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Sample records for negative estrogen receptor

  1. Targeting Epigenetics Therapy for Estrogen Receptor-Negative Breast Cancers

    DTIC Science & Technology

    2014-10-01

    AWARD NUMBER: W81XWH-13-1-0400 TITLE: Targeting Epigenetics Therapy for Estrogen Receptor...2014 4. TITLE AND SUBTITLE Targeting Epigenetics Therapy for Estrogen Receptor-Negative Breast Cancers 5a. CONTRACT NUMBER 5b...estrogen- receptor positive breast cancer, estrogen receptor negative breast cancer, epigenetics , nuclear hormone receptor, estrogen Overall

  2. Fulvestrant, a selective estrogen receptor down-regulator, sensitizes estrogen receptor negative breast tumors to chemotherapy.

    PubMed

    Jiang, Donghai; Huang, Yuan; Han, Ning; Xu, Mingjie; Xu, Liang; Zhou, Lin; Wang, Shu; Fan, Weimin

    2014-05-01

    Drug resistance frequently results in poor prognosis and high 5-year recurrence rate in estrogen receptor-negative (ER-) breast cancer patients. Herein, we examined the reversal effects of fulvestrant on multidrug resistance (MDR) in ER- breast cancer cells. Co-administration of fulvestrant significantly sensitized ER- MDR tumors to paclitaxel both in vitro and in vivo. Further analyses indicated that fulvestrant did not affect P-gp expression, but could inhibit P-gp function and subsequently reverse P-gp mediated drug resistance in ER- breast cancer cells. These results showed that combination of fulvestrant and chemotherapeutic agents might provide an effective treatment for ER- MDR breast cancers.

  3. Novel Strategies for the Treatment of Estrogen Receptor-Negative Breast Cancer

    DTIC Science & Technology

    2009-04-01

    findings contained in this report are those of the author(s) and should not be construed as an official Department of the Army position , policy or decision...of breast cancer have focused on the entire genome to identify genes differentially expressed between estrogen receptor (ER)- positive and ER-negative...tumors. Kinase expression knock-down studies show that many of these kinases are essential for the growth of ER-negative, but not ER- positive

  4. 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

  5. Gemini vitamin D analogues inhibit estrogen receptor-positive and estrogen receptor-negative mammary tumorigenesis without hypercalcemic toxicity.

    PubMed

    Lee, Hong Jin; Paul, Shiby; Atalla, Nadi; Thomas, Paul E; Lin, Xinjie; Yang, Ill; Buckley, Brian; Lu, Gang; Zheng, Xi; Lou, You-Rong; Conney, Allan H; Maehr, Hubert; Adorini, Luciano; Uskokovic, Milan; Suh, Nanjoo

    2008-11-01

    Numerous preclinical, epidemiologic, and clinical studies have suggested the benefits of vitamin D and its analogues for the prevention and treatment of cancer. However, the hypercalcemic effects have limited the use of 1alpha,25(OH)(2)D(3), the hormonally active form of vitamin D. To identify vitamin D analogues with better efficacy and low toxicity, we have tested >60 novel Gemini vitamin D analogues with a unique structure of two side chains for growth inhibition of breast cancer cells. Our initial studies found that some Gemini analogues are 5-15 times more active than 1alpha,25(OH)(2)D(3) in growth inhibition assay. In vivo experiments were designed to study the inhibitory effect of selected Gemini vitamin D analogues against mammary carcinogenesis by using (a) an N-methyl-N-nitrosourea-induced estrogen receptor (ER)-positive mammary tumor model and (b) an MCF10DCIS.com xenograft model of ER-negative mammary tumors. Among vitamin D analogues we tested, Gemini 0072 [1alpha,25-dihydroxy-20S-21(3-trideuteromethyl-3-hydroxy-4,4,4-trideuterobutyl)-23-yne-26,27-hexafluoro-19-nor-cholecalciferol] and Gemini 0097 [1alpha,25-dihydroxy-20R-21(3-trideuteromethyl-3-hydroxy-4,4,4-trideuterobutyl)-23-yne-26,27-hexafluoro-19-nor-cholecalciferol] administration inhibited by 60% the NMU-induced mammary tumor burden compared with the NMU-treated control group, but these compounds were devoid of hypercalcemia toxicity. In an ER-negative xenograft model, Gemini 0097 significantly suppressed tumor growth without hypercalcemia toxicity. We found that the inhibitory effect of Gemini 0097 was associated with an increased level of cyclin-dependent kinase inhibitor p21 and the insulin-like growth factor binding protein 3 in both ER-positive and ER-negative mammary tumors. Our results suggest that Gemini vitamin D analogues may be potent agents for the prevention and treatment of both ER-positive and ER-negative breast cancer without hypercalcemia toxicity.

  6. The Immunophilin-Like Protein XAP2 Is a Negative Regulator of Estrogen Signaling through Interaction with Estrogen Receptor α

    PubMed Central

    Berg, Petra; Korbonits, Marta; Pongratz, Ingemar

    2011-01-01

    XAP2 (also known as aryl hydrocarbon receptor interacting protein, AIP) is originally identified as a negative regulator of the hepatitis B virus X-associated protein. Recent studies have expanded the range of XAP2 client proteins to include the nuclear receptor family of transcription factors. In this study, we show that XAP2 is recruited to the promoter of ERα regulated genes like the breast cancer marker gene pS2 or GREB1 and negatively regulate the expression of these genes in MCF-7 cells. Interestingly, we show that XAP2 downregulates the E2-dependent transcriptional activation in an estrogen receptor (ER) isoform-specific manner: XAP2 inhibits ERα but not ERβ-mediated transcription. Thus, knockdown of intracellular XAP2 levels leads to increased ERα activity. XAP2 proteins, carrying mutations in their primary structures, loose the ability of interacting with ERα and can no longer regulate ER target gene transcription. Taken together, this study shows that XAP2 exerts a negative effect on ERα transcriptional activity and may thus prevent ERα-dependent events. PMID:21984905

  7. C-myc gene chromatin of estrogen receptor positive and negative breast cancer cells.

    PubMed

    Miller, T L; Huzel, N J; Davie, J R; Murphy, L C

    1993-02-01

    Expression of the c-myc protooncogene is estrogen regulated in estrogen receptor (ER) positive, hormone-dependent human breast cancer cells, but it is constitutively active in ER negative, hormone-independent breast cancer cells. To determine whether these differences are reflected in c-myc chromatin, DNase I hypersensitive sites (DHS) were mapped. Six DHS were detected in all cell lines studied, with DHS 3(2) being more prominent than DHS 3(1). The accessibility of DHS 2 was markedly greater in ER negative cells than in ER positive cells, and this relative accessibility remained unchanged when cells were grown in estrogen free medium. DHS 2, 3(1) and 3(2) map near the P0, P1 and P2 promoters, respectively. An analysis of promoter usage demonstrated that P2 was the preferred promoter. Thus, the differences in the accessibility of DHS 2 in c-myc chromatin of ER positive and negative cells likely reflects alterations in DNA-protein interactions in this region.

  8. 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.

  9. 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

  10. Accumulation of the advanced glycation end product carboxymethyl lysine in breast cancer is positively associated with estrogen receptor expression and unfavorable prognosis in estrogen receptor-negative cases.

    PubMed

    Nass, Norbert; Ignatov, Atanas; Andreas, Ludwig; Weißenborn, Christine; Kalinski, Thomas; Sel, Saadettin

    2016-12-23

    Advanced glycation end products (AGEs) accumulate as a result of high concentrations of reactive aldehydes, oxidative stress, and insufficient degradation of glycated proteins. AGEs are therefore accepted biomarkers for aging, diabetes, and several degenerative diseases. Due to the Warburg effect and increased oxidative stress, cancer cells frequently accumulate significant amounts of AGEs. As the accumulation of AGEs may reflect the metabolic state and receptor signaling, we evaluated the potential prognostic and predictive value of this biomarker. We used immunohistochemistry to determine the AGE Nε-carboxymethyl lysine (CML) in 213 mammary carcinoma samples and Western blotting to detect AGEs in cell cultures. Whereas no significant correlation between hormone receptor status and CML was observed in cell lines, CML accumulation in tumors was positively correlated with the presence of estrogen receptor alpha, the postmenopausal state, and age. A negative correlation was found for grade III carcinomas and triple-negative cases. In a retrospective Kaplan-Meier survival analysis, there was a statistical trend that high CML accumulation correlated with a more favorable prognosis (relapse-free survival, RFS) under tamoxifen treatment (p = 0.1). In estrogen receptor-negative cases, the high CML content was significantly correlated with an unfavorable outcome (RFS) of chemotherapy (p = 0.046). CML is a therefore a potentially predictive marker for the treatment of breast cancer patients with tamoxifen or chemotherapy.

  11. Calcitriol restores antiestrogen responsiveness in estrogen receptor negative breast cancer cells: A potential new therapeutic approach

    PubMed Central

    2014-01-01

    Background Approximately 30% of breast tumors do not express the estrogen receptor (ER) α, which is necessary for endocrine therapy approaches. Studies are ongoing in order to restore ERα expression in ERα-negative breast cancer. The aim of the present study was to determine if calcitriol induces ERα expression in ER-negative breast cancer cells, thus restoring antiestrogen responses. Methods Cultured cells derived from ERα-negative breast tumors and an ERα-negative breast cancer cell line (SUM-229PE) were treated with calcitriol and ERα expression was assessed by real time PCR and western blots. The ERα functionality was evaluated by prolactin gene expression analysis. In addition, the effects of antiestrogens were assessed by growth assay using the XTT method. Gene expression of cyclin D1 (CCND1), and Ether-à-go-go 1 (EAG1) was also evaluated in cells treated with calcitriol alone or in combination with estradiol or ICI-182,780. Statistical analyses were determined by one-way ANOVA. Results Calcitriol was able to induce the expression of a functional ERα in ER-negative breast cancer cells. This effect was mediated through the vitamin D receptor (VDR), since it was abrogated by a VDR antagonist. Interestingly, the calcitriol-induced ERα restored the response to antiestrogens by inhibiting cell proliferation. In addition, calcitriol-treated cells in the presence of ICI-182,780 resulted in a significant reduction of two important cell proliferation regulators CCND1 and EAG1. Conclusions Calcitriol induced the expression of ERα and restored the response to antiestrogens in ERα-negative breast cancer cells. The combined treatment with calcitriol and antiestrogens could represent a new therapeutic strategy in ERα-negative breast cancer patients. PMID:24678876

  12. Gene expression profiles of estrogen receptor positive and estrogen receptor negative breast cancers are detectable in histologically normal breast epithelium

    PubMed Central

    Graham, Kelly; Ge, Xijin; de las Morenas, Antonio; Tripathi, Anusri; Rosenberg, Carol L.

    2010-01-01

    Purpose Previously, we found that gene expression in histologically normal breast epithelium (NlEpi) from women at high breast cancer risk can resemble gene expression in NlEpi from cancer-containing breasts. Therefore, we hypothesized that gene expression characteristic of a cancer subtype might be seen in NlEpi of breasts containing that subtype. Experimental Design We examined gene expression in 46 cases of microdissected NlEpi from untreated women undergoing breast cancer surgery. From 30 age-matched cases (15 estrogen receptor (ER)+, 15 ER-) we used Affymetryix U133A arrays. From 16 independent cases (9 ER+, 7 ER-), we validated selected genes using qPCR. We then compared gene expression between NlEpi and invasive breast cancer using 4 publicly available datasets. Results We identified 198 genes that are differentially expressed between NlEpi from breasts with ER+ (NlEpiER+) compared to ER- cancers (NlEpiER-). These include genes characteristic of ER+ and ER- cancers (e.g., ESR1, GATA3, and CX3CL1, FABP7). QPCR validated the microarray results in both the 30 original cases and the 16 independent cases. Gene expression in NlEpiER+ and NlEpiER- resembled gene expression in ER+ and ER- cancers, respectively: 25-53% of the genes or probes examined in 4 external datasets overlapped between NlEpi and the corresponding cancer subtype. Conclusions Gene expression differs in NlEpi of breasts containing ER+ compared to ER- breast cancers. These differences echo differences in ER+ and ER- invasive cancers. NlEpi gene expression may help elucidate subtype-specific risk signatures, identify early genomic events in cancer development and locate targets for prevention and therapy. PMID:21059815

  13. A common variant at the TERT-CLPTM1L locus is associated with estrogen receptor-negative breast cancer.

    PubMed

    Haiman, Christopher A; Chen, Gary K; Vachon, Celine M; Canzian, Federico; Dunning, Alison; Millikan, Robert C; Wang, Xianshu; Ademuyiwa, Foluso; Ahmed, Shahana; Ambrosone, Christine B; Baglietto, Laura; Balleine, Rosemary; Bandera, Elisa V; Beckmann, Matthias W; Berg, Christine D; Bernstein, Leslie; Blomqvist, Carl; Blot, William J; Brauch, Hiltrud; Buring, Julie E; Carey, Lisa A; Carpenter, Jane E; Chang-Claude, Jenny; Chanock, Stephen J; Chasman, Daniel I; Clarke, Christine L; Cox, Angela; Cross, Simon S; Deming, Sandra L; Diasio, Robert B; Dimopoulos, Athanasios M; Driver, W Ryan; Dünnebier, Thomas; Durcan, Lorraine; Eccles, Diana; Edlund, Christopher K; Ekici, Arif B; Fasching, Peter A; Feigelson, Heather S; Flesch-Janys, Dieter; Fostira, Florentia; Försti, Asta; Fountzilas, George; Gerty, Susan M; Giles, Graham G; Godwin, Andrew K; Goodfellow, Paul; Graham, Nikki; Greco, Dario; Hamann, Ute; Hankinson, Susan E; Hartmann, Arndt; Hein, Rebecca; Heinz, Judith; Holbrook, Andrea; Hoover, Robert N; Hu, Jennifer J; Hunter, David J; Ingles, Sue A; Irwanto, Astrid; Ivanovich, Jennifer; John, Esther M; Johnson, Nicola; Jukkola-Vuorinen, Arja; Kaaks, Rudolf; Ko, Yon-Dschun; Kolonel, Laurence N; Konstantopoulou, Irene; Kosma, Veli-Matti; Kulkarni, Swati; Lambrechts, Diether; Lee, Adam M; Marchand, Loïc Le; Lesnick, Timothy; Liu, Jianjun; Lindstrom, Sara; Mannermaa, Arto; Margolin, Sara; Martin, Nicholas G; Miron, Penelope; Montgomery, Grant W; Nevanlinna, Heli; Nickels, Stephan; Nyante, Sarah; Olswold, Curtis; Palmer, Julie; Pathak, Harsh; Pectasides, Dimitrios; Perou, Charles M; Peto, Julian; Pharoah, Paul D P; Pooler, Loreall C; Press, Michael F; Pylkäs, Katri; Rebbeck, Timothy R; Rodriguez-Gil, Jorge L; Rosenberg, Lynn; Ross, Eric; Rüdiger, Thomas; Silva, Isabel dos Santos; Sawyer, Elinor; Schmidt, Marjanka K; Schulz-Wendtland, Rüdiger; Schumacher, Fredrick; Severi, Gianluca; Sheng, Xin; Signorello, Lisa B; Sinn, Hans-Peter; Stevens, Kristen N; Southey, Melissa C; Tapper, William J; Tomlinson, Ian; Hogervorst, Frans B L; Wauters, Els; Weaver, JoEllen; Wildiers, Hans; Winqvist, Robert; Van Den Berg, David; Wan, Peggy; Xia, Lucy Y; Yannoukakos, Drakoulis; Zheng, Wei; Ziegler, Regina G; Siddiq, Afshan; Slager, Susan L; Stram, Daniel O; Easton, Douglas; Kraft, Peter; Henderson, Brian E; Couch, Fergus J

    2011-10-30

    Estrogen receptor (ER)-negative breast cancer shows a higher incidence in women of African ancestry compared to women of European ancestry. In search of common risk alleles for ER-negative breast cancer, we combined genome-wide association study (GWAS) data from women of African ancestry (1,004 ER-negative cases and 2,745 controls) and European ancestry (1,718 ER-negative cases and 3,670 controls), with replication testing conducted in an additional 2,292 ER-negative cases and 16,901 controls of European ancestry. We identified a common risk variant for ER-negative breast cancer at the TERT-CLPTM1L locus on chromosome 5p15 (rs10069690: per-allele odds ratio (OR) = 1.18 per allele, P = 1.0 × 10(-10)). The variant was also significantly associated with triple-negative (ER-negative, progesterone receptor (PR)-negative and human epidermal growth factor-2 (HER2)-negative) breast cancer (OR = 1.25, P = 1.1 × 10(-9)), particularly in younger women (<50 years of age) (OR = 1.48, P = 1.9 × 10(-9)). Our results identify a genetic locus associated with estrogen receptor negative breast cancer subtypes in multiple populations.

  14. Tetratricopeptide Repeat Domain 9A Negatively Regulates Estrogen Receptor Alpha Activity

    PubMed Central

    Shrestha, Smeeta; Sun, Yang; Lufkin, Thomas; Kraus, Petra; Or, Yuzuan; Garcia, Yenni A.; Guy, Naihsuan; Ramos, Paola; Cox, Marc B.; Tay, Fiona; Lin, Valerie CL

    2015-01-01

    Tetratricopeptide repeat domain 9A (TTC9A) is a target gene of estrogen and progesterone. It is over-expressed in breast cancer. However, little is known about the physiological function of TTC9A. The objectives of this study were to establish a Ttc9a knockout mouse model and to study the consequence of Ttc9a gene inactivation. The Ttc9a targeting vector was generated by replacing the Ttc9a exon 1 with a neomycin cassette. The mice homozygous for Ttc9a exon 1 deletion appear to grow normally and are fertile. However, further characterization of the female mice revealed that Ttc9a deficiency is associated with greater body weight, bigger thymus and better mammary development in post-pubertal mice. Furthermore, Ttc9a deficient mammary gland was more responsive to estrogen treatment with greater mammary ductal lengthening, ductal branching and estrogen target gene induction. Since Ttc9a is induced by estrogen in estrogen target tissues, these results suggest that Ttc9a is a negative regulator of estrogen function through a negative feedback mechanism. This is supported by in vitro evidence that TTC9A over-expression attenuated ERα activity in MCF-7 cells. Although TTC9A does not bind to ERα or its chaperone protein Hsp90 directly, TTC9A strongly interacts with FKBP38 and FKBP51, both of which interact with ERα and Hsp90 and modulate ERα activity. It is plausible therefore that TTC9A negatively regulates ERα activity through interacting with co-chaperone proteins such as FKBP38 and FKBP51. PMID:25798063

  15. Tetratricopeptide repeat domain 9A negatively regulates estrogen receptor alpha activity.

    PubMed

    Shrestha, Smeeta; Sun, Yang; Lufkin, Thomas; Kraus, Petra; Or, Yuzuan; Garcia, Yenni A; Guy, Naihsuan; Ramos, Paola; Cox, Marc B; Tay, Fiona; Lin, Valerie C L

    2015-01-01

    Tetratricopeptide repeat domain 9A (TTC9A) is a target gene of estrogen and progesterone. It is over-expressed in breast cancer. However, little is known about the physiological function of TTC9A. The objectives of this study were to establish a Ttc9a knockout mouse model and to study the consequence of Ttc9a gene inactivation. The Ttc9a targeting vector was generated by replacing the Ttc9a exon 1 with a neomycin cassette. The mice homozygous for Ttc9a exon 1 deletion appear to grow normally and are fertile. However, further characterization of the female mice revealed that Ttc9a deficiency is associated with greater body weight, bigger thymus and better mammary development in post-pubertal mice. Furthermore, Ttc9a deficient mammary gland was more responsive to estrogen treatment with greater mammary ductal lengthening, ductal branching and estrogen target gene induction. Since Ttc9a is induced by estrogen in estrogen target tissues, these results suggest that Ttc9a is a negative regulator of estrogen function through a negative feedback mechanism. This is supported by in vitro evidence that TTC9A over-expression attenuated ERα activity in MCF-7 cells. Although TTC9A does not bind to ERα or its chaperone protein Hsp90 directly, TTC9A strongly interacts with FKBP38 and FKBP51, both of which interact with ERα and Hsp90 and modulate ERα activity. It is plausible therefore that TTC9A negatively regulates ERα activity through interacting with co-chaperone proteins such as FKBP38 and FKBP51.

  16. Tamoxifen Citrate or Z-Endoxifen Hydrochloride in Treating Patients With Locally Advanced or Metastatic, Estrogen Receptor-Positive, HER2-Negative Breast Cancer

    ClinicalTrials.gov

    2017-04-12

    Estrogen Receptor Positive; HER2/Neu Negative; Recurrent Breast Carcinoma; Stage III Breast Cancer; Stage IIIA Breast Cancer; Stage IIIB Breast Cancer; Stage IIIC Breast Cancer; Stage IV Breast Cancer

  17. FLT PET in Measuring Treatment Response in Patients With Newly Diagnosed Estrogen Receptor-Positive, HER2-Negative Stage I-III Breast Cancer

    ClinicalTrials.gov

    2016-06-02

    Estrogen Receptor Positive; HER2/Neu Negative; Male Breast Carcinoma; Stage IA Breast Cancer; Stage IB Breast Cancer; Stage IIA Breast Cancer; Stage IIB Breast Cancer; Stage IIIA Breast Cancer; Stage IIIB Breast Cancer; Stage IIIC Breast Cancer

  18. The aryl hydrocarbon receptor mediates raloxifene-induced apoptosis in estrogen receptor-negative hepatoma and breast cancer cells

    PubMed Central

    O'Donnell, E F; Koch, D C; Bisson, W H; Jang, H S; Kolluri, S K

    2014-01-01

    Identification of new molecular targets for the treatment of breast cancer is an important clinical goal, especially for triple-negative breast cancer, which is refractory to existing targeted treatments. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor known primarily as the mediator of dioxin toxicity. However, the AhR can also inhibit cellular proliferation in a ligand-dependent manner and act as a tumor suppressor in mice, and thus may be a potential anticancer target. To investigate the AhR as an anticancer target, we conducted a small molecule screen to discover novel AhR ligands with anticancer properties. We identified raloxifene, a selective estrogen receptor (ER) modulator currently used in the clinic for prevention of ER-positive breast cancer and osteoporosis in post-menopausal women, as an AhR activator. Raloxifene directly bound the AhR and induced apoptosis in ER-negative mouse and human hepatoma cells in an AhR-dependent manner, indicating that the AhR is a molecular target of raloxifene and mediates raloxifene-induced apoptosis in the absence of ER. Raloxifene selectively induced apoptosis of triple-negative MDA-MB-231 breast cancer cells compared with non-transformed mammary epithelial cells via the AhR. Combined with recent data showing that raloxifene inhibits triple-negative breast cancer xenografts in vivo (Int J Oncol. 43(3):785-92, 2013), our results support the possibility of repurposing of raloxifene as an AhR-targeted therapeutic for triple-negative breast cancer patients. To this end, we also evaluated the role of AhR expression on survival of patients diagnosed with breast cancer. We found that higher expression of the AhR is significantly associated with increased overall survival and distant metastasis-free survival in both hormone-dependent (ER-positive) and hormone-independent (ER and progesterone receptor (PR)-negative) breast cancers. Together, our data strongly support the possibility of using the Ah

  19. The aryl hydrocarbon receptor mediates raloxifene-induced apoptosis in estrogen receptor-negative hepatoma and breast cancer cells.

    PubMed

    O'Donnell, E F; Koch, D C; Bisson, W H; Jang, H S; Kolluri, S K

    2014-01-30

    Identification of new molecular targets for the treatment of breast cancer is an important clinical goal, especially for triple-negative breast cancer, which is refractory to existing targeted treatments. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor known primarily as the mediator of dioxin toxicity. However, the AhR can also inhibit cellular proliferation in a ligand-dependent manner and act as a tumor suppressor in mice, and thus may be a potential anticancer target. To investigate the AhR as an anticancer target, we conducted a small molecule screen to discover novel AhR ligands with anticancer properties. We identified raloxifene, a selective estrogen receptor (ER) modulator currently used in the clinic for prevention of ER-positive breast cancer and osteoporosis in post-menopausal women, as an AhR activator. Raloxifene directly bound the AhR and induced apoptosis in ER-negative mouse and human hepatoma cells in an AhR-dependent manner, indicating that the AhR is a molecular target of raloxifene and mediates raloxifene-induced apoptosis in the absence of ER. Raloxifene selectively induced apoptosis of triple-negative MDA-MB-231 breast cancer cells compared with non-transformed mammary epithelial cells via the AhR. Combined with recent data showing that raloxifene inhibits triple-negative breast cancer xenografts in vivo (Int J Oncol. 43(3):785-92, 2013), our results support the possibility of repurposing of raloxifene as an AhR-targeted therapeutic for triple-negative breast cancer patients. To this end, we also evaluated the role of AhR expression on survival of patients diagnosed with breast cancer. We found that higher expression of the AhR is significantly associated with increased overall survival and distant metastasis-free survival in both hormone-dependent (ER-positive) and hormone-independent (ER and progesterone receptor (PR)-negative) breast cancers. Together, our data strongly support the possibility of using the Ah

  20. Aromatase overexpression induces malignant changes in estrogen receptor α negative MCF-10A cells.

    PubMed

    Wang, J; Gildea, J J; Yue, W

    2013-10-31

    Estrogen is a risk factor of breast cancer. Elevated expression of aromatase (estrogen synthase) in breast tissues increases local estradiol concentrations and is associated with breast cancer development, but the causal relationship between aromatase and breast cancer has not been identified. Accumulating data suggest that both estrogen receptor (ER)-dependent and -independent effects are involved in estrogen carcinogenesis. We established a model by expressing aromatase in ERα- MCF-10A human breast epithelial cells to investigate ERα-independent effects of estrogen in the process of malignant transformation. Overexpression of aromatase significantly increased anchorage-independent growth. Parental- or vector-expressing MCF-10A cells did not form colonies under the same conditions. The anchorage-independent growth of MCF-10A(arom) cells can be completely abolished by pre-treatment with the aromatase inhibitor, letrozole. Neither MCF-10A(arom) nor MCF-10A(vector) cells grown in monolayer were affected by short-term exposure to estradiol. Enhanced motility is another characteristic of cellular transformation. Motility of MCF-10A(arom) cells was increased, which could be inhibited by letrozole. Increases in stem cell population in breast cancer tissues are associated with tumor recurrence and metastasis. CD44(high)/CD24(low) is a stem cell marker. We found that CD24 mRNA levels were reduced in MCF-10A(arom) cells compared with those in parental- and vector-transfected cells. By examining individual clones of MCF-10A(arom) with various aromatase activities, we found that the CD24 mRNA levels were inversely correlated with aromatase activity. The ability of MCF-10A(arom) cells to form mammospheres in the absence of serum was increased. Our results suggest that overexpression of aromatase in MCF-10A cells causes malignant transformation. Estrogen metabolite-mediated genotoxicity and induction of a stem cell/progenitor cell population are possible mechanisms. These

  1. A model of spontaneous mouse mammary tumor for human estrogen receptor- and progesterone receptor-negative breast cancer

    PubMed Central

    ZHENG, LIXIANG; ZHOU, BUGAO; MENG, XIANMING; ZHU, WEIFENG; ZUO, AIREN; WANG, XIAOMIN; JIANG, RUNDE; YU, SHIPING

    2014-01-01

    Breast cancer (BC) is the most frequently malignancy in women. Therefore, establishment of an animal model for the development of preventative measures and effective treatment for tumors is required. A novel heterogeneous spontaneous mammary tumor animal model of Kunming mice was generated. The purpose of this study was to characterize the spontaneous mammary tumor model. Histopathologically, invasive nodular masses of pleomorphic tubular neoplastic epithelial cells invaded fibro-vascular stroma, adjacent dermis and muscle tissue. Metastatic spread through blood vessel into liver and lungs was observed by hematoxylin eosin staining. No estrogen receptor (ER) or progesterone receptor (PR) immunoreactivity was detected in their associated malignant tumors, human epidermal growth factor receptor-2 (HER-2) protein weak expression was found by immunohistochemistry. High expression of vascular endothelial growth factor (VEGF), moderate or high expression of c-Myc and cyclin D1 were observed in tumor sections at different stages (2, 4, 6 and 8 weeks after cancer being found) when compared with that of the normal mammary glands. The result showed that the model is of an invasive ductal carcinoma. Remarkably in the mouse model, ER and PR-negative and HER2 weak positivity are observed. The high or moderate expressions of breast cancer markers (VEGF, c-Myc and cyclin D1) in mammary cancer tissue change at different stages. To our knowledge, this is the first report of a spontaneous mammary model displaying colony-strain, outbred mice. This model will be an attractive tool to understand the biology of anti-hormonal breast cancer in women. PMID:25230850

  2. Effects of neuron-specific estrogen receptor (ER) α and ERβ deletion on the acute estrogen negative feedback mechanism in adult female mice.

    PubMed

    Cheong, Rachel Y; Porteous, Robert; Chambon, Pierre; Abrahám, István; Herbison, Allan E

    2014-04-01

    The negative feedback mechanism through which 17β-estradiol (E2) acts to suppress the activity of the GnRH neurons remains unclear. Using inducible and cell-specific genetic mouse models, we examined the estrogen receptor (ER) isoforms expressed by neurons that mediate acute estrogen negative feedback. Adult female mutant mice in which ERα was deleted from all neurons in the neonatal period failed to exhibit estrous cycles or negative feedback. Adult mutant female mice with neonatal neuronal ERβ deletion exhibited normal estrous cycles, but a failure of E2 to suppress LH secretion was seen in ovariectomized mice. Mutant mice with a GnRH neuron-selective deletion of ERβ exhibited normal cycles and negative feedback, suggesting no critical role for ERβ in GnRH neurons in acute negative feedback. To examine the adult roles of neurons expressing ERα, an inducible tamoxifen-based Cre-LoxP approach was used to ablate ERα from neurons that express calmodulin kinase IIα in adults. This resulted in mice with no estrous cycles, a normal increase in LH after ovariectomy, but an inability of E2 to suppress LH secretion. Finally, acute administration of ERα- and ERβ-selective agonists to adult ovariectomized wild-type mice revealed that activation of ERα suppressed LH secretion, whereas ERβ agonists had no effect. This study highlights the differences in adult reproductive phenotypes that result from neonatal vs adult ablation of ERα in the brain. Together, these experiments expand previous global knockout studies by demonstrating that neurons expressing ERα are essential and probably sufficient for the acute estrogen negative feedback mechanism in female mice.

  3. Spontaneous feline mammary intraepithelial lesions as a model for human estrogen receptor- and progesterone receptor-negative breast lesions

    PubMed Central

    2010-01-01

    Background Breast cancer is the most frequently diagnosed cancer in women. Intraepithelial lesions (IELs), such as usual ductal hyperplasia (UH), atypical ductal hyperplasia (ADH), and ductal carcinoma in situ (DCIS) are risk factors that predict a woman's chance of developing invasive breast cancer. Therefore, a comparative study that establishes an animal model of pre-invasive lesions is needed for the development of preventative measures and effective treatment for both mammary IELs and tumors. The purpose of this study was to characterize the histologic and molecular features of feline mammary IELs and compare them with those in women. Methods Formalin-fixed, paraffin-embedded specimens (n = 205) from 203 female cats with clinical mammary disease were retrieved from the archives of the Purdue University Animal Disease Diagnostic Laboratory and Veterinary Teaching Hospital (West Lafayette, IN), and the Department of Pathology and Veterinary Clinic, School of Veterinary Medicine (Sassari, Italy). Histologic sections, stained with hematoxylin and eosin (HE), were evaluated for the presence of IELs in tissue adjacent to excised mammary tumors. Lesions were compared to those of humans. Immunohistochemistry for estrogen receptor (ER-alpha), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER-2/neu) and Ki-67 was performed in IELs and adjacent tumor tissues. Results Intraepithelial lesions were found in 57 of 203 (28%) feline mammary specimens and were categorized as UH (27%), ADH (29%), and DCIS (44%). Most IELs with atypia (ADH and DCIS) were associated with mammary cancer (91%), whereas UH was associated with benign lesions in 53% of cases. Feline IELs were remarkably similar to human IELs. No ER or PR immunoreactivity was detected in intermediate-grade or high-grade DCIS or their associated malignant tumors. HER-2 protein overexpression was found in 27% of IELs. Conclusion The remarkable similarity of feline mammary IELs to those of humans

  4. Dormancy Signatures and Metastasis in Estrogen Receptor Positive and Negative Breast Cancer

    PubMed Central

    Kim, Ryung S.; Avivar-Valderas, Alvaro; Estrada, Yeriel; Bragado, Paloma; Sosa, Maria Soledad; Aguirre-Ghiso, Julio A.; Segall, Jeffrey E.

    2012-01-01

    Breast cancers can recur after removal of the primary tumor and treatment to eliminate remaining tumor cells. Recurrence may occur after long periods of time during which there are no clinical symptoms. Tumor cell dormancy may explain these prolonged periods of asymptomatic residual disease and treatment resistance. We generated a dormancy gene signature from published experimental models and applied it to both breast cancer cell line expression data as well as four published clinical studies of primary breast cancers. We found that estrogen receptor (ER) positive breast cell lines and primary tumors have significantly higher dormancy signature scores (P<0.0000001) than ER- cell lines and tumors. In addition, a stratified analysis combining all ER+ tumors in four studies indicated 2.1 times higher hazard of recurrence among patients whose tumors had low dormancy scores (LDS) compared to those whose tumors had high dormancy scores (HDS) (p<0.000005). The trend was shown in all four individual studies. Suppression of two dormancy genes, BHLHE41 and NR2F1, resulted in increased in vivo growth of ER positive MCF7 cells. The patient data analysis suggests that disseminated ER positive tumor cells carrying a dormancy signature are more likely to undergo prolonged dormancy before resuming metastatic growth. Furthermore, genes identified with this approach might provide insight into the mechanisms of dormancy onset and maintenance as well as dormancy models using human breast cancer cell lines. PMID:22530051

  5. Molecular apocrine breast cancers are aggressive estrogen receptor negative tumors overexpressing either HER2 or GCDFP15

    PubMed Central

    2013-01-01

    Introduction Molecular apocrine (MA) tumors are estrogen receptor (ER) negative breast cancers characterized by androgen receptor (AR) expression. We analyzed a group of 58 transcriptionally defined MA tumors and proposed a new tool to identify these tumors. Methods We performed quantitative reverse transcription PCR (qRT-PCR) for ESR1, AR, FOXA1 and AR-related genes, and immunohistochemistry (IHC) for ER, PR, Human Epidermal Growth Factor Receptor 2 (HER2), CK5/6, CK17, EGFR, Ki67, AR, FOXA1 and GCDFP15 and we analyzed clinical features. Results MA tumors were all characterized by ESR1(-) AR(+) FOXA1(+) and AR-related genes positive mRNA profile. IHC staining on these tumors showed 93% ER(-), only 58% AR(+) and 90% FOXA1(+). 67% and 57% MA tumors were HER2(3+) and GCDFP15(+), respectively. Almost all MA tumors (94%) had the IHC signature HER2(3+) or GCDFP15(+) but none of the 13 control basal-like (BL) tumors did. Clinically, MA tumors were rather aggressive, with poor prognostic factors. Conclusion MA tumors could be better defined by their qRT-PCR-AR profile than by AR IHC. In addition, we found that HER2 or GCDFP15 protein overexpression is a sensitive and specific tool to differentiate MA from BL in the context of ER negative tumors. A composite molecular and IHC signature could, therefore, help to identify MA tumors in daily practice. PMID:23663520

  6. Expression and prognostic value of estrogen receptor β in patients with triple-negative and triple-positive breast cancer.

    PubMed

    Guo, Liying; Zhu, Qianwen; Aisimutuola, Mulati; Yilamu, Dilimina; Liu, Sha; Jakulin, Adina

    2015-06-01

    The aim of the present study was to investigate the expression of estrogen receptor β (ERβ) in triple-negative and triple-positive breast cancer patients, and evaluate its utility as a prognostic factor. Between January 2000 and December 2010, primary tumor tissue samples were collected from 234 subjects, including 107 triple-negative and 127 triple-positive breast cancer patients. The samples were embedded in paraffin and immunohistochemical staining was conducted to determine the expression levels of ERβ. The Kaplan-Meier method was used to analyze patient survival rates. ERβ expression was observed in 38/107 patients (35.5%) with triple-negative breast cancer and 63/127 patients (49.6%) with triple-positive breast cancer. The ERβ expression rate was significantly decreased in the patients with triple-negative breast cancer, as compared with those with triple-positive breast cancer (P=0.03). Analysis of the survival rates indicated that patients with triple-negative breast cancer and positive ERβ expression exhibited poor disease progression-free survival (DFS) compared with those with negative ERβ expression (P=0.021). However, no statistically significant difference was observed in the DFS between the triple-positive breast cancer patients with positive and negative ERβ expression. Therefore, the expression of ERβ varies between triple-negative and triple-positive breast cancer patients. In addition, positive expression of ERβ indicates a poor prognosis in triple-negative breast cancer patients; however, this is not the case for triple-positive breast cancer patients.

  7. KISS1R induces invasiveness of estrogen receptor-negative human mammary epithelial and breast cancer cells.

    PubMed

    Cvetkovic, Donna; Dragan, Magdalena; Leith, Sean J; Mir, Zuhaib M; Leong, Hon S; Pampillo, Macarena; Lewis, John D; Babwah, Andy V; Bhattacharya, Moshmi

    2013-06-01

    Kisspeptins (KPs), peptide products of the KISS1 metastasis-suppressor gene, are endogenous ligands for a G protein-coupled receptor (KISS1R). KISS1 acts as a metastasis suppressor in numerous human cancers. However, recent studies have demonstrated that an increase in KISS1 and KISS1R expression in patient breast tumors correlates with higher tumor grade and metastatic potential. We have shown that KP-10 stimulates invasion of estrogen receptor α (ERα)-negative MDA-MB-231 breast cancer cells via transactivation of the epidermal growth factor receptor (EGFR). Here, we report that either KP-10 treatment of ERα-negative nonmalignant mammary epithelial MCF10A cells or expression of KISS1R in MCF10A cells induced a mesenchymal phenotype and stimulated invasiveness. Similarly, exogenous expression of KISS1R in ERα-negative SKBR3 breast cancer cells was sufficient to trigger invasion and induced extravasation in vivo. In contrast, KP-10 failed to transactivate EGFR or stimulate invasiveness in the ERα-positive MCF7 and T47D breast cancer cells. This suggested that ERα negatively regulates KISS1R-dependent breast cancer cell migration, invasion, and EGFR transactivation. In support of this, we found that these KP-10-induced effects were ablated upon exogenous expression of ERα in the MDA-MB-231 cells, by down-regulating KISS1R expression. Lastly, we have identified IQGAP1, an actin cytoskeletal binding protein as a novel binding partner of KISS1R, and have shown that KISS1R regulates EGFR transactivation in breast cancer cells in an IQGAP1-dependent manner. Overall, our data strongly suggest that the ERα status of mammary cells dictates whether KISS1R may be a novel clinical target for treating breast cancer metastasis.

  8. Loss of Yes-associated protein (YAP) expression is associated with estrogen and progesterone receptors negativity in invasive breast carcinomas

    PubMed Central

    Tufail, Rozina; Jorda, Mercy; Zhao, Wei; Reis, Isildinha; Nawaz, Zafar

    2011-01-01

    Yes-associated protein (YAP) is a well characterized transcriptional coactivator that interacts with various transcription factors and modulates their transcriptional activities. Phosphorylation of YAP by specific kinases regulates its cellular distribution and transcriptional activation functions. Sequestration of phosphorylated YAP in cytoplasm results in the reduction of transcription from its target genes. Since, YAP has been characterized as a coactivator of estrogen (ER) and progesterone (PR) receptors, we examined the immunohistochemical expression profile of YAP and correlation of YAP expression with that of ER and PR in normal (40 samples) and tumor breast (226 samples) from microarray tissue samples using immunohistochemistry. Here we show that YAP expression is significantly reduced in invasive carcinoma samples compared to normal breast tissues, which express high levels of YAP (YAP was positive for 45.1% of invasive carcinoma samples vs. 82.5% of normal samples p<.0001). Furthermore, our data shows that reduced expression of YAP in invasive carcinoma samples is significantly associated with ER negativity (YAP was negative for 59.9% in ER negative vs. 38.9% in ER positive invasive carcinoma samples, p=0.007) and PR negativity (YAP was negative for 60.1% in PR negative vs. 28.9% in PR positive, p=0.0004). Among invasive carcinoma samples, 42.9% were YAP, ER and PR negative, whereas only 7.5% were found to be YAP, ER and PR positive. On the contrary, 20 out of 23 (87%) normal breast tissues that were positive for ER and PR were also positive for YAP. These data suggest that YAP may act as a tumor suppressor in invasive breast carcinomas and it can also be used as a molecular marker for ER and PR negative breast tumors. PMID:21399893

  9. Location of triple-negative breast cancers: comparison with estrogen receptor-positive breast cancers on MR imaging.

    PubMed

    Kim, Won Hwa; Han, Wonshik; Chang, Jung Min; Cho, Nariya; Park, In Ae; Moon, Woo Kyung

    2015-01-01

    There has been a major need to better understand the biological characteristics of triple-negative breast cancers. Compared with estrogen receptor (ER)-positive cancers, several magnetic resonance (MR) imaging findings have been reported as characteristic findings. However, information regarding their location has not been described. Our study was to compare the location of triple-negative breast cancers with that of ER-positive breast cancers using magnetic resonance (MR) imaging. The locations of 1102 primary breast cancers (256 triple-negative and 846 ER-positive) in 1090 women (mean, 52.1 years) were reviewed using three-dimensional (3D) coordinates. The x-axis measurement was recorded as the transverse distance from the posterior nipple line; y-axis measurement as the anteroposterior distance from the chest wall; z-axis measurement as the superoinferior distance from the posterior nipple line. The association between breast cancer subtype and tumor location was evaluated using multiple linear regression analysis. Triple-negative breast cancers were significantly closer to the chest wall than ER-positive breast cancers in absolute (1.8 cm vs. 2.3 cm, P < .0001) and normalized (0.21 vs. 0.25, P < .0001) y-axis distances. The x- and z-axes distances were not significantly different between triple-negative and ER-positive breast cancers. Multiple linear regression analysis revealed that age, mammographic density, axillary nodal status, and triple-negative subtype were significantly associated with absolute and normalized distances from the chest wall (all P < .05). Our results show that triple-negative breast cancers have a tendency toward a posterior or prepectoral location compared with ER-positive breast cancers.

  10. CSrc and Her2 Signaling Pathways Cooperate With Estrogen to Promote Estrogen Receptor Phosphorylation, Ubiquitination and Proteolysis in ER Negative Breast Cancers

    DTIC Science & Technology

    2005-03-01

    on estradiol. Biochemical and Biophysical Research Communications 213:24-31. 30. Nawaz,Z., Lonard,D.M., Dennis,A.P., Smith,C.L., and O’Malley,B.W...function of estrogen receptor alpha in human breast cancer cells. Biochemical and Biophysical Research Communications 281:259-265. 36. Nawaz,Z., Lonard,D.M

  11. Irradiation of juvenile, but not adult, mammary gland increases stem cell self-renewal and estrogen receptor negative tumors.

    PubMed

    Tang, Jonathan; Fernandez-Garcia, Ignacio; Vijayakumar, Sangeetha; Martinez-Ruis, Haydeliz; Illa-Bochaca, Irineu; Nguyen, David H; Mao, Jian-Hua; Costes, Sylvain V; Barcellos-Hoff, Mary Helen

    2014-03-01

    Children exposed to ionizing radiation have a substantially greater breast cancer risk than adults; the mechanism for this strong age dependence is not known. Here we show that pubertal murine mammary glands exposed to sparsely or densely ionizing radiation exhibit enrichment of mammary stem cell and Notch pathways, increased mammary repopulating activity indicative of more stem cells, and propensity to develop estrogen receptor (ER) negative tumors thought to arise from stem cells. We developed a mammary lineage agent-based model (ABM) to evaluate cell inactivation, self-renewal, or dedifferentiation via epithelial-mesenchymal transition (EMT) as mechanisms by which radiation could increase stem cells. ABM rejected cell inactivation and predicted increased self-renewal would only affect juveniles while dedifferentiation could act in both juveniles and adults. To further test self-renewal versus dedifferentiation, we used the MCF10A human mammary epithelial cell line, which recapitulates ductal morphogenesis in humanized fat pads, undergoes EMT in response to radiation and transforming growth factor β (TGFβ) and contains rare stem-like cells that are Let-7c negative or express both basal and luminal cytokeratins. ABM simulation of population dynamics of double cytokeratin cells supported increased self-renewal in irradiated MCF10A treated with TGFβ. Radiation-induced Notch concomitant with TGFβ was necessary for increased self-renewal of Let-7c negative MCF10A cells but not for EMT, indicating that these are independent processes. Consistent with these data, irradiating adult mice did not increase mammary repopulating activity or ER-negative tumors. These studies suggest that irradiation during puberty transiently increases stem cell self-renewal, which increases susceptibility to developing ER-negative breast cancer.

  12. The CYP1B1_1358_GG genotype is associated with estrogen receptor-negative breast cancer.

    PubMed

    Justenhoven, Christina; Pierl, Christiane B; Haas, Susanne; Fischer, Hans-Peter; Baisch, Christian; Hamann, Ute; Harth, Volker; Pesch, Beate; Brüning, Thomas; Vollmert, Caren; Illig, Thomas; Dippon, Jürgen; Ko, Yon-Dschun; Brauch, Hiltrud

    2008-09-01

    Cytochrome P450 1B1 (CYP1B1) is a major enzyme in the initial catabolic step of estradiol (E2) metabolism and belongs to the multitude of genes regulated by the estrogen receptor alpha (ERalpha). The common non-synonymous polymorphisms CYP1B1_1358_A>G and CYP1B1_1294_C>G increase CYP1B1 enzymatic activity. Given a relationship between CYP1B1 and breast tumor E2 level as well as E2 level and breast tumor ERalpha expression it is of interest to know whether CYP1B1 polymorphisms have an impact on the ERalpha status of breast cancer. We genotyped the GENICA population-based breast cancer case-control collection (1,021 cases, 1,015 controls) by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and investigated in cases the association between genotypes and tumor ERalpha status (739 ERalpha positive cases; 212 ERalpha negative cases) by logistic regression. We observed a significant association between the homozygous variant CYP1B1_1358_GG genotype and negative ERalpha status (P = 0.005; OR 2.82, 95% CI: 1.37-5.82) with a highly significant Ptrend for CYP1B1_1358_A>G and negative ERalpha status (P = 0.003). We also observed an association of CYP1B1_1358_GG and negative PR status (P = 0.015; OR 2.36, 95% CI: 1.18-4.70) and a Ptrend of 0.111 for CYP1B1_1358_A>G and negative progesterone receptor (PR) status. We conclude that the CYP1B1_1358_A>G polymorphism has an impact on ERalpha status in breast cancer in that the CYP1B1_1358_GG genotype known to encode higher CYP1B1 activity is associated with ERalpha negativity.

  13. The nuclear factor kappa B (NF-κB): A potential therapeutic target for estrogen receptor negative breast cancers

    PubMed Central

    Biswas, Debajit K.; Dai, Sun-Chun; Cruz, Antonio; Weiser, Barbara; Graner, Edgard; Pardee, Arthur B.

    2001-01-01

    The effect of a kinase inhibitor Go6796 on growth of epidermal growth factor (EGF)-stimulated estrogen receptor negative (ER−) breast cancer cells in vivo and role of nuclear factor kappa B (NF-κB) on tumorogenesis have been investigated. This was studied in an animal model by implanting ER− mouse mammary epithelial tumor cells (CSMLO) in syngeneic A-J mice. (i) Local administration of Go6976 an inhibitor of protein kinases C alpha and beta inhibited growth of tumors and caused extensive necrotic degeneration and regression of the tumors without causing any microscopically detectable damage to the vital organs liver and lung. (ii) Stable expression of dominant-negative mutants of the beta subunit (dnIkkβ) of the inhibitory kappa B (IκB) kinase (dnIkk) that selectively blocked activation of NF-κB caused loss of tumorigenic potential of CSMLO cells. Stable expression of dnIkkβ also blocked phorbol 12-myristate 13-acetate (PMA)-induced activation of NF-κB and overexpression of cyclin D1, concomitantly with the loss or reduced tumorigenic potential of these cells. Thus, results from in vivo and in vitro experiments strongly suggest the involvement of NF-κB in ER− mammary epithelial cell-mediated tumorigenesis. We propose that blocking NF-κB activation not only inhibits cell proliferation, but also antagonizes the antiapoptotic role of this transcription factor in ER− breast cancer cells. Thus, NF-κB is a potential target for therapy of EGFR family receptor-overexpressing ER− breast cancers. PMID:11517301

  14. Impact of palbociclib combinations on treatment of advanced estrogen receptor-positive/human epidermal growth factor 2-negative breast cancer

    PubMed Central

    Boér, Katalin

    2016-01-01

    Breast cancer is a heterogeneous disease with multiple subgroups based on clinical and molecular characteristics. For the largest subgroup of breast cancers, hormone receptor-positive/human epidermal growth factor 2 (HER2)-negative tumors, hormone treatment is the mainstay of therapy and is likely to result in significant improvement in disease outcomes. However, some of these cancers demonstrate de novo or acquired resistance to endocrine therapy. Despite intensive research to develop new strategies to enhance the efficacy of currently available treatment options for hormone receptor-positive breast cancer, progress has been slow, and there were few advances for a period of 10 years. In 2012, a new molecularly targeted therapeutic strategy, inhibition of mammalian target of rapamycin with everolimus, was introduced into clinical practice. Everolimus, in combination with a steroidal aromatase inhibitor, exemestane, resulted in an increase in progression-free survival, but not overall survival in patients with estrogen receptor (ER)+ve advanced disease who had progressed on hormone therapy. In 2015, the first cyclin-dependent kinases 4/6 (CDK4/6) inhibitor, palbociclib, received accelerated US Food and Drug Administration approval for use in combination with letrozole for the treatment of postmenopausal ER+ve/HER2−ve advanced breast cancer as initial, endocrine-based therapy. The addition of palbociclib to endocrine therapy resulted in longer progression-free survival than letrozole alone. One year later, palbociclib received a new indication, use in combination with fulvestrant, in both premenopausal and postmenopausal females with advanced breast cancer of the same subtype with disease progression following endocrine therapy. Adding palbociclib to fulvestrant resulted in a significantly increased median progression-free survival compared to fulvestrant monotherapy. These new combination regimens of palbociclib with endocrine agents represent an important

  15. Mechanisms for the activity of heterocyclic cyclohexanone curcumin derivatives in estrogen receptor negative human breast cancer cell lines.

    PubMed

    Somers-Edgar, Tiffany J; Taurin, Sebastien; Larsen, Lesley; Chandramouli, Anupama; Nelson, Mark A; Rosengren, Rhonda J

    2011-02-01

    Estrogen receptor (ER)-negative breast cancer is an aggressive form that currently requires more drug treatment options. Thus, we have further modified cyclohexanone derivatives of curcumin and examined them for cytotoxicity towards ER-negative human breast cancer cells. Two of the analogs screened elicited increased cytotoxic potency compared to curcumin and other previously studied derivatives. Specifically, 2,6-bis(pyridin-3-ylmethylene)-cyclohexanone (RL90) and 2,6-bis(pyridin-4-ylmethylene)-cyclohexanone (RL91) elicited EC(50) values of 1.54 and 1.10 µM, respectively, in MDA-MB-231 cells and EC(50) values of 0.51 and 0.23 in SKBr3 cells. All other new compounds examined were less potent than curcumin, which elicited EC(50) values of 7.6 and 2.4 µM in MDA-MB-231 and SKBr3 cells, respectively. Mechanistic analyses demonstrated that RL90 and RL91 significantly induced G(2)/M-phase cell cycle arrest and apoptosis. RL90 and RL91 also modulated the expression of key cell signaling proteins, specifically, in SKBr3 cells, protein levels of Her-2, Akt, and NFκB were decreased in a time-dependent manner, while activity of stress kinases JNK1/2 and P38 MAPK were increased. Signaling events in MDA-MB-231 cells were differently implicated, as EGFR protein levels were decreased and activity of GSK-3β transiently decreased, while β-catenin protein level and activity of P38 MAPK, Akt, and JNK1/2 were transiently increased. In conclusion replacement of the phenyl group of cyclohexanone derived curcumin derivatives with heterocyclic rings forms a class of second-generation analogs that are more potent than both curcumin and other derivatives. These new derivatives provide a platform for the further development of drugs for the treatment of ER-negative breast cancer.

  16. Indispensability of chemotherapy in estrogen receptor-negative early breast cancer in elderly women with diabetes mellitus.

    PubMed

    Jia, Xiaoqing; Hong, Qi; Cheng, Jingyi; Li, Jianwei; Wang, Yujie; Mo, Miao; Shao, Zhimin; Shen, Zhenzhou; Liu, Guangyu

    2015-04-01

    To evaluate whether chemotherapy is indispensable in elderly patients with early estrogen receptor (ER)-negative breast cancer and diabetes mellitus (DM), the data on 112 patients, ≥70 years of age, with early, operable ER-negative breast cancer who were treated at the Cancer Hospital of Fudan University, Shanghai, China, between 2000 and 2010, were analyzed. The overall survival (OS), disease-free survival (DFS), and breast cancer-specific survival (BCS) were compared. Survival analysis was performed using the Kaplan-Meier method. The Cox proportional hazards model was used to evaluate the prognostic value of DM and chemotherapy for OS, DFS, and BCS. The univariate Cox regression analysis revealed that DM at diagnosis, the number of positive lymph nodes, and radiotherapy were associated with OS, the number of positive lymph nodes, human epidermal growth factor 2 (HER2/neu) status, and radiotherapy were associated with DFS, and the number of positive lymph nodes, tumor size, HER2/neu status, chemotherapy, and radiotherapy were associated with BCS. The subsequent multivariate analysis identified DM at diagnosis (hazard ratio [HR]=3.797; 95% confidence interval [CI], 1.515-9.520; P=0.004) as an independent prognostic factor for OS (with the addition of chemotherapy regimen). Chemotherapy was not an independent prognostic factor for either OS (HR=1.275; 95% CI, 0.614-2.646; P=0.515) or DFS (HR=0.849; 95% CI, 0.445-1.619; P=0.619) when other possible factors that may affect the results were adjusted. In conclusion, chemotherapy was not found to be indispensable for elderly (≥70 years of age) female patients with early ER-negative breast cancer with DM because, particularly in such patients, the treatment of DM may be more important compared with chemotherapy.

  17. The Circadian Rhythm Gene Arntl2 Is a Metastasis Susceptibility Gene for Estrogen Receptor-Negative Breast Cancer

    PubMed Central

    Ha, Ngoc-Han; Long, Jirong; Cai, Qiuyin; Shu, Xiao Ou

    2016-01-01

    Breast cancer mortality is primarily due to metastasis rather than primary tumors, yet relatively little is understood regarding the etiology of metastatic breast cancer. Previously, using a mouse genetics approach, we demonstrated that inherited germline polymorphisms contribute to metastatic disease, and that these single nucleotide polymorphisms (SNPs) could be used to predict outcome in breast cancer patients. In this study, a backcross between a highly metastatic (FVB/NJ) and low metastatic (MOLF/EiJ) mouse strain identified Arntl2, a gene encoding a circadian rhythm transcription factor, as a metastasis susceptibility gene associated with progression, specifically in estrogen receptor-negative breast cancer patients. Integrated whole genome sequence analysis with DNase hypersensitivity sites reveals SNPs in the predicted promoter of Arntl2. Using CRISPR/Cas9-mediated substitution of the MOLF promoter, we demonstrate that the SNPs regulate Arntl2 transcription and affect metastatic burden. Finally, analysis of SNPs associated with ARNTL2 expression in human breast cancer patients revealed reproducible associations of ARNTL2 expression quantitative trait loci (eQTL) SNPs with disease-free survival, consistent with the mouse studies. PMID:27656887

  18. Biologic Roles of Estrogen Receptor-β and Insulin-Like Growth Factor-2 in Triple-Negative Breast Cancer

    PubMed Central

    Elshimali, Yahya; Garbán, Hermes; Elashoff, David; Vadgama, Jaydutt; Goodglick, Lee

    2015-01-01

    Triple-negative breast cancer (TNBC) occurs in 10–15% of patients yet accounts for almost half of all breast cancer deaths. TNBCs lack expression of estrogen and progesterone receptors and HER-2 overexpression and cannot be treated with current targeted therapies. TNBCs often occur in African American and younger women. Although initially responsive to some chemotherapies, TNBCs tend to relapse and metastasize. Thus, it is critical to find new therapeutic targets. A second ER gene product, termed ERβ, in the absence of ERα may be such a target. Using human TNBC specimens with known clinical outcomes to assess ERβ expression, we find that ERβ1 associates with significantly worse 5-year overall survival. Further, a panel of TNBC cell lines exhibit significant levels of ERβ protein. To assess ERβ effects on proliferation, ERβ expression in TNBC cells was silenced using shRNA, resulting in a significant reduction in TNBC proliferation. ERβ-specific antagonists similarly suppressed TNBC growth. Growth-stimulating effects of ERβ may be due in part to downstream actions that promote VEGF, amphiregulin, and Wnt-10b secretion, other factors associated with tumor promotion. In vivo, insulin-like growth factor-2 (IGF-2), along with ERβ1, is significantly expressed in TNBC and stimulates high ERβ mRNA in TNBC cells. This work may help elucidate the interplay of metabolic and growth factors in TNBC. PMID:25874233

  19. A novel curcumin derivative increases the cytotoxicity of raloxifene in estrogen receptor-negative breast cancer cell lines.

    PubMed

    Taurin, Sebastien; Nimick, Mhairi; Larsen, Lesley; Rosengren, Rhonda J

    2016-01-01

    There is a need for new, safe and efficacious drug therapies for the treatment of estrogen receptor (ER)-negative breast cancers. Raloxifene and the 2nd generation curcumin derivative 2,6-bis(pyridin-4-ylmethylene)-cyclohexanone (RL91) have been shown to inhibit the growth of ER-negative breast cancer cells in vitro and in vivo. We investigated whether RL91 could enhance the growth-suppressive effects mediated by raloxifene in MDA-MB-231, MDA-MB-468, Hs578t and SkBr3 human breast cancer cell lines. The cytotoxicity was consistent across the cell lines but RL91 was more potent. EC50 values for RL91 were 1.2-2 µM while EC50 values for raloxifene were 9.6-11.2 µM. When the cells were treated with raloxifene (15 µM), RL91 (1 µM) or a combination of the two for 6-72 h, the combination treatment consistently elicited significantly greater cytotoxicity compared to all other treatments. In SkBr3 cells the combination treatment caused significantly more cells to undergo G1 arrest compared to raloxifene. In all cell lines apoptosis was synergistically induced by the combination treatment, as shown by both flow cytometery and cleaved caspase-3. Furthermore, the stress kinase p38 was increased and EFGR isoforms were decreased by both raloxifene and raloxifene + RL91. The anti-angiogenic anti-metastatic potential of raloxifene was not increased by RL91, as MDA-MB-231 cell migration and invasion as well as endothelial tube formation by HUVEC cells was not different between raloxifene (10 µM) and the combination of raloxifene + RL91. Thus, our findings provide evidence that RL91 increases the ability of raloxifene to suppress ER-negative cancer cell growth by increasing the number of apoptotic cells. The broad effect of this drug combination across a range of ER-negative breast cancer cell lines indicates that this drug combination should be explored further in order to find a safe and efficacious therapy for ER-negative breast cancer.

  20. Expression of sarcosine metabolism-related proteins in estrogen receptor negative breast cancer according to the androgen receptor and HER-2 status

    PubMed Central

    Kim, Min Ju; Jung, Woo Hee; Koo, Ja Seung

    2015-01-01

    The aim of this study is to investigate the expression of sarcosine metabolism related proteins according to androgen receptor (AR) and HER-2 status in estrogen receptor (ER) negative breast cancer and to analyze its clinical implications. Tissue microarray was constructed for a total of 334 cases of ER negative breast cancer. Immunohistochemical stain was conducted for sarcosine metabolism related proteins such as glycine N-methyltransferase (GNMT), sarcosine dehydrogenase (SARDH), and l-pipecolic acid oxidase (PIPOX). There were 131 AR positive, 205 AR negative cases and 143 HER-2 positive, 193 HER-2 negative cases. When subdividing into four groups according to AR and HER-2 status, there were 55 AR(+)/HER-2(-) cases, 76 AR(+)/HER-2(+) cases, 67 AR(-)/HER-2(+) cases and 138 AR(-)/HER-2(-) cases. GNMT and PIPOX expression was highest in the AR(+)/HER-2(-) group while expressed lowest in the AR(-)/HER-2(-) group (P<0.001). Stromal PIPOX expression was highest in the AR(-)/HER-2(+) group and lowest in the AR(-)/HER-2(-) group (P=0.010). GNMT and PIPOX expression was higher in the AR positive group compared with those of AR negative group (P=0.001, and P<0.001, respectively), while tumoral and stromal PIPOX expression showed a significant association with HER-2 positivity (P=0.006, and P=0.005, respectively). AR positive group had the highest ratio of low sarcosine type while the AR negative group had the highest ratio of null type (P<0.001). In conclusion, ER negative breast cancer showed different expression of sarcosine metabolism related proteins according to AR and HER-2 status. GNMT and PIPOX expression was high in the AR positive group while tumoral and stromal PIPOX expression was high in the HER-2 positive group. PMID:26339363

  1. Estrogen receptors in breast carcinoma.

    PubMed

    Huaman, A

    1979-11-01

    On the basis of estrogen receptor assays, breast carcinomas are presently classified as estrogen-dependent tumors, which respond to endocrine therapy, and autonomous tumors, for which endocrine therapy is useless. This paper presents a short review of the biochemical principles of estrogen dependence, the procedures used to determine estrogen receptors, and the clinical applications of the findings of these assay procedures. Biobhemically, the estroogen dependence of normal breast cells is explained as a biochemical reaction occurring between the circulating estradiol and the breast cell, which occurs in 3 steps: 1) circulating estradiol penetrates the cellular membrane by passive diffusion, followed by 2) combining of estradiol with the estrogen-binding protein (estrophilin) and formation of an estrogen receptor complex which undergoes activation and translocation into the nucleus, to result in 3) the activated steroid receptor which combines with the nuclear charomatin and stimulates ribonucleic acid synthesis for the formation of estradiol binding proteins or estradiol receptors. The cytosol method of Wittliff et al. is described in brief and entails radioactive competitive analysis; the other available laboratory procedure is immunofluorescence of tumor sections. Quantification of estrogen receptor content can be used clinically to decide on ablative endocrine therapy, to determine the effectiveness of anti-estrogen administration, to determine the primary site of metastatic carcinoma, and as a screenng device.

  2. CpG island methylation profile of estrogen receptor alpha in Iranian females with triple negative or non-triple negative breast cancer: new marker of poor prognosis.

    PubMed

    Ramezani, Fatemeh; Salami, Siamak; Omrani, Mir Davood; Maleki, Davood

    2012-01-01

    One decade early onset of the breast cancer in Iranian females was reported but the basis of the observed difference has remained unclear and difference in gene silencing by epigenetic processes is suggested. Hence, this study was sought to map the methylation status of ER gene CpG islands and its impact on clinicopathological factors of triple negative and non-triple negative ductal cell carcinoma of the breast in Iranian females. Surgically resected formalin-fixed paraffin-embedded breast tissues from sixty Iranian women with confirmed invasive ductal carcinoma were assessed by methylation-specific PCR using primer sets encompassing some of the 29 CpGs across the ER gene CpG island. The estrogen and progesterone receptors, Her-2 overexpression, and nuclear accumulation of P53 were examined using immunohistochemistry (IHC). Methylated ER3, ER4, and ER5 were found in 41.7, 11.3, and 43.3% of the samples, respectively. Significantly higher methylation of ER4 was found in the tumors with nuclear accumulation of P53, and significantly higher methylation of ER5 was found in patients with lymph node involvement and tumor with bigger size or higher grades. Furthermore, significantly higher rate of ER5 methylation was found in patients with Her-2+ tumors and in postmenopausal patients with ER-, PgR-, or ER-/PgR- tumors. However, no significant difference in ERs methylation status was found between triple negative and non-triple negative tumors in pre- and postmenopausal patients. Findings revealed that aberrant hypermethylation of ER-a gene frequently occur in Iranian women with invasive ductal cell carcinoma of the breast. However, methylation of different CpG islands produced a diverse impact on the prognosis of breast cancer, and ER5 was found to be the most frequently methylated region in the Iranian women, and could serve as a marker of poor prognosis.

  3. 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

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

    PubMed

    Zhao, Xiao-Dan; Dong, Ni; Man, Hong-Tao; Fu, Zhong-Lin; Zhang, Mei-Hong; Kou, Shuang; Ma, Shi-Liang

    2013-09-01

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

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

    PubMed Central

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

    2013-01-01

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

  6. 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

  7. Identification of Potential Glycoprotein Biomarkers in Estrogen Receptor Positive (ER+) and Negative (ER-) Human Breast Cancer Tissues by LC-LTQ/FT-ICR Mass Spectrometry

    PubMed Central

    Semaan, Suzan M.; Wang, Xu; Marshall, Alan G.; Sang, Qing-Xiang Amy

    2012-01-01

    Breast cancer is the second most fatal cancer in American women. To increase the life expectancy of patients with breast cancer new diagnostic and prognostic biomarkers and drug targets must be identified. A change in the glycosylation on a glycoprotein often causes a change in the function of that glycoprotein; such a phenomenon is correlated with cancerous transformation. Thus, glycoproteins in human breast cancer estrogen receptor positive (ER+) tissues and those in the more advanced stage of breast cancer, estrogen receptor negative (ER-) tissues, were compared. Glycoproteins showing differences in glycosylation were examined by 2-dimensional gel electrophoresis with double staining (glyco- and total protein staining) and identified by reversed-phase nano-liquid chromatography coupled with a hybrid linear quadrupole ion trap/ Fourier transform ion cyclotron resonance mass spectrometer. Among the identified glycosylated proteins are alpha 1 acid glycoprotein, alpha-1-antitrypsin, calmodulin, and superoxide dismutase mitochondrial precursor that were further verified by Western blotting for both ER+ and ER- human breast tissues. Results show the presence of a possible glycosylation difference in alpha-1-antitrypsin, a potential tumor-derived biomarker for breast cancer progression, which was expressed highest in the ER- samples. PMID:22773931

  8. Estrogen/Progesterone Receptor Negativity and HER2 Positivity Predict Locoregional Recurrence in Patients With T1a,bN0 Breast Cancer

    SciTech Connect

    Albert, Jeffrey M.; Gonzalez-Angulo, Ana M.; Guray, Merih; Sahin, Aysegul

    2010-08-01

    Purpose: Data have suggested that the molecular features of breast cancer are important determinants of outcome; however, few studies have correlated these features with locoregional recurrence (LRR). In the present study, we evaluated estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) as predictors of LRR in patients with lymph node-negative disease and tumors {<=}1 cm, because these patients often do not receive adjuvant chemotherapy or trastuzumab. Methods and Materials: The data from 911 patients with stage T1a,bN0 breast cancer who had received definitive treatment at our institution between 1997 and 2002 were retrospectively reviewed. We prospectively analyzed ER/PR/HER2 expression from the archival tissue blocks of 756 patients. These 756 patients represented the cohort for the present study. Results: With a median follow-up of 6.0 years, the 5- and 8-year Kaplan-Meier LRR rate was 1.6% and 5.9%, respectively, with no difference noted in those who underwent breast conservation therapy vs. mastectomy (p = .347). The 8-year LRR rates were greater in the patients with ER-negative (10.6% vs. 4.2%, p = .016), PR-negative (9.0% vs. 4.2%, p = .009), or HER2-positive (17.5% vs. 3.9%, p = 0.009) tumors. On multivariate analysis, ER-negative and PR-negative disease (hazard ratio, 2.37; p = .046) and HER2-positive disease (hazard ratio, 3.13, p = .016) independently predicted for LRR. Conclusion: Patients with ER/PR-negative or HER2-positive T1a,bN0 breast cancer had a greater risk of LRR. Therapeutic strategies, such as the use of chemotherapy and/or anti-HER2 therapies, should be considered for future clinical trials for these patients.

  9. Antineoplastic effects of α-santalol on estrogen receptor-positive and estrogen receptor-negative breast cancer cells through cell cycle arrest at G2/M phase and induction of apoptosis.

    PubMed

    Santha, Sreevidya; Bommareddy, Ajay; Rule, Brittny; Guillermo, Ruth; Kaushik, Radhey S; Young, Alan; Dwivedi, Chandradhar

    2013-01-01

    Anticancer efficacy and the mechanism of action of α-santalol, a terpenoid isolated from sandalwood oil, were investigated in human breast cancer cells by using p53 wild-type MCF-7 cells as a model for estrogen receptor (ER)-positive and p53 mutated MDA-MB-231 cells as a model for ER-negative breast cancer. α-Santalol inhibited cell viability and proliferation in a concentration and time-dependent manner in both cells regardless of their ER and/or p53 status. However, α-santalol produced relatively less toxic effect on normal breast epithelial cell line, MCF-10A. It induced G2/M cell cycle arrest and apoptosis in both MCF-7 and MDA-MB-231 cells. Cell cycle arrest induced by α-santalol was associated with changes in the protein levels of BRCA1, Chk1, G2/M regulatory cyclins, Cyclin dependent kinases (CDKs), Cell division cycle 25B (Cdc25B), Cdc25C and Ser-216 phosphorylation of Cdc25C. An up-regulated expression of CDK inhibitor p21 along with suppressed expression of mutated p53 was observed in MDA-MB-231 cells treated with α-santalol. On the contrary, α-santalol did not increase the expression of wild-type p53 and p21 in MCF-7 cells. In addition, α-santalol induced extrinsic and intrinsic pathways of apoptosis in both cells with activation of caspase-8 and caspase-9. It led to the activation of the executioner caspase-6 and caspase-7 in α-santalol-treated MCF-7 cells and caspase-3 and caspase-6 in MDA-MB-231 cells along with strong cleavage of poly(ADP-ribose) polymerase (PARP) in both cells. Taken together, this study for the first time identified strong anti-neoplastic effects of α-santalol against both ER-positive and ER-negative breast cancer cells.

  10. GWAS in the SIGNAL/PHARE clinical cohort restricts the association between the FGFR2 locus and estrogen receptor status to HER2-negative breast cancer patients.

    PubMed

    Cox, David G; Curtit, Elsa; Romieu, Gilles; Fumoleau, Pierre; Rios, Maria; Bonnefoi, Hervé; Bachelot, Thomas; Soulié, Patrick; Jouannaud, Christelle; Bourgeois, Hugues; Petit, Thierry; Tennevet, Isabelle; Assouline, David; Mathieu, Marie-Christine; Jacquin, Jean-Philippe; Lavau-Denes, Sandrine; Darut-Jouve, Ariane; Ferrero, Jean-Marc; Tarpin, Carole; Lévy, Christelle; Delecroix, Valérie; Trillet-Lenoir, Véronique; Cojocarasu, Oana; Meunier, Jérôme; Pierga, Jean-Yves; Faure-Mercier, Céline; Blanché, Hélène; Sahbatou, Mourad; Boland, Anne; Bacq, Delphine; Besse, Céline; Deleuze, Jean-François; Pauporté, Iris; Thomas, Gilles; Pivot, Xavier

    2016-11-22

    Genetic polymorphisms are associated with breast cancer risk. Clinical and epidemiological observations suggest that clinical characteristics of breast cancer, such as estrogen receptor or HER2 status, are also influenced by hereditary factors. To identify genetic variants associated with pathological characteristics of breast cancer patients, a Genome Wide Association Study was performed in a cohort of 9365 women from the French nationwide SIGNAL/PHARE studies (NCT00381901/RECF1098). Strong association between the FGFR2 locus and ER status of breast cancer patients was observed (ER-positive n=6211, ER-negative n=2516; rs3135718 OR=1.34 p=5.46×10-12). This association was limited to patients with HER2-negative tumors (ER-positive n=4267, ER-negative n=1185; rs3135724 OR=1.85 p=1.16×10-11). The FGFR2 locus is known to be associated with breast cancer risk. This study provides sound evidence for an association between variants in the FGFR2 locus and ER status among breast cancer patients, particularly among patients with HER2-negative disease. This refinement of the association between FGFR2 variants and ER-status to HER2-negative disease provides novel insight to potential biological and clinical influence of genetic polymorphisms on breast tumors.

  11. GWAS in the SIGNAL/PHARE clinical cohort restricts the association between the FGFR2 locus and estrogen receptor status to HER2-negative breast cancer patients

    PubMed Central

    Cox, David G.; Curtit, Elsa; Romieu, Gilles; Fumoleau, Pierre; Rios, Maria; Bonnefoi, Hervé; Bachelot, Thomas; Soulié, Patrick; Jouannaud, Christelle; Bourgeois, Hugues; Petit, Thierry; Tennevet, Isabelle; Assouline, David; Mathieu, Marie-Christine; Jacquin, Jean-Philippe; Lavau-Denes, Sandrine; Darut-Jouve, Ariane; Ferrero, Jean-Marc; Tarpin, Carole; Lévy, Christelle; Delecroix, Valérie; Trillet-Lenoir, Véronique; Cojocarasu, Oana; Meunier, Jérôme; Pierga, Jean-Yves; Faure-Mercier, Céline; Blanché, Hélène; Sahbatou, Mourad; Boland, Anne; Bacq, Delphine; Besse, Céline; Deleuze, Jean-François; Pauporté, Iris; Thomas, Gilles; Pivot, Xavier

    2016-01-01

    Genetic polymorphisms are associated with breast cancer risk. Clinical and epidemiological observations suggest that clinical characteristics of breast cancer, such as estrogen receptor or HER2 status, are also influenced by hereditary factors. To identify genetic variants associated with pathological characteristics of breast cancer patients, a Genome Wide Association Study was performed in a cohort of 9365 women from the French nationwide SIGNAL/PHARE studies (NCT00381901/RECF1098). Strong association between the FGFR2 locus and ER status of breast cancer patients was observed (ER-positive n=6211, ER-negative n=2516; rs3135718 OR=1.34 p=5.46×10−12). This association was limited to patients with HER2-negative tumors (ER-positive n=4267, ER-negative n=1185; rs3135724 OR=1.85 p=1.16×10−11). The FGFR2 locus is known to be associated with breast cancer risk. This study provides sound evidence for an association between variants in the FGFR2 locus and ER status among breast cancer patients, particularly among patients with HER2-negative disease. This refinement of the association between FGFR2 variants and ER-status to HER2-negative disease provides novel insight to potential biological and clinical influence of genetic polymorphisms on breast tumors. PMID:27764800

  12. Does androgen receptor have a prognostic role in patients with estrogen/progesterone-negative and c-erbB-2-positive breast cancer?

    PubMed

    Arslan, Cagatay; Isik, Metin; Guler, Gulnur; Kulac, Ibrahim; Solak, Mustafa; Turker, Burcu; Ozisik, Yavuz; Altundag, Kadri

    2012-09-01

    Recently, it has been shown that androgen and androgen receptor (AR) also have an important role in the pathogenesis and outcome of breast cancer. However, their significance in different subtypes of breast cancer is still under investigation. The aim of this study was to study the effects of AR on clinicopathological features and prognosis in patients with estrogen and progesterone receptor (ER/PR)-negative, HER2-positive breast cancer. Tumor paraffin-embedded blocks from archives were used for AR study. Data of patients with ER/PR-negative and HER2-positive breast cancer diagnosed at our institute between 1999 and 2010 were recorded and analyzed retrospectively. We studied 36 patients with ER/PR-negative and HER2-positive breast cancer for AR status. Sixteen of them (44.4%) showed AR positivity. The median age was 47 and 56 years for AR-negative and -positive patients, respectively (P = 0.03). The number of postmenopausal patients was higher in the AR-positive than -negative group (56 vs 30%) (P = 0.01). Other demographic data were similar in both group. Histopathological parameters and tumor and nodal stages were similar in both groups. Trastuzumab treatment was more frequently given to AR-positive than -negative patients (94 vs 44%) (P = 0.01). Median follow-up was 47.1 and 34.7 months in AR-negative and -positive groups, respectively (P = 0.03). Relapse occurred in six and four patients in AR-negative and -positive groups. Median progression-free survival (PFS) was similar in both groups (15.7 and 19.6 months in AR-negative and -positive patients, respectively; P = 0.56). Two patients died at 23.4 and 46 months of follow-up in the AR-negative group. There were no deaths in the AR-positive group. Overall survival analyses were not done as a result of an unmet number of events. Median PFS was similar in AR-positive and -negative in that group of patients with ER/PR-negative and HER2-positive breast cancer. However AR-positive patients were more frequently

  13. Kruppel-like Factor 9 is a Negative Regulator of Ligand-dependent Estrogen Receptor Alpha Signaling in Ishikawa Endometrial Adenocarcinoma Cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Estrogen (E) and progesterone (P), acting through their respective receptors and other nuclear proteins, exhibit opposing activities in target cells. We previously reported that Krüppel-like factor 9 (KLF9) cooperates with progesterone receptor (PR) to facilitate P-dependent gene transcription in ut...

  14. A Phase II Study Evaluating the Role of Androgen Receptors as Targets for Therapy of Pre-treated Post-menopausal Patients With ER/PgR-negative/AR-positive or ER and/or PgRpositive/ AR-positive Metastatic Breast Cancer (ARTT)

    ClinicalTrials.gov

    2016-09-28

    Metastatic Breastcancer; Estrogen Receptor Positive Breast Cancer; Estrogen Receptor Negative Neoplasm; Progesterone Receptor Positive Tumor; Progesterone Receptor Negative Neoplasm; Androgen Receptor Gene Overexpression

  15. Caffeic Acid Phenethyl Ester Increases Radiosensitivity of Estrogen Receptor-Positive and -Negative Breast Cancer Cells by Prolonging Radiation-Induced DNA Damage

    PubMed Central

    Khoram, Nastaran Masoudi; Bigdeli, Bahareh; Nikoofar, Alireza

    2016-01-01

    Purpose Breast cancer is an important cause of death among women. The development of radioresistance in breast cancer leads to recurrence after radiotherapy. Caffeic acid phenethyl ester (CAPE), a polyphenolic compound of honeybee propolis, is known to have anticancer properties. In this study, we examined whether CAPE enhanced the radiation sensitivity of MDA-MB-231 (estrogen receptor-negative) and T47D (estrogen receptor-positive) cell lines. Methods The cytotoxic effect of CAPE on MDA-MB-231 and T47D breast cancer cells was evaluated by performing an 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay. To assess clonogenic ability, MDA-MB-231 and T47D cells were treated with CAPE (1 µM) for 72 hours before irradiation, and then, a colony assay was performed. A comet assay was used to determine the number of DNA strand breaks at four different times. Results CAPE decreased the viability of both cell lines in a dose- and time-dependent manner. In the clonogenic assay, pretreatment of cells with CAPE before irradiation significantly reduced the surviving fraction of MDA-MB-231 cells at doses of 6 and 8 Gy. A reduction in the surviving fraction of T47D cells was observed relative to MDA-MB-231 at lower doses of radiation. Additionally, CAPE maintained radiation-induced DNA damage in T47D cells for a longer period than in MDA-MB-231 cells. Conclusion Our results indicate that CAPE impairs DNA damage repair immediately after irradiation. The induction of radiosensitivity by CAPE in radioresistant breast cancer cells may be caused by prolonged DNA damage. PMID:27066092

  16. Targeting of interleukin (IL)-17A inhibits PDL1 expression in tumor cells and induces anticancer immunity in an estrogen receptor-negative murine model of breast cancer.

    PubMed

    Ma, Yun-Feng; Chen, Chen; Li, Dongqing; Liu, Min; Lv, Zhuang-Wei; Ji, Yanhong; Xu, Jiru

    2017-01-31

    The expression of IL-17A and programmed death ligand 1 (PDL1) is increased in estrogen receptor-negative breast cancer. IL-17A promotes tumor cell survival and invasiveness and inhibits the antitumor immune response. The PDL1-PD1 (programmed death protein 1) signaling pathway promotes escape from immune surveillance in tumor cells. The pro-tumor properties of IL-17A and PDL1 in various cancers have been previously examined; however, the relationship and roles of IL-17A and PDL1 in ER-negative breast cancer have not been evaluated. Therefore, we assessed whether IL-17A promotes PDL1 expression in tumor cells and whether targeting of IL-17A could inhibit ER-negative breast cancer progression in a murine model. Our study revealed that IL-17A promoted PDL1 expression in human and mouse cells. In the murine cancer model, targeting of IL-17A inhibited PDL1 expression in the tumor microenvironment, decreased the percentage of Treg cells in tumor-infiltrating lymphocytes, and promoted CD4+ and CD8+ T cells to secrete interferon gamma. More importantly, treatment with combined anti-IL-17A and anti-PDL1 antibodies enhanced antitumor effects in favor of tumor eradication. Thus, our study established a pro-tumor role of IL-17A in promoting tumor immune escape and supports the development of a novel cytokine immunotherapy against breast cancer.

  17. Impact of suppression of tumorigenicity 14 (ST14)/serine protease 14 (Prss14) expression analysis on the prognosis and management of estrogen receptor negative breast cancer

    PubMed Central

    Kim, Sauryang; Yang, Jae Woong; Kim, Chungho; Kim, Moon Gyo

    2016-01-01

    To elucidate the role of a type II transmembrane serine protease, ST14/Prss14, during breast cancer progression, we utilized publically accessible databases including TCGA, GEO, NCI-60, and CCLE. Survival of breast cancer patients with high ST14/Prss14 expression is significantly poor in estrogen receptor (ER) negative populations regardless of the ratios of ST14/Prss14 to its inhibitors, SPINT1 or SPINT2. In a clustering of 1085 selected EMT signature genes, ST14/Prss14 is located in the same cluster with CDH3, and closer to post-EMT markers, CDH2, VIM, and FN1 than to the pre-EMT marker, CDH1. Coexpression analyses of known ST14/Prss14 substrates and transcription factors revealed context dependent action. In cell lines, paradoxically, ST14/Prss14 expression is higher in the ER positive group and located closer to CDH1 in clustering. This apparent contradiction is not likely due to ST14/Prss14 expression in a cancer microenvironment, nor due to negative regulation by ER. Genes consistently coexpressed with ST14/Prss14 include transcription factors, ELF5, GRHL1, VGLL1, suggesting currently unknown mechanisms for regulation. Here, we report that ST14/Prss14 is an emerging therapeutic target for breast cancer where HER2 is not applicable. In addition we suggest that careful conclusions should be drawn not exclusively from the cell line studies for target development. PMID:27167193

  18. Synergistic epigenetic reactivation of estrogen receptor-α (ERα) by combined green tea polyphenol and histone deacetylase inhibitor in ERα-negative breast cancer cells

    PubMed Central

    2010-01-01

    Background The status of estrogen receptor-α (ERα) is critical to the clinical prognosis and therapeutic approach in breast cancer. ERα-negative breast cancer is clinically aggressive and has a poor prognosis because of the lack of hormone target-directed therapies. Previous studies have shown that epigenetic regulation plays a major role in ERα silencing in human breast cancer cells. Dietary green tea polyphenol, (-)-epigallocatechin-3-gallate (EGCG), is believed to be an anticancer agent in part through its regulation of epigenetic processes. Results In our current studies, we found that EGCG can reactivate ERα expression in ERα-negative MDA-MB-231 breast cancer cells. Combination studies using EGCG with the histone deacetylase (HDAC) inhibitor, trichostatin A (TSA), revealed a synergistic effect of reactivation of ERα expression in ERα-negative breast cancer cells. Reactivation of ERα expression by EGCG and TSA treatment was found to sensitize ERα-dependent cellular responses to activator 17β-estradiol (E2) and antagonist tamoxifen in ERα-negative breast cancer cells. We also found that EGCG can lead to remodeling of the chromatin structure of the ERα promoter by altering histone acetylation and methylation status thereby resulting in ERα reactivation. A decreased binding of the transcription repressor complex, Rb/p130-E2F4/5-HDAC1-SUV39H1-DNMT1, in the regulatory region of the ERα promoter also contributes to ERα transcriptional activation through treatment with EGCG and/or TSA. Conclusions Collectively, these studies show that green tea EGCG can restore ERα expression by regulating epigenetic mechanisms, and this effect is enhanced when combined with an HDAC inhibitor. This study will facilitate more effective uses of combination approaches in breast cancer therapy and will help to explore more effective chemotherapeutic strategies toward hormone-resistant breast cancer. PMID:20946668

  19. From Breast Cancer to Antimicrobial: Combating Extremely Resistant Gram-Negative "Superbugs" Using Novel Combinations of Polymyxin B with Selective Estrogen Receptor Modulators.

    PubMed

    Hussein, Maytham H; Schneider, Elena K; Elliott, Alysha G; Han, Meiling; Reyes-Ortega, Felisa; Morris, Faye; Blastovich, Mark A T; Jasim, Raad; Currie, Bart; Mayo, Mark; Baker, Mark; Cooper, Matthew A; Li, Jian; Velkov, Tony

    2016-12-09

    Novel therapeutic approaches are urgently needed to combat nosocomial infections caused by extremely drug-resistant (XDR) "superbugs." This study aimed to investigate the synergistic antibacterial activity of polymyxin B in combination with selective estrogen receptor modulators (SERMs) against problematic Gram-negative pathogens. In vitro synergistic antibacterial activity of polymyxin B and the SERMs tamoxifen, raloxifene, and toremifene was assessed using the microdilution checkerboard and static time-kill assays against a panel of Gram-negative isolates. Polymyxin B and the SERMs were ineffective when used as monotherapy against polymyxin-resistant minimum inhibitory concentration ([MIC] ≥8 mg/L) Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii. However, when used in combination, clinically relevant concentrations of polymyxin B and SERMs displayed synergistic killing against the polymyxin-resistant P. aeruginosa, K. pneumoniae, and A. baumannii isolates as demonstrated by a ≥2-3 log10 decrease in bacterial count (CFU/ml) after 24 hours. The combination of polymyxin B with toremifene demonstrated very potent antibacterial activity against P. aeruginosa biofilms in an artificial sputum media assay. Moreover, polymyxin B combined with toremifene synergistically induced cytosolic green fluorescence protein release, cytoplasmic membrane depolarization, permeabilizing activity in a nitrocefin assay, and an increase of cellular reactive oxygen species from P. aeruginosa cells. In addition, scanning and transmission electron micrographs showed that polymyxin B in combination with toremifene causes distinctive damage to the outer membrane of P. aeruginosa cells, compared with treatments with each compound per se. In conclusion, the combination of polymyxin B and SERMs illustrated a synergistic activity against XDR Gram-negative pathogens, including highly polymyxin-resistant P. aeruginosa isolates, and represents a novel combination

  20. Toll-like receptor 4 as a predictor of clinical outcomes of estrogen receptor-negative breast cancer in Saudi women.

    PubMed

    Semlali, Abdelhabib; Jalouli, Maroua; Parine, Narasimha Reddy; Al Amri, Abdullah; Arafah, Maha; Al Naeem, Abdulrahman; Abdullah Ajaj, Sanaa; Rouabhia, Mahmoud; Alanazi, Mohammad Saud

    2017-01-01

    The aim of this study was to investigate the association of the common polymorphisms of Toll-like receptor 4 (TLR-4) with breast cancer development in the Saudi Arabian population. Four TLR-4 polymorphisms (rs2770150, rs10759931, rs10759932, and rs4986790) were studied using 127 breast cancer patients and 117 controls. Relative expression of TLR-4 protein in the breast tumor and the matched normal breast tissues was determined in a large cohort of 70 clinical breast samples in a tissue micro-array format by immunohistochemistry using a specific anti-TLR-4 antibody. Our results demonstrated an increase in TLR-4 expression in estrogen receptor (ER)-, postmenopausal breast cancer patients compared to normal. We also demonstrated that the G allele of single-nucleotide polymorphism rs10759931 was found to be significantly higher in frequency among patients (36.3%) compared to the control group (26.7%), suggesting that this polymorphism is strongly associated with the development of breast cancer in this ethnic population. In addition, the TLR-4 polymorphism rs2770150 was shown to be highly correlated with breast cancer in patients over 48 years of age. The TLR-4 polymorphism rs4986790 was also found to be associated with this malignancy in the ER- patient groups. Our results suggested firstly that the variation in TLR-4 gene expression may influence breast cancer development and secondly a closely linked association between TLR-4 gene polymorphism and ER status. Our study provides support for a better understanding of the implication of TLR-4 polymorphism in breast tumorigenesis and for its eventual use as a cancer biomarker.

  1. Toll-like receptor 4 as a predictor of clinical outcomes of estrogen receptor-negative breast cancer in Saudi women

    PubMed Central

    Semlali, Abdelhabib; Jalouli, Maroua; Parine, Narasimha Reddy; Al Amri, Abdullah; Arafah, Maha; Al Naeem, Abdulrahman; Abdullah Ajaj, Sanaa; Rouabhia, Mahmoud; Alanazi, Mohammad Saud

    2017-01-01

    The aim of this study was to investigate the association of the common polymorphisms of Toll-like receptor 4 (TLR-4) with breast cancer development in the Saudi Arabian population. Four TLR-4 polymorphisms (rs2770150, rs10759931, rs10759932, and rs4986790) were studied using 127 breast cancer patients and 117 controls. Relative expression of TLR-4 protein in the breast tumor and the matched normal breast tissues was determined in a large cohort of 70 clinical breast samples in a tissue micro-array format by immunohistochemistry using a specific anti-TLR-4 antibody. Our results demonstrated an increase in TLR-4 expression in estrogen receptor (ER)−, postmenopausal breast cancer patients compared to normal. We also demonstrated that the G allele of single-nucleotide polymorphism rs10759931 was found to be significantly higher in frequency among patients (36.3%) compared to the control group (26.7%), suggesting that this polymorphism is strongly associated with the development of breast cancer in this ethnic population. In addition, the TLR-4 polymorphism rs2770150 was shown to be highly correlated with breast cancer in patients over 48 years of age. The TLR-4 polymorphism rs4986790 was also found to be associated with this malignancy in the ER− patient groups. Our results suggested firstly that the variation in TLR-4 gene expression may influence breast cancer development and secondly a closely linked association between TLR-4 gene polymorphism and ER status. Our study provides support for a better understanding of the implication of TLR-4 polymorphism in breast tumorigenesis and for its eventual use as a cancer biomarker. PMID:28280355

  2. Variants in the vitamin D pathway, serum levels of vitamin D, and estrogen receptor negative breast cancer among African-American women: a case-control study

    PubMed Central

    2012-01-01

    Introduction American women of African ancestry (AA) are more likely than European Americans (EA) to have estrogen receptor (ER)-negative breast cancer. 25-hydroxyvitamin D (25OHD) is low in AAs, and was associated with ER-negative tumors in EAs. We hypothesized that racial differences in 25OHD levels, as well as in inherited genetic variations, may contribute, in part, to the differences in tumor characteristics. Methods In a case (n = 928)-control (n = 843) study of breast cancer in AA and EA women, we measured serum 25OHD levels in controls and tested associations between risk and tag single nucleotide polymorphisms (SNPs) in VDR, CYP24A1 and CYP27B1, particularly by ER status. Results More AAs had severe vitamin D deficiency (< 10 ng/ml) than EAs (34.3% vs 5.9%), with lowest levels among those with the highest African ancestry. Associations for SNPs differed by race. Among AAs, VDR SNP rs2239186, associated with higher serum levels of 25OHD, decreased risk after correction for multiple testing (OR = 0.53, 95% CI = 0.31-0.79, p by permutation = 0.03), but had no effect in EAs. The majority of associations were for ER-negative breast cancer, with seven differential associations between AA and EA women for CYP24A1 (p for interaction < 0.10). SNP rs27622941 was associated with a > twofold increased risk of ER-negative breast cancer among AAs (OR = 2.62, 95% CI = 1.38-4.98), but had no effect in EAs. rs2209314 decreased risk among EAs (OR = 0.38, 95% CI = 0.20-0.73), with no associations in AAs. The increased risk of ER-negative breast cancer in AAs compared to EAs was reduced and became non-significant (OR = 1.20, 95% CI = 0.80-1.79) after adjusting for these two CYP24A1 SNPs. Conclusions These data suggest that genetic variants in the vitamin D pathway may be related to the higher prevalence of ER-negative breast cancer in AA women. PMID:22480149

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

    PubMed Central

    Kala, Rishabh; Tollefsbol, Trygve O.

    2016-01-01

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

  4. 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.

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

    PubMed Central

    2011-01-01

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

  6. Assessment of estrogen receptor--histone interactions.

    PubMed Central

    Kallos, J; Fasy, T M; Hollander, V P

    1981-01-01

    Several different in vitro binding assays show that the estrogen receptor from rabbit uterus interacts selectively with purified histones from calf thymus. The estrogen receptor binds strongly to histones H2B and H2A, moderately to histones H3 and H4, and poorly to histone H1. In the presence of histones H2B or H2A, the position at which the estrogen receptor focuses in an isoelectric gradient is shifted to a more basic zone. Kinetic experiments show that, if histone H2B is bound to a DNA, the estrogen receptor dissociates more slowly from that DNA. The portion of the estrogen receptor molecule required for binding to histone H2B is relatively stable to tryptic digestion; in contrast, the portion of the receptor molecule responsible for DNA binding is promptly lost during limited tryptic digestion. These in vitro findings suggest that the mechanism by which the estrogen receptor selectively alters gene expression may involve specific contacts with histone molecules. PMID:6942408

  7. Inverse agonist of estrogen-related receptor α suppresses the growth of triple negative breast cancer cells through ROS generation and interaction with multiple cell signaling pathways.

    PubMed

    Wu, Ying-Min; Chen, Zhuo-Jia; Jiang, Guan-Min; Zhang, Kun-Shui; Liu, Qiao; Liang, Shu-Wei; Zhou, Yan; Huang, Hong-Bin; Du, Jun; Wang, Hong-Sheng

    2016-03-15

    There is an urgent clinical need for targeted therapy approaches for triple-negative breast cancer (TNBC) patients. Increasing evidences suggested that the expression of estrogen-related receptor alpha (ERRα) was correlate with unfavorable clinical outcomes of breast cancer patients. We here show that inhibition of ERRα by its inverse agonist XCT-790 can suppress the proliferation, decrease G2/M phases, and induce mitochondrial-related apoptosis of TNBC cells. XCT-790 elevates the proteins related to endoplasmic reticulum (ER) stress such as ATF4/6, XBT-1 and CHOP. It also increases the expression of growth inhibition related proteins such as p53 and p21. Further, XCT-790 can increase the generation of reactive oxygen species (ROS) in TNBC cells mainly through inhibition of SOD1/2. While ROS scavenger NAC abolishes XCT-790 induced ER-stress and growth arrest. XCT-790 treatment can rapidly activate the signal molecules including ERK1/2, p38-MAPK, JNK, Akt, p65, and IκBα, while NAC attenuates effects of XCT-790 induced phosphorylation of ERK1/2, p38-MAPK and Akt. Further, the inhibitors of ERK1/2, JNK, Akt, and NF-κB attenuate XCT-790 induced ROS generation. These data suggest that AKT/ROS and ERK/ROS positive feedback loops, NF-κB/ROS, and ROS/p38-MAPK, are activated in XCT-790 treated TNBC cells. In vivo experiments show that XCT-790 significantly suppresses the growth of MDA-MB-231 xenograft tumors, which is associated with up regulation of p53, p21, ER-stress related proteins while down regulation of bcl-2. The present discovery makes XCT-790 a promising candidate drug and lays the foundation for future development of ERRα-based therapies for TNBC patients.

  8. Function of Estrogen Receptor Tryosine Phosphorylation

    DTIC Science & Technology

    1998-07-01

    6219 TITLE: Function of Estrogen Receptor Tryosine Phosphorylation PRINCIPAL INVESTIGATOR: Matthew R. Yudt CONTRACTING ORGANIZATION: University of...Estrogen Receptor Tryosine Phosphorylation ~DAMD17-96-1-6219 6. AUTHOR(S) Matthew R. Yudt 7. PERFORMING ORGANIZATION NAME11S) AND AODRESS(ES...this model, tyrosine 537 (Y537) phosphorylation of one monomer interacts with another tyrosine phosphorylated monomer to constitute an hER dimer

  9. [Estrogen receptors and the mammary gland].

    PubMed

    Barrón, A; Bermejo, L; Castro, I

    1997-01-01

    For several decades it has been known that steroid hormones, estrogen and progesterone, regulate some genes involved in the growth, proliferation and differentiation of the mammary-gland in animals and humans. In the last years, the presence or absence of the nuclear estrogen receptor has been used by clinicians as a marker for tumor malignancy, as a prognostic index or as an important parameter for hormonal therapy with anti-estrogenic compounds of some hormone-dependent breast cancers. This review shows some advances in the knowledge of the structure, function, molecular mechanisms of estrogenic activity, and interaction with proteins like protooncogenes and growth factors. Also, we refer to the role of the estrogen receptor in the physiophatology of breast cancer.

  10. Function of Estrogen Receptor Tryosine Phosphorylation

    DTIC Science & Technology

    1997-07-01

    localization of the receptors, ligand binding, DNA binding, transcriptional activation, and receptor turnover ( LeGoff et al. 1994; Lahooti et al. 1994...1040-1049 (1995). LeGoff P., M.M. Montano, D.J. Schodin, and B. Katzenellenbogen. Phosphorylation of the Human Estrogen Receptor. J. Biol. Chem

  11. SCREENING CHEMICALS FOR ESTROGEN RECEPTOR ...

    EPA Pesticide Factsheets

    The U.S. Environmental Protection Agency (EPA) is considering the use high-throughput and computational methods for regulatory applications in the Endocrine Disruptor Screening Program (EDSP). To use these new tools for regulatory decision making, computational methods must be appropriately validated. Traditional validations of toxicity tests are time intensive, evaluate a relatively small number of chemicals, and are not well-suited to high-throughput methods. Here we describe a multi-step, performance-based validation establishing scientific confidence in new computational methods and demonstrating these tools are sufficiently robust to be used in a regulatory context. Results from 18 estrogen receptor (ER) ToxCast high-throughput screening assays, measuring different points along the signaling pathway with different assay technologies, were integrated into a computational model. The resulting ToxCast ER model scores range from 0 (no activity) to 1 (bioactivity of the native ligand, 17β-estradiol) and can discriminate ER bioactivity from assay-specific interference and cytotoxicity. ToxCast ER model performance was evaluated for 40 in vitro and 43 in vivo reference chemicals. ToxCast ER model results were also compared to EDSP Tier 1 screening assays in current regulatory practice for a diverse set of more than 100 chemicals. ToxCast ER model accuracy was 95% when compared to the large set of in vitro and in vivo reference chemicals. In addition, the T

  12. Nucleophosmin/B23 is a negative regulator of estrogen receptor α expression via AP2γ in endometrial cancer cells

    PubMed Central

    Lee, Li-Yu; Yang, Lan-Yan; Tsai, Chia-Lung; Wang, Hsin-Shih; Lai, Chyong-Huey

    2016-01-01

    Endometrial cancers expressing estrogen and progesterone receptors respond to hormonal therapy. The disappearance of steroid hormone receptor expression is common in patients with recurrent disease, ultimately hampering the clinical utility of hormonal therapy. Here, we demonstrate for the first time that nucleophosmin (NPM1/B23) suppression can restore the expression of estrogen receptor α (ESR1/ERα) in endometrial cancer cells. Mechanistically, B23 and activator protein-2γ (TFAP2C/AP2γ) form a complex that acts as a transcriptional repressor of ERα. Our results indicate that B23 or AP2γ knockdown can restore ERα levels and activate ERα-regulated genes (e.g., cathepsin D, EBAG9, and TFF1/pS2). Moreover, AP2γ knockdown in a xenograft model sensitizes endometrial cancer cells to megesterol acetate through the upregulation of ERα expression. An increased immunohistochemical expression of AP2γ is an adverse prognostic factor in endometrial cancer. In summary, B23 and AP2γ may act in combination to suppress ERα expression in endometrial cancer cells. The inhibition of B23 or AP2γ can restore ERα expression and can serve as a potential strategy for sensitizing hormone-refractory endometrial cancers to endocrine therapy. PMID:27527851

  13. GDC-0941 and Cisplatin in Treating Patients With Androgen Receptor-Negative Triple Negative Metastatic Breast Cancer

    ClinicalTrials.gov

    2015-08-17

    Estrogen Receptor Negative Breast Cancer; Human Epidermal Growth Factor 2 Negative Carcinoma of Breast; Triple Negative Breast Cancer; Recurrent Breast Cancer; Stage IV Breast Cancer; Triple-negative Breast Cancer

  14. Divergent effects of insulin-like growth factor-1 receptor expression on prognosis of estrogen receptor positive versus triple negative invasive ductal breast carcinoma.

    PubMed

    Hartog, Hermien; Horlings, Hugo M; van der Vegt, Bert; Kreike, Bas; Ajouaou, Abderrahim; van de Vijver, Marc J; Marike Boezen, H; de Bock, Geertruida H; van der Graaf, Winette T A; Wesseling, Jelle

    2011-10-01

    The insulin-like growth factor type 1 receptor (IGF1R) is involved in progression of breast cancer and resistance to systemic treatment. Targeting IGF1R signaling may, therefore, be beneficial in systemic treatment. We report the effect of IGF1R expression on prognosis in invasive ductal breast carcinoma (IDC), the most common type of breast cancer. Immunohistochemistry was performed on tumor tissue of a consecutive cohort of 429 female patients treated for operable primary IDC. Associations between IGF1R expression with clinicopathological parameters, disease free survival (DFS) and breast cancer specific survival (BCSS) were evaluated by multivariate analyses focusing on ER-positive and triple negative IDC (TN-IDC). To enlarge the TN-IDCs cohort, we analyzed a combined dataset of 51 TN-IDC tumors from our series with 64 TN-IDCs with similar clinicopathological parameters. Patients with tumors expressing cytoplasmic IGF1R have a longer DFS and BCSS (DFS: HR 0.46, 95% CI 0.27-0.49, P = 0.005, BCSS: HR 0.38, 95% CI 0.19-0.74, P = 0.005). This effect was most prominent in ER-positive tumors. However, in a combined series of 105 TN-IDCs cytoplasmic IGF1R expression was associated with a shorter DFS (HR = 2.29, 95% CI 1.08-4.84, P = 0.03), also when combined in a multivariate model, including well-known prognostic factors (HR 2.06; 95% CI 0.95-4.47; P = 0.07). IGF1R expression in ER-positive IDC is strongly related to a favorable DFS and BCSS, but to a shorter DFS in TN-IDC tumors. This divergent effect of IGF1R expression in subgroups of IDC may affect selection of patients for IGF1R targeted therapy.

  15. Estrogen receptor transcription and transactivation: Estrogen receptor alpha and estrogen receptor beta - regulation by selective estrogen receptor modulators and importance in breast cancer

    PubMed Central

    S Katzenellenbogen, Benita; A Katzenellenbogen, John

    2000-01-01

    Estrogens display intriguing tissue-selective action that is of great biomedical importance in the development of optimal therapeutics for the prevention and treatment of breast cancer, for menopausal hormone replacement, and for fertility regulation. Certain compounds that act through the estrogen receptor (ER), now referred to as selective estrogen receptor modulators (SERMs), can demonstrate remarkable differences in activity in the various estrogen target tissues, functioning as agonists in some tissues but as antagonists in others. Recent advances elucidating the tripartite nature of the biochemical and molecular actions of estrogens provide a good basis for understanding these tissue-selective actions. As discussed in this thematic review, the development of optimal SERMs should now be viewed in the context of two estrogen receptor subtypes, ERα and ERβ, that have differing affinities and responsiveness to various SERMs, and differing tissue distribution and effectiveness at various gene regulatory sites. Cellular, biochemical, and structural approaches have also shown that the nature of the ligand affects the conformation assumed by the ER-ligand complex, thereby regulating its state of phosphorylation and the recruitment of different coregulator proteins. Growth factors and protein kinases that control the phosphorylation state of the complex also regulate the bioactivity of the ER. These interactions and changes determine the magnitude of the transcriptional response and the potency of different SERMs. As these critical components are becoming increasingly well defined, they provide a sound basis for the development of novel SERMs with optimal profiles of tissue selectivity as medical therapeutic agents. PMID:11250726

  16. Estrogen increases renal oxytocin receptor gene expression.

    PubMed

    Ostrowski, N L; Young, W S; Lolait, S J

    1995-04-01

    Estrogens have been implicated in the sodium and fluid imbalances associated with the menstrual cycle and late pregnancy. An estrogen-dependent role for renal oxytocin receptors in fluid homeostasis is suggested by the present findings which demonstrate that estradiol benzoate treatment increases the expression of the oxytocin receptor messenger ribonucleic acid and 125I-OTA binding to oxytocin receptors in the renal cortex and medullary collecting ducts of ovariectomized female rats. Moreover, estradiol induced high levels of oxytocin receptor expression in outer stripe proximal tubules of ovariectomized female and adrenalectomized male rats. Proximal tubule induction was inhibited in a dose-dependent manner by the antiestrogen tamoxifen, but cortical expression of oxytocin receptors in macula densa cells was unaffected by tamoxifen. These data demonstrate cell-specific regulation of oxytocin receptor expression in macula densa and proximal tubule cells, and suggest a important role for these receptors in mediating estrogen-induced alterations in renal fluid dynamics by possibly affecting glomerular filtration and water and solute reabsorption during high estrogen states.

  17. The role of estrogens and estrogen receptor signaling pathways in cancer and infertility: the case of schistosomes.

    PubMed

    Botelho, Mónica C; Alves, Helena; Barros, Alberto; Rinaldi, Gabriel; Brindley, Paul J; Sousa, Mário

    2015-06-01

    Schistosoma haematobium, a parasitic flatworm that infects more than 100 million people, mostly in the developing world, is the causative agent of urogenital schistosomiasis, and is associated with a high incidence of squamous cell carcinoma (SCC) of the bladder. Schistosomiasis haematobia also appears to negatively influence fertility, and is particularly associated with female infertility. Given that estrogens and estrogen receptors are key players in human reproduction, we speculate that schistosome estrogen-like molecules may contribute to infertility through hormonal imbalances. Here, we review recent findings on the role of estrogens and estrogen receptors on both carcinogenesis and infertility associated with urogenital schistosomiasis and discuss the basic hormonal mechanisms that might be common in cancer and infertility.

  18. MEMBRANE ESTROGEN RECEPTOR REGULATION OF HYPOTHALAMIC FUNCTION

    PubMed Central

    Micevych, Paul E.; Kelly, Martin J.

    2012-01-01

    Over the decades, our understanding of estrogen receptor (ER) function has evolved. Today we are confronted by at least two nuclear ERs: ERα and ERβ; and a number of putative membrane ERs, including ERα, ERβ, ER-X, GPR30 and Gq-mER. These receptors all bind estrogens or at least estrogenic compounds and activate intracellular signaling pathways. In some cases, a well-defined pharmacology, and physiology has been discovered. In other cases, the identity or the function remains to be elucidated. This mini-review attempts to synthesize our understanding of 17β-estradiol membrane signaling within hypothalamic circuits involved in homeostatic functions focusing on reproduction and energy balance. PMID:22538318

  19. Function of Estrogen Receptor Tryosine Phosphorylation

    DTIC Science & Technology

    1999-07-01

    phosphotyrosyl peptide that blocks dimerization of the human estrogen receptor. Proceedings of the National Academy of Sciences of the United States of America... Vivat , V., Chambon, P., Moras, D., and Gronemeyer, H. (1996) Nat. Struct. Biol. 3, 87-94 8. Shiau, A. K., Barstad, D., Loria, P. M., Cheng, L

  20. 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...

  1. Selectively targeting estrogen receptors for cancer treatment

    PubMed Central

    Shanle, Erin K.; Xu, Wei

    2010-01-01

    Estrogens regulate growth and development through the action of two distinct estrogen receptors (ERs), ERα and ERβ, which mediate proliferation and differentiation of cells. For decades, ERα mediated estrogen signaling has been therapeutically targeted to treat breast cancer, most notably with the selective estrogen receptor modulator (SERM) tamoxifen. Selectively targeting ERs occurs at two levels: tissue selectivity and receptor subtype selectivity. SERMs have been developed with emphasis on tissue selectivity to target ER signaling for breast cancer treatment. Additionally, new approaches to selectively target the action of ERα going beyond ligand-dependent activity are under current investigation. As evidence of the anti-proliferative role of ERβ accumulates, selectively targeting ERβ is an attractive approach for designing new cancer therapies with the emphasis shifted to designing ligands with subtype selectivity. This review will present the mechanistic and structural features of ERs that determine tissue and subtype selectivity with an emphasis on current approaches to selectively target ERα and ERβ for cancer treatment. PMID:20708050

  2. High coffee intake, but not caffeine, is associated with reduced estrogen receptor negative and postmenopausal breast cancer risk with no effect modification by CYP1A2 genotype.

    PubMed

    Lowcock, Elizabeth C; Cotterchio, Michelle; Anderson, Laura N; Boucher, Beatrice A; El-Sohemy, Ahmed

    2013-01-01

    Associations between caffeine and coffee consumption and breast cancer risk are uncertain, with studies suggesting inverse and null associations. Variation in cytochrome P450 1A2 (CYP1A2), a gene responsible for caffeine metabolism, may modify these associations. Cases (n = 3,062) were recruited through the Ontario Cancer Registry and controls (n = 3,427) through random digit dialing. Logistic regression was used to evaluate associations between breast cancer risk and intakes of 7 caffeine-containing items and total caffeine, and examine whether a genetic variant in CYP1A2 (rs762551) modified these associations. Analyses were stratified by estrogen receptor (ER), menopausal, and smoking status. Generally, coffee and caffeine were not associated with breast cancer risk; however, a significant reduction in risk was observed with the highest category of coffee consumption [≥5 cups per day vs. never, multivariate-adjusted odds ratio (MVOR) = 0.71, 95% confidence interval (CI): 0.51, 0.98]. Variant rs762551 did not modify associations. In stratified analyses, high coffee intake was associated with reduced risk of ER- (MVOR = 0.41, 95% CI: 0.19, 0.92) and postmenopausal breast cancer (MVOR = 0.63, 95% CI: 0.43, 0.94). High coffee consumption, but not total caffeine, may be associated with reduced risk of ER- and postmenopausal breast cancers, independent of CYP1A2 genotype. Further studies are needed to replicate these findings.

  3. 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.

  4. Cell Cycle Regulation of Estrogen and Androgen Receptor

    DTIC Science & Technology

    2002-07-01

    Estrogen and Androgen Receptor PRINCIPAL INVESTIGATOR: Elisabeth D. Martinez CONTRACTING ORGANIZATION: Georgetown University Medical Center...Cycle Regulation of Estrogen and Androgen DAMD17-99-1-9199 Receptor 6. AUTHOR(S) Elisabeth D. Martinez 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES...with androgens. 14. SUBJECT TERMS 15. NUMBER OF PAGES breast cancer, cell cycle, androgen receptor, estrogen receptor, non- 66 steroidal activators, L

  5. Associations between estrogen receptor-negative breast cancer and timing of reproductive events differ between African American and European American women.

    PubMed

    Ambrosone, Christine B; Zirpoli, Gary R; Bovbjerg, Dana Howard; Shankar, Jyoti; Hong, Chi-Chen; McCann, Susan E; Ruszczyk, Melanie; Khoury, Thaer; Yao, Song; Ciupak, Gregory L; Jandorf, Lina; Pawlish, Karen S; Bandera, Elisa V

    2014-06-01

    The effects of reproductive factors on breast cancer risk seem to differ by estrogen receptor (ER) status. Menarche and first live birth (FLB) tend to occur at younger ages in African Americans (AA) than European Americans (EA), and could play a role in breast cancer disparities. In the Women's Circle of Health Study, a case-control study of breast cancer in EA and AA women, in-person interviews were conducted to collect epidemiologic data, including reproductive histories. Data on ER status, abstracted from pathology reports, were available for 814 AA and 538 EA breast cancer cases, and were analyzed with 1015 AA and 715 EA controls, to evaluate associations between subgroups and age at menarche, age at FLB, and the interval between those ages. Among AA women, later age at menarche (≥14 years) was associated with reduced risk of both ER(+) and ER(-) breast cancer, with ORs strongest for ER(-) disease [OR = 0.57; 95% confidence interval (CI), 0.37-0.88]; associations were weaker and nonsignificant for EA women. There were no significant associations with age at FLB, but AA women with a FLB within 15 years of menarche had increased risk of ER(-) disease (OR = 2.26; 95% CI, 1.29-3.95), with no significant associations among EAs. In our data, earlier age at menarche and shorter intervals until FLB are associated with ER(-) breast cancer in AA women; differential distributions by race of these and other reproductive risk factors could contribute to the higher prevalence of ER(-) breast cancer in AA women. Cancer Epidemiol Biomarkers Prev; 23(6); 1115-20. ©2014 AACR.

  6. Radiobrominated triphenylethylenes as estrogen receptor binding radiopharmaceuticals

    SciTech Connect

    Seevers, R.H.; Meese, R.C.; Friedman, A.M.; DeSombre, E.R.

    1985-05-01

    Estrogen receptor binding radiopharmaceuticals have potential for use in the diagnosis and treatment of cancers of the female reproductive system. Tamoxifen is an antiestrogen derived from the triphenylethylene skeleton which is used in the treatment of mammary carcinoma. Hydroxytamoxifen is a metabolite of tamoxifen which binds tightly to the estrogen receptor. Two triphenylethylene derivatives based on the structure of hydroxytamoxifen have been prepared: 1-bromo-1-phenyl-2- (2-dimethylamino)-4-ethoxyphenyl -2-(4-hydroxyphenyl) ethene (1) where the ethyl group of hydroxytamoxifen has been replaced by a bromine, and 1-bromo-1-phenyl-2,2-(4-hydroxyphenyl) ethene (2) with a similar substitution and also lacking the aminoethoxy side chain believed to confer antiestrogenicity. Both 1 and 2 bind strongly to the estrogen receptor. 2 has been labeled with the Auger electron emitting nuclide Br-80m in moderate yields in high specific activity using either N-bromosuccinimide or N-bromophthalimide and shows promise as a potential radiotherapy agent.

  7. Acyl-CoA synthetase-4, a new regulator of mTOR and a potential therapeutic target for enhanced estrogen receptor function in receptor-positive and -negative breast cancer

    PubMed Central

    Dattilo, Melina A.; Solano, Angela R.; Maloberti, Paula M.; Podesta, Ernesto J.

    2015-01-01

    Although the role of acyl-CoA synthetase 4 (ACSL4) in mediating an aggressive phenotype is well accepted, there is little evidence as to the early steps through which ACSL4 increases tumor growth and progression. In this study, and by means of the stable transfection of MCF-7 cells with ACSL4 using the tetracycline Tet-Off system (MCF-7 Tet-Off/ACSL4), we identify the mTOR pathway as one of the main specific signatures of ACSL4 expression and demonstrate the partial involvement of the lipoxygenase pathway in the activation of mTOR. The specificity of ACSL4 action on mTOR signaling is also determined by doxycycline inhibition of ACSL4 expression in MCF-7 Tet-Off/ACSL4 cells, by the expression of ACSL4 in the non-aggressive T47D breast cancer cell line and by knocking down this enzyme expression in the MDA-MB-231 breast cancer cells, which constitutively express ACSL4. ACSL4 regulates components of the two complexes of the mTOR pathway (mTORC1/2), along with upstream regulators and substrates. We show that mTOR inhibitor rapamycin and ACSL4 inhibitor rosiglitazone can act in combination to inhibit cell growth. In addition, we demonstrate a synergistic effect on cell growth inhibition by the combination of rosiglitazone and tamoxifen, an estrogen receptor α (ERα) inhibitor. Remarkably, this synergistic effect is also evident in the triple negative MDA-MB-231 cells in vitro and in vivo. These results suggest that ACSL4 could be a target to restore tumor hormone dependence in tumors with poor prognosis for disease-free and overall survival, in which no effective specifically targeted therapy is readily available. PMID:26536660

  8. Acyl-CoA synthetase-4, a new regulator of mTOR and a potential therapeutic target for enhanced estrogen receptor function in receptor-positive and -negative breast cancer.

    PubMed

    Orlando, Ulises D; Castillo, Ana F; Dattilo, Melina A; Solano, Angela R; Maloberti, Paula M; Podesta, Ernesto J

    2015-12-15

    Although the role of acyl-CoA synthetase 4 (ACSL4) in mediating an aggressive phenotype is well accepted, there is little evidence as to the early steps through which ACSL4 increases tumor growth and progression. In this study, and by means of the stable transfection of MCF-7 cells with ACSL4 using the tetracycline Tet-Off system (MCF-7 Tet-Off/ACSL4), we identify the mTOR pathway as one of the main specific signatures of ACSL4 expression and demonstrate the partial involvement of the lipoxygenase pathway in the activation of mTOR. The specificity of ACSL4 action on mTOR signaling is also determined by doxycycline inhibition of ACSL4 expression in MCF-7 Tet-Off/ACSL4 cells, by the expression of ACSL4 in the non-aggressive T47D breast cancer cell line and by knocking down this enzyme expression in the MDA-MB-231 breast cancer cells, which constitutively express ACSL4. ACSL4 regulates components of the two complexes of the mTOR pathway (mTORC1/2), along with upstream regulators and substrates.We show that mTOR inhibitor rapamycin and ACSL4 inhibitor rosiglitazone can act in combination to inhibit cell growth. In addition, we demonstrate a synergistic effect on cell growth inhibition by the combination of rosiglitazone and tamoxifen, an estrogen receptor α (ERα) inhibitor. Remarkably, this synergistic effect is also evident in the triple negative MDA-MB-231 cells in vitro and in vivo.These results suggest that ACSL4 could be a target to restore tumor hormone dependence in tumors with poor prognosis for disease-free and overall survival, in which no effective specifically targeted therapy is readily available.

  9. Cell Cycle Regulation of Estrogen and Androgen Receptor

    DTIC Science & Technology

    2001-07-01

    EC50 . "* It has been established that the estrogen receptor shows highest activity when the cells are treated by serum starvation and are mainly in GO...of Estrogen and Androgen Receptor PRINCIPAL INVESTIGATOR: Elisabeth D. Martinez CONTRACTING ORGANIZATION: Georgetown University Medical Center... Estrogen and Androgen Receptor DAMD 17-99-1- 9199 6. AUTHOR(S) Elisabeth D. Martinez 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING

  10. Synergistic activation of estrogen receptor with combinations of environmental chemicals

    SciTech Connect

    Arnold, S.F.; Klotz, D.M.; Collins, B.M.

    1996-06-07

    Certain chemicals in the environment are estrogenic. The low potencies of the compounds, when studied singly, suggest that they may have little effect on biological systems. The estrogenic potencies of combinations of such chemicals were screened in a simple yeast estrogen potencies of combination of such chemicals were screened in a simple yeast estrogen systems (YES) containing human estrogen receptor (hER). Combinations of two weak environmental estrogens, such as dieldrin, endosulfan, or toxaphene, were 100 times as potent in hER-mediated transactivation as any chemical alone. Hydroxylated polychlorinated biphenyls shown previously to synergistically alter sexual development in turtles also synergized in the YES. The synergistic interaction of chemical mixtures with the estrogen receptor may have profound environmental implications. These results may represent a previously uncharacterized level of regulation of estrogen-associated responses. 32 refs., 3 figs., 3 tabs.

  11. 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.

  12. 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

  13. Estrogen patient package insert: medication acceptance despite negative attitudes

    SciTech Connect

    Weintraub, M.; Glickstein, S.; Lasagna, L.

    1981-08-01

    We surveyed 100 women receiving short courses of estrogen post partum to suppress lactation. Thirty six had significant apprehension about estrogens, but took them. These women were significantly older and better educated and 92% of them were married. In contrast, only one third of the ''nonapprehensive'' women were married and they had significantly lower family incomes. More of the apprehensive women read the estrogen patient package insert (PPI) and almost 30% developed negative attitudes toward estrogens. The major concerns of these women reflected information in the PPI about cancer and thromboembolism. The reasons given for taking estrogens despite apprehension included the lower risk of short courses, assurance from physicians, nurses, or family members, and the desired therapeutic effect. These women should not be given the current estrogen PPI, which was designed to warn women of the risks of long-term estrogen use; a PPI should be written specifically for patients receiving short courses. Similar problems will arise with the PPIs for other medications that have different risks for different therapeutic indications.

  14. [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).

  15. [Cardiovascular effects of selective estrogen receptor modulators. Current perspectives].

    PubMed

    Simoncini, Tommaso; Mannella, Paolo; Genazzani, Andrea R

    2003-02-01

    The use of hormone replacement therapy (HRT) after the menopause for the prevention of the long-term complications of estrogen deprivation has recently been questioned after the publication of large clinical trials that failed to show benefits for postmenopausal women. Although these trials risk to dump the widespread opinion of the cardioprotective effects of long-term estrogen use, they have many pitfalls that prevent a direct clinical application of these negative results. Furthermore, the large amount of epidemiological and experimental evidence indicating estrogens as protective on the vascular system cannot be ignored, and efforts should be devoted to understand the reasons for the discrepancy of results of these recent large trials. In the meanwhile, different molecules should be studied in depth as for the actions on the cardiovascular system, and their specific mechanisms of actions should be elucidated. Selective estrogen receptor modulators (SERM) are a promising family of molecules and some of these compounds have positive effects on cardiovascular risk parameters as well as on vascular cells. Large trials are ongoing to study the impact of these substances on cardiovascular risk, and the near future should provide us with answers on the possible use of SERM as possible safer alternatives to HRT for the long-term prevention of cardiovascular disease in postmenopausal women.

  16. The Effect of Prolonged Cold Ischemia Time on Estrogen Receptor Immunohistochemistry in Breast Cancer

    PubMed Central

    Li, Xiaoxian; Deavers, Michael T.; Guo, Ming; Liu, Ping; Gong, Yun; Albarracin, Constance T.; Middleton, Lavinia P.; Huo, Lei

    2013-01-01

    To facilitate accurate detection of estrogen receptor expression in breast tumors, the American Society of Clinical Oncology/College of American Pathologists recommends that cold ischemia time be kept under 1 h. However, data to address the upper threshold of cold ischemia time are limited. While it is our routine practice to keep cold ischemia time under 1 h for breast core biopsy specimens, this is difficult for surgical specimens because of the comprehensive intraoperative assessment performed at our institution. In this retrospective study, we compared estrogen receptor immunohistochemical staining results in paired breast tumor core biopsy specimens and resection specimens with cold ischemia times ranging from 64 to 357 min in 97 patients. The staining category (≥10%, positive; 1-9%, low positive; <1%, negative) between the core biopsy and resection specimens changed for 5 patients (5%). The weighted Kappa statistic for estrogen receptor staining category between the two specimen types was 0.86 (95% confidence interval, 0.74-0.99), indicating good concordance. The difference in the percentage of estrogen receptor staining between core biopsy and resection was not significantly associated with cold ischemia time (P = 0.81, Spearman correlation). Although we did not observe significant associations between the difference in estrogen receptor staining in the two specimen types and cold ischemia time after placing the patients in three groups of ‘increase’, ‘decrease’ and ‘no change’ using a difference of 25% in estrogen receptor staining percentage as the cutoff, a trend of decreased estrogen receptor staining with cold ischemia time > 2 h was detected. No statistically significant association was found between the change of estrogen receptor staining and the history of neoadjuvant chemotherapy. Our findings indicate that prolonged cold ischemia time up to 4 h (97% of our cohort) in the practice setting of our institution has minimal clinical impact

  17. 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

  18. Steroid binding domain of porcine estrogen receptor

    SciTech Connect

    Koike, S.; Nii, A.; Sakai, M.; Muramatsu, M.

    1987-05-05

    For the purpose of characterizing the estrogen binding domain of porcine estrogen receptor (ER), the authors have made use of affinity labeling of partially purified ER with (/sup 3/H)tamoxifen aziridine. The labeling is very efficient and selective particularly after partial purification of ER. A 65,000-dalton (65-kDa) band was detected on the fluorogram of a sodium dodecyl sulfate-polyacrylamide gel, together with a 50-kDa band and a few more smaller bands. The 50-kDa protein appears to be a degradation product of the 65-kDa protein in view of the similar peptide map. ER was affinity labeled before or after controlled limited proteolysis with either trypsin, papain, or ..cap alpha..-chymotrypsin. The labeling patterns of limited digests indicate that a fragment of about 30 kDa is relatively resistant to proteases and has a full and specific binding activity to estrogen, whereas smaller fragments have lost much of the binding activity. This fragment is very hydrophobic and probably corresponds to the carboxy half of ER.

  19. 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.

  20. Estrogen Receptor Alpha G525L Knock-In-Mice

    DTIC Science & Technology

    2006-03-01

    Padilla-Banks E, Clark G, Newbold RR. Assessing estrogenic activity of phytochemicals using transcriptional activation and immature mouse...AD_________________ Award Number: W81XWH-04-1-0347 TITLE: Estrogen Receptor Alpha G525L...TITLE AND SUBTITLE Estrogen Receptor Alpha G525L Knock-In Mice 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-04-1-0347 5c. PROGRAM ELEMENT

  1. Pembrolizumab and Enobosarm in Treating Patients With Androgen Receptor Positive Metastatic Triple Negative Breast Cancer

    ClinicalTrials.gov

    2017-04-04

    Androgen Receptor Positive; Estrogen Receptor Negative; HER2/Neu Negative; Progesterone Receptor Negative; Recurrent Breast Carcinoma; Stage III Breast Cancer; Stage IIIA Breast Cancer; Stage IIIB Breast Cancer; Stage IIIC Breast Cancer; Stage IV Breast Cancer; Triple-Negative Breast Carcinoma

  2. Radiotherapy Can Decrease Locoregional Recurrence and Increase Survival in Mastectomy Patients With T1 to T2 Breast Cancer and One to Three Positive Nodes With Negative Estrogen Receptor and Positive Lymphovascular Invasion Status

    SciTech Connect

    Yang, P.S.; Chen, C.M.; Liu, M.C.; Jian, J.M.; Horng, C.F.; Liu, M.J.; Yu, B.L.; Lee, M.Y.; Chi, C.W.

    2010-06-01

    Purpose: To define a subgroup of patients at high risk of locoregional recurrence (LRR) who might be benefit from postmastectomy radiotherapy in invasive breast cancer and tumor size <5 cm with one to three involved axillary lymph nodes (T1-2 N1). Methods and Materials: Between April 1991 and December 2005, 544 patients with T1-2 N1 invasive breast cancer were treated with modified radical mastectomy. Of the 544 patients, 383 patients (70.4%) had no radiotherapy, and 161 patients (29.6%) received radiotherapy. We retrospectively compared these two patient groups. Results: With a median follow-up of 40.3 months, LRR occurred in 40 (7.4%) of 544 patients. On univariate analysis, high nuclear grade (p = 0.04), negative estrogen receptor (ER) status (p = 0.001), presence of lymphovascular invasion (LVI) (p = 0.003), and no radiotherapy (p = 0.0015) were associated with a significantly higher rate of LRR. Negative ER status (hazard ratio = 5.1) and presence of LVI (hazard ratio = 2.5) were the risk factors for LRR with statistical significance in the multivariate analysis. Radiotherapy reduced the LRR in patients with the following characteristics: age <40 years, T2 stage, high nuclear grade, negative ER status, and presence of LVI. For 41 patients with negative ER and positive LVI status, radiotherapy can reduce LRR from 10 of 25 (40%) to 2 of 16 (12.5%) and increase the 5-year overall survival from 43.7% to 87.1%. Conclusion: Radiotherapy can reduce LRR and increase survival in T1-2 N1 breast cancer patients with negative ER status and presence of LVI.

  3. 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. ...

  4. 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

  5. Estrogen Receptor Ligands: A Review (2013–2015)

    PubMed Central

    Farzaneh, Shabnam; Zarghi, Afshin

    2016-01-01

    Estrogen receptors (ERs) are a group of compounds named for their importance in both menstrual and estrous reproductive cycles. They are involved in the regulation of various processes ranging from tissue growth maintenance to reproduction. Their action is mediated through ER nuclear receptors. Two subtypes of the estrogen receptor, ERα and ERβ, exist and exhibit distinct cellular and tissue distribution patterns. In humans, both receptor subtypes are expressed in many cells and tissues, and they control key physiological functions in various organ systems. Estrogens attract great attention due to their wide applications in female reproductive functions and treatment of some estrogen-dependent cancers and osteoporosis. This paper provides a general review of ER ligands published in international journals patented between 2013 and 2015. The broad physiological profile of estrogens has attracted the attention of many researchers to develop new estrogen ligands as therapeutic molecules for various clinical purposes. After the discovery of the ERβ receptor, subtype-selective ligands could be used to elicit beneficial estrogen-like activities and reduce adverse side effects, based on the different distributions and relative levels of the two ER subtypes in different estrogen target tissues. Therefore, recent literature has focused on selective estrogen ligands as highly promising agents for the treatment of some types of cancer, as well as for cardiovascular, inflammatory, and neurodegenerative diseases. Estrogen receptors are nuclear transcription factors that are involved in the regulation of many complex physiological functions in humans. Selective estrogen ligands are highly promising targets for treatment of some types of cancer, as well as for cardiovascular, inflammatory and neurodegenerative diseases. Extensive structure-activity relationship studies of ER ligands based on small molecules indicate that many different structural scaffolds may provide high

  6. Maternal Regulation of Estrogen Receptor α Methylation

    PubMed Central

    Champagne, Frances A.; Curley, James P.

    2008-01-01

    Summary Advances in molecular biology have provided tools for studying the epigenetic factors which modulate gene expression. DNA methylation is an epigenetic modification which can have sustained effects on transcription and is associated with long-term gene silencing. In this review, we focus on the regulation of estrogen receptor alpha (ERα) expression by hormonal and environmental cues, the consequences of these cues for female maternal and sexual behavior and recent studies which explore the role of DNA methylation in mediating these developmental effects, with particular focus on the mediating role of maternal care. The methylation status of ERα has implications for reproductive behavior, cancer susceptibility and recovery from ischemic injury suggesting an epigenetic basis for risk and resilience across the life span. PMID:18644464

  7. Both estrogen receptor alpha and estrogen receptor beta agonists enhance cell proliferation in the dentate gyrus of adult female rats.

    PubMed

    Mazzucco, C A; Lieblich, S E; Bingham, B I; Williamson, M A; Viau, V; Galea, L A M

    2006-09-15

    This study investigated the involvement of estrogen receptors alpha and beta in estradiol-induced enhancement of hippocampal neurogenesis in the adult female rat. Subtype selective estrogen receptor agonists, propyl-pyrazole triol (estrogen receptor alpha agonist) and diarylpropionitrile (estrogen receptor beta agonist) were examined for each receptor's contribution, individual and cooperative, for estradiol-enhanced hippocampal cell proliferation. Estradiol increases hippocampal cell proliferation within 4 h [Ormerod BK, Lee TT, Galea LA (2003) Estradiol initially enhances but subsequently suppresses (via adrenal steroids) granule cell proliferation in the dentate gyrus of adult female rats. J Neurobiol 55:247-260]. Therefore, animals received s.c. injections of estradiol (10 microg), propyl-pyrazole triol and diarylpropionitrile alone (1.25, 2.5, 5.0 mg/0.1 ml dimethylsulfoxide) or in combination (2.5 mg propyl-pyrazole triol+2.5 mg diarylpropionitrile/0.1 ml dimethylsulfoxide) and 4 h later received an i.p. injection of the cell synthesis marker, bromodeoxyuridine (200 mg/kg). Diarylpropionitrile enhanced cell proliferation at all three administered doses (1.25 mg, P<0.008; 2.5 mg, P<0.003; 5 mg, P<0.005), whereas propyl-pyrazole triol significantly increased cell proliferation (P<0.0002) only at the dose of 2.5 mg. Our results demonstrate both estrogen receptor alpha and estrogen receptor beta are individually involved in estradiol-enhanced cell proliferation. Furthermore both estrogen receptor alpha and estrogen receptor beta mRNA was found co-localized with Ki-67 expression in the hippocampus albeit at low levels, indicating a potential direct influence of each receptor subtype on progenitor cells and their progeny. Dual receptor activation resulted in reduced levels of cell proliferation, supporting previous studies suggesting that estrogen receptor alpha and estrogen receptor beta may modulate each other's activity. Our results also suggest that a component

  8. Molecular Cloning, Characterization, and Chromosome Mapping of Reptilian Estrogen Receptors

    PubMed Central

    Katsu, Yoshinao; Matsubara, Kazumi; Kohno, Satomi; Matsuda, Yoichi; Toriba, Michihisa; Oka, Kaori; Guillette, Louis J.; Ohta, Yasuhiko; Iguchi, Taisen

    2010-01-01

    In many vertebrates, steroid hormones are essential for ovarian differentiation during a critical developmental stage as well as promoting the growth and differentiation of the adult female reproductive system. Although studies have been extensively conducted in mammals and a few fish, amphibians, and bird species, the molecular mechanisms of sex steroid hormone (estrogens) action have been poorly examined in reptiles. Here, we evaluate hormone receptor and ligand interactions in two species of snake, the Okinawa habu (Protobothrops flavoviridis, Viperidae) and the Japanese four-striped rat snake (Elaphe quadrivirgata, Colubridae) after the isolation of cDNAs encoding estrogen receptor α (ESR1) and estrogen receptor β (ESR2). Using a transient transfection assay with mammalian cells, the transcriptional activity of reptilian (Okinawa habu, Japanese four-striped rat snake, American alligator, and Florida red-belly freshwater turtle) ESR1 and ESR2 was examined. All ESR proteins displayed estrogen-dependent activation of transcription via an estrogen-response element-containing promoter; however, the responsiveness to various estrogens was different. Further, we determined the chromosomal locations of the snake steroid hormone receptor genes. ESR1 and ESR2 genes were localized to the short and long arms of chromosome 1, respectively, whereas androgen receptor was localized to a pair of microchromosomes in the two snake species examined. These data provide basic tools that allow future studies examining receptor-ligand interactions and steroid endocrinology in snakes and also expands our knowledge of sex steroid hormone receptor evolution. PMID:20926589

  9. Expression of Estrogen Receptor Alpha in Malignant Melanoma

    PubMed Central

    Rajabi, Parvin; Bagheri, Marzieh; Hani, Mohsen

    2017-01-01

    Background: Features of malignant melanoma (MM) vary in the different geographic regions of the world. This may be attributable to environmental, ethnic, and genetic factors. The aim of this study was to determine the expression of estrogen receptor alpha (ER-α) in MM in Isfahan, Iran. Materials and Methods: This study was planned as a descriptive, analytical, cross-sectional investigation. During this study, paraffin-embedded tissue blocks of patients with a histopathologic diagnosis of MM was studied for ER-α using immunohistochemistry (IHC). Results: In this study, 38 patients (female/male; 20/18) with a definite diagnosis of malignant cutaneous melanoma and mean age of 52.4 ± 11.2 years were investigated. Using envision IHC staining, there were not any cases with ER-α expression. Conclusion: In confirmation to the most previous studies, expression of ER-α was negative in MM. It is recommended to investigate the expression of estrogen receptor beta and other markers in MM. PMID:28299306

  10. 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...

  11. 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

  12. In Vivo Imaging of Activated Estrogen Receptors in Utero by Estrogens and Bisphenol A

    PubMed Central

    Lemmen, Josephine G.; Arends, Roel J.; van der Saag, Paul T.; van der Burg, Bart

    2004-01-01

    Environmental estrogens are of particular concern when exposure occurs during embryonic development. Although there are good models to study estrogenic activity of chemicals in adult animals, developmental exposure is much more difficult to test. The weak estrogenic activity of the environmental estrogen bisphenol A (BPA) in embryos is controversial. We have recently generated transgenic mice that carry a reporter construct with estrogen-responsive elements coupled to luciferase. We show that, using this in vivo model in combination with the IVIS imaging system, activation of estrogen receptors (ERs) by maternally applied BPA and other estrogens can be detected in living embryos in utero. Eight hours after exposure to 1 mg/kg BPA, ER transactivation could be significantly induced in the embryos. This was more potent than would be estimated from in vitro assays, although its intrinsic activity is still lower than that of diethylstilbestrol and 17β-estradiol dipropionate. On the basis of these results, we conclude that the estrogenic potency of BPA estimated using in vitro assays might underestimate its estrogenic potential in embryos. PMID:15531440

  13. In vivo imaging of activated estrogen receptors in utero by estrogens and bisphenol A.

    PubMed

    Lemmen, Josephine G; Arends, Roel J; van der Saag, Paul T; van der Burg, Bart

    2004-11-01

    Environmental estrogens are of particular concern when exposure occurs during embryonic development. Although there are good models to study estrogenic activity of chemicals in adult animals, developmental exposure is much more difficult to test. The weak estrogenic activity of the environmental estrogen bisphenol A (BPA) in embryos is controversial. We have recently generated transgenic mice that carry a reporter construct with estrogen-responsive elements coupled to luciferase. We show that, using this in vivo model in combination with the IVIS imaging system, activation of estrogen receptors (ERs) by maternally applied BPA and other estrogens can be detected in living embryos in utero. Eight hours after exposure to 1 mg/kg BPA, ER transactivation could be significantly induced in the embryos. This was more potent than would be estimated from in vitro assays, although its intrinsic activity is still lower than that of diethylstilbestrol and 17beta-estradiol dipropionate. On the basis of these results, we conclude that the estrogenic potency of BPA estimated using in vitro assays might underestimate its estrogenic potential in embryos.

  14. Whole-genome cartography of estrogen receptor alpha binding sites.

    PubMed

    Lin, Chin-Yo; Vega, Vinsensius B; Thomsen, Jane S; Zhang, Tao; Kong, Say Li; Xie, Min; Chiu, Kuo Ping; Lipovich, Leonard; Barnett, Daniel H; Stossi, Fabio; Yeo, Ailing; George, Joshy; Kuznetsov, Vladimir A; Lee, Yew Kok; Charn, Tze Howe; Palanisamy, Nallasivam; Miller, Lance D; Cheung, Edwin; Katzenellenbogen, Benita S; Ruan, Yijun; Bourque, Guillaume; Wei, Chia-Lin; Liu, Edison T

    2007-06-01

    Using a chromatin immunoprecipitation-paired end diTag cloning and sequencing strategy, we mapped estrogen receptor alpha (ERalpha) binding sites in MCF-7 breast cancer cells. We identified 1,234 high confidence binding clusters of which 94% are projected to be bona fide ERalpha binding regions. Only 5% of the mapped estrogen receptor binding sites are located within 5 kb upstream of the transcriptional start sites of adjacent genes, regions containing the proximal promoters, whereas vast majority of the sites are mapped to intronic or distal locations (>5 kb from 5' and 3' ends of adjacent transcript), suggesting transcriptional regulatory mechanisms over significant physical distances. Of all the identified sites, 71% harbored putative full estrogen response elements (EREs), 25% bore ERE half sites, and only 4% had no recognizable ERE sequences. Genes in the vicinity of ERalpha binding sites were enriched for regulation by estradiol in MCF-7 cells, and their expression profiles in patient samples segregate ERalpha-positive from ERalpha-negative breast tumors. The expression dynamics of the genes adjacent to ERalpha binding sites suggest a direct induction of gene expression through binding to ERE-like sequences, whereas transcriptional repression by ERalpha appears to be through indirect mechanisms. Our analysis also indicates a number of candidate transcription factor binding sites adjacent to occupied EREs at frequencies much greater than by chance, including the previously reported FOXA1 sites, and demonstrate the potential involvement of one such putative adjacent factor, Sp1, in the global regulation of ERalpha target genes. Unexpectedly, we found that only 22%-24% of the bona fide human ERalpha binding sites were overlapping conserved regions in whole genome vertebrate alignments, which suggest limited conservation of functional binding sites. Taken together, this genome-scale analysis suggests complex but definable rules governing ERalpha binding and gene

  15. Characterization and Consequences of Estrogen Receptor Exon Five Deletion.

    DTIC Science & Technology

    1997-08-01

    the assembly of an adhesion belt (whose contraction has been implicated in lumen formation during gland development) [17], and tight junctions...down regulation by gonadotropins. Molecular Endocrinology, 1997. 11: p. 172-182. 87. Kuiper , G., et al., Cloning of a novel estrogen receptor...and K. Korach, Editorial: A new actor in the estrogen receptor drama - enter ER-B3. Endocrinology, 1997. 138(3): p. 861-862. 90. Kuiper , G.G.J.M., et

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

    PubMed

    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.

  17. 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

  18. Estrogen receptor-related receptors in the killifish Fundulus heteroclitus: diversity, expression, and estrogen responsiveness.

    PubMed

    Tarrant, A M; Greytak, S R; Callard, G V; Hahn, M E

    2006-08-01

    The estrogen receptor-related receptors (ERRs) are a group of nuclear receptors that were originally identified on the basis of sequence similarity to the estrogen receptors. The three mammalian ERR genes have been implicated in diverse physiological processes ranging from placental development to maintenance of bone density, but the diversity, function, and regulation of ERRs in non-mammalian species are not well understood. In this study, we report the cloning of four ERR cDNAs from the Atlantic killifish, Fundulus heteroclitus, along with adult tissue expression and estrogen responsiveness. Phylogenetic analysis indicates that F. heteroclitus (Fh)ERRalpha is an ortholog of the single ERRalpha identified in mammals, pufferfish, and zebrafish. FhERRbetaa and FhERRbetab are co-orthologs of the mammalian ERRbeta. Phylogenetic placement of the fourth killifish ERR gene, tentatively identified as FhERRgammab, is less clear. The four ERRs showed distinct, partially overlapping mRNA expression patterns in adult tissues. FhERRalpha was broadly expressed. FhERRbetaa was expressed at apparently low levels in eye, brain, and ovary. FhERRbetab was expressed more broadly in liver, gonad, eye, brain, and kidney. FhERRgammab was expressed in multiple tissues including gill, heart, kidney, and eye. Distinct expression patterns of FhERRbetaa and FhERRbetab are consistent with subfunctionalization of the ERRbeta paralogs. Induction of ERRalpha mRNA by exogenous estrogen exposure has been reported in some mammalian tissues. In adult male killifish, ERR expression did not significantly change following estradiol injection, but showed a trend toward a slight induction (three- to five-fold) of ERRalpha expression in heart. In a second, more targeted experiment, expression of ERRalpha in adult female killifish was downregulated 2.5-fold in the heart following estradiol injection. In summary, our results indicate that killifish contain additional ERR genes relative to mammals, including

  19. Estrogen-induced SDF-1α production promotes the progression of ER-negative breast cancer via the accumulation of MDSCs in the tumor microenvironment

    PubMed Central

    Ouyang, Liquan; Chang, Weilong; Fang, Bin; Qin, Jieting; Qu, Xincai; Cheng, Fanjun

    2016-01-01

    Estrogen plays a role in the processes of tumorigenesis, metastasis, and drug resistance in estrogen receptor (ER)-positive breast cancer (BC). Whether estrogen contributes to ER-negative BC is unclear. Here, we aimed to investigate whether estrogen could stimulate the secretion of stromal-derived factor-1 (SDF-1α) by cancer-associated fibroblasts (CAFs) to promote the progression of ER-negative BC. We transplanted ER-negative BC cells into ovariectomized mice, which was followed by continuous injection of estrogen, and found that estrogen promoted the tumorigenesis of BC. Furthermore, High levels of SDF-1α and tumor-infiltrating myeloid-derived suppressor cells (MDSCs) were detected in the estrogen treatment group. Estrogen stimulates secretion of SDF-1α by CAFs extracted from BC patients. Recombinant SDF-1α could recruit MDSCs isolated from bone marrow cells of mice. In addition, the co-culture of CAFs and MDSCs demonstrated that the recruitment of MDSCs was increased when CAFs were exposed to estrogen. Using AMD3100 to block the SDF-1α/CXCR4 axis or gemcitabine to delete MDSCs, we observed that both of these agents could neutralize the effect of estrogen on tumorigenesis. Together, these results suggest that estrogen may promote the progression of ER-negative BC by stimulating CAFs to secrete SDF-1α, which can recruit MDSCs to the tumor microenvironment to exert tumor-promoting effects. PMID:27996037

  20. Estrogen-induced SDF-1α production promotes the progression of ER-negative breast cancer via the accumulation of MDSCs in the tumor microenvironment.

    PubMed

    Ouyang, Liquan; Chang, Weilong; Fang, Bin; Qin, Jieting; Qu, Xincai; Cheng, Fanjun

    2016-12-20

    Estrogen plays a role in the processes of tumorigenesis, metastasis, and drug resistance in estrogen receptor (ER)-positive breast cancer (BC). Whether estrogen contributes to ER-negative BC is unclear. Here, we aimed to investigate whether estrogen could stimulate the secretion of stromal-derived factor-1 (SDF-1α) by cancer-associated fibroblasts (CAFs) to promote the progression of ER-negative BC. We transplanted ER-negative BC cells into ovariectomized mice, which was followed by continuous injection of estrogen, and found that estrogen promoted the tumorigenesis of BC. Furthermore, High levels of SDF-1α and tumor-infiltrating myeloid-derived suppressor cells (MDSCs) were detected in the estrogen treatment group. Estrogen stimulates secretion of SDF-1α by CAFs extracted from BC patients. Recombinant SDF-1α could recruit MDSCs isolated from bone marrow cells of mice. In addition, the co-culture of CAFs and MDSCs demonstrated that the recruitment of MDSCs was increased when CAFs were exposed to estrogen. Using AMD3100 to block the SDF-1α/CXCR4 axis or gemcitabine to delete MDSCs, we observed that both of these agents could neutralize the effect of estrogen on tumorigenesis. Together, these results suggest that estrogen may promote the progression of ER-negative BC by stimulating CAFs to secrete SDF-1α, which can recruit MDSCs to the tumor microenvironment to exert tumor-promoting effects.

  1. 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

  2. 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.

  3. Delayed puberty and estrogen resistance in a woman with estrogen receptor α variant.

    PubMed

    Quaynor, Samuel D; Stradtman, Earl W; Kim, Hyung-Goo; Shen, Yiping; Chorich, Lynn P; Schreihofer, Derek A; Layman, Lawrence C

    2013-07-11

    Although androgen resistance has been characterized in men with a normal chromosome complement and mutations in the androgen-receptor gene, a mutation in the gene encoding estrogen receptor α (ESR1) was previously described only in one man and not, to our knowledge, in a woman. We now describe an 18-year-old woman without breast development and with markedly elevated serum levels of estrogens and bilateral multicystic ovaries. She was found to have a homozygous loss-of-function ESR1 mutation in a completely conserved residue that interferes with estrogen signaling. Her clinical presentation was similar to that in the mouse orthologue knockout. This case shows that disruption of ESR1 causes profound estrogen resistance in women. (Funded by the National Institutes of Health.).

  4. The Molecular, Cellular and Clinical Consequences of Targeting the Estrogen Receptor Following Estrogen Deprivation Therapy

    PubMed Central

    Fan, Ping; Maximov, Philipp Y.; Curpan, Ramona F.; Abderrahman, Balkees; Jordan, V. Craig

    2015-01-01

    During the past twenty years our understanding of the control of breast tumor development, growth and survival has changed dramatically. The once long forgotten application of high dose synthetic estrogen therapy as the first chemical therapy to treat any cancer has been resurrected, refined and reinvented as the new biology of estrogen-induced apoptosis. High dose estrogen therapy was cast aside once tamoxifen, from its origins as a failed “morning after pill”, was reinvented as the first targeted therapy to treat any cancer. The current understanding of the mechanism of estrogen-induced apoptosis is described as a consequence of acquired resistance to long term antihormone therapy in estrogen receptor (ER) positive breast cancer. The ER signal transduction pathway remains a target for therapy in breast cancer despite “antiestrogen” resistance, but becomes a regulator of resistance. Multiple mechanisms of resistance come into play: Selective ER Modulator (SERM) stimulated growth, growth factor/ER crosstalk, estrogen-induced apoptosis and mutations of ER. But it is with the science of estrogen-induced apoptosis that the next innovation in women’s health will be developed. Recent evidence suggests that the glucocorticoid properties of medroxyprogesterone acetate blunt estrogen-induced apoptosis in estrogen deprived breast cancer cell populations. As a result breast cancer develops during long-term Hormone Replacement Therapy (HRT). A new synthetic progestin with estrogen-like properties, such as the 19 nortestosterone derivatives used in oral contraceptives, will continue to protect the uterus from unopposed estrogen stimulation but at the same time, reinforce apoptosis in vulnerable populations of nascent breast cancer cells. PMID:26052034

  5. 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

  6. Laccase-mediated transformations of endocrine disrupting chemicals abolish binding affinities to estrogen receptors and their estrogenic activity in zebrafish.

    PubMed

    Torres-Duarte, Cristina; Viana, María Teresa; Vazquez-Duhalt, Rafael

    2012-10-01

    Endocrine disrupting chemicals (EDCs) are known to mainly affect aquatic organisms, producing negative effects in aquaculture. Transformation of the estrogenic compounds 17β-estradiol (E2), bisphenol-A (BPA), nonylphenol (NP), and triclosan (TCS) by laccase of Coriolopsis gallica was studied. Laccase is able to efficiently transform them into polymers. The estrogenic activity of the EDCs and their laccase transformation products was evaluated in vitro as their affinity for the human estrogen receptor alpha (hERα) and for the ligand binding domain of zebrafish (Danio rerio) estrogen receptor alpha (zfERαLBD). E2, BPA, NP, and TCS showed higher affinity for the zfERαLBD than for hERα. After laccase treatment, no affinity was found, except a marginal affinity of E2 products for the zfERαLBD. Endocrine disruption studies in vivo on zebrafish were performed using the induction of vitellogenin 1 as a biomarker (VTG1 mRNA levels). The use of enzymatic bioreactors, containing immobilized laccase, efficiently eliminates the endocrine activity of BPA and TCS, and significantly reduces the effects of E2. The potential use of enzymatic reactors to eliminate the endocrine activity of EDCs in supply water for aquaculture is discussed.

  7. Photoperiod affects estrogen receptor α, estrogen receptor β and aggressive behavior

    PubMed Central

    Trainor, Brian C.; Rowland, Michael R.; Nelson, Randy J.

    2007-01-01

    Estrogens have important effects on male and female social behavior. Despite growing knowledge of the anatomy and behavioral effects of the two predominant estrogen receptor subtypes in mammals (ERα and ERβ), relatively little is known about how these receptors respond to salient environmental stimuli. Many seasonally breeding species respond to changing photoperiods that predict seasonal changes in resource availability. We characterized the effects of photoperiod on aggressive behavior in two species of Peromyscus that exhibit gonadal regression in short days. P. polionotus (old field mice) were more aggressive than P. maniculatus (deer mice) and both species were more aggressive in short days. We used immunocytochemistry and real-time polymerase chain reaction to characterize the effects of photoperiod on ERα and ERβ expression. In both species ERα-immunoreactive staining in the posterior bed nucleus of the stria terminalis (BNST) was increased in short vs. long days. Both species had reduced ERβ-immunoreactive expression in the posterior BNST in short days. In the medial amygdala ERβ immunoreactivity was increased in long days for both species. Using real-time polymerase chain reaction on punch samples that included the BNST, we observed that ERα mRNA was increased and ERβ mRNA was decreased in short days. These data suggest that the effects of photoperiod on ERα and ERβ expression may thus have important behavioral consequences. PMID:17614949

  8. 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.

  9. 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

  10. Delay in post-ovariectomy estrogen replacement negates estrogen-induced augmentation of post-exercise muscle satellite cell proliferation.

    PubMed

    Mangan, Gary; Iqbal, Sobia; Hubbard, Andrew; Hamilton, Victoria; Bombardier, Eric; Tiidus, Peter M

    2015-11-01

    This study examined the effects of a delay in post-ovariectomy replacement of 17β-estradiol (estrogen) on the post-exercise proliferation of muscle satellite cells. Nine-week-old, ovariectomized, female Sprague-Dawley rats (n = 64) were distributed among 8 groups based on estrogen status (0.25 mg estrogen pellet or sham), exercise status (90 min run at 17 m·min(-1) and a grade of -13.5° or unexercised), and estrogen replacement ("proximal", estrogen replacement within 2 weeks; or "delayed", estrogen replacement at 11 weeks following ovariectomy). Significant increases in satellite cells were found in the soleus and white gastrocnemius muscle (immunofluorescent colocalization of nuclei with Pax7) 72 h following eccentric exercise (p < 0.05) in all exercised groups. Proximal E2 replacement resulted in a further augmentation of muscle satellite cells in exercised rats (p < 0.05) relative to the delayed estrogen replacement group. Expression of PI3K was unaltered and phosphorylation of Akt relative to total Akt increased following estrogen supplementation and exercise. Exercise alone did not alter the expression levels of Akt. An 11 week delay in post-ovariectomy estrogen replacement negated the augmenting influence seen with proximal (2 week delay) post-ovariectomy estrogen replacement on post-exercise muscle satellite cell proliferation. This effect appears to be independent of the PI3K-Akt signaling pathway.

  11. Estrogen Receptors and Their Implications in Colorectal Carcinogenesis

    PubMed Central

    Caiazza, Francesco; Ryan, Elizabeth J.; Doherty, Glen; Winter, Desmond C.; Sheahan, Kieran

    2015-01-01

    Upon binding their cognate receptors, ERα (ESR1) and ERβ (ESR2), estrogens activate intracellular signaling cascades that have important consequences for cellular behavior. Historically linked to carcinogenesis in reproductive organs, estrogens have also been implicated in the pathogenesis of different cancer types of non-reproductive tissues including the colon. ERβ is the predominant estrogen receptor expressed in both normal and malignant colonic epithelium. However, during colon cancer progression, ERβ expression is lost, suggesting that estrogen signaling may play a role in disease progression. Estrogens may in fact exert an anti-tumor effect through selective activation of pro-apoptotic signaling mediated by ERβ, inhibition of inflammatory signals and modulation of the tumor microenvironment. In this review, we analyze the estrogen pathway as a possible therapeutic avenue in colorectal cancer, we report the most recent experimental evidence to explain the cellular and molecular mechanisms of estrogen-mediated protection against colorectal tumorigenesis, and we discuss future challenges and potential avenues for targeted therapy. PMID:25699240

  12. Estrogen receptor polymorphisms: significance to human physiology, disease and therapy.

    PubMed

    Figtree, Gemma A; Noonan, Jonathon E; Bhindi, Ravinay; Collins, Peter

    2009-01-01

    Other than its well-recognized effects on reproductive physiology, estrogen has important actions in a wide variety of other body systems with important examples including bone, blood vessels and the heart. These effects are seen in both females and males. Investigators have hypothesized those genetic variants in the genes coding for estrogen signaling proteins may cause variable sensitivity to the hormone and influence an individual's estrogen-sensitive phenotypes. The most obvious candidate genes are the estrogen receptors alpha and (ERalpha and beta). However, the regulation of these genes is complex and not well understood. Furthermore, their coding exons, and regulatory sequences are dispersed across large segments of the genome. A number of common polymorphisms have been identified in both ERalpha and ERbeta, with variable degrees of evidence of their direct biological significance and their association with human disease. The identification of genetic variations associated with altered estrogen response is of potential public health importance. Insights may be gained into the pathogenesis of estrogen sensitive diseases such as osteoporosis, breast cancer and cardiovascular disease contributing to the development and application of newer therapies for these disorders. Furthermore, genetic variants that alter sensitivity to estrogen may affect both therapeutic and harmful responses to exogenous estrogen administered in the form of the oral contraceptive pill or hormone replacement therapy. This clinical significance has led to the publication of a number of patents which will be reviewed.

  13. Characterization and Consequences of Estrogen Receptor Exon Five Deletion.

    DTIC Science & Technology

    1998-08-01

    adhesion belt (whose 127 contraction has been implicated in lumen formation during gland development) (17), and tight junctions (necessary for...G.G.J.M. Kuiper , J.-A. Gustafsson, and O.-K. Park-Sarge, Estrogen receptor-fl mRNA expression in rat ovary: down regulation by gonadotropins...Molecular Endocrinology, 1997. 11: p. 172-182. 87. Kuiper , G., E. Enmark, M. Pelto-Huikko, S. Nilsson, and J.-A. Gustafsson, Cloning of a novel estrogen

  14. Functional associations between two estrogen receptors, environmental estrogens, and sexual disruption in the roach (Rutilus rutilus).

    PubMed

    Katsu, Yoshinao; Lange, Anke; Urushitani, Hiroshi; Ichikawa, Rie; Paull, Gregory C; Cahill, Laura L; Jobling, Susan; Tyler, Charles R; Iguchi, Taisen

    2007-05-01

    Wild male roach (Rutilus rutilus) living in U.K. rivers contaminated with estrogenic effluents from wastewater treatment works show feminized responses and have a reduced reproductive capability, but the chemical causation of sexual disruption in the roach has not been established. Feminized responses were induced in male roach exposed to environmentally relevant concentrations of the pharmaceutical estrogen 17alpha-ethinylestradiol, EE2 (up to 4 ng/ L), during early life (from fertilization to 84 days posthatch, dph), and these effects were signaled by altered patterns of expression of two cloned roach estrogen receptor (ER) subtypes, ERalpha. and ERbeta, in the brain and gonad/ liver. Transactivation assays were developed for both roach ER subtypes and the estrogenic potencies of steroidal estrogens differed markedly at the different ER subtypes. EE2 was by far the most potent chemical, and estrone (E1, the most prevalent environmental steroid in wastewater discharges) was equipotent with estradiol (E2) in activating the ERs. Comparison of the EC50 values for the compounds tested showed that ERbeta was 3-21-fold more sensitive to natural steroidal estrogens and 54-fold more sensitive to EE2 as compared to ERalpha. These findings add substantial support to the hypothesis that steroidal estrogens play a significant role in the induction of intersex in roach populations in U.K. rivers and that the molecular approach described could be usefully applied to understand interspecies sensitivity to xenoestrogens.

  15. 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.

  16. Mechanism of the estrogen receptor interaction with 4-hydroxytamoxifen

    SciTech Connect

    Sasson, S.; Notides, A.C.

    1988-04-01

    The binding mechanism of the estrogen receptor with 4-(/sup 3/H)hydroxytamoxifen was investigated. The equilibrium binding analysis with 4-(/sup 3/H)hydroxytamoxifen indicated a positive cooperative interaction: the Scatchard plot was convex and the Hill coefficient was 1.4-1.5. This binding appears similar to the positively cooperative interaction of the estrogen receptor with (/sup 3/H)estradiol. However, a competitive binding assay with a saturating concentration of (/sup 3/H) estradiol and variable concentrations of 4-hydroxytamoxifen produced nonparallel displacement curves indicating that the binding mechanism of the receptor with these two ligands is different. The competitive binding assay with (/sup 3/H)estradiol and 4-hydroxytamoxifen at constant molar ratios demonstrated that the receptor's affinity for estradiol was reduced and the receptor preferentially bound 4-hydroxytamoxifen. These data suggest that 4-hydroxytamoxifen interacts with the receptor differently than estradiol; it antagonizes the binding of estradiol when these two ligands are simultaneously present.

  17. Glyphosate induces human breast cancer cells growth via estrogen receptors.

    PubMed

    Thongprakaisang, Siriporn; Thiantanawat, Apinya; Rangkadilok, Nuchanart; Suriyo, Tawit; Satayavivad, Jutamaad

    2013-09-01

    Glyphosate is an active ingredient of the most widely used herbicide and it is believed to be less toxic than other pesticides. However, several recent studies showed its potential adverse health effects to humans as it may be an endocrine disruptor. This study focuses on the effects of pure glyphosate on estrogen receptors (ERs) mediated transcriptional activity and their expressions. Glyphosate exerted proliferative effects only in human hormone-dependent breast cancer, T47D cells, but not in hormone-independent breast cancer, MDA-MB231 cells, at 10⁻¹² to 10⁻⁶M in estrogen withdrawal condition. The proliferative concentrations of glyphosate that induced the activation of estrogen response element (ERE) transcription activity were 5-13 fold of control in T47D-KBluc cells and this activation was inhibited by an estrogen antagonist, ICI 182780, indicating that the estrogenic activity of glyphosate was mediated via ERs. Furthermore, glyphosate also altered both ERα and β expression. These results indicated that low and environmentally relevant concentrations of glyphosate possessed estrogenic activity. Glyphosate-based herbicides are widely used for soybean cultivation, and our results also found that there was an additive estrogenic effect between glyphosate and genistein, a phytoestrogen in soybeans. However, these additive effects of glyphosate contamination in soybeans need further animal study.

  18. p150/Glued Modifies Nuclear Estrogen Receptor Function

    PubMed Central

    Lee, Soo Jung; Chae, Christina; Wang, Michael M.

    2009-01-01

    Estrogen modulates gene expression through interactions with estrogen receptors (ERs) that bind chromosomal target genes. Recent studies have suggested an interaction between the cytoskeletal system and estrogen signaling; these have implicated a role of cytoplasmic microtubules in scaffolding ERα and enhancing nongenomic function; in addition, other experiments demonstrate that dynein light chain 1 may chaperone ERα to the nucleus, indirectly increasing transcriptional potency. Actin/myosin and dynein light chain 1 are also required for estrogen-mediated chromosomal movement that is required for transcriptional up-regulation of ERα targets. We present evidence that the dynactin component, p150/glued, directly influences the potency of nuclear ER function. Increasing the stoichiometric ratio of p150/glued and ERα by overexpression enhances estrogen responses. ERα enhancement by p150/glued does not appear to be influenced by shifts in subcellular localization because microtubule disruption fails to increase nuclear ERα. Rather, we find that modest amounts of p150/glued reside in the nucleus of cells, suggesting that it plays a direct role in nuclear transcription. Notably, p150/glued is recruited to the pS2 promoter in the presence of hormone, and, in MCF-7 cells, knockdown of p150/glued levels reduces estrogen-dependent transcription. Our results suggest that p150/glued modulates estrogen sensitivity in cells through nuclear mechanisms. PMID:19228793

  19. Phytoestrogens from Psoralea corylifolia reveal estrogen receptor-subtype selectivity.

    PubMed

    Xin, D; Wang, H; Yang, J; Su, Y-F; Fan, G-W; Wang, Y-F; Zhu, Y; Gao, X-M

    2010-02-01

    The seed of Psoralea corylifolia L. (PCL), a well-known traditional Chinese medicine, has been applied as a tonic or an aphrodisiac agent and commonly used as a remedy for bone fracture, osteomalacia and osteoporosis in China. In our study, the estrogen receptor subtype-selective activities of the extracts and compounds derived from PCL were analyzed using the HeLa cell assay. The different fractions including petroleum ether, CH(2)Cl(2) and EtOAc fractions of the EtOH extract of PCL showed significant activity in activating either ERalpha or ERbeta whereas the n-BuOH fraction showed no estrogenic activity. Further chromatographic purification of the active fractions yielded seven compounds including the two coumarins isopsoralen and psoralen, the four flavonoids isobavachalcone, bavachin, corylifol A and neobavaisoflavone, and the meroterpene phenol, bakuchiol. In reporter gene assay, the two coumarins (10(-8)-10(-5)M) acted as ERalpha-selective agonists while the other compounds (10(-9)-10(-6)M) activated both ERalpha and ERbeta. The estrogenic activities of all compounds could be completely suppressed by the pure estrogen antagonist, ICI 182,780, suggesting that the compounds exert their activities through ER. Only psoralen and isopsoralen as ERalpha agonists promoted MCF-7 cell proliferation significantly. Although all the compounds have estrogenic activity, they may exert different biological effects. In conclusion, both ER subtype-selective and nonselective activities in compounds derived from PCL suggested that PCL could be a new source for selective estrogen-receptor modulators.

  20. 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.

  1. 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

  2. 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

    2010-02-05

    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.

  3. RIME proteomics of estrogen and progesterone receptors in breast cancer

    PubMed Central

    D’Santos, Clive; Taylor, Christopher; Carroll, Jason S.; Mohammed, Hisham

    2015-01-01

    Nuclear receptors play an important role in transcriptional regulation of diverse cellular processes and is also relevant in diseases such as cancer. In breast cancer, the nuclear receptorsestrogen receptor (ER) and progesterone receptor (PR) are classical markers of the disease and are used to classify breast cancer subtypes. Using a recently developed affinity purification MS technique (RIME) [1], we investigate the protein interactors of ER and PR in breast cancer cell lines upon stimulation by the ligands – estrogen and progesterone. The data is deposited at proteomeXchange (PXD002104) and is part of a publication [2] that explains the link between the two nuclear receptors and potential consequences of this in breast cancer. In this manuscript, we describe the methodology used and provide details on experimental procedures, analysis methods and analysis of raw data. The purpose of this article is to enable reproducibility of the data and provide technical recommendations on performing RIME in hormonal contexts. PMID:26543891

  4. Estrogen receptor-alpha mediates estrogen facilitation of baroreflex heart rate responses in conscious mice.

    PubMed

    Pamidimukkala, Jaya; Xue, Baojian; Newton, Leslie G; Lubahn, Dennis B; Hay, Meredith

    2005-03-01

    Estrogen facilitates baroreflex heart rate responses evoked by intravenous infusion of ANG II and phenylephrine (PE) in ovariectomized female mice. The present study aims to identify the estrogen receptor subtype involved in mediating these effects of estrogen. Baroreflex responses to PE, ANG II, and sodium nitroprusside (SNP) were tested in intact and ovariectomized estrogen receptor-alpha knockout (ERalphaKO) with (OvxE+) or without (OvxE-) estrogen replacement. Wild-type (WT) females homozygous for the ERalpha(+/+) were used as controls. Basal mean arterial pressures (MAP) and heart rates were comparable in all the groups except the ERalphaKO-OvxE+ mice. This group had significantly smaller resting MAP, suggesting an effect of estrogen on resting vascular tone possibly mediated by the ERbeta subtype. Unlike the WT females, estrogen did not facilitate baroreflex heart rate responses to either PE or ANG II in the ERalphaKO-OvxE+ mice. The slope of the line relating baroreflex heart rate decreases with increases in MAP evoked by PE was comparable in ERalphaKO-OvxE- (-6.97 +/- 1.4 beats.min(-1).mmHg(-1)) and ERalphaKO-OvxE+ (-6.18 +/- 1.3) mice. Likewise, the slope of the baroreflex bradycardic responses to ANG II was similar in ERalphaKO-OvxE- (-3.87 +/- 0.5) and ERalphaKO-OvxE+(-2.60 +/- 0.5) females. Data suggest that estrogen facilitation of baroreflex responses to PE and ANG II is predominantly mediated by ERalpha subtype. A second important observation in the present study is that the slope of ANG II-induced baroreflex bradycardia is significantly blunted compared with PE in the intact as well as the ERalphaKO-OvxE+ females. We have previously reported that this ANG II-mediated blunting of cardiac baroreflexes is observed only in WT males and not in ovariectomized WT females independent of their estrogen replacement status. The present data suggest that in females lacking ERalpha, ANG II causes blunting of cardiac baroreflexes similar to males and may be

  5. A common variant at the TERT-CLPTM1L locus is associated with estrogen receptor–negative breast cancer

    PubMed Central

    Haiman, Christopher A; Chen, Gary K; Vachon, Celine M; Canzian, Federico; Dunning, Alison; Millikan, Robert C; Wang, Xianshu; Ademuyiwa, Foluso; Ahmed, Shahana; Ambrosone, Christine B; Baglietto, Laura; Balleine, Rosemary; Bandera, Elisa V; Beckmann, Matthias W; Berg, Christine D; Bernstein, Leslie; Blomqvist, Carl; Blot, William J; Brauch, Hiltrud; Buring, Julie E; Carey, Lisa A; Carpenter, Jane E; Chang-Claude, Jenny; Chanock, Stephen J; Chasman, Daniel I; Clarke, Christine L; Cox, Angela; Cross, Simon S; Deming, Sandra L; Diasio, Robert B; Dimopoulos, Athanasios M; Driver, W Ryan; Dünnebier, Thomas; Durcan, Lorraine; Eccles, Diana; Edlund, Christopher K; Ekici, Arif B; Fasching, Peter A; Feigelson, Heather S; Flesch-Janys, Dieter; Fostira, Florentia; Försti, Asta; Fountzilas, George; Gerty, Susan M; Giles, Graham G; Godwin, Andrew K; Goodfellow, Paul; Graham, Nikki; Greco, Dario; Hamann, Ute; Hankinson, Susan E; Hartmann, Arndt; Hein, Rebecca; Heinz, Judith; Holbrook, Andrea; Hoover, Robert N; Hu, Jennifer J; Hunter, David J; Ingles, Sue A; Irwanto, Astrid; Ivanovich, Jennifer; John, Esther M; Johnson, Nicola; Jukkola-Vuorinen, Arja; Kaaks, Rudolf; Ko, Yon-Dschun; Kolonel, Laurence N; Konstantopoulou, Irene; Kosma, Veli-Matti; Kulkarni, Swati; Lambrechts, Diether; Lee, Adam M; Le Marchand, Loïc; Lesnick, Timothy; Liu, Jianjun; Lindstrom, Sara; Mannermaa, Arto; Margolin, Sara; Martin, Nicholas G; Miron, Penelope; Montgomery, Grant W; Nevanlinna, Heli; Nickels, Stephan; Nyante, Sarah; Olswold, Curtis; Palmer, Julie; Pathak, Harsh; Pectasides, Dimitrios; Perou, Charles M; Peto, Julian; Pharoah, Paul D P; Pooler, Loreall C; Press, Michael F; Pylkäs, Katri; Rebbeck, Timothy R; Rodriguez-Gil, Jorge L; Rosenberg, Lynn; Ross, Eric; Rüdiger, Thomas; Silva, Isabel dos Santos; Sawyer, Elinor; Schmidt, Marjanka K; Schulz-Wendtland, Rüdiger; Schumacher, Fredrick; Severi, Gianluca; Sheng, Xin; Signorello, Lisa B; Sinn, Hans-Peter; Stevens, Kristen N; Southey, Melissa C; Tapper, William J; Tomlinson, Ian; Hogervorst, Frans B L; Wauters, Els; Weaver, JoEllen; Wildiers, Hans; Winqvist, Robert; Van Den Berg, David; Wan, Peggy; Xia, Lucy Y; Yannoukakos, Drakoulis; Zheng, Wei; Ziegler, Regina G; Siddiq, Afshan; Slager, Susan L; Stram, Daniel O; Easton, Douglas; Kraft, Peter; Henderson, Brian E; Couch, Fergus J

    2012-01-01

    Estrogen receptor (ER)-negative breast cancer shows a higher incidence in women of African ancestry compared to women of European ancestry. In search of common risk alleles for ER-negative breast cancer, we combined genome-wide association study (GWAS) data from women of African ancestry (1,004 ER-negative cases and 2,745 controls) and European ancestry (1,718 ER-negative cases and 3,670 controls), with replication testing conducted in an additional 2,292 ER-negative cases and 16,901 controls of European ancestry. We identified a common risk variant for ER-negative breast cancer at the TERT-CLPTM1L locus on chromosome 5p15 (rs10069690: per-allele odds ratio (OR) = 1.18 per allele, P = 1.0 × 10−10). The variant was also significantly associated with triple-negative (ER-negative, progesterone receptor (PR)-negative and human epidermal growth factor-2 (HER2)-negative) breast cancer (OR = 1.25, P = 1.1 × 10−9), particularly in younger women (<50 years of age) (OR = 1.48, P = 1.9 × 10−9). Our results identify a genetic locus associated with estrogen receptor negative breast cancer subtypes in multiple populations. PMID:22037553

  6. 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

  7. Estrogen receptor-beta, estrogen receptor-alpha, and progesterone resistance in endometriosis.

    PubMed

    Bulun, Serdar E; Cheng, You-Hong; Pavone, Mary Ellen; Xue, Qing; Attar, Erkut; Trukhacheva, Elena; Tokunaga, Hideki; Utsunomiya, Hiroki; Yin, Ping; Luo, Xia; Lin, Zhihong; Imir, Gonca; Thung, Stephen; Su, Emily J; Kim, J Julie

    2010-01-01

    Loss of progesterone signaling in the endometrium may be a causal factor in the development of endometriosis, and progesterone resistance is commonly observed in women with this disease. In endometriotic stromal cells, the levels of progesterone receptor (PR), particularly the PR-B isoform, are significantly decreased, leading to a loss of paracrine signaling. PR deficiency likely underlies the development of progesterone resistance in women with endometriosis who no longer respond to progestin therapy. Here we review the complex epigenetic and transcriptional mechanisms leading to PR deficiency. The initial event may involve deficient methylation of the estrogen receptor (ER)beta promoter resulting in pathologic overexpression of ERbeta in endometriotic stromal cells. We speculate that alterations in the relative levels of ERbeta and ERalpha in endometrial tissue dictate E2-regulated PR expression, such that a decreased ERalpha-tauomicron-ERbeta ratio may result in suppression of PR. In this review, we propose a molecular model that may be responsible for changes in ERbeta and ERalpha leading to PR loss and progesterone resistance in endometriosis.

  8. Sex Hormones and Cardiometabolic Health: Role of Estrogen and Estrogen Receptors.

    PubMed

    Clegg, Deborah; Hevener, Andrea L; Moreau, Kerrie L; Morselli, Eugenia; Criollo, Alfredo; Van Pelt, Rachael E; Vieira-Potter, Victoria J

    2017-02-17

    With increased life expectancy, women will spend over three decades of life post-menopause. The menopausal transition increases susceptibility to metabolic diseases such as obesity, diabetes, cardiovascular disease, and cancer. Thus, it is more important than ever to develop effective hormonal treatment strategies to protect aging women. Understanding the role of estrogens, and their biological actions mediated by estrogen receptors (ERs), in the regulation of cardiometabolic health is of paramount importance to discover novel targeted therapeutics. In this brief review, we provide a detailed overview of the literature, from basic science findings to human clinical trial evidence, supporting a protective role of estrogens and their receptors, specifically ERα, in maintenance of cardiometabolic health. In so doing, we provide a concise mechanistic discussion of some of the major tissue-specific roles of estrogens signaling through ERα. Taken together, evidence suggests that targeted, perhaps receptor-specific, hormonal therapies can and should be used to optimize the health of women as they transition through menopause, while reducing the undesired complications that have limited the efficacy and use of traditional hormone replacement interventions.

  9. Preliminary genetic imaging study of the association between estrogen receptor-α gene polymorphisms and harsh human maternal parenting.

    PubMed

    Lahey, Benjamin B; Michalska, Kalina J; Liu, Chunyu; Chen, Qi; Hipwell, Alison E; Chronis-Tuscano, Andrea; Waldman, Irwin D; Decety, Jean

    2012-09-06

    A failure of neural changes initiated by the estrogen surge in late pregnancy to reverse the valence of infant stimuli from aversive to rewarding is associated with dysfunctional maternal behavior in nonhuman mammals. Estrogen receptor-α plays the crucial role in mediating these neural effects of estrogen priming. This preliminary study examines associations between estrogen receptor-α gene polymorphisms and human maternal behavior. Two polymorphisms were associated with human negative maternal parenting. Furthermore, hemodynamic responses in functional magnetic resonance imaging to child stimuli in neural regions associated with social cognition fully mediated the association between genetic variation and negative parenting. This suggests testable hypotheses regarding a biological pathway between genetic variants and dysfunctional human maternal parenting.

  10. Estrogen Receptor Mutants/Variants in Human Breast Cancer.

    DTIC Science & Technology

    1997-12-01

    Recherche Louis- Charles Simard, Montreal, Canada. Four nor- mal human breast tissues from reduction mammoplasties of pre- menopausal women were obtained...to hormone resistance. Cancer Res 1990; 50: 6208-17. 22. Karnik PS, Kulkarni S, Lui XP, Budd GT, Bukowski RM. Estrogen receptor mutations in

  11. Estrogen Receptor Polymorphisms and the Vascular Effects of Hormone Therapy

    PubMed Central

    Rossouw, Jacques; Bray, Paul; Liu, Jingmin; Kooperberg, Charles; Hsia, Judith; Lewis, Cora; Cushman, Mary; Bonds, Denise; Hendrix, Susan; Papanicolaou, George; Howard, Tim; Herrington, David

    2010-01-01

    Objective To test whether estrogen receptor polymorphisms modify the effects of postmenopausal hormone therapy on biomarkers and on risk of coronary heart disease events, stroke, or venous thrombo-embolism. Methods and Results The design was a nested case-control study in the Women’s Health Initiative trials of postmenopausal hormone therapy. The study included all cases in the first 4 years: coronary heart disease, 359; stroke, 248; venous thrombo-embolism, 217). Six estrogen receptor-αand one estrogen receptor-β polymorphisms were genotyped; 8 biomarkers known to be affected by hormone therapy were measured at baseline and one year after randomization. The polymorphisms were not associated with risk of vascular events, and did not modify the increased risks of coronary heart disease, stroke, or venous thrombo-embolism due to hormone therapy. However, a reduced response of plasmin-antiplasmin (PAP) to hormone therapy was noted for ESR1 IVS1-354 (interaction P<0.0001, corrected for multiple comparisons P=0.014) and ESR1 IVS1-1415 (interaction P<0.0001, corrected P= 0.014). Conclusions Estrogen receptor polymorphisms reduce the effect of postmenopausal hormone therapy on PAP, a marker of coagulation and fibrinolysis. However screening for ER polymorphisms to identify women at less risk of adverse cardiovascular outcomes is not likely to be useful for making HT treatment decisions. PMID:21106950

  12. Design and structure of stapled peptides binding to estrogen receptors.

    PubMed

    Phillips, Chris; Roberts, Lee R; Schade, Markus; Bazin, Richard; Bent, Andrew; Davies, Nichola L; Moore, Rob; Pannifer, Andrew D; Pickford, Andrew R; Prior, Stephen H; Read, Christopher M; Scott, Andrew; Brown, David G; Xu, Bin; Irving, Stephen L

    2011-06-29

    Synthetic peptides that specifically bind nuclear hormone receptors offer an alternative approach to small molecules for the modulation of receptor signaling and subsequent gene expression. Here we describe the design of a series of novel stapled peptides that bind the coactivator peptide site of estrogen receptors. Using a number of biophysical techniques, including crystal structure analysis of receptor-stapled peptide complexes, we describe in detail the molecular interactions and demonstrate that all-hydrocarbon staples modulate molecular recognition events. The findings have implications for the design of stapled peptides in general.

  13. Multi-epitope Folate Receptor Alpha Peptide Vaccine, Sargramostim, and Cyclophosphamide in Treating Patients With Triple Negative Breast Cancer

    ClinicalTrials.gov

    2017-01-24

    Bilateral Breast Carcinoma; Estrogen Receptor Negative; HER2/Neu Negative; Progesterone Receptor Negative; Stage IB Breast Cancer; Stage II Breast Cancer; Stage IIA Breast Cancer; Stage IIB Breast Cancer; Stage III Breast Cancer; Stage IIIA Breast Cancer; Stage IIIB Breast Cancer; Stage IIIC Breast Cancer; Stage IV Breast Cancer; Triple-Negative Breast Carcinoma; Unilateral Breast Carcinoma

  14. Estrogen Accelerates Cell Proliferation through Estrogen Receptor α during Rat Liver Regeneration after Partial Hepatectomy

    PubMed Central

    Batmunkh, Baatarsuren; Choijookhuu, Narantsog; Srisowanna, Naparee; Byambatsogt, Uugantsetseg; Synn Oo, Phyu; Noor Ali, Mohmand; Yamaguchi, Yuya; Hishikawa, Yoshitaka

    2017-01-01

    Although estrogen is implicated in the regulation of cell growth and differentiation in many organs, the exact mechanism for liver regeneration is not completely understood. We investigated the effect of estrogen on liver regeneration in male and female Wistar rats after 70% partial hepatectomy (PHx) and performed immunohistochemistry, western blotting and Southwestern histochemistry. 17β-estradiol (E2) and ICI 182,780 were injected into male rats on the day before PHx. The proliferating cell nuclear antigen (PCNA) labeling index reached a maximum at 48 hr after PHx in males, and at 36 hr in females and E2-treated male rats. Estrogen receptor α (ERα) was expressed in zones 1 and 2 in male rats, but was found in all zones in female rats. Interestingly, ERα was not detected at 6–12 hr after PHx but was found at 24–168 hr in male rats. However, ERα expression was found at all sampling time-points in female and E2-treated male rats. The activity of estrogen responsive element binding proteins was detected from 12 hr after PHx in male rats but was found from 6 hr in female and E2-treated male rats. ERα was co-expressed with PCNA during liver regeneration. These results indicate that estrogen may play an important role in liver regeneration through ERα. PMID:28386149

  15. Targeting the androgen receptor in triple-negative breast cancer.

    PubMed

    Gucalp, Ayca; Traina, Tiffany A

    Triple-negative breast cancer represents approximately 15%-20% of all newly diagnosed breast cancers, but it accounts for a disproportionate number of breast cancer-related deaths each year. Owing to the lack of estrogen, progesterone, and human epidermal growth factor receptor 2 expression, patients with triple-negative breast cancer do not benefit from generally well-tolerated and effective therapies targeting the estrogen and human epidermal growth factor receptor 2 signaling pathways and are faced with an increased risk of disease progression and poorer overall survival. The heterogeneity of triple-negative breast cancer has been increasingly recognized and this may lead to therapeutic opportunities because of newly defined oncogenic drivers and targets. A subset of triple-negative breast tumors expresses the androgen receptor (AR) and this may benefit from treatments that inhibit the AR-signaling pathway. The first proof-of-concept trial established activity of the AR antagonist, bicalutamide, in patients with advanced AR+ triple-negative breast cancer. Since that time, evidence further supports the activity of other next-generation AR-targeted agents such as enzalutamide. Not unlike in estrogen receptor-positive breast cancer, mechanisms of resistance are being investigated and rationale exists for thoughtful, well-designed combination regimens such as AR antagonism with CDK4/6 pathway inhibitors or PI3K inhibitors. Furthermore, novel agents developed for the treatment of prostate cancer, which reduce androgen production such as abiraterone acetate and seviteronel, are being tested as well. This review summarizes the underlying biology of AR signaling in breast cancer development and the available clinical trial data for the use of anti-androgen therapy in the treatment of AR+ triple-negative breast cancer.

  16. Estrogen receptor genes in gastropods: phylogenetic divergence and gene expression responses to a synthetic estrogen.

    PubMed

    Hultin, Cecilia L; Hallgren, Per; Hansson, Maria C

    2016-11-01

    Endocrine disrupting chemicals (EDCs) have the potential to affect development and reproduction in gastropods. However, one is today lacking basic understanding of the Molluscan endocrine system and one can therefore not fully explain these EDC-induced affects. Furthermore, only a few genes that potentially may be connected to the endocrine system have been sequenced in gastropods. An example is the estrogen receptor gene (er) that have been identified in a restricted number of freshwater and marine gastropods. Here, we have identified a new partial coding sequence of an estrogen receptor gene (er) in the European common heterobranch Radix balthica. The following phylogenetic analysis divided the ers of heterobranchs and ceanogastropods in two branches. Furthermore, exposure to the synthetic estrogen 17α-ethinylestradiol (EE2) showed that exposure could significantly affect er expression level in the heterobranch R. balthica. This paper is the first that phylogenetically compares gastropods' er, basal er expression profiles, and transcriptional estrogenic responses in gastropods from two different evolutionary groups.

  17. Activation of the G protein-coupled estrogen receptor, but not estrogen receptor α or β, rapidly enhances social learning.

    PubMed

    Ervin, Kelsy Sharice Jean; Mulvale, Erin; Gallagher, Nicola; Roussel, Véronique; Choleris, Elena

    2015-08-01

    Social learning is a highly adaptive process by which an animal acquires information from a conspecific. While estrogens are known to modulate learning and memory, much of this research focuses on individual learning. Estrogens have been shown to enhance social learning on a long-term time scale, likely via genomic mechanisms. Estrogens have also been shown to affect individual learning on a rapid time scale through cell-signaling cascades, rather than via genomic effects, suggesting they may also rapidly influence social learning. We therefore investigated the effects of 17β-estradiol and involvement of the estrogen receptors (ERs) using the ERα agonist propyl pyrazole triol, the ERβ agonist diarylpropionitrile, and the G protein-coupled ER 1 (GPER1) agonist G1 on the social transmission of food preferences (STFP) task, within a time scale that focused on the rapid effects of estrogens. General ER activation with 17β-estradiol resulted in a modest facilitation of social learning, with mice showing a preference up to 30min of testing. Specific activation of the GPER1 also rapidly enhanced social learning, with mice showing a socially learned preference up to 2h of testing. ERα activation instead shortened the expression of a socially learned food preference, while ERβ activation had little to no effects. Thus, rapid estrogenic modulation of social learning in the STFP may be the outcome of competing action at the three main receptors. Hence, estrogens' rapid effects on social learning likely depend on the specific ERs present in brain regions recruited during social learning.

  18. Molecular biology of beta-estradiol-estrogen receptor complex binding to estrogen response element and the effect on cell proliferation.

    PubMed

    Heger, Zbynek; Zitka, Ondrej; Krizkova, Sona; Beklova, Miroslava; Kizek, Rene; Adam, Vojtech

    2013-01-01

    Group of estrogen pollutants, where the highest estrogen activity is reported at estradiol, is characterized by the fact that even at very low concentrations have potential to cause xenoestrogenic effects. During exposure of excessive amounts of estradiols may be produced undesirable effects resulting in the feminization of males of water organisms. The presence of estradiols in drinking water implies also a risk for the human population in the form of cancers of endocrine systems, abnormalities in reproduction or dysfunctions of neuronal and immune system. Currently, the research is focused mainly to uncover the relationship between the estrogen receptors binding affinity with an estrogen response element and estradiol. In this review we summarized facts about molecular biological principles of β estradiol-estrogen receptor complex binding with estrogen response element and its successive effect on cancer genes expression.

  19. 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…

  20. 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 ...

  1. Estrogen binding and estrogen receptor activity in the human prostate: a preliminary report.

    PubMed

    Fondo, E Y; Menendez-Botet, C J; Schwartz, M K; Whitmore, W F

    1981-03-01

    Assay of estrogen receptor activity in prostates from patients who ranged in age from 22 to 78 years and had not received any previous hormonal therapy was carried out by incubation of cytosols with (3)H-estradiol in the presence and absence of excess, nonradioactive estradiol. Hyperplastic prostatic tissues were used in the study. The kinetics of each reaction were studied and analysis of the data revealed 3.4 to 35.7 femtomoles of receptor protein per mg of cytosol protein; the dissociation constants obtained from a Scatchard plot ranged from 1.1 × 10(-10) to 1.2 × 10(-8)M.The small number of patients prevents realistic quantitative assessment of the apparent estrogen binding activity demonstrated in these preliminary studies, but the qualitative identification of such activity provides possible grounds for further insight into the hormonal mechanisms in the pathophysiology of prostatic diseases and of their responses to endocrine therapy.

  2. Histone Deacetylase Inhibitors Equipped with Estrogen Receptor Modulation Activity

    PubMed Central

    Gryder, Berkley E.; Rood, Michael K.; Johnson, Kenyetta A.; Patil, Vishal; Raftery, Eric D.; Yao, Li-Pan D.; Rice, Marcie; Azizi, Bahareh; Doyle, Donald F.; Oyelere, Adegboyega K.

    2013-01-01

    We described a set of novel histone deacetylase inhibitors (HDACi) equipped with either an antagonist or an agonist of the estrogen receptor (ER) to confer selective activity against breast cancers. These bifunctional compounds potently inhibit HDAC at nanomolar concentrations, and either agonize or antagonize ERα and ERβ. The ER antagonist activities of tamoxifen-HDACi conjugates (Tam-HDACi) are nearly identical to those of tamoxifen. Conversely, ethynyl-estradiol HDACi conjugates (EED-HDACi) have attenuated ER agonist activities relative to the parent ethynyl-estradiol. In silico docking analysis provides structural basis for the trends of ER agonism/antagonism and ER subtype selectivity. Excitingly, lead Tam-HDACi conjugates show anticancer activity that is selectively more potent against MCF-7 (ERα positive breast) compared to MDA-MB-231 (triple negative breast cancer), DU145 (prostate cancer) or Vero (non-cancerous cell line). This dual-targeting approach illustrates the utility of designing small molecules with an emphasis on cell-type selectivity, not merely improved potency, working towards a higher therapeutic index at the earliest stages of drug development. PMID:23786452

  3. Rat uterine oxytocin receptor and estrogen receptor α and β mRNA levels are regulated by estrogen through multiple estrogen receptors.

    PubMed

    Murata, Takuya; Narita, Kazumi; Ichimaru, Toru

    2014-03-07

    Estrogen action is mediated through several types of receptors (ERs), such as ERα, ERβ and putative membrane ERs. Oxytocin receptor (OTR) and ER expression levels in the rat uterus are regulated by estrogen; however, which types of ERs are involved has not been elucidated. This study examined OTR, ERα and ERβ levels in ovariectomized rats treated with 17β-estradiol (E2), an ERα agonist (PPT), an ERβ agonist (DPN) or estren (Es). E2 and PPT increased OTR mRNA levels and decreased ERα and ERβ mRNA levels 3 and 6 h posttreatment. DPN decreased ERα and ERβ mRNA levels at 3 and 6 h, while OTR mRNA levels increased at 3 h and decreased at 6 h. OTR mRNA levels increased 3 h after the Es treatment and then declined until 6 h. ERα and ERβ mRNA levels decreased by 3 h and remained low until 6 h posttreatment with Es. The ER antagonist ICI182,780 (ICI) suppressed the increases in OTR mRNA levels induced 3 h after the Es treatment. However, ICI and tamoxifen (Tam) had no significant effect on ERα and ERβ mRNA levels in the Es-treated or vehicle-treated group. In intact rats, proestrus-associated increases in OTR mRNA levels were antagonized by both ICI and Tam. However, decreases in ERα and ERβ mRNA levels were not antagonized by Tam and ICI, respectively. Therefore, uterine OTR gene expression is upregulated by estrogen through the classical nuclear (or non-nuclear) ERs, ERα and ERβ, while the levels of these ERs are downregulated by estrogen through multiple pathways including Es-sensitive nonclassical ERs.

  4. Neonatal oxytocin alters subsequent estrogen receptor alpha protein expression and estrogen sensitivity in the female rat.

    PubMed

    Perry, Adam N; Paramadilok, Auratip; Cushing, Bruce S

    2009-12-14

    In most species, the effects of oxytocin (OT) on female reproductive behavior are dependent upon estrogen, which increases both OT and OT receptor expression. It is also becoming apparent that OT neurotransmission can influence estrogen signaling, especially during development, as neonatal OT manipulations in prairie voles alter ERalpha expression and estrogen-dependent behaviors. We tested the hypothesis that OT developmentally programs ERalpha expression and estrogen sensitivity in female Sprague-Dawley rats, a species previously used to establish the estrogen-dependence of OT signaling in adulthood. OT treatment for the first postnatal week significantly increased ERalpha-immunoreactivity in the ventromedial nucleus of the hypothalamus (VMH), but not in the medial preoptic area (MPOA). Conversely, neonatal OT antagonist (OTA) treatment significantly reduced ERalpha-immunoreactivity in the MPOA, but not in the VMH. Both treatments increased OT-immunoreactivity in the paraventricular nucleus of the hypothalamus (PVN) and reduced estrogen sensitivity, indicated by reduced sexual receptivity following chronic estradiol benzoate (EB) administration. Behavioral deficits in OTA-treated females were apparent during both paced and non-paced tests with 0.5 microg EB (but not 5.0 or 10.0 microg EB), whereas deficits in OT-treated females were only observed during the initial paced test with 0.5 and 5.0 microg EB (but not 10.0 microg EB). The current results demonstrate that OT can positively regulate ERalpha expression within the MPOA and VMH during development; however, endogenous OT selectively programs ERalpha expression within the MPOA. Thus, exogenous OT or OTA exposure during development may have long-term consequences on behavior through stable changes in ERalpha and OT expression.

  5. 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...

  6. 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

  7. 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...

  8. The membrane estrogen receptor GPR30 mediates cadmium-induced proliferation of breast cancer cells

    SciTech Connect

    Yu Xinyuan; Filardo, Edward J.; Shaikh, Zahir A.

    2010-05-15

    Cadmium (Cd) is a nonessential metal that is dispersed throughout the environment. It is an endocrine-disrupting element which mimics estrogen, binds to estrogen receptor alpha (ERalpha), and promotes cell proliferation in breast cancer cells. We have previously published that Cd promotes activation of the extracellular regulated kinases, erk-1 and -2 in both ER-positive and ER-negative human breast cancer cells, suggesting that this estrogen-like effect of Cd is not associated with the ER. Here, we have investigated whether the newly appreciated transmembrane estrogen receptor, G-protein coupled receptor 30 (GPR30), may be involved in Cd-induced cell proliferation. Towards this end, we compared the effects of Cd in ER-negative human SKBR3 breast cancer cells in which endogenous GPR30 signaling was selectively inhibited using a GPR30 interfering mutant. We found that Cd concentrations from 50 to 500 nM induced a proliferative response in control vector-transfected SKBR3 cells but not in SKBR3 cells stably expressing interfering mutant. Similarly, intracellular cAMP levels increased about 2.4-fold in the vector transfectants but not in cells in which GPR30 was inactivated within 2.5 min after treatment with 500 nM Cd. Furthermore, Cd treatment rapidly activated (within 2.5 min) raf-1, mitogen-activated protein kinase kinase, mek-1, extracellular signal regulated kinases, erk-1/2, ribosomal S6 kinase, rsk, and E-26 like protein kinase, elk, about 4-fold in vector transfectants. In contrast, the activation of these signaling molecules in SKBR3 cells expressing the GPR30 mutant was only about 1.4-fold. These results demonstrate that Cd-induced breast cancer cell proliferation occurs through GPR30-mediated activation in a manner that is similar to that achieved by estrogen in these cells.

  9. 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

  10. Pembrolizumab and Ruxolitinib Phosphate in Treating Patients With Metastatic Stage IV Triple Negative Breast Cancer

    ClinicalTrials.gov

    2017-03-15

    Breast Carcinoma Metastatic in the Bone; Estrogen Receptor Negative; HER2/Neu Negative; Progesterone Receptor Negative; Recurrent Breast Carcinoma; Stage IV Breast Cancer; Triple-Negative Breast Carcinoma

  11. Anti-proliferative effects of estrogen receptor-modulating compounds isolated from Rheum palmatum.

    PubMed

    Kang, Se Chan; Lee, Chang Min; Choung, Eui Su; Bak, Jong Phil; Bae, Jong Jin; Yoo, Hyun Sook; Kwak, Jong Hwan; Zee, Ok Pyo

    2008-06-01

    The Rheum palmatum L., a traditional medicine in Korea, was screened for their estrogenic activity in a recombinant yeast system with a human estrogen receptor (ER) expression plasmid and a reporter plasmid used in a previous study. The EC50 values of the n-hexane, dichloromethane, ethyl acetate, n-butanol, and water fractions of the methanolic extract of R. palmatum in the yeast-based estrogenicity assay system were 0.145, 0.093, 0.125, 1.459, 2.853 microg/mL, respectively, with marked estrogenic activity in the dichloromethane fraction. Using an activity-guided fractionation approach, five known anthraquinones, chrysophanol (1), physcion (2), emodin (3), aloe-emodin (4) and rhein (5), were isolated from the dichloromethane fraction. Compound 3 had the highest estrogenic relative potency (RP, 17bestradiol = 1.00) (6.3 x 10(-2)), followed by compound 4 (3.8 x 10(-3)), compound 5 (2.6 x 10(-4)), a compound 1 (2.1 x 10(-4)). Also, compound 3 and fraction 3 (which contained compound 3) of the dichloromethane fraction of R. palmatum showed strong cytotoxicity in both ER-positive (MCF-7) and-negative (MDA-MB-231) breast cancer cell lines.

  12. Cancer therapy using natural ligands that target estrogen receptor beta

    PubMed Central

    Sareddy, Gangadhara R; Vadlamudi, Ratna K.

    2016-01-01

    Estrogen receptor beta (ERβ) is one of the two key receptors (ERα, ERβ) that facilitate biological actions of 17β-estradiol (E2). ERβ is widely expressed in many tissues, and its expression is reduced or lost during progression of many tumors. ERβ facilitates estrogen signaling by both genomic (classical and non-classical) and extra-nuclear signaling. Emerging evidence suggests that ERβ functions as a tissue-specific tumor suppressor with anti-proliferative actions. Recent studies have identified a number of naturally available selective ERβ agonists. Targeting ERβ using its naturally available ligands is an attractive approach for treating and preventing cancers. This review presents the beneficial actions of ERβ signaling and clinical utility of several natural ERβ ligands as potential cancer therapy. PMID:26614454

  13. 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. PMID:27626480

  14. 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.

  15. Cloning, expression and functional characterization of carp, Cyprinus carpio, estrogen receptors and their differential activations by estrogens.

    PubMed

    Katsu, Yoshinao; Lange, Anke; Miyagawa, Shinichi; Urushitani, Hiroshi; Tatarazako, Norishisa; Kawashima, Yukio; Tyler, Charles R; Iguchi, Taisen

    2013-01-01

    Sex-steroid hormones are essential for normal reproductive activity in both sexes. Estrogens are necessary for ovarian differentiation during a critical developmental stage in vertebrates and promote the growth and differentiation of the female reproductive system. Importantly, environmental estrogens can influence the reproductive system and have been shown to disrupt gametogenesis in males. To understand the molecular mechanisms of estrogen actions and to evaluate estrogen receptor ligand interactions in the carp, Cyprinus carpio, a species used widely for both field- and laboratory-based studies, we cloned all three carp estrogen receptors (ER; ERα, ERβ1 and ERβ2) and applied an estrogen-responsive (ERE)-luciferase reporter assay system to characterize the interactions of these receptors with steroidal and synthetic estrogens. DNA fragments encoding all three ERs in carp, ERα, ERβ1 and ERβ2, were obtained from the ovary using degenerate primer sets and PCR techniques, and full-length carp ER (cER) cDNAs were then obtained using RACE (rapid amplification of the cDNA end) techniques. Amino acid sequences of cERs showed overall homology of 46% (α vs β1), 49% (α vs β2) and 53% (β1 vs β2). In the transient transfection ERE-luciferase reporter assay system (using mammalian cells) the cER proteins displayed estrogen-dependent activation of transcription and cERβ2 showed a higher sensitivity to the natural steroid oestrogen, 17β-estradiol, than cERα. The assay system developed is a powerful assay for toxicology and provides a tool for future studies examining the receptor-environmental chemical interactions and estrogen-disrupting mechanisms in carp. The data presented also expand our knowledge of estrogen receptor evolution.

  16. Aromatase, estrogen receptors and brain development in fish and amphibians.

    PubMed

    Coumailleau, Pascal; Pellegrini, Elisabeth; Adrio, Fátima; Diotel, Nicolas; Cano-Nicolau, Joel; Nasri, Ahmed; Vaillant, Colette; Kah, Olivier

    2015-02-01

    Estrogens affect brain development of vertebrates, not only by impacting activity and morphology of existing circuits, but also by modulating embryonic and adult neurogenesis. The issue is complex as estrogens can not only originate from peripheral tissues, but also be locally produced within the brain itself due to local aromatization of androgens. In this respect, teleost fishes are quite unique because aromatase is expressed exclusively in radial glial cells, which represent pluripotent cells in the brain of all vertebrates. Expression of aromatase in the brain of fish is also strongly stimulated by estrogens and some androgens. This creates a very intriguing positive auto-regulatory loop leading to dramatic aromatase expression in sexually mature fish with elevated levels of circulating steroids. Looking at the effects of estrogens or anti-estrogens in the brain of adult zebrafish showed that estrogens inhibit rather than stimulate cell proliferation and newborn cell migration. The functional meaning of these observations is still unclear, but these data suggest that the brain of fish is experiencing constant remodeling under the influence of circulating steroids and brain-derived neurosteroids, possibly permitting a diversification of sexual strategies, notably hermaphroditism. Recent data in frogs indicate that aromatase expression is limited to neurons and do not concern radial glial cells. Thus, until now, there is no other example of vertebrates in which radial progenitors express aromatase. This raises the question of when and why these new features were gained and what are their adaptive benefits. This article is part of a Special Issue entitled: Nuclear receptors in animal development.

  17. 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

  18. Multiple Estrogen Receptor Subtypes Influence Ingestive Behavior in Female Rodents

    PubMed Central

    Santollo, Jessica; Daniels, Derek

    2015-01-01

    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 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

  19. Splice isoform estrogen receptors as integral transmembrane proteins.

    PubMed

    Kim, Kyung Hee; Toomre, Derek; Bender, Jeffrey R

    2011-11-01

    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.

  20. 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.

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

    PubMed

    Pinto, Caroline; Grimaldi, Marina; Boulahtouf, Abdelhay; Pakdel, Farzad; Brion, François; Aït-Aïssa, Sélim; Cavaillès, Vincent; Bourguet, William; Gustafsson, Jan-Ake; Bondesson, Maria; Balaguer, Patrick

    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.

  2. 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.

  3. Nuclear estrogen receptor molecular heterogeneity in the mouse uterus

    SciTech Connect

    Golding, T.S.; Korach, K.S.

    1988-01-01

    Holomeric estrogen receptor (ER) prepared from ovariectomized mouse uteri displays heterogeneous electrophoretic mobility when analyzed by NaDodSO/sub 4//PAGE. ER derived from nuclei (ER/sub n/) appears as a closely spaced doublet having apparent molecular masses of 66.4 and 65 kDa, while ER from the cytosolic compartment (ER/sub c/) has a single band of 65 kDa. Both partially purified ER/sub c/ and the 8S form of unactivated ER/sub c/ show only the 65-kDa band. The appearance of the ER/sub n/ doublet is hormonally inducible, and the relative proportions of the two doublet bands are influenced by the type of hormone treatment, with weakly estrogenic compounds yielding the lower band as predominant while potent estrogens increase the proportion of the upper band. Steroid binding of the ER/sub n/ doublet was determined by (/sup 3/H)tamoxifen aziridine affinity labeling of both the 66.4- and the 65-kDa peptides; binding to the 65-kDa peptide was predominant. The ER/sub n/ doublet displays a time dependency after estrogen administration with maximal amounts occurring in a bimodal fashion at 1 and 8 hr.

  4. Molecular cloning and characterization of hagfish estrogen receptors.

    PubMed

    Nishimiya, Osamu; Katsu, Yoshinao; Inagawa, Hiroyuki; Hiramatsu, Naoshi; Todo, Takashi; Hara, Akihiko

    2017-01-01

    One or more distinct forms of the nuclear estrogen receptor (ER) have been isolated from many vertebrates to date. To better understand the molecular evolution of ERs, we cloned and characterized er cDNAs from the inshore hagfish, Eptatretus burgeri, a modern representative of the most primitive vertebrates, the agnathans. Two er cDNAs, er1 and er2, were isolated from the liver of a reproductive female hagfish. A phylogenetic analysis placed hagfish ER1 into a position prior to the divergence of vertebrate ERs. Conversely, hagfish ER2 was placed at the base of the vertebrate ERβ clade. The tissue distribution patterns of both ER subtype mRNAs appeared to be different, suggesting that each subtype has different physiological roles associated with estrogen actions. An estrogen responsive-luciferase reporter assay using mammalian HEK293 cells was used to functionally characterize these hagfish ERs. Both ER proteins displayed estrogen-dependent activation of transcription. These results clearly demonstrate that the hagfish has two functional ER subtypes.

  5. 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.

  6. Evaluation of an enzyme immunoassay for estrogen receptors in human breast cancers.

    PubMed

    Nicholson, R I; Colin, P; Francis, A B; Keshra, R; Finlay, P; Williams, M; Elston, C W; Blamey, R W; Griffiths, K

    1986-08-01

    An estrogen receptor enzyme immunoassay kit (ER-EIA) has been evaluated in 70 human breast carcinomas against a routine cytoplasmic [3H]estradiol binding assay (ERU). A linear correlation between the ER-EIA and the ERU was observed for binding values up to 400 fmol/mg of cytosol protein. Above this value, the ERU underestimates the concentration of receptor. The ERU gave a lower number of estrogen receptor-positive tumors (50 of 70) than did the ER-EIA assay (59 of 70). In the ERU-negative ER-EIA-positive tumors, receptor values as determined by the ER-EIA assay all fell below 50 fmol/mg of protein (mean, 19.9 +/- 4.2 fmol/mg of protein). Application of an exchange procedure which estimates the total steroid binding capacity of the cytosol gave positive results in 7 of 9 ERU-negative ER-EIA-positive tumors (mean, 16.9 +/- 2.95 fmol/mg of protein). Subdivision of the binding data according to the menopausal status of the patient indicates low receptor values in premenopausal women by each assay. A correlation between the ER-EIA assay and the histological grade of tumors was observed; Grade I well-differentiated tumors were all positive, while Grade II and III tumors were 86% and 75% positive, respectively. No correlation between the ER-EIA assay and tumor lymph node stage or tumor size was observed.

  7. Hippocampal cytosolic estrogen receptors regulate fear generalization in females.

    PubMed

    Lynch, Joseph F; Winiecki, Patrick; Vanderhoof, Tyler; Riccio, David C; Jasnow, Aaron M

    2016-04-01

    Generalization of fear responses is a symptom of many anxiety disorders and we have previously demonstrated that female rats generalize fear to a neutral context at a faster rate compared to males. This effect is due in part, to activation of ER and modulation of memory retrieval mechanisms resulting in fear generalization. Given that the effects of estradiol on fear generalization required approximately 24h, our data suggested possible genomic actions on fear generalization. To determine whether these actions were due to cytosolic versus membrane bound receptors, female rats were given infusions of ICI 182,780, a cytosolic estrogen receptor antagonist, into the lateral ventricle or dorsal hippocampus simultaneously with estradiol treatment or with an ER agonist (DPN). Infusions of ICI into the lateral ventricle or the dorsal hippocampus blocked fear generalization induced by peripheral or central treatment with estradiol or DPN, suggesting that estradiol acts through cytosolic ERβ receptors. In further support of these findings, intracerebroventricular or intra-hippocampal infusions of bovine serum conjugated estradiol (E2-BSA), activating membrane-bound estrogen receptors only, did not induce fear generalization. Moreover, rats receiving intra-hippocampal infusions of the ERK/MAPK inhibitor, U0126, continued to display estradiol-induced generalization, again suggesting that membrane-bound estrogen receptors do not contribute to fear generalization. Overall, these data suggest that estradiol-induced enhancements in fear generalization are mediated through activation of cytosolic/nuclear ER within the dorsal hippocampus. This region seems to be an important locus for the effects of estradiol on fear generalization although additional neuroanatomical regions have yet to be identified.

  8. 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 ...

  9. 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...

  10. Distinct mechanisms of endocrine disruption of DDT-related pesticides toward estrogen receptor α and estrogen-related receptor γ.

    PubMed

    Zhuang, Shulin; Zhang, Jing; Wen, Yuezhong; Zhang, Chunlong; Liu, Weiping

    2012-11-01

    Dichlorodiphenyltrichloroethane (DDT) is ubiquitous in the environment, and the exposure to DDT and its related pesticides has long been linked to endocrine disruption. The mechanism of endocrine disruption toward targeted receptors, however, remains unclear. Probing the molecular recognition of DDT analogs by targeted receptors at the atomic level is critical for deciphering this mechanism. Molecular dynamics (MD) simulations were applied to probe the molecular recognition process of DDT and its five analogs, including dichlordiphenyldichloroethylene (DDE), dichlorodiphenyldichloroethane (DDD), methoxychlor (MXC), p,p'-hydroxy-DDT (HPTE), and dicofol by human estrogen receptor (ER) α and human ER-related receptor (ERR) γ. Van der Waals interactions mainly drive the interactions of DDT analogs with ERα ligand-binding domain (LBD) and ERRγ LBD. Minor structural changes of DDT analogs in the number and position of chlorine and phenolic hydroxyl moiety cause differences in binding modes through aromatic stacking and hydrogen bonding and thus affect differently conformational changes of ERα LBD and ERRγ LBD. The binding of DDT analogs affects the helix 12 orientation of ERα LBD but causes no rearrangement of helix 12 of ERRγ LBD. These results extend our understanding of how DDT analogs exert their estrogen-disrupting effects toward different receptors via multiple mechanisms.

  11. Novel biosensors for the detection of estrogen receptor ligands.

    PubMed

    De, Siddhartha; Macara, Ian G; Lannigan, Deborah A

    2005-08-01

    There exists a significant need for the detection of novel estrogen receptor (ER) ligands for pharmaceutical uses, especially for treating complications associated with menopause. We have developed fluorescence resonance energy transfer (FRET)-based biosensors that permit the direct in vitro detection of ER ligands. These biosensors contain an ER ligand-binding domain (LBD) flanked by the FRET donor fluorophore, cyan fluorescent protein (CFP), and the acceptor fluorophore, yellow fluorescent protein (YFP). The ER-LBD has been modified so that Ala 430 has been changed to Asp, which increases the magnitude of the FRET signal in response to ligand-binding by more than four-fold compared to the wild-type LBD. The binding of agonists can be distinguished from that of antagonists on the basis of the distinct ligand-induced conformations in the ER-LBD. The approach to binding equilibrium occurs within 30min, and the FRET signal is stable over 24h. The biosensor demonstrates a high signal-to-noise, with a Z' value (a statistical determinant of assay quality) of 0.72. The affinity of the ER for different ligands can be determined using a modified version of the biosensor in which a truncated YFP and an enhanced CFP are used. Thus, we have developed platforms for high-throughput screens for the identification of novel estrogen receptor ligands. Moreover, we have demonstrated that this FRET technology can be applied to other nuclear receptors, such as the androgen receptor.

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

    PubMed Central

    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

  13. Bazedoxifene: a novel selective estrogen receptor modulator for postmenopausal osteoporosis.

    PubMed

    de Villiers, T J

    2010-06-01

    Several new selective estrogen receptor modulators (SERMs) are currently under clinical development for the prevention and/or treatment of postmenopausal osteoporosis, with the goal of optimizing the estrogen receptor agonist/antagonist activity in target tissues. Bazedoxifene is a novel SERM under clinical investigation for the prevention and treatment of postmenopausal osteoporosis. Emerging clinical data have shown that bazedoxifene is effective in preventing bone loss and osteoporotic fractures in postmenopausal women, with no evidence of breast or endometrial stimulation. Two large, prospective, international phase 3 studies have been completed. In postmenopausal women at risk for osteoporosis, bazedoxifene has been shown to preserve bone mineral density and to reduce bone turnover. In postmenopausal women with osteoporosis, bazedoxifene has demonstrated significant protection against new vertebral fractures and against non-vertebral fractures in women at higher fracture risk. The treatment effects of bazedoxifene were supported by findings from independent re-analyses using the Fracture Risk Assessment Tool (FRAX), which showed that bazedoxifene significantly reduced the risk of all clinical and morphometric vertebral fracture and of non-vertebral fracture in women at or above a FRAX-based threshold. Bazedoxifene was generally safe and well tolerated in the phase 3 studies and showed neutral effects on the breast and an excellent endometrial safety profile; such attributes allow for the partnering of bazedoxifene with conjugated estrogens for menopausal symptom relief. Collectively, these results suggest that bazedoxifene may be a promising new therapy for the prevention and treatment of postmenopausal osteoporosis as a monotherapy or in combination with conjugated estrogens in menopausal hormone therapy.

  14. 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

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

    PubMed

    Lee, Cynthia Wei-Sheng; Ho, Ing-Kang

    2013-09-08

    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.

  16. 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.

  17. The Role of Estrogen Related Receptor in Modulating Estrogen Receptor Mediated Transcription in Breast Cancer Cells

    DTIC Science & Technology

    2005-04-01

    receptors ) by demonstrating that mitochondrial biogenesis and fatty acid P- oxidation , processes ERRa is known to regulate , are robustly...gluconeogenesis, and fatty acid oxidation (Lin 2003; Puigserver 1998; Wu 1999; Yoon 2001). In addition to its activity on a number of nuclear receptors , this...in target cells. They were generated by replacing the receptor interaction domains in peroxisome proliferator activated receptor

  18. Inhibition of angiogenesis by selective estrogen receptor modulators through blockade of cholesterol trafficking rather than estrogen receptor antagonism.

    PubMed

    Shim, Joong Sup; Li, Ruo-Jing; Lv, Junfang; Head, Sarah A; Yang, Eun Ju; Liu, Jun O

    2015-06-28

    Selective estrogen receptor modulators (SERM) including tamoxifen are known to inhibit angiogenesis. However, the underlying mechanism, which is independent of their action on the estrogen receptor (ER), has remained largely unknown. In the present study, we found that tamoxifen and other SERM inhibited cholesterol trafficking in endothelial cells, causing a hyper-accumulation of cholesterol in late endosomes/lysosomes. Inhibition of cholesterol trafficking by tamoxifen was accompanied by abnormal subcellular distribution of vascular endothelial growth factor receptor-2 (VEGFR2) and inhibition of the terminal glycosylation of the receptor. Tamoxifen also caused perinuclear positioning of lysosomes, which in turn trapped the mammalian target of rapamycin (mTOR) in the perinuclear region of endothelial cells. Abnormal distribution of VEGFR2 and mTOR and inhibition of VEGFR2 and mTOR activities by tamoxifen were significantly reversed by addition of cholesterol-cyclodextrin complex to the culture media of endothelial cells. Moreover, high concentrations of tamoxifen inhibited endothelial and breast cancer cell proliferation in a cholesterol-dependent, but ER-independent, manner. Together, these results unraveled a previously unrecognized mechanism of angiogenesis inhibition by tamoxifen and other SERM, implicating cholesterol trafficking as an attractive therapeutic target for cancer treatment.

  19. HDAC3 regulates stability of estrogen receptor α mRNA

    SciTech Connect

    Oie, Shohei; Matsuzaki, Kazuya; Yokoyama, Wataru; Murayama, Akiko; Yanagisawa, Junn

    2013-03-08

    Highlights: ► HDAC inhibitors decrease the stability of ERα mRNA in MCF-7 cells. ► HDAC3 is involved in maintaining ERα mRNA stability in MCF-7 cells. ► ERα mRNA instability by knockdown of HDAC3 reduces the estrogen-dependent proliferation of ERα-positive MCF-7 cells. ► HDAC3 specific inhibitor will be one of new drugs for ERα-positive breast cancers. -- Abstract: Estrogen receptor alpha (ERα) expression is a risk factor for breast cancer. HDAC inhibitors have been demonstrated to down-regulate ERα expression in ERα-positive breast cancer cell lines, but the molecular mechanisms are poorly understood. Here, we showed that HDAC inhibitors decrease the stability of ERα mRNA, and that knockdown of HDAC3 decreases the stability of ERα mRNA and suppresses estrogen-dependent proliferation of ERα-positive MCF-7 breast cancer cells. In the Oncomine database, expression levels of HDAC3 in ERα-positive tumors are higher than those in ERα-negative tumors, thus suggesting that HDAC3 is necessary for ERα mRNA stability, and is involved in the estrogen-dependent proliferation of ERα-positive tumors.

  20. 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

  1. Tamoxifen regulation of bone growth and endocrine function in the ovariectomized rat: discrimination of responses involving estrogen receptor α/estrogen receptor β, G protein-coupled estrogen receptor, or estrogen-related receptor γ using fulvestrant (ICI 182780).

    PubMed

    Fitts, James M; Klein, Robert M; Powers, C Andrew

    2011-07-01

    Tamoxifen is a selective estrogen receptor (ER) modulator, but it is also a deactivating ligand for estrogen-related receptor-γ (ERRγ) and a full agonist for the G protein-coupled estrogen receptor (GPER). Fulvestrant is a selective ER down-regulator that lacks agonist effects on ERα/ERβ, is inactive on ERRγ, but acts as a full agonist on GPER. Fulvestrant effects on tamoxifen actions on uterine and somatic growth, bone, the growth hormone (GH)-insulin-like growth factor I (IGF-I) axis, and pituitary prolactin were analyzed to pharmacologically discriminate tamoxifen effects that may be mediated by ERα/ERβ versus ERRγ versus GPER. Ovariectomized rats received tamoxifen (0.6 mg/kg/daily) plus fulvestrant at 0, 3, 6, or 12 mg/kg/daily for 5 weeks; controls received vehicle or 6 mg/kg fulvestrant daily. Tamoxifen effects to increase uterine weight, decrease serum IGF-I, increase pituitary prolactin, and increase bone mineral density could be fully blocked by fulvestrant, indicating mediation by ERα/ERβ. Tamoxifen effects to decrease pituitary GH, tibia length, and body weight were only partially blocked by fulvestrant, indicating involvement of mechanisms unrelated to ERα/ERβ. Fulvestrant did not inhibit tamoxifen actions to reduce total pituitary protein, again indicating effects not mediated by ERα/ERβ. Tamoxifen actions to reduce serum GH were mimicked rather than inhibited by fulvestrant, pharmacological features consistent with GPER involvement. However, fulvestrant alone increased IGF-I and also blocked tamoxifen-evoked IGF-I decreases; thus fulvestrant effects on serum GH might reflect increased IGF-I feedback inhibition. Fulvestrant alone had no effect on the other parameters. The findings indicate that mechanisms unrelated to ERα/ERβ contribute to tamoxifen effects on body weight, bone growth, and pituitary function.

  2. Estrogen-related receptor alpha and cancer: axis of evil.

    PubMed

    Ranhotra, Harmit S

    2015-01-01

    Cancer is perhaps the fastest growing non-communicable disease in the human population worldwide. Although the molecular mechanism of cancer initiation and progression is known to some extent, however, the majority of pathways responsible for its onset, development and progression are largely unknown. Many members of the nuclear receptors (NRs) superfamily of transcriptional factors have key roles in cancer. Estrogen-related receptor alpha (ERRα) is one of the members of the NR superfamily and studies have linked it with a wide variety of cancers. In endocrine-related cancers such as breast cancer, ERRα regulates a number of target genes directing cell proliferation and growth independent of estrogen receptor alpha (ERα). Knockdown of ERRα in a number of cancer tissues and cell lines significantly reduced tumor growth and malignancy indicating dependence on ERRα activity. The pro-angiogenesis factor vascular endothelial growth factor expression has been shown to be regulated by ERRα and has implications in several types of cancer. The effect of ERRα on cancers seems to be multipronged via regulation of cell cycle regulators, osteopontin, hypoxia inducible factor-1 as well as several energy metabolism genes that are part of glycolysis, TCA cycle, lipogenesis, etc., providing a metabolic twist to cancer. In this article, the action of ERRα on various types of cancers including new developments in this field shall be reviewed.

  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. Prothymosin Alpha Selectively Enhances Estrogen Receptor Transcriptional Activity by Interacting with a Repressor of Estrogen Receptor Activity

    PubMed Central

    Martini, Paolo G. V.; Delage-Mourroux, Regis; Kraichely, Dennis M.; Katzenellenbogen, Benita S.

    2000-01-01

    We find that prothymosin alpha (PTα) 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 PTα 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 PTα, 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. PTα increases the magnitude of ERα transcriptional activity three- to fourfold. It shows lesser enhancement of ERβ 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 PTα 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 PTα (or SRC-1) for regulation of ER transcriptional activity and suppresses the ER stimulation by PTα or SRC-1, indicating that REA can function as an anticoactivator in cells. Our data support a model in which PTα, 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 PTα 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 its ability to selectively enhance

  5. The Estrogen Receptor-β Expression in De Quervain's Disease.

    PubMed

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

    2015-11-04

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

  6. G protein-coupled estrogen receptor protects from atherosclerosis.

    PubMed

    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

    2014-12-23

    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.

  7. 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

  8. Estrogen receptor beta as target for colorectal cancer prevention.

    PubMed

    Williams, Cecilia; DiLeo, Alfredo; Niv, Yaron; Gustafsson, Jan-Åke

    2016-03-01

    Colorectal cancer (CRC) is a leading cause of death in the United States. Despite its slow development and the capacity for early diagnosis, current preventive approaches are not sufficient. However, a role for estrogen has been demonstrated in multiple epidemiologic studies, which may benefit CRC prevention. A large body of evidence from preclinical studies indicates that expression of the estrogen receptor beta (ERβ/ESR2) demonstrates an inverse relationship with the presence of colorectal polyps and stage of tumors, and can mediate a protective response. Natural compounds, including phytoestrogens, or synthetic ERβ selective agonists, can activate or upregulate ERβ in the colon and promote apoptosis in preclinical models and in clinical experience. Importantly, this activity has been associated with a reduction in polyp formation and, in rodent models of CRC, has been shown to lower incidence of colon adenocarcinoma. Collectively, these findings indicate that targeted activation of ERβ may represent a novel clinical approach for management of colorectal adenomatous polyps and prevention of colorectal carcinoma in patients at risk for this condition. In this review, we discuss the potential of new chemopreventive or dietary approaches based on estrogen signaling.

  9. Dietary Estrogens Act through Estrogen Receptor-Mediated Processes and Show No Antiestrogenicity in Cultured Breast Cancer Cells.

    PubMed Central

    Makela, S; Davis, VL; Tally, WC; Korkman, J; Salo, L; Vihko, R; Santti, R; Korach, KS

    1994-01-01

    Dietary estrogens are believed to exert their estrogenic or antiestrogenic (chemopreventive) action in estrogen responsive cells by interacting with the estrogen receptor (ER). The present study was undertaken to evaluate a direct role of ER in estrogenic or antiestrogenic activities of three dietary estrogens (coumestrol, genistein and zearalenone). HeLa cells were transiently co-transfected with an expression vector for ER and an estrogen-responsive reporter gene construct. Coumestrol, genistein, and zearalenone all increased the activity of the reporter gene, only in the presence of the ER, and the activation was blocked with the ER antagonist ICI 164,384, demonstrating an ER-specific, agonist response. In addition, in MCF-7 cells, coumestrol and zearalenone increased the expression of the estrogen-responsive pS2 gene. Coumestrol and genistein inhibited the purified estrogen-specific 17ß-hydroxysteroid oxidoreductase enzyme and the conversion of estrone to 17ß-estradiol in T-47D cells, which contain this enzyme. However, they did not inhibit the estrone-induced proliferation of T-47D cells. In conclusion, coumestrol, genistein, and zearalenone are all potent estrogens in vitro, and they act through ER mediated mechanism. Our findings give no evidence to support the idea that these compounds act as antiestrogens through competition for the binding sites of ER or by inhibition of the conversion of estrone to 17ß-estradiol in breast cancer cells, since this effect was nullified by their agonist action on cell proliferation. Therefore, their suggested chemopreventive action in estrogen-related cancers must be mediated through other mechanisms. Images Figure 2. A Figure 2. B Figure 2. C Figure 2. D Figure 2. E Figure 3. A Figure 3. B Figure 4. A Figure 4. B Figure 4. C Figure 4. D Figure 4. E Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. A Figure 9. B Figure 9. C PMID:9679118

  10. 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

  11. [Roles of G protein-coupled estrogen receptor in the male reproductive system].

    PubMed

    Chen, Kai-hong; Zhang, Xian; Jiang, Xue-wu

    2016-02-01

    The G protein-coupled estrogen receptor (GPER), also known as G protein-coupled receptor 30 (GPR30), was identified in the recent years as a functional membrane receptor different from the classical nuclear estrogen receptors. This receptor is widely expressed in the cortex, cerebellum, hippocampus, heart, lung, liver, skeletal muscle, and the urogenital system. It is responsible for the mediation of nongenomic effects associated with estrogen and its derivatives, participating in the physiological activities of the body. The present study reviews the molecular structure, subcellular localization, signaling pathways, distribution, and function of GPER in the male reproductive system.

  12. Effect of anti-PMSG on distribution of estrogen receptor alpha and progesterone receptor in mouse ovary, oviduct and uterus.

    PubMed

    Lin, Zi Li; Ni, He Min; Liu, Yun Hai; Sheng, Xi Hui; Cui, Xiang Shun; Kim, Nam Hyung; Guo, Yong

    2015-10-01

    It is well established that estrogen and progesterone are critical endogenous hormones that are essential for implantation and pregnancy in females. However, the distribution of estrogen receptor α (ERα) and progesterone receptor (PR) in female reproductive tracts is elusive. Herein, we report that after serial treatments with pregnant mare's serum gonadotrophin (PMSG) with or without anti-PMSG (AP), mice could regulate the distribution of ERα and PR in the murine ovary, oviduct and uterus and the level of estradiol in serum. ERα and PR regulation by PMSG and anti-PMSG was estrous cycle-dependent and critical for promoting the embryo-implantation period. Furthermore, our results suggested that AP-42 h treatment is more effective than the other treatments. In contrast, other treatment groups also affected the distribution of ERα and PR in mouse reproductive tracts. Thus, we found that anti-PMSG has the potential to restore the distribution of ERα and PR, which could effectively reduce the negative impact of residual estrogen caused by the normal superovulation effect of PMSG in mice.

  13. 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...

  14. Stimulation of Estrogen Receptor Signaling in Breast Cancer by a Novel Chaperone Synuclein Gamma

    DTIC Science & Technology

    2006-06-01

    AD_________________ Award Number: W81XWH- 04 -1-0569 TITLE: Stimulation of estrogen receptor...Stimulation of estrogen receptor signaling in breast cancer by a novel chaperone 5a. CONTRACT NUMBER synuclein gamma 5b. GRANT NUMBER W81XWH- 04 -1...UNIT NUMBER 7 . PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER North Shore University Hospital

  15. Relaxant Effects of the Selective Estrogen Receptor Modulator, Bazedoxifene, and Estrogen Receptor Agonists in Isolated Rabbit Basilar Artery.

    PubMed

    Castelló-Ruiz, María; Salom, Juan B; Fernández-Musoles, Ricardo; Burguete, María C; López-Morales, Mikahela A; Arduini, Alessandro; Jover-Mengual, Teresa; Hervás, David; Torregrosa, Germán; Alborch, Enrique

    2016-10-01

    We have previously shown that the selective estrogen receptor modulator, bazedoxifene, improves the consequences of ischemic stroke. Now we aimed to characterize the effects and mechanisms of action of bazedoxifene in cerebral arteries. Male rabbit isolated basilar arteries were used for isometric tension recording and quantitative polymerase chain reaction. Bazedoxifene relaxed cerebral arteries, as 17-β-estradiol, 4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol [estrogen receptor (ER) α agonist], and G1 [G protein-coupled ER (GPER) agonist] did it (4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol > bazedoxifene = G1 > 17-β-estradiol). 2,3-Bis(4-hydroxyphenyl)-propionitrile (ERβ agonist) had no effect. Expression profile of genes encoding for ERα (ESR1), ERβ (ESR2), and GPER was GPER > ESR1 > ESR2. As to the endothelial mechanisms, endothelium removal, N-nitro-L-arginine methyl ester, and indomethacin, did not modify the relaxant responses to bazedoxifene. As to the K channels, both a high-K medium and the Kv blocker, 4-aminopyridine, inhibited the bazedoxifene-induced relaxations, whereas tetraethylammonium (nonselective K channel blocker), glibenclamide (selective KATP blocker) or iberiotoxin (selective KCa blocker) were without effect. Bazedoxifene also inhibited both Ca- and Bay K8644-elicited contractions. Therefore, bazedoxifene induces endothelium-independent relaxations of cerebral arteries through (1) activation of GPER and ERα receptors; (2) increase of K conductance through Kv channels; and (3) inhibition of Ca entry through L-type Ca channels. Such a profile is compatible with the beneficial effects of estrogenic compounds (eg, SERMs) on vascular function and, specifically, that concerning the brain. Therefore, bazedoxifene could be useful in the treatment of cerebral disorders in which the cerebrovascular function is compromised (eg, stroke).

  16. Bridging hypoxia, inflammation and estrogen receptors in thyroid cancer progression.

    PubMed

    Tafani, Marco; De Santis, Elena; Coppola, Luigi; Perrone, Giulietta A; Carnevale, Ilaria; Russo, Andrea; Pucci, Bruna; Carpi, Angelo; Bizzarri, Mariano; Russo, Matteo A

    2014-02-01

    Thyroid cancer is a common endocrine-related cancer with a higher incidence in women than in men. Thyroid tumors are classified on the basis of their histopathology as papillary, follicular, medullary, and undifferentiated or anaplastic. Epidemiological and in vitro or in vivo studies have suggested a correlation between incidence of thyroid malignancies and hormones. In particular, growing evidence indicates a role of estrogens and estrogen receptors (ERs) in thyroid tumorigenesis, reprogramming and progression. In this scenario, estrogens are hypothesized to contribute to the observed female predominance of thyroid cancer in reproductive years. However, the precise contribution of estrogens in thyroid proliferative disease initiation and progression is not well understood. HIF-1α and NF-κB are two transcription factors very frequently activated in tumors and involved in tumor growth, progression and resistance to chemotherapy. In fact, HIF-1α and NF-κB together regulate transcription of over a thousand genes that, in turn, control vital cellular processes such as adaptation to the hypoxia, metabolic and differentiation reprogramming, inflammatory-reparative response, extracellular matrix digestion, migration and invasion, adhesion, etc. Because of this wide involvement, they could control in an integrated manner the origin of the malignant phenotype. Interestingly, hypoxia and inflammation have been sequentially bridged in tumors by the discovery that alarmin receptors genes such as RAGE, P2X7 and some TLRs are activated by HIF-1α; and that, in turn, alarmin receptors strongly activate NF-κB and proinflammatory gene expression, evidencing all the hallmarks of the malignant phenotype. Recently, a large number of drugs have been identified that inhibit one or both transcription factors with promising results in terms of controlling tumor progression. In addition, many of these inhibitors are natural compounds or off-label drugs already used to cure other

  17. Quantitative structure-activity relationships (QSARs) for estrogen binding to the estrogen receptor: predictions across species.

    PubMed Central

    Tong, W; Perkins, R; Strelitz, R; Collantes, E R; Keenan, S; Welsh, W J; Branham, W S; Sheehan, D M

    1997-01-01

    The recognition of adverse effects due to environmental endocrine disruptors in humans and wildlife has focused attention on the need for predictive tools to select the most likely estrogenic chemicals from a very large number of chemicals for subsequent screening and/or testing for potential environmental toxicity. A three-dimensional quantitative structure-activity relationship (QSAR) model using comparative molecular field analysis (CoMFA) was constructed based on relative binding affinity (RBA) data from an estrogen receptor (ER) binding assay using calf uterine cytosol. The model demonstrated significant correlation of the calculated steric and electrostatic fields with RBA and yielded predictions that agreed well with experimental values over the entire range of RBA values. Analysis of the CoMFA three-dimensional contour plots revealed a consistent picture of the structural features that are largely responsible for the observed variations in RBA. Importantly, we established a correlation between the predicted RBA values for calf ER and their actual RBA values for human ER. These findings suggest a means to begin to construct a more comprehensive estrogen knowledge base by combining RBA assay data from multiple species in 3D-QSAR based predictive models, which could then be used to screen untested chemicals for their potential to bind to the ER. Another QSAR model was developed based on classical physicochemical descriptors generated using the CODESSA (Comprehensive Descriptors for Structural and Statistical Analysis) program. The predictive ability of the CoMFA model was superior to the corresponding CODESSA model. Images Figure 2. Figure 3. Figure 4. Figure 5. PMID:9353176

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

    PubMed

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

    2013-02-08

    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 increases breast cancer cell radiosensitivity compared with radiation alone. These findings have salient implications for designing clinical trials using fulvestrant and radiation therapy.

  19. 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

  20. 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

  1. 3-Methylcholanthrene and other aryl hydrocarbon receptor agonists directly activate estrogen receptor alpha.

    PubMed

    Abdelrahim, Maen; Ariazi, Eric; Kim, Kyounghyun; Khan, Shaheen; Barhoumi, Rola; Burghardt, Robert; Liu, Shengxi; Hill, Denise; Finnell, Richard; Wlodarczyk, Bogdan; Jordan, V Craig; Safe, Stephen

    2006-02-15

    3-Methylcholanthrene (3MC) is an aryl hydrocarbon receptor (AhR) agonist, and it has been reported that 3MC induces estrogenic activity through AhR-estrogen receptor alpha (ER alpha) interactions. In this study, we used 3MC and 3,3',4,4',5-pentachlorobiphenyl (PCB) as prototypical AhR ligands, and both compounds activated estrogen-responsive reporter genes/gene products (cathepsin D) in MCF-7 breast cancer cells. The estrogenic responses induced by these AhR ligands were inhibited by the antiestrogen ICI 182780 and by the transfection of a small inhibitory RNA for ER alpha but were not affected by the small inhibitory RNA for AhR. These results suggest that 3MC and PCB directly activate ER alpha, and this was confirmed in a competitive ER alpha binding assay and in a fluorescence resonance energy transfer experiment in which PCB and 3MC induced CFP-ER alpha/YFP-ER alpha interactions. In a chromatin immunoprecipitation assay, PCB and 3MC enhanced ER alpha (but not AhR) association with the estrogen-responsive region of the pS2 gene promoter. Moreover, in AhR knockout mice, 3MC increased uterine weights and induced expression of cyclin D1 mRNA levels. These results show that PCB and 3MC directly activate ER alpha-dependent transactivation and extend the number of ligands that activate both AhR and ER alpha.

  2. 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.

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

    PubMed Central

    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 hr. 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 hr prior. The estrogenic antagonism of this presynaptic inhibition was observed in anorexigenic POMC 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

  4. Immunolocalization of androgen receptor, aromatase cytochrome P450, estrogen receptor alpha and estrogen receptor beta proteins during the breeding season in scent glands of muskrats (Ondatra zibethicus).

    PubMed

    Lu, Lu; Zhang, Haolin; Lv, Na; Ma, Xiaoting; Tian, Long; Hu, Xiao; Liu, Shuqiang; Xu, Meiyu; Weng, Qiang; Watanabe, Gen; Taya, Kazuyoshi

    2011-10-01

    Aromatase cytochrome P450 (P450arom) is an enzyme that catalyzes the conversion of androgen to estrogen. Expression of P450arom in extra-gonadal sites and locally-synthesized estrogen play an important role in physiological conditions. The purpose of this study was to investigate the cellular immunolocalization of androgen receptor (AR), P450arom, estrogen receptor alpha (ERa) and estrogen receptor beta (ERβ) in muskrat scent glands during the breeding season. Histological observation and immunohistochemistry of AR, P450arom, ERa and ERβ were performed in the muskrat scent glands. In addition, total proteins were extracted from scent glandular tissues in the breeding season and were used for Western blotting analysis for AR, P450arom, ERα and ERβ. Histologically, glandular cells, interstitial cells, epithelial cells of the excretory duct and the excretory tubules were identified in the muskrat scent glands during the breeding season. AR was only observed in glandular cells of scent glands; P450arom was expressed in glandular cells and epithelial cells of the excretory duct; ERα was found in glandular cells, interstitial cells and epithelial cells of the excretory duct, whereas ERβ was present in glandular cells and epithelial cells of the excretory duct. Also, the positive signals of AR, P450arom, ERα and ERβ by Western blotting were all observed in scent glandular tissues. These results suggested that the scent gland is the target organ of androgens and estrogens, and that estrogens may play an important autocrine or paracrine role in glandular function of the muskrats.

  5. Results With Accelerated Partial Breast Irradiation in Terms of Estrogen Receptor, Progesterone Receptor, and Human Growth Factor Receptor 2 Status

    SciTech Connect

    Wilder, Richard B.; Curcio, Lisa D.; Khanijou, Rajesh K.; Eisner, Martin E.; Kakkis, Jane L.; Chittenden, Lucy; Agustin, Jeffrey; Lizarde, Jessica; Mesa, Albert V.; Macedo, Jorge C.; Ravera, John; Tokita, Kenneth M.

    2010-11-01

    Purpose: To report our results with accelerated partial breast irradiation (APBI) in terms of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2/neu) status. Methods and Materials: Between February 2003 and June 2009, 209 women with early-stage breast carcinomas were treated with APBI using multicatheter, MammoSite, or Contura brachytherapy to 34 Gy in 10 fractions twice daily over 5-7 days. Three patient groups were defined by receptor status: Group 1: ER or PR (+) and HER-2/neu (-) (n = 180), Group 2: ER and PR (-) and HER-2/neu (+) (n = 10), and Group 3: ER, PR, and HER-2/neu (-) (triple negative breast cancer, n = 19). Median follow-up was 22 months. Results: Group 3 patients had significantly higher Scarff-Bloom-Richardson scores (p < 0.001). The 3-year ipsilateral breast tumor control rates for Groups 1, 2, and 3 were 99%, 100%, and 100%, respectively (p = 0.15). Group 3 patients tended to experience relapse in distant sites earlier than did non-Group 3 patients. The 3-year relapse-free survival rates for Groups 1, 2, and 3 were 100%, 100%, and 81%, respectively (p = 0.046). The 3-year cause-specific and overall survival rates for Groups 1, 2, and 3 were 100%, 100%, and 89%, respectively (p = 0.002). Conclusions: Triple negative breast cancer patients typically have high-grade tumors with significantly worse relapse-free, cause-specific, and overall survival. Longer follow-up will help to determine whether these patients also have a higher risk of ipsilateral breast tumor relapse.

  6. A Study Evaluating INIPARIB in Combination With Chemotherapy to Treat Triple Negative Breast Cancer Brain Metastasis

    ClinicalTrials.gov

    2016-02-17

    Estrogen Receptor Negative (ER-Negative) Breast Cancer; Progesterone Receptor Negative (PR-Negative) Breast Cancer; Human Epidermal Growth Factor Receptor 2 Negative (HER2-Negative) Breast Cancer; Brain Metastases

  7. Contribution of a membrane estrogen receptor to the estrogenic regulation of body temperature and energy homeostasis.

    PubMed

    Roepke, Troy A; Bosch, Martha A; Rick, Elizabeth A; Lee, Benjamin; Wagner, Edward J; Seidlova-Wuttke, Dana; Wuttke, Wolfgang; Scanlan, Thomas S; Rønnekleiv, Oline K; Kelly, Martin J

    2010-10-01

    The hypothalamus is a key region of the central nervous system involved in the control of homeostasis, including energy and core body temperature (Tc). 17β-Estradiol (E2) regulates Tc, in part, via actions in the basal hypothalamus and preoptic area. E2 primarily controls hypothalamic functions via the nuclear steroid receptors, estrogen receptor α/β. However, we have previously described an E2-responsive, Gq-coupled membrane receptor that reduces the postsynaptic inhibitory γ-aminobutyric acid-ergic tone and attenuates postovariectomy body weight gain in female guinea pigs through the administration of a selective Gq-mER ligand, STX. To determine the role of Gq-mER in regulating Tc, energy and bone homeostasis, ovariectomized female guinea pigs, implanted ip with temperature probes, were treated with STX or E2 for 7-8 wk. Tc was recorded for 4 wk, whereas food intake and body weight were monitored daily. Bone density and fat accumulation were determined postmortem. Both E2 and STX significantly reduced Tc in the females compared with controls. STX, similar to E2, reduced food intake and fat accumulation and increased tibial bone density. Therefore, a Gq-mER-coupled signaling pathway appears to be involved in maintaining homeostatic functions and may constitute a novel therapeutic target for treatment of hypoestrogenic symptoms.

  8. Contribution of a Membrane Estrogen Receptor to the Estrogenic Regulation of Body Temperature and Energy Homeostasis

    PubMed Central

    Roepke, Troy A.; Bosch, Martha A.; Rick, Elizabeth A.; Lee, Benjamin; Wagner, Edward J.; Seidlova-Wuttke, Dana; Wuttke, Wolfgang; Scanlan, Thomas S.; Rønnekleiv, Oline K.; Kelly, Martin J.

    2010-01-01

    The hypothalamus is a key region of the central nervous system involved in the control of homeostasis, including energy and core body temperature (Tc). 17β-Estradiol (E2) regulates Tc, in part, via actions in the basal hypothalamus and preoptic area. E2 primarily controls hypothalamic functions via the nuclear steroid receptors, estrogen receptor α/β. However, we have previously described an E2-responsive, Gq-coupled membrane receptor that reduces the postsynaptic inhibitory γ-aminobutyric acid-ergic tone and attenuates postovariectomy body weight gain in female guinea pigs through the administration of a selective Gq-mER ligand, STX. To determine the role of Gq-mER in regulating Tc, energy and bone homeostasis, ovariectomized female guinea pigs, implanted ip with temperature probes, were treated with STX or E2 for 7–8 wk. Tc was recorded for 4 wk, whereas food intake and body weight were monitored daily. Bone density and fat accumulation were determined postmortem. Both E2 and STX significantly reduced Tc in the females compared with controls. STX, similar to E2, reduced food intake and fat accumulation and increased tibial bone density. Therefore, a Gq-mER-coupled signaling pathway appears to be involved in maintaining homeostatic functions and may constitute a novel therapeutic target for treatment of hypoestrogenic symptoms. PMID:20685867

  9. Tamoxifen Dependent Interaction Between the Estrogen Receptor and a Novel P21 Activated Kinase

    DTIC Science & Technology

    2002-06-01

    AD Award Number: DAMDl7-01-1-0149 TITLE: Tamoxifen Dependent Interaction Between the Estrogen Receptor and a Novel P21 Activated Kinase PRINCIPAL...Tamoxifen Dependent Interaction Between the DAMD17-00-1-0114 Estrogen Receptor and a Novel P21 Activated Kinase 6. AUTHOR(S) Steven P. Balk, M.D., Ph.D. 7...Z, Karas RH, nisms of androgen receptor activation and function. J Mendelsohn ME, Shaul PW 1999 Estrogen receptor a Steroid Biochem Mol Biol 69:307

  10. Histone methylase MLL1 and MLL3 coordinate with estrogen receptors in estrogen-mediated HOXB9 expression

    PubMed Central

    Ansari, Khairul I.; Shrestha, Bishakha; Hussain, Imran; Kasiri, Sahba; Mandal, Subhrangsu S.

    2011-01-01

    Homeobox gene HOXB9 is a critical player in development of mammary gland and sternum and in regulation of Renin which is closely linked with blood pressure control. Our studies demonstrated that HOXB9 gene is transcriptionally regulated by estrogen (E2). HOXB9 promoter contains several estrogen-response elements (ERE). Reporter assay based experiments demonstrated that HOXB9 promoter EREs are estrogen-responsive. Estrogen receptors ERα and ERβ are essential for E2-mediated transcriptional activation of HOXB9. Chromatin immuno-precipitation assay demonstrated that ERs bind to HOXB9 EREs as a function of E2. Similarly, histone methylases MLL1 and MLL3 also bind to HOXB9 EREs and play critical role in E2-mediated transcriptional activation of HOXB9. Overall, our studies demonstrated that HOXB9 is an E2-responsive gene and ERs coordinate with MLL1 and MLL3 in E2-mediated transcriptional regulation of HOXB9. PMID:21428455

  11. 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

  12. Xenoestrogens down-regulate aryl-hydrocarbon receptor nuclear translocator 2 mRNA expression in human breast cancer cells via an estrogen receptor alpha-dependent mechanism.

    PubMed

    Qin, Xian-Yang; Zaha, Hiroko; Nagano, Reiko; Yoshinaga, Jun; Yonemoto, Junzo; Sone, Hideko

    2011-10-10

    Environmental chemicals with estrogenic activity, known as xenoestrogens, may cause impaired reproductive development and endocrine-related cancers in humans by disrupting endocrine functions. Aryl-hydrocarbon receptor nuclear translocator 2 (ARNT2) is believed to play important roles in a variety of physiological processes, including estrogen signaling pathways, that may be involved in the pathogenesis and therapeutic responses of endocrine-related cancers. However, much of the underlying mechanism remains unknown. In this study, we investigated whether ARNT2 expression is regulated by a range of representative xenoestrogens in human cancer cell lines. Bisphenol A (BPA), benzyl butyl phthalate (BBP), and 1,1,1-trichloro-2,2-bis(2-chlorophenyl-4-chlorophenyl)ethane (o,p'-DDT) were found to be estrogenic toward BG1Luc4E2 cells by an E-CALUX bioassay. ARNT2 expression was downregulated by BPA, BBP, and o,p'-DDT in a dose-dependent manner in estrogen receptor 1 (ESR1)-positive MCF-7 and BG1Luc4E2 cells, but not in estrogen receptor-negative LNCaP cells. The reduction in ARNT2 expression in cells treated with the xenoestrogens was fully recovered by the addition of a specific ESR1 antagonist, MPP. In conclusion, we have shown for the first time that ARNT2 expression is modulated by xenoestrogens by an ESR1-dependent mechanism in MCF-7 breast cancer cells.

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

    PubMed

    Gorska, Magdalena; Wyszkowska, Roksana Maja; Kuban-Jankowska, Alicja; Wozniak, Michal

    2016-05-01

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

  14. Dietary acrylamide intake and estrogen and progesterone receptor-defined postmenopausal breast cancer risk.

    PubMed

    Pedersen, Grete S; Hogervorst, Janneke G F; Schouten, Leo J; Konings, Erik J M; Goldbohm, R Alexandra; van den Brandt, Piet A

    2010-07-01

    Acrylamide, a potential human carcinogen, has been discovered in a variety of heat-treated carbohydrate-rich food products. Previously, dietary acrylamide intake was shown to be associated with endocrine-related cancers in humans. We assessed the association between dietary acrylamide intake and risk of postmenopausal breast cancer stratified by estrogen and progesterone receptor status. This study was embedded within the Netherlands Cohort Study on diet and cancer, which was initiated in 1986 enrolling 62,573 women aged 55-69 years at baseline. After 13.3 years of follow-up, 2225 incident breast cancer cases were ascertained, with hormone receptor status information for 43%. Cox proportional hazards analysis was applied to determine hazard ratios in quintiles of dietary acrylamide intake stratifying on estrogen receptor (ER) and progesterone receptor (PR) and smoking status. No association was observed for overall breast cancer or receptor-negative breast cancer risk, irrespective of smoking status. A statistically non-significantly increased risk of ER positive, PR positive and joint receptor-positive breast cancer was found in never-smoking women. The multivariable-adjusted hazard ratios were 1.31 (95% CI: 0.87-1.97, P (trend) = 0.26) for ER+, 1.47 (0.86-2.51, P (trend) = 0.14) for PR+, and 1.43 (0.83-2.46, P (trend) = 0.16) for ER+PR+, when comparing women in the highest quintile of acrylamide intake (median 36.8 microg/day) to women in the lowest (median 9.5 microg/day). This study showed some indications of a positive association between dietary acrylamide intake and receptor-positive breast cancer risk in postmenopausal never-smoking women. Further studies are needed to confirm or refute our observations.

  15. Cyclopeptide RA-V inhibits cell adhesion and invasion in both estrogen receptor positive and negative breast cancer cells via PI3K/AKT and NF-κB signaling pathways.

    PubMed

    Leung, Hoi-Wing; Wang, Zhe; Yue, Grace Gar-Lee; Zhao, Si-Meng; Lee, Julia Kin-Ming; Fung, Kwok-Pui; Leung, Ping-Chung; Lau, Clara Bik-San; Tan, Ning-Hua

    2015-08-01

    Cyclopeptide RA-V has potent anti-tumor and anti-angiogenic activities, but its potential anti-metastatic activity is unknown. Cancer cells acquire invasive ability to degrade and adhere to extracellular matrix (ECM), allowing them to migrate to adjacent tissues and ultimately metastasize. Hence, the present study aimed to investigate the effects of RA-V on cell adhesion, migration, invasion and matrix degradation, and its underlying mechanism in two human breast cancer cell lines MCF-7 (ER-positive) and MDA-MB-231 (ER-negative). Our results demonstrated that RA-V (12.5 nM) can significantly inhibit breast cancer cell adhesion and migration via interfering cofilin signaling and chemokine receptors involved in cell migration. RA-V reduced the expressions of vascular intracellular adhesion molecule (VCAM), intracellular adhesion molecule (ICAM), focal adhesion kinase (FAK) and integrins. The activities and expressions of matrix metalloproteinases (MMPs), tissue inhibitors of matrix metalloproteinases (TIMPs) and urokinase-type of plasminogen activator (uPA) were also inhibited by RA-V. Furthermore, RA-V inhibits the expressions of EGFR, PI3K/AKT and NF-κB signaling molecules, and reduces the binding of β-estradiol to ER via affecting binding ability of ER in MCF-7 cells. RA-V inhibits breast cancer cell migration, adhesion and ECM degradation in vitro, implying that RA-V is a potential anti-metastatic agent in breast cancer, and likely acts via PI3K/AKT and NF-κB signaling pathways in both ER-positive and ER-negative breast cancer cells.

  16. Licorice Root Components in Dietary Supplements are Selective Estrogen Receptor Modulators with a Spectrum of Estrogenic and Anti-Estrogenic Activities

    PubMed Central

    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

  17. 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

  18. Estrogen receptor agonists/antagonists in breast cancer therapy: A critical review.

    PubMed

    Jameera Begam, A; Jubie, S; Nanjan, M J

    2017-04-01

    Estrogens display intriguing tissue selective action that is of great biomedical importance in the development of optimal therapeutics for the prevention and treatment of breast cancer. There are also strong evidences to show that both endogenous and exogenous estrogens are involved in the pathogenesis of breast cancer. Tamoxifen has been the only drug of choice for more than 30years to treat patients with estrogen related (ER) positive breast tumors. There is a need therefore, for identifying newer, potential and novel candidates for breast cancer. Keeping this in view, the present review focuses on selective estrogen receptor modulators and estrogen antagonists such as sulfatase and aromatase inhibitors involved in breast cancer therapy. A succinct and critical overview of the structure of estrogen receptors, their signaling and involvement in breast carcinogenesis are herein described.

  19. A lipid-modified estrogen derivative that treats breast cancer independent of estrogen receptor expression through simultaneous induction of autophagy and apoptosis.

    PubMed

    Sinha, Sutapa; Roy, Sayantani; Reddy, Bathula Surendar; Pal, Krishnendu; Sudhakar, Godeshala; Iyer, Seethalakshmi; Dutta, Shamit; Wang, Enfeng; Vohra, Pawan Kumar; Roy, Karnati Rammohan; Reddanna, Pallu; Mukhopadhyay, Debabrata; Banerjee, Rajkumar

    2011-03-01

    It is a challenge to develop a universal single drug that can treat breast cancer at single- or multiple-stage complications, yet remains nontoxic to normal cells. The challenge is even greater when breast cancer-specific, estrogen-based drugs are being developed that cannot act against multistaged breast cancer complications owing to the cells differential estrogen receptor (ER) expression status and their possession of drug-resistant and metastatic phenotypes. We report here the development of a first cationic lipid-conjugated estrogenic derivative (ESC8) that kills breast cancer cells independent of their ER expression status. This ESC8 molecule apparently is nontoxic to normal breast epithelial cells, as well as to other noncancer cells. ESC8 induces apoptosis through an intrinsic pathway in ER-negative MDA-MB-231 cells. In addition, ESC8 treatment induces autophagy in these cells by interfering with the mTOR activity. This is the first example of an estrogen structure-based molecule that coinduces apoptosis and autophagy in breast cancer cells. Further in vivo study confirms the role of this molecule in tumor regression. Together, our results open new perspective of breast cancer chemotherapy through a single agent, which could provide the therapeutic benefit across all stages of breast cancer.

  20. Modulation of the estrogen receptor structure, evidence of a heterogeneity

    SciTech Connect

    Toulas, C.; Guilbaud, N.; Delassus, F.; Bayard, F.; Faye, J.C. )

    1990-01-01

    In order to analyse the molecular weight polymorphism of the estrogen receptor (ER) in MCF-7 cells, we have developed a procedure which allowed in situ linkage of ER by (3H) tamoxifen aziridine and provided labelled proteins in conditions which minimized protease activities. After labelling, cell lysis was performed in SDS buffer containing various concentrations of mercaptoethanol. Proteins extracted with phenolic solution and precipitated by cold acetone were analysed by SDS PAGE. It appears that beside the form of 67 kDa already described, binding entities of tamoxifen aziridine were also present at a molecular mass of 110 kDa and 45 kDa. On the other hand, investigations on the effect of 12-0-Tetradecanoyl Phorbol 13-Acetate (TPA) showed that TPA induces a decrease of the 67 kDa entity.

  1. Estrogens Induce Expression of Membrane-Associated Estrogen Receptor α Isoforms in Lactotropes

    PubMed Central

    Zárate, Sandra; Jaita, Gabriela; Ferraris, Jimena; Eijo, Guadalupe; Magri, María L.; Pisera, Daniel; Seilicovich, Adriana

    2012-01-01

    Estrogens are key to anterior pituitary function, stimulating hormone release and controlling cell fate to achieve pituitary dynamic adaptation to changing physiological conditions. In addition to their classical mechanism of action through intracellular estrogen receptors (ERs), estrogens exert rapid actions via cell membrane-localized ERs (mERs). We previously showed that E2 exerts a rapid pro-apoptotic action in anterior pituitary cells, especially in lactotropes and somatotropes, through activation of mERs. In the present study, we examined the involvement of mERα in the rapid pro-apoptotic action of estradiol by TUNEL in primary cultures of anterior pituitary cells from ovariectomized rats using a cell-impermeable E2 conjugate (E2-BSA) and an ERα selective antagonist (MPP dihydrochloride). We studied mERα expression during the estrous cycle and its regulation by gonadal steroids in vivo by flow cytometry. We identified ERα variants in the plasma membrane of anterior pituitary cells during the estrous cycle and studied E2 regulation of these mERα variants in vitro by surface biotinylation and Western Blot. E2-BSA-induced apoptosis was abrogated by MPP in total anterior pituitary cells and lactotropes. In cycling rats, we detected a higher number of lactotropes and a lower number of somatotropes expressing mERα at proestrus than at diestrus. Acute E2 treatment increased the percentage of mERα-expressing lactotropes whereas it decreased the percentage of mERα-expressing somatotropes. We detected three mERα isoforms of 66, 39 and 22 kDa. Expression of mERα66 and mERα39 was higher at proestrus than at diestrus, and short-term E2 incubation increased expression of these two mERα variants. Our results indicate that the rapid apoptotic action exerted by E2 in lactotropes depends on mERα, probably full-length ERα and/or a 39 kDa ERα variant. Expression and activation of mERα variants in lactotropes could be one of the mechanisms through which E2

  2. 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

  3. 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.

  4. Rapid yeast estrogen bioassays stably expressing human estrogen receptors alpha and beta, and green fluorescent protein: a comparison of different compounds with both receptor types.

    PubMed

    Bovee, Toine F H; Helsdingen, Richard J R; Rietjens, Ivonne M C M; Keijer, Jaap; Hoogenboom, Ron L A P

    2004-07-01

    Previously, we described the construction of a rapid yeast bioassay stably expressing human estrogen receptor (hERalpha) and yeast enhanced green fluorescent protein (yEGFP) in response to estrogens. In the present study, the properties of this assay were further studied by testing a series of estrogenic compounds. Furthermore, a similar assay was developed based on the stable expression of human estrogen receptor beta (hERbeta). When exposed to 17beta-estradiol, the maximum transcriptional activity of the ERbeta cytosensor was only about 40% of the activity observed with ERalpha, but the concentration where half-maximal activation is reached (EC50), was about five times lower. The relative estrogenic potencies (REP), defined as the ratio between the EC50 of 17beta-estradiol and the EC50 of the compound, of the synthetic hormones dienestrol, hexestrol and especially mestranol were higher with ER, while DES was slightly more potent with ERbeta. The gestagens progesterone and medroxyprogesterone-acetate showed no response, whereas the androgen testosterone showed a very weak response. The anabolic agent, 19-nortestosterone showed a clear dose-related response with estrogen receptor but not beta. The phytoestrogens coumestrol, genistein, genistin, daidzein, daidzin and naringenin were relatively more potent with ERbeta. Ranking of the estrogenic potency with ER was: 17beta-estradiol > 8-prenylnaringenin > coumestrol > zearalenone > genistein > genistin > naringenin. The ranking with the ERbeta was: 17beta-estradiol > coumestrol > genistein > zearalenone > 8-prenylnaringen > daidzein > naringenin > genistin > daidzin. The hop estrogen 8-prenylnaringenin is relatively more potent with ERalpha. These data show that the newly developed bioassays are valuable tools for the rapid and high-throughput screening for estrogenic activity.

  5. Alteration of Large-Scale Chromatin Structure by Estrogen Receptor

    PubMed Central

    Nye, Anne C.; Rajendran, Ramji R.; Stenoien, David L.; Mancini, Michael A.; Katzenellenbogen, Benita S.; Belmont, Andrew S.

    2002-01-01

    The estrogen receptor (ER), a member of the nuclear hormone receptor superfamily important in human physiology and disease, recruits coactivators which modify local chromatin structure. Here we describe effects of ER on large-scale chromatin structure as visualized in live cells. We targeted ER to gene-amplified chromosome arms containing large numbers of lac operator sites either directly, through a lac repressor-ER fusion protein (lac rep-ER), or indirectly, by fusing lac repressor with the ER interaction domain of the coactivator steroid receptor coactivator 1. Significant decondensation of large-scale chromatin structure, comparable to that produced by the ∼150-fold-stronger viral protein 16 (VP16) transcriptional activator, was produced by ER in the absence of estradiol using both approaches. Addition of estradiol induced a partial reversal of this unfolding by green fluorescent protein-lac rep-ER but not by wild-type ER recruited by a lac repressor-SRC570-780 fusion protein. The chromatin decondensation activity did not require transcriptional activation by ER nor did it require ligand-induced coactivator interactions, and unfolding did not correlate with histone hyperacetylation. Ligand-induced coactivator interactions with helix 12 of ER were necessary for the partial refolding of chromatin in response to estradiol using the lac rep-ER tethering system. This work demonstrates that when tethered or recruited to DNA, ER possesses a novel large-scale chromatin unfolding activity. PMID:11971975

  6. Serum estrogen receptor bioactivity and breast cancer risk among postmenopausal women

    PubMed Central

    Lim, Vanessa W; Li, Jun; Gong, Yinhan; Jin, Aizhen; Yuan, Jian-Min; Yong, Eu Leong; Koh, Woon-Puay

    2014-01-01

    The estrogen levels of Asian women are different from those of Western women, and this could affect estrogen receptor (ER) bioactivity and breast cancer risk. We conducted a case-control study of 169 postmenopausal breast cancer cases and 426 matched controls nested within a population-based prospective cohort, The Singapore Chinese Health Study, to evaluate serum levels of estrogens and their receptor (ERα and ERβ)-mediated estrogenic activities in relation to breast cancer risk. Breast cancer cases had higher levels of estrogens and estrogen receptor mediated bioactivities in baseline serum than controls. Compared to the lowest quartile, women in the highest quartile for estrone or ERα-mediated bioactivity had increased breast cancer risk. After additional adjustment for ERβ bioactivity, free E2 and estrone; serum ERα-mediated estrogenic activity remained associated with increased breast cancer risk. Compared to the lowest quartile, women in the highest quartile for ERα-mediated bioactivity had an odds ratio of 2.39 (95% confidence interval=1.17–4.88, p for trend=0.016). Conversely, the positive association between estrone and cancer risk became null after adjustment for ERα-mediated estrogenic activity, suggesting that the effect of estrone could be mediated through ERα. Identification of the factor(s) contributing to increased ERα-mediated estrogenic bioactivity in sera, and its role as a predictor for breast cancer risk needs to be validated in future studies. PMID:24322303

  7. 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}.

  8. An estrogen receptor model to describe the regulation of prolactin synthesis by antiestrogens in vitro.

    PubMed

    Lieberman, M E; Gorski, J; Jordan, V C

    1983-04-25

    A hypothetical model of the ligand interaction with the estrogen receptor binding site has been developed to describe the structural features necessary to initiate or to inhibit prolactin synthesis in vitro. The biological potency of the binding ligands is directly related to their relative binding affinity (RBA) for the estrogen receptor. The relative potencies of antiestrogens to inhibit estradiol-stimulated prolactin synthesis was trans-monohydroxytamoxifen identical to cis-monohydroxytamoxifen identical to tamoxifen, consistent with their RBAs for uterine estrogen receptor. Similarly the relative potency of estrogens to stimulate prolactin synthesis was diethylstilbestrol identical to estradiol greater than ICI 77,949 greater than ICI 47,699 identical to zuclomiphene, consistent with their RBAs. The compound LY126412 (trioxifene without the aminoethoxy side chain) did not interact with the estrogen receptor at the concentrations tested (10(-8)--10(-6) M) or exhibit estrogenic or antiestrogenic properties using the prolactin synthesis assay. Overall, the ligand-receptor model stresses the structural requirement for high affinity binding and the critical positioning of the alkylamino-ethoxy side chain in space (in relation to the ligand-binding site on the estrogen receptor) to prevent prolactin synthesis.

  9. 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...

  10. Estrogenic activity and estrogen receptor beta binding of the UV filter 3-benzylidene camphor. Comparison with 4-methylbenzylidene camphor.

    PubMed

    Schlumpf, Margret; Jarry, Hubert; Wuttke, Wolfgang; Ma, Risheng; Lichtensteiger, Walter

    2004-07-01

    UV filters represent new classes of estrogenic [Environ. Health Perspect. 109 (2001) 239] or antiandrogenic [Toxicol. Sci. 74 (2003) 43] chemicals. We tested 3-benzylidene camphor (3-BC), reported as estrogenic in fish [Pharmacol. Toxicol. 91 (2002) 204], and mammalian systems in comparison to 4-methylbenzylidene camphor (4-MBC), shown to be active in rats, and analyzed binding to estrogen receptor subtypes. 3-BC and 4-MBC stimulated MCF-7 cell proliferation (EC(50): 0.68 and 3.9 microM). The uterotrophic assay of 3-BC (oral gavage) in immature rats showed unexpected potency with ED50 45.3mg/kg per day; lowest effective dose 2mg/kg per day, and maximum effect with 70% of ethinylestradiol. After comparing with literature data, we found that the oral 3-BC was considerably more potent than oral bisphenol A and almost as active as subcutaneous genistein. 3-BC and 4-MBC displaced 16alpha 125I-estradiol from porcine uterine cytosolic receptors (IC(50): 14.5 and 112 microM), and from recombinant human estrogen receptor beta (hERbeta) (IC(50): 3-BC, 11.8 microM; 4-MBC, 35.3 microM), whereas no displacement was detected at human estrogen receptor alpha (hERalpha) up to 3mM. This subtype selectivity makes the two camphor derivatives interesting model compounds. Their activity on immature rat uterus is not easily explained by ERbeta activation. It cannot be excluded that active metabolites with possibly different receptor binding characteristics are formed in vivo.

  11. Bioassays for estrogenic activity: development and validation of estrogen receptor (ERalpha/ERbeta) and breast cancer proliferation bioassays to measure serum estrogenic activity in clinical studies.

    PubMed

    Li, J; Lee, L; Gong, Y; Shen, P; Wong, S P; Wise, Stephen D; Yong, E L

    2009-02-01

    Standard estrogenic prodrugs such as estradiol valerate (E2V) and increasingly popular phytoestrogen formulations are commonly prescribed to improve menopausal health. These drugs are metabolized to numerous bioactive compounds, known or unknown, which may exert combinatorial estrogenic effects in vivo. The aim of this study is to develop and validate estrogen receptor (ER) alpha/ERbeta reporter gene and MCF-7 breast cancer cell proliferation bioassays to quantify serum estrogenic activities in a clinical trial setting. We measured changes in serum estrogenicity following ingestion of E2V and compared this to mass spectrometric measurements of its bioactive metabolites, estrone and 17beta-stradiol. ERalpha bioactivity of the 192 serum samples correlated well (R = 79%) with 17beta-estradiol levels, and adding estrone improved R to 0.83 (likelihood ratio test, P < 0.0001), suggesting that the ERalpha assay reflects summated activity of compounds in serum. ERbeta correlated moderately (R = 0.52) with estrone and 17beta-estradiol, with an estrone/17beta-estradiol coefficient ratio that was twice that of ERalpha, indicating estrone was more active on a molar basis in the ERbeta assay. Unlike the ERalpha and ERbeta bioassays, MCF-7 cell proliferation was driven by 17beta-estradiol, and addition of estrone did not increase the predictive value of the model, suggesting that the driver or drivers for breast cancer cell proliferation were not the same as for ERalpha and ERbeta transactivation. In contrast, a decoction of the traditional Chinese medicinal herb Epimedium pubescens did not induce significant changes in estrogenic bioactivity over baseline. These data indicate that ERalpha/ERbeta reporter gene and MCF-7 breast cancer cell proliferation bioassays reflect different aspects of estrogenic activity and that these assays suggest that the Epimedium formulation tested is unlikely to exert significant estrogenic effects in humans.

  12. Vascular estrogen receptors and endothelium-derived nitric oxide production in the mouse aorta. Gender difference and effect of estrogen receptor gene disruption.

    PubMed Central

    Rubanyi, G M; Freay, A D; Kauser, K; Sukovich, D; Burton, G; Lubahn, D B; Couse, J F; Curtis, S W; Korach, K S

    1997-01-01

    The present study was designed to test the hypothesis that estrogen receptors (ER) in the blood vessel wall play a role in the modulation of the release of endothelium-derived nitric oxide (EDNO). Both basal and stimulated release of EDNO were determined in aortic rings isolated from female and male wild-type and male homozygous estrogen receptor knock-out (ERKO) mice. 125I-17beta-estradiol binding in aortic tissue showed significantly more high affinity cytosolic- nuclear-binding sites in male compared with female wildtype mice. Estrogen receptor transcripts were present in the aorta of male wild-type mice, but they were absent in male ERKO animals. Basal release of EDNO (determined by endothelium-dependent contraction caused by NG-nitro-arginine) was significantly higher in aorta of wild-type male mice compared with wild-type female mice, and significantly lower in the aorta of male ERKO compared with male wild-type mice. Acetylcholine-induced endothelium-dependent relaxation was similar in all groups studied. No difference was observed in the activity of calcium-dependent nitric oxide synthase in homogenates of lungs and brain taken from male wild-type and ERKO mice. These studies show a significant association between the number of estrogen receptors and basal release of EDNO in the aorta of mice, and suggest that decreased vascular estrogen receptor number may represent a novel risk factor for cardiovascular diseases. PMID:9153286

  13. 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...

  14. 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.

  15. 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…

  16. 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…

  17. G-protein-coupled estrogen receptor agonist suppresses airway inflammation in a mouse model of asthma through IL-10.

    PubMed

    Itoga, Masamichi; Konno, Yasunori; Moritoki, Yuki; Saito, Yukiko; Ito, Wataru; Tamaki, Mami; Kobayashi, Yoshiki; Kayaba, Hiroyuki; Kikuchi, Yuta; Chihara, Junichi; Takeda, Masahide; Ueki, Shigeharu; Hirokawa, Makoto

    2015-01-01

    Estrogen influences the disease severity and sexual dimorphism in asthma, which is caused by complex mechanisms. Besides classical nuclear estrogen receptors (ERαβ), G-protein-coupled estrogen receptor (GPER) was recently established as an estrogen receptor on the cell membrane. Although GPER is associated with immunoregulatory functions of estrogen, the pathophysiological role of GPER in allergic inflammatory lung disease has not been examined. We investigated the effect of GPER-specific agonist G-1 in asthmatic mice. GPER expression in asthmatic lung was confirmed by immunofluorescent staining. OVA-sensitized BALB/c and C57BL/6 mice were treated with G-1 by daily subcutaneous injections during an airway challenge phase, followed by histological and biochemical examination. Strikingly, administration of G-1 attenuated airway hyperresponsiveness, accumulation of inflammatory cells, and levels of Th2 cytokines (IL-5 and IL-13) in BAL fluid. G-1 treatment also decreased serum levels of anti-OVA IgE antibodies. The frequency of splenic Foxp3+CD4+ regulatory T cells and IL-10-producing GPER+CD4+ T cells was significantly increased in G-1-treated mice. Additionally, splenocytes isolated from G-1-treated mice showed greater IL-10 production. G-1-induced amelioration of airway inflammation and IgE production were abolished in IL-10-deficient mice. Taken together, these results indicate that extended GPER activation negatively regulates the acute asthmatic condition by altering the IL-10-producing lymphocyte population. The current results have potential importance for understanding the mechanistic aspects of function of estrogen in allergic inflammatory response.

  18. Effect of nonpersistent pesticides on estrogen receptor, androgen receptor, and aryl hydrocarbon receptor.

    PubMed

    Medjakovic, Svjetlana; Zoechling, Alfred; Gerster, Petra; Ivanova, Margarita M; Teng, Yun; Klinge, Carolyn M; Schildberger, Barbara; Gartner, Michael; Jungbauer, Alois

    2014-10-01

    Nonpersistent pesticides are considered less harmful for the environment, but their impact as endocrine disruptors has not been fully explored. The pesticide Switch was applied to grape vines, and the maximum residue concentration of its active ingredients was quantified. The transactivation potential of the pesticides Acorit, Frupica, Steward, Reldan, Switch, Cantus, Teldor, and Scala and their active compounds (hexythiazox, mepanipyrim, indoxacarb, chlorpyrifos-methyl, cyprodinil, fludioxonil, boscalid, fenhexamid, and pyrimethanil) were tested on human estrogen receptor α (ERα), androgen receptor (AR) and arylhydrocarbon receptor (AhR) in vitro. Relative binding affinities of the pure pesticide constituents for AR and their effect on human breast cancer and prostate cancer cell lines were evaluated. Residue concentrations of Switch's ingredients were below maximum residue limits. Fludioxonil and fenhexamid were ERα agonists (EC50 -values of 3.7 and 9.0 μM, respectively) and had time-dependent effects on endogenous ERα-target gene expression (cyclin D1, progesterone receptor, and nuclear respiratory factor 1) in MCF-7 human breast cancer cells. Fludioxonil, mepanipyrim, cyprodinil, pyrimethanil, and chlorpyrifos-methyl were AhR-agonists (EC50 s of 0.42, 0.77, 1.4, 4.6, and 5.1 μM, respectively). Weak AR binding was shown for chlorpyrifos-methyl, cyprodinil, fenhexamid, and fludioxonil. Assuming a total uptake which does not take metabolism and clearance rates into account, our in vitro evidence suggests that pesticides could activate pathways affecting hormonal balance, even within permitted limits, thus potentially acting as endocrine disruptors.

  19. 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

  20. Polyester monomers lack ability to bind and activate both androgenic and estrogenic receptors as determined by in vitro and in silico methods.

    PubMed

    Osimitz, Thomas G; Welsh, William J; Ai, Ni; Toole, Colleen

    2015-01-01

    The paper presents results from the screening of seven monomers used by Eastman Chemical to make various polymers. Ethylene glycol, diethylene glycol, polytetramethylene glycol, isophthalic acid, monosodium-5-sulfoisophthalic acid, 1,4-cyclohexanedicarboxylic acid, and dimethylcyclohexanedicarboxylate were screened for potential androgenicity or estrogenicity. The following studies were conducted: QSAR for binding to the AR and ER, in vitro Androgen Receptor Binding Assay, in vitro Estrogen Receptor Binding Assays (alpha and beta isoforms), in vitro Androgen Receptor Transactivation Assay in human cells, and in vitro Estrogen Receptor Transactivation Assay in human cells. None of the QSAR models predicted that any of the monomers possessed appreciable binding affinity for either AR or ER. Binding assays showed no evidence of interaction with either the AR or the alpha or beta ER receptors. Similarly, the AR and ER transactivation assays were negative. Moreover, six of the seven monomers have been subjected to 13-week and developmental toxicity studies in rats with no androgen- or estrogen-related effects being noted. Given the negative results of the in vitro screening assays (except PMG which demonstrated cytotoxicity) as well as available repeated dose and developmental and reproductive studies, the data suggest that none of the monomers tested exhibit androgenic or estrogenic hazards.

  1. Thiophene-Core Estrogen Receptor Ligands Having Superagonist Activity

    PubMed Central

    Min, Jian; Wang, Pengcheng; Srinivasan, Sathish; Nwachukwu, Jerome C.; Guo, Pu; Huang, Minjian; Carlson, Kathryn E.; Katzenellenbogen, John A.; Nettles, Kendall W.; Zhou, Hai-Bing

    2013-01-01

    To probe the importance of the heterocyclic core of estrogen receptor (ER) ligands, we prepared a series of thiophene-core ligands by Suzuki cross-coupling of aryl boronic acids with bromo-thiophenes, and we assessed their receptor binding and cell biological activities. The disposition of the phenol substituents on the thiophene core, at alternate or adjacent sites, and the nature of substituents on these phenols all contribute to binding affinity and subtype selectivity. Most of the bis(hydroxyphenyl)-thiophenes were ERβ selective, whereas the tris(hydroxyphenyl)-thiophenes were ERα selective; analogous furan-core compounds generally have lower affinity and less selectivity. Some diarylthiophenes show distinct superagonist activity in reporter gene assays, giving maximal activities 2–3 times that of estradiol, and modeling suggests that these ligands have a different interaction with a hydrogen-bonding residue in helix-11. Ligand-core modification may be a new strategy for developing ER ligands whose selectivity is based on having transcriptional activity greater than that of estradiol. PMID:23586645

  2. Estrogen receptor alpha inhibits RLR-mediated immune response via ubiquitinating TRAF3.

    PubMed

    Wang, Changxing; Huang, Yue; Sheng, Jianzhong; Huang, Hefeng; Zhou, Jun

    2015-10-01

    RIG-I-like receptors (RLRs) function as key sentinel receptor for invading viruses. Moderate activation of RLR signaling is critical for efficient viral clearance without harmful immunopathology. Estrogen receptor alpha (ERα) is a member of the nuclear receptor superfamily of ligand-activated transcription factors and is involved in the regulation of innate immune responses. However, the effects of ERα on RLR signaling and the molecular mechanisms are poorly understood. In this study, we identify ERα as a negative regulator of RLR-triggered antiviral immune responses. The expression level of ERα is upregulated following RLR activation in macrophages. In the absence of ligand, VSV infection phosphorylates ERα at serine 167. ERα inhibits VSV-induced IRF3 activation. We further demonstrate that ERα directly interacts with TRAF3 and promotes K48-linked proteasomal degradation of TRAF3. Consistently, ERα inhibits VSV-triggered IFN-β production in macrophages in a ligand independent mechanism. Thus, ERα functions as a negative feedback regulator of RLR-triggered antiviral immune responses. These findings also provide the insights that separate the immune effects of ERα from its ligand-induced hormonal effects.

  3. 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.

  4. Autocrine role of estrogens in the augmentation of luteinizing hormone receptor formation in cultured rat granulosa cells.

    PubMed

    Kessel, B; Liu, Y X; Jia, X C; Hsueh, A J

    1985-06-01

    The effects of estrogens on gonadotropin-stimulated luteinizing hormone (LH) receptor formation were examined in primary cultures of rat granulosa cells. Granulosa cells were cultured for 3 days with increasing concentrations of follicle-stimulating hormone (FSH) in the presence or absence of native and synthetic estrogens. Follicle-stimulating hormone stimulated LH receptor formation in a dose-dependent fashion, and estrogens enhanced the FSH-stimulated LH receptor content by decreasing the apparent ED50 of FSH. At 6.25 ng/ml FSH, the enhancement in LH receptor was estrogen dose dependent, with an ED50 value of about 3 X 10(-9) M for 17 beta-estradiol. The increased LH receptor content seen in cells treated with FSH and estrogen was correlated with increased cAMP production by these cells in response to LH stimulation. Time course studies revealed enhancement of FSH-stimulated LH receptor induction at 48 and 72 h of culture. Granulosa cells were also cultured with FSH for 2 days to induce functional LH receptors, then further cultured for 3 days with LH in the presence or absence of estrogens. At 30 ng/ml LH, increasing concentrations of estrogens maintained LH receptor content in a dose-dependent fashion, with their relative estrogenic potencies in keeping with reported binding affinities to estrogen receptors. An autocrine role of estrogens on LH receptor formation was further tested in granulosa cells treated with FSH and an aromatase substrate (androstenedione) to increase estrogen biosynthesis. Cotreatment with semipurified estrogen antibodies partially blocked the FSH stimulation of LH receptors, whereas nonimmune serum was ineffective. Also, inclusion of diethylstilbestrol prevented the inhibitory effect of the estrogen antibodies. Thus, local estrogens in ovarian follicles may play an autocrine role in granulosa cells to enhance LH receptor formation and to increase granulosa cell responsiveness to the LH surge, with subsequent ovulation and adequate

  5. Estrogen receptor alpha polymorphisms and the risk of malignancies.

    PubMed

    Anghel, Andrei; Narita, Diana; Seclaman, Edward; Popovici, Emilian; Anghel, Mariana; Tamas, Liviu

    2010-12-01

    Estrogens represent risk factors for endocrine-related cancers and play also an important role in the development and progression of other malignancies. In order to analyze the associations between estrogen receptor gene alpha polymorphisms and cancers susceptibility, we genotyped six single nucleotide polymorphisms (SNPs) in 163 Caucasian cancer patients--103 breast cancers and 60 other malignancies (colorectal, bladder, hepatocellular carcinoma and acute myeloid leukemia)--and 114 healthy controls using hybridization probes. We performed Armitage`s association trend-test to evaluate the risk. Linkage disequilibrium (LD) was assessed for each pair of markers. The genotypes CC and CT of rs3798577 were significantly associated with the cancers risk (p-trend breast = 4 × 10(-5); p-trend cancers = 1 × 10(-5)); in discrepancy with breast cancer where the C-allele represented the risk allele, for bladder, hepatocellular carcinomas and leukemia, the T allele seems to confer susceptibility. The minor G allele of rs1801132 was protective in our cases (p = 1 × 10(-4)); for rs2228480, the heterozygous frequency was higher for cancer groups (p = 0.03); the SNP pairs rs2228480&rs3798577 and rs2234693&rs9340799 were in low LD; the haplotypes T-A of rs2234693&rs9340799 and G-C of rs2228480&rs3798577 showed a trend to be higher represented in breast cancers; T allele of rs2234693 was higher expressed in breast, colon cancers and leukemia; rs2077647 was associated with colon (p = 0.008, C-risk allele) and bladder (p = 0.01, T-risk allele) cancers. We concluded that ESR1 polymorphisms may have distinct impact in carcinogenesis and further genotyping will establish whether these findings remain significant in larger cohorts.

  6. 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

  7. Δ(9)-Tetrahydrocannabinol disrupts estrogen-signaling through up-regulation of estrogen receptor β (ERβ).

    PubMed

    Takeda, Shuso; Yoshida, Kazutaka; Nishimura, Hajime; Harada, Mari; Okajima, Shunsuke; Miyoshi, Hiroko; Okamoto, Yoshiko; Amamoto, Toshiaki; Watanabe, Kazuhito; Omiecinski, Curtis J; Aramaki, Hironori

    2013-07-15

    Δ(9)-Tetrahydrocannabinol (Δ(9)-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 Δ(9)-THC exposures markedly suppresses 17β-estradiol (E2)- induced MCF-7 cell proliferation. We demonstrate that these effects result from Δ(9)-THC's ability to inhibit E2-liganded ERα activation. Mechanistically, the data obtained from biochemical analyses revealed that (i) Δ(9)-THC up-regulates ERβ, a repressor of ERα, inhibiting the expression of E2/ERα-regulated genes that promote cell growth and that (ii) Δ(9)-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 Δ(9)-THC's antiestrogenic activities are mediated by the ERβ disruption of E2/ERα signaling.

  8. 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

  9. 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

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

    PubMed Central

    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

  11. Drug targeting of estrogen receptor signaling in the cardiovascular system: preclinical and clinical studies.

    PubMed

    Sanz-González, Silvia M; Cano, Antonio; Valverde, M A; Hermenegildo, Carlos; Andrés, Vicente

    2004-04-01

    Atherosclerosis and associated coronary heart disease events have lower prevalence in women than in men, especially during young adult years. Although multiple lines of evidence suggest that estrogens contribute to this difference, the efficacy of hormone replacement therapy for the prevention of cardiovascular disease in postmenopausal women is controversial. The protective action of estrogen in the cardiovascular system appears to be mediated indirectly by an effect on serum lipoprotein and triglyceride profiles and on the expression of coagulant and fibrinolytic proteins, and by a direct effect on the vessel wall itself. Estrogen has both rapid effects involving alteration of membrane ionic permeability and activation of membrane-bound enzymes and increases in endothelial cell nitric oxide synthase activity, as well as longer-term effects on gene expression that are mediated, at least in part, by the ligand-activated transcription factors, estrogen receptor alpha and beta. Compounds with pure antiestrogenic activity and selective estrogen receptor modulators that regulate estrogen receptor function in a tissue-specific manner have been developed in an attempt to achieve the cardioprotective effects of estrogens while minimizing the undesirable risks associated with hormone replacement therapy (e.g., endometrial and breast cancer). In this review, we will discuss recent developments on the mechanisms of estrogen action in the cardiovascular system. The results of clinical trials testing the long-term efficacy of hormone replacement therapy for the treatment of cardiovascular disease will also be discussed.

  12. Effects of the estrogen receptor antagonist fulvestrant on F344 rat prolactinoma models.

    PubMed

    Cao, Lei; Gao, Hua; Gui, Songbai; Bai, Giwei; Lu, Runchun; Wang, Fei; Zhang, Yazhuo

    2014-02-01

    The relationship between estrogen and prolactinoma is well documented. But the anti-tumor effects of a pure estrogen receptor antagonist fulvestrant on prolactinomas, especially in vivo, and the possible mechanisms are still unclear. Therefore, the aim of this study was to evaluate the effects of fulvestrant and the involvement of the Wnt signaling pathway on rat prolactinoma models. Forty female F344 rat prolactinoma models were established by subcutaneous administration of 10 mg 17β-estradiol for 6 weeks. Rats were intramuscularly injected with fulvestrant (0, 0.5, 3, 20, 40 mg/kg), and tumor size, weight and serum prolactin (PRL) levels were evaluated before and after fulvestrant treatment at 3, 7 and 14 days. Expression of estrogen receptor α (ERα), β-catenin and Wnt inhibitory factor-1 (WIF-1) in prolactinomas was measured using quantitative PCR and western blotting, and methylation of the WIF-1 promoter was investigated using pyrosequencing. Tumor size, weight and serum PRL levels were inhibited in dose-dependent and time-dependent manners after fulvestrant treatments. β-catenin expression was downregulated but WIF-1 expression was upregulated following fulvestrant treatment. The methylation of the CpG site of the WIF-1 promoter was negatively correlated to the expression of WIF-1. In addition, the anti-cell proliferation of fulvestrant on GH3 cells was partly disrupted by Wnt signaling pathway agonist SB 216763. In conclusion, fulvestrant inhibited tumor proliferation and PRL secretion of prolactinomas via ERα, and the Wnt signaling pathway was involved in this anti-tumor effect. Therefore, fulvestrant may be a potential new drug for prolactinomas.

  13. Role of the Neddylation Enzyme Uba3, A New Estrogen Receptor Corepressor, in Breast Cancer

    DTIC Science & Technology

    2005-05-01

    expression of ERa in tumors with acquired resistance, such as disruptions in the NEDD8, CHIP or other ubiquitin or ubiquitin- associated / protein receptor...estrogen. Faseb J 18 :81-93 13. Fan M, Park A, Nephew KP. Interactions between estrogen receptor and the COOH terminus of the Hsp70- interacting protein ...responses. An attenuated transcrip- target proteins is primarily conferred by E3, regulation tional response has been associated with down-regula- of

  14. Alcohol consumption negates estrogen-mediated myocardial repair in ovariectomized mice by inhibiting endothelial progenitor cell mobilization and function.

    PubMed

    Mackie, Alexander R; Krishnamurthy, Prasanna; Verma, Suresh K; Thorne, Tina; Ramirez, Veronica; Qin, Gangjian; Abramova, Tatiana; Hamada, Hiromichi; Losordo, Douglas W; Kishore, Raj

    2013-06-21

    We have shown previously that estrogen (estradiol, E2) supplementation enhances voluntary alcohol consumption in ovariectomized female rodents and that increased alcohol consumption impairs ischemic hind limb vascular repair. However, the effect of E2-induced alcohol consumption on post-infarct myocardial repair and on the phenotypic/functional properties of endothelial progenitor cells (EPCs) is not known. Additionally, the molecular signaling of alcohol-estrogen interactions remains to be elucidated. This study examined the effect of E2-induced increases in ethanol consumption on post-infarct myocardial function/repair. Ovariectomized female mice, implanted with 17β-E2 or placebo pellets were given access to alcohol for 6 weeks and subjected to acute myocardial infarction. Left ventricular functions were consistently depressed in mice consuming ethanol compared with those receiving only E2. Alcohol-consuming mice also displayed significantly increased infarct size and reduced capillary density. Ethanol consumption also reduced E2-induced mobilization and homing of EPCs to injured myocardium compared with the E2-alone group. In vitro, exposure of EPCs to ethanol suppressed E2-induced proliferation, survival, and migration and markedly altered E2-induced estrogen receptor-dependent cell survival signaling and gene expression. Furthermore, ethanol-mediated suppression of EPC biology was endothelial nitric oxide synthase-dependent because endothelial nitric oxide synthase-null mice displayed an exaggerated response to post-acute myocardial infarction left ventricular functions. These data suggest that E2 modulation of alcohol consumption, and the ensuing EPC dysfunction, may negatively compete with the beneficial effects of estrogen on post-infarct myocardial repair.

  15. Reciprocal roles of DBC1 and SIRT1 in regulating estrogen receptor α activity and co-activator synergy

    PubMed Central

    Ji Yu, Eun; Kim, Seok-Hyung; Heo, Kyu; Ou, Chen-Yin; Kim, Jeong Hoon

    2011-01-01

    Estrogen receptor α (ERα) plays critical roles in development and progression of breast cancer. Because ERα activity is strictly dependent upon the interaction with coregulators, coregulators are also believed to contribute to breast tumorigenesis. Cell Cycle and Apoptosis Regulator 1 (CCAR1) is an important co-activator for estrogen-induced gene expression and estrogen-dependent growth of breast cancer cells. Here, we identified Deleted in Breast Cancer 1 (DBC1) as a CCAR1 binding protein. DBC1 was recently shown to function as a negative regulator of the NAD-dependent protein deacetylase SIRT1. DBC1 associates directly with ERα and cooperates synergistically with CCAR1 to enhance ERα function. DBC1 is required for estrogen-induced expression of a subset of ERα target genes as well as breast cancer cell proliferation and for estrogen-induced recruitment of ERα to the target promoters in a gene-specific manner. The mechanism of DBC1 action involves inhibition of SIRT1 interaction with ERα and of SIRT1-mediated deacetylation of ERα. SIRT1 also represses the co-activator synergy between DBC1 and CCAR1 by binding to DBC1 and disrupting its interaction with CCAR1. Our results indicate that DBC1 and SIRT1 play reciprocal roles as major regulators of ERα activity, by regulating DNA binding by ERα and by regulating co-activator synergy. PMID:21596782

  16. Distribution of estrogen and progesterone receptors isoforms in endometrial cancer

    PubMed Central

    2014-01-01

    Background 70–80% of sporadic endometrial carcinomas are defined as endometrioid carcinoma (EC). Early-stage, well differentiated endometrial carcinomas usually retain expression of estrogen and progesterone receptors (ER and PR, respectively), as advanced stage, poorly differentiated tumors often lack one or both of these receptors. Well-described EC prognosis includes tumor characteristics, such as depth of myometrial invasion. Therefore, in the current study, we evaluated the expression profile of ER and PR isoforms, including ER-α, PR-A and PR–B, in correlation to EC tumor histological depth. Methods Using immunohistochemistry and image analysis software, the expression of ER-α, PR-A, PR–B and Ki67 was assessed in endometrial stroma and epithelial glands of superficial, deep and extra-tumoral sections of 15 paraffin embedded EC specimens, and compared to 5 biopsies of non-malignant endometrium. Results Expression of PR-A and ER-α was found to be lower in EC compared to nonmalignant tissue, as the stromal expression was dramatically reduced compared to epithelial cells. Expression ratios of both receptors were significantly high in superficial and deep portions of EC; in non-tumoral portion of EC were close to the ratios of nonmalignant endometrium. PR-B expression was low in epithelial glands of EC superficial and deep portions, and high in the extra-tumoral region. Elevated PR-B expression was found in stroma of EC, as well. Conclusions The ratio of ER-α and PR-A expression in the epithelial glands and the stroma of EC biopsies may serve as an additional parameter in the histological evaluation of EC tumor. Virtual slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1155060506119016 PMID:24684970

  17. Ontogeny of cells containing estrogen receptor-like immunoreactivity in the Brazilian opossum brain.

    PubMed

    Fox, C A; Ross, L R; Jacobson, C D

    1991-11-19

    In this study, we have used the Brazilian short-tailed opossum (Monodelphis domestica) as a model to study the ontogeny of estrogen receptors in the mammalian brain. Monodelphis is a small, pouchless marsupial which breeds well under laboratory conditions and whose young are born in an immature sexually undifferentiated state. The Abbott H222 monoclonal rat estrogen receptor antibody (gift of Abbott Laboratories) was utilized in an indirect immunohistochemical procedure to detect estrogen receptors in developing opossum brains. Estrogen receptors were first expressed in the dorsomedial and ventromedial hypothalamus of the opossum 10 days after birth (10PN). Most regions that contained estrogen receptor-like immunoreactivity (ER LI) in the adult opossum contained ER LI at 15 PN. These areas include the lateral septum, medial preoptic area, bed nucleus of the stria terminalis, periventricular preoptic area and hypothalamus, amygdala, dorsomedial and ventromedial hypothalamic nuclei, arcuate nucleus, ventral premammillary nucleus, and the midbrain central grey. The number of cells that contain ER LI increased through 60PN in all regions that will contain ER LI in the adult opossum. These results indicate that estrogen receptors are present in early development of the Monodelphis brain and may mark the beginning of a critical period for sexual differentiation of the opossum brain.

  18. Phorbol ester induced phosphorylation of the estrogen receptor in intact MCF-7 human breast cancer cells

    SciTech Connect

    Knabbe, C.; Lippman, M.E.; Greene, G.L.; Dickson, R.B.

    1986-05-01

    Recent studies with a variety of cellular receptors have shown that phorbol ester induced phosphorylation modulates ligand binding and function. In this study the authors present direct evidence that the estrogen receptor in MCF-7 human breast cancer cells is a phosphoprotein whose phosphorylation state can be enhanced specifically by phorbol-12-myristate-13-acetate (PMA). Cells were cultured to 6h in the presence of (/sup 32/P)-orthophosphate. Whole cell extracts were immunoprecipitated with a monoclonal antibody (D58) against the estrogen receptor and subjected to SDS-polyacrylamide electrophoresis. Autoradiography showed a specific band in the region of 60-62 kDa which was significantly increased in preparations from PMA treated cells. Phospho-amino acid analysis demonstrated specific phosphorylation of serine and threonine residues. Cholera toxin or forskolin did not change the phosphorylation state of this protein. In a parallel binding analysis PMA led to a rapid decrease of estrogen binding sites. The estrogen induction of both progesterone receptors and growth in semisolid medium was blocked by PMA, whereas the estrogen induction of the 8kDa protein corresponding to the ps2 gene product and of the 52 kDa protein was not affected. In conclusion, phorbol esters can induce phosphorylation of the estrogen receptor. This process may be associated with the inactivation of certain receptor functions.

  19. Receptors for leptin and estrogen in the subcommissural organ of rabbits are differentially modulated by fasting.

    PubMed

    Dall'Aglio, Cecilia; Ceccarelli, Piero; Pascucci, Luisa; Brecchia, Gabriele; Boiti, Cristiano

    2006-12-08

    In rabbits, the fasting-dependent reduction of LH secretion is likely mediated by leptin and estrogens via receptors in the brain. For the first time, using immunohistochemistry, the presence and regulation of receptors for leptin (Ob-R) and estradiol-17beta subtype alpha (ERalpha) were studied in the subcommissural organ (SCO) of rabbits, which were fed either ad libitum (control) or fasted for 48 h (treated) to verify whether this brain structure is a potential site of integration for metabolism and reproduction. In control rabbits, the cytoplasm of glial cells lining the SCO evidenced strong Ob-R immunoreactivity, whereas both ependymal and hypendymal cells of this glandular-like structure were negative. The Ob-R positive glial cells were identified as fibrous astrocytes using the phosphotungstic acid-hematoxylin histochemical (PTAH) and glial fibrillary acidic protein (GFAP) immunohistochemical techniques. ERalpha immunoreactive nuclei were detectable exclusively in the specialized cells forming the SCO, whereas surrounding astrocytes and neurons were negative. Compared to controls, in fasted rabbits, the staining of Ob-R immunoreaction was reduced in the cytoplasm of positive astrocytes, but greatly enhanced in plasma membranes, whereas the number of ERalpha immunoreactive SCO cells was increased (13.2+/-2.7 vs. 5.2+/-2.0, P<0.01). Ependymal cells lining the third ventricle were negative for both Ob-R and ERalpha. Our results indicate, although indirectly, that the SCO, together with the astrocytes in close contact with this structure, is a likely target for nutritional and gonadal signals carried by leptin and estrogens, suggesting that these specialized glial cells may regulate reproduction and metabolism through mechanisms still unknown.

  20. LSD1 engages a corepressor complex for the activation of the estrogen receptor α by estrogen and cAMP

    PubMed Central

    Bennesch, Marcela A.; Segala, Gregory; Wider, Diana; Picard, Didier

    2016-01-01

    The estrogen receptor α (ERα) is a transcription factor that can be directly activated by estrogen or indirectly by other signaling pathways. We previously reported that activation of the unliganded ERα by cAMP is mediated by phosphorylation of the transcriptional coactivator CARM1 by protein kinase A (PKA), allowing CARM1 to bind ERα directly. This being insufficient by itself to activate ERα, we looked for additional factors and identified the histone H3 demethylase LSD1 as a substrate of PKA and an important mediator of this signaling crosstalk as well as of the response to estrogen. Surprisingly, ERα engages not only LSD1, but its partners of the CoREST corepressor complex and the molecular chaperone Hsp90. The recruitment of Hsp90 to promote ERα transcriptional activity runs against the steroid receptor paradigm and suggests that it might be involved as an assembly factor or scaffold. In a breast cancer cell line, which is resistant to the anti-estrogen tamoxifen because of constitutively activated PKA, some interactions are constitutive and drug combinations partially rescue tamoxifen sensitivity. In ERα-positive breast cancer patients, high expression of the genes encoding some of these factors correlates with poor prognosis. Thus, these mechanisms might contribute to ERα-driven breast cancer. PMID:27325688

  1. Estradiol-induced modulation of estrogen receptor-beta and GABA within the adult neocortex: a potential transsynaptic mechanism for estrogen modulation of BDNF.

    PubMed

    Blurton-Jones, Mathew; Tuszynski, Mark H

    2006-12-01

    Estrogen influences brain-derived neurotrophic factor (BDNF) expression in the neocortex. However, BDNF-producing cortical neurons do not express detectable levels of nuclear estrogen receptors; instead, the most abundant cortical nuclear estrogen receptor, ER-beta, is present in GABAergic neurons, prompting us to test the hypothesis that estrogen effects on BDNF are mediated via cortical inhibitory interneurons. Adult female ovariectomized rats were provided acute estrogen replacement and the number of cortical GABA, ER-beta, and ER-beta/GABA double-labeled neurons was examined. Within 48 hours of injection of 17-beta-estradiol, the number of perirhinal neurons double-labeled for ER-beta/GABA was reduced by 28% (P<0.01 compared to vehicle-treated ovariectomized controls), and all cells expressing detectable levels of GABA were reduced by 19% (P<0.01). To investigate potential relationships between estrogen receptors, GABAergic neurons, and BDNF-expressing cells, brain sections were double- or triple-labeled for ER-beta, GABAergic, and BDNF immunomarkers. The findings indicated that ER-beta-bearing inhibitory neurons project onto other GABAergic neurons that lack nuclear estrogen receptors; these inhibitory neurons in turn innervate BDNF-expressing excitatory cells. High estrogen states reduce cortical GABA levels, presumably releasing inhibition on BDNF-expressing neurons. This identifies a putative two-step transsynaptic mechanism whereby estrogen availability modulates expression of inhibitory transmitters, resulting in increased BDNF expression.

  2. 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.

  3. Estrogen Receptor Alpha G525L Knock-In Mice

    DTIC Science & Technology

    2007-03-01

    response to endogenous estrogens. These female estrogen non-responsive ERα knock-in (ENERKI) mice had immature and hypoplastic uterine and vaginal ...developing mice as well as in adult animals with genetically induced mammary cancers through PPT administration or withdrawal. 15. SUBJECT TERMS estrogen...is a crucial therapeutic target for hormone dependent breast cancers . More effective treatment and prevention strategies are likely to emerge from

  4. Immunohistochemical profiling of estrogen-related receptor gamma in rat brain and colocalization with estrogen receptor alpha in the preoptic area.

    PubMed

    Tanida, Takashi; Matsuda, Ken Ichi; Yamada, Shunji; Kawata, Mitsuhiro; Tanaka, Masaki

    2017-03-15

    Estrogen-related receptor (ERR) is a member of the nuclear receptor superfamily that has strong homology with estrogen receptor (ER) α. Despite the lack of endogenous ligands, ERR serves as transcription factors through their constitutively active structure with or without interaction with ERα. Among the three subtypes of ERR (α, β, and γ), ERRγ is highly expressed in brain, but the distribution of ERRγ is poorly characterized. Therefore, we investigated ERRγ immunoreactivity throughout the rostro-caudal axis in rat brain. Immunohistochemistry revealed localization of ERRγ protein in the cell nucleus, and a ubiquitous distribution of ERRγ in brain regions including the olfactory bulb, cerebrum, brain stem, and cerebellum. Selective intense immunoreactivity was observed in the reticular thalamic nucleus, zona incerta, circular nucleus, interpeduncular nucleus, pontine nucleus, and parasolitary nucleus. Most ERRγ-immunoreactive (ir) regions were also positive for ERα and/or ERβ, which suggests that ERRγ is involved in modulation of estrogen signaling in adult rat brain. Double immunofluorescence demonstrated colocalization of ERRγ with ERα within the anteroventral periventricular nucleus of the preoptic area (AVPV) and medial preoptic nucleus (MPO), which are major target sites for estrogen action. The results of this study suggest that ERRγ function in the brain is affected by estrogens through an interaction with ERα. The findings also provide basic information on brain region-specific ERRγ function.

  5. Transformation of the rat uterine estrogen receptor after partial purification.

    PubMed

    Nielsen, S; Notides, A C

    1975-02-13

    Warming crude ratuterine cytosol after the addition of [3H] estradiol accelerates the association of the 4-S estrogen-binding protein with a second macromolecule, resulting in the formation of the 5-S estrogen-binding protein. To determine whether the 5-S estrogen-binding protein consists of two similar or dissimilar subunits, uterine cytosol was subjected to a number of fractionation procedures that separate macromolecules by solubility, molecular gel sieving, sedimentation rate, ionic charge, and heat lability. Following each of these methods, the fraction containing the 4-S estrogen-binding protein was incubated at 28 degrees C; each of the these 4-S estrogen-binding protein-containing fractions retained its capacity to completely transform to the 5-S estrogen-binding protein. In samples subjected to partial purification procedures, it was necessary that the buffer contain 40 mM Tris, 60 mM Tris, 60 mM KC1, 1-10 MM dithiothreitol, and 1 M urea at pH 7.4, in order to accomplish the 4-S to 5-S estrogen-binding protein transformation at 25 degrees C. Formation of the 5-S estrogen-binding protein requires association of the 4-Estrogen-binding protein with a molecule identical to or very similar to itself.

  6. Estrogen receptor and progesterone receptor synthesis and degradation in target cells

    SciTech Connect

    Nardulli, A.M.

    1987-01-01

    It was the intent of this study to determine the turnover of the estrogen receptor (ER) and progesterone receptors (PR) in rat uterine and human breast cancer cells, respectively, and to examine the effect of estrogen and progestin on PR levels. The rates of synthesis and degradation of ER were determined in rat uterine cells in vitro and in vivo. The affinity labeling antiestrogen, (/sup 3/H)tamoxifen aziridine, was used in pulse chase experiments to show that the 65,000 molecular weight ER has a half-life of 3-4h in primary cultures of rat uterine cells in vitro and in the intact rat uterus in vivo. Density shift analyses using dense (/sup 15/N, /sup 13/C, /sup 2/H) amino acid incorporation corroborate the rapid turnover of ER in rat uterine cell cultures. The regulation of PR by progestins in T47D human breast cancer cells was examined using density shift-dense amino acid incorporation. When T47D cells, which normally maintain high PR levels, are exposed to progestin (R5020), PR levels decline. Receptor half-life, which is 21h in control cells, is reduced to 6h when cells are exposed to 20 nM (/sup 3/H)R5020. In addition, PR synthesis rate declines exponentially following R5020 exposure. The reduction in receptor level is thus due to dramatic increases in PR degradation as well as marked decreases in PR synthesis.

  7. CTCF modulates Estrogen Receptor function through specific chromatin and nuclear matrix interactions

    PubMed Central

    Fiorito, Elisa; Sharma, Yogita; Gilfillan, Siv; Wang, Shixiong; Singh, Sachin Kumar; Satheesh, Somisetty V.; Katika, Madhumohan R.; Urbanucci, Alfonso; Thiede, Bernd; Mills, Ian G.; Hurtado, Antoni

    2016-01-01

    Enhancer regions and transcription start sites of estrogen-target regulated genes are connected by means of Estrogen Receptor long-range chromatin interactions. Yet, the complete molecular mechanisms controlling the transcriptional output of engaged enhancers and subsequent activation of coding genes remain elusive. Here, we report that CTCF binding to enhancer RNAs is enriched when breast cancer cells are stimulated with estrogen. CTCF binding to enhancer regions results in modulation of estrogen-induced gene transcription by preventing Estrogen Receptor chromatin binding and by hindering the formation of additional enhancer-promoter ER looping. Furthermore, the depletion of CTCF facilitates the expression of target genes associated with cell division and increases the rate of breast cancer cell proliferation. We have also uncovered a genomic network connecting loci enriched in cell cycle regulator genes to nuclear lamina that mediates the CTCF function. The nuclear lamina and chromatin interactions are regulated by estrogen-ER. We have observed that the chromatin loops formed when cells are treated with estrogen establish contacts with the nuclear lamina. Once there, the portion of CTCF associated with the nuclear lamina interacts with enhancer regions, limiting the formation of ER loops and the induction of genes present in the loop. Collectively, our results reveal an important, unanticipated interplay between CTCF and nuclear lamina to control the transcription of ER target genes, which has great implications in the rate of growth of breast cancer cells. PMID:27638884

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

    PubMed Central

    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

  9. Estrogen receptor agonists for attenuation of neuroinflammation and neurodegeneration

    PubMed Central

    Chakrabarti, Mrinmay; Haque, Azizul; Banik, Naren L.; Nagarkatti, Prakash; Nagarkatti, Mitzi; Ray, Swapan K.

    2014-01-01

    Recent results from laboratory investigations and clinical trials indicate important roles for estrogen receptor (ER) agonists in protecting the central nervous system (CNS) from noxious consequences of neuroinflammation and neurodegeneration. Neurodegenerative processes in several CNS disorders including spinal cord injury (SCI), multiple sclerosis (MS), Parkinson's disease (PD), and Alzheimer's disease (AD) are associated with activation of microglia and astrocytes, which drive the resident neuroinflammatory response. During neurodegenerative processes, activated microglia and astrocytes cause deleterious effects on surrounding neurons. The inhibitory activity of ER agonists on microglia activation might be a beneficial therapeutic option for delaying the onset or progression of neurodegenerative injuries and diseases. Recent studies suggest that ER agonists can provide neuroprotection by modulation of cell survival mechanisms, synaptic reorganization, regenerative responses to axonal injury, and neurogenesis process. The anti-inflammatory and neuroprotective actions of ER agonists are mediated mainly via two ERs known as ERα and ERβ. Although some studies have suggested that ER agonists may be deleterious to some neuronal populations, the potential clinical benefits of ER agonists for augmenting cognitive function may triumph over the associated side effects. Also, understanding the modulatory activities of ER agonists on inflammatory pathways will possibly lead to the development of selective anti-inflammatory molecules with neuroprotective roles in different CNS disorders such as SCI, MS, PD, and AD in humans. Future studies should be concentrated on finding the most plausible molecular pathways for enhancing protective functions of ER agonists in treating neuroinflammatory and neurodegenerative injuries and diseases in the CNS. PMID:25245209

  10. Estrogen receptors regulate innate immune cells and signaling pathways.

    PubMed

    Kovats, Susan

    2015-04-01

    Humans show strong sex differences in immunity to infection and autoimmunity, suggesting sex hormones modulate immune responses. Indeed, receptors for estrogens (ERs) regulate cells and pathways in the innate and adaptive immune system, as well as immune cell development. ERs are ligand-dependent transcription factors that mediate long-range chromatin interactions and form complexes at gene regulatory elements, thus promoting epigenetic changes and transcription. ERs also participate in membrane-initiated steroid signaling to generate rapid responses. Estradiol and ER activity show profound dose- and context-dependent effects on innate immune signaling pathways and myeloid cell development. While estradiol most often promotes the production of type I interferon, innate pathways leading to pro-inflammatory cytokine production may be enhanced or dampened by ER activity. Regulation of innate immune cells and signaling by ERs may contribute to the reported sex differences in innate immune pathways. Here we review the recent literature and highlight several molecular mechanisms by which ERs regulate the development or functional responses of innate immune cells.

  11. Urethral dysfunction in female mice with estrogen receptor β deficiency.

    PubMed

    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.

  12. Disruption of the estrogen receptor β gene in mice causes myeloproliferative disease resembling chronic myeloid leukemia with lymphoid blast crisis

    PubMed Central

    Shim, Gil-Jin; Wang, Ling; Andersson, Sandra; Nagy, Noémi; Kis, Loránd Levente; Zhang, Qinghong; Mäkelä, Sari; Warner, Margaret; Gustafsson, Jan-Åke

    2003-01-01

    Proliferation of pluripotent, bone marrow stem cells, which develop to lymphoid and myeloid progenitors, is negatively regulated by estrogen. Although in estrogen deficiency and in estrogen receptor knockout mice there is significant alteration in bone marrow hematopoiesis, the effects of aging on estrogen receptor deficiencies in mice have not been investigated yet. In this study we show that by 1.5 years of age, estrogen receptor β knockout (ERβ–/–) mice develop pronounced splenomegaly that is much more severe in females than in males. Further characterization of these mice revealed myelogenous hyperplasia in bone marrow, an increase in the number of granulocytes and B lymphocytes in blood, lymphadenopathy, and infiltration of leukocytes in the liver and lung. Analysis by flow cytometry of the bone marrow cells revealed that the percentage and total number of Gr-1hi/Mac-1hi-positive granulocytes were increased by 15–30% and 100%, respectively. The numbers of B cells in the bone marrow and spleen were significantly higher in ERβ–/– mice than in WT littermates. Some of the ERβ–/– mice also had a severe lymphoproliferative phenotype. Thus the absence of ERβ results in a myeloproliferative disease resembling human chronic myeloid leukemia with lymphoid blast crisis. Our results indicate a previously unknown role for ERβ in regulating the differentiation of pluripotent hematopoietic progenitor cells and suggest that the ERβ–/– mouse is a potential model for myeloid and lymphoid leukemia. Furthermore, we suggest that ERβ agonists might have clinical value in the treatment of leukemia. PMID:12740446

  13. Definition of the molecular basis for estrogen receptor-related receptor-alpha-cofactor interactions.

    PubMed

    Gaillard, Stéphanie; Dwyer, Mary A; McDonnell, Donald P

    2007-01-01

    Estrogen receptor-related receptor-alpha (ERRalpha) is an orphan nuclear receptor that does not appear to require a classical small molecule ligand to facilitate its interaction with coactivators and/or hormone response elements within target genes. Instead, the apo-receptor is capable of interacting in a constitutive manner with coactivators that stimulate transcription by acting as protein ligands. We have screened combinatorial phage libraries for peptides that selectively interact with ERRalpha to probe the architecture of the ERRalpha-coactivator pocket. In this manner, we have uncovered a fundamental difference in the mechanism by which this receptor interacts with peroxisome proliferator-activated receptor-gamma coactivator-1alpha, as compared with members of the steroid receptor coactivator subfamily of coactivators. Our findings suggest that it may be possible to develop ERRalpha ligands that exhibit different pharmacological activities as a consequence of their ability to differentially regulate coactivator recruitment. In addition, these findings have implications beyond ERRalpha because they suggest that subtle alterations in the structure of the activation function-2 pocket within any nuclear receptor may enable differential recruitment of coactivators, an observation of notable pharmaceutical importance.

  14. G-protein Coupled Estrogen Receptor, Estrogen Receptor α, and Progesterone Receptor Immunohistochemistry in the Hypothalamus of Aging Female Rhesus Macaques Given Long-Term Estradiol Treatment

    PubMed Central

    NAUGLE, MICHELLE M.; NGUYEN, LONG T.; MERCERON, TYLER K.; FILARDO, EDWARD; JANSSEN, WILLIAM G.M.; MORRISON, JOHN H.; RAPP, PETER R.; GORE, ANDREA C.

    2014-01-01

    Steroid hormone receptors are widely and heterogeneously expressed in the brain, and are regulated by age and gonadal hormones. Our goal was to quantify effects of aging, long-term estradiol (E2) treatment, and their interactions, on expression of G protein-coupled estrogen receptor (GPER), estrogen receptor α (ERα) and progesterone receptor (PR) immunoreactivity in two hypothalamic regions, the arcuate (ARC) and the periventricular area (PERI) of rhesus monkeys as a model of menopause and hormone replacement. Ovariectomized (OVX) rhesus macaques were young (~11 years) or aged (~25 years), given oil (vehicle) or E2 every 3 weeks for 2 years. Immunohistochemistry and stereologic analysis of ERα, PR, and GPER was performed. More effects were detected for GPER than the other two receptors. Specifically, GPER cell density in the ARC and PERI, and the percent of GPER-immunoreactive cells in the PERI, were greater in aged than in young monkeys. In addition, we mapped the qualitative distribution of GPER in the monkey hypothalamus and nearby regions. For ERα, E2 treated monkeys tended to have higher cell density than vehicle monkeys in the ARC. The percent of PR density in the PERI tended to be higher in E2 than vehicle monkeys of both ages. This study shows that the aged hypothalamus maintains expression of hormone receptors with age, and that long-term cyclic E2 treatment has few effects on their expression, although GPER was affected more than ERα or PR. This result is surprising in light of evidence for E2 regulation of the receptors studied here, and differences may be due to the selected regions, long-term nature of E2 treatment, among other possibilities. PMID:24862737

  15. Negative effects of alcohol intake and estrogen deficiency combination on osseointegration in a rat model.

    PubMed

    de Deco, Camila Porto; da Silva Marchini, Adriana Mathias Pereira; Bárbara, Mary Anne Moreira; de Vasconcellos, Luana Marotta Reis; da Rocha, Rosilene Fernandes; Marchini, Leonardo

    2011-12-01

    Alcohol intake and estrogen deficiency can both affect bone physiology and have shown to have an adverse effect on dental implant therapy. However, the combination of both factors on osseointegration is unknown. The aim of this study was to evaluate osseointegration in rats fed with alcohol and presenting induced estrogen deficiency. Ninety-six female rats were divided according to diet and hormonal condition into 6 groups as follows: group Sh-W: sham (simulated ovariectomy) control, food and water ad libitum; group Sh-Et: sham, food and 20% ethanol solution ad libitum; group Sh-Su: sham, food and sucrose solution controlled to ensure an isocaloric diet in relation to Sh-Et; group Ov-W: ovariectomy, food and water ad libitum; group Ov-Et: ovariectomy, food and 20% ethanol solution ad libitum; and group Ov-Su: ovariectomy, food and sucrose solution controlled to ensure an isocaloric diet as Ov-Et. The groups were subdivided according to time of euthanasia: 30 and 45 days after placement of implants. Implant surgery was performed 1 month after ovariectomy or sham. After euthanasia, the femurs were removed and evaluated by histomorphometry. Groups Ov-Et and Ov-Su showed the lowest percentage of bone-to-implant contact. The combination of alcohol intake and estrogen deficiency, and the combination of estrogen deficiency and reduced ingestion of food can negatively affect osseointegration in rats.

  16. Bisphenol A regulates the estrogen receptor alpha signaling in developing hippocampus of male rats through estrogen receptor.

    PubMed

    Xu, Xiao-Bin; He, Ye; Song, Chen; Ke, Xin; Fan, Shi-Jun; Peng, Wei-Jie; Tan, Ruei; Kawata, Mitsuhiro; Matsuda, Ken-Ichi; Pan, Bing-Xing; Kato, Nobumasa

    2014-12-01

    Bisphenol A (BPA), one of the most common environmental endocrine disruptors, has been recognized to have wide adverse effects on the brain development and behavior. These adversities are related to its ability to bind estrogen receptor (ER) with subsequent alteration of its expression in the target areas. However, very little is known about whether BPA exposure also affects ER phosphorylation and its translocation to nucleus during postnatal development, two critical steps for its function. Here, we found that during development from postnatal day 7 (P7) to P21, the alpha subtype of ER (ERα) in the hippocampus of male rats experienced remarkable alterations in terms of its expression, phosphorylation and translocation to nucleus. Exposure to low level of BPA had bidirectional, development-dependent effects on the expression of ERα mRNA and protein, but decreased ERα phosphorylation and impaired its translocation to nucleus throughout the period investigated. Treatment with low dose of ICI 182,780 (ICI), an ER antagonist to block the binding of ER with BPA, reversed the altered ERα following BPA exposure, highlighting critical involvement of ER. Moreover, ICI treatment rescued the hippocampus-dependent behavioral deficits in the adult rats experiencing early-life BPA exposure. Overall, our results indicate that BPA interferes with the ERα signaling in the developing hippocampus in an ER-dependent manner, which may underlie its adverse behavioral and cognitive outcomes in adult animals.

  17. Aryl hydrocarbon receptor-independent activation of estrogen receptor-dependent transcription by 3-methylcholanthrene.

    PubMed

    Shipley, Jonathan M; Waxman, David J

    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(50)) was >100-fold higher for an ER reporter (27-57 muM) 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 17beta-estradiol. In Ishikawa cells, 3MC, but not BZ126 or TCDD, stimulated ERalpha-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.

  18. Synthesis of Triphenylethylene Bisphenols as Aromatase Inhibitors that Also Modulate Estrogen Receptors

    PubMed Central

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

    2016-01-01

    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

  19. Molecular cloning and characterization of ligand- and species-specificity of amphibian estrogen receptors.

    PubMed

    Katsu, Yoshinao; Taniguchi, Ena; Urushitani, Hiroshi; Miyagawa, Shinichi; Takase, Minoru; Kubokawa, Kaoru; Tooi, Osamu; Oka, Tomohiro; Santo, Noriaki; Myburgh, Jan; Matsuno, Akira; Iguchi, Taisen

    2010-09-01

    Estrogens are essential for normal reproductive activity in both males and females as well as for ovarian differentiation during a critical developmental stage in most vertebrates. To understand the molecular mechanisms of estrogen action and to evaluate estrogen receptor ligand interactions in amphibians, we isolated cDNAs encoding the estrogen receptors (ERalpha and ERbeta) from the Japanese firebelly newt (Cynops pyrrhogaster), Tokyo salamander (Hynobius tokyoensis), axolotl (Ambystoma mexicanum), and Raucous toad (Bufo rangeri). Full-length amphibian ER cDNAs were obtained using 5' and 3' rapid amplification of cDNA ends. The predicted amino acid sequences of these amphibian ERs showed a high degree of amino acid sequence identity (over 70%) to each other. We analyzed the relationships of these amphibian ER sequences to other vertebrate ER sequences by constructing a phylogenetic tree. We verified that these were bona fide estrogen receptors using receptor dependent reporter gene assays. We analyzed the effects of natural estrogens, ethinylestradiol, and DDT and its metabolites on the transactivation of the four amphibian species listed above, and Xenopus tropicalis ERs and found that there were species-specific differences in the sensitivity of these ERs to hormones and environmental chemicals. These findings will expand our knowledge of endocrine-disrupting events in amphibians.

  20. 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.

  1. Expression and functional roles of G-protein-coupled estrogen receptor (GPER) in human eosinophils.

    PubMed

    Tamaki, Mami; Konno, Yasunori; Kobayashi, Yoshiki; Takeda, Masahide; Itoga, Masamichi; Moritoki, Yuki; Oyamada, Hajime; Kayaba, Hiroyuki; Chihara, Junichi; Ueki, Shigeharu

    2014-07-01

    Sexual dimorphism in asthma links the estrogen and allergic immune responses. The function of estrogen was classically believed to be mediated through its nuclear receptors, i.e., estrogen receptors (ERs). However, recent studies established the important roles of G-protein-coupled estrogen receptor (GPER/GPR30) as a novel membrane receptor for estrogen. To date, the role of GPER in allergic inflammation is poorly understood. The purpose of this study was to examine whether GPER might affect the functions of eosinophils, which play an important role in the pathogenesis of asthma. Here, we demonstrated that GPER was expressed in purified human peripheral blood eosinophils both at the mRNA and protein levels. Although GPER agonist G-1 did not induce eosinophil chemotaxis or chemokinesis, preincubation with G-1 enhanced eotaxin (CCL11)-directed eosinophil chemotaxis. G-1 inhibited eosinophil spontaneous apoptosis and caspase-3 activities. The anti-apoptotic effect was not affected by the cAMP-phospodiesterase inhibitor rolipram or phosphoinositide 3-kinase inhibitors. In contrast to resting eosinophils, G-1 induced apoptosis and increased caspase-3 activities when eosinophils were co-stimulated with IL-5. No effect of G-1 was observed on eosinophil degranulation in terms of release of eosinophil-derived neurotoxin (EDN). The current study indicates the functional capacities of GPER on human eosinophils and also provides the previously unrecognized mechanisms of interaction between estrogen and allergic inflammation.

  2. A robotic BG1Luc reporter assay to detect estrogen receptor agonists.

    PubMed

    Stoner, Matthew A; Yang, Chun Z; Bittner, George D

    2014-08-01

    Endocrine disrupting chemicals with estrogenic activity (EA) have been associated with various adverse health effects. US agencies (ICCVAM/NICEATM) tasked to assess in vitro transcription activation assays to detect estrogenic receptor (ER) agonists for EA have recently validated a BG1Luc assay in manual format, but prefer robotic formats. We have developed a robotic BG1Luc EA assay to detect EA that demonstrated 100% concordance with ICCVAM meta-analyses and ICCVAM BG1Luc results in manual format for 27 ICCVAM test substances, i.e. no false negatives or false positives. This robotic assay also consistently assessed other, more problematic ICCVAM test substances such as clomiphene citrate, L-thyroxin, and tamoxifen. Agonist responses using this robotic BG1Luc assay were consistently inhibited by the ER antagonist ICI 182,780, confirming that agonist responses were due to binding to ERs rather than to a non-specific agonist response. This robotic assay also detected EA in complex mixtures of substances such as extracts of personal care products, plastic resins or plastic consumer products. This robotic BG1Luc assay had at least as high accuracy and greater sensitivity and repeatability when compared to its manual version or to the other ICCVAM/OECD validated assays for EA (manual BG1Luc and CERI).

  3. The Relationship between Bone Mineral Density and Estrogen Receptor Positivity in Patients with Breast Cancer

    PubMed Central

    İyigün, Zeynep Erdoğan; Pilancı, Kezban Nur; Çabuk, Fatmagül Kuşku; İlgün, Serkan; Ordu, Çetin; Duymaz, Tomris; Alço, Gül; Çelebi, Filiz; Sarsenov, Dauren; İzci, Filiz; Öztürk, Alper; Ağaçayak, Filiz; Köksal, Ülkühan İner; Aktepe, Fatma; Eralp, Yeşim; Özmen, Vahit

    2016-01-01

    Objective The effect of estrogen on bone mineral density (BMD) and breast cancer has been known for a long time. The aim of this study was to compare of the BMD of patients with breast cancer and healthy individuals, and to investigate the degree of correlation of estrogen receptor (ER) with BMD. Materials and Methods Seventy-one patients with postmenopausal breast cancer and 79 healthy dividuals were included in the study. The patient demographics (age, menopause age, body mass index, number of children, BMD, Z scores, and estrogen status for breast cancer patients) were taken from hospital records. Results No significant difference was detected between the case and control groups in lumbar region Z scores (p=0.074). At the femur neck, the control group Z scores was higher than patient group (p=0.002). BMI was higher in the patients with breast cancer (p=0.001). There was no statistically significant correlation between ER positivity, BMD, and BMI in ER-positive patients (p=0.495, p=0.8, p=0.846, respectively). There was no difference between the Z scores when the patients were divided into two groups as ER positive and negative (p=0.156, p=0.335, respectively). Conclusion This study revealed that there is no difference in lumbar region Z scores between patients with breast cancer and heathy controls; however, the Z scores were higher in the femur neck in the control group, and the BMI was lower in the patient group. Tumor ER positivity does not positively affect BMD.

  4. Estrogen effects on angiotensin receptors are modulated by pituitary in female rats

    SciTech Connect

    Douglas, J.G.

    1987-01-01

    The present studies were designed to test the hypothesis that changes in angiotensin II (ANG II) receptors might modulate the layered target tissue responsiveness accompanying estradiol administration. Estradiol was infused continuously in oophorectomized female rats. Aldosterone was also infused in control and experimental animals to avoid estrogen-induced changes in renin and ANG II. ANG II binding constants were determined in radioreceptor assays. Estradiol increased binding site concentration in adrenal glomerulosa by 76% and decreased binding sites of uterine myometrium and glomeruli by 45 and 24%, respectively. There was an accompanying increase in the affinity of ANG II binding to adrenal glomerulosa and uterine myometrium. Because estrogen is a potent stimulus of prolactin release from the pituitary of rodents, studies were also designed to test the hypothesis that prolactin may mediate some or all of the estrogen-induced effects observed. Hypophysectomy abolished estradiol stimulation of prolactin release and most ANG II receptor changes. Prolactin administration to pituitary intact rats was associated with a 50% increase in receptor density of adrenal glomerulosa simulating estradiol administration. However, the changes in glomeruli and uterine myometrium were opposite in that both tissues also increased receptor density, suggesting that prolactin was not the sole mediator of the estrogen-induced receptor changes. In conclusion, regulation of ANG II receptors in a number of diverse target tissues by estradiol is complex with contributions from estrogens and pituitary factors, which include but do not exclusively involve prolactin.

  5. Estrogen Receptor (ER)-α36 Is Involved in Estrogen- and Tamoxifen-Induced Neuroprotective Effects in Ischemic Stroke Models

    PubMed Central

    Fang, Chen; Ji, Xiaofei; Liang, Xiaofeng; Liu, Yang; Han, Chao; Huang, Liang; Zhang, Qiqi; Li, Hongyan; Zhang, Yejun; Liu, Jinqiu

    2015-01-01

    The neuroprotection by estrogen (E2) and tamoxifen is well documented in experimental stroke models; however, the exact mechanism is unclear. A membrane-based estrogen receptor, ER-α36, has been identified. Postmenopausal-levels of E2 act through ER-α36 to induce osteoclast apoptosis due to a prolonged activation of the mitogen-activated protein kinase (MAPK)/extracellular signal-related kinase (ERK) signaling. We hypothesized that ER-α36 may play a role in the neuroprotective activities of estrogen and tamoxifen. Here, we studied ER-α36 expression in the brain, as well as its neuroprotective effects against oxygen and glucose deprivation (OGD) in PC12 cells. We found that ER-α36 was expressed in both rat and human brain. In addition, OGD-induced cell death was prevented by l nmol/L 17β-estradiol (E2β). E2β activates the MAPK/ERK signaling pathway in PC12 cells under basal and OGD conditions by interacting with ER-α36 and also induces ER-α36 expression. Low-dose of tamoxifen up-regulated ER-α36 expression and enhanced neuronal survival in an ovariectomized ischemic stroke model. Furthermore, low-dose of tamoxifen enhanced neuroprotective effects by modulating activates or suppress ER-α36. Our results thus demonstrated that ER-α36 is involved in neuroprotective activities mediated by both estrogen and tamoxifen. PMID:26484775

  6. Solubilization of the chromatin-bound estrogen receptor from chicken liver and fractionation on hydroxylapatite.

    PubMed

    Gschwendt, M

    1976-08-16

    1. High-affinity estrogen-binding sites can be solubilized from the liver chromatin of estrogenized chickens by treatment of the chromatin with 2 M KCL/5 M urea and fractionation on hydroxylapatite. Two estrogen-binding proteins are eluted from hydroxylapatite columns by 20mM phosphate (binding protein I) and 200mMphosphate (binding protein II), respectively. 2. The binding protein I is part of a non-histone protein fraction containing acid-soluble and insoluble proteins, whereas the binding protein II elutes together with high molecular weight nonhistone proteins containing acid insoluble proteins only. Both binding proteins exhibit the smae affinity for estradiol (Kd approximately 10(-9) M). 3. From chromatin of untreated chickens very small amounts of binding protein I (0.1 pmol/mg protein compared to 1.9 pmol/mg protein from estrogenized chickens) with the smae affinity for estradiol as that from estrogenized animals can be solubilized. Binding protein II is not detectable. 4. The "soluble nuclear estrogen receptor" extracted from crude liver nucleir of estrogenized chickens by 0.5 M KCL behaves on hydroxylapatite very similarly to salt/urea-dissociated chromatin with respect to the binding protein I. No binding protein II, however, can be demonstrated. 5. Chromatography of various preparations on Bio-Gel A-1.5 m indicates that the binding protein II is a residual chromatin fragment containing an unseparated binding protein-DNA complex, whereas the binding protein I represents the solubilized nucleic-acid-free chromosomal estrogen receptor. The "soluble nuclear receptor" and the binding protein I, however, are not identical with respect to their chromatographic behaviour on Bio-Gel A-1.5m, even though their estrogen binding entity remaining after trypsin treatment seems to be very similar.

  7. 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.

  8. The emerging role of estrogen receptor-β in human reproduction.

    PubMed

    Su, Emily J; Xin, Hong; Monsivais, Diana

    2012-01-01

    Knowledge surrounding estrogen and estrogen receptor biology continues to evolve, and the diversity of their actions and complexity of their mechanisms are becoming increasingly evident. Estrogen receptor (ER) regulation of reproduction is no exception. Although it is well established that estrogen and ERα play key roles in mediating several reproductive biological processes, such as myometrial and endometrial growth, increasing evidence suggests that ERβ is also an important factor. ERβ is a key mediator in folliculogenesis and may also play a role in stimulating ovulation and regulating aspects of luteinization. ERβ is also expressed in higher quantities than ERα in the human myometrium and cervix during pregnancy, and thus it may play a part in the initiation of labor and parturition. Finally, ERβ is the sole ER expressed within the endothelium of the endometrium and the fetoplacental vasculature, and studies suggest that its role may contribute to angiogenic and vasomotor changes that play a role in both implantation and regulation of fetoplacental blood flow.

  9. Identification of G protein-coupled estrogen receptor in human and pig spermatozoa.

    PubMed

    Rago, V; Giordano, F; Brunelli, E; Zito, D; Aquila, S; Carpino, A

    2014-06-01

    Estrogens are known to influence functional properties of mammalian spermatozoa inducing rapid responses through the classical estrogen receptors (ERα and ERβ). Recently, the G protein-coupled estrogen receptor (GPER) has been identified as mediator of fast non-genomic estrogen effects in different cells. This work investigated the expression of GPER in human and pig spermatozoa using immunofluorescence, Western blot analysis and RT-PCR. GPER was found to be confined to the mid-piece of human sperm cells, whereas it was detected in the acrosomal region, the equatorial segment and the mid-piece of pig spermatozoa. Furthermore, in the male gametes of both species, the immunoblots of sperm extracts revealed a band at ~42 kDa, consistent with the GPER molecular weight, and RT-PCR detected the GPER transcripts. This is the first report demonstrating the expression of GPER in human and pig mature sperm cells and evidencing its species-specific cellular localization.

  10. Estrogen receptor-alpha gene expression in the cortex: sex differences during development and in adulthood.

    PubMed

    Wilson, Melinda E; Westberry, Jenne M; Trout, Amanda L

    2011-03-01

    17β-estradiol is a hormone with far-reaching organizational, activational and protective actions in both male and female brains. The organizational effects of early estrogen exposure are essential for long-lasting behavioral and cognitive functions. Estradiol mediates many of its effects through the intracellular receptors, estrogen receptor-alpha (ERα) and estrogen receptor-beta (ERβ). In the rodent cerebral cortex, estrogen receptor expression is high early in postnatal life and declines dramatically as the animal approaches puberty. This decline is accompanied by decreased expression of ERα mRNA. This change in expression is the same in both males and females in the developing isocortex and hippocampus. An understanding of the molecular mechanisms involved in the regulation of estrogen receptor alpha (ERα) gene expression is critical for understanding the developmental, as well as changes in postpubertal expression of the estrogen receptor. One mechanism of suppressing gene expression is by the epigenetic modification of the promoter regions by DNA methylation that results in gene silencing. The decrease in ERα mRNA expression during development is accompanied by an increase in promoter methylation. Another example of regulation of ERα gene expression in the adult cortex is the changes that occur following neuronal injury. Many animal studies have demonstrated that the endogenous estrogen, 17β-estradiol, is neuroprotective. Specifically, low levels of estradiol protect the cortex from neuronal death following middle cerebral artery occlusion (MCAO). In females, this protection is mediated through an ERα-dependent mechanism. ERα expression is rapidly increased following MCAO in females, but not in males. This increase is accompanied by a decrease in methylation of the promoter suggesting a return to the developmental program of gene expression within neurons. Taken together, during development and in adulthood, regulation of ERα gene expression in the

  11. Proximal and distal regulation of the HYAL1 gene cluster by the estrogen receptor α in breast cancer cells

    PubMed Central

    Edjekouane, Lydia; Benhadjeba, Samira; Jangal, Maïka; Fleury, Hubert; Gévry, Nicolas; Carmona, Euridice; Tremblay, André

    2016-01-01

    Chromosomal and genome abnormalities at the 3p21.3 locus are frequent events linked to epithelial cancers, including ovarian and breast cancers. Genes encoded in the 3p21.3 cluster include HYAL1, HYAL2 and HYAL3 members of hyaluronidases involved in the breakdown of hyaluronan, an abundant component of the vertebrate extracellular matrix. However, the transcriptional regulation of HYAL genes is poorly defined. Here, we identified the estrogen receptor ERα as a negative regulator of HYAL1 expression in breast cancer cells. Integrative data mining using METABRIC dataset revealed a significant inverse correlation between ERα and HYAL1 gene expression in human breast tumors. ChIP-Seq analysis identified several ERα binding sites within the 3p21.3 locus, supporting the role of estrogen as an upstream signal that diversely regulates the expression of 3p21.3 genes at both proximal and distal locations. Of these, HYAL1 was repressed by estrogen through ERα binding to a consensus estrogen response element (ERE) located in the proximal promoter of HYAL1 and flanked by an Sp1 binding site, required to achieve optimal estrogen repression. The repressive chromatin mark H3K27me3 was increased at the proximal HYAL1 ERE but not at other EREs contained in the cluster, providing a mechanism to selectively downregulate HYAL1. The HYAL1 repression was also specific to ERα and not to ERβ, whose expression did not correlate with HYAL1 in human breast tumors. This study identifies HYAL1 as an ERα target gene and provides a functional framework for the direct effect of estrogen on 3p21.3 genes in breast cancer cells. PMID:27764788

  12. 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

  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.

  14. Structure, tissue distribution and estrogen regulation of splice variants of the sea bream estrogen receptor α gene.

    PubMed

    Pinto, P I S; Teodósio, R; Socorro, S; Power, D M; Canário, A V M

    2012-07-15

    Estrogen actions are mainly mediated by specific nuclear estrogen receptors (ERs), for which different genes and a diversity of transcript variants have been identified, mainly in mammals. In this study, we investigated the presence of ER splice variants in the teleost fish gilthead sea bream (Sparus auratus), by comparison with the genomic organization of the related species Takifugu rubripes. Two exon2-deleted ERα transcript variants were isolated from liver cDNA of estradiol-treated fish. The ΔE2 variant lacks ERα exon 2, generating a premature termination codon and a putative C-terminal truncated receptor, while the ΔE2,3* variant contains an in-frame deletion of exon 2 and part of exon 3 and codes for a putative ERα protein variant lacking most of the DNA-binding domain. Both variants were expressed at very low levels in several female and male sea bream tissues, and their expression was highly inducible in liver by estradiol-17β treatment with a strong positive correlation with the typical wild-type (wt) ERα response in this tissue. These findings identify novel estrogen responsive splice variants of fish ERα, and provide the basis for future studies to investigate possible modulation of wt-ER actions by splice variants.

  15. 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

  16. Triple-negative breast cancer risk in women is defined by the defect of estrogen signaling: preventive and therapeutic implications

    PubMed Central

    Suba, Zsuzsanna

    2014-01-01

    Epidemiologic studies strongly support that triple-negative breast cancers (TNBCs) may be distinct entities as compared with estrogen receptor (ER)+ tumors, suggesting that the etiologic factors, clinical characteristics, and therapeutic possibilities may vary by molecular subtypes. Many investigations propose that reproductive factors and exogenous hormone use differently or even quite inversely affect the risk of TNBCs and ER+ cancers. Controversies concerning the exact role of even the same risk factor in TNBC development justify that the biological mechanisms behind the initiation of both TNBCs and non-TNBCs are completely obscure. To arrive at a comprehensive understanding of the etiology of different breast cancer subtypes, we should also reconsider our traditional concepts and beliefs regarding cancer risk factors. Malignancies are multicausal, but the disturbance of proper estrogen signaling seems to be a crucial risk factor for the development of mammary cancers. The grade of defect in metabolic and hormonal equilibrium is directly associated with TNBC risk for women during their whole life. Inverse impact of menopausal status or parity on the development of ER+ and ER− breast cancers may not be possible; these controversial results derive from the misinterpretation of percentage-based statistical evaluations. Exogenous or parity-associated excessive estrogen supply is suppressive against breast cancer, though the lower the ER expression of tumors, the weaker the anticancer capacity. In women, the most important preventive strategy against breast cancers – included TNBCs – is the strict control and maintenance of hormonal equilibrium from early adolescence through the whole lifetime, particularly during the periods of great hormonal changes. PMID:24482576

  17. 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

  18. EPO-independent functional EPO receptor in breast cancer enhances estrogen receptor activity and promotes cell proliferation

    SciTech Connect

    Reinbothe, Susann; Larsson, Anna-Maria; Vaapil, Marica; Wigerup, Caroline; Sun, Jianmin; Jögi, Annika; Neumann, Drorit; Rönnstrand, Lars; Påhlman, Sven

    2014-02-28

    Highlights: • New anti-human EPOR antibody confirms full-length EPOR expression in breast cancer cells. • Proliferation of breast cancer cells is not affected by rhEPO treatment in vitro. • EPOR knockdown impairs proliferation of ERa positive breast cancer cells. • EPOR knockdown reduces AKT phosphorylation and ERa activity. - Abstract: The main function of Erythropoietin (EPO) and its receptor (EPOR) is the stimulation of erythropoiesis. Recombinant human EPO (rhEPO) is therefore used to treat anemia in cancer patients. However, clinical trials have indicated that rhEPO treatment might promote tumor progression and has a negative effect on patient survival. In addition, EPOR expression has been detected in several cancer forms. Using a newly produced anti-EPOR antibody that reliably detects the full-length isoform of the EPOR we show that breast cancer tissue and cells express the EPOR protein. rhEPO stimulation of cultured EPOR expressing breast cancer cells did not result in increased proliferation, overt activation of EPOR (receptor phosphorylation) or a consistent activation of canonical EPOR signaling pathway mediators such as JAK2, STAT3, STAT5, or AKT. However, EPOR knockdown experiments suggested functional EPO receptors in estrogen receptor positive (ERα{sup +}) breast cancer cells, as reduced EPOR expression resulted in decreased proliferation. This effect on proliferation was not seen in ERα negative cells. EPOR knockdown decreased ERα activity further supports a mechanism by which EPOR affects proliferation via ERα-mediated mechanisms. We show that EPOR protein is expressed in breast cancer cells, where it appears to promote proliferation by an EPO-independent mechanism in ERα expressing breast cancer cells.

  19. Long-term estrogen therapy and 5-HT(2A) receptor binding in postmenopausal women; a single photon emission tomography (SPET) study.

    PubMed

    Compton, J; Travis, M J; Norbury, R; Erlandsson, K; van Amelsvoort, T; Daly, E; Waddington, W; Matthiasson, P; Eersels, J L H; Whitehead, M; Kerwin, R W; Ell, P J; Murphy, D G M

    2008-01-01

    Variation in estrogen level is reported by some to affect brain maturation and memory. The neurobiological basis for this may include modulation of the serotonergic system. No neuroimaging studies have directly examined the effect of extended estrogen therapy (ET), on the 5-HT(2A) receptor in human brain. We investigated the effect of long-term ET on cortical 5-HT(2A) receptor availability in postmenopausal women. In a cross-sectional study, we compared cortical 5-HT(2A) receptor availability in 17 postmenopausal ERT-naive women and 17 long-term oophorectomised estrogen-users, age- and IQ-matched using single photon emission tomography and the selective 5-HT(2A) receptor ligand (123)I-5-I-R91150. Also, we used the Revised Wechsler Memory Scale to relate memory function to 5-HT(2A) receptor availability. Never-users had significantly higher 5-HT(2A) receptor availability than estrogen-users in hippocampus (1.17 vs. 1.11, respectively, p=0.02), although this did not remain significant after correction for multiple comparisons. Hippocampal 5-HT(2A) receptor availability correlated negatively with verbal and general memory and delayed recall (r=-0.45, p=0.01; r=-0.40, p=0.02; r=-0.36, p=0.04). Right superior temporal 5-HT(2A) receptor availability correlated negatively with verbal memory (r=-0.36, p=0.04). In estrogen-users, receptor availability correlated negatively with verbal and general memory (r=-0.70, p=0.002; r=-0.69, p=0.002); and in never-users, receptor availability negatively correlated with attention and concentration (r=-0.54, p=0.02). Long-term ET may be associated with lower 5-HT(2A) receptor availability in hippocampus. This may reflect increased activity within the serotonergic pathway leading to down-regulation of post-synaptic receptor. Also, increased availability of the 5-HT(2A) receptor in hippocampus is associated with poorer memory function.

  20. Enhanced noscapine delivery using estrogen-receptor-targeted nanoparticles for breast cancer therapy.

    PubMed

    Madan, Jitender; Gundala, Sushma R; Kasetti, Yoganjaneyulu; Bharatam, Prasad V; Aneja, Ritu; Katyal, Anju; Jain, Upendra K

    2014-07-01

    Noscapine (Nos), an orally available plant-derived antitussive alkaloid, is in phase II clinical trials for cancer chemotherapy. It has extensively been shown to inhibit tumor growth in nude mice bearing human xenografts of hematopoietic, breast, lung, ovarian, brain, and prostate origin. However, high tumor-suppressive Nos dosages encumber the development of oral controlled-release formulations because of a short biological half-life (<2 h), poor absorption, low aqueous solubility, and extensive first-pass metabolism. Here, we present the design, fabrication, optimization, characterization, and biological evaluation of estrone-conjugated noscapine-loaded gelatin nanoparticles (Nos-ES-GN) for targeting estrogen-receptor-positive breast cancer MCF-7 cells. Gelatin nanoparticles (GN) were a uniformly compact size, stable at physiological pH, and showed a drug entrapment efficiency of 66.1±5.9 and 65.2±5.6% for Nos-GN and Nos-ES-GN, respectively. The secondary structure of gelatin nanocoacervates was predicted using circular dichroism and in-silico molecular modeling. Our data suggest that ethanol-fabricated GN retained the α-helical content of gelatin, whereas acetone favored the formation of random coils. The conjugation of estrone to Nos-GN did not affect the release rate of the drug, and both formulations followed first-order release kinetics with an initial burst, followed by a slow release. The IC50 value of Nos-ES-GN was 21.2 μmol/l, which was ∼50% lower than the free drug (43.3 μmol/l), suggesting targeted drug delivery. Our cell uptake study carried out in an estrogen-receptor-positive (MCF-7) and negative (MDA-MB-231) cancer cell lines showed greater accumulation of Nos-ES-GN in MCF-7 cells instead of MDA-MB-231 cells. Our data indicated that estrone-conjugated nanoparticles may potentially be used for targeting breast cancer cells.

  1. 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.

  2. Role of the Neddylation Enzyme Uba3, a New Estrogen Receptor Corepressor, in Breast Cancer

    DTIC Science & Technology

    2005-09-01

    Taylor CW, Akinaga S, Whitesell L 2001 Destabilization of steroid receptors by heat shock protein 90- binding drugs: a ligand- 510 independent approach...or ubiquitin- associated / protein receptor degradation pathways, may thus present an important therapeutic target for future drug intervention. For the... 18 :81-93 13. Fan M, Park A, Nephew KP. Interactions between estrogen receptor and the COOH terminus of the Hsp70-interacting protein (CHIP) (Mol

  3. The interaction site for tamoxifen aziridine with the bovine estrogen receptor

    SciTech Connect

    Ratajczak, T.; Wilkinson, S.P.; Brockway, M.J.; Haehnel, R.M.; Moritz, R.L.; Begg, G.S.; Simpson, R.J.

    1989-08-15

    Calf uterine estrogen receptor was covalently labeled with ({sup 3}H)tamoxifen aziridine during affinity chromatography purification. After carboxymethylation, affinity labeled receptor was digested with trypsin under limit conditions and the labeled peptides were fractionated by reversed-phase high performance liquid chromatography into one major and two minor components. Sequence analysis of the dominant labeled fragment indicated the facile cleavage of label during Edman degradation but identified two peptides, both derived from the extreme carboxyl terminus of the steroid-binding domain. The 17 residues of one peptide were fully conserved in all estrogen receptors. This fragment contained five nucleophilic amino acids and was considered as the more favored interaction site for tamoxifen aziridine. A corresponding region of the glucocorticoid receptor has recently been identified as one of three major contact sites for glucocorticoids. A comparison of amino acid physical characteristics in the hormone-binding domains of human estrogen and glucocorticoid receptors demonstrated an excellent structural correlation between the two regions and delineated elements in the estrogen receptor which may be directly involved in estradiol binding.

  4. The effects of fulvestrant, an estrogen receptor antagonist, on the proliferation, differentiation and mineralization of osteoprecursor cells.

    PubMed

    Park, Jun-Beom

    2013-02-01

    Fulvestrant is a novel type of endocrine treatment and is considered to be a potent inhibitor of breast cancer cell proliferation. Fulvestrant is reported to work by downregulating as well as degrading the estrogen receptor, leading to an inhibition of estrogen signaling through the estrogen receptor. The effects of various doses of fulvestrant for bone cells have not yet been fully investigated. In the present study, the effects of fulvestrant on osteoprecursor cells were evaluated. The effect on cell viability was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and protein measurement. Differentiation and mineralization were examined using an alkaline phosphatase activity (ALP) test and Alizarin red S staining. The protein expression of osteocalcin was evaluated using western blot analysis. Cultures grown in the presence of fulvestrant at concentrations of 0.1-10 µM did not show any significant change in cell proliferation. Cultures grown in the presence of fulvestrant showed a dose-dependent reduction in ALP activity, however, statistically significant differences were not achieved. Cultures grown in the presence of fulvestrant presented with a dose-dependent reduction in mineralization with a statistically significant difference at the 10 µM concentration. The use of fulvestrant may produce negative effects on the mineralization of osteoprecursor cells, while long-term use of fulvestrant may have detrimental effects on osteoblastic activity.

  5. 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...

  6. 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...

  7. beta-estradiol influences differentiation of hippocampal neurons in vitro through an estrogen receptor-mediated process.

    PubMed

    Audesirk, T; Cabell, L; Kern, M; Audesirk, G

    2003-01-01

    We utilized morphometric analysis of 3 day cultures of hippocampal neurons to determine the effects of both estradiol and the synthetic estrogen receptor modulator raloxifene on several parameters of neuronal growth and differentiation. These measurements included survival, neurite production, dendrite number, and axon and dendrite length and branching. 17 beta-Estradiol (10 nM) selectively stimulated dendrite branching; this effect was neither mimicked by alpha-estradiol, nor blocked by the estrogen receptor antagonist ICI 182780. The selective estrogen receptor modulator raloxifene (100 nM) neither mimicked nor reversed the effects of estradiol on dendritic branching. Western immunoblotting for the alpha and beta subtypes of estrogen receptor revealed the presence of alpha, but not beta, estrogen receptors in our hippocampal cultures. There is growing recognition of the effects of 17 beta-estradiol on neuronal development and physiology, with implications for brain sexual dimorphism, plasticity, cognition, and the maintenance of cognitive function during aging. The role of estradiol in hippocampal neuronal differentiation and function has particular implications for learning and memory. These data support the hypothesis that 17 beta-estradiol is acting via alpha estrogen receptors in influencing hippocampal development in vitro. Raloxifene, prescribed to combat osteoporosis in post-menopausal women, is a selective estrogen receptor modulator with tissue-specific agonist/antagonist properties. Because raloxifene had no effect on dendritic branching, we hypothesize that it does not interact with the alpha estrogen receptor in this experimental paradigm.

  8. 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

  9. Progestin, estrogen and androgen G-protein coupled receptors in fish gonads.

    PubMed

    Thomas, Peter; Dressing, Gwen; Pang, Yefei; Berg, Hakan; Tubbs, Christopher; Benninghoff, Abby; Doughty, Kelly

    2006-04-01

    The identities of the membrane receptors mediating the majority of rapid, cell surface-initiated, nongenomic (i.e. nonclassical) steroid actions described to date are unclear. Two novel 7-transmembrane spanning proteins, representing two distinct classes of steroid membrane receptors, membrane progestin receptor alpha (mPRalpha) and a membrane estrogen receptor (mER), GPR30, have recently been identified in several vertebrate species. Evidence that both receptors activate G-proteins and function as G-protein coupled receptors (GPCRs) is briefly reviewed. New data on progestin actions on fish gametes suggest a widespread involvement of mPRalpha in oocyte maturation and sperm hyperactivity in this vertebrate group. Information on the second messenger pathways activated upon estrogen binding to a membrane estrogen receptor in croaker gonads and preliminary evidence for the presence of a GPR30-like protein in fish gonads are discussed. Finally, initial characterization of the ligand binding, G-protein activation and molecular size of a membrane androgen receptor (mAR) in croaker ovaries suggests the presence of a third unique steroid receptor in fish gonads that also may function as a GPCR.

  10. The role of estrogen receptor α in the regulation of bone and growth plate cartilage.

    PubMed

    Börjesson, A E; Lagerquist, M K; Windahl, S H; Ohlsson, C

    2013-11-01

    Estrogens are important endocrine regulators of skeletal growth and maintenance in both females and males. Studies have demonstrated that the estrogen receptor (ER)-α is the main mediator of these estrogenic effects in bone. Therefore, estrogen signaling via ERα is a target both for affecting longitudinal bone growth and bone remodeling. However, treatment with estradiol (E2) leads to an increased risk of side effects such as venous thromboembolism and breast cancer. Thus, an improved understanding of the signaling pathways of ERα will be essential in order to find better bone specific treatments with minimal adverse effects for different estrogen-related bone disorders. This review summarizes the recent data regarding the intracellular signaling mechanisms, in vivo, mediated by the ERα activation functions (AFs), AF-1 and AF-2, and the effect on bone, growth plate and other estrogen responsive tissues. In addition, we review the recent cell-specific ERα-deleted mouse models lacking ERα specifically in neuronal cells or growth plate cartilage. The newly characterized signaling pathways of estrogen, described in this review, provide a better understanding of the ERα signaling pathways, which may facilitate the design of new, bone-specific treatment strategies with minimal adverse effects.

  11. Tumor suppressor ING4 inhibits estrogen receptor activity in breast cancer cells

    PubMed Central

    Keenen, Madeline M; Kim, Suwon

    2016-01-01

    Resistance to antiestrogen therapy remains a significant problem in breast cancer. Low expression of inhibitor of growth 4 (ING4) in primary tumors has been correlated with increased rates of recurrence in estrogen receptor-positive (ER+) breast cancer patients, suggesting a role for ING4 in ER signaling. This study provides evidence that ING4 inhibits ER activity. ING4 overexpression increased the sensitivity of T47D and MCF7 ER+ breast cancer cells to hormone deprivation. ING4 attenuated maximal estrogen-dependent cell growth without affecting the dose–response of estrogen. These results indicated that ING4 functions as a noncompetitive inhibitor of estrogen signaling and may inhibit estrogen-independent ER activity. Supportive of this, treatment with fulvestrant but not tamoxifen rendered T47D cells sensitive to hormone deprivation as did ING4 overexpression. ING4 did not affect nuclear ERα protein expression, but repressed selective ER-target gene transcription. Taken together, these results demonstrated that ING4 inhibited estrogen-independent ER activity, suggesting that ING4-low breast tumors recur faster due to estrogen-independent ER activity that renders tamoxifen less effective. This study puts forth fulvestrant as a proposed therapy choice for patients with ING4-low ER+ breast tumors. PMID:27895513

  12. 17β-Estradiol Inhibits Wound Healing in Male Mice via Estrogen Receptor

    PubMed Central

    Gilliver, Stephen C.; Emmerson, Elaine; Campbell, Laura; Chambon, Pierre; Hardman, Matthew J.; Ashcroft, Gillian S.

    2010-01-01

    Although estrogens have long been known to accelerate healing in females, their roles in males remain to be established. To address this, we have investigated the influence of 17β-estradiol on acute wound repair in castrated male mice. We report that sustained exposure to estrogen markedly delays wound re-epithelialization. Our use of hairless mice revealed this response to be largely independent of hair follicle cycling, whereas other studies demonstrated that estrogen minimally influences wound inflammation in males. Additionally, we report reduced collagen accumulation and increased gelatinase activities in the wounds of estrogen-treated mice. Increased wound matrix metalloproteinase (MMP)-2 activity in these animals may i) contribute to their inability to heal skin wounds optimally and ii) stem, at least in part, from effects on the overall levels and spatial distribution of membrane-type 1-MMP and tissue inhibitor of MMP (TIMP)-3, which respectively facilitate and prevent MMP-2 activation. Using mice rendered null for either the α or β isoform of the estrogen receptor, we identified estrogen receptor-α as the likely effector of estrogen’s inhibitory effects on healing. PMID:20448060

  13. Serum estrogen receptor bioactivity and breast cancer risk among postmenopausal women.

    PubMed

    Lim, Vanessa W; Li, Jun; Gong, Yinhan; Jin, Aizhen; Yuan, Jian-Min; Yong, Eu Leong; Koh, Woon-Puay

    2014-04-01

    The estrogen levels of Asian women are different from those of Western women, and this could affect estrogen receptor (ER) bioactivity and breast cancer risk. We conducted a case-control study in 169 postmenopausal breast cancer cases and 426 matched controls nested within a population-based prospective cohort study, the Singapore Chinese Health Study, to evaluate the serum levels of estrogens and their receptor (ERα and ERβ)-mediated estrogenic activities in relation to breast cancer risk. Breast cancer cases had higher levels of estrogens and ER-mediated bioactivities in baseline serum than the controls. Compared with those in the lowest quartile, women in the highest quartile for estrone (E1) or ERα-mediated bioactivity had increased breast cancer risk. After additional adjustment for ERβ bioactivity, free estradiol, and E1 levels, serum ERα-mediated bioactivity remained associated with increased breast cancer risk. Compared with those in the lowest quartile, women in the highest quartile for ERα-mediated bioactivity had an odds ratio of 2.39 (95% CI=1.17-4.88; P for trend=0.016). Conversely, the positive association between E1 and cancer risk became null after adjustment for ERα-mediated bioactivity, suggesting that the effect of E1 could be mediated through ERα. Factor(s) contributing to increased ERα-mediated estrogenic bioactivity in serum and its role as a predictor for breast cancer risk need to be validated in future studies.

  14. Non-nuclear-initiated actions of the estrogen receptor protect cortical bone mass.

    PubMed

    Bartell, Shoshana M; Han, Li; Kim, Ha-neui; Kim, Sung Hoon; Katzenellenbogen, John A; Katzenellenbogen, Benita S; Chambliss, Ken L; Shaul, Philip W; Roberson, Paula K; Weinstein, Robert S; Jilka, Robert L; Almeida, Maria; Manolagas, Stavros C

    2013-04-01

    Extensive evidence has suggested that at least some of the effects of estrogens on bone are mediated via extranuclear estrogen receptor α signaling. However, definitive proof for this contention and the extent to which such effects may contribute to the overall protective effects of estrogens on bone maintenance have remained elusive. Here, we investigated the ability of a 17β-estradiol (E2) dendrimer conjugate (EDC), incapable of stimulating nuclear-initiated actions of estrogen receptor α, to prevent the effects of ovariectomy (OVX) on the murine skeleton. We report that EDC was as potent as an equimolar dose of E2 in preventing bone loss in the cortical compartment that represents 80% of the entire skeleton, but was ineffective on cancellous bone. In contrast, E2 was effective in both compartments. Consistent with its effect on cortical bone mass, EDC partially prevented the loss of both vertebral and femoral strength. In addition, EDC, as did E2, prevented the OVX-induced increase in osteoclastogenesis, osteoblastogenesis, and oxidative stress. Nonetheless, the OVX-induced decrease in uterine weight was unaltered by EDC but was restored by E2. These results demonstrate that the protection of cortical bone mass by estrogens is mediated, at least in part, via a mechanism that is distinct from the classic mechanism of estrogen action on reproductive organs.

  15. The Expanding Complexity of Estrogen Receptor Signaling in the Cardiovascular System.

    PubMed

    Menazza, Sara; Murphy, Elizabeth

    2016-03-18

    Estrogen has important effects on cardiovascular function including regulation of vascular function, blood pressure, endothelial relaxation, and the development of hypertrophy and cardioprotection. However, the mechanisms by which estrogen mediates these effects are still poorly understood. As detailed in this review, estrogen can regulate transcription by binding to 2 nuclear receptors, ERα and ERβ, which differentially regulate gene transcription. ERα and ERβ regulation of gene transcription is further modulated by tissue-specific coactivators and corepressors. Estrogen can bind to ERα and ERβ localized at the plasma membrane as well as G-protein-coupled estrogen receptor to initiate membrane delimited signaling, which enhances kinase signaling pathways that can have acute and long-term effects. The kinase signaling pathways can also mediate transcriptional changes and can synergize with the ER to regulate cell function. This review will summarize the beneficial effects of estrogen in protecting the cardiovascular system through ER-dependent mechanisms with an emphasis on the role of the recently described ER membrane signaling mechanisms.

  16. Cooperative binding of estrogen receptor to imperfect estrogen-responsive DNA elements correlates with their synergistic hormone-dependent enhancer activity.

    PubMed

    Martinez, E; Wahli, W

    1989-12-01

    The Xenopus vitellogenin (vit) gene B1 estrogen-inducible enhancer is formed by two closely adjacent 13 bp imperfect palindromic estrogen-responsive elements (EREs), i.e. ERE-2 and ERE-1, having one and two base substitutions respectively, when compared to the perfect palindromic consensus ERE (GGTCANNNTGACC). Gene transfer experiments indicate that these degenerated elements, on their own, have a low or no regulatory capacity at all, but in vivo act together synergistically to confer high receptor- and hormone-dependent transcription activation to the heterologous HSV thymidine kinase promoter. Thus, the DNA region upstream of the vitB1 gene comprising these two imperfect EREs separated by 7 bp, was called the vitB1 estrogen-responsive unit (vitB1 ERU). Using in vitro protein-DNA interaction techniques, we demonstrate that estrogen receptor dimers bind cooperatively to the imperfect EREs of the vitB1 ERU. Binding of a first receptor dimer to the more conserved ERE-2 increases approximately 4- to 8-fold the binding affinity of the receptor to the adjacent less conserved ERE-1. Thus, we suggest that the observed synergistic estrogen-dependent transcription activation conferred by the pair of hormone-responsive DNA elements of the vit B1 ERU is the result of cooperative binding of two estrogen receptor dimers to these two adjacent imperfect EREs.

  17. 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

  18. Leptin receptor expression during the progression of endometrial carcinoma is correlated with estrogen and progesterone receptors

    PubMed Central

    Méndez-López, Luis Fernando; Zavala-Pompa, Angel; Cortés-Gutiérrez, Elva I.; Cerda-Flores, Ricardo M.

    2016-01-01

    Introduction The hormone leptin, which is produced in the adipose tissue, may influence tumorigenesis directly via its receptor (Ob-R). Thus, a role for Ob-R in endometrial carcinogenesis has been proposed. However, most studies neither included samples of the entire histological progression of endometrial carcinoma nor examined Ob-R jointly with the estrogen and progesterone receptors (ER and PR, respectively). Material and methods To determine the fluctuations of Ob-R, ER, and PR during the histological progression of endometrial carcinoma, we assessed their expression via immunohistochemistry (IHC) in six histological types of endometrium (proliferative, secretory, nonatypical and atypical hyperplasia, and endometrioid and nonendometrioid endometrial carcinoma), in which we performed histopathological and digital scoring for the quantification of receptors. Results We found that Ob-R expression was positively correlated with that of ER and PR (r = 1, p < 0.001; r = 0.943, p < 0.005, respectively), and there was a significant difference in Ob-R expression among proliferative normal endometrium, hyperplasias, and carcinomas, according to their relative digitally scored Ob-R expression (p < 0.001). In addition, we observed that Ob-R expression in the secretory endometrium was more similar to that of carcinomas than to its proliferative counterpart. Conclusions These results indicate that Ob-R expression fluctuates during endometrial carcinogenesis in correlation with ER and PR, suggesting that Ob-R expression in vivo is highly dependent on estrogen and progesterone activities in the endometrium and on its ER and PR status, as suggested previously by in vitro studies. PMID:28144276

  19. Palbociclib in Combination With Tamoxifen as First Line Therapy for Metastatic Hormone Receptor Positive Breast Cancer

    ClinicalTrials.gov

    2017-03-28

    Hormone Receptor Positive Malignant Neoplasm of Breast; Human Epidermal Growth Factor 2 Negative Carcinoma of Breast; Estrogen Receptor Positive Breast Cancer; Progesterone Receptor Positive Tumor; Metastatic Breast Cancer

  20. Food-associated estrogenic compounds induce estrogen receptor-mediated luciferase gene expression in transgenic male mice.

    PubMed

    Ter Veld, Marcel G R; Zawadzka, E; van den Berg, J H J; van der Saag, Paul T; Rietjens, Ivonne M C M; Murk, Albertinka J

    2008-07-30

    The present paper aims at clarifying to what extent seven food-associated compounds, shown before to be estrogenic in vitro, can induce estrogenic effects in male mice with an estrogen receptor (ER)-mediated luciferase (luc) reporter gene system. The luc induction was determined in different tissues 8h after dosing the ER-luc male mice intraperitoneally (IP) or 14h after oral dosing. Estradiol-propionate (EP) was used as a positive control at 0.3 and 1mg/kg bodyweight (bw), DMSO as solvent control. The food-associated estrogenic compounds tested at non-toxic doses were bisphenol A (BPA) and nonylphenol (NP) (both at 10 and 50mg/kgbw), dichlorodiphenyldichloroethylene (p,p'-DDE; at 5 and 25mg/kgbw), quercetin (at 1.66 and 16.6mg/kgbw), di-isoheptyl phthalate (DIHP), di-(2-ethylhexyl) phthalate (DEHP) and di-(2-ethylhexyl) adipate (DEHA) all at 30 and 100mg/kgbw. In general IP dosing resulted in higher luc inductions than oral dosing. EP induced luc activity in the liver in a statistically significant dose-related way with the highest induction of all compounds tested which was 20,000 times higher than the induction by the DMSO-control. NP, DDE, DEHA and DIHP did not induce luc activity in any of the tissues tested. BPA induced luc in the liver up to 420 times via both exposure routes. BPA, DEHP and quercetin induced luc activity in the liver after oral exposure. BPA (50mg/kgbw IP) also induced luc activity in the testis, kidneys and tibia. The current study reveals that biomarker-responses in ER-luc male mice occur after a single oral exposure to food-associated estrogenic model compounds at exposure levels 10 to 10(4) times higher than the established TDI's for some of these compounds. Given the facts that (i) the present study did not include chronic exposure and that (ii) simultaneous exposure to multiple estrogenic compounds may be a realistic exposure scenario, it remains to be seen whether this margin is sufficiently high.

  1. Interplay between estrogen response element sequence and ligands controls in vivo binding of estrogen receptor to regulated genes.

    PubMed

    Krieg, Adam J; Krieg, Sacha A; Ahn, Bonnie S; Shapiro, David J

    2004-02-06

    To examine the role of the estrogen response element (ERE) sequence in binding of liganded estrogen receptor (ER) to promoters, we analyzed in vivo interaction of liganded ER with the imperfect ERE in the pS2 gene and the composite estrogen-responsive unit (ERU) in the proteinase inhibitor 9 (PI-9) gene. In transient transfections of ER-positive HepG2-ER7 cells, PI-9 was strongly induced by estrogen, moxestrol (MOX), and 4-hydroxytamoxifen (OHT). PI-9 was not induced by raloxifene or ICI 182,780. Quantitative reverse transcriptase-PCR showed that moxestrol strongly induced cellular PI-9 and pS2 mRNAs, whereas OHT moderately induced PI-9 mRNA and weakly induced pS2 mRNA. Chromatin immunoprecipitation experiments demonstrated strong and similar association of 17beta-estradiol-hERalpha and MOX-hERalpha with the PI-9 ERU and with the pS2 ERE. Binding of MOX-hERalpha to the PI-9 ERU and the pS2 ERE was rapid and continuous. Although MOX-hERalpha bound strongly to the PI-9 ERU and less well to the pS2 ERE in chromatin immunoprecipitation, gel shift assays showed that estrogen-hERalpha binds with higher affinity to the deproteinized pS2 ERE than to the PI-9 ERU. Across a broad range of OHT concentrations, OHT-hERalpha associated strongly with the pS2 ERE and weakly with the PI-9 ERU. ICI-hERalpha bound poorly to the PI-9 ERU and effectively to the pS2 ERE. Raloxifene-hERalpha and MOX-hERalpha exhibited similar binding to the PI-9 ERU and the pS2 ERE. These studies demonstrate that ER ligand and ERE sequence work together to regulate in vivo binding of ER to estrogen-responsive promoters.

  2. Selective Estrogen Receptor Modulators Suppress Hif1α Protein Accumulation in Mouse Osteoclasts

    PubMed Central

    Iwasaki, Ryotaro; Kobayashi, Tami; Watanabe, Ryuichi; Oike, Takatsugu; Toyama, Yoshiaki; Matsumoto, Morio; Nakamura, Masaya; Kawana, Hiromasa; Nakagawa, Taneaki; Miyamoto, Takeshi

    2016-01-01

    Anti-bone resorptive drugs such as bisphosphonates, the anti-RANKL antibody (denosumab), or selective estrogen receptor modulators (SERMs) have been developed to treat osteoporosis. Mechanisms underlying activity of bisphosphonates or denosumab in this context are understood, while it is less clear how SERMs like tamoxifen, raloxifene, or bazedoxifene inhibit bone resorption. Recently, accumulation of hypoxia inducible factor 1 alpha (Hif1α) in osteoclasts was shown to be suppressed by estrogen in normal cells. In addition, osteoclast activation and decreased bone mass seen in estrogen-deficient conditions was found to require Hif1α. Here, we used western blot analysis of cultured osteoclast precursor cells to show that tamoxifen, raloxifene, or bazedoxifene all suppress Hif1α protein accumulation. The effects of each SERM on osteoclast differentiation differed in vitro. Our results suggest that interventions such as the SERMs evaluated here could be useful to inhibit Hif1α and osteoclast activity under estrogen-deficient conditions. PMID:27802325

  3. Memo interacts with c-Src to control Estrogen Receptor alpha sub-cellular localization.

    PubMed

    Frei, Anna; MacDonald, Gwen; Lund, Ingrid; Gustafsson, Jan-Åke; Hynes, Nancy E; Nalvarte, Ivan

    2016-08-30

    Understanding the complex interaction between growth factor and steroid hormone signaling pathways in breast cancer is key to identifying suitable therapeutic strategies to avoid progression and therapy resistance. The interaction between these two pathways is of paramount importance for the development of endocrine resistance. Nevertheless, the molecular mechanisms behind their crosstalk are still largely obscure. We previously reported that Memo is a small redox-active protein that controls heregulin-mediated migration of breast cancer cells. Here we report that Memo sits at the intersection between heregulin and estrogen signaling, and that Memo controls Estrogen Receptor alpha (ERα) sub-cellular localization, phosphorylation, and function downstream of heregulin and estrogen in breast cancer cells. Memo facilitates ERα and c-Src interaction, ERα Y537 phosphorylation, and has the ability to control ERα extra-nuclear localization. Thus, we identify Memo as an important key mediator between the heregulin and estrogen signaling pathways, which affects both breast cancer cell migration and proliferation.

  4. Estrogen receptor-β in mitochondria: implications for mitochondrial bioenergetics and tumorigenesis.

    PubMed

    Liao, Tien-Ling; Tzeng, Chii-Ruey; Yu, Chao-Lan; Wang, Yi-Pei; Kao, Shu-Huei

    2015-09-01

    Estrogen enhances mitochondrial function by enhancing mitochondrial biogenesis and sustaining mitochondrial energy-transducing capacity. Shifts in mitochondrial bioenergetic pathways from oxidative phosphorylation to glycolysis have been hypothesized to be involved in estrogen-induced tumorigenesis. Studies have shown that mitochondria are an important target of estrogen. Estrogen receptor-β (ERβ) has been shown to localize to mitochondria in a ligand-dependent or -independent manner and can affect mitochondrial bioenergetics and anti-apoptotic signaling. However, the functional role of mitochondrial ERβ in tumorigenesis remains unclear. Clinical studies of ERβ-related tumorigenesis have shown that ERβ stimulates mitochondrial metabolism to meet the high energy demands of processes such as cell proliferation, cell survival, and transformation. Thus, in elucidating the precise role of mitochondrial ERβ in cell transformation and tumorigenesis, it will be particularly valuable to explore new approaches for the development of medical treatments targeting mitochondrial ERβ-mediated mitochondrial function and preventing apoptosis.

  5. 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

  6. Veliparib and Carboplatin in Treating Patients With HER2-Negative Metastatic Breast Cancer

    ClinicalTrials.gov

    2017-03-28

    BRCA1 Mutation Carrier; BRCA2 Mutation Carrier; Estrogen Receptor Negative; Estrogen Receptor Positive; HER2/Neu Negative; Progesterone Receptor Negative; Progesterone Receptor Positive; Recurrent Breast Carcinoma; Stage IIIB Breast Cancer; Stage IIIC Breast Cancer; Stage IV Breast Cancer; Triple-Negative Breast Carcinoma

  7. Targeting Epigenetics Therapy for Estrogen Receptor-Negative Breast Cancers

    DTIC Science & Technology

    2015-10-01

    chosen for its intrinsic inhibitory activity against fungi , bacteria, and malignant cancer.230–232 One com- pound synthesized in the series (27; Figure 7...We subsequently attributed this stability to protection by LSD1 binding, since in a CoREST siRNA knockdown normally LSD1 is unstable and rapidly...Peptide Science) might protect the cell from potentially toxic formaldehyde or regulate access of the substrate to the FAD within the active site. It is not

  8. [Chronic administration of estrogen receptors antagonist reduces degree of hypoxia-induced pulmonary hypertension caused by chronic injections of estrogen in ovariectomised female Wistar rats].

    PubMed

    Kovaleva, Iu O; Artem'eva, M M; Medvedev, O S; Medvedeva, N A

    2013-01-01

    As we showed previously, administration of estradiol in different doses (5 and 15 mcg per day for 21 day) initiates the development of pulmonary arterial hypertension (PAH) in ovariectomised female Wistar rats. The aim of current study was to analyze the involvement of antagonist of estrogen receptors type a- and beta- ICI 182,780 (fulvestrant) in development of hypoxia-induced pulmonary arterial hypertension. Ovariectomised female rats were separated into 5 groups received subcutaneously for 1 month : 1. Estrogen 15 mcg per day. 2. Estrogen 60 mcg per day 3. Antagonist of estrogen receptors type alpha- and beta- fulvestrant 150 mcg per day. 4. Estrogen 15 mcg/d + fulvestrant 150 mcg/d. 5. Propylenglycol as a control group. PAH was induced by exposure to hypobaric hypoxia. Rats were housed in a hypobaric chamber at simulated altitude of 5000 m, 10 h a day, 2 wk (O2 concentration reduced to 10%). We suppose that the development of pulmonary hypertension in ovariectomised female Wistar rats caused by administration of estrogen (15 mcg and 60 mcg per day for 1 month) is mediated by estrogen receptors type alpha- and beta-.

  9. Determination of the Role of Estrogen Receptors and Estrogen Regulated Genes in B Cell Autoreactivity

    DTIC Science & Technology

    2011-07-01

    Medical Research Manhasset, NY 11030 Systemic lupus erythematosus is an autoimmune disease that occurs preferentially in women. We have developed a...Introduction: There is abundant clinical data that estrogen can increase risk of developing systemic lupus erythematosus (SLE) and disease...crux of systemic lupus erythematosus (SLE). SLE is characterized by an array of antibodies against self-antigens (3,4). Anti–double-stranded (ds) DNA

  10. Determination of the Role of Estrogen Receptors and Estrogen Regulated Genes in B Cell Autoreactivity

    DTIC Science & Technology

    2010-07-01

    14. ABSTRACT Systemic lupus erythematosus (SLE) is an autoimmune disease that occurs preferentially in women. In murine models of SLE, it is... Systemic Lupus , Estrogen, BCR Signaling, B Cell Maturation, B Cell Selection 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF...therefore, be important to test ERα antagonists in murine studies of B cell development and in murine models of lupus . This approach to therapy might

  11. Determination of the Role of Estrogen Receptors and Estrogen Regulated Genes in B cell Autoreactivity. Addendum

    DTIC Science & Technology

    2012-07-01

    14. ABSTRACT Systemic lupus erythematosus is an autoimmune disease that occurs preferentially in women. We have developed a murine model...4 Introduction: There is abundant clinical data that estrogen can increase risk of developing systemic lupus erythematosus (SLE) and disease...Kawabata, D., Pinto-Rodriguez, D., Grimaldi, C. and Diamond B. Hormonal regulator of B cell function and systemic lupus erythematosus . Lupus 17:528

  12. Estrogen-like activity of perfluoroalkyl acids in vivo and interaction with human and rainbow trout estrogen receptors in vitro.

    PubMed

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

    2011-03-01

    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 (IC(50)) values of 15.2-289 μM. Additionally, PFOA, PFNA, PFDA, PFUnDA, and perlfuorooctane sulfonate (PFOS) significantly enhanced human ERα-dependent transcriptional activation at concentrations ranging from 10-1000 nM. 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.

  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. Selective Estrogen Receptor Modulators: Cannabinoid Receptor Inverse Agonists with Differential CB1 and CB2 Selectivity

    PubMed Central

    Franks, Lirit N.; Ford, Benjamin M.; Prather, Paul L.

    2016-01-01

    Selective estrogen receptor modulators (SERMs) are used to treat estrogen receptor (ER)-positive breast cancer and osteoporosis. Interestingly, tamoxifen and newer classes of SERMs also exhibit cytotoxic effects in cancers devoid of ERs, indicating a non-estrogenic mechanism of action. Indicative of a potential ER-independent target, reports demonstrate that tamoxifen binds to cannabinoid receptors (CBRs) with affinity in the low μM range and acts as an inverse agonist. To identify cannabinoids with improved pharmacological properties relative to tamoxifen, and further investigate the use of different SERM scaffolds for future cannabinoid drug development, this study characterized the affinity and activity of SERMs in newer structural classes at CBRs. Fourteen SERMs from five structurally distinct classes were screened for binding to human CBRs. Compounds from four of five SERM classes examined bound to CBRs. Subsequent studies fully characterized CBR affinity and activity of one compound from each class. Ospemifine (a triphenylethylene) selectively bound to CB1Rs, while bazedoxifine (an indole) bound to CB2Rs with highest affinity. Nafoxidine (a tetrahydronaphthalene) and raloxifene (RAL; a benzothiaphene) bound to CB1 and CB2Rs non-selectively. All four compounds acted as inverse agonists at CB1 and CB2Rs, reducing basal G-protein activity with IC50 values in the nM to low μM range. Ospemifine, bazedoxifene and RAL also acted as inverse agonists to elevate basal intracellular cAMP levels in intact CHO-hCB2 cells. The four SERMs examined also acted as CB1 and CB2R antagonists in the cAMP assay, producing rightward shifts in the concentration-effect curve of the CBR agonist CP-55,940. In conclusion, newer classes of SERMs exhibit improved pharmacological characteristics (e.g., in CBR affinity and selectivity) relative to initial studies with tamoxifen, and thus suggest that different SERM scaffolds may be useful for development of safe and selective drugs acting

  16. Genotypes of vitamin D and estrogen receptors in pre and perimenopausal women from Córdoba, Argentina.

    PubMed

    Ulla, María; Pérez, Adriana; Elías, Vanina; Binci, Miriam; Pretel, Esteban; Castro, María; Talamoni, Juan; Costero, Beatriz; Mammana, Mónica; Babini, Silvana; Díaz de Barboza, Gabriela; Tolosa de Talamoni, Nori

    2007-01-01

    The aim of this study was to determine the frequency of vitamin D receptor and estrogen receptor genotypes and their relationship with the lumbar spine or femoral neck bone mineral density in healthy pre and perimenopausal women from Córdoba (Argentina) and adjacent areas. Genotypes were assessed by restriction fragment length polymorphism-polymerase chain reaction technique. Bsm I and Fok I for vitamin D receptor gene and Xbal and Pvull for estrogen receptor gene were used as restrictases. Two hundred and ten healthy pre and perimenopausal women were recruited and analyzed by age. Calcemia and serum parathyroid hormone did not change, but serum P and beta-CrossLaps decreased with age. Femoral neck bone mineral density decreased significantly after 30 years old. Vitamin D receptor and estrogen receptor genotype frequencies were similar to those from other Caucasian women. No association between vitamin D receptor and estrogen receptor genotypes with the lumbar spine or femoral neck bone mineral density has been detected. Analysis of interaction between vitamin D receptor and estrogen receptor genes using covariates such as age, height and body mass index did not show any influence of the combination of those genotypes on bone mineral density. Lifestyle, smoking and alcohol intake had no effect on lumbar spine and femoral neck bone mineral density. To conclude, these data do not support the hypothesis that vitamin D receptor and estrogen receptor genotypes influence on lumbar spine and femoral neck bone mineral density in healthy pre and perimenopausal women from this area of Argentina.

  17. 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

  18. A demonstration of the uncertainty in predicting the estrogenic activity of individual chemicals and mixtures from an in vitro estrogen receptor transcriptional activation assay (T47D-KBluc) to the in vivo uterotrophic assay using oral exposure

    EPA Science Inventory

    In vitro estrogen receptor assays are valuable screening tools for identifying environmental samples and chemicals that display estrogenic activity. However, in vitro potency cannot necessarily be extrapolated to estimates of in vivo potency because in vitro assays are currently...

  19. Estrogen Stimulation of Kiss1 Expression in the Medial Amygdala Involves Estrogen Receptor-α But Not Estrogen Receptor-β.

    PubMed

    Stephens, Shannon B Z; Chahal, Navdeep; Munaganuru, Nagambika; Parra, Ruby A; Kauffman, Alexander S

    2016-10-01

    The neuropeptide kisspeptin, encoded by Kiss1, regulates reproduction by stimulating GnRH secretion. Neurons synthesizing kisspeptin are predominantly located in the hypothalamic anteroventral periventricular (AVPV) and arcuate nuclei, but smaller kisspeptin neuronal populations also reside in extrahypothalamic brain regions, such as the medial amygdala (MeA). In adult rodents, estradiol (E2) increases Kiss1 expression in the MeA, as in the AVPV. However, unlike AVPV and arcuate nuclei kisspeptin neurons, little else is currently known about the development, regulation, and function of MeA Kiss1 neurons. We first assessed the developmental onset of MeA Kiss1 expression in males and found that MeA Kiss1 expression is absent at juvenile ages but significantly increases during the late pubertal period, around postnatal day 35, coincident with increases in circulating sex steroids. We next tested whether developmental MeA Kiss1 expression could be induced early by E2 exposure prior to puberty. We found that juvenile mice given short-term E2 had greatly increased MeA Kiss1 expression at postnatal day 18. Although MeA Kiss1 neurons are known to be E2 up-regulated, the specific estrogen receptor (ER) pathway(s) mediating this stimulation are unknown. Using adult ERα knockout and ERβ knockout mice, we next determined that ERα, but not ERβ, is required for maximal E2-induced MeA Kiss1 expression in both sexes. These results delineate both the developmental time course of MeA Kiss1 expression and the specific ER signaling pathway required for E2-induced up-regulation of Kiss1 in this extrahypothalamic brain region. These findings will help drive future studies ascertaining the potential functions of this understudied kisspeptin population.

  20. Mas receptor is involved in the estrogen-receptor induced nitric oxide-dependent vasorelaxation.

    PubMed

    Sobrino, Agua; Vallejo, Susana; Novella, Susana; Lázaro-Franco, Macarena; Mompeón, Ana; Bueno-Betí, Carlos; Walther, Thomas; Sánchez-Ferrer, Carlos; Peiró, Concepción; Hermenegildo, Carlos

    2017-04-01

    The Mas receptor is involved in the angiotensin (Ang)-(1-7) vasodilatory actions by increasing nitric oxide production (NO). We have previously demonstrated an increased production of Ang-(1-7) in human umbilical vein endothelial cells (HUVEC) exposed to estradiol (E2), suggesting a potential cross-talk between E2 and the Ang-(1-7)/Mas receptor axis. Here, we explored whether the vasoactive response and NO-related signalling exerted by E2 are influenced by Mas. HUVEC were exposed to 10nM E2 for 24h in the presence or absence of the selective Mas receptor antagonist A779, and the estrogen receptor (ER) antagonist ICI182780 (ICI). E2 increased Akt and endothelial nitric oxide synthase (eNOS) mRNA and protein expression, measured by RT-PCR and Western blot, respectively. Furthermore, E2 increased Akt activity (determined by the levels of phospho-Ser(473)) and eNOS activity (by the enhanced phosphorylation of Ser(1177), the activated form), resulting in increased NO production, which was measured by the fluorescence probe DAF-2-FM. These signalling events were dependent on ER and Mas receptor activation, since they were abolished in the presence of ICI or A779. In ex-vivo functional experiments performed with a small-vessel myograph in isolated mesenteric vessels from wild-type mice pre-contracted with noradrenaline, the relaxant response to physiological concentrations of E2 was blocked by ICI and A779, to the same extent to that obtained in the vessels isolated from Mas-deficient. In conclusion, E2 induces NO production and vasodilation through mechanisms that require Mas receptor activation.

  1. Fulvestrant-induced cell death and proteasomal degradation of estrogen receptor α protein in MCF-7 cells require the CSK c-Src tyrosine kinase.

    PubMed

    Yeh, Wei-Lan; Shioda, Keiko; Coser, Kathryn R; Rivizzigno, Danielle; McSweeney, Kristen R; Shioda, Toshi

    2013-01-01

    Fulvestrant is a representative pure antiestrogen and a Selective Estrogen Receptor Down-regulator (SERD). In contrast to the Selective Estrogen Receptor Modulators (SERMs) such as 4-hydroxytamoxifen that bind to estrogen receptor α (ERα) as antagonists or partial agonists, fulvestrant causes proteasomal degradation of ERα protein, shutting down the estrogen signaling to induce proliferation arrest and apoptosis of estrogen-dependent breast cancer cells. We performed genome-wide RNAi knockdown screenings for protein kinases required for fulvestrant-induced apoptosis of the MCF-7 estrogen-dependent human breast caner cells and identified the c-Src tyrosine kinase (CSK), a negative regulator of the oncoprotein c-Src and related protein tyrosine kinases, as one of the necessary molecules. Whereas RNAi knockdown of CSK in MCF-7 cells by shRNA-expressing lentiviruses strongly suppressed fulvestrant-induced cell death, CSK knockdown did not affect cytocidal actions of 4-hydroxytamoxifen or paclitaxel, a chemotherapeutic agent. In the absence of CSK, fulvestrant-induced proteasomal degradation of ERα protein was suppressed in both MCF-7 and T47D estrogen-dependent breast cancer cells whereas the TP53-mutated T47D cells were resistant to the cytocidal action of fulvestrant in the presence or absence of CSK. MCF-7 cell sensitivities to fulvestrant-induced cell death or ERα protein degradation was not affected by small-molecular-weight inhibitors of the tyrosine kinase activity of c-Src, suggesting possible involvement of other signaling molecules in CSK-dependent MCF-7 cell death induced by fulvestrant. Our observations suggest the importance of CSK in the determination of cellular sensitivity to the cytocidal action of fulvestrant.

  2. The deletion of the estrogen receptor α gene reduces susceptibility to estrogen-induced cholesterol cholelithiasis in female mice

    PubMed Central

    de Bari, Ornella; Wang, Helen H.; Portincasa, Piero; Liu, Min; Wang, David Q.-H.

    2015-01-01

    Compelling evidence has demonstrated that estrogen is a critical risk factor for gallstone formation and enhances cholesterol cholelithogenesis through the hepatic estrogen receptor α (ERα), but not ERβ. To study the lithogenic mechanisms of estrogen through ERα, we investigated whether the deletion of Erα protects against gallstone formation in ovariectomized (OVX) female mice fed a lithogenic diet and treated with 17β-estradiol (E2) at 0 or 6 μg/day for 56 days. Our results showed that the prevalence of gallstones was reduced from 100% in OVX ERα (+/+) mice to 30% in OVX ERα (−/−) mice in response to high doses of E2 and the lithogenic diet for 56 days. Hepatic cholesterol secretion was significantly diminished in OVX ERα (−/−) mice compared to OVX ERα (+/+) mice even fed the lithogenic diet and treated with E2 for 56 days. These alterations decreased bile lithogenicity by reducing cholesterol saturation index of gallbladder bile. Immunohistochemical studies revealed that ERα was expressed mainly in the gallbladder smooth muscle cells. High levels of E2 impaired gallbladder emptying function mostly through the ERα and cholecystokinin-1 receptor pathway, leading to gallbladder stasis in OVX ERα (+/+) mice. By contrast, gallbladder emptying function was greatly improved in OVX ERα (−/−) mice. This markedly retarded cholesterol crystallization and the growth and agglomeration of solid cholesterol crystals into microlithiasis and stones. In conclusion, the deletion of Erα reduces susceptibility to the formation of E2-induced gallstones by diminishing hepatic cholesterol secretion, desaturating gallbladder bile, and improving gallbladder contraction function in female mice. PMID:26232687

  3. 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

  4. Characterization of Estrogen-Receptor-Targeted Contrast-Agents in Solution, Breast Cancer Cells and Tumors in vivo

    PubMed Central

    Pais, Adi; Biton, Inbal Eti; Margalit, Raanan; Degani, Hadassa

    2012-01-01

    The estrogen receptor (ER) is a major prognostic biomarker of breast cancer, currently determined in surgical specimens by immunohistochemistry. Two new ER targeted probes, pyridine-tetra-acetate-Gd chelate (PTA-Gd) conjugated either to 17β-estradiol (EPTA-Gd) or to tamoxifen (TPTA-Gd), were explored as contrast agents for molecular imaging of ER. In solution both probes exhibited a micromolar ER binding-affinity, fast water exchange-rate (~107s−1) and water proton-relaxivity of 4.7 to 6.8 mM−1s−1. In human breast cancer cells, both probes acted as estrogen agonists and enhanced the water protons T1 relaxation-rate and relaxivity in ER-positive as compared to ER-negative cells, with EPTA-Gd showing a higher ER-specific relaxivity than TPTA-Gd. In studies of breast cancer tumors in vivo EPTA-Gd induced the highest enhancement in ER-positive tumors as compared to ER-negative tumors and muscle tissue, enabling in vivo detection of ER. TPTA-Gd demonstrated the highest enhancement in muscle tissue indicating non specific interaction of this agent with muscle components. The extracellular contrast agents, PTA-Gd and GdDTPA, showed no difference in the perfusion capacity of ER-positive and negative tumors confirming the specific interaction of EPTA-Gd with ER. These findings lay a basis for the molecular imaging of the estrogen receptor using EPTA-Gd as a template for further developments. PMID:22887470

  5. Neuroprotective effect of estrogen: role of nonsynaptic NR2B-containing NMDA receptors.

    PubMed

    Liu, Shui-bing; Zhao, Ming-gao

    2013-04-01

    Excessive activation of N-methyl-D-aspartate receptors (NMDARs) has been implicated in the pathophysiology of chronic neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, and Huntington's disease. Some studies reported that NR2A and NR2B play different roles in the central nervous system (CNS). The NR2A subunit is primarily found in the synapses and is required for glutamate-mediated neuronal survival. On the other hand, the NR2B subunit is primarily found in the extrasynaptic sites and is required for glutamate-mediated neuronal death in both in vitro and in vivo experiments. Estrogen is a steroid hormone well known for its widespread effects such as neuroprotection in the brain. Classically, estrogen can bind to two kinds of nuclear receptors, namely, estrogen receptor α (ERα) and estrogen receptor β (ERβ), and produce physiological and neuroprotective effects. Aside from nuclear receptors, estrogen has one membrane receptor, which can either be G-protein-coupled receptor 30 (GPR30), Gq-mER, or ER-X. NMDA exposure clearly promotes NR2B subunit phosphorylation at Ser-1303 and causes neuronal cell death. GPR30 mediates rapid non-genomic effects to protect neurons against injury by inhibiting p-DAPK1 dephosphorylation, which inhibits NR2B subunit phosphorylation at Ser-1303. In addition, NMDA exposure and global ischemia activate the autophagy pathway and induce cell death, which are markedly blocked by the NR2B antagonist Ro 25-6981. Thus, NR2B signaling, autophagy induction and cell death may be closely related. Ro 25-6981 inhibits the dissociation of the NR2B-Beclin-1 signaling complex and delays autophagy in vivo, thus confirming the link between NR2B signaling and autophagy. In short, ERα, ERβ, and GPR30 are involved in the neuroprotection of estrogen in the CNS. Additional research must be conducted to reveal the mechanism of estrogen action fully and to identify better targets for the development of more effective drugs. This

  6. Truncating Prolactin Receptor Mutations Promote Tumor Growth in Murine Estrogen Receptor-Alpha Mammary Carcinomas.

    PubMed

    Griffith, Obi L; Chan, Szeman Ruby; Griffith, Malachi; Krysiak, Kilannin; Skidmore, Zachary L; Hundal, Jasreet; Allen, Julie A; Arthur, Cora D; Runci, Daniele; Bugatti, Mattia; Miceli, Alexander P; Schmidt, Heather; Trani, Lee; Kanchi, Krishna-Latha; Miller, Christopher A; Larson, David E; Fulton, Robert S; Vermi, William; Wilson, Richard K; Schreiber, Robert D; Mardis, Elaine R

    2016-09-27

    Estrogen receptor alpha-positive (ERα+) luminal tumors are the most frequent subtype of breast cancer. Stat1(-/-) mice develop mammary tumors that closely recapitulate the biological characteristics of this cancer subtype. To identify transforming events that contribute to tumorigenesis, we performed whole genome sequencing of Stat1(-/-) primary mammary tumors and matched normal tissues. This investigation identified somatic truncating mutations affecting the prolactin receptor (PRLR) in all tumor and no normal samples. Targeted sequencing confirmed the presence of these mutations in precancerous lesions, indicating that this is an early event in tumorigenesis. Functional evaluation of these heterozygous mutations in Stat1(-/-) mouse embryonic fibroblasts showed that co-expression of truncated and wild-type PRLR led to aberrant STAT3 and STAT5 activation downstream of the receptor, cellular transformation in vitro, and tumor formation in vivo. In conclusion, truncating mutations of PRLR promote tumor growth in a model of human ERα+ breast cancer and warrant further investigation.

  7. 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

  8. Androgen and estrogen receptors are present in primary cultures of human synovial macrophages.

    PubMed

    Cutolo, M; Accardo, S; Villaggio, B; Barone, A; Sulli, A; Coviello, D A; Carabbio, C; Felli, L; Miceli, D; Farruggio, R; Carruba, G; Castagnetta, L

    1996-02-01

    Macrophages, as antigen-processing and -presenting cells to T lymphocytes, play a key role in the immune system and are suspected to be target cells of the sex hormone-related dimorphism in the immune response peculiar to rheumatoid arthritis (RA) pathology. In the present study, the use of specific monoclonal antibodies revealed immunostaining for androgen and estrogen receptors in primary cultures of macrophages obtained from synovial tissues of patients affected by RA and controls without RA disease. Soluble and nuclear type I (high affinity, low capacity) and type II (lower affinity, greater capacity) sites of androgen or estrogen binding were detected in primary cultures of RA macrophages using radioligand binding assay. Higher levels of type I and type II estrogen receptor compared to those of androgen receptor were found, particularly in the soluble fraction; however, contrary to what was observed in whole synovial tissues, higher steroid receptor concentrations were found in the soluble than in the nuclear fraction of RA synovial macrophages. Binding affinities and receptor contents of cultured synovial macrophages were comparable to those previously reported in other well established sex hormone-responsive cells and tissues. Further, specific messenger ribonucleic acids for sex hormone receptors, encoding for a sequence of the DNA-binding domain of the receptor proteins were revealed by RT-PCR.

  9. New method for predicting estrogen receptor status utilizing breast MRI texture kinetic analysis

    NASA Astrophysics Data System (ADS)

    Chaudhury, Baishali; Hall, Lawrence O.; Goldgof, Dmitry B.; Gatenby, Robert A.; Gillies, Robert; Drukteinis, Jennifer S.

    2014-03-01

    Magnetic Resonance Imaging (MRI) of breast cancer typically shows that tumors are heterogeneous with spatial variations in blood flow and cell density. Here, we examine the potential link between clinical tumor imaging and the underlying evolutionary dynamics behind heterogeneity in the cellular expression of estrogen receptors (ER) in breast cancer. We assume, in an evolutionary environment, that ER expression will only occur in the presence of significant concentrations of estrogen, which is delivered via the blood stream. Thus, we hypothesize, the expression of ER in breast cancer cells will correlate with blood flow on gadolinium enhanced breast MRI. To test this hypothesis, we performed quantitative analysis of blood flow on dynamic contrast enhanced MRI (DCE-MRI) and correlated it with the ER status of the tumor. Here we present our analytic methods, which utilize a novel algorithm to analyze 20 volumetric DCE-MRI breast cancer tumors. The algorithm generates post initial enhancement (PIE) maps from DCE-MRI and then performs texture features extraction from the PIE map, feature selection, and finally classification of tumors into ER positive and ER negative status. The combined gray level co-occurrence matrices, gray level run length matrices and local binary pattern histogram features allow quantification of breast tumor heterogeneity. The algorithm predicted ER expression with an accuracy of 85% using a Naive Bayes classifier in leave-one-out cross-validation. Hence, we conclude that our data supports the hypothesis that imaging characteristics can, through application of evolutionary principles, provide insights into the cellular and molecular properties of cancer cells.

  10. Serum estrogen and tumor-positive estrogen receptor-alpha are strong prognostic classifiers of non-small-cell lung cancer survival in both men and women.

    PubMed

    Olivo-Marston, Susan E; Mechanic, Leah E; Mollerup, Steen; Bowman, Elise D; Remaley, Alan T; Forman, Michele R; Skaug, Vidar; Zheng, Yun-Ling; Haugen, Aage; Harris, Curtis C

    2010-10-01

    The role of tumor estrogen receptors (ERs) and serum estrogen in lung cancer is inconclusive. We investigated the hypothesis that ERs and functional single-nucleotide polymorphisms in the estrogen biosynthesis pathway are associated with poorer lung cancer survival. Lung cancer patients (n = 305) from a National Cancer Institute-Maryland (NCI-MD) case-case cohort in the Baltimore metropolitan area were used as a test cohort. To validate, 227 cases from the NCI-MD case-control cohort and 293 cases from a Norwegian lung cancer cohort were studied. Information on demographics, tobacco and reproductive histories was collected in an interviewer-administered questionnaire. Serum estrogen, progesterone, tumor messenger RNA expression of hormone receptors and germ line DNA polymorphisms were analyzed for associations with lung cancer survival. Patients in the highest tertile of serum estrogen had worse survival in all three cohorts (P combined < 0.001). Furthermore, the variant allele of estrogen receptor alpha (ER-α) polymorphism (rs2228480) was significantly associated with increased tumor ER-α levels and worse survival in all three cohorts [hazard ratio (HR) = 2.59, 95% confidence interval (CI): 1.20- 4.01; HR = 1.76, 95% CI: 1.08-2.87 and HR = 2.85, 95% CI: 1.31-4.36). Other polymorphisms associated with lower serum estrogen correlated with improved survival. Results were independent of gender and hormone replacement therapy. We report a significant association of increased serum estrogen with poorer survival among lung cancer male and female patients. Understanding the genetic control of estrogen biosynthesis and response in lung cancer could lead to improved prognosis and therapy.

  11. 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...

  12. 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...

  13. 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...

  14. COMPARATIVE DOCKING STUDIES OF THE BINDING OF POLYCYCLIC AROMATIC HYDROCARBONS TO THE ESTROGEN RECEPTOR

    EPA Science Inventory

    The interactions of several PAHs, and some of their possible metabolites, with the ligand binding domain of the estrogen receptor have been examined using molecular docking and quantum mechanical methods. The geometries of the PAHs were optimized at the Hartree-Fock level and the...

  15. Tetrahydroisoquinoline Phenols: Selective Estrogen Receptor Downregulator Antagonists with Oral Bioavailability in Rat

    PubMed Central

    2015-01-01

    A series of tetrahydroisoquinoline phenols was modified to give an estrogen receptor downregulator-antagonist profile. Optimization around the core, alkyl side chain, and pendant aryl ring resulted in compounds with subnanomolar levels of potency. The phenol functionality was shown to be required to achieve highly potent compounds, but unusually this was compatible with obtaining high oral bioavailabilities in rat. PMID:26819673

  16. A subpopulation of estrogen receptors are modified by O-linked N-acetylglucosamine.

    PubMed

    Jiang, M S; Hart, G W

    1997-01-24

    Estrogen receptors (ER) are ligand-inducible transcription factors regulated by Ser(Thr)-O-phosphorylation. Many transcription factors and eukaryotic RNA polymerase II itself are also dynamically modified by Ser(Thr)-O-linked N-acetylglucosamine moieties (O-GlcNAc). Here we report that subpopulations of murine, bovine, and human estrogen receptors are modified by O-GlcNAc. O-GlcNAc moieties were detected on insect cell-expressed, mouse ER (mER) by probing with bovine milk galactosyltransferase, followed by structural analysis. Wheat germ agglutinin-Sepharose affinity chromatography also readily detected terminal GlcNAc residues on subpopulations of ER purified from calf uterus, from human breast cancer cells (MCF-7), or from mER produced by in vitro translation. These data suggest that greater than 10% of these populations of estrogen receptors bear O-GlcNAc. Site mapping of insect cell expressed mER localized one major site of O-GlcNAc addition to Thr-575, within a PEST region of the carboxyl-terminal F domain. Based upon their relative resistance to both hexosaminidase and to in vitro galactosylation, O-GlcNAc moieties appear to be largely buried on native mER. This dynamic saccharide modification, like phosphorylation, may play a role in modulating the dimerization, stability, or transactivation functions of estrogen receptors.

  17. 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...

  18. 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

  19. 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.

  20. The Impact of 27-Hydroxycholesterol, a Macrophage-Produced Estrogen Receptor and Liver X Receptor Agonist, on Breast Cancer Pathophysiology

    DTIC Science & Technology

    2011-02-01

    Umetani M , Shaul PW, Mangelsdorf DJ, McDonnell DP 2008 27- hydroxycholesterol is an endogenous selective estrogen receptor modulator. Mol Endocrinol 22:65...receptor alpha. Endocrinology 141:4180-4184 5. Umetani M , Domoto H, Gormley AK, Yuhanna IS, Cummins CL, Javitt NB, Korach KS, Shaul PW, Mangelsdorf...angiogenesis in polyoma middle T transgenic mouse mammary tumor explants. Breast Cancer Res Treat 78:1-6 11. Maglione JE, Moghanaki D, Young LJ, Manner CK

  1. Estrogen receptors colocalize with low-affinity nerve growth factor receptors in cholinergic neurons of the basal forebrain.

    PubMed Central

    Toran-Allerand, C D; Miranda, R C; Bentham, W D; Sohrabji, F; Brown, T J; Hochberg, R B; MacLusky, N J

    1992-01-01

    The rodent and primate basal forebrain is a target of a family of endogenous peptide signaling molecules, the neurotrophins--nerve growth factor, brain-derived neurotrophic factor, and neurotrophin 3--and of the gonadal steroid hormone estrogen, both of which have been implicated in cholinergic function. To investigate whether or not these ligands may act on the same neurons in the developing and adult rodent basal forebrain, we combined autoradiography with 125I-labeled estrogen and either nonisotopic in situ hybridization histochemistry or immunohistochemistry. We now report colocalization of intranuclear estrogen binding sites with the mRNA and immunoreactive protein for the low-affinity nerve growth factor receptor, which binds all three neurotrophins, and for the cholinergic marker enzyme choline acetyltransferase (acetyl-CoA:choline O-acetyltransferase, EC 2.3.1.6). Colocalization of estrogen and low-affinity nerve growth factor receptors implies that their ligands may act on the same neuron, perhaps synergistically, to regulate the expression of specific genes or gene networks that may influence neuronal survival, differentiation, regeneration, and plasticity. That cholinergic neurons in brain regions subserving cognitive functions may be regulated not only by the neurotrophins but also by estrogen may have considerable relevance for the development and maintenance of neural substrates of cognition. If estrogen-neurotrophin interactions are important for survival of target neurons, then clinical conditions associated with estrogen deficiency could contribute to the atrophy or death of these neurons. These findings have implications for the subsequent decline in those differentiated neural functions associated with aging and Alzheimer disease. Images PMID:1316615

  2. HOXC6 is transcriptionally regulated via coordination of MLL histone methylase and estrogen receptor under estrogen environment

    PubMed Central

    Ansari, Khairul I.; Hussain, Imran; Shrestha, Bishakha; Kasiri, Sahba; Mandal, Subhrangsu S.

    2011-01-01

    Homeobox containing gene HOXC6 is a critical player in mammary gland development, milk production and is overexpressed in breast and prostate cancer. We demonstrated that HOXC6 is transcriptionally regulated by estrogen (E2). HOXC6 promoter contains two putative estrogen-response elements (EREs), termed as ERE11/2 and ERE21/2. Promoter analysis using luciferase based reporter assay demonstrated that both EREs are responsive to E2, ERE11/2 being more responsive than ERE21/2. Estrogen receptors, ERα and ERβ, bind to these EREs in an E2-dependent manner and antisense-mediated knockdown of ERs suppressed the E2-dependent activation of HOXC6 expression. Similarly, knockdown of histone methylases, MLL2 and MLL3, decreased E2-mediated activation of HOXC6. However, depletion of MLL1 or MLL4 showed no significant effect. MLL2 and MLL3 were bound to the HOXC6 EREs in an E2-dependent manner. In contrast, MLL1 and MLL4 that were bound to the HOXC6 promoter in the absence of E2, decreased upon exposure to E2. MLL2 and MLL3 play key roles in histone H3K4-trimethylation and recruitment of general transcription factors and RNAP II in the HOXC6 promoter during E2-dependent transactivation. Nuclear receptor corepressors N-CoR and SAFB1 were bound in the HOXC6 promoter in absence of E2 and that binding were decreased upon E2-treatment indicating their critical roles in suppressing HOXC6 gene expression under non-activated condition. Knockdown of either ERα or ERβ abolished E2-dependent recruitment of MLL2 and MLL3 into the HOXC6 promoter demonstrating key roles of ERs in recruitment of these MLLs into HOXC6 promoter. Overall, our studies demonstrated that HOXC6 is an estrogen-responsive gene and histone methylases MLL2 and MLL3, in coordination with ERα and ERβ, transcriptionally regulate HOXC6 in an E2-dependent manner. PMID:21683083

  3. Potential of Selective Estrogen Receptor Modulators as Treatments and Preventives of Breast Cancer

    PubMed Central

    Peng, Jing; Sengupta, Surojeet; Jordan, V Craig

    2013-01-01

    Estrogen plays vital roles in human health and diseases. Estrogen mediates its actions almost entirely by binding to estrogen receptors (ER), alpha and beta which further function as transcription factors. Selective estrogen receptor modulators (SERMs) are synthetic molecules which bind to ER and can modulate its transcriptional capabilities in different ways in diverse estrogen target tissues. Tamoxifen, the prototypical SERM, is extensively used for targeted therapy of ER positive breast cancers and is also approved as the first chemo-preventive agent for lowering breast cancer incidence in high risk women. The therapeutic and preventive efficacy of tamoxifen was initially proven by series of experiments in the laboratory which laid the foundation of its clinical use. Unfortunately, use of tamoxifen is associated with de-novo and acquired resistance and some undesirable side effects. The molecular study of the resistance provides an opportunity to precisely understand the mechanism of SERM action which may further help in designing new and improved SERMs. Recent clinical studies reveal that another SERM, raloxifene, which is primarily used to treat post-menopausal osteoporosis, is as efficient as tamoxifen in preventing breast cancers with fewer side effects. Overall, these findings open a new horizon for SERMs as a class of drug which not only can be used for therapeutic and preventive purposes of breast cancers but also for various other diseases and disorders. Major efforts are therefore directed to make new SERMs with a better therapeutic profile and fewer side effects. PMID:19519291

  4. Androgen and estrogen receptor mediated mechanisms of testosterone action in male rat pelvic autonomic ganglia

    PubMed Central

    Purves-Tyson, T.D.; Arshi, M.S.; Handelsman, D. J.; Cheng, Y.; Keast, J. R.

    2007-01-01

    Although male reproductive function is primarily androgen dependent, many studies suggest that estrogens have direct actions on the male reproductive organs. Pelvic autonomic neurons provide the motor control of the internal reproductive organs and the penis and various properties of these neurons are affected by endogenous androgens. However, the possible role of estrogens at this site has not been examined. Here we have investigated the significance of estrogens produced by aromatisation of testosterone in the physiological actions of androgens on adult male rat pelvic ganglion neurons. RT-PCR studies showed that aromatase and both estrogen receptors (ERα and ERβ) are expressed in these ganglia. Western blotting also showed that aromatase is expressed in male pelvic ganglia. Using immunohistochemical visualisation, ERα was predominantly expressed by nitric oxide synthase (NOS)-positive parasympathetic pelvic ganglion neurons. In vivo studies showed that the decrease in pelvic ganglion soma size caused by gonadectomy could be prevented by administration of testosterone (T) or dihydrotestosterone (DHT), but not 17β-estradiol (E2), showing that this maintenance action of testosterone is mediated entirely by androgenic mechanisms. However, in vitro studies of cultured pelvic ganglion neurons revealed that T, DHT and E each stimulated the growth of longer and more complex neurites in both noradrenergic and cholinergic NOS-expressing neurons. The effects of T were attenuated by either androgen or estrogen receptor antagonists, or by inhibition of aromatase. Together these studies demonstrate that estrogens are likely to be synthesised in the male pelvic ganglia, produced from testosterone by local aromatase. The effects of androgens on axonal growth are likely to be at least partly mediated by estrogenic mechanisms, which may be important for understanding disease-, aging- and injury-induced plasticity in this part of the nervous system. PMID:17629410

  5. Modulation of estrogen receptor-beta isoforms by phytoestrogens in breast cancer cells.

    PubMed

    Cappelletti, Vera; Miodini, Patrizia; Di Fronzo, Giovanni; Daidone, Maria Grazia

    2006-05-01

    High consumption of phytoestrogen-rich food correlates with reduced incidence of breast cancer. However, the effect of phytoestrogens on growth of pre-existing breast tumors presents concerns when planning the use of phytoestrogens as chemoprevention st rategy. Genistein, the active phytoestrogen in soy, displays weak estrogenic activity mediated by estrogen receptor (ER) with a preferential binding for the ER-beta species. However, no information is at present available on the interaction between phytoestrogens and the various isoforms generated by alternative splicing. In two human breast cancer cell lines, T47D and BT20, which express variable levels of ER-beta, the effect of genistein and quercetin was evaluated singly and in comparison with 17beta-estradiol, on mRNA expression of estrogen receptor-beta (ER-beta) isoforms evaluated by a triple primer RT-PCR assay. In T47D cells estradiol caused a 6-fold up-regulation of total ER-beta, and modified the relative expression pattern of the various isoforms, up-regulating the beta2 and down-regulating the beta5 isoform. Genistein up-regulated ER-beta2 and ER-beta1 in T47D cells, and after treatment the ER-beta2 isoform became prevalent, while in BT20 cells it almost doubled the percent contribution of ER-beta1 and ER-beta2 to total ER-beta. Quercetin did not alter the total levels nor the percent distribution of ER-beta isoforms in either cell line. Genistein, through the modulation of ER-beta isoform RNA expression inhibited estrogen-promoted cell growth, without interfering on estrogen-regulated transcription. ER-beta and its ER-beta mRNA isoforms may be involved in a self-limiting mechanism of estrogenic stimulation promoted either by the natural hormone or by weaker estrogen agonists like genistein.

  6. 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

  7. Interaction of 14-3-3 proteins with the estrogen receptor alpha F domain provides a drug target interface.

    PubMed

    De Vries-van Leeuwen, Ingrid J; da Costa Pereira, Daniel; Flach, Koen D; Piersma, Sander R; Haase, Christian; Bier, David; Yalcin, Zeliha; Michalides, Rob; Feenstra, K Anton; Jiménez, Connie R; de Greef, Tom F A; Brunsveld, Luc; Ottmann, Christian; Zwart, Wilbert; de Boer, Albertus H

    2013-05-28

    Estrogen receptor alpha (ERα) is involved in numerous physiological and pathological processes, including breast cancer. Breast cancer therapy is therefore currently directed at inhibiting the transcriptional potency of ERα, either by blocking estrogen production through aromatase inhibitors or antiestrogens that compete for hormone binding. Due to resistance, new treatment modalities are needed and as ERα dimerization is essential for its activity, interference with receptor dimerization offers a new opportunity to exploit in drug design. Here we describe a unique mechanism of how ERα dimerization is negatively controlled by interaction with 14-3-3 proteins at the extreme C terminus of the receptor. Moreover, the small-molecule fusicoccin (FC) stabilizes this ERα/14-3-3 interaction. Cocrystallization of the trimeric ERα/14-3-3/FC complex provides the structural basis for this stabilization and shows the importance of phosphorylation of the penultimate Threonine (ERα-T(594)) for high-affinity interaction. We confirm that T(594) is a distinct ERα phosphorylation site in the breast cancer cell line MCF-7 using a phospho-T(594)-specific antibody and by mass spectrometry. In line with its ERα/14-3-3 interaction stabilizing effect, fusicoccin reduces the estradiol-stimulated ERα dimerization, inhibits ERα/chromatin interactions and downstream gene expression, resulting in decreased cell proliferation. Herewith, a unique functional phosphosite and an alternative regulation mechanism of ERα are provided, together with a small molecule that selectively targets this ERα/14-3-3 interface.

  8. 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.

  9. Fulvestrant-mediated inhibition of estrogen receptor signaling slows lung cancer progression.

    PubMed

    Tang, Hexiao; Liao, Yongde; Zhang, Chao; Chen, Guang; Xu, Liqiang; Liu, Zhaoguo; Fu, Shengling; Yu, Li; Zhou, Sheng

    2014-01-01

    Estrogens are key signaling molecules that regulate various physiological processes such as cell growth, development, and differentiation. They also play a major role in many pathological conditions, such as hormone-dependent cancer. The importance of inhibiting estrogen receptor signaling in diseases of estrogen target tissues, such as breast cancer, is well documented. However, the role of estrogen signaling in diseases of nontarget tissues, such as lung cancer, is not well characterized. The aim of the current study is to examine the expression of estrogen receptor β (ERβ) and the roles of estradiol (E2) and fulvestrant on the progression of lung cancer. Tissue microarray (TMA) and immunohistochemistry (IHC) analyses were used to detect the expression of aromatase, ERα, and ERβ in 198 patients. We performed analyses to determine if there was any correlation among these three proteins. A mouse model of urethane-induced lung adenocarcinoma was used in the study. Mice were divided into three treatment groups: blank control, E2 alone, and E2 + fulvestrant (ERβ antagonist). Western blot analysis and fluorescence quantitative PCR (FQ-PCR) were used to measure expression of ERβ protein and mRNA levels, respectively. ERβ, but not ERα, was overexpressed in NSCLC samples. Lung cancer progression in mice treated with E2 was significantly increased compared to either the control group or the E2 + fulvestrant group. Mice in the E2 treatment group had significantly increased expression of ERβ at both the mRNA and protein levels compared to mice treated with E2 + fulvestrant or control. Our data suggest that ERβ promotes lung cancer progression in mice and that this progression can be inhibited with fulvestrant. These findings may help elucidate the role of ERβ in lung cancer and suggest that estrogen receptor antagonists, such as fulvestrant, may be therapeutically beneficial for the treatment of the disease.

  10. 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.

  11. Estrogen Receptor-Targeted Contrast Agents for Molecular Magnetic Resonance Imaging of Breast Cancer Hormonal Status

    PubMed Central

    Pais, Adi; Degani, Hadassa

    2016-01-01

    The estrogen receptor (ER) α is overexpressed in most breast cancers, and its level serves as a major prognostic factor. It is important to develop quantitative molecular imaging methods that specifically detect ER in vivo and assess its function throughout the entire primary breast cancer and in metastatic breast cancer lesions. This study presents the biochemical and molecular features, as well as the magnetic resonance imaging (MRI) effects of two novel ER-targeted contrast agents (CAs), based on pyridine-tetra-acetate-Gd(III) chelate conjugated to 17β-estradiol (EPTA-Gd) or to tamoxifen (TPTA-Gd). The experiments were conducted in solution, in human breast cancer cells, and in severe combined immunodeficient mice implanted with transfected ER-positive and ER-negative MDA-MB-231 human breast cancer xenografts. Binding studies with ER in solution and in human breast cancer cells indicated affinities in the micromolar range of both CAs. Biochemical and molecular studies in breast cancer cell cultures showed that both CAs exhibit estrogen-like agonistic activity, enhancing cell proliferation, as well as upregulating cMyc oncogene and downregulating ER expression levels. The MRI longitudinal relaxivity was significantly augmented by EPTA-Gd in ER-positive cells as compared to ER-negative cells. Dynamic contrast-enhanced studies with EPTA-Gd in vivo indicated specific augmentation of the MRI water signal in the ER-positive versus ER-negative xenografts, confirming EPTA-Gd-specific interaction with ER. In contrast, TPTA-Gd did not show increased enhancement in ER-positive tumors and did not appear to interact in vivo with the tumors’ ER. However, TPTA-Gd was found to interact strongly with muscle tissue, enhancing muscle signal intensity in a mechanism independent of the presence of ER. The specificity of EPTA-Gd interaction with ER in vivo was further verified by acute and chronic competition with tamoxifen. The chronic tamoxifen treatment also revealed that this

  12. 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.

  13. 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.

  14. Ospemifene: a novel selective estrogen receptor modulator for treatment of dyspareunia.

    PubMed

    Eder, Scott Evan

    2014-09-01

    Ospemifene is a novel, oral selective estrogen receptor modulator that has been approved in the USA for treatment of dyspareunia. The decline in estrogen during menopause creates vulvovaginal changes that can cause symptoms that adversely impact women psychosexually. Many women are reluctant to discuss painful sex and providers must proactively inquire about sexuality issues. Ospemifene has been shown to reverse changes associated with vulvovaginal atrophy and relieve symptoms of dyspareunia. Safety studies of treatment up to 52 weeks have shown ospemifene to be safe with no impact on endometrial hyperplasia/carcinoma, venous thrombotic events or pelvic organ prolapse. Further studies are needed to evaluate its role in bone and breast health.

  15. What's New in Estrogen Receptor Action in the Female Reproductive Tract:

    PubMed Central

    Hewitt, Sylvia C.; Winuthayanon, Wipawee; Korach, Kenneth S.

    2016-01-01

    Estrogen receptor alpha (ERα) is a critical player in development and function of the female reproductive system. Perturbations in ERα response can affect wide-ranging aspects of health in humans as well as in livestock and wildlife. Because of its long-known and broad impact, ERα mechanisms of action continue to be the focus on cutting-edge research efforts. Consequently, novel insights have greatly advanced understanding of every aspect of estrogen signaling. In this review, we attempt to briefly outline the current understanding of ERα mediated mechanisms in the context of the female reproductive system. PMID:26826253

  16. Onalespib and Paclitaxel in Treating Patients With Advanced Triple Negative Breast Cancer

    ClinicalTrials.gov

    2017-02-02

    Estrogen Receptor Negative; HER2/Neu Negative; Progesterone Receptor Negative; Recurrent Breast Carcinoma; Stage III Breast Cancer; Stage IIIA Breast Cancer; Stage IIIB Breast Cancer; Stage IIIC Breast Cancer; Stage IV Breast Cancer; Triple-Negative Breast Carcinoma

  17. Quercetin and epigallocatechin gallate inhibit glucose uptake and metabolism by breast cancer cells by an estrogen receptor-independent mechanism

    SciTech Connect

    Moreira, Liliana; Araújo, Isabel; Costa, Tito; Correia-Branco, Ana; Faria, Ana; Martel, Fátima; Keating, Elisa

    2013-07-15

    In this study we characterized {sup 3}H-2-deoxy-D-glucose ({sup 3}H -DG) uptake by the estrogen receptor (ER)-positive MCF7 and the ER-negative MDA-MB-231 human breast cancer cell lines and investigated the effect of quercetin (QUE) and epigallocatechin gallate (EGCG) upon {sup 3}H-DG uptake, glucose metabolism and cell viability and proliferation. In both MCF7 and MDA-MB-231 cells {sup 3}H-DG uptake was (a) time-dependent, (b) saturable with similar capacity (V{sub max}) and affinity (K{sub m}), (c) potently inhibited by cytochalasin B, an inhibitor of the facilitative glucose transporters (GLUT), (d) sodium-independent and (e) slightly insulin-stimulated. This suggests that {sup 3}H-DG uptake by both cell types is mediated by members of the GLUT family, including the insulin-responsive GLUT4 or GLUT12, while being independent of the sodium-dependent glucose transporter (SGLT1). QUE and EGCG markedly and concentration-dependently inhibited {sup 3}H-DG uptake by MCF7 and by MDA-MB-231 cells, and both compounds blocked lactate production by MCF7 cells. Additionally, a 4 h-treatment with QUE or EGCG decreased MCF7 cell viability and proliferation, an effect that was more potent when glucose was available in the extracellular medium. Our results implicate QUE and EGCG as metabolic antagonists in breast cancer cells, independently of estrogen signalling, and suggest that these flavonoids could serve as therapeutic agents/adjuvants even for ER-negative breast tumors. -- Highlights: • Glucose uptake by MCF7 and MDA-MB-231 cells is mainly mediated by GLUT1. • QUE and EGCG inhibit cellular glucose uptake thus abolishing the Warburg effect. • This process induces cytotoxicity and proliferation arrest in MCF7 cells. • The flavonoids’ effects are independent of estrogen receptor signalling.

  18. 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.

  19. Estrogen receptor alpha prevents bladder cancer via INPP4B inhibited akt pathway in vitro and in vivo.

    PubMed

    Hsu, Iawen; Yeh, Chiuan-Ren; Slavin, Spencer; Miyamoto, Hiroshi; Netto, George J; Tsai, Yu-Chieh; Muyan, Mesut; Wu, Xue-Ru; Messing, Edward M; Guancial, Elizabeth A; Yeh, Shuyuan

    2014-09-15

    Clinical reports show males have a higher bladder cancer (BCa) incidence than females. The sexual difference of BCa occurrence suggests that estrogen and its receptors may affect BCa development. Estrogen receptor alpha (ERα) is the classic receptor to convey estrogen signaling, however, the function of ERα in BCa development remains largely unknown. To understand the in vivo role of ERα in BCa development, we generated total and urothelial specific ERα knockout mice (ERαKO) and used the pre- carcinogen BBN to induce BCa. Earlier reports showed that ERα promotes breast and ovarian cancers in females. Surprisingly and of clinical importance, our results showed that ERα inhibits BCa development and loss of the ERα gene results in an earlier onset and higher incidence of BBN-induced in vivo mouse BCa. Supportively, carcinogen induced malignant transformation ability was reduced in ERα expressing urothelial cells as compared to ERα negative cells. Mechanism studies suggest that ERα could control the expression of INPP4B to reduce AKT activity and consequently reduce BCa cell growth. In addition, IHC staining of clinical sample analyses show that INPP4B expression, in correlation with reduced ERα, is significantly reduced in human BCa specimens. Together, this is the first report using the in vivo cre-loxP gene knockout mouse model to characterize ERα roles in BCa development. Our studies provide multiple in vitro cell studies and in vivo animal model data as well as human BCa tissue analyses to prove ERα plays a protective role in BCa initiation and growth at least partly via modulating the INPP4B/Akt pathway.

  20. Specific mutations in the estrogen receptor change the properties of antiestrogens to full agonists.

    PubMed Central

    Mahfoudi, A; Roulet, E; Dauvois, S; Parker, M G; Wahli, W

    1995-01-01

    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. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:7753783

  1. Role of direct estrogen receptor signaling in wear particle-induced osteolysis

    PubMed Central

    Nich, Christophe; Rao, Allison J.; Valladares, Roberto D.; Li, Chenguang; Christman, Jane E.; Antonios, Joseph K.; Yao, Zhenyu; Zwingenberger, Stefan; Petite, Hervé; Hamadouche, Moussa; Goodman, Stuart B.

    2014-01-01

    Estrogen withdrawal following surgical ovariectomy was recently shown to mitigate particle-induced osteolysis in the murine calvarial model. Currently, we hypothesize that estrogen receptors (ERs) were involved in this paradoxical phenomenon. To test this hypothesis, we first evaluated polyethylene (PE) particle-induced osteolysis in the murine calvarial model, using wild type (WT) C57BL6J female mice, ERα deficient (ERαKO) mice, and WT mice either treated with 17β-estradiol (E2) or with the ER pan-antagonist ICI 182,780. According to micro-CT and histomorphometry, we showed that bone resorption was consistently altered in both ERαKO and ICI 182,780 treated mice as compared to WT and E2 groups. Then, we demonstrated that ER disruption consistently decreased both PE and polymethylmethacrylate (PMMA) particle-induced production of TNF-α by murine macrophages in vitro. Similar results were obtained following ER blockade using ICI 182,780 in RAW 264.7 and WT macrophages. ER disruption and pre treatment with ICI 182,780 resulted in a consistent down-regulation of particle-induced TNF-α mRNA expression relative to WT macrophages or untreated RAW cells. These results indicate that the response to wear particles involves estrogen receptors in female mice, as part of macrophage activation. Estrogen receptors may be considered as a future therapeutic target for particle-induced osteolysis. PMID:23113918

  2. Selective human Estrogen Receptor Partial Agonists (ShERPAs) for Tamoxifen-Resistant Breast Cancer

    PubMed Central

    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.

    2016-01-01

    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

  3. Expression of estrogen receptor β1 in colorectal cancer: correlation with clinicopathological variables.

    PubMed

    Rath-Wolfson, Lea; Purim, Ofer; Ram, Edward; Morgenstern, Sara; Koren, Rumelia; Brenner, Baruch

    2012-06-01

    Colorectal cancer (CRC) is a common malignancy in both genders with a high death rate, accounting for about 56,000 each year in the USA only. In this study we examined the differences in CRC between the genders. We also looked for differences in the staining of the tumors and adjacent colonic mucosa to estrogen receptor β1 and its possible prognostic value. Fifty-five specimens from patients who underwent resection of colon cancer in our institute were sectioned and stained for estrogen receptor β1. The histopathological slides were evaluated for positive staining in the tumor and the normal colonic mucosa as well. The results were statistically analyzed. Positive estrogen receptor β1 stain was found in the nuclei of the tumor cells. We noted positive stain also in the cytoplasm of the tumor cells. Similar findings were observed in the normal colonic mucosa. Statistically significant differences were found regarding the positivity of the staining between the deceased and surviving patients, men/women and those who had metastases vs. the non-metastatic ones. Our data suggest that there is an estrogen influence on the development and progression of colon cancer. Furthermore, it was found to be higher in the more severe cases.

  4. Estrogen-mediated regulation of Igf1 transcription and uterine growth involves direct binding of estrogen receptor alpha to estrogen-responsive elements.

    PubMed

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

    2010-01-22

    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 ER alpha (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 ER alpha 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 (E(2)), but not in KIKO or alpha ERKO uteri, indicating ER alpha- and ERE-dependent regulation. ER alpha binds to a potential Stat5a ERE. We hypothesize that E(2) increases Stat5a transcript through ERE binding; that ER alpha, 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 E(2), 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 ER alpha-DNA interaction is required to increase Igf1 transcription. Additionally, full ER alpha function is needed to mediate other cellular signals of the growth factor for uterine growth.

  5. Variations in the levels of estrogen receptors in prolactin producing pituitary tumor cells.

    PubMed

    Noteboom, W D; Durham, J B; Mitra, R

    1982-05-01

    The binding of [3H]-17 beta-estradiol in cells and cytoplasmic fractions of three different prolactin producing pituitary tumor lines was compared and found to vary widely. The concentration of estrogen receptors of the MtTW10 rat tumor line was high in early passages, but receptor levels decreased with subsequent passages in animals. Over a period of 12 months, the estrogen binding capacity in low speed supernatant fractions of cell homogenates decreased from 61.5 fmol [3H]-17 beta-estradiol per mg protein to less than 10 fmol [3H]-17 beta-estradiol per mg protein. A similar decrease in receptor concentration was found in MtTW10 cells which were adapted to in vitro culture. The concentration of receptor in low speed supernatant fractions of cultured GH3 rat tumor cells remained between 60 and 80 fmol [3H]-17 beta-estradiol per mg protein throughout the entire period of experimentation. In contrast, no high affinity receptors could be detected in similar fractions of the human pituitary cell line, 18-54, when cultured either in the presence or absence of serum. The Kd for the estradiol:receptor complex was determined to be 1.0 x 10(-10) M for receptors from MtTW10 cells and remained constant as the concentration of receptors declined. The receptors in both MtTW10 and GH3 cells were found to exist as 8s molecular species which are converted to 4s species by a temperature dependent process. The binding of estrogen to 8s and 4s receptors at 4 degrees C was shown to occur in the presence of 3 mg/ml of digitonin.

  6. Can estrogen receptor overexpression in normal tissues due to previous estrogen deprivation explain the fulvestrant efficacy in breast cancer therapy?

    PubMed

    Kurbel, Sven

    2012-12-01

    Fulvestrant is a down-regulator of estrogen receptors (ERs) with still evolving optimal dosage for ER-positive breast cancer patients. The CONFIRM phase III trial in women with advanced breast cancer proved fulvestrant 500-mg to be associated with a longer time till progression (TTP) than the 250-mg schedule. Detailed results suggest that the fulvestrant in both schedules depended on the previous endocrine therapy. All complete responses and the only significant TTP difference between the two schedules was found among women previously treated with tamoxifen (TAM) and not in women after aromatase inhibitors (AIs). Noting that TAM competes with estrogen binding to ERs is important, so the optimal TAM dosage produces drug concentrations comparable to concentrations of available ER ligands. All AIs diminish production of the main ER ligand, so the optimal AI dosage depends on the overall pool of aromatase molecules in the body. Both treatments are not directly related to the pool of available ERs in the body. Here proposed interpretation is that estrogen deprivation due to years of endocrine breast cancer therapy increases ER expression in breast cancer cells and in other healthy estrogen target tissues. The breast cancer exposure to fulvestrant depends on the presence of all ERs in the body. Only when this overall pool is sufficiently saturated with fulvestrant, we can expect to achieve some breast cancer response due to down-regulation of ER in cancer tissue. The CONFIRM data suggest that among patients switching from TAM to fulvestrant, only the 500-mg schedule could down-regulate the moderately enlarged total body ER pool and thus induce breast cancer regression. In patients switching from previous AI treatments, both 250 and 500-mg schedules were unable to prolong the TTP, suggesting that in both doses, fulvestrant showed no efficacy since the overall ER pool was more enlarged after AIs. Fulvestrant might be more effective before TAM and AIs, in the first line

  7. Sumoylation of TCF21 downregulates the transcriptional activity of estrogen receptor-alpha

    PubMed Central

    Ao, Xiang; Li, Shujing; Xu, Zhaowei; Yang, Yangyang; Chen, Min; Jiang, Xiao; Wu, Huijian

    2016-01-01

    Aberrant estrogen receptor-α (ERα) signaling is recognized as a major contributor to the development of breast cancer. However, the molecular mechanism underlying the regulation of ERα in breast cancer is still inconclusive. In this study, we showed that the transcription factor 21 (TCF21) interacted with ERα, and repressed its transcriptional activity in a HDACs-dependent manner. We also showed that TCF21 could be sumoylated by the small ubiquitin-like modifier SUMO1, and this modification could be reversed by SENP1. Sumoylation of TCF21 occurred at lysine residue 24 (K24). Substitution of K24 with arginine resulted in complete abolishment of sumoylation. Sumoylation stabilized TCF21, but did not affect its subcellular localization. Sumoylation of TCF21 also enhanced its interaction with HDAC1/2 without affecting its interaction with ERα. Moreover, sumoylation of TCF21 promoted its repression of ERα transcriptional activity, and increased the recruitment of HDAC1/2 to the pS2 promoter. Consistent with these observations, sumoylation of TCF21 could inhibit the growth of ERα-positive breast cancer cells and decreased the proportion of S-phase cells in the cell cycle. These findings suggested that TCF21 might act as a negative regulator of ERα, and its sumoylation inhibited the transcriptional activity of ERα through promoting the recruitment of HDAC1/2. PMID:27028856

  8. Assessment of two automated imaging systems in evaluating estrogen receptor status in breast carcinoma.

    PubMed

    Gokhale, Sumita; Rosen, Daniel; Sneige, Nour; Diaz, Leslie K; Resetkova, Erika; Sahin, Aysegul; Liu, Jinsong; Albarracin, Constance T

    2007-12-01

    Immunohistochemical staining for estrogen receptor (ER) status is widely used in the management of breast cancer. These stains have traditionally been scored manually, which results in generally good agreement among observers when the cases are strongly positive. However, significant interobserver and intraobserver differences in scoring can occur in borderline or weakly staining cases. Recently, automated systems have been proposed to provide a more sensitive and objective method of ER quantification. The ChromaVision Automated Cellular Imaging System and the Applied Imaging Ariol SL-50 quantify the color intensity of the immunoreactive product. To assess the accuracy of these 2 automated systems and to compare them to one another and to manual scoring, we performed immunostaining for ER on 64 cases of breast cancer. The percentages of positive cells were scored manually by 4 pathologists and by the 2 imaging systems. A discrepancy in scoring was defined as that which resulted in the reclassification of a case from negative to positive or vice versa. Our results showed significant agreement between the 2 automated systems. When automated scores were compared with the manual scores, only 5 of the 64 cases (7%) were discrepant. In 4 of these, the percentage of cells staining for ER was low (0% to 20%). Overall, the 2 systems were comparable, and discrepant results were most frequently seen when analyzing tumors with low levels of ER positive cells.

  9. Fulvestrant reverses doxorubicin resistance in multidrug-resistant breast cell lines independent of estrogen receptor expression.

    PubMed

    Huang, Yuan; Jiang, Donghai; Sui, Meihua; Wang, Xiaojia; Fan, Weimin

    2017-02-01

    Drug resistance, a major obstacle to successful cancer chemotherapy, frequently occurs in recurrent or metastatic breast cancer and results in poor clinical response. Fulvestrant is a new type of selective estrogen receptor (ER) downregulator and a promising endocrine therapy for breast cancer. In this study, we evaluated the combination treatment of fulvestrant and doxorubicin in ER-negative multidrug-resistant (MDR) breast cancer cell lines Bads‑200 and Bats‑72. Fulvestrant potentiated doxorubicin-induced cytotoxicity, apoptosis and G2/M arrest with upregulation of cyclin B1. It functioned as a substrate for P-glycoprotein (P-gp) without affecting its expression. Furthermore, fulvestrant not only restored the intracellular accumulation of doxorubicin but also relocalized it to the nuclei in Bats‑72 and Bads‑200 cells, which may be another potential mechanism of reversal of P-gp mediated doxorubicin resistance. These results indicated that the combination of fulvestrant and doxorubicin-based chemotherapy may be feasible and effective for patients with advanced breast cancer.

  10. Paralemmin-1 is over-expressed in estrogen-receptor positive breast cancers

    PubMed Central

    2012-01-01

    Background Paralemmin-1 is a phosphoprotein lipid-anchored to the cytoplasmic face of membranes where it functions in membrane dynamics, maintenance of cell shape, and process formation. Expression of paralemmin-1 and its major splice variant (Δ exon 8) as well as the extent of posttranslational modifications are tissue- and development-specific. Paralemmin-1 expression in normal breast and breast cancer tissue has not been described previously. Results Paralemmin-1 mRNA and protein expression was evaluated in ten breast cell lines, 26 primary tumors, and 10 reduction mammoplasty (RM) tissues using real time RT-PCR. Paralemmin-1 splice variants were assessed in tumor and RM tissues using a series of primers and RT-PCR. Paralemmin-1 protein expression was examined in cell lines using Western Blots and in 31 ductal carcinomas in situ, 65 infiltrating ductal carcinomas, and 40 RM tissues using immunohistochemistry. Paralemmin-1 mRNA levels were higher in breast cancers than in RM tissue and estrogen receptor (ER)-positive tumors had higher transcript levels than ER-negative tumors. The Δ exon 8 splice variant was detected more frequently in tumor than in RM tissues. Protein expression was consistent with mRNA results showing higher paralemmin-1 expression in ER-positive tumors. Conclusions The differential expression of paralemmin-1 in a subset of breast cancers suggests the existence of variation in membrane dynamics that may be exploited to improve diagnosis or provide a therapeutic target. PMID:22574838

  11. Body Mass Index and Breast Cancer Risk According to Postmenopausal Estrogen-Progestin Use and Hormone Receptor Status

    PubMed Central

    Munsell, Mark F.; Sprague, Brian L.; Berry, Donald A.; Chisholm, Gary; Trentham-Dietz, Amy

    2014-01-01

    To assess the joint relationships among body mass index, menopausal status, and breast cancer according to breast cancer subtype and estrogen-progestin medication use, we conducted a meta-analysis of 89 epidemiologic reports published in English during 1980–2012 identified through a systematic search of bibliographic databases. Pooled analysis yielded a summary risk ratio of 0.78 (95% confidence interval (CI): 0.67, 0.92) for hormone receptor–positive premenopausal breast cancer associated with obesity (body mass index (weight (kg)/height (m)2) ≥30 compared with <25). Obesity was associated with a summary risk ratio of 1.39 (95% CI: 1.14, 1.70) for receptor-positive postmenopausal breast cancer. For receptor-negative breast cancer, the summary risk ratios of 1.06 (95% CI: 0.70, 1.60) and 0.98 (95% CI: 0.78, 1.22) associated with obesity were null for both premenopausal and postmenopausal women, respectively. Elevated postmenopausal breast cancer risk ratios associated with obesity were limited to women who never took estrogen-progestin therapy, with risk ratios of 1.42 (95% CI: 1.30, 1.55) among never users and 1.18 (95% CI: 0.98, 1.42) among users; too few studies were available to examine this relationship according to receptor subtype. Future research is needed to confirm whether obesity is unrelated to receptor-negative breast cancer in populations of postmenopausal women with low prevalence of hormone medication use. PMID:24375928

  12. Nucleosome dynamics: HMGB1 relaxes canonical nucleosome structure to facilitate estrogen receptor binding.

    PubMed

    Joshi, Sachindra R; Sarpong, Yaw C; Peterson, Ronald C; Scovell, William M

    2012-11-01

    High mobility group protein 1 (HMGB1) interacts with DNA and chromatin to influence the regulation of transcription, DNA repair and recombination. We show that HMGB1 alters the structure and stability of the canonical nucleosome (N) in a nonenzymatic, ATP-independent manner. Although estrogen receptor (ER) does not bind to its consensus estrogen response element within a nucleosome, HMGB1 restructures the nucleosome to facilitate strong ER binding. The isolated HMGB1-restructured nucleosomes (N' and N″) remain stable and exhibit characteristics distinctly different from the canonical nucleosome. These findings complement previous studies that showed (i) HMGB1 stimulates in vivo transcriptional activation at estrogen response elements and (ii) knock down of HMGB1 expression by siRNA precipitously reduced transcriptional activation. The findings indicate that one aspect of the mechanism of HMGB1 action involves a restructuring of the nucleosome that appears to relax structural constraints within the nucleosome.

  13. Coordinate patterns of estrogen receptor, progesterone receptor, and Wilms tumor 1 expression in the histopathologic distinction of ovarian from endometrial serous adenocarcinomas.

    PubMed

    Fadare, Oluwole; James, Samuel; Desouki, Mohamed M; Khabele, Dineo

    2013-10-01

    The purpose of this study is to assess whether composite or coordinate immunoexpression patterns of estrogen receptor (ER), progesterone receptor (PR), and Wilms tumor 1 (WT1) gene can significantly distinguish between endometrial serous carcinoma (ESC) and ovarian serous carcinoma (OSC). Immunohistochemical analyses were performed on whole tissue sections from 22 uterus-confined ESCs and on a tissue microarray of 140 high-grade, pan-stage OSCs, using antibodies to ER, PR, and WT-1. Estrogen receptor, PR, and WT1 expressions were present in 37%, 49%, and 81% of OSC, respectively, but these markers were also present in 18%, 27%, and 36% of ESC. The ER+/PR+/WT1+ coordinate profile was identified in 33.6% of OSC but in none of ESC (P = .0006), resulting in a calculated sensitivity and specificity of this profile for OSC of 33.6% and 100%, respectively. By contrast, the ER-/PR-/WT1- coordinate profile was identified in 41% of ESC but in only 6.4% of OSC (P = .0001), resulting in a calculated sensitivity and specificity of this profile for ESC of 50% and 94%. In summary, in the differential diagnosis between OSC and ESC, positivity for all 3 markers favors an extrauterine origin, whereas negativity for all 3 markers is supportive of an endometrial origin. The use of single markers for this purpose is not recommended, as each lacks optimal discriminatory power. Coordinate profiles, in general, have a high specificity but low sensitivity in this differential diagnosis.

  14. 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.

  15. Estrogen receptor-targeted optical imaging of breast cancer cells with near-infrared fluorescent dye

    NASA Astrophysics Data System (ADS)

    Jose, Iven; Deodhar, Kodand; Chiplunkar, Shuba V.; Patkar, Meena

    2010-02-01

    compared to ICG, which was established by the partition coefficient studies. The replacement of the sodium ion in the ester by a larger glucosammonium ion was found to enhance the hydrophilicity and reduce the toxic effect on the cell lines. The excitation and emission peaks for the conjugate were recorded in the NIR region as 750nm and 788nm respectively. The ester was found nontoxic on adenocarcinoma breast cancer cell lines MCF-7/MDA-MB-231. Specific binding and endocytosis of the estrogen-labeled conjugate was studied on the MCF-7 (ER positive) and MDA-MB-231 (ER negative). Conjugate staining of MCF-7 cells showed ~ 4-fold increase in signal intensity compared to MDA-MB- 231. Further, estrogen molecules were found to be specifically localized to the nuclear region of MCF-7 cells, whereas MDA-MB-231 showed plasma membrane staining. This technique offers the potential of noninvasive detection of hormone receptor status in breast cancer cells and would help in decreasing the load of unnecessary biopsies. Here, we have reported the progress made in the development of a novel NIR external contrast agent and the work is in progress to use this conjugate for the molecular based, diagnostic imaging of breast cancer.

  16. The Relationship Among HOXA10, Estrogen Receptor α, Progesterone Receptor, and Progesterone Receptor B Proteins in Rectosigmoid Endometriosis

    PubMed Central

    Pereira, Ricardo Mendes Alves; da Rocha, André Monteiro; Cogliati, Bruno; Baracat, Edmund Chada; Taylor, Hugh S.; da Motta, Eduardo Leme Alves; Serafini, Paulo Cesar

    2015-01-01

    Background: Very few studies have evaluated the expression of homeobox A10 (HOXA10) and steroid (estrogen and progesterone) receptors exclusively in deep endometriosis. Conclusions drawn from studies evaluating peritoneal and ovarian endometriosis are usually generalized to explain the pathogenesis of the disease as a whole. We aimed to evaluate the expression of HOXA10, estrogen receptor α (ER-α), progesterone receptor (PR), and PR-B in rectosigmoid endometriosis (RE), a typical model of deep disease. Methods: We used RE samples from 18 consecutive patients to construct tissue microarray blocks. Nine patients each were operated during the proliferative and secretory phases of the menstrual cycle. We quantified the expressions of proteins by immunohistochemistry using the modified Allred score. Result: The HOXA10 was expressed in the stroma of nodules during the secretory phase in 5 of the 18 patients. Expression of ER-α (in 16 of 18 patients), PR (in 17 of 18 patients), and PR-B (17 of 18 patients) was moderate to strong in the glands and stroma of nodules during both phases. Expression of both PR (P = .023) and PR-B (P = .024) was significantly greater during the secretory phase. Conclusion: The HOXA10 is expressed in RE, where it likely imparts the de novo identity of endometriotic lesions. The ER-α, PR, and PR-B are strongly expressed in RE, which differs from previous studies investigating peritoneal and ovarian lesions. This suggests different routes of pathogenesis for each of the 3 types of endometriosis. PMID:25217304

  17. Role of androgen and estrogen receptors for the action of dehydroepiandrosterone (DHEA).

    PubMed

    Engdahl, Cecilia; Lagerquist, Marie K; Stubelius, Alexandra; Andersson, Annica; Studer, Erik; Ohlsson, Claes; Westberg, Lars; Carlsten, Hans; Forsblad-d'Elia, Helena

    2014-03-01

    Dehydroepiandrosterone (DHEA) is an abundant steroid hormone, and its mechanism of action is yet to be determined. The aim of this study was to elucidate the importance of androgen receptors (ARs) and estrogen receptors (ERs) for DHEA function. Orchidectomized C57BL/6 mice were treated with DHEA, DHT, 17β-estradiol-3-benzoate (E2), or vehicle. Orchidectomized AR-deficient (ARKO) mice and wild-type (WT) littermates were treated with DHEA or vehicle for 2.5 weeks. At termination, bone mineral density (BMD) was evaluated, thymus and seminal vesicles were weighted, and submandibular glands (SMGs) were histologically examined. To evaluate the in vivo ER activation of the classical estrogen signaling pathway, estrogen response element reporter mice were treated with DHEA, DHT, E2, or vehicle, and a reporter gene was investigated in different sex steroid-sensitive organs after 24 hours. DHEA treatment increased trabecular BMD and thymic atrophy in both WT and ARKO mice. In WT mice, DHEA induced enlargement of glands in the SMGs, whereas this effect was absent in ARKO mice. Furthermore, DHEA was able to induce activation of classical estrogen signaling in bone, thymus, and seminal vesicles but not in the SMGs. In summary, the DHEA effects on trabecular BMD and thymus do not require signaling via AR and DHEA can activate the classical estrogen signaling in these organs. In contrast, DHEA induction of gland size in the SMGs is dependent on AR and does not involve classical estrogen signaling. Thus, both ERs and ARs are involved in mediating the effects of DHEA in an organ-dependent manner.

  18. Aberrant methylation of imprinted genes is associated with negative hormone receptor status in invasive breast cancer

    PubMed Central

    Barrow, Timothy M; Barault, Ludovic; Ellsworth, Rachel E; Harris, Holly R; Binder, Alexandra M; Valente, Allyson L; Shriver, Craig D; Michels, Karin B

    2015-01-01

    Epigenetic regulation of imprinted genes enables monoallelic expression according to parental origin, and its disruption is implicated in many cancers and developmental disorders. The expression of hormone receptors is significant in breast cancer as they are indicators of cancer cell growth rate and determine response to endocrine therapies. We investigated the frequency of aberrant events and variation in DNA methylation at nine imprinted sites in invasive breast cancer and examined the association with estrogen and progesterone receptor status. Breast tissue and blood from patients with invasive breast cancer (n=38) and benign breast disease (n=30) were compared to those from healthy individuals (n=36), matched to the cancer patients by age at diagnosis, ethnicity, BMI, menopausal status, and familial history of cancer. DNA methylation and allele-specific expression were analyzed by pyrosequencing. Tumor-specific methylation changes at IGF2 DMR2 were observed in 59% of cancer patients, IGF2 DMR0 in 38%, DIRAS3 DMR in 36%, GRB10 ICR in 23%, PEG3 DMR in 21%, MEST ICR in 19%, H19 ICR in 18%, KvDMR in 8%, and SNRPN/SNURF ICR in 4%. Variation of methylation was significantly greater in breast tissue from cancer patients than healthy individuals and benign breast disease. Aberrant methylation of three or more sites was significantly associated with negative estrogen-alpha (Fisher’s Exact Test, p=0.02) and progesterone-A (p=0.02) receptor status. Aberrant events and increased variation of imprinted gene DNA methylation therefore appear to be frequent in invasive breast cancer and are associated with negative estrogen and progesterone receptor status, without loss of monoallelic expression. PMID:25560175

  19. Serum Sclerostin Levels Negatively Correlate with Parathyroid Hormone Levels and Free Estrogen Index in Postmenopausal Women

    PubMed Central

    Mirza, Faryal S.; Padhi, I. Desmond; Raisz, Lawrence G.; Lorenzo, Joseph A.

    2010-01-01

    Context: Sclerostin is a negative regulator of bone formation. Objective: The aim of the study was to compare serum sclerostin levels in premenopausal and postmenopausal women and evaluate its relationship to estrogen, TH, bone turnover, and bone mass. Design, Setting, and Participants: We conducted a cross-sectional observational study of healthy community-dwelling pre- and postmenopausal women. Intervention(s): There were no interventions. Main Outcome Measure(s): We compared serum sclerostin levels in pre- and postmenopausal women and correlated sclerostin levels with female sex hormones, calciotropic hormones, bone turnover markers, and bone mineral density. Results: Premenopausal women were 26.8 yr old, and postmenopausal women were 56.8 yr old. Postmenopausal women had lower values for estradiol (30 ± 23 vs. 10 ± 4 pg/ml; P < 0.001), estrone (61 ± 24 vs. 29 ± 10 pg/ml; P <0.001), and free estrogen index (FEI) (6 ± 4 vs. 3 ± 2 pmol/nmol; P = 0.008) and significantly lower bone mineral density at all sites compared to premenopausal women, with no significant differences in levels of PTH, 25-hydroxy or 1,25-dihydroxy vitamin D levels. Postmenopausal women had significantly higher serum sclerostin levels (1.16 ± 0.38 ng/ml vs. 0.48 ± 0.15 ng/ml; P < 0.001). Because most of the premenopausal women were on oral contraceptives, subsequent analyses were limited to postmenopausal women. There were significant negative correlations between sclerostin and FEI and sclerostin and PTH in this group. Using multiple regression analysis, both FEI (β = −0.629; P = 0.002) and PTH (β = −0.554; P = 0.004) were found to be independent predictors of sclerostin levels in postmenopausal women. Conclusions: Our findings suggest that serum sclerostin levels are regulated by both estrogens and PTH in postmenopausal women. These findings need to be explored further in larger prospective studies. PMID:20156921

  20. Requirement for Estrogen Receptor Alpha in a Mouse Model for Human Papillomavirus-Associated Cervical Cancer

    PubMed Central

    Chung, Sang-Hyuk; Wiedmeyer, Kerri; Shai, Anny; Korach, Kenneth S.; Lambert, Paul F.

    2008-01-01

    The majority of human cervical cancers are associated with the high-risk human papillomaviruses (HPVs), which encode the potent E6 and E7 oncogenes. Upon prolonged treatment with physiological levels of exogenous estrogen, K14E7 transgenic mice expressing HPV-16 E7 oncoprotein in their squamous epithelia succumb to uterine cervical cancer. Furthermore, prolonged withdrawal of exogenous estrogen results in complete or partial regression of tumors in this mouse model. In the current study we investigated whether estrogen receptor alpha (ERα) is required for the development of cervical cancer in K14E7 transgenic mice. We demonstrate that exogenous estrogen fails to promote either dysplasia or cervical cancer in K14E7/ERα−/− mice despite the continued presence of the presumed cervical cancer precursor cell type, reserve cells, and evidence for E7 expression therein. We also observed that cervical cancers in our mouse models are strictly associated with atypical squamous metaplasia (ASM), which is believed to be the precursor for cervical cancer in women. Consistently, E7 and exogenous estrogen failed to promote ASM in the absence of ERα. We conclude that ERα plays a crucial role at an early stage of cervical carcinogenesis in this mouse model. PMID:19047174

  1. HOXC6 Is transcriptionally regulated via coordination of MLL histone methylase and estrogen receptor in an estrogen environment.

    PubMed

    Ansari, Khairul I; Hussain, Imran; Shrestha, Bishakha; Kasiri, Sahba; Mandal, Subhrangsu S

    2011-08-12

    Homeobox (HOX)-containing gene HOXC6 is a critical player in mammary gland development and milk production, and is overexpressed in breast and prostate cancers. We demonstrated that HOXC6 is transcriptionally regulated by estrogen (E2). HOXC6 promoter contains two putative estrogen response elements (EREs), termed as ERE1(1/2) and ERE2(1/2). Promoter analysis using luciferase-based reporter assay demonstrated that both EREs are responsive to E2, with ERE1(1/2) being more responsive than ERE2(1/2). Estrogen receptors (ERs) ERα and ERβ bind to these EREs in an E2-dependent manner, and antisense-mediated knockdown of ERs suppressed the E2-dependent activation of HOXC6 expression. Similarly, knockdown of histone methylases MLL2 and MLL3 decreased the E2-mediated activation of HOXC6. However, depletion of MLL1 or MLL4 showed no significant effect. MLL2 and MLL3 were bound to the HOXC6 EREs in an E2-dependent manner. In contrast, MLL1 and MLL4 that were bound to the HOXC6 promoter in the absence of E2 decreased upon exposure to E2. MLL2 and MLL3 play key roles in histone H3 lysine-4 trimethylation and in the recruitment of general transcription factors and RNA polymerase II in the HOXC6 promoter during E2-dependent transactivation. Nuclear receptor corepressors N-CoR and SAFB1 were bound in the HOXC6 promoter in the absence of E2, and that binding was decreased upon E2 treatment, indicating their critical roles in suppressing HOXC6 gene expression under nonactivated conditions. Knockdown of either ERα or ERβ abolished E2-dependent recruitment of MLL2 and MLL3 into the HOXC6 promoter, demonstrating key roles of ERs in the recruitment of these mixed lineage leukemias into the HOXC6 promoter. Overall, our studies demonstrated that HOXC6 is an E2-responsive gene, and that histone methylases MLL2 and MLL3, in coordination with ERα and ERβ, transcriptionally regulate HOXC6 in an E2-dependent manner.

  2. Estrogenic effects of natural and synthetic compounds including tibolone assessed in Saccharomyces cerevisiae expressing the human estrogen alpha and beta receptors.

    PubMed

    Hasenbrink, Guido; Sievernich, André; Wildt, Ludwig; Ludwig, Jost; Lichtenberg-Fraté, Hella

    2006-07-01

    The human estrogen receptors (hER)alpha and hERbeta, differentially expressed and localized in various tissues and cell types, mediate transcriptional activation of target genes. These encode a variety of physiological reproductive and nonreproductive functions involved in energy metabolism, salt balance, immune system, development, and differentiation. As a step toward developing a screening assay for the use in applications where significant numbers of compounds or complex matrices need to be tested for (anti) estrogenic bioactivity, hERalpha and hERbeta were expressed in a genetically modified Saccharomyces cerevisiae strain, devoid of three endogenous xenobiotic transporters (PDR5, SNQ2, and YOR1). By using receptor-mediated transcriptional activation of the green fluorescent protein optimized for expression in yeast (yEGFP) as reporter 17 natural, comprising estrogens and phytoestrogens or synthetic compounds among which tibolone with its metabolites, gestagens, and antiestrogens were investigated. The reporter assay deployed a simple and robust protocol for the rapid detection of estrogenic effects within a 96-well microplate format. Results were expressed as effective concentrations (EC50) and correlated to other yeast based and cell line assays. Tibolone and its metabolites exerted clear estrogenic effects, though considerably less potent than all other natural and synthetic compounds. For the blood serum of two volunteers, considerable higher total estrogenic bioactivity than single estradiol concentrations as determined by immunoassay was found. Visualization of a hERalpha/GFP fusion protein in yeast revealed a sub cellular cytosolic localization. This study demonstrates the versatility of (anti) estrogenic bioactivity determination using sensitized S. cerevisiae cells to assess estrogenic exposure and effects.

  3. Combinations of physiologic estrogens with xenoestrogens alter calcium and kinase responses, prolactin release, and membrane estrogen receptor trafficking in rat pituitary cells

    PubMed Central

    2010-01-01

    Background Xenoestrogens such as alkylphenols and the structurally related plastic byproduct bisphenol A have recently been shown to act potently via nongenomic signaling pathways and the membrane version of estrogen receptor-α. Though the responses to these compounds are typically measured individually, they usually contaminate organisms that already have endogenous estrogens present. Therefore, we used quantitative medium-throughput screening assays to measure the effects of physiologic estrogens in combination with these xenoestrogens. Methods We studied the effects of low concentrations of endogenous estrogens (estradiol, estriol, and estrone) at 10 pM (representing pre-development levels), and 1 nM (representing higher cycle-dependent and pregnancy levels) in combinations with the same levels of xenoestrogens in GH3/B6/F10 pituitary cells. These levels of xenoestrogens represent extremely low contamination levels. We monitored calcium entry into cells using Fura-2 fluorescence imaging of single cells. Prolactin release was measured by radio-immunoassay. Extracellular-regulated kinase (1 and 2) phospho-activations and the levels of three estrogen receptors in the cell membrane (ERα, ERβ, and GPER) were measured using a quantitative plate immunoassay of fixed cells either permeabilized or nonpermeabilized (respectively). Results All xenoestrogens caused responses at these concentrations, and had disruptive effects on the actions of physiologic estrogens. Xenoestrogens reduced the % of cells that responded to estradiol via calcium channel opening. They also inhibited the activation (phosphorylation) of extracellular-regulated kinases at some concentrations. They either inhibited or enhanced rapid prolactin release, depending upon concentration. These latter two dose-responses were nonmonotonic, a characteristic of nongenomic estrogenic responses. Conclusions Responses mediated by endogenous estrogens representing different life stages are vulnerable to very

  4. The Natural Estrogenic Compound Diarylheptanoid (D3): In Vitro Mechanisms of Action and in Vivo Uterine Responses via Estrogen Receptor α

    PubMed Central

    Winuthayanon, Wipawee; Piyachaturawat, Pawinee; Suksamrarn, Apichart; Burns, Katherine A.; Arao, Yukitomo; Hewitt, Sylvia C.; Pedersen, Lars C.

    2013-01-01

    Background: Diarylheptanoid (D3) isolated from the medicinal plant, Curcuma comosa, has estrogenic activity. Objective: We aimed to elucidate the mechanism(s) of D3 action and compare it with that of 17β-estradiol (E2) using both in vitro and in vivo uterine models. Methods: We used human uterine (Ishikawa) cells to determine the estrogenic action of D3 on the activation and nuclear translocation of estrogen receptor α (ERα). In addition, we further characterized the uterine response to D3 treatment in vivo. Results: D3 activated an estrogen responsive element (ERE) luciferase reporter through ERα, and molecular modeling suggested that D3 could be accommodated in the ERα binding pocket. Using modified ERα to assay ligand-dependent nuclear translocation, we observed D3-dependent ERα interaction and translocation. In mouse uteri, early- and late-phase estrogen-regulated gene responses were increased in D3-treated ovariectomized wild-type animals, in a manner similar to that of E2; no response was seen in ERα knockout animals. We observed a divergence in estrogen responses after D3 treatment: D3 induced robust DNA synthesis in uterine epithelial cells, linked to an increase in cell-cycle–related genes; however, no increase in uterine weight was observed 24 hr after treatment. D3 also affected uterine progesterone receptor expression patterns similar to E2. When D3 and E2 were administered together, we observed no additive or antagonistic effects of D3 on E2. Our findings suggest that D3 is a weak estrogenic agonist compound. Conclusion: D3 is a weakly acting phytoestrogen that mimics the mitogenic responses produced by E2 in an ERα-dependent manner, but it is unable to increase uterine weight or enhance or antagonize the effects of estrogen. PMID:23552522

  5. Estrogen negatively regulates epithelial wound healing and protective lipid mediator circuits in the cornea.

    PubMed

    Wang, Samantha B; Hu, Kyle M; Seamon, Kyle J; Mani, Vinidhra; Chen, Yangdi; Gronert, Karsten

    2012-04-01

    Estrogen receptors (ERs) are expressed in leukocytes and in every ocular tissue. However, sex-specific differences and the role of estradiol in ocular inflammatory-reparative responses are not well understood. We found that female mice exhibited delayed corneal epithelial wound closure and attenuated polymorphonuclear (PMN) leukocyte responses, a phenotype recapitulated by estradiol treatment both in vivo (topically in male mice) and in vitro (corneal epithelial cell wound healing). The cornea expresses 15-lipoxygenase (15-LOX) and receptors for lipoxin A(4) (LXA(4)), which have been implicated in an intrinsic lipid circuit that regulates corneal inflammation and wound healing. Delayed epithelial wound healing correlated with lower expression of 15-LOX in the regenerated epithelium of female mice. Estradiol in vitro and in vivo down-regulated epithelial 15-LOX expression and LXA(4) formation, while estradiol abrogation of epithelial wound healing was completely reversed by treatment with LXA(4). More important, ERβ and ERα selectively regulated epithelial wound healing, PMN cell recruitment, and activity of the intrinsic 15-LOX/LXA(4) circuit. Our results demonstrate for the first time a sex-specific difference in the corneal reparative response, which is mediated by ERβ and ERα selective regulation of the epithelial and PMN 15-LOX/LXA(4) circuit. These findings may provide novel insights into the etiology of sex-specific ocular inflammatory diseases.

  6. Effect of estrogen agonists and antagonists on induction of progesterone receptor in a rat hypothalamic cell line.

    PubMed

    Fitzpatrick, S L; Berrodin, T J; Jenkins, S F; Sindoni, D M; Deecher, D C; Frail, D E

    1999-09-01

    Estrogen is essential in the hypothalamus for the central regulation of reproduction. To understand the molecular mechanism(s) of estrogen action in the hypothalamus, immortalized rat embryonic hypothalamic cell lines were characterized for steroid receptors and subcloned. Scatchard analysis of the D12 subclone demonstrated one high affinity estrogen receptor-binding site (Kd = 31.3+/-1.9 pM) with a Bmax of 30.8+/-0.8 fmol/mg. Estrogen receptor-alpha protein was identified by Western blot and gel shift analyses. Treatment with estradiol (48 h) stimulated progesterone receptor (PR) messenger RNA expression and binding to [3H]R5020, a synthetic progestin. Because the agonist or antagonist activity of estrogen mimetics can be cell type dependent, the activities of various estrogen mimetics were determined in D12 cells. ICI 182,780 (IC50 = 0.63 nM), raloxifene (IC50 = 1 nM), enclomiphene (IC50 = 77 nM), and tamoxifen (IC50 = 174 nM) inhibited the induction of PR by estradiol, and none of these compounds significantly stimulated PR when given alone. In contrast, 17alpha-ethynyl estradiol (EC50 = 0.014 nM), zuclomiphene (EC50 = 100 nM), and genistein (EC50 = 17.5 nM) functioned as estrogen agonists in these cells. In addition, the estrogen-induced progesterone receptor activated a progesterone response element reporter construct in response to progestins. Thus, the D12 rat hypothalamic cell line provides a useful model for characterizing tissue-selective estrogenic compounds, identifying estrogen- and progesterone-regulated hypothalamic genes, and understanding the molecular mechanisms of steroid action in various physiological processes mediated by the hypothalamus.

  7. Inverse relationship between estrogen receptor and epidermal growth factor receptor mRNA levels in human breast cancer cell lines.

    PubMed

    Lee, C S; Hall, R E; Alexander, I E; Koga, M; Shine, J; Sutherland, R L

    1990-01-01

    Epidermal growth factor receptors (EGF-R) are present in a number of human breast cancer cell lines and tumor biopsies. Furthermore, it has been suggested that EGF-R levels are higher in estrogen receptor negative (ER-) than in ER+ human breast tumors and that EGF-R status may be a prognostic indicator in breast cancer. The present study was undertaken to establish whether there is a quantitative relationship between EGF-R and ER mRNA concentrations in a series of 10 well-characterized human breast cancer cell lines. All cell lines expressed detectable quantities of EGF-R mRNA by Northern analysis but the relative abundance of EGF-R mRNA varied more than 50-fold. Two transcripts corresponding to the 10.5- and 5.8-kb mRNAs described in other cell types were present but in different relative proportions in different cell lines. When these lines were divided into an ER+ and an ER- group based on their ability to bind estradiol, ER- cell lines were shown to express significantly higher concentrations of EGF-R mRNA than did ER+ cell lines (p less than 0.005). Furthermore, linear-regression analysis revealed a significant inverse relationship between ER and EGF-R mRNA concentrations both within the group of 10 human breast cancer cell lines as a whole (r = 0.66) and within the 6 functionally ER + lines (r = 0.77). This demonstration of a significant (p less than 0.005) inverse relationship between the concentrations of ER and EGF-R mRNAs in ER + cell lines raises the possibility of reciprocal regulation of the expression of these genes in human breast cancer.

  8. Comparative study on transcriptional activity of 17 parabens mediated by estrogen receptor α and β and androgen receptor.

    PubMed

    Watanabe, Yoko; Kojima, Hiroyuki; Takeuchi, Shinji; Uramaru, Naoto; Ohta, Shigeru; Kitamura, Shigeyuki

    2013-07-01

    The structure-activity relationships of parabens which are widely used as preservatives for transcriptional activities mediated by human estrogen receptor α (hERα), hERβ and androgen receptor (hAR) were investigated. Fourteen of 17 parabens exhibited hERα and/or hERβ agonistic activity at concentrations of ≤ 1 × 10(-5)M, whereas none of the 17 parabens showed AR agonistic or antagonistic activity. Among 12 parabens with linear alkyl chains ranging in length from C₁ to C₁₂, heptylparaben (C₇) and pentylparaben (C₅) showed the most potent ERα and ERβ agonistic activity in the order of 10(-7)M and 10(-8)M, respectively, and the activities decreased in a stepwise manner as the alkyl chain was shortened to C₁ or lengthened to C₁₂. Most parabens showing estrogenic activity exhibited ERβ-agonistic activity at lower concentrations than those inducing ERα-agonistic activity. The estrogenic activity of butylparaben was markedly decreased by incubation with rat liver microsomes, and the decrease of activity was blocked by a carboxylesterase inhibitor. These results indicate that parabens are selective agonists for ERβ over ERα; their interactions with ERα/β are dependent on the size and bulkiness of the alkyl groups; and they are metabolized by carboxylesterases, leading to attenuation of their estrogenic activity.

  9. A comparative study of antiestrogen action: temporal patterns of antagonism of estrogen stimulated uterine growth and effects on estrogen receptor levels.

    PubMed

    Ferguson, E R; Katzenellenbogen, B S

    1977-05-01

    Studies were undertaken to ascertain the effects of structural modification of two well-known antiestrogens (CI-628 and U-11,100A) on their estrogenic and antiestrogenic potencies and temporal patterns of effectiveness in the immature rat uterus. Changes in the chemical structures of these anti-estrogens produce compounds with markedly different affinities for the uterine estrogen receptor as measured in an in vitro cell-free cytosol system; binding affinities relative to estradiol (100%) are: CI-628, 4%; CI-680, 34%; 94X1127 (94X),222%; U-11,100A (UA), 6%; and U-23,469 (U-23), 0.1%. Although all five antiestrogens (daily injections of 50 microng over three days) appear equally effective in stimulating 72 h uterine weight when given alone, or in blocking the estradiol-stimulated weight increase when given with estradiol, marked differences in their potencies are noted when the effects of the compounds are monitored beyond 24 h following a single injection. The compounds CI-628, CI-680 and UA (50 microng sc in saline), which have a methylated hydroxyl group (at the site analogous to the steroid position 3), show a prolonged maintenance of elevated levels of nuclear receptor (beyond 48 h) and elevated uterine weight (until 72 h); this correlates with a prolonged period of depressed cytoplasmic receptor levels (beyond 48 h) and prolonged uterine insensitivity to estrogen (beyond 36 h as monitored by 3 h wet weight response). In contrast, a single injection of 50 microng of 94X (having a free hydroxyl group) or U-23 (with a side chain and central ring different from UA) maintained nuclear receptor levels elevated for only 12 h (94X) or 36 h (U-23) and uterine weights declined after 36-48 h; cytoplasmic receptor levels remained depressed for only 12 h (94X) or 24 h (U-23) and then returned to control levels or above by 36 h. These latter compounds likewise evoked the shortest period of uterine insensitivity to estrogen (ineffective as antagonists by 36 h). Comparative

  10. Selective estrogen receptor modulators for postmenopausal osteoporosis: current state of development.

    PubMed

    Gennari, Luigi; Merlotti, Daniela; Valleggi, Fabrizio; Martini, Giuseppe; Nuti, Ranuccio

    2007-01-01

    Selective estrogen receptor modulators (SERMs) are structurally different compounds that interact with intracellular estrogen receptors in target organs as estrogen receptor agonists and antagonists. These drugs have been intensively studied over the past decade and have proven to be a highly versatile group for the treatment of different conditions associated with aging, including hormone-responsive cancer and osteoporosis. Tamoxifen and toremifene are currently used to treat advanced breast cancer and also have beneficial effects on bone mineral density and serum lipids in postmenopausal women. Raloxifene is the only SERM approved worldwide for the prevention and treatment of postmenopausal osteoporosis and vertebral fractures. However, although these SERMs have many benefits, they may also be responsible for some potentially very serious adverse effects, such as thromboembolic disorders and, in the case of tamoxifen, uterine cancer. These adverse effects represent a major concern given that long-term therapy is required to prevent osteoporosis. Moreover, both preclinical and clinical reports suggest that tamoxifen, toremifene and raloxifene are considerably less potent than estrogen. The search for the 'ideal' SERM, which would have estrogenic effects on bone and serum lipids, neutral effects on the uterus, and antiestrogenic effects on breast tissue, but none of the adverse effects associated with current therapies, is currently under way. Ospemifene, lasofoxifene, bazedoxifene and arzoxifene, which are new SERM molecules with potential greater efficacy and potency than previous SERMs, are currently under investigation for use in the treatment and prevention of osteoporosis. These drugs have been shown to be comparably effective to conventional hormone replacement therapy in animal models of osteoporosis, with potential indications for an improved safety profile. Clinical efficacy data from ongoing phase III trials are awaited so that a true understanding of

  11. Identification of a GPER/GPR30 Antagonist with Improved Estrogen Receptor Counterselectivity

    PubMed Central

    Dennis, Megan K.; Field, Angela S.; Burai, Ritwik; Ramesh, Chinnasamy; Petrie, Whitney K.; Bologa, Cristian G.; Oprea, Tudor I.; Yamaguchi, Yuri; Hayashi, Shin-ichi; Sklar, S. Larry A.; Hathaway, Helen J.; Arterburn, Jeffrey B.; Prossnitz, Eric R.

    2011-01-01

    GPER/GPR30 is a seven-transmembrane G protein-coupled estrogen receptor that regulates many aspects of mammalian biology and physiology. We have previously described both a GPER-selective agonist G-1 and antagonist G15 based on a tetrahydro-3H-cyclopenta[c]quinoline scaffold. The antagonist lacks an ethanone moiety that likely forms important hydrogen bonds involved in receptor activation. Computational docking studies suggested that the lack of the ethanone substituent in G15 could minimize key steric conflicts, present in G-1, that limit binding within the ERα ligand binding pocket. In this report, we identify low-affinity cross-reactivity of the GPER antagonist G15 to the classical estrogen receptor ERα. To generate an antagonist with enhanced selectivity, we therefore synthesized an isosteric G-1 derivative, G36, containing an isopropyl moiety in place of the ethanone moiety. We demonstrate that G36 shows decreased binding and activation of ERα, while maintaining its antagonist profile towards GPER. G36 selectively inhibits estrogen-mediated activation of PI3K by GPER but not ERα. It also inhibits estrogen- and G-1-mediated calcium mobilization as well as ERK1/2 activation, with no effect on EGF-mediated ERK1/2 activation. Similar to G15, G36 inhibits estrogen- and G-1-stimulated proliferation of uterine epithelial cells in vivo. The identification of G36 as a GPER antagonist with improved ER counterselectivity represents a significant step towards the development of new highly selective therapeutics for cancer and other diseases. PMID:21782022

  12. Pregnancy and estrogen receptor β expression in a large congenital nevus

    PubMed Central

    Nading, Mary Alice; Nanney, Lillian B.; Ellis, Darrel L.

    2013-01-01

    Introduction Large congenital nevi carry a slightly increased risk for the development of melanoma. Pregnancy poses an additional challenge in monitoring these patients as little is known regarding the effects of increased estrogen levels on congenital nevi. Observation A young woman was observed to have clinical lightening of her garment nevus and satellite nevi during two sequential pregnancies. Post-partum, the patient experienced darkening and re-pigmentation within her large garment nevus, with continued lightening of nearby satellite lesions. In addition to photographic documentation of these changes, biopsies taken during pregnant and non-pregnant periods were evaluated with immunohistochemistry for estrogen receptor beta (ERβ), the predominant estrogen receptor in nevi and melanomas. Biopsies taken during pregnancy showed a decrease in nuclear staining for ERβ when compared to biopsies taken following pregnancy. These changes in ERβ expression were not associated with histological atypia either during pregnancy or following delivery. Conclusion Congenital nevi may be unique in their response to altered estrogen levels. Given the slightly increased risk for the development of melanoma in giant congenital nevi and the dearth of information available regarding the effects of pregnancy on congenital nevi, this case illustrates the need for further study of these pigmented lesions. PMID:19528425

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

    SciTech Connect

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

    2012-09-07

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

  14. Phytoestrogens induce differential estrogen receptor alpha- or Beta-mediated responses in transfected breast cancer cells.

    PubMed

    Harris, D M; Besselink, E; Henning, S M; Go, V L W; Heber, D

    2005-09-01

    Increased intake of phytoestrogens may be associated with a lower risk of cancer in the breast and several other sites, although there is controversy surrounding this activity. One of the mechanisms proposed to explain the activity of phytoestrogens is their ability to bind and activate human estrogen receptor alpha (ERalpha) and human estrogen receptor beta (ERbeta). Nine phytoestrogens were tested for their ability to transactivate ERalpha or ERbeta at a range of doses. Mammary adenocarcinoma (MCF-7) cells were co-transfected with either ERalpha or ERbeta, and an estrogen-response element was linked to a luciferase reporter gene. Dose-dependent responses were compared with the endogenous ligand 17beta-estradiol. Purified genistein, daidzein, apigenin, and coumestrol showed differential and robust transactivation of ERalpha- and ERbeta-induced transcription, with an up to 100-fold stronger activation of ERbeta. Equol, naringenin, and kaempferol were weaker agonists. When activity was evaluated against a background of 0.5 nM 17beta-estradiol, the addition of genistein, daidzein, and resveratrol superstimulated the system, while kaempferol and quercetin were antagonists at the highest doses. This transfection assay provides an excellent model to evaluate the activation of ERalpha and ERbeta by different phytoestrogens in a breast cancer context and can be used as a screening bioassay tool to evaluate the estrogenic activity of extracts of herbs and foods.

  15. MODELING THE BINDING OF THE METABOLITES OF SOME POLYCYCLIC AROMTIC HYDROCARBONS TO THE LIGAND BINDING DOMAIN OF THE ESTROGEN RECEPTOR

    EPA Science Inventory

    Modeling the binding of the metabolites of some Polycyclic Aromatic Hydrocarbons to the ligand binding domain of the estrogen receptor
    James Rabinowitz, Stephen Little, Katrina Brown, National Health and Environmental Effects Research Laboratory, Research Triangle Park, NC; Un...

  16. Understanding the selectivity of genistein for human estrogen receptor-beta using X-ray crystallography and computational methods.

    PubMed

    Manas, Eric S; Xu, Zhang B; Unwalla, Rayomand J; Somers, William S

    2004-12-01

    We present X-ray crystallographic and molecular modeling studies of estrogen receptors-alpha and -beta complexed with the estrogen receptor-beta-selective phytoestrogen genistein, and coactivator-derived NR box peptides containing an LXXLL motif. We demonstrate that the ligand binding mode is essentially identical when genistein is bound to both isoforms, despite the considerably weaker affinity of this ligand for estrogen receptor-alpha. In addition, we examine subtle differences between binding site residues, providing an explanation for why genistein is modestly selective for the beta isoform. To this end, we also present the results of quantum chemical studies and thermodynamic arguments that yield insight to the nature of the interactions leading to estrogen receptor-beta selectivity. The importance of our analysis to structure-based drug design is discussed.

  17. Sex-specificity and estrogen-dependence of kappa opioid receptor-mediated antinociception and antihyperalgesia

    PubMed Central

    Lawson, Kera P.; Nag, Subodh; Thompson, Analisa D.; Mokha, Sukhbir S.

    2010-01-01

    This investigation determined whether activation of the kappa opioid receptor (KOR) in the spinal cord produces estrogen-dependent, sex-specific modulation of acute and inflammation-induced persistent nociception. We demonstrate for the first time that KOR antinociception and gene expression are enhanced by exogenous or endogenous estrogen in the female. The lack of KOR antinociception and KOR gene expression are not altered by hormonal status (testosterone or estrogen) in males. Cannulae were implanted intrathecally in male, gonadectomized male (GDX), intact and ovariectomized female (OVX) Sprague-Dawley rats. Estradiol was injected subcutaneously, 48 h before testing (GDX+E and OVX+E). Intrathecal injection of U50, 488H, a selective KOR agonist, dose dependently increased heat-evoked tail flick latencies (TFLs) in proestrous and OVX+E groups, but not in male, GDX, GDX+E, OVX, and diestrous groups. Further, estrogen dose-dependently enhanced the effect of U50,488H in OVX rats. KOR selective antagonist, nor-binaltorphimine (Nor-BNI), blocked the antinociceptive effect of U50,488H. U50,488H reversed the carrageenan-induced thermal hyperalgesia in OVX+E rats, but not in male or OVX rats. However, U50,488H treatment did not alter mechanical thresholds in any group, with or without inflammation. KOR gene expression was enhanced in proestrous and OVX+E groups as compared to any other group. We conclude that selective activation of KOR in the spinal cord produces sex-specific, stimulus- and estrogen-dependent attenuation of acute and inflammatory pain in the rat via estrogen-induced upregulation of the KOR gene expression in the spinal cord. These findings may further implicate estrogen dependence of KOR effects in learning, epilepsy, stress response, addiction etc. Selective activation of the kappa opioid receptor by intrathecal U50,488H produces antinociception and antihyperalgesia which are sex-specific, stimulus dependent and require the presence of estrogen. PMID

  18. Female mice lacking estrogen receptor-alpha in osteoblasts have compromised bone mass and strength.

    PubMed

    Melville, Katherine M; Kelly, Natalie H; Khan, Sohaib A; Schimenti, John C; Ross, F Patrick; Main, Russell P; van der Meulen, Marjolein C H

    2014-02-01

    Reduced bioavailability of estrogen increases skeletal fracture risk in postmenopausal women, but the mechanisms by which estrogen regulates bone mass are incompletely understood. Because estrogen signaling in bone acts, in part, through estrogen receptor alpha (ERα), mice with global deletion of ERα (ERαKO) have been used to determine the role of estrogen signaling in bone biology. These animals, however, have confounding systemic effects arising from other organs, such as increased estrogen and decreased insulin-like growth factor 1 (IGF-1) serum levels, which may independently affect bone. Mice with tissue-specific ERα deletion in chondrocytes, osteoblasts, osteocytes, or osteoclasts lack the systemic effects seen in the global knockout, but show that presence of the receptor is important for the function of each cell type. Although bone mass is reduced when ERα is deleted from osteoblasts, no study has determined if this approach reduces whole bone strength. To address this issue, we generated female osteoblast-specific ERαKO mice (pOC-ERαKO) by crossing mice expressing a floxed ERα gene (ERα(fl/fl)) with mice transgenic for the osteocalcin-Cre promoter (OC-Cre). Having confirmed that serum levels of estrogen and IGF-1 were unaltered, we focused on relating bone mechanics to skeletal phenotype using whole bone mechanical testing, microcomputed tomography, histology, and dynamic histomorphometry. At 12 and 18 weeks of age, pOC-ERαKO mice had decreased cancellous bone mass in the proximal tibia, vertebra, and distal femur, and decreased cortical bone mass in the tibial midshaft, distal femoral cortex, and L5 vertebral cortex. Osteoblast activity was reduced in cancellous bone of the proximal tibia, but osteoclast number was unaffected. Both femora and vertebrae had decreased whole bone strength in mechanical tests to failure, indicating that ERα in osteoblasts is required for appropriate bone mass and strength accrual in female mice. This p

  19. Involvement of Human Estrogen Related Receptor Alpha 1 (hERR 1) in Breast Cancer and Hormonally Insensitive Disease

    DTIC Science & Technology

    2000-08-01

    Coutts, A., and Watson , P. The pathophysiological role of estrogen receptor variants in human breast cancer, J Steroid Biochem Mol Biol. 65: 175-80, 1998...breast cancer, Clin Cancer Res. 6: 512-8, 2000. 37. Leygue, E., Dotzlaw, H., Watson , P. H., and Murphy, L. C. Altered estrogen receptor alpha and beta...amphiregulin and CRIPTO in human normal and malignant breast tissues, Int J Cancer. 65: 51-6, 1996. 124. Depowski, P. L., Brien, T. P., Sheehan, C. E

  20. Prognostic Impact of Pregnancy After Breast Cancer According to Estrogen Receptor Status: A Multicenter Retrospective Study

    PubMed Central

    Azim, Hatem A.; Kroman, Niels; Paesmans, Marianne; Gelber, Shari; Rotmensz, Nicole; Ameye, Lieveke; De Mattos-Arruda, Leticia; Pistilli, Barbara; Pinto, Alvaro; Jensen, Maj-Britt; Cordoba, Octavi; de Azambuja, Evandro; Goldhirsch, Aron; Piccart, Martine J.; Peccatori, Fedro A.

    2013-01-01

    Purpose We questioned the impact of pregnancy on disease-free survival (DFS) in women with history of breast cancer (BC) according to estrogen receptor (ER) status. Patients and Methods A multicenter, retrospective cohort study in which patients who became pregnant any time after BC were matched (1:3) to patients with BC with similar ER, nodal status, adjuvant therapy, age, and year of diagnosis. To adjust for guaranteed time bias, each nonpregnant patient had to have a disease-free interval at least equal to the time elapsing between BC diagnosis and date of conception of the matched pregnant one. The primary objective was DFS in patients with ER-positive BC. DFS in the ER-negative cohort, whole population, and overall survival (OS) were secondary objectives. Subgroup analyses included DFS according to pregnancy outcome and BC–pregnancy interval. With a two-sided α = 5% and β = 20%, 645 ER-positive patients were required to detect a hazard ratio (HR) = 0.65. Results A total of 333 pregnant patients and 874 matched nonpregnant patients were analyzed, of whom 686 patients had an ER-positive disease. No difference in DFS was observed between pregnant and nonpregnant patients in the ER-positive (HR = 0.91; 95% CI, 0.67 to 1.24, P = .55) or the ER-negative (HR = 0.75; 95% CI, 0.51 to 1.08, P = .12) cohorts. However, the pregnant group had better OS (HR = 0.72; 95% CI, 0.54 to 0.97, P = .03), with no interaction according to ER status (P = .11). Pregnancy outcome and BC–pregnancy interval did not seem to impact the risk of relapse. Conclusion Pregnancy after ER-positive BC does not seem to reduce the risk of BC recurrence. PMID:23169515

  1. Fatty acid synthase regulates estrogen receptor-α signaling in breast cancer cells

    PubMed Central

    Menendez, J A; Lupu, R

    2017-01-01

    Fatty acid synthase (FASN), the key enzyme for endogenous synthesis of fatty acids, is overexpressed and hyperactivated in a biologically aggressive subset of sex steroid-related tumors, including breast carcinomas. Using pharmacological and genetic approaches, we assessed the molecular relationship between FASN signaling and estrogen receptor alpha (ERα) signaling in breast cancer. The small compound C75, a synthetic slow-binding inhibitor of FASN activity, induced a dramatic augmentation of estradiol (E2)-stimulated, ERα-driven transcription. FASN and ERα were both necessary for the synergistic activation of ERα transcriptional activity that occurred following co-exposure to C75 and E2: first, knockdown of FASN expression using RNAi (RNA interference) drastically lowered (>100 fold) the amount of E2 required for optimal activation of ERα-mediated transcriptional activity; second, FASN blockade synergistically increased E2-stimulated ERα-mediated transcriptional activity in ERα-negative breast cancer cells stably transfected with ERα, but not in ERα-negative parental cells. Non-genomic, E2-regulated cross-talk between the ERα and MAPK pathways participated in these phenomena. Thus, treatment with the pure antiestrogen ICI 182 780 or the potent and specific inhibitor of MEK/ERK, U0126, was sufficient to abolish the synergistic nature of the interaction between FASN blockade and E2-stimulated ERα transactivation. FASN inhibition suppressed E2-stimulated breast cancer cell proliferation and anchorage-independent colony formation while promoting the reduction of ERα protein. FASN blockade resulted in the increased expression and nuclear accumulation of the cyclin-dependent kinase inhibitors p21WAF1/CIP1 and p27Kip1, two critical mediators of the therapeutic effects of antiestrogen in breast cancer, while inactivating AKT, a key mediator of E2-promoted anchorage-independent growth. The ability of FASN to regulate E2/ERα signaling may represent a

  2. Lipid metabolism genes in contralateral unaffected breast and estrogen receptor status of breast cancer.

    PubMed

    Wang, Jun; Scholtens, Denise; Holko, Michelle; Ivancic, David; Lee, Oukseub; Hu, Hong; Chatterton, Robert T; Sullivan, Megan E; Hansen, Nora; Bethke, Kevin; Zalles, Carola M; Khan, Seema A

    2013-04-01

    Risk biomarkers that are specific to estrogen receptor (ER) subtypes of breast cancer would aid the development and implementation of distinct prevention strategies. The contralateral unaffected breast of women with unilateral breast cancer (cases) is a good model for defining subtype-specific risk because women with ER-negative (ER-) index primaries are at high risk for subsequent ER-negative primary cancers. We conducted random fine needle aspiration of the unaffected breasts of cases. Samples from 30 subjects [15 ER-positive (ER+) and 15 ER- cases matched for age, race and menopausal status] were used for Illumina expression array analysis. Findings were confirmed using quantitative real-time PCR (qRT-PCR) in the same samples. A validation set consisting of 36 subjects (12 ER+, 12 ER- and 12 standard-risk healthy controls) was used to compare gene expression across groups. ER- case samples displayed significantly higher expression of 18 genes/transcripts, 8 of which were associated with lipid metabolism on gene ontology analysis (GO: 0006629). This pattern was confirmed by qRT-PCR in the same samples, and in the 24 cases of the validation set. When compared to the healthy controls in the validation set, significant overexpression of 4 genes (DHRS2, HMGCS2, HPGD and ACSL3) was observed in ER- cases, with significantly lower expression of UGT2B11 and APOD in ER+ cases, and decreased expression of UGT2B7 in both subtypes. These data suggest that differential expression of lipid metabolism genes may be involved in the risk for subtypes of breast cancer, and are potential biomarkers of ER-specific breast cancer risk.

  3. Impact of estrogen receptor α gene and oxytocin receptor gene polymorphisms on female sexuality.

    PubMed

    Armeni, Anastasia K; Assimakopoulos, Konstantinos; Marioli, Dimitra; Koika, Vassiliki; Michaelidou, Euthychia; Mourtzi, Niki; Iconomou, Gregoris; Georgopoulos, Neoklis A

    2017-01-01

    Over the past decades, research attention has increasingly been paid to the neurobiological component of sexual behavior. The aim of the present study was to investigate the correlation of estrogen receptor α (ERA) gene polymorphism (rs2234693-PvuII) (T→C substitution) and oxytocin receptor gene polymorphism (rs53576) (G→A substitution) with sexuality parameters of young, healthy women. One hundred thirty-three Greek heterosexual women, students in higher education institutions, 20-25 years of age, sexually active, with normal menstrual cycles (28-35 days), were recruited in the study. Exclusion criteria were chronic and/or major psychiatric diseases, use of oral contraceptive pills (OCs), polycystic ovary syndrome (PCOS), thyroid diseases as well as drugs that are implicated in hypothalamus-pituitary-gonadal axis. T allele (wildtype) of rs2234693 (PvuII) polymorphism of ERA gene was correlated with increased levels of arousal and lubrication, whereas A allele (polymorphic) of rs53576 (OXTR) polymorphism was correlated with increased arousal levels. The simultaneous presence of both T allele of rs2234693 (PvuII) and A allele of rs53576 (OXTR) polymorphisms (T + A group) was correlated with increased arousal, orgasm levels as well as female sexual function index full score. To our knowledge, this is the first study to investigate the interaction between ERA and OXTR with regard to sexual function in women. Female sexuality is a complex behavioral trait that encompasses both biological and psychological components. It seems that variability in female sexual response stems from genetic variability that characterizes endocrine, neurotransmitter and central nervous system influences.

  4. Impact of estrogen receptor α gene and oxytocin receptor gene polymorphisms on female sexuality

    PubMed Central

    Armeni, Anastasia K; Assimakopoulos, Konstantinos; Marioli, Dimitra; Koika, Vassiliki; Michaelidou, Euthychia; Mourtzi, Niki; Iconomou, Gregoris

    2017-01-01

    Over the past decades, research attention has increasingly been paid to the neurobiological component of sexual behavior. The aim of the present study was to investigate the correlation of estrogen receptor α (ERA) gene polymorphism (rs2234693-PvuII) (T→C substitution) and oxytocin receptor gene polymorphism (rs53576) (G→A substitution) with sexuality parameters of young, healthy women. One hundred thirty-three Greek heterosexual women, students in higher education institutions, 20–25 years of age, sexually active, with normal menstrual cycles (28–35 days), were recruited in the study. Exclusion criteria were chronic and/or major psychiatric diseases, use of oral contraceptive pills (OCs), polycystic ovary syndrome (PCOS), thyroid diseases as well as drugs that are implicated in hypothalamus–pituitary–gonadal axis. T allele (wildtype) of rs2234693 (PvuII) polymorphism of ERA gene was correlated with increased levels of arousal and lubrication, whereas A allele (polymorphic) of rs53576 (OXTR) polymorphism was correlated with increased arousal levels. The simultaneous presence of both T allele of rs2234693 (PvuII) and A allele of rs53576 (OXTR) polymorphisms (T + A group) was correlated with increased arousal, orgasm levels as well as female sexual function index full score. To our knowledge, this is the first study to investigate the interaction between ERA and OXTR with regard to sexual function in women. Female sexuality is a complex behavioral trait that encompasses both biological and psychological components. It seems that variability in female sexual response stems from genetic variability that characterizes endocrine, neurotransmitter and central nervous system influences. PMID:28069897

  5. MIBE acts as antagonist ligand of both estrogen receptor α and GPER in breast cancer cells

    PubMed Central

    2012-01-01

    Introduction The multiple biological responses to estrogens are mainly mediated by the classical estrogen receptors ERα and ERβ, which act as ligand-activated transcription factors. ERα exerts a main role in the development of breast cancer; therefore, the ER antagonist tamoxifen has been widely used although its effectiveness is limited by de novo and acquired resistance. Recently, GPR30/GPER, a member of the seven-transmembrane G protein-coupled receptor family, has been implicated in mediating the effects of estrogens in various normal and cancer cells. In particular, GPER triggered gene expression and proliferative responses induced by estrogens and even ER antagonists in hormone-sensitive tumor cells. Likewise, additional ER ligands showed the ability to bind to GPER eliciting promiscuous and, in some cases, opposite actions through the two receptors. We synthesized a novel compound (ethyl 3-[5-(2-ethoxycarbonyl-1-methylvinyloxy)-1-methyl-1H-indol-3-yl]but-2-enoate), referred to as MIBE, and investigated its properties elicited through ERα and GPER in breast cancer cells. Methods Molecular modeling, binding experiments and functional assays were performed in order to evaluate the biological action exerted by MIBE through ERα and GPER in MCF7 and SkBr3 breast cancer cells. Results MIBE displayed the ability to act as an antagonist ligand for ERα and GPER as it elicited inhibitory effects on gene transcription and growth effects by binding to both receptors in breast cancer cells. Moreover, GPER was required for epidermal growth factor receptor (EGFR) and ERK activation by EGF as ascertained by using MIBE and performing gene silencing experiments. Conclusions Our findings provide novel insights on the functional cross-talk between GPER and EGFR signaling. Furthermore, the exclusive antagonistic activity exerted by MIBE on ERα and GPER could represent an innovative pharmacological approach targeting breast carcinomas which express one or both receptors at

  6. Soy isoflavones--benefits and risks from nature's selective estrogen receptor modulators (SERMs).

    PubMed

    Setchell, K D

    2001-10-01

    Phytoestrogens have become one of the more topical areas of interest in clinical nutrition. These non-nutrient bioactive compounds are ubiquitous to the plant kingdom and possess a wide range of biological properties that contribute to the many different health-related benefits reported for soy foods and flaxseeds--two of the most abundant dietary sources of phytoestrogens. Reviewed is the recent knowledge related to their pharmacokinetics and clinical effects, focusing mainly on isoflavones that are found in high concentrations in soy foods. Arguments are made for considering soy isoflavones as natural sele