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Morthen MK, Tellefsen S, Richards SM, Lieberman SM, Rahimi Darabad R, Kam WR, Sullivan DA. Testosterone Influence on Gene Expression in Lacrimal Glands of Mouse Models of Sjögren Syndrome. Invest Ophthalmol Vis Sci 2019; 60:2181-2197. [PMID: 31108549 PMCID: PMC6528840 DOI: 10.1167/iovs.19-26815] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Purpose Sjögren syndrome is an autoimmune disorder that occurs almost exclusively in women and is associated with extensive inflammation in lacrimal tissue, an immune-mediated destruction and/or dysfunction of glandular epithelial cells, and a significant decrease in aqueous tear secretion. We discovered that androgens suppress the inflammation in, and enhance the function of, lacrimal glands in female mouse models (e.g., MRL/MpJ-Tnfrsf6lpr [MRL/lpr]) of Sjögren syndrome. In contrast, others have reported that androgens induce an anomalous immunopathology in lacrimal glands of nonobese diabetic/LtJ (NOD) mice. We tested our hypothesis that these hormone actions reflect unique, strain- and tissue-specific effects, which involve significant changes in the expression of immune-related glandular genes. Methods Lacrimal glands were obtained from age-matched, adult, female MRL/lpr and NOD mice after treatment with vehicle or testosterone for up to 3 weeks. Tissues were processed for analysis of differentially expressed mRNAs using CodeLink Bioarrays and Affymetrix GeneChips. Data were analyzed with bioinformatics and statistical software. Results Testosterone significantly influenced the expression of numerous immune-related genes, ontologies, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in lacrimal glands of MRL/lpr and NOD mice. The nature of this hormone-induced immune response was dependent upon the autoimmune strain, and was not duplicated within lacrimal tissues of nonautoimmune BALB/c mice. The majority of immune-response genes regulated by testosterone were of the inflammatory type. Conclusions Our findings support our hypothesis and indicate a major role for the lacrimal gland microenvironment in mediating androgen effects on immune gene expression.
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Affiliation(s)
- Mathias Kaurstad Morthen
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, Massachusetts, United States.,Department of Medical Biochemistry, Oslo University Hospital/Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Sara Tellefsen
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, Massachusetts, United States.,Department of Medical Biochemistry, Oslo University Hospital/Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Stephen M Richards
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, Massachusetts, United States.,Department of Genetics & Evolution, School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - Scott M Lieberman
- Stead Family Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Raheleh Rahimi Darabad
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, Massachusetts, United States.,Department of Clinical Anesthesia, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | - Wendy R Kam
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, Massachusetts, United States.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - David A Sullivan
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, Massachusetts, United States.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
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Sullivan DA, Rocha EM, Aragona P, Clayton JA, Ding J, Golebiowski B, Hampel U, McDermott AM, Schaumberg DA, Srinivasan S, Versura P, Willcox MDP. TFOS DEWS II Sex, Gender, and Hormones Report. Ocul Surf 2017; 15:284-333. [PMID: 28736336 DOI: 10.1016/j.jtos.2017.04.001] [Citation(s) in RCA: 236] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 04/16/2017] [Indexed: 12/21/2022]
Abstract
One of the most compelling features of dry eye disease (DED) is that it occurs more frequently in women than men. In fact, the female sex is a significant risk factor for the development of DED. This sex-related difference in DED prevalence is attributed in large part to the effects of sex steroids (e.g. androgens, estrogens), hypothalamic-pituitary hormones, glucocorticoids, insulin, insulin-like growth factor 1 and thyroid hormones, as well as to the sex chromosome complement, sex-specific autosomal factors and epigenetics (e.g. microRNAs). In addition to sex, gender also appears to be a risk factor for DED. "Gender" and "sex" are words that are often used interchangeably, but they have distinct meanings. "Gender" refers to a person's self-representation as a man or woman, whereas "sex" distinguishes males and females based on their biological characteristics. Both gender and sex affect DED risk, presentation of the disease, immune responses, pain, care-seeking behaviors, service utilization, and myriad other facets of eye health. Overall, sex, gender and hormones play a major role in the regulation of ocular surface and adnexal tissues, and in the difference in DED prevalence between women and men. The purpose of this Subcommittee report is to review and critique the nature of this role, as well as to recommend areas for future research to advance our understanding of the interrelationships between sex, gender, hormones and DED.
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Affiliation(s)
- David A Sullivan
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA.
| | - Eduardo M Rocha
- Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
| | - Pasquale Aragona
- Department of Biomedical Sciences, Ocular Surface Diseases Unit, University of Messina, Messina, Sicily, Italy
| | - Janine A Clayton
- National Institutes of Health Office of Research on Women's Health, Bethesda, MD, USA
| | - Juan Ding
- Schepens Eye Research Institute, Massachusetts Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Blanka Golebiowski
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - Ulrike Hampel
- Department of Ophthalmology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Alison M McDermott
- The Ocular Surface Institute, College of Optometry, University of Houston, Houston, TX, USA
| | - Debra A Schaumberg
- Harvard School of Public Health, Boston, MA, USA; University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Sruthi Srinivasan
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Ontario, Canada
| | - Piera Versura
- Department of Specialized, Experimental, and Diagnostic Medicine, University of Bologna, Bologna, Italy
| | - Mark D P Willcox
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
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Zhang H, Wu J, Keller JM, Yeung K, Keller ET, Fu Z. Transcriptional regulation of RKIP expression by androgen in prostate cells. Cell Physiol Biochem 2012; 30:1340-50. [PMID: 23095933 DOI: 10.1159/000343323] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Raf kinase inhibitory protein (RKIP) is a scaffolding molecule in the PEBP family that sequesters certain signaling molecules away from their pathways, thereby abrogating intracellular growth signals. RKIP has been assigned multiple functions and is associated with an increasing number of diseases through its involvement with signal transduction pathways. We previously demonstrated that RKIP is highly expressed in human normal prostate epithelial cells and plays a pivotal role during prostate cancer (PCa) progression. Whether RKIP is subject to endocrine regulation has not been reported. METHODS The effect of dihydrotestosterone (DHT) on RKIP expression in normal prostate epithelial cells was determined by real-time RT-PCR and Western blot. Report assay was performed to determine whether the regulation of RKIP by androgens is at the transcriptional level. The binding of androgen receptor (AR) to the RKIP promoter was determined by EMSA and Chromatin Immunoprecipitation (ChIP) assays. To determine whether RKIP was regulated by androgen in vivo, we examined RKIP expression level in response to castration in 6-8 week old C57BL/6 male mice. RESULTS Here we report that DHT positively regulates the transcription of RKIP in the normal prostate epithelial cells. The anti-androgen bicalutamide blocked androgen-mediated regulation of RKIP, which indicates that this regulation is mediated through AR. Transfection of the cells with a RKIP promoter-driven luciferase reporter vector showed that DHT increased RKIP promoter activity in parallel with changes in expression. EMSA demonstrates that AR binds to a putative ARE in the RKIP promoter, which was further validated by ChIP assay. Importantly, these data are further supported by our in vivo experiment where castrated mice had less RKIP expression in their prostate glands than sham-operated mice. CONCLUSIONS Collectively, the results establish RKIP as a novel androgen target gene. Androgens induce RKIP expression through AR-mediated transcriptional modulation of the RKIP promoter in the prostate. This is the first demonstration of endocrine regulation of the metastasis suppressor gene RKIP.
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Affiliation(s)
- Honglai Zhang
- University of Michigan Comprehensive Cancer Center and Department of Urology, University of Michigan Health System, Ann Arbor, MI 48109, USA
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Piekarski DJ, Seto T, Zucker I. The protein synthesis inhibitor anisomycin reduces sex behavior during a critical period after testosterone treatment in male Syrian hamsters. Physiol Behav 2011; 105:215-9. [PMID: 21896280 DOI: 10.1016/j.physbeh.2011.08.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 08/20/2011] [Accepted: 08/23/2011] [Indexed: 11/25/2022]
Abstract
Testosterone (T) is critical for maintaining male sexual behavior (MSB) in rodents, in part by altering protein synthesis in a well-defined neural circuit. The specific timing of protein synthesis essential for expression of MSB has never been investigated. We administered the protein synthesis inhibitor anisomycin (Ani) to castrated male Syrian hamsters treated sc with 100 μg T in an aqueous vehicle once weekly; this T regimen maintains MSB while elevating circulating T concentrations for only a few hours after each injection. Hamsters were injected s.c. with the vehicle or 12.5 mg Ani at one of several times relative to T administration; MSB was assessed once per week, 6 days after the previous T injection, for 5 weeks. Anisomycin administered 6-12 h after T injection significantly reduced the expression of sexual behavior, whereas Ani treatment between 3 h before and 3 h after T injection did not impair MSB. This experiment is the first to assess the specific timing of protein synthesis relative to a T pulse that is required for the expression of MSB. The demarcation of a critical interval for T-induced protein synthesis necessary for maintenance of MSB should facilitate specification of the genomic, proteomic, and biochemical cascades that subserve actions of T on male copulation.
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Affiliation(s)
- David J Piekarski
- Department of Psychology, University of California, Berkeley, Berkeley, CA 94720, USA.
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Abstract
Testosterone is the most abundant circulating androgen, and can be converted to dihydrotestosterone (DHT), a more potent androgen, by the 5α-reductase enzymes in target tissues. Current treatments for prostate cancer consist of reducing androgen levels by chemical or surgical castration or pure antiandrogen therapy that directly targets the androgen receptor (AR). Although these therapies reduce tumor burden and AR activity, the cancer inevitably recurs within 18-30 months. An approach targeting the androgen-AR axis at different levels could, therefore, improve the efficacy of prostate cancer therapy. Inhibition of 5α-reductase is one such approach; however, the two largest trials to investigate the use of the 5α-reductase inhibitors (5ARIs) finasteride and dutasteride in patients with prostate cancer have shown that, although the incidence of cancer was reduced by 5ARI treatment, those cancers that were detected were more aggressive than in patients treated with placebo. Thus, the best practice for using these drugs to prevent and treat prostate cancer remains unclear.
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Shah S, Hess-Wilson JK, Webb S, Daly H, Godoy-Tundidor S, Kim J, Boldison J, Daaka Y, Knudsen KE. 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene stimulates androgen independence in prostate cancer cells through combinatorial activation of mutant androgen receptor and mitogen-activated protein kinase pathways. Mol Cancer Res 2008; 6:1507-20. [PMID: 18819937 DOI: 10.1158/1541-7786.mcr-07-2166] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Therapy resistance represents a major clinical challenge in disseminated prostate cancer for which only palliative treatment is available. One phenotype of therapy-resistant tumors is the expression of somatic, gain-of-function mutations of the androgen receptor (AR). Such mutant receptors can use noncanonical endogenous ligands (e.g., estrogen) as agonists, thereby promoting recurrent tumor formation. Additionally, selected AR mutants are sensitized to the estrogenic endocrine-disrupting compound (EDC) bisphenol A, present in the environment. Herein, screening of additional EDCs revealed that multiple tumor-derived AR mutants (including T877A, H874Y, L701H, and V715M) are sensitized to activation by the pesticide 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene (DDE), thus indicating that this agent may impinge on AR signaling in cancer cells. Further investigation showed that DDE induced mutant AR recruitment to the prostate-specific antigen regulatory region, concomitant with an enhancement of target gene expression, and androgen-independent proliferation. By contrast, neither AR activation nor altered cellular proliferation was observed in cells expressing wild-type AR. Activation of signal transduction pathways was also observed based on rapid phosphorylation of mitogen-activated protein kinase (MAPK) and vasodilator-stimulated phosphoprotein, although only MAPK activation was associated with DDE-induced cellular proliferation. Functional analyses showed that both mutant AR and MAPK pathways contribute to the proliferative action of DDE, as evidenced through selective abrogation of each pathway. Together, these data show that exposure to environmentally relevant doses of EDCs can promote androgen-independent cellular proliferation in tumor cells expressing mutant AR and that DDE uses both mutant AR and MAPK pathways to exert its mitogenic activity.
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Affiliation(s)
- Supriya Shah
- Kimmel Cancer Center and Department of Cancer, Thomas Jefferson University, Philadelphia, PA 19107, USA
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Sullivan DA. Tearful relationships? Sex, hormones, the lacrimal gland, and aqueous-deficient dry eye. Ocul Surf 2007; 2:92-123. [PMID: 17216082 DOI: 10.1016/s1542-0124(12)70147-7] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Sex and the endocrine system exert a significant influence on the physiology and pathophysiology of the lacrimal gland. The purpose of this article is to briefly review the nature and magnitude of these interactions between sex, hormones and lacrimal tissue, and to address how they may relate to the pathogenesis of aqueous-deficient dry eye. Towards this end, this article has a 3-fold approach: first, to summarize the influence of androgens, estrogens, glucocorticoids, mineralocorticoids, retinoic acid, prolactin, alpha-melanocyte stimulating hormone, adrenocorticotropic hormone, luteinizing hormone, follicle-stimulating hormone, growth hormone, thyroid-stimulating hormone, arginine vasopressin, oxytocin, thyroxine, parathyroid hormone, insulin, glucagon, melatonin, human chorionic gonadotropin and cholecystokinin on the structure and function of the lacrimal gland; second, to discuss the mechanism of action of each hormone on lacrimal tissue; and third, to discuss the clinical relevance of the endocrine-lacrimal gland interrelationship, with a particular focus on each hormone's role (i.e. if relevant) in the development of aqueous-tear deficiency.
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Affiliation(s)
- David A Sullivan
- Schepens Eye Research Institute and Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114, USA.
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Wetherill YB, Hess-Wilson JK, Comstock CES, Shah SA, Buncher CR, Sallans L, Limbach PA, Schwemberger S, Babcock GF, Knudsen KE. Bisphenol A facilitates bypass of androgen ablation therapy in prostate cancer. Mol Cancer Ther 2006; 5:3181-90. [PMID: 17172422 DOI: 10.1158/1535-7163.mct-06-0272] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Prostatic adenocarcinomas depend on androgen for growth and survival. First line treatment of disseminated disease exploits this dependence by specifically targeting androgen receptor function. Clinical evidence has shown that androgen receptor is reactivated in recurrent tumors despite the continuance of androgen deprivation therapy. Several factors have been shown to restore androgen receptor activity under these conditions, including somatic mutation of the androgen receptor ligand-binding domain. We have shown previously that select tumor-derived mutants of the androgen receptor are receptive to activation by bisphenol A (BPA), an endocrine-disrupting compound that is leached from polycarbonate plastics and epoxy resins into the human food supply. Moreover, we have shown that BPA can promote cell cycle progression in cultured prostate cancer cells under conditions of androgen deprivation. Here, we challenged the effect of BPA on the therapeutic response in a xenograft model system of prostate cancer containing the endogenous BPA-responsive AR-T877A mutant protein. We show that after androgen deprivation, BPA enhanced both cellular proliferation rates and tumor growth. These effects were mediated, at least in part, through androgen receptor activity, as prostate-specific antigen levels rose with accelerated kinetics in BPA-exposed animals. Thus, at levels relevant to human exposure, BPA can modulate tumor cell growth and advance biochemical recurrence in tumors expressing the AR-T877A mutation.
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Affiliation(s)
- Yelena B Wetherill
- Department of Cell and Cancer Biology, Vontz Center for Molecular Studies, University of Cincinnati College of Medicine, 3125 Eden Avenue, ML 0521, Cincinnati, OH 45267-0521, USA
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Unraveling androgen receptor interactomes by an array-based method: discovery of proto-oncoprotein c-Rel as a negative regulator of androgen receptor. Exp Cell Res 2006; 312:3782-95. [PMID: 17011549 DOI: 10.1016/j.yexcr.2006.07.017] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2005] [Revised: 06/29/2006] [Accepted: 07/24/2006] [Indexed: 01/11/2023]
Abstract
The androgen receptor (AR) plays a key role in the development and function of male reproductive organs. Using a high-throughput transcription factor-transcription factor (TF-TF) interaction array method, we captured the AR interactomes in androgen-responsive LNCaP cells. Several known and unknown partners of AR, including AP-2, Pax 3/5 (BSAP), c-Rel, RREB-1, LIII BP, and NPAS2 were identified. We investigated one unreported AR-associated transcription factor, the proto-oncoprotein c-Rel, in detail. C-Rel belongs to the NF-kB/Rel families and is persistently active in a number of diseases, including cancer. The presence of c-Rel transcript, protein, and its in vitro and in vivo association with AR was determined. Co-localization of c-Rel with AR both in cytoplasm and nucleus was confirmed by indirect immunofluorescence analysis. Chromatin immunoprecipitation data indicated that c-Rel, like AR, is a part of the nucleoprotein complex regulating the androgen-responsive prostate-specific antigen (PSA) promoter. Overexpression of c-Rel downregulated the promoter activity of both PSA and GRE4-TATA-Luc plasmids in LNCaP and COS cells. Analysis of AR and c-Rel protein levels indicated that the promoter downregulation was not due to reciprocal decrease in the amounts of AR or c-Rel. In summary, we have identified several new partners of AR by using the TF-TF array method and have provided the first evidence of a functional role for c-Rel in androgen-responsive human prostate cancer cells.
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Stangelberger A, Schally AV, Varga JL, Zarandi M, Cai RZ, Baker B, Hammann BD, Armatis P, Kanashiro CA. Inhibition of human androgen-independent PC-3 and DU-145 prostate cancers by antagonists of bombesin and growth hormone releasing hormone is linked to PKC, MAPK and c-jun intracellular signalling. Eur J Cancer 2005; 41:2735-44. [PMID: 16291086 DOI: 10.1016/j.ejca.2005.08.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2005] [Revised: 07/26/2005] [Accepted: 08/02/2005] [Indexed: 11/29/2022]
Abstract
Bombesin/gastrin-releasing peptide (BN/GRP) antagonists RC-3940-II and RC-3940-Et, and growth hormone-releasing hormone (GHRH) antagonists MZ-J-7-118 and RC-J-29-18 inhibit the growth of human androgen-independent PC-3 and DU-145 prostate cancers in nude mice. Additive inhibitory effects were observed after treatment with both classes of analogs. In the present study, we investigated the effects of these antagonists on intracellular signalling pathways of protein kinase C (PKC), mitogen activated protein kinases (MAPK) and c-fos and c-jun oncogenes that are involved in tumour cell proliferation. In PC-3 tumours, antagonists of BN/GRP and GHRH decreased significantly the expression of PKC isoforms alpha (alpha), eta (eta) and zeta (zeta) and increased that of delta (delta) PKC protein. MAPK was not detectable. In DU-145 tumours, which constitutively express MAPK, all treatments strongly decreased the levels of p42/44 MAPK. Treatment with the antagonists tended to reduce m-RNA for c-jun in both tumour models. In proliferation assays in vitro, inhibitors of PKC and MAPK diminished growth of DU-145 and PC-3 cells. These findings suggest that antagonists of BN/GRP and GHRH inhibit the growth of androgen-independent prostate cancer by affecting intracellular signalling mechanisms of PKC, MAPK and c-jun.
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Affiliation(s)
- Anton Stangelberger
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, 1601 Perdido St., New Orleans, LA 70112-1262, USA
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Goodin JL, Rutherford CL. Characterization of human ribosomal S3a gene expression during adenosine 3':5' cyclic monophosphate induced neuroendocrine differentiation of LNCaP cells. Regulation of S3a gene expression in LNCaP. Mol Biol Rep 2002; 29:301-16. [PMID: 12463423 DOI: 10.1023/a:1020457400377] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Elevation of intracellular cAMP levels in the human prostatic adenocarcinoma cell line LNCaP results in the induction of reversible neuroendocrine differentiation and cell growth arrest. We have used the differential display technique to identify genes that are differentially expressed during cAMP induced neuroendocrine differentiation in LNCaP cells. We identified the human ribosomal S3a gene as being down regulated in response to LNCaP differentiation. The S3a gene is known to be expressed at high levels in both tumors and cancer cell lines. It has also been shown that down regulation of S3a is associated with a loss of the transformed phenotype. In order to better ascertain the mechanism by which S3a gene expression is decreased during differentiation, the promoter region for this gene was analyzed. Electrophoretic mobility shift assay, antibody supershift assays, site-directed mutagenesis, and luciferase reporter gene analysis were employed to authenticate the roles of several transcription factors in the regulation of the S3a gene. We found that two cyclic AMP response elements, a Sp1 element, and a GA-binding protein element were involved in the regulation of S3a gene expression. The CRE elements were found to be necessary for high level expression of the 53a gene in undifferentiated LNCaP cells. Mutations in the CRE elements abolished CREB-1 binding and resulted in a 57% decrease in S3a gene expression. The addition of cAMP elevating agents to LNCaP cells in sufficient quantity to induce differentiation generated a 50% decrease in S3a gene expression. These results suggest that the CRE elements participate in cAMP-induced down regulation of gene expression. Furthermore, our experiments demonstrate that occupation of the GABP binding site results in a substantial decrease in S3a promoter activity.
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Affiliation(s)
- Jeremy L Goodin
- Department of Biology, 2119 Derring Hall, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
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Abstract
The normal prostate and early-stage prostate cancers depend on androgens for growth and survival, and androgen ablation therapy causes them to regress. Cancers that are not cured by surgery eventually become androgen independent, rendering anti-androgen therapy ineffective. But how does androgen independence arise? We predict that understanding the pathways that lead to the development of androgen-independent prostate cancer will pave the way to effective therapies for these, at present, untreatable cancers.
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Affiliation(s)
- B J Feldman
- Department of Medicine, Stanford University School of Medicine, California 94305-5103, USA.
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Chapter 17. Selective androgen receptor modulators (SARMs). ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2001. [DOI: 10.1016/s0065-7743(01)36057-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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