1
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Limaye AM, Asangani I, Kalyani T, Kondaiah P. Changes in gene expression following androgen receptor blockade is not equivalent to androgen ablation by castration in the rat ventral prostate. J Biosci 2008; 33:209-20. [PMID: 18535355 DOI: 10.1007/s12038-008-0038-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Involution of the rat ventral prostate and concomitant modulation of gene expression post-castration is a well- documented phenomenon. While the rat castration model has been extensively used to study androgen regulation of gene expression in the ventral prostate,it is not clear whether all the gene expression changes post-castration are due to androgen depletion alone. To obtain insights into this, we performed differential display reverse transcriptase polymerase chain reaction (DD-RT-PCR) which resulted in the identification of castration and/or flutamide-regulated genes in the rat ventral prostate. These include clusterin, methionine adenosyl transferase II alpha, and prostate-specific transcripts such as PBPC1BS, S100RVP and A7. While clusterin, PBPC1BS and methionine adenosyl transferase II alpha are regulated by both castration and flutamide, S100 RVP and A7 are regulated by castration alone. Interestingly, we show that flutamide, unlike castration, does not induce apoptosis in the rat ventral prostate epithelium, which could be an underlying cause for the differential effects of castration and flutamide treatment. We propose that castration leads to enrichment and depletion of stromal and epithelial cell types, respectively, resulting in erroneous conclusions on some of the cell type-specific transcripts as being androgen regulated.
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Affiliation(s)
- Anil M Limaye
- Chromatin Biology Lab, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560 064, India
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2
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Godoy A, Watts A, Sotomayor P, Montecinos VP, Huss WJ, Onate SA, Smith GJ. Androgen receptor is causally involved in the homeostasis of the human prostate endothelial cell. Endocrinology 2008; 149:2959-69. [PMID: 18292195 PMCID: PMC2408806 DOI: 10.1210/en.2007-1078] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Androgen deprivation causes a reduction of blood flow in the prostate gland that precedes temporally apoptosis of the epithelium. The acute response of prostate endothelial cells to androgen deprivation suggested they represent a primary target for androgen. However, rat prostate endothelial cells were reported not to express androgen receptor (AR), and the role of the androgen axis in human prostate endothelial cell (HPEC) homeostasis was poorly characterized. In this study AR expression was detected in HPEC in vivo in clinical specimens of benign prostate and prostate cancer, and AR function as a transcription factor was demonstrated in HPEC in primary xenografts of human benign prostate tissue transplanted into severe combined immunodeficient mice by iv administration of adenoviral mouse mammary tumor virus-driven luciferase expression vector. AR expression and functionality were maintained in vitro in primary cultures of HPEC that coexpressed CD31, CD34, von Willebrand factor, intercellular adhesion molecule, vascular endothelial growth factor receptor 1, and vascular endothelial growth factor receptor 2 but did not express prostate-specific antigen. AR expression in primary cultures of HPEC isolated from surgical specimens of benign prostate was validated using RT-PCR, cDNA sequencing, immunocytochemistry, and Western blot analyses. Scatchard analyses demonstrated a single ligand-binding site for R1881 in primary cultures of HPEC, with dissociation constant of 0.25 nm, and AR-mediated transcriptional activity was demonstrated using adenoviral mouse mammary tumor virus-driven luciferase reporters. Dihydrotestosterone increased proliferation in primary cultures of HPEC in a dose-dependent manner without modulating endothelial tube formation in Matrigel (BD Biosciences, Bedford, MA). Therefore, HPECs express functional AR, and androgen plays a direct role in modulating HPEC biology.
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Affiliation(s)
- Alejandro Godoy
- Department of Urologic Oncology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, New York 14263, USA
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3
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Klokk TI, Kurys P, Elbi C, Nagaich AK, Hendarwanto A, Slagsvold T, Chang CY, Hager GL, Saatcioglu F. Ligand-specific dynamics of the androgen receptor at its response element in living cells. Mol Cell Biol 2007; 27:1823-43. [PMID: 17189428 PMCID: PMC1820481 DOI: 10.1128/mcb.01297-06] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2006] [Revised: 08/24/2006] [Accepted: 12/08/2006] [Indexed: 12/29/2022] Open
Abstract
Androgens have key roles in normal physiology and in male sexual differentiation as well as in pathological conditions such as prostate cancer. Androgens act through the androgen receptor (AR), which is a ligand-modulated transcription factor. Antiandrogens block AR function and are widely used in disease states, but little is known about their mechanism of action in vivo. Here, we describe a rapid differential interaction of AR with target genomic sites in living cells in the presence of agonists which coincides with the recruitment of BRM ATPase complex and chromatin remodeling, resulting in transcriptional activation. In contrast, the interaction of antagonist-bound or mutant AR with its target was found to be kinetically different: it was dramatically faster, occurred without chromatin remodeling, and resulted in the lack of transcriptional inhibition. Fluorescent resonance energy transfer analysis of wild-type AR and a transcriptionally compromised mutant at the hormone response element showed that intramolecular interactions between the N and C termini of AR play a key functional role in vivo compared to intermolecular interactions between two neighboring ARs. These data provide a kinetic and mechanistic basis for regulation of gene expression by androgens and antiandrogens in living cells.
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MESH Headings
- Adenocarcinoma/pathology
- Androgen Antagonists/pharmacology
- Androgens/pharmacology
- Anilides/pharmacology
- Animals
- Cell Line, Tumor
- Chromatin Assembly and Disassembly
- Cyproterone Acetate/pharmacology
- Dihydrotestosterone/pharmacology
- Female
- Fluorescence Recovery After Photobleaching
- Flutamide/analogs & derivatives
- Flutamide/pharmacology
- Genes, Reporter
- Green Fluorescent Proteins/metabolism
- In Situ Hybridization, Fluorescence
- Ligands
- Luciferases/metabolism
- Mammary Neoplasms, Animal/pathology
- Mammary Tumor Virus, Mouse/genetics
- Metribolone/pharmacology
- Mice
- Microscopy, Video
- Mifepristone/pharmacology
- Models, Biological
- Nitriles/pharmacology
- Plasmids
- Promoter Regions, Genetic
- Receptors, Androgen/drug effects
- Receptors, Androgen/metabolism
- Response Elements/physiology
- Testosterone/pharmacology
- Tosyl Compounds/pharmacology
- Transcription, Genetic
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Affiliation(s)
- Tove I Klokk
- Department of Molecular Biosciences, University of Oslo, Postboks 1041 Blindern, 0316 Oslo, Norway
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4
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Whitaker HC, Hanrahan S, Totty N, Gamble SC, Waxman J, Cato ACB, Hurst HC, Bevan CL. Androgen receptor is targeted to distinct subcellular compartments in response to different therapeutic antiandrogens. Clin Cancer Res 2005; 10:7392-401. [PMID: 15534116 DOI: 10.1158/1078-0432.ccr-04-0388] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Antiandrogens are routinely used in the treatment of prostate cancer. Although they are known to prevent activation of the androgen receptor (AR), little is known about the mechanisms involved. This report represents the first study of the localization of wild-type AR following expression at physiologic relevant levels in prostate cells and treatment with androgen and antiandrogens. EXPERIMENTAL DESIGN We have characterized a cellular model for prostate cancer using in situ cellular fractionation, proteomics, and confocal microscopy and investigated the effect of antiandrogens in clinical use on the subcellular localization of the AR. RESULTS Different antiandrogens have diverse effects on the subcellular localization of the AR. Treatment with androgen results in translocation from the cytoplasm to the nucleoplasm, whereas the antiandrogens hydroxyflutamide and bicalutamide lead to reversible association with the nuclear matrix. In contrast, treatment with the antiandrogen cyproterone acetate results in AR association with cytoplasmic membranes and irreversible retention within the cytoplasm. In addition, we demonstrate that AR translocation requires ATP and the cytoskeleton, regardless of ligand. CONCLUSIONS These results reveal that not all antiandrogens work via the same mechanism and suggest that an informed sequential treatment regime may benefit prostate cancer patients. The observed subnuclear and subcytoplasmic associations of the AR suggest new areas of study to investigate the role of the AR in the response and resistance of prostate cancer to antiandrogen therapy.
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Affiliation(s)
- Hayley C Whitaker
- Prostate Cancer Research Group, Department of Cancer Medicine, Faculty of Medicine, Imperial College London, London, United Kingdom
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5
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Seo J, Lozano MM, Dudley JP. Nuclear matrix binding regulates SATB1-mediated transcriptional repression. J Biol Chem 2005; 280:24600-9. [PMID: 15851481 DOI: 10.1074/jbc.m414076200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Special AT-rich binding protein 1 (SATB1) originally was identified as a protein that bound to the nuclear matrix attachment regions (MARs) of the immunoglobulin heavy chain intronic enhancer. Subsequently, SATB1 was shown to repress many genes expressed in the thymus, including interleukin-2 receptor alpha, c-myc, and those encoded by mouse mammary tumor virus (MMTV), a glucocorticoid-responsive retrovirus. SATB1 binds to MARs within the MMTV provirus to repress transcription. To address the role of the nuclear matrix in SATB1-mediated repression, a series of SATB1 deletion constructs was used to determine protein localization. Wild-type SATB1 localized to the soluble nuclear, chromatin, and nuclear matrix fractions. Mutants lacking amino acids 224-278 had a greatly diminished localization to the nuclear matrix, suggesting the presence of a nuclear matrix targeting sequence (NMTS). Transient transfection experiments showed that NMTS fusions to green fluorescent protein or LexA relocalized these proteins to the nuclear matrix. Difficulties with previous assay systems prompted us to develop retroviral vectors to assess effects of different SATB1 domains on expression of MMTV proviruses or integrated reporter genes. SATB1 overexpression repressed MMTV transcription in the presence and absence of functional glucocorticoid receptor. Repression was alleviated by deletion of the NMTS, which did not affect DNA binding, or by deletion of the MAR-binding domain. Our studies indicate that both nuclear matrix association and DNA binding are required for optimal SATB1-mediated repression of the integrated MMTV promoter and may allow insulation from cellular regulatory elements.
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MESH Headings
- Animals
- Cell Line, Tumor
- Cell Nucleus/metabolism
- DNA/chemistry
- DNA Primers/chemistry
- Dimerization
- Fibroblasts/metabolism
- Gene Deletion
- Genes, Reporter
- Green Fluorescent Proteins/metabolism
- Humans
- Interleukin-2 Receptor alpha Subunit
- Introns
- Jurkat Cells
- Ligands
- Mammary Glands, Animal
- Mammary Tumor Virus, Mouse/genetics
- Matrix Attachment Region Binding Proteins/metabolism
- Matrix Attachment Region Binding Proteins/physiology
- Mice
- Microscopy, Fluorescence
- Mutation
- Plasmids/metabolism
- Polymerase Chain Reaction
- Promoter Regions, Genetic
- Protein Binding
- Protein Structure, Tertiary
- Proto-Oncogene Proteins c-myc/metabolism
- RNA/metabolism
- Rats
- Receptors, Glucocorticoid/metabolism
- Receptors, Interleukin/metabolism
- Recombinant Fusion Proteins/chemistry
- Retroviridae/genetics
- Ribonucleases/metabolism
- Subcellular Fractions
- Transcription, Genetic
- Transfection
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Affiliation(s)
- Jin Seo
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
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6
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Zhao J, Bauman WA, Huang R, Caplan AJ, Cardozo C. Oxandrolone blocks glucocorticoid signaling in an androgen receptor-dependent manner. Steroids 2004; 69:357-66. [PMID: 15219414 DOI: 10.1016/j.steroids.2004.01.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2003] [Revised: 12/10/2003] [Accepted: 01/16/2004] [Indexed: 11/22/2022]
Abstract
The anabolic steroid oxandrolone is increasingly used to preserve or restore muscle mass in those with HIV infection or serious burns. These effects are mediated, in part, by the androgen receptor (AR). Anti-glucocorticoid effects have also been reported for some anabolic steroids, and the goal of our studies was to determine whether oxandrolone had a similar mechanism of action. Studies with in vitro translated glucocorticoid receptor (GR), however, showed no inhibition of cortisol binding by oxandrolone. Conversely, experiments in cell culture systems demonstrated significant antagonism of cortisol-induced transcriptional activation by oxandrolone in cells expressing both the AR and GR. Inhibition was not overcome by increased cortisol concentration, and no inhibition by oxandrolone was observed in cells expressing GR alone, confirming that non-competitive mechanisms were involved. AR-dependent repression of transcriptional activation by oxandrolone was also observed with the synthetic glucocorticoids dexamethasone and methylprednisolone. Furthermore, the AR antagonists 2-hydroxyflutamide and DDE also repressed GR transactivation in an AR-dependent manner. A mutant AR lacking a functional nuclear localization signal (AR(4RKM)) was active in oxandrolone-mediated repression of GR even though oxandrolone-bound AR(4RKM) failed to enter the nucleus and did not affect nuclear import of GR. These data indicate a novel action of oxandrolone to suppress glucocorticoid action via crosstalk between AR and GR.
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Affiliation(s)
- Jingbo Zhao
- Rehabilitation and Research Development Center of Excellence for the Medical Consequences of Spinal Cord Injury, VA Medical Center, Bronx, NY, USA
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7
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Wang Q, Fondell JD. Generation of a mammalian cell line stably expressing a tetracycline-regulated epitope-tagged human androgen receptor: implications for steroid hormone receptor research. Anal Biochem 2001; 289:217-30. [PMID: 11161315 DOI: 10.1006/abio.2000.4960] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The androgen receptor (AR) is hormone-activated transcription factor that regulates the expression of genes involved in differentiation, development, and maintenance of male reproductive functions. To establish a useful model system for studying molecular mechanisms of AR action, we generated a HeLa-derived cell line (termed E19) that stably expresses human AR. Because overexpression of AR in cultured cells can be cytotoxic, we placed AR expression under the control of a tetracycline-regulated promoter. The stably expressed AR also contains an N-terminal FLAG-epitope tag (f:AR) that provides an advantageous method for immunopurification. We show that f:AR expression in E19 cells can be precisely modulated by varying the concentration of tetracycline or its chemical derivative doxycycline in the growth media. The functional activity of E19-expressed f:AR is demonstrated in vivo by its ability to activate transiently transfected AR reporter genes in an androgen-dependent manner, and in vitro by its ability to specifically bind AR-response elements using DNA-mobility shift assays. We further show that f:AR in androgen-stimulated E19 cells is markedly phosphorylated and coimmunopurifies with the transcriptional coactivator CREB-binding protein (CBP). The implications of these findings on steroid receptor research and the identification of receptor coregulatory factors will be discussed.
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Affiliation(s)
- Q Wang
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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8
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Huang W, Shostak Y, Tarr P, Sawyers C, Carey M. Cooperative assembly of androgen receptor into a nucleoprotein complex that regulates the prostate-specific antigen enhancer. J Biol Chem 1999; 274:25756-68. [PMID: 10464314 DOI: 10.1074/jbc.274.36.25756] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Prostate cancer is characterized by elevated serum levels of prostate-specific antigen (PSA). PSA gene expression is controlled by an androgen-responsive transcriptional enhancer. Our study suggests that formation of a nucleoprotein complex, encompassing 170 base pairs of enhancer DNA, mediates androgen-responsive PSA enhancer activity. The complex is assembled by cooperative binding of androgen receptor to at least four tandem, nonconsensus androgen response elements (AREs). Systematic mutagenesis of the AREs demonstrated that they act synergistically to stimulate androgen receptor-responsive gene expression. We discuss a mechanism whereby a combination of high androgen receptor levels in the prostate and low affinity AREs contribute to the cell type specificity and activity of the enhancer.
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Affiliation(s)
- W Huang
- Department of Biological Chemistry, Box 1737, UCLA School of Medicine, Los Angeles, California 90095, USA
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9
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Wiren K, Keenan E, Zhang X, Ramsey B, Orwoll E. Homologous androgen receptor up-regulation in osteoblastic cells may be associated with enhanced functional androgen responsiveness. Endocrinology 1999; 140:3114-24. [PMID: 10385404 DOI: 10.1210/endo.140.7.6753] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although androgens have myriad effects on the skeleton, the regulation of androgen action in bone is not well understood. Androgen receptors (ARs) are known to play an important role in mediating androgen action. We have examined the effects of androgens and other sex steroids on AR levels in osteoblastic cells in vitro using two clonal human cell lines, SaOS-2 and U-2 OS. AR protein levels were quantitated both by specific androgen binding studies and Western analyses, and AR messenger RNA was measured with RNase protection assays. Potential changes in AR functionality was assessed by reporter assays. Treatment of osteoblastic cells with the nonaromatizable androgen 5alpha-dihydrotestosterone (DHT) increased specific androgen binding 2-to 4-fold. Similar increases in AR protein levels were documented by Western analysis in both cell lines. The androgen-mediated increase in receptor levels was time and dose dependent as well as androgen specific. Steady-state AR messenger RNA levels were also increased by DHT. When AR concentrations in osteoblastic cells were elevated with exogenous receptor, there was an enhancement of DHT responsiveness, measured by increased trans-activation of an androgen-responsive promoter. Thus, androgen exposure increased androgen receptor protein levels and specific androgen binding in osteoblastic cells. Androgen action as measured by androgen-mediated transcriptional activation is enhanced in the presence of elevated AR levels. Consequently, these studies have revealed an additional means by which androgens may modulate skeletal metabolism.
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Affiliation(s)
- K Wiren
- Veterans Affairs Medical Center, Department of Behavioral Neuroscience, Oregon Health Sciences University, Portland 97201, USA.
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10
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Wiren KM, Zhang X, Chang C, Keenan E, Orwoll ES. Transcriptional up-regulation of the human androgen receptor by androgen in bone cells. Endocrinology 1997; 138:2291-300. [PMID: 9165014 DOI: 10.1210/endo.138.6.5163] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Androgen regulation of androgen receptor (AR) expression has been observed in a variety of tissues, generally as inhibition, and is thought to attenuate cellular responses to androgen. AR is expressed in osteoblasts, the bone-forming cell, suggesting direct actions of androgens on bone. Here we characterized the effect of androgen exposure on AR gene expression in human osteoblastic SaOS-2 and U-2 OS cells. Treatment of osteoblastic cells with the nonaromatizable androgen 5alpha-dihydrotestosterone increased AR steady state messenger RNA levels in a time- and dose-dependent fashion. Reporter assays with 2.3 kilobases of the proximal 5'-flanking region of the human AR promoter linked to the chloramphenicol acetyltransferase gene in transfected cultures showed that up-regulation of AR promoter activity by androgen was time and dose dependent. Treatment with other steroid hormones, including progesterone, 17beta-estradiol, and dexamethasone, was without effect. The antiandrogen hydroxyflutamide completely antagonized androgen up-regulation. Thus, in contrast to many other androgen target tissues, androgen exposure increases steady state AR messenger RNA levels in osteoblasts. This regulation occurs at least partially at the level of transcription, is mediated by the 5'-promoter region of the AR gene, and is dependent on functional AR. These results suggest that physiological concentrations of androgens have significant effects on AR expression in skeletal tissue.
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Affiliation(s)
- K M Wiren
- Bone and Mineral Research Unit, Veterans Affairs Medical Center, Portland, Oregon 97201, USA.
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11
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Toney JH, Chen Y, Rutledge SJ, Schmidt A, Elbrecht A. Non-steroidal L-245,976 acts as a classical antiandrogen in vitro. J Steroid Biochem Mol Biol 1997; 60:131-6. [PMID: 9182867 DOI: 10.1016/s0960-0760(96)00164-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Non-steroidal antiandrogens have been employed in the management of prostate cancer, but the mechanism of action is unclear due to a lack of good tissue culture models. The growth of a hamster ductus deferens cell line (DDT1) is highly dependent upon the addition of 10 nM testosterone to synthetic serum-free media. We describe a non-steroidal compound N-(4-chlorophenyl)-(Z,Z)-2,3-bis(-cyclopropylmethylene) cyclopentanecarboxamide (L-245976) which antagonizes the action of testosterone on DDT1 cells at 10 microM but exhibits little or no effect on cell growth by itself. This compound also blocks the binding of 3H-dihydrotestosterone (DHT) to the human androgen receptor (AR) with an IC50 of approximately 28 microM. In addition, L-245976 was found to antagonize DHT-dependent transactivation of the AR via the probasin gene promoter at comparable doses with no agonist activity.
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Affiliation(s)
- J H Toney
- Department of Biochemistry, Merck Research Laboratories, Rahway, NJ 07065-0900, U.S.A
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12
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Grant ES, Batchelor KW, Habib FK. Androgen independence of primary epithelial cultures of the prostate is associated with a down-regulation of androgen receptor gene expression. Prostate 1996; 29:339-49. [PMID: 8977630 DOI: 10.1002/(sici)1097-0045(199612)29:6<339::aid-pros1>3.0.co;2-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Epithelial cells cultured from prostatic acini do not demonstrate significant (P > 0.05) growth response to the testosterone metabolite dihydrotestosterone (DHT) at concentrations of 0.001-10.0 nM. In addition, the nonsteroidal antiandrogen hydroxyflutamide (HO-F) does not influence primary epithelial cell proliferation in this concentration range. METHODS Northern blotting carried out with an androgen reception (AR)-specific cDNA probe indicated that the extent of AR gene expression in six unpassaged primary prostatic epithelial cell cultures was insufficient to elicit a detectable signal upon autoradiography. However, RT/PCR analysis of total RNA using two sets of intron-spanning androgen receptor (AR) primers demonstrates the presence of full-length receptor transcripts in two BPH-derived epithelial cell cultures (BPH1 and BPH2) as well as a carcinoma-derived culture (CaP1). RESULTS AR-positive LNCaP cells transfected with the AR reporter plasmid pMMTV/SPAP exhibit significant increases (P < 0.05) in SPAP production upon treatment with DHT. pMMTV/SPAP-transfected primary epithelial cells exhibit no such response when pulsed with either androgen or anti-androgen. CONCLUSIONS These results indicate that the lack of significant AR gene expression underlies the androgen independence of primary prostatic epithelial cell cultures.
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MESH Headings
- Androgen Antagonists/pharmacology
- Androgens/pharmacology
- Androgens/physiology
- Base Sequence
- Blotting, Northern
- Cell Division/drug effects
- Cell Division/physiology
- DNA, Neoplasm/analysis
- DNA, Neoplasm/chemistry
- DNA, Neoplasm/genetics
- Dihydrotestosterone/pharmacology
- Dose-Response Relationship, Drug
- Down-Regulation/drug effects
- Down-Regulation/physiology
- Epithelium/chemistry
- Epithelium/drug effects
- Epithelium/pathology
- Flutamide/analogs & derivatives
- Flutamide/pharmacology
- Gene Expression Regulation, Neoplastic/physiology
- Humans
- Male
- Molecular Sequence Data
- Polymerase Chain Reaction
- Prostatic Neoplasms/chemistry
- Prostatic Neoplasms/pathology
- Prostatic Neoplasms/physiopathology
- RNA, Messenger/analysis
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- Receptors, Androgen/analysis
- Receptors, Androgen/genetics
- Receptors, Androgen/physiology
- Transfection
- Tumor Cells, Cultured
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Affiliation(s)
- E S Grant
- Department of Surgery/Urology, University of Edinburgh, U.K
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13
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Warriar N, Yu C, Pagé N, Govindan MV. Substitution of Cys-560 by Phe, Trp, Tyr, and Ser in the first zinc finger of human androgen receptor affects hormonal sensitivity and transcriptional activation. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(19)62007-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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