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Taurin S, Nehoff H, van Aswegen T, Rosengren RJ, Greish K. A novel role for raloxifene nanomicelles in management of castrate resistant prostate cancer. BIOMED RESEARCH INTERNATIONAL 2014; 2014:323594. [PMID: 24689036 PMCID: PMC3932713 DOI: 10.1155/2014/323594] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 12/26/2013] [Indexed: 01/11/2023]
Abstract
Of patients with castrate resistant prostate cancer (CRPC), less than 25-33% survive more than five years. Recent studies have implicated estrogen, acting either alone or synergistically with androgens in the development of castrate resistant prostate cancer. Several in vitro and in vivo studies, as well as a limited number of clinical trials, have highlighted the potential of selective estrogen receptor modulators, such as raloxifene (Ral) for the treatment of castrate resistant prostate cancer. However, the poor oral bioavailability and metabolism of selective estrogen receptor modulators limit their efficiency in clinical application. To overcome these limitations, we have used styrene co-maleic acid (SMA) micelle to encapsulate raloxifene. Compared to free drug, SMA-Ral micelles had 132 and 140% higher cytotoxicity against PC3 and DU 145 prostate cell lines, respectively. SMA-Ral effectively inhibits cell cycle progression, increases apoptosis, and alters the integrity of tumor spheroid models. In addition, the micellar system induced changes in expression and localization of estrogen receptors, epidermal growth factor receptor (EGFR), and downstream effectors associated with cell proliferation and survival. Finally, SMA-Ral treatment decreased migration and invasion of castrate resistant prostate cancer cell lines. In conclusion, SMA-Ral micelles can potentially benefit new strategies for clinical management of castrate resistant prostate cancer.
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Affiliation(s)
- Sebastien Taurin
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - Hayley Nehoff
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - Thalita van Aswegen
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - Rhonda J. Rosengren
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - Khaled Greish
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
- Department of Oncology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
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Meyer JL, Zimbardi D, Podgaec S, Amorim RL, Abrão MS, Rainho CA. DNA methylation patterns of steroid receptor genes ESR1, ESR2 and PGR in deep endometriosis compromising the rectum. Int J Mol Med 2014; 33:897-904. [PMID: 24481237 DOI: 10.3892/ijmm.2014.1637] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Accepted: 12/17/2013] [Indexed: 11/06/2022] Open
Abstract
Endometriosis is characterized by the presence of endometrial-like tissue located outside the uterine cavity. Recent evidence suggests that endometriosis may be an epigenetic disease, as well as an estrogen-dependent disease. Based on the unique steroid hormone receptor expression profile observed in endometriotic lesions as compared to eutopic endometrium, the present study aimed to gain further insight into the DNA methylation patterns of alternative promoters of the steroid receptor genes ESR1, ESR2 and PGR in intestinal deep endometriosis, one of the most aggressive forms of endometriosis. The DNA methylation patterns were evaluated by methylation-specific polymerase chain reaction (MS-PCR) after bisulfite modification in 44 endometriotic tissues as well as in 7 matched eutopic endometrium. No differences in the DNA methylation were observed for the ESR1 and ESR2 genes. Methylation of the PGR gene was observed in 39% (17 out of 44) and 19% (7 out of 37) of the cases in the promoter regions B (PGRB) and A (PGRA), respectively. Both PGR promoter regions were methylated in 3 cases. PGRB methylated alleles were detected exclusively in the endometriotic lesions when compared to the eutopic endometrium obtained from the same patient. The effect of DNA methylation in inhibiting the PGR gene expression was corroborated by immuno-staining for PgR protein in a subset of tissue samples. The present study demonstrated that epigenetic changes occur in both promoter regions of the PGR gene in intestinal endometriosis. Since eutopic and ectopic tissues do not respond sufficiently to progesterone in women with endometriosis, further study is necessary to evaluate the effect of epigenetic alterations in progesterone-resistance in this enigmatic disease.
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Affiliation(s)
- Joana Ladeira Meyer
- Department of Genetics, Institute of Biosciences, São Paulo State University (UNESP), Botucatu, São Paulo, Brazil
| | - Daniela Zimbardi
- Department of Genetics, Institute of Biosciences, São Paulo State University (UNESP), Botucatu, São Paulo, Brazil
| | - Sérgio Podgaec
- Department of Obstetrics and Gynecology, São Paulo University (USP), São Paulo, Brazil
| | - Renee Laufer Amorim
- Department of Clinical Veterinary Medicine, São Paulo State University (UNESP), Botucatu, São Paulo, Brazil
| | - Maurício Simões Abrão
- Department of Obstetrics and Gynecology, São Paulo University (USP), São Paulo, Brazil
| | - Cláudia Aparecida Rainho
- Department of Genetics, Institute of Biosciences, São Paulo State University (UNESP), Botucatu, São Paulo, Brazil
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Rižner TL. Estrogen biosynthesis, phase I and phase II metabolism, and action in endometrial cancer. Mol Cell Endocrinol 2013; 381:124-39. [PMID: 23911898 DOI: 10.1016/j.mce.2013.07.026] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Revised: 05/30/2013] [Accepted: 07/22/2013] [Indexed: 12/21/2022]
Abstract
Endometrial cancer is the most common gynecological malignancy in the developed World. Based on their histopathology, clinical manifestation, and epidemiology, the majority of endometrial cancer cases can be divided into two groups: the more prevalent type 1 which is associated with unopposed estrogen exposure; and the less common type 2, which is usually not associated with hyper-estrogenic factors. This manuscript overviews the published data on the expression of genes encoding the estrogen biosynthetic enzymes, the phase I and phase II estrogen metabolic enzymes, and the estrogen receptors in endometrial cancer, at the mRNA, protein and enzyme activity levels. The potential role of altered expression of these enzymes and receptors in cancerous versus control endometrial tissue, and the implication of estrogens in tumor initiation and promotion, are discussed. Finally, based on the published data, a model of estrogen metabolism and actions is proposed for pre-cancerous and cancerous endometrial tissue, and the role of the estrogens in the progression of endometrial cancer from endometrial hyperplasia is suggested.
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Affiliation(s)
- Tea Lanišnik Rižner
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia.
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Cotter KA, Yershov A, Novillo A, Callard GV. Multiple structurally distinct ERα mRNA variants in zebrafish are differentially expressed by tissue type, stage of development and estrogen exposure. Gen Comp Endocrinol 2013; 194:217-29. [PMID: 24090614 PMCID: PMC3862120 DOI: 10.1016/j.ygcen.2013.09.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 09/04/2013] [Accepted: 09/18/2013] [Indexed: 10/26/2022]
Abstract
It is well established that estrogen-like environmental chemicals interact with the ligand-binding site of estrogen receptors (ERs) to disrupt transcriptional control of estrogen responsive targets. Here we investigate the possibility that estrogens also impact splicing decisions on estrogen responsive genes, such as that encoding ERα itself. Targeted PCR cloning was applied to identify six ERα mRNA variants in zebrafish. Sequencing revealed alternate use of transcription and translation start sites, multiple exon deletions, intron retention and alternate polyadenylation. As determined by quantitative (q)PCR, N-terminal mRNA variants predicting long (ERαA(L)) and short (ERα(S)) isoforms were differentially expressed by tissue-type, sex, stage of development and estrogen exposure. Whereas ERα(L) mRNA was diffusely distributed in liver, brain, heart, eye, and gonads, ERα(S) mRNA was preferentially expressed in liver (female>male) and ovary. Neither ERα(L) nor ERα(S) transcripts varied significantly during development, but 17β-estradiol selectively increased accumulation of ERα(S) mRNA (∼170-fold by 120 hpf), an effect mimicked by bisphenol-A and diethylstilbestrol. Significantly, a C-truncated variant (ERα(S)-Cx) lacking most of the ligand binding and AF-2 domains was transcribed exclusively from the short isoform promoter and was similar to ERα(S) in its tissue-, stage- and estrogen inducible expression. These results support the idea that promoter choice and alternative splicing of the esr1 gene of zebrafish are part of the autoregulatory mechanism by which estrogen modulates subsequent ERα expression, and further suggest that environmental estrogens could exert some of their toxic effects by altering the relative abundance of structurally and functionally distinct ERα isoforms.
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Affiliation(s)
- Kellie A. Cotter
- Boston University Department of Biology, 5 Cummington Mall, Boston, MA 02215, USA
| | - Anya Yershov
- Boston University Department of Biology, 5 Cummington Mall, Boston, MA 02215, USA
| | - Apolonia Novillo
- Boston University Department of Biology, 5 Cummington Mall, Boston, MA 02215, USA
| | - Gloria V. Callard
- Boston University Department of Biology, 5 Cummington Mall, Boston, MA 02215, USA
- Corresponding author: (617-353-8980)
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Ronchetti SA, Miler EA, Duvilanski BH, Cabilla JP. Cadmium mimics estrogen-driven cell proliferation and prolactin secretion from anterior pituitary cells. PLoS One 2013; 8:e81101. [PMID: 24236210 PMCID: PMC3827476 DOI: 10.1371/journal.pone.0081101] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 10/09/2013] [Indexed: 12/21/2022] Open
Abstract
Cadmium (Cd) is a heavy metal of considerable occupational and environmental concern affecting wildlife and human health. Recent studies indicate that Cd, like other heavy metals, can mimic effects of 17β-estradiol (E2) involving E2 receptor (ER) activation. Lactotrophs, the most abundant cell type in anterior pituitary gland, are the main target of E2, which stimulates cell proliferation and increases prolactin secretion through ERα. The aim of this work was to examine whether Cd at nanomolar concentrations can induce cell proliferation and prolactin release in anterior pituitary cells in culture and whether these effects are mediated through ERs. Here we show that 10 nM Cd was able to stimulate lactotroph proliferation in anterior pituitary cell cultures from female Wistar rats and also in GH3 lactosomatotroph cell line. Proliferation of somatotrophs and gonadotrophs were not affected by Cd exposure. Cd promoted cell cycle progression by increasing cyclins D1, D3 and c-fos expression. Cd enhanced prolactin synthesis and secretion. Cd E2-like effects were blocked by the pure ERs antagonist ICI 182,780 supporting that Cd acts through ERs. Further, both Cd and E2 augmented full-length ERαexpression and its 46 kDa-splicing variant. In addition, when co-incubated Cd was shown to interact with E2 by inducing ERα mRNA expression which indicates an additive effect between them. This study shows for the first time that Cd at nanomolar concentration displays xenoestrogenic activities by inducing cell growth and stimulating prolactin secretion from anterior pituitary cells in an ERs-dependent manner. Cd acting as a potent xenoestrogen can play a key role in the aetiology of different pathologies of the anterior pituitary and in estrogen-responsive tissues which represent considerable risk to human health.
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Affiliation(s)
- Sonia A. Ronchetti
- Instituto de Investigaciones Biomédicas (UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Eliana A. Miler
- Instituto de Investigaciones Biomédicas (UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Beatriz H. Duvilanski
- Instituto de Investigaciones Biomédicas (UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Jimena P. Cabilla
- Instituto de Investigaciones Biomédicas (UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
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56
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Yakimchuk K, Jondal M, Okret S. Estrogen receptor α and β in the normal immune system and in lymphoid malignancies. Mol Cell Endocrinol 2013; 375:121-9. [PMID: 23707618 DOI: 10.1016/j.mce.2013.05.016] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 05/14/2013] [Accepted: 05/18/2013] [Indexed: 02/07/2023]
Abstract
Estrogens regulate various normal and pathophysiological processes including cancers. Cellular signaling by estrogens is mediated by estrogen receptor α (ERα) and β (ERβ), respectively. Binding of agonists to the ERs affects gene transcription. The main endogenous estrogen, 17β-estradiol (E2), binds to both ERα and ERβ with similar affinity. However, the ligand-binding pocket of ERα and ERβ are slightly different which has allowed the development of selective ER ligands. Importantly, while estrogens via ERα stimulate proliferation, signaling via ERβ inhibits proliferation and promotes apoptosis. In both normal and cancer cells the ERs are co-expressed with ER splice variants which may modify the transcriptional activity of the wild-type receptors. Estrogens have prominent effects on immune functions and both ERα and ERβ are expressed in immune cells and lymphoid malignancies. With regard to lymphoid malignancies, most show estrogen influence as several epidemiological studies of lymphoid cancers demonstrate gender differences in incidence and prognosis with males being more affected. In line with these findings, recent results generated by us have shown that ERβ selective agonists inhibit growth and induce apoptosis in human and murine lymphomas in vivo in xenograft experiments. This suggests that ERβ selective agonists in the future may be useful in the treatment of lymphomas.
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Affiliation(s)
- Konstantin Yakimchuk
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, SE-141 83 Huddinge, Sweden
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57
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Classical estrogen receptors and ERα splice variants in the mouse. PLoS One 2013; 8:e70926. [PMID: 23940668 PMCID: PMC3733772 DOI: 10.1371/journal.pone.0070926] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 06/24/2013] [Indexed: 12/18/2022] Open
Abstract
Estrogens exert a variety of effects in both reproductive and non-reproductive tissues. With the discovery of ERα splice variants, prior assumptions concerning tissue-specific estrogen signaling need to be re-evaluated. Accordingly, we sought to determine the expression of the classical estrogen receptors and ERα splice variants across reproductive and non-reproductive tissues of male and female mice. Western blotting revealed that the full-length ERα66 was mainly present in female reproductive tissues but was also found in non-reproductive tissues at lower levels. ERα46 was most highly expressed in the heart of both sexes. ERα36 was highly expressed in the kidneys and liver of female mice but not in the kidneys of males. ERβ was most abundant in non-reproductive tissues and in the ovaries. Because the kidney has been reported to be the most estrogenic non-reproductive organ, we sought to elucidate ER renal expression and localization. Immunofluorescence studies revealed ERα66 in the vasculature and the glomerulus. It was also found in the brush border of the proximal tubule and in the cortical collecting duct of female mice. ERα36 was evident in mesangial cells and tubular epithelial cells of both sexes, as well as podocytes of females but not males. ERβ was found primarily in the podocytes in female mice but was also present in the mesangial cells in both sexes. Within the renal cortex, ERα46 and ERα36 were mainly located in the membrane fraction although they were also present in the cytosolic fraction. Given the variability of expression patterns demonstrated herein, identification of the specific estrogen receptors expressed in a tissue is necessary for interpreting estrogenic effects. As this study revealed expression of the ERα splice variants at multiple sites within the kidney, further studies are warranted in order to elucidate the contribution of these receptors to renal estrogen responsiveness.
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58
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Burris TP, Solt LA, Wang Y, Crumbley C, Banerjee S, Griffett K, Lundasen T, Hughes T, Kojetin DJ. Nuclear receptors and their selective pharmacologic modulators. Pharmacol Rev 2013; 65:710-78. [PMID: 23457206 PMCID: PMC11060414 DOI: 10.1124/pr.112.006833] [Citation(s) in RCA: 185] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Nuclear receptors are ligand-activated transcription factors and include the receptors for steroid hormones, lipophilic vitamins, sterols, and bile acids. These receptors serve as targets for development of myriad drugs that target a range of disorders. Classically defined ligands that bind to the ligand-binding domain of nuclear receptors, whether they are endogenous or synthetic, either activate receptor activity (agonists) or block activation (antagonists) and due to the ability to alter activity of the receptors are often termed receptor "modulators." The complex pharmacology of nuclear receptors has provided a class of ligands distinct from these simple modulators where ligands display agonist/partial agonist/antagonist function in a tissue or gene selective manner. This class of ligands is defined as selective modulators. Here, we review the development and pharmacology of a range of selective nuclear receptor modulators.
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Affiliation(s)
- Thomas P Burris
- The Scripps Research Institute, 130 Scripps Way 2A1, Jupiter, FL 33458, USA.
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59
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Schoen J, Sharbati S, Ritter J, Jewgenow K. Feline Gonads Exhibit Tissue Specific Alternative Splicing of Oestrogen Receptor Alpha (ESR1). Reprod Domest Anim 2012; 47 Suppl 6:30-4. [DOI: 10.1111/rda.12065] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 07/19/2012] [Indexed: 11/29/2022]
Affiliation(s)
- J Schoen
- Institute of Veterinary Biochemistry; Freie Universität Berlin; Berlin; Germany
| | - S Sharbati
- Institute of Veterinary Biochemistry; Freie Universität Berlin; Berlin; Germany
| | | | - K Jewgenow
- Leibniz Institute for Zoo and Wildlife Research (IZW); Berlin; Germany
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60
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CYP1B1 and hormone-induced cancer. Cancer Lett 2012; 324:13-30. [DOI: 10.1016/j.canlet.2012.04.021] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2012] [Revised: 04/21/2012] [Accepted: 04/24/2012] [Indexed: 12/11/2022]
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Zárate S, Jaita G, Ferraris J, Eijo G, Magri ML, Pisera D, Seilicovich A. Estrogens induce expression of membrane-associated estrogen receptor α isoforms in lactotropes. PLoS One 2012; 7:e41299. [PMID: 22844453 PMCID: PMC3402499 DOI: 10.1371/journal.pone.0041299] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 06/19/2012] [Indexed: 12/21/2022] Open
Abstract
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 participates in anterior pituitary cell renewal during the estrous cycle.
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Affiliation(s)
- Sandra Zárate
- Instituto de Investigaciones Biomédicas, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Gabriela Jaita
- Instituto de Investigaciones Biomédicas, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Jimena Ferraris
- Instituto de Investigaciones Biomédicas, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Guadalupe Eijo
- Instituto de Investigaciones Biomédicas, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - María L. Magri
- Instituto de Investigaciones Biomédicas, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Daniel Pisera
- Instituto de Investigaciones Biomédicas, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Adriana Seilicovich
- Instituto de Investigaciones Biomédicas, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
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Gutiérrez S, Sosa LDV, Petiti JP, Mukdsi JH, Mascanfroni ID, Pellizas CG, De Paul AL, Cambiasso MJ, Torres AI. 17β-Estradiol stimulates the translocation of endogenous estrogen receptor α at the plasma membrane of normal anterior pituitary cells. Mol Cell Endocrinol 2012; 355:169-79. [PMID: 22366173 DOI: 10.1016/j.mce.2012.02.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 02/03/2012] [Accepted: 02/07/2012] [Indexed: 11/21/2022]
Abstract
In the present work we aimed at identifying ERα in the plasma membrane of normal anterior pituitary cells and investigated if 17β-estradiol was able to induce their subcellular redistribution. Our results show that about 8% of anterior pituitary cells expressed ERα in the plasma membrane, with the geometrical mean fluorescence intensity being increased after steroid hormone treatment. 17β-Estradiol and the selective ERα agonist PPT induced an increase of ERα expression in the plasma membrane and activated the PKCα/ERK 1/2 pathway in a time-course not compatible with genomic actions, thus supporting the notion of membrane-initiated effects. These findings suggest that 17β-estradiol stimulates the translocation of endogenous ERα to the plasma membrane, consequently modulating this ER pool and leading to cellular biological effects in normal anterior pituitary gland.
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Affiliation(s)
- Silvina Gutiérrez
- Centro de Microscopía Electrónica, Universidad Nacional de Córdoba, Haya de la Torre esq, Enrique Barros, Ciudad Universitaria, CP 5000 Córdoba, Argentina.
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64
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Ishunina TA, Swaab DF. Decreased alternative splicing of estrogen receptor-α mRNA in the Alzheimer's disease brain. Neurobiol Aging 2012; 33:286-296.e3. [DOI: 10.1016/j.neurobiolaging.2010.03.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Revised: 02/19/2010] [Accepted: 03/16/2010] [Indexed: 01/15/2023]
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65
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Marques YMFS, Giudice FS, Freitas VM, Abreu e Lima MDCC, Hunter KD, Speight PM, Machado de Sousa SCO. Oestrogen receptor β in adenoid cystic carcinoma of salivary glands. Histopathology 2012; 60:609-16. [PMID: 22260414 DOI: 10.1111/j.1365-2559.2011.04095.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
AIMS This study aimed to describe the expression of oestrogen receptor (ER)α, ERβ and aromatase in salivary gland adenoid cystic carcinoma (ACC). METHODS AND RESULTS ERα, ERβ and aromatase expression was analysed by immunohistochemistry in tissue microarray blocks from 38 cases of ACC and seven normal salivary glands. The intracellular localization and amount of total protein expression were investigated by immunofluorescence and western blotting in an ACC cell line. Western blotting analysis showed overexpression of ERα, ERβ and aromatase in the ACC cell line; however, with immunofluorescence, only ERβ was shown to be expressed in the nucleus. Immunohistochemistry revealed positive nuclear expression of ERβ, positive cytoplasmic expression of aromatase and a lack of ERα expression as compared with normal salivary glands. CONCLUSIONS The nuclear expression of ERβ indicates that oestrogen may be active in ACC and possibly able to mediate E2-targeted gene transcription. This study strongly suggests that ERβ may be involved in tumour progression, playing a role in tumour development, and thus corroborating the indication for ER antagonists in the clinical control of ACC. This study opens a new perspective on the potential use of anti-oestrogens and aromatase inhibitors as therapeutic agents against ACC.
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Affiliation(s)
- Yonara M F S Marques
- Department of Oral Pathology, University of São Paulo, Av. Lineu Prestes 2227, São Paulo ⁄ SP, Brazil.
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AL-BADER MD, MALATIALI SA, REDZIC ZB. Expression of Estrogen Receptor α and β in Rat Astrocytes in Primary Culture: Effects of Hypoxia and Glucose Deprivation. Physiol Res 2011; 60:951-60. [DOI: 10.33549/physiolres.932167] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Estrogen replacement therapy could play a role in the reduction of injury associated with cerebral ischemia in vivo, which could be, at least partially, a consequence of estrogen influence of glutamate buffering by astrocytes during hypoxia/ischemia. Estrogen exerts biological effects through interaction with its two receptors: estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ), which are both expressed in astrocytes. This study explored effects of hypoxia and glucose deprivation (HGD), alone or followed by 1 h recovery, on ERα and ERβ expression in primary rat astrocyte cultures following 1 h exposure to: a) 5 % CO2 in air (control group-CG); b) 2 % O2/5 % CO2 in N2 with glucose deprivation (HGD group-HGDG); or c) the HGDG protocol followed by 1 h CG protocol (recovery group-RG). ERα mRNA expression decreased in HGDG. At the protein level, full-length ERα (67 kDa) and three ERα-immunoreactive protein bands (63, 60 and 52 kDa) were detected. A significant decrease in the 52 kDa band was seen in HGDG, while a significant decrease in expression of the full length ERα was seen in the RG. ERβ mRNA and protein expression (a 54 kDa single band) did not change. The observed decrease in ERα protein may limit estrogen-mediated signalling in astrocytes during hypoxia and recovery.
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Affiliation(s)
| | | | - Z. B. REDZIC
- Department of Physiology, Faculty of Medicine, Kuwait University, Kuwait
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67
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Comparative analysis of the ERα/ERβ ratio and neurotensin and its high-affinity receptor in myometrium, uterine leiomyoma, atypical leiomyoma, and leiomyosarcoma. Int J Gynecol Pathol 2011; 30:354-63. [PMID: 21623207 DOI: 10.1097/pgp.0b013e31820918cb] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Deregulated steroids are involved in different hormone-dependent tumors, including benign and malignant uterine neoplasms. Leiomyomas (LM) are estrogen and progesterone-dependent benign tumors, whereas "bizarre or atypical LMs" (AL) are considered a subgroup of LM and clinically benign, although their malignant potential is suspect. Uterine leiomyosarcomas (LMS) are malignant smooth muscle tumors, and ovarian steroids may control their growth. Estrogen effects are mediated by 2 receptors, estrogen receptors (ER) α and β, and the ratio of both receptors seems to be a critical parameter in the estrogen-mediated carcinogenic process. Estradiol induces the expression of neurotensin (NTS), and the coupling of this peptide with its high-affinity receptor, NTS1, has been involved in the regulation of tumoral cell growth. Given the importance of these markers in tumor development, we aim to determine the status of ERα and ERβ in the myometrium and LM, AL, and LMS, concomitantly with the expression of NTS/NTS receptor 1 in these tumors. For that purpose, we use immunohistochemistry for all markers analyzed and in-situ hybridization to detect NTS mRNA. These data suggest that LMS are estrogen-dependent tumors, which may use NTS as an autocrine growth factor. In addition, the phenotype of AL with regard to ERα and ERβ status and NTS expression is closer to LMS than LM; thus, a potential malignization of this tumor is feasible.
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68
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Le Romancer M, Poulard C, Cohen P, Sentis S, Renoir JM, Corbo L. Cracking the estrogen receptor's posttranslational code in breast tumors. Endocr Rev 2011; 32:597-622. [PMID: 21680538 DOI: 10.1210/er.2010-0016] [Citation(s) in RCA: 211] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Estrogen signaling pathways, because of their central role in regulating the growth and survival of breast tumor cells, have been identified as suitable and efficient targets for cancer therapies. Agents blocking estrogen activity are already widely used clinically, and many new molecules have entered clinical trials, but intrinsic or acquired resistance to treatment limits their efficacy. The basic molecular studies underlying estrogen signaling have defined the critical role of estrogen receptors (ER) in many aspects of breast tumorigenesis. However, important knowledge gaps remain about the role of posttranslational modifications (PTM) of ER in initiation and progression of breast carcinogenesis. Whereas major attention has been focused on the phosphorylation of ER, many other PTM (such as acetylation, ubiquitination, sumoylation, methylation, and palmitoylation) have been identified as events modifying ER expression and stability, subcellular localization, and sensitivity to hormonal response. This article will provide an overview of the current and emerging knowledge on ER PTM, with a particular focus on their deregulation in breast cancer. We also discuss their clinical relevance and the functional relationship between PTM. A thorough understanding of the complete picture of these modifications in ER carcinogenesis might not only open new avenues for identifying new markers for prognosis or prediction of response to endocrine therapy but also could promote the development of novel therapeutic strategies.
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Affiliation(s)
- Muriel Le Romancer
- Université de Lyon, Centre de Recherche en Cancérologie de Lyon, Centre Léon Bérard, Bâtiment Cheney D, 28 rue Laennec, 69373 Lyon Cedex 08, France.
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69
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Kim KH, Toomre D, Bender JR. Splice isoform estrogen receptors as integral transmembrane proteins. Mol Biol Cell 2011; 22:4415-23. [PMID: 21937726 PMCID: PMC3216666 DOI: 10.1091/mbc.e11-05-0416] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Use of ecliptic pHluorin-fused ER46 and TIRFM identifies ER46 as a type I transmembrane protein in live human ECs. The transmembrane mutant ER46-Ile386Cys obscures the N-terminal ectodomain and effects a marked reduction in membrane-impermeant estrogen binding, with diminished rapid eNOS activation and NO production. 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.
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Affiliation(s)
- Kyung Hee Kim
- Departments of Internal Medicine (Cardiovascular Medicine) and Immunobiology and the Raymond and Beverly Sackler Foundation Cardiovascular Laboratory, Yale University School of Medicine, New Haven, CT 06511, USA
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70
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Vouk K, Smuc T, Guggenberger C, Ribič-Pucelj M, Sinkovec J, Husen B, Thole H, Houba P, Thaete C, Adamski J, Rižner TL. Novel estrogen-related genes and potential biomarkers of ovarian endometriosis identified by differential expression analysis. J Steroid Biochem Mol Biol 2011; 125:231-42. [PMID: 21397694 DOI: 10.1016/j.jsbmb.2011.03.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Revised: 02/28/2011] [Accepted: 03/04/2011] [Indexed: 10/18/2022]
Abstract
In the search for novel biomarkers of endometriosis, we selected 152 genes from the GeneLogic database based on results of genome-wide expression analysis of ovarian endometriosis, plus 20 genes related to estrogen metabolism and action. We then performed low-density array analysis of these 172 genes on 11 ovarian endometriosis samples and 9 control endometrium samples. Principal component analysis of the gene expression levels showed clear separation between the endometriosis and control groups. We identified 78 genes as differentially expressed. Based on Ingenuity pathway analysis, these differentially expressed genes were arranged into groups according to biological function. These analyses revealed that 32 differentially expressed genes are estrogen related, 23 of which have not been reported previously in connection with endometriosis. Functional annotation showed that 25 and 22 genes are associated with the biological terms "secreted" and "extracellular region", respectively. Differential expression of 4 out of 5 genes related to estrogen metabolism and action (ESR1, ESR2, PGR and BGN) was also confirmed by immunohistochemistry. Our study thus reveals differential expression of several genes that have not previously been associated with endometriosis and that encode potential novel biomarkers and drug targets.
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Affiliation(s)
- Katja Vouk
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Vrazov trg, 2, 1000 Ljubljana, Slovenia
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71
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Abstract
Early work on the hormonal basis of prostate cancer focused on the role of androgens, but more recently estrogens have been implicated as potential agents in the development and progression of prostate cancer. In this article, we review the epidemiological, laboratory and clinical evidence that estrogen may play a causative role in human prostate cancer, as well as rodent and grafted in vivo models. We then review recent literature highlighting potential mechanisms by which estrogen may contribute to prostate cancer, including estrogenic imprinting and epigenetic modifications, direct genotoxicity, hyperprolactinemia, inflammation and immunologic changes, and receptor-mediated actions. We discuss the work performed so far separating the actions of the different known estrogen receptors (ERs), ERα and ERβ, as well as G-protein-coupled receptor 30 and their specific roles in prostate disease. Finally, we predict that future work in this field will involve more investigations into epigenetic changes, experiments using new models of hormonal dysregulation in developing human prostate tissue, and continued delineation of the roles of the different ER subtypes, as well as their downstream signaling pathways that may serve as therapeutic targets.
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Affiliation(s)
- Jason L Nelles
- Department of Urology, University of Illinois at Chicago, 820 South Wood Street, MC 955, Chicago, IL 60612, USA
| | - Wen-Yang Hu
- Department of Urology, University of Illinois at Chicago, 820 South Wood Street, MC 955, Chicago, IL 60612, USA
| | - Gail S Prins
- Department of Urology, University of Illinois at Chicago, 820 South Wood Street, MC 955, Chicago, IL 60612, USA
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Ishii H, Shoda Y, Yomogida K, Hamada T, Sakuma Y. Identification of C-terminally and N-terminally truncated estrogen receptor α variants in the mouse. J Steroid Biochem Mol Biol 2011; 124:38-46. [PMID: 21251978 DOI: 10.1016/j.jsbmb.2011.01.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 12/10/2010] [Accepted: 01/07/2011] [Indexed: 10/18/2022]
Abstract
We re-examined mouse ERα mRNA variants using rapid amplification of cDNA ends (RACE) and RT-PCR. Our analysis showed the presence of several mRNA variants containing unique 5'- or 3'-nucleotide sequences. We mapped the cDNA sequences on the mouse genome, and identified four novel 3'-terminal and 5'-leader exons in the intronic region between exons 4 and 5. RT-PCR analysis revealed that the expression patterns of the C-terminally truncated ERα products (CTERPs) were similar to that of Wild-type ERα and that the N-terminally truncated ERα products (NTERPs) appeared to have different expression profiles. Moreover, we constructed expression vectors and analyzed the subcellular localization and the transcriptional activation abilities of the variant proteins in transfected HEK293 cells using immunocytochemistry and luciferase reporter assay. The CTERP variants localized in the nuclei and constitutively activated estrogen response element (ERE)-driven promoters, while the NTERP variant was located in the extra-nuclear regions and had no ability to activate the ERE promoters in the presence or absence of 10 nM estradiol. Our results indicate that the mouse ERα gene is more complex than previously thought in terms of genomic organization and that alternative splicing and alternative usage of intronic promoters contribute to the remarkable diversity of ERα mRNAs and proteins.
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Affiliation(s)
- Hirotaka Ishii
- Department of Physiology, Nippon Medical School, Tokyo, Japan.
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The estrogen receptor alpha-derived peptide ERα17p (P(295)-T(311)) exerts pro-apoptotic actions in breast cancer cells in vitro and in vivo, independently from their ERα status. Mol Oncol 2010; 5:36-47. [PMID: 21163714 DOI: 10.1016/j.molonc.2010.11.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 11/09/2010] [Accepted: 11/09/2010] [Indexed: 11/22/2022] Open
Abstract
In recent years, our knowledge on estrogen receptors (ER) has been modified profoundly with the identification and the deciphering of the role of its protein effectors, as well as with the deeper insight of its molecular structure/function dynamics, characteristics associated with its nucleo-cytoplasmic-membrane shuttling properties. Also, significant progress has been made concerning its turn-over and associated final proteasomal degradation processes. These advances could lead in the near future to the design and the synthesis of novel receptor-interacting drugs. Recently, a number of receptor-related peptides acting as specific ER ligands have been identified and extensively studied with respect to their estrogenic/antiestrogenic activities. Among them, ERα17p, a synthetic analog of the P(295)-T(311) sequence of ERα, has been shown to exert pseudo-estrogenic effects by interacting in the close vicinity of its hinge region (BF3 domain). Remarkably, this sequence appears as the epicenter of a number of post-transcriptional modifications as well as of the recruitment of co-regulators, suggesting that it would play a key role in ERα functions. Here, we provide evidence that ERα17p induces apoptosis in ERα-positive (MCF-7, T47D) and -negative (MDA-MB-231, SK-BR-3) breast cancer cells by an ERα-independent membrane mechanism, triggering major pro-apoptotic signaling cascades. Finally, ERα17p induces the regression of breast ERα-negative cancer tumor xenografts, without apparent toxicity, suggesting that it could represent a new attractive tool for the development of future promising therapeutic approaches, and providing a novel insight to ER regulation of cell fate.
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Elevated oestrogen receptor splice variant ERαΔ5 expression in tumour-adjacent hormone-responsive tissue. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2010; 7:3871-89. [PMID: 21139866 PMCID: PMC2996214 DOI: 10.3390/ijerph7113871] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 10/27/2010] [Accepted: 10/29/2010] [Indexed: 12/25/2022]
Abstract
Susceptibility to prostate or endometrial cancer is linked with obesity, a state of oestrogen excess. Oestrogen receptor (ER) splice variants may be responsible for the tissue-level of ER activity. Such micro-environmental regulation may modulate cancer initiation and/or progression mechanisms. Real-time reverse transcriptase (RT) polymerase chain reaction (PCR) was used to quantitatively assess the levels of four ER splice variants (ERαΔ3, ERαΔ5, ERβ2 and ERβ5), plus the full-length parent isoforms ERα and ERβ1, in high-risk [tumour-adjacent prostate (n = 10) or endometrial cancer (n = 9)] vs. low-risk [benign prostate (n = 12) or endometrium (n = 9)], as well as a comparison of UK (n = 12) vs. Indian (n = 15) benign prostate. All three tissue groups expressed the ER splice variants at similar levels, apart from ERαΔ5. This splice variant was markedly raised in all of the tumour-adjacent prostate samples compared to benign tissues. Immunofluorescence analysis for ERβ2 in prostate tissue demonstrated that such splice variants are present in comparable, if not greater, amounts as the parent full-length isoform. This small pilot study demonstrates the ubiquitous nature of ER splice variants in these tissue sites and suggests that ERαΔ5 may be involved in progression of prostate adenocarcinoma.
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75
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Martin FL, Patel II, Sozeri O, Singh PB, Ragavan N, Nicholson CM, Frei E, Meinl W, Glatt H, Phillips DH, Arlt VM. Constitutive expression of bioactivating enzymes in normal human prostate suggests a capability to activate pro-carcinogens to DNA-damaging metabolites. Prostate 2010; 70:1586-99. [PMID: 20687231 DOI: 10.1002/pros.21194] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND The constitutive bioactivating capacity of human prostate may play a role in determining risk of adenocarcinoma developing in this tissue. Expression of candidate enzymes that convert exogenous and/or endogenous agents into reactive DNA-damaging species would suggest the potential to generate initiating events in prostate cancer (CaP). METHODS Normal prostate tissues from UK-resident Caucasians (n = 10) were collected following either radical retropubic prostatectomy (RRP) or cystaprostatectomy (CyP). An analysis of gene and protein expression of candidate metabolizing enzymes, including cytochrome P450 (CYP)1A1, CYP1A2, CYP1B1, N-acetyltransferase 1 (NAT1), sulfotransferase (SULT)1A1, SULT1A3, NAD(P)H:quinone oxidoreductase (NQO1), prostaglandin H synthase 1 (cyclooxygenase 1; COX1), and CYP oxidoreductase (POR) was carried out. Quantitative real-time reverse transcriptase polymerase chain reaction, Western blot, and immunohistochemical analysis were conducted. RESULTS Except for CYP1A1 and CYP1A2, the metabolizing enzymes examined appeared to be expressed with minimal inter-individual variation (in general, approximately two- to fivefold) in the expression levels. Enzymes such as CYP1B1 and NQO1 that are capable of bioactivating pro-carcinogens to reactive metabolites were readily identifiable in human prostate. Immunohistochemical analysis showed that although some expression is located in the stroma, the majority is localized to epithelial cells lining the glandular elements of the tissue; these are the cells from which CaP might arise. CONCLUSION Constitutive expression of bioactivating enzymes confers the potential to convert a range of exogenous and/or endogenous agents to reactive species capable of inducing DNA damaging events. These findings suggest an organ capability for pro-carcinogen activation that could play an important role in the etiology of human CaP.
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Affiliation(s)
- Francis L Martin
- Centre for Biophotonics, Lancaster Environment Centre, Lancaster University, Lancaster, UK.
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76
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Constitutively active androgen receptor splice variants expressed in castration-resistant prostate cancer require full-length androgen receptor. Proc Natl Acad Sci U S A 2010; 107:16759-65. [PMID: 20823238 DOI: 10.1073/pnas.1012443107] [Citation(s) in RCA: 493] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Androgen receptor (AR) splice variants lacking the ligand binding domain (ARVs), originally isolated from prostate cancer cell lines derived from a single patient, are detected in normal and malignant human prostate tissue, with the highest levels observed in late stage, castration-resistant prostate cancer. The most studied variant (called AR-V7 or AR3) activates AR reporter genes in the absence of ligand and therefore, could play a role in castration resistance. To explore the range of potential ARVs, we screened additional human and murine prostate cancer models using conventional and next generation sequencing technologies and detected several structurally diverse AR isoforms. Some, like AR-V7/AR3, display gain of function, whereas others have dominant interfering activity. We also find that ARV expression increases acutely in response to androgen withdrawal, is suppressed by testosterone, and in some models, is coupled to full-length AR (AR-FL) mRNA production. As expected, constitutively active, ligand-independent ARVs such as AR-V7/AR3 are sufficient to confer anchorage-independent (in vitro) and castration-resistant (in vivo) growth. Surprisingly, this growth is blocked by ligand binding domain-targeted antiandrogens, such as MDV3100, or by selective siRNA silencing of AR-FL, indicating that the growth-promoting effects of ARVs are mediated through AR-FL. These data indicate that the increase in ARV expression in castrate-resistant prostate cancer is an acute response to castration rather than clonal expansion of castration or antiandrogen-resistant cells expressing gain of function ARVs, and furthermore, they provide a strategy to overcome ARV function in the clinic.
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Jiao H, Liu C, Guo W, Peng L, Chen Y, Martin FL. Association of CYP1B1 Polymorphisms with Breast Cancer: A Case-Control Study in the Han Population in Ningxia Hui Autonomous Region, P. R. China. Biomark Insights 2010; 5:21-7. [PMID: 20212917 PMCID: PMC2832340 DOI: 10.4137/bmi.s4094] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Studies investigating possible associations between cytochrome P4501B1 (CYP1B1) polymorphisms and breast cancer risk have been inconsistent. We set out to ascertain whether there might be an association between polymorphisms in exon 2 (codon 119, G→T) and exon 3 (codon 432, G→C) of CYP1B1 and breast cancer in a Chinese Han population in the rural region of Ningxia. Using an allele-specific polymerase chain reaction method and direct DNA sequencing, the presence or absence of the two CYP1B1 polymorphisms was investigated. Genotype and allele frequencies were analyzed in breast cancer cases (n = 152) and healthy age-matched controls (n = 156). The odds ratio (OR) of 119G→T or 432G→C in breast cancer cases and controls was 3.3 (95% CI: 1.28 to 8.28) and 2.8 (95% CI: 1.04 to 7.51), respectively. In addition, the OR for people with both polymorphisms (119T and 432C) was 4.69 (95% CI: 1.97 to 11.19). Our results suggest that certain polymorphisms in the CYP1B1 gene might increase risk for breast cancer among Han Chinese, perhaps because they influence the efficiency of CYP1B1 bio-transformation of oestrogens or pro-carcinogens into DNA-reactive electrophiles that may act as cancer-initiating agents.
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Affiliation(s)
- Haiyan Jiao
- Department of Medical Genetics and Cell Biology, Ningxia Medical University, Yinchuan, Ningxia, 750004, P. R. China
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Henderson VW, Brinton RD. Menopause and mitochondria: windows into estrogen effects on Alzheimer's disease risk and therapy. PROGRESS IN BRAIN RESEARCH 2010; 182:77-96. [PMID: 20541661 PMCID: PMC5776041 DOI: 10.1016/s0079-6123(10)82003-5] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Metabolic derangements and oxidative stress are early events in Alzheimer's disease pathogenesis. Multi-faceted effects of estrogens include improved cerebral metabolic profile and reduced oxidative stress through actions on mitochondria, suggesting that a woman's endogenous and exogenous estrogen exposures during midlife and in the late post-menopause might favourably influence Alzheimer risk and symptoms. This prediction finds partial support in the clinical literature. As expected, early menopause induced by oophorectomy may increase cognitive vulnerability; however, there is no clear link between age at menopause and Alzheimer risk in other settings, or between natural menopause and memory loss. Further, among older post-menopausal women, initiating estrogen-containing hormone therapy increases dementia risk and probably does not improve Alzheimer's disease symptoms. As suggested by the 'critical window' or 'healthy cell' hypothesis, better outcomes might be expected from earlier estrogen exposures. Some observational results imply that effects of hormone therapy on Alzheimer risk are indeed modified by age at initiation, temporal proximity to menopause, or a woman's health. However, potential methodological biases warrant caution in interpreting observational findings. Anticipated results from large, ongoing clinical trials [Early Versus Late Intervention Trial with Estradiol (ELITE), Kronos Early Estrogen Prevention Study (KEEPS)] will help settle whether midlife estrogen therapy improves midlife cognitive skills but not whether midlife estrogen exposures modify late-life Alzheimer risk. Estrogen effects on mitochondria adumbrate the potential relevance of estrogens to Alzheimer's disease. However, laboratory models are inexact embodiments of Alzheimer pathogenesis and progression, making it difficult to surmise net effects of estrogen exposures. Research needs include better predictors of adverse cognitive outcomes, biomarkers for risks associated with hormone therapy, and tools for monitoring brain function and disease progression.
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Affiliation(s)
- Victor W Henderson
- Department of Health Research & Policy (Epidemiology), Stanford University, Stanford, CA, USA.
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