db/db mice. Diabetic hearts showed a gene expression pattern characterized by the up-regulation of genes involved in lipid oxidation, together with an abnormal expression of genes related to the cardiac contractile function. A screening for potential regulators of the genes differentially expressed in diabetic mice found that estrogen-related receptor γ (ERRγ) was increased in heart of db/db mice. Overexpression of ERRγ in cultured cardiomyocytes was sufficient to promote the expression of genes involved in lipid oxidation, increase palmitate oxidation and induce cardiomyocyte hypertrophy. Our findings strongly support a role for ERRγ in the metabolic alterations that underlie the development of diabetic cardiomyopathy. PMID:27062900

  7. Differential estrogen receptor binding of estrogenic substances: a species comparison.

    PubMed

    Matthews, J; Celius, T; Halgren, R; Zacharewski, T

    2000-11-15

    The study investigated the ability of 34 natural and synthetic chemicals to compete with [3H]17beta-estradiol (E2) for binding to bacterially expressed glutathione-S-transferase (GST)-estrogen receptors (ER) fusion proteins from five different species. Fusion proteins consisted of the ER D, E and F domains of human alpha (GST-hERalphadef), mouse alpha (GST-mERalphadef), chicken (GST-cERdef), green anole (GST-aERdef) and rainbow trout ERs (GST-rtERdef). All five fusion proteins displayed high affinity for E2 with dissociation constants (K(d)) ranging from 0.3 to 0.9 nM. Although, the fusion proteins exhibited similar binding preferences and binding affinities for many of the chemicals, several differences were observed. For example, alpha-zearalenol bound with greater affinity to GST-rtERdef than E2, which was in contrast to other GST-ERdef fusion proteins examined. Coumestrol, genistein and naringenin bound with higher affinity to the GST-aERdef, than to the other GST-ERdef fusion proteins. Many of the industrial chemicals examined preferentially bound to GST-rtERdef. Bisphenol A, 4-t-octylphenol and o,p' DDT bound with approximately a ten-fold greater affinity to GST-rtERdef than to other GST-ERdefs. Methoxychlor, p,p'-DDT, o,p'-DDE, p,p'-DDE, alpha-endosulfan and dieldrin weakly bound to the ERs from the human, mouse, chicken and green anole. In contrast, these compounds completely displaced [3H]E2 from GST-rtERdef. These results demonstrate that ERs from different species exhibit differential ligand preferences and relative binding affinities for estrogenic compounds and that these differences may be due to the variability in the amino acid sequence within their respective ER ligand binding domains. PMID:11162928

  8. Inhibition of Advanced Glycation End Products (AGEs) Accumulation by Pyridoxamine Modulates Glomerular and Mesangial Cell Estrogen Receptor α Expression in Aged Female Mice

    PubMed Central

    Xia, Xiaomei; Cai, Weijing; Choi, Rhea; Striker, Gary E.; Elliot, Sharon J.

    2016-01-01

    Age-related increases in oxidant stress (OS) play a role in regulation of estrogen receptor (ER) expression in the kidneys. In this study, we establish that in vivo 17β-estradiol (E2) replacement can no longer upregulate glomerular ER expression by 21 months of age in female mice (anestrous). We hypothesized that advanced glycation end product (AGE) accumulation, an important source of oxidant stress, contributes to these glomerular ER expression alterations. We treated 19-month old ovariectomized female mice with pyridoxamine (Pyr), a potent AGE inhibitor, in the presence or absence of E2 replacement. Glomerular ERα mRNA expression was upregulated in mice treated with both Pyr and E2 replacement and TGFβ mRNA expression decreased compared to controls. Histological sections of kidneys demonstrated decreased type IV collagen deposition in mice receiving Pyr and E2 compared to placebo control mice. In addition, anti-AGE defenses Sirtuin1 (SIRT1) and advanced glycation receptor 1 (AGER1) were also upregulated in glomeruli following treatment with Pyr and E2. Mesangial cells isolated from all groups of mice demonstrated similar ERα, SIRT1, and AGER1 expression changes to those of whole glomeruli. To demonstrate that AGE accumulation contributes to the observed age-related changes in the glomeruli of aged female mice, we treated mesangial cells from young female mice with AGE-BSA and found similar downregulation of ERα, SIRT1, and AGER1 expression. These results suggest that inhibition of intracellular AGE accumulation with pyridoxamine may protect glomeruli against age-related oxidant stress by preventing an increase of TGFβ production and by regulation of the estrogen receptor. PMID:27428057

  9. Estrogen receptor beta (ERβ) mediates expression of β-catenin and proliferation in prostate cancer cell line PC-3.

    PubMed

    Lombardi, Ana Paola G; Pisolato, Raisa; Vicente, Carolina M; Lazari, Maria Fatima M; Lucas, Thaís F G; Porto, Catarina S

    2016-07-15

    The aim of the present study was to characterize the mechanism underlying estrogen effects on the androgen-independent prostate cancer cell line PC-3. 17β-estradiol and the ERβ-selective agonist DPN, but not the ERα-selective agonist PPT, increased the incorporation of [methyl-(3)H]thymidine and the expression of Cyclin D2, suggesting that ERβ mediates the proliferative effect of estrogen on PC-3 cells. In addition, upregulation of Cyclin D2 and incorporation of [methyl-(3)H]thymidine induced by 17β-estradiol and DPN were blocked by the ERβ-selective antagonist PHTPP in PC-3 cells. Upregulation of Cyclin D2 and incorporation of [methyl-(3)H]thymidine induced by DPN were also blocked by PKF118-310, a compound that disrupts β-catenin-TCF (T-cell-specific transcription factor) complex, suggesting the involvement of β-catenin in the estradiol effects in PC-3 cells. A diffuse immunostaining for non-phosphorylated β-catenin was detected in the cytoplasm of PC-3 cells. Low levels of non-phosphorylated β-catenin immunostaining were also detected near the plasma membrane and in nuclei. Treatment of PC-3 cells with 17β-estradiol or DPN markedly increased non-phosphorylated β-catenin expression. These effects were blocked by pretreatment with the ERβ-selective antagonist PHTPP, PI3K inhibitor Wortmannin or AKT inhibitor MK-2206, indicating that ERβ-PI3K/AKT mediates non-phosphorylated β-catenin expression. Cycloheximide blocked the DPN-induced upregulation of non-phosphorylated β-catenin, suggesting de novo synthesis of this protein. In conclusion, these results suggest that estrogen may play a role in androgen-independent prostate cancer cell proliferation through a novel pathway, involving ERβ-mediated activation of β-catenin. PMID:27107935

  10. Upregulation of estrogen receptor expression in the uterus of ovariectomized B6C3F1 mice and Ishikawa cells treated with bromoethane

    SciTech Connect

    Aoyama, Hiroaki; Couse, John F.; Hewitt, Sylvia C.; Haseman, Joseph K.; He, Hong; Zheng, Xiaolin; Majstoravich, Sonja; Korach, Kenneth S.; Dixon, D. . E-mail: dixon@niehs.nih.gov

    2005-12-15

    In a 2-year NTP bioassay, Bromoethane (BE) was found to induce endometrial neoplasms in the uterus of B6C3F1 mice [; ]. In women, hormonal influences, such as 'unopposed' estrogenic stimulus, have been implicated as important etiologic factors in uterine cancer. BE, however, does not affect the serum concentrations of sex hormones in female B6C3F1 mice [] and the mechanism of BE-induced uterine carcinogenesis still remains unclear. In the present study, we examined the estrogenic effects of BE on the uterus of ovariectomized B6C3F1 mice and on Ishikawa cells. Groups of 6 mice were given daily s.c. injections of 0, 100, 500 or 1000 mg BE/kg for 3 consecutive days. Mice treated with 17{beta}-estradiol served as positive controls. Mice were necropsied 24 h after the final injection, and uteri were weighed and examined histologically and immunohistochemically along with the vagina. Changes observed in the estrogen-treated mice included increased uterine weights, edema and inflammation of the endometrium, increased epithelial layers of the uterine and vaginal lumens and keratinization of the vaginal epithelium. In the BE-treated mice, no such changes occurred; however, immunohistochemical staining of the uterus revealed a significant increase in immunoexpression of the estrogen receptor alpha (ER{alpha}) in the two higher dose groups. Analysis of mRNA also showed slightly increased uterine ER{alpha} expression in these groups. Upregulated expression of ER{alpha} was confirmed in BE-treated Ishikawa cells, in which Western blotting analyses identified an intense signal at approximately 66 kDa, which is consistent with ER{alpha}. These data suggest that upregulated expression of ER{alpha} may be important in the induction of endometrial neoplasms in BE-treated mice.

  11. Binding of estrogen receptors to switch sites and regulatory elements in the immunoglobulin heavy chain locus of activated B cells suggests a direct influence of estrogen on antibody expression.

    PubMed

    Jones, Bart G; Penkert, Rhiannon R; Xu, Beisi; Fan, Yiping; Neale, Geoff; Gearhart, Patricia J; Hurwitz, Julia L

    2016-09-01

    Females and males differ in antibody isotype expression patterns and in immune responses to foreign- and self-antigens. For example, systemic lupus erythematosus is a condition that associates with the production of isotype-skewed anti-self antibodies, and exhibits a 9:1 female:male disease ratio. To explain differences between B cell responses in males and females, we sought to identify direct interactions of the estrogen receptor (ER) with the immunoglobulin heavy chain locus. This effort was encouraged by our previous identification of estrogen response elements (ERE) in heavy chain switch (S) regions. We conducted a full-genome chromatin immunoprecipitation analysis (ChIP-seq) using DNA from LPS-activated B cells and an ERα-specific antibody. Results revealed ER binding to a wide region of DNA, spanning sequences from the JH cluster to Cδ, with peaks in Eμ and Sμ sites. Additional peaks of ERα binding were coincident with hs1,2 and hs4 sites in the 3' regulatory region (3'RR) of the heavy chain locus. This first demonstration of direct binding of ER to key regulatory elements in the immunoglobulin locus supports our hypothesis that estrogen and other nuclear hormone receptors and ligands may directly influence antibody expression and class switch recombination (CSR). Our hypothesis encourages the conduct of new experiments to evaluate the consequences of ER binding. A better understanding of ER:DNA interactions in the immunoglobulin heavy chain locus, and respective mechanisms, may ultimately translate to better control of antibody expression, better protection against pathogens, and prevention of pathologies caused by auto-immune disease. PMID:27494228

  12. Hormone Binding to Recombinant Estrogen Receptors from Human, Alligator, Quail, Salamander, and Fathead Minnow

    EPA Science Inventory

    In this work, a 96-well plate estrogen receptor binding assay was developed to facilitate the direct comparison of chemical binding to full-length recombinant estrogen receptors across vertebrate classes. Receptors were generated in a baculovirus expression system. This approach ...

  13. Kaempferol is an estrogen-related receptor alpha and gamma inverse agonist.

    PubMed

    Wang, Junjian; Fang, Fang; Huang, Zhiyan; Wang, Yanfei; Wong, Chiwai

    2009-02-18

    Kaempferol is a dietary flavonoid that is thought to function as a selective estrogen receptor modulator. In this study, we established that kaempferol also functions as an inverse agonist for estrogen-related receptors alpha and gamma (ERRalpha and ERRgamma). We demonstrated that kaempferol binds to ERRalpha and ERRgamma and blocks their interaction with coactivator peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1alpha). Kaempferol also suppressed the expressions of ERR-target genes pyruvate dehydrogenase kinase 2 and 4 (PDK2 and PDK4). This evidence suggests that kaempferol may exert some of its biological effect through both estrogen receptors and estrogen-related receptors. PMID:19171140

  14. Tibolone protects astrocytic cells from glucose deprivation through a mechanism involving estrogen receptor beta and the upregulation of neuroglobin expression.

    PubMed

    Avila-Rodriguez, Marco; Garcia-Segura, Luis Miguel; Hidalgo-Lanussa, Oscar; Baez, Eliana; Gonzalez, Janneth; Barreto, George E

    2016-09-15

    Tibolone, a synthetic steroid used for the prevention of osteoporosis and the treatment of climacteric symptoms in post-menopausal women, may exert tissue selective estrogenic actions acting on estrogen receptors (ERs). We previously showed that tibolone protects human T98G astroglial cells against glucose deprivation (GD). In this study we have explored whether the protective effect of tibolone on these cells is mediated by ERs. Experimental studies showed that both ERα and ERβ were involved in the protection by tibolone on GD cells, being ERβ preferentially involved on these actions over ERα. Tibolone increased viability of GD cells by a mechanism fully blocked by an ERβ antagonist and partially blocked by an ERα antagonist. Furthermore, ERβ inhibition prevented the effect of tibolone on nuclear fragmentation, ROS and mitochondrial membrane potential in GD cells. The protective effect of tibolone was mediated by neuroglobin. Tibolone upregulated neuroglobin in T98G cells and primary mouse astrocytes by a mechanism involving ERβ and neuroglobin silencing prevented the protective action of tibolone on GD cells. In summary, tibolone protects T98G cells by a mechanism involving ERβ and the upregulation of neuroglobin. PMID:27250720

  15. Steroid receptor coactivator-1 mediates estrogenic actions to prevent body weight gain in female mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Estrogen receptor-alpha (ERalpha) expressed by hypothalamic proopiomelanocortin and steroidogenic factor-1 neurons largely mediates the antiobesity effects of estrogens in females. However, the critical molecular events that are coupled to ERalpha and mediate estrogenic effects on energy balance rem...

  16. Estrogen receptor-associated proteins: possible mediators of hormone-induced transcription.

    PubMed

    Halachmi, S; Marden, E; Martin, G; MacKay, H; Abbondanza, C; Brown, M

    1994-06-01

    The estrogen receptor is a transcription factor which, when bound to estradiol, binds DNA and regulates expression of estrogen-responsive genes. A 160-kilodalton estrogen receptor-associated protein, ERAP160, was identified that exhibits estradiol-dependent binding to the receptor. Mutational analysis of the receptor shows that its ability to activate transcription parallels its ability to bind ERAP160. Antiestrogens are unable to promote ERAP160 binding and can block the estrogen-dependent interaction of the receptor and ERAP160 in a dose-dependent manner. This evidence suggests that ERAP160 may mediate estradiol-dependent transcriptional activation by the estrogen receptor. Furthermore, the ability of antiestrogens to block estrogen receptor-ERAP160 complex formation could account for their therapeutic effects in breast cancer. PMID:8197458

  17. A Single Neonatal Injection of Ethinyl Estradiol Impairs Passive Avoidance Learning and Reduces Expression of Estrogen Receptor α in the Hippocampus and Cortex of Adult Female Rats

    PubMed Central

    Shiga, Tatsuomi; Nakamura, Takahiro J.; Komine, Chiaki; Goto, Yoshikuni; Mizoguchi, Yasushi; Yoshida, Midori; Kondo, Yasuhiko; Kawaguchi, Maiko

    2016-01-01

    Although perinatal exposure of female rats to estrogenic compounds produces irreversible changes in brain function, it is still unclear how the amount and timing of exposure to those substances affect learning function, or if exposure alters estrogen receptor α (ERα) expression in the hippocampus and cortex. In adult female rats, we investigated the effects of neonatal exposure to a model estrogenic compound, ethinyl estradiol (EE), on passive avoidance learning and ERα expression. Female Wistar-Imamichi rats were subcutaneously injected with oil, 0.02 mg/kg EE, 2 mg/kg EE, or 20 mg/kg 17β-estradiol within 24 h after birth. All females were tested for passive avoidance learning at the age of 6 weeks. Neonatal 0.02 mg/kg EE administration significantly disrupted passive avoidance compared with oil treatment in gonadally intact females. In a second experiment, another set of experimental females, treated as described above, was ovariectomized under pentobarbital anesthesia at 10 weeks of age. At 15–17 weeks of age, half of each group received a subcutaneous injection of 5 μg estradiol benzoate a day before the passive avoidance learning test. Passive avoidance learning behavior was impaired by the 0.02 mg/kg EE dose, but notably only in the estradiol benzoate-injected group. At 17–19 weeks of age, hippocampal and cortical samples were collected from rats with or without the 5 μg estradiol benzoate injection, and western blots used to determine ERα expression. A significant decrease in ERα expression was observed in the hippocampus of the estradiol-injected, neonatal EE-treated females. The results demonstrated that exposure to EE immediately after birth decreased learning ability in adult female rats, and that this may be at least partly mediated by the decreased expression of ERα in the hippocampus. PMID:26741502

  18. A Single Neonatal Injection of Ethinyl Estradiol Impairs Passive Avoidance Learning and Reduces Expression of Estrogen Receptor α in the Hippocampus and Cortex of Adult Female Rats.

    PubMed

    Shiga, Tatsuomi; Nakamura, Takahiro J; Komine, Chiaki; Goto, Yoshikuni; Mizoguchi, Yasushi; Yoshida, Midori; Kondo, Yasuhiko; Kawaguchi, Maiko

    2016-01-01

    Although perinatal exposure of female rats to estrogenic compounds produces irreversible changes in brain function, it is still unclear how the amount and timing of exposure to those substances affect learning function, or if exposure alters estrogen receptor α (ERα) expression in the hippocampus and cortex. In adult female rats, we investigated the effects of neonatal exposure to a model estrogenic compound, ethinyl estradiol (EE), on passive avoidance learning and ERα expression. Female Wistar-Imamichi rats were subcutaneously injected with oil, 0.02 mg/kg EE, 2 mg/kg EE, or 20 mg/kg 17β-estradiol within 24 h after birth. All females were tested for passive avoidance learning at the age of 6 weeks. Neonatal 0.02 mg/kg EE administration significantly disrupted passive avoidance compared with oil treatment in gonadally intact females. In a second experiment, another set of experimental females, treated as described above, was ovariectomized under pentobarbital anesthesia at 10 weeks of age. At 15-17 weeks of age, half of each group received a subcutaneous injection of 5 μg estradiol benzoate a day before the passive avoidance learning test. Passive avoidance learning behavior was impaired by the 0.02 mg/kg EE dose, but notably only in the estradiol benzoate-injected group. At 17-19 weeks of age, hippocampal and cortical samples were collected from rats with or without the 5 μg estradiol benzoate injection, and western blots used to determine ERα expression. A significant decrease in ERα expression was observed in the hippocampus of the estradiol-injected, neonatal EE-treated females. The results demonstrated that exposure to EE immediately after birth decreased learning ability in adult female rats, and that this may be at least partly mediated by the decreased expression of ERα in the hippocampus. PMID:26741502

  19. Estrogen anti-inflammatory activity on human monocytes is mediated through cross-talk between estrogen receptor ERα36 and GPR30/GPER1.

    PubMed

    Pelekanou, Vasiliki; Kampa, Marilena; Kiagiadaki, Foteini; Deli, Alexandra; Theodoropoulos, Panayiotis; Agrogiannis, George; Patsouris, Efstratios; Tsapis, Andreas; Castanas, Elias; Notas, George

    2016-02-01

    Estrogens are known modulators of monocyte/macrophage functions; however, the underlying mechanism has not been clearly defined. Recently, a number of estrogen receptor molecules and splice variants were identified that exert different and sometimes opposing actions. We assessed the expression of estrogen receptors and explored their role in mediating estrogenic anti-inflammatory effects on human primary monocytes. We report that the only estrogen receptors expressed are estrogen receptor-α 36-kDa splice variant and G-protein coupled receptor 30/G-protein estrogen receptor 1, in a sex-independent manner. 17-β-Estradiol inhibits the LPS-induced IL-6 inflammatory response, resulting in inhibition of NF-κB transcriptional activity. This is achieved via a direct physical interaction of ligand-activated estrogen receptor-α 36-kDa splice variant with the p65 component of NF-κB in the nucleus. G-protein coupled receptor 30/G-protein estrogen receptor 1, which also physically interacts with estrogen receptor-α 36-kDa splice variant, acts a coregulator in this process, because its inhibition blocks the effect of estrogens on IL-6 expression. However, its activation does not mimic the effect of estrogens, on neither IL-6 nor NF-κB activity. Finally, we show that the estrogen receptor profile observed in monocytes is not modified during their differentiation to macrophages or dendritic cells in vitro and is shared in vivo by macrophages present in atherosclerotic plaques. These results position estrogen receptor-α 36-kDa splice variant and G-protein coupled receptor 30 as important players and potential therapeutic targets in monocyte/macrophage-dependent inflammatory processes. PMID:26394816

  20. Estrogen-related receptor gamma (ERRgamma) mediates oxygen-dependent induction of aromatase (CYP19) gene expression during human trophoblast differentiation.

    PubMed

    Kumar, Premlata; Mendelson, Carole R

    2011-09-01

    Differentiation of human cytotrophoblasts to syncytiotrophoblast and the associated induction of aromatase/hCYP19 gene expression are dependent upon a critical O(2) tension; however, the underlying molecular mechanisms remain undefined. In this study, we provide compelling evidence that expression of the orphan nuclear receptor, estrogen-related receptor γ (ERRγ), is also O(2) dependent, induced during human syncytiotrophoblast differentiation, and plays an obligatory role in the induction of placenta-specific hCYP19I.1 gene expression. Treatment with the selective ERRγ agonist, DY131, or overexpression of ERRγ, stimulated hCYP19 expression in syncytiotrophoblast. Overexpression of ERRγ prevented effects of hypoxia to repress hCYP19 gene expression in cultured trophoblasts. Conversely, small interfering RNA-mediated knockdown of endogenous ERRγ in primary trophoblasts markedly inhibited hCYP19 expression. Promoter and site-directed mutagenesis studies in transfected placental cells identified a nuclear receptor element within placenta-specific hCYP19 promoter I.1 required for ERRγ-stimulated activity. Recruitment of endogenous ERRγ to the nuclear receptor element region in hCYP19 promoter during trophoblast differentiation, assessed by chromatin immunoprecipitation, was prevented by hypoxia. Deferoxamine-induced hypoxia-inducible factor-1α (HIF-1α) levels decreased ERRγ expression, whereas knockdown of endogenous HIF-1α prevented ERRγ suppression by hypoxia. Chromatin immunoprecipitation analysis of trophoblasts cultured in hypoxia revealed recruitment of HIF-1α to one of two putative hypoxia response elements in the ERRγ promoter, providing in vivo evidence of a direct HIF-1α involvement in ERRγ expression. Collectively, these novel findings identify ERRγ as an O(2)-dependent transcription factor and HIF-1α target gene that serves a critical role in the induction of hCYP19 expression during human trophoblast differentiation. PMID:21757507

  1. Estrogen-Related Receptor γ (ERRγ) Mediates Oxygen-Dependent Induction of Aromatase (CYP19) Gene Expression during Human Trophoblast Differentiation

    PubMed Central

    Kumar, Premlata

    2011-01-01

    Differentiation of human cytotrophoblasts to syncytiotrophoblast and the associated induction of aromatase/hCYP19 gene expression are dependent upon a critical O2 tension; however, the underlying molecular mechanisms remain undefined. In this study, we provide compelling evidence that expression of the orphan nuclear receptor, estrogen-related receptor γ (ERRγ), is also O2 dependent, induced during human syncytiotrophoblast differentiation, and plays an obligatory role in the induction of placenta-specific hCYP19I.1 gene expression. Treatment with the selective ERRγ agonist, DY131, or overexpression of ERRγ, stimulated hCYP19 expression in syncytiotrophoblast. Overexpression of ERRγ prevented effects of hypoxia to repress hCYP19 gene expression in cultured trophoblasts. Conversely, small interfering RNA-mediated knockdown of endogenous ERRγ in primary trophoblasts markedly inhibited hCYP19 expression. Promoter and site-directed mutagenesis studies in transfected placental cells identified a nuclear receptor element within placenta-specific hCYP19 promoter I.1 required for ERRγ-stimulated activity. Recruitment of endogenous ERRγ to the nuclear receptor element region in hCYP19 promoter during trophoblast differentiation, assessed by chromatin immunoprecipitation, was prevented by hypoxia. Deferoxamine-induced hypoxia-inducible factor-1α (HIF-1α) levels decreased ERRγ expression, whereas knockdown of endogenous HIF-1α prevented ERRγ suppression by hypoxia. Chromatin immunoprecipitation analysis of trophoblasts cultured in hypoxia revealed recruitment of HIF-1α to one of two putative hypoxia response elements in the ERRγ promoter, providing in vivo evidence of a direct HIF-1α involvement in ERRγ expression. Collectively, these novel findings identify ERRγ as an O2-dependent transcription factor and HIF-1α target gene that serves a critical role in the induction of hCYP19 expression during human trophoblast differentiation. PMID:21757507

  2. Moving Toward Integrating Gene Expression Profiling Into High-Throughput Testing: A Gene Expression Biomarker Accurately Predicts Estrogen Receptor α Modulation in a Microarray Compendium.

    PubMed

    Ryan, Natalia; Chorley, Brian; Tice, Raymond R; Judson, Richard; Corton, J Christopher

    2016-05-01

    Microarray profiling of chemical-induced effects is being increasingly used in medium- and high-throughput formats. Computational methods are described here to identify molecular targets from whole-genome microarray data using as an example the estrogen receptor α (ERα), often modulated by potential endocrine disrupting chemicals. ERα biomarker genes were identified by their consistent expression after exposure to 7 structurally diverse ERα agonists and 3 ERα antagonists in ERα-positive MCF-7 cells. Most of the biomarker genes were shown to be directly regulated by ERα as determined by ESR1 gene knockdown using siRNA as well as through chromatin immunoprecipitation coupled with DNA sequencing analysis of ERα-DNA interactions. The biomarker was evaluated as a predictive tool using the fold-change rank-based Running Fisher algorithm by comparison to annotated gene expression datasets from experiments using MCF-7 cells, including those evaluating the transcriptional effects of hormones and chemicals. Using 141 comparisons from chemical- and hormone-treated cells, the biomarker gave a balanced accuracy for prediction of ERα activation or suppression of 94% and 93%, respectively. The biomarker was able to correctly classify 18 out of 21 (86%) ER reference chemicals including "very weak" agonists. Importantly, the biomarker predictions accurately replicated predictions based on 18 in vitro high-throughput screening assays that queried different steps in ERα signaling. For 114 chemicals, the balanced accuracies were 95% and 98% for activation or suppression, respectively. These results demonstrate that the ERα gene expression biomarker can accurately identify ERα modulators in large collections of microarray data derived from MCF-7 cells. PMID:26865669

  3. The analysis of estrogen receptor-α positive breast cancer stem-like cells unveils a high expression of the serpin proteinase inhibitor PI-9: Possible regulatory mechanisms.

    PubMed

    Lauricella, Marianna; Carlisi, Daniela; Giuliano, Michela; Calvaruso, Giuseppe; Cernigliaro, Cesare; Vento, Renza; D'Anneo, Antonella

    2016-07-01

    Breast cancer stem cells seem to play important roles in breast tumor recurrence and endocrine therapy resistance, although the underlying mechanisms have not been well established. Moreover, in some tumor systems the immunosurveillance failure against cancer cells has been related to the presence of the granzyme B inhibitor PI-9. This study explored the status of PI-9 in tumorspheres isolated from estrogen receptor-α positive (ERα+) breast cancer MCF7 cells. Studies were performed in tertiary tumorspheres which possess high levels of stemness markers (Nanog, Oct3/4 and Sox2) and self-renewal ability. The exposure to estrogens (17-β estradiol and genistein) increased the number and sizes of tumorspheres, promoting cell proliferation as demonstrated by the increase in the proliferating cell nuclear antigen (PCNA). The study of the three isoforms (66, 46 and 36 kDa) of ERα disclosed that tertiary tumorspheres exhibit a marked increase in ERα36, while the level of ERα66, which is highly expressed in MCF7 cells, declines. Although it is known that PI-9 is a transcriptional target of ERα66, surprisingly in tertiary tumorspheres, despite the reduced level of ERα66, the protein and mRNA content of PI-9 is higher than in MCF7 cells. Treatment with estrogens further increased PI-9 level while decreased that of ERα66 isoform thus excluding the involvement of this receptor isoform in the event. Moreover, our studies also provided evidence that tertiary tumorspheres express elevated levels of CXCR4 and phospho-p38, suggesting that the high PI-9 content might be ascribed to the activation of the proliferative CXCR4/phospho-p38 axis. Taken together, these events could supply a selective advantage to breast cancer stem cells by interfering with immunosurveillance systems and open up the avenue to new possible targets for breast cancer treatment. PMID:27121069

  4. Reversal of fortune: estrogen receptor-β in endometriosis.

    PubMed

    Simmen, Rosalia C M; Kelley, Angela S

    2016-08-01

    Enhanced inflammation and reduced apoptosis sustain the growth of endometriotic lesions. Alterations in the expression of estrogen receptor-alpha (ERα) and estrogen receptor-beta (ERβ) accompany the conversion of resident endometrial cells within the normal uterine environment to ectopic lesions located in extrauterine sites. Recent studies highlighted in this focused review linked ERβ to dysregulation of apoptotic and inflammatory networks involving novel interacting partners in endometriosis. The elucidation of these nongenomic actions of ERβ using human cells and mouse models is an important step in understanding key regulatory pathways that are disrupted leading to disease establishment and progression. PMID:27272520

  5. Purified estrogen receptor enhances in vitro transcription.

    PubMed

    Nigro, V; Molinari, A M; Armetta, I; de Falco, A; Abbondanza, C; Medici, N; Puca, G A

    1992-07-31

    An in vitro transcription system was developed to investigate the mechanisms of gene regulation by the estrogen receptor (ER). ER purified from calf uterus was highly active in enhancing RNA transcription from a template DNA containing estrogen response elements (EREs) upstream from a minimal promoter. Under the conditions employed, no addition of tissue specific factors was required and both estrogen or antiestrogens were ineffective. The stimulation of transcription correlated with the copy number of EREs in the template. The addition of competitor ERE oligonucleotides specifically inhibited the ER-induced transcription. We suggest that the ER may be involved in the formation of the stable initiation complex. PMID:1497666

  6. Changes in the expression of aromatase, estrogen receptor α and β in mandibular condylar cartilage of rats induced by disordered occlusion

    PubMed Central

    2012-01-01

    Background Estrogens play an important role in modulating the morphology and function of temporomandibular joints (TMJs), which is suggested to act via estrogen receptors (ERs). The present study was to investigate the expression of aggrecan, collagen type II (Col II), Col X, aromatase, ERα and ERβ in degenerative changes of mandibular condylar cartilage. Methods Forty male and 40 female 8-week-old rats were enrolled in this study. In experimental groups, the disordered occlusion was created by moving the first molars mesially and the third ones distally. Immunohistochemistry and real-time PCR were performed at the end of the second or fourth week. Results Degenerative changes, characterized by interrupted continuity of hypertrophic layer, pyknotic and eosinophilic lesion with few nuclei, areas filled with eosinophilic nuclei, were observed in more joints from female experimental groups than male ones. However, thickening changes in hypertrophic layer were only found in male experimental groups. The gene expression of Col II, Col X and aggrecan increased in 4-wk male experimental subgroup (both P < 0.01), but decreased in 2-wk and 4-wk female subgroups (P < 0.05). The gene expression of ERα decreased in 2-wk male and female experimental subgroups (both P < 0.01), however, that of ERβ increased except the 2-wk female experimental subgroup (all P < 0.01). The expression of aromatase decreased in both male and female experimental subgroups (all P<0.01). Conclusions Mandibular condylar cartilage responses differently to the disordered occlusion in male and female rats. The levels of locally synthesized estrogen, ERα and ERβ may have limited attribution, if any, to the sex-specific cartilage response. PMID:23020785

  7. Differential expression of estrogen-related receptors beta and gamma (ERRbeta and ERRgamma) and their clinical significance in human prostate cancer.

    PubMed

    Fujimura, Tetsuya; Takahashi, Satoru; Urano, Tomohiko; Ijichi, Nobuhiro; Ikeda, Kazuhiro; Kumagai, Jinpei; Murata, Taro; Takayama, Kenichi; Horie-Inoue, Kuniko; Ouchi, Yasuyoshi; Muramatsu, Masami; Homma, Yukio; Inoue, Satoshi

    2010-03-01

    Estrogen-related receptor (ERR) is a nuclear receptor that modulates the estrogen-signaling pathway. Here, we investigated the expression of both ERRbeta and ERRgamma in human prostate tissues. Using original rabbit polyclonal anti-ERRbeta and anti-ERRgamma antibodies, the expression of ERRbeta and ERRgamma was evaluated by immunohistochemical analysis of cancerous lesions (n = 107) and benign foci (n = 92), obtained by radical prostatectomy. Stained slides were evaluated for the proportion of immunoreactive cells and their staining intensity. Total immunoreactivity scores (IR scores; range, 0-8) were calculated as the sum of the proportion and intensity scores. The relationship between the clinicopathological characteristics of the patients and the expression of the three ERRs (ERRalpha, ERR beta, and ERR gamma) was evaluated. IR scores for ERRbeta and ERRgamma were significantly lower in cancerous lesions than that in benign foci (P < 0.0001, for both). Clinicopathological analyses revealed that the patients with low ERRgamma IR scores (expression of ERRbeta and ERRgamma in prostate tissue. The combined evaluation of the expression of ERRalpha and ERRgamma could be a significant prognostic factor for prostate cancer. PMID:20128821

  8. The Ontogeny of Nuclear Estrogen Receptor Isoform Expression and the Effect of 17β Estradiol in Embryonic Rainbow Trout (Oncorhynchus mykiss)

    PubMed Central

    Boyce-Derricott, Josh; Nagler, James J.; Cloud, J.G.

    2009-01-01

    Ligand bound nuclear estrogen receptor (ER) acts as a transcription factor regulating the expression of estrogen dependent genes. There are four nuclear ER isoforms in rainbow trout (Oncorhynchus mykiss). The objective of this study was to measure whole body mRNA levels of the two ERα isoforms (α1/α2) and the two ERβ isoforms (β1/β2) in male and female embryos from 50 to 600 degree-days (DD; days post-fertilization x water temperature) and in embryos exposed to vehicle or 17β-estradiol E2) for 2 hours at 230, 240 and 250 DD. All four isoforms were detected at every time point in both sexes. Sexual dimorphism was rarely observed; at 50 DD the level of ERα2 mRNA was significantly greater in males than in females and at 100 DD the level of ERβ1 mRNA was significantly greater in females than in males (p<0.05). Expression profiles of the two ERα isoforms were slightly different from one another, whereas the ERβ isoforms exhibited similar expression patterns. The effect of E2 was not different between male and female embryos. The level of ERα1 mRNA increased significantly at 240 DD; a similar but not statistically significant trend was observed at 230 and 250 DD. Despite the critical role of estrogen during sex differentiation in rainbow trout, the receptivity to this hormone as measured by the response in mRNA levels of ER appears to be largely the same between males and females and ERα1 is the only E2 responsive isoform. PMID:19818378

  9. Different regions of the estrogen receptor are required for synergistic action with the glucocorticoid and progesterone receptors.

    PubMed

    Cato, A C; Ponta, H

    1989-12-01

    Estrogen and progesterone or estrogen and glucocorticoid receptors functionally cooperate in gene activation if their cognate binding sites are close to one another. These interactions have been described as synergism of action of the steroid receptors. The mechanism by which synergism is achieved is not clear, although protein-protein interaction of the receptors is one of the favorite models. In transfection experiments with receptor expression vectors and a reporter gene containing estrogen and progesterone-glucocorticoid receptor binding sites, we have examined the effects that different portions of the various receptors have on synergism. N-terminal domains of the chicken progesterone and human glucocorticoid receptors, when deleted, abolished the synergistic action of these receptors with the estrogen receptor. Deletion of the carboxy-terminal amino acids 341 to 595 of the estrogen receptor produced a mutant receptor that could not trans-activate on its own. This mutant receptor did not affect the action of the glucocorticoid receptor but functioned synergistically with the progesterone receptor. We therefore conclude that the synergistic action of the receptors for estrogen and progesterone is mechanistically different from the synergistic action of the receptors for estrogen and glucocorticoid. PMID:2586523

  10. Estrogen and estrogen receptor alpha promotes malignancy and osteoblastic tumorigenesis in prostate cancer

    PubMed Central

    Mishra, Sweta; Tai, Qin; Gu, Xiang; Schmitz, James; Poullard, Ashley; Fajardo, Roberto J.; Mahalingam, Devalingam; Chen, Xiaodong; Zhu, Xueqiong; Sun, Lu-Zhe

    2015-01-01

    The role of estrogen signaling in regulating prostate tumorigenesis is relatively underexplored. Although, an increasing body of evidence has linked estrogen receptor beta (ERβ) to prostate cancer, the function of estrogen receptor alpha (ERα) in prostate cancer is not very well studied. We have discovered a novel role of ERα in the pathogenesis of prostate tumors. Here, we show that prostate cancer cells express ERα and estrogen induces oncogenic properties in prostate cancer cells through ERα. Importantly, ERα knockdown in the human prostate cancer PacMetUT1 cells as well as pharmacological inhibition of ERα with ICI 182,780 inhibited osteoblastic lesion formation and lung metastasis in vivo. Co-culture of pre-osteoblasts with cancer cells showed a significant induction of osteogenic markers in the pre-osteoblasts, which was attenuated by knockdown of ERα in cancer cells suggesting that estrogen/ERα signaling promotes crosstalk between cancer and osteoblastic progenitors to stimulate osteoblastic tumorigenesis. These results suggest that ERα expression in prostate cancer cells is essential for osteoblastic lesion formation and lung metastasis. Thus, inhibition of ERα signaling in prostate cancer cells may be a novel therapeutic strategy to inhibit the osteoblastic lesion development as well as lung metastasis in patients with advanced prostate cancer. PMID:26575018

  11. Cofactors of LIM Domains Associate with Estrogen Receptor α to Regulate the Expression of Noncoding RNA H19 and Corneal Epithelial Progenitor Cell Function.

    PubMed

    Klein, Rachel Herndon; Stephens, Denise N; Ho, Hsiang; Chen, Jefferson K; Salmans, Michael L; Wang, Winnie; Yu, Zhengquan; Andersen, Bogi

    2016-06-17

    Cofactors of LIM domain proteins, CLIM1 and CLIM2, are widely expressed transcriptional cofactors that are recruited to gene regulatory regions by DNA-binding proteins, including LIM domain transcription factors. In the cornea, epithelium-specific expression of a dominant negative (DN) CLIM under the keratin 14 (K14) promoter causes blistering, wounding, inflammation, epithelial hyperplasia, and neovascularization followed by epithelial thinning and subsequent epidermal-like differentiation of the corneal epithelium. The defects in corneal epithelial differentiation and cell fate determination suggest that CLIM may regulate corneal progenitor cells and the transition to differentiation. Consistent with this notion, the K14-DN-Clim corneal epithelium first exhibits increased proliferation followed by fewer progenitor cells with decreased proliferative potential. In vivo ChIP-sequencing experiments with corneal epithelium show that CLIM binds to and regulates numerous genes involved in cell adhesion and proliferation, including limbally enriched genes. Intriguingly, CLIM associates primarily with non-LIM homeodomain motifs in corneal epithelial cells, including that of estrogen receptor α. Among CLIM targets is the noncoding RNA H19 whose deregulation is associated with Silver-Russell and Beckwith-Wiedemann syndromes. We demonstrate here that H19 negatively regulates corneal epithelial proliferation. In addition to cell cycle regulators, H19 affects the expression of multiple cell adhesion genes. CLIM interacts with estrogen receptor α at the H19 locus, potentially explaining the higher expression of H19 in female than male corneas. Together, our results demonstrate an important role for CLIM in regulating the proliferative potential of corneal epithelial progenitors and identify CLIM downstream target H19 as a regulator of corneal epithelial proliferation and adhesion. PMID:27129775

  12. Development of a Competitive Binding Assay System with Recombinant Estrogen Receptors from Multiple Species

    EPA Science Inventory

    ABSTRACT In the current study, we developed a new system using full-length recombinant baculovirus-expressed estrogen receptors which allows for direct comparison of binding across species. Estrogen receptors representing five vertebrate classes were compared: human (hERα), quai...

  13. Estrogen Receptor Expression Is High But Is of Lower Intensity in Tubular Carcinoma Than in Well-Differentiated Invasive Ductal Carcinoma

    PubMed Central

    Jorns, Julie M.; Thomas, Dafydd G.; Healy, Patrick N.; Daignault, Stephanie; Vickery, Tammi L.; Snider, Jacqueline E.; Mardis, Elaine R.; Davies, Sherri R.; Ellis, Matthew J.; Visscher, Daniel W.

    2015-01-01

    Context Tubular carcinoma (TC) is a rare, luminal A subtype of breast carcinoma with excellent prognosis, for which adjuvant chemotherapy is usually contraindicated. Objective To examine the levels of estrogen receptor (ER) and progesterone receptor expression in cases of TC and well-differentiated invasive ductal carcinoma as compared to normal breast glands and to determine if any significant differences could be detected via molecular testing. Design We examined ER and progesterone receptor via immunohistochemistry in tubular (N = 27), mixed ductal/tubular (N = 16), and well-differentiated ductal (N = 27) carcinomas with comparison to surrounding normal breast tissue. We additionally performed molecular subtyping of 10 TCs and 10 ductal carcinomas via the PAM50 assay. Results Although ER expression was high for all groups, TC had statistically significantly lower ER staining percentage (ER%) (P = .003) and difference in ER expression between tumor and accompanying normal tissue (P = .02) than well-differentiated ductal carcinomas, with mixed ductal/tubular carcinomas falling between these 2 groups. Mean ER% was 79%, 87%, and 94%, and mean tumor-normal ER% differences were 13.6%, 25.9%, and 32.6% in tubular, mixed, and ductal carcinomas, respectively. Most tumors that had molecular subtyping were luminal A (9 of 10 tubular and 8 of 10 ductal), and no significant differences in specific gene expression between the 2 groups were identified. Conclusions Tubular carcinoma exhibited decreased intensity in ER expression, closer to that of normal breast parenchyma, likely as a consequence of a high degree of differentiation. Lower ER% expression by TC may represent a potential pitfall when performing commercially available breast carcinoma prognostic assays that rely heavily on ER-related gene expression. PMID:25357113

  14. Bridging the Gap From Screening Assays to Estrogenic Effects in Fish: Potential Roles of Multiple Estrogen Receptor Subtypes

    PubMed Central

    2015-01-01

    This study seeks to delineate the ligand interactions that drive biomarker induction in fish exposed to estrogenic pollutants and provide a case study on the capacity of human (h) estrogen receptor (ER)-based in vitro screening assays to predict estrogenic effects in aquatic species. Adult male Japanese medaka (Oryzias latipes) were exposed to solutions of singular steroidal estrogens or to the estrogenic extract of an anaerobic swine waste lagoon. All exposure concentrations were calibrated to be equipotent based on the yeast estrogen screen (YES), which reports activation of hERα. These exposures elicited significantly different magnitudes of hepatic vitellogenin and choriogenin gene induction in the male medaka. Effects of the same YES-calibrated solutions in the T47D-KBluc assay, which reports activation of hERα and hERβ, generally recapitulated observations in medaka. Using competitive ligand binding assays, it was found that the magnitude of vitellogenin/choriogenin induction by different estrogenic ligands correlated positively with preferential binding affinity for medaka ERβ subtypes, which are highly expressed in male medaka liver prior to estrogen exposure. Results support emerging evidence that ERβ subtypes are critically involved in the teleost estrogenic response, with the ERα:ERβ ratio being of particular importance. Accordingly, incorporation of multiple ER subtypes into estrogen screening protocols may increase predictive value for the risk assessment of aquatic systems, including complex estrogenic mixtures. PMID:24422420

  15. Estrogen receptor expert system overview and examples

    EPA Science Inventory

    The estrogen receptor expert system (ERES) is a rule-based system developed to prioritize chemicals based upon their potential for binding to the ER. The ERES was initially developed to predict ER affinity of chemicals from two specific EPA chemical inventories, antimicrobial pe...

  16. Low Concentrations of o,p’-DDT Inhibit Gene Expression and Prostaglandin Synthesis by Estrogen Receptor-Independent Mechanism in Rat Ovarian Cells

    PubMed Central

    Liu, Jing; Zhao, Meirong; Zhuang, Shulin; Yang, Yan; Yang, Ye; Liu, Weiping

    2012-01-01

    o,p’-DDT is an infamous xenoestrogen as well as a ubiquitous and persistent pollutant. Biomonitoring studies show that women have been internally exposed to o,p’-DDT at range of 0.3–500 ng/g (8.46×10−10 M−1.41×10−6 M) in blood and other tissues. However, very limited studies have investigated the biological effects and mechanism(s) of o,p’-DDT at levels equal to or lower than current exposure levels in human. In this study, using primary cultures of rat ovarian granulosa cells, we determined that very low doses of o,p’-DDT (10−12−10−8 M) suppressed the expression of ovarian genes and production of prostaglandin E2 (PGE2). In vivo experiments consistently demonstrated that o,p’-DDT at 0.5–1 mg/kg inhibited the gene expression and PGE2 levels in rat ovary. The surprising results from the receptor inhibitors studies showed that these inhibitory effects were exerted independently of either classical estrogen receptors (ERs) or G protein-coupled receptor 30 (GPR30). Instead, o,p’-DDT altered gene expression or hormone action via inhibiting the activation of protein kinase A (PKA), rather than protein kinase C (PKC). We further revealed that o,p’-DDT directly interfered with the PKA catalytic subunit. Our novel findings support the hypothesis that exposure to low concentrations of o,p’-DDT alters gene expression and hormone synthesis through signaling mediators beyond receptor binding, and imply that the current exposure levels of o,p’-DDT observed in the population likely poses a health risk to female reproduction. PMID:23209616

  17. Low concentrations of o,p'-DDT inhibit gene expression and prostaglandin synthesis by estrogen receptor-independent mechanism in rat ovarian cells.

    PubMed

    Liu, Jing; Zhao, Meirong; Zhuang, Shulin; Yang, Yan; Yang, Ye; Liu, Weiping

    2012-01-01

    o,p'-DDT is an infamous xenoestrogen as well as a ubiquitous and persistent pollutant. Biomonitoring studies show that women have been internally exposed to o,p'-DDT at range of 0.3-500 ng/g (8.46×10(-10) M-1.41×10(-6) M) in blood and other tissues. However, very limited studies have investigated the biological effects and mechanism(s) of o,p'-DDT at levels equal to or lower than current exposure levels in human. In this study, using primary cultures of rat ovarian granulosa cells, we determined that very low doses of o,p'-DDT (10(-12)-10(-8) M) suppressed the expression of ovarian genes and production of prostaglandin E2 (PGE2). In vivo experiments consistently demonstrated that o,p'-DDT at 0.5-1 mg/kg inhibited the gene expression and PGE2 levels in rat ovary. The surprising results from the receptor inhibitors studies showed that these inhibitory effects were exerted independently of either classical estrogen receptors (ERs) or G protein-coupled receptor 30 (GPR30). Instead, o,p'-DDT altered gene expression or hormone action via inhibiting the activation of protein kinase A (PKA), rather than protein kinase C (PKC). We further revealed that o,p'-DDT directly interfered with the PKA catalytic subunit. Our novel findings support the hypothesis that exposure to low concentrations of o,p'-DDT alters gene expression and hormone synthesis through signaling mediators beyond receptor binding, and imply that the current exposure levels of o,p'-DDT observed in the population likely poses a health risk to female reproduction. PMID:23209616

  18. Expression of Estrogen Receptor Coactivator Proline-, Glutamic Acid- and Leucine-Rich Protein 1 within Paraspinal Muscles in Adolescents with Idiopathic Scoliosis

    PubMed Central

    Skibinska, Izabela; Tomaszewski, Marek; Andrusiewicz, Miroslaw; Urbaniak, Paulina; Czarnecka-Klos, Roza; Shadi, Milud; Kotwicki, Tomasz; Kotwicka, Malgorzata

    2016-01-01

    Purpose The aim of this study was to detect and assess the estrogen receptor (ESR) coactivator PELP1 expression within human paraspinal skeletal muscles in patients suffering from idiopathic scoliosis. Methods During surgical correction of scoliosis the muscle biopsies harvested in 29 females. Presence of PELP1, ESR1 and ESR2 genes transcripts was studied using RT-qPCR technique while immunohistochemistry and western blot methods were used to detect the PEPL1 protein presence. Results PELP1 expression in deep paraspinal muscles revealed higher than in superficial back muscles (p = 0.005). Positive immunohistochemical staining for PELP1 was observed in the nuclei of the paraspinal muscle cells. Western blot revealed PELP1 protein in all samples. No significant difference in PELP1 expression between the convex and the concave scoliosis side (p>0.05) was found. In deep paraspinal back muscles, a significant correlation between the PELP1 expression level on the concave side and the Cobb angle (r = 0.4; p<0.05) was noted as well as between the PELP1 and ESR1 expression level (r = 0.7; p<0.05) while no correlation between PELP1 and ESR2 expression level was found. Conclusion To our knowledge, three techniques for the first time demonstrated the presence of the PELP1 in paraspinal muscles of patients with idiopathic scoliosis. The PELP1 potential regulatory impact on back muscle function is to be further investigated. PMID:27045366

  19. Designer interface peptide grafts target estrogen receptor alpha dimerization.

    PubMed

    Chakraborty, S; Asare, B K; Biswas, P K; Rajnarayanan, R V

    2016-09-01

    The nuclear transcription factor estrogen receptor alpha (ERα), triggered by its cognate ligand estrogen, regulates a variety of cellular signaling events. ERα is expressed in 70% of breast cancers and is a widely validated target for anti-breast cancer drug discovery. Administration of anti-estrogen to block estrogen receptor activation is still a viable anti-breast cancer treatment option but anti-estrogen resistance has been a significant bottle-neck. Dimerization of estrogen receptor is required for ER activation. Blocking ERα dimerization is therefore a complementary and alternative strategy to combat anti-estrogen resistance. Dimer interface peptide "I-box" derived from ER residues 503-518 specifically blocks ER dimerization. Recently using a comprehensive molecular simulation we studied the interaction dynamics of ERα LBDs in a homo-dimer. Based on this study, we identified three interface recognition peptide motifs LDKITDT (ERα residues 479-485), LQQQHQRLAQ (residues 497-506), and LSHIRHMSNK (residues 511-520) and reported the suitability of using LQQQHQRLAQ (ER 497-506) as a template to design inhibitors of ERα dimerization. Stability and self-aggregation of peptide based therapeutics poses a significant bottle-neck to proceed further. In this study utilizing peptide grafted to preserve their pharmacophoric recognition motif and assessed their stability and potential to block ERα mediated activity in silico and in vitro. The Grafted peptides blocked ERα mediated cell proliferation and viability of breast cancer cells but did not alter their apoptotic fate. We believe the structural clues identified in this study can be used to identify novel peptidometics and small molecules that specifically target ER dimer interface generating a new breed of anti-cancer agents. PMID:27462021

  20. Immunohistochemical Expression of Estrogen and Progesterone Receptors in Human Colorectal Adenoma and Carcinoma Using Specified Automated Cellular Image Analysis System: A Clinicopathological Study

    PubMed Central

    Qasim, Ban Jumaa; Ali, Hussam Hasson; Hussein, Alaa Ghani

    2011-01-01

    Objectives To evaluate the immunohistochemical expression of estrogen receptors (ER) and progesterone receptors (PR) in colorectal adenoma and adenocarcinoma and to correlate this immunohistochemical expression with different clinicopathological parameters. Methods The study was retrospectively designed. A total of 86 tissue samples, including 33 paraffin blocks from patients with colorectal adenomas, 33 paraffin blocks from patients with colorectal adenocarcinomas and a control group of 20 samples of non-tumorous colonic tissue, were included in the study. Results The frequency of expression of ER and PR showed a gradual increase from control through adenoma to carcinoma. The frequencies of expression of ER in the control, adenoma and carcinoma were (10%, 15.15% and 42.42% respectively, p<0.001), while the frequency of expression for PR were (10%, 24.24% and 36.36% respectively, p<0.001). Strong ER and PR staining was mainly seen in carcinoma cases (42.42%, 36.36%, respectively) in comparison with adenoma (9.09%, 15.15%, respectively) and control (0%, 0%, respectively). The three digital parameters of ER and PR immunohistochemical expression (Area [A], Number of objects [N], and intensity [I]) were significantly increased in a sequence of normal mucosa-adenoma-carcinoma. There was a significant positive correlation between ER and PR in adenoma (r=0.312, p=0.034) and carcinoma (r=0.321, p=0.0398). Conclusion ER and PR expression increased in a sequence of; normal colonic mucosa-adenoma-carcinoma, and a positive correlation was observed between ER and PR expression in colonic adenoma and carcinoma specimen indicating that ER and PR may play a role in colorectal carcinogenesis. PMID:22125723

  1. Shu-Gan-Liang-Xue Decoction Simultaneously Down-regulates Expressions of Aromatase and Steroid Sulfatase in Estrogen Receptor Positive Breast Cancer Cells

    PubMed Central

    Fu, Xue-song; Li, Ping-ping

    2011-01-01

    Objective Estradiol (E2) plays an important role in the development of breast cancer. In postmenopausal women, the estrogen can be synthesized via aromatase (CYP19) pathway and steroid-sulfatase (STS) pathway in peripheral tissues, when the production in ovary has ceased. The objective of our study was to explore the effects of Shu-Gan-Liang-Xue Decoction (SGLXD) on the expressions of CYP19 and STS in estrogen receptor positive breast cancer MCF-7 and T47D cells. Methods The effects of SGLXD on the cell viability of MCF-7 and T47D were analyzed by MTT assay. By quantitative real-time RT-PCR and Western blot, we evaluated the mRNA and protein expressions of CYP19 and STS in MCF-7 and T47D cells after SGLXD treatment. Results By MTT assay, the cell viability rates of MCF-7 and T47D were significantly inhibited by SGLXD in a dose-dependent manner, the IC50 values were 40.07 mg/ml for MCF-7 cells and 25.62 mg/ml for T47D cells, respectively. As evidenced by real-time PCR and Western blot, the high concentrations of SGLXD significantly down-regulated the expressions of CYP19 and STS both in the transcript level and the protein level. Conclusion The results suggest that SGLXD is a potential dual aromatase-sulfatase inhibitor by simultaneously down-regulating the expressions of CYP19 and STS in MCF-7 and T47D cells. PMID:23467843

  2. ERα Mediates Estrogen-Induced Expression of the Breast Cancer Metastasis Suppressor Gene BRMS1

    PubMed Central

    Ma, Hongtao; Gollahon, Lauren S.

    2016-01-01

    Recently, estrogen has been reported as putatively inhibiting cancer cell invasion and motility. This information is in direct contrast to the paradigm of estrogen as a tumor promoter. However, data suggests that the effects of estrogen are modulated by the receptor isoform with which it interacts. In order to gain a clearer understanding of the role of estrogen in potentially suppressing breast cancer metastasis, we investigated the regulation of estrogen and its receptor on the downstream target gene, breast cancer metastasis suppressor 1 (BRMS1) in MCF-7, SKBR3, TTU-1 and MDA-MB-231 breast cancer cells. Our results showed that estrogen increased the transcription and expression of BRMS1 in the ERα positive breast cancer cell line, MCF-7. Additionally, the ERα specific agonist PPT also induced the transcription and expression of BRMS1. However, the two remaining estrogen receptor (ER) subtype agonists had no effect on BRMS1 expression. In order to further examine the influence of ERα on BRMS1 expression, ERα expression was knocked down using siRNA (siERα). Western blot analysis showed that siERα reduced estrogen-induced and PPT-induced BRMS1 expression. In summary, this study demonstrates estrogen, via its α receptor, positively regulates the expression of BRMS1, providing new insight into a potential inhibitory effect of estrogen on metastasis suppression. PMID:26821020

  3. Estrogen receptor transcription and transactivation: Estrogen receptor knockout mice: what their phenotypes reveal about mechanisms of estrogen action.

    PubMed

    Curtis Hewitt, S; Couse, J F; Korach, K S

    2000-01-01

    Natural, synthetic and environmental estrogens have numerous effects on the development and physiology of mammals. Estrogen is primarily known for its role in the development and functioning of the female reproductive system. However, roles for estrogen in male fertility, bone, the circulatory system and immune system have been established by clinical observations regarding sex differences in pathologies, as well as observations following menopause or castration. The primary mechanism of estrogen action is via binding and modulation of activity of the estrogen receptors (ERs), which are ligand-dependent nuclear transcription factors. ERs are found in highest levels in female tissues critical to reproduction, including the ovaries, uterus, cervix, mammary glands and pituitary gland. Since other affected tissues have extremely low levels of ER, indirect effects of estrogen, for example induction of pituitary hormones that affect the bone, have been proposed. The development of transgenic mouse models that lack either estrogen or ER have proven to be valuable tools in defining the mechanisms by which estrogen exerts its effects in various systems. The aim of this article is to review the mouse models with disrupted estrogen signaling and describe the associated phenotypes. PMID:11250727

  4. Relationship between estrogen receptor-binding and estrogenic activities of environmental estrogens and suppression by flavonoids.

    PubMed

    Han, Dal-Ho; Denison, Michael S; Tachibana, Hirofumi; Yamada, Koji

    2002-07-01

    In this study, we investigated the estrogenic activity of environmental estrogens by a competition binding assay using a human recombinant estrogens receptor (hERbeta) and by a proliferation assay using MCF-7 cells and a sulforhodamine-B assay. In the binding assay, pharmaceuticals had a stronger binding activity to hERbeta than that of some phytoestrogens (coumestrol, daidzein, genistein, luteolin, chrysin, flavone, and naringenin) or industrial chemicals, but phytoestrogens such as coumestrol had a binding activity as strong as pharmaceuticals such as 17alpha-ethynylestradiol (EE), tamoxifen (Tam), and mestranol. In the proliferation assay, pharmaceuticals such as diethylstilbestrol, EE, Tam, and clomiphene, and industrial chemicals such as 4-nonylphenol, bisphenol A, and 4-dihydroxybiphenyl had a proliferation-stimulating activity as strong as 17beta-estradiol (ES). In addition, we found that phytoestrogens such as coumestrol, daidzein, luteolin, and quercetin exerted a proliferation stimulating activity as strong as ES. Furthermore, we examined the suppression of proliferation-stimulating activity, induced by environmental estrogen, by flavonoids, such as daidzein, genistein, quercetin, and luteolin, and found that these flavonoids suppressed the induction of the proliferation-stimulating activity of environmental estrogens. The suppressive effect of flavonoids suggests that these compounds have anti-estrogenic and anti-cancer activities. PMID:12224631

  5. Estrogen receptors and human disease: an update

    PubMed Central

    Burns, Katherine A.

    2016-01-01

    A myriad of physiological processes in mammals are influenced by estrogens and the estrogen receptors (ERs), ERα and ERβ. As we reviewed previously, given the widespread role for estrogen in normal human physiology, it is not surprising that estrogen is implicated in the development or progression of a number of diseases. In this review, we are giving a 5-year update of the literature regarding the influence of estrogens on a number of human cancers (breast, ovarian, colorectal, prostate, and endometrial), endometriosis, fibroids, and cardiovascular disease. A large number of sophisticated experimental studies have provided insights into human disease, but for this review, the literature citations were limited to articles published after our previous review (Deroo and Korach in J Clin Invest 116(3):561–570, 2006) and will focus in most cases on human data and clinical trials. We will describe the influence in which estrogen’s action, through one of or both of the ERs, mediates the aforementioned human disease states. PMID:22648069

  6. High Expression of Three-Gene Signature Improves Prediction of Relapse-Free Survival in Estrogen Receptor-Positive and Node-Positive Breast Tumors.

    PubMed

    Thakkar, Arvind; Raj, Hemanth; Ravishankar; Muthuvelan, Bhaskaran; Balakrishnan, Arun; Padigaru, Muralidhara

    2015-01-01

    The objective of the present study was to validate prognostic gene signature for estrogen receptor alpha-positive (ER03B1+) and lymph node (+) breast cancer for improved selection of patients for adjuvant therapy. In our previous study, we identified a group of seven genes (GATA3, NTN4, SLC7A8, ENPP1, MLPH, LAMB2, and PLAT) that show elevated messenger RNA (mRNA) expression levels in ERα (+) breast cancer patient samples. The prognostic values of these genes were evaluated using gene expression data from three public data sets of breast cancer patients (n = 395). Analysis of ERα (+) breast cancer cohort (n = 195) showed high expression of GATA3, NTN4, and MLPH genes significantly associated with longer relapse-free survival (RFS). Next cohort of ERα (+) and node (+) samples (n = 109) revealed high mRNA expression of GATA3, SLC7A8, and MLPH significantly associated with longer RFS. Multivariate analysis of combined three-gene signature for ERα (+) cohort, and ERα (+) and node (+) cohorts showed better hazard ratio than individual genes. The validated three-gene signature sets for ERα (+) cohort, and ERα (+) and node (+) cohort may have potential clinical utility since they demonstrated predictive and prognostic ability in three independent public data sets. PMID:26648682

  7. [Wogonin inhibits IGF-1-stimulated cell growth and estrogen receptor α expression in breast adenocarcinoma cell and angiogenesis of chick chorioallantoic membrane].

    PubMed

    Ma, Xing; Xie, Kun-Peng; Shang, Fei; Huo, Hong-Nan; Wang, Li-Meng; Xie, Ming-Jie

    2012-04-25

    The aim of the present study was to investigate the involvements of insulin-like growth factor-1 (IGF-1) and estrogen receptor α (ERα) in the inhibitory effect of wogonin on the breast adenocarcinoma growth. Moreover, the effect of wogonin on the angiogenesis of chick chorioallantoic membrane (CAM) was also investigated. MCF-7 cells (human breast adenocarcinoma cell line) were subjected to several drugs, including IGF-1, wogonin and ER inhibitor ICI182780, alone or in combination. MTT assay was used to detect breast cancer proliferation. Western blot was used to analyze ERα and p-Akt expression levels. CAM models prepared from 6-day chicken eggs were employed to evaluate angiogenesis inhibition. The results showed wogonin and ICI182780 both exhibited a potent ability to blunt IGF-1-stimulated MCF-7 cell growth. Either of wogonin and ICI182780 significantly inhibited ERα and p-Akt expressions in IGF-1-treated cells. The inhibitory effect of wogonin showed no difference from that of ICI182780 on IGF-1-stimulated expressions of ERα and p-Akt. Meanwhile, wogonin at different concentrations showed significant inhibitory effect on CAM angiogenesis. These results suggest the inhibitory effect of wogonin on breast adenocarcinoma growth via inhibiting IGF-1-mediated PI3K-Akt pathway and regulating ERα expression. Furthermore, wogonin has a strong anti-angiogenic effect on CAM model. PMID:22513472

  8. High Expression of Three-Gene Signature Improves Prediction of Relapse-Free Survival in Estrogen Receptor-Positive and Node-Positive Breast Tumors

    PubMed Central

    Thakkar, Arvind; Raj, Hemanth; Ravishankar; Muthuvelan, Bhaskaran; Balakrishnan, Arun; Padigaru, Muralidhara

    2015-01-01

    The objective of the present study was to validate prognostic gene signature for estrogen receptor alpha-positive (ER03B1+) and lymph node (+) breast cancer for improved selection of patients for adjuvant therapy. In our previous study, we identified a group of seven genes (GATA3, NTN4, SLC7A8, ENPP1, MLPH, LAMB2, and PLAT) that show elevated messenger RNA (mRNA) expression levels in ERα (+) breast cancer patient samples. The prognostic values of these genes were evaluated using gene expression data from three public data sets of breast cancer patients (n = 395). Analysis of ERα (+) breast cancer cohort (n = 195) showed high expression of GATA3, NTN4, and MLPH genes significantly associated with longer relapse-free survival (RFS). Next cohort of ERα (+) and node (+) samples (n = 109) revealed high mRNA expression of GATA3, SLC7A8, and MLPH significantly associated with longer RFS. Multivariate analysis of combined three-gene signature for ERα (+) cohort, and ERα (+) and node (+) cohorts showed better hazard ratio than individual genes. The validated three-gene signature sets for ERα (+) cohort, and ERα (+) and node (+) cohort may have potential clinical utility since they demonstrated predictive and prognostic ability in three independent public data sets. PMID:26648682

  9. Stromal Clues in Endometrial Carcinoma: Loss of Expression of β-Catenin, Epithelial-Mesenchymal Transition Regulators, and Estrogen-Progesterone Receptor

    PubMed Central

    Sayar, Ilyas; Ceyran, Ayse B.; Ibiloglu, Ibrahim; Akalin, Ibrahim; Firat, Ugur; Kosemetin, Duygu; Engin Zerk, Pinar; Aydin, Abdullah

    2016-01-01

    Epithelial-stroma interactions in the endometrium are known to be responsible for physiological functions and emergence of several pathologic lesions. Periglandular stromal cells act on endometrial cells in a paracrine manner through sex hormones. In this study, we immunohistochemically evaluated the expression of epithelial-mesenchymal transition regulators (SNAIL/SLUG, TWIST, ZEB1), adhesion molecules (β-catenin and E-cadhenin), estrogen (ER)-progesterone (PR) receptor and their correlation with each other in 30 benign, 148 hyperplastic (EH), and 101 endometrioid-type endometrial carcinoma (EC) endometria. In the epithelial component, loss of expression in E-cadherin, ER and PR, and overexpression of TWIST and ZEB1 were significantly higher in EC than in EH (P<0.01). In the periglandular stromal component, β-catenin and SNAIL/SLUG expression were significantly higher in normal endometrium and simple without atypical EH compared with complex atypical EH and EC (P<0.01). In addition, periglandular stromal TWIST expression was significantly higher in EH group compared with EC (P<0.05). There was significantly negative correlation between β-catenin and ER, TWIST and ER, and TWIST and PR in hyperplastic and carcinomatous glandular epithelium, whereas there was a significantly positive correlation between β-catenin and SNAIL-SLUG, β-catenin and TWIST, β-catenin and ER, β-catenin and PR, SNAIL-SLUG and ER, SNAIL-SLUG and PR, TWIST and ER, TWIST and PR, in periglandular/cancer-associated stromal cells (P<0.01). In conclusion, the pattern of positive and negative correlations in the expression of epithelial-mesenchymal transition regulators (SNAIL-SLUG and TWIST), sex hormone receptors (ER and PR), and β-catenin between ECs and hyperplasia, as well as between epithelium and stroma herein, is suggestive of a significant role for these proteins and their underlying molecular processes in the development of endometrial carcinomas. PMID:26367784

  10. Activation of Estrogen Receptor Transfected into a Receptor-Negative Brest Cancer Cell Line Decreases the Metastatic and Invasive Potential of the Cells

    NASA Astrophysics Data System (ADS)

    Garcia, Marcel; Derocq, Danielle; Freiss, Gilles; Rochefort, Henri

    1992-12-01

    Breast cancers containing estrogen receptors are responsive to antiestrogen treatment and have a better prognosis than estrogen receptor-negative tumors. The loss of estrogen and progesterone receptors appears to be associated with a progression to less-differentiated tumors. We transfected the human estrogen receptor into the estrogen receptor-negative metastatic breast cancer cell line MDA-MB-231 in an attempt to restore their sensitivity to antiestrogens. Two stable sublines of MDA-MB-231 cells (HC1 and HE5) expressing functional estrogen receptors were studied for their ability to grow and invade in vitro and to metastasize in athymic nude mice. The number and size of lung metastases developed by these two sublines in ovariectomized nude mice was not markedly altered by tamoxifen but was inhibited 3-fold by estradiol. Estradiol also significantly inhibited in vitro cell proliferation of these sublines and their invasiveness in Matrigel, a reconstituted basement membrane, whereas the antiestrogens 4-hydroxytamoxifen and ICI 164,384 reversed these effects. These results show that estradiol inhibits the metastatic ability of estrogen receptornegative breast cancer cells following transfection with the estrogen receptor, whereas estrogen receptor-positive breast cancers are stimulated by estrogen, indicating that factors other than the estrogen receptor are involved in progression toward hormone independence. Reactivation or transfer of the estrogen receptor gene can therefore be considered as therapeutic approaches to hormone-independent cancers

  11. Estrogen receptor profiling and activity in cardiac myocytes.

    PubMed

    Pugach, Emily K; Blenck, Christa L; Dragavon, Joseph M; Langer, Stephen J; Leinwand, Leslie A

    2016-08-15

    Estrogen signaling appears critical in the heart. However a mechanistic understanding of the role of estrogen in the cardiac myocyte is lacking. Moreover, there are multiple cell types in the heart and multiple estrogen receptor (ER) isoforms. Therefore, we studied expression, localization, transcriptional and signaling activity of ERs in isolated cardiac myocytes. We found only ERα RNA (but no ERβ RNA) in cardiac myocytes using two independent methods. The vast majority of full-length ERα protein (ERα66) localizes to cardiac myocyte nuclei where it is competent to activate transcription. Alternate isoforms of ERα encoded by the same genomic locus (ERα46 and ERα36) have differential transcriptional activity in cardiac myocytes but also primarily localize to nuclei. In contrast to other reports, no ERα isoform is competent to activate MAPK or PI3K signaling in cardiac myocytes. Together these data support a role for ERα at the level of transcription in cardiac myocytes. PMID:27164442

  12. Selective estrogen receptor modulators: tissue specificity and clinical utility

    PubMed Central

    Martinkovich, Stephen; Shah, Darshan; Planey, Sonia Lobo; Arnott, John A

    2014-01-01

    Selective estrogen receptor modulators (SERMs) are a diverse group of nonsteroidal compounds that function as agonists or antagonists for estrogen receptors (ERs) in a target gene-specific and tissue-specific fashion. SERM specificity involves tissue-specific expression of ER subtypes, differential expression of co-regulatory proteins in various tissues, and varying ER conformational changes induced by ligand binding. To date, the major clinical applications of SERMs are their use in the prevention and treatment of breast cancer, the prevention of osteoporosis, and the maintenance of beneficial serum lipid profiles in postmenopausal women. However, SERMs have also been found to promote adverse effects, including thromboembolic events and, in some cases, carcinogenesis, that have proven to be obstacles in their clinical utility. In this review, we discuss the mechanisms of SERM tissue specificity and highlight the therapeutic application of well-known and emergent SERMs. PMID:25210448

  13. Estrogen and progesterone receptors in primary cutaneous melanoma.

    PubMed

    Ellis, D L; Wheeland, R G; Solomon, H

    1985-01-01

    Using a variety of techniques, estrogen and progesterone receptors have previously been identified in variable percentages of malignant melanomas. We examined 10 primary superficial spreading melanomas (SSM) with a fluorescent hormone-binding technique for estrogen and progesterone cytoplasmic receptors. Of these 6 SSM were markedly positive for estrogen and progesterone binding. Patients with dysplastic nevus syndrome (DNS) or a family history of DNS were markedly positive for estrogen and progesterone binding. A single patient with lentigo maligna and another patient with lentigo maligna melanoma were negative for estrogen and progesterone binding. None of the 21 control intradermal nevi examined for estrogen and progesterone binding exhibited marked positivity. PMID:3965520

  14. Estrogen-related receptor alpha is critical for the growth of estrogen receptor-negative breast cancer.

    PubMed

    Stein, Rebecca A; Chang, Ching-Yi; Kazmin, Dmitri A; Way, James; Schroeder, Thies; Wergin, Melanie; Dewhirst, Mark W; McDonnell, Donald P

    2008-11-01

    Expression of estrogen-related receptor alpha (ERRalpha) has recently been shown to carry negative prognostic significance in breast and ovarian cancers. The specific role of this orphan nuclear receptor in tumor growth and progression, however, is yet to be fully understood. The significant homology between estrogen receptor alpha (ERalpha) and ERRalpha initially suggested that these receptors may have similar transcriptional targets. Using the well-characterized ERalpha-positive MCF-7 breast cancer cell line, we sought to gain a genome-wide picture of ERalpha-ERRalpha cross-talk using an unbiased microarray approach. In addition to generating a host of novel ERRalpha target genes, this study yielded the surprising result that most ERRalpha-regulated genes are unrelated to estrogen signaling. The relatively small number of genes regulated by both ERalpha and ERRalpha led us to expand our study to the more aggressive and less clinically treatable ERalpha-negative class of breast cancers. In this setting, we found that ERRalpha expression is required for the basal level of expression of many known and novel ERRalpha target genes. Introduction of a small interfering RNA directed to ERRalpha into the highly aggressive breast carcinoma MDA-MB-231 cell line dramatically reduced the migratory potential of these cells. Although stable knockdown of ERRalpha expression in MDA-MB-231 cells had no effect on in vitro cell proliferation, a significant reduction of tumor growth rate was observed when these cells were implanted as xenografts. Our results confirm a role for ERRalpha in breast cancer growth and highlight it as a potential therapeutic target for estrogen receptor-negative breast cancer. PMID:18974123

  15. Estrogen Receptor beta binds Sp1 and recruits a Corepressor Complex to the Estrogen Receptor alpha Gene Promoter

    PubMed Central

    Bartella, V; Rizza, P; Barone, I; Zito, D; Giordano, F; Giordano, C; Catalano, S; Mauro, L; Sisci, D; Panno, ML; Fuqua, SA; Andò, Sebastiano

    2015-01-01

    Human estrogen receptors (ERs) alpha and beta are crucially involved in the regulation of mammary growth and development. Normal breast tissues display a prevalently expression of ER beta than ER alpha, which drastically increases during breast tumorogenesis. So, it is reasonable to assume how a dysregulation of the two estrogen receptor subtypes may induce breast cancer development. However, the molecular mechanism underlying the opposite role played by the two estrogen receptors on tumor cell growth remains to be elucidated. In the present study, we have demonstrated that ER beta overexpression in breast cancer cells decreases cell proliferation and down-regulates ER alpha mRNA and protein content along with a concomitant repression of estrogen-regulated genes. Transient transfection experiments, using a vector containing the human ER alpha promoter region, showed that elevated levels of the ER beta down-regulated basal ER alpha promoter activity. Furthermore, side-directed mutagenesis and deletion analysis have revealed that the proximal GC-rich motifs at −223 and −214 is crucial for the ER beta-induced ER alpha down-regulation in breast cancer cells. This occurred through ER beta-Sp1 protein-protein interaction within the ER alpha promoter region and the recruitment of a corepressor complex containing NCoR/SMRT (nuclear receptor corepressor/silencing mediator of retinoic acid and thyroid hormone receptor), accompanied by hypoacetylation of histone H4 and displacement of RNA polymerase II. Silencing of NCoR gene expression by RNA interference reversed the down-regulatory effect of ER beta on ER alpha gene expression and cell proliferation. Our results provide evidence for a novel mechanism by which overexpression of ER beta through NCoR is able to down regulate ER alpha gene expression, thus inhibiting ER alpha’s driving role on breast cancer cell growth. PMID:22622808

  16. Unraveling the estrogen receptor (er) genes in Atlantic salmon (Salmo salar) reveals expression differences between the two adult life stages but little impact from polychlorinated biphenyl (PCB) load.

    PubMed

    Nikoleris, Lina; Hansson, Maria C

    2015-01-15

    Estrogen receptors (ers) not only are activated by hormones but also interact with many human-derived environmental contaminants. Here, we present evidence for four expressed er genes in Atlantic salmon cDNA - two more ers (erα2 and erβ2) than previously published. To determine if er gene expression differs between two adult life-stages we sampled 20 adult salmon from the feeding phase in the Baltic Sea and during migration in the River Mörrum, Sweden. Results show that all four er genes are present in the investigated tissues, except for erα2 not appearing in the spleen. Overall, a profile analysis reveals the erα1 gene to be the most highly expressed er gene in both female and male Baltic Sea salmon tissues, and also in female River Mörrum salmon. In contrast, this gene has the lowest gene expression level of the four er genes in male salmon from the River Mörrum. The erα2 gene is expressed at the lowest levels in both female/male Baltic Sea salmon and in female River Mörrum salmon. Statistical analyses indicate a significant and complex interaction where both sex and adult life stage can impact er gene expression. Regression analyses did not demonstrate any significant relationship between polychlorinated biphenyl (PCB) body burden and er gene expression level, suggesting that accumulated pollutants from the Baltic Sea may be deactivated inside the salmon's lipid tissues and have limited impact on er activity. This study is the first comprehensive analysis of four er gene expression levels in two wild salmon populations from two different adult life stages where information about PCB load is also available. PMID:25451980

  17. Molecular cloning of estrogen receptor alpha of the Nile crocodile.

    PubMed

    Katsu, Yoshinao; Myburgh, Jan; Kohno, Satomi; Swan, Gerry E; Guillette, Louis J; Iguchi, Taisen

    2006-03-01

    Estrogens are essential for normal reproductive activity in female and male vertebrates. In female reptiles, they are essential for ovarian differentiation during a critical developmental stage. To understand the molecular mechanisms of estrogen action in the Nile crocodile (Crocodylus niloticus), we have isolated cDNA encoding the estrogen receptor alpha (ERalpha) from the ovary. Degenerate PCR primers specific to ER were designed and used to amplify Nile crocodile cDNA from the ovary. The full-length Nile crocodile ERalpha cDNA was obtained using 5' and 3' rapid amplification cDNA ends (RACE). The deduced amino acid sequence of the Nile crocodile ERalpha showed high identity to the American alligator ERalpha (98%), caiman ER (98%), lizard ER (82%) and chicken ERalpha (92%), although phylogenetic analysis suggested profound differences in the rate of sequence evolution for vertebrate ER sequences. Expression of ERalpha was observed in the ovary and testis of juvenile Nile crocodiles. These data provide a novel tool allowing future studies examining the regulation and ontogenic expression of ERalpha in crocodiles and expands our knowledge of estrogen receptor evolution. PMID:16455277

  18. Molecular cloning and characterization of estrogen receptor gene in the scallop Chlamys farreri: expression profiles in response to endocrine disrupting chemicals.

    PubMed

    Zhang, Hui; Pan, Luqing; Zhang, Lin

    2012-06-01

    In order to gain insights into the mechanism of sex steroid signaling in molluscs, the full-length cDNA of estrogen receptor (ER) was isolated and characterized from Chlamys farreri for the first time. The positions of cysteine residues and other residues around them that constitute the two zinc finger motifs and the P-box are conserved. Phylogenetic analysis revealed that the CfER is an ortholog of the other mollusk ERs. Tissue distribution analysis of the CfER mRNA revealed that the expression of ER mRNA was observed in various tissues, and highest in the gonad of males and females. C. farreri were exposed for 10 days to endocrine disrupting chemicals including Benzo(a)pyrene (B(a)p) and polybrominated diphenyl ethers (BDE-47). B(a)p exposure at 0.4 and 2 μg/L caused significant increase in mRNA expression of ER and VTG, but B(a)p at 10 μg/L down-regulated CfER and VTG mRNA expression compared to control. Varying increase of ER and VTG mRNA transcripts was resulted in by BDE-47 at 0.1, 1 and 10 μg/L. These results elucidate potential roles of CfER induced by xenobiotics in C. farreri and can be helpful for investigating the mechanism of sex steroid signaling in bivalve mollusks. PMID:22507668

  19. Breast Cancer Proteomics – Differences in Protein Expression between Estrogen Receptor-Positive and -Negative Tumors Identified by Tandem Mass Tag Technology

    PubMed Central

    Ruckhäberle, Eugen; Karn, Thomas; Hanker, Lars; Schwarz, Josef; Schulz-Knappe, Peter; Kuhn, Karsten; Böhm, Gitte; Selzer, Stefan; Erhard, Neukum; Engels, Knut; Holtrich, Uwe; Kaufmann, Manfred; Rody, Achim

    2010-01-01

    Background Proteomic analysis has become an effective tool in breast cancer research. In this study, we applied the new gel-free tandem mass tag (TMT) reference method for the first time in breast cancer. Materials and Methods Proteomic analysis was used to compare 10 estrogen receptor (ER)-positive and 10 ER-negative samples. The results of the proteomic approach were validated by Western blot, immunohistochemistry and gene expression analysis. Results 17 proteins with significant differences in expression were identified. 13 proteins were overexpressed in ER-negative tumors and 4 were overexpressed in ER-positive samples. All these proteins were characterized by relatively high cellular abundance. Conclusions Our results demonstrate that the gel-free TMT approach allows the quantification of differences in protein expression levels. Further improvement of the sensitivity by subfractionation of the tissue should allow also the identification of low-abundance proteins and might lead to the use of this method in breast cancer research. PMID:22619634

  20. A Lower PBMC Estrogen Receptor α Gene Expression in Chronic Hepatitis B Is Associated with a Sustained Virological Response to Pegylated Interferon.

    PubMed

    Zhang, Tingting; Zhang, Zhenhua; Zhang, Yafei; Ye, Jun; Li, Xu

    2016-02-01

    The aim of this study was to investigate possible involvement of estrogen receptor α (ESR1) in responding to pegylated interferon alpha-2a (PEG IFNα-2a) therapy in chronic hepatitis B (CHB) patients. A total of 106 HBeAg-positive patients and 52 healthy controls were enrolled into this study. ESR1 messenger RNA (mRNA) expression in peripheral blood mononuclear cells was quantified at the baseline, during treatment (weeks 4 and 12), and at the end of treatment (week 48) by real-time reverse transcriptase-polymerase chain reaction assay (RT-PCR). The sequence polymorphism of ESR1 (rs2077647, rs2234693, rs9340799, and rs9322354) was analyzed using the Sequenom MassARRAY Analyzer. Our results suggested that the most accurate prediction of nonresponder in female patients was the baseline alanine aminotransferase (ALT) in combination with ESR1 expression at week 4 of treatment (area under the receiver operating characteristic curve [AUC] = 0.908). Combining the baseline ALT with ESR1 mRNA expression at the end of treatment showed the best prediction of sustained virological response in male patients (AUC = 0.818). Internal validation was assessed by bootstrap cross-validation. These results may have clinical relevance and warrant future validation in studies with larger cohorts. PMID:26485345

  1. Expression of Aquaporins in the Efferent Ductules, Sperm Counts, and Sperm Motility in Estrogen Receptor-α Deficient Mice Fed Lab Chow Versus Casein

    PubMed Central

    RUZ, RICARDO; GREGORY, MARY; SMITH, CHARLES E.; CYR, DANIEL G.; LUBAHN, DENNIS B.; HESS, REX A.; HERMO, LOUIS

    2006-01-01

    Estrogens play an important role in the male reproductive tract, and this is especially so for the efferent ductules, where α-estrogen receptors (ERα) have been localized. Mice deficient in ERα (αERKO mice) are infertile, and the effect appears to be due in part to retention of water at the level of the efferent ductules. In the present study, we examined the consequences of ERα deletion on the distribution of certain aquaporins (AQPs), water protein channels, in the efferent ductules and on sperm numbers and motility. In addition, the effects of feeding mice a regular lab chow diet, which contains phytoestrogens, known to affect male reproductive tract functions, and a casein diet, which lacks phytoestrogens, were also assessed. Light microscope immunolocalizations of AQP-1 and AQP-9 revealed dramatic reduction and patchier staining in αERKO mice with distal areas of the efferent ductules being more affected than proximal areas. No other changes in immunolocalizations were noted as a consequence of diet. Computer-assisted sperm analyses demonstrated a 62% reduction in cauda epididymal sperm/ml in αERKO mice fed lab chow, whereas 87% fewer sperm/ml were observed in αERKO mice fed casein, suggesting an enhanced role for sperm production and concentration in a diet containing phytoestrogens. All sperm motility parameters were altered to some degree in αERKO mice fed lab chow. Alterations in sperm motility parameters were also detected, but were less dramatic in αERKO mice fed casein. These data suggest that the decrease in AQP expression in the efferent ductules of αERKO mice contributes in part to water retention in this tissue, eventually leading to backflow of water into the testis, with subsequent decreases in sperm concentration and motility. The data also suggest that phytoestrogens, which are present in regular lab chow, can influence the male reproductive tract with and without the presence of ERα, promoting efferent ductule and epididymal

  2. Comparison of immunocytochemical estrogen receptor assay, estrogen receptor enzyme immunoassay, and radioligand-labeled estrogen receptor assay in human breast cancer and uterine tissue

    SciTech Connect

    Heubner, A.; Beck, T.; Grill, H.J.; Pollow, K.

    1986-08-01

    Determination of estrogen receptor content in 82 breast cancer specimens with immunocytochemical estrogen receptor assay (ER-EIA) (Abbott) was compared with our routinely used binding assay using /sup 125/I-estradiol as radioligand with Scatchard plot analysis of the binding data. Although the estrogen receptor content measured with the ER-EIA was approximately 2-fold higher compared with the binding assay, the immunochemical method proved to be a useful alternative for estrogen receptor determination. Furthermore, it is possible to detect estrogen receptors in FPLC Superose 12 (size exclusion column) eluates or in the fractions obtained after sucrose density centrifugation using the ER-EIA. Forty breast cancer samples were analyzed utilizing the immunocytochemical technique (ER-ICA) for visualization of the estrogen receptor content in frozen tumor tissues in relationship to the quantitative results obtained with the ER-EIA assay. Specific staining for estrogen receptor was confined only to the cell nucleus, was distributed irregularly among the tumor cells, and was variable in intensity. The staining intensity and the percentage of positively stained cells increased with increasing level of cytosolic estrogen receptor. In 27 of 40 cases the immunocytochemical results correlated well with the ER-EIA assay. Nine cases were ER-ICA negative with positive ER-EIA, and four were ER-ICA positive with negative ER-EIA.

  3. Estrogen-related receptor γ (ERRγ) regulates oxygen-dependent expression of voltage-gated potassium (K+) channels and tissue kallikrein during human trophoblast differentiation.

    PubMed

    Luo, Yanmin; Kumar, Premlata; Mendelson, Carole R

    2013-06-01

    Estrogen-related receptor γ (ERRγ) serves a critical O2-dependent regulatory role in the differentiation of human cytotrophoblasts to syncytiotrophoblast. In this study, we investigated expression of genes encoding tissue kallikrein (KLK1) and voltage-gated K(+) channels (KV7) during differentiation of human trophoblasts in culture and the roles of ERRγ and O2 tension in their regulation. Expression of KLK1 and the KV7 channel subunits, KCNQ1, KCNE1, KCNE3, and KCNE5, increased during differentiation of cultured human trophoblast cells in a 20% O2 environment. Notably, together with ERRγ, expression of KLK1, KCNQ1, KCNE1, KCNE3, and KCNE5 was markedly reduced when cells were cultured in a hypoxic environment (2% O2). Moreover, upon transduction of trophoblast cells with short hairpin RNAs for endogenous ERRγ, KLK1, KCNQ1, KCNE1, and KCNE3 expression was significantly decreased. Promoter and site-directed mutagenesis studies in transfected cells identified putative ERRγ response elements within the KLK1 and KCNE1 5'-flanking regions required for ERRγ-stimulated transcriptional activity. Binding of endogenous ERRγ to these ERRγ response elements increased during trophoblast differentiation in culture and was inhibited by hypoxia. The KV7 blocker linopirdine reduced human chorionic gonadotropin secretion and aggregation of cultured human trophoblasts, suggesting a possible role of KV7 channels in cell fusion and differentiation. Illumina gene expression arrays of cultured human trophoblast cells revealed several genes upregulated during syncytiotrophoblast differentiation and downregulated upon ERRγ knockdown involved in cell differentiation, adhesion, and synthesis of steroid and peptide hormones required for placental development and function. Collectively, these findings suggest that ERRγ mediates O2-dependent expression of genes involved in human trophoblast differentiation, function, and vascular homeostasis. PMID:23584901

  4. Estrogen-Related Receptor γ (ERRγ) Regulates Oxygen-Dependent Expression of Voltage-gated Potassium (K+) Channels and Tissue Kallikrein during Human Trophoblast Differentiation

    PubMed Central

    Luo, Yanmin; Kumar, Premlata

    2013-01-01

    Estrogen-related receptor γ (ERRγ) serves a critical O2-dependent regulatory role in the differentiation of human cytotrophoblasts to syncytiotrophoblast. In this study, we investigated expression of genes encoding tissue kallikrein (KLK1) and voltage-gated K+ channels (KV7) during differentiation of human trophoblasts in culture and the roles of ERRγ and O2 tension in their regulation. Expression of KLK1 and the KV7 channel subunits, KCNQ1, KCNE1, KCNE3, and KCNE5, increased during differentiation of cultured human trophoblast cells in a 20% O2 environment. Notably, together with ERRγ, expression of KLK1, KCNQ1, KCNE1, KCNE3, and KCNE5 was markedly reduced when cells were cultured in a hypoxic environment (2% O2). Moreover, upon transduction of trophoblast cells with short hairpin RNAs for endogenous ERRγ, KLK1, KCNQ1, KCNE1, and KCNE3 expression was significantly decreased. Promoter and site-directed mutagenesis studies in transfected cells identified putative ERRγ response elements within the KLK1 and KCNE1 5′-flanking regions required for ERRγ-stimulated transcriptional activity. Binding of endogenous ERRγ to these ERRγ response elements increased during trophoblast differentiation in culture and was inhibited by hypoxia. The KV7 blocker linopirdine reduced human chorionic gonadotropin secretion and aggregation of cultured human trophoblasts, suggesting a possible role of KV7 channels in cell fusion and differentiation. Illumina gene expression arrays of cultured human trophoblast cells revealed several genes upregulated during syncytiotrophoblast differentiation and downregulated upon ERRγ knockdown involved in cell differentiation, adhesion, and synthesis of steroid and peptide hormones required for placental development and function. Collectively, these findings suggest that ERRγ mediates O2-dependent expression of genes involved in human trophoblast differentiation, function, and vascular homeostasis. PMID:23584901

  5. Integration of Nuclear- and Extranuclear-Initiated Estrogen Receptor Signaling in Breast Cancer Cells

    ERIC Educational Resources Information Center

    Madak Erdogan, Zeynep

    2009-01-01

    Estrogenic hormones exert their effects through binding to Estrogen Receptors (ERs), which work in concert with coregulators and extranuclear signaling pathways to control gene expression in normal as well as cancerous states, including breast tumors. In this thesis, we have used multiple genome-wide analysis tools to elucidate various ways that…

  6. Deoxybenzoins are novel potent selective estrogen receptor modulators.

    PubMed

    Papoutsi, Zoi; Kassi, Eva; Fokialakis, Nikolas; Mitakou, Sofia; Lambrinidis, George; Mikros, Emmanuel; Moutsatsou, Paraskevi

    2007-09-01

    Deoxybenzoins are plant compounds with similar structure to isoflavones. In this study, we evaluated the ability of two synthesized deoxybenzoins (compound 1 and compound 2) (a) to influence the activity of the estrogen receptor subtypes ERalpha and ERbeta in HeLa cells co-transfected with an estrogen response element-driven luciferase reporter gene and ERalpha- or ERbeta-expression vectors, (b) to modulate the IGFBP-3 and pS2 protein in MCF-7 breast cancer cells, (c) to induce mineralization of KS483 osteoblasts and (d) to affect the cell viability of endometrial (Ishikawa) and breast (MCF-7, MDA-MB-231) cancer cells. Docking and binding energy calculations were performed using the mixed Monte Carlo/Low Mode search method (Macromodel 6.5). Compound 1 displayed significant estrogenic activity via ERbeta but no activity via ERalpha. Compound 2 was an estrogen-agonist via ERalpha and antagonist via ERbeta. Both compounds increased, like the pure antiestrogen ICI182780, the IGFBP-3 levels. Compound 2 induced, like 17beta-estradiol, significant mineralization in osteoblasts. The cell viability of Ishikawa cells was unchanged in the presence of either compound. Compound 1 increased MCF-7 cell viability consistently with an increase in pS2 levels, whereas compound 2 inhibited the cell viability. Molecular modeling confirmed the agonistic or antagonistic behaviour of compound 2 via ER subtypes. Compound 2, being an agonist in osteoblasts, an antagonist in breast cancer cells, with no estrogenic effects in endometrial cancer cells, makes it a potential selective estrogen receptor modulator and a choice for hormone replacement therapy. PMID:17659312

  7. Loss of BRCA1 leads to an increase in epidermal growth factor receptor expression in mammary epithelial cells, and epidermal growth factor receptor inhibition prevents estrogen receptor-negative cancers in BRCA1-mutant mice

    PubMed Central

    2011-01-01

    Introduction Women who carry a BRCA1 mutation typically develop "triple-negative" breast cancers (TNBC), defined by the absence of estrogen receptor (ER), progesterone receptor and Her2/neu. In contrast to ER-positive tumors, TNBCs frequently express high levels of epidermal growth factor receptor (EGFR). Previously, we found a disproportionate fraction of progenitor cells in BRCA1 mutation carriers with EGFR overexpression. Here we examine the role of EGFR in mammary epithelial cells (MECs) in the emergence of BRCA1-related tumors and as a potential target for the prevention of TNBC. Methods Cultures of MECs were used to examine EGFR protein levels and promoter activity in response to BRCA1 suppression with inhibitory RNA. EGFR was assessed by immunoblot and immunofluorescence analysis, real-time reverse transcriptase-polymerase chain reaction assay (RT-PCR) and flow cytometry. Binding of epidermal growth factor (EGF) to subpopulations of MECs was examined by Scatchard analysis. The responsiveness of MECs to the EGFR inhibitor erlotinib was assessed in vitro in three-dimensional cultures and in vivo. Mouse mammary tumor virus-Cre recombinase (MMTV-Cre) BRCA1flox/flox p53+/- mice were treated daily with erlotinib or vehicle control, and breast cancer-free survival was analyzed using the Kaplan-Meier method. Results Inhibition of BRCA1 in MECs led to upregulation of EGFR with an inverse correlation of BRCA1 with cellular EGFR protein levels (r2 = 0.87) and to an increase in cell surface-expressed EGFR. EGFR upregulation in response to BRCA1 suppression was mediated by transcriptional and posttranslational mechanisms. Aldehyde dehydrogenase 1 (ALDH1)-positive MECs expressed higher levels of EGFR than ALDH1-negative MECs and were expanded two- to threefold in the BRCA1-inhibited MEC population. All MECs were exquisitely sensitive to EGFR inhibition with erlotinib in vitro. EGFR inhibition in MMTV-Cre BRCA1flox/flox p53+/- female mice starting at age 3 months increased

  8. Folate- and vitamin B12-deficient diet during gestation and lactation alters cerebellar synapsin expression via impaired influence of estrogen nuclear receptor α.

    PubMed

    Pourié, Grégory; Martin, Nicolas; Bossenmeyer-Pourié, Carine; Akchiche, Nassila; Guéant-Rodriguez, Rosa Maria; Geoffroy, Andréa; Jeannesson, Elise; El Hajj Chehadeh, Sarah; Mimoun, Khalid; Brachet, Patrick; Koziel, Violette; Alberto, Jean-Marc; Helle, Deborah; Debard, Renée; Leininger, Brigitte; Daval, Jean-Luc; Guéant, Jean-Louis

    2015-09-01

    Deficiency in the methyl donors vitamin B12 and folate during pregnancy and postnatal life impairs proper brain development. We studied the consequences of this combined deficiency on cerebellum plasticity in offspring from rat mothers subjected to deficient diet during gestation and lactation and in rat neuroprogenitor cells expressing cerebellum markers. The major proteomic change in cerebellum of 21-d-old deprived females was a 2.2-fold lower expression of synapsins, which was confirmed in neuroprogenitors cultivated in the deficient condition. A pathway analysis suggested that these proteomic changes were related to estrogen receptor α (ER-α)/Src tyrosine kinase. The influence of impaired ER-α pathway was confirmed by abnormal negative geotaxis test at d 19-20 and decreased phsophorylation of synapsins in deprived females treated by ER-α antagonist 1,3-bis(4-hydroxyphenyl)-4-methyl-5-[4-(2-piperidinylethoxy)phenol]-1H-pyrazole dihydrochloride (MPP). This effect was consistent with 2-fold decreased expression and methylation of ER-α and subsequent decreased ER-α/PPAR-γ coactivator 1 α (PGC-1α) interaction in deficiency condition. The impaired ER-α pathway led to decreased expression of synapsins through 2-fold decreased EGR-1/Zif-268 transcription factor and to 1.7-fold reduced Src-dependent phosphorylation of synapsins. The treatment of neuroprogenitors with either MPP or PP1 (4-(4'-phenoxyanilino)-6,7-dimethoxyquinazoline, 6,7-dimethoxy-N-(4-phenoxyphenyl)-4-quinazolinamine, SKI-1, Src-l1) Src inhibitor produced similar effects. In conclusion, the deficiency during pregnancy and lactation impairs the expression of synapsins through a deregulation of ER-α pathway. PMID:26018677

  9. CDK9 inhibitors selectively target estrogen receptor-positive breast cancer cells through combined inhibition of MYB and MCL-1 expression

    PubMed Central

    Mitra, Partha; Yang, Ren-Ming; Sutton, James; Ramsay, Robert G.; Gonda, Thomas J.

    2016-01-01

    Our previous studies showed that MYB is required for proliferation of, and confers protection against apoptosis on, estrogen receptor-positive (ER+ve) breast cancer cells, which are almost invariably also MYB+ve. We have also shown that MYB expression in ER+ve breast cancer cells is regulated at the level of transcriptional elongation and as such, is suppressed by CDK9i. Here we examined the effects of CDK9i on breast cancer cells and the involvement of MYB in these effects. ER+ve breast cancer cell lines including MCF-7 were much more sensitive (> 10 times) to killing by CDK9i than ER−ve/MYB−ve cells. Moreover, surviving cells showed a block at the G2/M phase of the cell cycle. Importantly, ectopic MYB expression conferred resistance to apoptosis induction, cell killing and G2/M accumulation. Expression of relevant MYB target genes including BCL2 and CCNB1 was suppressed by CDK9 inhibition, and this too was reversed by ectopic MYB expression. Nevertheless, inhibition of BCL2 alone either by MYB knockdown or by ABT-199 treatment was insufficient for significant induction of apoptosis. Further studies implied that suppression of MCL-1, a well-documented target of CDK9 inhibition, was additionally required for apoptosis induction, while maximal levels of apoptosis induced by CDK9i are likely to also involve inhibition of BCL2L1 expression. Taken together these data suggest that MYB regulation of BCL2 underlies the heightened sensitivity of ER+ve compared to ER−ve breast cancer cells to CDK9 inhibition, and that these compounds represent a potential therapeutic for ER+ve breast cancers and possibly other MYB-dependent cancers. PMID:26812885

  10. Support of a bi-faceted role of estrogen receptor beta in estrogen receptor alpha positive breast cancer cells

    PubMed Central

    Jonsson, Philip; Katchy, Anne; Williams, Cecilia

    2013-01-01

    Expression of estrogen receptor alpha (ERα) in breast cancer identifies patients most likely to respond to endocrine treatment. The second estrogen receptor, ERβ, is also expressed in breast tumors, but its function and therapeutic potential needs further study. Whereas in vitro studies have established that ERβ opposes transcriptional and proliferative functions of ERα, several clinical studies report its correlation to proliferative markers and poorer prognosis. The data demonstrating that ERβ opposes ERα are primarily based on transient expression of ERβ. Here, we explored the functions of constitutively expressed ERβ in ERα-positive breast cancer lines MCF7 and T47D. We found that ERβ, under these conditions heterodimerized with ERα in presence and absence of 17β-estradiol, and induced genome-wide transcriptional changes. Widespread anti-ERα signaling was, however, not observed and ERβ was not anti-proliferative. Tamoxifen antagonized proliferation and ER-mediated gene regulation both in the presence and absence of ERβ. In conclusion, ERβ’s role in cells adapted to its expression appears to differ from its role in cells with transient expression. Our study is important because it provides a deeper understanding of ERβ’s role in breast tumors that co-express both receptors and supports an emerging bi-faceted role of ERβ. PMID:24192230

  11. Estrogen-related receptor γ controls hepatic CB1 receptor-mediated CYP2E1 expression and oxidative liver injury by alcohol

    PubMed Central

    Jang, Hyun-Hee; Park, Jinyoung; Kim, Jung Ran; Koh, Minseob; Jeong, Won-Il; Koo, Seung-Hoi; Park, Tae-Sik; Yun, Chul-Ho; Park, Seung Bum; Chiang, John Y L; Lee, Chul-Ho; Choi, Hueng-Sik

    2013-01-01

    Background The hepatic endocannabinoid system and cytochrome P450 2E1 (CYP2E1), a key enzyme causing alcohol-induced reactive oxygen species (ROS) generation, are major contributors to the pathogenesis of alcoholic liver disease. The nuclear hormone receptor oestrogen-related receptor γ (ERRγ) is a constitutively active transcriptional activator regulating gene expression. Objective To investigate the role of ERRγ in the alcohol-mediated regulation of CYP2E1 and to examine the possibility to control alcohol-mediated oxidative stress and liver injury through an ERRγ inverse agonist. Design For chronic alcoholic hepatosteatosis study, C57BL/6J wild-type and CB1−/− mice were administered alcohol for 4 weeks. GSK5182 and chlormethiazole (CMZ) were given by oral gavage for the last 2 weeks of alcohol feeding. Gene expression profiles and biochemical assays were performed using the liver or blood of mice. Results Hepatic ERRγ gene expression induced by alcohol-mediated activation of CB1 receptor results in induction of CYP2E1, while liver-specific ablation of ERRγ gene expression blocks alcohol-induced expression of CYP2E1 in mouse liver. An ERRγ inverse agonist significantly ameliorates chronic alcohol-induced liver injury in mice through inhibition of CYP2E1-mediated generation of ROS, while inhibition of CYP2E1 by CMZ abrogates the beneficial effects of the inverse agonist. Finally, chronic alcohol-mediated ERRγ and CYP2E1 gene expression, ROS generation and liver injury in normal mice were nearly abolished in CB1−/− mice. Conclusions ERRγ, as a previously unrecognised transcriptional regulator of hepatic CB1 receptor, controls alcohol-induced oxidative stress and liver injury through CYP2E1 induction, and its inverse agonist could ameliorate oxidative liver injury due to chronic alcohol exposure. PMID:23023167

  12. Hispolon inhibits the growth of estrogen receptor positive human breast cancer cells through modulation of estrogen receptor alpha

    SciTech Connect

    Jang, Eun Hyang; Jang, Soon Young; Cho, In-Hye; Hong, Darong; Jung, Bom; Park, Min-Ju; Kim, Jong-Ho

    2015-08-07

    Human estrogen receptor α (ERα) is a nuclear transcription factor that is a major therapeutic target in breast cancer. The transcriptional activity of ERα is regulated by certain estrogen-receptor modulators. Hispolon, isolated from Phellinus linteus, a traditional medicinal mushroom called Sanghwang in Korea, has been used to treat various pathologies, such as inflammation, gastroenteric disorders, lymphatic diseases, and cancers. In this latter context, Hispolon has been reported to exhibit therapeutic efficacy against various cancer cells, including melanoma, leukemia, hepatocarcinoma, bladder cancer, and gastric cancer cells. However, ERα regulation by Hispolon has not been reported. In this study, we investigated the effects of Hispolon on the growth of breast cancer cells. We found that Hispolon decreased expression of ERα at both mRNA and the protein levels in MCF7 and T47D human breast cancer cells. Luciferase reporter assays showed that Hispolon decreased the transcriptional activity of ERα. Hispolon treatment also inhibited expression of the ERα target gene pS2. We propose that Hispolon, an anticancer drug extracted from natural sources, inhibits cell growth through modulation of ERα in estrogen-positive breast cancer cells and is a candidate for use in human breast cancer chemotherapy. - Highlights: • Hispolon decreased ERα expression at both mRNA and protein levels. • Hispolon decreased ERα transcriptional activity. • Hispolon treatment inhibited expression of ERα target gene pS2. • Shikonin is a candidate chemotherapeutic target in the treatment of human breast cancer.

  13. Ontogeny of the estrogen receptor in the chick oviduct.

    PubMed

    Joensuu, T K; Tuohimaa, P J

    1989-01-01

    The distribution of estrogen receptor (ER) in the chick oviduct was studied immunohistochemically with monoclonal antibody H222, known to recognize chick ER [1]. The ontogeny of ER appeared to be very dependent on cellular differentiation. In the undifferentiated oviduct ER was located in the epithelial, mesothelial, stromal and smooth muscle cells. During differentiation ER disappeared from the surface epithelium, mesothelium, stromal and smooth muscle cells. At the onset of differentiation the protodifferentiated gland cells invaginated into the underlying stroma; these cells expressed ER. In the fully differentiated chick oviduct ER was located only in the tubular gland cells, which correlates with the known transcriptional activity of estrogen-induced ovalbumin-gene. However, we have reported estrogen dependency of PR also in ER-negative stromal cells, the mechanism being so far unknown. It is possible that there are mechanisms other than ER regulating the expression of PR. Estrogen-induced differentiation did not differ from normal maturation in regard to the distribution of ER. Since stromal, epithelial, mesothelial and smooth muscle cells were ER-negative in the mature oviduct, the concentration of ER, i.e. ER binding sites/cell is underestimated when whole tissue homogenates are used. PMID:2626020

  14. No substantial changes in estrogen receptor and estrogen-related receptor orthologue gene transcription in Marisa cornuarietis exposed to estrogenic chemicals☆☆☆

    PubMed Central

    Bannister, Richard; Beresford, Nicola; Granger, David W.; Pounds, Nadine A.; Rand-Weaver, Mariann; White, Roger; Jobling, Susan; Routledge, Edwin J.

    2013-01-01

    Estrogen receptor orthologues in molluscs may be targets for endocrine disruptors, although mechanistic evidence is lacking. Molluscs are reported to be highly susceptible to effects caused by very low concentrations of environmental estrogens which, if substantiated, would have a major impact on the risk assessment of many chemicals. The present paper describes the most thorough evaluation to-date of the susceptibility of Marisa cornuarietis ER and ERR gene transcription to modulation by vertebrate estrogens in vivo and in vitro. We investigated the effects of estradiol-17β and 4-tert-Octylphenol exposure on in vivo estrogen receptor (ER) and estrogen-related receptor (ERR) gene transcription in the reproductive and neural tissues of the gastropod snail M. cornuarietis over a 12-week period. There was no significant effect (p > 0.05) of treatment on gene transcription levels between exposed and non-exposed snails. Absence of a direct interaction of estradiol-17β and 4-tert-Octylphenol with mollusc ER and ERR protein was also supported by in vitro studies in transfected HEK-293 cells. Additional in vitro studies with a selection of other potential ligands (including methyl-testosterone, 17α-ethinylestradiol, 4-hydroxytamoxifen, diethylstilbestrol, cyproterone acetate and ICI182780) showed no interaction when tested using this assay. In repeated in vitro tests, however, genistein (with mcER-like) and bisphenol-A (with mcERR) increased reporter gene expression at high concentrations only (>10−6 M for Gen and >10−5 M for BPA, respectively). Like vertebrate estrogen receptors, the mollusc ER protein bound to the consensus vertebrate estrogen-response element (ERE). Together, these data provide no substantial evidence that mcER-like and mcERR activation and transcript levels in tissues are modulated by the vertebrate estrogen estradiol-17β or 4-tert-Octylphenol in vivo, or that other ligands of vertebrate ERs and ERRs (with the possible exception of

  15. Expression of Estrogen Receptor Beta Predicts Oncologic Outcome of pT3 Upper Urinary Tract Urothelial Carcinoma Better Than Aggressive Pathological Features

    PubMed Central

    Luo, Hao Lun; Sung, Ming Tse; Tsai, Eing Mei; Lin, Chang Shen; Lee, Nai Lun; Chung, Yueh-Hua; Chiang, Po Hui

    2016-01-01

    Upper urinary tract urothelial carcinoma (UT-UC) is rare and treatment options or prognostic markers are limited. There is increasing evidence indicating that urothelial carcinoma may be an endocrine-related cancer. The aim of this study was to analyze the prognostic effect of estrogen receptor beta (ERβ) on the outcome of UT-UC. From 2005 to 2012, this study included 105 patients with pT3 UT-UC. Perioperative factors, pathological features, and ERβ immunostaining were reviewed and prognostic effects were examined by multivariate analysis. This study divided patients into either the ERβ-high (n = 52) or ERβ-low (n = 53) group and analyzed their oncologic outcomes. All pathological features except infiltrating tumor architecture (significantly higher incidence in ERβ-low group, p = 0.004) are symmetric in both groups. Low ERβ expression was significantly correlated with local recurrence and distant metastasis in univariate analysis (p = 0.035 and 0.004, respectively) and multivariate analysis (p = 0.05 and 0.008, respectively). Cell line study also proved that knock down of ERβ cause less UTUC proliferation and migration. In addition, ERβ agonist also enhanced the cytotoxic and migration inhibition effect of cisplatin and ERβ antagonist cause the UTUC cell more resistant to cisplatin. This result may help identify patients in need of adjuvant therapy or develop potential targeted therapy. PMID:27052470

  16. Novel mammalian cell lines expressing reporter genes for the detection of environmental chemicals activating endogenous aryl hydrocarbon receptors (ArhR) or estrogen receptors (ER).

    PubMed

    Minh, Si Do; Below, Sabine; Müller, Christian; Hildebrandt, Jan-Peter

    2008-12-01

    We have constructed two vector systems (pDMS5, pSAB2) containing the promoter regions of the human CYP1A1 gene including xenobiotic response elements or the promoter region of the Xenopus laevis vitellogenin A2 gene including estrogen response elements, respectively, and the genes for green fluorescent protein and firefly luciferase. These vectors were transfected into CHO-K1 cells. Transiently transfected cells consistently responded to 1 nmol/l TCDD (dioxin) or 10 nmol/l 17ss-estradiol, respectively, with a 3-5 fold increase in luciferase activity. Permanent cell lines were selected by culturing transiently transfected cells under continued presence of antibiotics and dilution cloning. Cells which had stably integrated the vector-DNA into the genomic DNA were selected. SiF6 cells responded to treatment with TCDD, PCB126, benzo(a)pyrene or indirubin-3'-monoxime in the concentration range between 0 and 1 micromol/l. SiG12 cells responded to treatment with bisphenol A, 4-MBC and DDT in the concentration range between 0 and 10 micromol/l. Compared with the controls, luciferase mRNA-abundance (semi-quantitative RT-PCR) and luciferase activity (luminescence assay) were elevated up to 3-fold. Resveratrol or tamoxifen, respectively, worked as full antagonists. Luciferase expression was increased upon treatment of cells with extracts of spiked soil samples indicating that our systems are suited for screening of environmental samples. PMID:18835349

  17. Pubertal activation of estrogen receptor α in the medial amygdala is essential for the full expression of male social behavior in mice.

    PubMed

    Sano, Kazuhiro; Nakata, Mariko; Musatov, Sergei; Morishita, Masahiro; Sakamoto, Toshiro; Tsukahara, Shinji; Ogawa, Sonoko

    2016-07-01

    Testosterone plays a central role in the facilitation of male-type social behaviors, such as sexual and aggressive behaviors, and the development of their neural bases in male mice. The action of testosterone via estrogen receptor (ER) α, after being aromatized to estradiol, has been suggested to be crucial for the full expression of these behaviors. We previously reported that silencing of ERα in adult male mice with the use of a virally mediated RNAi method in the medial preoptic area (MPOA) greatly reduced sexual behaviors without affecting aggressive behaviors whereas that in the medial amygdala (MeA) had no effect on either behavior. It is well accepted that testosterone stimulation during the pubertal period is necessary for the full expression of male-type social behaviors. However, it is still not known whether, and in which brain region, ERα is involved in this developmental effect of testosterone. In this study, we knocked down ERα in the MeA or MPOA in gonadally intact male mice at the age of 21 d and examined its effects on the sexual and aggressive behaviors later in adulthood. We found that the prepubertal knockdown of ERα in the MeA reduced both sexual and aggressive behaviors whereas that in the MPOA reduced only sexual, but not aggressive, behavior. Furthermore, the number of MeA neurons was reduced by prepubertal knockdown of ERα. These results indicate that ERα activation in the MeA during the pubertal period is crucial for male mice to fully express their male-type social behaviors in adulthood. PMID:27325769

  18. Swimming suppresses hepatic vitellogenesis in European female silver eels as shown by expression of the estrogen receptor 1, vitellogenin1 and vitellogenin2 in the liver

    PubMed Central

    2010-01-01

    Background When European silver eels (Anguilla anguilla) venture into the Atlantic Ocean for their 6,000 km semelparous spawning run to the Sargasso Sea, they are still in a prepubertal stage. Further sexual development appears to be blocked by dopaminergic inhibition of hypothalamus and pituitary activity. Recently, we found that swimming for several weeks in freshwater stimulated the incorporation of fat droplets in the oocytes. So, it was hypothesized that long term swimming in seawater would release the inhibition further and would also stimulate the production of vitellogenin by the liver. Methods For this study a swim-flume was constructed to allow simulated migration of migratory female silver eels for 3 months (1,420 km) in natural seawater at 20 degrees C. Primers were designed for polymerase chain reactions to measure the mRNA expression of estrogen receptor 1 (esr1), vitellogenin1 (vtg1) and vitellogenin2 (vtg2) genes in the liver of European female silver eels. Results In comparison to resting eels, swimming eels showed a diminished expression of esr1, vtg1 and vtg2 in the liver. They also had lower plasma calcium (Ca; indicative of vitellogenin) levels in their blood. This showed that vitellogenesis is more strongly suppressed in swimming than in resting eels. However, when eels were subsequently stimulated by 3 weekly carp pituitary extract injections, the expression of the same genes and plasma levels of Ca strongly increased in both groups to similar levels, thus equalizing the initial differences between resting and swimming. Conclusions It is concluded that vitellogenesis remains suppressed during resting and even more during swimming. The fact that swimming stimulates fat deposition in the oocytes but suppresses vitellogenesis indicates that these events are separated in nature and occur sequentially. Swimming-suppressed vitellogenesis may imply that in nature eels undergo vitellogenesis and final maturation near or at the spawning grounds. PMID

  19. Raloxifene induces cell death and inhibits proliferation through multiple signaling pathways in prostate cancer cells expressing different levels of estrogen receptor α and β.

    PubMed

    Rossi, V; Bellastella, G; De Rosa, C; Abbondanza, C; Visconti, D; Maione, L; Chieffi, P; Della Ragione, F; Prezioso, D; De Bellis, A; Bellastella, A; Sinisi, A A

    2011-05-01

    Raloxifene (RAL), a selective estrogen receptor (ER) modulator (SERM) seems to induce apoptosis in both androgen-dependent and -independent prostate cell (PC) lines via activation of ERβ and an antagonistic effect on ERα. In this study, we evaluated the effects of RAL on epithelial PC growth using the two following in vitro models: the androgen-dependent cell line EPN which expressed both ERs; and a stabilized epithelial cell line derived from a prostate cancer specimen (CPEC), which expressed low levels of ERβ and lacked ERα. In EPN cells, there was an increase in the pre-G1 apoptotic peak and a reduction in the S phase of the cell cycle with G0/G1 arrest after E2 or RAL treatment; bcl-2 mRNA and Bcl-2 protein levels were significantly reduced, while activated caspase-3 and Par-4 levels increased significantly after either E2 or RAL treatment; in addition, c-myc transcript was inhibited after 10(-6)  M RAL treatment. A dose-dependent increase of metallothionein II gene RNA level was also induced by RAL in EPN. In CPEC, there was only a weak apoptotic peak associated with caspase-3 activation and Par-4 increase after either E2 or RAL treatment; while c-myc transcript level increased. RAL induced a rapid but transient phosphorylation of ERK 1/2 in EPN cells but generated a sustained effect in CPEC. These findings suggest that RAL effects on PC growth control in vitro are cell-specific, depending on ERβ or ERβ/ERα relative expression levels. Moreover, this study demonstrated that RAL affected both transcriptional regulation and non-genomic signals, which resulted in the modulation of multiple signaling pathways of apoptosis and of cell cycle progression. PMID:20945400

  20. Isolation of the human anionic glutathione S-transferase cDNA and the relation of its gene expression to estrogen-receptor content in primary breast cancer

    SciTech Connect

    Moscow, J.A.; Townsend, A.J.; Goldsmith, M.E.; Whang-Peng, J.; Vickers, P.J.; Poisson, R.; Legault-Poisson, S.; Myers, C.E.; Cowan, K.H.

    1988-09-01

    The development of multidrug resistance in MCF7 human breast cancer cells is associated with overexpression of P-glycoprotein, changes in activities of several detoxication enzymes, and loss of hormone sensitivity and estrogen receptors (ERs). The authors have cloned the cDNA for one of the drug-detoxifying enzymes overexpressed in multidrug-resistant MCF7 cells (Adr/sup R/ MCF7), the anionic isozyme of glutathione S-transferase (GST/pi/). Hybridization with this GST/pi/ cDNA, GST/pi/-1, demonstrated that increased GST/pi/ activity in Adr/sup R/ MCF7 cells is associated with overexpression but not with amplification of the gene. They mapped the GST/pi/ gene to human chromosome 11q13 by in situ hybridization. Since multidrug resistance and GST/pi/ overexpression are associated with the loss of ERs in Adr/sup R/ MCF7 cells, they examined several other breast cancer cell lines that were not selected for drug resistance. In each of these cell lines they found an inverse association between GST/pi/ expression and ER content. They also examined RNA from 21 primary breast cancers and found a similar association between GST/pi/ expression and ER content in vivo. The finding of similar patterns of expression of a drug-detoxifying enzyme and of ERs in vitro as well as in vivo suggests that ER-negative breast cancer cells may have greater protection against antineoplastic agents conferred by GST/pi/ than ER-positive tumors.

  1. Cyclin D1 stimulation of estrogen receptor transcriptional activity independent of cdk4.

    PubMed Central

    Neuman, E; Ladha, M H; Lin, N; Upton, T M; Miller, S J; DiRenzo, J; Pestell, R G; Hinds, P W; Dowdy, S F; Brown, M; Ewen, M E

    1997-01-01

    Cyclin D1 plays an important role in the development of breast cancer and is required for normal breast cell proliferation and differentiation associated with pregnancy. We show that ectopic expression of cyclin D1 can stimulate the transcriptional activity of the estrogen receptor in the absence of estradiol and that this activity can be inhibited by 4-hydroxytamoxifen and ICI 182,780. Cyclin D1 can form a specific complex with the estrogen receptor. Stimulation of the estrogen receptor by cyclin D1 is independent of cyclin-dependent kinase 4 activation. Cyclin D1 may manifest its oncogenic potential in breast cancer in part through binding to the estrogen receptor and activation of the transcriptional activity of the receptor. PMID:9271411

  2. Mouse monoclonal antibodies against estrogen receptor.

    PubMed

    De Rosa, Caterina; Rossi, Valentina; Abbondanza, Ciro

    2014-01-01

    The production of monoclonal antibodies, by cloning hybridoma derived from the fusion of myeloma cells and spleen lymphocytes, has allowed to obtain great advances in many fields of biological knowledge. The use of specific antibodies to the estrogen receptor, in fact, has been an invaluable method to bring out its mechanisms of action and its effects, both genomic and extra-genomic. Here we describe, step by step, the production of monoclonal antibodies, starting from protocol for antigen preparation to the selection of antibody-secreting hybridoma. PMID:25182770

  3. Insights from the Study of Animals Lacking Functional Estrogen Receptor

    NASA Astrophysics Data System (ADS)

    Korach, Kenneth S.

    1994-12-01

    Estrogen hormones produce physiological actions within a variety of target sites in the body and during development by activating a specific receptor protein. Hormone responsiveness for the estrogen receptor protein was investigated at different stages of development with the use of gene knockout techniques because no natural genetic mutants have been described. A mutant mouse line without a functional estrogen receptor was created and is being used to assess estrogen responsiveness. Both sexes of these mutant animals are infertile and show a variety of phenotypic changes, some of which are associated with the gonads, mammary glands, reproductive tracts, and skeletal tissues.

  4. Selectivity of natural, synthetic and environmental estrogens for zebrafish estrogen receptors

    SciTech Connect

    Pinto, Caroline; Grimaldi, Marina; Boulahtouf, Abdelhay; Pakdel, Farzad; Brion, François; Aït-Aïssa, Sélim; Cavaillès, Vincent; Bourguet, William; Gustafsson, Jan-Ake; and others

    2014-10-01

    Zebrafish, Danio rerio, is increasingly used as an animal model to study the effects of pharmaceuticals and environmental estrogens. As most of these estrogens have only been tested on human estrogen receptors (ERs), it is necessary to measure their effects on zebrafish ERs. In humans there are two distinct nuclear ERs (hERα and hERβ), whereas the zebrafish genome encodes three ERs, zfERα and two zfERβs (zfERβ1 and zfERβ2). In this study, we established HeLa-based reporter cell lines stably expressing each of the three zfERs. We first reported that estrogens more efficiently activate the zfERs at 28 °C as compared to 37 °C, thus reflecting the physiological temperature of zebrafish in wildlife. We then showed significant differences in the ability of agonist and antagonist estrogens to modulate activation of the three zfER isotypes in comparison to hERs. Environmental compounds (bisphenol A, alkylphenols, mycoestrogens) which are hER panagonists and hERβ selective agonists displayed greater potency for zfERα as compared to zfERβs. Among hERα selective synthetic agonists, PPT did not activate zfERα while 16α-LE2 was the most zfERα selective compound. Altogether, these results confirm that all hER ligands control in a similar manner the transcriptional activity of zfERs although significant differences in selectivity were observed among subtypes. The zfER subtype selective ligands that we identified thus represent new valuable tools to dissect the physiological roles of the different zfERs. Finally, our work also points out that care has to be taken in transposing the results obtained using the zebrafish as a model for human physiopathology. - Highlights: • Zebrafish is increasingly used to study the effects of estrogens. • We assessed the activity of pharmaceutical and environmental estrogens on zfERs. • Environmental estrogens displayed greater potency for zfERα compared to zfERβs. • hERβ selective agonists displayed greater potency for zf

  5. A Novel Combinatorial Epigenetic Therapy Using Resveratrol and Pterostilbene for Restoring Estrogen Receptor-α (ERα) Expression in ERα-Negative Breast Cancer Cells

    PubMed Central

    Kala, Rishabh; Tollefsbol, Trygve O.

    2016-01-01

    Breast cancer is the second most common cancer and a leading cause of cancer death in women. Specifically, estrogen receptor-α (ERα)-negative breast cancers are clinically more aggressive and normally do not respond to conventional hormone-directed therapies such as tamoxifen. Although epigenetic-based therapies such as 5-aza-2’-deoxycytidine and/or trichostatin A as DNA methyltransferase (DNMT) and histone deacetylase (HDAC) inhibitors, respectively, can regulate the expression of ERα, this can often lead to a number of side effects. Plant-based dietary compounds such as resveratrol and pterostilbene in novel combinatorial therapy provides new avenues to target these side effects and provide similar results with a higher level of safety. Here, we report that combinatorial resveratrol and pterostilbene leads to the reactivation of ERα expression in ERα-negative breast cancer cells in a time-dependent manner. Chromatin immunoprecipitation analysis of the ERα promoter in each cell type revealed an increase in enrichment of acetyl-H3, acetyl-H3lysine9 (H3K9) and acetyl-H4 active chromatin markers in the ERα promoter region after combinatorial treatment. This treatment also resulted in a significant change in HDAC and histone acetyl transferase (HAT) enzyme activity in these cells after 3 days of treatments. The combination resulted in a significant decrease in DNMT enzyme activity and 5-methylcytosine levels in MDA-MB-157 breast cancer cells. Moreover, reactivation of ERα expression by resveratrol combined with pterostilbene was found to sensitize ERα-dependent response to 17β-estradiol (E2)-mediated cellular proliferation and antagonist 4-hydroxytamoxifen (4-OHT)-mediated inhibition of cellular proliferation in ERα-negative breast cancer cells. E2 and 4-OHT further affected the ERα-responsive downstream progesterone receptor (PGR) gene in ERα reactivated MDA-MB-157 cells. Collectively, our findings provide a new and safer way of restoring ER

  6. Estrogen regulation of chicken riboflavin carrier protein gene is mediated by ERE half sites without direct binding of estrogen receptor.

    PubMed

    Bahadur, Urvashi; Ganjam, Goutham K; Vasudevan, Nandini; Kondaiah, Paturu

    2005-02-28

    Estrogen is an important steroid hormone that mediates most of its effects on regulation of gene expression by binding to intracellular receptors. The consensus estrogen response element (ERE) is a 13bp palindromic inverted repeat with a three nucleotide spacer. However, several reports suggest that many estrogen target genes are regulated by diverse elements, such as imperfect EREs and ERE half sites (ERE 1/2), which are either the proximal or the distal half of the palindrome. To gain more insight into ERE half site-mediated gene regulation, we used a region from the estrogen-regulated chicken riboflavin carrier protein (RCP) gene promoter that contains ERE half sites. Using moxestrol, an analogue of estrogen and transient transfection of deletion and mutation containing RCP promoter/reporter constructs in chicken hepatoma (LMH2A) cells, we identified an estrogen response unit (ERU) composed of two consensus ERE 1/2 sites and one non-consensus ERE 1/2 site. Mutation of any of these sites within this ERU abolishes moxestrol response. Further, the ERU is able to confer moxestrol responsiveness to a heterologous promoter. Interestingly, RCP promoter is regulated by moxestrol in estrogen responsive human MCF-7 cells, but not in other cell lines such as NIH3T3 and HepG2 despite estrogen receptor-alpha (ER-alpha) co transfection. Electrophoretic mobility shift assays (EMSAs) with promoter regions encompassing the half sites and nuclear extracts from LMH2A cells show the presence of a moxestrol-induced complex that is abolished by a polyclonal anti-ERalpha antibody. Surprisingly, estrogen receptor cannot bind to these promoter elements in isolation. Thus, there appears to be a definite requirement for some other factor(s) in addition to estrogen receptor, for the generation of a suitable response of this promoter to estrogen. Our studies therefore suggest a novel mechanism of gene regulation by estrogen, involving ERE half sites without direct binding of ER to the

  7. Receptor interconversion model of hormone action. 3. Estrogen receptor mediated repression of reporter gene activity in A431 cells.

    PubMed

    Nag, A; Park, I; Krust, A; Smith, R G

    1990-03-20

    The chicken estrogen receptor exists in three interconvertible forms, two of which bind estradiol with high affinity and one which lacks the capacity to bind estradiol. Interconversion is regulated by reactions involving ATP/Mg2+. By cotransfecting into A431 cells estrogen receptor cDNA in an expression vector together with the pA2 (-821/-87) tk-CAT vitellogenin construct, we demonstrate that constitutive expression of chloramphenicol acetyltransferase (CAT) activity can be regulated either by selection of ligand or by modifying phosphorylation reactions in the recipient cells. In the presence of estrogen receptors, constitutive expression of CAT activity is inhibited in three situations: (i) in the absence of an estrogenic ligand; (ii) in the presence of an anti-estrogen; and (iii) in the presence of an estrogenic ligand together with 12-O-tetradecanoylphorbol 13-acetate (TPA). Estrogen receptor mediated repression of constitutive CAT activity is not observed with the pA2 (-331/-87) tk-CAT construct, indicating that DNA sequences required for repression are located between -821 and -331 base pairs upstream of the transcription initiation site. PMID:2346742

  8. Licorice root components in dietary supplements are selective estrogen receptor modulators with a spectrum of estrogenic and anti-estrogenic activities.

    PubMed

    Boonmuen, Nittaya; Gong, Ping; Ali, Zulfiqar; Chittiboyina, Amar G; Khan, Ikhlas; Doerge, Daniel R; Helferich, William G; Carlson, Kathryn E; Martin, Teresa; Piyachaturawat, Pawinee; Katzenellenbogen, John A; Katzenellenbogen, Benita S

    2016-01-01

    Licorice root extracts are often consumed as botanical dietary supplements by menopausal women as a natural alternative to pharmaceutical hormone replacement therapy. In addition to their components liquiritigenin (Liq) and isoliquiritigenin (Iso-Liq), known to have estrogenic activity, licorice root extracts also contain a number of other flavonoids, isoflavonoids, and chalcones. We have investigated the estrogenic activity of 7 of these components, obtained from an extract of Glycyrrhiza glabra powder, namely Glabridin (L1), Calycosin (L2), Methoxychalcone (L3), Vestitol (L4), Glyasperin C (L5), Glycycoumarin (L6), and Glicoricone (L7), and compared them with Liq, Iso-Liq, and estradiol (E2). All components, including Liq and Iso-Liq, have low binding affinity for estrogen receptors (ERs). Their potency and efficacy in stimulating the expression of estrogen-regulated genes reveal that Liq and Iso-Liq and L2, L3, L4, and L6 are estrogen agonists. Interestingly, L3 and L4 have an efficacy nearly equivalent to E2 but with a potency ca. 10,000-fold less. The other components, L1, L5 and L7, acted as partial estrogen antagonists. All agonist activities were reversed by the antiestrogen, ICI 182,780, or by knockdown of ERα with siRNA, indicating that they are ER dependent. In HepG2 hepatoma cells stably expressing ERα, only Liq, Iso-Liq, and L3 stimulated estrogen-regulated gene expression, and in all cases gene stimulation did not occur in HepG2 cells lacking ERα. Collectively, these findings classify the components of licorice root extracts as low potency, mixed ER agonists and antagonists, having a character akin to that of selective estrogen receptor modulators or SERMs. PMID:26631549

  9. Oxytocin and Estrogen Receptor β in the Brain: An Overview

    PubMed Central

    Acevedo-Rodriguez, Alexandra; Mani, Shaila K.; Handa, Robert J.

    2015-01-01

    Oxytocin (OT) is a neuropeptide synthesized primarily by neurons of the paraventricular and supraoptic nuclei of the hypothalamus. These neurons have axons that project into the posterior pituitary and release OT into the bloodstream to promote labor and lactation; however, OT neurons also project to other brain areas where it plays a role in numerous brain functions. OT binds to the widely expressed OT receptor (OTR), and, in doing so, it regulates homeostatic processes, social recognition, and fear conditioning. In addition to these functions, OT decreases neuroendocrine stress signaling and anxiety-related and depression-like behaviors. Steroid hormones differentially modulate stress responses and alter OTR expression. In particular, estrogen receptor β activation has been found to both reduce anxiety-related behaviors and increase OT peptide transcription, suggesting a role for OT in this estrogen receptor β-mediated anxiolytic effect. Further research is needed to identify modulators of OT signaling and the pathways utilized and to elucidate molecular mechanisms controlling OT expression to allow better therapeutic manipulations of this system in patient populations. PMID:26528239

  10. Estrogen Receptor-α in the Medial Amygdala Prevents Stress-Induced Elevations in Blood Pressure in Females.

    PubMed

    Hinton, Antentor Othrell; He, Yanlin; Xia, Yan; Xu, Pingwen; Yang, Yongjie; Saito, Kenji; Wang, Chunmei; Yan, Xiaofeng; Shu, Gang; Henderson, Alexander; Clegg, Deborah J; Khan, Sohaib A; Reynolds, Corey; Wu, Qi; Tong, Qingchun; Xu, Yong

    2016-06-01

    Psychological stress contributes to the development of hypertension in humans. The ovarian hormone, estrogen, has been shown to prevent stress-induced pressor responses in females by unknown mechanisms. Here, we showed that the antihypertensive effects of estrogen during stress were blunted in female mice lacking estrogen receptor-α in the brain medial amygdala. Deletion of estrogen receptor-α in medial amygdala neurons also resulted in increased excitability of these neurons, associated with elevated ionotropic glutamate receptor expression. We further demonstrated that selective activation of medial amygdala neurons mimicked effects of stress to increase blood pressure in mice. Together, our results support a model where estrogen acts on estrogen receptorexpressed by medial amygdala neurons to prevent stress-induced activation of these neurons, and therefore prevents pressor responses to stress. PMID:27091896

  11. Developmental regulation of the estrogen receptor and the estrogen responsiveness of five yolk protein genes in the avian liver.

    PubMed Central

    Evans, M I; O'Malley, P J; Krust, A; Burch, J B

    1987-01-01

    The magnitude of the expression of five yolk protein genes in the avian liver in response to exogenous estradiol is shown to be developmentally regulated. Though each of these yolk protein genes gains the capacity to respond to estradiol during embryonic development, we demonstrate that maximal responses for the different genes are achieved at distinct ages between 1 and 6 weeks after hatching. This observation prompted us to look for possible correlations between yolk protein gene expression and changes in the expression of estrogen receptors that might also occur after hatching. We discovered that indeed the maximal level of nuclear estrogen receptors (assayed following the administration of estradiol) increases progressively over this same period of development from approximately 1000 receptors per cell at 1 week after hatching to approximately 3500 receptors per cell at 6 weeks after hatching. The latter number represents the fully mature state, as comparable levels of receptors are present in the livers of egg-laying hens. Thus, though increases in the expression of estrogen receptors during embryonic liver development have previously been reported, our results indicate that the changes that occur after hatching are quantitatively far more significant to the developmental program for this transcription factor. PMID:3479803

  12. Endometrial expression of telomerase, progesterone, and estrogen receptors during the implantation window in patients with recurrent implantation failure.

    PubMed

    Long, N; Liu, N; Liu, X L; Li, J; Cai, B Y; Cai, X

    2016-01-01

    Telomerase plays a critical role in cell proliferation and senescence, but the exact involvement of endometrial telomerase in recurrent implantation failure (RIF) is unknown. We collected endometrial biopsies from RIF patients (N = 30) and fertile women (N = 30). Real-time PCR was performed for detecting changes in telomerase reverse transcriptase (Tert), ER alpha, and PR expression at the transcript level, and the correlation between the variable expressions of these genes was tested using regression analysis. Then, western blot and immunohistochemistry were used to analyze the expression profiles of TERT and ER alpha at the protein level. Compared to the control, Tert expression was substantially increased, whereas ER alpha expression significantly decreased in the endometrium with RIF. No change was observed in PR expression. Tert expression was inversely associated with ER alpha expression. TERT protein expression in RIF patients was also clearly elevated, and was localized to both the endometrial epithelium and stromal cells. However, the signals for ER alpha in the stromal cells were weaker than those in the control. Expression of endometrial telomerase was substantially enhanced as ER alpha decreased in RIF patients during the implantation window. PMID:27323161

  13. Estrophilin immunoreactivity versus estrogen receptor binding activity in meningiomas: evidence for multiple estrogen binding sites

    SciTech Connect

    Lesch, K.P.; Schott, W.; Gross, S.

    1987-09-01

    The existence of estrogen receptors in human meningiomas has long been a controversial issue. This may be explained, in part, by apparent heterogeneity of estrogen binding sites in meningioma tissue. In this study, estrogen receptors were determined in 58 meningiomas with an enzyme immunoassay using monoclonal antibodies against human estrogen receptor protein (estrophilin) and with a sensitive radioligand binding assay using /sup 125/I-labeled estradiol (/sup 125/I-estradiol) as radioligand. Low levels of estrophilin immunoreactivity were found in tumors from 62% of patients, whereas radioligand binding activity was demonstrated in about 46% of the meningiomas examined. In eight (14%) tissue samples multiple binding sites for estradiol were observed. The immunoreactive binding sites correspond to the classical, high affinity estrogen receptors: the Kd for /sup 125/I-estradiol binding to the receptor was approximately 0.2 nM and the binding was specific for estrogens. The second, low affinity class of binding sites considerably influenced measurement of the classical receptor even at low ligand concentrations. The epidemiological and clinical data from patients with meningiomas, and the existence of specific estrogen receptors confirmed by immunochemical detection, may be important factors in a theory of oncogenesis.

  14. Prognostic value of the expression of estrogen receptor β in patients with non-small cell lung cancer: a meta-analysis

    PubMed Central

    Ma, Lihong; Zhan, Ping; Liu, Yafang; Zhou, Zejun; Zhu, Qingqing; Miu, Yingying; Wang, Xiaoxia; Jin, Jiajia; Li, Qian

    2016-01-01

    Background Lung cancer remains the leading cause of cancer-related deaths in men and the second leading cause in women worldwide. It is becoming increasingly clear that estrogen and estrogen receptors are involved in the pathogenesis and development of lung cancer. However, observational studies on the prognostic role of estrogen receptor β (ERβ) in non-small cell lung cancer (NSCLC) are controversial. Methods To clarify the impact of ERβ in NSCLC survival, we performed this meta-analysis that included eligible studies. The combined hazard ratios (HR) and their corresponding 95% confidence intervals (CIs) were calculated in terms of overall survival. Results A total of eleven studies with 3,300 patients were evaluable for this meta-analysis. Our results suggested that ERβ overexpression had no relationship on survival of patients with NSCLC, the HR (95% CI) was 1.000 (0.954–1.047) overall. Moreover, there was no heterogeneity between the studies. Conclusions ERβ overexpression indicates no relationship of prognosis for patients with NSCLC. PMID:27186517

  15. Novel drugs that target the estrogen-related receptor alpha: their therapeutic potential in breast cancer

    PubMed Central

    May, Felicity EB

    2014-01-01

    The incidence of breast cancer continues to rise: 1.7 million women were diagnosed with and 521,000 women died from breast cancer in 2012. This review considers first current treatment options: surgery; radiotherapy; and systemic endocrine, anti-biological, and cytotoxic therapies. Clinical management includes prevention, early detection by screening, treatment with curative intent, management of chronic disease, and palliative control of advanced breast cancer. Next, the potential of novel drugs that target DNA repair, growth factor dependence, intracellular and intercellular signal transduction, and cell cycle are considered. Estrogen-related receptor alpha has attracted attention as a therapeutic target in triple-negative breast cancers with de novo resistance to, and in breast cancers with acquired resistance to, endocrine therapies such as antiestrogens and aromatase inhibitors. Estrogen-related receptor alpha is an orphan receptor and transcription factor. Its activity is regulated by coregulator proteins and posttranslational modification. It is an energy sensor that controls adaptation to energy demand and may facilitate glycolytic metabolism and mitochondrial oxidative respiration in breast cancer cells. Estrogen-related receptor alpha increases breast cancer cell migration, proliferation, and tumor development. It is expressed at high levels in estrogen receptor-negative tumors, and is proposed to activate estrogen-responsive genes in endocrine-resistant tumors. The structures and functions of the ligand-binding domains of estrogen receptor alpha and estrogen-related receptor alpha, their ability to bind estrogens, phytoestrogens, and synthetic ligands, and the effects of ligand agonists, antagonists, and inverse agonists on biological activity, are evaluated. Synthetic ligands of estrogen-related receptor alpha have activity in preclinical models of metabolic disorders, diabetes, osteoporosis, and oncology. The clinical settings in which these novel

  16. DHEA metabolites activate estrogen receptors alpha and beta

    PubMed Central

    Michael Miller, Kristy K.; Al-Rayyan, Numan; Ivanova, Margarita M.; Mattingly, Kathleen A.; Ripp, Sharon L.; Klinge, Carolyn M.; Prough, Russell A.

    2012-01-01

    Dehydroepiandrosterone (DHEA) levels were reported to associate with increased breast cancer risk in postmenopausal women, but some carcinogen-induced rat mammary tumor studies question this claim. The purpose of this study was to determine how DHEA and its metabolites affect estrogen receptors α or β (ERα or ERβ) -regulated gene transcription and cell proliferation. In transiently transfected HEK-293 cells, androstenediol, DHEA, and DHEA-S activated ERα. In ERβ transfected HepG2 cells, androstenedione, DHEA, androstenediol, and 7-oxo DHEA stimulated reporter activity. ER antagonists ICI 182,780 (fulvestrant) and 4-hydroxytamoxifen, general P450 inhibitor miconazole, and aromatase inhibitor exemestane inhibited activation by DHEA or metabolites in transfected cells. ERβ-selective antagonist R,R-THC (R,R-cis-diethyl tetrahydrochrysene) inhibited DHEA and DHEA metabolite transcriptional activity in ERβ-transfected cells. Expression of endogenous estrogen-regulated genes: pS2, progesterone receptor, cathepsin D1, and nuclear respiratory factor-1 was increased by DHEA and its metabolites in an ER-subtype, gene, and cell-specific manner. DHEA metabolites, but not DHEA, competed with 17β-estradiol for ERα and ERβ binding and stimulated MCF-7 cell proliferation, demonstrating that DHEA metabolites interact directly with ERα and ERβ in vitro, modulating estrogen target genes in vivo. PMID:23123738

  17. Pancreatic Insulin Content Regulation by the Estrogen Receptor ERα

    PubMed Central

    Alonso-Magdalena, Paloma; Ropero, Ana B.; Carrera, M. Pilar; Cederroth, Christopher R.; Baquié, Mathurin; Gauthier, Benoit R.; Nef, Serge; Stefani, Enrico; Nadal, Angel

    2008-01-01

    The function of pancreatic β-cells is the synthesis and release of insulin, the main hormone involved in blood glucose homeostasis. Estrogen receptors, ERα and ERβ, are important molecules involved in glucose metabolism, yet their role in pancreatic β-cell physiology is still greatly unknown. In this report we show that both ERα and ERβ are present in pancreatic β-cells. Long term exposure to physiological concentrations of 17β-estradiol (E2) increased β-cell insulin content, insulin gene expression and insulin release, yet pancreatic β-cell mass was unaltered. The up-regulation of pancreatic β-cell insulin content was imitated by environmentally relevant doses of the widespread endocrine disruptor Bisphenol-A (BPA). The use of ERα and ERβ agonists as well as ERαKO and ERβKO mice suggests that the estrogen receptor involved is ERα. The up-regulation of pancreatic insulin content by ERα activation involves ERK1/2. These data may be important to explain the actions of E2 and environmental estrogens in endocrine pancreatic function and blood glucose homeostasis. PMID:18446233

  18. Research progress on the reproductive and non-reproductive endocrine tumors by estrogen-related receptors.

    PubMed

    Xu, Zhixiang; Liu, Jun; Gu, Lipeng; Ma, Xiaodong; Huang, Bin; Pan, Xuejun

    2016-04-01

    Oncologists have traditionally considered that tumorigenesis are closely related to classical nuclear estrogen receptors (ERs), such as estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ), through the ligands binding and target gene transcription induction. Estrogen-related receptors (ERRs) have similar structures with ERs, which are also gradually thought to be relevant to reproductive endocrine tumor diseases, even non-reproductive endocrine tumors. In this review, different subtypes of ERRs and their structures firstly will be introduced, then the expression patterns in gynecological oncology (i.e., breast cancer, endometrial cancer, and ovarian cancer), male genitourinary system malignancy especially prostatic cancer along with other non-reproductive endocrine tumors (i.e., lung cancer, colorectal cancer, and liver cancer) will be described, and simultaneously the role of tumorigenesis related to ERRs will be discussed. Therefore, the review is benefit to explore the way of tumor prevention and treatment. PMID:26802897

  19. Phytoestrogens Activate the Estrogen Receptor in HepG2 Cells.

    PubMed

    Kelly, Lynne A

    2016-01-01

    Phytoestrogens are popular alternatives to estrogen therapy however their effects on hemostasis in postmenopausal women are unknown. This chapter describes a protocol to determine the effect of the phytoestrogens genistein, daidzein and equol, on the expression of key genes from the hemostatic system in human hepatocyte cell models and to determine the role of estrogen receptors in mediating any response seen using in vitro culture systems and Taqman(®) gene expression analysis. PMID:26585156

  20. Effects of pyridoxal 5'-phosphate on uterine estrogen receptor. II. Inhibition of estrogen . receptor transformation.

    PubMed

    Traish, A; Müller, R E; Wotiz, H H

    1980-05-10

    Previous observations suggested that pyridoxal 5'-phosphate was capable of inhibiting estrogen . receptor (R . E2) activation, or translocation to the nucleus, or both. The present study attempts to define more specifically the locus of this action. To this end we have examined the physicochemical alteration produced by interaction of pyridoxal 5'-phosphate with estrogen . receptor complex, using sucrose density gradient analysis and dissociation kinetics. Receptor transformation was inhibited when activation was performed in the presence of pyridoxal 5'-phosphate. This effect was protein- and pyridoxal 5'-phosphate concentration-dependent. When pyridoxal 5'-phosphate was introduced postactivation it did not have any effect on the activated receptor, but when similar treatment was followed by NABH4 reduction, the complex reverted to the monomeric entity. The dissociation behavior obtained with cytosol R . E2, warmed in the presence of pyridoxal 5'-phosphate, showed a biphasic curve suggesting that a significant portion of receptors remained nonactivated as demonstrated by the fast dissociating component. Due to the fact that Tris buffers cannot be used for pyridoxal 5'-phosphate experiments, we have used a borate buffer which resulted in a displacement of the sedimentation values from a 4S to 4.6 S for the unactivated receptor and 5S to 6 S for the activated form. The observations reported suggest that at least the initial effect of pyridoxal 5'-phosphate results in the inhibition of cytosolic receptor transformation from the nonactivated to the activated form. PMID:7372667

  1. Estrogen receptor mutations in tamoxifen-resistant breast cancer.

    PubMed

    Karnik, P S; Kulkarni, S; Liu, X P; Budd, G T; Bukowski, R M

    1994-01-15

    Clinical resistance to antiestrogens like tamoxifen is a major problem in the treatment of hormone-dependent breast cancers. Since the estrogen receptor plays a central role in mediating the effects of estrogens and antiestrogens, we hypothesized that mutations in the estrogen receptor could be one mechanism by which breast tumors evolve from a hormone-dependent to a hormone-independent phenotype. The eight exons of the estrogen receptor complementary DNA from 20 tamoxifen-resistant and 20 tamoxifen-sensitive tumors were screened by Single Strand Conformation Polymorphism (SSCP), and the variant conformers were sequenced to identify the nucleotide changes. A 42-base pair replacement was found in exon 6 of a tamoxifen-resistant tumor. A single base pair deletion in exon 6 of a tamoxifen-resistant metastatic tumor but not in the primary tumor was detected in another case. If translated, both these mutations could generate truncated receptors with an intact DNA-binding domain and a defective hormone-binding domain that could constitutively activate transcription of previously estrogen-responsive genes. The remaining 18 of 20 tamoxifen-resistant tumors did not contain mutations in any of the 8 exons of the estrogen receptor complementary DNA. These results suggest that mutations in the estrogen receptor occur at a low frequency and do not account for most estrogen-independent, tamoxifen-resistant breast tumors. PMID:8275466

  2. Factors associated with concordant estrogen receptor expression at diagnosis and centralized re-assay in a Danish population-based breast cancer study

    PubMed Central

    Cronin-Fenton, Deirdre P.; Hellberg, Ylva; Lauridsen, Kristina L.; Ahern, Thomas P.; Garne, Jens Peter; Rosenberg, Carol; Silliman, Rebecca A.; Sørensen, Henrik Toft; Lash, Timothy L.; Hamilton-Dutoit, Stephen

    2011-01-01

    Background Estrogen receptor (ER) expression predicts tamoxifen response, which halves the risk of breast cancer recurrence. We examined clinical factors associated with concordance between ER expression at diagnosis and centralized re-assay, and the association of concordance with breast cancer recurrence. Materials and Methods We used immunohistochemistry to assess ER expression on archived fixed, paraffin-embedded breast carcinoma tissue excised from women aged 35–69 years, diagnosed 1985–2001 in Jutland, Denmark. We calculated the percentage agreement, positive predictive value (PPV) and negative predictive value (NPV) of ER status at diagnosis and re-assay. We used logistic regression to investigate factors associated with concordance, and its association with recurrence (odds ratios (OR) and associated 95% confidence intervals (95%CI)). Results ER was re-assayed in 91% of patients (n=1530). Concordance was better in ER+ than ER− tumors (PPV=94% versus NPV=75%). Factors associated with concordance included menopausal status, tumor size, surgical procedure, diagnostic period, lymph node status and time to recurrence. ER+ women at diagnosis who re-assayed ER+ were less likely to have recurrent disease (OR=0.49, 95% CI=0.28, 0.86) than those who re-assayed ER−. In originally ER− women, concordance was not associated with recurrence (OR=0.97, 95% CI=0.66, 1.42). Conclusions Several clinical factors were associated with ER assay concordance. Some women were ineffectively treated with tamoxifen, or required but did not receive tamoxifen. We observed almost exactly the protective effect of endocrine therapy among tamoxifen-treated ER+ women whose tumors expressed the ER on re-assay, compared with those ER− on re-assay. Diagnostic pathology results for ER+ tumors appear a valid and useful resource for research studies. However, those for ER− tumors have lower validity. Study-specific considerations regarding the aims, diagnostic period, and consequences

  3. Hindbrain Administration of Estradiol Inhibits Feeding and Activates Estrogen Receptor-α-Expressing Cells in the Nucleus Tractus Solitarius of Ovariectomized Rats

    PubMed Central

    Thammacharoen, Sumpun; Lutz, Thomas A.; Geary, Nori; Asarian, Lori

    2008-01-01

    17β-Estradiol (E2), acting via estrogen receptor (ER)-α, inhibits feeding in animals. One mechanism apparently involves an increase in the satiating potency of cholecystokinin (CCK) released from the small intestine by ingested food. For example, the satiating potency of intraduodenal lipid infusions is increased by E2 in ovariectomized rats; this increased satiation is dependent on CCK, and it is accompanied by increases in the numbers of ERα-positive cells that express c-Fos in a subregion of the caudal nucleus tractus solitarius (cNTS) that receives abdominal vagal afferent projections. To test whether direct administration of E2 to this area of the hindbrain is sufficient to inhibit food intake, we first implanted 0.2 μg estradiol benzoate (EB) in cholesterol or cholesterol alone either sc or onto the surface of the hindbrain over the cNTS. Food intake was significantly reduced after hindbrain EB implants but not after sc EB implants. Next we verified that equimolar hindbrain implants of E2 and EB had similar feeding-inhibitory effects and determined that only small amounts of E2 reached brain areas outside the dorsal caudal hindbrain after hindbrain implants of 3H-labeled E2. Neither plasma estradiol concentration nor plasma inflammatory cytokine concentration was increased by either hindbrain or sc EB implants. Finally, hindbrain EB implants, but not sc implants, increased c-Fos in ERα-positive cells in the cNTS after ip injection of 4 μg/kg CCK-8. We conclude that E2, acting via ERα in cNTS neurons, including neurons stimulated by ip CCK, is sufficient to inhibit feeding. PMID:18096668

  4. MODELING THE EFFECTS OF FLEXIBILITY ON THE BINDING OF ENVIRONMENTAL ESTROGENS TO THE ESTROGEN RECEPTOR

    EPA Science Inventory

    Modeling the effects of flexibility on the binding of environmental estrogens to the estrogen receptor
    There are many reports of environmental endocrine disruption in the literature, yet it has been difficult to identify the specific chemicals responsible for these effects. ...

  5. CERAPP: Collaborative Estrogen Receptor Activity Prediction Project

    PubMed Central

    Mansouri, Kamel; Abdelaziz, Ahmed; Rybacka, Aleksandra; Roncaglioni, Alessandra; Tropsha, Alexander; Varnek, Alexandre; Zakharov, Alexey; Worth, Andrew; Richard, Ann M.; Grulke, Christopher M.; Trisciuzzi, Daniela; Fourches, Denis; Horvath, Dragos; Benfenati, Emilio; Muratov, Eugene; Wedebye, Eva Bay; Grisoni, Francesca; Mangiatordi, Giuseppe F.; Incisivo, Giuseppina M.; Hong, Huixiao; Ng, Hui W.; Tetko, Igor V.; Balabin, Ilya; Kancherla, Jayaram; Shen, Jie; Burton, Julien; Nicklaus, Marc; Cassotti, Matteo; Nikolov, Nikolai G.; Nicolotti, Orazio; Andersson, Patrik L.; Zang, Qingda; Politi, Regina; Beger, Richard D.; Todeschini, Roberto; Huang, Ruili; Farag, Sherif; Rosenberg, Sine A.; Slavov, Svetoslav; Hu, Xin; Judson, Richard S.

    2016-01-01

    Background: Humans are exposed to thousands of man-made chemicals in the environment. Some chemicals mimic natural endocrine hormones and, thus, have the potential to be endocrine disruptors. Most of these chemicals have never been tested for their ability to interact with the estrogen receptor (ER). Risk assessors need tools to prioritize chemicals for evaluation in costly in vivo tests, for instance, within the U.S. EPA Endocrine Disruptor Screening Program. Objectives: We describe a large-scale modeling project called CERAPP (Collaborative Estrogen Receptor Activity Prediction Project) and demonstrate the efficacy of using predictive computational models trained on high-throughput screening data to evaluate thousands of chemicals for ER-related activity and prioritize them for further testing. Methods: CERAPP combined multiple models developed in collaboration with 17 groups in the United States and Europe to predict ER activity of a common set of 32,464 chemical structures. Quantitative structure–activity relationship models and docking approaches were employed, mostly using a common training set of 1,677 chemical structures provided by the U.S. EPA, to build a total of 40 categorical and 8 continuous models for binding, agonist, and antagonist ER activity. All predictions were evaluated on a set of 7,522 chemicals curated from the literature. To overcome the limitations of single models, a consensus was built by weighting models on scores based on their evaluated accuracies. Results: Individual model scores ranged from 0.69 to 0.85, showing high prediction reliabilities. Out of the 32,464 chemicals, the consensus model predicted 4,001 chemicals (12.3%) as high priority actives and 6,742 potential actives (20.8%) to be considered for further testing. Conclusion: This project demonstrated the possibility to screen large libraries of chemicals using a consensus of different in silico approaches. This concept will be applied in future projects related to other

  6. Estrogen and Estrogen Receptor-α-Mediated Transrepression of Bile Salt Export Pump.

    PubMed

    Chen, Yuan; Vasilenko, Alex; Song, Xiulong; Valanejad, Leila; Verma, Ruchi; You, Sangmin; Yan, Bingfang; Shiffka, Stephanie; Hargreaves, Leeza; Nadolny, Christina; Deng, Ruitang

    2015-04-01

    Among diseases unique to pregnancy, intrahepatic cholestasis of pregnancy is the most prevalent disorder with elevated serum bile acid levels. We have previously shown that estrogen 17β-estradiol (E2) transrepresses bile salt export pump (BSEP) through an interaction between estrogen receptor (ER)-α and farnesoid X receptor (FXR) and transrepression of BSEP by E2/ERα is an etiological contributing factor to intrahepatic cholestasis of pregnancy. Currently the mechanistic insights into such transrepression are not fully understood. In this study, the dynamics of coregulator recruitment to BSEP promoter after FXR activation and E2 treatment were established with quantitative chromatin immunoprecipitation assays. Coactivator peroxisome proliferator-activated receptor-γ coactivator-1 was predominantly recruited to the BSEP promoter upon FXR activation, and its recruitment was decreased by E2 treatment. Meanwhile, recruitment of nuclear receptor corepressor was markedly increased upon E2 treatment. Functional evaluation of ERα and ERβ chimeras revealed that domains AC of ERα are the determinants for ERα-specific transrepression on BSEP. Further studies with various truncated ERα proteins identified the domains in ERα responsible for ligand-dependent and ligand-independent transrepression. Truncated ERα-AD exhibited potent ligand-independent transrepressive activity, whereas ERα-CF was fully capable of transrepressing BSEP ligand dependently in vitro in Huh 7 cells and in vivo in mice. Both ERα-AD and ERα-CF proteins were associated with FXR in the coimmunoprecipitation assays. In conclusion, E2 repressed BSEP expression through diminishing peroxisome proliferator-activated receptor-γ coactivator-1 recruitment with a concurrent increase in nuclear receptor corepressor recruitment to the BSEP promoter. Domains AD and CF in ERα mediated ligand-independent and ligand-dependent transrepression on BSEP, respectively, through interacting with FXR. PMID:25675114

  7. Dynamic Estrogen Receptor Interactomes Control Estrogen-Responsive Trefoil Factor (TFF) Locus Cell-Specific Activities

    PubMed Central

    Quintin, Justine; Le Péron, Christine; Palierne, Gaëlle; Bizot, Maud; Cunha, Stéphanie; Sérandour, Aurélien A.; Avner, Stéphane; Henry, Catherine; Percevault, Frédéric; Belaud-Rotureau, Marc-Antoine; Huet, Sébastien; Watrin, Erwan; Eeckhoute, Jérôme; Legagneux, Vincent; Salbert, Gilles

    2014-01-01

    Estradiol signaling is ideally suited for analyzing the molecular and functional linkages between the different layers of information directing transcriptional regulations: the DNA sequence, chromatin modifications, and the spatial organization of the genome. Hence, the estrogen receptor (ER) can bind at a distance from its target genes and engages timely and spatially coordinated processes to regulate their expression. In the context of the coordinated regulation of colinear genes, identifying which ER binding sites (ERBSs) regulate a given gene still remains a challenge. Here, we investigated the coordination of such regulatory events at a 2-Mb genomic locus containing the estrogen-sensitive trefoil factor (TFF) cluster of genes in breast cancer cells. We demonstrate that this locus exhibits a hormone- and cohesin-dependent reduction in the plasticity of its three-dimensional organization that allows multiple ERBSs to be dynamically brought to the vicinity of estrogen-sensitive genes. Additionally, by using triplex-forming oligonucleotides, we could precisely document the functional links between ER engagement at given ERBSs and the regulation of particular genes. Hence, our data provide evidence of a formerly suggested cooperation of enhancers toward gene regulation and also show that redundancy between ERBSs can occur. PMID:24752895

  8. Estrogen receptor beta agonists in neurobehavioral investigations.

    PubMed

    Choleris, Elena; Clipperton, Amy E; Phan, Anna; Kavaliers, Martin

    2008-07-01

    Neurobehavioral investigations into the functions of estrogen receptor (ER)alpha and ERbeta have utilized 'knockout' mice, phytoestrogens and, more recently, ER-specific agonists. Feeding, sexual, aggressive and social behavior, anxiety, depression, drug abuse, pain perception, and learning (and associated synaptic plasticity) are affected by ERalpha and ERbeta in a manner that is dependent upon the specific behavior studied, gender and developmental stage. Overall, ERalpha and ERbeta appear to function together to foster sociosexual behavior while inhibiting behaviors that, if occurring at the time of behavioral estrous, may compete with reproduction (eg, feeding). Recently developed pharmacological tools have limited selectivity and availability to the research community at large, as they are not commercially available. The development of highly selective, commercially available ERbeta-specific antagonists would greatly benefit preclinical and applied research. PMID:18600582

  9. Amphipathic Benzenes Are Designed Inhibitors of the Estrogen Receptor α/Steroid Receptor Coactivator Interaction

    PubMed Central

    Gunther, Jillian R.; Moore, Terry W.; Collins, Margaret L.; Katzenellenbogen, John A.

    2008-01-01

    We report here on the design, synthesis and evaluation of small molecule inhibitors of the interaction between a steroid receptor coactivator and estrogen receptor α. These inhibitors are based upon an amphipathic benzene scaffold whose hydrophobic face mimics the leucine-rich α-helical consensus sequence on the steroid receptor coactivators that interacts with a shallow groove on estrogen receptor α. Several of these molecules are among the most potent inhibitors of this interaction described to date, and they are active at low micromolar concentrations in both in vitro models of estrogen receptor action and in cell-based assays of estrogen receptor-mediated coactivator interaction and transcription. PMID:18484708

  10. Temperature dependence of estrogen binding: importance of a subzone in the ligand binding domain of a novel piscine estrogen receptor.

    PubMed

    Tan, N S; Frecer, V; Lam, T J; Ding, J L

    1999-11-11

    The full length estrogen receptor from Oreochromis aureus (OaER) was cloned and expressed in vitro and in vivo as a functional transcription factor. Amino acid residues involved in the thermal stability of the receptor are located at/near subzones beta1 and beta3, which are highly conserved in other non-piscine species but not in OaER. Hormone binding studies, however, indicate that OaER is thermally stable but exhibited a approximately 3-fold reduced affinity for estrogen at elevated temperatures. Transfection of OaER into various cell lines cultured at different temperatures displayed a significant estrogen dose-response shift compared with that of chicken ER (cER). At 37 degrees C, OaER requires approximately 80-fold more estrogen to achieve half-maximal stimulation of CAT. Lowering of the incubation temperature from 37 degrees C to 25 degrees C or 20 degrees C resulted in a 4-fold increase in its affinity for estrogen. The thermally deficient transactivation of OaER at temperatures above 25 degrees C was fully prevented by high levels of estrogen. Thus, compared to cER, the OaER exhibits reduced affinity for estrogen at elevated temperature as reflected in its deficient transactivation capability. Amino acid replacements of OaER beta3 subzones with corresponding amino acids from cER could partially rescue this temperature sensitivity. The three-dimensional structure of the OaER ligand binding domain (LBD) was modelled based on conformational similarity and sequence homology with human RXRalpha apo, RARgamma holo and ERalpha LBDs. Unliganded and 17beta-estradiol-liganded OaER LBD retained the overall folding pattern of the nuclear receptor LBDs. The residues at/near the subzone beta3 of the LBD constitute the central core of OaER structure. Thus, amino acid alteration at this region potentially alters the structure and consequently its temperature-dependent ligand binding properties. PMID:10559464

  11. Mixture Effects of Estrogenic Pesticides at the Human Estrogen Receptor α and β.

    PubMed

    Seeger, Bettina; Klawonn, Frank; Nguema Bekale, Boris; Steinberg, Pablo

    2016-01-01

    Consumers of fruits and vegetables are frequently exposed to small amounts of hormonally active pesticides, some of them sharing a common mode of action such as the activation of the human estrogen receptor α (hERα) or β (hERβ). Therefore, it is of particular importance to evaluate risks emanating from chemical mixtures, in which the individual pesticides are present at human-relevant concentrations, below their corresponding maximum residue levels. Binary and ternary iso-effective mixtures of estrogenic pesticides at effect concentrations eliciting a 1 or 10% effect in the presence or absence of 17β-estradiol were tested experimentally at the hERα in the yeast-based estrogen screen (YES) assay as well as in the human U2-OS cell-based ERα chemical-activated luciferase gene expression (ERα CALUX) assay and at the hERβ in the ERβ CALUX assay. The outcome was then compared to predictions calculated by means of concentration addition. In most cases, additive effects were observed with the tested combinations in all three test systems, an observation that supports the need to expand the risk assessment of pesticides and consider cumulative risk assessment. An additional testing of mixture effects at the hERβ showed that most test substances being active at the hERα could also elicit additive effects at the hERβ, but the hERβ was less sensitive. In conclusion, effects of the same ligands at the hERα and the hERβ could influence the estrogenic outcome under physiological conditions. PMID:26812056

  12. Down-regulation of PROS1 Gene Expression by 17β-Estradiol via Estrogen Receptor α (ERα)-Sp1 Interaction Recruiting Receptor-interacting Protein 140 and the Corepressor-HDAC3 Complex*

    PubMed Central

    Suzuki, Atsuo; Sanda, Naomi; Miyawaki, Yuhri; Fujimori, Yuta; Yamada, Takayuki; Takagi, Akira; Murate, Takashi; Saito, Hidehiko; Kojima, Tetsuhito

    2010-01-01

    Pregnant women show a low level of protein S (PS) in plasma, which is known to be a risk for deep venous thrombosis. 17β-Estradiol (E2), an estrogen that increases in concentration in the late stages of pregnancy, regulates the expression of various genes via the estrogen receptor (ER). Here, we investigated the molecular mechanisms behind the reduction in PS levels caused by E2 in HepG2-ERα cells, which stably express ERα, and also the genomic ER signaling pathway, which modulates the ligand-dependent repression of the PSα gene (PROS1). We observed that E2 repressed the production of mRNA and antigen of PS. A luciferase reporter assay revealed that E2 down-regulated PROS1 promoter activity and that this E2-dependent repression disappeared upon the deletion or mutation of two adjacent GC-rich motifs in the promoter. An electrophoretic mobility shift assay and DNA pulldown assay revealed that the GC-rich motifs were associated with Sp1, Sp3, and ERα. In a chromatin immunoprecipitation assay, we found ERα-Sp protein-promoter interaction involved in the E2-dependent repression of PROS1 transcription. Furthermore, we demonstrated that E2 treatment recruited RIP140 and the NCoR-SMRT-HDAC3 complex to the PROS1 promoter, which hypoacetylated chromatin. Taken together, this suggested that E2 might repress PROS1 transcription depending upon ERα-Sp1 recruiting transcriptional repressors in HepG2-ERα cells and, consequently, that high levels of E2 leading to reduced levels of plasma PS would be a risk for deep venous thrombosis in pregnant women. PMID:20200160

  13. Clinical significance of estrogen receptor beta in breast cancer.

    PubMed

    Saji, Shigehira; Hirose, Makiko; Toi, Masakazu

    2005-11-01

    Ever since the estrogen receptor (ER) beta was discovered in 1996, we have been trying to determine its value as a prognostic and/or predictive factor in breast cancer and its potential as a novel target for pharmacological intervention. Recent progress in cellular experiments has shown that ERbeta works as counter partner of ERalpha through inhibition of the transactivating function of ERalpha by heterodimerization, distinct regulation on several specific promoters by ERalpha or ERbeta, and ERbeta-specific regulated genes which are probably related to its anti-proliferative properties. Accumulated data from protein studies in breast cancer tissues indicate that positive expression of ERbeta appears to correlate with a favorable prognosis. Although the number of studies is small, a positive response to tamoxifen treatment is observed in both ERalpha- and ERbeta-positive populations. The significance of ERbeta2/cx, a splicing variant of ERbeta, remains controversial and needs to be analyzed in further studies. We postulate that a combined evaluation of ERbetacx with progesterone receptor may help the stratification of ERalpha-positive breast cancer. Epidemiological studies of hormone replacement therapy and isoflavone (genistein) consumption indicate the possible contribution of ERbeta-specific signaling in breast cancer prevention. A selective estrogen receptor modulator, which works as an antagonist of ERalpha and an agonist of ERbeta, may be a promising chemo-preventive treatment. PMID:16273360

  14. Localization of androgen receptors and estrogen receptors in the same cells of the songbird brain

    SciTech Connect

    Gahr, M. )

    1990-12-01

    Estrogens and androgens each have unique effects but act together for the neural differentiation and control of sexual behaviors in male vertebrates, such as the canary. The neuronal basis for these synergistic effects is elusive because the spatial relation between estrogen target cells and androgen target cells is unknown. This study localized estrogen receptor (ER)-containing cells by using immunocytochemistry and androgen receptor (AR)-containing cells by using autoradiography in the same sections of the male canary brain. Three cell types, those containing only ER, those containing only AR, and those containing both ER and AR, were found in tissue-specific frequencies. The midbrain nucleus intercollicularis exhibited the highest number of cells expressing both ER and AR, whereas ER and AR are expressed only in disjunctive cell populations in the forebrain nucleus hyperstriatalis ventrale, pars caudale. Synergistic effects of androgens and estrogens for the neural behavorial control could result from cells containing both ER and AR (intracellular) and from neural circuits containing ER and AR in different cells (intercellular).

  15. Abnormal Vascular Function and Hypertension in Mice Deficient in Estrogen Receptor β

    NASA Astrophysics Data System (ADS)

    Zhu, Yan; Bian, Zhao; Lu, Ping; Karas, Richard H.; Bao, Lin; Cox, Daniel; Hodgin, Jeffrey; Shaul, Philip W.; Thorén, Peter; Smithies, Oliver; Gustafsson, Jan-Åke; Mendelsohn, Michael E.

    2002-01-01

    Blood vessels express estrogen receptors, but their role in cardiovascular physiology is not well understood. We show that vascular smooth muscle cells and blood vessels from estrogen receptor β (ERβ)-deficient mice exhibit multiple functional abnormalities. In wild-type mouse blood vessels, estrogen attenuates vasoconstriction by an ERβ-mediated increase in inducible nitric oxide synthase expression. In contrast, estrogen augments vasoconstriction in blood vessels from ERβ-deficient mice. Vascular smooth muscle cells isolated from ERβ-deficient mice show multiple abnormalities of ion channel function. Furthermore, ERβ-deficient mice develop sustained systolic and diastolic hypertension as they age. These data support an essential role for ERβ in the regulation of vascular function and blood pressure.

  16. G Protein-coupled Estrogen Receptor Protects from Atherosclerosis

    PubMed Central

    Meyer, Matthias R.; Fredette, Natalie C.; Howard, Tamara A.; Hu, Chelin; Ramesh, Chinnasamy; Daniel, Christoph; Amann, Kerstin; Arterburn, Jeffrey B.; Barton, Matthias; Prossnitz, Eric R.

    2014-01-01

    Coronary atherosclerosis and myocardial infarction in postmenopausal women have been linked to inflammation and reduced nitric oxide (NO) formation. Natural estrogen exerts protective effects on both processes, yet also displays uterotrophic activity. Here, we used genetic and pharmacologic approaches to investigate the role of the G protein-coupled estrogen receptor (GPER) in atherosclerosis. In ovary-intact mice, deletion of gper increased atherosclerosis progression, total and LDL cholesterol levels and inflammation while reducing vascular NO bioactivity, effects that were in some cases aggravated by surgical menopause. In human endothelial cells, GPER was expressed on intracellular membranes and mediated eNOS activation and NO formation, partially accounting for estrogen-mediated effects. Chronic treatment with G-1, a synthetic, highly selective small molecule agonist of GPER, reduced postmenopausal atherosclerosis and inflammation without uterotrophic effects. In summary, this study reveals an atheroprotective function of GPER and introduces selective GPER activation as a novel therapeutic approach to inhibit postmenopausal atherosclerosis and inflammation in the absence of uterotrophic activity. PMID:25532911

  17. Estrogen inhibits RANKL-stimulated osteoclastic differentiation of human monocytes through estrogen and RANKL-regulated interaction of estrogen receptor-{alpha} with BCAR1 and Traf6

    SciTech Connect

    Robinson, Lisa J.; Yaroslavskiy, Beatrice B.; Griswold, Reed D.; Zadorozny, Eva V.; Guo, Lida; Tourkova, Irina L.; Blair, Harry C.

    2009-04-15

    The effects of estrogen on osteoclast survival and differentiation were studied using CD14-selected mononuclear osteoclast precursors from peripheral blood. Estradiol at {approx} 1 nM reduced RANKL-dependent osteoclast differentiation by 40-50%. Osteoclast differentiation was suppressed 14 days after addition of RANKL even when estradiol was withdrawn after 18 h. In CD14+ cells apoptosis was rare and was not augmented by RANKL or by 17-{beta}-estradiol. Estrogen receptor-{alpha} (ER{alpha}) expression was strongly down-regulated by RANKL, whether or not estradiol was present. Mature human osteoclasts thus cannot respond to estrogen via ER{alpha}. However, ER{alpha} was present in CD14+ osteoclast progenitors, and a scaffolding protein, BCAR1, which binds ER{alpha} in the presence of estrogen, was abundant. Immunoprecipitation showed rapid ({approx} 5 min) estrogen-dependent formation of ER{alpha}-BCAR1 complexes, which were increased by RANKL co-treatment. The RANKL-signaling intermediate Traf6, which regulates NF-{kappa}B activity, precipitated with this complex. Reduction of NF-{kappa}B nuclear localization occurred within 30 min of RANKL stimulation, and estradiol inhibited the phosphorylation of I{kappa}B in response to RANKL. Inhibition by estradiol was abolished by siRNA knockdown of BCAR1. We conclude that estrogen directly, but only partially, curtails human osteoclast formation. This effect requires BCAR1 and involves a non-genomic interaction with ER{alpha}.

  18. SPONTANEOUS AIRWAY HYPERRESPONSIVENESS IN ESTROGEN RECEPTOR-A DEFICIENT MICE

    EPA Science Inventory

    Rationale: Airway hyperresponsiveness is a critical feature of asthma. Substantial epidemiologic evidence supports a role for female sex hormones in modulating lung function and airway hyperresponsiveness in humans. Objectives: To examine the role of estrogen receptors in modulat...

  19. ESTROGEN RECEPTORS AND THE REGULATION OF NEURAL STRESS RESPONSES

    PubMed Central

    Handa, Robert J.; Mani, Shaila K.; Uht, Rosalie M.

    2012-01-01

    It is now well established that estrogens can influence a panoply of physiological and behavioral functions. In many instances, the effects of estrogens are mediated by the ‘classical’ actions of two different estrogen receptors (ER), alpha or beta. Estrogen receptor alpha and beta appear to have opposing actions in the control of stress responses and modulate different neurotransmitter or neuropeptide systems. Studies elucidating the molecular mechanisms for such regulatory processes are currently in progress. Furthermore, the use of ERalpha and ERbeta knockout mouse lines has allowed the exploration of the importance of these receptors in behavioral responses such as anxiety-like and depressive-like behaviors. This review examines some of the recent advances in our knowledge of hormonal control of neuroendocrine and behavioral responses to stress and underscore the importance of these receptors as future therapeutic targets for control of stress-related signaling pathways. PMID:22538291

  20. Binding of Estrogenic Compounds to Recombinant Estrogen Receptor-α: Application to Environmental Analysis

    PubMed Central

    Pillon, Arnaud; Boussioux, Anne-Marie; Escande, Aurélie; Aït-Aïssa, Sélim; Gomez, Elena; Fenet, Hélène; Ruff, Marc; Moras, Dino; Vignon, Françoise; Duchesne, Marie-Josèphe; Casellas, Claude; Nicolas, Jean-Claude; Balaguer, Patrick

    2005-01-01

    Estrogenic activity in environmental samples could be mediated through a wide variety of compounds and by various mechanisms. High-affinity compounds for estrogen receptors (ERs), such as natural or synthetic estrogens, as well as low-affinity compounds such as alkylphenols, phthalates, and polychlorinated biphenyls are present in water and sediment samples. Furthermore, compounds such as polycyclic aromatic hydrocarbons, which do not bind ERs, modulate estrogen activity by means of the aryl hydrocarbon receptor (AhR). In order to characterize compounds that mediate estrogenic activity in river water and sediment samples, we developed a tool based on the ER-αligand-binding domain, which permitted us to estimate contaminating estrogenic compound affinities. We designed a simple transactivation assay in which compounds of high affinity were captured by limited amounts of recombinant ER-αand whose capture led to a selective inhibition of transactivation. This approach allowed us to bring to light that water samples contain estrogenic compounds that display a high affinity for ERs but are present at low concentrations. In sediment samples, on the contrary, we showed that estrogenic compounds possess a low affinity and are present at high concentration. Finally, we used immobilized recombinant ER-αto separate ligands for ER and AhR that are present in river sediments. Immobilized ER-α, which does not retain dioxin-like compounds, enabled us to isolate and concentrate ER ligands to facilitate their further analysis. PMID:15743715

  1. Estrogenic Compounds, Estrogen Receptors and Vascular Cell Signaling in the Aging Blood Vessels

    PubMed Central

    Smiley, Dia A.; Khalil, Raouf A.

    2010-01-01

    The cardiovascular benefits of menopausal hormone therapy (MHT) remain controversial. The earlier clinical observations that cardiovascular disease (CVD) was less common in MHT users compared to non-users suggested cardiovascular benefits of MHT. Also, experimental studies have identified estrogen receptors ERα, ERβ and GPR30, which mediate genomic or non-genomic effects in vascular endothelium, smooth muscle, and extracellular matrix (ECM). However, data from randomized clinical trials (RCTs), most notably the Women's Health Initiative (WHI) study, have challenged the cardiovascular benefits and highlighted adverse cardiovascular events with MHT. The discrepancies have been attributed to the design of RCTs, the subjects' advanced age and preexisting CVD, and the form of estrogen used. The discrepancies may also stem from age-related changes in vascular ER amount, distribution, integrity, and post-receptor signaling pathways as well as structural changes in the vasculature. Age-related changes in other sex hormones such as testosterone may also alter the hormonal environment and influence the cardiovascular effects of estrogen. Investigating the chemical properties, structure-activity relationship and pharmacology of natural and synthetic estrogens should improve the effectiveness of conventional MHT. Further characterization of phytoestrogens, selective estrogen-receptor modulators (SERMs), and specific ER agonists may provide substitutes to conventional MHT. Conditions with excess or low estrogen levels such as polycystic ovary syndrome (PCOS) and Turner syndrome may provide insight into the development and regulation of ER and the mechanisms of aberrant estrogen-ER interactions. The lessons learned from previous RCTs have led to more directed studies such as the Kronos Early Estrogen Prevention Study (KEEPS). Careful design of experimental models and RCTs, coupled with the development of specific ER modulators, hold the promise of improving the actions of

  2. Regulation of Baboon Fetal Pituitary Prolactin Expression by Estrogen1

    PubMed Central

    Pepe, Gerald J.; Lynch, Terrie J.; Davies, William A.; Albrecht, Eugene D.

    2009-01-01

    We previously showed that fetal adrenal fetal zone growth was increased and the number of follicles in the fetal ovary reduced in baboons in which estradiol was suppressed by treatment with the aromatase inhibitor letrozole between mid and late gestation periods. Because adrenal/ovarian development was restored in animals treated with letrozole and estradiol, and both tissues express estrogen receptor, we proposed that estrogen regulates fetal adrenal/ovary development via a direct action. However, because prolactin can modulate fetal adrenal and adult pituitary/ovarian function, the current study determined whether estrogen action involved estradiol-regulated changes in fetal prolactin/luteinizing hormone (LH) expression. Fetal prolactin levels and the number of prolactin-positive fetal pituitary cells (per 0.37 mm2) were increased (P < 0.01) between mid (6 ± 1 ng/ml; 15.8 ± 2.4) and late (257 ± 28 ng/ml; 57.3 ± 5.1) gestation, reduced (P < 0.01) in late-gestation fetuses in which estradiol was suppressed (>95%) by letrozole (61 ± 11 ng/ml; 19.3 ± 2.0), and minimally but not significantly increased by letrozole and estradiol (99 ± 11 ng/ml; 32.7 ± 5.2). In contrast, the number of LH-positive fetal pituitary cells decreased (P < 0.01) between mid (48.8 ± 9.5) and late (17.4 ± 3.2) gestation, remained elevated (P < 0.01) in estrogen-suppressed animals (56.6 ± 5.1), and was partially but not significantly decreased by letrozole-estradiol (28.8 ± 5.2). We conclude that estrogen regulates fetal pituitary prolactin and LH expression and fetal prolactin levels. However, because prolactin and LH expressions in estrogen-suppressed fetuses were inversely related to previously demonstrated changes in adrenal/ovarian development, we propose that estrogen regulates the fetal ovary and adrenal gland directly and not via action on the fetal pituitary gland. PMID:19176882

  3. Sharing the Roles: An Assessment of Japanese Medaka Estrogen Receptors in Vitellogenin Induction.

    PubMed

    Lee Pow, Crystal S D; Yost, Erin E; Aday, D Derek; Kullman, Seth W

    2016-08-16

    Teleost fish express at least three estrogen receptor (ER) subtypes. To date, however, the individual role of these ER subtypes in regulating expression of estrogen responsive genes remains ambiguous. Here, we investigate putative roles of three ER subtypes in Japanese medaka (Oryzias latipes), using vitellogenin (VTG) I and II as model genes. We identify specific ligand/receptor/promoter dynamics, using transient transactivation assays that incorporate luciferase reporters comprising 3kb promoter/enhancer regions of medaka VTGI and VTGII genes. Four steroidal estrogens (17β-estradiol, estrone, estriol, and 17α-estradiol) were tested in these assays. Results indicate that all three medaka ERs (mERs) are capable of initiating transactivation of both VTG I and II, with ERβ2 exhibiting greatest activity. Promoter deletion analysis suggests that ligand-specific receptor transactivation and utilization of regional-specific estrogen response elements may be associated with differential activities of each medaka ER. Further, cluster analysis of in vivo gene expression and in vitro transactivation suggests that all three ER subtypes putatively play a role in up-regulation of VTG. Results illustrate that preferential ligand/receptor/promoter interactions may have direct implications for VTG gene expression and other ER-mediated regulatory functions that are relevant to the risk assessment of estrogenic compounds. PMID:27391190

  4. Identification and characterization of estrogen receptor-related receptor alpha and gamma in human glioma and astrocytoma cells.

    PubMed

    Gandhari, Mukesh K; Frazier, Chester R; Hartenstein, Julia S; Cloix, Jean-Francois; Bernier, Michel; Wainer, Irving W

    2010-02-01

    The purpose of this study was to examine expression and function of estrogen receptor-related receptors (ERRs) in human glioma and astrocytoma cell lines. These estrogen receptor-negative cell lines expressed ERRalpha and ERRgamma proteins to varying degree in a cell context dependent manner, with U87MG glioma cells expressing both orphan nuclear receptors. Cell proliferation assays were performed in the presence of ERR isoform-specific agonists and antagonists, and the calculated EC(50) and IC(50) values were consistent with previous reported values determined in other types of cancer cell lines. Induction of luciferase expression under the control of ERR isoform-specific promoters was also observed in these cells. These results indicate that ERRalpha and ERRgamma are differentially expressed in these tumor cell lines and likely contribute to agonist-dependent ERR transcriptional activity. PMID:19822186

  5. Identification and characterization of estrogen receptor-related receptor alpha and gamma in human glioma and astrocytoma cells

    PubMed Central

    Gandhari, Mukesh K; Frazier, Chester R; Hartenstein, Julia S; Cloix, Jean-Francois; Bernier, Michel; Wainer, Irving W.

    2009-01-01

    The purpose of this study was to examine expression and function of estrogen receptor-related receptors (ERRs) in human glioma and astrocytoma cell lines. These estrogen receptor-negative cell lines expressed ERRα and ERRγ proteins to varying degree in a cell context dependent manner, with U87MG glioma cells expressing both orphan nuclear receptors. Cell proliferation assays were performed in the presence of ERR isoform-specific agonists and antagonists, and the calculated EC50 and IC50 values were consistent with previous reported values determined in other types of cancer cell lines. Induction of luciferase expression under the control of ERR isoform-specific promoters was also observed in these cells. These results indicate that ERRα and ERRγ are differentially expressed in these tumor cell lines and likely contribute to agonist-dependent ERR transcriptional activity. PMID:19822186

  6. Estrogen receptor beta and truncated variants enhance the expression of transfected MMP-1 promoter constructs in response to specific mechanical loading

    PubMed Central

    2014-01-01

    Background Joint diseases such as osteoarthritis (OA) predominantly afflict post-menopausal women, suggesting a pertinent role for female hormones. Estrogen receptor beta (ER-β) has been detected in connective tissues of the knee joint suggesting that these tissues are responsive to the hormone estrogen. Matrix metalloproteinase-1 (MMP-1) activity contributes to cartilage degradation, a key factor leading to OA development in synovial joints. Two polymorphic forms of MMP-1 exist due to a deletion/insertion of the guanine residue in the promoter, and the 2G allelic variant of MMP-1 exhibits more activity than the 1G allele. Previous studies have demonstrated that the polymorphic forms of the human MMP-1 are influenced by the modulating effects of estrogen receptor isoforms. In addition to hormonal influences, physiological factors such as altered mechanical loading are also contributory features of OA. In the present study, the combined influence of biomechanical and hormonal variables on the activity of MMP-1 isoforms was evaluated. We hypothesized that the combined effects of ER-β and sheer stress will differentially activate the two allelic forms of MMP-1 in a hormone-independent manner. Methods HIG-82 synoviocytes were transiently transfected with 1G or 2G alleles (±) ER-β and subjected to either shear or equibiaxial stress. Next, 1G/2G promoter activity was measured to determine the combined influence of physiological stimuli. Truncated ER-β constructs were used to determine the importance of different domains of ER-β on 1G/2G activation. Results The 2G allele exhibited a constitutively higher activity than the 1G allele, which was further increased when the transfected cells were subject to shear stress, but not equibiaxial stress. Moreover, the combination of ER-β and shear stress further increased the activity levels of the 1G/2G allelic variants. Additionally, select AF-2 truncated ER-β variants led to increased activity levels for the 2G allele

  7. ROLE OF ESTROGEN RECEPTOR-α ON FOOD DEMAND ELASTICITY

    PubMed Central

    Minervini, Vanessa; Rowland, Neil E.; Robertson, Kimberly L.; Foster, Thomas C.

    2016-01-01

    Estrogens have been shown to have an inhibitory effect on food intake under free-feeding conditions, yet the effects of estrogens on food-maintained operant responding have been studied to a much lesser extent and, thus, are not well understood. Therefore, the purpose of the present experiment was to use a behavioral economics paradigm to assess differences in demand elasticity between mice with knockout of the estrogen receptor subtype α, knockout of subtype β, and their wild type controls. The mice responded in a closed economy, and the price of food was increased by increasing the fixed-ratio response requirement every four sessions. Overall, we found that mice with the knockout of receptor subtype α had the most elastic demand functions. Therefore, under these conditions, estrogens increased food seeking via activation of the receptor subtype α. The results were inconsistent with those reported by previous studies that employed free-feeding conditions. PMID:25869426

  8. Role of estrogen receptor-α on food demand elasticity.

    PubMed

    Minervini, Vanessa; Rowland, Neil E; Robertson, Kimberly L; Foster, Thomas C

    2015-05-01

    Estrogens have been shown to have an inhibitory effect on food intake under free-feeding conditions, yet the effects of estrogens on food-maintained operant responding have been studied to a much lesser extent and, thus, are not well understood. Therefore, the purpose of the present experiment was to use a behavioral economics paradigm to assess differences in demand elasticity between mice with knockout of the estrogen receptor subtype α, knockout of subtype β, and their wild type controls. The mice responded in a closed economy, and the price of food was increased by increasing the fixed-ratio response requirement every four sessions. Overall, we found that mice with the knockout of receptor subtype α had the most elastic demand functions. Therefore, under these conditions, estrogens increased food seeking via activation of the receptor subtype α. The results were inconsistent with those reported by previous studies that employed free-feeding conditions. PMID:25869426

  9. International Union of Basic and Clinical Pharmacology. XCVII. G Protein–Coupled Estrogen Receptor and Its Pharmacologic Modulators

    PubMed Central

    2015-01-01

    Estrogens are critical mediators of multiple and diverse physiologic effects throughout the body in both sexes, including the reproductive, cardiovascular, endocrine, nervous, and immune systems. As such, alterations in estrogen function play important roles in many diseases and pathophysiological conditions (including cancer), exemplified by the lower prevalence of many diseases in premenopausal women. Estrogens mediate their effects through multiple cellular receptors, including the nuclear receptor family (ERα and ERβ) and the G protein–coupled receptor (GPCR) family (GPR30/G protein–coupled estrogen receptor [GPER]). Although both receptor families can initiate rapid cell signaling and transcriptional regulation, the nuclear receptors are traditionally associated with regulating gene expression, whereas GPCRs are recognized as mediating rapid cellular signaling. Estrogen-activated pathways are not only the target of multiple therapeutic agents (e.g., tamoxifen, fulvestrant, raloxifene, and aromatase inhibitors) but are also affected by a plethora of phyto- and xeno-estrogens (e.g., genistein, coumestrol, bisphenol A, dichlorodiphenyltrichloroethane). Because of the existence of multiple estrogen receptors with overlapping ligand specificities, expression patterns, and signaling pathways, the roles of the individual receptors with respect to the diverse array of endogenous and exogenous ligands have been challenging to ascertain. The identification of GPER-selective ligands however has led to a much greater understanding of the roles of this receptor in normal physiology and disease as well as its interactions with the classic estrogen receptors ERα and ERβ and their signaling pathways. In this review, we describe the history and characterization of GPER over the past 15 years focusing on the pharmacology of steroidal and nonsteroidal compounds that have been employed to unravel the biology of this most recently recognized estrogen receptor. PMID

  10. How to target estrogen receptor-negative breast cancer?

    PubMed

    Rochefort, H; Glondu, M; Sahla, M E; Platet, N; Garcia, M

    2003-06-01

    Estrogen receptor (ER)-positive breast cancers generally have a better prognosis and are often responsive to anti-estrogen therapy, which is the first example of a successful therapy targeted on a specific protein, the ER. Unfortunately ER-negative breast cancers are more aggressive and unresponsive to anti-estrogens. Other targeted therapies are thus urgently needed, based on breast cancer oncogene inhibition or suppressor gene activation as far as molecular studies have demonstrated the alteration of expression, or structure of these genes in human breast cancer. Using the MDA-MB.231 human breast cancer cell line as a model of ER-negative breast cancers, we are investigating two of these approaches in our laboratory. Our first approach was to transfect the ER or various ER-deleted variants into an ER-negative cell line in an attempt to recover anti-estrogen responsiveness. The unliganded receptor, and surprisingly estradiol, were both found to inhibit tumor growth and invasiveness in vitro and in vivo. The mechanisms of these inhibitions in ER-negative cancer cells are being studied, in an attempt to target the ER sequence responsible for such inhibition in these cancer cells. Another strategy is trying to inhibit the activity or expression of an oncogene specifically overexpressed in most breast cancers. This approach was recently shown by others to be efficient in breast cancer therapy with HER2-Neu oncogene amplification using Herceptin. Without excluding other molecular putative targets, we have focused our research on cathepsin D as a potential target, since it is often overexpressed in aggressive human breast cancers, including ER-negative tumors, and rarely associated with HER2-Neu amplification. Our first results obtained in vitro on cell lines and in vivo in tumor xenografts in nude mice, illustrate that the mode of action of cathepsin D in breast cancer is useful to guide the development of these therapies. In the past 20 years we have learned that the

  11. Estrogen receptor beta signals to inhibition of cardiac fibrosis.

    PubMed

    Pedram, Ali; Razandi, Mahnaz; Narayanan, Ramesh; Levin, Ellis R

    2016-10-15

    Cardiac fibrosis evolves from the cardiac hypertrophic state. In this respect, estrogen and estrogen receptor beta (ERβ) inhibit the effects of cardiac hypertrophic peptides that also stimulate fibrosis. Here we determine details of the anti-fibrotic functions of ERβ. In acutely isolated rat cardiac fibroblasts. E2 or a specific ERβ agonist (βLGND2) blocked angiotensin II (AngII) signaling to fibrosis. This resulted from ERβ activating protein kinase A and AMP kinase, inhibiting both AngII de-phosphorylation of RhoA and the resulting stimulation of Rho kinase. Inhibition of Rho kinase from ERβ signaling resulted in marked decrease of TGFβ expression, connective tissue growth factor production and function, matrix metalloproteinases 2 and 9 expression and activity, and the conversion of fibroblasts to myofibroblasts. Production of collagens I and III were also significantly decreased. Several important aspects were corroborated in-vivo from βLGND2-treated mice that underwent AngII-induced cardiac hypertrophy. Thus, ERβ in cardiac fibroblasts prevents key aspects of cardiac fibrosis development. PMID:27321970

  12. The other estrogen receptor in the plasma membrane: implications for the actions of environmental estrogens.

    PubMed Central

    Watson, C S; Pappas, T C; Gametchu, B

    1995-01-01

    Environmental or nutritional estrogenic toxicants are thought to mediate developmental and carcinogenic pathologies. Estrogen receptor (ER) measurements are currently used to predict hormonal responsiveness; therefore all ER subpopulations should be considered. We have been involved in the immunoidentification and characterization of membrane steroid receptors in several systems and have recently shown that binding of estradiol (E2) to a subpopulation of ERs (mER) residing in the plasma membrane of GH3 pituitary tumor cells mediates the rapid release of prolactin (PRL). Here we review these findings and present other important characterizations of these receptors such as trypsin and serum susceptibility, movement in the membrane, confocal localization to the membrane, binding to and function of impeded ligands, and immunoseparation of cells bearing mER. We plan to use this system as a model for both the physiological and pathological nongenomic effects of estrogens and estrogenic xenobiotics. Specifically, it should be useful as an in vitro assay system for the ability of estrogenic xenobiotics to cause rapid PRL release as an example of nongenomic estrogen effects. Images Figure 4. A Figure 4. B Figure 4. C Figure 4. D Figure 4. E Figure 4. F Figure 5. A Figure 5. B Figure 6. A Figure 6. B Figure 6. C Figure 7. A Figure 7. B Figure 7. C Figure 7. D PMID:8593873

  13. Estrogen receptor transcription and transactivation: Structure-function relationship in DNA- and ligand-binding domains of estrogen receptors

    PubMed Central

    Ruff, Marc; Gangloff, Monique; Marie Wurtz, Jean; Moras, Dino

    2000-01-01

    Estrogen receptors are members of the nuclear receptor steroid family that exhibit specific structural features, ligand-binding domain sequence identity and dimeric interactions, that single them out. The crystal structures of their DNA-binding domains give some insight into how nuclear receptors discriminate between DNA response elements. The various ligand-binding domain crystal structures of the two known estrogen receptor isotypes (α and β) allow one to interpret ligand specificity and reveal the interactions responsible for stabilizing the activation helix H12 in the agonist and antagonist positions. PMID:11250728

  14. G-protein Coupled Estrogen Receptor, Estrogen Receptor α, and Progesterone Receptor Immunohistochemistry in the Hypothalamus of Aging Female Rhesus Macaques Given Long-Term Estradiol Treatment

    PubMed Central

    NAUGLE, MICHELLE M.; NGUYEN, LONG T.; MERCERON, TYLER K.; FILARDO, EDWARD; JANSSEN, WILLIAM G.M.; MORRISON, JOHN H.; RAPP, PETER R.; GORE, ANDREA C.

    2014-01-01

    Steroid hormone receptors are widely and heterogeneously expressed in the brain, and are regulated by age and gonadal hormones. Our goal was to quantify effects of aging, long-term estradiol (E2) treatment, and their interactions, on expression of G protein-coupled estrogen receptor (GPER), estrogen receptor α (ERα) and progesterone receptor (PR) immunoreactivity in two hypothalamic regions, the arcuate (ARC) and the periventricular area (PERI) of rhesus monkeys as a model of menopause and hormone replacement. Ovariectomized (OVX) rhesus macaques were young (~11 years) or aged (~25 years), given oil (vehicle) or E2 every 3 weeks for 2 years. Immunohistochemistry and stereologic analysis of ERα, PR, and GPER was performed. More effects were detected for GPER than the other two receptors. Specifically, GPER cell density in the ARC and PERI, and the percent of GPER-immunoreactive cells in the PERI, were greater in aged than in young monkeys. In addition, we mapped the qualitative distribution of GPER in the monkey hypothalamus and nearby regions. For ERα, E2 treated monkeys tended to have higher cell density than vehicle monkeys in the ARC. The percent of PR density in the PERI tended to be higher in E2 than vehicle monkeys of both ages. This study shows that the aged hypothalamus maintains expression of hormone receptors with age, and that long-term cyclic E2 treatment has few effects on their expression, although GPER was affected more than ERα or PR. This result is surprising in light of evidence for E2 regulation of the receptors studied here, and differences may be due to the selected regions, long-term nature of E2 treatment, among other possibilities. PMID:24862737

  15. Notch-1 activates estrogen receptor-α-dependent transcription via IKKα in breast cancer cells

    PubMed Central

    Hao, L; Rizzo, P; Osipo, C; Pannuti, A; Wyatt, D; Cheung, LW-K; Sonenshein, G; Osborne, BA; Miele, L

    2016-01-01

    Approximately 80% of breast cancers express the estrogen receptor-α (ERα) and are treated with anti-estrogens. Resistance to these agents is a major cause of mortality. We have shown that estrogen inhibits Notch, whereas anti-estrogens or estrogen withdrawal activate Notch signaling. Combined inhibition of Notch and estrogen signaling has synergistic effects in ERα-positive breast cancer models. However, the mechanisms whereby Notch-1 promotes the growth of ERα-positive breast cancer cells are unknown. Here, we demonstrate that Notch-1 increases the transcription of ERα-responsive genes in the presence or absence of estrogen via a novel chromatin crosstalk mechanism. Our data support a model in which Notch-1 can activate the transcription of ERα-target genes via IKKα-dependent cooperative chromatin recruitment of Notch–CSL–MAML1 transcriptional complexes (NTC) and ERα, which promotes the recruitment of p300. CSL binding elements frequently occur in close proximity to estrogen-responsive elements (EREs) in the human and mouse genomes. Our observations suggest that a hitherto unknown Notch-1/ERα chromatin crosstalk mediates Notch signaling effects in ERα-positive breast cancer cells and contributes to regulate the transcriptional functions of ERα itself. PMID:19838210

  16. Estrogen, vascular estrogen receptor and hormone therapy in postmenopausal vascular disease.

    PubMed

    Khalil, Raouf A

    2013-12-15

    Cardiovascular disease (CVD) is less common in premenopausal women than men of the same age or postmenopausal women, suggesting vascular benefits of estrogen. Estrogen activates estrogen receptors ERα, ERβ and GPR30 in endothelium and vascular smooth muscle (VSM), which trigger downstream signaling pathways and lead to genomic and non-genomic vascular effects such as vasodilation, decreased VSM contraction and growth and reduced vascular remodeling. However, randomized clinical trials (RCTs), such as the Women's Health Initiative (WHI) and Heart and Estrogen/progestin Replacement Study (HERS), have shown little vascular benefits and even adverse events with menopausal hormone therapy (MHT), likely due to factors related to the MHT used, ER profile, and RCT design. Some MHT forms, dose, combinations or route of administration may have inadequate vascular effects. Age-related changes in ER amount, distribution, integrity and post-ER signaling could alter the vascular response to MHT. The subject's age, preexisting CVD, and hormone environment could also reduce the effects of MHT. Further evaluation of natural and synthetic estrogens, phytoestrogens, and selective estrogen-receptor modulators (SERMs), and the design of appropriate MHT combinations, dose, route and 'timing' could improve the effectiveness of conventional MHT and provide alternative therapies in the peri-menopausal period. Targeting ER using specific ER agonists, localized MHT delivery, and activation of specific post-ER signaling pathways could counter age-related changes in ER. Examination of the hormone environment and conditions associated with hormone imbalance such as polycystic ovary syndrome may reveal the causes of abnormal hormone-receptor interactions. Consideration of these factors in new RCTs such as the Kronos Early Estrogen Prevention Study (KEEPS) could enhance the vascular benefits of estrogen in postmenopausal CVD. PMID:24099797

  17. Estrogen, Vascular Estrogen Receptor and Hormone Therapy in Postmenopausal Vascular Disease

    PubMed Central

    Khalil, Raouf A.

    2013-01-01

    Cardiovascular disease (CVD) is less common in premenopausal women than men of the same age or postmenopausal women, suggesting vascular benefits of estrogen. Estrogen activates estrogen receptors ERα, ERβ and GPR30 in endothelium and vascular smooth muscle (VSM), which trigger downstream signaling pathways and lead to genomic and non-genomic vascular effects such as vasodilation, decreased VSM contraction and growth and reduced vascular remodeling. However, randomized clinical trials (RCTs), such as the Women’s Health Initiative (WHI) and Heart and Estrogen/progestin Replacement Study (HERS), have shown little vascular benefits and even adverse events with menopausal hormone therapy (MHT), likely due to factors related to the MHT used, ER profile, and RCT design. Some MHT forms, dose, combinations or route of administration may have inadequate vascular effects. Age-related changes in ER amount, distribution, integrity and post-ER signaling could alter the vascular response to MHT. The subject’s age, preexisting CVD, and hormone environment could also reduce the effects of MHT. Further evaluation of natural and synthetic estrogens, phytoestrogens, and selective estrogen-receptor modulators (SERMs), and the design of appropriate MHT combinations, dose, route and 'timing' could improve the effectiveness of conventional MHT and provide alternative therapies in the peri-menopausal period. Targeting ER using specific ER agonists, localized MHT delivery, and activation of specific post-ER signaling pathways could counter age-related changes in ER. Examination of the hormone environment and conditions associated with hormone imbalance such as polycystic ovary syndrome may reveal the causes of abnormal hormone-receptor interactions. Consideration of these factors in new RCTs such as the Kronos Early Estrogen Prevention Study (KEEPS) could enhance the vascular benefits of estrogen in postmenopausal CVD. PMID:24099797

  18. Investigation of the Effects of Subchronic Low Dose Oral Exposure to Bisphenol A (BPA) and Ethinyl Estradiol (EE) on Estrogen Receptor Expression in the Juvenile and Adult Female Rat Hypothalamus

    PubMed Central

    Rebuli, Meghan E.; Cao, Jinyan; Sluzas, Emily; Delclos, K. Barry; Camacho, Luísa; Lewis, Sherry M.; Vanlandingham, Michelle M.; Patisaul, Heather B.

    2014-01-01

    Concerns have been raised regarding the long-term impacts of early life exposure to the ubiquitous environmental contaminant bisphenol A (BPA) on brain organization. Because BPA has been reported to affect estrogen signaling, and steroid hormones play a critical role in brain sexual differentiation, there is also concern that BPA exposure could alter neural sex differences. Here, we examine the impact of subchronic exposure from gestation to adulthood to oral doses of BPA below the current no-observed-adverse-effect level (NOAEL) of 5 mg/kg body weight (bw)/day on estrogen receptor (ESR) expression in sexually dimorphic brain regions of prepubertal and adult female rats. The dams were gavaged daily with vehicle (0.3% carboxymethylcellulose), 2.5, 25, 260, or 2700 μg BPA/kg bw/day, or 0.5 or 5.0 μg ethinyl estradiol (EE)/kg bw/day from gestational day 6 until labor began. Offspring were then gavaged directly from the day after birth until the day before scheduled sacrifice on postnatal days 21 or 90. Using in situ hybridization, one or more BPA doses produced significant decreases in Esr1 expression in the juvenile female rat anteroventral periventricular nucleus (AVPV) of the hypothalamus and significant decreases in Esr2 expression in the adult female rat AVPV and medial preoptic area (MPOA), relative to vehicle controls. BPA did not simply reproduce EE effects, indicating that BPA is not acting solely as an estrogen mimic. The possible consequences of long-term changes in hypothalamic ESR expression resulting from subchronic low dose BPA exposure on neuroendocrine effects are discussed and being addressed in ongoing, related work. PMID:24752507

  19. Estrogen Receptor Beta in the Brain: From Form to Function

    PubMed Central

    Weiser, Michael J.; Foradori, Chad D.; Handa, Robert J.

    2008-01-01

    Estrogens have numerous effects on the brain, both in adulthood and during development. These actions of estrogen are mediated by two distinct estrogen receptor (ER) systems, ER alpha (ERα) and ER beta (ERβ). In brain, ERα plays a critical role in regulating reproductive neuroendocrine function and behavior, however, a definitive role for ERβ in any neurobiological function has been slow in forthcoming. Clues to the function of ERβ in the central nervous system can be gleaned from the neuroanatomical distribution of ERβ and the phenotypes of neurons that express ERβ. ERβ immunoreactivity has been found in populations of GnRH, CRH, vasopressin, oxytocin and prolactin containing neurons in the hypothalamus. Utilizing subtype-selective estrogen receptor agonists can help determine the roles for ERβ in non-reproductive behaviors in rat models. ERβ selective agonists exert potent anxiolytic activity when animals were tested in a number of behavioral paradigms. Consistent with this, ERβ selective agonists also inhibited the ACTH and corticosterone response to stress. In contrast, ERα selective agonists were found to be anxiogenic and correspondingly increased the hormonal stress response. Taken together, our studies implicate ERβ as an important modulator of some non-reproductive neurobiological systems. The molecular and neuroanatomical targets of estrogen that are mediated by ERβ remain to be determined. A number of splice variants of ERβ mRNA have been reported in brain tissue. Imaging of eGFP labeled chimeric receptor proteins transfected into cell lines show that ERβ splice variation can alter trafficking patterns and function. The originally described ERβ (herein termed ER-β1) is characterized by possessing a high affinity for estradiol. Similar to ERα, it is localized in the nucleus and is trafficked to nuclear sites termed “hyperspeckles” following ligand binding. In contrast, ER-β2 contains an 18 amino acid insert within the ligand

  20. G protein-coupled estrogen receptor-selective ligands modulate endometrial tumor growth.

    PubMed

    Petrie, Whitney K; Dennis, Megan K; Hu, Chelin; Dai, Donghai; Arterburn, Jeffrey B; Smith, Harriet O; Hathaway, Helen J; Prossnitz, Eric R

    2013-01-01

    Endometrial carcinoma is the most common cancer of the female reproductive tract. GPER/GPR30 is a 7-transmembrane spanning G protein-coupled receptor that has been identified as the third estrogen receptor, in addition to ERα and ERβ. High GPER expression is predictive of poor survival in endometrial and ovarian cancer, but despite this, the estrogen-mediated signaling pathways and specific estrogen receptors involved in endometrial cancer remain unclear. Here, employing ERα-negative Hec50 endometrial cancer cells, we demonstrate that GPER mediates estrogen-stimulated activation of ERK and PI3K via matrix metalloproteinase activation and subsequent transactivation of the EGFR and that ER-targeted therapeutic agents (4-hydroxytamoxifen, ICI182,780/fulvestrant, and Raloxifene), the phytoestrogen genistein, and the "ERα-selective" agonist propylpyrazole triol also function as GPER agonists. Furthermore, xenograft tumors of Hec50 cells yield enhanced growth with G-1 and estrogen, the latter being inhibited by GPER-selective pharmacologic antagonism with G36. These results have important implications with respect to the use of putatively ER-selective ligands and particularly for the widespread long-term use of "ER-targeted" therapeutics. Moreover, our findings shed light on the potential mechanisms of SERM/SERD side effects reported in many clinical studies. Finally, our results provide the first demonstration that pharmacological inhibition of GPER activity in vivo prevents estrogen-mediated tumor growth. PMID:24379833

  1. G Protein-Coupled Estrogen Receptor-Selective Ligands Modulate Endometrial Tumor Growth

    PubMed Central

    Petrie, Whitney K.; Dennis, Megan K.; Dai, Donghai; Arterburn, Jeffrey B.; Smith, Harriet O.; Hathaway, Helen J.; Prossnitz, Eric R.

    2013-01-01

    Endometrial carcinoma is the most common cancer of the female reproductive tract. GPER/GPR30 is a 7-transmembrane spanning G protein-coupled receptor that has been identified as the third estrogen receptor, in addition to ERα and ERβ. High GPER expression is predictive of poor survival in endometrial and ovarian cancer, but despite this, the estrogen-mediated signaling pathways and specific estrogen receptors involved in endometrial cancer remain unclear. Here, employing ERα-negative Hec50 endometrial cancer cells, we demonstrate that GPER mediates estrogen-stimulated activation of ERK and PI3K via matrix metalloproteinase activation and subsequent transactivation of the EGFR and that ER-targeted therapeutic agents (4-hydroxytamoxifen, ICI182,780/fulvestrant, and Raloxifene), the phytoestrogen genistein, and the “ERα-selective” agonist propylpyrazole triol also function as GPER agonists. Furthermore, xenograft tumors of Hec50 cells yield enhanced growth with G-1 and estrogen, the latter being inhibited by GPER-selective pharmacologic antagonism with G36. These results have important implications with respect to the use of putatively ER-selective ligands and particularly for the widespread long-term use of “ER-targeted” therapeutics. Moreover, our findings shed light on the potential mechanisms of SERM/SERD side effects reported in many clinical studies. Finally, our results provide the first demonstration that pharmacological inhibition of GPER activity in vivo prevents estrogen-mediated tumor growth. PMID:24379833

  2. Differences in expression of proliferation-associated genes and RANKL across the menstrual cycle in estrogen receptor-positive primary breast cancer.

    PubMed

    Haynes, Ben P; Viale, Giuseppe; Galimberti, Viviana; Rotmensz, Nicole; Gibelli, Bianca; Smith, Ian E; Dowsett, Mitch

    2014-11-01

    The purpose of this study is to determine if there are differences in the expression of estrogen-regulated genes (ERGs), proliferation-associated genes and the progesterone effector RANKL, in premenopausal ER+ breast cancer as a result of the major changes in hormone levels that occur through the menstrual cycle. Primary ER+ tumours from 174 patients were assigned to one of three menstrual cycle windows: W1 (days 27-35 + 1-6), W2 (days 7-16) and W3 (days 17-26). RNA expression of 42 genes, including 24 putative genes associated with plasma E2 levels, seven proliferation genes and RANKL was measured. Expression of PGR, TFF1, GREB1 and PDZK1 followed the previously reported pattern: a higher level in W2 compared to W1 while W3 had an intermediate value, mirroring changes in plasma estradiol. Of the other 20 ERGs, four (RUNX1, AGR2, SERPINA3 and SERPINA5) showed significant differences (p = 0.009-0.049) in expression across the menstrual cycle. The expression of six of seven proliferation-associated genes varied across the cycle but differently from the ERGs, being 20-35 % lower in W3 compared to W1 and W2 (p = 0.004-0.031). Expression of RANKL was 2.5 to 3-fold highest in W3 (p = 0.0001) and negatively correlated to the expression of the proliferation-associated genes (r = -0.37; p < 0.0001). Expression of proliferation-associated genes and RANKL in ER+ breast tumours varies across the menstrual cycle showing a different rhythm to that of ERGs. This may affect the interpretation of gene expression profiles but may be exploitable as an endogenous test of endocrine responsiveness. PMID:25367875

  3. Comparative analysis of the interaction of various estrogens with the estrogen-receptor system of the uterus

    SciTech Connect

    Fanchenko, N.D.; Alekseeva, M.L.; Minina, L.S.; Novikov, E.A.; Khel'mun, D.K.

    1986-05-20

    The binding of various labeled estrogens under conditions of equilibrium in the cytosol of the uterus of sexually immature Wistar rats was studied. An analysis of the data obtained, as well as the kinetics of the dissociation of the complexes of the ligands used with specific high-affinity estrogen-binding sites of the cytosol, suggested that the population of estrogen receptors in the rat uterus is homogeneous. The possibility of intracellular regulation of the action of estrogens in the target cell in the presence of a homogeneous population of receptors, both at the receptor and at the post-receptor stages, is suggested.

  4. Brain aromatase (Cyp19A2) and estrogen receptors, in larvae and adult pejerrey fish Odontesthes bonariensis: Neuroanatomical and functional relations

    USGS Publications Warehouse

    Strobl-Mazzulla, P. H.; Lethimonier, C.; Gueguen, M.M.; Karube, M.; Fernandino, J.I.; Yoshizaki, G.; Patino, R.; Strussmann, C.A.; Kah, O.; Somoza, G.M.

    2008-01-01

    Although estrogens exert many functions on vertebrate brains, there is little information on the relationship between brain aromatase and estrogen receptors. Here, we report the cloning and characterization of two estrogen receptors, ?? and ??, in pejerrey. Both receptors' mRNAs largely overlap and were predominantly expressed in the brain, pituitary, liver, and gonads. Also brain aromatase and estrogen receptors were up-regulated in the brain of estradiol-treated males. In situ hybridization was performed to study in more detail, the distribution of the two receptors in comparison with brain aromatase mRNA in the brain of adult pejerrey. The estrogen receptors' mRNAs exhibited distinct but partially overlapping patterns of expression in the preoptic area and the mediobasal hypothalamus, as well as in the pituitary gland. Moreover, the estrogen receptor ??, but not ??, were found to be expressed in cells lining the preoptic recess, similarly as observed for brain aromatase. Finally, it was shown that the onset expression of brain aromatase and both estrogen receptors in the head of larvae preceded the morphological differentiation of the gonads. Because pejerrey sex differentiation is strongly influenced by temperature, brain aromatase expression was measured during the temperature-sensitive window and was found to be significantly higher at male-promoting temperature. Taken together these results suggest close neuroanatomical and functional relationships between brain aromatase and estrogen receptors, probably involved in the sexual differentiation of the brain and raising interesting questions on the origin (central or peripheral) of the brain aromatase substrate. ?? 2008 Elsevier Inc.

  5. Structural and Functional Diversity of Estrogen Receptor Ligands

    PubMed Central

    Farooq, Amjad

    2015-01-01

    Estrogen receptors, comprised of ERα and ERβ isoforms in mammals, act as ligand-modulated transcription factors and orchestrate a plethora of cellular functions from sexual development and reproduction to metabolic homeostasis. Herein, I revisit the structural basis of the binding of ERα to DNA and estradiol in light of the recent discoveries and emerging trends in the field of nuclear receptors. A particular emphasis of this review is on the chemical and structural diversity of an ever-increasing repertoire of physiological, environmental and synthetic ligands of estrogen receptors that ultimately modulate their interactions with cognate DNA located within the promoters of estrogen-responsive genes. In particular, modulation of estrogen receptors by small molecule ligands represents an important therapeutic goal toward the treatment of a wide variety of human pathologies including breast cancer, cardiovascular disease, osteoporosis and obesity. Collectively, this article provides an overview of a wide array of small organic and inorganic molecules that can fine-tune the physiological function of estrogen receptors, thereby bearing a direct impact on human health and disease. PMID:25866274

  6. Reactivation of apolipoprotein II gene transcription by cycloheximide reveals two steps in the deactivation of estrogen receptor-mediated transcription.

    PubMed

    Sensel, M G; Binder, R; Lazier, C B; Williams, D L

    1994-03-01

    In this report, we describe apolipoprotein II (apoII) gene expression in cell lines derived by stable expression of the chicken estrogen receptor in LMH chicken hepatoma cells. In cell lines expressing high levels of receptor (LMH/2A), apoII gene expression is increased by estrogen 300-fold compared with levels in the receptor-deficient parent LMH line. LMH/2A cells show apoII mRNA induction and turnover kinetics similar to those in chicken liver. Inhibition of protein synthesis with cycloheximide (CHX) or puromycin following estrogen withdrawal superinduces apoII mRNA without affecting apoII mRNA stability. Superinduction is due to an estrogen-independent reactivation of apoII gene transcription. The apoII gene can be reactivated by CHX for up to 24 h following hormone withdrawal, suggesting that the gene is in a repressed yet transcriptionally competent state. These results reveal two distinct events necessary for termination of estrogen receptor-mediated transcription. The first event, removal of hormone, is sufficient to stop transcription when translation is ongoing. The second event is revealed by the CHX-induced superinduction of apoII mRNA following hormone withdrawal. This superinduction suggests that deactivation of estrogen receptor-mediated transcription requires a labile protein. Furthermore, reactivation of apoII gene expression by CHX and estrogen is additive, suggesting that estrogen is unable to overcome repression completely. Thus, a labile protein may act to repress estrogen receptor-mediated transcription of the apoII gene. PMID:8114707

  7. Expression of endogenous and transfected apolipoprotein II and vitellogenin II genes in an estrogen responsive chicken liver cell line.

    PubMed

    Binder, R; MacDonald, C C; Burch, J B; Lazier, C B; Williams, D L

    1990-02-01

    A recently described chicken liver cell line, LMH, was characterized to evaluate responsiveness to estrogen. Expression of the endogenous apolipoprotein (apo) II gene was induced by 17 beta-estradiol when LMH cells were cultured with chicken serum. The response was low and yielded apoll mRNA at only 0.3% of the level seen in estrogenized rooster liver. Higher levels of apoll mRNA were achieved when LMH cells were transiently transfected with an expression plasmid for estrogen receptor. A transfected apoll gene was strongly expressed only when cotransfected with receptor. Expression of the endogenous vitellogenin (VTG) II gene was not detected. However, when cotransfected with a receptor expression plasmid, VTG II reporter plasmids were expressed in LMH cells in response to 17 beta-estradiol. These results suggest that estrogen responsiveness of LMH cells is limited by the availability of functional receptor. Low levels of estrogen receptor mRNA were detected in LMH cells, and receptor binding sites and mRNA were greatly increased following transient transfection with a receptor expression plasmid. Using this transient transfection protocol, several VTG II reporter plasmids were compared in LMH cells and chick embryo fibroblasts. A plasmid containing VTG II estrogen response elements linked to a heterologous promoter was regulated by estrogen in both cell types. In contrast, reporter plasmids containing the VTG II promoter were regulated by estrogen in LMH cells but were not expressed at all in chick embryo fibroblasts. These results suggest that regulation of the VTG II gene involves cell type-specific elements in addition to estrogen response elements.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2330000

  8. Estradiol and Estrogen Receptor Agonists Oppose Oncogenic Actions of Leptin in HepG2 Cells.

    PubMed

    Shen, Minqian; Shi, Haifei

    2016-01-01

    Obesity is a significant risk factor for certain cancers, including hepatocellular carcinoma (HCC). Leptin, a hormone secreted by white adipose tissue, precipitates HCC development. Epidemiology data show that men have a much higher incidence of HCC than women, suggesting that estrogens and its receptors may inhibit HCC development and progression. Whether estrogens antagonize oncogenic action of leptin is uncertain. To investigate potential inhibitory effects of estrogens on leptin-induced HCC development, HCC cell line HepG2 cells were treated with leptin in combination with 17 β-estradiol (E2), estrogen receptor-α (ER-α) selective agonist PPT, ER-β selective agonist DPN, or G protein-coupled ER (GPER) selective agonist G-1. Cell number, proliferation, and apoptosis were determined, and leptin- and estrogen-related intracellular signaling pathways were analyzed. HepG2 cells expressed a low level of ER-β mRNA, and leptin treatment increased ER-β expression. E2 suppressed leptin-induced HepG2 cell proliferation and promoted cell apoptosis in a dose-dependent manner. Additionally E2 reversed leptin-induced STAT3 and leptin-suppressed SOCS3, which was mainly achieved by activation of ER-β. E2 also enhanced ERK via activating ER-α and GPER and activated p38/MAPK via activating ER-β. To conclude, E2 and its receptors antagonize the oncogenic actions of leptin in HepG2 cells by inhibiting cell proliferation and stimulating cell apoptosis, which was associated with reversing leptin-induced changes in SOCS3/STAT3 and increasing p38/MAPK by activating ER-β, and increasing ERK by activating ER-α and GPER. Identifying roles of different estrogen receptors would provide comprehensive understanding of estrogenic mechanisms in HCC development and shed light on potential treatment for HCC patients. PMID:26982332

  9. Estradiol and Estrogen Receptor Agonists Oppose Oncogenic Actions of Leptin in HepG2 Cells

    PubMed Central

    Shen, Minqian; Shi, Haifei

    2016-01-01

    Obesity is a significant risk factor for certain cancers, including hepatocellular carcinoma (HCC). Leptin, a hormone secreted by white adipose tissue, precipitates HCC development. Epidemiology data show that men have a much higher incidence of HCC than women, suggesting that estrogens and its receptors may inhibit HCC development and progression. Whether estrogens antagonize oncogenic action of leptin is uncertain. To investigate potential inhibitory effects of estrogens on leptin-induced HCC development, HCC cell line HepG2 cells were treated with leptin in combination with 17 β-estradiol (E2), estrogen receptor-α (ER-α) selective agonist PPT, ER-β selective agonist DPN, or G protein-coupled ER (GPER) selective agonist G-1. Cell number, proliferation, and apoptosis were determined, and leptin- and estrogen-related intracellular signaling pathways were analyzed. HepG2 cells expressed a low level of ER-β mRNA, and leptin treatment increased ER-β expression. E2 suppressed leptin-induced HepG2 cell proliferation and promoted cell apoptosis in a dose-dependent manner. Additionally E2 reversed leptin-induced STAT3 and leptin-suppressed SOCS3, which was mainly achieved by activation of ER-β. E2 also enhanced ERK via activating ER-α and GPER and activated p38/MAPK via activating ER-β. To conclude, E2 and its receptors antagonize the oncogenic actions of leptin in HepG2 cells by inhibiting cell proliferation and stimulating cell apoptosis, which was associated with reversing leptin-induced changes in SOCS3/STAT3 and increasing p38/MAPK by activating ER-β, and increasing ERK by activating ER-α and GPER. Identifying roles of different estrogen receptors would provide comprehensive understanding of estrogenic mechanisms in HCC development and shed light on potential treatment for HCC patients. PMID:26982332

  10. Estrogen Exhibits a Biphasic Effect on Prostate Tumor Growth through the Estrogen Receptor β-KLF5 Pathway

    PubMed Central

    Osakabe, Asami; Waku, Tsuyoshi; Suzuki, Takashi; Akaogi, Kensuke; Fujimura, Tetsuya; Homma, Yukio; Inoue, Satoshi; Yanagisawa, Junn

    2015-01-01

    Estrogens are effective in the treatment of prostate cancer; however, the effects of estrogens on prostate cancer are enigmatic. In this study, we demonstrated that estrogen (17β-estradiol [E2]) has biphasic effects on prostate tumor growth. A lower dose of E2 increased tumor growth in mouse xenograft models using DU145 and PC-3 human prostate cancer cells, whereas a higher dose significantly decreased tumor growth. We found that anchorage-independent apoptosis in these cells was inhibited by E2 treatment. Similarly, in vivo angiogenesis was suppressed by E2. Interestingly, these effects of E2 were abolished by knockdown of either estrogen receptor β (ERβ) or Krüppel-like zinc finger transcription factor 5 (KLF5). Ιn addition, E2 suppressed KLF5-mediated transcription through ERβ, which inhibits proapoptotic FOXO1 and proangiogenic PDGFA expression. Furthermore, we revealed that a nonagonistic ER ligand GS-1405 inhibited FOXO1 and PDGFA expression through the ERβ-KLF5 pathway and regulated prostate tumor growth without ERβ transactivation. Therefore, these results suggest that E2 biphasically modulates prostate tumor formation by regulating KLF5-dependent transcription through ERβ and provide a new strategy for designing ER modulators, which will be able to regulate prostate cancer progression with minimal adverse effects due to ER transactivation. PMID:26483416

  11. The G protein-coupled estrogen receptor as a modulator of neoplastic transformation.

    PubMed

    Jacenik, Damian; Cygankiewicz, Adam I; Krajewska, Wanda M

    2016-07-01

    Estrogens play a crucial role in the regulation of physiological and pathophysiological processes. These hormones act through specific receptors, most notably the canonical estrogen receptors α and β (ERα and ERβ) and their truncated forms as well as the G protein-coupled estrogen receptor (GPER). Several studies have shown that GPER is expressed in many normal and cancer cells, including those of the breast, endometrium, ovary, testis and lung. Hormonal imbalance is one possible cause of cancer development. An accumulating body of evidence indicates that GPER is involved in the regulation of cancer cell proliferation, migration and invasion, it may act as a mediator of microRNA, and is believed to modulate the inflammation associated with neoplastic transformation. Furthermore, used in various treatment regimens anti-estrogens such as tamoxifen, raloxifen and fulvestrant (ICI 182.780), antagonists/modulators of canonical estrogen receptors, were found to be GPER agonists. This review presents the current knowledge about the potential role of GPER in neoplastic transformation. PMID:27107933

  12. Wedelolactone induces growth of breast cancer cells by stimulation of estrogen receptor signalling.

    PubMed

    Nehybova, Tereza; Smarda, Jan; Daniel, Lukas; Brezovsky, Jan; Benes, Petr

    2015-08-01

    Wedelolactone, a plant coumestan, was shown to act as anti-cancer agent for breast and prostate carcinomas in vitro and in vivo targeting multiple cellular proteins including androgen receptors, 5-lipoxygenase and topoisomerase IIα. It is cytotoxic to breast, prostate, pituitary and myeloma cancer cell lines in vitro at μM concentrations. In this study, however, a novel biological activity of nM dose of wedelolactone was demonstrated. Wedelolactone acts as agonist of estrogen receptors (ER) α and β as demonstrated by transactivation of estrogen response element (ERE) in cells transiently expressing either ERα or ERβ and by molecular docking of this coumestan into ligand binding pocket of both ERα and ERβ. In breast cancer cells, wedelolactone stimulates growth of estrogen receptor-positive cells, expression of estrogen-responsive genes and activates rapid non-genomic estrogen signalling. All these effects can be inhibited by pretreatment with pure ER antagonist ICI 182,780 and they are not observed in ER-negative breast cancer cells. We conclude that wedelolactone acts as phytoestrogen in breast cancer cells by stimulating ER genomic and non-genomic signalling pathways. PMID:25934092

  13. G protein-coupled receptor 30 is an estrogen receptor in the plasma membrane

    SciTech Connect

    Funakoshi, Takeshi; Yanai, Akie; Shinoda, Koh; Kawano, Michio M.; Mizukami, Yoichi . E-mail: mizukami@yamaguchi-u.ac.jp

    2006-08-04

    Recently, GPR30 was reported to be a novel estrogen receptor; however, its intracellular localization has remained controversial. To investigate the intracellular localization of GPR30 in vivo, we produced four kinds of polyclonal antibodies for distinct epitopes on GPR30. Immunocytochemical observations using anti-GPR30 antibody and anti-FLAG antibody show that FLAG-GPR30 localizes to the plasma membrane 24 h after transfection. Treatment with estrogen (17{beta}-estradiol or E2) causes an elevation in the intracellular Ca{sup 2+} concentration ([Ca{sup 2+}]{sub i}) within 10 s in HeLa cells expressing FLAG-GPR30. In addition, E2 induces the translocation of GPR30 from the plasma membrane to the cytoplasm by 1 h after stimulation. Immunohistochemical analysis shows that GPR30 exists on the cell surface of CA2 pyramidal neuronal cells. The images on transmission electron microscopy show that GPR30 is localized to a particular region associated with the plasma membranes of the pyramidal cells. These data indicate that GPR30, a transmembrane receptor for estrogen, is localized to the plasma membrane of CA2 pyramidal neuronal cells of the hippocampus in rat brain.

  14. Genetic Polymorphisms in the EGFR (R521K) and Estrogen Receptor (T594T) Genes, EGFR and ErbB-2 Protein Expression, and Breast Cancer Risk in Tunisia

    PubMed Central

    Kallel, Imen; Rebai, Maha; Khabir, Abdelmajid; Farid, Nadir R.; Rebaï, Ahmed

    2009-01-01

    We evaluated the association of epidermal growth factor receptor (EGFR) 142285G>A (R521K) and estrogen receptor alpha (ESR1) 2014G>A (T594T) single nucleotide polymorphisms with breast cancer risk and prognosis in Tunisian patients. EGFR 142285G>A and ESR1 2014G>A were genotyped in a sample of 148 Tunisian breast cancer patients and 303 controls using PCR-RFLP method. Immunohistochemitsry was used to evaluate the expression levels of EGFR, HER2, ESR1, progesterone receptor and BCL2 in tumors. We found no evidence for an association between EGFR R521K polymorphism and breast cancer risk. However, we found that the homozygous GG (Arg) genotype was more prevalent in patients with lymph node metastasis (P = .03) and high grade tumors (P = .011). The ESR1 2014G allele showed significant association with breast cancer risk (P = .025). The GG genotype was associated with HER2 overexpression and this association withstood univariate and multivariate analyses (P = .009; P = .021, resp.). These data suggest that the R521K might be a prognostic factor, because it correlates with both tumor grade and nodule status. The higher expression of HER2 in ESR1 T594T GG patients suggests the possibility that ESR1 gene polymorphisms accompanied by HER2 expression might influence the pathogenesis of breast cancers. PMID:19636371

  15. Estrogen receptor-α is localized to neurofibrillary tangles in Alzheimer’s disease

    PubMed Central

    Wang, Chunyu; Zhang, Fan; Jiang, Sirui; Siedlak, Sandra L.; Shen, Lu; Perry, George; Wang, Xinglong; Tang, Beisha; Zhu, Xiongwei

    2016-01-01

    The female predominance for developing Alzheimer disease (AD) suggests the involvement of gender specific factor(s) such as a reduced estrogen-estrogen receptor signaling in the pathogenesis of AD. The potential role of ERα in AD pathogenesis has been explored by several groups with mixed results. We revisited this issue of expression and distribution of ERα in AD brain using a specific ERα antibody. Interestingly, we found that ERα co-localized with neurofibrillary pathology in AD brain and further demonstrated that ERα interacts with tau protein in vivo. Immunoprecipitaion experiments found increased ERα-tau interaction in the AD cases, which may account for ERα being sequestered in neuronal tau pathology. Indeed, tau overexpression in M17 cells leads to interruption of estrogen signaling. Our data support the idea that sequestration of ERα by tau pathology underlies the loss of estrogen neuroprotection during the course of AD. PMID:26837465

  16. Regulation of specific target genes and biological responses by estrogen receptor subtype agonists

    PubMed Central

    Leitman, Dale C.; Paruthiyil, Sreenivasan; Vivar, Omar I.; Saunier, Elise F.; Herber, Candice B.; Cohen, Isaac; Tagliaferri, Mary; Speed, Terence P.

    2010-01-01

    Estrogenic effects are mediated through two estrogen receptor (ER) subtypes, ERα and ERβ. Estrogens are the most commonly prescribed drugs to treat menopausal conditions, but by non-selectively triggering both ERα and ERβ pathways in different tissues they can cause serious adverse effects. The different sizes of the binding pockets and sequences of their activation function domains indicate that ERα and ERβ should have different specificities for ligands and biological responses that can be exploited for designing safer and more selective estrogens. ERα and ERβ regulate different genes by binding to different regulatory elements and recruiting different transcription and chromatin remodeling factors that are expressed in a cell-specific manner. ERα- and ERβ-selective agonists have been identified that demonstrate that the two ERs produce distinct biological effects. ERα and ERβ agonists are promising new approach for treating specific conditions associated with menopause. PMID:20951642

  17. Artemisinin selectively decreases functional levels of estrogen receptor-alpha and ablates estrogen-induced proliferation in human breast cancer cells.

    PubMed

    Sundar, Shyam N; Marconett, Crystal N; Doan, Victor B; Willoughby, Jamin A; Firestone, Gary L

    2008-12-01

    MCF7 cells are an estrogen-responsive human breast cancer cell line that expresses both estrogen receptor (ER) alpha and ERbeta. Treatment of MCF7 cells with artemisinin, an antimalarial phytochemical from the sweet wormwood plant, effectively blocked estrogen-stimulated cell cycle progression induced by either 17beta-estradiol (E(2)), an agonist for both ERs, or by propyl pyrazole triol (PPT), a selective ERalpha agonist. Artemisinin strongly downregulated ERalpha protein and transcripts without altering expression or activity of ERbeta. Transfection of MCF7 cells with ERalpha promoter-linked luciferase reporter plasmids revealed that the artemisinin downregulation of ERalpha promoter activity accounted for the loss of ERalpha expression. Artemisinin treatment ablated the estrogenic induction of endogenous progesterone receptor (PR) transcripts by either E(2) or PPT and inhibited the estrogenic stimulation of a luciferase reporter plasmid driven by consensus estrogen response elements (EREs). Chromatin immunoprecipitation assays revealed that artemisinin significantly downregulated the level of endogeneous ERalpha bound to the PR promoter, whereas the level of bound endogeneous ERbeta was not altered. Treatment of MCF7 cells with artemisinin and the pure antiestrogen fulvestrant resulted in a cooperative reduction of ERalpha protein levels and enhanced G(1) cell cycle arrest compared with the effects of either compound alone. Our results show that artemisinin switches proliferative human breast cancer cells from expressing a high ERalpha:ERbeta ratio to a condition in which ERbeta predominates, which parallels the physiological state linked to antiproliferative events in normal mammary epithelium. PMID:18784357

  18. Alterations of gene expression of sodium channels in dorsal root ganglion neurons of estrogen receptor knockout (ERKO) mice induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP).

    PubMed

    Ding, Haixia; Wang, Qiang; Liu, Jingli; Qian, Wenyi; Wang, Wenjuan; Wang, Jun; Gao, Rong; Xiao, Hang

    2012-08-01

    Estrogen receptors (ERα and ERβ) mediate the neuroprotection of estrogens against MPTP-induced striatal dopamine (DA) depletion. Pain is an important and distressing symptom in Parkinson's disease (PD). Voltage-gated sodium channels in sensory neurons are involved in the development of neuropathic pain. In this study, MPTP caused changes in nociception and alterations of gene expression of voltage-gated sodium channels in dorsal root ganglion (DRG) neurons in ER knockout (ERKO) mice were investigated. We found that administration of MPTP (11 mg/kg) to WT mice led to an extensive depletion of DA and its two metabolites, αERKO mice were observed to be more susceptible to MPTP toxicity than βERKO or WT mice. In addition, we found that the mRNA levels of TTX-S and TTX-R sodium channel subtypes were differentially affected in MPTP-treated WT animals. The MPTP-induced up-regulation of Nav1.1 and Nav1.9, down-regulation of Nav1.6 in DRG neurons may be through ERβ, up-regulation of Nav1.7 and down-regulation of Nav1.8 are dependent on both ERα and ERβ. Therefore, the MPTP-induced alterations of gene expression of sodium channels in DRG neurons could be an important mechanism to affect excitability and nociceptive thresholds, and the ERs appear to play a role in nociception in PD. PMID:22371119

  19. Regulation of vitellogenin (vtg1) and estrogen receptor (er) gene expression in zebrafish (Danio rerio) following the administration of Cd²⁺ and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

    PubMed

    Chen, Ying Ying; Chan, King Ming

    2016-03-01

    We evaluated the individual and joint estrogenic effects of cadmium (Cd(2+)) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the zebrafish liver (ZFL) cell line, zebrafish embryo, larvae and the liver of adult zebrafish. The mRNA expression of vtg1 was inhibited by Cd(2+), but unaffected by TCDD in ZFL cells. Similar changes in the mRNA levels of ERα, ERβ1, ERβ2 and GPER (G protein coupled estrogen receptor) in ZFL cells were also observed. Deletion mutants of vtg1 gene promoters were constructed to investigate transcriptional regulation, and we found that all of the constructs failed to respond to TCDD or Cd(2+). However, after co-transfection with a vtg1 promoter-luciferase construct to the ERα, ERβ1, ERβ2 and GPER expression vectors, decreased luciferase activity was observed in the ERα co-transfection group after treatment with Cd(2+), suggesting that ERα participates in vtg1 transcriptional regulation and is affected by Cd(2+). Differences in the regulation of the mRNA levels of these genes were also observed between different developmental stages and between the livers of male and female zebrafish. PMID:26799766

  20. Estrogen-related receptor β (ERRβ) – renaissance receptor or receptor renaissance?

    PubMed Central

    Divekar, Shailaja D.; Tiek, Deanna M.; Fernandez, Aileen; Riggins, Rebecca B.

    2016-01-01

    Estrogen-related receptors (ERRs) are founding members of the orphan nuclear receptor (ONR) subgroup of the nuclear receptor superfamily. Twenty-seven years of study have yet to identify cognate ligands for the ERRs, though they have firmly placed ERRα and ERRγ at the intersection of cellular metabolism and oncogenesis. The pace of discovery for novel functions of ERRβ, however, has until recently been somewhat slower than that of its family members. ERRβ has also been largely ignored in summaries and perspectives of the ONR literature. Here, we provide an overview of established and emerging knowledge of ERRβ in mouse, man, and other species, highlighting unique aspects of ERRβ biology that set it apart from the other two estrogen-related receptors, with a focus on the impact of alternative splicing on the structure and function of this receptor. PMID:27507929

  1. Estrogen-related receptor β (ERRβ) - renaissance receptor or receptor renaissance?

    PubMed

    Divekar, Shailaja D; Tiek, Deanna M; Fernandez, Aileen; Riggins, Rebecca B

    2016-01-01

    Estrogen-related receptors (ERRs) are founding members of the orphan nuclear receptor (ONR) subgroup of the nuclear receptor superfamily. Twenty-seven years of study have yet to identify cognate ligands for the ERRs, though they have firmly placed ERRα and ERRγ at the intersection of cellular metabolism and oncogenesis. The pace of discovery for novel functions of ERRβ, however, has until recently been somewhat slower than that of its family members. ERRβ has also been largely ignored in summaries and perspectives of the ONR literature. Here, we provide an overview of established and emerging knowledge of ERRβ in mouse, man, and other species, highlighting unique aspects of ERRβ biology that set it apart from the other two estrogen-related receptors, with a focus on the impact of alternative splicing on the structure and function of this receptor. PMID:27507929

  2. Epithelial estrogen receptor 1 intrinsically mediates squamous differentiation in the mouse vagina

    PubMed Central

    Miyagawa, Shinichi; Iguchi, Taisen

    2015-01-01

    Estrogen-mediated actions in female reproductive organs are tightly regulated, mainly through estrogen receptor 1 (ESR1). The mouse vaginal epithelium cyclically exhibits cell proliferation and differentiation in response to estrogen and provides a unique model for analyzing the homeostasis of stratified squamous epithelia. To address the role of ESR1-mediated tissue events during homeostasis, we analyzed mice with a vaginal epithelium-specific knockout of Esr1 driven by keratin 5-Cre (K5-Esr1KO). We show here that loss of epithelial ESR1 in the vagina resulted in aberrant epithelial cell proliferation in the suprabasal cell layers and led to failure of keratinized differentiation. Gene expression analysis showed that several known estrogen target genes, including erbB growth factor ligands, were not induced by estrogen in the K5-Esr1KO mouse vagina. Organ culture experiments revealed that the addition of erbB growth factor ligands, such as amphiregulin, could activate keratinized differentiation in the absence of epithelial ESR1. Thus, epithelial ESR1 integrates estrogen and growth factor signaling to mediate regulation of cell proliferation in squamous differentiation, and our results provide new insights into estrogen-mediated homeostasis in female reproductive organs. PMID:26438838

  3. Estrogen receptor independent neurotoxic mechanism of bisphenol A, an environmental estrogen

    PubMed Central

    Lee, Yoot Mo; Seong, Min Jae; Lee, Jae Woong; Lee, Yong Kyung; Kim, Tae Myoung; Nam, Sang-Yoon; Kim, Dae Joong; Yun, Young Won; Kim, Tae Seong; Han, Soon Young

    2007-01-01

    Bisphenol A (BPA), a ubiquitous environmental contaminant, has been shown to cause developmental toxicity and carcinogenic effects. BPA may have physiological activity through estrogen receptor (ER) -α and -β, which are expressed in the central nervous system. We previously found that exposure of BPA to immature mice resulted in behavioral alternation, suggesting that overexposure of BPA could be neurotoxic. In this study, we further investigated the molecular neurotoxic mechanisms of BPA. BPA increased vulnerability (decrease of cell viability and differentiation, and increase of apoptotic cell death) of undifferentiated PC12 cells and cortical neuronal cells isolated from gestation 18 day rat embryos in a concentration-dependent manner (more than 50 µM). The ER antagonists, ICI 182,780, and tamoxifen, did not block these effects. The cell vulnerability against BPA was not significantly different in the PC12 cells overexpressing ER-α and ER-β compared with PC12 cells expressing vector alone. In addition, there was no difference observed between BPA and 17-β estradiol, a well-known agonist of ER receptor in the induction of neurotoxic responses. Further study of the mechanism showed that BPA significantly activated extracellular signal-regulated kinase (ERK) but inhibited anti-apoptotic nuclear factor kappa B (NF-κB) activation. In addition, ERK-specific inhibitor, PD 98,059, reversed BPA-induced cell death and restored NF-κB activity. This study demonstrated that exposure to BPA can cause neuronal cell death which may eventually be related with behavioral alternation in vivo. However, this neurotoxic effect may not be directly mediated through an ER receptor, as an ERK/NF-κB pathway may be more closely involved in BPA-induced neuronal toxicity. PMID:17322771

  4. Estrogen receptor beta is a novel therapeutic target for photoaging.

    PubMed

    Chang, Ken C N; Wang, Yihe; Oh, Inn Gyung; Jenkins, Susan; Freedman, Leonard P; Thompson, Catherine C; Chung, Jin Ho; Nagpal, Sunil

    2010-05-01

    One of the many harmful factors faced by the skin is solar UV radiation, which damages skin by inducing chronic low-grade inflammation through increased expression of proinflammatory cytokines, metalloproteinases (MMPs) and cyclooxygenase-2 (COX-2). Estrogen receptors (ERs) alpha and beta are ligand-dependent transcription factors that are expressed in skin, and an ERbeta agonist has previously shown efficacy in vivo in models of pain and inflammation. Because ERbeta does not carry the breast and uterine proliferation liabilities of ERalpha, we decided to explore the possibility of using ERbeta as a target for photoaging. We show that ERbeta-selective compounds suppressed the expression of cytokines and MMPs in activated keratinocytes and fibroblast-based in vitro models of photoaging. Furthermore, in activated dermal fibroblasts, ERbeta-selective compounds also inhibited COX-2. These activities of ERbeta ligands in skin cells correlated with the expression levels of ERbeta and showed reversal by treatment with a potent synthetic ER antagonist. Furthermore, the pharmacology of ERbeta-selective compound was observed in wild-type but not in skin cells obtained from ERbeta knockout mice. Finally, we demonstrate that a synthetic ERbeta agonist inhibited UV-induced photodamage and skin wrinkle formation in a murine model of photoaging. Therefore, the potential of an ERbeta ligand to regulate multiple pathways underlying the cause of photoaging suggests ERbeta to be a novel therapeutic target for the prevention and treatment of photoaging. PMID:20110405

  5. Estrogen receptor 1 and 2 mRNA expression and protein localization in the porcine endometrium during the estrous cycle and early pregnancy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Between d 10 and 12 of gestation, the pig embryo undergoes elongation and produces estrogen, which serves as the key molecule for maternal recognition of pregnancy. Around d 15 of gestation, the embryo begins its superficial implantation with the endometrium and a second spike in estrogen occurs fro...

  6. Gene expression profiling in Ishikawa cells: A fingerprint for estrogen active compounds

    SciTech Connect

    Boehme, Kathleen; Simon, Stephanie

    2009-04-01

    Several anthropogenous and naturally occurring substances, referred to as estrogen active compounds (EACs), are able to interfere with hormone and in particular estrogen receptor signaling. EACs can either cause adverse health effects in humans and wildlife populations or have beneficial effects on estrogen-dependent diseases. The aim of this study was to examine global gene expression profiles in estrogen receptor (ER)-proficient Ishikawa plus and ER-deficient Ishikawa minus endometrial cancer cells treated with selected well-known EACs (Diethylstilbestrol, Genistein, Zearalenone, Resveratrol, Bisphenol A and o,p'-DDT). We also investigated the effect of the pure antiestrogen ICI 182,780 (ICI) on the expression patterns caused by these compounds. Transcript levels were quantified 24 h after compound treatment using Illumina BeadChip Arrays. We identified 87 genes with similar expression changes in response to all EAC treatments in Ishikawa plus. ICI lowered the magnitude or reversed the expression of these genes, indicating ER dependent regulation. Apart from estrogenic gene regulation, Bisphenol A, o,p'-DDT, Zearalenone, Genistein and Resveratrol displayed similarities to ICI in their expression patterns, suggesting mixed estrogenic/antiestrogenic properties. In particular, the predominant antiestrogenic expression response of Resveratrol could be clearly distinguished from the other test compounds, indicating a distinct mechanism of action. Divergent gene expression patterns of the phytoestrogens, as well as weaker estrogenic gene expression regulation determined for the anthropogenous chemicals Bisphenol A and o,p'-DDT, warrants a careful assessment of potential detrimental and/or beneficial effects of EACs. The characteristic expression fingerprints and the identified subset of putative marker genes can be used for screening chemicals with an unknown mode of action and for predicting their potential to exert endocrine disrupting effects.

  7. CITED2 modulates estrogen receptor transcriptional activity in breast cancer cells

    SciTech Connect

    Lau, Wen Min; Doucet, Michele; Huang, David; Weber, Kristy L.; Kominsky, Scott L.

    2013-07-26

    Highlights: •The effects of elevated CITED2 on ER function in breast cancer cells are examined. •CITED2 enhances cell growth in the absence of estrogen and presence of tamoxifen. •CITED2 functions as a transcriptional co-activator of ER in breast cancer cells. -- Abstract: Cbp/p300-interacting transactivator with Glu/Asp-rich carboxy-terminal domain 2 (CITED2) is a member of the CITED family of non-DNA binding transcriptional co-activators of the p300/CBP-mediated transcription complex. Previously, we identified CITED2 as being overexpressed in human breast tumors relative to normal mammary epithelium. Upon further investigation within the estrogen receptor (ER)-positive subset of these breast tumor samples, we found that CITED2 mRNA expression was elevated in those associated with poor survival. In light of this observation, we investigated the effect of elevated CITED2 levels on ER function. While ectopic overexpression of CITED2 in three ER-positive breast cancer cell lines (MCF-7, T47D, and CAMA-1) did not alter cell proliferation in complete media, growth was markedly enhanced in the absence of exogenous estrogen. Correspondingly, cells overexpressing CITED2 demonstrated reduced sensitivity to the growth inhibitory effects of the selective estrogen receptor modulator, 4-hydroxytamoxifen. Subsequent studies revealed that basal ER transcriptional activity was elevated in CITED2-overexpressing cells and was further increased upon the addition of estrogen. Similarly, basal and estrogen-induced expression of the ER-regulated genes trefoil factor 1 (TFF1) and progesterone receptor (PGR) was higher in cells overexpressing CITED2. Concordant with this observation, ChIP analysis revealed higher basal levels of CITED2 localized to the TFF-1 and PGR promoters in cells with ectopic overexpression of CITED2, and these levels were elevated further in response to estrogen stimulation. Taken together, these data indicate that CITED2 functions as a transcriptional co

  8. Estrogen Regulation of Anti-Apoptotic Bcl-2 Family Member Mcl-1 Expression in Breast Cancer Cells

    PubMed Central

    Schacter, Jennifer L.; Henson, Elizabeth S.; Gibson, Spencer B.

    2014-01-01

    Estrogen is implicated as an important factor in stimulating breast cancer cell proliferation, and presence of estrogen receptor (ER) is an indication of a good prognosis in breast cancer patients. Mcl-1 is an anti-apoptotic Bcl-2 family member that is often over expressed in breast tumors, correlating with poor survival. In breast cancer, it was been previously shown that epidermal growth factor receptors up-regulate Mcl-1 but the role of estrogen in increasing Mcl-1 expression was unknown. In ERα positive cell lines MCF-7 and ZR-75, estrogen treatment increased Mcl-1 expression at both the protein and mRNA level. In two ERα negative cell lines, SK-BR-3 and MDA-MB-231, estrogen failed to increase in Mcl-1 protein expression. We found that ERα antagonists decreased estrogen mediated Mcl-1 expression at both the protein and mRNA level. Upon knockdown of ERα, Mcl-1 mRNA expression after estrogen treatment was also decreased. We also found that ERα binds to the Mcl-1 promoter at a region upstream of the translation start site containing a half ERE site. Streptavidin-pull down assay showed that both ERα and transcription factor Sp1 bind to this region. These results suggest that estrogen is involved in regulating Mcl-1 expression specifically through a mechanism involving ERα. PMID:24971890

  9. Female Mice Lacking Estrogen Receptor-α in Hypothalamic Proopiomelanocortin (POMC) Neurons Display Enhanced Estrogenic Response on Cortical Bone Mass

    PubMed Central

    Farman, H. H.; Windahl, S. H.; Westberg, L.; Isaksson, H.; Egecioglu, E.; Schele, E.; Ryberg, H.; Jansson, J. O.; Tuukkanen, J.; Koskela, A.; Xie, S. K.; Hahner, L.; Zehr, J.; Clegg, D. J.; Lagerquist, M. K.

    2016-01-01

    Estrogens are important regulators of bone mass and their effects are mainly mediated via estrogen receptor (ER)α. Central ERα exerts an inhibitory role on bone mass. ERα is highly expressed in the arcuate (ARC) and the ventromedial (VMN) nuclei in the hypothalamus. To test whether ERα in proopiomelanocortin (POMC) neurons, located in ARC, is involved in the regulation of bone mass, we used mice lacking ERα expression specifically in POMC neurons (POMC-ERα−/−). Female POMC-ERα−/− and control mice were ovariectomized (OVX) and treated with vehicle or estradiol (0.5 μg/d) for 6 weeks. As expected, estradiol treatment increased the cortical bone thickness in femur, the cortical bone mechanical strength in tibia and the trabecular bone volume fraction in both femur and vertebrae in OVX control mice. Importantly, the estrogenic responses were substantially increased in OVX POMC-ERα−/− mice compared with the estrogenic responses in OVX control mice for cortical bone thickness (+126 ± 34%, P < .01) and mechanical strength (+193 ± 38%, P < .01). To test whether ERα in VMN is involved in the regulation of bone mass, ERα was silenced using an adeno-associated viral vector. Silencing of ERα in hypothalamic VMN resulted in unchanged bone mass. In conclusion, mice lacking ERα in POMC neurons display enhanced estrogenic response on cortical bone mass and mechanical strength. We propose that the balance between inhibitory effects of central ERα activity in hypothalamic POMC neurons in ARC and stimulatory peripheral ERα-mediated effects in bone determines cortical bone mass in female mice. PMID:27254004

  10. Female Mice Lacking Estrogen Receptor-α in Hypothalamic Proopiomelanocortin (POMC) Neurons Display Enhanced Estrogenic Response on Cortical Bone Mass.

    PubMed

    Farman, H H; Windahl, S H; Westberg, L; Isaksson, H; Egecioglu, E; Schele, E; Ryberg, H; Jansson, J O; Tuukkanen, J; Koskela, A; Xie, S K; Hahner, L; Zehr, J; Clegg, D J; Lagerquist, M K; Ohlsson, C

    2016-08-01

    Estrogens are important regulators of bone mass and their effects are mainly mediated via estrogen receptor (ER)α. Central ERα exerts an inhibitory role on bone mass. ERα is highly expressed in the arcuate (ARC) and the ventromedial (VMN) nuclei in the hypothalamus. To test whether ERα in proopiomelanocortin (POMC) neurons, located in ARC, is involved in the regulation of bone mass, we used mice lacking ERα expression specifically in POMC neurons (POMC-ERα(-/-)). Female POMC-ERα(-/-) and control mice were ovariectomized (OVX) and treated with vehicle or estradiol (0.5 μg/d) for 6 weeks. As expected, estradiol treatment increased the cortical bone thickness in femur, the cortical bone mechanical strength in tibia and the trabecular bone volume fraction in both femur and vertebrae in OVX control mice. Importantly, the estrogenic responses were substantially increased in OVX POMC-ERα(-/-) mice compared with the estrogenic responses in OVX control mice for cortical bone thickness (+126 ± 34%, P < .01) and mechanical strength (+193 ± 38%, P < .01). To test whether ERα in VMN is involved in the regulation of bone mass, ERα was silenced using an adeno-associated viral vector. Silencing of ERα in hypothalamic VMN resulted in unchanged bone mass. In conclusion, mice lacking ERα in POMC neurons display enhanced estrogenic response on cortical bone mass and mechanical strength. We propose that the balance between inhibitory effects of central ERα activity in hypothalamic POMC neurons in ARC and stimulatory peripheral ERα-mediated effects in bone determines cortical bone mass in female mice. PMID:27254004

  11. Analysis of informativeness of immunohistochemical and flow cytometric methods for estrogen receptor α assessment.

    PubMed

    Bogush, T A; Dudko, E A; Rodionova, M V; Bogush, E A; Kirsanov, V J; Rodionov, V V; Vorotnikov, I K

    2015-01-01

    Informative capacity analysis of immunohistochemistry (IHC) and flow cytometry (FCM) in the assessment of estrogen receptor α (ERα) expression in breast cancer tissue was performed. Similar frequencies of expression were shown by both methods: 27% of ERα-negative and 73% ERα-positive cases. However, IHC evaluation detected low levels in only 20% of ERα-positive cases, whereas low levels of ERα detected by FCM were 2 times more often (48%). Moreover, FCM revealed positive expression (23-60%) in 33% of IHC ERα-negative cases. Among IHC ER-positive cases, zero ERα expression was detected by FCM in 12.5%. The approaches to minimize errors in routine clinical determination of the estrogen receptor status were proposed. PMID:26728725

  12. Defining a minimal estrogen receptor DNA binding domain.

    PubMed Central

    Mader, S; Chambon, P; White, J H

    1993-01-01

    The estrogen receptor (ER) is a transcriptional regulator which binds to cognate palindromic DNA sequences known as estrogen response elements (EREs). A 66 amino acid core region which contains two zinc fingers and is highly conserved among the nuclear receptors is essential for site specific DNA recognition. However, it remains unclear how many flanking amino acids in addition to the zinc finger core are required for DNA binding. Here, we have characterized the minimal DNA binding region of the human ER by analysing the DNA binding properties of a series of deletion mutants expressed in bacteria. We find that the 66 amino acid zinc finger core of the DBD fails to bind DNA, and that the C-terminal end of the minimal ER DBD required for binding to perfectly palindromic EREs corresponds to the limit of 100% amino acid homology between the chicken and human receptors, which represents the boundary between regions C and D in the ER. Moreover, amino acids of region D up to 30 residues C-terminal to the zinc fingers greatly stabilize DNA binding by the DBD to perfectly palindromic EREs and are absolutely required for formation of gel retardation complexes by the DBD on certain physiological imperfectly palindromic EREs. These results indicate that in addition to the zinc finger core, amino acids C-terminal to the core in regions C and D play a key role in DNA binding by the ER, particularly to imperfectly palindromic response elements. The ER DBD expressed in E. coli binds as a dimer to ERE palindromes in a highly cooperative manner and forms only low levels of monomeric protein-DNA complexes on either palindromic or half-palindromic response elements. Conversion of ER amino acids 222 to 226, which lie within region C, to the corresponding residues of the human RAR alpha abolishes formation of dimeric protein-DNA complexes. Conversely, replacement of the same region of RAR alpha with ER residues 222 to 226 creates a derivative that, unlike the RAR alpha DBD, binds

  13. Genomic agonism and phenotypic antagonism between estrogen and progesterone receptors in breast cancer.

    PubMed

    Singhal, Hari; Greene, Marianne E; Tarulli, Gerard; Zarnke, Allison L; Bourgo, Ryan J; Laine, Muriel; Chang, Ya-Fang; Ma, Shihong; Dembo, Anna G; Raj, Ganesh V; Hickey, Theresa E; Tilley, Wayne D; Greene, Geoffrey L

    2016-06-01

    The functional role of progesterone receptor (PR) and its impact on estrogen signaling in breast cancer remain controversial. In primary ER(+) (estrogen receptor-positive)/PR(+) human tumors, we report that PR reprograms estrogen signaling as a genomic agonist and a phenotypic antagonist. In isolation, estrogen and progestin act as genomic agonists by regulating the expression of common target genes in similar directions, but at different levels. Similarly, in isolation, progestin is also a weak phenotypic agonist of estrogen action. However, in the presence of both hormones, progestin behaves as a phenotypic estrogen antagonist. PR remodels nucleosomes to noncompetitively redirect ER genomic binding to distal enhancers enriched for BRCA1 binding motifs and sites that link PR and ER/PR complexes. When both hormones are present, progestin modulates estrogen action, such that responsive transcriptomes, cellular processes, and ER/PR recruitment to genomic sites correlate with those observed with PR alone, but not ER alone. Despite this overall correlation, the transcriptome patterns modulated by dual treatment are sufficiently different from individual treatments, such that antagonism of oncogenic processes is both predicted and observed. Combination therapies using the selective PR modulator/antagonist (SPRM) CDB4124 in combination with tamoxifen elicited 70% cytotoxic tumor regression of T47D tumor xenografts, whereas individual therapies inhibited tumor growth without net regression. Our findings demonstrate that PR redirects ER chromatin binding to antagonize estrogen signaling and that SPRMs can potentiate responses to antiestrogens, suggesting that cotargeting of ER and PR in ER(+)/PR(+) breast cancers should be explored. PMID:27386569

  14. Binding of type II nuclear receptors and estrogen receptor to full and half-site estrogen response elements in vitro.

    PubMed Central

    Klinge, C M; Bodenner, D L; Desai, D; Niles, R M; Traish, A M

    1997-01-01

    The mechanism by which retinoids, thyroid hormone (T3) and estrogens modulate the growth of breast cancer cells is unclear. Since nuclear type II nuclear receptors, including retinoic acid receptor (RAR), retinoid X receptor (RXR) and thyroid hormone receptor (TR), bind direct repeats (DR) of the estrogen response elements (ERE) half-site (5'-AGGTCA-3'), we examined the ability of estrogen receptor (ER) versus type II nuclear receptors, i.e. RARalpha, beta and gamma, RXRbeta, TRalpha and TRbeta, to bind various EREs in vitro . ER bound a consensus ERE, containing a perfectly palindromic 17 bp inverted repeat (IR), as a homodimer. In contrast, ER did not bind to a single ERE half-site. Likewise, ER did not bind two tandem (38 bp apart) half-sites, but low ER binding was detected to three tandem copies of the same half-site. RARalpha,beta or gamma bound both ERE and half-site constructs as a homodimer. RXRbeta did not bind full or half-site EREs, nor did RXRbeta enhance RARalpha binding to a full ERE. However, RARalpha and RXRbeta bound a half-site ERE cooperatively forming a dimeric complex. The RARalpha-RXRbeta heterodimer bound the Xenopus vitellogenin B1 estrogen responsive unit, with two non-consensus EREs, with higher affinity than one or two copies of the full or half-site ERE. Both TRalpha and TRbeta bound the full and the half-site ERE as monomers and homodimers and cooperatively as heterodimers with RXRbeta. We suggest that the cellular concentrations of nuclear receptors and their ligands, and the nature of the ERE or half-site sequence and those of its flanking sequences determine the occupation of EREs in estrogen-regulated genes in vivo . PMID:9115356

  15. Synthesis of 3-alkyl naphthalenes as novel estrogen receptor ligands

    SciTech Connect

    Fang, Jing; Akwabi-Ameyaw, Adwoa; Britton, Jonathan E.; Katamreddy, Subba R.; Navas III, Frank; Miller, Aaron B.; Williams, Shawn P.; Gray, David W.; Orband-Miller, Lisa A.; Shearin, Jean; Heyer, Dennis

    2009-06-24

    A series of estrogen receptor ligands based on a 3-alkyl naphthalene scaffold was synthesized using an intramolecular enolate-alkyne cycloaromatization as the key step. Several of these compounds bearing a C6-OH group were shown to be high affinity ligands. All compounds had similar ER{alpha} and ER{beta} binding affinity ranging from micromolar to low nanomolar.

  16. RELATIVE BINDING AFFINITY OF ALKYLPHENOLS TO RAINBOW TROUT ESTROGEN RECEPTOR

    EPA Science Inventory

    RELATIVE BINDING AFFINITY OF ALKYLPHENOLS TO RAINBOW TROUT ESTROGEN RECEPTOR. T R Henry1, J S Denny2 and P K Schmieder2. USEPA, ORD, NHEERL, 1Experimental Toxicology Division and 2Mid-Continent Ecology Division, Duluth, MN, USA.
    The USEPA has been mandated to screen industria...

  17. Identification of Estrogen Response Element in Aquaporin-3 Gene that Mediates Estrogen-induced Cell Migration and Invasion in Estrogen Receptor-positive Breast Cancer

    PubMed Central

    Huang, Yi-Ting; Zhou, Jun; Shi, Shuai; Xu, Hai-Yan; Qu, Fan; Zhang, Dan; Chen, Yi-Ding; Yang, Jing; Huang, He-Feng; Sheng, Jian-Zhong

    2015-01-01

    Accumulating evidence suggests that aquaporins (AQPs) may facilitate tumor development. The molecular pathways connecting the pathological functions of AQPs are unclear and need to be better defined. This study aimed to investigate whether AQP3, one of the AQPs expressed highly in breast cancer, had any clinical implication in estrogen-receptor (ER) positive breast cancer, and explore the regulatory mechanisms of AQP3 in estrogen-related breast cancer progression. Here we show that AQP3 is an important enforcer of migration and invasion in breast cancer. We, for the first time, reported that ER-positive breast cancer tissues obtained from premenopausal patients had higher AQP3 expression when compared to those obtained from postmenopausal patients. Estrogen directly upregulates AQP3 by activating ERE in the promoter of the AQP3 gene. The upregulation of AQP3 can influence the expression of molecules related to epithelial-mesenchymal transition and the reorganization of actin-cytoskeleton, resulting in enhancement of cell migration and invasion in ER-positive breast cancer cells. PMID:26219409

  18. Ritonavir binds to and downregulates estrogen receptors: Molecular mechanism of promoting early atherosclerosis

    SciTech Connect

    Xiang, Jin; Wang, Ying; Su, Ke; Liu, Min; Hu, Peng-Chao; Ma, Tian; Li, Jia-Xi; Wei, Lei; Zheng, Zhongliang; Yang, Fang

    2014-10-01

    Estrogenic actions are closely related to cardiovascular disease. Ritonavir (RTV), a human immunodeficiency virus (HIV) protease inhibitor, induces atherosclerosis in an estrogen-related manner. However, how RTV induce pathological phenotypes through estrogen pathway remains unclear. In this study, we found that RTV increases thickness of coronary artery walls of Sprague Dawley rats and plasma free fatty acids (FFA) levels. In addition, RTV could induce foam cell formation, downregulate both estrogen receptor α (ERα) and ERβ expression, upregulate G protein-coupled estrogen receptor (GPER) expression, and all of them could be partially blocked by 17β-estradiol (E2), suggesting RTV acts as an antagonist for E2. Computational modeling shows a similar interaction with ERα between RTV and 2-aryl indoles, which are highly subtype-selective ligands for ERα. We also found that RTV directly bound to ERα and selectively inhibited the nuclear localization of ERα, and residue Leu536 in the hydrophobic core of ligand binding domain (LBD) was essential for the interaction with RTV. In addition, RTV did not change the secondary structure of ERα-LBD like E2, which explained how ERα lost the capacity of nuclear translocation under the treatment of RTV. All of the evidences suggest that ritonavir acts as an antagonist for 17β-estradiol in regulating α subtype estrogen receptor function and early events of atherosclerosis. - Graphical abstract: RTV directly binds to ERα and Leu536 in the hydrophobic core of ligand binding domain is essential for the interaction. - Highlights: • RTV increases the thickness of rat coronary artery wall and foam cell formation. • RTV downregulates the expression of ERα and ERβ. • RTV inhibits ERα promoter activity. • RTV directly binds to ERα and the key amino acid is Leu536. • RTV inhibits the nuclear translocation of ERα and GPER.

  19. DIFFERENCES IN SENSITIVITY BUT NOT SELECTIVITY OF XENOESTROGEN BINDING TO ALLIGATOR VERSUS HUMAN ESTROGEN RECEPTOR ALPHA

    PubMed Central

    Rider, Cynthia V.; Hartig, Phillip C.; Cardon, Mary C.; Lambright, Christy R.; Bobseine, Kathy L.; Guillette, Louis J.; Gray, L. Earl; Wilson, Vickie S.

    2010-01-01

    Reproductive abnormalities in alligators exposed to contaminants in Lake Apopka, Florida, USA represent a clear example of endocrine disruption in wildlife. Several of these contaminants that are not able to bind to mammalian estrogen receptors (such as atrazine and cyanazine) have previously been reported to bind to the alligator estrogen receptor from oviductal tissue. Binding of known Lake Apopka contaminants to full length estrogen receptors alpha from human (hERα) and alligator (aERα) was assessed in a side-by-side comparison within the same assay system. Baculovirus-expressed recombinant hERα and aERα were used in a competitive binding assay. Atrazine and cyanazine were not able to bind to either receptor. p,p′-Dicofol was able to bind to aERα with a concentration inhibiting 50% of binding (IC50) of 4 μM, while only partially displacing 17β-estradiol (E2) from hERα and yielding a projected IC50 of 45 μM. Chemicals that only partially displaced E2 from either receptor, including some dichlorodiphenyltrichloroethane (DDT) metabolites and trans-nonachlor, appeared to have higher affinity for aERα than hERα. p,p′-Dicofol-mediated transcriptional activation through aERα and hERα was assessed to further explore the preferential binding of p,p′-dicofol to aERα over hERα. p,p′-Dicofol was able to stimulate transcriptional activation in a similar manner with both receptors. However, the in vitro results obtained with p,p′-dicofol were not reflected in an in vivo mammalian model, where Kelthane™ (mixed o,p′-and p,p′-dicofol isomers) did not elicit estrogenic effects. In conclusion, although there was no evidence of exclusively species-specific estrogen receptor binders, some xenoestrogens, especially p,p′-dicofol, had a higher affinity for aERα than for hERα. PMID:20821664

  20. Computational estimation of rainbow trout estrogen receptor binding affinities for environmental estrogens

    SciTech Connect

    Shyu, Conrad; Cavileer, Timothy D.; Nagler, James J.; Ytreberg, F. Marty

    2011-02-01

    Environmental estrogens have been the subject of intense research due to their documented detrimental effects on the health of fish and wildlife and their potential to negatively impact humans. A complete understanding of how these compounds affect health is complicated because environmental estrogens are a structurally heterogeneous group of compounds. In this work, computational molecular dynamics simulations were utilized to predict the binding affinity of different compounds using rainbow trout (Oncorhynchus mykiss) estrogen receptors (ERs) as a model. Specifically, this study presents a comparison of the binding affinity of the natural ligand estradiol-17{beta} to the four rainbow trout ER isoforms with that of three known environmental estrogens 17{alpha}-ethinylestradiol, bisphenol A, and raloxifene. Two additional compounds, atrazine and testosterone, that are known to be very weak or non-binders to ERs were tested. The binding affinity of these compounds to the human ER{alpha} subtype is also included for comparison. The results of this study suggest that, when compared to estradiol-17{beta}, bisphenol A binds less strongly to all four receptors, 17{alpha}-ethinylestradiol binds more strongly, and raloxifene has a high affinity for the {alpha} subtype only. The results also show that atrazine and testosterone are weak or non-binders to the ERs. All of the results are in excellent qualitative agreement with the known in vivo estrogenicity of these compounds in the rainbow trout and other fishes. Computational estimation of binding affinities could be a valuable tool for predicting the impact of environmental estrogens in fish and other animals.

  1. Estrogen receptor is not primarily responsible for altered responsiveness of ovalbumin mRNA induction in the oviduct from genetically selected high- and low-albumen chicken lines.

    PubMed

    Muramatsu, T; Hiramatsu, H; Park, H M; Okumura, J; Kawashima, M; Miyoshi, S

    1997-04-01

    The role of estrogen receptor on ovalbumin mRNA induction by steroid hormones was investigated in primary cultures of oviduct cells from estrogen-stimulated immature chicks of genetically selected high- and low-albumen egg laying lines (H- and L-lines). In experiment 1, the extent of ovalbumin mRNA induction and changes in estrogen and progesterone receptors were compared between the oviduct cells from H- and L-lines with or without steroid hormones in the culture medium. In experiment 2, the effect of estrogen receptor gene transfection on the induction of ovalbumin mRNA was studied in the oviduct cells from the L-line chicks. The results showed a close correlation of the changes in ovalbumin mRNA with the numbers of nuclear and total estrogen receptors in the oviduct cells but not with the numbers of nuclear and total progesterone receptors. Estrogen receptor gene transfection induced ovalbumin mRNA to a moderate extent in the absence of the steroid hormones. To our surprise, however, estrogen receptor gene transfection apparently suppressed the ovalbumin mRNA responsiveness to estrogen to a considerable extent. It was concluded, therefore, that the extent of estrogen receptor expression might not be primarily responsible for the differences in responsiveness to steroid hormones of oviduct cells from genetically selected H- and L-line chickens. PMID:9149392

  2. Progesterone receptor modulates estrogen receptor-α action in breast cancer

    PubMed Central

    Mohammed, Hisham; Russell, I. Alasdair; Stark, Rory; Rueda, Oscar M.; Hickey, Theresa E.; Tarulli, Gerard A.; Serandour, Aurelien A. A.; Birrell, Stephen N.; Bruna, Alejandra; Saadi, Amel; Menon, Suraj; Hadfield, James; Pugh, Michelle; Raj, Ganesh V.; Brown, Gordon D.; D’Santos, Clive; Robinson, Jessica L. L.; Silva, Grace; Launchbury, Rosalind; Perou, Charles M.; Stingl, John; Caldas, Carlos; Tilley, Wayne D.; Carroll, Jason S.

    2015-01-01

    Summary Progesterone receptor (PR) expression is employed as a biomarker of estrogen receptor-α (ERα) function and breast cancer prognosis. We now show that PR is not merely an ERα-induced gene target, but is also an ERα-associated protein that modulates its behaviour. In the presence of agonist ligands, PR associates with ERα to direct ERα chromatin binding events within breast cancer cells, resulting in a unique gene expression programme that is associated with good clinical outcome. Progesterone inhibited estrogen-mediated growth of ERα+ cell line xenografts and primary ERα+ breast tumour explants and had increased anti-proliferative effects when coupled with an ERα antagonist. Copy number loss of PgR is a common feature in ERα+ breast cancers, explaining lower PR levels in a subset of cases. Our findings indicate that PR functions as a molecular rheostat to control ERα chromatin binding and transcriptional activity, which has important implications for prognosis and therapeutic interventions. PMID:26153859

  3. Tristetraprolin Represses Estrogen Receptor α Transactivation in Breast Cancer Cells*

    PubMed Central

    Barrios-García, Tonatiuh; Tecalco-Cruz, Angeles; Gómez-Romero, Vania; Reyes-Carmona, Sandra; Meneses-Morales, Iván; León-Del-Río, Alfonso

    2014-01-01

    Estrogen receptor α (ERα) mediates the effects of 17β-estradiol (E2) in normal mammary gland, and it is a key participant in breast cancer tumor development. ERα transactivation activity is mediated by the synergistic interaction of two domains designated AF1 and AF2. The function of AF2 is to recruit coactivator and corepressor proteins that allow ERα to oscillate between the roles of transcriptional activator and repressor. In contrast, the mechanism responsible for AF-1 transcriptional activity is not completely understood. In this study, we identified tristetraproline (TTP) as a novel ERα-associated protein. TTP expression in MCF7 cells repressed ERα transactivation and reduced MCF7 cell proliferation and the ability of the cells to form tumors in a mouse model. We show that TTP transcriptional activity is mediated through its recruitment to the promoter region of ERα target genes and its interaction with histone deacetylases, in particular with HDAC1. TTP expression attenuates the coactivating activity of SRC-1, suggesting that exchange between TTP and other coactivators may play an important role in fine-tuning ERα transactivation. These results indicate that TTP acts as a bona fide ERα corepressor and suggest that this protein may be a contributing factor in the development of E2-dependent tumors in breast cancer. PMID:24737323

  4. Estrogen Receptor α Regulates Dlx3-Mediated Osteoblast Differentiation

    PubMed Central

    Lee, Sung Ho; Oh, Kyo-Nyeo; Han, Younho; Choi, You Hee; Lee, Kwang-Youl

    2016-01-01

    Estrogen receptor α (ER-α), which is involved in bone metabolism and breast cancer, has been shown to have transcriptional targets. Dlx3 is essential for the skeletal development and plays an important role in osteoblast differentiation. Various osteogenic stimulators and transcription factors can induce the protein expression of Dlx3. However, the regulatory function of ER-α in the Dlx3 mediated osteogenic process remains unknown. Therefore, we investigated the regulation of Dlx3 and found that ER-α is a positive regulator of Dlx3 transcription in BMP2-induced osteoblast differentiation. We also found that ER-α interacts with Dlx3 and increases its transcriptional activity and DNA binding affinity. Furthermore, we demonstrated that the regulation of Dlx3 activity by ER-α is independent of the ligand (estradiol) binding domain. These results indicate that Dlx3 is a novel target of ER-α, and that ER-α regulates the osteoblast differentiation through modulation of Dlx3 expression and/or interaction with Dlx3. PMID:26674964

  5. Developmental expression and estrogen responses of endocrine genes in juvenile yellow perch (Perca flavescens)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The present study examines the expression of growth-regulating genes (gh, prl, smtl and igf1b), the estrogen receptors (esr1 and esr2a) and aromatase (cyp19a1a) in developing yellow perch. To gain an initial understanding into the endocrine control of growth preceding and involved with sexual size d...

  6. Δ9-Tetrahydrocannabinol Disrupts Estrogen-Signaling through Up-Regulation of Estrogen Receptor β (ERβ)

    PubMed Central

    Takeda, Shuso; Yoshida, Kazutaka; Nishimura, Hajime; Harada, Mari; Okajima, Shunsuke; Miyoshi, Hiroko; Okamoto, Yoshiko; Amamoto, Toshiaki; Watanabe, Kazuhito; Omiecinski, Curtis J.; Aramaki, Hironori

    2014-01-01

    Δ9-Tetrahydrocannabinol (Δ9-THC) has been reported as possessing antiestrogenic activity, although the mechanisms underlying these effects are poorly delineated. In this study, we used the estrogen receptor α (ERα)-positive human breast cancer cell line, MCF-7, as an experimental model and showed that Δ9-THC exposures markedly suppresses 17β-estradiol (E2)- induced MCF-7 cell proliferation. We demonstrate that these effects result from Δ9-THC’s ability to inhibit E2-liganded ERα activation. Mechanistically, the data obtained from biochemical analyses revealed that (i) Δ9-THC up-regulates ERβ, a repressor of ERα, inhibiting the expression of E2/ERα-regulated genes that promote cell growth and that (ii) Δ9-THC induction of ERβ modulates E2/ERα signaling in the absence of direct interaction with the E2 ligand binding site. Therefore, the data presented support the concept that Δ9-THC’s antiestrogenic activities are mediated by the ERβ disruption of E2/ERα signaling. PMID:23718638

  7. Ginsenoside Rg3 increases nitric oxide production via increases in phosphorylation and expression of endothelial nitric oxide synthase: Essential roles of estrogen receptor-dependent PI3-kinase and AMP-activated protein kinase

    SciTech Connect

    Hien, Tran Thi; Kim, Nak Doo; Pokharel, Yuba Raj; Oh, Seok Jeong; Lee, Moo Yeol; Kang, Keon Wook

    2010-08-01

    We previously showed that ginsenosides increase nitric oxide (NO) production in vascular endothelium and that ginsenoside Rg3 (Rg3) is the most active one among ginseng saponins. However, the mechanism for Rg3-mediated nitric oxide production is still uncertain. In this study, we determined whether Rg3 affects phosphorylation and expression of endothelial nitric oxide synthase (eNOS) in ECV 304 human endothelial cells. Rg3 increased both the phosphorylation and the expression of eNOS in a concentration-dependent manner and a maximal effect was found at 10 {mu}g/ml of Rg3. The enzyme activities of phosphatidylinositol 3-kinase (PI3-kinase), c-Jun N-terminal kinase (JNK), and p38 kinase were enhanced as were estrogen receptor (ER)- and glucocorticoid receptor (GR)-dependent reporter gene transcriptions in Rg3-treated endothelial cells. Rg3-induced eNOS phosphorylation required the ER-mediated PI3-kinase/Akt pathway. Moreover, Rg3 activates AMP-activated protein kinase (AMPK) through up-regulation of CaM kinase II and Rg3-stimulated eNOS phosphorylation was reversed by AMPK inhibition. The present results provide a mechanism for Rg3-stimulated endothelial NO production.

  8. Activity and intracellular location of estrogen receptors α and β in human bronchial epithelial cells

    PubMed Central

    Ivanova, Margarita M.; Mazhawidza, Williard; Dougherty, Susan M.; Minna, John D.; Klinge, Carolyn M.

    2009-01-01

    Gender differences in lung disease and cancer are well-established. We reported estrogenic transcriptional responses in lung adenocarcinoma cells from females but not males despite similar estrogen receptor (ER) expression. Here we tested the hypothesis that normal human bronchial epithelial cells (HBECs) show gender-independent estrogenic responses. We report that a small sample of HBECs express ~twice as much ERβ as ERα.ERα and ERβ were located in the cytoplasm, nucleus, and mitochondria. In contrast to lung adenocarcinoma cells, estradiol (E2) induced estrogen response element (ERE)-mediated luciferase reporter activity in transiently transfected HBECs regardless of donor gender. Overexpression of ERα-VP16 increased ERE-mediated transcriptional activity in all HBECs. E2 increased and 4-hydroxytamoxifen and ICI 182,780 inhibited HBEC proliferation and cyclin D1 expression in a cell line-specific manner. In conclusion, the response of HBECs to ER ligands is gender-independent suggesting that estrogenic sensitivity may be acquired during lung carcinogenesis. PMID:19433257

  9. Estrogen receptor-α signaling in osteoblast progenitors stimulates cortical bone accrual

    PubMed Central

    Almeida, Maria; Iyer, Srividhya; Martin-Millan, Marta; Bartell, Shoshana M.; Han, Li; Ambrogini, Elena; Onal, Melda; Xiong, Jinhu; Weinstein, Robert S.; Jilka, Robert L.; O’Brien, Charles A.; Manolagas, Stavros C.

    2012-01-01

    The detection of estrogen receptor-α (ERα) in osteoblasts and osteoclasts over 20 years ago suggested that direct effects of estrogens on both of these cell types are responsible for their beneficial effects on the skeleton, but the role of ERα in osteoblast lineage cells has remained elusive. In addition, estrogen activation of ERα in osteoclasts can only account for the protective effect of estrogens on the cancellous, but not the cortical, bone compartment that represents 80% of the entire skeleton. Here, we deleted ERα at different stages of differentiation in murine osteoblast lineage cells. We found that ERα in osteoblast progenitors expressing Osterix1 (Osx1) potentiates Wnt/β-catenin signaling, thereby increasing proliferation and differentiation of periosteal cells. Further, this signaling pathway was required for optimal cortical bone accrual at the periosteum in mice. Notably, this function did not require estrogens. The osteoblast progenitor ERα mediated a protective effect of estrogens against endocortical, but not cancellous, bone resorption. ERα in mature osteoblasts or osteocytes did not influence cancellous or cortical bone mass. Hence, the ERα in both osteoblast progenitors and osteoclasts functions to optimize bone mass but at distinct bone compartments and in response to different cues. PMID:23221342

  10. Pomegranate extract demonstrate a selective estrogen receptor modulator profile in human tumor cell lines and in vivo models of estrogen deprivation.

    PubMed

    Sreeja, Sreekumar; Santhosh Kumar, Thankayyan R; Lakshmi, Baddireddi S; Sreeja, Sreeharshan

    2012-07-01

    Selective estrogen receptor modulators (SERMs) are estrogen receptor (ER) ligands exhibiting tissue-specific agonistic or antagonistic biocharacter and are used in the hormonal therapy for estrogen-dependent breast cancers. Pomegranate fruit has been shown to exert antiproliferative effects on human breast cancer cells in vitro. In this study, we investigated the tissue-specific estrogenic/antiestrogenic activity of methanol extract of pericarp of pomegranate (PME). PME was evaluated for antiproliferative activity at 20-320 μg/ml on human breast (MCF-7, MDA MB-231) endometrial (HEC-1A), cervical (SiHa, HeLa), ovarian (SKOV3) carcinoma and normal breast fibroblast (MCF-10A) cells. Competitive radioactive binding studies were carried out to ascertain whether PME interacts with ER. The reporter gene assay measured the estrogenic/antiestrogenic activity of PME in MCF-7 and MDA MB-231 cells transiently transfected with plasmids coding estrogen response elements with a reporter gene (pG5-ERE-luc) and wild-type ERα (hEG0-ER). PME inhibited the binding of [³H] estradiol to ER and suppressed the growth and proliferation of ER-positive breast cancer cells. PME binds ER and down-regulated the transcription of estrogen-responsive reporter gene transfected into breast cancer cells. The expressions of selected estrogen-responsive genes were down-regulated by PME. Unlike 17β-estradiol [1 mg/kg body weight (BW)] and tamoxifen (10 mg/kg BW), PME (50 and 100 mg/kg BW) did not increase the uterine weight and proliferation in ovariectomized mice and its cardioprotective effects were comparable to that of 17β-estradiol. In conclusion, our findings suggest that PME displays a SERM profile and may have the potential for prevention of estrogen-dependent breast cancers with beneficial effects in other hormone-dependent tissues. PMID:21839626

  11. DNA Repair, Redox Regulation and Modulation of Estrogen Receptor Alpha Mediated Transcription

    ERIC Educational Resources Information Center

    Curtis-Ducey, Carol Dianne

    2009-01-01

    Interaction of estrogen receptor [alpha] (ER[alpha]) with 17[beta]-estradiol (E[subscript 2]) facilitates binding of the receptor to estrogen response elements (EREs) in target genes, which in turn leads to recruitment of coregulatory proteins. To better understand how estrogen-responsive genes are regulated, our laboratory identified a number of…

  12. Binding and transactivation of the largemouth bass estrogen receptors by model compounds

    EPA Science Inventory

    Environmental estrogens (EEs) are chemicals in the environment that can elicit adverse effects on estrogen (E2) signaling by binding with the estrogen receptors (ERs). In largemouth bass (LMB), the physiological actions of E2 are primarily mediated via three receptors (ERα, ERßb ...

  13. Activation of transgenic estrogen receptor-beta by selected phytoestrogens in a stably transduced rat serotonergic cell line.

    PubMed

    Amer, Dena A M; Kretzschmar, Georg; Müller, Nicole; Stanke, Nicole; Lindemann, Dirk; Vollmer, Günter

    2010-06-01

    Many flavonoids, a major group of phenolic plant-derived secondary metabolites, are known to possess estrogen-like bioactivities. However, little is known about their estrogenic properties in the central nervous system due to the lack of suitable cellular models expressing sufficient amounts of functional estrogen receptor beta (ERbeta). To overcome this deficit, we have created a cellular model, which is serotonergic in origin, to study properties of estrogenic substances by stably transducing RN46A-B14 cells derived from raphe nuclei region of the rat brain with a lentiviral vector encoding a human ERbeta. We clearly showed that the transgenic human ERbeta is a spontaneously expressed and a functional receptor. We have further assessed the estrogenicity of three different isoflavones and four different naringenin-type flavanones in this cell line utilizing a luciferase reporter gene assay. Genistein (GEN), Daidzein (DAI), Equol (EQ), Naringenin (NAR) and 8-prenylnaringenin (8-PN) showed strong estrogenic activity in a concentration-dependent manner as compared to 7-(O-prenyl)naringenin-4'-acetate (7-O-PN) which was only slightly estrogenic and 6-(1,1-dimethylallyl)naringenin (6-DMAN) that neither showed estrogenic nor anti-estrogenic activity in our model. All observed effects could be antagonized by the anti-estrogen fulvestrant. Moreover, co-treatment of cells with 17beta-estradiol (E2) and either GEN or DAI showed a slight additive effect as compared to EQ. On the other hand, 8-PN in addition to 7-O-PN, but not NAR and 6-DMAN, were able to slightly antagonize the responses triggered by E2. Our newly established cellular model may prove to be a useful tool in explicating basic physiological properties of ERbeta in the brain and may help unravel molecular and cellular mechanisms involved in serotonergic mood regulation by estrogen or potential plant-derived secondary metabolites. PMID:20433925

  14. Selective estrogen receptor-beta (SERM-beta) compounds modulate raphe nuclei tryptophan hydroxylase-1 (TPH-1) mRNA expression and cause antidepressant-like effects in the forced swim test.

    PubMed

    Clark, J A; Alves, S; Gundlah, C; Rocha, B; Birzin, E T; Cai, S-J; Flick, R; Hayes, E; Ho, K; Warrier, S; Pai, L; Yudkovitz, J; Fleischer, R; Colwell, L; Li, S; Wilkinson, H; Schaeffer, J; Wilkening, R; Mattingly, E; Hammond, M; Rohrer, S P

    2012-11-01

    Estrogen acts through two molecularly distinct receptors termed estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) which bind estradiol with similar affinities and mediate the effects of estrogen throughout the body. ERα plays a major role in reproductive physiology and behavior, and mediates classic estrogen signaling in such tissues as the uterus, mammary gland, and skeleton. ERβ, however, modulates estrogen signaling in the ovary, the immune system, prostate, gastrointestinal tract, and hypothalamus, and there is some evidence that ERβ can regulate ERα activity. Moreover, ERβ knockout studies and receptor distribution analyses in the CNS suggest that this receptor may play a role in the modulation of mood and cognition. In recent years several ERβ-specific compounds (selective estrogen receptor beta modulators; SERM-beta) have become available, and research suggests potential utility of these compounds in menopausal symptom relief, breast cancer prevention, diseases that have an inflammatory component, osteoporosis, cardiovascular disease, and inflammatory bowel disease, as well as modulation of mood, and anxiety. Here we demonstrate an antidepressant-like effect obtained using two SERM-beta compounds, SERM-beta1 and SERM-beta2. These compounds exhibit full agonist activity at ERβ in a cell based estrogen response element (ERE) transactivation assay. SERM-beta1 and 2 are non-proliferative with respect to breast as determined using the MCF-7 breast cancer cell-based assay and non-proliferative in the uterus as determined by assessing the effects of SERM-beta compounds on immature rat uterine weight and murine uterine weight. In vivo SERM-beta1 and 2 are brain penetrant and display dose dependent efficacy in the murine dorsal raphe assays for induction of tryptophan hydroxylase mRNA and progesterone receptor protein. These compounds show activity in the murine forced swim test and promote hippocampal neurogenesis acutely in rats. Taken

  15. Zinc finger protein 131 inhibits estrogen signaling by suppressing estrogen receptor {alpha} homo-dimerization

    SciTech Connect

    Oh, Yohan; Chung, Kwang Chul

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer ZNF131 directly interacts with ER{alpha}. Black-Right-Pointing-Pointer The binding affinity of ZNF131 to ER{alpha} increases upon E2 stimulation. Black-Right-Pointing-Pointer ZNF131 inhibits ER{alpha}-mediated trans-activation by suppressing its homo-dimerization. Black-Right-Pointing-Pointer ZNF131 inhibits ER{alpha}-dimerization and E2-induced breast cancer cell proliferation. Black-Right-Pointing-Pointer ZNF131 inhibits estrogen signaling by acting as an ER{alpha}-co-repressor. -- Abstract: Steroid hormone estrogen elicits various physiological functions, many of which are mediated through two structurally and functionally distinct estrogen receptors, ER{alpha} and ER{beta}. The functional role of zinc finger protein 131 (ZNF131) is poorly understood, but it is assumed to possess transcriptional regulation activity due to the presence of a DNA binding motif. A few recent reports, including ours, revealed that ZNF131 acts as a negative regulator of ER{alpha} and that SUMO modification potentiates the negative effect of ZNF131 on estrogen signaling. However, its molecular mechanism for ER{alpha} inhibition has not been elucidated in detail. Here, we demonstrate that ZNF131 directly interacts with ER{alpha}, which consequently inhibits ER{alpha}-mediated trans-activation by suppressing its homo-dimerization. Moreover, we show that the C-terminal region of ZNF131 containing the SUMOylation site is necessary for its inhibition of estrogen signaling. Taken together, these data suggest that ZNF131 inhibits estrogen signaling by acting as an ER{alpha}-co-repressor.

  16. Changes over time in the impact of gene-expression profiles on the administration of adjuvant chemotherapy in estrogen receptor positive early stage breast cancer patients: A nationwide study.

    PubMed

    Kuijer, A; Drukker, C A; Elias, S G; Smorenburg, C H; Th Rutgers, E J; Siesling, S; van Dalen, Th

    2016-08-15

    Ten years ago gene-expression profiles were introduced to aid adjuvant chemotherapy decision making in breast cancer. Since then subsequent national guidelines gradually expanded the indication area for adjuvant chemotherapy. In this nation-wide study the evolution of the proportion of patients with estrogen-receptor positive (ER+) tumors receiving adjuvant chemotherapy in relation to gene-expression profile use in patient groups that became newly eligible for chemotherapy according to national guideline changes over time is assessed. Data on all surgically treated early breast cancer patients diagnosed between 2004-2006 and 2012-2014 were obtained from the Netherlands Cancer Registry. ER+/Her2- patients with tumor-characteristics making them eligible for gene-expression testing in both cohorts and a discordant chemotherapy recommendation over time (2004 guideline not recommending and 2012 guideline recommending chemotherapy) were identified. We identified 3,864 patients eligible for gene-expression profile use during both periods. Gene-expression profiles were deployed in 5% and 35% of the patients in the respective periods. In both periods the majority of patients was assigned to a low genomic risk-profile (67% and 69%, respectively) and high adherence rates to the test result were observed (86% and 91%, respectively). Without deploying a gene-expression profile 8% and 52% (p <0.001) of the respective cohorts received chemotherapy while 21% and 28% of these patients received chemotherapy when a gene-expression profile was used (p 0.191). In conclusion, in ER+/Her2- early stage breast cancer patients gene-expression profile use was associated with a consistent proportion of patients receiving chemotherapy despite an adjusted guideline-based recommendation to administer chemotherapy. PMID:27062369

  17. A meta-analysis to evaluate the cellular processes regulated by the interactome of endogenous and over-expressed estrogen receptor alpha

    PubMed Central

    Simões, Joana; Amado, Francisco M.

    2015-01-01

    The nature of the proteins complexes that regulate ERα subcellular localization and activity is still an open question in breast cancer biology. Identification of such complexes will help understand development of endocrine resistance in ER+ breast cancer. Mass spectrometry (MS) has allowed comprehensive analysis of the ERα interactome. We have compared six published works analyzing the ERα interactome of MCF-7 and HeLa cells in order to identify a shared or different pathway-related fingerprint. Overall, 806 ERα interacting proteins were identified. The cellular processes were differentially represented according to the ERα purification methodology, indicating that the methodologies used are complementary. While in MCF-7 cells, the interactome of endogenous and over-expressed ERα essentially represents the same biological processes and cellular components, the proteins identified were not over-lapping; thus, suggesting that the biological response may differ as the regulatory/participating proteins in these complexes are different. Interestingly, biological processes uniquely associated to ERα over-expressed in HeLa cell line included L-serine biosynthetic process, cellular amino acid biosynthetic process and cell redox homeostasis. In summary, all the approaches analyzed in this meta-analysis are valid and complementary; in particular, for those cases where the processes occur at low frequency with normal ERα levels, and can be identified when the receptor is over-expressed. However special effort should be put into validating these findings in cells expressing physiological ERα levels. PMID:26097882

  18. Genomic agonism and phenotypic antagonism between estrogen and progesterone receptors in breast cancer

    PubMed Central

    Singhal, Hari; Greene, Marianne E.; Tarulli, Gerard; Zarnke, Allison L.; Bourgo, Ryan J.; Laine, Muriel; Chang, Ya-Fang; Ma, Shihong; Dembo, Anna G.; Raj, Ganesh V.; Hickey, Theresa E.; Tilley, Wayne D.; Greene, Geoffrey L.

    2016-01-01

    The functional role of progesterone receptor (PR) and its impact on estrogen signaling in breast cancer remain controversial. In primary ER+ (estrogen receptor–positive)/PR+ human tumors, we report that PR reprograms estrogen signaling as a genomic agonist and a phenotypic antagonist. In isolation, estrogen and progestin act as genomic agonists by regulating the expression of common target genes in similar directions, but at different levels. Similarly, in isolation, progestin is also a weak phenotypic agonist of estrogen action. However, in the presence of both hormones, progestin behaves as a phenotypic estrogen antagonist. PR remodels nucleosomes to noncompetitively redirect ER genomic binding to distal enhancers enriched for BRCA1 binding motifs and sites that link PR and ER/PR complexes. When both hormones are present, progestin modulates estrogen action, such that responsive transcriptomes, cellular processes, and ER/PR recruitment to genomic sites correlate with those observed with PR alone, but not ER alone. Despite this overall correlation, the transcriptome patterns modulated by dual treatment are sufficiently different from individual treatments, such that antagonism of oncogenic processes is both predicted and observed. Combination therapies using the selective PR modulator/antagonist (SPRM) CDB4124 in combination with tamoxifen elicited 70% cytotoxic tumor regression of T47D tumor xenografts, whereas individual therapies inhibited tumor growth without net regression. Our findings demonstrate that PR redirects ER chromatin binding to antagonize estrogen signaling and that SPRMs can potentiate responses to antiestrogens, suggesting that cotargeting of ER and PR in ER+/PR+ breast cancers should be explored. PMID:27386569

  19. Occurrence and cellular distribution of estrogen receptors ERα and ERβ in the testis and epididymal region of roosters.

    PubMed

    Oliveira, André G; Dornas, Rubem A P; Mahecha, Germán A B; Oliveira, Cleida A

    2011-02-01

    Estrogen signaling is required for the maintenance of male reproductive function and is mediated by the estrogen receptors ERα and ERβ. These receptors are widely distributed in mammalian reproductive tissues, but information is limited in non-mammalian species including birds. The aim of this study was to investigate the occurrence and cellular distribution of ERα and ERβ in the testis and epididymal region of roosters. The results showed for the first time that ERβ was the predominant receptor detected in the testis, being expressed in the somatic and some germ cells. Within the epididymal region, ERβ was strongly expressed in all segments, whereas the most intense reaction for ERα was found in the distal efferent ductules. The differential expression of ERα and ERβ within the rooster testis and epididymal region suggests that these organs may be a target for different actions of estrogen. PMID:21118691

  20. Function of G-Protein-Coupled Estrogen Receptor-1 in Reproductive System Tumors

    PubMed Central

    Qian, Hongyan; Xuan, Jingxiu; Liu, Yuan; Shi, Guixiu

    2016-01-01

    The G-protein-coupled estrogen receptor-1 (GPER-1), also known as GPR30, is a novel estrogen receptor mediating estrogen receptor signaling in multiple cell types. The progress of estrogen-related cancer is promoted by GPER-1 activation through mitogen-activated protein kinases (MAPK), phosphoinositide 3-kinase (PI3K), and phospholipase C (PLC) signaling pathways. However, this promoting effect of GPER-1 is nonclassic estrogen receptor (ER) dependent manner. In addition, clinical evidences revealed that GPER-1 is associated with estrogen resistance in estrogen-related cancer patients. These give a hint that GPER-1 may be a novel therapeutic target for the estrogen-related cancers. However, preclinical studies also found that GPER-1 activation of its special agonist G-1 inhibits cancer cell proliferation. This review aims to summarize the characteristics and complex functions of GPER-1 in cancers. PMID:27314054

  1. COMPARISON OF FATHEAD MINNOW AND HUMAN ESTROGEN RECEPTOR BINDING TO ENDOCRINE DISRUPTING COMPOUNDS

    EPA Science Inventory

    Environmental estrogens have the potential to disrupt endocrine function in a myriad of species. However, in vitro assays designed to detect and characterize endocrine disrupting chemicals (EDCs) typically utilize mammalian estrogen receptors. Our overall objective is to charac...

  2. INDUCTION OF MAMMARY GLAND DEVELOPMENT IN ESTROGEN RECEPTOR-ALPHA KNOCKOUT MICE

    EPA Science Inventory

    Mammary glands from the estrogen receptor knockout ( ERKO) mouse do not undergo ductal morphogenesis or alveolar development. Disrupted Er signaling may result in reduced estrogen-responsive gene products in the mammary gland or reduced mammotropic hormones that contribute t...

  3. Pharmacodynamic imaging guides dosing of a selective estrogen receptor degrader

    PubMed Central

    Heidari, Pedram; Deng, Francis; Esfahani, Shadi A.; Leece, Alicia K.; Shoup, Timothy M.; Vasdev, Neil; Mahmood, Umar

    2015-01-01

    Purpose Estrogen receptor (ER) targeting is key in management of receptor-positive breast cancer (BrCa). Currently, there are no methods to optimize anti-ER therapy dosing. This study assesses the utility of 16α-18F-fluoroestradiol (18F-FES) PET for fulvestrant dose optimization in a preclinical ER+ BrCa model. Experimental Design In vitro, 18F-FES retention was compared to ERα protein expression (ELISA) and ESR1 mRNA transcription (qPCR) in MCF7 cells (ER+) after treatment with different fulvestrant doses. MCF7 xenografts were grown in ovariectomized nude mice and assigned to vehicle, low- (0.05mg), medium- (0.5mg) or high-dose (5mg) fulvestrant treatment groups (5–7 per group). Two and three days after fulvestrant treatment, PET/CT was performed using 18F-FES and 18F-FDG, respectively. ER expression was assessed by immunohistochemistry, ELISA, and qPCR on xenografts. Tumor proliferation was assessed using Ki-67 immunohistochemistry. Results In vitro, we observed a parallel graded reduction in 18F-FES uptake and ER expression with increased fulvestrant doses, despite enhancement of ER mRNA transcription. In xenografts, ER expression significantly decreased with increased fulvestrant dose, despite similar mRNA expression and Ki-67 staining among the treatment groups. We observed a significant dose-dependent reduction of 18F-FES PET mean standardized uptake value (SUVmean) with fulvestrant treatment, but no significant difference among the treatment groups in 18F-FDG PET SUVmean.. Conclusion We demonstrated that 18F-FES uptake mirrors the dose-dependent changes in functional ER expression with fulvestrant resulting in ER degradation and/or blockade; these precede changes in tumor metabolism and proliferation. Quantitative 18F-FES PET may be useful for tracking early efficacy of ER blockade/degradation and guiding ER-targeted therapy dosing in BrCa patients. PMID:25609068

  4. Estrogen-responsive genes encoding egg yolk proteins vitellogenin and apolipoprotein II in chicken are differentially regulated by selective estrogen receptor modulators.

    PubMed

    Ratna, Warren N; Bhatt, Vrushank D; Chaudhary, Kawshik; Bin Ariff, Ammar; Bavadekar, Supriya A; Ratna, Haran N

    2016-02-01

    In a hen, large quantities of the egg yolk proteins, apolipoprotein II (apo-II) and vitellogenin (VG), are expressed in the liver and transported to the oviduct during egg production. Estrogenic stimulation of the hepatic expression of apo-II and VG is due to both transcriptional increase and mRNA stabilization. The nucleolytic degradation of apo-II messenger RNA (mRNA) is prevented by estrogen-regulated mRNA-stabilizing factor (E-RmRNASF). Gene-specific effects of a select panel of selective estrogen receptor modulators (SERMs) on the hepatic expression of the estrogen-responsive genes encoding apo-II, VG, and E-RmRNASF in the chicken liver were investigated. In the present study, 6-week-old roosters were treated with the vehicle, estrogen, the SERMs genistein, resveratrol, tamoxifen, pterostilbene, raloxifene, catechin, and clomiphene or a combination of estrogen and a 200-fold excess of each of the SERMs. Results from mRNA stabilization studies conducted to investigate the stimulation of expression of E-RmRNASF in the liver by these agents showed that the expression of E-RmRNASF in the liver was stimulated by estrogen and the SERMs genistein, resveratrol, tamoxifen, pterostilbene, and catechin but not by the vehicle, clomiphene or raloxifene. The expression of apo-II and VG from the aforementioned treatments was determined by Northern blot analysis, RNase protection assays, and Western blot analysis. The transcription and protein expression of both apo-II and VG genes were seen in response to treatment with estrogen but not with the SERMs or combinations of estrogen and each of the SERMs. The SERMs that stimulated the expression of E-RmRNASF antagonized the stimulation of the expression of both apo-II and VG by estrogen, demonstrating a gene-specific, selective regulation of the aforementioned genes in the chicken liver by the SERMs. The above panel of SERMs may likely have adverse effects on egg production. PMID:26452509

  5. Requirement for Estrogen Receptor Alpha in a Mouse Model for Human Papillomavirus-Associated Cervical Cancer

    PubMed Central

    Chung, Sang-Hyuk; Wiedmeyer, Kerri; Shai, Anny; Korach, Kenneth S.; Lambert, Paul F.

    2008-01-01

    The majority of human cervical cancers are associated with the high-risk human papillomaviruses (HPVs), which encode the potent E6 and E7 oncogenes. Upon prolonged treatment with physiological levels of exogenous estrogen, K14E7 transgenic mice expressing HPV-16 E7 oncoprotein in their squamous epithelia succumb to uterine cervical cancer. Furthermore, prolonged withdrawal of exogenous estrogen results in complete or partial regression of tumors in this mouse model. In the current study we investigated whether estrogen receptor alpha (ERα) is required for the development of cervical cancer in K14E7 transgenic mice. We demonstrate that exogenous estrogen fails to promote either dysplasia or cervical cancer in K14E7/ERα−/− mice despite the continued presence of the presumed cervical cancer precursor cell type, reserve cells, and evidence for E7 expression therein. We also observed that cervical cancers in our mouse models are strictly associated with atypical squamous metaplasia (ASM), which is believed to be the precursor for cervical cancer in women. Consistently, E7 and exogenous estrogen failed to promote ASM in the absence of ERα. We conclude that ERα plays a crucial role at an early stage of cervical carcinogenesis in this mouse model. PMID:19047174

  6. Immunohistochemical detection of estrogen receptors in fish scales.

    PubMed

    Pinto, P I S; Estêvão, M D; Redruello, B; Socorro, S M; Canário, A V M; Power, D M

    2009-01-01

    Calcium mobilization from internal stores, such as scales, induced by 17beta-estradiol during sexual maturation in salmonids is well documented. This calcium mobilization from scales is proposed to be mediated by the estrogen receptor (ER). However, the ER subtypes involved and signaling mechanisms responsible for this effect remain to be fully characterized. In the present study, we have localized ERalpha, ERbetaa and ERbetab proteins in juvenile and adult sea bream (Sparus auratus) and Mozambique tilapia (Oreochromis mossambicus) scales by immunohistochemistry with sea bream ER subtype specific antibodies. The three ERs were detected in isolated or small groups of round cells, in the basal layer of the scales of both juvenile and adult fish and the localization and signal intensity varied with the species and age of the animals. The ERs may be co-localized in cells of the scale posterior region that expressed tartrate-resistant acid phosphatase (TRAP), a marker for osteoclasts. These results suggest that the calcium mobilizing action of 17beta-estradiol on fish scales is via its direct action on ERs localized in osteoclasts. PMID:18977356

  7. The CYP17A1 inhibitor abiraterone exhibits estrogen receptor agonist activity in breast cancer.

    PubMed

    Capper, Cameron P; Larios, José M; Sikora, Matthew J; Johnson, Michael D; Rae, James M

    2016-05-01

    Cytochrome P450 17A1 (CYP17A1) is the requisite enzyme for synthesis of sex steroids, including estrogens and androgens. As such, inhibition of CYP17A1 is a target for inhibiting the growth of hormone-dependent cancers including prostate and breast cancer. Abiraterone, is a first in class potent and selective CYP17A1 inhibitor that has been approved for the treatment of castration-resistant prostate cancer. Given that, androgens are the precursors for estrogen production, it has been proposed that abiraterone could be an effective form of treatment for estrogen receptor (ER)-positive breast cancer, though its utility in this context has yet to be established. Abiraterone has a core steroid-like chemical structure, and so we hypothesized that it may bind to nuclear steroid receptors including ER and have estrogenic activity. We tested this hypothesis by investigating abiraterone's ability to directly modulate ER signaling in breast cancer cell line models. We show that abiraterone directly activates ER, induces ER-target gene expression, and elicits estrogen-response-element reporter activity in the ER-positive cell lines MCF-7 and T47D. Abiraterone also induced cell proliferation by ~2.5-fold over vehicle in both MCF-7 and T47D cells. Importantly, abiraterone-induced cell proliferation and ER-activity was blocked by the selective estrogen receptor downregulator (SERD) fulvestrant, confirming that abiraterone directly acts at the ER. These data suggest that abiraterone should be combined with other ER antagonists when used for the clinical management of ER-positive breast cancer. PMID:27083183

  8. Changes in estrogen receptor signaling alters the timekeeping system in male mice.

    PubMed

    Blattner, Margaret S; Mahoney, Megan M

    2015-11-01

    Circadian rhythms are modulated by steroid hormones; however, the mechanisms of this action are not fully understood, particularly in males. In females estradiol regulates activity level, pattern of expression, and free running period (tau). We tested the hypothesis that activity level and distribution in male mice includes both classical and "non-classical" actions of estrogens at the estrogen receptor subtype 1 (ESR1). We used transgenic mice with mutations in their estrogen response pathways: ESR1 knock-out (ERKO) mice lack the ability to respond to estrogens via ESR1. "Non-classical" estrogen receptor knock-in (NERKI) mice have an inserted ESR1 receptor with a mutation in the estrogen-response-element binding domain, allowing activation via non-genomic and second messenger pathways. Gonadectomized male NERKI, ERKO, and wildtype (WT) littermates were given oil, or low or high dose estradiol and daily activity parameters were quantified. Estradiol shortened the ratio of activity in the light relative to dark (LD ratio), shortened tau, advanced the time of activity onset, and altered responsiveness to light cues administered in the late subjective night, suggesting modulation by an ESR1-independent mechanism. Estradiol treatment in NERKI but not WT males altered the timing of activity onset, LD ratio, and the behavioral response to light cues. These results may represent disruptions in the balance of genomic/nongenomic or ESR1/ESR2 signaling pathways. We also found a significant genotype effect on total activity, LD ratio, tau, and activity duration. These data provide new information about the role of ESR1-dependent and independent signaling pathways on the timekeeping system in male mice. PMID:26241171

  9. Nonsteroidal Bivalent Estrogen Ligands - An Application of the Bivalent Concept to the Estrogen Receptor

    PubMed Central

    Shan, Min; Carlson, Kathryn E.; Bujotzek, Alexander; Wellner, Anja; Gust, Ronald; Weber, Marcus; Katzenellenbogen, John A.; Haag, Rainer

    2013-01-01

    The estrogen receptor (ER) is a hormone-regulated transcription factor that binds, as a dimer, to estrogens and to specific DNA sequences. To explore at a fundamental level the geometric and topological features of bivalent-ligand binding to the ER dimer, dimeric ER crystal structures were used to rationally design nonsteroidal bivalent estrogen ligands. Guided by this structure-based ligand design, we prepared two series of bivalent ligands (agonists and antagonists) tethered by flexible spacers of varying lengths (7–47Å) and evaluated their ER-binding affinities for the two ER subtypes and their biological activities in cell lines. Bivalent ligands based on the agonist diethylstilbestrol (DES) proved to be poor candidates, but bivalent ligands based on the antagonist hydroxytamoxifen (OHT) were well suited for intensive study. Binding affinities of the OHT-based bivalent ligands were related to spacer length in a distinctive fashion, reaching two maximum values at 14 and 29Å in both ER subtypes. These results demonstrate that the bivalent concept can operate in determining ER-ligand binding affinity and suggest that two distinct modes operate for the binding of bivalent estrogen ligands to the ER dimers, an intermolecular as well as an intramolecular mode. Our insights, particularly the possibility of intramolecular bivalent binding on a single ER monomer, may provide an alternative strategy to prepare more selective and active ER antagonists for endocrine therapy of breast cancer. PMID:23312071

  10. Estrogen receptors alpha mediates postischemic inflammation in chronically estrogen-deprived mice.

    PubMed

    Cordeau, Pierre; Lalancette-Hébert, Mélanie; Weng, Yuan Cheng; Kriz, Jasna

    2016-04-01

    Estrogens are known to exert neuroprotective and immuneomodulatory effects after stroke. However, at present, little is known about the role of estrogens and its receptors in postischemic inflammation after menopause. Here, we provide important in vivo evidence of a distinct shift in microglial phenotypes in the model of postmenopause brain. Using a model-system for live imaging of microglial activation in the context of chronic estrogen- and ERα-deficiency associated with aging, we observed a marked deregulation of the TLR2 signals and/or microglial activation in ovariectomized and/or ERα knockout mice. Further analysis revealed a 5.7-fold increase in IL-6, a 4.7-fold increase in phospho-Stat3 levels suggesting an overactivation of JAK/STAT3 pathway and significantly larger infarction in ERα knockouts chronically deprived of estrogen. Taken together, our results suggest that in the experimental model of menopause and/or aging, ERα mediates innate immune responses and/or microglial activation, and ischemia-induced production of IL-6. Based on our results, we propose that the loss of functional ERα may lead to deregulation of postischemic inflammatory responses and increased vulnerability to ischemic injury in aging female brains. PMID:26973103

  11. Hormone- and DNA-binding mechanisms of the recombinant human estrogen receptor.

    PubMed

    Obourn, J D; Koszewski, N J; Notides, A C

    1993-06-22

    We have investigated the hormone- and DNA-binding mechanisms of the wild-type human estrogen receptor (hER) overproduced in insect cells using a baculovirus expression system. The recombinant hER was indistinguishable in size (67 kDa) and immunogenically from the native human estrogen receptor in MCF-7 breast carcinoma cells. The recombinant hER was purified to 70-80% homogeneity with a two-step procedure that included ammonium sulfate precipitation and oligonucleotide affinity chromatography using a unique Teflon affinity matrix. The recombinant hER bound estradiol with a positively cooperative mechanism. At hER concentrations in excess of 13 nM the Hill coefficient reached a maximal value of 1.6, whereas, at lower hER concentrations, the Hill coefficient approached 1.0, suggesting that the hER was dissociated to the monomeric species and site-site interactions were diminished. The hER specifically bound an estrogen responsive element (ERE) from chicken vitellogenin II gene as measured by the gel mobility assay, ethylation, and thymine interference footprinting. Specific interference patterns suggest a two-fold symmetry of the hER binding to the ERE with each monomer of the hER bound in the major groove of the DNA. These data indicate that the recombinant hER is valuable to define the biochemical and structural properties of the native estrogen receptor. PMID:8512933

  12. Specific mutations in the estrogen receptor change the properties of antiestrogens to full agonists.

    PubMed

    Mahfoudi, A; Roulet, E; Dauvois, S; Parker, M G; Wahli, W

    1995-05-01

    The estrogen receptor (ER) stimulates transcription of target genes by means of its two transcriptional activation domains, AF-1 in the N-terminal part of the receptor and AF-2 in its ligand-binding domain. AF-2 activity is dependent upon a putative amphipathic alpha-helix between residues 538 and 552 in the mouse ER. Point mutagenesis of conserved hydrophobic residues within this region reduces estrogen-dependent transcriptional activation without affecting hormone and DNA binding significantly. Here we show that these mutations dramatically alter the pharmacology of estrogen antagonists. Both tamoxifen and ICI 164,384 behave as strong agonists in HeLa cells expressing the ER mutants. In contrast to the wild-type ER, the mutant receptors maintain nuclear localization and DNA-binding activity after ICI 164,384 treatment. Structural alterations in AF-2 caused by gene mutations such as those described herein or by estrogen-independent signaling pathways may account for the insensitivity of some breast cancers to tamoxifen treatment. PMID:7753783

  13. Rapid Signaling Actions of Environmental Estrogens in Developing Granule Cell Neurons Are Mediated by Estrogen Receptor β

    PubMed Central

    Le, Hoa H.; Belcher, Scott M.

    2010-01-01

    Estrogenic endocrine disrupting chemicals (EDCs) constitute a diverse group of man-made chemicals and natural compounds derived from plants and microbial metabolism. Estrogen-like actions are mediated via the nuclear hormone receptor activity of estrogen receptor (ER)α and ERβ and rapid regulation of intracellular signaling cascades. Previous study defined cerebellar granule cell neurons as estrogen responsive and that granule cell precursor viability was developmentally sensitive to estrogens. In this study experiments using Western blot analysis and pharmacological approaches have characterized the receptor and signaling modes of action of selective and nonselective estrogen ligands in developing cerebellar granule cells. Estrogen treatments were found to briefly increase ERK1/2-phosphorylation and then cause prolonged depression of ERK1/2 activity. The sensitivity of granule cell precursors to estrogen-induced cell death was found to require the integrated activation of membrane and intracellular ER signaling pathways. The sensitivity of granule cells to selective and nonselective ER agonists and a variety of estrogenic and nonestrogenic EDCs was also examined. The ERβ selective agonist DPN, but not the ERα selective agonist 4,4′,4′-(4-propyl-[1H]-pyrazole-1,3,5-triyl) trisphenol or other ERα-specific ligands, stimulated cell death. Only EDCs with selective or nonselective ERβ activities like daidzein, equol, diethylstilbestrol, and bisphenol A were observed to induce E2-like neurotoxicity supporting the conclusion that estrogen sensitivity in granule cells is mediated via ERβ. The presented results also demonstrate the utility of estrogen sensitive developing granule cells as an in vitro assay for elucidating rapid estrogen-signaling mechanisms and to detect EDCs that act at ERβ to rapidly regulate intracellular signaling. PMID:20926581

  14. Estrogen protects against amyloid-β toxicity by estrogen receptor α-mediated inhibition of Daxx translocation.

    PubMed

    Mateos, Laura; Persson, Torbjörn; Katoozi, Shirin; Kathozi, Shirin; Gil-Bea, Francisco Javier; Cedazo-Minguez, Angel

    2012-01-11

    Estrogen was shown to promote neuronal survival against several neurotoxic insults including β-amyloid (Aβ). The proposed mechanism includes the activation of the mitogen activated protein kinase/extracellular signal-regulated kinase (Mapk/Erk), phosphatidylinositol 3-kinase/Akt pathways and the upregulation of antiapoptotic proteins. On the other hand, Aβ neurotoxicity depends on the activation of apoptosis signal-regulating kinase 1 (Ask1), and both Ask1 activity and Aβ toxicity are inhibited by thioredoxin-1 (Trx1). Here, we explored the possibility that estrogen could protect cells against Aβ(1-42) toxicity by inhibiting the Ask1 cascade or by modulating Trx1. Cytosolic translocation of death-associated protein Daxx was used as indicator of Ask1 activity. Using human SH-SY5Y neuroblastoma cells, 17β-estradiol (E2) and specific agonists for estrogen receptor (ER) α or β we demonstrated that nM concentrations of E2 protected against Aβ(1-42) by a mechanism depending upon ERα stimulation, Akt activation and Ask1 inhibition. Moreover, this protection would occur independently of ERβ and the induction of Trx1 expression. Our results emphasize the importance of Ask1 cascade in Aβ toxicity, and of ERα and Ask1 as targets for developing new neuroprotective drugs. PMID:22119000

  15. Urethral Dysfunction in Female Mice with Estrogen Receptor β Deficiency

    PubMed Central

    Chen, Yung-Hsiang; Chen, Chao-Jung; Yeh, Shuyuan; Lin, Yu-Ning; Wu, Yang-Chang; Hsieh, Wen-Tsong; Wu, Bor-Tsang; Ma, Wen-Lung; Chen, Wen-Chi; Chang, Chawnshang; Chen, Huey-Yi

    2014-01-01

    Estrogen has various regulatory functions in the growth, development, and differentiation of the female urogenital system. This study investigated the roles of ERβ in stress urinary incontinence (SUI). Wild-type (ERβ+/+) and knockout (ERβ−/−) female mice were generated (aged 6–8 weeks, n = 6) and urethral function and protein expression were measured. Leak point pressures (LPP) and maximum urethral closure pressure (MUCP) were assessed in mice under urethane anesthesia. After the measurements, the urethras were removed for proteomic analysis using label-free quantitative proteomics by nano-liquid chromatography–mass spectrometry (LC-MS/MS) analysis. The interaction between these proteins was further analysed using MetaCore. Lastly, Western blot was used to confirm the candidate proteins. Compared with the ERβ+/+ group, the LPP and MUCP values of the ERβ−/− group were significantly decreased. Additionally, we identified 85 differentially expressed proteins in the urethra of ERβ−/− female mice; 57 proteins were up-regulated and 28 were down-regulated. The majority of the ERβ knockout-modified proteins were involved in cell-matrix adhesion, metabolism, immune response, signal transduction, nuclear receptor translational regelation, and muscle contraction and development. Western blot confirmed the up-regulation of myosin and collagen in urethra. By contrast, elastin was down-regulated in the ERβ−/− mice. This study is the first study to estimate protein expression changes in urethras from ERβ−/− female mice. These changes could be related to the molecular mechanism of ERβ in SUI. PMID:25275480

  16. Perilipin, a critical regulator of fat storage and breakdown, is a target gene of estrogen receptor-related receptor {alpha}

    SciTech Connect

    Akter, Mst. Hasina; Yamaguchi, Tomohiro; Hirose, Fumiko; Osumi, Takashi

    2008-04-11

    Perilipin is a protein localized on lipid droplet surfaces in adipocytes and steroidogenic cells, playing a central role in regulated lipolysis. Expression of the perilipin gene is markedly induced during adipogenesis. We found that transcription from the perilipin gene promoter is activated by an orphan nuclear receptor, estrogen receptor-related receptor (ERR){alpha}. A response element to this receptor was identified in the promoter region by a gene reporter assay, the electrophoretic-gel mobility-shift assay and the chromatin immunoprecipitation assay. Peroxisome proliferator-activated receptor {gamma} coactivator (PGC)-1{alpha} enhanced, whereas small heterodimer partner (SHP) repressed, the transactivating function of ERR{alpha} on the promoter. Thus, the perilipin gene expression is regulated by a transcriptional network controlling energy metabolism, substantiating the functional importance of perilipin in the maintenance of body energy balance.

  17. Gene expression responses in male fathead minnows exposed to binary mixtures of an estrogen and antiestrogen

    PubMed Central

    Garcia-Reyero, Natàlia; Kroll, Kevin J; Liu, Li; Orlando, Edward F; Watanabe, Karen H; Sepúlveda, María S; Villeneuve, Daniel L; Perkins, Edward J; Ankley, Gerald T; Denslow, Nancy D

    2009-01-01

    Background Aquatic organisms are continuously exposed to complex mixtures of chemicals, many of which can interfere with their endocrine system, resulting in impaired reproduction, development or survival, among others. In order to analyze the effects and mechanisms of action of estrogen/anti-estrogen mixtures, we exposed male fathead minnows (Pimephales promelas) for 48 hours via the water to 2, 5, 10, and 50 ng 17α-ethinylestradiol (EE2)/L, 100 ng ZM 189,154/L (a potent antiestrogen known to block activity of estrogen receptors) or mixtures of 5 or 50 ng EE2/L with 100 ng ZM 189,154/L. We analyzed gene expression changes in the gonad, as well as hormone and vitellogenin plasma levels. Results Steroidogenesis was down-regulated by EE2 as reflected by the reduced plasma levels of testosterone in the exposed fish and down-regulation of genes in the steroidogenic pathway. Microarray analysis of testis of fathead minnows treated with 5 ng EE2/L or with the mixture of 5 ng EE2/L and 100 ng ZM 189,154/L indicated that some of the genes whose expression was changed by EE2 were blocked by ZM 189,154, while others were either not blocked or enhanced by the mixture, generating two distinct expression patterns. Gene ontology and pathway analysis programs were used to determine categories of genes for each expression pattern. Conclusion Our results suggest that response to estrogens occurs via multiple mechanisms, including canonical binding to soluble estrogen receptors, membrane estrogen receptors, and other mechanisms that are not blocked by pure antiestrogens. PMID:19594897

  18. Aryl hydrocarbon receptor-independent activation of estrogen receptor-dependent transcription by 3-methycholanthrene

    SciTech Connect

    Shipley, Jonathan M.; Waxman, David J. . E-mail: djw@bu.edu

    2006-06-01

    Aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that stimulates transcription directed by xenobiotic response elements upstream of target genes. Recently, AhR ligands were reported to induce formation of an AhR-estrogen receptor (ER) complex, which can bind to estrogen response elements (EREs) and stimulate transcription of ER target genes. Presently, we investigate the effect of the AhR ligands 3-methylcholanthrene (3MC), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 3,3',4,4',5-pentachlorobiphenyl (BZ126) on ERE-regulated luciferase reporter activity and endogenous ER target gene expression. In MCF-7 human breast cancer cells, 3MC induced transcription of ER reporter genes containing native promoter sequences of the ER-responsive genes complement 3 and pS2 and heterologous promoters regulated by isolated EREs. Dose-response studies revealed that the concentration of 3MC required to half-maximally activate transcription (EC{sub 5}) was >100-fold higher for an ER reporter (27-57 {mu}M) than for an AhR reporter (86-250 nM) in both MCF-7 cells and in human endometrial cancer Ishikawa cells. 3MC also stimulated expression of the endogenous ER target genes amphiregulin, cathepsin D and progesterone receptor, albeit to a much lower extent than was achieved following stimulation with 17{beta}-estradiol. In Ishikawa cells, 3MC, but not BZ126 or TCDD, stimulated ER{alpha}-dependent reporter activity but did not induce expression of endogenous ER target genes. Finally, studies carried out in the AhR-positive rat hepatoma cell line 5L and the AhR-deficient variant BP8 demonstrated that ER reporter activity could be induced by 3MC in a manner that was independent of AhR and thus distinct from the AhR-ER 'hijacking' mechanism described recently. 3MC may thus elicit estrogenic activity by multiple mechanisms.

  19. Effects of Pubertal Exposure to Dietary Soy on Estrogen Receptor Activity in the Breast of Cynomolgus Macaques.

    PubMed

    Dewi, Fitriya N; Wood, Charles E; Willson, Cynthia J; Register, Thomas C; Lees, Cynthia J; Howard, Timothy D; Huang, Zhiqing; Murphy, Susan K; Tooze, Janet A; Chou, Jeff W; Miller, Lance D; Cline, J Mark

    2016-05-01

    Endogenous estrogens influence mammary gland development during puberty and breast cancer risk during adulthood. Early-life exposure to dietary or environmental estrogens may alter estrogen-mediated processes. Soy foods contain phytoestrogenic isoflavones (IF), which have mixed estrogen agonist/antagonist properties. Here, we evaluated mammary gland responses over time in pubertal female cynomolgus macaques fed diets containing either casein/lactalbumin (n = 12) or soy protein containing a human-equivalent dose of 120 mg IF/day (n = 17) for approximately 4.5 years spanning menarche. We assessed estrogen receptor (ER) expression and activity, promoter methylation of ERs and their downstream targets, and markers of estrogen metabolism. Expression of ERα and classical ERα response genes (TFF1, PGR, and GREB1) decreased with maturity, independent of diet. A significant inverse correlation was observed between TFF1 mRNA and methylation of CpG sites within the TFF1 promoter. Soy effects included lower ERβ expression before menarche and lower mRNA for ERα and GREB1 after menarche. Expression of GATA-3, an epithelial differentiation marker that regulates ERα-mediated transcription, was elevated before menarche and decreased after menarche in soy-fed animals. Soy did not significantly alter expression of other ER activity markers, estrogen-metabolizing enzymes, or promoter methylation for ERs or ER-regulated genes. Our results demonstrate greater ER expression and activity during the pubertal transition, supporting the idea that this life stage is a critical window for phenotypic modulation by estrogenic compounds. Pubertal soy exposure decreases mammary ERα expression after menarche and exerts subtle effects on receptor activity and mammary gland differentiation. Cancer Prev Res; 9(5); 385-95. ©2016 AACR. PMID:27006379

  20. Biomarker Genes for Detecting Estrogenic Activity of Endocrine Disruptors via Estrogen Receptors

    PubMed Central

    Jung, Eui-Man; An, Beum-Soo; Yang, Hyun; Choi, Kyung-Chul; Jeung, Eui-Bae

    2012-01-01

    Endocrine disruptors (EDs) are compounds used in various industrial products, drugs, and cosmetics. They can be found in the environment and disturb the endocrine and reproductive systems, resulting in adverse effects to humans and wildlife such as birth defects and developmental disorders. Since several EDs have a structure similar to that of endogenous steroid hormones such as estrogens, they intend to have an affinity for steroid hormone receptors and alter hormone-mediated metabolism by binding to these receptors. EDs are therefore a global concern and assays should be developed to efficiently determine whether these compounds are detrimental to biological systems. Diverse experimental methods may help determine the endocrine disrupting potential of EDs and evaluate the adverse effects of a single and/or combination of these reagents. Currently, biomarkers have been employed to objectively measure EDs potency and understand the underlying mechanisms. Further studies are required to develop ideal screening methods and biomarkers to determine EDs potency at environmentally relevant concentrations. In this review, we describe the biomarkers for estrogenicity of EDs identified both in vitro and in vivo, and introduce a biomarker, cabindin-D9k (CaBP-9k), that may be used to assess estrogenic activity of EDs. PMID:22690157

  1. Renal LRP2 expression in man and chicken is estrogen-responsive.

    PubMed

    Plieschnig, Julia A; Gensberger, Eva T; Bajari, Tarek M; Schneider, Wolfgang J; Hermann, Marcela

    2012-10-15

    In mammals, low-density lipoprotein receptor-related protein-2 (LRP2) is an endocytic receptor that binds multiple ligands and is essential for a wide range of physiological processes. To gain new insights into the biology of this complex protein, we have initiated the molecular characterization of the LRP2 homolog from an oviparous species, the chicken (Gallus gallus). The galline LRP2 cDNA encodes a membrane protein of 4658 residues. Overall, the galline and human proteins are 73% identical, indicating that the avian gene has been well conserved over 300 million years. Unexpectedly, LRP2 transcript and protein levels in the kidney of females and estrogen-treated roosters were significantly higher than those in untreated males. The estrogen-responsiveness of avian LRP2 may be related to the dramatic differences in lipoprotein metabolism between mature roosters and laying hens. Newly identified potential estrogen-responsive elements (ERE) in the human and galline LRP2 gene, and additional Sp1 sites present in the promoter of the chicken gene, are compatible with both direct estrogen induction via the classical ligand-induced ERE pathway and the indirect transcription factor crosstalk pathway engaging the Sp1 sites. In agreement with this assumption, estrogen induction of LRP2 was observed not only in primary cultured chicken kidney cells, but also human kidney cell lines. These findings point to novel regulatory features of the LRP2 gene resulting in sex-specific receptor expression. PMID:22868208

  2. Non-genomic estrogen/estrogen receptor α promotes cellular malignancy of immature ovarian teratoma in vitro.

    PubMed

    Hung, Yao-Ching; Chang, Wei-Chun; Chen, Lu-Min; Chang, Ying-Yi; Wu, Ling-Yu; Chung, Wei-Min; Lin, Tze-Yi; Chen, Liang-Chi; Ma, Wen-Lung

    2014-06-01

    Malignant immature ovarian teratomas (IOTs) most often occur in women of reproductive age. It is unclear, however, what roles estrogenic signaling plays in the development of IOT. In this study, we examined whether estrogen receptors (ERα and β) promote the cellular malignancy of IOT. Estradiol (E2), PPT (propylpyrazole), and DPN (diarylpropionitrile) (ERα- and β-specific agonists, respectively), as well as ERα- or ERβ-specific short hairpin (sh)RNA were applied to PA-1 cells, a well-characterized IOT cell line. Cellular tumorigenic characteristics, for example, cell migration/invasion, expression of the cancer stem/progenitor cell marker CD133, and evidence for epithelial-mesenchymal transition (EMT) were examined. In PA-1 cells that expressed ERα and ERβ, we found that ERα promoted cell migration and invasion. We also found that E2/ERα signaling altered cell behavior through non-classical transactivation function. Our data show non-genomic E2/ERα activations of focal adhesion kinase-Ras homolog gene family member A (FAK-RhoA) and ERK governed cell mobility capacity. Moreover, E2/ERα signaling induces EMT and overexpression of CD133 through upregulation micro-RNA 21 (miR21; IOT stem/progenitor promoter), and ERK phosphorylations. Furthermore, E2/ERα signaling triggers a positive feedback regulatory loop within miR21 and ERK. At last, expression levels of ERα, CD133, and EMT markers in IOT tissue samples were examined by immunohistochemistry. We found that cytosolic ERα was co-expressed with CD133 and mesenchymal cell markers but not epithelial cell markers. In conclusion, estrogenic signals exert malignant transformation capacity of cancer cells, exclusively through non-genomic regulation in female germ cell tumors. PMID:24142535

  3. Splice isoform estrogen receptors as integral transmembrane proteins

    PubMed Central

    Kim, Kyung Hee; Toomre, Derek; Bender, Jeffrey R.

    2011-01-01

    In addition to enhancing or repressing transcription, steroid hormone receptors rapidly transduce kinase activation signals. On ligand engagement, an N-terminus–truncated splice isoform of estrogen receptor (ER) α, ER46, triggers membrane-initiated signals, resulting in endothelial nitric oxide synthase (eNOS) activation and endothelial NO production. The orientation of ER46 at the plasma membrane is incompletely defined. With the use of ecliptic pHluorin-fused ER46, total internal reflection fluorescence microscopy in live human endothelial cells illustrates that ER46 can topologically conform to a type I transmembrane protein structure. Mutation of isoleucine-386 at the center of ER46's transmembrane hydrophobic core prevents membrane spanning, obscures the N-terminal ectodomain, and effects a marked reduction in membrane-impermeant estrogen binding with diminished rapid eNOS activation and NO production, despite maintained genomic induction of an estrogen response element–luciferase reporter. Thus there exist pools of transmembrane steroid hormone receptors that are efficient signaling molecules and potential novel therapeutic targets. PMID:21937726

  4. Multiple estrogen receptor subtypes influence ingestive behavior in female rodents.

    PubMed

    Santollo, Jessica; Daniels, Derek

    2015-12-01

    Postmenopausal women are at an increased risk of obesity and cardiovascular-related diseases. This is attributable, at least in part, to loss of the ovarian hormone estradiol, which inhibits food and fluid intake in humans and laboratory animal models. Although the hypophagic and anti-dipsogenic effects of estradiol have been well documented for decades, the precise mechanisms underlying these effects are not fully understood. An obvious step toward addressing this open question is identifying which estrogen receptor subtypes are involved and what intracellular processes are involved. This question, however, is complicated not only by the variety of estrogen receptor subtypes that exist, but also because many subtypes have multiple locations of action (i.e. in the nucleus or in the plasma membrane). This review will highlight our current understanding of the roles that specific estrogen receptor subtypes play in mediating estradiol's anorexigenic and anti-dipsogenic effects along with highlighting the many open questions that remain. This review will also describe recent work being performed by our laboratory aimed at answering these open questions. PMID:26037634

  5. Klotho/fibroblast growth factor 23- and PTH-independent estrogen receptor-α-mediated direct downregulation of NaPi-IIa by estrogen in the mouse kidney.

    PubMed

    Webster, Rose; Sheriff, Sulaiman; Faroqui, Rashma; Siddiqui, Faraaz; Hawse, John R; Amlal, Hassane

    2016-08-01

    Estrogen treatment causes renal phosphate (Pi) wasting and hypophosphatemia in rats and humans; however, the signaling mechanisms mediating this effect are still poorly understood. To determine the specific roles of estrogen receptor isoforms (ERα and ERβ) and the Klotho pathway in mediating these effects, we studied the effects of estrogen on renal Pi handling in female mice with null mutations of ERα or ERβ or Klotho and their wild type (WT) using balance studies in metabolic cages. Estrogen treatment of WT and ERβ knockout (KO) mice caused a significant reduction in food intake along with increased renal phosphate wasting. The latter resulted from a significant downregulation of NaPi-IIa and NaPi-IIc protein abundance. The mRNA expression levels of both transporters were unchanged in estrogen-treated mice. These effects on both food intake and renal Pi handling were absent in ERα KO mice. Estrogen treatment of Klotho KO mice or parathyroid hormone (PTH)-depleted thyroparathyroidectomized mice exhibited a significant downregulation of NaPi-IIa with no change in the abundance of NaPi-IIc. Estrogen treatment of a cell line (U20S) stably coexpressing both ERα and ERβ caused a significant downregulation of NaPi-IIa protein when transiently transfected with a plasmid containing full-length or open-reading frame (ORF) 3'-untranslated region (UTR) but not 5'-UTR ORF of mouse NaPi-IIa transcript. In conclusion, estrogen causes phosphaturia and hypophosphatemia in mice. These effects result from downregulation of NaPi-IIa and NaPi-IIc proteins in the proximal tubule through the activation of ERα. The downregulation of NaPi-IIa by estrogen involves 3'-UTR of its mRNA and is independent of Klotho/fibroblast growth factor 23 and PTH signaling pathways. PMID:27194721

  6. Breast-related effects of selective estrogen receptor modulators and tissue-selective estrogen complexes

    PubMed Central

    2014-01-01

    A number of available treatments provide relief of menopausal symptoms and prevention of postmenopausal osteoporosis. However, as breast safety is a major concern, new options are needed, particularly agents with an improved mammary safety profile. Results from several large randomized and observational studies have shown an association between hormone therapy, particularly combined estrogen-progestin therapy, and a small increased risk of breast cancer and breast pain or tenderness. In addition, progestin-containing hormone therapy has been shown to increase mammographic breast density, which is an important risk factor for breast cancer. Selective estrogen receptor modulators (SERMs) provide bone protection, are generally well tolerated, and have demonstrated reductions in breast cancer risk, but do not relieve menopausal symptoms (that is, vasomotor symptoms). Tissue-selective estrogen complexes (TSECs) pair a SERM with one or more estrogens and aim to blend the positive effects of the components to provide relief of menopausal symptoms and prevention of postmenopausal osteoporosis without stimulating the breast or endometrium. One TSEC combination pairing conjugated estrogens (CEs) with the SERM bazedoxifene (BZA) has completed clinical development and is now available as an alternative option for menopausal therapy. Preclinical evidence suggests that CE/BZA induces inhibitory effects on breast tissue, and phase 3 clinical studies suggest breast neutrality, with no increases seen in breast tenderness, breast density, or cancer. In non-hysterectomized postmenopausal women, CE/BZA was associated with increased bone mineral density and relief of menopausal symptoms, along with endometrial safety. Taken together, these results support the potential of CE/BZA for the relief of menopausal symptoms and prevention of postmenopausal osteoporosis combined with breast and endometrial safety. PMID:25928299

  7. Evolution of estrogen receptors in ray-finned fish and their comparative responses to estrogenic substances.

    PubMed

    Tohyama, Saki; Miyagawa, Shinichi; Lange, Anke; Ogino, Yukiko; Mizutani, Takeshi; Ihara, Masaru; Tanaka, Hiroaki; Tatarazako, Norihisa; Kobayashi, Tohru; Tyler, Charles R; Iguchi, Taisen

    2016-04-01

    In vertebrates, estrogens play fundamental roles in regulating reproductive activities through estrogen receptors (ESRs), and disruption of estrogen signaling is now of global concern for both wildlife and human health. To date, ESRs of only a limited number of species have been characterized. We investigated the functional diversity and molecular basis or ligand sensitivity of ESRs among ray-finned fish species (Actinopterygii), the most variable group within vertebrates. We cloned and characterized ESRs from several key species in the evolution of ray-finned fish including bichir (Polypteriformes, ESR1 and ESR2) at the basal lineage of ray-finned fish, and arowana (Osteoglossiformes, ESR1 and ESR2b) and eel (Anguilliformes, ESR1, ESR2a and ESR2b) both belonging to ancient early-branching lineages of teleosts, and suggest that ESR2a and ESR2b emerged through teleost-specific whole genome duplication, but an ESR1 paralogue has been lost in the early lineage of euteleost fish species. All cloned ESR isoforms showed similar responses to endogenous and synthetic steroidal estrogens, but they responded differently to non-steroidal estrogenic endocrine disrupting chemicals (EDCs) (e.g., ESR2a exhibits a weaker reporter activity compared with ESR2b). We show that variation in ligand sensitivity of ESRs can be attributed to phylogeny among species of different taxonomic groups in ray-finned fish. The molecular information provided contributes both to understanding of the comparative role of ESRs in the reproductive biology of fish and their comparative responses to EDCs. PMID:26707410

  8. Selective binding of the estrogen receptor to one strand of the estrogen responsive element.

    PubMed Central

    Mukherjee, R

    1993-01-01

    The human estrogen receptor (hER) activates gene transcription by binding to cognate palindromic sequences called estrogen responsive elements (ERE). I used gel retardation assays and oligonucleotides containing the ERE from the Xenopus vitellogenin gene to study the interaction of the hER with the ERE. I observed that the hER bound to double-stranded ERE and to the single strand of the ERE that had T in the center with nearly equal affinity, but not to the strand which had A in the center. Interchanging the two central nucleotides changed the strand specificity. Binding of the hER to a single strand is extremely sensitive to temperature. Initial recognition of one of the two strands of the ERE may be involved in the binding of the hER to the ERE. Images PMID:8332462

  9. The membrane estrogen receptor GPR30 mediates cadmium-induced proliferation of breast cancer cells

    SciTech Connect

    Yu Xinyuan; Filardo, Edward J.; Shaikh, Zahir A.

    2010-05-15

    Cadmium (Cd) is a nonessential metal that is dispersed throughout the environment. It is an endocrine-disrupting element which mimics estrogen, binds to estrogen receptor alpha (ERalpha), and promotes cell proliferation in breast cancer cells. We have previously published that Cd promotes activation of the extracellular regulated kinases, erk-1 and -2 in both ER-positive and ER-negative human breast cancer cells, suggesting that this estrogen-like effect of Cd is not associated with the ER. Here, we have investigated whether the newly appreciated transmembrane estrogen receptor, G-protein coupled receptor 30 (GPR30), may be involved in Cd-induced cell proliferation. Towards this end, we compared the effects of Cd in ER-negative human SKBR3 breast cancer cells in which endogenous GPR30 signaling was selectively inhibited using a GPR30 interfering mutant. We found that Cd concentrations from 50 to 500 nM induced a proliferative response in control vector-transfected SKBR3 cells but not in SKBR3 cells stably expressing interfering mutant. Similarly, intracellular cAMP levels increased about 2.4-fold in the vector transfectants but not in cells in which GPR30 was inactivated within 2.5 min after treatment with 500 nM Cd. Furthermore, Cd treatment rapidly activated (within 2.5 min) raf-1, mitogen-activated protein kinase kinase, mek-1, extracellular signal regulated kinases, erk-1/2, ribosomal S6 kinase, rsk, and E-26 like protein kinase, elk, about 4-fold in vector transfectants. In contrast, the activation of these signaling molecules in SKBR3 cells expressing the GPR30 mutant was only about 1.4-fold. These results demonstrate that Cd-induced breast cancer cell proliferation occurs through GPR30-mediated activation in a manner that is similar to that achieved by estrogen in these cells.

  10. A new avenue for obtaining insight into the functional characteristics of long noncoding RNAs associated with estrogen receptor signaling

    PubMed Central

    Wu, Liangcai; Xu, Qianqian; Zhang, Haohai; Li, Ming; Zhu, Chengpei; Jiang, Minjie; Sang, Xinting; Zhao, Yi; Sun, Qiang; Zhao, Haitao

    2016-01-01

    Estrogen receptor signalling plays important regulatory roles in multiple mammalian physiological processes. Dysregulation of estrogen receptor (ER) expression and/or its associated signalling pathway is strongly associated with the development, progression, transition, and endocrine-resistance of breast cancer. Non-coding transcripts are essential regulators of almost every level of gene regulation. However, few long non-coding transcripts (lncRNAs) associated with the estrogen receptor signalling pathway have been well-described. We used array-based methods to identify 33 estrogen receptor agitation-related (ERAR) lncRNAs. A coding–non-coding gene co-expression network analysis suggested that 15 ERAR lncRNAs were associated with mitosis, DNA damage, and DNA repair. Kaplan–Meier analysis indicated that five ERAR lncRNAs selected using the Random Forest-Recursive Feature Elimination algorithm were significantly correlated with endocrine resistance-free survival and distant metastasis-free survival as well as disease free survival. Our results suggest that ERAR lncRNAs may serve as novel biomarkers for guiding breast cancer treatment and prognosis. Furthermore, our findings reveal a new avenue by which estrogen receptor signalling can be further explored. PMID:27539025

  11. Orphan nuclear receptor estrogen-related receptor γ (ERRγ) is key regulator of hepatic gluconeogenesis.

    PubMed

    Kim, Don-Kyu; Ryu, Dongryeol; Koh, Minseob; Lee, Min-Woo; Lim, Donghyun; Kim, Min-Jung; Kim, Yong-Hoon; Cho, Won-Jea; Lee, Chul-Ho; Park, Seung Bum; Koo, Seung-Hoi; Choi, Hueng-Sik

    2012-06-22

    Glucose homeostasis is tightly controlled by hormonal regulation of hepatic glucose production. Dysregulation of this system is often associated with insulin resistance and diabetes, resulting in hyperglycemia in mammals. Here, we show that the orphan nuclear receptor estrogen-related receptor γ (ERRγ) is a novel downstream mediator of glucagon action in hepatic gluconeogenesis and demonstrate a beneficial impact of the inverse agonist GSK5182. Hepatic ERRγ expression was increased by fasting-dependent activation of the cAMP-response element-binding protein-CRTC2 pathway. Overexpression of ERRγ induced Pck1 and G6PC gene expression and glucose production in primary hepatocytes, whereas abolition of ERRγ gene expression attenuated forskolin-mediated induction of gluconeogenic gene expression. Deletion and mutation analyses of the Pck1 promoter showed that ERRγ directly regulates the Pck1 gene transcription via ERR response elements of the Pck1 promoter as confirmed by ChIP assay and in vivo imaging analysis. We also demonstrate that GSK5182, an inverse agonist of ERRγ, specifically inhibits the transcriptional activity of ERRγ in a PGC-1α dependent manner. Finally, the ERRγ inverse agonist ameliorated hyperglycemia through inhibition of hepatic gluconeogenesis in db/db mice. Control of hepatic glucose production by an ERRγ-specific inverse agonist is a new potential therapeutic approach for the treatment of type 2 diabetes. PMID:22549789

  12. Orphan Nuclear Receptor Estrogen-Related Receptor γ (ERRγ) Is Key Regulator of Hepatic Gluconeogenesis*

    PubMed Central

    Kim, Don-Kyu; Ryu, Dongryeol; Koh, Minseob; Lee, Min-Woo; Lim, Donghyun; Kim, Min-Jung; Kim, Yong-Hoon; Cho, Won-Jea; Lee, Chul-Ho; Park, Seung Bum; Koo, Seung-Hoi; Choi, Hueng-Sik

    2012-01-01

    Glucose homeostasis is tightly controlled by hormonal regulation of hepatic glucose production. Dysregulation of this system is often associated with insulin resistance and diabetes, resulting in hyperglycemia in mammals. Here, we show that the orphan nuclear receptor estrogen-related receptor γ (ERRγ) is a novel downstream mediator of glucagon action in hepatic gluconeogenesis and demonstrate a beneficial impact of the inverse agonist GSK5182. Hepatic ERRγ expression was increased by fasting-dependent activation of the cAMP-response element-binding protein-CRTC2 pathway. Overexpression of ERRγ induced Pck1 and G6PC gene expression and glucose production in primary hepatocytes, whereas abolition of ERRγ gene expression attenuated forskolin-mediated induction of gluconeogenic gene expression. Deletion and mutation analyses of the Pck1 promoter showed that ERRγ directly regulates the Pck1 gene transcription via ERR response elements of the Pck1 promoter as confirmed by ChIP assay and in vivo imaging analysis. We also demonstrate that GSK5182, an inverse agonist of ERRγ, specifically inhibits the transcriptional activity of ERRγ in a PGC-1α dependent manner. Finally, the ERRγ inverse agonist ameliorated hyperglycemia through inhibition of hepatic gluconeogenesis in db/db mice. Control of hepatic glucose production by an ERRγ-specific inverse agonist is a new potential therapeutic approach for the treatment of type 2 diabetes. PMID:22549789

  13. Estrogen receptor-mediated effects of isoflavone supplementation were not observed in whole-genome gene expression profiles of peripheral blood mononuclear cells in postmenopausal, equol-producing women.

    PubMed

    van der Velpen, Vera; Geelen, Anouk; Schouten, Evert G; Hollman, Peter C; Afman, Lydia A; van 't Veer, Pieter

    2013-06-01

    Isoflavones (genistein, daidzein, and glycitein) are suggested to have benefits as well as risks for human health. Approximately one-third of the Western population is able to metabolize daidzein into the more potent metabolite equol. Having little endogenous estradiol, equol-producing postmenopausal women who use isoflavone supplements to relieve their menopausal symptoms could potentially be at high risk of adverse effects of isoflavone supplementation. The current trial aimed to study the effects of intake of an isoflavone supplement rich in daidzein compared with placebo on whole-genome gene expression profiles of peripheral blood mononuclear cells (PBMCs) in equol-producing, postmenopausal women. Thirty participants received an isoflavone supplement or a placebo for 8 wk each in a double-blind, randomized cross-over design. The isoflavone supplement was rich in daidzein (60%) and provided 94 mg isoflavones (aglycone equivalents) daily. Gene expression in PBMCs was significantly changed (P < 0.05) in 357 genes after the isoflavone intervention compared with placebo. Gene set enrichment analysis revealed downregulated clusters of gene sets involved in inflammation, oxidative phosphorylation, and cell cycle. The expression of estrogen receptor (ER) target genes and gene sets related to ER signaling were not significantly altered, which may be explained by the low ERα and ERβ expression in PBMCs. The observed downregulated gene sets point toward potential beneficial effects of isoflavone supplementation with respect to prevention of cancer and cardiovascular disease. However, whether ER-related effects of isoflavones are beneficial or harmful should be studied in tissues that express ERs. PMID:23616509

  14. Colocalization of Estrogen Receptors with the Fluorescent Tamoxifen Derivative, FLTX1, Analyzed by Confocal Microscopy.

    PubMed

    Morales, Araceli; Marín, Raquel; Marrero-Alonso, Jorge; Boto, Alicia; Díaz, Mario

    2016-01-01

    Tamoxifen is a selective estrogen receptor modulator that competitively binds the ligand-binding domain of estrogen receptors. Binding of tamoxifen displaces its cognate ligand, 17β-estradiol, thereby hampering the activation of estrogen receptors. Cellular labeling of ER is typically carried out using specific antibodies which require permeabilization of cells, incubation with secondary antibodies, and are expensive and time consuming. In this article, we describe the usefulness of FLTX1, a novel fluorescent tamoxifen derivative, which allows the labeling of estrogen receptors in immunocytochemistry and immunohistochemistry studies, both under permeabilized and non-permeabilized conditions. Further, besides labeling canonical estrogen receptors, this novel fluorescent probe is also suitable for the identification of unconventional targets such membrane estrogen receptors as well as other noncanonical targets, some of which are likely responsible for the number of undesired side effects reported during long-term tamoxifen treatments. PMID:26585134

  15. Estrogen-dependent expression of sine oculis homeobox 1 in the mouse uterus during the estrous cycle.

    PubMed

    Bae, Sijeong; Kwon, Hwang; Yoon, Hyemin; Park, Miseon; Kim, Hye-Ryun; Song, Haengseok; Hong, Kwonho; Choi, Youngsok

    2016-04-01

    The sine oculis homeobox 1 (SIX1) is a member of the Six gene family. SIX1 is involved in tissue development by regulating proliferation, apoptosis, and differentiation. However, function of SIX1 in the uterus remains unknown. Here, we found that Six1 expression is regulated along the estrous cycle in mouse uterus. Six1 expression was significantly increased at estrus stage and decreased at the rest of stages. SIX1 is detected in the luminal and glandular epithelium of uterine endometrium at the estrus stage. Estrogen injection increased Six1 expression in the ovariectomized mouse uterus, whereas progesterone had no effect on its expression. Estrogen receptor antagonist inhibited estrogen-induced Six1 expression. Our findings imply that SIX1 may play a role as an important regulator to orchestrate the dynamic of uterine endometrium in response to estrogen level during the estrous cycle. These results will give us a better understanding of uterine biology. PMID:26940739

  16. HDAC3 regulates stability of estrogen receptor α mRNA

    SciTech Connect

    Oie, Shohei; Matsuzaki, Kazuya; Yokoyama, Wataru; Murayama, Akiko; Yanagisawa, Junn

    2013-03-08

    Highlights: ► HDAC inhibitors decrease the stability of ERα mRNA in MCF-7 cells. ► HDAC3 is involved in maintaining ERα mRNA stability in MCF-7 cells. ► ERα mRNA instability by knockdown of HDAC3 reduces the estrogen-dependent proliferation of ERα-positive MCF-7 cells. ► HDAC3 specific inhibitor will be one of new drugs for ERα-positive breast cancers. -- Abstract: Estrogen receptor alpha (ERα) expression is a risk factor for breast cancer. HDAC inhibitors have been demonstrated to down-regulate ERα expression in ERα-positive breast cancer cell lines, but the molecular mechanisms are poorly understood. Here, we showed that HDAC inhibitors decrease the stability of ERα mRNA, and that knockdown of HDAC3 decreases the stability of ERα mRNA and suppresses estrogen-dependent proliferation of ERα-positive MCF-7 breast cancer cells. In the Oncomine database, expression levels of HDAC3 in ERα-positive tumors are higher than those in ERα-negative tumors, thus suggesting that HDAC3 is necessary for ERα mRNA stability, and is involved in the estrogen-dependent proliferation of ERα-positive tumors.

  17. Estrogen receptor α and G-protein coupled estrogen receptor 1 are localized to GABAergic neurons in the dorsal striatum.

    PubMed

    Almey, Anne; Milner, Teresa A; Brake, Wayne G

    2016-05-27

    Estrogens affect dopamine transmission in the striatum, increasing dopamine availability, maintaining D2 receptor density, and reducing the availability of the dopamine transporter. Some of these effects of estrogens are rapid, suggesting that they are mediated by membrane associated receptors. Recently our group demonstrated that there is extra-nuclear labeling for ERα, ERβ, and GPER1 in the striatum, but that ERα and GPER1 are not localized to dopaminergic neurons in this region. GABAergic neurons are the most common type of neuron in the striatum, and changes in GABA transmission affect dopamine transmission. Thus, to determine whether ERα or GPER1 are localized to GABAergic neurons, we double labeled the striatum with antibodies for ERα or GPER1 and GABA and examined them using electron microscopy. Ultrastructural analysis revealed that ERα and GPER1 are localized exclusively to extranuclear sites in the striatum, and ∼35% of the dendrites and axon terminals labeled for these receptors contain GABA immunoreactivity. Binding at membrane-associated ERα and GPER1 could account for rapid estrogen-induced decreases in GABA transmission in the striatum, which, in turn, could affect dopamine transmission in this region. PMID:27080432

  18. Estrogen-related receptor gamma modulates energy metabolism target genes in human trophoblast.

    PubMed

    Poidatz, D; Dos Santos, E; Brulé, A; De Mazancourt, P; Dieudonné, M N

    2012-09-01

    Placenta growth and functions depend on correct trophoblast migration, proliferation, and differentiation. The placenta has a critical role in gas and nutrient transport. To accomplish these numerous functions, the placenta depends on a highly efficient energy metabolism control. Recent studies showed that the orphan nuclear receptor Estrogen-Related Receptor gamma (ERRγ) is highly expressed in human placentas. As ERRγ has been described as a major energy metabolism regulator, we investigated ERRγ expression and putative roles on energy homeostasis in human trophoblast from first trimester placentas. First, we showed that ERRγ expression level increased during pregnancy and that ERRγ was more abundant in villous than in extravillous trophoblasts. We also observed that ERRγ expression increased during trophoblast differentiation. Second, we demonstrated that mitochondrial biogenesis and expression of some energy metabolism target genes decreased when ERRγ expression was impaired. Altogether, these results suggest that ERRγ could be implicated in the energy metabolism regulation of human trophoblasts. PMID:22763271

  19. Rapid screening of environmental chemicals for estrogen receptor binding capacity.

    PubMed Central

    Bolger, R; Wiese, T E; Ervin, K; Nestich, S; Checovich, W

    1998-01-01

    Over the last few years, an increased awareness of endocrine disrupting chemicals (EDCs) and their potential to affect wildlife and humans has produced a demand for practical screening methods to identify endocrine activity in a wide range of environmental and industrial chemicals. While it is clear that in vivo methods will be required to identify adverse effects produced by these chemicals, in vitro assays can define particular mechanisms of action and have the potential to be employed as rapid and low-cost screens for use in large scale EDC screening programs. Traditional estrogen receptor (ER) binding assays are useful for characterizing a chemical's potential to be an estrogen-acting EDC, but they involve displacement of a radioactive ligand from crude receptor preparations at low temperatures. The usefulness of these assays for realistically determining the ER binding interactions of weakly estrogenic environmental and industrial compounds that have low aqueous solubility is unclear. In this report, we present a novel fluorescence polarization (FP) method that measures the capacity of a competitor chemical to displace a high affinity fluorescent ligand from purified, recombinant human ER-[alpha] at room temperature. The ER-[alpha] binding interactions generated for 15 natural and synthetic compounds were found to be similar to those determined with traditional receptor binding assays. We also discuss the potential to employ this FP technology to binding studies involving ER-ss and other receptors. Thus, the assay introduced in this study is a nonradioactive receptor binding method that shows promise as a high throughput screening method for large-scale testing of environmental and industrial chemicals for ER binding interactions. Images Figure 2 Figure 3 Figure 4 PMID:9721254

  20. The G Protein-Coupled Estrogen Receptor Agonist G-1 Inhibits Nuclear Estrogen Receptor Activity and Stimulates Novel Phosphoproteomic Signatures.

    PubMed

    Smith, L Cody; Ralston-Hooper, Kimberly J; Ferguson, P Lee; Sabo-Attwood, Tara

    2016-06-01

    Estrogen exerts cellular effects through both nuclear (ESR1 and ESR2) and membrane-bound estrogen receptors (G-protein coupled estrogen receptor, GPER); however, it is unclear if they act independently or engage in crosstalk to influence hormonal responses. To investigate each receptor's role in proliferation, transcriptional activation, and protein phosphorylation in breast cancer cells (MCF-7), we employed selective agonists for ESR1 propyl-pyrazole-triol (PPT), ESR2 diarylpropionitrile (DPN), and GPER (G-1) and also determined the impact of xenoestrogens bisphenol-A (BPA) and genistein on these effects. As anticipated, 17β-estradiol (E2), PPT, DPN, BPA, and genistein each enhanced proliferation and activation of an ERE-driven reporter gene whereas G-1 had no significant impact. However, G-1 significantly reduced E2-, PPT-, DPN-, BPA-, and genistein-induced proliferation and ERE activation at doses greater than 500 nM indicating that G-1 mediated inhibition is not ESR isotype specific. As membrane receptors initiate cascades of phosphorylation events, we performed a global phosphoproteomic analysis on cells exposed to E2 or G-1 to identify potential targets of receptor crosstalk via downstream protein phosphorylation targets. Of the 211 phosphorylated proteins identified, 40 and 13 phosphoproteins were specifically modified by E2 and G-1, respectively. Subnetwork enrichment analysis revealed several processes related to cell cycle were specifically enriched by G-1 compared with E2. Further there existed a number of newly identified proteins that were specifically phosphorylated by G-1. These phosphorylation networks highlight specific proteins that may modulate the inhibitory effects of G-1 and suggest a novel role for interference with nuclear receptor activity driven by E2 and xenoestrogens. PMID:27026707

  1. Estrogen receptor-alpha promotes alternative macrophage activation during cutaneous repair.

    PubMed

    Campbell, Laura; Emmerson, Elaine; Williams, Helen; Saville, Charis R; Krust, Andrée; Chambon, Pierre; Mace, Kimberly A; Hardman, Matthew J

    2014-09-01

    Efficient local monocyte/macrophage recruitment is critical for tissue repair. Recruited macrophages are polarized toward classical (proinflammatory) or alternative (prohealing) activation in response to cytokines, with tight temporal regulation crucial for efficient wound repair. Estrogen acts as a potent anti-inflammatory regulator of cutaneous healing. However, an understanding of estrogen/estrogen re