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Sample records for estrogen receptor modulator

  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. [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

  3. 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

  4. 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

  5. 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

  6. Specific regulation of male rat liver cytosolic estrogen receptor by the modulator of the glucocorticoid receptor.

    PubMed

    Celiker, M Y; Haas, A; Saunders, D; Litwack, G

    1993-08-31

    Modulator is a novel low-molecular-weight organic compound that regulates activities of glucocorticoid and mineralocorticoid receptors as well as protein kinase C. In this study we show that male rat liver cytosolic estrogen receptor activation is inhibited by modulator in a dose-dependent manner. Fifty percent inhibition is obtained with 1 unit/ml modulator purified from bovine liver which is within the physiological concentration for modulator. However, sheep uterine cytosolic estrogen and androgen receptors are insensitive to regulation by modulator. Exogenous sodium molybdate treatment inhibits activation of all of these receptors of liver or uterus origin in an identical manner, further differentiating the effects of modulator and the molybdate anion. PMID:8363596

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. Selective estrogen receptor modulators accelerate cutaneous wound healing in ovariectomized female mice.

    PubMed

    Hardman, Matthew J; Emmerson, Elaine; Campbell, Laura; Ashcroft, Gillian S

    2008-02-01

    A lack of systemic hormones in elderly postmenopausal women leads to delayed cutaneous wound healing. This effect can be reversed by systemic or topical estrogen replacement in both humans and rodent models. Over recent years selective estrogen receptor modulators have been developed in an attempt to achieve the beneficial effects of estrogen clinically, while minimizing the detrimental side effects. The effects of selective estrogen receptor modulators on the skin are poorly understood, and the effects on wound healing have not been assessed. In this study we treated 10-wk-old ovariectomized mice with estradiol, tamoxifen (TAM), raloxifene (RAL), or vehicle and examined the effect on healing of full-thickness incisional wounds. Both TAM and RAL substantially accelerate healing, associated with a dampened inflammatory response and altered inflammatory cytokine profile. In vitro TAM and RAL demonstrate antiinflammatory activity comparable to estrogen. These results have significant implications for the clinical modulation of wound healing. PMID:17974625

  12. 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

  13. Antileishmanial Activity of the Estrogen Receptor Modulator Raloxifene

    PubMed Central

    Reimão, Juliana Q.; Miguel, Danilo C.; Taniwaki, Noemi N.; Trinconi, Cristiana T.; Yokoyama-Yasunaka, Jenicer K. U.; Uliana, Silvia R. B.

    2014-01-01

    Background The treatment of leishmaniasis relies mostly on parenteral drugs with potentially serious adverse effects. Additionally, parasite resistance in the treatment of leishmaniasis has been demonstrated for the majority of drugs available, making the search for more effective and less toxic drugs and treatment regimens a priority for the control of leishmaniasis. The aims of this study were to evaluate the antileishmanial activity of raloxifene in vitro and in vivo and to investigate its mechanism of action against Leishmania amazonensis. Methodology/Principal Findings Raloxifene was shown to possess antileishmanial activity in vitro against several species with EC50 values ranging from 30.2 to 38.0 µM against promastigotes and from 8.8 to 16.2 µM against intracellular amastigotes. Raloxifene's mechanism of action was investigated through transmission electron microscopy and labeling with propidium iodide, DiSBAC2(3), rhodamine 123 and monodansylcadaverine. Microscopic examinations showed that raloxifene treated parasites displayed autophagosomes and mitochondrial damage while the plasma membrane remained continuous. Nonetheless, plasma membrane potential was rapidly altered upon raloxifene treatment with initial hyperpolarization followed by depolarization. Loss of mitochondrial membrane potential was also verified. Treatment of L. amazonensis – infected BALB/c mice with raloxifene led to significant decrease in lesion size and parasite burden. Conclusions/Significance The results of this work extend the investigation of selective estrogen receptor modulators as potential candidates for leishmaniasis treatment. The antileishmanial activity of raloxifene was demonstrated in vitro and in vivo. Raloxifene produces functional disorder on the plasma membrane of L. amazonensis promastigotes and leads to functional and morphological disruption of mitochondria, which culminate in cell death. PMID:24810565

  14. Synthesis of Triphenylethylene Bisphenols as Aromatase Inhibitors That Also Modulate Estrogen Receptors.

    PubMed

    Lv, Wei; Liu, Jinzhong; Skaar, Todd C; O'Neill, Elizaveta; Yu, Ge; Flockhart, David A; Cushman, Mark

    2016-01-14

    A series of triphenylethylene bisphenol analogues of the selective estrogen receptor modulator (SERM) tamoxifen were synthesized and evaluated for their abilities to inhibit aromatase, bind to estrogen receptor α (ER-α) and estrogen receptor β (ER-β), and antagonize the activity of β-estradiol in MCF-7 human breast cancer cells. The long-range goal has been to create dual aromatase inhibitor (AI)/selective estrogen receptor modulators (SERMs). The hypothesis is that in normal tissue the estrogenic SERM activity of a dual AI/SERM could attenuate the undesired effects stemming from global estrogen depletion caused by the AI activity of a dual AI/SERM, while in breast cancer tissue the antiestrogenic SERM activity of a dual AI/SERM could act synergistically with AI activity to enhance the antiproliferative effect. The potent aromatase inhibitory activities and high ER-α and ER-β binding affinities of several of the resulting analogues, together with the facts that they antagonize β-estradiol in a functional assay in MCF-7 human breast cancer cells and they have no E/Z isomers, support their further development in order to obtain dual AI/SERM agents for breast cancer treatment. PMID:26704594

  15. 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

  16. Estrogen Receptor β Activation Rapidly Modulates Male Sexual Motivation through the Transactivation of Metabotropic Glutamate Receptor 1a.

    PubMed

    Seredynski, Aurore L; Balthazart, Jacques; Ball, Gregory F; Cornil, Charlotte A

    2015-09-23

    In addition to the transcriptional activity of their liganded nuclear receptors, estrogens, such as estradiol (E2), modulate cell functions, and consequently physiology and behavior, within minutes through membrane-initiated events. The membrane-associated receptors (mERs) underlying the acute effects of estrogens on behavior have mostly been documented in females where active estrogens are thought to be of ovarian origin. We determined here, by acute intracerebroventricular injections of specific agonists and antagonists, the type(s) of mERs that modulate rapid effects of brain-derived estrogens on sexual motivation in male Japanese quail. Brain aromatase blockade acutely inhibited sexual motivation. Diarylpropionitrile (DPN), an estrogen receptor β (ERβ)-specific agonist, and to a lesser extent 17α-estradiol, possibly acting through ER-X, prevented this effect. In contrast, drugs targeting ERα (PPT and MPP), GPR30 (G1 and G15), and the Gq-mER (STX) did not affect sexual motivation. The mGluR1a antagonist LY367385 significantly inhibited sexual motivation but mGluR2/3 and mGluR5 antagonists were ineffective. LY367385 also blocked the behavioral restoration induced by E2 or DPN, providing functional evidence that ERβ interacts with metabotropic glutamate receptor 1a (mGluR1a) signaling to acutely regulate male sexual motivation. Together these results show that ERβ plays a key role in sexual behavior regulation and the recently uncovered cooperation between mERs and mGluRs is functional in males where it mediates the acute effects of estrogens produced centrally in response to social stimuli. The presence of an ER-mGluR interaction in birds suggests that this mechanism emerged relatively early in vertebrate history and is well conserved. Significance statement: The membrane-associated receptors underlying the acute effects of estrogens on behavior have mostly been documented in females, where active estrogens are thought to be of ovarian origin. Using acute

  17. Estrogen Receptor β Activation Rapidly Modulates Male Sexual Motivation through the Transactivation of Metabotropic Glutamate Receptor 1a

    PubMed Central

    Seredynski, Aurore L.; Balthazart, Jacques; Ball, Gregory F.

    2015-01-01

    In addition to the transcriptional activity of their liganded nuclear receptors, estrogens, such as estradiol (E2), modulate cell functions, and consequently physiology and behavior, within minutes through membrane-initiated events. The membrane-associated receptors (mERs) underlying the acute effects of estrogens on behavior have mostly been documented in females where active estrogens are thought to be of ovarian origin. We determined here, by acute intracerebroventricular injections of specific agonists and antagonists, the type(s) of mERs that modulate rapid effects of brain-derived estrogens on sexual motivation in male Japanese quail. Brain aromatase blockade acutely inhibited sexual motivation. Diarylpropionitrile (DPN), an estrogen receptor β (ERβ)-specific agonist, and to a lesser extent 17α-estradiol, possibly acting through ER-X, prevented this effect. In contrast, drugs targeting ERα (PPT and MPP), GPR30 (G1 and G15), and the Gq-mER (STX) did not affect sexual motivation. The mGluR1a antagonist LY367385 significantly inhibited sexual motivation but mGluR2/3 and mGluR5 antagonists were ineffective. LY367385 also blocked the behavioral restoration induced by E2 or DPN, providing functional evidence that ERβ interacts with metabotropic glutamate receptor 1a (mGluR1a) signaling to acutely regulate male sexual motivation. Together these results show that ERβ plays a key role in sexual behavior regulation and the recently uncovered cooperation between mERs and mGluRs is functional in males where it mediates the acute effects of estrogens produced centrally in response to social stimuli. The presence of an ER–mGluR interaction in birds suggests that this mechanism emerged relatively early in vertebrate history and is well conserved. SIGNIFICANCE STATEMENT The membrane-associated receptors underlying the acute effects of estrogens on behavior have mostly been documented in females, where active estrogens are thought to be of ovarian origin. Using acute

  18. 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

  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. 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

  1. From empirical to mechanism-based discovery of clinically useful Selective Estrogen Receptor Modulators (SERMs)

    PubMed Central

    Wardell, Suzanne E.; Nelson, Erik R.; McDonnell, Donald P.

    2014-01-01

    Our understanding of the molecular mechanisms underlying the pharmacological actions of estrogen receptor (ER) ligands has evolved considerably in recent years. Much of this knowledge has come from a detailed dissection of the mechanism(s) of action of the Selective Estrogen Receptor Modulators (SERMs) tamoxifen and raloxifene, drugs whose estrogen receptor (ER) agonist/antagonist properties are influenced by the cell context in which they operate. These studies have revealed that notwithstanding differences in drug pharmokinetics, the activity of an ER ligand is determined primarily by (a) the impact that a given ligand has on the receptor conformation and (b) the ability of structurally distinct ER-ligand complexes to interact with functionally distinct coregulators. Exploitation of the established relationships between ER structure and activity has led to the development of improved SERMs with more favorable therapeutic properties and of tissue-selective estrogen complexes, drugs in which a SERM and an ER agonist are combined to yield a blended activity that results in distinct clinical profiles. Remarkably, endogenous ligands that exhibit SERM activity have also been identified. One of these ligands, 27-hydroxycholesterol (27HC), has been shown to manifest ER-dependent pathological activities in the cardiovascular system, bone and mammary gland. Whereas the physiological activity of 27HC remains to be determined, its discovery highlights how cells have adopted mechanisms to allow the same receptor ligand complex to manifest different activities in different cells, and also how these processes can be exploited for new drug development. PMID:25084324

  2. 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

  3. Selective Estrogen Receptor Modulation Increases Hippocampal Activity during Probabilistic Association Learning in Schizophrenia

    PubMed Central

    Kindler, Jochen; Weickert, Cynthia Shannon; Skilleter, Ashley J; Catts, Stanley V; Lenroot, Rhoshel; Weickert, Thomas W

    2015-01-01

    People with schizophrenia show probabilistic association learning impairment in conjunction with abnormal neural activity. The selective estrogen receptor modulator (SERM) raloxifene preserves neural activity during memory in healthy older men and improves memory in schizophrenia. Here, we tested the extent to which raloxifene modifies neural activity during learning in schizophrenia. Nineteen people with schizophrenia participated in a twelve-week randomized, double-blind, placebo-controlled, cross-over adjunctive treatment trial of the SERM raloxifene administered orally at 120 mg daily to assess brain activity during probabilistic association learning using functional magnetic resonance imaging (fMRI). Raloxifene improved probabilistic association learning and significantly increased fMRI BOLD activity in the hippocampus and parahippocampal gyrus relative to placebo. A separate region of interest confirmatory analysis in 21 patients vs 36 healthy controls showed a positive association between parahippocampal neural activity and learning in patients, but no such relationship in the parahippocampal gyrus of healthy controls. Thus, selective estrogen receptor modulation by raloxifene concurrently increases activity in the parahippocampal gyrus and improves probabilistic association learning in schizophrenia. These results support a role for estrogen receptor modulation of mesial temporal lobe neural activity in the remediation of learning disabilities in both men and women with schizophrenia. PMID:25829142

  4. 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…

  5. Selective Estrogen Receptor Modulation by Larrea nitida on MCF-7 Cell Proliferation and Immature Rat Uterus

    PubMed Central

    Ahn, Hye-Na; Jeong, Si-Yeon; Bae, Gyu-Un; Chang, Minsun; Zhang, Dongwei; Liu, Xiyuan; Pei, Yihua; Chin, Young-Won; Lee, Joongku; Oh, Sei-Ryang; Song, Yun Seon

    2014-01-01

    Larrea nitida is a plant that belongs to the Zygophyllaceae family and is widely used in South America to treat inflammatory diseases, tumors and menstrual pain. However, its pharmacological activity remains unclear. In this study we evaluated the property of selective estrogen receptor modulator (SERM) of Larrea nitida extracts (LNE) as a phytoestrogen that can mimic, modulate or disrupt the actions of endogenous estrogens, depending on the tissue and relative amount of other SERMs. To investigate the property of SERM of LNE, we performed MCF-7 cell proliferation assays, estrogen response element (ERE)-luciferase reporter gene assay, human estrogen receptor (hER) binding assays and in vivo uterotrophic assay. To gain insight into the active principles, we performed a bioassay-guided analysis of LNE employing solvents of various polarities and using classical column chromatography, which yielded 16 fractions (LNs). LNE showed high binding affinities for hERα and hERβ with IC50 values of 1.20 ×10−7 g/ml and 1.00×10−7 g/ml, respectively. LNE induced 17β-estradiol (E2)-induced MCF-7 cell proliferation, however, it reduced the proliferation in the presence of E2. Furthermore, LNE had an atrophic effect in the uterus of immature rats through reducing the expression level of progesterone receptor (PR) proteins. LN08 and LN10 had more potent affinities for binding on hER α and β than other fractions. Our results indicate that LNE had higher binding affinities for hERβ than hERα, and showed SERM properties in MCF-7 breast cancer cells and the rat uterus. LNE may be useful for the treatment of estrogen-related conditions, such as female cancers and menopause. PMID:25143815

  6. Discovery of a sulfamate-based steroid sulfatase inhibitor with intrinsic selective estrogen receptor modulator properties.

    PubMed

    Ouellet, Charles; Maltais, René; Ouellet, Étienne; Barbeau, Xavier; Lagüe, Patrick; Poirier, Donald

    2016-08-25

    Steroid sulfatase (STS), the enzyme which converts inactive sulfated steroid precursors into active hormones, is a promising therapeutic target for the treatment of estrogen-sensitive breast cancer. We report herein the synthesis and in vitro study of dual-action STS inhibitors with selective estrogen-receptor modulator (SERM) effects. A library of tetrahydroisoquinoline-N-substituted derivatives (phenolic compounds) was synthesized by solid-phase chemistry and tested on estrogen-sensitive breast cancer T-47D cells. Three phenolic compounds devoid of estrogenic activity and toxicity emerged from this screening. Their sulfamate analogs were then synthesized, tested in STS-transfected HEK-293 cells, and found to be potent inhibitors of the enzyme (IC50 of 3.9, 8.9, and 16.6 nM). When tested in T-47D cells they showed no estrogenic activity and produced a moderate antiestrogenic activity. The compounds were further tested on osteoblast-like Saos-2 cells and found to significantly stimulate their proliferation as well as their alkaline phosphatase activity, thus suggesting a SERM activity. These results are supported by molecular docking experiments. PMID:27155470

  7. Placental Kisspeptins Differentially Modulate Vital Parameters of Estrogen Receptor-Positive and -Negative Breast Cancer Cells.

    PubMed

    Rasoulzadeh, Zahra; Ghods, Roya; Kazemi, Tohid; Mirzadegan, Ebrahim; Ghaffari-Tabrizi-Wizsy, Nassim; Rezania, Simin; Kazemnejad, Somaieh; Arefi, Soheila; Ghasemi, Jamileh; Vafaei, Sedigheh; Mahmoudi, Ahmad-Reza; Zarnani, Amir-Hassan

    2016-01-01

    Kisspeptins (KPs) are major regulators of trophoblast and cancer invasion. Thus far, limited and conflicting data are available on KP-mediated modulation of breast cancer (BC) metastasis; mostly based on synthetic KP-10, the most active fragment of KP. Here, we report for the first time comprehensive functional effects of term placental KPs on proliferation, adhesion, Matrigel invasion, motility, MMP activity and pro-inflammatory cytokine production in MDA-MB-231 (estrogen receptor-negative) and MCF-7 (estrogen receptor-positive). KPs were expressed at high level by term placental syncytiotrophoblasts and released in soluble form. Placental explant conditioned medium containing KPs (CM) significantly reduced proliferation of both cell types compared to CM without (w/o) KP (CM-w/o KP) in a dose- and time-dependent manner. In MDA-MB-231 cells, placental KPs significantly reduced adhesive properties, while increased MMP9 and MMP2 activity and stimulated invasion. Increased invasiveness of MDA-MB-231 cells after CM treatment was inhibited by KP receptor antagonist, P-234. CM significantly reduced motility of MCF-7 cells at all time points (2-30 hr), while it stimulated motility of MDA-MB-231 cells. These effects were reversed by P-234. Co-treatment with selective ER modulators, Tamoxifen and Raloxifene, inhibited the effect of CM on motility of MCF-7 cells. The level of IL-6 in supernatant of MCF-7 cells treated with CM was higher compared to those treated with CM-w/o KP. Both cell types produced more IL-8 after treatment with CM compared to those treated with CM-w/o KP. Taken together, our observations suggest that placental KPs differentially modulate vital parameters of estrogen receptor-positive and -negative BC cells possibly through modulation of pro-inflammatory cytokine production. PMID:27101408

  8. Placental Kisspeptins Differentially Modulate Vital Parameters of Estrogen Receptor-Positive and -Negative Breast Cancer Cells

    PubMed Central

    Rasoulzadeh, Zahra; Ghods, Roya; Kazemi, Tohid; Mirzadegan, Ebrahim; Ghaffari-Tabrizi-Wizsy, Nassim; Rezania, Simin; Kazemnejad, Somaieh; Arefi, Soheila; Ghasemi, Jamileh; Vafaei, Sedigheh; Mahmoudi, Ahmad-Reza; Zarnani, Amir-Hassan

    2016-01-01

    Kisspeptins (KPs) are major regulators of trophoblast and cancer invasion. Thus far, limited and conflicting data are available on KP-mediated modulation of breast cancer (BC) metastasis; mostly based on synthetic KP-10, the most active fragment of KP. Here, we report for the first time comprehensive functional effects of term placental KPs on proliferation, adhesion, Matrigel invasion, motility, MMP activity and pro-inflammatory cytokine production in MDA-MB-231 (estrogen receptor-negative) and MCF-7 (estrogen receptor-positive). KPs were expressed at high level by term placental syncytiotrophoblasts and released in soluble form. Placental explant conditioned medium containing KPs (CM) significantly reduced proliferation of both cell types compared to CM without (w/o) KP (CM-w/o KP) in a dose- and time-dependent manner. In MDA-MB-231 cells, placental KPs significantly reduced adhesive properties, while increased MMP9 and MMP2 activity and stimulated invasion. Increased invasiveness of MDA-MB-231 cells after CM treatment was inhibited by KP receptor antagonist, P-234. CM significantly reduced motility of MCF-7 cells at all time points (2–30 hr), while it stimulated motility of MDA-MB-231 cells. These effects were reversed by P-234. Co-treatment with selective ER modulators, Tamoxifen and Raloxifene, inhibited the effect of CM on motility of MCF-7 cells. The level of IL-6 in supernatant of MCF-7 cells treated with CM was higher compared to those treated with CM-w/o KP. Both cell types produced more IL-8 after treatment with CM compared to those treated with CM-w/o KP. Taken together, our observations suggest that placental KPs differentially modulate vital parameters of estrogen receptor-positive and -negative BC cells possibly through modulation of pro-inflammatory cytokine production. PMID:27101408

  9. Detection of Endogenous Selective Estrogen Receptor Modulators such as 27-Hydroxycholesterol.

    PubMed

    Nelson, Erik R

    2016-01-01

    The estrogen receptors (ERs) belong to the nuclear receptor superfamily, and as such act as ligand inducible transcription factors, mediating the effects of estrogens. However, their pharmacology is complex, having the ability to be differentially activated by ligands. Such ligands possess the ability to behave as either ER-agonists or ER-antagonists, depending on the cellular and tissue context, and have been termed Selective Estrogen Receptor Modulators (SERMs). Several SERMs have been identified with clinical relevance such as tamoxifen and raloxifene. Recently, 27-hydroxycholesterol has been characterized as the first identified endogenous SERM leading to the notion that other endogenous SERMs may exist, each having potential pathophysiological functions. This, coupled with the historic pharmaceutical interest as well as growing concern over chemicals in the environment with the ability to behave like SERMs, has increased the demand for assays to detect SERM-like activity. Here, we describe a common, straightforward in vitro assay investigating the induction of classic ER-target genes in MCF7 breast cancer cells, allowing one to identify ligands with SERM-like activity. PMID:26585155

  10. 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

  11. Selective Estrogen Receptor Modulator Delivery of Quinone Warheads to DNA Triggering Apoptosis in Breast Cancer Cells

    PubMed Central

    Peng, Kuan-wei; Wang, Huali; Qin, Zhihui; Wijewickrama, Gihani T.; Lu, Meiling; Wang, Zhican; Bolton, Judy L.; Thatcher, Gregory R. J.

    2009-01-01

    Estrogen exposure is a risk factor for breast cancer and estrogen oxidative metabolites have been implicated in chemical carcinogenesis. Oxidation of the catechol metabolite of estrone (4-OHE) and the β-naphthohydroquinone metabolite of equilenin (4-OHEN) gives o-quinones that produce ROS and damage DNA by adduction and oxidation. To differentiate hormonal and chemical carcinogensis pathways in estrogen receptor positive ER(+) cells, catechol or β-naphthohydroquinone warheads were conjugated to the selective estrogen receptor modulator (SERM) desmethylarzoxifene (DMA). ER binding was retained in the DMA conjugates; both were antiestrogens with submicromolar potency in mammary and endometrial cells. Cytotoxicity, apoptosis, and caspase-3/7 activation were compared in ER(+) and ER(−)MDA-MB-231 cells, and production of ROS was detected using a fluorescent reporter. Comparison was made to DMA, isolated warheads, and a DMA-mustard. Conjugation of warheads to DMA increased cytotoxicity accompanied by induction of apoptosis and activation of caspase-3/7. Activation of caspase-3/7, induction of apoptosis, and cytotoxicity were all increased significantly in ER(+) cells for the DMA conjugates. ROS production was localized in the nucleus for conjugates in ER(+) cells. Observations are compatible with β-naphthohydroquinone and catechol groups being concentrated in the nucleus by ER binding, where oxidation and ROS production result, concomitant with caspase-dependent apoptosis. The results suggest DNA damage induced by catechol estrogen metabolites can be amplified in ER(+) cells independent of hormonal activity. The novel conjugation of quinone warheads to an ER-targeting SERM gives ER-dependent, enhanced apoptosis in mammary cancer cells of potential application in cancer therapy. PMID:19839584

  12. Effects of Estrogen Receptor Modulators on Morphine Induced Sensitization in Mice Memory

    PubMed Central

    Anoush, Mahdieh; Jani, Ali; Sahebgharani, Moosa; Jafari, Mohammad Reza

    2015-01-01

    Objective: In this study, the effects of estradiol valerate and raloxifenea selective estrogen receptor modulator; (SERM) on morphine induced sensitization were examined in mice memory, according to the step-down passive avoidance task. Method: The mice received morphine or estradiol and raloxifene for three days alone or in combination with morphine. After a drug free period of 5 days, the subjects received saline or morphine as pre- training treatments followed by a pre-test saline administration. The memory retrieval was evaluated using step-down passive avoidance test both on the training and test day. Results: The results illustrated that the three- day administration of morphine induced sensitization through the enhancement of memory retrieval (morphine induced sensitization in mice memory). Both the three- day administration of estradiol valerate alone and with morphine (5 mg/kg) restored memory. On the other hand, the three- day administration of raloxifene had no effect on memory retrieval alone, but declined morphine induced sensitization in mice memory. Conclusion: The results of the study indicated that there is an interaction between estrogen receptor modulators and morphine induced sensitization in mice memory. PMID:26877753

  13. Selective estrogen receptor modulator (SERM) lasofoxifene forms reactive quinones similar to estradiol.

    PubMed

    Michalsen, Bradley T; Gherezghiher, Teshome B; Choi, Jaewoo; Chandrasena, R Esala P; Qin, Zhihui; Thatcher, Gregory R J; Bolton, Judy L

    2012-07-16

    The bioactivation of both endogenous and equine estrogens to electrophilic quinoid metabolites has been postulated as a contributing factor in carcinogenic initiation and/or promotion in hormone sensitive tissues. Bearing structural resemblance to estrogens, extensive studies have shown that many selective estrogen receptor modulators (SERMs) are subject to similar bioactivation pathways. Lasofoxifene (LAS), a third generation SERM which has completed phase III clinical trials for the prevention and treatment of osteoporosis, is currently approved in the European Union for this indication. Previously, Prakash et al. (Drug Metab. Dispos. (2008) 36, 1218-1226) reported that similar to estradiol, two catechol regioisomers of LAS are formed as primary oxidative metabolites, accounting for roughly half of the total LAS metabolism. However, the potential for further oxidation of these catechols to electrophilic o-quinones has not been reported. In the present study, LAS was synthesized and its oxidative metabolism investigated in vitro under various conditions. Incubation of LAS with tyrosinase, human liver microsomes, or rat liver microsomes in the presence of GSH as a trapping reagent resulted in the formation of two mono-GSH and two di-GSH catechol conjugates which were characterized by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Similar conjugates were also detected in incubations with P450 3A4, P450 2D6, and P450 1B1 supersomes. Interestingly, these conjugates were also detected as major metabolites when compared to competing detoxification pathways such as glucuronidation and methylation. The 7-hydroxylasofoxifene (7-OHLAS) catechol regioisomer was also synthesized and oxidized either chemically or enzymatically to an o-quinone that was shown to form depurinating adducts with DNA. Collectively, these data show that analogous to estrogens, LAS is oxidized to catechols and o-quinones which could potentially contribute to in vivo toxicity for this SERM

  14. The Selective Estrogen Receptor Modulator (SERM) Lasofoxifene Forms Reactive Quinones Similar to Estradiol

    PubMed Central

    Michalsen, Bradley T.; Gherezghiher, Teshome B.; Choi, Jaewoo; Esala, R.; Chandrasena, P.; Qin, Zhihui; Thatcher, Gregory R.J.; Bolton, Judy L.

    2012-01-01

    The bioactivation of both endogenous and equine estrogens to electrophilic quinoid metabolites has been postulated as a contributing factor in carcinogenic initiation and/or promotion in hormone sensitive tissues. Bearing structural resemblance to estrogens, extensive studies have shown that many selective estrogen receptor modulators (SERMs) are subject to similar bioactivation pathways. Lasofoxifene (LAS), a third generation SERM which has completed Phase III clinical trials for the prevention and treatment of osteoporosis, is currently approved in the European Union for this indication. Previously, Prakash et al. (Drug Metab. Dispos. 2008, 36, 1218-26) reported that similar to estradiol, two catechol regioisomers of LAS are formed as primary oxidative metabolites, accounting for roughly half of total LAS metabolism. However, the potential for further oxidation of these catechols to electrophilic o-quinones has not been reported. In the present study, LAS was synthesized and its oxidative metabolism investigated in vitro under various conditions. Incubation of LAS with tyrosinase, human liver microsomes, or rat liver microsomes in the presence of GSH as a trapping reagent resulted in formation of two mono-GSH and two di-GSH catechol conjugates which were characterized by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Similar conjugates were also detected in incubations with P450 3A4, P450 2D6, and P450 1B1 supersomes. Interestingly, these conjugates were also detected as major metabolites when compared to competing detoxification pathways such as glucuronidation and methylation. The 7-hydroxylasofoxifene (7-OHLAS) catechol regioisomer was also synthesized and oxidized either chemically or enzymatically to an o-quinone that was shown to form depurinating adducts with DNA. Collectively, these data show that analogous to estrogens, LAS is oxidized to catechols and o-quinones which could potentially contribute to in vivo toxicity for this SERM. PMID

  15. Differential network analysis reveals the genome-wide landscape of estrogen receptor modulation in hormonal cancers

    PubMed Central

    Hsiao, Tzu-Hung; Chiu, Yu-Chiao; Hsu, Pei-Yin; Lu, Tzu-Pin; Lai, Liang-Chuan; Tsai, Mong-Hsun; Huang, Tim H.-M.; Chuang, Eric Y.; Chen, Yidong

    2016-01-01

    Several mutual information (MI)-based algorithms have been developed to identify dynamic gene-gene and function-function interactions governed by key modulators (genes, proteins, etc.). Due to intensive computation, however, these methods rely heavily on prior knowledge and are limited in genome-wide analysis. We present the modulated gene/gene set interaction (MAGIC) analysis to systematically identify genome-wide modulation of interaction networks. Based on a novel statistical test employing conjugate Fisher transformations of correlation coefficients, MAGIC features fast computation and adaption to variations of clinical cohorts. In simulated datasets MAGIC achieved greatly improved computation efficiency and overall superior performance than the MI-based method. We applied MAGIC to construct the estrogen receptor (ER) modulated gene and gene set (representing biological function) interaction networks in breast cancer. Several novel interaction hubs and functional interactions were discovered. ER+ dependent interaction between TGFβ and NFκB was further shown to be associated with patient survival. The findings were verified in independent datasets. Using MAGIC, we also assessed the essential roles of ER modulation in another hormonal cancer, ovarian cancer. Overall, MAGIC is a systematic framework for comprehensively identifying and constructing the modulated interaction networks in a whole-genome landscape. MATLAB implementation of MAGIC is available for academic uses at https://github.com/chiuyc/MAGIC. PMID:26972162

  16. Differential network analysis reveals the genome-wide landscape of estrogen receptor modulation in hormonal cancers.

    PubMed

    Hsiao, Tzu-Hung; Chiu, Yu-Chiao; Hsu, Pei-Yin; Lu, Tzu-Pin; Lai, Liang-Chuan; Tsai, Mong-Hsun; Huang, Tim H-M; Chuang, Eric Y; Chen, Yidong

    2016-01-01

    Several mutual information (MI)-based algorithms have been developed to identify dynamic gene-gene and function-function interactions governed by key modulators (genes, proteins, etc.). Due to intensive computation, however, these methods rely heavily on prior knowledge and are limited in genome-wide analysis. We present the modulated gene/gene set interaction (MAGIC) analysis to systematically identify genome-wide modulation of interaction networks. Based on a novel statistical test employing conjugate Fisher transformations of correlation coefficients, MAGIC features fast computation and adaption to variations of clinical cohorts. In simulated datasets MAGIC achieved greatly improved computation efficiency and overall superior performance than the MI-based method. We applied MAGIC to construct the estrogen receptor (ER) modulated gene and gene set (representing biological function) interaction networks in breast cancer. Several novel interaction hubs and functional interactions were discovered. ER+ dependent interaction between TGFβ and NFκB was further shown to be associated with patient survival. The findings were verified in independent datasets. Using MAGIC, we also assessed the essential roles of ER modulation in another hormonal cancer, ovarian cancer. Overall, MAGIC is a systematic framework for comprehensively identifying and constructing the modulated interaction networks in a whole-genome landscape. MATLAB implementation of MAGIC is available for academic uses at https://github.com/chiuyc/MAGIC. PMID:26972162

  17. 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

  18. Modulators of estrogen receptor inhibit proliferation and migration of prostate cancer cells.

    PubMed

    Piccolella, Margherita; Crippa, Valeria; Messi, Elio; Tetel, Marc J; Poletti, Angelo

    2014-01-01

    In the initial stages, human prostate cancer (PC) is an androgen-sensitive disease, which can be pharmacologically controlled by androgen blockade. This therapy often induces selection of androgen-independent PC cells with increased invasiveness. We recently demonstrated, both in cells and mice, that a testosterone metabolite locally synthetized in prostate, the 5α-androstane-3β, 17β-diol (3β-Adiol), inhibits PC cell proliferation, migration and invasion, acting as an anti-proliferative/anti-metastatic agent. 3β-Adiol is unable to bind androgen receptor (AR), but exerts its protection against PC by specifically interacting with estrogen receptor beta (ERβ). Because of its potential retro-conversion to androgenic steroids, 3β-Adiol cannot be used "in vivo", thus, the aims of this study were to investigate the capability of four ligands of ERβ (raloxifen, tamoxifen, genistein and curcumin) to counteract PC progression by mimicking the 3β-Adiol activity. Our results demonstrated that raloxifen, tamoxifen, genistein and curcumin decreased DU145 and PC3 cell proliferation in a dose-dependent manner; in addition, all four compounds significantly decreased the detachment of cells seeded on laminin or fibronectin. Moreover, raloxifen, tamoxifen, genistein and curcumin-treated DU145 and PC3 cells showed a significant decrease in cell migration. Notably, all these effects were reversed by the anti-estrogen, ICI 182,780, suggesting that their actions are mediated by the estrogenic pathway, via the ERβ, the only isoform present in these PCs. In conclusion, these data demonstrate that by selectively activating the ERβ, raloxifen, tamoxifen, genistein and curcumin inhibit human PC cells proliferation and migration favoring cell adesion. These synthetic and natural modulators of ER action may exert a potent protective activity against the progression of PC even in its androgen-independent status. PMID:24184124

  19. Selective estrogen receptor modulators differentially alter the immune response of gilthead seabream juveniles.

    PubMed

    Rodenas, M C; Cabas, I; García-Alcázar, A; Meseguer, J; Mulero, V; García-Ayala, A

    2016-05-01

    17α-ethynylestradiol (EE2), a synthetic estrogen used in oral contraceptives and hormone replacement therapy, tamoxifen (Tmx), a selective estrogen-receptor modulator used in hormone replacement therapy, and G1, a G protein-coupled estrogen receptor (GPER) selective agonist, differentially increased the hepatic vitellogenin (vtg) gene expression and altered the immune response in adult gilthead seabream (Sparus aurata L.) males. However, no information exists on the effects of these compounds on the immune response of juveniles. This study aims, for the first time, to investigate the effects of the dietary intake of EE2, Tmx or G1 on the immune response of gilthead seabream juveniles and the capacity of the immune system of the specimens to recover its functionality after ceasing exposures (recovery period). The specimens were immunized with hemocyanin in the presence of aluminium adjuvant 1 (group A) or 120 (group B) days after the treatments ceased (dpt). The results indicate that EE2 and Tmx, but not G1, differentially promoted a transient alteration in hepatic vtg gene expression. Although all three compounds did not affect the production of reactive oxygen intermediates, they inhibited the induction of interleukin-1β (il1b) gene expression after priming. Interestingly, although Tmx increased the percentage of IgM-positive cells in both head kidney and spleen during the recovery period, the antibody response of vaccinated fish varied depending on the compound used and when the immunization was administered. Taken together, our results suggest that these compounds differentially alter the capacity of fish to respond to infection during ontogeny and, more interestingly, that the adaptive immune response remained altered to an extent that depends on the compound. PMID:27012396

  20. 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

  1. Renoprotective effects of a selective estrogen receptor modulator, Raloxifene in an animal model of diabetic nephropathy

    PubMed Central

    Dixon, Alexis; Corinne, C. Wells; Singh, Sandhya; Babayan, Regina; Maric, Christine

    2011-01-01

    Background/Aims Our previous studies have shown that supplementation with 17-β estradiol (E2) from the onset of diabetes attenuates diabetic nephropathy. But, E2 is accompanied by feminizing effects as well as adverse side effects on other organs. The current study examined the renoprotective effects of a selective estrogen receptor modulator, raloxifene (RAL), in an experimental model of diabetic nephropathy. RAL activates estrogen receptors and estrogen receptor-mediated cellular events without the side effects of E2. Methods The study was performed in Sprague-Dawley non-diabetic (ND), streptozotocin (STZ)-induced diabetic (D) and STZ-induced diabetic+raloxifene (D+RAL) rats (n=6/group). Results After 12 weeks of treatment, D was associated with increased albumin excretion (UAE; ND, 4.2±0.4; ND, 41.3±9.0 mg/day), glomerulosclerosis (GSI; ND, 0.26±0.04; D, 1.86±0.80 AU), tubulointerstitial fibrosis (TIFI; ND, 0.37±0.05; D, 2.12±0.50 AU), increased collagen type I (CI; ND, 1.31±0.07; D, 4.65±0.09 ROD), collagen type IV (CIV; ND, 0.64±0.03; D, 1.37±0.11 ROD) and transforming growth factor beta protein expression (TGF-β; ND, 0.65±0.08; D, 1.25±0.10 ROD), increased density of CD68-positive cells (CD68; ND, 1.37±3.02; D, 29.2±1.74 cells/mm2) and increased plasma levels of interleukin-6 (IL-6; ND, 14.8±5.0; D, 51.3±14.0 pg/ml). Treatment with RAL partially or fully attenuated these processes (UAE, 21.0±5.0 mg/day; GSI, 0.40±0.06 AU; TIFI, 0.20±0.04 AU; CI, 2.55±0.49 ROD; CIV, 0.70±0.09 ROD; TGF-β, 0.91±0.08 ROD; CD68, 6.03±2.38 cells/mm2; IL-6, 31.2±5.0 pg/ml). Conclusions Our data indicate that treatment with RAL attenuates albuminuria and renal structural changes associated with diabetes. PMID:17308373

  2. Modulation of Runx2 Activity by Estrogen Receptor-α: Implications for Osteoporosis and Breast Cancer

    PubMed Central

    Khalid, Omar; Baniwal, Sanjeev K.; Purcell, Daniel J.; Leclerc, Nathalie; Gabet, Yankel; Stallcup, Michael R.; Coetzee, Gerhard A.; Frenkel, Baruch

    2008-01-01

    The transcription factors Runx2 and estrogen receptor-α (ERα) are involved in numerous normal and disease processes, including postmenopausal osteoporosis and breast cancer. Using indirect immunofluorescence microscopy and pull-down techniques, we found them to colocalize and form complexes in a ligand-dependent manner. Estradiol-bound ERα strongly interacted with Runx2 directly through its DNA-binding domain and only indirectly through its N-terminal and ligand-binding domains. Runx2’s amino acids 417–514, encompassing activation domain 3 and the nuclear matrix targeting sequence, were sufficient for interaction with ERα’s DNA-binding domain. As a consequence of the interaction, Runx2’s transcriptional activation activity was strongly repressed, as shown by reporter assays in COS7 cells, breast cancer cells, and late-stage MC3T3-E1 osteoblast cultures. Metaanalysis of gene expression in 779 breast cancer biopsies indicated negative correlation between the expression of ERα and Runx2 target genes. Selective ER modulators (SERM) induced ERα-Runx2 interactions but led to various functional outcomes. The regulation of Runx2 by ERα may play key roles in osteoblast and breast epithelial cell growth and differentiation; hence, modulation of Runx2 by native and synthetic ERα ligands offers new avenues in selective ER modulator evaluation and development. PMID:18755791

  3. 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

  4. 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

  5. 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.

  6. 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

  7. 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

  8. 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

  9. Clinically used selective estrogen receptor modulators affect different steps of macrophage-specific reverse cholesterol transport

    PubMed Central

    Fernández-Suárez, María E.; Escolà-Gil, Joan C.; Pastor, Oscar; Dávalos, Alberto; Blanco-Vaca, Francisco; Lasunción, Miguel A.; Martínez-Botas, Javier; Gómez-Coronado, Diego

    2016-01-01

    Selective estrogen receptor modulators (SERMs) are widely prescribed drugs that alter cellular and whole-body cholesterol homeostasis. Here we evaluate the effect of SERMs on the macrophage-specific reverse cholesterol transport (M-RCT) pathway, which is mediated by HDL. Treatment of human and mouse macrophages with tamoxifen, raloxifene or toremifene induced the accumulation of cytoplasmic vesicles of acetyl-LDL-derived free cholesterol. The SERMs impaired cholesterol efflux to apolipoprotein A-I and HDL, and lowered ABCA1 and ABCG1 expression. These effects were not altered by the antiestrogen ICI 182,780 nor were they reproduced by 17β-estradiol. The treatment of mice with tamoxifen or raloxifene accelerated HDL-cholesteryl ester catabolism, thereby reducing HDL-cholesterol concentrations in serum. When [3H]cholesterol-loaded macrophages were injected into mice intraperitoneally, tamoxifen, but not raloxifene, decreased the [3H]cholesterol levels in serum, liver and feces. Both SERMs downregulated liver ABCG5 and ABCG8 protein expression, but tamoxifen reduced the capacity of HDL and plasma to promote macrophage cholesterol efflux to a greater extent than raloxifene. We conclude that SERMs interfere with intracellular cholesterol trafficking and efflux from macrophages. Tamoxifen, but not raloxifene, impair M-RCT in vivo. This effect is primarily attributable to the tamoxifen-mediated reduction of the capacity of HDL to promote cholesterol mobilization from macrophages. PMID:27601313

  10. Clinically used selective estrogen receptor modulators affect different steps of macrophage-specific reverse cholesterol transport.

    PubMed

    Fernández-Suárez, María E; Escolà-Gil, Joan C; Pastor, Oscar; Dávalos, Alberto; Blanco-Vaca, Francisco; Lasunción, Miguel A; Martínez-Botas, Javier; Gómez-Coronado, Diego

    2016-01-01

    Selective estrogen receptor modulators (SERMs) are widely prescribed drugs that alter cellular and whole-body cholesterol homeostasis. Here we evaluate the effect of SERMs on the macrophage-specific reverse cholesterol transport (M-RCT) pathway, which is mediated by HDL. Treatment of human and mouse macrophages with tamoxifen, raloxifene or toremifene induced the accumulation of cytoplasmic vesicles of acetyl-LDL-derived free cholesterol. The SERMs impaired cholesterol efflux to apolipoprotein A-I and HDL, and lowered ABCA1 and ABCG1 expression. These effects were not altered by the antiestrogen ICI 182,780 nor were they reproduced by 17β-estradiol. The treatment of mice with tamoxifen or raloxifene accelerated HDL-cholesteryl ester catabolism, thereby reducing HDL-cholesterol concentrations in serum. When [(3)H]cholesterol-loaded macrophages were injected into mice intraperitoneally, tamoxifen, but not raloxifene, decreased the [(3)H]cholesterol levels in serum, liver and feces. Both SERMs downregulated liver ABCG5 and ABCG8 protein expression, but tamoxifen reduced the capacity of HDL and plasma to promote macrophage cholesterol efflux to a greater extent than raloxifene. We conclude that SERMs interfere with intracellular cholesterol trafficking and efflux from macrophages. Tamoxifen, but not raloxifene, impair M-RCT in vivo. This effect is primarily attributable to the tamoxifen-mediated reduction of the capacity of HDL to promote cholesterol mobilization from macrophages. PMID:27601313

  11. [Efficacy and safety of selective estrogen receptor modulators in patients with advanced chronic kidney disease].

    PubMed

    Nakai, Kentaro

    2016-09-01

    Selective estrogen receptor modulators(SERMs)have beneficial effects on the improvement of bone mineral density of the spine and hip, and decrease the vertebral fracture in postmenopausal women. Similar to patients with advanced chronic kidney disease, including dialysis patients, however, SERMs cannot decrease the risk of hip fracture, which is extremely high in Japanese dialysis patients. One of the most important disadvantages of SERMs is an increase in the risk of venous thromboembolic events and fatal stroke in high-risk groups of the Framingham Stroke Risk Score. On the other hand, SERMs may be used in unique osteoporosis drugs for reducing the incidence and progression of breast cancer. Moreover, SERMs attenuate oxidative stress and may lessen the deterioration of kidney function in patients with chronic kidney disease. The evidences for the efficacy and safety of SERMs in patients with advanced chronic kidney disease are insufficient, and knowledge concerning the selection and indication of osteoporosis drugs for those patients need to be developed. PMID:27561348

  12. Measuring selective estrogen receptor modulator (SERM)-membrane interactions with second harmonic generation.

    PubMed

    Stokes, Grace Y; Conboy, John C

    2014-01-29

    The interaction of selective estrogen receptor modulators (SERMs) with lipid membranes has been measured at clinically relevant serum concentrations using the label-free technique of second harmonic generation (SHG). The SERMs investigated in this study include raloxifene, tamoxifen, and the tamoxifen metabolites 4-hydroxytamoxifen, N-desmethyltamoxifen, and endoxifen. Equilibrium association constants (Ka) were measured for SERMs using varying lipid compositions to examine how lipid phase, packing density, and cholesterol content impact SERM-membrane interactions. Membrane-binding properties of tamoxifen and its metabolites were compared on the basis of hydroxyl group substitution and amine ionization to elucidate how the degree of drug ionization impacts membrane partitioning. SERM-membrane interactions were probed under multiple pH conditions, and drug adsorption was observed to vary with the concentration of soluble neutral species. The agreement between Ka values derived from SHG measurements of the interactions between SERMs and artificial cell membranes and independent observations of the SERMs efficacy from clinical studies suggests that quantifying membrane adsorption properties may be important for understanding SERM action in vivo. PMID:24410282

  13. Modulation of estrogen and epidermal growth factor receptors by rosemary extract in breast cancer cells.

    PubMed

    González-Vallinas, Margarita; Molina, Susana; Vicente, Gonzalo; Sánchez-Martínez, Ruth; Vargas, Teodoro; García-Risco, Mónica R; Fornari, Tiziana; Reglero, Guillermo; Ramírez de Molina, Ana

    2014-06-01

    Breast cancer is the leading cause of cancer-related mortality among females worldwide, and therefore the development of new therapeutic approaches is still needed. Rosemary (Rosmarinus officinalis L.) extract possesses antitumor properties against tumor cells from several organs, including breast. However, in order to apply it as a complementary therapeutic agent in breast cancer, more information is needed regarding the sensitivity of the different breast tumor subtypes and its effect in combination with the currently used chemotherapy. Here, we analyzed the antitumor activities of a supercritical fluid rosemary extract (SFRE) in different breast cancer cells, and used a genomic approach to explore its effect on the modulation of ER-α and HER2 signaling pathways, the most important mitogen pathways related to breast cancer progression. We found that SFRE exerts antitumor activity against breast cancer cells from different tumor subtypes and the downregulation of ER-α and HER2 receptors by SFRE might be involved in its antitumor effect against estrogen-dependent (ER+) and HER2 overexpressing (HER2+) breast cancer subtypes. Moreover, SFRE significantly enhanced the effect of breast cancer chemotherapy (tamoxifen, trastuzumab, and paclitaxel). Overall, our results support the potential utility of SFRE as a complementary approach in breast cancer therapy. PMID:24615943

  14. The Evolution of Nonsteroidal Antiestrogens to become Selective Estrogen Receptor Modulators

    PubMed Central

    Jordan, V. Craig; McDaniel, Russell; Agboke, Fadeke; Maximov, Philipp Y.

    2014-01-01

    applications for selective estrogen receptor (ER) modulation. This idea was to establish a new group of medicines now called Selective ER Modulators (SERMs). Today there are 5 SERMs FDA approved (one other in Europe) for applications ranging from the reduction of breast cancer risk and osteoporosis to the reduction of menopausal hot flashes and improvements in dyspareunia and vaginal lubrication. This article charts the origins of the current path for progress in women’s health with SERMs. PMID:24949934

  15. The sexually dimorphic role of adipose and adipocyte estrogen receptors in modulating adipose tissue expansion, inflammation, and fibrosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our data demonstrate that estrogens, estrogen receptor-alpha (ERalpha), and estrogen receptor-ßeta (ERßeta) regulate adipose tissue distribution, inflammation, fibrosis, and glucose homeostasis, by determining that alphaERKO mice have increased adipose tissue inflammation and fibrosis prior to obesi...

  16. ERbeta-selective estrogen receptor modulators produce antianxiety behavior when administered systemically to ovariectomized rats.

    PubMed

    Walf, Alicia A; Frye, Cheryl A

    2005-09-01

    17beta-Estradiol (E2) may influence anxiety behavior; however, its effects and mechanisms are not well understood. To determine whether E2's effects on anxiety behavior may involve actions at intracellular estrogen receptor (ER) alpha or beta isoforms, selective ER modulators (SERMs) were administered (10 microg; s.c.) to ovariectomized rats 48 h before testing for anxiety behavior. Rats received sesame oil vehicle, 17beta-E2, which has a high affinity for ERalpha and ERbeta, or SERMs that vary in their activity at ERalpha and beta. ERalpha-selective SERMs were propyl pyrazole triol (PPT), which has more selective effects at ERalpha, than does the other ERalpha SERM utilized, 17alpha-E2, which also binds ERbeta. ERbeta-selective SERMs were diarylpropionitrile (DPN) and 7,12-dihydrocoumestan (coumestrol). DPN is more selective at ERbeta than coumestrol, which also binds ERalpha. 17beta-E2 and ERbeta-selective SERMs (DPN, coumestrol) produced clear antianxiety behavior in the open field, elevated plus maze, emergence, light-dark transition, defensive freezing, and Vogel punished drinking tasks. Anxiety behavior of rats administered ERalpha-selective SERMs (PPT, 17alpha-E2) was not different from vehicle; however, PPT and 17alpha-E2 enhanced sexual receptivity in a manner similar to 17beta-E2. Coadministration of tamoxifen (10 mg/kg) blocked the antianxiety behavior produced by 17beta-E2, DPN, or coumestrol. Together, these data suggest that actions at ERbeta may underlie some of E2's antianxiety effects. PMID:15798780

  17. A novel carborane analog, BE360, with a carbon-containing polyhedral boron-cluster is a new selective estrogen receptor modulator for bone

    SciTech Connect

    Hirata, Michiko; Inada, Masaki; Matsumoto, Chiho; Takita, Morichika; Ogawa, Takumi; Endo, Yasuyuki; Miyaura, Chisato

    2009-03-06

    Carboranes are a class of carbon-containing polyhedral boron-cluster compounds with globular geometry and hydrophobic surface that interact with hormone receptors. Estrogen deficiency results in marked bone loss due to increased osteoclastic bone resorption in females, but estrogen replacement therapy is not generally used for postmenopausal osteoporosis due to the risk of uterine cancer. We synthesized a novel carborane compound BE360 to clarify its anti-osteoporosis activity. BE360 showed a high binding affinity to estrogen receptors (ER), ER{alpha} and ER{beta}. In ovariectomized (OVX) mice, femoral bone volume was markedly reduced and BE360 dose-dependently restored bone loss in OVX mice. However, BE360 did not exhibit any estrogenic activity in the uterus. BE360 also restored bone loss in orchidectomized mice without androgenic action in the sex organs. Therefore, BE360 is a novel selective estrogen receptor modulator (SERM) that may offer a new therapy option for osteoporosis.

  18. 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

  19. Evaluation of the Biological Activity of Opuntia ficus indica as a Tissue- and Estrogen Receptor Subtype-Selective Modulator.

    PubMed

    An, Byoung Ha; Jeong, Hyesoo; Zhou, Wenmei; Liu, Xiyuan; Kim, Soolin; Jang, Chang Young; Kim, Hyun-Sook; Sohn, Johann; Park, Hye-Jin; Sung, Na-Hye; Hong, Cheol Yi; Chang, Minsun

    2016-06-01

    Phytoestrogens are selective estrogen receptor modulators (SERMs) with potential for use in hormone replacement therapy (HRT) to relieve peri/postmenopausal symptoms. This study was aimed at elucidating the molecular mechanisms underlying the SERM properties of the extract of Korean-grown Opuntia ficus-indica (KOFI). The KOFI extract induced estrogen response element (ERE)-driven transcription in breast and endometrial cancer cell lines and the expression of endogenous estrogen-responsive genes in breast cancer cells. The flavonoid content of different KOFI preparations affected ERE-luciferase activities, implying that the flavonoid composition likely mediated the estrogenic activities in cells. Oral administration of KOFI decreased the weight gain and levels of both serum glucose and triglyceride in ovariectomized (OVX) rats. Finally, KOFI had an inhibitory effect on the 17β-estradiol-induced proliferation of the endometrial epithelium in OVX rats. Our data demonstrate that KOFI exhibited SERM activity with no uterotrophic side effects. Therefore, KOFI alone or in combination with other botanical supplements, vitamins, or minerals may be an effective and safe alternative active ingredient to HRTs, for the management of postmenopausal symptoms. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26989859

  20. High-Dose Estrogen and Clinical Selective Estrogen Receptor Modulators Induce Growth Arrest, p21, and p53 in Primate Ovarian Surface Epithelial Cells

    SciTech Connect

    Wright, Jay W.; Stouffer, Richard L.; Rodland, Karin D.

    2005-06-09

    Ovarian cancer is the most lethal gynecological cancer affecting women. Hormone-based therapies are variably successful in treating ovarian cancer, but the reasoning behind these therapies is paradoxical. Clinical reagents such as tamoxifen are considered to inhibit or reverse tumor growth by competitive inhibition of the estrogen receptor (ER); however high dose estrogen is as clinically effective as tamoxifen, and it is unlikely that estrogen is acting by blocking ER activity; however, it may be activating a unique function of the ER that is nonmitogenic. For poorly defined reasons, 90% of varian cancers derive from the ovarian surface epithelium (OSE). In vivo the ER-positive OSE is exposed to high estrogen levels, reaching micromolar concentrations in dominant ovarian follicles. Using cultured OSE cells in vitro, we show that these levels of estradiol (1 ug/ml; {approx}3um) block the actions of serum growth factors, activate the G1 phase retinoblastoma AQ:A checkpoint, and induce p21, an inhibitor of kinases that normally inactivate the retinoblastoma checkpoint. We also show that estradiol increases p53 levels, which may contribute to p21 induction. Supporting the hypothesis that clinical selective ER modulators activate this novel ER function, we find that micromolar doses of tamoxifen and the ''pure antiestrogen'' ICI 182,780 elicit the same effects as estradiol. We propose that, in the context of proliferation, these data clarify some paradoxical aspects of hormone-based therapy and suggest that fuller understanding of normal ER function is necessary to improve therapeutic strategies that target the ER. (J Clin Endocrinol Metab 90: 0000-0000, 2005)

  1. 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

  2. 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

  3. 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

  4. Human glutathione S-transferase P1-1 functions as an estrogen receptor α signaling modulator

    SciTech Connect

    Liu, Xiyuan; An, Byoung Ha; Kim, Min Jung; Park, Jong Hoon; Kang, Young Sook; Chang, Minsun

    2014-09-26

    Highlights: • GSTP induces the classical ERα signaling event. • The functional GSTP is a prerequisite for GSTP-induced ERα transcription activity. • The expression of RIP140, a transcription cofactor, was inhibited by GSTP protein. • We propose the novel non-enzymatic role of GSTP. - Abstract: Estrogen receptor α (ERα) plays a crucial role in estrogen-mediated signaling pathways and exerts its action as a nuclear transcription factor. Binding of the ligand-activated ERα to the estrogen response element (ERE) is a central part of ERα-associated signal transduction pathways and its aberrant modulation is associated with many disease conditions. Human glutathione S-transferase P1-1 (GSTP) functions as an enzyme in conjugation reactions in drug metabolism and as a regulator of kinase signaling pathways. It is overexpressed in tumors following chemotherapy and has been associated with a poor prognosis in breast cancer. In this study, a novel regulatory function of GSTP has been proposed in which GSTP modulates ERE-mediated ERα signaling events. Ectopic expression of GSTP was able to induce the ERα and ERE-mediated transcriptional activities in ERα-positive but GSTP-negative MCF7 human breast cancer cells. This inductive effect of GSTP on the ERE-transcription activity was diminished when the cells express a mutated form of the enzyme or are treated with a GSTP-specific chemical inhibitor. It was found that GSTP inhibited the expression of the receptor interacting protein 140 (RIP140), a negative regulator of ERα transcription, at both mRNA and protein levels. Our study suggests a novel non-enzymatic role of GSTP which plays a significant role in regulating the classical ERα signaling pathways via modification of transcription cofactors such as RIP140.

  5. Estrogen receptor KO mice study on rapid modulation of spines and long-term depression in the hippocampus.

    PubMed

    Murakami, Gen; Hojo, Yasushi; Ogiue-Ikeda, Mari; Mukai, Hideo; Chambon, Pierre; Nakajima, Kohei; Ooishi, Yuuki; Kimoto, Tetsuya; Kawato, Suguru

    2015-09-24

    Rapid modulation of hippocampal synaptic plasticity through synaptic estrogen receptors is an essential topic. We analyzed estradiol-induced modulation of CA1 dendritic spines using adult male ERαKO and ERβKO mice. A 2h treatment of estradiol particularly increased the density of middle-head spines (diameter 0.3-0.4 µm) in wild type mouse hippocampal slices. The enhancement of spinogenesis was completely suppressed by MAP kinase inhibitor. Estradiol-induced increase in middle-head spines was observed in ERβKO mice (which express ERα), but not in ERαKO, indicating that ERα is necessary for the spinogenesis. Direct observation of the dynamic estradiol-induced enhancing effect on rapid spinogenesis was performed using time-lapse imaging of spines in hippocampal live slices from yellow fluorescent protein expressed mice. Both appearance and disappearance of spines occurred, and the number of newly appeared spines was significantly greater than that of disappeared spines, resulting in the net increase of the spine density within 2h. As another type of synaptic modulation, we observed that estradiol rapidly enhanced N-methyl-D-aspartate (NMDA)-induced long-term depression (LTD) in CA1 of the wild type mouse hippocampus. In contrast, estradiol did not enhance NMDA-LTD in ERαKO mice, indicating the involvement of ERα in the estrogen signaling. This article is part of a Special Issue entitled SI: Brain and Memory. PMID:25498865

  6. BA321, a novel carborane analog that binds to androgen and estrogen receptors, acts as a new selective androgen receptor modulator of bone in male mice.

    PubMed

    Watanabe, Kenta; Hirata, Michiko; Tominari, Tsukasa; Matsumoto, Chiho; Endo, Yasuyuki; Murphy, Gillian; Nagase, Hideaki; Inada, Masaki; Miyaura, Chisato

    2016-09-01

    Carboranes are a class of carbon-containing polyhedral boron cluster compounds with globular geometry and hydrophobic surface that interact with hormone receptors such as estrogen receptor (ER) and androgen receptor (AR). We have synthesized BA321, a novel carborane compound, which binds to AR. We found here that it also binds to ERs, ERα and ERβ. In orchidectomized (ORX) mice, femoral bone mass was markedly reduced due to androgen deficiency and BA321 restored bone loss in the male, whilst the decreased weight of seminal vesicle in ORX mice was not recovered by administration of BA321. In female mice, BA321 acts as a pure estrogen agonist, and restored both the loss of bone mass and uterine atrophy due to estrogen deficiency in ovariectomized (OVX) mice. In bone tissues, the trabecular bone loss occurred in both ORX and OVX mice, and BA321 completely restored the trabecular bone loss in both sexes. Cortical bone loss occurred in ORX mice but not in OVX mice, and BA321 clearly restored cortical bone loss due to androgen deficiency in ORX mice. Therefore, BA321 is a novel selective androgen receptor modulator (SARM) that may offer a new therapy option for osteoporosis in the male. PMID:27402268

  7. A precisely substituted benzopyran targets androgen refractory prostate cancer cells through selective modulation of estrogen receptors.

    PubMed

    Kumar, Rajeev; Verma, Vikas; Sharma, Vikas; Jain, Ashish; Singh, Vishal; Sarswat, Amit; Maikhuri, Jagdamba P; Sharma, Vishnu L; Gupta, Gopal

    2015-03-15

    Dietary consumption of phytoestrogens like genistein has been linked with lower incidence of prostate cancer. The estradiol-like benzopyran core of genistein confers estrogen receptor-β (ER-β) selectivity that imparts weak anti-proliferative activity against prostate cancer cells. DL-2-[4-(2-piperidinoethoxy)phenyl]-3-phenyl-2H-1-benzopyran (BP), a SERM designed with benzopyran core, targeted androgen independent prostate cancer (PC-3) cells 14-times more potently than genistein, ~25% more efficiently than tamoxifen and 6.5-times more actively than ICI-182780, without forfeiting significant specificity in comparison to genistein. BP increased apoptosis (annexin-V and TUNEL labeling), arrested cell cycle, and significantly increased caspase-3 activity along with mRNA expressions of estrogen receptor (ER)-β and FasL (qPCR) in PC-3 cells. In classical ERE-luc reporter assay BP behaved as a potent ER-α antagonist and ER-β agonist. Accordingly, it decreased expression of ER-α target PS2 (P<0.01) and increased expression of ER-β target TNF-α (P<0.05) genes in PC-3. ER-β deficient PC-3 (siRNA-transfected) was resistant to apoptotic and anti-proliferative actions of SERMs, including stimulation of FasL expression by BP. BP significantly inhibited phosphorylation of Akt and ERK-1/2, JNK and p38 in PC-3 (immunoblotting), and thus adopted a multi-pathway mechanism to exert a more potent anti-proliferative activity against prostate cancer cells than natural and synthetic SERMs. Its precise ER-subtype specific activity presents a unique lead structure for further optimization. PMID:25655200

  8. 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.

  9. 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

  10. Pharmacological activation of estrogen receptors-α and -β differentially modulates keratinocyte differentiation with functional impact on wound healing

    PubMed Central

    PERŽEĽOVÁ, VLASTA; SABOL, FRANTIŠEK; VASILENKO, TOMÁŠ; NOVOTNÝ, MARTIN; KOVÁČ, IVAN; SLEZÁK, MARTIN; ĎURKÁČ, JÁN; HOLLÝ, MARTIN; PILÁTOVÁ, MARTINA; SZABO, PAVOL; VARINSKÁ, LENKA; ČRIEPOKOVÁ, ZUZANA; KUČERA, TOMÁŠ; KALTNER, HERBERT; ANDRÉ, SABINE; GABIUS, HANS-JOACHIM; MUČAJI, PAVEL; SMETANA, KAREL; GÁL, PETER

    2016-01-01

    Estrogen deprivation is considered responsible for many age-related processes, including poor wound healing. Guided by previous observations that estradiol accelerates re-epithelialization through estrogen receptor (ER)-β, in the present study, we examined whether selective ER agonists [4,4′,4″-(4-propyl [1H] pyrazole-1,3,5-triyl)-trisphenol (PPT), ER-α agonist; 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN), ER-β agonist] affect the expression of basic proliferation and differentiation markers (Ki-67, keratin-10, -14 and -19, galectin-1 and Sox-2) of keratinocytes using HaCaT cells. In parallel, ovariectomized rats were treated daily with an ER modulator, and wound tissue was removed 21 days after wounding and routinely processed for basic histological analysis. Our results revealed that the HaCaT keratinocytes expressed both ER-α and -β, and thus are well-suited for studying the effects of ER agonists on epidermal regeneration. The activation of ER-α produced a protein expression pattern similar to that observed in the control culture, with a moderate expression of Ki-67 being observed. However, the activation of ER-β led to an increase in cell proliferation and keratin-19 expression, as well as a decrease in galectin-1 expression. Fittingly, in rat wounds treated with the ER-β agonist (DPN), epidermal regeneration was accelerated. In the present study, we provide information on the mechanisms through which estrogens affect the expression patterns of selected markers, thus modulating keratinocyte proliferation and differentiation; in addition, we demonstrate that the pharmacological activation of ER-α and -β has a direct impact on wound healing. PMID:26397183

  11. A precisely substituted benzopyran targets androgen refractory prostate cancer cells through selective modulation of estrogen receptors

    SciTech Connect

    Kumar, Rajeev; Verma, Vikas; Sharma, Vikas; Jain, Ashish; Singh, Vishal; Sarswat, Amit; Maikhuri, Jagdamba P.; Sharma, Vishnu L.; Gupta, Gopal

    2015-03-15

    Dietary consumption of phytoestrogens like genistein has been linked with lower incidence of prostate cancer. The estradiol-like benzopyran core of genistein confers estrogen receptor-β (ER-β) selectivity that imparts weak anti-proliferative activity against prostate cancer cells. DL-2-[4-(2-piperidinoethoxy)phenyl]-3-phenyl-2H-1-benzopyran (BP), a SERM designed with benzopyran core, targeted androgen independent prostate cancer (PC-3) cells 14-times more potently than genistein, ~ 25% more efficiently than tamoxifen and 6.5-times more actively than ICI-182780, without forfeiting significant specificity in comparison to genistein. BP increased apoptosis (annexin-V and TUNEL labeling), arrested cell cycle, and significantly increased caspase-3 activity along with mRNA expressions of estrogen receptor (ER)-β and FasL (qPCR) in PC-3 cells. In classical ERE-luc reporter assay BP behaved as a potent ER-α antagonist and ER-β agonist. Accordingly, it decreased expression of ER-α target PS2 (P < 0.01) and increased expression of ER-β target TNF-α (P < 0.05) genes in PC-3. ER-β deficient PC-3 (siRNA-transfected) was resistant to apoptotic and anti-proliferative actions of SERMs, including stimulation of FasL expression by BP. BP significantly inhibited phosphorylation of Akt and ERK-1/2, JNK and p38 in PC-3 (immunoblotting), and thus adopted a multi-pathway mechanism to exert a more potent anti-proliferative activity against prostate cancer cells than natural and synthetic SERMs. Its precise ER-subtype specific activity presents a unique lead structure for further optimization. - Highlights: • BP with benzopyran core of genistein was identified for ER-β selective action. • BP was 14-times more potent than genistien in targeting prostate cancer cells. • It behaved as a potent ER-β agonist and ER-α antagonist in gene reporter assays. • BP's anti-proliferative action was inhibited significantly in ER-β deficient cells. • BP — a unique lead structure

  12. Comparative metabolic study between two selective estrogen receptor modulators, toremifene and tamoxifen, in human liver microsomes.

    PubMed

    Watanabe, Miyuki; Watanabe, Noriko; Maruyama, Sakiko; Kawashiro, Takashi

    2015-10-01

    Toremifene (TOR) and Tamoxifen (TAM) are widely used as endocrine therapy for estrogen receptor positive breast cancer. Poor metabolizers of TAM are likely to have worse clinical outcomes than patients who exhibit normal TAM metabolism due to lower plasma level of its active metabolite, 4-hydroxy-N-desmethyl (4OH-NDM) tamoxifen (endoxifen). In this study, we examined the role of individual cytochrome P450 (CYP) isoforms in the metabolism of TOR to N-desmethyl (NDM), 4-hydroxy (4OH) and 4OH-NDM metabolites in comparison with TAM using human liver microsomes (HLMs) with selective chemical inhibitors for each CYP isoform and recombinant CYP proteins. Similar levels of NDM metabolites were formed for both TOR and TAM, and N-demethylation of both compounds was primarily carried out by CYP3A4. We found that the formation of 4OH-NDM-TOR was catalyzed both by CYP2C9 and CYP2D6, whereas the formation of 4OH-TAM and endoxifen was specifically catalyzed by CYP2D6 in HLMs. Our results suggest that the potential contribution of CYP2D6 in the bioactivation pathway of TOR may be lower compared to TAM, and may have a different impact on clinical outcome than CYP2D6 polymorphisms. PMID:26423799

  13. Estrogen-related receptor alpha modulates lactate dehydrogenase activity in thyroid tumors.

    PubMed

    Mirebeau-Prunier, Delphine; Le Pennec, Soazig; Jacques, Caroline; Fontaine, Jean-Fred; Gueguen, Naig; Boutet-Bouzamondo, Nathalie; Donnart, Audrey; Malthièry, Yves; Savagner, Frédérique

    2013-01-01

    Metabolic modifications of tumor cells are hallmarks of cancer. They exhibit an altered metabolism that allows them to sustain higher proliferation rates in hostile environment outside the cell. In thyroid tumors, the expression of the estrogen-related receptor α (ERRα), a major factor of metabolic adaptation, is closely related to the oxidative metabolism and the proliferative status of the cells. To elucidate the role played by ERRα in the glycolytic adaptation of tumor cells, we focused on the regulation of lactate dehydrogenases A and B (LDHA, LDHB) and the LDHA/LDHB ratio. Our study included tissue samples from 10 classical and 10 oncocytic variants of follicular thyroid tumors and 10 normal thyroid tissues, as well as samples from three human thyroid tumor cell lines: FTC-133, XTC.UC1 and RO82W-1. We identified multiple cis-acting promoter elements for ERRα, in both the LDHA and LDHB genes. The interaction between ERRα and LDH promoters was confirmed by chromatin immunoprecipitation assays and in vitro analysis for LDHB. Using knock-in and knock-out cellular models, we found an inverse correlation between ERRα expression and LDH activity. This suggests that thyroid tumor cells may reprogram their metabolic pathways through the up-regulation of ERRα by a process distinct from that proposed by the recently revisited Warburg hypothesis. PMID:23516535

  14. 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

  15. The LIM/homeodomain protein islet-1 modulates estrogen receptor functions.

    PubMed

    Gay, F; Anglade, I; Gong, Z; Salbert, G

    2000-10-01

    LIM/Homeodomain (HD) proteins are classically considered as major transcriptional regulators which, in cooperation with other transcription factors, play critical roles in the developing nervous system. Among LIM/HD proteins, Islet-1 (ISL1) is the earliest known marker of motoneuron differentiation and has been extensively studied in this context. However, ISL1 expression is not restricted to developing motoneurons. In both embryonic and adult central nervous system of rodent and fish, ISL1 is found in discrete brain areas known to express the estrogen receptor (ER). These observations led us to postulate the possible involvement of ISL1 in the control of brain functions by steroid hormones. Dual immunohistochemistry for ISL1 and ER provided evidence for ISL1-ER coexpression by the same neuronal subpopulation within the rat hypothalamic arcuate nucleus. The relationship between ER and ISL1 was further analyzed at the molecular level and we could show that 1) ISL1 directly interacts in vivo and in vitro with the rat ER, as well as with various other nuclear receptors; 2) ISL1-ER interaction is mediated, at least in part, by the ligand binding domain of ER and is significantly strengthened by estradiol; 3) as a consequence, ISL1 prevents ER dimerization in solution, thus leading to a strong and specific inhibition of ER DNA binding activity; 4) ISL1, via its N-terminal LIM domains, specifically inhibits the ER-driven transcriptional activation in some promoter contexts, while ER can serve as a coactivator for ISL1 in other promoter contexts. Taken together, these data suggest that ISL1-ER cross-talk could differentially regulate the expression of ER and ISL1 target genes. PMID:11043578

  16. Testosterone attenuates and the selective estrogen receptor modulator, raloxifene, potentiates amphetamine-induced locomotion in male rats.

    PubMed

    Purves-Tyson, Tertia D; Boerrigter, Danny; Allen, Katherine; Zavitsanou, Katerina; Karl, Tim; Djunaidi, Vanezha; Double, Kay L; Desai, Reena; Handelsman, David J; Weickert, Cynthia Shannon

    2015-04-01

    Although sex steroids are known to modulate brain dopamine, it is still unclear how testosterone modifies locomotor behaviour controlled, at least in part, by striatal dopamine in adolescent males. Our previous work suggests that increasing testosterone during adolescence may bias midbrain neurons to synthesise more dopamine. We hypothesised that baseline and amphetamine-induced locomotion would differ in adult males depending on testosterone exposure during adolescence. We hypothesised that concomitant stimulation of estrogen receptor signaling, through a selective estrogen receptor modulator (SERM), raloxifene, can counter testosterone effects on locomotion. Male Sprague-Dawley rats at postnatal day 45 were gonadectomised (G) or sham-operated (S) prior to the typical adolescent testosterone increase. Gonadectomised rats were either given testosterone replacement (T) or blank implants (B) for six weeks and sham-operated (i.e. intact or endogenous testosterone group) were given blank implants. Subgroups of sham-operated, gonadectomised and gonadectomised/testosterone-replaced rats were treated with raloxifene (R, 5mg/kg) or vehicle (V), daily for the final four weeks. There were six groups (SBV, GBV, GTV, SBR, GBR, GTR). Saline and amphetamine-induced (1.25mg/kg) locomotion in the open field was measured at PND85. Gonadectomy increased amphetamine-induced locomotion compared to rats with endogenous or with exogenous testosterone. Raloxifene increased amphetamine-induced locomotion in rats with either endogenous or exogenous testosterone. Amphetamine-induced locomotion was negatively correlated with testosterone and this relationship was abolished by raloxifene. Lack of testosterone during adolescence potentiates and testosterone exposure during adolescence attenuates amphetamine-induced locomotion. Treatment with raloxifene appears to potentiate amphetamine-induced locomotion and to have an opposite effect to that of testosterone in male rats. PMID:25747465

  17. Estrogen receptors modulate striatal metabotropic receptor type 5 in intact and MPTP male mice model of Parkinson's disease.

    PubMed

    Al-Sweidi, S; Morissette, M; Di Paolo, T

    2016-07-01

    Glutamate is the most important brain excitatory neurotransmitter and glutamate overactivity is well documented in Parkinson's disease (PD). Metabotropic glutamate (mGlu) receptors are reported to interact with membrane estrogen receptors (ERs) and more specifically the mGlu5 receptor subtype. 17β-estradiol and mGlu5 antagonists have neuroprotective effects in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. We previously reported that ERα and ERβ are involved in neuroprotection following MPTP toxicity. The present study investigated the implication of ERs on the mGlu5 receptor adaptive response to MPTP toxicity in the brain of wild type (WT), ER knockout (ERKO)α and ERKOβ male mice. Autoradiography of [(3)H]ABP688 specific binding to striatal mGlu5 receptors showed a dorsal/ventral gradient similar for WT, ERKOα and ERKOβ mice with higher values ventrally. The lateral septum had highest [(3)H]ABP688 specific binding that remained unchanged in all experimental groups. ERKOα and ERKOβ mice had similarly lower striatal [(3)H]ABP688 specific binding than WT mice as measured also by Western blots. MPTP dose-dependently decreased striatal [(3)H]ABP688 specific binding in WT but not in ERKOα and ERKOβ mice; this correlated positively with striatal dopamine concentrations. A 17β-estradiol treatment for 10 days left unchanged striatal [(3)H]ABP688 specific binding of unlesioned mice of the three genotypes. 17β-estradiol treatment for 5 days before MPTP and for 5 days after partially prevented the mGlu5 receptor decrease only in WT MPTP mice and this was associated with higher BDNF striatal contents. These results thus show that in male mice ERs affect striatal mGlu5 receptor levels and their response to MPTP. PMID:26873133

  18. Inverse agonist of estrogen-related receptor γ controls Salmonella typhimurium infection by modulating host iron homeostasis.

    PubMed

    Kim, Don-Kyu; Jeong, Jae-Ho; Lee, Ji-Min; Kim, Kwang Soo; Park, Seung-Hwan; Kim, Yong Deuk; Koh, Minseob; Shin, Minsang; Jung, Yoon Seok; Kim, Hyung-Seok; Lee, Tae-Hoon; Oh, Byung-Chul; Kim, Jae Il; Park, Hwan Tae; Jeong, Won-Il; Lee, Chul-Ho; Park, Seung Bum; Min, Jung-Joon; Jung, Sook-In; Choi, Seok-Yong; Choy, Hyon E; Choi, Hueng-Sik

    2014-04-01

    In response to microbial infection, expression of the defensin-like peptide hepcidin (encoded by Hamp) is induced in hepatocytes to decrease iron release from macrophages. To elucidate the mechanism by which Salmonella enterica var. Typhimurium (S. typhimurium), an intramacrophage bacterium, alters host iron metabolism for its own survival, we examined the role of nuclear receptor family members belonging to the NR3B subfamily in mouse hepatocytes. Here, we report that estrogen-related receptor γ (ERRγ, encoded by Esrrg) modulates the intramacrophage proliferation of S. typhimurium by altering host iron homeostasis, and we demonstrate an antimicrobial effect of an ERRγ inverse agonist. Hepatic ERRγ expression was induced by S. typhimurium-stimulated interleukin-6 signaling, resulting in an induction of hepcidin and eventual hypoferremia in mice. Conversely, ablation of ERRγ mRNA expression in liver attenuated the S. typhimurium-mediated induction of hepcidin and normalized the hypoferremia caused by S. typhimurium infection. An inverse agonist of ERRγ ameliorated S. typhimurium-mediated hypoferremia through reduction of ERRγ-mediated hepcidin mRNA expression and exerted a potent antimicrobial effect on the S. typhimurium infection, thereby improving host survival. Taken together, these findings suggest an alternative approach to control multidrug-resistant intracellular bacteria by modulating host iron homeostasis. PMID:24658075

  19. Estradiol and isotype-selective estrogen receptor agonists modulate the mesocortical dopaminergic system in gonadectomized female rats.

    PubMed

    Sárvári, Miklós; Deli, Levente; Kocsis, Pál; Márk, László; Maász, Gábor; Hrabovszky, Erik; Kalló, Imre; Gajári, Dávid; Vastagh, Csaba; Sümegi, Balázs; Tihanyi, Károly; Liposits, Zsolt

    2014-10-01

    The mesocortical dopaminergic pathway projecting from the ventral tegmental area (VTA) to the prefrontal cortex (PFC) contributes to the processing of reward signals. This pathway is regulated by gonadal steroids including estradiol. To address the putative role of estradiol and isotype-selective estrogen receptor (ER) agonists in the regulation of the rodent mesocortical system, we combined fMRI, HPLC-MS and qRT-PCR techniques. In fMRI experiments adult, chronically ovariectomized rats, treated with either vehicle, estradiol, ERα agonist 16α-lactone-estradiol (LE2) or ERβ agonist diarylpropionitrile (DPN), received a single dose of d-amphetamine-sulphate (10mg/kg, i.p.) and BOLD responses were monitored in the VTA and the PFC. Ovariectomized rats showed no significant response to amphetamine. In contrast, the VTA of ER agonist-substituted ovariectomized rats showed robust amphetamine-evoked BOLD increases. The PFC of estradiol-replaced animals was also responsive to amphetamine. Mass spectroscopic analysis of dopamine and its metabolites revealed a two-fold increase in both dopamine and 3,4-dihydroxyphenylacetic acid content of the PFC in estradiol-replaced animals compared to ovariectomized controls. qRT-PCR studies revealed upregulation of dopamine transporter and dopamine receptor in the VTA and PFC, respectively, of ER agonist-treated ovariectomized animals. Collectively, the results indicate that E2 and isotype-selective ER agonists can powerfully modulate the responsiveness of the mesocortical dopaminergic system, increase the expression of key genes related to dopaminergic neurotransmission and augment the dopamine content of the PFC. In a broader sense, the findings support the concept that the manifestation of reward signals in the PFC is dependent on the actual estrogen milieu of the brain. PMID:24976584

  20. Acute relaxation of mouse duodenum [correction of duodenun] by estrogens. Evidence for an estrogen receptor-independent modulation of muscle excitability.

    PubMed

    Díaz, Mario; Ramírez, Cristina M; Marin, Raquel; Marrero-Alonso, Jorge; Gómez, Tomás; Alonso, Rafael

    2004-10-01

    17-beta-Estradiol, the stereoisomer 17-alpha-estradiol and the synthetic estrogen diethylstilbestrol (DES), all caused a rapid (<3 min) dose-dependent reversible relaxation of mouse duodenal spontaneous activity, reduced basal tone and depressed the responses to CaCl(2) and KCl. The steroidal antiestrogen 7alpha-[9-[(4,4,5,5,5,-pentafluoropenty)sulphinyl]nonyl]-estra-1,3,5(19)-triene-3,17beta-diol (ICI182,780) failed to either mimic or prevent the effect of 17-beta-estradiol. The effect of estrogens was unrelated to activation of nitric oxide (NO), mitogen-activated protein kinase (MAPK), protein kinase A (PKA), protein kinase G (PKG) or protein kinase C (PKC). Estrogen-induced relaxation was partially reversed by 1,4-dihydro-2,6-dimethyl-5-nitro-4-[2-(trifluoromethyl)phenyl]-pyridine-3-carboxilic acid methyl ester (BAY-K8644), depolarization, or by application of tetraethylammonium or 4-aminopyridine, but not by glibenclamide, apamin, charybdotoxin, paxilline or verruculogen. The effects of BAY-K8644 and K(+) channel blockers were synergistic, and allowed relaxed tissues to recover spontaneous activity and basal tone. We hypothesize that the rapid non-genomic spasmolytic effect of estrogens on mouse duodenal muscle might be triggered by an estrogen-receptor-independent mechanism likely involving activation of tetraethylamonium- and 4-aminopyridine-sensitive K(+) channels and inhibition of L-type Ca2(+) channels on the smooth muscle cells. PMID:15464075

  1. 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,...

  2. 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

  3. 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

  4. 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...

  5. Estrogen-related receptor α regulates skeletal myocyte differentiation via modulation of the ERK MAP kinase pathway.

    PubMed

    Murray, Jennifer; Huss, Janice M

    2011-09-01

    Myocyte differentiation involves complex interactions between signal transduction pathways and transcription factors. The estrogen-related receptors (ERRs) regulate energy substrate uptake, mitochondrial respiration, and biogenesis and may target structural gene programs in striated muscle. However, ERRα's role in regulating myocyte differentiation is not known. ERRα and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) are coordinately upregulated with metabolic and skeletal muscle-specific genes early in myogenesis. We analyzed effects of ERRα overexpression and loss of function in myogenic models. In C2C12 myocytes ERRα overexpression accelerated differentiation, whereas XCT790 treatment delayed myogenesis and resulted in myotubes with fewer mitochondria and disorganized sarcomeres. ERRα-/- primary myocytes showed delayed myogenesis, resulting in structurally immature myotubes with reduced sarcomeric assembly and mitochondrial function. However, sarcomeric and metabolic gene expression was unaffected or upregulated in ERRα-/- cells. Instead, ERRα-/- myocytes exhibited aberrant ERK activation early in myogenesis, consistent with delayed myotube formation. XCT790 treatment also increased ERK phosphorylation in C2C12, whereas ERRα overexpression decreased early ERK activation, consistent with the opposing effects of these treatments on differentiation. The transient induction of MAP kinase phosphatase-1 (MKP-1), which mediates ERK dephosphorylation at the onset of myogenesis, was lost in ERRα-/- myocytes and in XCT790-treated C2C12. The ERRα-PGC-1α complex activates the Dusp1 gene, which encodes MKP-1, and ERRα occupies the proximal 5' regulatory region during early differentiation in C2C12 myocytes. Finally, treatment of ERRα-/- myocytes with MEK inhibitors rescued normal ERK signaling and myogenesis. Collectively, these data demonstrate that ERRα is required for normal skeletal myocyte differentiation via modulation of MAP

  6. Estrogen-related receptor α regulates skeletal myocyte differentiation via modulation of the ERK MAP kinase pathway

    PubMed Central

    Murray, Jennifer

    2011-01-01

    Myocyte differentiation involves complex interactions between signal transduction pathways and transcription factors. The estrogen-related receptors (ERRs) regulate energy substrate uptake, mitochondrial respiration, and biogenesis and may target structural gene programs in striated muscle. However, ERRα's role in regulating myocyte differentiation is not known. ERRα and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) are coordinately upregulated with metabolic and skeletal muscle-specific genes early in myogenesis. We analyzed effects of ERRα overexpression and loss of function in myogenic models. In C2C12 myocytes ERRα overexpression accelerated differentiation, whereas XCT790 treatment delayed myogenesis and resulted in myotubes with fewer mitochondria and disorganized sarcomeres. ERRα−/− primary myocytes showed delayed myogenesis, resulting in structurally immature myotubes with reduced sarcomeric assembly and mitochondrial function. However, sarcomeric and metabolic gene expression was unaffected or upregulated in ERRα−/− cells. Instead, ERRα−/− myocytes exhibited aberrant ERK activation early in myogenesis, consistent with delayed myotube formation. XCT790 treatment also increased ERK phosphorylation in C2C12, whereas ERRα overexpression decreased early ERK activation, consistent with the opposing effects of these treatments on differentiation. The transient induction of MAP kinase phosphatase-1 (MKP-1), which mediates ERK dephosphorylation at the onset of myogenesis, was lost in ERRα−/− myocytes and in XCT790-treated C2C12. The ERRα-PGC-1α complex activates the Dusp1 gene, which encodes MKP-1, and ERRα occupies the proximal 5′ regulatory region during early differentiation in C2C12 myocytes. Finally, treatment of ERRα−/− myocytes with MEK inhibitors rescued normal ERK signaling and myogenesis. Collectively, these data demonstrate that ERRα is required for normal skeletal myocyte differentiation via

  7. Synthesis and structure-activity relationships of analogs of EM-652 (acolbifene), a pure selective estrogen receptor modulator. Study of nitrogen substitution.

    PubMed

    Gauthier, Sylvain; Cloutier, Julie; Dory, Yves L; Favre, Alexandre; Mailhot, Josée; Ouellet, Carl; Schwerdtfeger, Annette; Mérand, Yves; Martel, Céline; Simard, Jacques; Labrie, Fernand

    2005-04-01

    EM-652 (acolbifene) analogs have been synthesized as selective estrogen receptor modulators. Substitution on the nitrogen atom of these 2H-1-benzopyran derivatives has been studied for its influence on antiestrogenic activity. Binding to the rat estrogen receptor, inhibition of estradiol-stimulated proliferation of T-47D breast cancer cells, as well as antiuterotrophic and uterotrophic activities in ovariectomized mice have been evaluated. 2H-1-Benzopyran 1b (EM-343, racemic form of EM-652), which contains a piperidine ring, shows the best pharmacological profile; RBA = 380, IC50 value = 0.110 nM (in T-47D cells), as well as 63% and 84% antiuterotrophic inhibitions at the 7.5 and 75 nmol doses, respectively. PMID:15968821

  8. Estrogen receptor 1 (ESR1; ERα), not ESR2 (ERβ), modulates estrogen-induced sex reversal in the American alligator, a species with temperature-dependent sex determination.

    PubMed

    Kohno, Satomi; Bernhard, Melissa C; Katsu, Yoshinao; Zhu, Jianguo; Bryan, Teresa A; Doheny, Brenna M; Iguchi, Taisen; Guillette, Louis J

    2015-05-01

    All crocodilians and many turtles exhibit temperature-dependent sex determination where the temperature of the incubated egg, during a thermo-sensitive period (TSP), determines the sex of the offspring. Estrogens play a critical role in sex determination in crocodilians and turtles, as it likely does in most nonmammalian vertebrates. Indeed, administration of estrogens during the TSP induces male to female sex reversal at a male-producing temperature (MPT). However, it is not clear how estrogens override the influence of temperature during sex determination in these species. Most vertebrates have 2 forms of nuclear estrogen receptor (ESR): ESR1 (ERα) and ESR2 (ERβ). However, there is no direct evidence concerning which ESR is involved in sex determination, because a specific agonist or antagonist for each ESR has not been tested in nonmammalian species. We identified specific pharmaceutical agonists for each ESR using an in vitro transactivation assay employing American alligator ESR1 and ESR2; these were 4,4',4''-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol (PPT) and 7-bromo-2-(4-hydroxyphenyl)-1,3-benzoxazol-5-ol (WAY 200070), respectively. Alligator eggs were exposed to PPT or WAY 200070 at a MPT just before the TSP, and their sex was examined at the last stage of embryonic development. Estradiol-17β and PPT, but not WAY 200070, induced sex reversal at a MPT. PPT-exposed embryos exposed to the highest dose (5.0 μg/g egg weight) exhibited enlargement and advanced differentiation of the Müllerian duct. These results indicate that ESR1 is likely the principal ESR involved in sex reversal as well as embryonic Müllerian duct survival and growth in American alligators. PMID:25714813

  9. Relationship Between Breast Density and Selective Estrogen-Receptor Modulators, Aromatase Inhibitors, Physical Activity, and Diet: A Systematic Review.

    PubMed

    Ekpo, Ernest U; Brennan, Patrick C; Mello-Thoms, Claudia; McEntee, Mark F

    2016-06-01

    Background Lower breast density (BD) is associated with lower risk of breast cancer and may serve as a biomarker for the efficacy of chemopreventive strategies. This review explores parameters that are thought to be associated with lower BD. We conducted a systematic review of articles published to date using the PRISMA strategy. Articles that assessed change in BD with estrogen-receptor modulators (tamoxifene [TAM], raloxifene [RLX], and tibolone) and aromatase inhibitors (AIs), as well as cross-sectional and longitudinal studies (LSs) that assessed association between BD and physical activity (PA) or diet were reviewed. Results Ten studies assessed change in BD with TAM; all reported TAM-mediated BD decreases. Change in BD with RLX was assessed by 11 studies; 3 reported a reduction in BD. Effect of tibolone was assessed by 5 RCTs; only 1 reported change in BD. AI-mediated BD reduction was reported by 3 out of 10 studies. The association between PA and BD was assessed by 21 studies; 4 reported an inverse association. The relationship between diet and BD was assessed in 34 studies. All studies on calcium and vitamin D as well as vegetable intake reported an inverse association with BD in premenopausal women. Two RCTs demonstrated BD reduction with a low-fat, high-carbohydrate intervention. Conclusion TAM induces BD reduction; however, the effect of RLX, tibolone, and AIs on BD is unclear. Although data on association between diet and BD in adulthood are contradictory, intake of vegetables, vitamin D, and calcium appear to be associated with lower BD in premenopausal women. PMID:27130722

  10. Trichostatin A and 5 Aza-2' deoxycytidine decrease estrogen receptor mRNA stability in ER positive MCF7 cells through modulation of HuR.

    PubMed

    Pryzbylkowski, Peter; Obajimi, Oluwakemi; Keen, Judith Clancy

    2008-09-01

    Trichostatin A (TSA) and 5-Aza 2'deoxycytidine (AZA), two well characterized pharmacologic inhibitors of histone deacetylation and DNA methylation, affect estrogen receptor alpha (ER) levels differently in ER-positive versus ER-negative breast cancer cell lines. Whereas pharmacologic inhibition of these epigenetic mechanisms results in re-expression and increased estrogen receptor alpha (ER) levels in ER-negative cells, treatment in ER-positive MCF7 cells results in decreased ER mRNA and protein levels. This decrease is dependent upon protein interaction with the ER 3'UTR. Actinomycin D studies showed a 37.5% reduction in ER mRNA stability from 4 to 1.5 h in AZA/TSA treated MCF7 cell lines; an effect not seen in 231ER + cells transfected with the ER coding region but lacking incorporation of the 3'UTR. AZA/TSA do not appear to directly interact with the 3'UTR but rather decrease stability through altered subcellular localization of the RNA binding protein, HuR. siRNA inhibition of HuR expression reduces both the steady-state and stability of ER mRNA, suggesting that HuR plays a critical role in the control of ER mRNA stability. Our data suggest that epigenetic modulators can alter stability through modulation of HuR subcellular distribution. Taken together, these data provide a novel anti-estrogenic mechanism for AZA and TSA in ER positive human breast cancer cells. PMID:17891453

  11. A Chemocentric Informatics Approach to Drug Discovery: Identification and Experimental Validation of Selective Estrogen Receptor Modulators as ligands of 5-Hydroxytryptamine-6 Receptors and as Potential Cognition Enhancers

    PubMed Central

    Hajjo, Rima; Setola, Vincent; Roth, Bryan L.; Tropsha, Alexander

    2012-01-01

    We have devised a chemocentric informatics methodology for drug discovery integrating independent approaches to mining biomolecular databases. As a proof of concept, we have searched for novel putative cognition enhancers. First, we generated Quantitative Structure- Activity Relationship (QSAR) models of compounds binding to 5-hydroxytryptamine-6 receptor (5HT6R), a known target for cognition enhancers, and employed these models for virtual screening to identify putative 5-HT6R actives. Second, we queried chemogenomics data from the Connectivity Map (http://www.broad.mit.edu/cmap/) with the gene expression profile signatures of Alzheimer’s disease patients to identify compounds putatively linked to the disease. Thirteen common hits were tested in 5-HT6R radioligand binding assays and ten were confirmed as actives. Four of them were known selective estrogen receptor modulators that were never reported as 5-HT6R ligands. Furthermore, nine of the confirmed actives were reported elsewhere to have memory-enhancing effects. The approaches discussed herein can be used broadly to identify novel drug-target-disease associations. PMID:22537153

  12. Molecular identification of potential selective estrogen receptor modulator (SERM) like properties of phytoestrogens in the human breast cancer cell line MCF-7.

    PubMed

    Diel, P; Olff, S; Schmidt, S; Michna, H

    2001-08-01

    Numerous epidemiologic studies revealed that ethnic populations with higher dietary intake of phytoestrogens have the lowest incidence for breast cancer. The molecular mechanisms which may be responsible for this cancer protective action of phytoestrogens are so far only barely characterised. There are some hints that phytoestrogens may act like selective estrogen receptor modulators (SERMs) on the breast. For this reason we have investigated potential SERM-like properties of the phytoestrogens daidzein (Dai), coumestrol (Cou), and genistein (Gen) in the human breast cancer cell line MCF-7. Effects of these substances on progesterone (PR) and estrogen receptor alpha (ER) mRNA expression and estrogen receptor alpha protein levels were studied in comparison to estradiol (E2) and the synthetic SERMs raloxifene (Ral) and faslodex (ICI 182 780). PR mRNA expression was up-regulated after administration of Cou, whereas treatment with Dai and Gen induced only a faint increase. ER mRNA expression was down-regulated by Cou but not affected by Dai and Gen. The content of ER protein in the breast cancer cells was strongly decreased by Gen, only a faint reduction could be observed following administration of Cou, whereas administration of Dai slightly increases ER protein levels. In summary and in comparison to the effects observed after administration of E2, Ral, and ICI it turned out that Cou shows molecular properties which are very similar to an estrogen receptor agonist like E2, whereas the molecular properties of Gen are comparable to the SERMs ICI and Ral. These results clearly indicate that phytoestrogens differ significantly in regard to their molecular action on breast cancer cells and can be subdivided into distinct functional categories. PMID:11509969

  13. Two high-affinity ligand binding states of uterine estrogen receptor distinguished by modulation of hydrophobic environment

    SciTech Connect

    Hutchens, T.W.; Li, C.M.; Zamah, N.M.; Besch, P.K.

    1987-02-10

    The steroid binding function of soluble (cytosolic) estrogen receptors from calf uteri was evaluated under conditions known to modify the extent of hydrophobic interaction with receptor-associated proteins. Receptor preparations were equilibrated into 6 M urea buffers and control buffers by chromatography through small columns of Sephadex G-25 or by dialysis at 0.6 /sup 0/C. Equilibrium dissociation constants (K/sub d/) and binding capacities (n) of experimental and control receptor preparations were determined by 13-point Scatchard analyses using concentrations of 17..beta..-(/sup 3/H)estradiol from 0.05 to 10 nM. Nonspecific binding was determined at each concentration by parallel incubations with a 200-fold molar excess of the receptor-specific competitor diethylstilbestrol. The control receptor population was consistently found to be a single class of binding sites with a high affinity for estradiol which was unaffected by G-25 chromatography, by dialysis, by dilution, or by the presence of 0.4 M KCl. However, equilibration into 6 M urea induced a discrete (10-fold) reduction in receptor affinity to reveal a second, thermodynamically stable, high-affinity binding state. The presence of 0.4 M KCl did not significantly influence the discrete change in receptor affinity induced by urea. The effects of urea on both receptor affinity and binding capacity were reversible, suggesting a lack of covalent modification. These results demonstrate nonenzymatic means by which not only the binding capacity but also the affinity of receptor for estradiol can be reversibly controlled, suggesting that high concentrations of urea might be more effectively utilized during the physicochemical characterization and purification of steroid receptor proteins.

  14. 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

  15. CHEMICAL MODIFICATION MODULATES ESTROGENIC ACTIVITY, OXIDATIVE REACTIVITY, & METABOLIC STABILITY IN 4′F-DMA, A NEW BENZOTHIOPHENE SELECTIVE ESTROGEN RECEPTOR MODULATOR

    PubMed Central

    Liu, Hong; Bolton, Judy L.; Thatcher, Gregory R. J.

    2008-01-01

    The benzothiophene SERMs raloxifene and arzoxifene, in the clinic or clinical trials for treatment of breast cancer and postmenopausal symptoms, are highly susceptible to oxidative metabolism and formation of electrophilic metabolites. 4′F-DMA, fluoro-substituted desmethyl arzoxifene (DMA), showed attenuated oxidation to quinoids in incubation with rat hepatocytes as well as in rat and human liver microsomes. Incubations of 4′F-DMA with hepatocytes yielded only one glucuronide conjugate and no GSH conjugates; whereas DMA underwent greater metabolism giving two glucuronide conjugates, one sulfate conjugate, and two GSH conjugates. Phase I and phase II metabolism was further evaluated in human small intestine microsomes and in human intestinal Caco-2 cells. In comparison to DMA, 4′F-DMA formed significantly less glucuronide and sulfate conjugates. The formation of quinoids was futher explored in hepatocytes in which DMA was observed to give concentration and time dependent depletion of GSH accompanied by damage to DNA which showed inverse dependence on GSH; in contrast, GSH depletion and DNA damage were almost completely abrogated in incubations with 4′F-DMA. 4′F-DMA shows ligand binding affinity to ERα and ERβ with similarity to both raloxifene and to DMA. ER-mediated biological activity was measured with the ERE-luciferase reporter system in transfected MCF-7 cells and Ishikawa cells, and in MCF-7 cells proliferation was measured. In all systems, 4′F-DMA exhibited anitestrogenic acitivty of comparable potency to raloxifene, but did not manifest estrogenic properties, mirroring previous results on inhibition of estradiol-mediated induction of alkaline phosphatase activity in Ishikawa cells. These results suggest that 4′F-DMA might be an improved benzothiophene SERM with similar antiestrogenic activity to raloxifene, but improved metabolic stability and attenuated toxicity; showing that simple chemical modification can abrogate oxidative bioactivation

  16. 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

  17. 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

  18. 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

  19. Evidences for antiosteoporotic and selective estrogen receptor modulator activity of silymarin compared with ethinylestradiol in ovariectomized rats.

    PubMed

    El-Shitany, Nagla A; Hegazy, Sahar; El-Desoky, Karema

    2010-02-01

    Recently, growing multiple uses of silymarin (SIL) as a complementary and alternative medicine, for alcohol-induced liver disease, acute and chronic viral hepatitis, as well as some other nonhepatic indications have been reported. Therefore, more attention should be paid for the hormonal side effects of SIL. Since the available data on the possible estrogenic effects of SIL is rather rare, this study aimed to further elucidate the different estrogenic effects and antiosteoporotic activity of SIL in ovariectomized (OVX) rats. OVX rats were treated chronically (12 weeks) with ethinylestradiol (EE) or SIL. Uterine and body weight were measured in all animals. Biochemical markers of bone formation (total alkaline phosphatase (ALP), calcium, phosphorus and osteocalcin), endocrinological analysis (estradiol (E2), luteinizing hormone (LH), follicle stimulating hormone (FSH) and parathyroid hormone (PTH)) and serum total cholesterol and total lipids were estimated. Formalin fixed femora and uteri specimens were used for histopathological examination. In addition, the binding property of SIL to the two estrogen receptors (ER) subtypes was tested by molecular docking. EE (strong) and SIL (mild) stimulated uterine weight (increased uterus hyperplastic endometrial glands) but EE only prevented body weight gain following OVX. Treatment of OVX rats with both EE and SIL resulted in protection of trabecula thickness, decreased serum levels of ALP and increased serum levels of both calcium and phosphorus. In contrast to EE, SIL did not decrease OVX induced serum osteocalcin. EE not SIL decreased serum cholesterol, total lipids, LH and FSH and increased serum E2. Both EE and SIL increased serum PTH. The docking study revealed a high affinity of SIL towards ERbeta. In conclusion, findings derived in the present study presented an overview of SIL many estrogenic effects in OVX rats. SIL significantly prevents the bone loss in rats induced by OVX with mild proliferative effects in

  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. 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

  2. An Estrogen Receptor-α Knock-In Mutation Provides Evidence of Ligand-Independent Signaling and Allows Modulation of Ligand-Induced Pathways in Vivo

    PubMed Central

    Sinkevicius, Kerstin W.; Burdette, Joanna E.; Woloszyn, Karolina; Hewitt, Sylvia C.; Hamilton, Katherine; Sugg, Sonia L.; Temple, Karla A.; Wondisford, Fredric E.; Korach, Kenneth S.; Woodruff, Teresa K.; Greene, Geoffrey L.

    2008-01-01

    Estrogen-nonresponsive estrogen receptor-α (ERα) knock-in (ENERKI) mice were generated to distinguish between ligand-induced and ligand-independent ER-α actions in vivo. These mice have a mutation [glycine 525 to leucine (G525L)] in the ligand-binding domain of ERα, which significantly reduces ERα interaction with and response to endogenous estrogens, whereas not affecting growth factor activation of ligand-independent pathways. ENERKI mice had hypoplastic uterine tissues and rudimentary mammary gland ductal trees. Females were infertile due to anovulation, and their ovaries contained hemorrhagic cystic follicles because of chronically elevated levels of LH. The ENERKI phenotype confirmed that ligand-induced activation of ERα is crucial in the female reproductive tract and mammary gland development. Growth factor treatments induced uterine epithelial proliferation in ovariectomized ENERKI females, directly demonstrating that ERα ligand-independent pathways were active. In addition, the synthetic ERα selective agonist propyl pyrazole triol (PPT) and ER agonist diethylstilbestrol (DES) were still able to activate ligand-induced G525L ERα pathways in vitro. PPT treatments initiated at puberty stimulated ENERKI uterine development, whereas neonatal treatments were needed to restore mammary gland ductal elongation, indicating that neonatal ligand-induced ERα activation may prime mammary ducts to become more responsive to estrogens in adult tissues. This is a useful model for in vivo evaluation of ligand-induced ERα pathways and temporal patterns of response. DES did not stimulate an ENERKI uterotrophic response. Because ERβ may modulate ERα activation and have an antiproliferative function in the uterus, we hypothesize that ENERKI animals were particularly sensitive to DES-induced inhibition of ERα due to up-regulated uterine ERβ levels. PMID:18339713

  3. Integrating medicinal chemistry, organic/combinatorial chemistry, and computational chemistry for the discovery of selective estrogen receptor modulators with Forecaster, a novel platform for drug discovery.

    PubMed

    Therrien, Eric; Englebienne, Pablo; Arrowsmith, Andrew G; Mendoza-Sanchez, Rodrigo; Corbeil, Christopher R; Weill, Nathanael; Campagna-Slater, Valérie; Moitessier, Nicolas

    2012-01-23

    As part of a large medicinal chemistry program, we wish to develop novel selective estrogen receptor modulators (SERMs) as potential breast cancer treatments using a combination of experimental and computational approaches. However, one of the remaining difficulties nowadays is to fully integrate computational (i.e., virtual, theoretical) and medicinal (i.e., experimental, intuitive) chemistry to take advantage of the full potential of both. For this purpose, we have developed a Web-based platform, Forecaster, and a number of programs (e.g., Prepare, React, Select) with the aim of combining computational chemistry and medicinal chemistry expertise to facilitate drug discovery and development and more specifically to integrate synthesis into computer-aided drug design. In our quest for potent SERMs, this platform was used to build virtual combinatorial libraries, filter and extract a highly diverse library from the NCI database, and dock them to the estrogen receptor (ER), with all of these steps being fully automated by computational chemists for use by medicinal chemists. As a result, virtual screening of a diverse library seeded with active compounds followed by a search for analogs yielded an enrichment factor of 129, with 98% of the seeded active compounds recovered, while the screening of a designed virtual combinatorial library including known actives yielded an area under the receiver operating characteristic (AU-ROC) of 0.78. The lead optimization proved less successful, further demonstrating the challenge to simulate structure activity relationship studies. PMID:22133077

  4. The aryl hydrocarbon receptor and estrogen receptor alpha differentially modulate nuclear factor erythroid-2-related factor 2 transactivation in MCF-7 breast cancer cells

    SciTech Connect

    Lo, Raymond; Matthews, Jason

    2013-07-15

    Nuclear factor erythroid-2-related factor 2 (NRF2; NFE2L2) plays an important role in mediating cellular protection against reactive oxygen species. NRF2 signaling is positively modulated by the aryl hydrocarbon receptor (AHR) but inhibited by estrogen receptor alpha (ERα). In this study we investigated the crosstalk among NRF2, AHR and ERα in MCF-7 breast cancer cells treated with the NRF2 activator sulforaphane (SFN), a dual AHR and ERα activator, 3,3′-diindolylmethane (DIM), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or 17β-estradiol (E2). SFN-dependent increases in NADPH-dependent oxidoreductase 1 (NQO1) and heme oxygenase I (HMOX1) mRNA levels were significantly reduced after co-treatment with E2. E2-dependent repression of NQO1 and HMOX1 was associated with increased ERα but reduced p300 recruitment and reduced histone H3 acetylation at both genes. In contrast, DIM + SFN or TCDD + SFN induced NQO1 and HMOX1 mRNA expression to levels higher than SFN alone, which was prevented by RNAi-mediated knockdown of AHR. DIM + SFN but not TCDD + SFN also induced recruitment of ERα to NQO1 and HMOX1. However, the presence of AHR at NQO1 and HMOX1 restored p300 recruitment and histone H3 acetylation, thereby reversing the ERα-dependent repression of NRF2. Taken together, our study provides further evidence of functional interplay among NRF2, AHR and ERα signaling pathways through altered p300 recruitment to NRF2-regulated target genes. - Highlights: • We examined crosstalk among ERα, AHR, and NRF2 in MCF-7 breast cancer cells. • AHR enhanced the mRNA expression levels of two NRF2 target genes – HMOX1 and NQO1. • ERα repressed HMOX1 and NQO1 expression via decreased histone acetylation. • AHR prevented ERα-dependent repression of HMOX1 and NQO1.

  5. 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

  6. 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

  7. 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.

  8. [Effects of SERMs on bone health. Evidence for the selective estrogen receptor modulator raloxifene: its evolving role in the treatment of osteoporosis].

    PubMed

    Ohta, Hiroaki

    2010-03-01

    The 2000 NIH definition of osteoporosis may now call for revision in light of evidence accumulated through clinical studies in the last decade. Of note, as bone quality is now becoming available for evaluation, it is becoming clear that bone quality contributes to bone strength to a far greater degree than was previously assumed and the myth of bone mineral density is now quickly losing ground. Against this background, the role of the selective estrogen receptor modulator raloxifene (RLX) is undergoing a reevaluation. No doubt RLX fills an important role as a therapeutic for osteoporosis given its mechanisms of action which are distinct from those of the bisphosphonates, and is expected to have an increasingly larger role in osteoporosis management. PMID:20190360

  9. 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

  10. The uterine and vascular actions of estetrol delineate a distinctive profile of estrogen receptor α modulation, uncoupling nuclear and membrane activation

    PubMed Central

    Abot, Anne; Fontaine, Coralie; Buscato, Mélissa; Solinhac, Romain; Flouriot, Gilles; Fabre, Aurélie; Drougard, Anne; Rajan, Shyamala; Laine, Muriel; Milon, Alain; Muller, Isabelle; Henrion, Daniel; Adlanmerini, Marine; Valéra, Marie-Cécile; Gompel, Anne; Gerard, Céline; Péqueux, Christel; Mestdagt, Mélanie; Raymond-Letron, Isabelle; Knauf, Claude; Ferriere, François; Valet, Philippe; Gourdy, Pierre; Katzenellenbogen, Benita S; Katzenellenbogen, John A; Lenfant, Françoise; Greene, Geoffrey L; Foidart, Jean-Michel; Arnal, Jean-François

    2014-01-01

    Estetrol (E4) is a natural estrogen with a long half-life produced only by the human fetal liver during pregnancy. The crystal structures of the estrogen receptor α (ERα) ligand-binding domain bound to 17β-estradiol (E2) and E4 are very similar, as well as their capacity to activate the two activation functions AF-1 and AF-2 and to recruit the coactivator SRC3. In vivo administration of high doses of E4 stimulated uterine gene expression, epithelial proliferation, and prevented atheroma, three recognized nuclear ERα actions. However, E4 failed to promote endothelial NO synthase activation and acceleration of endothelial healing, two processes clearly dependent on membrane-initiated steroid signaling (MISS). Furthermore, E4 antagonized E2 MISS-dependent effects in endothelium but also in MCF-7 breast cancer cell line. This profile of ERα activation by E4, uncoupling nuclear and membrane activation, characterizes E4 as a selective ER modulator which could have medical applications that should now be considered further. PMID:25214462

  11. Adjunctive selective estrogen receptor modulator increases neural activity in the hippocampus and inferior frontal gyrus during emotional face recognition in schizophrenia.

    PubMed

    Ji, E; Weickert, C S; Lenroot, R; Kindler, J; Skilleter, A J; Vercammen, A; White, C; Gur, R E; Weickert, T W

    2016-01-01

    Estrogen has been implicated in the development and course of schizophrenia with most evidence suggesting a neuroprotective effect. Treatment with raloxifene, a selective estrogen receptor modulator, can reduce symptom severity, improve cognition and normalize brain activity during learning in schizophrenia. People with schizophrenia are especially impaired in the identification of negative facial emotions. The present study was designed to determine the extent to which adjunctive raloxifene treatment would alter abnormal neural activity during angry facial emotion recognition in schizophrenia. Twenty people with schizophrenia (12 men, 8 women) participated in a 13-week, randomized, double-blind, placebo-controlled, crossover trial of adjunctive raloxifene treatment (120 mg per day orally) and performed a facial emotion recognition task during functional magnetic resonance imaging after each treatment phase. Two-sample t-tests in regions of interest selected a priori were performed to assess activation differences between raloxifene and placebo conditions during the recognition of angry faces. Adjunctive raloxifene significantly increased activation in the right hippocampus and left inferior frontal gyrus compared with the placebo condition (family-wise error, P<0.05). There was no significant difference in performance accuracy or reaction time between active and placebo conditions. To the best of our knowledge, this study provides the first evidence suggesting that adjunctive raloxifene treatment changes neural activity in brain regions associated with facial emotion recognition in schizophrenia. These findings support the hypothesis that estrogen plays a modifying role in schizophrenia and shows that adjunctive raloxifene treatment may reverse abnormal neural activity during facial emotion recognition, which is relevant to impaired social functioning in men and women with schizophrenia. PMID:27138794

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. Nitrosation, nitration, and autoxidation of the selective estrogen receptor modulator raloxifene by nitric oxide, peroxynitrite, and reactive nitrogen/oxygen species.

    PubMed

    Toader, Violeta; Xu, Xudong; Nicolescu, Adrian; Yu, Linning; Bolton, Judy L; Thatcher, Gregory R J

    2003-10-01

    The regulation of estrogenic and antiestrogenic effects by selective estrogen receptor modulators (SERMs) provides the basis for use in long-term therapy in cancer chemoprevention and postmenopausal osteoporosis. However, the evidence for carcinogenic properties within this class requires study of potential pathways of toxicity. There is strong evidence for the elevation of cellular levels of NO in tissue treated with SERMs, including the benzothiophene derivative, raloxifene, in part via up-regulation of nitric oxide synthases. Therefore, the reactions of 17beta-estradiol (E(2)), raloxifene, and an isomer with NO, peroxynitrite, and reactive nitrogen/oxygen species (RNOS) generated from NO(2)(-)/H(2)O(2) systems were examined. Peroxynitrite from bolus injection or slow release from higher concentrations of 3-morpholinosydnonimine (SIN-1) reacted with the benzothiophenes and E(2) to give aromatic ring nitration, whereas peroxynitrite, produced from the slow decomposition of lower concentrations of SIN-1, was relatively unreactive toward E(2) and yielded oxidation and nitrosation products with raloxifene and its isomer. The oxidation and nitrosation products formed were characterized as a dimer and quinone oxime derivative. Interestingly, the reaction of the benzothiophenes with NO in aerobic solution efficiently generated the same oxidation products. Stable quinone oximes are not unprecedented but have not been previously reported as products of RNOS-mediated metabolism. The reaction of glutathione (GSH) with the quinone oxime gave both GSH adducts from Michael addition and reduction to the corresponding o-aminophenol. The ready autoxidation of raloxifene, observed in the presence of NO, is the first such observation on the reactivity of SERMs and is potentially a general phenomenon of significance to SERM chemical toxicology. PMID:14565768

  18. Modulation of vitellogenin synthesis through estrogen receptor beta-1 in goldfish (Carassius auratus) juveniles exposed to 17-{beta} estradiol and nonylphenol

    SciTech Connect

    Soverchia, L.; Ruggeri, B.; Palermo, F.; Mosconi, G.; Cardinaletti, G.; Scortichini, G.; Gatti, G.; Polzonetti-Magni, A.M. . E-mail: alberta.polzonetti@unicam.it

    2005-12-15

    Many synthetic chemicals, termed xenoestrogens, have been shown to interact as agonists with the estrogen receptor (ER) to elicit biological responses similar to those of natural hormones. To date, the regulation of vitellogenesis in oviparous vertebrates has been widely used for evaluation of estrogenic effects. Therefore, Carassius auratus juveniles were chosen as a fish model for studying the effects of estradiol-17{beta} and different concentrations (10{sup -6} and 10{sup -7} M) of 4-nonylphenol (4-NP) on the expression of liver ER{beta}-1 subtype; plasma vitellogenin and sex steroids (androgens and estradiol-17{beta}) were also evaluated together with the bioaccumulation process, through mass-spectrometry. C. auratus is a species widespread in the aquatic environment and, on the toxicological point of view, can be considered a good 'sentinel' species. Juveniles of goldfish were maintained in tanks with only tap water or water with different concentrations (10{sup -6} and 10{sup -7} M) of 4-nonylphenol (4-NP), or 10{sup -7} M of estradiol-17{beta}. After 3 weeks of treatment, animals were anesthetized within 5 min after capture, and blood was immediately collected into heparinized syringes by cardiac puncture and stored at -70 deg. C; the gonads were fixed, then frozen and stored at -70 deg. C; the whole fish, liver, and muscle tissues were harvested and immediately stored at -70 deg. C for molecular biology experiments and bioaccumulation measurements. The estrogenic effects of 4-NP were evidenced by the presence of plasma vitellogenin in juveniles exposed both to estradiol-17{beta} and the two doses of 4-NP; moreover, exposure to 4-NP also increased aromatization of androgens, as suggested by decreasing androgens and increasing estradiol-17{beta} plasma levels. The changes of these parameters were in agreement with the increasing transcriptional rate of ER{beta}-1 mRNA in the liver, demonstrating that both estradiol-17{beta} and 4-NP modulate the vitellogenin

  19. Modulation of thymosin beta 4 by estrogen.

    PubMed

    Suh, B Y; Naylor, P H; Goldstein, A L; Rebar, R W

    1985-02-15

    The endocrine thymus produces several hormone-like peptides (generically termed thymosins) which control development of the thymic-dependent lymphoid system and participate in the process of immune regulation. In addition, recent literature supports the hypothesis that gonadal steroids in general and estrogens in particular affect the immune system. To determine whether steroid hormones modulate secretion of thymic peptides, basal concentrations of thymosins alpha 1 and beta 4 were determined by radioimmunoassay in morning blood samples from 87 women in various clinical states. Basal concentrations of thymosin alpha 1 were similar in all women sampled. Basal levels of thymosin beta 4 were similar in normal women during the early follicular phase, women with premature ovarian failure, postmenopausal women not receiving estrogen, and individuals with gonadal dysgenesis. However, the marked variability of basal levels in premature ovarian failure and in postmenopausal women suggests that these groups are quite heterogeneous. Thymosin beta 4 concentrations were reduced in castrated women not receiving estrogen and were decreased more in both postmenopausal women and castrated women who were on chronic estrogen therapy. These data suggest that estrogens can modulate the circulating levels of thymosin beta 4 but not of thymosin alpha 1. We do not yet know whether sex steroids modulate secretion of other thymic peptides. PMID:2983555

  20. 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

  1. 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...

  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. Estrogen increases the permeability of the cultured human cervical epithelium by modulating cell deformability.

    PubMed

    Gorodeski, G I

    1998-09-01

    Estrogens increase secretion of cervical mucus in females. The objective of this research was to study the mechanisms of estrogen action. The experimental models were human CaSki (endocervical) and hECE (ectocervical) epithelial cells cultured on filters. Incubation in steroid-free medium increased transepithelial electrical resistance (RTE) and decreased epithelial permeability to the cell-impermeant acid pyranine. Estrogen treatment reversed the effects, indicating estrogen decreases epithelial paracellular resistance. The estrogen effect was time and dose related (EC50 approximately 1 nM) and specific (estradiol = diethylstilbestrol > estrone, estriol; no effect by progesterone, testosterone, or cortisol) and was blocked by progesterone, tamoxifen, and ICI-182780 (an estrogen receptor antagonist). Estrogen treatment did not modulate dilution potential or changes in RTE in response to diC8 or to low extracellular Ca2+ (modulators of tight junctional resistance). In contrast, estrogen augmented decreases in RTE in response to hydrostatic and hypertonic gradients [modulators of resistance of lateral intercellular space (RLIS)], suggesting estrogen decreases RLIS. Estrogen decreased cervical cell size, shortened response time relative to changes in cell size after hypertonic challenge, and augmented the decrease in cell size in response to hypertonic and hydrostatic gradients. Lowering luminal NaCl had no significant effect on RTE, and the Cl- channel blocker diphenylamine-2-carboxylate attenuated the hypertonicity-induced decrease in cell size to the same degree in control and estrogen-treated cells, suggesting estrogen effects on permeability and cell size are not mediated by modulating Na+ or Cl- transport. In contrast, estrogen increased cellular G-actin levels, suggesting estrogens shift actin steady-state toward G-actin and the cervical cell cytoskeleton toward a more flexible structure. We suggest that the mechanism by which estrogens decrease RLIS and

  4. 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

  5. Selective Estrogen Receptor Modulator-Associated Nonalcoholic Fatty Liver Disease Improved Survival in Patients With Breast Cancer: A Retrospective Cohort Analysis.

    PubMed

    Zheng, Qiufan; Xu, Fei; Nie, Man; Xia, Wen; Qin, Tao; Qin, Ge; An, Xin; Xue, Cong; Peng, Roujun; Yuan, Zhongyu; Shi, Yanxia; Wang, Shusen

    2015-10-01

    Selective estrogen receptor modulator (SERM)-associated nonalcoholic fatty liver disease (NAFLD) might be related to treatment efficacy in patients with breast cancer because of circulating estrogen antagonism. The aim of the study was to investigate the relationship between NAFLD and survival outcomes in patients with breast cancer who were treated with tamoxifen or toremifene. This single-center, retrospective, cohort study included 785 eligible patients who received tamoxifen or toremifene, after curative resection for breast cancer, at the Sun Yat-sen University Cancer Center between January 2005 and December 2009. Data were extracted from patient medical records. All patients underwent abdominal ultrasonography, at least once, at baseline and at the annual follow-up. Patients who were diagnosed with NAFLD on ultrasonography were classified into the NAFLD or the non-NAFLD arm at the 3-year follow-up visit. Univariate and multivariate Cox regression analyses were conducted to evaluate any associations between NAFLD and disease-free survival (DFS) or overall survival (OS). One hundred fifty-eight patients were diagnosed with NAFLD. Patients who developed NAFLD had better DFS and OS compared with those who did not. Univariate analyses revealed that the 5-year DFS rates were 91.56% and 85.01% for the NAFLD and non-NAFLD arms, respectively (hazard ratio [HR], 0.59; 95% confidence interval [CI], 0.37-0.96; log-rank P = 0.032). The 5-year OS rates were 96.64% and 93.31% for the NAFLD and non-NAFLD arms, respectively (HR, 0.39; 95% CI, 0.16-0.99; log-rank P = 0.039). Multivariate analysis revealed that NAFLD was an independent prognostic factor for DFS, improving the DFS rate by 41% compared with that in the non-NAFLD arm (HR, 0.59; 95% CI, 0.36-0.96; P = 0.033). SERM-associated NAFLD was independently associated with improved DFS and might be useful for predicting treatment responses in breast cancer patients treated with SERMs. PMID:26448028

  6. 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

  7. 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

  8. A randomized study on pharmacodynamic effects of vaginal rings delivering the progesterone receptor modulator, Ulipristal acetate. Research for a novel estrogen-free, method of contraception

    PubMed Central

    Huang, YongMei; Jensen, Jeffrey T.; Brache, Vivian; Cochon, Leila; Williams, Alistair; Miranda, Maria-José; Croxatto, Horacio; Kumar, Narender; Sussman, Heather; Hoskin, Elena; Plagianos, Marlena; Roberts, Kevin; Merkatz, Ruth; Blithe, Diana; Sitruk-Ware, Regine

    2014-01-01

    Objective To determine whether a 3-month contraceptive vaginal ring (CVR) delivering ulipristal acetate (UPA) can inhibit ovulation in 90% of cycles. Study Design This was a randomized dose-finding parallel group clinical trial. Fifty-five healthy women with normal ovulation at baseline were randomized to receive a low-dose (1500μg/day) or a high-dose (2500μg/d) UPA-CVR for two consecutive 12-week treatment periods, followed by a recovery cycle. A subgroup of women received levonorgestrel (LNG) 1.5 mg orally twice (at the end of both 12-week ring periods) or once (at the end of the 24-week treatment). The primary outcome was ovulation suppression assessed by transvaginal ultrasound and hormone levels. Secondary outcomes included endometrial safety and bleeding patterns. Results All subjects showed normal ovulation at baseline and recovery. Ovulation suppression was seen in 81.8% (95% CI: 73.3%, 88.5%) and 86.1% (95% CI: 78.1%, 92%) of treatment cycles with low and high-dose, respectively. Benign progesterone receptor modulator associated endometrial changes (PAEC) were seen during treatment; 78.8% at week 24, but resolved at recovery cycle. A few cases of heavy bleeding occurred near the end of the 24-week treatment, but a single dose of LNG every 12weeks reduced the increase in endometrial thickness during the second treatment period and prevented excessive bleeding. Conclusion The 3-month UPA-CVR may become an effective long-acting, user-controlled estrogen-free contraceptive. The greatest suppression of ovulation was seen with the 2500 μg/d ring. PMID:25193534

  9. Human splicing factor SPF45 (RBM17) confers broad multidrug resistance to anticancer drugs when overexpressed--a phenotype partially reversed by selective estrogen receptor modulators.

    PubMed

    Perry, William L; Shepard, Robert L; Sampath, Janardhan; Yaden, Benjamin; Chin, William W; Iversen, Philip W; Jin, Shengfang; Lesoon, Andrea; O'Brien, Kathryn A; Peek, Victoria L; Rolfe, Mark; Shyjan, Andrew; Tighe, Michelle; Williamson, Mark; Krishnan, Venkatesh; Moore, Robert E; Dantzig, Anne H

    2005-08-01

    The splicing factor SPF45 (RBM17) is frequently overexpressed in many solid tumors, and stable expression in HeLa cells confers resistance to doxorubicin and vincristine. In this study, we characterized stable transfectants of A2780 ovarian carcinoma cells. In a 3-day cytotoxicity assay, human SPF45 overexpression conferred 3- to 21-fold resistance to carboplatin, vinorelbine, doxorubicin, etoposide, mitoxantrone, and vincristine. In addition, resistance to gemcitabine and pemetrexed was observed at the highest drug concentrations tested. Knockdown of SPF45 in parental A2780 cells using a hammerhead ribozyme sensitized A2780 cells to etoposide by approximately 5-fold relative to a catalytically inactive ribozyme control and untransfected cells, suggesting a role for SPF45 in intrinsic resistance to some drugs. A2780-SPF45 cells accumulated similar levels of doxorubicin as vector-transfected and parental A2780 cells, indicating that drug resistance is not due to differences in drug accumulation. Efforts to identify small molecules that could block SPF45-mediated drug resistance revealed that the selective estrogen receptor (ER) modulators tamoxifen and LY117018 (a raloxifene analogue) partially reversed SPF45-mediated drug resistance to mitoxantrone in A2780-SPF45 cells from 21-fold to 8- and 5-fold, respectively, but did not significantly affect the mitoxantrone sensitivity of vector control cells. Quantitative PCR showed that ERbeta but not ERalpha was expressed in A2780 transfectants. Coimmunoprecipitation experiments suggest that SPF45 and ERbeta physically interact in vivo. Thus, SPF45-mediated drug resistance in A2780 cells may result in part from effects of SPF45 on the transcription or alternate splicing of ERbeta-regulated genes. PMID:16061639

  10. BE360, a new selective estrogen receptor modulator, produces antidepressant and antidementia effects through the enhancement of hippocampal cell proliferation in olfactory bulbectomized mice.

    PubMed

    Nakagawasai, Osamu; Nemoto, Wataru; Onogi, Hiroshi; Moriya, Takahiro; Lin, Jia-Rong; Odaira, Takayo; Yaoita, Fukie; Ogawa, Takumi; Ohta, Kiminori; Endo, Yasuyuki; Tan-No, Koichi

    2016-01-15

    We have reported that the carborane compound BE360 is a novel selective estrogen receptor modulator and new therapy option for osteoporosis. The aim of this study was to explore the effects and underlying mechanisms of BE360 on depressive-like behavior and memory impairment in the olfactory bulbectomized (OBX) mice, an experimental animal model of depression and dementia. BE360 was administered subcutaneously to mice using a mini-osmotic pump for 2 weeks. Depressive-like behavior was measured as the reduced intake of a sweet solution in the sucrose preference test. Short-term memory was assessed using the Y-maze test. Cell proliferation was assessed by the analysis of cells expressing 5-bromo-2'-deoxyuridine (BrdU) uptake. The expression of phosphorylated cyclic-AMP response element binding protein (pCREB) and brain-derived neurotrophic factor (BDNF) were measured by immunoblot. The depressive-like behavior and memory impairment in OBX mice were improved by the chronic treatment with BE360. Immunohistochemical analysis showed that the number of BrdU-positive cells in the dentate gyrus of the hippocampus significantly decreased in OBX mice whereas they increased after the chronic treatment with BE360. Immunoblotting studies revealed that pCREB and BDNF were significantly increased in the hippocampus of OBX mice treated with BE360. The present study has shown that BE360 has antidepressant and antidementia effects characterized by hippocampal cell proliferation potentially activated via CREB/BDNF signaling pathways. These results indicate that BE360 may have valuable therapeutic potential against depression and neurodegenerative diseases. PMID:26497104

  11. Estrogen receptor β and oxytocin interact to modulate anxiety-like behavior and neuroendocrine stress reactivity in adult male and female rats.

    PubMed

    Kudwa, Andrea E; McGivern, Robert F; Handa, Robert J

    2014-04-22

    The hypothalamic-pituitary-adrenal (HPA) axis is activated in response to stressors and is controlled by neurons residing in the paraventricular nucleus of the hypothalamus (PVN). Although gonadal steroid hormones can influence HPA reactivity to stressors, the exact mechanism of action is not fully understood. It is known, however, that estrogen receptor β (ERβ) inhibits HPA reactivity and decreases anxiety-like behavior in rodents. Since ERβ is co-expressed with oxytocin (OT) in neurons of the PVN, an ERβ-selective agonist was utilized to test the whether ERβ decreases stress-induced HPA reactivity and anxiety-like behaviors via an OTergic pathway. Adult gonadectomized male and female rats were administered diarylpropionitrile, or vehicle, peripherally for 5days. When tested for anxiety-like behavior on the elevated plus maze (EPM), diarylpropionitrile-treated males and females significantly increased time on the open arm of the EPM compared to vehicle controls indicating that ERβ reduces anxiety-like behaviors. One week after behavioral evaluation, rats were subjected to a 20minute restraint stress. Treatment with diarylpropionitrile reduced CORT and ACTH responses in both males and females. Subsequently, another group of animals was implanted with cannulae directed at the lateral ventricle. One week later, rats underwent the same protocol as above but with the additional treatment of intracerebroventricular infusion with an OT antagonist (des Gly-NH2 d(CH2)5 [Tyr(Me)(2), Thr(4)] OVT) or VEH, 20min prior to behavioral evaluation. OT antagonist treatment blocked the effects of diarylpropionitrile on the display of anxiety-like behaviors and plasma CORT levels. These data indicate that ERβ and OT interact to modulate the HPA reactivity and the display of anxiety-like behaviors. PMID:24631553

  12. 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

  13. 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

  14. 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.

  15. Phosphorylation of N-methyl-D-aspartic acid receptor-associated neuronal nitric oxide synthase depends on estrogens and modulates hypothalamic nitric oxide production during the ovarian cycle

    PubMed Central

    Parkash, Jyoti; D'Anglemont De Tassigny, Xavier; Bellefontaine, Nicole; Campagne, Celine; Mazure, Danièle; Buée-Scherrer, Valérie; Prevot, Vincent

    2010-01-01

    Within the preoptic region, nitric oxide (NO) production varies during the ovarian cycle and has the ability to impact hypothalamic reproductive function. One mechanism for the regulation of NO release mediated by estrogens during the estrous cycle includes physical association of the calcium-activated neuronal NO synthase (nNOS) enzyme with the glutamate N-methyl-D-aspartate (NMDA) receptor channels via the postsynaptic density 95 (PSD 95) scaffolding protein. Here, we demonstrate that endogenous variations in estrogens levels during the estrous cycle also coincide with corresponding changes in the state of nNOS Ser1412 phosphorylation, the level of association of this isoform with the NMDA receptor/PSD-95 complex at the plasma membrane and the activity of NOS. Neuronal NOS Ser1412 phosphorylation is maximal on the afternoon of proestrus, when both the levels of estrogens and the physical association of nNOS with NMDA receptors are highest. Estradiol mimicked these effects in ovariectomized (OVX) rats. In addition, the catalytic activity of NOS in membrane protein extracts from the preoptic region, i.e., independent of any functional protein-protein interactions or cell-cell signaling, was significantly increased in estradioltreated OVX rats compared to OVX rats. Finally, λ phosphatase-mediated nNOS dephosphorylation dramatically impaired NOS activity in preoptic region protein extracts, thus demonstrating the important role of phosphorylation in the regulation of NO production in the preoptic region. Taken together, these results yield new insights into the regulation of neuron-derived NO production by gonadal steroids within the preoptic region and raise the possibility that changes in nNOS phosphorylation during fluctuating physiological conditions may be involved in the hypothalamic control of key neuroendocrine functions, such as reproduction. PMID:20371700

  16. 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

  17. 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.

  18. 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

  19. Bioanalytical high-throughput selected reaction monitoring-LC/MS determination of selected estrogen receptor modulators in human plasma: 2000 samples/day.

    PubMed

    Zweigenbaum, J; Henion, J

    2000-06-01

    The high-throughput determination of small molecules in biological matrixes has become an important part of drug discovery. This work shows that increased throughput LC/MS/MS techniques can be used for the analysis of selected estrogen receptor modulators in human plasma where more than 2000 samples may be analyzed in a 24-h period. The compounds used to demonstrate the high-throughput methodology include tamoxifen, raloxifene, 4-hydroxytamoxifen, nafoxidine, and idoxifene. Tamoxifen and raloxifene are used in both breast cancer therapy and osteoporosis and have shown prophylactic potential for the reduction of the risk of breast cancer. The described strategy provides LC/MS/MS separation and quantitation for each of the five test articles in control human plasma. The method includes sample preparation employing liquid-liquid extraction in the 96-well format, an LC separation of the five compounds in less than 30 s, and selected reaction monitoring detection from low nano- to microgram per milliter levels. Precision and accuracy are determined where each 96-well plate is considered a typical "tray" having calibration standards and quality control (QC) samples dispersed through each plate. A concept is introduced where 24 96-well plates analyzed in 1 day is considered a "grand tray", and the method is cross-validated with standards placed only at the beginning of the first plate and the end of the last plate. Using idoxifene-d5 as an internal standard, the results obtained for idoxifene and tamoxifen satisfy current bioanalytical method validation criteria on two separate days where 2112 and 2304 samples were run, respectively. Method validation included 24-h autosampler stability and one freeze-thaw cycle stability for the extracts. Idoxifene showed acceptable results with accuracy ranging from 0.3% for the high quality control (QC) to 15.4% for the low QC and precision of 3.6%-13.9% relative standard deviation. Tamoxifen showed accuracy ranging from 1.6% to 13

  20. Kaempferol inhibits cancer cell growth by antagonizing estrogen-related receptor α and γ activities.

    PubMed

    Wang, Haibin; Gao, Minghui; Wang, Junjian

    2013-11-01

    Kaempferol is a dietary flavonoid that can function as a selective estrogen receptor modulator (SERM). Estrogen-related receptors alpha and gamma (ERRα and ERRγ) are orphan nuclear receptors that play important roles in mitochondrial biogenesis and cancer development. We have shown that kaempferol can functionally antagonize the activities of ERRs based on both response element reporter systems and target gene analysis. Kaempferol modulation of mitochondrial function and suppression cancer cell growth has been confirmed. These findings suggest that kaempferol may exert their anti-cancer activities through antagonizing ERRs activities. PMID:23852933

  1. [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

  2. Design and Synthesis of Norendoxifen Analogues with Dual Aromatase Inhibitory and Estrogen Receptor Modulatory Activities

    PubMed Central

    Lv, Wei; Liu, Jinzhong; Skaar, Todd C.; Flockhart, David A.; Cushman, Mark

    2015-01-01

    Both selective estrogen receptor modulators and aromatase inhibitors are widely used for the treatment of breast cancer. Compounds with both aromatase inhibitory and estrogen receptor modulatory activities could have special advantages for treatment of breast cancer. Our previous efforts led to the discovery of norendoxifen as the first compound with dual aromatase inhibitory and estrogen receptor binding activities. To optimize its efficacy and aromatase selectivity versus other cytochrome P450 enzymes, a series of structurally related norendoxifen analogues were designed and synthesized. The most potent compound, 4'-hydroxynorendoxifen (10), displayed elevated inhibitory potency against aromatase and enhanced affinity for estrogen receptors when compared to norendoxifen. The selectivity of 10 for aromatase versus other cytochrome P450 enzymes was also superior to norendoxifen. 4'-Hydroxynorendoxifen is therefore an interesting lead for further development to obtain new anticancer agents of potential value for the treatment of breast cancer. PMID:25751283

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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.

  8. Corncob bedding alters the effects of estrogens on aggressive behavior and reduces estrogen receptor-α expression 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

  9. 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

  10. 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

  11. Phytoestrogens and Mycoestrogens Induce Signature Structure Dynamics Changes on Estrogen Receptor α.

    PubMed

    Chen, Xueyan; Uzuner, Ugur; Li, Man; Shi, Weibing; Yuan, Joshua S; Dai, Susie Y

    2016-01-01

    Endocrine disrupters include a broad spectrum of chemicals such as industrial chemicals, natural estrogens and androgens, synthetic estrogens and androgens. Phytoestrogens are widely present in diet and food supplements; mycoestrogens are frequently found in grains. As human beings and animals are commonly exposed to phytoestrogens and mycoestrogens in diet and environment, it is important to understand the potential beneficial or hazardous effects of estrogenic compounds. Many bioassays have been established to study the binding of estrogenic compounds with estrogen receptor (ER) and provided rich data in the literature. However, limited assays can offer structure information with regard to the ligand/ER complex. Our current study surveys the global structure dynamics changes for ERα ligand binding domain (LBD) when phytoestrogens and mycoestrogens bind. The assay is based on the structure dynamics information probed by hydrogen deuterium exchange mass spectrometry and offers a unique viewpoint to elucidate the mechanism how phytoestrogens and mycoestrogens interact with estrogen receptor. The cluster analysis based on the hydrogen deuterium exchange (HDX) assay data reveals a unique pattern when phytoestrogens and mycoestrogens bind with ERα LBD compared to that of estradiol and synthetic estrogen modulators. Our study highlights that structure dynamics could play an important role in the structure function relationship when endocrine disrupters interact with estrogen receptors. PMID:27589781

  12. 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.

  13. A selective estrogen receptor modulator inhibits TNF-alpha-induced apoptosis by activating ERK1/2 signaling pathway in vascular endothelial cells.

    PubMed

    Yu, Jing; Eto, Masato; Akishita, Masahiro; Okabe, Tetsuro; Ouchi, Yasuyoshi

    2009-07-01

    Tumor necrosis factor (TNF-alpha) is a pleiotropic cytokine exerting both inflammatory and cell death activity and is thought to play a role in the pathogenesis of atherosclerosis. The present study was designed to examine whether the raloxifene analogue, LY117018 could inhibit TNF-alpha-induced apoptosis in vascular endothelial cells and to clarify the involved mechanisms. Apoptosis of endothelial cells was determined by DNA fragmentation assay and the activation of caspase-3. LY117018 significantly inhibited TNF-alpha-induced caspase-3 activation and cell DNA fragmentation levels in bovine carotid artery endothelial cells. The inhibitory effect of LY117018 was abolished by an estrogen receptor antagonist ICI 182,780. p38 MAPK, JNK, ERK1/2 and Akt have been shown to act as apoptotic or anti-apoptotic signals. TNF-alpha stimulated the phosphorylation levels of p38 MAPK, JNK, ERK1/2 and Akt in vascular endothelial cells. TNF-alpha-induced apoptosis was significantly decreased by SB203580, a p38 MAPK inhibitor or SP600125, a JNK inhibitor, but was enhanced by an ERK1/2 pathway inhibitor, PD98059 or a PI3-kinase/Akt pathway inhibitor, wortmannin. The anti-apoptotic effect of LY117018 was abrogated only by PD98059 but was not affected by the inhibitors for p38 MAPK, JNK, or Akt. LY117018 stimulated the further increase in phosphorylation of ERK1/2 in TNF-alpha treated endothelial cells but it did not affect phosphorylation levels of p38 MAPK, JNK or Akt. These results suggest that LY 110718 prevents caspase-3 dependent apoptosis induced by TNF-alpha in vascular endothelial cells through activation of the estrogen receptors and the ERK1/2 signaling pathway. PMID:19275968

  14. 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

  15. 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

  16. 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

  17. Homology Modeling, Validation and Dynamics of the G Protein-coupled Estrogen Receptor 1 (GPER-1).

    PubMed

    Bruno, Agostino; Aiello, Francesca; Costantino, Gabriele; Radi, Marco

    2016-09-01

    Estrogens exert their action mainly by binding three receptors, namely estrogen receptors α and β (ERα and ERβ) and GPER-1 (G-protein coupled estrogen receptor 1). While the patho-physiological role of both ERα and ERβ has been deeply investigated, the role of GPER-1 in estrogens' signaling has not been clearly defined yet. Unfortunately, only few GPER-1 selective ligands were discovered so far, and the real efficiency of such compounds is still matter of debate. To better understand the physiological relevance of GPER-1, new selective chemical probes are higly needed. In this scenario, we report herein the generation and validation of a three-dimensional (3-D) GPER-1 homology model by means of docking studies and molecular dynamics simulations. The model thus generated was employed to (i) decipher the structural basis underlying the ability of estrogens and some Selective Estrogen Receptor Modulators (SERMs) to bind GPER-1 and classical ERα and ERβ, and (ii) generate a reliable G1/GPER-1 complex useful in rationalizing the pharmacological profile of G1 reported in the literature. The G1/GPER-1 complex herein reported could be further exploited in drug design approaches aimed at improving the pharmacological profile of G1 or at identifying new chemical entities (NCEs) as potential modulators of GPER-1. PMID:27546037

  18. 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. ...

  19. The Role of Estrogen Modulators in Male Hypogonadism and Infertility

    PubMed Central

    Rambhatla, Amarnath; Mills, Jesse N.; Rajfer, Jacob

    2016-01-01

    Estradiol, normally considered a female hormone, appears to play a significant role in men in a variety of physiologic functions, such as bone metabolism, cardiovascular health, and testicular function. As such, estradiol has been targeted by male reproductive and sexual medicine specialists to help treat conditions such as infertility and hypogonadism. The compounds that modulate estradiol levels in these clinical conditions are referred to as selective estrogen receptor modulators (SERMs) and aromatase inhibitors (AIs). In a certain subset of infertile men, particularly those with hypogonadism, or those who have a low serum testosterone to estradiol ratio, there is some evidence suggesting that SERMs and AIs can reverse the low serum testosterone levels or the testosterone to estradiol imbalance and occasionally improve any associated infertile or subfertile state. This review focuses on the role these SERMs and AIs play in the aforementioned reproductive conditions. PMID:27601965

  20. The Role of Estrogen Modulators in Male Hypogonadism and Infertility.

    PubMed

    Rambhatla, Amarnath; Mills, Jesse N; Rajfer, Jacob

    2016-01-01

    Estradiol, normally considered a female hormone, appears to play a significant role in men in a variety of physiologic functions, such as bone metabolism, cardiovascular health, and testicular function. As such, estradiol has been targeted by male reproductive and sexual medicine specialists to help treat conditions such as infertility and hypogonadism. The compounds that modulate estradiol levels in these clinical conditions are referred to as selective estrogen receptor modulators (SERMs) and aromatase inhibitors (AIs). In a certain subset of infertile men, particularly those with hypogonadism, or those who have a low serum testosterone to estradiol ratio, there is some evidence suggesting that SERMs and AIs can reverse the low serum testosterone levels or the testosterone to estradiol imbalance and occasionally improve any associated infertile or subfertile state. This review focuses on the role these SERMs and AIs play in the aforementioned reproductive conditions. PMID:27601965

  1. 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

  2. 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

  3. 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

  4. Prothymosin alpha selectively enhances estrogen receptor transcriptional activity by interacting with a repressor of estrogen receptor activity.

    PubMed

    Martini, P G; Delage-Mourroux, R; Kraichely, D M; Katzenellenbogen, B S

    2000-09-01

    We find that prothymosin alpha (PTalpha) selectively enhances transcriptional activation by the estrogen receptor (ER) but not transcriptional activity of other nuclear hormone receptors. This selectivity for ER is explained by PTalpha interaction not with ER, but with a 37-kDa protein denoted REA, for repressor of estrogen receptor activity, a protein that we have previously shown binds to ER, blocking coactivator binding to ER. We isolated PTalpha, known to be a chromatin-remodeling protein associated with cell proliferation, using REA as bait in a yeast two-hybrid screen with a cDNA library from MCF-7 human breast cancer cells. PTalpha increases the magnitude of ERalpha transcriptional activity three- to fourfold. It shows lesser enhancement of ERbeta transcriptional activity and has no influence on the transcriptional activity of other nuclear hormone receptors (progesterone receptor, glucocorticoid receptor, thyroid hormone receptor, or retinoic acid receptor) or on the basal activity of ERs. In contrast, the steroid receptor coactivator SRC-1 increases transcriptional activity of all of these receptors. Cotransfection of PTalpha or SRC-1 with increasing amounts of REA, as well as competitive glutathione S-transferase pulldown and mammalian two-hybrid studies, show that REA competes with PTalpha (or SRC-1) for regulation of ER transcriptional activity and suppresses the ER stimulation by PTalpha or SRC-1, indicating that REA can function as an anticoactivator in cells. Our data support a model in which PTalpha, which does not interact with ER, selectively enhances the transcriptional activity of the ER but not that of other nuclear receptors by recruiting the repressive REA protein away from ER, thereby allowing effective coactivation of ER with SRC-1 or other coregulators. The ability of PTalpha to directly interact in vitro and in vivo with REA, a selective coregulator of the ER, thereby enabling the interaction of ER with coactivators, appears to explain

  5. 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

  6. Estrogen receptor α in cancer-associated fibroblasts suppresses prostate cancer invasion via modulation of thrombospondin 2 and matrix metalloproteinase 3.

    PubMed

    Slavin, Spencer; Yeh, Chiuan-Ren; Da, Jun; Yu, Shengqiang; Miyamoto, Hiroshi; Messing, Edward M; Guancial, Elizabeth; Yeh, Shuyuan

    2014-06-01

    The prostate cancer (PCa) microenvironment contains active stromal cells known as cancer-associated fibroblasts (CAF) that may play important roles in influencing tumor progression. Here we studied the role of CAF estrogen receptor alpha (ERα) and found that it could protect against PCa invasion. Immunohistochemistry on prostatectomy specimens showed that PCa patients with ERα-positive stroma had a significantly lower risk for biochemical recurrence. In vitro invasion assays further confirmed that the stromal ERα was able to reduce PCa cell invasion. Dissection of the molecular mechanism revealed that the CAF ERα could function through a CAF-epithelial interaction via selectively upregulating thrombospondin 2 (Thbs2) and downregulating matrix metalloproteinase 3 (MMP3) at the protein and messenger RNA levels. Chromatin immunoprecipitation assays further showed that ERα could bind to an estrogen response element on the promoter of Thbs2. Importantly, knockdown of Thbs2 led to increased MMP3 expression and interruption of the ERα mediated invasion suppression, providing further evidence of an ERα-Thbs2-MMP3 axis in CAF. In vivo studies using athymic nude mice injected with CWR22Rv1 (22Rv1) PCa epithelial cells and CAF cells ± ERα also confirmed that mice coimplanted with PCa cells and CAF ERα+ cells had less tumor foci in the pelvic lymph nodes, less metastases, and tumors showed less angiogenesis, MMP3, and MMP9 (an MMP3 downstream target) positive staining. Together, these data suggest that CAF ERα could play protective roles in suppressing PCa metastasis. Our results may lead to developing new and alternative therapeutic approaches to battle PCa via controlling ERα signaling in CAF. PMID:24374826

  7. No effect of different estrogen receptor ligands on cognition in adult female monkeys.

    PubMed

    Lacreuse, Agnès; Wilson, Mark E; Herndon, James G

    2009-03-01

    Many studies in women and animal models suggest that estrogens affect cognitive function. Yet, the mechanisms by which estrogens may impact cognition remain unclear. The goal of the present study was to assess the effects of different estrogen receptor (ER) ligands on cognitive function in adult ovariectomized female rhesus monkeys. The monkeys were tested for 6 weeks on a battery of memory and attentional tasks administered on a touchscreen: the object, face, and spatial versions of the Delayed Recognition Span Test (DRST) and a Visual Search task. Following a 2-week baseline period with oil vehicle treatment, monkeys were randomly assigned to one of 3 treatment groups: estradiol benzoate (EB), selective ERbeta agonist (diarylpropionitrile DPN) or selective ER modulator tamoxifen (TAM). In each treatment group, monkeys received oil vehicle for 2 weeks and the drug for 2 weeks, in a cross-over design. After a 4-week washout, a subset of monkeys was re-tested on the battery when treated with a selective ERalpha agonist (propyl-pyrazole-triol, PPT) or oil vehicle. Overall, drug treatments had no or negligible effects on cognitive performance. These results support the contention that exogenous estrogens and selective estrogen receptor modulators (SERMS) do not significantly affect cognition in young adult female macaques. Additional studies are needed to determine whether the cognitive effects of estrogens in monkeys of more advanced age are mediated by ERbeta, ERalpha or complex interactions between the two receptors. PMID:19101578

  8. Insights into Rapid Modulation of Neuroplasticity by Brain Estrogens

    PubMed Central

    Woolfrey, Kevin M.; Penzes, Peter

    2013-01-01

    Converging evidence from cellular, electrophysiological, anatomic, and behavioral studies suggests that the remodeling of synapse structure and function is a critical component of cognition. This modulation of neuroplasticity can be achieved through the actions of numerous extracellular signals. Moreover, it is thought that it is the integration of different extracellular signals regulation of neuroplasticity that greatly influences cognitive function. One group of signals that exerts powerful effects on multiple neurologic processes is estrogens. Classically, estrogens have been described to exert their effects over a period of hours to days. However, there is now increasing evidence that estrogens can rapidly influence multiple behaviors, including those that require forebrain neural circuitry. Moreover, these effects are found in both sexes. Critically, it is now emerging that the modulation of cognition by rapid estrogenic signaling is achieved by activation of specific signaling cascades and regulation of synapse structure and function, cumulating in the rewiring of neural circuits. The importance of understanding the rapid effects of estrogens on forebrain function and circuitry is further emphasized as investigations continue to consider the potential of estrogenic-based therapies for neuropathologies. This review focuses on how estrogens can rapidly influence cognition and the emerging mechanisms that underlie these effects. We discuss the potential sources and the biosynthesis of estrogens within the brain and the consequences of rapid estrogenic-signaling on the remodeling of neural circuits. Furthermore, we argue that estrogens act via distinct signaling pathways to modulate synapse structure and function in a manner that may vary with cell type, developmental stage, and sex. Finally, we present a model in which the coordination of rapid estrogenic-signaling and activity-dependent stimuli can result in long-lasting changes in neural circuits

  9. Estrogen response element and the promoter context of the human and mouse lactoferrin genes influence estrogen receptor alpha-mediated transactivation activity in mammary gland cells.

    PubMed

    Stokes, Kenya; Alston-Mills, Brenda; Teng, Christina

    2004-10-01

    A critical step in estrogen action is the recognition of estrogen responsive elements (EREs) by liganded estrogen receptor. Our current studies were designed to determine whether an extended estrogen response element half-site (ERRE) contributes to the differential estrogen responses of the human and mouse lactoferrin overlapping chicken ovalbumin upstream promoter/ERE sequences (estrogen response modules, ERMs) in the context of their natural promoters. Transient transfections of MCF-7 cells show that liganded estrogen receptor alpha (ERalpha) activates transcription of the human lactoferrin ERM fourfold higher than the mouse lactoferrin ERM in the context of their natural promoters. Since the ERRE of the human lactoferrin gene naturally occurs 18 bp upstream from the ERM and is absent in the mouse lactoferrin gene promoter, we created a chimeric mouse lactoferrin CAT reporter, which now encodes the ERRE in the identical location as in the human lactoferrin gene. The addition of the ERRE in the mouse lactoferrin gene rendered this reporter extremely responsive to estrogen stimulation. Using limited protease digestions and electrophoretic mobility shift assays, we showed that the binding and protease sensitivity of ERalpha bound to the mouse ERM with or without the ERRE, differed. Importantly, occupancy of additional nuclear receptors at the ERRE may contribute to ERalpha binding and activation. Furthermore, the presence of ERRE influences the selectivity of coactivators in liganded ERalpha-mediated transcriptional activity. When the receptor is bound to human and mouse plus genes, which contain the ERRE, steroid receptor coactivator (SRC)-2 was preferred, while SRC-1 and SRC-3 coactivators selectively enhanced the mouse lactoferrin gene activity. Moreover, peroxisome proliferator activated receptor-gamma coactivator-1 (PGC-1alpha) and PGC-1-related estrogen receptor coactivator (PERC) robustly increase the transcriptional function of ERalpha in the presence of the

  10. Estrogenic modulation of auditory processing: a vertebrate comparison

    PubMed Central

    Caras, Melissa L.

    2013-01-01

    Sex-steroid hormones are well-known regulators of vocal motor behavior in several organisms. A large body of evidence now indicates that these same hormones modulate processing at multiple levels of the ascending auditory pathway. The goal of this review is to provide a comparative analysis of the role of estrogens in vertebrate auditory function. Four major conclusions can be drawn from the literature: First, estrogens may influence the development of the mammalian auditory system. Second, estrogenic signaling protects the mammalian auditory system from noise- and age-related damage. Third, estrogens optimize auditory processing during periods of reproductive readiness in multiple vertebrate lineages. Finally, brain-derived estrogens can act locally to enhance auditory response properties in at least one avian species. This comparative examination may lead to a better appreciation of the role of estrogens in the processing of natural vocalizations and may provide useful insights toward alleviating auditory dysfunctions emanating from hormonal imbalances. PMID:23911849

  11. Estrogen binding, receptor mRNA, and biologic response in osteoblast-like osteosarcoma cells

    SciTech Connect

    Komm, B.S.; Terpening, C.M.; Benz, D.J.; Graeme, K.A.; Gallegos, A.; Korc, M.; Greene, G.L.; O'Malley, B.W.; Haussler, M.R.

    1988-07-01

    High specific activity estradiol labeled with iodine-125 was used to detect approximately 200 saturable, high-affinity (dissociation constant approximately equal to 1.0 nM) nuclear binding sites in rat (ROS 17/2.8) and human (HOS TE85) clonal osteoblast-like osteosarcoma cells. Of the steroids tested, only testosterone exhibited significant cross-reactivity with estrogen binding. RNA blot analysis with a complementary DNA probe to the human estrogen receptor revealed putative receptor transcripts of 6 to 6.2 kilobases in both rat and human osteosarcoma cells. Type I procollagen and transforming growth factor-beta messenger RNA levels were enhanced in cultured human osteoblast-like cells treated with 1 nM estradiol. Thus, estrogen can act directly on osteoblasts by a receptor-mediated mechanism and thereby modulate the extracellular matrix and other proteins involved in the maintenance of skeletal mineralization and remodeling.

  12. 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

  13. 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

  14. 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

  15. 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

  16. Endocrine disrupting chemicals targeting estrogen receptor signaling: Identification and mechanisms of action

    PubMed Central

    Shanle, Erin K.; Xu, Wei

    2011-01-01

    Many endocrine disrupting chemicals (EDCs) adversely impact estrogen signaling by interacting with two estrogen receptors (ERs): ERα and ERβ. Though the receptors have similar ligand binding and DNA binding domains, ERα and ERβ have some unique properties in terms of ligand selectivity and target gene regulation. EDCs that target ER signaling can modify genomic and non-genomic ER activity through direct interactions with ERs, indirectly through transcription factors like the aryl hydrocarbon receptor (AhR), or through modulation of metabolic enzymes that are critical for normal estrogen synthesis and metabolism. Many EDCs act through multiple mechanisms as exemplified by chemicals that bind both AhR and ER, such as 3-methylcholanthrene. Other EDCs that target ER signaling include phytoestrogens, bisphenolics, and organochlorine pesticides and many alter normal ER signaling through multiple mechanisms. EDCs can also display tissue-selective ER agonist and antagonist activities similar to selective estrogen receptor modulators (SERMs) designed for pharmaceutical use. Thus, biological effects of EDCs need to be carefully interpreted because EDCs can act through complex tissue-selective modulation of ERs and other signaling pathways in vivo. Current requirements by the U.S. Environmental Protection Agency require some in vitro and cell-based assays to identify EDCs that target ER signaling through direct and metabolic mechanisms. Additional assays may be useful screens for identifying EDCs that act through alternative mechanisms prior to further in vivo study. PMID:21053929

  17. 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

  18. 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

  19. In vivo dissection of the estrogen receptor alpha: uncoupling of its physiological effects and medical perspectives.

    PubMed

    Arnal, Jean-François; Gourdy, Pierre; Lenfant, Françoise

    2013-05-01

    Given this widespread role for estrogen in human physiology, it is not surprising that estrogen influence the pathophysiology of numerous diseases, including cancer (of the reproductive tract as breast, endometrial but also colorectal, prostate…), as well as neurodegenerative, inflammatory-immune, cardiovascular and metabolic diseases, and osteoporosis. These actions are mediated by the activation of estrogen receptors (ER) alpha (ERα) and beta (ERβ), which regulate target gene transcription (genomic action) through two independent activation functions (AF)-1 and AF-2, but can also elicit rapid membrane initiated steroid signals (MISS). Targeted ER gene inactivation has shown that although ERβ plays an important role in the central nervous system and in the heart, ERα appears to play a prominent role in most of the other tissues. Pharmacological activation or inhibition of ERα and/or ERβ provides already the basis for many therapeutic interventions, from contraception or hormone replacement at menopause to prevention of the recurrence of breast cancer. However, the use of these estrogens or selective estrogen receptors modulators (SERMs) have also induced undesired effects. Thus, an important challenge consists now to uncouple the beneficial actions from other deleterious ones. We summarize here an in vivo molecular "dissection" that allows to delineate in mouse the role of the main "subfunctions" of the receptor. This could pave the way to an optimization of the ER modulation. PMID:23566615

  20. 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

  1. 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

  2. Not lost in translation: Emerging clinical importance of the G protein-coupled estrogen receptor GPER.

    PubMed

    Barton, Matthias

    2016-07-01

    It has been 20years that the G protein-coupled estrogen receptor (GPER) was cloned as the orphan receptor GPR30 from multiple cellular sources, including vascular endothelial cells. Here, I will provide an overview of estrogen biology and the historical background leading to the discovery of rapid vascular estrogen signaling. I will also review the recent advances in the understanding of the mechanisms underlying GPER function, its role in physiology and disease, some of the currently available GPER-targeting drugs approved for clinical use such as SERMs (selective estrogen receptor modulators) and SERDs (selective estrogen receptor downregulators). Many of currently used drugs such as tamoxifen, raloxifene, or faslodex™/fulvestrant were discovered targeting GPER many years after they had been introduced to the clinics for entirely different purposes. This has important implications for the clinical use of these drugs and their modes of action, which I have termed 'reverse translational medicine'. In addition, environmental pollutants known as 'endocrine disruptors' have been found to bind to GPER. This article also discusses recent evidence in these areas as well as opportunities in translational clinical medicine and GPER research, including medical genetics, personalized medicine, prevention, and its theranostic use. PMID:26921679

  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. Current medical treatment of estrogen receptor-positive breast cancer

    PubMed Central

    Lumachi, Franco; Santeufemia, Davide A; Basso, Stefano MM

    2015-01-01

    Approximately 80% of breast cancers (BC) are estrogen receptor (ER)-positive and thus endocrine therapy (ET) should be considered complementary to surgery in the majority of patients. The advantages of oophorectomy, adrenalectomy and hypophysectomy in women with advanced BC have been demonstrated many years ago, and currently ET consist of (1) ovarian function suppression (OFS), usually obtained using gonadotropin-releasing hormone agonists (GnRHa); (2) selective estrogen receptor modulators or down-regulators (SERMs or SERDs); and (3) aromatase inhibitors (AIs), or a combination of two or more drugs. For patients aged less than 50 years and ER+ BC, there is no conclusive evidence that the combination of OFS and SERMs (i.e., tamoxifen) or chemotherapy is superior to OFS alone. Tamoxifen users exhibit a reduced risk of BC, both invasive and in situ, especially during the first 5 years of therapy, and extending the treatment to 10 years further reduced the risk of recurrences. SERDs (i.e., fulvestrant) are especially useful in the neoadjuvant treatment of advanced BC, alone or in combination with either cytotoxic agents or AIs. There are two types of AIs: type I are permanent steroidal inhibitors of aromatase, while type II are reversible nonsteroidal inhibitors. Several studies demonstrated the superiority of the third-generation AIs (i.e., anastrozole and letrozole) compared with tamoxifen, and adjuvant therapy with AIs reduces the recurrence risk especially in patients with advanced BC. Unfortunately, some cancers are or became ET-resistant, and thus other drugs have been suggested in combination with SERMs or AIs, including cyclin-dependent kinase 4/6 inhibitors (palbociclib) and mammalian target of rapamycin (mTOR) inhibitors, such as everolimus. Further studies are required to confirm their real usefulness. PMID:26322178

  5. 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

  6. Structural insights into Resveratrol’s antagonist and partial agonist actions on estrogen receptor alpha

    PubMed Central

    2013-01-01

    Background Resveratrol, a naturally occurring stilbene, has been categorized as a phytoestrogen due to its ability to compete with natural estrogens for binding to estrogen receptor alpha (ERα) and modulate the biological responses exerted by the receptor. Biological effects of resveratrol (RES) on estrogen receptor alpha (ERα) remain highly controversial, since both estrogenic and anti-estrogenic properties were observed. Results Here, we provide insight into the structural basis of the agonist/antagonist effects of RES on ERα ligand binding domain (LBD). Using atomistic simulation, we found that RES bound ERα monomer in antagonist conformation, where Helix 12 moves away from the ligand pocket and orients into the co-activator binding groove of LBD, is more stable than RES bound ERα in agonist conformation, where Helix 12 lays over the ligand binding pocket. Upon dimerization, the agonistic conformation of RES-ERα dimer becomes more stable compared to the corresponding monomer but still remains less stable compared to the corresponding dimer in antagonist conformation. Interestingly, while the binding pocket and the binding contacts of RES to ERα are similar to those of pure agonist diethylstilbestrol (DES), the binding energy is much less and the hydrogen bonding contacts also differ providing clues for the partial agonistic character of RES on ERα. Conclusions Our Molecular Dynamics simulation of RES-ERα structures with agonist and antagonist orientations of Helix 12 suggests RES action is more similar to Selective Estrogen Receptor Modulator (SERM) opening up the importance of cellular environment and active roles of co-regulator proteins in a given system. Our study reveals that potential co-activators must compete with the Helix 12 and displace it away from the activator binding groove to enhance the agonistic activity. PMID:24160181

  7. 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...

  8. 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

  9. 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

  10. 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

  11. 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

  12. Estrogen Receptors Alpha (ERα) and Beta (ERβ): Subtype-Selective Ligands and Clinical Potential

    PubMed Central

    Paterni, Ilaria; Granchi, Carlotta; Katzenellenbogen, John A.; Minutolo, Filippo

    2014-01-01

    Estrogen receptors alpha (ERα) and beta (ERβ) are nuclear transcription factors that are involved in the regulation of many complex physiological processes in humans. Modulation of these receptors by prospective therapeutic agents is currently being considered for prevention and treatment of a wide variety of pathological conditions, such as, cancer, metabolic and cardiovascular diseases, neurodegeneration, inflammation, and osteoporosis. This review provides an overview and update of compounds that have been recently reported as modulators of ERs, with a particular focus on their potential clinical applications. PMID:24971815

  13. 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

  14. 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

  15. 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

  16. 17β-Estradiol modulates the prolactin secretion induced by TRH through membrane estrogen receptors via PI3K/Akt in female rat anterior pituitary cell culture.

    PubMed

    Sosa, Liliana d V; Gutiérrez, Silvina; Petiti, Juan P; Palmeri, Claudia M; Mascanfroni, Iván D; Soaje, Marta; De Paul, Ana L; Torres, Alicia I

    2012-05-01

    Considering that estradiol is a major modulator of prolactin (PRL) secretion, the aim of the present study was to analyze the role of membrane estradiol receptor-α (mERα) in the regulatory effect of this hormone on the PRL secretion induced by thyrotropin-releasing hormone (TRH) by focusing on the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway activation. Anterior pituitary cell cultures from female rats were treated with 17β-estradiol (E(2), 10 nM) and its membrane-impermeable conjugated estradiol (E(2)-BSA, 10 nM) alone or coincubated with TRH (10 nM) for 30 min, with PRL levels being determined by RIA. Although E(2), E(2)-BSA, TRH, and E(2)/TRH differentially increased the PRL secretion, the highest levels were achieved with E(2)-BSA/TRH. ICI-182,780 did not modify the TRH-induced PRL release but significantly inhibited the PRL secretion promoted by E(2) or E(2)-BSA alone or in coincubation with TRH. The PI3K inhibitors LY-294002 and wortmannin partially inhibited the PRL release induced by E(2)-BSA, TRH, and E(2)/TRH and totally inhibited the PRL levels stimulated by E(2)-BSA/TRH, suggesting that the mER mediated the cooperative effect of E(2) on TRH-induced PRL release through the PI3K pathway. Also, the involvement of this kinase was supported by the translocation of its regulatory subunit p85α from the cytoplasm to the plasma membrane in the lactotroph cells treated with E(2)-BSA and TRH alone or in coincubation. A significant increase of phosphorylated Akt was induced by E(2)-BSA/TRH. Finally, the changes of ERα expression in the plasmalemma of pituitary cells were examined by confocal microscopy and flow cytometry, which revealed that the mobilization of intracellular ERα to the plasma membrane of lactotroph cells was only induced by E(2). These finding showed that E(2) may act as a modulator of the secretory response of lactotrophs induced by TRH through mER, with the contribution by PI3K/Akt pathway activation providing a new

  17. 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.

  18. 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...

  19. 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.

  20. 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

  1. Selective Human Estrogen Receptor Partial Agonists (ShERPAs) for Tamoxifen-Resistant Breast Cancer.

    PubMed

    Xiong, Rui; Patel, Hitisha K; Gutgesell, Lauren M; Zhao, Jiong; Delgado-Rivera, Loruhama; Pham, Thao N D; Zhao, Huiping; Carlson, Kathryn; Martin, Teresa; Katzenellenbogen, John A; Moore, Terry W; Tonetti, Debra A; Thatcher, Gregory R J

    2016-01-14

    Almost 70% of breast cancers are estrogen receptor α (ERα) positive. Tamoxifen, a selective estrogen receptor modulator (SERM), represents the standard of care for many patients; however, 30-50% develop resistance, underlining the need for alternative therapeutics. Paradoxically, agonists at ERα such as estradiol (E2) have demonstrated clinical efficacy in patients with heavily treated breast cancer, although side effects in gynecological tissues are unacceptable. A drug that selectively mimics the actions of E2 in breast cancer therapy but minimizes estrogenic effects in other tissues is a novel, therapeutic alternative. We hypothesized that a selective human estrogen receptor partial agonist (ShERPA) at ERα would provide such an agent. Novel benzothiophene derivatives with nanomolar potency in breast cancer cell cultures were designed. Several showed partial agonist activity, with potency of 0.8-76 nM, mimicking E2 in inhibiting growth of tamoxifen-resistant breast cancer cell lines. Three ShERPAs were tested and validated in xenograft models of endocrine-independent and tamoxifen-resistant breast cancer, and in contrast to E2, ShERPAs did not cause significant uterine growth. PMID:26681208

  2. 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

  3. 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

  4. 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 ...

  5. 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

  6. 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.

  7. 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

  8. 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

  9. 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...

  10. 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...

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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

  20. Polymorphic AAAG repeat length in estrogen-related receptor gamma (ERRγ) and risk of breast cancer in Iranian women.

    PubMed

    Karimi, Padideh; Hematti, Simin; Safari, Foruzan; Tavassoli, Manoochehr

    2013-11-01

    Estrogen-related receptors (ERRs) alpha, beta, and gamma are orphan nuclear receptors that modulate the estrogen signaling pathway and play roles in the regulation of breast cancer cell growth. To determine the association between breast cancer risk and alleles of the tetranucleotide repeat (AAAG)n in the intron of ERRγ gene, a case-control study of 200 breast cancer patients and 200 controls was performed in Iranian women. Our results demonstrate that women with short AAAG repeat are at higher risk of breast cancer (OR 7). This result suggests a possible involvement of polymorphic AAAG repeat of ERRγ gene in regulating its expression. PMID:24125170

  1. 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

  2. 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

  3. 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

  4. Ability of xeno- and phytoestrogens to modulate expression of estrogen-sensitive genes in rat uterus: estrogenicity profiles and uterotropic activity.

    PubMed

    Diel, P; Schulz, T; Smolnikar, K; Strunck, E; Vollmer, G; Michna, H

    2000-05-01

    The function of the uterus is regulated by female sex steroids and it is, therefore, used as the classical target organ to detect estrogenic action. Uterine response to estrogens involves the activation of a large pattern of estrogen-sensitive genes. This fact offers the opportunity to analyze the estrogenic activity of xeno- and phytoestrogens, and the mechanisms of their molecular action by a correlation of the uterotropic activity and their ability to modulate the expression of estrogen-sensitive genes. We have analyzed the expression of androgen receptor (AR), progesterone receptor (PR), estrogen receptor (ER), clusterin (CLU), complement C3 (C3), and GAPDH mRNA in the rat uterus following oral administration of ethinylestradiol (EE), bisphenol A (BPA), o,p'-DDT (DDT), p-tert-octylphenol (OCT) and daidzein (DAI). A significant stimulation of the uterine wet weight could be observed after administration of all the substances. The activity of all analyzed compounds to stimulate uterine weight was low in comparison to EE. DDT has the highest activity to stimulate uterine weight whereas BPA and DAI turned out to be less potent. The analysis of gene expression revealed a very specific profile of molecular action in response to the different compounds which cannot be detected by judging the uterotropic response alone. A dose dependent analysis revealed that C3 mRNA is already modulated at doses where no uterotropic response was detectable. Although DAI and BPA were very weak stimulators of uterine growth, these substances were able to alter the expression of AR, ER and C3 very strongly. Based on these investigations the analyzed compounds can be subdivided into distinct classes: First, compounds which exhibit a similar gene expression fingerprint as EE (e.g. OCT); second, compounds exhibiting a significant uterotropic activity, but inducing a pattern of gene expression different from EE (e.g. DDT); and third, compounds like BPA and especially DAI which exhibit a very

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. To modulate and be modulated: estrogenic influences on auditory processing of communication signals within a socio-neuro-endocrine framework.

    PubMed

    Yoder, Kathleen M; Vicario, David S

    2012-02-01

    Gonadal hormones modulate behavioral responses to sexual stimuli, and communication signals can also modulate circulating hormone levels. In several species, these combined effects appear to underlie a two-way interaction between circulating gonadal hormones and behavioral responses to socially salient stimuli. Recent work in songbirds has shown that manipulating local estradiol levels in the auditory forebrain produces physiological changes that affect discrimination of conspecific vocalizations and can affect behavior. These studies provide new evidence that estrogens can directly alter auditory processing and indirectly alter the behavioral response to a stimulus. These studies show that: 1) Local estradiol action within an auditory area is necessary for socially relevant sounds to induce normal physiological responses in the brains of both sexes; 2) These physiological effects occur much more quickly than predicted by the classical time-frame for genomic effects; 3) Estradiol action within the auditory forebrain enables behavioral discrimination among socially relevant sounds in males; and 4) Estradiol is produced locally in the male brain during exposure to particular social interactions. The accumulating evidence suggests a socio-neuro-endocrinology framework in which estradiol is essential to auditory processing, is increased by a socially relevant stimulus, acts rapidly to shape perception of subsequent stimuli experienced during social interactions, and modulates behavioral responses to these stimuli. Brain estrogens are likely to function similarly in both songbird sexes because aromatase and estrogen receptors are present in both male and female forebrain. Estrogenic modulation of perception in songbirds and perhaps other animals could fine-tune male advertising signals and female ability to discriminate them, facilitating mate selection by modulating behaviors. PMID:22201281

  11. 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

  12. The estrogen receptor-α-induced microRNA signature regulates itself and its transcriptional response

    PubMed Central

    Castellano, Leandro; Giamas, Georgios; Jacob, Jimmy; Coombes, R. Charles; Lucchesi, Walter; Thiruchelvam, Paul; Barton, Geraint; Jiao, Long R.; Wait, Robin; Waxman, Jonathan; Hannon, Gregory J.; Stebbing, Justin

    2009-01-01

    Following estrogenic activation, the estrogen receptor-α (ERα) directly regulates the transcription of target genes via DNA binding. MicroRNAs (miRNAs) modulated by ERα have the potential to fine tune these regulatory systems and also provide an alternate mechanism that could impact on estrogen-dependent developmental and pathological systems. Through a microarray approach, we identify the subset of microRNAs (miRNAs) modulated by ERα, which include upregulation of miRNAs derived from the processing of the paralogous primary transcripts (pri-) mir-17–92 and mir-106a-363. Characterization of the mir-17–92 locus confirms that the ERα target protein c-MYC binds its promoter in an estrogen-dependent manner. We observe that levels of pri-mir-17–92 increase earlier than the mature miRNAs derived from it, implicating precursor cleavage modulation after transcription. Pri-mir-17–92 is immediately cleaved by DROSHA to pre-miR-18a, indicating that its regulation occurs during the formation of the mature molecule from the precursor. The clinical implications of this novel regulatory system were confirmed by demonstrating that pre-miR-18a was significantly upregulated in ERα-positive compared to ERα-negative breast cancers. Mechanistically, miRNAs derived from these paralogous pri-miRNAs (miR-18a, miR-19b, and miR-20b) target and downregulate ERα, while a subset of pri-miRNA-derived miRNAs inhibit protein translation of the ERα transcriptional p160 coactivator, AIB1. Therefore, different subsets of miRNAs identified act as part of a negative autoregulatory feedback loop. We propose that ERα, c-MYC, and miRNA transcriptional programs invoke a sophisticated network of interactions able to provide the wide range of coordinated cellular responses to estrogen. PMID:19706389

  13. Estrogen receptor β in Alzheimer's disease: From mechanisms to therapeutics.

    PubMed

    Zhao, Liqin; Woody, Sarah K; Chhibber, Anindit

    2015-11-01

    Alzheimer's disease (AD) disproportionally affects women and men. The female susceptibility for AD has been largely associated with the loss of ovarian sex hormones during menopause. This review examines the current understanding of the role of estrogen receptor β (ERβ) in the regulation of neurological health and its implication in the development and intervention of AD. Since its discovery in 1996, research conducted over the last 15-20 years has documented a great deal of evidence indicating that ERβ plays a pivotal role in a broad spectrum of brain activities from development to aging. ERβ genetic polymorphisms have been associated with cognitive impairment and increased risk for AD predominantly in women. The role of ERβ in the intervention of AD has been demonstrated by the alteration of AD pathology in response to treatment with ERβ-selective modulators in transgenic models that display pronounced plaque and tangle histopathological presentations as well as learning and memory deficits. Future studies that explore the potential interactions between ERβ signaling and the genetic isoforms of human apolipoprotein E (APOE) in brain aging and development of AD-risk phenotype are critically needed. The current trend of lost-in-translation in AD drug development that has primarily been based on early-onset familial AD (FAD) models underscores the urgent need for novel models that recapitulate the etiology of late-onset sporadic AD (SAD), the most common form of AD representing more than 95% of the current human AD population. Combining the use of FAD-related models that generally have excellent face validity with SAD-related models that hold more reliable construct validity would together increase the predictive validity of preclinical findings for successful translation into humans. PMID:26307455

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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 ...

  19. 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

  20. Estrogen Modulates Expression of Tight Junction Proteins in Rat Vagina

    PubMed Central

    Oh, Kyung-Jin; Ahn, Kyuyoun

    2016-01-01

    Background. The objectives of this study were to investigate the localization of tight junctions and the modulation of zonula occludens- (ZO-) 1, occludin and claudin-1 expression by estrogen in castrated female rat vagina. Female Sprague-Dawley rats (230–240 g, n = 45) were divided into three groups and subjected to a sham operation (control group, n = 15), bilateral ovariectomy (Ovx group, n = 15), or bilateral ovariectomy followed by daily subcutaneous injection of 17β-estradiol (50 μg/kg/day, Ovx + Est group, n = 15). The cellular localization and expression of ZO-1, occludin, and claudin-1 were determined in each group by immunohistochemistry and western blot. Results. Expression of ZO-1 was diffuse in all groups, with the highest intensity in the superficial epithelium in the control group. Occludin was localized in the intermediate and basal epithelium. Claudin-1 was most intense in the superficial layer of the vaginal epithelium in the control group. Expression of ZO-1, occludin, and claudin-1 was significantly decreased after ovariectomy and was restored to the level of the control after estrogen replacement. Conclusions. Tight junctions are distinctly localized in rat vagina, and estrogen modulates the expression of tight junctions. Further researches are needed to clarify the functional role of tight junctions in vaginal lubrication. PMID:27127786

  1. Social memory associated with estrogen receptor polymorphisms in women.

    PubMed

    Karlsson, Sara; Henningsson, Susanne; Hovey, Daniel; Zettergren, Anna; Jonsson, Lina; Cortes, Diana S; Melke, Jonas; Laukka, Petri; Fischer, Håkan; Westberg, Lars

    2016-06-01

    The ability to recognize the identity of faces and voices is essential for social relationships. Although the heritability of social memory is high, knowledge about the contributing genes is sparse. Since sex differences and rodent studies support an influence of estrogens and androgens on social memory, polymorphisms in the estrogen and androgen receptor genes (ESR1, ESR2, AR) are candidates for this trait. Recognition of faces and vocal sounds, separately and combined, was investigated in 490 subjects, genotyped for 10 single nucleotide polymorphisms (SNPs) in ESR1, four in ESR2 and one in the AR Four of the associations survived correction for multiple testing: women carrying rare alleles of the three ESR2 SNPs, rs928554, rs1271572 and rs1256030, in linkage disequilibrium with each other, displayed superior face recognition compared with non-carriers. Furthermore, the uncommon genotype of the ESR1 SNP rs2504063 was associated with better recognition of identity through vocal sounds, also specifically in women. This study demonstrates evidence for associations in women between face recognition and variation in ESR2, and recognition of identity through vocal sounds and variation in ESR1. These results suggest that estrogen receptors may regulate social memory function in humans, in line with what has previously been established in mice. PMID:26955855

  2. 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

  3. 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...

  4. 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

  5. Impaired estrogen sensitivity in bone by inhibiting both estrogen receptor alpha and beta pathways.

    PubMed

    Ogawa, S; Fujita, M; Ishii, Y; Tsurukami, H; Hirabayashi, M; Ikeda, K; Orimo, A; Hosoi, T; Ueda, M; Nakamura, T; Ouchi, Y; Muramatsu, M; Inoue, S

    2000-07-14

    Although it is well established that estrogen deficiency causes osteoporosis among the postmenopausal women, the involvement of estrogen receptor (ER) in its pathogenesis still remains uncertain. In the present study, we have generated rats harboring a dominant negative ERalpha, which inhibits the actions of not only ERalpha but also recently identified ERbeta. Contrary to our expectation, the bone mineral density (BMD) of the resulting transgenic female rats was maintained at the same level with that of the wild-type littermates when sham-operated. In addition, ovariectomy-induced bone loss was observed almost equally in both groups. Strikingly, however, the BMD of the transgenic female rats, after ovariectomized, remained decreased even if 17beta-estradiol (E(2)) was administrated, whereas, in contrast, the decrease of littermate BMD was completely prevented by E(2). Moreover, bone histomorphometrical analysis of ovariectomized transgenic rats revealed that the higher rates of bone turnover still remained after treatment with E(2). These results demonstrate that the prevention from the ovariectomy-induced bone loss by estrogen is mediated by ER pathways and that the maintenance of BMD before ovariectomy might be compensated by other mechanisms distinct from ERalpha and ERbeta pathways. PMID:10806217

  6. Estrogen Signalling and the Metabolic Syndrome: Targeting the Hepatic Estrogen Receptor Alpha Action

    PubMed Central

    Matic, Marko; Bryzgalova, Galyna; Gao, Hui; Antonson, Per; Humire, Patricia; Omoto, Yoko; Portwood, Neil; Pramfalk, Camilla; Efendic, Suad; Berggren, Per-Olof; Gustafsson, Jan-Åke; Dahlman-Wright, Karin

    2013-01-01

    An increasing body of evidence now links estrogenic signalling with the metabolic syndrome (MS). Despite the beneficial estrogenic effects in reversing some of the MS symptoms, the underlying mechanisms remain largely undiscovered. We have previously shown that total estrogen receptor alpha (ERα) knockout (KO) mice exhibit hepatic insulin resistance. To determine whether liver-selective ablation of ERα recapitulates metabolic phenotypes of ERKO mice we generated a liver-selective ERαKO mouse model, LERKO. We demonstrate that LERKO mice have efficient reduction of ERα selectively within the liver. However, LERKO and wild type control mice do not differ in body weight, and have a comparable hormone profile as well as insulin and glucose response, even when challenged with a high fat diet. Furthermore, LERKO mice display very minor changes in their hepatic transcript profile. Collectively, our findings indicate that hepatic ERα action may not be the responsible factor for the previously identified hepatic insulin resistance in ERαKO mice. PMID:23451233

  7. 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

  8. Sex differences in opioid analgesia and addiction: interactions among opioid receptors and estrogen receptors

    PubMed Central

    2013-01-01

    Opioids are widely used as the pain reliever and also notorious for being addictive drugs. Sex differences in the opioid analgesia and addiction have been reported and investigated in human subjects and animal models. Yet, the molecular mechanism underlying the differences between males and females is still unclear. Here, we reviewed the literature describing the sex differences in analgesic responses and addiction liabilities to clinically relevant opioids. The reported interactions among opioids, estrogens, opioid receptors, and estrogen receptors are also evaluated. We postulate that the sex differences partly originated from the crosstalk among the estrogen and opioid receptors when stimulated by the exogenous opioids, possibly through common secondary messengers and the downstream gene transcriptional regulators. PMID:24010861

  9. Receptor subtypes and signal transduction mechanisms contributing to the estrogenic attenuation of cannabinoid-induced changes in energy homeostasis.

    PubMed

    Washburn, Neal; Borgquist, Amanda; Wang, Kate; Jeffery, Garrett S; Kelly, Martin J; Wagner, Edward J

    2013-01-01

    We examined the receptor subtypes and signal transduction mechanisms contributing to the estrogenic modulation of cannabinoid-induced changes in energy balance. Food intake and, in some cases, O2 consumption, CO2 production and the respiratory exchange ratio were evaluated in ovariectomized female guinea pigs treated s.c. with the cannabinoid receptor agonist WIN 55,212-2 or its cremephor/ethanol/0.9% saline vehicle, and either with estradiol benzoate (EB), the estrogen receptor (ER) α agonist PPT, the ERβ agonist DPN, the Gq-coupled membrane ER agonist STX, the GPR30 agonist G-1 or their respective vehicles. Patch-clamp recordings were performed in hypothalamic slices. EB, STX, PPT and G-1 decreased daily food intake. Of these, EB, STX and PPT blocked the WIN 55,212-2-induced increase in food intake within 1-4 h. The estrogenic diminution of cannabinoid-induced hyperphagia correlated with a rapid (within 15 min) attenuation of cannabinoid-mediated decreases in glutamatergic synaptic input onto arcuate neurons, which was completely blocked by inhibition of protein kinase C (PKC) and attenuated by inhibition of protein kinase A (PKA). STX, but not PPT, mimicked this rapid estrogenic effect. However, PPT abolished the cannabinoid-induced inhibition of glutamatergic neurotransmission in cells from animals treated 24 h prior. The estrogenic antagonism of this presynaptic inhibition was observed in anorexigenic proopiomelanocortin neurons. These data reveal that estrogens negatively modulate cannabinoid-induced changes in energy balance via Gq-coupled membrane ER- and ERα-mediated mechanisms involving activation of PKC and PKA. As such, they further our understanding of the pathways through which estrogens act to temper cannabinoid sensitivity in regulating energy homeostasis in females. PMID:22538462

  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. The SEEM: selective estrogen enzyme modulators in breast cancer.

    PubMed

    Pasqualini, J R; Ebert, C; Chetrite, G S

    1999-12-01

    Human breast cancer tissue contains all the enzymes (estrone sulfatase, 17 beta-hydroxysteroid dehydrogenase, aromatase) involved in the last steps of estradiol biosynthesis. This tissue also contains sulfotransferase for the formation of the biologically inactive estrogen sulfates. In the past years, it has been demonstrated that various progestins (promegestone, nomegestrol acetate, medrogestone) as well as tibolone and its metabolites are potent inhibitors of sulfatase and 17 beta-hydroxysteroid dehydrogenase activities. It was also shown that medrogestone, nomegestrol acetate, promegestone or tibolone can stimulate the sulfotransferase activity for the local production of estrogen sulfates. All these data, in addition to numerous agents which can block the aromatase action, lead to the new concept of Selective Estrogen Enzyme Modulators (SEEM) which can largely apply to breast cancer tissue. The exploration of various progestins and other active agents in trials with breast cancer patients, showing an inhibitory effect on sulfatase and 17 beta-hydroxysteroid dehydrogenase, or a stimulatory effect on sulfotransferase, will provide a new option in the treatment of this disease. PMID:10862262

  12. The selective estrogen enzyme modulator (SEEM) in breast cancer.

    PubMed

    Chetrite, G S; Pasqualini, J R

    2001-01-01

    Human breast cancer tissue contains all the enzymes (estrone sulfatase, 17beta-hydroxysteroid dehydrogenase, aromatase) involved in the last steps of estradiol biosynthesis. This tissue also contains sulfotransferase for the formation of the biologically inactive estrogen sulfates. In the last years, it was demonstrated that various progestins (promegestone, nomegestrol acetate, medrogestone), as well as tibolone and its metabolites are potent inhibitors of sulfatase and 17beta-hydroxysteroid dehydrogenase activities. It was also shown that medrogestone, nomegestrol acetate, promegestone or tibolone can stimulate the sulfotransferase activity for the local production of estrogen sulfates. All these data, in addition to numerous agents, which can block the aromatase action, lead to the new concept of selective estrogen enzyme modulators (SEEM), which can largely apply to breast cancer tissue. The exploration of various progestins and other active agents in trials with breast cancer patients, showing an inhibitory effect on sulfatase and 17beta-hydroxysteroid dehydrogenase, or a stimulatory effect on sulfotransferase, will provide a new possibility in the treatment of this disease. PMID:11384867

  13. 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

  14. 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

  15. 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

  16. The unliganded long isoform of estrogen receptor beta stimulates brain ryanodine receptor single channel activity alongside with cytosolic Ca2+

    PubMed Central

    Rybalchenko, Volodymyr; Grillo, Michael A.; Gastinger, Matthew J.; Rybalchenko, Nataliya; Payne, Andrew J.; Koulen, Peter

    2010-01-01

    Ca2+ release from intracellular stores mediated by endoplasmic reticulum membrane ryanodine receptors (RyR) plays a key role in activating and synchronizing downstream Ca2+-dependent mechanisms, in different cells varying from apoptosis to nuclear transcription and development of defensive responses. Recently discovered, atypical “non-genomic” effects mediated by estrogen receptors (ER) include rapid Ca2+ release upon estrogen exposure in conditions implicitly suggesting involvement of RyRs. In the present study, we report various levels of co-localization between RyR type 2 (RyR2) and ER type β (ERβ) in the neuronal cell line HT-22, indicating a possible functional interaction. Electrophysiological analyses revealed a significant increase in single channel ionic currents generated by mouse brain RyRs after application of the soluble monomer of the long form ERβ (ERβ1). The effect was due to a strong increase in open probability of RyR higher open channel sublevels at cytosolic [Ca2+] concentrations of 100 nM, suggesting a synergistic action of ERβ1 and Ca2+ in RyR activation, and a potential contribution to Ca2+-induced Ca2+ release rather than to basal intracellular Ca2+ concentration level at rest. This RyR/ERβ interaction has potential effects on cellular physiology, including roles of shorter ERβ isoforms and modulation of the RyR/ERβ complexes by exogenous estrogens. PMID:19899956

  17. 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

  18. The Wedelolactone Derivative Inhibits Estrogen Receptor-Mediated Breast, Endometrial, and Ovarian Cancer Cells Growth

    PubMed Central

    Xu, Defeng; Lin, Tzu-Hua; Cheng, Max A.; Chen, Lu-Min; Chang, Chawnshang; Yeh, Shuyuan

    2014-01-01

    Estrogen and estrogen receptor (ER)-mediated signaling pathways play important roles in the etiology and progression of human breast, endometrial, and ovarian cancers. Attenuating ER activities by natural products and their derivatives is a relatively practical strategy to control and reduce breast, endometrial, and ovarian cancer risk. Here, we found 3-butoxy-1,8,9-trihydroxy-6H-benzofuro[3,2-c]benzopyran-6-one (BTB), a new derivative of wedelolactone, could effectively inhibit the 17-estradiol (E2)-induced ER transactivation and suppress the growth of breast cancer as well as endometrial and ovarian cancer cells. Our results indicate that 2.5 μM BTB effectively suppresses ER-positive, but not ER-negative, breast, endometrial, and ovarian cancer cells. Furthermore, our data indicate that BTB can modulate ER transactivation and suppress the expression of E2-mediated ER target genes (Cyclin D1, E2F1, and TERT) in the ER-positive MCF-7, Ishikawa, and SKOV-3 cells. Importantly, this BTB mediated inhibition of ER activity is selective since BTB does not suppress the activities of other nuclear receptors, including glucocorticoid receptor and progesterone receptor, suggesting that BTB functions as a selective ER signaling inhibitor with the potential to treat breast, endometrial, and ovarian cancers. PMID:25221777

  19. 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...

  20. Emergence of constitutively active estrogen receptor-α mutations in pretreated advanced estrogen receptor positive breast cancer

    PubMed Central

    Meric-Bernstam, Funda; Gonzalez-Angulo, Ana Maria; Ferrer-Lozano, Jaime; Perez-Fidalgo, Jose A.; Cristofanilli, Massimo; Gómez, Henry; Arteaga, Carlos L.; Giltnane, Jennifer; Balko, Justin M.; Cronin, Maureen T; Jarosz, Mirna; Sun, James; Hawryluk, Matthew; Lipson, Doron; Otto, Geoff; Ross, Jeffrey S; Dvir, Addie; Soussan-Gutman, Lior; Wolf, Ido; Rubinek, Tamar; Gilmore, Lauren; Schnitt, Stuart; Come, Steven E.; Pusztai, Lajos; Stephens, Philip; Brown, Myles; Miller, Vincent A.

    2014-01-01

    Purpose We undertook this study to determine the prevalence of estrogen receptor (ER) α (ESR1) mutations throughout the natural history of hormone dependent breast cancer and to delineate the functional roles of the most commonly detected alterations. Experimental Design We studied a total of 249 tumor specimens from 208 patients. The specimens include 134 ER positive (ER+/HER2–) and, as controls, 115 ER negative (ER−) tumors. The ER+ samples consist of 58 primary breast cancers and 76 metastatic samples. All tumors were sequenced to high unique coverage using next generation sequencing targeting the coding sequence of the estrogen receptor and an additional 182 cancer-related genes. Results Recurring somatic mutations in codons 537 and 538 within the ligand-binding domain of ER were detected in ER+ metastatic disease. Overall, the frequency of these mutations was 12% (9/76, 95% CI 6%-21%) in metastatic tumors and in a subgroup of patients who received an average of 7 lines of treatment the frequency was 20% (5/25, 95% CI 7%-41%). These mutations were not detected in primary or treatment naïve ER+ cancer or in any stage of ER− disease. Functional studies in cell line models demonstrate that these mutations render estrogen receptor constitutive activity and confer partial resistance to currently available endocrine treatments. Conclusions In this study we show evidence for the temporal selection of functional ESR1 mutations as potential drivers of endocrine resistance during the progression of ER positive breast cancer. PMID:24398047

  1. 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

  2. Estrogen synthesis in the central nucleus of the amygdala following middle cerebral artery occlusion: role in modulating neurotransmission.

    PubMed

    Saleh, T M; Connell, B J; Legge, C; Cribb, A E

    2005-01-01

    Stroke-induced lesions of the insular cortex in the brain have been linked to autonomic dysfunction (sympathoexcitation) leading to arrhythmogenesis and sudden cardiac death. In experimental models, systemic estrogen administration in male rats has been shown to reduce stroke-induced cell death in the insular cortex as well as prevent sympathoexcitation. The central nucleus of the amygdala has been postulated to mediate sympathoexcitatory output from the insular cortex. We therefore set out to determine if endogenous estrogen levels within the central nucleus of the amygdala are altered following stroke and if microinjection of estrogen into the central nucleus of the amygdala modulates autonomic tone. Plasma estrogen concentrations were not altered by middle cerebral artery occlusion (22.86+/-0.14 pg/ml vs. 21.24+/-0.33 pg/ml; P>0.05). In contrast, estrogen concentrations in the central nucleus of the amygdala increased significantly following middle cerebral artery occlusion (from 20.83+/-0.54 pg/ml to 76.67+/-1.59 pg/ml; P<0.05). Local infusion of an aromatase inhibitor, letrozole, into the central nucleus of the amygdala at the time of middle cerebral artery occlusion prevented the increase in estrogen concentration suggesting that this increase was dependent on aromatization from testosterone. Furthermore, bilateral microinjection of estrogen (0.5 microM in 200 nl) directly into the central nucleus of the amygdala significantly decreased arterial pressure and sympathetic tone and increased baroreflex sensitivity, and these effects were enhanced following co-injection with either an N-methyl-D-aspartate or non-N-methyl-D-aspartate receptor antagonist. Taken together, the results suggest that middle cerebral artery occlusion resulted in synthesis of estrogen within the central nucleus of the amygdala and that this enhanced estrogen level may act to attenuate overstimulation of central nucleus of the amygdala neurons to prevent middle cerebral artery occlusion

  3. Differential Effect of Phosphorylation-Defective Survivin on Radiation Response in Estrogen Receptor-Positive and -Negative Breast Cancer

    PubMed Central

    Li, Li; Larson, Richard; Xu, Wei; Woodward, Wendy A.

    2015-01-01

    Survivin is a key member of the inhibitor of apoptosis protein family, and is considered a promising therapeutic target due to its universal overexpression in cancers. Survivin is implicated in cellular radiation response through its role in apoptosis, cell division, and DNA damage response. In the present study, analysis of publically available data sets showed that survivin gene expression increased with breast cancer stage (p < 0.00001) and was significantly higher in estrogen receptor-negative cancers as compared to estrogen receptor-positive cancers (p = 9e-46). However, survivin was prognostic in estrogen receptor-positive tumors (p = 0.03) but not in estrogen receptor-negative tumors (p = 0.28). We assessed the effect of a survivin dominant-negative mutant on colony-formation (2D) and mammosphere-formation (3D) efficiency, and radiation response in the estrogen receptor-positive MCF7 and estrogen receptor-negative SUM149 breast cancer cell lines. The colony-formation efficiency was significantly lower in the dominant-negative survivin-transduced cells versus control MCF7 cells (0.42 vs. 0.58, p < 0.01), but it was significantly higher in dominant-negative population versus control-transduced SUM149 cells (0.29 vs. 0.20, p < 0.01). A similar, non-significant, trend in mammosphere-formation efficiency was observed. We compared the radiosensitivity of cells stably expressing dominant-negative survivin with their controls in both cell lines under 2D and 3D culture conditions following exposure to increasing doses of radiation. We found that the dominant-negative populations were radioprotective in MCF7 cells but radiosensitive in SUM149 cells compared to the control-transduced population; further, Taxol was synergistic with the survivin mutant in SUM149 but not MCF7. Our data suggests that survivin modulation influences radiation response differently in estrogen receptor-positive and estrogen receptor-negative breast cancer subtypes, warranting further

  4. 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

  5. Plasma membrane localization and function of the estrogen receptor α variant (ER46) in human endothelial cells

    PubMed Central

    Li, Lei; Haynes, M. Page; Bender, Jeffrey R.

    2003-01-01

    Estrogen receptor (ER) α variants have been identified in an array of nonendothelial cells. We previously demonstrated that estrogen rapidly induces nitric oxide release via a phosphatidylinositol 3-kinase/Akt/endothelial nitric-oxide synthase (eNOS) pathway in EA.hy926 cells (immortalized human endothelial cells), which express a 46-kDa ER. We now confirm that, due to alternative splicing, the 46-kDa endothelial cell protein (ER46) is an amino-terminal truncated product of full-length ERα (ER66). ER46 is expressed in the plasma membrane, cytosol, and nucleus of resting, estrogen-deprived cells. Flow cytometric and immunofluorescence microscopic analyses demonstrated that the ER46 C but not N terminus is Ab-accessible in the plasma membrane. Inhibition of palmitoylation with tunicamycin and [3H]palmitic acid labeling demonstrated an estrogen-induced, palmitoylation-dependent plasma membrane ER46 recruitment, with reorganization into caveolae. In reconstituted, estrogen-stimulated COS-7 (ER-null) cells, membrane ER46 more efficiently triggered membrane eNOS phosphorylation than ER66. Conversely, ER66 more efficiently mediated estrogen response element reporter-gene transactivation than ER46. These results demonstrate that ER46 is localized and further dynamically targeted to the plasma membrane in a palmitoylation-dependent manner. ER46 more efficiently modulates membrane-initiated estrogen actions, including eNOS activation, than full-length ER66. These findings may have important implications in vascular-specific targeting of estrogen receptor agonists. PMID:12682286

  6. Synthesis and estrogen receptor affinity of a 4-hydroxytamoxifen-labeled ligand for diagnostic imaging.

    PubMed

    Lashley, Matthew R; Niedzinski, Edmund J; Rogers, Jane M; Denison, Michael S; Nantz, Michael H

    2002-12-01

    A 10-step synthesis of a novel 4-hydroxytamoxifen-DTPA ligand (HOTam-DTPA) is reported. Tamoxifen and its primary metabolite 4-hydroxytamoxifen are common estrogen receptor ligands. Consequently, tamoxifen has found utility as the targeting component of various diagnostic agents for selective imaging of estrogen receptor-rich tissue, specifically breast cancer. An L-aspartic acid-derived DTPA analogue was attached to the ethyl side chain of 4-hydroxy-tamoxifen using N,N'-dimethylethylenediamine as a hydrophilic linker. A competitve estrogen receptor binding assay using [3H]-17beta-estradiol was performed to determine the effect of the ethyl side chain modification on estrogen receptor affinity. The results show that while the relative affinity of HOTam-DTPA for the estrogen receptor is approximately 10-fold lower than that of tamoxifen, it still remains a potent ligand at relatively low concentrations. PMID:12413861

  7. Estrogen-related receptor γ is an in vivo receptor of bisphenol A.

    PubMed

    Tohmé, Marie; Prud'homme, Sophie M; Boulahtouf, Abdel; Samarut, Eric; Brunet, Frédéric; Bernard, Laure; Bourguet, William; Gibert, Yann; Balaguer, Patrick; Laudet, Vincent

    2014-07-01

    Bisphenol A (BPA) is an endocrine disruptor that displays estrogenic activity. Several reports suggest that BPA may have estrogen receptor-independent effects. In zebrafish, 50 μM BPA exposure induces otic vesicle abnormalities, including otolith aggregation. The purpose of this study was to test if BPA action was mediated in vivo during zebrafish development by the orphan nuclear estrogen related receptor (ERR) γ. Combining pharmacological and functional approaches, we demonstrate that the zebrafish ERRγ mediates BPA-induced malformations in otoliths. Using different bisphenol derivatives, we show that different compounds can induce a similar otolith phenotype than BPA and that the binding affinity of these derivatives to the zebrafish ERRγ correlates with their ability to induce otolith malformations. Morpholino knockdown of ERRγ function suppresses the BPA effect on otoliths whereas overexpression of ERRγ led to a BPA-like otolith phenotype. Moreover, a subphenotypical dose of BPA (1 μM) combined with ERRγ overexpression led to a full-dose (50 μM) BPA otolith phenotype. We therefore conclude that ERRγ mediates the otic vesicle phenotype generated by BPA. Our results suggest that the range of pathways perturbed by this compound and its potential harmful effect are larger than expected.-Tohmé, M., Prud'homme, S. M., Boulahtouf, A., Samarut, E., Brunet, F., Bernard, L., Bourguet, W., Gibert, Y., Balaguer, P., Laudet, V. Estrogen-related receptor γ is an in vivo receptor of bisphenol A. PMID:24744145

  8. 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

  9. Bioluminescence imaging of estrogen receptor activity during breast cancer progression

    PubMed Central

    Vantaggiato, Cristina; Dell’Omo, Giulia; Ramachandran, Balaji; Manni, Isabella; Radaelli, Enrico; Scanziani, Eugenio; Piaggio, Giulia; Maggi, Adriana; Ciana, Paolo

    2016-01-01

    Estrogen receptors (ER) are known to play an important regulatory role in mammary gland development as well as in its neoplastic transformation. Although several studies highlighted the contribution of ER signaling in the breast transformation, little is known about the dynamics of ER state of activity during carcinogenesis due to the lack of appropriate models for measuring the extent of receptor signaling in time, in the same animal. To this aim, we have developed a reporter mouse model for the non-invasive in vivo imaging of ER activity: the ERE-Luc reporter mouse. ERE-Luc is a transgenic mouse generated with a firefly luciferase (Luc) reporter gene driven by a minimal promoter containing an estrogen responsive element (ERE). This model allows to measure receptor signaling in longitudinal studies by bioluminescence imaging (BLI). Here, we have induced sporadic mammary cancers by treating systemically ERE-Luc reporter mice with DMBA (9,10-dimethyl 1,2-benzanthracene) and measured receptor signaling by in vivo imaging in individual animals from early stage until a clinically palpable tumor appeared in the mouse breast. We showed that DMBA administration induces an increase of bioluminescence in the whole abdominal area 6 h after treatment, the signal rapidly disappears. Several weeks later, strong bioluminescence is observed in the area corresponding to the mammary glands. In vivo and ex vivo imaging analysis demonstrated that this bioluminescent signal is localized in the breast area undergoing neoplastic transformation. We conclude that this non-invasive assay is a novel relevant tool to identify the activation of the ER signaling prior the morphological detection of the neoplastic transformation. PMID:27069764

  10. Bioluminescence imaging of estrogen receptor activity during breast cancer progression.

    PubMed

    Vantaggiato, Cristina; Dell'Omo, Giulia; Ramachandran, Balaji; Manni, Isabella; Radaelli, Enrico; Scanziani, Eugenio; Piaggio, Giulia; Maggi, Adriana; Ciana, Paolo

    2016-01-01

    Estrogen receptors (ER) are known to play an important regulatory role in mammary gland development as well as in its neoplastic transformation. Although several studies highlighted the contribution of ER signaling in the breast transformation, little is known about the dynamics of ER state of activity during carcinogenesis due to the lack of appropriate models for measuring the extent of receptor signaling in time, in the same animal. To this aim, we have developed a reporter mouse model for the non-invasive in vivo imaging of ER activity: the ERE-Luc reporter mouse. ERE-Luc is a transgenic mouse generated with a firefly luciferase (Luc) reporter gene driven by a minimal promoter containing an estrogen responsive element (ERE). This model allows to measure receptor signaling in longitudinal studies by bioluminescence imaging (BLI). Here, we have induced sporadic mammary cancers by treating systemically ERE-Luc reporter mice with DMBA (9,10-dimethyl 1,2-benzanthracene) and measured receptor signaling by in vivo imaging in individual animals from early stage until a clinically palpable tumor appeared in the mouse breast. We showed that DMBA administration induces an increase of bioluminescence in the whole abdominal area 6 h after treatment, the signal rapidly disappears. Several weeks later, strong bioluminescence is observed in the area corresponding to the mammary glands. In vivo and ex vivo imaging analysis demonstrated that this bioluminescent signal is localized in the breast area undergoing neoplastic transformation. We conclude that this non-invasive assay is a novel relevant tool to identify the activation of the ER signaling prior the morphological detection of the neoplastic transformation. PMID:27069764

  11. Raloxifene and anti-estrogenic Gonadorelin inhibits intestinal tumorigenesis by modulating immune cells and decreasing stem like cells

    PubMed Central

    Janakiram, Naveena B.; Mohammed, Altaf; Brewer, Misty; Bryant, Taylor; Biddick, Laura; Lightfoot, Stan; Pathuri, Gopal; Gali, Hariprasad; Rao, Chinthalapally V.

    2014-01-01

    Studies suggest that estrogen plays a contributing role in colorectal cancer (CRC). This project examined the preventive effects of raloxifene, a selective estrogen receptor modulator (SERM), and gonadorelin, an anti-estrogenic drug, in female ApcMin/+ mouse intestinal tumorigenesis. Six-week-old ApcMin/+ mice were fed diet containing 1 ppm raloxifene or control diet. Gonadorelin (150ng/mouse) was injected subcutaneously into one treatment group. Intestinal tumors were evaluated for tumor multiplicity and size. Mice treated with raloxifene and gonadorelin showed colon tumor inhibition of 80% and 75% respectively. Both drugs significantly inhibited small intestinal tumor multiplicity and size (75 – 65%, P< 0.0001). Raloxifene and gonadorelin showed significant tumor inhibition with 98% and 94% inhibition of polyps >2 mm in size. In mice fed with raloxifene or injected with gonadorelin, tumors showed significantly reduced proliferating cell nuclear antigen expression (58-65%, P< 0.0001).Raloxifene treatment decreased β-catenin, cyclin D1, laminin 1β, Ccl6 and stem like cells (Lgr 5, EpCAM, CD44/CD24), as well as suppressed inflammatory genes (COX-2, mPGES-1, 5-LOX,). Gonadorelin showed significant decrease in COX-2, mPGES-1, iNOS, and stem like cells or increased NK cells and chemokines required for NK cells. Both drugs were effective in suppressing tumor growth albeit with different mechanisms. These observations show that either suppression of estrogen levels or modulation of estrogen receptor dramatically suppresses small intestinal and colonic tumor formation in female ApcMin/+ mice. These results support the concept of chemoprevention by these agents in reducing endogenous levels of estrogen or modulating ER signaling. PMID:24431404

  12. Lessons from the dissection of the activation functions (AF-1 and AF-2) of the estrogen receptor alpha in vivo.

    PubMed

    Arnal, Jean-François; Fontaine, Coralie; Abot, Anne; Valera, Marie-Cécile; Laurell, Henrik; Gourdy, Pierre; Lenfant, Françoise

    2013-06-01

    Estrogens influence most of the physiological processes in mammals, including but not limited to reproduction, cognition, behavior, vascular system, metabolism and bone integrity. Given this widespread role for estrogen in human physiology, it is not surprising that estrogen influence the pathophysiology of numerous diseases, including cancer (of the reproductive tract as breast, endometrial but also colorectal, prostate,…), as well as neurodegenerative, inflammatory-immune, cardiovascular and metabolic diseases, and osteoporosis. These actions are mediated by the activation of estrogen receptors (ER) alpha (ERα) and beta (ERβ), which regulate target gene transcription (genomic action) through two independent activation functions (AF)-1 and AF-2, but can also elicit rapid membrane initiated steroid signals (MISS). Targeted ER gene inactivation has shown that although ERβ plays an important role in the central nervous system and in the heart, ERα appears to play a prominent role in most of the other tissues. Pharmacological activation or inhibition of ERα and/or ERβ provides already the basis for many therapeutic interventions, from hormone replacement at menopause to prevention of the recurrence of breast cancer. However, the use of these estrogens or selective estrogen receptors modulators (SERMs) have also induced undesired effects. Thus, an important challenge consists now to uncouple the beneficial actions from other deleterious ones. The in vivo molecular "dissection" of ERα represents both a molecular and integrated approach that already allowed to delineate in mouse the role of the main "subfunctions" of the receptor and that could pave the way to an optimization of the ER modulation. PMID:23200732

  13. 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

  14. 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

  15. Effects of gamma irradiation on the DNA-protein complex between the estrogen response element and the estrogen receptor

    NASA Astrophysics Data System (ADS)

    Štísová, Viktorie; Goffinont, Stephane; Spotheim-Maurizot, Melanie; Davídková, Marie

    2010-08-01

    Signaling by estrogens, risk factors in breast cancer, is mediated through their binding to the estrogen receptor protein (ER), followed by the formation of a complex between ER and a DNA sequence, called estrogen response element (ERE). Anti-estrogens act as competitive inhibitors by blocking the signal transduction. We have studied in vitro the radiosensitivity of the complex between ERα, a subtype of this receptor, and a DNA fragment bearing ERE, as well as the influence of an estrogen (estradiol) or an anti-estrogen (tamoxifen) on this radiosensitivity. We observe that the complex is destabilized upon irradiation with γ rays in aerated aqueous solution. The analysis of the decrease of binding abilities of the two partners shows that destabilization is mainly due to the damage to the protein. The destabilization is reduced when irradiating in presence of tamoxifen and is increased in presence of estradiol. These effects are due to opposite influences of the ligands on the loss of binding ability of ER. The mechanism that can account for our results is: binding of estradiol or tamoxifen induces distinct structural changes of the ER ligand-binding domain that can trigger (by allostery) distinct structural changes of the ER DNA-binding domains and thus, can differently affect ER-ERE interaction.

  16. Allosteric Modulation of Chemoattractant Receptors

    PubMed Central

    Allegretti, Marcello; Cesta, Maria Candida; Locati, Massimo

    2016-01-01

    Chemoattractants control selective leukocyte homing via interactions with a dedicated family of related G protein-coupled receptor (GPCR). Emerging evidence indicates that the signaling activity of these receptors, as for other GPCR, is influenced by allosteric modulators, which interact with the receptor in a binding site distinct from the binding site of the agonist and modulate the receptor signaling activity in response to the orthosteric ligand. Allosteric modulators have a number of potential advantages over orthosteric agonists/antagonists as therapeutic agents and offer unprecedented opportunities to identify extremely selective drug leads. Here, we resume evidence of allosterism in the context of chemoattractant receptors, discussing in particular its functional impact on functional selectivity and probe/concentration dependence of orthosteric ligands activities. PMID:27199992

  17. Structural and Functional Profiling of Environmental Ligands for Estrogen Receptors

    PubMed Central

    Delfosse, Vanessa; Grimaldi, Marina; Cavaillès, Vincent

    2014-01-01

    Background: Individuals are exposed daily to environmental pollutants that may act as endocrine-disrupting chemicals (EDCs), causing a range of developmental, reproductive, metabolic, or neoplastic diseases. With their mostly hydrophobic pocket that serves as a docking site for endogenous and exogenous ligands, nuclear receptors (NRs) can be primary targets of small molecule environmental contaminants. However, most of these compounds are chemically unrelated to natural hormones, so their binding modes and associated hormonal activities are hardly predictable. Objectives: We conducted a correlative analysis of structural and functional data to gain insight into the mechanisms by which 12 members of representative families of pollutants bind to and activate the estrogen receptors ERα and ERβ. Methods: We used a battery of biochemical, structural, biophysical, and cell-based approaches to characterize the interaction between ERs and their environmental ligands. Results: Our study revealed that the chemically diverse compounds bound to ERs via varied sets of protein–ligand interactions, reflecting their differential activities, binding affinities, and specificities. We observed xenoestrogens binding to both ERs—with affinities ranging from subnanomolar to micromolar values—and acting in a subtype-dependent fashion as full agonists or partial agonists/antagonists by using different combinations of the activation functions 1 and 2 of ERα and ERβ. Conclusions: The precise characterization of the interactions between major environmental pollutants and two of their primary biological targets provides rational guidelines for the design of safer chemicals, and will increase the accuracy and usefulness of structure-based computational methods, allowing for activity prediction of chemicals in risk assessment. Citation: Delfosse V, Grimaldi M, Cavaillès V, Balaguer P, Bourguet W. 2014. Structural and functional profiling of environmental ligands for estrogen

  18. Estrogen replacement therapy-induced neuroprotection against brain ischemia-reperfusion injury involves the activation of astrocytes via estrogen receptor β

    PubMed Central

    Ma, Yulong; Guo, Hang; Zhang, Lixia; Tao, Liang; Yin, Anqi; Liu, Zhaoyu; Li, Yan; Dong, Hailong; Xiong, Lize; Hou, Wugang

    2016-01-01

    The incidence of ischemic stroke is significantly increased in postmenopausal women. However, the neuroprotective effects of estrogen replacement therapy (ERT) against stroke remain controversial, and the role of astrocytes in ERT has rarely been explored. In this study, we investigated the effects of estrogen and selective estrogen receptor (ER) agonists on astrocytes activation and neuronal apoptosis in mice under conditions of cell culture oxygen and glucose deprivation and reperfusion (OGD-R), and global cerebral ischemia (GCI). We demonstrated that hippocampal astrocytes primarily express ERβ. In astrocytes, 2.5–20 nM 17β-estradiol (E2) or 10 nM DPN (ERβ agonist) not 10 nM PPT (ERα agonist), significantly increased GFAP expression. And 10 nM E2, DPN or E2+MPP (ERα antagonist), but not PPT or E2+PHTPP (ERβ antagonist), significantly reduced neuronal apoptosis following the subjection of astrocyte and neuronal cocultures to OGD-R. We also found that either 50 μg/kg E2 or 8 mg/kg DPN replacement (3 weeks) significantly increased GFAP expression and reduced GCI-induced neuronal apoptosis in hippocampal CA1 region of ovariectomized mice. These results indicate that estrogen-induced neuroprotection against ischemia-reperfusion injury involves activation of astrocytes via ERβ. Thus, the discovery and design of astrocyte-selective ERβ modulators may offer a new strategy for ERT of ischemic stroke. PMID:26891996

  19. 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

  20. 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

  1. The Intestinal Microbiome and Estrogen Receptor-Positive Female Breast Cancer.

    PubMed

    Kwa, Maryann; Plottel, Claudia S; Blaser, Martin J; Adams, Sylvia

    2016-08-01

    The huge communities of residential microbes, including bacteria, viruses, Archaea, and Eukaryotes, that colonize humans are increasingly recognized as playing important roles in health and disease. A complex populous ecosystem, the human gastrointestinal (GI) tract harbors up to 10(11) bacterial cells per gram of luminal content, whose collective genome, the gut metagenome, contains a vastly greater number of individual genes than the human genome. In health, the function of the microbiome might be considered to be in dynamic equilibrium with the host, exerting both local and distant effects. However, 'disequilibrium' may contribute to the emergence of disease, including malignancy. In this review, we discuss how the intestinal bacterial microbiome and in particular how an 'estrobolome,' the aggregate of enteric bacterial genes capable of metabolizing estrogens, might affect women's risk of developing postmenopausal estrogen receptor-positive breast cancer. Estrobolome composition is impacted by factors that modulate its functional activity. Exploring variations in the composition and activities of the estrobolome in healthy individuals and in women with estrogen-driven breast cancer may lead to development of microbiome-based biomarkers and future targeted interventions to attenuate cancer risk. PMID:27107051

  2. Selective Estrogen Receptor β Agonist LY500307 as a Novel Therapeutic Agent for Glioblastoma

    PubMed Central

    Sareddy, Gangadhara R.; Li, Xiaonan; Liu, Jinyou; Viswanadhapalli, Suryavathi; Garcia, Lauren; Gruslova, Aleksandra; Cavazos, David; Garcia, Mike; Strom, Anders M.; Gustafsson, Jan-Ake; Tekmal, Rajeshwar Rao; Brenner, Andrew; Vadlamudi, Ratna K.

    2016-01-01

    Glioblastomas (GBM), deadly brain tumors, have greater incidence in males than females. Epidemiological evidence supports a tumor suppressive role of estrogen; however, estrogen as a potential therapy for GBM is limited due to safety concerns. Since GBM express ERβ, a second receptor for estrogen, targeting ERβ with a selective agonist may be a potential novel GBM therapy. In the present study, we examined the therapeutic effect of the selective synthetic ERβ agonist LY500307 using in vitro and in vivo GBM models. Treatment with LY500307 significantly reduced the proliferation of GBM cells with no activity on normal astrocytes in vitro. ERβ agonists promoted apoptosis of GBM cells, and mechanistic studies using RNA sequencing revealed that LY500307 modulated several pathways related to apoptosis, cell cycle, and DNA damage response. Further, LY500307 sensitized GBM cells to several FDA-approved chemotherapeutic drugs including cisplatin, lomustine and temozolomide. LY500307 treatment significantly reduced the in vivo tumor growth and promoted apoptosis of GBM tumors in an orthotopic model and improved the overall survival of tumor-bearing mice in the GL26 syngeneic glioma model. Our results demonstrate that LY500307 has potential as a therapeutic agent for GBM. PMID:27126081

  3. Human sperm physiology: estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) influence sperm metabolism and may be involved in the pathophysiology of varicocele-associated male infertility.

    PubMed

    Guido, Carmela; Perrotta, Ida; Panza, Salvatore; Middea, Emilia; Avena, Paola; Santoro, Marta; Marsico, Stefania; Imbrogno, Pietro; Andò, Sebastiano; Aquila, Saveria

    2011-12-01

    The mechanisms by which varicocele affects fertility remain undetermined. Estrogens play a key role in the human male reproduction and human sperm expresses the estrogen receptors (ERs) and aromatase. In this study, by Western blotting we evidenced the ERs content concomitantly in healthy sperm and in oligoastenoteratozoospermic (OAT) samples without and with varicocele. In varicocele a strong reduction of the ERβ was observed, while the ERα was almost absent. Besides, transmission electron microscopy (TEM) confirmed the reduction of ERs expression in "varicocele" sperm, indicating that varicocele has a detrimental effect on sperm structure at molecular level. To further define the estrogen significance in male gamete and the pathophysiology of varicocele we investigated both the expression of ERα and ERβ in normal and pathologic sperm samples as well as we evaluated estradiol (E2) action on lipid and glucose sperm metabolism. Responses to E2 treatments on cholesterol efflux, protein tyrosine phosphorylations, motility, and acrosin activity in varicocele sperm were reduced or absent. The evaluation of the triglycerides content, lipase and acyl-CoA dehydrogenase activities, suggest that E2 exerts a lipolytic effect on human sperm metabolism. Concerning glucose metabolism, it appears that E2 induces G6PDH activity concomitantly to the insulin secretion. In "varicocele" sperm, the E2 did not induce energy expenditure. OAT sperm had E2-responsiveness but in a lesser extent with respect healthy sperm. This study discovered a novel role for E2/ERs in human sperm physiology, since they modulate sperm metabolism and new detrimental effects related to the pathophysiology of the varicocele condition. PMID:21344398

  4. Evaluation of the pharmacological activities of RAD1901, a selective estrogen receptor degrader.

    PubMed

    Wardell, Suzanne E; Nelson, Erik R; Chao, Christina A; Alley, Holly M; McDonnell, Donald P

    2015-10-01

    Endocrine therapy, using tamoxifen or an aromatase inhibitor, remains a first-line treatment for estrogen receptor 1 (ESR1) positive breast cancer. However, tumor resistance limits the duration of response. The clinical efficacy of fulvestrant, a selective ER degrader (SERD) that triggers receptor degradation, has confirmed that ESR1 often remains engaged in endocrine therapy resistant cancers. Recently developed, selective ER modulators (SERMs)/SERD hybrids (SSHs) that facilitate ESR1 degradation in breast cancer cells and reproductive tissues have been advanced as an alternative treatment for advanced breast cancer, particularly in the metastatic setting. RAD1901 is one SSH currently being evaluated clinically that is unique among ESR1 modulators in that it readily enters the brain, a common site of breast cancer metastasis. In this study, RAD1901 inhibited estrogen activation of ESR1 in vitro and in vivo, inhibited estrogen-dependent breast cancer cell proliferation and xenograft tumor growth, and mediated dose-dependent downregulation of ESR1 protein. However, doses of RAD1901 insufficient to induce ESR1 degradation were shown to result in the activation of ESR1 target genes and in the stimulation of xenograft tumor growth. RAD1901 is an SSH that exhibits complex pharmacology in breast cancer models, having dose-dependent agonist/antagonist activity displayed in a tissue-selective manner. It remains unclear how this unique pharmacology will impact the utility of RAD1901 for breast cancer treatment. However, being the only SERD currently known to access the brain, RAD1901 merits evaluation as a targeted therapy for the treatment of breast cancer brain metastases. PMID:26162914

  5. 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

  6. 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

  7. Circular Permutation Probes for Illuminating Phosphorylation of Estrogen Receptor.

    PubMed

    Kim, Sung-Bae; Tao, Hiroaki

    2016-01-01

    The present protocol demonstrates a new strategy for imaging ligand-triggered protein phosphorylation using circularly permutated luciferases (cpLuc): (1) a luciferase is first fragmented into two segments for creating new N- and C-terminal ends in the hydrophilic region, (2) the original N- and C-terminal ends are circularly permutated and linked via a GS linker, whereas the new ends made by fragmentation are correspondingly linked with two proteins of interest. When the new ends of the cpLuc are linked with the ligand-binding domain of estrogen receptor (ER LBD) and Src homology two domain of Src (SH2), the estrogen can trigger phosphorylation of the ER LBD and consequent intramolecular ER LBD-SH2 binding. This interaction triggers an approximation of the adjacent fragments of split-cpLuc recovering the enzyme activity. This probe design greatly improves signal-to-noise (S/N) ratios upon tracing weak protein-protein interactions (PPIs) in mammalian cells. PMID:27424903

  8. 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

  9. Wnt-5a signaling restores tamoxifen sensitivity in estrogen receptor-negative breast cancer cells

    PubMed Central

    Ford, Caroline E.; Ekström, Elin J.; Andersson, Tommy

    2009-01-01

    One third of all breast cancers are estrogen receptor alpha (ERα) negative, carry a poor overall prognosis, and do not respond well to currently available endocrine therapies. New treatment strategies are therefore required. Loss of Wnt-5a has previously been correlated with loss of ERα in clinical breast cancer samples, and we sought to investigate this association further. Three breast cancer cell lines (MDA-MB-231, MDA-MB-468, and 4T1) lacking expression of ERα and Wnt-5a, and one breast cancer cell line (T47D) expressing both proteins were used in this study. Wnt-5a signaling was generated in ERα-negative cell lines via stimulation with either recombinant Wnt-5a protein or a Wnt-5a-derived hexapeptide (Foxy-5) possessing Wnt-5a signaling properties. ERα expression was restored at both mRNA and protein level, after treatment with recombinant Wnt-5a or Foxy-5. This restoration of expression occurred in parallel with a reduction in methylation of the ERα promoter. Up-regulated ERα could be activated, initiate transcription of progesterone receptor and pS2, and activate an estrogen response element reporter construct. Significantly, breast cancer cells re-expressing ERα responded to treatment with the selective estrogen receptor modulator tamoxifen, as measured by induction of apoptosis and cell growth inhibition. Finally, Foxy-5 also increased ERα expression in an in vivo model of ERα-negative breast cancer. This represents the first evidence that Wnt-5a signaling acts to re-establish ERα expression in ERα-negative breast cancer cells. Our data suggest that combinatorial therapy with Foxy-5 and tamoxifen should be considered as a future treatment possibility for ERα-negative breast cancer patients. PMID:19237581

  10. The selective estrogen enzyme modulators in breast cancer: a review.

    PubMed

    Pasqualini, Jorge R

    2004-06-01

    biologically inactive estrogen sulfates. In recent years, it was demonstrated that various progestins (promegestone, nomegestrol acetate, medrogestone, dydrogesterone, norelgestromin), tibolone and its metabolites, as well as other steroidal (e.g. sulfamates) and non-steroidal compounds, are potent sulfatase inhibitors. Various progestins can also block 17beta-hydroxysteroid dehydrogenase activities. In other studies, it was shown that medrogestone, nomegestrol acetate, promegestone or tibolone can stimulate the sulfotransferase activity for the local production of estrogen sulfates. All these data, in addition to numerous agents which can block the aromatase action, lead to the new concept of 'Selective Estrogen Enzyme Modulators' (SEEM) which can largely apply to breast cancer tissue. The exploration of various progestins and other active agents in trials with breast cancer patients, showing an inhibitory effect on sulfatase and 17beta-hydroxysteroid dehydrogenase, or a stimulatory effect on sulfotransferase and consequently on the levels of tissular levels of E(2), will provide a new possibility in the treatment of this disease. PMID:15172700

  11. Modulation of Estrogen Chemical Carcinogenesis by Botanical Supplements used for Postmenopausal Women’s Health

    PubMed Central

    Snelten, Courtney S.; Dietz, Birgit; Bolton, Judy L.

    2012-01-01

    Breast cancer risk has been associated with long-term estrogen exposure including traditional hormone therapy (HT, formally hormone replacement therapy). To avoid traditional HT and associated risks, women have been turning to botanical supplements such as black cohosh, red clover, licorice, hops, dong gui, and ginger to relieve menopausal symptoms despite a lack of efficacy evidence. The mechanisms of estrogen carcinogenesis involve both hormonal and chemical pathways. Botanical supplements could protect women from estrogen carcinogenesis by modulating key enzymatic steps [aromatase, P4501B1, P4501A1, catechol-O-methyltransferase (COMT), NAD(P)H quinone oxidoreductase 1 (NQO1), and reactive oxygen species (ROS) scavenging] in estradiol metabolism leading to estrogen carcinogenesis as outlined in Figure 1. This review summarizes the influence of popular botanical supplements used for women’s health on these key steps in the estrogen chemical carcinogenesis pathway, and suggests that botanical supplements may have added chemopreventive benefits by modulating estrogen metabolism. PMID:24223609

  12. 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...

  13. Fetal brain regional responses to cerebral hypoperfusion: modulation by estrogen.

    PubMed

    Wood, Charles E; Giroux, Damian; Gridley, Kelly

    2003-12-12

    We have previously demonstrated that cerebral hypoperfusion stimulates several physiological and molecular responses which are components of homeostatic reflexes. Physiological increases in fetal plasma estradiol concentration modulate fetal brain responsiveness to hypotension. In the present study, we tested the effect of cerebral hypoperfusion and/or estradiol on the expression of Fos, the protein product of the gene c-fos in late-gestation fetal sheep. We hypothesized that estrogen and cerebral hypoperfusion alone would augment Fos abundance in various brain regions, including the hypothalamus and brainstem, and that estrogen would augment or otherwise modify the Fos response to cerebral hypoperfusion. Singleton or twin fetuses of time-dated pregnant ewes were chronically catheterized and fitted with an extravascular balloon occluder around the brachiocephalic artery using aseptic techniques. In one-half of the fetuses, we implanted a pellet subcutaneously which released estradiol at a rate of 5 mg in 21 days. Fetuses were studied at least 5 days after surgery (124-128 days' gestation, term is approximately 147 days). One-half of the fetuses were subjected to a 10-min period of brachiocephalic occlusion (BCO). One hour after the start of the experiment, the ewe and fetus were euthanized and the fetal brain was rapidly recovered, dissected, and frozen in a polypropylene tube in an acetone/dry ice bath. Brain tissue was homogenized in a boiling lysis buffer, and protein concentrations measured using the Bradford method. Extracted proteins were electrophoresed on 7.5% polyacrylamide gels, transferred to nitrocellulose membranes, and probed for Fos. In most brain regions, estradiol or BCO altered the expression of Fos. Analyzed by two-way analysis of variance, there was a statistically significant (p<0.05) interaction between estradiol and BCO in brainstem, cerebellum, and hippocampus, nearly significant in hypothalamus (p=0.07) and not statistically significant in

  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. 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. 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

  18. 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}.

  19. 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

  20. 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

  1. 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

  2. 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

  3. Identification and Biological Evaluation of Coactivator Binding Inhibitors for the Estrogen Receptor

    ERIC Educational Resources Information Center

    Gunther, Jillian Rebecca

    2009-01-01

    The physiologic effects of estrogen action through the estrogen receptor (ER) are widespread, as this hormone exerts actions in both reproductive (e.g., uterus) and non-reproductive (e.g., bone, brain) tissues in both men and women. As such, the regulation of the activity of this ligand-activated transcription factor is highly relevant to the…

  4. 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…

  5. Estrogen receptor mutations in breast cancer--new focus on an old target.

    PubMed

    Segal, Corrinne V; Dowsett, Mitch

    2014-04-01

    Recent studies have provided strong evidence for the emergence of substantial numbers of constitutively active ESR1 mutations in estrogen receptor-positive metastatic breast cancer that are undetected in primary disease. Some of these mutants remain partially sensitive to current anti-estrogen therapies but effective therapeutics targeted at them may require new approaches. PMID:24583794

  6. KRÜPPEL-LIKE FACTOR 9 AND REGULATION OF ENDOMETRIAL ESTROGEN RECEPTOR-ALPHA SIGNALING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Endometrial cancer risk is linked to aberrant estrogen receptor-alpha (ER alpha) signaling caused by increased ER alpha activation due to hyper-estrogenic environments or mutations in growth-regulatory factors. We had shown that ER alpha signaling is attenuated by the Sp1-related transcription facto...

  7. The relationship between ovarian steroids and uterine estrogen receptors during late pregnancy

    SciTech Connect

    Cathey, T.M.; Chung, Kyung W. )

    1991-01-01

    Although a direct interdependence exists between the ovarian steroids, estrogen and progesterone, the exact role of these two hormones during pregnancy, especially late pregnancy, is not completely understood. Investigations have been conducted to determine whether the circulating levels of progesterone and estrogen or changes in the ratio of progesterone/estrogen in relation to the concentration of uterine estrogen receptors are associated with triggering parturition. Ninety-day old female rats were sacrificed at gestation days 14, 16, 18, 20 and two days post-partum. The plasma levels of estradiol and progesterone were measured by solid-phase radioimmunoassay. Uterine cytosol was subjected to a charcoal binding assay to determine the concentration of estrogen receptors. Our findings demonstrate that there is a significant drop in both plasma progesterone and estradiol during late pregnancy. Also indicated is a significant increase in uterine estrogen receptors throughout late pregnancy. Finally, during this period there is a direct correlation between the shift in the progesterone/estrogen ratio and the increase in the concentration of uterine estrogen receptors in late pregnancy.

  8. Extranuclear Estrogen Receptors Mediate the Neuroprotective Effects of Estrogen in the Rat Hippocampus

    PubMed Central

    Yang, Fang; Zhang, Yi-dong; Wang, Rui-min; Brann, Darrell W.

    2010-01-01

    Background 17β-estradiol (E2) has been implicated to exert neuroprotective effects in the brain following cerebral ischemia. Classically, E2 is thought to exert its effects via genomic signaling mediated by interaction with nuclear estrogen receptors. However, the role and contribution of extranuclear estrogen receptors (ER) is unclear and was the subject of the current study. Methodology/Principal Findings To accomplish this goal, we employed two E2 conjugates (E2 dendrimer, EDC, and E2-BSA) that can interact with extranuclear ER and exert rapid nongenomic signaling, but lack the ability to interact with nuclear ER due to their inability to enter the nucleus. EDC or E2-BSA (10 µM) was injected icv 60 min prior to global cerebral ischemia (GCI). FITC-tagged EDC or E2-BSA revealed high uptake in the hippocampal CA1 region after icv injection, with a membrane (extranuclear) localization pattern in cells. Both EDC and E2-BSA exerted robust neuroprotection in the CA1 against GCI, and the effect was blocked by the ER antagonist, ICI182,780. EDC and E2-BSA both rapidly enhanced activation of the prosurvival kinases, ERK and Akt, while attenuating activation of the proapoptotic kinase, JNK following GCI, effects that were blocked by ICI182,780. Administration of an MEK or PI3K inhibitor blocked the neuroprotective effects of EDC and E2-BSA. Further studies showed that EDC increased p-CREB and BDNF in the CA1 region in an ERK- and Akt-dependent manner, and that cognitive outcome after GCI was preserved by EDC in an ER-dependent manner. Conclusions/Significance In conclusion, the current study demonstrates that activation of extranuclear ER results in induction of ERK-Akt-CREB-BDNF signaling in the hippocampal CA1 region, which significantly reduces ischemic neuronal injury and preserves cognitive function following GCI. The study adds to a growing literature that suggests that extranuclear ER can have important actions in the brain. PMID:20479872

  9. Estrogen

    MedlinePlus

    Estrogen is used to treat hot flushes ('hot flashes'; sudden strong feelings of heat and sweating) in ... and cause problems with the skin or nervous system), very high or very low levels of calcium ...

  10. Estrogen

    MedlinePlus

    ... estrogen tablets. If you will be taking Estrace® brand tablets, tell your doctor and pharmacist if you are allergic to aspirin or tartrazine (a food color additive). Ask your pharmacist or check the manufacturer's ...

  11. Association of estrogen receptor β and estrogen-related receptor α gene polymorphisms with bone mineral density in postmenopausal women.

    PubMed

    Shoukry, Amira; Shalaby, Sally M; Etewa, Rasha L; Ahmed, Hanan S; Abdelrahman, Hossam M

    2015-07-01

    The aim of the study was to investigate the possible association of AluI and RsaI polymorphisms of estrogen receptor β (ER-β) gene and 23-bp nucleotide repeat polymorphism of estrogen-related receptor α (ERRα) gene with bone mineral density (BMD) in postmenopausal Egyptian women. Two-hundred postmenopausal osteoporotic women as cases and 180 healthy age-matched postmenopausal women as controls were genotyped by PCR fragment length polymorphism for AluI, allele-specific PCR for RsaI, and by sizing of PCR products on agarose gels for ERRα repeats. sRANKL levels were estimated by ELISA. BMD measurements for spine and femoral neck were performed by dual energy X-ray absorptiometry. A significant difference between women with osteoporosis and controls regarding allele and genotype distributions of AluI G/A (OR 2.37, 95 % CI 1.77-3.18 and p < 0.001 for A allele) and ERRα polymorphisms (for the two repeats allele OR 2.08, 95 % CI 1.09-4.00, and p = 0.02). Osteoporotic women with the AluI AA + GA genotype or with the EERα 2,2 genotype had significantly lower BMD than did women with the other genotypes. Moreover, there was a significant increase of the mean values of sRANKL in carriers of AluI A, RsaI A alleles and in patients having 2,2 genotypes of ERRα (p < 0.001, p < 0.001, p = 0.02, respectively). We demonstrated an association of ER-β AluI G/A and ERRα 23-repeats polymorphisms with BMD in postmenopausal Egyptian women. A possible effect of ER-β and ERRα polymorphisms on the levels of sRANKL was estimated. PMID:25903400

  12. Dissection of Estrogen Receptor Alpha Signaling Pathways in Osteoblasts Using RNA-Sequencing

    PubMed Central

    Roforth, Matthew M.; Atkinson, Elizabeth J.; Levin, Ellis R.; Khosla, Sundeep; Monroe, David G.

    2014-01-01

    The effects of 17-β-estradiol in osteoblasts are primarily mediated by the nuclear transcription factors, estrogen receptor (ER)α and ERβ. ERs function through three general modes of action: DNA-binding dependent through estrogen response elements (EREs; designated nuclear ERE signaling); nuclear signaling via protein-protein interactions to other transcription factors (nuclear non-ERE signaling); and extra-nuclear signaling (membrane-bound functions of ERs). Identification of the specific transcriptional signatures regulated by each of these modes of action should contribute to an enhanced understanding of estrogen signaling in osteoblasts. To achieve this goal, we utilized specific mutations of ERα that eliminate the ability of the receptor to signal through a specific mode of action. The non-classical ERα knock-in (NERKI) mutation is incapable of signaling through direct DNA binding to EREs and the nuclear only ERα (NOER) mutation eliminates all membrane-localized signaling. Comparison of the gene expression patterns elicited by these mutations with the wild-type ERα (WT) pattern provides mode-specific data concerning transcriptional regulation by ERα. We expressed these constructs in the ER-negative osteoblastic cell line hFOB (−/+ estrogen) and performed global RNA-sequencing. Using a series of pair-wise comparisons, we generated three lists of genes that were regulated either by the nuclear ERE-dependent, nuclear ERE-independent, or extra-nuclear actions of ERα. Pathway and gene ontology analyses revealed that genes regulated through the nuclear ERE and nuclear non-ERE pathways were largely involved in transcriptional regulation, whereas genes regulated through extra-nuclear mechanisms are involved in cytoplasmic signaling transduction pathways. We also intersected our data with genes linked to bone density and fractures from a recent genome-wide association study and found 25 of 72 genes (35%) regulated by estrogen. These data provide a

  13. Estrogen stimulated migration and invasion of estrogen receptor-negative breast cancer cells involves an ezrin-dependent crosstalk between G protein-coupled receptor 30 and estrogen receptor beta signaling.

    PubMed

    Zhou, Kewen; Sun, Peng; Zhang, Yaxing; You, Xinchao; Li, Ping; Wang, Tinghuai

    2016-07-01

    Estrogen mediates important cellular activities in estrogen receptor negative (ER-) breast cancer cells via membrane associated G protein-coupled receptor 30 (GPR30). However, the biological role and mechanism of estrogen action on cell motility and invasion in this aggressive kind of tumors remains poorly understood. We showed here that treatment with 17β-estradiol (E2) in ER-negative cancer cells resulted in ezrin-dependent cytoskeleton rearrangement and elicited a stimulatory effect on cell migration and invasion. Mechanistically, E2 induced ezrin activation was mediated by distinct mechanisms in different cell contexts. In SK-BR-3 cells with a high GPR30/ERβ ratio, silencing of GPR30 was able to abolish E2 induced ERK1/2, AKT phosphorylation and ezrin activation, whereas in MDA-MB-231 cells with low GPR30/ERβ ratio, E2 stimulated ezrin activation was mediated by the ERβ/PI3K/AKT signaling pathway. Importantly, we showed that activation of GPR30 signaling significantly prevents ERβ activation induced ezrin phosphorylation, cell migration and invasion, indicating an antagonist effect between GPR30 and ERβ signaling in MDA-MB-231 cells. These findings highlight the important interplay between different estrogen receptors in estrogen induced cell motility and invasiveness in ER-negative breast cancer cells. PMID:26850467

  14. Interaction of vault particles with estrogen receptor in the MCF-7 breast cancer cell.

    PubMed

    Abbondanza, C; Rossi, V; Roscigno, A; Gallo, L; Belsito, A; Piluso, G; Medici, N; Nigro, V; Molinari, A M; Moncharmont, B; Puca, G A

    1998-06-15

    A 104-kD protein was coimmunoprecipitated with the estrogen receptor from the flowtrough of a phosphocellulose chromatography of MCF-7 cell nuclear extract. mAbs to this protein identified several cDNA clones coding for the human 104-kD major vault protein. Vaults are large ribonucleoprotein particles of unknown function present in all eukaryotic cells. They have a complex morphology, including several small molecules of RNA, but a single protein species, the major vault protein, accounts for >70% of their mass. Their shape is reminiscent of the nucleopore central plug, but no proteins of known function have been described to interact with them. Western blot analysis of vaults purified on sucrose gradient showed the presence of estrogen receptor co-migrating with the vault peak. The AER317 antibody to estrogen receptor coimmunoprecipitated the major vault protein and the vault RNA also in the 20,000 g supernatant fraction. Reconstitution experiments of estrogen receptor fragments with the major vault protein mapped the site of the interaction between amino acids 241 and 280 of human estrogen receptor, where the nuclear localization signal sequences are located. Estradiol treatment of cells increased the amount of major vault protein present in the nuclear extract and coimmunoprecipitated with estrogen receptor, whereas the anti-estrogen ICI182,780 had no effect. The hormone-dependent interaction of vaults with estrogen receptor was reproducible in vitro and was prevented by sodium molybdate. Antibodies to progesterone and glucocorticoid receptors were able to coimmunoprecipitate the major vault protein. The association of nuclear receptors with vaults could be related to their intracellular traffic. PMID:9628887

  15. Interaction of Vault Particles with Estrogen Receptor in the MCF-7 Breast Cancer Cell

    PubMed Central

    Abbondanza, Ciro; Rossi, Valentina; Roscigno, Annarita; Gallo, Luigi; Belsito, Angela; Piluso, Giulio; Medici, Nicola; Nigro, Vincenzo; Molinari, Anna Maria; Moncharmont, Bruno; Puca, Giovanni A.

    1998-01-01

    A 104-kD protein was coimmunoprecipitated with the estrogen receptor from the flowtrough of a phosphocellulose chromatography of MCF-7 cell nuclear extract. mAbs to this protein identified several cDNA clones coding for the human 104-kD major vault protein. Vaults are large ribonucleoprotein particles of unknown function present in all eukaryotic cells. They have a complex morphology, including several small molecules of RNA, but a single protein species, the major vault protein, accounts for >70% of their mass. Their shape is reminiscent of the nucleopore central plug, but no proteins of known function have been described to interact with them. Western blot analysis of vaults purified on sucrose gradient showed the presence of estrogen receptor co-migrating with the vault peak. The AER317 antibody to estrogen receptor coimmunoprecipitated the major vault protein and the vault RNA also in the 20,000 g supernatant fraction. Reconstitution experiments of estrogen receptor fragments with the major vault protein mapped the site of the interaction between amino acids 241 and 280 of human estrogen receptor, where the nuclear localization signal sequences are located. Estradiol treatment of cells increased the amount of major vault protein present in the nuclear extract and coimmunoprecipitated with estrogen receptor, whereas the anti-estrogen ICI182,780 had no effect. The hormone-dependent interaction of vaults with estrogen receptor was reproducible in vitro and was prevented by sodium molybdate. Antibodies to progesterone and glucocorticoid receptors were able to coimmunoprecipitate the major vault protein. The association of nuclear receptors with vaults could be related to their intracellular traffic. PMID:9628887

  16. Repression of estrogen receptor {beta} function by putative tumor suppressor DBC1

    SciTech Connect

    Koyama, Satoshi; Wada-Hiraike, Osamu; Nakagawa, Shunsuke; Tanikawa, Michihiro; Hiraike, Haruko; Miyamoto, Yuichiro; Sone, Kenbun; Oda, Katsutoshi; Fukuhara, Hiroshi; Nakagawa, Keiichi; Kato, Shigeaki; Yano, Tetsu; Taketani, Yuji

    2010-02-12

    It has been well established that estrogen is involved in the pathophysiology of breast cancer. Estrogen receptor (ER) {alpha} appears to promote the proliferation of cancer tissues, while ER{beta} can protect against the mitogenic effect of estrogen in breast tissue. The expression status of ER{alpha} and ER{beta} may greatly influence on the development, treatment, and prognosis of breast cancer. Previous studies have indicated that the deleted in breast cancer 1 (DBC1/KIAA1967) gene product has roles in regulating functions of nuclear receptors. The gene encoding DBC1 is a candidate for tumor suppressor identified by genetic search for breast cancer. Caspase-dependent processing of DBC1 promotes apoptosis, and depletion of the endogenous DBC1 negatively regulates p53-dependent apoptosis through its specific inhibition of SIRT1. In addition, DBC1 modulates ER{alpha} expression and promotes breast cancer cell survival by binding to ER{alpha}. Here we report an ER{beta}-specific repressive function of DBC1. Immunoprecipitation and immunofluorescence studies show that ER{beta} and DBC1 interact in a ligand-independent manner similar to ER{alpha}. In vitro pull-down assays revealed a direct interaction between DBC1 amino-terminus and activation function-1/2 domain of ER{beta}. Although DBC1 shows no influence on the ligand-dependent transcriptional activation function of ER{alpha}, the expression of DBC1 negatively regulates the ligand-dependent transcriptional activation function of ER{beta}in vivo, and RNA interference-mediated depletion of DBC1 stimulates the transactivation function of ER{beta}. These results implicate the principal role of DBC1 in regulating ER{beta}-dependent gene expressions.

  17. 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

  18. Image cytometry of estrogen receptors in breast carcinomas.

    PubMed

    Cohen, O; Brugal, G; Seigneurin, D; Demongeot, J

    1988-11-01

    A significant level of estrogen receptors (ER) in breast cancer cells is an indication of tumor differentiation and suggests that a homeostatic control of cell growth may persist in these cancers. In medical practice, the Dextran-coated charcoal assays (DCCA) are still the most frequently used test to characterize patients having ER-positive malignant breast tumors and for whom hormonal therapy is justified. Nevertheless, this routine biochemical technique is not satisfactory because it is a broad method unsuitable for revealing receptor tissue heterogeneity. However, immunocytochemical labeling, such as the ER-ICA method, which involves a monoclonal antibody linked to peroxidase, is a specific reaction for this purpose but which until now was not quantitative. The present study uses an original cell preparation technique combining the PAP reaction with toluidine blue counterstain for image analysis on the SAMBA system. Special software has been developed for the quantitative analysis of immunocytochemistry in cancers. Results obtained showed a high correlation between the DCCA values and the score derived from the mean ER concentration per positive tumor cell and the labeling index. In addition, intracell and intratumor heterogeneity can be displayed according to several parameters and were shown to vary according to tumor and to antiestrogen (Tamoxifen) presurgical therapy. PMID:2463134

  19. Selective binding of estrogen receptor α to ubiquitin chains.

    PubMed

    Pesiri, Valeria; Di Muzio, Elena; Polticelli, Fabio; Acconcia, Filippo

    2016-07-01

    Ubiquitin (Ub)-binding domains (UBDs) noncovalently contact the Ub modification on binding partners. Ub possesses seven lysine (K) residues (i.e., K6, K11, K27, K29, K33, K48, and K63) that can be used to form different chains based on different Ub linkage types (e.g., monoubiquitination/polyubiquitination). Thus, different Ub-based signals exist and are decoded by UBDs. Recently, we have reported the existence of two Ub binding surfaces located within the estrogen receptor α (ERα) protein. We have shown that the leucine (L) 429 and alanine (A) 430 ERα residues direct noncovalent receptor binding to K63-based Ub chains in vitro. However, mutation of L429 and A430 residues did not completely abolish the ability of ERα to associate with Ub in cell lines. Thus, we evaluated the possibility that one or both ERα Ub binding surfaces could non-covalently interact with other Ub chains. Here, we report that ERα selectively binds to specific Ub chains based on different Ub linkages and that ERα monoubiquitination requires non-covalent ERα:Ub binding. Considering the importance of the UBD:Ub interaction in the initiation and progression of many diseases (e.g., cancer), our data provide novel insights into ERα functions that could be relevant to ERα-related diseases. © 2016 IUBMB Life, 68(7):569-577, 2016. PMID:27193211

  20. Bromine-80m-labeled estrogens: Auger-electron emitting, estrogen receptor-directed ligands with potential for therapy of estrogen receptor positive cancers

    SciTech Connect

    DeSombre, E.R.; Mease, R.C.; Hughes, A.; Harper, P.V.; DeJesus, O.T.; Friedman, A.M.

    1988-01-01

    A triphenylbromoethylene, 1,1-bis(p-hydroxyphenyl)-2-bromo-2-phenylethylene, Br-BHPE, and a bromosteroidal estrogen, 17..cap alpha..- bromovinylestradiol, BrVE/sub 2/, were labeled with the Auger electron emitting nuclide bromine-80m, prepared by the (p,n) reaction with /sup 80/Se. To assess their potential as estrogen receptor (ER) directed therapeutic substrates the bromine-80m labeled estrogens were injected into immature female rats and the tissue distribution studied at 0.5 and 2 hours. Both radiobromoestrogens showed substantial diethylstilbesterol (DES)-inhibitable localization in the ER rich tissues, uterus, pituitary, ovary and vagina at both time points. While the percent dose per gram tissue was higher for the Br-BHPE, the BrVE/sub 2/ showed higher tissue to blood ratios, especially at 2 hr, reflecting the lower blood concentrations of radiobromine following administration of the steroidal bromoestrogen. Comparing intraperitoneal, intravenous and subcutaneous routes of administration for the radiobromine labeled Br-BHPE, the intraperitoneal route was particularly advantageous to provide maximum, DES-inhibitable concentrations in the peritoneal, ER-rich target organs, the uterus, ovary and vagina. While uterine concentrations after BrBHPE were from 10--48% dose/g and after BrVE/sub 2/ were 15--25% dose/g, similar treatment with /sup 80m/Br as sodium bromide showed uniform low concentrations in all tissues at about the levels seen in blood. The effective specific activity of (/sup 80m/Br)BrBHPE, assayed by specific binding to ER in rat uterine cytosol, was 8700 Ci/mmole. 23 refs., 9 figs., 2 tabs.

  1. 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

  2. Receptor-binding radiopharmaceuticals for imaging breast tumors: estrogen-receptor interactions and selectivity of tissue uptake of halogenated estrogen analogs

    SciTech Connect

    Katzenellenbogen J.A.; Carlson, K.E.; Heiman, D.F.; Goswami, R.

    1980-06-01

    Four halogenated estrogen analogs - o-fluorohexestrol, and 1-fluoro-, 1-bromo-, and 1-iodohexestrol - have been prepared and tritium-labeled in high specific activity, to investigate their potential as estrogen-receptor-based agents for imaging breast tumors. These compounds bind with high affinity in vitro to the cytoplasmic uterine estrogen receptor from rat and lamb and sediment as 8S receptor complexes on sucrose gradients. After 1 hr in immature rats, these compounds show high uptake into the uterus, but low uptakes (10 to 25% of the uterine levels) into most nontarget tissues. The uterine uptake is estrogen specific since it is depressed by excess nonradioactive estradiol. Uptake selectivity is greatest for the fluorohexestrols and decreases for the bromo and iodo compounds. In mature rats bearing DMBA-induced mammary tumors, selective uptake by the uterus and tumors is seen with 1-fluoro(/sup 3/H/sub 4/)hexestrol and o-fluoro(/sup 3/H/sub 3/)hexestrol. The studies indicate that these four halogenated hexestrols are promising candidates as estrogen-receptor-based agents for the imaging of human breast tumors.

  3. ERRF is essential for Estrogen-Estrogen Receptor alpha signaling pathway in ER positive breast cancer cells.

    PubMed

    Luo, Ang; Zhang, Xuan

    2016-05-27

    Estrogen-Estrogen Receptor alpha (ERα) belongs to one of the most important signaling pathways controlling breast tissue development and progression of breast cancer. ERRF was recently identified as a candidate breast cancer associated protein and showed positive association with ERα status in clinical samples and cell lines. To further explore the relationship between ERRF and ERα, we studied whether ERRF plays any roles in estrogen-ERα pathway. Knockdown of ERRF in ER positive breast cancer cells T-47D and BT-474 reduced the level of p-AKT, p-MAPK, and phosphorylation of ERα at Ser 118 and Ser 167, and the transcriptional activity of ERα was inhibited as well. Further mechanism study proved ERRF to be an interacting partner of ERα. In total, these data revealed that ERRF is essential for the activity of E2-ERα pathway. PMID:27125460

  4. Aprotinin inhibits the hormone binding of the estrogen receptor from calf uterus.

    PubMed

    Nigro, V; Medici, N; Abbondanza, C; Minucci, S; Molinari, A M; Puca, G A

    1989-11-15

    Micromolar concentrations of the proteinase inhibitor, aprotinin, produced a dose-dependent inhibition in the binding capacity of the estrogen receptor from calf uterus. Aprotinin inhibition was greater at 28 degrees C than at 4 degrees C and only occurred when conditions allowed the receptor transformation. When aprotinin was tested in the presence of transformation inhibitors, its effect was no longer seen. The binding capacity of the highly purified estrogen-binding subunit was similarly inhibited. PMID:2480113

  5. Binding affinity prediction of novel estrogen receptor ligands using receptor-based 3-D QSAR methods.

    PubMed

    Sippl, Wolfgang

    2002-12-01

    We have recently reported the development of a 3-D QSAR model for estrogen receptor ligands showing a significant correlation between calculated molecular interaction fields and experimentally measured binding affinity. The ligand alignment obtained from docking simulations was taken as basis for a comparative field analysis applying the GRID/GOLPE program. Using the interaction field derived with a water probe and applying the smart region definition (SRD) variable selection procedure, a significant and robust model was obtained (q(2)(LOO)=0.921, SDEP=0.345). To further analyze the robustness and the predictivity of the established model several recently developed estrogen receptor ligands were selected as external test set. An excellent agreement between predicted and experimental binding data was obtained indicated by an external SDEP of 0.531. Two other traditionally used prediction techniques were applied in order to check the performance of the receptor-based 3-D QSAR procedure. The interaction energies calculated on the basis of receptor-ligand complexes were correlated with experimentally observed affinities. Also ligand-based 3-D QSAR models were generated using program FlexS. The interaction energy-based model, as well as the ligand-based 3-D QSAR models yielded models with lower predictivity. The comparison with the interaction energy-based model and with the ligand-based 3-D QSAR models, respectively, indicates that the combination of receptor-based and 3-D QSAR methods is able to improve the quality of prediction. PMID:12413831

  6. 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

  7. Rapid effects of estrogens on behavior: environmental modulation and molecular mechanisms

    PubMed Central

    Laredo, Sarah A.; Landeros, Rosalina Villalon; Trainor, Brian C.

    2014-01-01

    Estradiol can modulate neural activity and behavior via both genomic and nongenomic mechanisms. Environmental cues have a major impact on the relative importance of these signaling pathways with significant consequences for behavior. First we consider how photoperiod modulates nongenomic estrogen signaling on behavior. Intriguingly, short days permit rapid effects of estrogens on aggression in both rodents and song sparrows. This highlights the importance of considering photoperiod as a variable in laboratory research. Next we review evidence for rapid effects of estradiol on ecologically-relevant behaviors including aggression, copulation, communication, and learning. We also address the impact of endocrine disruptors on estrogen signaling, such as those found in corncob bedding used in rodent research. Finally, we examine the biochemical mechanisms that may mediate rapid estrogen action on behavior in males and females. A common theme across these topics is that the effects of estrogens on social behaviors vary across different environmental conditions. PMID:24685383

  8. 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

  9. Interaction of stilbene compounds with human and rainbow trout estrogen receptors.

    PubMed

    Simmons, Denina Bobbie Dawn; Trudeau, Vance Lionel; Marlatt, Vicki Lee; Moon, Thomas William; Sherry, James P; Metcalfe, Chris David

    2008-02-01

    Compounds with stilbene structures are widely used as pharmaceuticals and personal care products (PPCPs) and are present in plants. A suite of stilbene-related compounds, including PPCPs and plant-derived compounds were tested in vitro for interactions with the human and rainbow trout estrogen receptors and in vivo with rainbow trout using vitellogenin levels as a biomarker. Among the compounds with antagonistic activity, the common structural similarity was (in addition to the stilbene backbone) the presence of 4-hydroxy substitution. Stilbene-related compounds found to act as inhibitors at the estrogen receptor included the plant-derived compound resveratrol and two formulations of fluorescent whitening agents used in detergents, 4,4'-bis(2-sulfostyryl)biphenyl and diaminostilbene-1. In the yeast estrogenicity screening assay, the concentrations which caused a 50% inhibition in estrogenic response (IC50s) with the human estrogen receptor ranged from 2.56 x 10(-6) to 2.56 x 10(-6) M. In the rainbow trout estrogen receptor assay, the IC50s ranged from 7.75 x 10(-8) to 1.11 x 10(-5) M. However, in the in vivo rainbow trout vitellogenin assay, tamoxifen was the only stilbene of the compounds tested to have a significant effect as an inhibitor of estrogenicity. PMID:18348622

  10. G-1-activated membrane estrogen receptors mediate increased contractility of the human myometrium.

    PubMed

    Maiti, K; Paul, J W; Read, M; Chan, E C; Riley, S C; Nahar, P; Smith, R

    2011-06-01

    Estrogens are key mediators of increased uterine contractility at labor. We sought to determine whether membrane-associated estrogen receptors, such as the recently described seven-transmembrane receptor G protein-coupled receptor 30 (GPR30), mediated some of this effect. Using human myometrium obtained at term cesarean section before or after the onset of labor, we demonstrated the presence of GPR30 mRNA and protein using quantitative RT-PCR and Western blotting. GPR30 receptor was localized to the cell membrane and often colocalized with calveolin-1. Using the specific estrogen membrane receptor agonist G-1 and myometrial explants, we showed that membrane receptor activation led to phosphorylation of MAPK and the actin-modifying small heat shock protein 27. Using myometrial strips incubated with G-1 or vehicle we demonstrated that estrogen membrane receptor activation increased the myometrial contractile response to oxytocin. These data suggest that activation of the plasma membrane estrogen receptor GPR30 likely participates in the physiology of the human myometrium during pregnancy and identifies it as a potential target to modify uterine activity. PMID:21427217

  11. 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

  12. 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.

  13. Zinc Modulation of Glycine Receptors

    PubMed Central

    Trombley, Paul Q.; Blakemore, Laura J.; Hill, Brook J.

    2011-01-01

    Glycine receptors are widely expressed in the mammalian central nervous system, and previous studies have demonstrated that glycine receptors are modulated by endogenous zinc. Zinc is concentrated in synaptic vesicles in several brain regions but is particularly abundant in the hippocampus and olfactory bulb. In the present study, we used patch-clamp electrophysiology of rat hippocampal and olfactory bulb neurons in primary culture to examine the effects of zinc on glycine receptors. Although glycine has been reported to reach millimolar concentrations during synaptic transmission, most previous studies on the effects of zinc on glycine receptors have used relatively low concentrations of glycine. High concentrations of glycine cause receptor desensitization. Our current results extend our previous demonstration that the modulatory actions of zinc are largely prevented when co-applied with desensitizing concentrations of glycine (300 μM), suggesting that the effects of zinc are dependent on the state of the receptor. In contrast, pre-application of 300 μM zinc, prior to glycine (300 μM) application, causes a slowly developing inhibition with a slow rate of recovery, suggesting that the timing of zinc and glycine release also influences the effects of zinc. Furthermore, previous evidence suggests that synaptically released zinc can gain intracellular access, and we provide the first demonstration that low concentrations of intracellular zinc can potentiate glycine receptors. These results support the notion that zinc has complex effects on glycine receptors and multiple factors may interact to influence the efficacy of glycinergic transmission. PMID:21530619

  14. Modern reproductive patterns associated with estrogen receptor positive but not negative breast cancer susceptibility

    PubMed Central

    Aktipis, C. Athena; Ellis, Bruce J.; Nishimura, Katherine K.; Hiatt, Robert A.

    2015-01-01

    It has long been accepted that modern reproductive patterns are likely contributors to breast cancer susceptibility because of their influence on hormones such as estrogen and the importance of these hormones in breast cancer. We conducted a meta-analysis to assess whether this ‘evolutionary mismatch hypothesis’ can explain susceptibility to both estrogen receptor positive (ER-positive) and estrogen receptor negative (ER-negative) cancer. Our meta-analysis includes a total of 33 studies and examines parity, age of first birth and age of menarche broken down by estrogen receptor status. We found that modern reproductive patterns are more closely linked to ER-positive than ER-negative breast cancer. Thus, the evolutionary mismatch hypothesis for breast cancer can account for ER-positive breast cancer susceptibility but not ER-negative breast cancer. PMID:25389105

  15. Modulation of estrogenic effects by environmental temperature and food availability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Endocrine-disrupting chemicals (EDCs), in combination with environmental influences, interfere with endocrine function in humans and wildlife. Estrogens are a type of EDC that may alter the hypothalamic-pituitary-gonadal axis in male fathead minnows, Pimephales promelas. The impact of estrogens on P...

  16. Effects of treadmill exercise training on cerebellar estrogen and estrogen receptors, serum estrogen, and motor coordination performance of ovariectomized rats

    PubMed Central

    Rauf, Saidah; Soejono, Sri Kadarsih; Partadiredja, Ginus

    2015-01-01

    Objective(s): The present study aims at examining the motor coordination performance, serum and cerebellar estrogen, as well as ERβ levels, of ovariectomized rats (as menopausal model) following regular exercise. Materials and Methods: Ten female Sprague Dawley rats aged 12 weeks old were randomly divided into two groups; all of which underwent ovariectomy. The first group was treated with regular exercise of moderate intensity, in which the rats were trained to run on a treadmill for 60 min per day for 12 weeks. The second group served as control. Rotarod test was carried out before and after exercise treatment. All rats were euthanized thereafter, and blood and cerebellums of the rats were collected. The serum and cerebellar estrogen as well as cerebellar ERβ levels were measured using ELISA assays. Results: The number of falls in the rotarod task of the exercise group was significantly lower than that of control group. The cerebellar estrogen level of the exercise group was significantly higher than that of control group. Accordingly, there was a significantly negative correlation between the number of falls and cerebellar estrogen level in the exercise group. Conclusion: The present study shows that a lengthy period of regular exercise improves the cerebellar estrogen level and motor coordination performance in ovariectomized rats. PMID:26221482

  17. Importance of Estrogenic Signaling and Its Mediated Receptors in Prostate Cancer.

    PubMed

    Lau, Kin-Mang; To, Ka-Fai

    2016-01-01

    Prostate cancer (PCa) treatment was first established by Huggins and Hodges in 1941, primarily described as androgen deprivation via interference of testicular androgen production. The disease remains incurable with relapse of hormone-refractory cancer after treatments. Epidemiological and clinical studies disclosed the importance of estrogens in PCa. Discovery of estrogen receptor ERβ prompted direct estrogenic actions, in conjunction with ERα, on PCa cells. Mechanistically, ERs upon ligand binding transactivate target genes at consensus genomic sites via interactions with various transcriptional co-regulators to mold estrogenic signaling. With animal models, Noble revealed estrogen dependencies of PCa, providing insight into potential uses of antiestrogens in the treatment. Subsequently, various clinical trials were conducted and molecular and functional consequences of antiestrogen treatment in PCa were delineated. Besides, estrogens can also trigger rapid non-genomic signaling responses initiated at the plasma membrane, at least partially via an orphan G-protein-coupled receptor GPR30. Activation of GPR30 significantly inhibited in vitro and in vivo PCa cell growth and the underlying mechanism was elucidated. Currently, molecular networks of estrogenic and antiestrogenic signaling via ERα, ERβ and GPR30 in PCa have not been fully deciphered. This crucial information could be beneficial to further developments of effective estrogen- and antiestrogen-based therapy for PCa patients. PMID:27589731

  18. Antidiabetic Actions of an Estrogen Receptor β Selective Agonist

    PubMed Central

    Alonso-Magdalena, Paloma; Ropero, Ana B.; García-Arévalo, Marta; Soriano, Sergi; Quesada, Iván; Muhammed, Sarheed J.; Salehi, Albert; Gustafsson, Jan-Ake; Nadal, Ángel

    2013-01-01

    The estrogen receptor β (ERβ) is emerging as an important player in the physiology of the endocrine pancreas. We evaluated the role and antidiabetic actions of the ERβ selective agonist WAY200070 as an insulinotropic molecule. We demonstrate that WAY200070 enhances glucose-stimulated insulin secretion both in mouse and human islets. In vivo experiments showed that a single administration of WAY200070 leads to an increase in plasma insulin levels with a concomitant improved response to a glucose load. Two-week treatment administration increased glucose-induced insulin release and pancreatic β-cell mass and improved glucose and insulin sensitivity. In addition, streptozotocin-nicotinamide–induced diabetic mice treated with WAY200070 exhibited a significant improvement in plasma insulin levels and glucose tolerance as well as a regeneration of pancreatic β-cell mass. Studies performed in db/db mice demonstrated that this compound restored first-phase insulin secretion and enhanced pancreatic β-cell mass. We conclude that ERβ agonists should be considered as new targets for the treatment of diabetes. PMID:23349481

  19. 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

  20. Screening Chemicals for Estrogen Receptor Bioactivity Using a Computational Model.

    PubMed

    Browne, Patience; Judson, Richard S; Casey, Warren M; Kleinstreuer, Nicole C; Thomas, Russell S

    2015-07-21

    The U.S. Environmental Protection Agency (EPA) is considering high-throughput and computational methods to evaluate the endocrine bioactivity of environmental chemicals. Here we describe a multistep, performance-based validation of new methods and demonstrate that these new tools are sufficiently robust to be used in the Endocrine Disruptor Screening Program (EDSP). Results from 18 estrogen receptor (ER) ToxCast high-throughput screening assays were integrated into a computational model that can discriminate bioactivity from assay-specific interference and cytotoxicity. Model scores range from 0 (no activity) to 1 (bioactivity of 17β-estradiol). ToxCast ER model performance was evaluated for reference chemicals, as well as results of EDSP Tier 1 screening assays in current practice. The ToxCast ER model accuracy was 86% to 93% when compared to reference chemicals and predicted results of EDSP Tier 1 guideline and other uterotrophic studies with 84% to 100% accuracy. The performance of high-throughput assays and ToxCast ER model predictions demonstrates that these methods correctly identify active and inactive reference chemicals, provide a measure of relative ER bioactivity, and rapidly identify chemicals with potential endocrine bioactivities for additional screening and testing. EPA is accepting ToxCast ER model data for 1812 chemicals as alternatives for EDSP Tier 1 ER binding, ER transactivation, and uterotrophic assays. PMID:26066997

  1. 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

  2. Identification of estrogen receptor α ligands with virtual screening techniques.

    PubMed

    Niinivehmas, Sanna P; Manivannan, Elangovan; Rauhamäki, Sanna; Huuskonen, Juhani; Pentikäinen, Olli T

    2016-03-01

    Utilization of computer-aided molecular discovery methods in virtual screening (VS) is a cost-effective approach to identify novel bioactive small molecules. Unfortunately, no universal VS strategy can guarantee high hit rates for all biological targets, but each target requires distinct, fine-tuned solutions. Here, we have studied in retrospective manner the effectiveness and usefulness of common pharmacophore hypothesis, molecular docking and negative image-based screening as potential VS tools for a widely applied drug discovery target, estrogen receptor α (ERα). The comparison of the methods helps to demonstrate the differences in their ability to identify active molecules. For example, structure-based methods identified an already known active ligand from the widely-used bechmarking decoy molecule set. Although prospective VS against one commercially available database with around 100,000 drug-like molecules did not retrieve many testworthy hits, one novel hit molecule with pIC50 value of 6.6, was identified. Furthermore, our small in-house compound collection of easy-to-synthesize molecules was virtually screened against ERα, yielding to five hit candidates, which were found to be active in vitro having pIC50 values from 5.5 to 6.5. PMID:26774287

  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. 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

  5. Endocrine disruption via estrogen receptors that participate in nongenomic signaling pathways

    PubMed Central

    Watson, Cheryl S.; Jeng, Yow-Juin; Guptarak, Jutatip

    2011-01-01

    When inappropriate (non-physiologic) estrogens affect organisms at critical times of estrogen sensitivity, disruption of normal endocrine functions can result. Non-physiologic estrogen mimetics (environmental, dietary, pharmaceutical) can signal rapidly and potently via the membrane versions of estrogen receptors, as can physiologic estrogens. Both physiologic and non-physiologic estrogens activate multiple signaling pathways, leading to altered cellular functions (eg. peptide release, cell proliferation or death, transport). Xenoestrogens’ mimicry of physiologic estrogens is imperfect. When superimposed, xenoestrogens can alter endogenous estrogens’ signaling and thereby disrupt normal signaling pathways, leading to malfunctions in many tissue types. Though these xenoestrogen actions occur rapidly via nongenomic signaling pathways, they can be sustained with continuing ligand stimulation, combinations of ligands, and signaling that perpetuates downstream, eventually also impinging on genomic regulation by controlling the activation state of transcription factors. Because via these pathways estrogens and xenoestrogens cause nonmonotonic stimulation patterns, they must be carefully tested for activity and toxicity over wide dose ranges. Nongenomic actions of xenoestrogens in combination with each other, and with physiologic estrogens, are still largely unexplored from these mechanistic perspectives. PMID:21300151

  6. Homeobox A7 stimulates breast cancer cell proliferation by up-regulating estrogen receptor-alpha

    SciTech Connect

    Zhang, Yu; Cheng, Jung-Chien; Huang, He-Feng; Leung, Peter C.K.

    2013-11-01

    Highlights: •HOXA7 regulates MCF7 cell proliferation. •HOXA7 up-regulates ERα expression. •HOXA7 mediates estrogen-induced MCF7 cell proliferation. -- Abstract: Breast cancer is the most common hormone-dependent malignancy in women. Homeobox (HOX) transcription factors regulate many cellular functions, including cell migration, proliferation and differentiation. The aberrant expression of HOX genes has been reported to be associated with human reproductive cancers. Estradiol (E2) and its nuclear receptors, estrogen receptor (ER)-alpha and ER-beta, are known to play critical roles in the regulation of breast cancer cell growth. However, an understanding of the potential relationship between HOXA7 and ER in breast cancer cells is limited. In this study, our results demonstrate that knockdown of HOXA7 in MCF7 cells significantly decreased cell proliferation and ERα expression. In addition, HOXA7 knockdown attenuated E2-induced cell proliferation as well as progesterone receptor (PR) expression. The stimulatory effects of E2 on cell proliferation and PR expression were abolished by co-treatment with ICI 182780, a selective ERα antagonist. In contrast, overexpression of HOXA7 significantly stimulated cell proliferation and ERα expression. Moreover, E2-induced cell proliferation, as well as PR expression, was enhanced by the overexpression of HOXA7. Neither knockdown nor overexpression of HOXA7 affected the ER-beta levels. Our results demonstrate a novel mechanistic role for HOXA7 in modulating breast cancer cell proliferation via regulation of ERα expression. This finding contributes to our understanding of the role HOXA7 plays in regulating the proliferation of ER-positive cancer cells.

  7. Suppression of estrogen receptor-alpha transactivation by thyroid transcription factor-2 in breast cancer cells

    SciTech Connect

    Park, Eunsook; Gong, Eun-Yeung; Romanelli, Maria Grazia; Lee, Keesook

    2012-05-11

    Highlights: Black-Right-Pointing-Pointer TTF-2 was expressed in mammary glands and breast cancer cells. Black-Right-Pointing-Pointer TTF-2 repressed ER{alpha} transactivation. Black-Right-Pointing-Pointer TTF-2 inhibited the proliferation of breast cancer cells. -- Abstract: Estrogen receptors (ERs), which mediate estrogen actions, regulate cell growth and differentiation of a variety of normal tissues and hormone-responsive tumors through interaction with cellular factors. In this study, we show that thyroid transcription factor-2 (TTF-2) is expressed in mammary gland and acts as ER{alpha} co-repressor. TTF-2 inhibited ER{alpha} transactivation in a dose-dependent manner in MCF-7 breast cancer cells. In addition, TTF-2 directly bound to and formed a complex with ER{alpha}, colocalizing with ER{alpha} in the nucleus. In MCF-7/TTF-2 stable cell lines, TTF-2 repressed the expression of endogenous ER{alpha} target genes such as pS2 and cyclin D1 by interrupting ER{alpha} binding to target promoters and also significantly decreased cell proliferation. Taken together, these data suggest that TTF-2 may modulate the function of ER{alpha} as a corepressor and play a role in ER-dependent proliferation of mammary cells.

  8. Evaluation of potential implication of membrane estrogen binding sites on ERE-dependent transcriptional activity and intracellular estrogen receptor-alpha regulation in MCF-7 breast cancer cells.

    PubMed

    Seo, Hye Sook; Leclercq, Guy

    2002-01-01

    The potential involvement of membrane estrogen binding sites in the induction of ERE-dependent transcriptional activity as well as in the regulation of intracellular estrogen receptor alpha (ER-alpha) level under estradiol (E2) stimulation was investigated. Our approach relied upon the use of two DCC-treated E2-BSA (bovine serum albumin) solutions (E2-6-BSA and E2-17-BSA). The absence of detectable free E2 in these solutions was established. Both E2-BSA conjugates led to a transient dose-dependent stimulation of the expression of ERE-luciferase (LUC) reporter gene in MVLN cells (MCF-7 cells stably transfected with a pVit-tk-LUC reporter plasmid), a property not recorded with free E2, which maintained enhanced transcriptional activity during the whole experiment. A very low concentration of E2 (10 pM) synergistically acted with E2-BSA conjugates. Hence, ERE-dependent transcriptional activity induced by these conjugates appeared to result from their known interactions with membrane estrogen binding sites. Anti-estrogens (AEs: 4-OH-TAM and RU 58,668), which antagonize genomic ER responses, abrogated the luciferase activity induced by E2-BSA conjugates, confirming a potential relationship between membrane-related signals and intracellular ER. Moreover, induction of luciferase was recorded when the cells were exposed to IBMX (3-isobutyl-1-methylxanthine) and cyclic nucleotides (cAMP/cGMP), suggesting the implication of the latter in the signal transduction pathway leading to the expression of the reporter gene. Growth factors (IGF-I, EGF and TGF-alpha) also slightly stimulated luciferase and synergistically acted with 10 pM E2, or 1 microM E2-BSA conjugates, in agreement with the concept of a cross-talk between steroids and peptides acting on the cell membrane. Remarkably, E2-BSA conjugates, IBMX and all investigated growth factors failed to down-regulate intracellular ER in MCF-7 cells, indicating the need for a direct intracellular interaction of the ligand with the

  9. Metabolic Effect of Estrogen Receptor Agonists on Breast Cancer Cells in the Presence or Absence of Carbonic Anhydrase Inhibitors

    PubMed Central

    Belkaid, Anissa; Čuperlović-Culf, Miroslava; Touaibia, Mohamed; Ouellette, Rodney J.; Surette, Marc E.

    2016-01-01

    Metabolic shift is one of the major hallmarks of cancer development. Estrogen receptor (ER) activity has a profound effect on breast cancer cell growth through a number of metabolic changes driven by its effect on transcription of several enzymes, including carbonic anhydrases, Stearoyl-CoA desaturase-1, and oncogenes including HER2. Thus, estrogen receptor activators can be expected to lead to the modulation of cell metabolism in estrogen receptor positive cells. In this work we have investigated the effect of 17β-estradiol, an ER activator, and ferulic acid, a carbonic anhydrase inhibitor, as well as ER activator, in the absence and in the presence of the carbonic anhydrase inhibitor acetazolamide on the metabolism of MCF7 cells and MCF7 cells, stably transfected to express HER2 (MCF7HER2). Metabolic profiles were studied using 1D and 2D metabolomic Nuclear Magnetic Resonance (NMR) experiments, combined with the identification and quantification of metabolites, and the annotation of the results in the context of biochemical pathways. Overall changes in hydrophilic metabolites were largest following treatment of MCF7 and MC7HER2 cells with 17β-estradiol. However, the carbonic anhydrase inhibitor acetazolamide had the largest effect on the profile of lipophilic metabolites. PMID:27240414

  10. Interaction of putative estrogens and the estrogen receptor system in Leydig cells in the BALB/c mouse testis resulting in the initiation of DNA synthesis

    SciTech Connect

    Juriansz, R.L.

    1986-01-01

    Continuous administration of estrogens for 7-9 months, both steroidal and nonsteroidal, to male BALB/c mice, leads to the formation of testicular Leydig cell tumors. Three days following the subcutaneous implantation of a pellet of estrogen in cholesterol, there is a peak in the incorporation of /sup 3/H-thymidine into the DNA of the interstitial cells. These effects are hypothesized to be mediated by the estrogen receptor system in the Leydig cell. Common experimental techniques for the measurement of hormone binding, such as dextran coated charcoal treatment, proved to be impossible to employ in this system, therefore a procedure was developed using hydroxyapatite to obtain binding data. The cytosolic estrogen receptor was found to have a dissociation constant for estradiol-17..beta.. of 6.5 x 10/sup -8/ M, while that of the nuclear estrogen receptor was 1.25 x 10/sup -8/ M. Competition assays were utilized to determine the cytosolic estrogen receptor's affinity for nonsteroidal estrogens, steroidal estrogens, and triphenylethylene.

  11. Metabolism Regulation by Estrogens and Their Receptors in the Central Nervous System Before and After Menopause.

    PubMed

    Coyoy, A; Guerra-Araiza, C; Camacho-Arroyo, I

    2016-08-01

    Estrogens through their intracellular receptors regulate various aspects of glucose and lipid metabolism. The effects of estrogens in metabolism can be mediated by their receptors located in different areas of the brain such as the hypothalamus, which is involved in the control of food intake, energy expenditure, and body weight homeostasis. Alterations in the metabolic regulation by estrogens participate in the pathogenesis of the metabolic syndrome and cardiovascular diseases in women. The metabolic syndrome is an important disease around the world, consisting in a combination of characteristics including abdominal obesity, dyslipidemia, hypertension, and insulin resistance. It increases the risk of cardiovascular disease and type 2 diabetes. It has been suggested that there is an increase in the incidence of metabolic syndrome during menopause due to estrogens deficiency. Estrogens replacement improves insulin sensitivity and reduces the risk of diabetes in rats. In the brain, estrogens through the interaction with their receptors regulate the activity of neurons involved in energy homeostasis, including appetite and satiety. Thus, estradiol and their receptors in the hypothalamus play a key role in metabolic syndrome development during menopause. PMID:27392117

  12. G protein-coupled receptor 30 mediates estrogen-induced proliferation of primordial germ cells via EGFR/Akt/β-catenin signaling pathway.

    PubMed

    Ge, Chutian; Yu, Minli; Zhang, Caiqiao

    2012-07-01

    In vertebrates, estrogens are required for the normal development and function of postnatal gonads. However, it remains unclear whether estrogens are able to modulate development of the fetal germ cells. Here, we show that, unexpectedly, chicken primordial germ cells (PGC) lacking estrogen receptor α/β still proliferate in response to 17β-estradiol (E(2)). This is due to the capacity of G protein-coupled receptor 30 (GPR30), existing on PGC, to directly bind E(2). Knockdown experiments suggest that GPR30 is required for E(2)-stimulated PGC proliferation. Furthermore, this estrogen-induced activation of GPR30 is revealed to occur through the Gβγ-subunit protein-dependent and through the matrix metalloproteinase-dependent transactivation of the epidermal growth factor receptor. Epidermal growth factor receptor activation results in a series of intracellular events, including activation of the phosphatidylinositol 3-kinase/serine-threonine kinase/β-catenin pathway, which are followed by the induction of c-fos, c-myc, cyclin D1/E, and B-cell lymphoma 2 expression, and the inhibition of B-cell lymphoma 2-associated X protein expression and caspase3/9 activity. This eventually leads to decreased apoptosis and increased PGC proliferation. Collectively, these findings offer novel insights into the dynamic mechanism of estrogen action on PGC proliferation and suggest that E(2)/GPR30 signaling might play an important role in regulating fetal germ cell development, particularly at the stage before sexual differentiation. PMID:22635679

  13. Ganoderma lucidum inhibits proliferation of human breast cancer cells by down-regulation of estrogen receptor and NF-kappaB signaling.

    PubMed

    Jiang, Jiahua; Slivova, Veronika; Sliva, Daniel

    2006-09-01

    Ganoderma lucidum, an oriental medical mushroom, has been used in Asia for the prevention and treatment of a variety of diseases, including cancer. We have previously demonstrated that G. lucidum inhibits growth and induces cell cycle arrest at G0/G1 phase through the inhibition of Akt/NF-kappaB signaling in estrogen-independent human breast cancer cells. However, the molecular mechanism(s) responsible for the inhibitory effects of G. lucidum on the proliferation of estrogen-dependent (MCF-7) and estrogen-independent (MDA-MB-231) breast cancer cells remain to be elucidated. Here, we show that G. lucidum inhibited the proliferation of breast cancer MCF-7 and MDA-MB-231 cells by the modulation of the estrogen receptor (ER) and NF-kappaB signaling. Thus, G. lucidum down-regulated the expression of ERalpha in MCF-7 cells but did not effect the expression of ERbeta in MCF-7 and MDA-MB-231 cells. In addition, G. lucidum inhibited estrogen-dependent as well as constitutive transactivation activity of ER through estrogen response element (ERE) in a reporter gene assay. G. lucidum decreased TNF-alpha-induced (MCF-7) as well as constitutive (MDA-MB-231) activity of NF-kappaB. The inhibition of ER and NF-kappaB pathways resulted in the down-regulation of expression of c-myc, finally suppressing proliferation of estrogen-dependent as well as estrogen-independent cancer cells. Collectively, these results suggest that G. lucidum inhibits proliferation of human breast cancer cells and contain biologically active compounds with specificity against estrogen receptor and NF-kappaB signaling, and implicate G. lucidum as a suitable herb for chemoprevention and chemotherapy of breast cancer. PMID:16865287

  14. 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.

  15. Implication of the estrogen receptors GPER, ESR1, ESR2 in post-testicular maturations of equine spermatozoa.

    PubMed

    Gautier, Camille; Barrier-Battut, Isabelle; Guénon, Isabelle; Goux, Didier; Delalande, Christelle; Bouraïma-Lelong, Hélène

    2016-07-01

    Estrogen receptors ESR1, ESR2 and GPER are present on mature ejaculated horse spermatozoa, suggesting these cells as putative targets for estrogens. Indeed, spermatozoa are exposed to high level of estrogens during the transit in the male and female genital tracts but their roles are not investigated. So, we evaluated in vitro the role of 17β-estradiol during post-testicular maturations: regulation of motility, capacitation and acrosome reaction. Moreover according to the pseudo-seasonal breeder status of the stallion, we analyzed the putative seasonal variations in the presence of ESRs in spermatozoa. We showed that ESRs are more present on stallion sperm during the breeding season. We showed that capacitation and acrosome reaction are independent of estradiol action in horse. Estradiol can weakly modulate the motility and this effect is strictly associated with GPER and not with ESR1 and ESR2. The subcellular localization of GPER in the neck on stallion sperm is coherent with this effect. It seems that estrogens are not major regulators of sperm maturations associated to mare genital tract, so they could act during the epididymal maturations. PMID:27222348

  16. 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

  17. Comparison between different forms of estrogen cytosol receptor and the nuclear receptor extracted by micrococcal nuclease.

    PubMed

    Rochefort, H; André, J

    1978-11-01

    As an approach to the mechanism of the nuclear translocation of estrogen receptor, the estradiol nuclear receptor (RN) of lamb endometrium was extracted with micrococcal nuclease at 2--4 degrees and compared to the "native" 8S and to the Ca2+-transformed cytosol receptors. After extensive digestion of chromatin, giving up to 10% perchloric acid-soluble DNA and a majority of nucleosome monomers, up to 80% of the RN was extracted and under low ionic strength. This RN was found to be completely different from the partially proteolyzed Ca2+-transformed cytosol receptor. It migrated with a sedimentation constant of 4 and 6 S. The Stokes radius of the predominant form as determined by ACA 34 chromatography was 5.3 nm. The calculated apparent molecular weights were 130,000 and 90,000, respectively. The RN was able to bind DNA and was eluted from a diethylaminoethyl cellulose column at 0.23 and 0.30 M KCl. We conclude that the mechanism proposed by Puca et al., according to which the Ca2+-transformed cytosol receptor is split by a Ca2+ receptor-transforming factor into a smaller form able to cross the nuclear membrane, is very unlikely. PMID:698961

  18. Transcriptional activation of nuclear estrogen receptor and progesterone receptor and its regulation.

    PubMed

    Xin, Qi-Liang; Qiu, Jing-Tao; Cui, Sheng; Xia, Guo-Liang; Wang, Hai-Bin

    2016-08-25

    Estrogen receptor (ER) and progesterone receptor (PR) are two important members of steroid receptors family, an evolutionarily conserved family of transcription factors. Upon binding to their ligands, ER and PR enter cell nucleus to interact with specific DNA element in the context of chromatin to initiate the transcription of diverse target genes, which largely depends on the timely recruitment of a wide range of cofactors. Moreover, the interactions between steroid hormones and their respective receptors also trigger post-translational modifications on these receptors to fine-tune their transcriptional activities. Besides the well-known phosphorylation modifications on tyrosine and serine/threonine residues, recent studies have identified several other covalent modifications, such as ubiquitylation and sumoylation. These post-translational modifications of steroid receptors affect its stability, subcellular localization, and/or cofactor recruitment; eventually influence the duration and extent of transcriptional activation. This review is to focus on the recent research progress on the transcriptional activation of nuclear ER and PR as well as their physiological functions in early pregnancy, which may help us to better understand related female reproductive diseases. PMID:27546504

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. Estrogen receptor- and aryl hydrocarbon receptor-mediated activities of a coal-tar creosote

    SciTech Connect

    Fielden, M.R.; Wu, Z.F.; Sinal, C.J.; Jury, H.H.; Bend, J.R.; Hammond, G.L.; Zacharewski, T.R.

    2000-05-01

    A coal-tar creosote was examined for estrogen receptor (ER)- and aryl hydrocarbon receptor (AhR)-mediated activity using a battery of mechanistically based assays. In vitro, creosote was found to bind to the mouse ER, bind to the human sex hormone-binding globulin, and elicit partial agonist activity in reporter gene assays in transiently transfected MCF-7 cells. Based on competitive binding to the mouse ER, creosote contains approximately 165 mg/L of estradiol-equivalents. Creosote effectively transformed the AhR in vitro and induced a Cyplal-regulated luciferase reporter gene in transiently transfected Hepa 1c1c7 cells. Based on dose-response curves, creosote contains approximately 730 mg/L of dioxin-equivalents. Creosote did not exhibit any AhR-mediated antiestrogenic activity in vitro. In vivo, creosote significantly induced liver pentoxyresorufin O-depentylation and ethoxyresorufin-O-deethylation (EROD) in a dose-dependent manner in ovariectomized (OVX) ICR mice, but did not increase uterine weight wet or vaginal cornification, due possibly to AhR-mediated antiestrogenic activity. In OVX DBA/2 mice, a strain less responsive to AhR ligands, creosote induced liver EROD to a lesser extent, but still did not show an increase in uterine wet weight or vaginal cornification. These results demonstrate that coal-tar creosote exhibits AhR- and ER-mediated activity in vitro, but its dioxinlike activity may suppress estrogenic responses in vivo.

  7. Disruption of androgen and estrogen receptor activity in prostate cancer by a novel dietary diterpene carnosol: implications for chemoprevention

    PubMed Central

    Johnson, Jeremy J.; Syed, Deeba N.; Suh, Yewseok; Heren, Chenelle R.; Saleem, Mohammad; Siddiqui, Imtiaz A.; Mukhtar, Hasan

    2010-01-01

    Emerging data is suggesting that estrogens, in addition to androgens, may also be contributing to the development of prostate cancer (PCa). In view of this notion agents that target estrogens, in addition to androgens, may be a novel approach for PCa chemoprevention and treatment. Thus, the identification and development of non-toxic dietary agents capable of disrupting androgen receptor (AR) in addition to estrogen receptor (ER) could be extremely useful in the management of PCa. Through molecular modeling we found carnosol, a dietary diterpene fits within the ligand binding domain of both AR and ER-α. Using a TR-FRET assay we found that carnosol interacts with both AR and ER-α and additional experiments confirmed that it functions as a receptor antagonist with no agonist effects. LNCaP, 22Rv1, and MCF7 cells treated with carnosol (20–40 µM) showed decreased protein expression of AR and ER-α. Oral administration of carnosol at 30 mg/kg five days weekly for 28 days to 22Rv1 PCa xenografted mice suppressed tumor growth by 36% (p = 0.028) and was associated with a decrease in serum PSA by 26% (p=0.0042). These properties make carnosol unique to any known anti-androgen or anti-estrogen investigated so far for the simultaneous disruption of AR and ER-α. We suggest that carnosol may be developed or chemically modified through more rigorous structure activity relationship studies for a new class of investigational agents - a dual AR/ER modulator. PMID:20736335

  8. 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 receptor-α expressed by medial amygdala neurons to prevent stress-induced activation of these neurons, and therefore prevents pressor responses to stress. PMID:27091896

  9. 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.

  10. Experimental Procedures for Demonstration of MicroRNA Mediated Enhancement of Functional Neuroprotective Effects of Estrogen Receptor Agonists.

    PubMed

    Chakrabarti, Mrinmay; Ray, Swapan K

    2016-01-01

    Protection of motoneurons is an important therapeutic goal in the treatment of neurological disorders. Recent reports have suggested that specific microRNAs (miRs) could modulate the expression of particular proteins for significant alterations in the pathogenesis of different neurological disorders. Thus, combination of overexpression of a specific neuroprotective miR and treatment with a neuroprotective agent could be a novel strategy for functional protection of motoneurons. The protocols described herein demonstrate that miR-7-1, a neuroprotective miR, can enhance the functional neuroprotective effects of estrogen receptor agonists such as 1,3,5-tris(4-hydroxyphenyl)-4-propyl-1H-pyrazole (PPT), Way 200070 (WAY), and estrogen (E2) in preventing apoptosis in A23187 calcium ionophore (CI) exposed VSC4.1 motoneurons. This article describes the protocols for the cell viability assay, transfection of VSC4.1 motoneurons with miRs, Annexin V/propidium iodide staining for apoptosis, Western blotting, patch-clamp recording of whole-cell membrane potential, and JC-1 staining for detection of mitochondrial membrane potential. Taken together, these protocols are used to demonstrate that miR-7-1 caused significant enhancement of the efficacy of estrogen receptor agonists for functional neuroprotection in VSC4.1 motoneurons. PMID:26585150

  11. Structural and functional characterization of aromatase, estrogen receptor, and their genes in endocrine-responsive and -resistant breast cancer cells.

    PubMed

    Chan, Hei Jason; Petrossian, Karineh; Chen, Shiuan

    2016-07-01

    Aromatase and estrogen receptor α (ER) are two key proteins for the proliferation of endocrine-responsive and -resistant breast cancers. Aromatase is an enzyme involved in the conversion of androgen (such as testosterone) to estrogen (such as 17β-estradiol). It is also a very effective therapeutic target for the treatment of endocrine-responsive breast cancer. Comparing endocrine-responsive and -resistant breast cancer, aromatase protein levels do not change significantly. Aromatase activity; however, can be increased via PI3K/Akt/IGFR signaling pathways in endocrine resistant cells. The activity of aromatase has been reported to be modulated by phosphorylation. The ER is an important steroid nuclear receptor in the proliferation of both endocrine-responsive and -resistant cells. Although the mutation or amplification of ER can cause endocrine resistance, it is not commonly found. Some point mutations and translocation events have been characterized and shown to promote estrogen-independent growth. Phosphorylation by cross-talk with growth factor pathways is one of the main mechanisms for ligand-independent activation of ER. Taken together, both ER and aromatase are important in ER-dependent breast cancer and the development of endocrine resistance. PMID:26277097

  12. Estrogen facilitates and the kappa and mu opioid receptors mediate antinociception produced by intrathecal (-)-pentazocine in female rats.

    PubMed

    Robinson, Douglas L; Nag, Subodh; Mokha, Sukhbir S

    2016-10-01

    Pentazocine, a mixed-action kappa opioid receptor (KOR) agonist, has high affinity for both KOR and the mu opioid receptor (MOR), and has been shown clinically to alleviate pain with a pronounced effect in women. However, whether local application of pentazocine in the spinal cord produces antinociception and the contribution of spinal KOR and MOR in mediating the effect of pentazocine in female rats remain unknown. Also, it is not known whether pentazocine-induced antinociception in females is estrogen-dependent. Hence, we investigated whether intrathecal (i.t.) (-)-pentazocine produces thermal antinociception and whether estrogen modulates the drug effect in female rats. Only the highest dose of pentazocine (500 nmol) was effective in producing antinociception in ovariectomized (OVX) rats. In contrast, pentazocine produced antinociception in estradiol-treated ovariectomized females (OVX+E) rats with the lowest effective dose being 250nmol. KOR or MOR mediated the effect of the lowest effective dose in OVX+E rats; however, MOR blockade extended the KOR-mediated effect of 500nmol pentazocine in both groups. In normally cycling females, the 250nmol dose was effective in producing antinociception at the proestrous, but not at the diestrous stage of the estrous cycle. Thus, estrogen facilitates and KOR or MOR mediates. the antinociceptive effect of i.t. (-)-pentazocine in female rats. Selective doses of (-)-pentazocine, with or without MOR blockade, may have a therapeutic benefit. PMID:27312267

  13. 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

  14. Three radioligands compared for determining cytoplasmic estrogen-receptor content of human breast carcinomas

    SciTech Connect

    Pieslor, P.C.; Gibson, R.E.; Eckelman, W.C.; Oates, K.K.; Cook, B.; Reba, R.C.

    1982-03-01

    Three radioligands were compared for use in a cytoplasmic estrogen-receptor assay, using pooled cytosol from human breast adenocarcinomas. The estrogen receptor content was determined in vitro by a dextran-coated charcoal method involving a 4-h incubation with and without diethylstilbestrol. Tritiated moxestrol failed to come to equilibrium in 4 h, thereby preventing the use of conventional one-component Scatchard analysis. The use of /sup 125/I-labeled estradiol resulted in a higher estimate of estrogen-receptor concentration than that obtained with use of tritiated estradiol. This overestimation was not corrected by Scatchard, double-reciprocal, or Woolf plots, or by two different methods of data analysis: least squares and ''robust.'' An underestimation of the specific activity of iodoestradiol with respect to that of tritiated estradiol and an unrecognized second component of nonreceptor binding could explain this disparity.

  15. 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

  16. Delineating the molecular mechanisms of tamoxifen's oncolytic actions in estrogen receptor-negative cancers.

    PubMed

    Radin, Daniel P; Patel, Parth

    2016-06-15

    Since its clinical inception, tamoxifen (TAM) has proved to be a powerful tool in treating estrogen receptor-positive breast cancers while exhibiting manageable side effects. Although TAM was synthesized as an estrogen receptor antagonist, reports have found that a significant fraction of women with estrogen receptor-negative cancers have benefitted from TAM treatment, suggesting the possibility of an alternate anti-cancer mechanism. In this paper, we present a review of recent and past literature in an attempt to clarify how TAM inhibits cell proliferation and induces apoptosis in cells lacking the estrogen receptor. Our analysis indicates that micromolar concentrations of TAM selectively elevate intracellular calcium concentrations in malignant cells, possibly by inversely agonizing cannabinoid receptors, producing considerable mitochondrial distress followed by the rapid production of reactive oxygen species. In response, cytoplasmic proteins such as JNK1 are activated, which mediates the activation of caspase-8. Fyn kinase auto phosphorylates in response to increased reactive oxygen species and directs the ubiquitin ligase c-Cbl to tag growth factor receptors for ubiquitination, potentially abrogating constitutively active survival pathways that are hallmarks of cancer progression. We attempt to differentiate the effect that TAM has on purified Protein Kinase C (PKC) compared to that in an intact cell, suggesting that low micromolar concentrations of TAM indirectly inhibit PKC by inducing EGFR destruction and high micromolar concentrations of TAM inhibits PKC through a direct binding mechanism. PMID:27083550

  17. Glyceollin, a novel regulator of mTOR/p70S6 in estrogen receptor positive breast cancer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An estimated 70% of breast cancer tumors utilize estrogen receptor (ER) signaling to maintain tumorigenesis, and targeting of the estrogen receptor is a common method of treatment for these tumor types. However, ER-positive (+) breast cancers often acquire drug resistant or altered ER activity in r...

  18. Integrated Summary Report: Validation of Two Binding Assays Using Human Recombinant Estrogen Receptor Alpha (hrERa)

    EPA Science Inventory

    This Integrated Summary Report (ISR) summarizes, in a single document, the results from an international multi-laboratory validation study conducted for two in vitro estrogen receptor (ER) binding assays. These assays both use human recombinant estrogen receptor, alpha subtype (h...

  19. 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

  20. 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

  1. Fulvestrant radiosensitizes human estrogen receptor-positive breast cancer cells

    SciTech Connect

    Wang, Jing; Yang, Qifeng; Haffty, Bruce G.; Li, Xiaoyan; Moran, Meena S.

    2013-02-08

    Highlights: ► Fulvestrant radiosensitizes MCF-7 cells. ► Fulvestrant increases G1 arrest and decreases S phase in MCF-7 cells. ► Fulvestrant down-regulates DNA-PKcs and RAD51 in MCF-7 cells. -- Abstract: The optimal sequencing for hormonal therapy and radiation are yet to be determined. We utilized fulvestrant, which is showing promise as an alternative to other agents in the clinical setting of hormonal therapy, to assess the cellular effects of concomitant anti-estrogen therapy (fulvestrant) with radiation (F + RT). This study was conducted to assess the effects of fulvestrant alone vs. F + RT on hormone-receptor positive breast cancer to determine if any positive or negative combined effects exist. The effects of F + RT on human breast cancer cells were assessed using MCF-7 clonogenic and tetrazolium salt colorimetric (MTT) assays. The assays were irradiated with a dose of 0, 2, 4, 6 Gy ± fulvestrant. The effects of F + RT vs. single adjuvant treatment alone on cell-cycle distribution were assessed using flow cytometry; relative expression of repair proteins (Ku70, Ku80, DNA-PKcs, Rad51) was assessed using Western Blot analysis. Cell growth for radiation alone vs. F + RT was 0.885 ± 0.013 vs. 0.622 ± 0.029 @2 Gy, 0.599 ± 0.045 vs. 0.475 ± 0.054 @4 Gy, and 0.472 ± 0.021 vs. 0.380 ± 0.018 @6 Gy RT (p = 0.003). While irradiation alone induced G2/M cell cycle arrest, the combination of F + RT induced cell redistribution in the G1 phase and produced a significant decrease in the proportion of cells in G2 phase arrest and in the S phase in breast cancer cells (p < 0.01). Furthermore, levels of repair proteins DNA-PKcs and Rad51 were significantly decreased in the cells treated with F + RT compared with irradiation alone. F + RT leads to a decrease in the surviving fraction, increased cell cycle arrest, down regulating of nonhomologous repair protein DNA-PKcs and homologous recombination repair protein RAD51. Thus, our findings suggest that F + RT

  2. Estrogen Receptor Immunoreactivity in Late-Gestation Fetal Lambs1

    PubMed Central

    Gorton, Lori M.; Mahoney, Megan M.; Magorien, Julie E.; Lee, Theresa M.; Wood, Ruth I.

    2009-01-01

    Prenatal androgens masculinize postnatal reproductive neuroendocrine function and behavior in sheep. Testosterone treatment of pregnant ewes during midgestation masculinizes sexual behavior and luteinizing hormone secretion in female lambs, presumably in part via aromatization and estrogen receptor (ESR) binding in the brain. We hypothesized that male and female sheep also differ in the number and distribution of ESR-containing neurons. If so, ESR expression should be sensitive to prenatal hormones delivered exogenously or in situ. ESR alpha (ESR1) was compared by immunocytochemistry in male and female lambs at the end of gestation, as well as in fetal females exposed prenatally to testosterone or dihydrotestosterone. ESR1-positive neurons were abundant in the posteromedial bed nucleus of the stria terminalis (BSTpm), medial preoptic area (MPOA), posterior medial amygdaloid nucleus (MeP), amygdalohippocampal area (AHi), ventromedial hypothalamic nuclei (VMH), and arcuate hypothalamic nuclei (ARC). In females, the ARC had the largest number of stained cells (mean ± SEM, 475.6 ± 57.4 cells/0.173 mm2), while staining intensity was greatest in the MPOA (mean ± SEM gray level, 31.3 ± 5.3). The mean ± SEM integrated gray level (IGL) was high in the ARC (0.63 ± 0.13) and in the MPOA (0.51 ± 0.08). The mean ± SEM IGL was low in the MeP (0.31 ± 0.10) and in the BSTpm (0.21 ± 0.06), while it was intermediate in the AHi (0.36 ± 0.10) and in the VMH (0.37 ± 0.07). ESR immunostaining was not significantly different in male and female fetal lambs, nor in females fetuses exposed prenatally to androgens (P > 0.05). However, ESR1 staining was significantly increased in the ARC, MPOA, and AHi of adult rams vs. adult ewes. These results suggest that brain ESR immunoreactivity in fetal lambs is unlikely to account for postnatal sex differences in reproductive function. Instead, sex differences in ESR emerge postnatally. PMID:19164175

  3. DNA homologous recombination factor SFR1 physically and functionally interacts with estrogen receptor alpha.

    PubMed

    Feng, Yuxin; Singleton, David; Guo, Chun; Gardner, Amanda; Pakala, Suresh; Kumar, Rakesh; Jensen, Elwood; Zhang, Jinsong; Khan, Sohaib

    2013-01-01

    Estrogen receptor alpha (ERα), a ligand-dependent transcription factor, mediates the expression of its target genes by interacting with corepressors and coactivators. Since the first cloning of SRC1, more than 280 nuclear receptor cofactors have been identified, which orchestrate target gene transcription. Aberrant activity of ER or its accessory proteins results in a number of diseases including breast cancer. Here we identified SFR1, a protein involved in DNA homologous recombination, as a novel binding partner of ERα. Initially isolated in a yeast two-hybrid screen, the interaction of SFR1 and ERα was confirmed in vivo by immunoprecipitation and mammalian one-hybrid assays. SFR1 co-localized with ERα in the nucleus, potentiated ER's ligand-dependent and ligand-independent transcriptional activity, and occupied the ER binding sites of its target gene promoters. Knockdown of SFR1 diminished ER's transcriptional activity. Manipulating SFR1 expression by knockdown and overexpression revealed a role for SFR1 in ER-dependent and -independent cancer cell proliferation. SFR1 differs from SRC1 by the lack of an intrinsic activation function. Taken together, we propose that SFR1 is a novel transcriptional modulator for ERα and a potential target in breast cancer therapy. PMID:23874500

  4. 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

  5. Regulation of estrogen receptor signaling in breast carcinogenesis and breast cancer therapy

    PubMed Central

    Zhou, Zhuan; Qiao, Joe X.; Shetty, Amit; Wu, George; Huang, Yi; Davidson, Nancy E.; Wan, Yong

    2014-01-01

    Estrogen and estrogen receptors (ERs) are critical regulators of breast epithelial cell proliferation, differentiation, and apoptosis. Compromised signaling vis-à-vis the estrogen receptor is believed to be a major contributing factor in the malignancy of breast cells. Targeting the ER signaling pathway has been a focal point in the development of breast cancer therapy. Although approximately 75 % of breast cancer patients are classified as luminal type (ER+), which predicts for response to endocrine-based therapy; however, innate or acquired resistance to endocrine-based drugs remains a serious challenge. The complexity of regulation for estrogen signaling coupled with the crosstalk of other oncogenic signaling pathways is a reason for endocrine therapy resistance. Alternative strategies that target novel molecular mechanisms are necessary to overcome this current and urgent gap in therapy. A thorough analysis of estrogen-signaling regulation is critical. In this review article, we will summarize current insights into the regulation of estrogen signaling as related to breast carcinogenesis and breast cancer therapy. PMID:25031550

  6. Regulation of Mitochondrial Respiratory Chain Biogenesis by Estrogens/Estrogen Receptors and Physiological, Pathological and Pharmacological Implications

    PubMed Central

    Chen, Jin-Qiang; Cammarata, Patrick R.; Baines, Christopher P.; Yager, James D.

    2009-01-01

    There has been increasing evidence pointing to the mitochondrial respiratory chain (MRC) as a novel and important target for the actions of 17β-estradiol(E2) and estrogen receptors (ER) in a number of cell types and tissues that have high demands for mitochondrial energy metabolism. This novel E2-mediated mitochondrial pathway involves the cooperation of both nuclear and mitochondrial ERα and ERβ and their co-activators on the coordinate regulation of both nuclear DNA- and mitochondrial DNA-encoded genes for MRC proteins. In this paper, we have: 1) comprehensively reviewed studies that reveal a novel role of estrogens and ERs in the regulation of MRC biogenesis; 2) discussed their physiological, pathological and pharmacological implications in the control of cell proliferation and apoptosis in relation to estrogen-mediated carcinogenesis, anticancer drug resistance in human breast cancer cells, neuro-protection for Alzheimer’s disease and Parkinson’s disease in brain, cardiovascular protection in human heart and their beneficial effects in lens physiology related to cataract in the eye; and 3) pointed out new research directions to address the key questions in this important and newly emerging area. We also suggest a novel conceptual approach that will contribute to innovative regimines for the prevention or treatment of a wide variety of medical complications based on E2/ER-mediated MRC biogenesis pathway. PMID:19559056

  7. Allosteric Modulation of Muscarinic Acetylcholine Receptors

    PubMed Central

    Jakubík, Jan; El-Fakahany, Esam E.

    2010-01-01

    An allosteric modulator is a ligand that binds to an allosteric site on the receptor and changes receptor conformation to produce increase (positive cooperativity) or decrease (negative cooperativity) in the binding or action of an orthosteric agonist (e.g., acetylcholine). Since the identification of gallamine as the first allosteric modulator of muscarinic receptors in 1976, this unique mode of receptor modulation has been intensively studied by many groups. This review summarizes over 30 years of research on the molecular mechanisms of allosteric interactions of drugs with the receptor and for new allosteric modulators of muscarinic receptors with potential therapeutic use. Identification of positive modulators of acetylcholine binding and function that enhance neurotransmission and the discovery of highly selective allosteric modulators are mile-stones on the way to novel therapeutic agents for the treatment of schizophrenia, Alzheimer’s disease and other disorders involving impaired cognitive function.

  8. Modulation by estrogen of synthesis of specific uterine proteins.

    PubMed

    Skipper, J K; Eakle, S D; Hamilton, T H

    1980-11-01

    The contemporary procedure for high resolution two dimensional gel electrophoresis was extended to include an initial nondenaturing dimension of electrophoresis. Use of the resulting three dimensional procedure revealed that the previously described single peak of estrogen-induced protein in the uterus of the rat contains at least three distinct proteins whose rates of synthesis are regulated by estrogen. These proteins were localized within partial protein maps, thereby providing definitive operational definitions for the detection and identification of each. It was unambiguously demonstrated that each of the three proteins is continuously synthesized in control uteri. These findings cast doubt on the simplistic hypothesis that estrogen induces a single key protein that triggers a "cascade" of sequential transcriptional events in the uterus. Our finding that the major uterine protein induced by estrogen is also synthesized in liver and muscle cells is significant in that it points to a more general cellular function for the protein, rather than a unique role within uterine cells. Finally, our procedure for three dimensional gel electrophoresis opens new avenues for the detection of minor proteins in heterogeneous protein mixtures, such as those from the tissues of higher animals. PMID:7428041

  9. 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

  10. 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

  11. 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

  12. In vitro binding of the purified hormone-binding subunit of the estrogen receptor to oligonucleotides containing natural or modified sequences of an estrogen-responsive element.

    PubMed

    Medici, N; Nigro, V; Abbondanza, C; Moncharmont, B; Molinari, A M; Puca, G A

    1991-04-01

    Estrogen receptor (ER) was purified from calf uterus by immunoaffinity chromatography in the absence of the ligand. The purified ER consists of a mixture of monomer and homodimer forms of 67-kDa hormone-binding subunit (no 90-kDa heat shock protein is present). The purified ER was incubated with a 32P-labeled 61-basepair oligonucleotide containing the sequence of the estrogen response element (ERE) of the Xenopus laevis A2 vitellogenin gene. DNA mobility shift assays showed formation of specific complexes of the ERE containing oligonucleotide with ER, formation which did not require and was not affected by estradiol or antiestrogenic molecules. Both the monomer and the dimer were equally able to interact with the ERE-containing oligonucleotide. Sucrose gradient experiments showed that only the ER monomer is able to interact with an oligonucleotide in which a single mutation destroyed the dyad symmetry of ERE. Multiple symmetric mutations which did not alter the dyad symmetry of ERE nevertheless totally destroyed the ability of the oligonucleotide to form complexes with either the monomeric or dimeric form of ER. These results suggest that ER is able to bind to ERE independently of the presence of estradiol or other proteins and, therefore, that estradiol does not act by modulating the ability of ER to bind to ERE on DNA. PMID:1922088

  13. Estrogen-Like Activity of Perfluoroalkyl Acids In Vivo and Interaction with Human and Rainbow Trout Estrogen Receptors In Vitro

    PubMed Central

    Benninghoff, Abby D.; Bisson, William H.; Koch, Daniel C.; Ehresman, David J.; Kolluri, Siva K.; Williams, David E.

    2011-01-01

    The objectives of this study were to determine the structural characteristics of perfluoroalkyl acids (PFAAs) that confer estrogen-like activity in vivo using juvenile rainbow trout (Oncorhynchus mykiss) as an animal model and to determine whether these chemicals interact directly with the estrogen receptor (ER) using in vitro and in silico species comparison approaches. Perfluorooctanoic (PFOA), perfluorononanoic (PFNA), perfluorodecanoic (PFDA), and perfluoroundecanoic (PFUnDA) acids were all potent inducers of the estrogen-responsive biomarker protein vitellogenin (Vtg) in vivo, although at fairly high dietary exposures. A structure-activity relationship for PFAAs was observed, where eight to ten fluorinated carbons and a carboxylic acid end group were optimal for maximal Vtg induction. These in vivo findings were corroborated by in vitro mechanistic assays for trout and human ER. All PFAAs tested weakly bound to trout liver ER with half maximal inhibitory concentration (IC50) values of 15.2–289μM. Additionally, PFOA, PFNA, PFDA, PFUnDA, and perlfuorooctane sulfonate (PFOS) significantly enhanced human ERα-dependent transcriptional activation at concentrations ranging from 10–1000nM. Finally, we employed an in silico computational model based upon the crystal structure for the human ERα ligand-binding domain complexed with E2 to structurally investigate binding of these putative ligands to human, mouse, and trout ERα. PFOA, PFNA, PFDA, and PFOS all efficiently docked with ERα from different species and formed a hydrogen bond at residue Arg394/398/407 (human/mouse/trout) in a manner similar to the environmental estrogens bisphenol A and nonylphenol. Overall, these data support the contention that several PFAAs are weak environmental xenoestrogens of potential concern. PMID:21163906

  14. 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.

  15. 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

  16. 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

  17. 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

  18. G protein-coupled estrogen receptor inhibits vascular prostanoid production and activity.

    PubMed

    Meyer, Matthias R; Fredette, Natalie C; Barton, Matthias; Prossnitz, Eric R

    2015-10-01

    Complications of atherosclerotic vascular disease, such as myocardial infarction and stroke, are the most common causes of death in postmenopausal women. Endogenous estrogens inhibit vascular inflammation-driven atherogenesis, a process that involves cyclooxygenase (COX)-derived vasoconstrictor prostanoids such as thromboxane A2. Here, we studied whether the G protein-coupled estrogen receptor (GPER) mediates estrogen-dependent inhibitory effects on prostanoid production and activity under pro-inflammatory conditions. Effects of estrogen on production of thromboxane A(2) were determined in human endothelial cells stimulated by the pro-inflammatory cytokine tumour necrosis factor alpha (TNF-α). Moreover, Gper-deficient (Gper(-/-)) and WT mice were fed a pro-inflammatory diet and underwent ovariectomy or sham surgery to unmask the role of endogenous estrogens. Thereafter, contractions to acetylcholine-stimulated endothelial vasoconstrictor prostanoids and the thromboxane-prostanoid receptor agonist U46619 were recorded in isolated carotid arteries. In endothelial cells, TNF-α-stimulated thromboxane A2 production was inhibited by estrogen, an effect blocked by the GPER-selective antagonist G36. In ovary-intact mice, deletion of Gper increased prostanoid-dependent contractions by twofold. Ovariectomy also augmented prostanoid-dependent contractions by twofold in WT mice but had no additional effect in Gper(-/-) mice. These contractions were blocked by the COX inhibitor meclofenamate and unaffected by the nitric oxide synthase inhibitor l-N(G)-nitroarginine methyl ester. Vasoconstrictor responses to U46619 did not differ between groups, indicating intact signaling downstream of thromboxane-prostanoid receptor activation. In summary, under pro-inflammatory conditions, estrogen inhibits vasoconstrictor prostanoid production in endothelial cells and activity in intact arteries through GPER. Selective activation of GPER may therefore be considered as a novel strategy to

  19. Multiple Beneficial Roles of Repressor of Estrogen Receptor Activity (REA) in Suppressing the Progression of Endometriosis.

    PubMed

    Zhao, Yuechao; Chen, Yiru; Kuang, Ye; Bagchi, Milan K; Taylor, Robert N; Katzenellenbogen, John A; Katzenellenbogen, Benita S

    2016-02-01

    Endometriosis is an estrogen-dependent, inflammation-driven gynecologic disorder in which endometrial tissue creates inflammatory lesions at extrauterine sites, leading to pelvic pain and impaired fertility. Although dysregulated estrogen receptor (ER) signaling has been implicated, understanding of this disease is incomplete and current therapies are of limited benefit. Using an immunocompetent syngeneic murine model, we used combinations of donor uterine tissue and/or recipient host mice with partial genetic deletion of the ER coregulator, repressor of ER activity (REA) (also known as prohibitin 2), to investigate roles of REA in the contributions of donor uterine tissue and host cell influences on endometriosis establishment and progression. Ectopic lesions derived from donor tissue with half the wild-type gene dosage of REA (REA(+/-)) grown in REA(+/-) hosts displayed enhanced proliferation, vascularization, and markedly increased neuron innervation and inflammatory responses, including elevated cytokine production, nuclear factor kappa B activation, cyclooxygenase-2 expression, and immune cell infiltration. Although lesion progression was greatest when REA was reduced in both donor tissue and host animals, other donor/host combinations indicated that distinct stimulatory inputs were derived from ectopic tissue (proliferative signals) and host cells (inflammatory signals). Importantly, depletion of REA in primary human endometriotic stromal cells led to elevated proliferation and expression of cell cycle regulators. Notably, REA was significantly lower in human endometriotic tissue versus normal human endometrium. Thus, REA modulates cross talk among multiple cell types in the uterine tissue and host background, serving as a brake on the estradiol-ER axis and restraining multiple aspects that contribute to the pathologic progression of endometriosis. PMID:26653759

  20. Transactivation Function-2 of Estrogen Receptor α Contains Transactivation Function-1-regulating Element*

    PubMed Central

    Arao, Yukitomo; Coons, Laurel A.; Zuercher, William J.; Korach, Kenneth S.

    2015-01-01

    ERα has a ligand-dependent transactivation function in the ligand binding domain of ERα C terminus (AF-2) and a ligand-independent activation function in the N terminus (AF-1). It is still not fully understood how AF-1 and AF-2 activities are regulated cooperatively by ligands. To evaluate the AF-1 involvement in the estrogenic activities of various compounds, we analyzed these transactivation functions using AF-1-truncated and AF-2-mutated ERα mutants. AF-2 is composed of two domains with flexible and static regions. We used an AF-2 flexible region mutant and an AF-2 static region mutant. Both mutants have been reported as non-E2 responsive due to disruption of E2-mediated coactivator recruitment to the AF-2. The AF-2 mutants were not activated by agonists, but surprisingly antagonists and selective estrogen receptor modulators (SERMs) activated the AF-2 mutants. This antagonist reversal activity was derived from AF-1. Furthermore, we demonstrated that the AF-2 contains an AF-1 suppression function using C-terminal-truncated ERα mutants. From these findings we hypothesized that the mutation of AF-2 disrupted its ability to suppress AF-1, causing the antagonist reversal. To assess the AF-2-mediated AF-1 suppression, we analyzed the transcription activity of physically separated AF-1 and AF-2 using a novel hybrid reporter assay. We observed that the AF-1 activity was not suppressed by the physically separated AF-2. Furthermore, SERMs did not induce the AF-1-mediated activity from the separated mutant AF-2, which differed from the intact protein. These results imply that SERM activity is dependent on a conformational change of the full-length ERα molecule, which allows for AF-1 activation. PMID:26028650

  1. Glucocorticoids and estrogens modulate the NF-κB pathway differently in the micro- and macrovasculature.

    PubMed

    Edgar, Abarca-Rojano; Judith, Pacheco-Yépez; Elisa, Drago-Serrano Maria; Rafael, Campos-Rodríguez

    2013-12-01

    Estrogens and glucocorticoids have synergistic effects in the micro and macrovasculature of endothelial cells (ECs), having pro-inflammatory effects in the former and inhibiting the expression of adhesion molecules in the latter. The molecular basis of these effects in the endothelium has not yet been clarified. We postulate that the ECs of the micro- and macrovasculature have different non-genomic mechanisms that regulate levels of preexisting complexes of glucocorticoids and estrogens with their respective receptors. Since these receptors are regulated by NF-κB, their expression could be critical to the activation of a pro- or anti-inflammatory response. In the macrovasculature the synergistic effects of estrogens and glucocorticoids on ECs may be through the inhibition of NF-κB, leading to the inhibition of the expression of inflammatory molecules. It seems likely that glucocorticoid-receptor and estrogen-receptor complexes directly bind to NF-κB proteins in the macrovasculature, resulting in the inhibition of an excessive proinflammatory response. Further insights into these processes may help clarify the role of the endothelial cells of different vascular beds during the inflammatory response and chronic inflammation, and thus contribute to the design of more effective therapeutic strategies for the prevention of diseases related to inflammation, including atherosclerosis, systemic lupus erythematosus and rheumatoid arthritis. PMID:24199951

  2. ESTROGENIC STATUS MODULATES DMBA-MEDIATED HEPATIC GENE EXPRESSION: MICROARRAY-BASED ANALYSIS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Estrogenic status in women influences the metabolism and toxicity of polycyclic aromatic hydrocarbons (PAH). The objective of this study was to examine the influence of estradiol (E2) on 7,12 dimethylbenz(a)anthracene (DMBA), a ligand for aryl hydrocarbon receptor, mediated changes on gene expressio...

  3. Endocrine disruptors differently influence estrogen receptor β and androgen receptor in male and female rat VSMC.

    PubMed

    Pellegrini, Marco; Bulzomi, Pamela; Lecis, Marco; Leone, Stefano; Campesi, Ilaria; Franconi, Flavia; Marino, Maria

    2014-08-01

    Sex steroid hormones differently control the major physiological processes in male and female organisms. In particular, their effects on vascular smooth muscle cells (VSMCs) migration are at the root of sex/gender-related differences reported in the cardiovascular system. Several exogenous substances, defined endocrine disruptor chemicals (EDCs), could interfere with these androgen and estrogen effects; however, the sex/gender-related susceptibility of VSMC motility to EDCs is completely unknown. Here, the effect of naturally occurring (naringenin, Nar) and synthetic (bisphenol A, BPA) EDCs on male and female VSMC motility has been evaluated. 17β-estradiol (E2, 0.1 nM-1 µM) induced a dose-dependent inhibition of motility in female-derived VSMC. In contrast, neither dihydrotestosterone (DHT, 0.01-100 nM) nor the common precursor of sex steroid hormones, testosterone (Tes, 0.01-100 nM) modified male-derived VSMC motility. Estrogen receptor (ER) β subtype-dependent activation of p38 was necessary for the E2 effect on cell motility. High BPA concentration prevented E2 effects in female-derived cells being without any effect in male-derived cells. Nar mimicked E2 effects on female-derived cells even in the presence of E2 or BPA. Intriguingly, Nar also inhibited the male-derived VSMC mobility. This latter effect was prevented by ERβ inhibitor, but not by the androgen receptor (AR) inhibitor. As a whole, ERβ-dependent signals in VSMC results more susceptible to the impact of EDCs than AR signals suggesting a possible high and overall susceptibility of female to EDCs. However, several male-derived cells, including VSMC, express ERβ, which could also serve as target of EDC disruption in male organisms. PMID:24347325

  4. 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

  5. Autocrine interferon-γ may affect malignant behavior and sensitivity to tamoxifen of MCF-7 via estrogen receptor β subtype.

    PubMed

    Niu, Xiu Long; Wang, Yue; Yao, Zhi; Duan, Hongjie; Li, Zhijun; Liu, Wenxing; Zhang, Hongjian; Deng, Wei Min

    2015-12-01

    Mitogenic actions of estrogens are mediated by two distinct estrogen receptors (ERs), which are critical in the progression and therapeutic response of breast cancer. ER expression is a dynamic phenomenon that is regulated by numerous factors, including cytokines, in the tumor microenvironment. Recently, studies have shown that autocrine production of IL-4 promotes cancer cell growth and there is negative correlation between tumor IL-4 and hormone receptor levels, suggesting that there is crosstalk between cytokine receptors and ER. Thus, we evaluated for interaction between the two ERs and the cytokines IL-4 and IFN-γ, and if this interaction modulates malignant behavior. We identified that ERβ exerts protective activity in the progression of breast cancer cell line MCF-7, which co-expresses ERα and ERβ. IFN-γ and IL-4 have the opposite effects on malignant biological behavior. Furthermore, we found positive correlation between IFN-γ and ERβ expression in MCF-7. We also determined that autocrine IFN-γ in MCF-7 increases mRNA expression of ERβ resulting in enhanced sensitivity to tamoxifen (TAM). These results indicate that ERβ and autocrine IFN-γ represent two putative targets for breast cancer therapy. PMID:26397740

  6. 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

  7. 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

  8. 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...

  9. Species comparisons in molecular and functional attributes of the androgen and estrogen receptor

    EPA Science Inventory

    While endocrine disrupting compounds (EDCs) have the potential to act via several mechanisms of action, one of the most widely studied is the ability of environmental chemicals to interact directly with either the estrogen (ER) or androgen receptor (AR). In vitro screening assay...

  10. NATURE OF BINDING INTERACTION OF SELECTED CHEMICALS WITH RAT ESTROGEN RECEPTORS

    EPA Science Inventory

    The US EPA is currently validating a rat uterine estrogen receptor (ER) binding assay as part of the Tier 1 Screening Battery for the Endocrine Disruptor Program. An eventual goal is to use interactive data to create computerized structure-activity models. However, more informati...

  11. Nature of the binding interaction for 50 structurally diverse chemicals with rat estrogen receptors

    EPA Science Inventory

    This study was conducted to characterize the estrogen receptor (ER)-binding affinities of 50 chemicals selected from among the high production volume chemicals under the U.S. EPA's (U.S. Environmental Protection Agency's) Toxic Substances Control Act inventory. The chemicals were...

  12. Prognostic usefulness of estrogen receptor immunocytochemical assays for human breast cancer.

    PubMed

    DeSombre, E R; Thorpe, S M; Rose, C; Blough, R R; Andersen, K W; Rasmussen, B B; King, W J

    1986-08-01

    Breast cancers of postmenopausal patients at high risk for recurrence participating in an adjuvant therapy protocol were independently assayed for estrogen receptor by conventional dextran-coated charcoal steroid binding assays and by immunocytochemistry (ER-ICA) to compare the two assays and to assess the prognostic usefulness of ER-ICA. The ER-ICA was based on a monoclonal antibody to the estrogen receptor and was applied to lightly fixed, frozen sections of the cancers. Excellent agreement was found between the two estrogen receptor methods. It was found that a combination of the distribution of ER-ICA stained cells and the overall staining intensity gave a statistically significant correlation with the quantitative estrogen receptor dextran-coated charcoal steroid binding assay value. In addition, the overall appraisal of the lesion as ER-ICA positive or negative as well as the ER-ICA staining intensity and proportion of ER-ICA stained cancer cells related to patient disease-free interval and survival, independent of patient lymph node involvement. This relationship of ER-ICA status to prognosis appeared not to relate only to responses to adjuvant tamoxifen treatment since it also was observed with patients who did not receive the antiestrogen. PMID:2425944

  13. Cloning and functional characterization of Chondrichthyes, cloudy catshark, Scyliorhinus torazame and whale shark, Rhincodon typus estrogen receptors.

    PubMed

    Katsu, Yoshinao; Kohno, Satomi; Narita, Haruka; Urushitani, Hiroshi; Yamane, Koudai; Hara, Akihiko; Clauss, Tonya M; Walsh, Michael T; Miyagawa, Shinichi; Guillette, Louis J; Iguchi, Taisen

    2010-09-15

    Sex-steroid hormones are essential for normal reproductive activity in both sexes in all vertebrates. Estrogens are required for ovarian differentiation during a critical developmental stage and promote the growth and differentiation of the female reproductive system following puberty. Recent studies have shown that environmental estrogens influence the developing reproductive system as well as gametogenesis, especially in males. To understand the molecular mechanisms of estrogen actions and to evaluate estrogen receptor-ligand interactions in Elasmobranchii, we cloned a single estrogen receptor (ESR) from two shark species, the cloudy catshark (Scyliorhinus torazame) and whale shark (Rhincodon typus) and used an ERE-luciferase reporter assay system to characterize the interaction of these receptors with steroidal and other environmental estrogens. In the transient transfection ERE-luciferase reporter assay system, both shark ESR proteins displayed estrogen-dependent activation of transcription, and shark ESRs were more sensitive to 17beta-estradiol compared with other natural and synthetic estrogens. Further, the environmental chemicals, bisphenol A, nonylphenol, octylphenol and DDT could activate both shark ESRs. The assay system provides a tool for future studies examining the receptor-ligand interactions and estrogen disrupting mechanisms in Elasmobranchii. PMID:20600039

  14. 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

  15. VASCULAR ACTIONS OF ESTROGENS: FUNCTIONAL IMPLICATIONS

    PubMed Central

    Miller, Virginia M.; Duckles, Sue P.

    2009-01-01

    The impact of estrogen exposure in preventing or treating cardiovascular disease is controversial. But it is clear that estrogen has important effects on vascular physiology and pathophysiology, with potential therapeutic implications. Therefore, it is the goal of this review to summarize, using an integrated approach, current knowledge of the vascular effects of estrogen, both in humans and in experimental animals. Aspects of estrogen synthesis and receptors, as well as general mechanisms of estrogenic action are reviewed with an emphasis on issues particularly relevant to the vascular system. Recent understanding of the impact of estrogen on mitochondrial function suggests that the longer lifespan of women compared to men may depend in part on the ability of estrogen to decrease production of reactive oxygen species in mitochondria. Mechanisms by which estrogen increases endothelial vasodilator function, promotes angiogenesis and modulates autonomic function are summarized. Key aspects of the relevant pathophysiology of inflammation, atherosclerosis, stroke, migraine and thrombosis are reviewed concerning current knowledge of estrogenic effects. A number of emerging concepts are addressed throughout. These include the importance of estrogenic formulation and route of administration and the impact of genetic polymorphisms, either in estrogen receptors or in enzymes responsible for estrogen metabolism, on responsiveness to hormone treatment. The importance of local metabolism of estrogenic precursors and the impact of timing for initiation of treatment and its duration are also considered. While consensus opinions are emphasized, controversial views are presented in order to stimulate future research. PMID:18579753

  16. Estrogen changes as a critical factor in modulation of central opioid tonus: possible correlations with post-menopausal migraine.

    PubMed

    Genazzani, A R; Petraglia, F; Volpe, A; Facchinetti, F

    1985-05-01

    The effects exerted by ovarian steroids on the modulation of opioid activity were investigated in post-menopausal migraine sufferers and in healthy controls. In order to evaluate central opioid tonus, plasma LH rise after naloxone injection was measured, bearing in mind the tonic inhibition of endogenous opioid on hypothalamic LH-RH. There was no response of plasma LH to naloxone in post-menopausal women or in patients submitted to ovariectomy in fertile life. When the subjects underwent a sequential estrogens + progestagens therapy, such a response was noted from the first month of treatment; progestagens alone were ineffective. The same phenomena were also evident in post-menopausal migraine sufferers. These data indicate that ovarian steroids modulate the activity of opiate receptors in both healthy women and migraine sufferers. Interestingly, replacement therapies through ovarian steroids restored the activity of central opioid tonus in patients affected by migraine. PMID:2990722

  17. Glycone-rich Soy Isoflavone Extracts Promote Estrogen Receptor Positive Breast Cancer Cell Growth.

    PubMed

    Johnson, Kailee A; Vemuri, Sravan; Alsahafi, Sameerh; Castillo, Rudy; Cheriyath, Venugopalan

    2016-01-01

    Due to the association of hormone replacement therapy (HRT) with breast cancer risk, estrogenically active soy isoflavones are considered as an HRT alternative to alleviate menopausal symptoms. However, several recent reports challenged the health benefits of soy isoflavones and associated them with breast cancer promotion. While glyconic isoflavones are the major constituents of soybean seeds, due to their low cell permeability, they are considered to be biologically inactive. The glyconic isoflavones may exert their effects on membrane-bound estrogen receptors or could be converted to aglycones by extracellular β-glucosidases. Therefore, we hypothesized that despite their low cell permeability, soybean cultivars with high glyconic isoflavones may promote breast cancer cell growth. To test this, composition and estrogenic activity of isoflavones from 54 commercial soybean cultivars were determined. Soybean seeds produced in identical climate and growth conditions were used to minimize the effects of extraneous factors on isoflavone profile and concentrations. The glyconic daidzin concentration negatively correlated with genistin and with other aglycones. Relative to control, isoflavone extracts from 51 cultivars were estrogenic and promoted the growth of estrogen receptor positive (ER+) breast cancer cell line MCF-7 from 1.14 to 4.59 folds and other three cultivars slightly reduced the growth. Among these, extracts from three cultivars were highly estrogenic and promoted MCF-7 cell growth by 2.59-4.64 folds (P<0.005). Among six isoflavones, daidzin was positively associated with MCF-7 cell growth (P<0.005, r = 0.13966), whereas the negative correlation between genistin and MCF-7 cell growth was nearly significant (P≤0.0562, r = -0.026141). Furthermore, in drug interaction studies daidzin-rich isoflavone extracts antagonized tamoxifen, an ER inhibitor. Taken together, our results suggest that the glyconic daidzin-rich soy isoflavone extracts may exert estrogenic

  18. [In vitro sensitivity of breast cancer tissue to adriablastin in the presence and absence of estrogen receptors].

    PubMed

    Olinia, A Ia; Vitola, G Ia; Nuke, I Ia; Zeĭkate, G A; Emzin'sh, D E

    1984-01-01

    The report deals with a comparison of estrogen receptor concentration in tumor tissue of breast cancer patients and sensitivity of the said tissue to adriablastin in short-term organ cultures. No relationship was established between tumor tissue sensitivity to adriablastin and presence or absence of estrogen receptors. It is necessary to identify both the concentration of specific hormone receptors and individual sensitivity to chemotherapy in order to work out individually-tailored schemes of treatment of breast cancer patients. PMID:6710944

  19. 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.

  20. 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

  1. Structure-Activity Relationships for the Antifungal Activity of Selective Estrogen Receptor Antagonists Related to Tamoxifen

    PubMed Central

    Butts, Arielle; Martin, Jennifer A.; DiDone, Louis; Bradley, Erin K.; Mutz, Mitchell; Krysan, Damian J.

    2015-01-01

    Cryptococcosis is one of the most important invasive fungal infections and is a significant contributor to the mortality associated with HIV/AIDS. As part of our program to repurpose molecules related to the selective estrogen receptor modulator (SERM) tamoxifen as anti-cryptococcal agents, we have explored the structure-activity relationships of a set of structurally diverse SERMs and tamoxifen derivatives. Our data provide the first insights into the structural requirements for the antifungal activity of this scaffold. Three key molecular characteristics affecting anti-cryptococcal activity emerged from our studies: 1) the presence of an alkylamino group tethered to one of the aromatic rings of the triphenylethylene core; 2) an appropriately sized aliphatic substituent at the 2 position of the ethylene moiety; and 3) electronegative substituents on the aromatic rings modestly improved activity. Using a cell-based assay of calmodulin antagonism, we found that the anti-cryptococcal activity of the scaffold correlates with calmodulin inhibition. Finally, we developed a homology model of C. neoformans calmodulin and used it to rationalize the structural basis for the activity of these molecules. Taken together, these data and models provide a basis for the further optimization of this promising anti-cryptococcal scaffold. PMID:26016941

  2. Estrogen-related receptor-α coordinates transcriptional programs essential for exercise tolerance and muscle fitness.

    PubMed

    Perry, Marie-Claude; Dufour, Catherine R; Tam, Ingrid S; B'chir, Wafa; Giguère, Vincent

    2014-12-01

    Muscle fitness is an important determinant of health and disease. However, the molecular mechanisms involved in the coordinate regulation of the metabolic and structural determinants of muscle endurance are still poorly characterized. Herein, we demonstrate that estrogen-related receptor α (ERRα, NR3B1) is essential for skeletal muscle fitness. Notably, we show that ERRα-null animals are hypoactive and that genetic or therapeutic disruption of ERRα in mice results in reduced exercise tolerance. Mice lacking ERRα also exhibited lactatemia at exhaustion. Gene expression profiling demonstrates that ERRα plays a key role in various metabolic processes important for muscle function including energy substrate transport and use (Ldhd, Slc16a1, Hk2, and Glul), the tricarboxylic acid cycle (Cycs, and Idh3g), and oxidative metabolism (Pdha1, and Uqcrq). Metabolomics studies revealed impairment in replenishment of several amino acids (eg, glutamine) during recovery to exercise. Moreover, loss of ERRα was found to alter the expression of genes involved in oxidative stress response (Hmox1), maintenance of muscle fiber integrity (Trim63, and Hspa1b), and muscle plasticity and neovascularization (Vegfa). Taken together, our study shows that ERRα plays a key role in directing transcriptional programs required for optimal mitochondrial oxidative potential and muscle fitness, suggesting that modulation of ERRα activity could be used to manage metabolic myopathies and/or promote the adaptive response to physical exercise. PMID:25361393

  3. Estrogen-Related Receptors and the control of bone cell fate.

    PubMed

    Carnesecchi, Julie; Vanacker, Jean-Marc

    2016-09-01

    Bone loss is naturally occurring in aging males and females and exacerbated in the latter after menopause, altogether leading to cumulative skeleton fragility and increased fracture risk. Two types of therapeutic strategies can be envisioned to counteract age- or menopause-associated bone loss, aiming at either reducing bone resorption exerted by osteoclasts or, alternatively, promoting bone formation by osteoblasts. We here summarize data suggesting that inhibition of the Estrogen-Related Receptors α and/or γ could promote bone formation and compensate for bone loss induced by ageing or estrogen-deficiency. PMID:26206717

  4. Identification of estrogen receptor-related receptor gamma as a direct transcriptional target of angiogenin.

    PubMed

    Ang, Jian; Sheng, Jinghao; Lai, Kairan; Wei, Saisai; Gao, Xiangwei

    2013-01-01

    Nuclear translocation of angiogenin (ANG) is essential for the proliferation of its target cells. ANG promotes rRNA synthesis, while whether it regulates mRNA transcription remains unknown. Using the chromatin immunoprecipitation method, we have identified 12 ANG-binding sequences. One of these sequences lies in the estrogen receptor-related receptor gamma (ERRγ) gene which we designated as ANG-Binding Sequence within ERRγ (ABSE). ABSE exhibited ANG-dependent repressor activity in the luciferase reporter system. Down-regulation of ANG increased ERRγ expression, and active gene marker level at the ABSE region. The expression levels of ERRγ targets genes, p21(WAF/CIP) and p27(KIP1), and the occupation of ERRγ on their promoter regions were increased in ANG-deficient cells accordingly. Furthermore, knockdown of ERRγ promoted the proliferation rate in ANG-deficient breast cancer cells. Finally, immunohistochemistry staining showed negative correlation between ANG and ERRγ in breast cancer tissue. Altogether, our study provides evidence that nuclear ANG directly binds to the ABSE of ERRγ gene and inhibits ERRγ transcription to promote breast cancer cell proliferation. PMID:23977052

  5. 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

  6. Identification of Estrogen Receptor-Related Receptor Gamma as a Direct Transcriptional Target of Angiogenin

    PubMed Central

    Ang, Jian; Sheng, Jinghao; Lai, Kairan; Wei, Saisai; Gao, Xiangwei

    2013-01-01

    Nuclear translocation of angiogenin (ANG) is essential for the proliferation of its target cells. ANG promotes rRNA synthesis, while whether it regulates mRNA transcription remains unknown. Using the chromatin immunoprecipitation method, we have identified 12 ANG-binding sequences. One of these sequences lies in the estrogen receptor-related receptor gamma (ERRγ) gene which we designated as ANG-Binding Sequence within ERRγ (ABSE). ABSE exhibited ANG-dependent repressor activity in the luciferase reporter system. Down-regulation of ANG increased ERRγ expression, and active gene marker level at the ABSE region. The expression levels of ERRγ targets genes, p21WAF/CIP and p27KIP1, and the occupation of ERRγ on their promoter regions were increased in ANG-deficient cells accordingly. Furthermore, knockdown of ERRγ promoted the proliferation rate in ANG-deficient breast cancer cells. Finally, immunohistochemistry staining showed negative correlation between ANG and ERRγ in breast cancer tissue. Altogether, our study provides evidence that nuclear ANG directly binds to the ABSE of ERRγ gene and inhibits ERRγ transcription to promote breast cancer cell proliferation. PMID:23977052

  7. 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

  8. 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

  9. 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

  10. Estrogen-mediated Regulation of Igf1 Transcription and Uterine Growth Involves Direct Binding of Estrogen Receptor α to Estrogen-responsive Elements*

    PubMed Central

    Hewitt, Sylvia C.; Li, Yin; Li, Leping; Korach, Kenneth S.

    2010-01-01

    Estrogen enables uterine proliferation, which depends on synthesis of the IGF1 growth factor. This proliferation and IGF1 synthesis requires the estrogen receptor (ER), which binds directly to target DNA sequences (estrogen-responsive elements or EREs), or interacts with other transcription factors, such as AP1, to impact transcription. We observe neither uterine growth nor an increase in Igf1 transcript in a mouse with a DNA-binding mutated ERα (KIKO), indicating that both Igf1 regulation and uterine proliferation require the DNA binding function of the ER. We identified several potential EREs in the Igf1 gene, and chromatin immunoprecipitation analysis revealed ERα binding to these EREs in wild type but not KIKO chromatin. STAT5 is also reported to regulate Igf1; uterine Stat5a transcript is increased by estradiol (E2), but not in KIKO or αERKO uteri, indicating ERα- and ERE-dependent regulation. ERα binds to a potential Stat5a ERE. We hypothesize that E2 increases Stat5a transcript through ERE binding; that ERα, either alone or together with STAT5, then acts to increase Igf1 transcription; and that the resulting lack of IGF1 impairs KIKO uterine growth. Treatment with exogenous IGF1, alone or in combination with E2, induces proliferation in wild type but not KIKO uteri, indicating that IGF1 replacement does not rescue the KIKO proliferative response. Together, these observations suggest in contrast to previous in vitro studies of IGF-1 regulation involving AP1 motifs that direct ERα-DNA interaction is required to increase Igf1 transcription. Additionally, full ERα function is needed to mediate other cellular signals of the growth factor for uterine growth. PMID:19920132

  11. Characterization of estrogenic receptor agonists and evaluation of estrogenic activity in the sediments of Liaohe River protected areas.

    PubMed

    Ke, Xin; Wang, Chunyong; Zhang, Haijun; Zhang, Yun; Gui, Shaofeng

    2015-11-15

    Estrogenic activity of 12 sediment samples from Liaohe River protected areas was evaluated by the recombinant yeast bioassays. The bioassay-derived 17β-estradiol equivalents of crude extracts (Bio-EEQcrudes) were between 52.2 and 207.6pg/g dry weight. The most concerned estrogenic receptor (ER) agonists including estrone (E1), 17β-estradiol (E2), estriol (E3), 17α-ethynylestradiol (EE2), 4-nonylphenols (4-NP), bisphenol A (BPA), and organochlorine pesticides (OCPs) were determined. The concentrations of E1, E2, E3, EE2, BPA, andΣ10OCPs ranged up to 203.3pg/g, 185.8pg/g, 237.7pg/g, 188.5pg/g, 51.0ng/g, and 3.6ng/g, respectively. Taken together with polarity-based fractionation, in vitro bioassay and chemical analysis, it indicated that E1, E2, and EE2 were the predominant ER agonists and were mainly from the discharge of domestic wastewater and breeding wastewater. Meanwhile, this study showed that the establishment of protected areas had not obviously reduced the ecological risk caused by ER agonists in Liaohe River protected areas sediments. PMID:26388445

  12. Estradiol coupling to human monocyte nitric oxide release is dependent on intracellular calcium transients: evidence for an estrogen surface receptor.

    PubMed

    Stefano, G B; Prevot, V; Beauvillain, J C; Fimiani, C; Welters, I; Cadet, P; Breton, C; Pestel, J; Salzet, M; Bilfinger, T V

    1999-10-01

    We tested the hypothesis that estrogen acutely stimulates constitutive NO synthase (cNOS) activity in human peripheral monocytes by acting on an estrogen surface receptor. NO release was measured in real time with an amperometric probe. 17beta-estradiol exposure to monocytes stimulated NO release within seconds in a concentration-dependent manner, whereas 17alpha-estradiol had no effect. 17beta-estradiol conjugated to BSA (E2-BSA) also stimulated NO release, suggesting mediation by a membrane surface receptor. Tamoxifen, an estrogen receptor inhibitor, antagonized the action of both 17beta-estradiol and E2-BSA, whereas ICI 182,780, a selective inhibitor of the nuclear estrogen receptor, had no effect. We further showed, using a dual emission microfluorometry in a calcium-free medium, that the 17beta-estradiol-stimulated release of monocyte NO was dependent on the initial stimulation of intracellular calcium transients in a tamoxifen-sensitive process. Leeching out the intracellular calcium stores abolished the effect of 17beta-estradiol on NO release. RT-PCR analysis of RNA obtained from the cells revealed a strong estrogen receptor-alpha amplification signal and a weak beta signal. Taken together, a physiological dose of estrogen acutely stimulates NO release from human monocytes via the activation of an estrogen surface receptor that is coupled to increases in intracellular calcium. PMID:10490972

  13. Membrane-localized estrogen receptor α is required for normal organ development and function.

    PubMed

    Pedram, Ali; Razandi, Mahnaz; Lewis, Michael; Hammes, Stephen; Levin, Ellis R

    2014-05-27

    Steroid receptors are found in discrete cellular locations, but it is unknown whether extranuclear pools are necessary for normal organ development. To assess this, we developed a point mutant estrogen receptor α (ERα) knockin mouse (C451A) that precludes palmitoylation and membrane trafficking of the steroid receptor in all organs. Homozygous knockin female mice (nuclear-only ERα [NOER]) show loss of rapid signaling that occurs from membrane ERα in wild-type mice. Multiple developmental abnormalities were found, including infertility, relatively hypoplastic uteri, abnormal ovaries, stunted mammary gland ductal development, and abnormal pituitary hormone regulation in NOER mice. These abnormalities were rescued in heterozygous NOER mice that were comparable to wild-type mice. mRNAs implicated in organ development were often poorly stimulated by estrogen only in homozygous NOER mice. We conclude that many organs require membrane ERα and resulting signal transduction to collaborate with nuclear ERα for normal development and function. PMID:24871949

  14. Uncoupling of 5-HT1A receptors in the brain by estrogens: regional variations in antagonism by ICI 182,780.

    PubMed

    Mize, A L; Young, L J; Alper, R H

    2003-04-01

    Previously we have shown that 17beta-estradiol (in vivo and in vitro) rapidly decreases the function of serotonin(1A) (5-HT(1A)) receptors, allowing us to hypothesize that 17beta-estradiol accomplished this via activation of a membrane estrogen receptor. Hippocampus and frontal cortex obtained from ovariectomized rats were incubated with 17beta-estradiol or bovine serum albumin (BSA)-estradiol in the presence or absence of the estrogen receptor (ER) antagonist ICI 182,780. Membranes were prepared to measure R(+)8-OH-DPAT-stimulated [(35)S]GTPgammaS binding (a measure of 5-HT(1A) receptor coupling and function). In both hippocampus and frontal cortex, 17beta-estradiol and BSA-estradiol (50 nM) decreased R(+)8-OH-DPAT-stimulated [(35)S]GTPgammaS binding. ICI 182,780 blocked the effect of both the estrogens in hippocampus, but only the effect of 17beta-estradiol in frontal cortex. Due to the inability of ICI 182,780 to block the effects of BSA-estradiol in frontal cortex, similar experiments were performed using the selective estrogen receptor modulator tamoxifen as the agonist. Tamoxifen (100 nM and 1 microM) decreased R(+)8-OH-DPAT-stimulated [(35)S]GTPgammaS binding. ICI 182,780 (1 microM) blocked the ability of tamoxifen to decrease 5-HT(1A) receptor coupling in the hippocampus, but not in the frontal cortex. Taken together, these data support the existence of a pharmacologically distinct ER in hippocampus vs. frontal cortex that might be responsible for rapid uncoupling of 5-HT(1A) receptors. PMID:12668044

  15. 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

  16. 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

  17. Outcomes of Estrogen Receptor Negative and Progesterone Receptor Positive Breast Cancer

    PubMed Central

    Chan, Melissa; Chang, Martin C.; González, Rosa; Lategan, Belinda; del Barco, Elvira; Vera-Badillo, Francisco; Quesada, Paula; Goldstein, Robyn; Cruz, Ignacio; Ocana, Alberto; Cruz, Juan J.; Amir, Eitan

    2015-01-01

    Purpose To describe the clinical features and outcomes of estrogen receptor negative (ER-) and progesterone receptor positive (PgR+) breast cancer. Methods We retrospectively reviewed a well-characterized database of sequential patients diagnosed with early stage invasive breast carcinoma. Outcomes of interest were time to relapse (TTR) and overall survival (OS). Multivariable Cox proportional hazards analysis was conducted to assess the association of ER-/PgR+ with TTR and OS in comparison to ER+ and to ER- and PgR negative (ER-/PgR-) tumors irrespective of HER2 status. ER and PgR expression was conservatively defined as 10% or greater staining of cancer cells. Results 815 patients were followed for a median of 40.5 months; 56 patients (7%) had ER-/PgR+, 624 (77%) had ER+ and 136 (17%) had ER-/PgR- phenotypes. Compared with ER+ tumors, ER-/PgR+ tumors were associated with younger age (50 versus 59 years, p=0.03), high grade (50% versus 24%, p<0.001) and more frequent HER2 overexpression/amplification (43% versus 14%, p<0.001). TTR for ER-/PgR+ was intermediate between ER+ and ER-/PgR- tumors, but was not significantly different from ER+ tumors. Recurrences in the ER-/PgR+ and ER-/PgR- groups occurred early in follow-up while in ER+ tumors recurrences continued to occur over the duration of follow-up. OS of ER-/PgR+ was similar to ER+ tumors and better than that of ER-/PgR- tumors. Conclusions The ER-/PgR+ phenotype is associated with higher grade with HER2 overexpression/amplification and occurs more commonly in younger women. Risk of relapse and death more closely resembles ER+ than ER-/PgR- tumors suggesting this phenotype represents a group of more aggressive hormone receptor positive tumors. PMID:26161666

  18. 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

  19. Role of c-Src and focal adhesion kinase in progression and metastasis of estrogen receptor-positive breast cancer

    SciTech Connect

    Planas-Silva, Maricarmen D. . E-mail: mcplanas@psu.edu; Bruggeman, Richard D.; Grenko, Ronald T.; Stanley Smith, J.

    2006-03-03

    The non-receptor tyrosine kinases c-Src and focal adhesion kinase (Fak) mediate signal transduction pathways that regulate cell proliferation, survival, invasion, and metastasis. Here, we investigated whether c-Src and Fak are activated during progression of hormone-dependent breast cancer. Maximally active c-Src was overexpressed in a subset of tamoxifen-resistant variants and in metastases of recurrent hormone-treated breast cancer. Active Fak was also frequently observed in these tumors. We also show that estrogen receptor (ER) can bind to Fak and that estrogen can modulate Fak autophosphorylation supporting a cross-talk between these two pathways. Inhibition of c-Src activity blocked proliferation of all tamoxifen-resistant variants, suggesting that inhibitors of c-Src-Fak activity may delay or prevent progression and metastasis of ER-positive tumors. These studies also raise the possibility that fully active forms of c-Src and Fak in breast tumors may be biomarkers to predict tamoxifen resistance and/or risk of recurrence in ER-positive breast cancer.

  20. Effects of coumestrol on estrogen receptor function and uterine growth in ovariectomized rats.

    PubMed Central

    Markaverich, B M; Webb, B; Densmore, C L; Gregory, R R

    1995-01-01

    Isoflavonoids and related compounds such as coumestrol have classically been categorized as phytoestrogens because these environmentally derived substances bind to the estrogen receptor (ER) and increase uterine wet weight in immature rats and mice. Assessment of the binding affinities of isoflavonoids for ER and subsequent effects on uterine growth suggest these compounds are less active estrogens than estradiol and therefore may reduce the risk of developing breast or prostate cancer in humans by preventing estradiol binding to ER. With the renewed interest in the relationships between environmental estrogens and cancer cause and prevention, we assessed the effects of the phytoestrogen coumestrol on uterotropic response in the immature, ovariectomized rat. Our studies demonstrated that in this animal model, coumestrol is an atypical estrogen that does not stimulate uterine cellular hyperplasia. Although acute (subcutaneous injection) or chronic (multiple injection or orally via drinking water) administration of coumestrol significantly increased uterine wet and dry weights, the phytoestrogen failed to increase uterine DNA content. The lack of true estrogenic activity was characterized by the inability of this phytoestrogen to cause cytosolic ER depletion, nuclear ER accumulation, or the stimulation of nuclear type II sites which characteristically precede estrogenic stimulation of cellular DNA synthesis and proliferation. In fact, subcutaneous or oral coumestrol treatment caused an atypical threefold induction of cytosolic ER without corresponding cytosolic depletion and nuclear accumulation of this receptor, and this increased the sensitivity of the uterus to subsequent stimulation by estradiol.(ABSTRACT TRUNCATED AT 250 WORDS) Images p574-a Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. PMID:7556010