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Sample records for androgen receptor sequence

  1. Sequence variation in the androgen receptor gene is not a common determinant of male sexual orientation

    SciTech Connect

    Macke, J.P.; Nathans, J.; King, V.L. ); Hu, N.; Hu, S.; Hamer, D.; Bailey, M. ); Brown, T. )

    1993-10-01

    To test the hypothesis that DNA sequence variation in the androgen receptor gene plays a causal role in the development of male sexual orientation, the authors have (1) measured the degree of concordance of androgen receptor alleles in 36 pairs of homosexual brothers, (2) compared the lengths of polyglutamine and polyglycine tracts in the amino-terminal domain of the androgen receptor in a sample of 197 homosexual males and 213 unselected subjects, and (3) screened the entire androgen receptor coding region for sequence variation by PCR and denaturing gradient-gel electrophoresis (DGGE) and/or single-strand conformation polymorphism analysis in 20 homosexual males with homosexual or bisexual brothers and one homosexual male with no homosexual brothers, and screened the amino-terminal domain of the receptor for sequence variation in an additional 44 homosexual males, 37 of whom had one or more first- or second-degree male relatives who were either homosexual or bisexual. These analyses show that (1) homosexual brothers are as likely to be discordant as concordant for androgen receptor alleles; (2) there are no large-scale differences between the distributions of polyglycine or polyglutamine tract lengths in the homosexual and control groups; and (3) coding region sequence variation is not commonly found within the androgen receptor gene of homosexual men. The DGGE screen identified two rare amino acid substitutions, ser[sup 205] -to-arg and glu[sup 793]-to-asp, the biological significance of which is unknown. 32 refs., 2 figs., 2 tabs.

  2. Sequence variation in the androgen receptor gene is not a common determinant of male sexual orientation.

    PubMed Central

    Macke, J P; Hu, N; Hu, S; Bailey, M; King, V L; Brown, T; Hamer, D; Nathans, J

    1993-01-01

    To test the hypothesis that DNA sequence variation in the androgen receptor gene plays a causal role in the development of male sexual orientation, we have (1) measured the degree of concordance of androgen receptor alleles in 36 pairs of homosexual brothers, (2) compared the lengths of polyglutamine and polyglycine tracts in the amino-terminal domain of the androgen receptor in a sample of 197 homosexual males and 213 unselected subjects, and (3) screened the the entire androgen receptor coding region for sequence variation by PCR and denaturing gradient-gel electrophoresis (DGGE) and/or single-strand conformation polymorphism analysis in 20 homosexual males with homosexual or bisexual brothers and one homosexual male with no homosexual brothers, and screened the amino-terminal domain of the receptor for sequence variation in an additional 44 homosexual males, 37 of whom had one or more first- or second-degree male relatives who were either homosexual or bisexual. These analyses show that (1) homosexual brothers are as likely to be discordant as concordant for androgen receptor alleles; (2) there are no large-scale differences between the distributions of polyglycine or polyglutamine tract lengths in the homosexual and control groups; and (3) coding region sequence variation is not commonly found within the androgen receptor gene of homosexual men. The DGGE screen identified two rare amino acid substitutions, ser205-to-arg and glu793-to-asp, the biological significance of which is unknown. Images Figure 2 PMID:8213813

  3. Natural disordered sequences in the amino terminal domain of nuclear receptors: lessons from the androgen and glucocorticoid receptors.

    PubMed

    McEwan, Iain J; Lavery, Derek; Fischer, Katharina; Watt, Kate

    2007-01-01

    Steroid hormones are a diverse class of structurally related molecules, derived from cholesterol, that include androgens, estrogens, progesterone and corticosteroids. They represent an important group of physiologically active signalling molecules that bind intracellular receptor proteins and regulate genes involved in developmental, reproductive and metabolic processes. The receptor proteins share structurally and functionally related ligand binding and DNA-binding domains, but possess distinct N-terminal domains (NTD) of unique length and amino acids sequence. The NTD contains sequences important for gene regulation, exhibit structure plasticity and are likely to contribute to the specificity of the steroid hormone/receptor response. PMID:17464357

  4. Natural disordered sequences in the amino terminal domain of nuclear receptors: lessons from the androgen and glucocorticoid receptors

    PubMed Central

    McEwan, Iain J.; Lavery, Derek; Fischer, Katharina; Watt, Kate

    2007-01-01

    Steroid hormones are a diverse class of structurally related molecules, derived from cholesterol, that include androgens, estrogens, progesterone and corticosteroids. They represent an important group of physiologically active signalling molecules that bind intracellular receptor proteins and regulate genes involved in developmental, reproductive and metabolic processes. The receptor proteins share structurally and functionally related ligand binding and DNA-binding domains, but possess distinct N-terminal domains (NTD) of unique length and amino acids sequence. The NTD contains sequences important for gene regulation, exhibit structure plasticity and are likely to contribute to the specificity of the steroid hormone/receptor response. PMID:17464357

  5. Structural analysis of complementary DNA and amino acid sequences of human and rat androgen receptors

    SciTech Connect

    Chang, C.; Kokontis, J.; Liao, S. )

    1988-10-01

    Structural analysis of cDNAs for human and rat androgen receptors (ARs) indicates that the amino-terminal regions of ARs are rich in oligo- and poly(amino acid) motifs as in some homeotic genes. The human AR has a long stretch of repeated glycines, whereas rat AR has a long stretch of glutamines. There is a considerable sequence similarity among ARs and the receptors for glucocorticoids, progestins, and mineralocorticoids within the steroid-binding domains. The cysteine-rich DNA-binding domains are well conserved. Translation of mRNA transcribed from AR cDNAs yielded 94- and 76-kDa proteins and smaller forms that bind to DNA and have high affinity toward androgens. These rat or human ARs were recognized by human autoantibodies to natural Ars. Molecular hybridization studies, using AR cDNAs as probes, indicated that the ventral prostate and other male accessory organs are rich in AR mRNA and that the production of AR mRNA in the target organs may be autoregulated by androgens.

  6. Androgen receptor genomic regulation

    PubMed Central

    Jin, Hong-Jian; Kim, Jung

    2013-01-01

    The transcriptional activity of the androgen receptor (AR) is not only critical for the normal development and function of the prostate but also pivotal to the onset and progression of prostate cancer (PCa). The studies of AR transcriptional regulation were previously limited to a handful of AR-target genes. Owing to the development of various high-throughput genomic technologies, significant advances have been made in recent years. Here we discuss the discoveries of genome-wide androgen-regulated genes in PCa cell lines, animal models and tissues using expression microarray and sequencing, the mapping of genomic landscapes of AR using Combining Chromatin Immunoprecipitation (ChIP)-on-chip and ChIP-seq assays, the interplay of transcriptional cofactors in defining AR binding profiles, and the genomic regulation and AR reprogramming in advanced PCa. PMID:25237629

  7. Mechanism of androgen receptor action.

    PubMed

    Li, Jin; Al-Azzawi, Farook

    2009-06-20

    Recent research provides a much more detailed understanding of the role of the androgen receptor in normal human development and physiology, its structure, and its functioning. This review discusses genomic and non-genomic actions of the androgen receptor, as well as their co-regulators. We also explore several clinically relevant aspects of the molecular biology of the androgen receptor and its co-regulators. PMID:19372015

  8. Androgen receptor polymorphism (CAG repeats) and androgenicity.

    PubMed

    Canale, D; Caglieresi, C; Moschini, C; Liberati, C D; Macchia, E; Pinchera, A; Martino, E

    2005-09-01

    Objective Polymorphism of the androgen receptor (AR) has been related to various pathophysiological conditions, such as osteoporosis and infertility. The objectives of this study were to evaluate the frequency of distribution in a normal Italian population and to assess CAG repeats (CAGr) in other conditions, such as hypoandrogenism, potentially influenced by AR polymorphism. Patients and measurements CAGr polymorphism was determined in a group of 91 healthy normoandrogenized subjects, 29 hypoandrogenized patients (hypoplasia of prostate and seminal vesicles, reduced beard or body hair, etc.) and 29 infertile patients by direct sequencing. Results The mean (+/- SD) number of CAG repeats [(CAGr)n] was 21.5 (+/- 1.7) in the control group, 21.4 (+/- 2.0) in the infertile patients and 24.0 (+/- 2.9) in the hypoandrogenic males. The difference was statistically significant between this last group and the other two (P < 0.0001), while there was no difference between normal controls and infertile patients. The frequency distribution showed a shift towards higher CAG length in hypoandrogenized patients compared to controls and infertile patients. If we used a cut-off point of 24.9 (2 SD above the mean), the percentage of patients with 25 or more CAGr repeats was 38% among hypoandrogenized patients, 7% among infertile patients and 5% among the control group. In hypoandrogenized subjects (CAGr)n correlated slightly with testis and prostate volume. The number of CAG repeats was not associated with any of the hormonal parameters, including testosterone, evaluated in the three groups. Conclusions Our normal population, representing subjects from Central Italy, is superimposable on other European populations with regard to (CAGr)n distribution. Hypoandrogenic males have a shift in the frequency distribution towards longer (CAGr)n. Infertile patients are not statistically different from the control group. These findings suggest that, given the same amount of circulating

  9. Alternatively Spliced Androgen Receptor Variants

    PubMed Central

    Dehm, Scott M.; Tindall, Donald J.

    2011-01-01

    Alternative splicing is an important mechanism for increasing functional diversity from a limited set of genes. De-regulation of this process is common in diverse pathologic conditions. The androgen receptor (AR) is a steroid receptor transcription factor with functions critical for normal male development as well as the growth and survival of normal and cancerous prostate tissue. Studies of AR function in androgen insensitivity syndrome (AIS) and prostate cancer (PCa) have demonstrated loss-of-function AR alterations in AIS, and gain-of-function AR alterations in PCa. Over the past two decades, AR gene alterations have been identified in various individuals with AIS, which disrupt normal AR splicing patterns and yield dysfunctional AR protein variants. More recently, altered AR splicing patterns have been identified as a mechanism of PCa progression and resistance to androgen-depletion therapy. Several studies have described the synthesis of alternatively spliced transcripts encoding truncated AR isoforms that lack the ligand-binding domain, which is the ultimate target of androgen depletion. Many of these truncated AR isoforms function as constitutively active, ligand-independent transcription factors that can support androgen-independent expression of AR target genes, as well as the androgen-independent growth of PCa cells. In this review, we will summarize the various alternatively spliced AR variants that have been discovered, with a focus on their role and origin in the pathologic conditions of AIS and PCa. PMID:21778211

  10. Androgen receptors in prostate cancer.

    PubMed

    Culig, Z; Klocker, H; Bartsch, G; Hobisch, A

    2002-09-01

    The androgen receptor (AR), a transcription factor that mediates the action of androgens in target tissues, is expressed in nearly all prostate cancers. Carcinoma of the prostate is the most frequently diagnosed neoplasm in men in industrialized countries. Palliative treatment for non-organ-confined prostate cancer aims to down-regulate the concentration of circulating androgen or to block the transcription activation function of the AR. AR function during endocrine therapy was studied in tumor cells LNCaP subjected to long-term steroid depletion; newly generated sublines could be stimulated by lower concentrations of androgen than parental cells and showed up-regulation of AR expression and activity as well as resistance to apoptosis. Androgenic hormones regulate the expression of key cell cycle regulators, cyclin-dependent kinase 2 and 4, and that of the cell cycle inhibitor p27. Inhibition of AR expression could be achieved by potential chemopreventive agents flufenamic acid, resveratrol, quercetin, polyunsaturated fatty acids and interleukin-1beta, and by the application of AR antisense oligonucleotides. In the clinical situation, AR gene amplification and point mutations were reported in patients with metastatic disease. These mutations generate receptors which could be activated by other steroid hormones and non-steroidal antiandrogens. In the absence of androgen, the AR could be activated by various growth-promoting (growth factors, epidermal growth factor receptor-related oncogene HER-2/neu) and pleiotropic (protein kinase A activators, interleukin-6) compounds as well as by inducers of differentiation (phenylbutyrate). AR function is modulated by a number of coactivators and corepressors. The three coactivators, TIF-2, SRC-1 and RAC3, are up-regulated in relapsed prostate cancer. New experimental therapies for prostate cancer are aimed to down-regulate AR expression and to overcome difficulties which occur because of the acquisition of agonistic properties

  11. Sequence of the intron/exon junctions of the coding region of the human androgen receptor gene and identification of a point mutation in a family with complete androgen insensitivity

    SciTech Connect

    Lubahn, D.B.; Simental, J.A.; Higgs, H.N.; Wilson, E.M.; French, F.S. ); Brown, T.R.; Migeon, C.J. )

    1989-12-01

    Androgens act through a receptor protein (AR) to mediate sex differentiation and development of the male phenotype. The authors have isolated the eight exons in the amino acid coding region of the AR gene from a human X chromosome library. Nucleotide sequences of the AR gene intron/exon boundaries were determined for use in designing synthetic oligonucleotide primers to bracket coding exons for amplification by the polymerase chain reaction. Genomic DNA was amplified from 46, XY phenotypic female siblings with complete androgen insensitivity syndrome. AR binding affinity for dihydrotestosterone in the affected siblings was lower than in normal males, but the binding capacity was normal. Sequence analysis of amplified exons demonstrated within the AR steroid-binding domain (exon G) a single guanine to adenine mutation, resulting in replacement of valine with methionine at amino acid residue 866. As expected, the carrier mother had both normal and mutant AR genes. Thus, a single point mutation in the steroid-binding domain of the AR gene correlated with the expression of an AR protein ineffective in stimulating male sexual development.

  12. RECOMBINANT ANDROGEN RECEPTOR (AR) BINDING ACROSS VERTEBRATE SPECIES: COMPARISON OF BINDING OF ENVIRONMENTAL COMPOUNDS TO HUMAN, RAINBOW TROUT AND FATHEAD MINNOW AR.

    EPA Science Inventory

    In vitro screening assays designed to identify androgen mimics or antagonists typically use mammalian (rat, human) androgen receptors (AR). Although the amino acid sequences of receptors from nonmammalian vertebrates are not identical to the mammalian receptors, it is uncertain ...

  13. The androgen receptor in health and disease.

    PubMed

    Matsumoto, Takahiro; Sakari, Matomo; Okada, Maiko; Yokoyama, Atsushi; Takahashi, Sayuri; Kouzmenko, Alexander; Kato, Shigeaki

    2013-01-01

    Androgens play pivotal roles in the regulation of male development and physiological processes, particularly in the male reproductive system. Most biological effects of androgens are mediated by the action of nuclear androgen receptor (AR). AR acts as a master regulator of downstream androgen-dependent signaling pathway networks. This ligand-dependent transcriptional factor modulates gene expression through the recruitment of various coregulator complexes, the induction of chromatin reorganization, and epigenetic histone modifications at target genomic loci. Dysregulation of androgen/AR signaling perturbs normal reproductive development and accounts for a wide range of pathological conditions such as androgen-insensitive syndrome, prostate cancer, and spinal bulbar muscular atrophy. In this review we summarize recent advances in understanding of the epigenetic mechanisms of AR action as well as newly recognized aspects of AR-mediated androgen signaling in both men and women. In addition, we offer a perspective on the use of animal genetic model systems aimed at eventually developing novel therapeutic AR ligands. PMID:23157556

  14. Interactions of methoxyacetic acid with androgen receptor

    SciTech Connect

    Bagchi, Gargi; Hurst, Christopher H.; Waxman, David J.

    2009-07-15

    Endocrine disruptive compounds (EDC) alter hormone-stimulated, nuclear receptor-dependent physiological and developmental processes by a variety of mechanisms. One recently identified mode of endocrine disruption is through hormone sensitization, where the EDC modulates intracellular signaling pathways that control nuclear receptor function, thereby regulating receptor transcriptional activity indirectly. Methoxyacetic acid (MAA), the primary, active metabolite of the industrial solvent ethylene glycol monomethyl ether and a testicular toxicant, belongs to this EDC class. Modulation of nuclear receptor activity by MAA could contribute to the testicular toxicity associated with MAA exposure. In the present study, we evaluated the impact of MAA on the transcriptional activity of several nuclear receptors including the androgen receptor (AR), which plays a pivotal role in the development and maturation of spermatocytes. AR transcriptional activity is shown to be increased by MAA through a tyrosine kinase signaling pathway that involves PI3-kinase. In a combinatorial setting with AR antagonists, MAA potentiated the AR response without significantly altering the EC{sub 50} for androgen responsiveness, partially alleviating the antagonistic effect of the anti-androgens. Finally, MAA treatment of TM3 mouse testicular Leydig cells markedly increased the expression of Cyp17a1 and Shbg while suppressing Igfbp3 expression by {approx} 90%. Deregulation of these genes may alter androgen synthesis and action in a manner that contributes to MAA-induced testicular toxicity.

  15. Adolescents and Androgens, Receptors and Rewards

    PubMed Central

    Sato, Satoru M.; Schulz, Kalynn M.; Sisk, Cheryl L.; Wood, Ruth I.

    2008-01-01

    Adolescence is associated with increases in pleasure-seeking behaviors, which, in turn, are shaped by the pubertal activation of the hypothalamo-pituitary-gonadal axis. In animal models of naturally rewarding behaviors, such as sex, testicular androgens contribute to the development and expression of the behavior in males. To effect behavioral maturation, the brain undergoes significant remodeling during adolescence, and many of the changes are likewise sensitive to androgens, presumably acting through androgen receptors (AR). Given the delicate interaction of gonadal hormones and brain development, it is no surprise that disruption of hormone levels during this sensitive period significantly alters adolescent and adult behaviors. In male hamsters, exposure to testosterone during adolescence is required for normal expression of adult sexual behavior. Males deprived of androgens during puberty display sustained deficits in mating. Conversely, androgens alone are not sufficient to induce mating in prepubertal males, even though brain AR are present before puberty. In this context, wide-spread use of anabolic-androgenic steroids (AAS) during adolescence is a significant concern. AAS abuse has the potential to alter both the timing and the levels of androgens in adolescent males. In hamsters, adolescent AAS exposure increases aggression, and causes lasting changes in neurotransmitter systems. In addition, AAS are themselves reinforcing, as demonstrated by self-administration of testosterone and other AAS. However, recent evidence suggests that the reinforcing effects of androgens may not require classical AR. Therefore, further examination of interactions between androgens and rewarding behaviors in the adolescent brain is required for a better understanding of AAS abuse. PMID:18343381

  16. Androgen receptor in human endothelial cells

    PubMed Central

    Torres-Estay, Verónica; Carreño, Daniela V; San Francisco, Ignacio F; Sotomayor, Paula; Godoy, Alejandro S; Smith, Gary J

    2015-01-01

    Androgen receptor (AR) is a ligand-inducible transcription factor, and a member of the steroid-thyroid-retinoid receptor superfamily, that mediates the biological effects of androgens in a wide range of physiological and pathological processes. AR expression was identified in vascular cells nearly 20 years ago, and recent research has shown that AR mediates a variety of actions of androgens in endothelial and vascular smooth muscle cells. In this mini-review, we review evidence indicating the importance of AR in human endothelial cell (HUVEC) homeostatic and pathogenic processes. Although a role for AR in the modulation of HUVEC biology is evident, the molecular mechanisms by which AR regulates HUVEC homeostasis and disease processes are not fully understood. Understanding these mechanisms could provide critical insights into the processes of pathogenesis of diseases ranging from cardiovascular disease to cancer that are major causes of human morbidity and mortality. PMID:25563353

  17. Androgen Receptor Repression of GnRH Gene Transcription

    PubMed Central

    Brayman, Melissa J.; Pepa, Patricia A.; Berdy, Sara E.

    2012-01-01

    Alterations in androgen levels lead to reproductive defects in both males and females, including hypogonadotropic hypogonadism, anovulation, and infertility. Androgens have been shown to down-regulate GnRH mRNA levels through an androgen receptor (AR)-dependent mechanism. Here, we investigate how androgen regulates expression from the GnRH regulatory region in the GT1-7 cell line, a model of GnRH neurons. A synthetic androgen, R1881, repressed transcription from the GnRH promoter (GnRH-P) in an AR-dependent manner, and liganded AR associated with the chromatin at the GnRH-P in live GT1-7 cells. The three known octamer-binding transcription factor-1 (Oct-1) binding sites in GnRH-P were required for AR-mediated repression, although other sequences were also involved. Although a multimer of the consensus Oct-1 binding site was not repressed, a multimer of the cluster of Oct-1, Pre-B cell leukemia transcription factor (Pbx)/Prep, and NK2 homeobox 1 (Nkx2.1) binding sites, found at −106/−91 in GnRH-P, was sufficient for repression. In fact, overexpression of any of these factors disrupted the androgen response, indicating that a balance of factors in this tripartite complex is required for AR repression. AR bound to this region in EMSA, indicating a direct interaction of AR with DNA or with other transcription factors bound to GnRH-P at this sequence. Collectively, our data demonstrate that GnRH transcription is repressed by AR via multiple sequences in GnRH-P, including three Oct-1 binding sites, and that this repression requires the complex interaction of several transcription factors. PMID:22074952

  18. Androgen receptor gene polymorphism in zebra species

    PubMed Central

    Ito, Hideyuki; Langenhorst, Tanya; Ogden, Rob; Inoue-Murayama, Miho

    2015-01-01

    Androgen receptor genes (AR) have been found to have associations with reproductive development, behavioral traits, and disorders in humans. However, the influence of similar genetic effects on the behavior of other animals is scarce. We examined the loci AR glutamine repeat (ARQ) in 44 Grevy's zebras, 23 plains zebras, and three mountain zebras, and compared them with those of domesticated horses. We observed polymorphism among zebra species and between zebra and horse. As androgens such as testosterone influence aggressiveness, AR polymorphism among equid species may be associated with differences in levels of aggression and tameness. Our findings indicate that it would be useful to conduct further studies focusing on the potential association between AR and personality traits, and to understand domestication of equid species. PMID:26236645

  19. Sequence Evolution and Expression of the Androgen Receptor and Other Pathway-Related Genes in a Unisexual Fish, the Amazon Molly, Poecilia formosa, and Its Bisexual Ancestors

    PubMed Central

    Zhu, Fangjun; Schlupp, Ingo; Tiedemann, Ralph

    2016-01-01

    The all-female Amazon molly (Poecilia formosa) originated from a single hybridization of two bisexual ancestors, Atlantic molly (Poecilia mexicana) and sailfin molly (Poecilia latipinna). As a gynogenetic species, the Amazon molly needs to copulate with a heterospecific male, but the genetic information of the sperm-donor does not contribute to the next generation, as the sperm only acts as the trigger for the diploid eggs’ embryogenesis. Here, we study the sequence evolution and gene expression of the duplicated genes coding for androgen receptors (ars) and other pathway-related genes, i.e., the estrogen receptors (ers) and cytochrome P450, family19, subfamily A, aromatase genes (cyp19as), in the Amazon molly, in comparison to its bisexual ancestors. Mollies possess–as most other teleost fish—two copies of the ar, er, and cyp19a genes, i.e., arα/arβ, erα/erβ1, and cyp19a1 (also referred as cyp19a1a)/cyp19a2 (also referred to as cyp19a1b), respectively. Non-synonymous single nucleotide polymorphisms (SNPs) among the ancestral bisexual species were generally predicted not to alter protein function. Some derived substitutions in the P. mexicana and one in P. formosa are predicted to impact protein function. We also describe the gene expression pattern of the ars and pathway-related genes in various tissues (i.e., brain, gill, and ovary) and provide SNP markers for allele specific expression research. As a general tendency, the levels of gene expression were lowest in gill and highest in ovarian tissues, while expression levels in the brain were intermediate in most cases. Expression levels in P. formosa were conserved where expression did not differ between the two bisexual ancestors. In those cases where gene expression levels significantly differed between the bisexual species, P. formosa expression was always comparable to the higher expression level among the two ancestors. Interestingly, erβ1 was expressed neither in brain nor in gill in the analyzed

  20. The Role of Androgen and Androgen Receptor in the Skin-Related Disorders

    PubMed Central

    Lai, Jiann-Jyh; Chang, Philip; Lai, Kuo-Pao; Chen, Lumin; Chang, Chawnshang

    2013-01-01

    Androgen and androgen receptor (AR) may play important roles in several skin related diseases, such as androgenetic alopecia and acne vulgaris. Current treatments for these androgen/AR-involved diseases, which target the synthesis of androgens or prevent its binding to AR, can cause significant adverse side effects. Based on the recent studies using AR knockout mice, it has been suggested that AR and androgens play distinct roles in the skin pathogenesis, and AR seems to be a better target than androgens for the treatment of these skin diseases. Here we review recent studies of androgen/AR roles in several skin-related disorders, including acne vulgaris, androgenetic alopecia, and hirsutism, as well as cutaneous wound healing. PMID:22829074

  1. Single strand conformation polymorphism analysis of androgen receptor gene mutations in patients with androgen insensitivity syndromes: Application for diagnosis, genetic counseling, and therapy

    SciTech Connect

    Hiort, O. Tufts-New England Medical Center, Boston, MA ); Huang, Q. ); Sinnecker, G.H.G.; Kruse, K. ); Sadeghi-Nejad, A.; Wolfe, H.J. ); Yandell, D.W. ) Harvard School of Public Health, Boston, MA )

    1993-07-01

    Recent studies indicate that mutations in the androgen receptor gene are associated with androgen insensitivity syndromes, a heterogeneous group of related disorders involving defective sexual differentiation in karyotypic males. In this report, the authors address the possibility of rapid mutational analysis of the androgen receptor gene for initial diagnosis, genetic counseling, and molecular subclassification of affected patients and their families. DNA from peripheral blood leukocytes of six patients from five families with various degrees of androgen insensitivity was studied. Exons 2 to 8 of the androgen receptor gene were analyzed using a combination of single strand conformation polymorphism analysis and direct DNA sequencing. Female family members were also studied to identify heterozygote carriers. Point mutations in the AR gene were identified in all six patients, and all mutations caused amino acid substitutions. One patient with incomplete androgen insensitivity was a mosaic for the mutation. Four of the five mothers, as well as a young sister of one patient, were carriers of the mutation present in the affected child. The data show that new mutations may occur in the androgen receptor gene leading to sporadic androgen insensitivity syndrome. Molecular genetic characterization of the variant allele can serve as a primary tool for diagnosis and subsequent therapy, and can provide a basis for distinguishing heterozygous carriers in familial androgen resistance. The identification of carriers is of substantial clinical importance for genetic counseling. 29 refs., 2 figs., 1 tab.

  2. Transcriptional up-regulation of the human androgen receptor by androgen in bone cells.

    PubMed

    Wiren, K M; Zhang, X; Chang, C; Keenan, E; Orwoll, E S

    1997-06-01

    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. PMID:9165014

  3. Genetic basis of endocrine disease 4: The spectrum of mutations in the androgen receptor gene that causes androgen resistance

    SciTech Connect

    McPhaul, M.J.; Marcelli, M.; Zoppi, S.; Griffin, J.E.; Wilson, J.D. )

    1993-01-01

    Mutations in the androgen receptor gene cause phenotypic abnormalities of male sexual development that range from a female phenotype (complete testicular feminization) to that of undervirilized or infertile men. Using the tools of molecular biology, the authors have analyzed androgen receptor gene mutations in 31 unrelated subjects with androgen resistance syndromes. Most of the defects are due to nucleotide changes that cause premature termination codons or single amino acid substitutions within the open reading frame encoding the androgen receptor, and the majority of these substitutions are localized in three regions of the androgen receptor: the DNA-binding domain and two segments of the androgen-binding domain. Less frequently, partial or complete gene deletions have been identified. Functional studies and immunoblot assays of the androgen receptors in patients with androgen resistance indicate that in most cases the phenotypic abnormalities are the result of impairment of receptor function or decreases in receptor abundance or both. 34 refs., 2 figs.

  4. RAINBOW TROUT ANDROGEN RECEPTOR ALPHA AND THE HUMAN ANDROGEN RECEPTOR: COMPARISONS IN THE COS WHOLE CELL BINDING ASSAY

    EPA Science Inventory

    Rainbow Trout Androgen Receptor Alpha And Human Androgen Receptor: Comparisons in the COS Whole Cell Binding Assay
    Mary C. Cardon, L. Earl Gray, Jr. and Vickie S. Wilson
    U.S. Environmental Protection Agency, ORD, NHEERL, Reproductive Toxicology Division, Research Triangle...

  5. RAINBOW TROUT ANDROGEN RECEPTOR ALPHA AND THE HUMAN ANDROGEN RECEPTOR: COMPARISONS IN THE COS WHOLE CELL BINDING ASSAY

    EPA Science Inventory

    RAINBOW TROUT ANDROGEN RECEPTOR ALPHA AND HUMAN ANDROGEN RECEPTOR: COMPARISONS IN THE COS WHOLE CELL BINDING ASSAY.
    MC Cardon, PC Hartig,LE Gray, Jr. and VS Wilson.
    U.S. EPA, ORD, NHEERL, RTD, Research Triangle Park, NC, USA.
    Typically, in vitro hazard assessments for ...

  6. Molecular pathways: targeting resistance in the androgen receptor for therapeutic benefit.

    PubMed

    Mostaghel, Elahe A; Plymate, Stephen R; Montgomery, Bruce

    2014-02-15

    Androgen receptor signaling is critical in the development and progression of prostate cancer, leading to intensive efforts to elucidate all potential points of inflection for therapeutic intervention. These efforts have revealed new mechanisms of resistance and raise the possibility that known mechanisms may become even more relevant in the context of effective androgen receptor suppression. These mechanisms include tumoral appropriation of alternative androgen sources, alterations in androgen receptor expression, androgen receptor mutations, truncated androgen receptor variants, alterations and cross-talk in recruitment of cofactors to androgen receptor binding sites in the genome, and androgen receptor-driven oncogenic gene fusions. New agents such as enzalutamide, EPI-001, androgen receptor-specific peptidomimetics, novel HSP90 inhibitors, and PARP inhibitors, as well as new approaches to cotargeting the androgen receptor pathway, point to the potential for more complete and durable control of androgen receptor-mediated growth. PMID:24305618

  7. Sensitization of androgen refractory prostate cancer cells to anti-androgens through re-expression of epigenetically repressed androgen receptor - Synergistic action of quercetin and curcumin.

    PubMed

    Sharma, Vikas; Kumar, Lokesh; Mohanty, Sujit K; Maikhuri, Jagdamba P; Rajender, Singh; Gupta, Gopal

    2016-08-15

    Epigenetic repression of Androgen Receptor (AR) gene by hypermethylation of its promoter causes resistance in prostate cancer (CaP) to androgen deprivation therapy with anti-androgens. Some dietary phytocompounds like quercetin (Q) and curcumin (C) with reported DNMT-inhibitory activity were tested for their ability to re-express the AR in AR-negative CaP cell lines PC3 and DU145. Combined treatment with Q+C was much more effective than either Q or C in inhibiting DNMT, causing global hypomethylation, restoring AR mRNA and protein levels and causing apoptosis via mitochondrial depolarization of PC3 and DU145. The functional AR protein expressed in Q+C treated cells sensitized them to dihydrotestosterone (DHT)-induced proliferation, bicalutamide-induced apoptosis, bound to androgen response element to increase luciferase activity in gene reporter assay and was susceptible to downregulation by AR siRNA. Bisulfite sequencing revealed high methylation of AR promoter CpG sites in AR-negative DU145 and PC3 cell lines that was significantly demethylated by Q+C treatment, which restored AR expression. Notable synergistic effects of Q+C combination in re-sensitizing androgen refractory CaP cells to AR-mediated apoptosis, their known safety in clinical use, and epidemiological evidences relating their dietary consumption with lower cancer incidences indicate their potential for use in chemoprevention of androgen resistance in prostate cancer. PMID:27132804

  8. Disruption of Androgen Receptor Signaling in Males by Environmental Chemicals

    PubMed Central

    Luccio-Camelo, Doug C.; Prins, Gail S

    2011-01-01

    Androgen-disruptors are environmental chemicals in that interfere with the biosynthesis, metabolism or action of endogenous androgens resulting in a deflection from normal male developmental programming and reproductive tract growth and function. Since male sexual differentiation is entirely androgen-dependent, it is highly susceptible to androgen-disruptors. Animal models and epidemiological evidence link exposure to androgen disrupting chemicals with reduced sperm counts, increased infertility, testicular dysgenesis syndrome, and testicular and prostate cancers. Further, there appears to be increased sensitivity to these agents during critical developmental windows when male differentiation is at its peak. A variety of in vitro and in silico approaches have been used to identify broad classes of androgen disrupting molecules that include organochlorinated pesticides, industrial chemicals, and plasticizers with capacity to ligand the androgen receptor. The vast majority of these synthetic molecules act as anti-androgens. This review will highlight the evidence for androgen disrupting chemicals that act through interference with the androgen receptor, discussing specific compounds for which there is documented in vivo evidence for male reproductive tract perturbations. PMID:21515368

  9. Identification of novel genes that regulate androgen receptor signaling and growth of androgen-deprived prostate cancer cells

    PubMed Central

    Levina, Elina; Ji, Hao; Chen, Mengqiang; Baig, Mirza; Oliver, David; Ohouo, Patrice; Lim, Chang-uk; Schools, Garry; Carmack, Steven; Ding, Ye; Broude, Eugenia V.; Roninson, Igor B.

    2015-01-01

    Prostate cancer progression to castration refractory disease is associated with anomalous transcriptional activity of the androgen receptor (AR) in an androgen-depleted milieu. To identify novel gene products whose downregulation transactivates AR in prostate cancer cells, we performed a screen of enzymatically-generated shRNA lenti-libraries selecting for transduced LNCaP cells with elevated expression of a fluorescent reporter gene under the control of an AR-responsive promoter. The shRNAs present in selected populations were analyzed using high-throughput sequencing to identify target genes. Highly enriched gene targets were then validated with siRNAs against selected genes, testing first for increased expression of luciferase from an AR-responsive promoter and then for altered expression of endogenous androgen-regulated genes in LNCaP cells. We identified 20 human genes whose silencing affected the expression of exogenous and endogenous androgen-responsive genes in prostate cancer cells grown in androgen-depleted medium. Knockdown of four of these genes upregulated the expression of endogenous AR targets and siRNAs targeting two of these genes (IGSF8 and RTN1) enabled androgen-independent proliferation of androgen-dependent cells. The effects of IGSF8 appear to be mediated through its interaction with a tetraspanin protein, CD9, previously implicated in prostate cancer progression. Remarkably, homozygous deletions of IGSF8 are found almost exclusively in prostate cancers but not in other cancer types. Our study shows that androgen independence can be achieved through the inhibition of specific genes and reveals a novel set of genes that regulate AR signaling in prostate cancers. PMID:26036626

  10. New insights into the androgen biotransformation in prostate cancer: A regulatory network among androgen, androgen receptors and UGTs.

    PubMed

    Qin, Xuan; Liu, Mingyao; Wang, Xin

    2016-04-01

    Androgen, as one kind of steroid hormones, is pivotal in the hormone-sensitive cancer, such as prostate cancer (PCa). The synthesis, elimination, and bioavailability of androgen in prostate cells have been proved to be a main cause of the carcinogenesis, maintenance and deterioration of PCa. This review illustrates the outlines of androgen biotransformation, and further discusses the different enzymes, especially UDP-glucuronyltransferases (UGTs) embedded in both benign and malignant prostate cells, which catalyze the reactions. Although many inhibitors of the enzymes responsible for the synthesis of androgens have been developed into drugs to fight against PCa, the elimination procedures metabolized by the UGTs are less emphasized. Thus the regulatory network among androgen, androgen receptors (AR) and UGTs is carefully reviewed in this article, indicating the determinant effects of UGTs on prostatic androgens and the regulation of AR. Finally, the hypothesis is also put forward that the regulators of UGTs may be developed to accelerate the androgen elimination and benefit PCa therapy. PMID:26926093

  11. Expression of a hyperactive androgen receptor leads to androgen-independent growth of prostate cancer cells.

    PubMed

    Hsieh, Chen-Lin; Cai, Changmeng; Giwa, Ahmed; Bivins, Aaronica; Chen, Shao-Yong; Sabry, Dina; Govardhan, Kumara; Shemshedini, Lirim

    2008-07-01

    Cellular changes that affect the androgen receptor (AR) can cause prostate cancer to transition from androgen dependent to androgen independent, which is usually lethal. One common change in prostate tumors is overexpression of the AR, which has been shown to lead to androgen-independent growth of prostate cancer cells. This led us to hypothesize that expression of a hyperactive AR would be sufficient for androgen-independent growth of prostate cancer cells. To test this hypothesis, stable lune cancer prostate (LNCaP) cell lines were generated, which express a virion phosphoprotein (VP)16-AR hybrid protein that contains full-length AR fused to the strong viral transcriptional activation domain VP16. This fusion protein elicited as much as a 20-fold stronger transcriptional activity than the natural AR. Stable expression of VP16-AR in LNCaP cells yielded androgen-independent cell proliferation, while under the same growth conditions the parental LNCaP cells exhibited only androgen-dependent growth. These results show that expression of a hyperactive AR is sufficient for androgen-independent growth of prostate cancer cells. To study the molecular basis of this enhanced growth, we measured the expression of soluble guanylyl cyclase-alpha1 (sGCalpha1), a subunit of the sGC, an androgen-regulated gene that has been shown to be involved in prostate cancer cell growth. Interestingly, the expression of sGCalpha1 is androgen independent in VP16-AR-expressing cells, in contrast to its androgen-induced expression in control LNCaP cells. RNA(I)-dependent inhibition of sGCalpha1 expression resulted in significantly reduced proliferation of VP16-AR cells, implicating an important role for sGCalpha1 in the androgen-independent growth of these cells. PMID:18469090

  12. Clinical, cytogenetic and molecular analysis of androgen insensitivity syndromes from south Indian cohort and detection and in-silico characterization of androgen receptor gene mutations.

    PubMed

    V G, Abilash; S, Radha; K M, Marimuthu; K, Thangaraj; S, Arun; S, Nishu; A, Mohana Priya; J, Meena; D, Anuradha

    2016-01-30

    Rare cases of 9 complete androgen insensitivity syndromes, 9 cases of partial androgen insensitivity syndromes and equal number of male control samples were selected for this study. Few strong variations in clinical features were noticed; Giemsa banded metaphase revealed a 46,XY karyotype and the frequency of chromosome aberrations were significantly higher when compared with control samples. DNA sequence analysis of the androgen receptor gene of androgen insensitivity syndromes revealed three missense mutations - c.C1713>G resulting in the replacement of a highly conserved histidine residue with glutamine p.(His571Glu) in DNA-binding domain, c.A1715>G resulting in the replacement of a highly conserved tyrosine residue with cysteine p.(Tyr572Cys) in DNA-binding domain and c.G2599>A resulting in the replacement of a highly conserved valine residue with methionine p.(Val867Met) in ligand-binding domain of androgen receptor gene respectively. The heterozygous type of mutations c.C1713>G and c.G2599>A observed in mothers of the patients for familial cases concluding that the mutation was inherited from the mother. The novel mutation c.C1713>G is reported first time in androgen insensitivity syndrome. In-silico analysis of mutations observed in androgen receptor gene of androgen insensitivity syndrome predicted that the substitution at Y572C and V867M could probably disrupt the protein structure and function. PMID:26688387

  13. Racial differences in the androgen/androgen receptor pathway in prostate cancer.

    PubMed Central

    Pettaway, C. A.

    1999-01-01

    Pathologic and epidemiologic data suggest that while little racial variation exists in prostate cancer prevalence ("autopsy cancer"), striking racial variation exists for the clinically diagnosed form of the disease. A review of the available literature was performed to define whether racial differences in serum androgen levels or qualitative or quantitative differences in the androgen receptor were correlated with prostate cancer incidence or severity. Black men were found to be exposed to higher circulating testosterone levels from birth to about age 35 years. Such differences were not consistently noted among older men. Significant differences also were found for dihydrotestosterone metabolites among black, white, and Asian men. Unique racial genetic polymorphisms were noted for the gene for 5 alpha-reductase type 2 among black and Asian men. Novel androgen receptor mutations recently have been described among Japanese, but not white, men with latent prostate cancer. Finally, androgen receptor gene polymorphisms leading to shorter or longer glutamine and glycine residues in the receptor protein are correlated with racial variation in the incidence and severity of prostate cancer. This same polymorphism also could explain racial variation in serum prostate-specific antigen levels. Collectively, these data strongly suggest racial differences within the androgen/androgen receptor pathway not only exist but could be one cause of clinically observed differences in the biology of prostate cancer among racial groups. Images Figure 1 PMID:10628124

  14. The effect of anabolic-androgenic steroids on aromatase activity and androgen receptor binding in the rat preoptic area.

    PubMed

    Roselli, C E

    1998-05-11

    The level of aromatase in the preoptic area of rats is transcriptionally regulated through a specific androgen-receptor mediated mechanism and can be used as a measure of central androgenic effect. Therefore, several commonly abused anabolic-androgenic steroids (AAS) were tested for their ability to induce aromatase activity in the preoptic area of castrated rats. In addition, we determined the relative binding affinities of these compounds for the androgen receptor, as well as their ability to bind androgen receptor in vivo following subcutaneous injections. All of the AAS compounds tested significantly stimulated POA aromatase activity above castrate levels. The compounds that produced the greatest stimulation of aromatase activity were those that bound most avidly to the androgen receptor in vitro (i.e., testosterone, dihydrotestosterone and nandrolone). In contrast, the 17alpha-alkylated compounds that were tested (stanozolol, danazol, methandrostenolone) modestly stimulated aromatase and were weak competitors for the androgen receptor. The subcutaneous injection of AAS compounds increased the concentrations of occupied nuclear androgen receptors in the brain, but the magnitude of effect was not related to their potency for inducing aromatase or their relative binding affinity for the androgen receptor suggesting that androgen receptor occupancy in POA is not correlated with the action of androgen on aromatase. The present results help explain the behavioral effects of AAS compounds in rats. PMID:9593936

  15. Androgens downregulate miR-21 expression in breast cancer cells underlining the protective role of androgen receptor

    PubMed Central

    Donà, Ada; Rizza, Pietro; Aquila, Saveria; Avena, Paola; Lanzino, Marilena; Pellegrino, Michele; Vivacqua, Adele; Tucci, Paola; Morelli, Catia; Andò, Sebastiano; Sisci, Diego

    2016-01-01

    Although the protective role of androgen receptor (AR) in breast cancer (BC) is well established, the mechanisms involved remains largely unexplored. MicroRNAs play fundamental roles in many biological processes, including tumor cell development and metastasis. Herein, we report that androgens reduce BC cells proliferation acting as a negative modulator of the onco-miRNA-21. The synthetic androgen miboleron (Mib) decreases BC cell proliferation induced by miR-21 over-expression and AR knockdown evidenced the requirement of AR in the down-regulation of miR-21 expression. These effects seem to be a general mechanism occurring in BC tissues. Chromatin immune-precipitation (ChIP) analysis disclosed the binding of AR to a specific ARE sequence in miR-21 proximal promoter and recognizes the recruitment of HDAC3 as component for AR-mediated transcriptional repression. Such event is associated to a significantly reduced PolII binding in Mib treated extracts confirming that activated AR is a transcriptional repressor of miR-21 expression, providing further insight into the protective role of androgens in breast cancer cells. Collectively, our data and the widespread AR expression in primary and metastatic breast tumours, suggest a careful examination of the therapeutic potential of androgens also in potentiating the effectiveness of anti-oestrogen adjuvant therapies. PMID:26862856

  16. Androgens downregulate miR-21 expression in breast cancer cells underlining the protective role of androgen receptor.

    PubMed

    Casaburi, Ivan; Cesario, Maria Grazia; Donà, Ada; Rizza, Pietro; Aquila, Saveria; Avena, Paola; Lanzino, Marilena; Pellegrino, Michele; Vivacqua, Adele; Tucci, Paola; Morelli, Catia; Andò, Sebastiano; Sisci, Diego

    2016-03-15

    Although the protective role of androgen receptor (AR) in breast cancer (BC) is well established, the mechanisms involved remains largely unexplored. MicroRNAs play fundamental roles in many biological processes, including tumor cell development and metastasis. Herein, we report that androgens reduce BC cells proliferation acting as a negative modulator of the onco-miRNA-21.The synthetic androgen miboleron (Mib) decreases BC cell proliferation induced by miR-21 over-expression and AR knockdown evidenced the requirement of AR in the down-regulation of miR-21 expression. These effects seem to be a general mechanism occurring in BC tissues.Chromatin immune-precipitation (ChIP) analysis disclosed the binding of AR to a specific ARE sequence in miR-21 proximal promoter and recognizes the recruitment of HDAC3 as component for AR-mediated transcriptional repression. Such event is associated to a significantly reduced PolII binding in Mib treated extracts confirming that activated AR is a transcriptional repressor of miR-21 expression, providing further insight into the protective role of androgens in breast cancer cells.Collectively, our data and the widespread AR expression in primary and metastatic breast tumours, suggest a careful examination of the therapeutic potential of androgens also in potentiating the effectiveness of anti-oestrogen adjuvant therapies. PMID:26862856

  17. Binding kinetics and physical properties of androgen receptor in androgen-dependent Shionogi mammary carcinoma 115.

    PubMed

    Nohno, T

    1981-02-01

    The characteristics of the androgen receptor in the cytoplasmic fraction of Shionogi carcinoma 115 were studied in vitro by means of charcoal adsorption assay, sucrose density gradient centrifugation, and polyacrylamide gel electrophoresis. The equilibrium dissociation constant for [3H]dihydrotestosterone (Kd = (2-5) X 10(-11) M) was estimated from independently determined rates of association and dissociation, and was lower by one order of magnitude than the value obtained by saturation analysis (Kd = (2-8) X 10(-10) M). Evaluation of the effect of temperature on receptor binding of androgen allowed the estimation of several thermodynamic parameters, including activation energies of association (4 kcal/mol) and dissociation (14 kcal/mol), the apparent free energy (-13 kcal/mol), enthalpy (-9 kcal/mol), and entropy (+14 cal/mol per K). The receptor was greatly stabilized when bound with androgen. The results indicate how the lability of the unbound receptor and slow rate of dihydrotestosterone-receptor interaction can influence the estimation of dissociation constants by usual saturation analysis. The sedimentation coefficient of androgen receptor in freshly prepared cytosol was 6S, and became 7S after storage for 2 months at -80 degrees C. The 7S conversion of the receptor was reversed by treatment with heparin. In all cases, a single 5S peak was obtained in the presence of 0.5 M KCl. On electrophoresis in heparin-containing polyacrylamide gel, protein-bound radioactive androgen migrated as a single peak (Rf = 0.5 in 5% gel). Differences in reported values for the sedimentation coefficient of androgen receptor in cytosol of Shionogi carcinoma 115 appear to be derived from aggregation of the receptor protein during the assay procedure. PMID:7240130

  18. [Role of androgen in the elderly. Current status of development of selective androgen receptor modulator].

    PubMed

    Yanase, Toshihiko

    2013-08-01

    The research to develop a drug, so called selective androgen receptor modulator (SARM) , which shows beneficial androgenic action on bone and muscle, but hardly possesses the stimulatory action on prostate has been making a progress. However, no drug is available in the market at present. Most of such drugs are developed, aiming at the application to age-related muscle reduction (sarcopenia) and osteoporosis. We are now trying to develop a SARM which may have beneficial effect on metabolic syndrome. PMID:23892218

  19. Artificial masculinization in tilapia involves androgen receptor activation.

    PubMed

    Golan, Matan; Levavi-Sivan, Berta

    2014-10-01

    Estrogens have a pivotal role in natural female sexual differentiation of tilapia while lack of steroids results in testicular development. Despite the fact that androgens do not participate in natural sex differentiation, synthetic androgens, mainly 17-α-methyltestosterone (MT) are effective in the production of all-male fish in aquaculture. The sex inversion potency of synthetic androgens may arise from their androgenic activity or else as inhibitors of aromatase activity. The current study is an attempt to differentiate between the two alleged activities in order to evaluate their contribution to the sex inversion process and aid the search for novel sex inversion agents. In the present study, MT inhibited aromatase activity, when applied in vitro as did the non-aromatizable androgen dihydrotestosterone (DHT). In comparison, exposure to fadrozole, a specific aromatase inhibitor, was considerably more effective. Androgenic activity of MT was evaluated by exposure of Sciaenochromis fryeri fry to the substance and testing for the appearance of blue color. Flutamide, an androgen antagonist, administered concomitantly with MT, reduced the appearance of the blue color and the sex inversion potency of MT in a dose-dependent manner. In tilapia, administration of MT, fadrozole or DHT resulted in efficient sex inversion while flutamide reduced the sex inversion potency of all three compounds. In the case of MT and DHT the decrease in sex inversion efficiency caused by flutamide is most likely due to the direct blocking of the androgen binding to its cognate receptor. The negative effect of flutamide on the efficiency of the fadrozole treatment may indicate that the masculinizing activity of fadrozole may be attributed to excess, un-aromatized, androgens accumulated in the differentiating gonad. The present study shows that when androgen receptors are blocked, there is a reduction in the efficiency of sex inversion treatments. Our results suggest that in contrast to

  20. Glucocorticoid Receptor Confers Resistance to Anti-Androgens by Bypassing Androgen Receptor Blockade

    PubMed Central

    Arora, Vivek K.; Schenkein, Emily; Murali, Rajmohan; Subudhi, Sumit K.; Wongvipat, John; Balbas, Minna D.; Shah, Neel; Cai, Ling; Efstathiou, Eleni; Logothetis, Chris; Zheng, Deyou; Sawyers, Charles L.

    2014-01-01

    Summary The treatment of advanced prostate cancer has been transformed by novel antiandrogen therapies such as enzalutamide. Here we identify induction of glucocorticoid receptor (GR) expression as a common feature of drug resistant tumors in a credentialed preclinical model, a finding also confirmed in patient samples. GR substituted for the androgen receptor (AR) to activate a similar but distinguishable set of target genes and was necessary for maintenance of the resistant phenotype. The GR agonist dexamethasone was sufficient to confer enzalutamide resistance whereas a GR antagonist restored sensitivity. Acute AR inhibition resulted in GR upregulation in a subset of prostate cancer cells due to relief of AR-mediated feedback repression of GR expression. These findings establish a novel mechanism of escape from AR blockade through expansion of cells primed to drive AR target genes via an alternative nuclear receptor upon drug exposure. PMID:24315100

  1. Substitution of synthetic chimpanzee androgen receptor for human androgen receptor in competitive binding and transcriptional activation assays for EDC screening

    EPA Science Inventory

    The potential effect of receptor-mediated endocrine modulators across species is of increasing concern. In attempts to address these concerns we are developing androgen and estrogen receptor binding assays using recombinant hormone receptors from a number of species across differ...

  2. Androgen receptor-related diseases: what do we know?

    PubMed

    Shukla, G C; Plaga, A R; Shankar, E; Gupta, S

    2016-05-01

    The androgen receptor (AR) and the androgen-AR signaling pathway play a significant role in male sexual differentiation and the development and function of male reproductive and non-reproductive organs. Because of AR's widely varied and important roles, its abnormalities have been identified in various diseases such as androgen insensitivity syndrome, spinal bulbar muscular atrophy, benign prostatic hyperplasia, and prostate cancer. This review provides an overview of the function of androgens and androgen-AR mediated diseases. In addition, the diseases delineated above are discussed with respect to their association with mutations and other post-transcriptional modifications in the AR. Finally, we present an introduction to the potential therapeutic application of most recent pharmaceuticals including miRNAs in prostate cancer that specifically target the transactivation function of the AR at post-transcriptional stages. PMID:26991422

  3. Constitutive Activity of the Androgen Receptor

    PubMed Central

    Chan, Siu Chiu; Dehm, Scott M.

    2014-01-01

    Prostate cancer (PCa) is the most frequently diagnosed cancer in the United States. The androgen receptor (AR) signaling axis is central to all stages of PCa pathophysiology and serves as the main target for endocrine-based therapy. The most advanced stage of the disease, castration resistant prostate cancer (CRPC), is presently incurable and accounts for most PCa mortality. In this review, we highlight the mechanisms by which the AR signaling axis can bypass endocrine-targeted therapies and drive progression of CRPC. These mechanisms include alterations in growth factor, cytokine, and inflammatory signaling pathways, altered expression or activity of transcriptional co-regulators, AR point mutations, and AR gene amplification leading to AR protein overexpression. Additionally, we will discuss the mechanisms underlying the synthesis of constitutively active AR splice variants (AR-Vs) lacking the COOH-terminal ligand binding domain, as well as the role and regulation of AR-Vs in supporting therapeutic resistance in CRPC. Finally, we summarize the ongoing development of inhibitors targeting discrete AR functional domains as well as the status of new biomarkers for monitoring the AR signaling axis in patients. PMID:24931201

  4. Aberrant splicing of androgenic receptor mRNA results in synthesis of a nonfunctional receptor protein in a patient with androgen insensitivity

    SciTech Connect

    Ris-Stalpers, C.; Kuiper, G.G.J.M.; Faber, P.W.; van Rooij, H.C.J.; Degenhart, H.J.; Trapman, J.; Brinkmann, A.O. ); Schweikert, H.U. ); Zegers, N.D. ); Hodgins, M.B. )

    1990-10-01

    Androgen insensitivity is a disorder in which the correct androgen response in an androgen target cell is impaired. The clinical symtpoms of this X chromosome-linked syndrome are presumed to be caused by mutations in the androgen receptor gene. The authors report a G {r arrow} T mutation in the splice donor site of intron 4 of the androgen receptor gene of a 46, XY subject lacking detectable androgen binding to the receptor and with the complete form of androgen insensitivity. This point mutation completely abolishes normal RNA splicing at the exon 4/intron 4 boundary and results in the activation of a cryptic splice donor site in exon 4, which leads to the deletion of 123 nucleotides from the mRNA. Translation of the mutant mRNA results in an androgen receptor protein {approx}5 kDa smaller than the wild type. This mutated androgen receptor protein was unable to bind androgens and unable to activate transcription of an androgen-regulated reporter gene construct. This mutation in the human androgen receptor gene demonstrates the importance of an intact steroid-binding domain for proper androgen receptor functioning in vivo.

  5. [The mechanisms of prostate cancer progression through androgen receptor].

    PubMed

    Goto, Yusuke; Sakamoto, Shinichi; Ichikawa, Tomohiko

    2016-01-01

    Androgen receptor(AR) has a critical role in prostate cancer(PCa) progression and targeting AR axis signaling by androgen deprivation therapy is a standard treatment for advanced PCa. Recently, the role of AR even in castration-resistant PCa(CRPC) is well recognized and emerging evidence suggests survival advantages of treatment by targeting AR in CRPC. This review outlines AR functions that contribute to PCa progression, AR structural alterations and AR activation via intracrine, co-factors, and kinase pathways in CRPC. Finally, we describe about recently reported bipolar androgen therapy as a novel treatment for CRPC targeting AR. PMID:26793880

  6. Androgen receptor: structure, role in prostate cancer and drug discovery

    PubMed Central

    Tan, MH Eileen; Li, Jun; Xu, H Eric; Melcher, Karsten; Yong, Eu-leong

    2015-01-01

    Androgens and androgen receptors (AR) play a pivotal role in expression of the male phenotype. Several diseases, such as androgen insensitivity syndrome (AIS) and prostate cancer, are associated with alterations in AR functions. Indeed, androgen blockade by drugs that prevent the production of androgens and/or block the action of the AR inhibits prostate cancer growth. However, resistance to these drugs often occurs after 2–3 years as the patients develop castration-resistant prostate cancer (CRPC). In CRPC, a functional AR remains a key regulator. Early studies focused on the functional domains of the AR and its crucial role in the pathology. The elucidation of the structures of the AR DNA binding domain (DBD) and ligand binding domain (LBD) provides a new framework for understanding the functions of this receptor and leads to the development of rational drug design for the treatment of prostate cancer. An overview of androgen receptor structure and activity, its actions in prostate cancer, and how structural information and high-throughput screening have been or can be used for drug discovery are provided herein. PMID:24909511

  7. Effects of androgen on immunohistochemical localization of androgen receptor and Connexin 43 in mouse ovary.

    PubMed

    Yang, Mei; Li, Jianhua; An, Yulin; Zhang, Shuiwen

    2015-10-01

    Androgens have essential roles in the regulation of follicular development and female fertility. Androgen excess is the leading defect in polycystic ovary syndrome (PCOS) patients and involved in the ovarian dysfunction. The aim of this study was to elucidate the regarding regulatory role of androgen in the follicular development of female mouse. Immunohistochemical staining and Western blot analyses were performed to detect androgen receptor (AR) and Connexin 43 (Cx43) expression in ovaries from both control and testosterone-treated group mice. In this study, localizations of AR and Cx43 were dramatically altered in testosterone-treated mouse ovaries. In addition, AR expression was significantly increased, whereas Cx43 expression was markedly decreased after testosterone treatment. Alterations of AR and Cx43 expression by testosterone with concomitant reduction of MII oocytes. Overall, these results suggest the involvement of androgen in the regulation of AR and Cx43 localizations in mouse ovary. Alterations of AR and Cx43 expression by testosterone may affect normal folliculogenesis. Together these findings will enable us to begin understanding the important roles of AR and Cx43 actions in the regulation of follicular development, as well as providing insights into the role of AR and Cx43 actions in the androgen-associated reproductive diseases such as PCOS. PMID:26206424

  8. Androgens induce sebaceous differentiation in sebocyte cells expressing a stable functional androgen receptor.

    PubMed

    Barrault, Christine; Garnier, Julien; Pedretti, Nathalie; Cordier-Dirikoc, Sevda; Ratineau, Emeline; Deguercy, Alain; Bernard, François-Xavier

    2015-08-01

    Androgens act through non-genomic and androgen receptor (AR)-dependent genomic mechanisms. AR is expressed in the sebaceous gland and the importance of androgens in the sebaceous function is well established. However, the in vitro models used to date have failed to evidence a clear genomic effect (e.g., modification of gene expression profile) of androgens on human sebocyte cells. In order to study the impact of active androgens in sebocytes, we constructed a stable human sebocyte cell line derived from SEBO662 [17] constitutively expressing a fully functional AR. In these SEBO662 AR+ cells, dihydrotestosterone (DHT) induced AR nuclear translocation and the strong modulation of a set of transcripts (RASD1, GREB1...) known to be androgen-sensitive in other androgenic cells and tissues. Moreover, we observed that DHT precociously down-regulated markers for immature follicular cells (KRT15, TNC) and for hair lineage (KRT75, FST) and up-regulated the expression of genes potentially related to sebocyte differentiation (MUC1/EMA, AQP3, FADS2). These effects were fully confirmed at the protein level. In addition, DHT-stimulated SEBO662 AR+, cultured in a low-calcium defined keratinocyte medium without serum or any complement, neosynthesize lipids, including sebum lipids, and store increased amounts of triglycerides in lipid droplets. DHT also induces morphological changes, increases cell size, and treatments over 7 days lead to a time-dependent increase in the population of apoptotic DNA-fragmented cells. Taken together, these results show for the first time that active androgens alone can engage immature sebocytes in a clear lipogenic differentiation process (Graphical abstract). These effects depend on the expression of a functional AR in these cells. This model should be of interest for revisiting the mechanisms of the sebaceous function in vitro and for the design of relevant pharmacological models for drug or compound testing. PMID:25864624

  9. Androgen insensitivity.

    PubMed

    Gottlieb, B; Pinsky, L; Beitel, L K; Trifiro, M

    1999-12-29

    The androgen receptor (AR) protein regulates transcription of certain genes. Usually, this activity depends upon a central DNA-binding domain that permits the binding of androgen-AR complexes to regulatory DNA sequences near or in a target gene. The AR also has a C-terminal androgen-binding domain (ABD) and an N-terminal modulatory domain. These domains interact among themselves and with coregulatory, nonreceptor proteins to determine vector control over a gene's transcription rate. The precise roles of these proteins are active research areas. Severe X-linked androgen receptor gene (AR) mutations cause complete androgen insensitivity, mild ones impair virilization with or without infertility, and moderate ones sometimes yield a wide phenotypic spectrum among sibs. Different expressivity may reflect variability of AR-interactive proteins. The family history must identify heterozygous XX females with sparse, delayed, or asymmetric pubic/axillary hair or delayed menarche and infertile XY maternal aunts or uncles. Mutation type and density vary along the length of the AR. N-terminal polyglutamine tract expansion limits AR transactivation, causing a form of mild androgen insensitivity. Analysis of ABD mutations that do not impair androgen binding or impair it selectively will illuminate its intradomain properties. For partial androgen insensitivity and mild androgen insensitivity, pharmacotherapy with certain androgens or other steroids may overcome some dysfunction of certain mutant ARs. Experience with this approach is limited; outcomes have been generally disappointing. PMID:10727996

  10. Different types of androgen receptor mutations in patients with complete androgen insensitivity syndrome.

    PubMed

    Shao, Jialiang; Hou, Jiangang; Li, Bingkun; Li, Dongyang; Zhang, Ning; Wang, Xiang

    2015-02-01

    Mutations of androgen receptor (AR) are the most frequent cause of 46, XY disorders of sex development and associated with a variety of phenotypes, ranging from phenotypic women (complete androgen insensitivity syndrome (CAIS)) to milder degrees of undervirilization (partial form or PAIS) or men with only infertility (mild form or MAIS). From 2009 to 2012, two young Chinese female individuals with CAIS from two families were referred to our hospital due to primary amenorrhea. Defects in testosterone (T) and dihydrotestosterone (DHT) synthesis were excluded. Physical examination revealed that the patients have normal female external genitalia, normal breast development, vellus hair in the axilla and on the arms and legs, but absence of pubic hair, and a blind-ending vagina. Two different types of AR mutations have been detected by sequencing of genomic DNA: Family A showed deletion of exon 2 in AR gene; Family B showed a single nucleotide C-to-T transition in exon 8 of AR gene resulting in a proline 893-to-leucine substitution (Pro893Leu). Testicular histology showed developmental immaturity of seminiferous tubules with the absence of spermatogenic cells or spermatozoa. No AR immunoreactivity was observed in either case. Three adult patients recovered well from bilateral orchiectomy. The juvenile patient of family B was followed up. Our present study on these two families revealed two different types of AR mutation. The definitive diagnosis of AIS was based on clinical examination and genetic investigations. Our findings verified the mechanism of CAIS and also enriched AR Gene Mutation Database. PMID:25674389

  11. Identification of a novel androgen receptor agonist (or “androgen mimic”) of environmental concern: spironolactone

    EPA Science Inventory

    Spironolactone is a pharmaceutical that acts as an androgen receptor (AR) antagonist in humans to treat certain conditions such as hirsutism, various dermatologic afflictions, and female pattern hair loss. The drug is also used to treat hypertension as a diuretic. With this commo...

  12. Antioxidants Abrogate Alpha-Tocopherylquinone-Mediated Down-Regulation of the Androgen Receptor in Androgen-Responsive Prostate Cancer Cells

    PubMed Central

    Fajardo, Alexandra M.; MacKenzie, Debra A.; Olguin, Sarah L.; Scariano, John K.; Rabinowitz, Ian; Thompson, Todd A.

    2016-01-01

    Tocopherylquinone (TQ), the oxidation product of alpha-tocopherol (AT), is a bioactive molecule with distinct properties from AT. In this study, AT and TQ are investigated for their comparative effects on growth and androgenic activity in prostate cancer cells. TQ potently inhibited the growth of androgen-responsive prostate cancer cell lines (e.g., LAPC4 and LNCaP cells), whereas the growth of androgen-independent prostate cancer cells (e.g., DU145 cells) was not affected by TQ. Due to the growth inhibitory effects induced by TQ on androgen-responsive cells, the anti-androgenic properties of TQ were examined. TQ inhibited the androgen-induced activation of an androgen-responsive reporter and inhibited the release of prostate specific antigen from LNCaP cells. TQ pretreatment was also found to inhibit AR activation as measured using the Multifunctional Androgen Receptor Screening assay. Furthermore, TQ decreased androgen-responsive gene expression, including TM4SF1, KLK2, and PSA over 5-fold, whereas AT did not affect the expression of androgen-responsive genes. Of importance, the antiandrogenic effects of TQ on prostate cancer cells were found to result from androgen receptor protein down-regulation produced by TQ that was not observed with AT treatment. Moreover, none of the androgenic endpoints assessed were affected by AT. The down-regulation of androgen receptor protein by TQ was abrogated by co-treatment with antioxidants. Overall, the biological actions of TQ were found to be distinct from AT, where TQ was found to be a potent inhibitor of cell growth and androgenic activity in androgen-responsive prostate cancer cells. PMID:26986969

  13. Enhanced evaluation of selective androgen receptor modulators in vivo.

    PubMed

    Otto-Duessel, M; He, M; Adamson, T W; Jones, J O

    2013-01-01

    Selective androgen receptor modulators (SARMs) are a class of drugs that control the activity of the androgen receptor (AR), which mediates the response to androgens, in a tissue-selective fashion. They are specifically designed to reduce the possible complications that result from the systemic inhibition or activation of AR in patients with diseases that involve androgen signalling. However, there are no ideal in vivo models for evaluating candidate SARMs. Therefore, we created a panel of androgen-responsive genes in clinically relevant AR expressing tissues including prostate, skin, bone, fat, muscle, brain and kidney. We used select genes from this panel to compare transcriptional changes in response to the full agonist dihydrotestosterone (DHT) and the SARM bolandiol at 16 h and 6 weeks. We identified several genes in each tissue whose expression at each of these time points correlates with the known tissue-specific effects of these compounds. For example, in the prostate we found four genes whose expression was much lower in animals treated with bolandiol compared with animals treated with DHT for 6 weeks, which correlated well with differences in prostate weight. We demonstrate that adding molecular measurements (androgen-regulated gene expression) to the traditional physiological measurements (tissue weights, etc.) makes the evaluation of potential SARMs more accurate, thorough and perhaps more rapid by allowing measurement of selectivity after only 16 h of drug treatment. PMID:23258627

  14. Optimizing Ligand Efficiency of Selective Androgen Receptor Modulators (SARMs).

    PubMed

    Handlon, Anthony L; Schaller, Lee T; Leesnitzer, Lisa M; Merrihew, Raymond V; Poole, Chuck; Ulrich, John C; Wilson, Joseph W; Cadilla, Rodolfo; Turnbull, Philip

    2016-01-14

    A series of selective androgen receptor modulators (SARMs) containing the 1-(trifluoromethyl)benzyl alcohol core have been optimized for androgen receptor (AR) potency and drug-like properties. We have taken advantage of the lipophilic ligand efficiency (LLE) parameter as a guide to interpret the effect of structural changes on AR activity. Over the course of optimization efforts the LLE increased over 3 log units leading to a SARM 43 with nanomolar potency, good aqueous kinetic solubility (>700 μM), and high oral bioavailability in rats (83%). PMID:26819671

  15. Cryptotanshinone Suppresses Androgen Receptor-mediated Growth in Androgen Dependent and Castration Resistant Prostate Cancer Cells

    PubMed Central

    Xu, Defeng; Lin, Tzu-Hua; Li, Shaoshun; Da, Jun; Wen, Xing-Qiao; Ding, Jiang; Chang, Chawnshang; Yeh, Shuyuan

    2012-01-01

    Androgen receptor (AR) is the major therapeutic target for the treatment of prostate cancer (PCa). Anti-androgens to reduce or prevent androgens binding to AR are widely used to suppress AR-mediated PCa growth; however, the androgen depletion therapy is only effective for a period of time. Here we found a natural product/Chinese herbal medicine cryptotanshinone (CTS), with a structure similar to dihydrotestosterone (DHT), can effectively inhibit the DHT-induced AR transactivation and prostate cancer cell growth. Our results indicated that 0.5 µM CTS effectively suppresses the growth of AR-positive PCa cells, but has little effect on AR negative PC-3 cells and non-malignant prostate epithelial cells. Furthermore, our data indicated that CTS could modulate AR transactivation and suppress the DHT-mediated AR target genes (PSA, TMPRSS2, and TMEPA1) expression in both androgen responsive PCa LNCaP cells and castration resistant CWR22rv1 cells. Importantly, CTS selective inhibits AR without repressing the activities of other nuclear receptors, including ERα, GR, and PR. The mechanistic studies indicate that CTS functions as an AR inhibitor to suppress androgen/AR-mediated cell growth and PSA expression by blocking AR dimerization and the AR–coregulator complex formation. Furthermore, we showed that CTS effectively inhibits CWR22Rv1 cell growth in the xenograft animal model. The previously un-described mechanisms of CTS may explain how CTS inhibits the growth of PCa cells and help us to establish new therapeutic concepts for the treatment of PCa. PMID:22154085

  16. Mutational analysis of the androgen receptor gene in two Chinese families with complete androgen insensitivity syndrome

    PubMed Central

    WANG, SONG; XU, HAIKUN; AN, WEI; ZHU, DECHUN; LI, DEJUN

    2016-01-01

    Androgens are essential for normal male sex differentiation and are responsible for the normal development of male secondary sexual characteristics at puberty. The physiological effects of androgens are mediated by the androgen receptor (AR). Mutations in the AR gene are the most common cause of androgen insensitivity syndrome. The present study undertook a genetic analysis of the AR gene in two unrelated families affected by complete androgen insensitivity syndrome (CAIS) in China. In family 1, a previously reported nonsense mutation (G-to-A; p.W751X) was identified in exon 5 of the AR gene. In addition, a novel missense mutation was detected in exon 6 of the AR gene from family 2; this mutation resulted in a predicted amino acid change from phenylalanine to serine at codon 804 (T-to-C; p.F804S) in the ligand-binding domain (LBD) of AR. Computer simulation of the structural changes generated by the p.F804S substitution revealed marked conformational alterations in the hydrophobic core responsible for the stability and function of the AR-LBD. In conclusion, the present study identified two mutations from two unrelated Chinese families affected by CAIS. The novel mutation (p.F804S) may provide insights into the molecular mechanism underlying CAIS. Furthermore, it expands on the number of mutational hot spots in the international AR mutation database, which may be useful in the future for prenatal diagnosis and genetic counseling. PMID:27284311

  17. Molecular analysis of the androgen receptor in ten prostate cancer specimens obtained before and after androgen ablation.

    PubMed

    Lamb, Dolores J; Puxeddu, Efisio; Malik, Nusrat; Stenoien, David L; Nigam, Rajni; Saleh, George Y; Mancini, Michael; Weigel, Nancy L; Marcelli, Marco

    2003-01-01

    Hormonal or androgen-ablation (AA) therapy is the predominant form of systemic treatment for metastatic prostate cancer. Although an initial response to AA is observed in 70%-80% of patients with advanced disease, most tumors eventually progress to androgen-independent growth, and only a minority of affected individuals are alive 5 years following initiation of treatment. Because AA induces a dramatic change in the hormonal milieu of the patient and because these tumors maintain the ability to proliferate, it is possible that this treatment selects a population of cells with mutated androgen receptors (ARs) that sustain growth despite the absence of circulating androgen. To test this hypothesis we investigated the molecular structure of the AR in 10 prostate cancer specimens obtained before and after AA. Tumors (coded A through L) were microdissected to uniquely enrich genomic DNA from cancer cells. Exons 1-8 of the AR were screened by polymerase chain reaction, single-stranded conformational polymorphism, and sequence analysis. A mutation consisting of an expansion of the polyglutamine (poly-Q) repeat from 20 (found in 100% of the sequences of specimens obtained before AA) to 26 (found in 70% of the sequences of specimens obtained after AA) was detected in patient F. The 26 glutamine (Q26) AR readily translocated to the nucleus upon addition of androgen, and did not show significant differences in its ability to bind (3)[H]-dihydrotestosterone compared to its wild-type counterpart. Nevertheless, analysis of transcriptional activity showed that the Q66 AR was transcriptionally 30%-50% less active than the wild-type molecule. Because clones of AR with an expanded poly-Q tract were detected only in the specimen from patient F obtained after AA, we conclude that in specific circumstances, AA treatments can select variant forms of the AR in the prostate of patients affected by prostate cancer. Further experiments are needed to conclusively determine whether the Q26

  18. Androgen receptor roles in hepatocellular carcinoma, cirrhosis, and hepatitis

    PubMed Central

    Ma, Wen-Lung; Lai, Hsueh-Chou; Yeh, Shuyuan; Cai, Xiujun; Chang, Chawnshang

    2014-01-01

    Summary Androgen/androgen receptor (AR) signaling plays important roles in normal liver function and in progression of liver diseases. In studies of non-cancerous liver diseases, AR knockout mouse models of liver disease have revealed that androgen/AR signaling suppresses the development of steatosis, virus-related hepatitis, and cirrhosis. In addition, studies have shown that targeting AR in bone marrow-derived mesenchymal stem cells (BM-MSCs) improves their self-renewal and migration potentials, thereby increasing the efficacy of BM-MSC transplantation as a way to control the progression of cirrhosis. Androgen/AR signaling is known to be involved in the initiation of carcinogen- or Hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). However, studies have demonstrated that AR, rather than androgen, plays the dominant role in cancer initiation. Therefore, targeting AR might be an appropriate therapy for patients with early-stage HCC. In contrast, androgen/AR signaling has been shown to suppress metastasis of HCC in patients with late-stage disease. In addition, there is evidence that therapy comprising Sorafenib and agents that enhance the functional expression of AR may suppress the progression of late-stage HCC. PMID:24424503

  19. Androgen receptor and histone lysine demethylases in ovine placenta.

    PubMed

    Cleys, Ellane R; Halleran, Jennifer L; Enriquez, Vanessa A; da Silveira, Juliano C; West, Rachel C; Winger, Quinton A; Anthony, Russell V; Bruemmer, Jason E; Clay, Colin M; Bouma, Gerrit J

    2015-01-01

    Sex steroid hormones regulate developmental programming in many tissues, including programming gene expression during prenatal development. While estradiol is known to regulate placentation, little is known about the role of testosterone and androgen signaling in placental development despite the fact that testosterone rises in maternal circulation during pregnancy and in placenta-induced pregnancy disorders. We investigated the role of testosterone in placental gene expression, and focused on androgen receptor (AR). Prenatal androgenization decreased global DNA methylation in gestational day 90 placentomes, and increased placental expression of AR as well as genes involved in epigenetic regulation, angiogenesis, and growth. As AR complexes with histone lysine demethylases (KDMs) to regulate AR target genes in human cancers, we also investigated if the same mechanism is present in the ovine placenta. AR co-immunoprecipitated with KDM1A and KDM4D in sheep placentomes, and AR-KDM1A complexes were recruited to a half-site for androgen response element (ARE) in the promoter region of VEGFA. Androgenized ewes also had increased cotyledonary VEGFA. Finally, in human first trimester placental samples KDM1A and KDM4D immunolocalized to the syncytiotrophoblast, with nuclear KDM1A and KDM4D immunostaining also present in the villous stroma. In conclusion, placental androgen signaling, possibly through AR-KDM complex recruitment to AREs, regulates placental VEGFA expression. AR and KDMs are also present in first trimester human placenta. Androgens appear to be an important regulator of trophoblast differentiation and placental development, and aberrant androgen signaling may contribute to the development of placental disorders. PMID:25675430

  20. Nonsteroidal Androgen Receptor Ligands: Versatile Syntheses and Biological Data

    PubMed Central

    2012-01-01

    We report herein a stereoselective and straightforward methodology for the synthesis of new androgen receptor ligands with (anti)-agonistic activities. Oxygen–nitrogen replacement in bicalutamide-like structures paves the way to the disclosure of a new class of analogues, including cyclized/nitrogen-substituted derivatives, with promising antiandrogen (or anabolic) activity. PMID:24900495

  1. ANDROGEN RECEPTOR ANTAGONISM BY THE ORGANOPHOSPHATE INSECTICIDE FENITROTHION

    EPA Science Inventory

    Androgen receptor antagonism by the organophosphate insecticide fenitrothion. Tamura, H., Maness, S.C., Reischmann, K. Dorman, D.C., Gray, L.E., and Gaido, K.W. (2000). Toxicol. Sci.

    Organophosphate insecticides represent one of the most widely used classes of pesticide...

  2. Alternative splicing of the androgen receptor in polycystic ovary syndrome.

    PubMed

    Wang, Fangfang; Pan, Jiexue; Liu, Ye; Meng, Qing; Lv, Pingping; Qu, Fan; Ding, Guo-Lian; Klausen, Christian; Leung, Peter C K; Chan, Hsiao Chang; Yao, Weimiao; Zhou, Cai-Yun; Shi, Biwei; Zhang, Junyu; Sheng, Jianzhong; Huang, Hefeng

    2015-04-14

    Polycystic ovary syndrome (PCOS) is one of the most common female endocrine disorders and a leading cause of female subfertility. The mechanism underlying the pathophysiology of PCOS remains to be illustrated. Here, we identify two alternative splice variants (ASVs) of the androgen receptor (AR), insertion and deletion isoforms, in granulosa cells (GCs) in ∼62% of patients with PCOS. AR ASVs are strongly associated with remarkable hyperandrogenism and abnormalities in folliculogenesis, and are absent from all control subjects without PCOS. Alternative splicing dramatically alters genome-wide AR recruitment and androgen-induced expression of genes related to androgen metabolism and folliculogenesis in human GCs. These findings establish alternative splicing of AR in GCs as the major pathogenic mechanism for hyperandrogenism and abnormal folliculogenesis in PCOS. PMID:25825716

  3. CLONING AND IN VITRO EXPRESSION AND CHARACTERIZATION OF THE ANDROGEN RECEPTOR AND ISOLATION OF ESTROGEN RECEPTOR α FROM THE FATHEAD MINNOW (PIMEPHALES PROMELAS)

    EPA Science Inventory

    In vitro screening assays designed to identify hormone mimics or antagonists typically use mammalian (rat, human) estrogen (ER) and androgen receptors (AR). Although we know that the amino acid sequences of steroid receptors in nonmammalian vertebrates are not identical to the ma...

  4. Mutated human androgen receptor gene detected in a prostatic cancer patient is also activated by estradiol

    SciTech Connect

    Elo, J.P.; Kvist, L.; Leinonen, K.; Isomaa, V.

    1995-12-01

    Androgens are necessary for the development of prostatic cancer. The mechanisms by which the originally androgen-dependent prostatic cancer cells are relieved of the requirement to use androgen for their growth are largely unknown. The human prostatic cancer cell line LNCaP has been shown to contain a point mutation in the human androgen receptor gene (hAR), suggesting that changes in the hAR may contribute to the abnormal hormone response of prostatic cells. To search for point mutations in the hAR, we used single strand conformation polymorphism analysis and a polymerase chain reaction direct sequencing method to screen 23 prostatic cancer specimens from untreated patients, 6 prostatic cancer specimens from treated patients, and 11 benign prostatic hyperplasia specimens. One mutation was identified in DNA isolated from prostatic cancer tissue, and the mutation was also detected in the leukocyte DNA of the patient and his offspring. The mutation changed codon 726 in exon E from arginine to leucine and was a germ line mutation. The mutation we found in exon E of the hAR gene does not alter the ligand binding specificity of the AR, but the mutated receptor was activated by estradiol to a significantly greater extent than the wild-type receptor. The AR gene mutation described in this study might be one explanation for the altered biological activity of prostatic cancer. 36 refs., 4 figs.

  5. New single nucleotide variation in the promoter region of androgen receptor (AR) gene in hypospadic patients

    PubMed Central

    Borhani, Nasim; Ghaffari Novin, Marefat; Manoochehri, Mehdi; Rouzrokh, Mohsen; Kazemi, Bahram; Koochaki, Ameneh; Hosseini, Ahmad; Masteri Farahani, Reza; Omrani, Mir Davood

    2014-01-01

    Background: Hypospadias is one of the most common congenital abnormalities in the male which is characterized by altered development of urethra, foreskin and ventral surface of the penis. Androgen receptor gene plays a critical role in the development of the male genital system by mediating the androgens effects. Objective: In present study, we looked for new variations in androgen receptor promoter and screened its exon 1 for five single nucleotide polymorphisms (SNP) in healthy and hypospadias Iranian men. Materials and Methods: In our study, at first DNA was extracted from patients (n=100) and controls (n=100) blood samples. Desired fragments of promoter and exon 1 were amplified using polymerase chain reaction. The promoter region was sequenced for the new variation and exone 1 screened for five SNPs (rs139767835, rs78686797, rs62636528, rs62636529, rs145326748) using restriction fragment length polymorphism technique. Results: The results showed a new single nucleotide variation (C→T) at -480 of two patients’ promoter region (2%). None of the mentioned SNPs were detected in patients and controls groups (0%). Conclusion: This finding indicates that new single nucleotide polymorphism in androgen receptor promoter may have role in etiology of hypospadias and development of this anomaly. This article extracted from Ph.D. thesis. (Nasim Borhani) PMID:24799883

  6. Enhanced Evaluation of Selective Androgen Receptor Modulators In Vivo

    PubMed Central

    Otto-Duessel, Maya; He, Miaoling; Adamson, Trinka W.; Jones, Jeremy O.

    2014-01-01

    Selective AR modulators (SARMs) are a class of drugs that control the activity of the androgen receptor (AR), which mediates the response to androgens, in a tissue-selective fashion. They are specifically designed to reduce the possible complications that result from the systemic inhibition or activation of AR in patients with diseases that involve androgen signaling. However, there are no ideal in vivo models for evaluating candidate SARMs. Therefore, we created a panel of androgen responsive genes in clinically-relevant AR expressing tissues including prostate, skin, bone, fat, muscle, brain, and kidney. We used select genes from this panel to compare transcriptional changes in response to the full agonist dihydrotestosterone (DHT) and the SARM bolandiol at 16h and 6wks. We identified several genes in each tissue whose expression at each of these time points correlates with the known tissue-specific effects of these compounds. For example, in the prostate we found four genes whose expression was much lower in animals treated with bolandiol compared to animals treated with DHT for 6wks, which correlated well with differences in prostate weight. We demonstrate that adding molecular measurements (androgen regulated gene expression) to the traditional physiological measurements (tissue weights, etc) makes the evaluation of potential SARMs more accurate, thorough, and perhaps more rapid by allowing measurement of selectivity after only 16 hours of drug treatment. PMID:23258627

  7. Cooperative demethylation by JMJD2C and LSD1 promotes androgen receptor-dependent gene expression.

    PubMed

    Wissmann, Melanie; Yin, Na; Müller, Judith M; Greschik, Holger; Fodor, Barna D; Jenuwein, Thomas; Vogler, Christine; Schneider, Robert; Günther, Thomas; Buettner, Reinhard; Metzger, Eric; Schüle, Roland

    2007-03-01

    Posttranslational modifications of histones, such as methylation, regulate chromatin structure and gene expression. Recently, lysine-specific demethylase 1 (LSD1), the first histone demethylase, was identified. LSD1 interacts with the androgen receptor and promotes androgen-dependent transcription of target genes by ligand-induced demethylation of mono- and dimethylated histone H3 at Lys 9 (H3K9) only. Here, we identify the Jumonji C (JMJC) domain-containing protein JMJD2C as the first histone tridemethylase regulating androgen receptor function. JMJD2C interacts with androgen receptor in vitro and in vivo. Assembly of ligand-bound androgen receptor and JMJD2C on androgen receptor-target genes results in demethylation of trimethyl H3K9 and in stimulation of androgen receptor-dependent transcription. Conversely, knockdown of JMJD2C inhibits androgen-induced removal of trimethyl H3K9, transcriptional activation and tumour cell proliferation. Importantly, JMJD2C colocalizes with androgen receptor and LSD1 in normal prostate and in prostate carcinomas. JMJD2C and LSD1 interact and both demethylases cooperatively stimulate androgen receptor-dependent gene transcription. In addition, androgen receptor, JMJD2C and LSD1 assemble on chromatin to remove methyl groups from mono, di and trimethylated H3K9. Thus, our data suggest that specific gene regulation requires the assembly and coordinate action of demethylases with distinct substrate specificities. PMID:17277772

  8. Androgen Receptor Structure, Function and Biology: From Bench to Bedside

    PubMed Central

    Davey, Rachel A; Grossmann, Mathis

    2016-01-01

    The actions of androgens such as testosterone and dihydrotestosterone are mediated via the androgen receptor (AR), a ligand-dependent nuclear transcription factor and member of the steroid hormone nuclear receptor family. Given its widespread expression in many cells and tissues, the AR has a diverse range of biological actions including important roles in the development and maintenance of the reproductive, musculoskeletal, cardiovascular, immune, neural and haemopoietic systems. AR signalling may also be involved in the development of tumours in the prostate, bladder, liver, kidney and lung. Androgens can exert their actions via the AR in a DNA binding-dependent manner to regulate target gene transcription, or in a non-DNA binding-dependent manner to initiate rapid, cellular events such as the phosphorylation of 2nd messenger signalling cascades. More recently, ligand-independent actions of the AR have also been identified. Given the large volume of studies relating to androgens and the AR, this review is not intended as an extensive review of all studies investigating the AR, but rather as an overview of the structure, function, signalling pathways and biology of the AR as well as its important role in clinical medicine, with emphasis on recent developments in this field. PMID:27057074

  9. Testosterone regulates keratin 33B expression in rat penis growth through androgen receptor signaling

    PubMed Central

    Ma, Yan-Min; Wu, Kai-Jie; Dang, Qiang; Shi, Qi; Gao, Yang; Guo, Peng; Xu, Shan; Wang, Xin-Yang; He, Da-Lin; Gong, Yong-Guang

    2014-01-01

    Androgen therapy is the mainstay of treatment for the hypogonadotropic hypogonadal micropenis because it obviously enhances penis growth in prepubescent microphallic patients. However, the molecular mechanisms of androgen treatment leading to penis growth are still largely unknown. To clarify this well-known phenomenon, we successfully generated a castrated male Sprague Dawley rat model at puberty followed by testosterone administration. Interestingly, compared with the control group, testosterone treatment stimulated a dose-dependent increase of penis weight, length, and width in castrated rats accompanied with a dramatic recovery of the pathological changes of the penis. Mechanistically, testosterone administration substantially increased the expression of androgen receptor (AR) protein. Increased AR protein in the penis could subsequently initiate transcription of its target genes, including keratin 33B (Krt33b). Importantly, we demonstrated that KRT33B is generally expressed in the rat penis and that most KRT33B expression is cytoplasmic. Furthermore, AR could directly modulate its expression by binding to a putative androgen response element sequence of the Krt33b promoter. Overall, this study reveals a novel mechanism facilitating penis growth after testosterone treatment in precastrated prepubescent animals, in which androgen enhances the expression of AR protein as well as its target genes, such as Krt33b. PMID:24994782

  10. Androgen receptor is overexpressed in boys with severe hypospadias, and ZEB1 regulates androgen receptor expression in human foreskin cells

    PubMed Central

    Qiao, Liang; Tasian, Gregory E.; Zhang, Haiyang; Cao, Mei; Ferretti, Max; Cunha, Gerald R.; Baskin, Laurence S.

    2012-01-01

    INTRODUCTION ZEB1 is overexpressed in patients with severe hypospadias. We examined the interaction between ZeB1 and the androgen receptor (AR) in vitro and the expression of AR in boys with hypospadias. RESULTS ZEB1 and AR colocalize to the nucleus. Estrogen upregulated ZEB1 and AR expression. Chromatin immunoprecipitation (ChIP) demonstrated that ZEB1 binds to an E-box sequence in the AR gene promoter. AR expression is higher in subjects with severe hypospadias than those with mild hypospadias and control subjects (P < 0.05). ZEB1 physically interacts with AR in human foreskin cells. DISCUSSION AR is overexpressed in patients with severe hypospadias. Environmental estrogenic compounds may increase the risk of hypospadias by facilitating the interaction between ZEB1 and AR. METHODS Hs68 cells, a fibroblast cell line derived from neonatal human foreskin, were exposed to 0, 10, and 100 nmol/l of estrogen, after which the cellular localization of ZEB1 and AR was assessed using immunocytochemistry. To determine if ZEB1 interacted with the AR gene, ChIP was performed using ZEB1 antibody and polymerase chain reaction (PCR) for AR. Second, AR expression was quantified using real-time PcR and western blot in normal subjects (n = 32), and subjects with mild (n = 16) and severe hypospadia (n = 16). PMID:22391641

  11. Classical androgen receptors in non-classical sites in the brain

    PubMed Central

    Sarkey, Sara; Azcoitia, Iñigo; Garcia-Segura, Luis Miguel; Garcia-Ovejero, Daniel; DonCarlos, Lydia L.

    2008-01-01

    Androgen receptors are expressed in many different neuronal populations in the central nervous system where they often act as transcription factors in the cell nucleus. However, recent studies have detected androgen receptor immunoreactivity in neuronal and glial processes of the adult rat neocortex, hippocampal formation, and amygdala as well as in the telencephalon of Eastern Fence and green anole lizards. This review discusses previously published findings on extranuclear androgen receptors, as well as new experimental results that begin to establish a possible functional role for androgen receptors in axons within cortical regions. Electron microscopic studies have revealed that androgen receptor immunoreactive processes in the rat brain correspond to axons, dendrites and glial processes. New results show that lesions of the dorsal CA1 region by local administration of ibotenic acid reduce the density of androgen receptor immunoreactive axons in the cerebral cortex and the amygdala, suggesting that these axons may originate in the hippocampus. Androgen receptor immunoreactivity in axons is also decreased by the intracerebroventricular administration of colchicine, suggesting that androgen receptor protein is transported from the perikaryon to the axons by fast axonal transport. Androgen receptors in axons located in the cerebral cortex and amygdala and originating in the hippocampus may play an important role in the rapid behavioral effects of androgens. PMID:18402960

  12. Selective androgen receptor modulators in preclinical and clinical development

    PubMed Central

    Narayanan, Ramesh; Mohler, Michael L.; Bohl, Casey E.; Miller, Duane D.; Dalton, James T.

    2008-01-01

    Androgen receptor (AR) plays a critical role in the function of several organs including primary and accessory sexual organs, skeletal muscle, and bone, making it a desirable therapeutic target. Selective androgen receptor modulators (SARMs) bind to the AR and demonstrate osteo- and myo-anabolic activity; however, unlike testosterone and other anabolic steroids, these nonsteroidal agents produce less of a growth effect on prostate and other secondary sexual organs. SARMs provide therapeutic opportunities in a variety of diseases, including muscle wasting associated with burns, cancer, or end-stage renal disease, osteoporosis, frailty, and hypogonadism. This review summarizes the current standing of research and development of SARMs, crystallography of AR with SARMs, plausible mechanisms for their action and the potential therapeutic indications for this emerging class of drugs. PMID:19079612

  13. Splice Variants of Androgen Receptor and Prostate Cancer

    PubMed Central

    Caffo, Orazio; Maines, Francesca; Veccia, Antonello; Kinspergher, Stefania; Galligioni, Enzo

    2016-01-01

    Over the last ten years, two new-generation hormonal drugs and two chemotherapeutic agents have been approved for the treatment of metastatic castration-resistant prostate cancer. Unfortunately, some patients have primary resistance to them and the others eventually develop secondary resistance. It has recently been suggested that the presence of androgen receptor splice variants plays a leading role in the primary and secondary resistance to the new hormonal drugs, whereas their presence seem to have only a partial effect on the activity of the chemotherapeutic agents. The aim of this paper is to review the published data concerning the role of androgen receptor splice variants in prostate cancer biology, and their potential use as biomarkers when making therapeutic decisions.

  14. Discovery of aryloxy tetramethylcyclobutanes as novel androgen receptor antagonists.

    PubMed

    Guo, Chuangxing; Linton, Angelica; Kephart, Susan; Ornelas, Martha; Pairish, Mason; Gonzalez, Javier; Greasley, Samantha; Nagata, Asako; Burke, Benjamin J; Edwards, Martin; Hosea, Natilie; Kang, Ping; Hu, Wenyue; Engebretsen, Jon; Briere, David; Shi, Manli; Gukasyan, Hovik; Richardson, Paul; Dack, Kevin; Underwood, Toby; Johnson, Patrick; Morell, Andrew; Felstead, Robert; Kuruma, Hidetoshi; Matsimoto, Hiroaki; Zoubeidi, Amina; Gleave, Martin; Los, Gerrit; Fanjul, Andrea N

    2011-11-10

    An aryloxy tetramethylcyclobutane was identified as a novel template for androgen receptor (AR) antagonists via cell-based high-throughput screening. Follow-up to the initial "hit" established 5 as a viable lead. Further optimization to achieve full AR antagonism led to the discovery of 26 and 30, both of which demonstrated excellent in vivo tumor growth inhibition upon oral administration in a castration-resistant prostate cancer (CRPC) animal model. PMID:21936524

  15. Nonsteroidal Selective Androgen Receptor Modulators Enhance Female Sexual Motivation

    PubMed Central

    Jones, Amanda; Hwang, Dong Jin; Duke, Charles B.; He, Yali; Siddam, Anjaiah; Miller, Duane D.

    2010-01-01

    Women experience a decline in estrogen and androgen levels after natural or surgically induced menopause, effects that are associated with a loss of sexual desire and bone mineral density. Studies in our laboratories have shown the beneficial effects of selective androgen receptor modulators (SARMs) in the treatment of osteoporosis and muscle wasting in animal models. A series of S-3-(phenoxy)-2-hydroxy-2-methyl-N-(4-cyano-3-trifluoromethyl-phenyl)-propionamide analogs was synthesized to evaluate the effects of B-ring substitutions on in vitro and in vivo pharmacologic activity, especially female sexual motivation. The androgen receptor (AR) relative binding affinities ranged from 0.1 to 26.5% (relative to dihydrotestosterone) and demonstrated a range of agonist activity at 100 nM. In vivo pharmacologic activity was first assessed by using male rats. Structural modifications to the B-ring significantly affected the selectivity of the SARMs, demonstrating that single-atom substitutions can dramatically and unexpectedly influence activity in androgenic (i.e., prostate) and anabolic (i.e., muscle) tissues. (S)-N-(4-cyano-3-trifluoromethyl-phenyl)-3-(3-fluoro,4-chlorophenoxy)-2-hydroxy-2-methyl-propanamide (S-23) displayed full agonist activity in androgenic and anabolic tissues; however, the remaining SARMs were more prostate-sparing, selectively maintaining the size of the levator ani muscle in castrated rats. The partner-preference paradigm was used to evaluate the effects of SARMs on female sexual motivation. With the exception of two four-halo substituted analogs, the SARMs increased sexual motivation in ovariectomized rats, with potency and efficacy comparable with testosterone propionate. These results indicate that the AR is important in regulating female libido given the nonaromatizable nature of SARMs and it could be a superior alternative to steroidal testosterone preparations in the treatment of hypoactive sexual desire disorder. PMID:20444881

  16. Binding properties of androgen receptors. Evidence for identical receptors in rat testis, epididymis, and prostate.

    PubMed

    Wilson, E M; French, F S

    1976-09-25

    Androgen receptors in crude and partially purified 105,000 X g supernatant fractions from rat testis, epididymis, and prostate were studied in vitro using a charcoal adsorption assay and sucrose gradient centrifugation. Androgen metabolism was eliminated during receptor purification allowing determination of the kinetics of [3H]-androgen-receptor complex formation. In all three tissues, receptors were found to have essentially identical capabilities to bind androgen, with the affinity for [3H] dihydrotestosterone being somewhat higher than for [3H] testosterone. Equilibrium dissociation constants for [3H] dihydrotestosterone and [3H] testosterone (KD = 2 to 5 X 10(-10) M) were estimated from independently determined rates of association (ka congruent to 6 X 10(7) M-1 h-1 for [3H] dihydrotestosterone and 2 X 10(8) M-1 h-1 for [3H] testosterone) and dissociation (t 1/2 congruent to 40 hr for [3H] dihydrotestosterone and 15 h [3H] testosterone). Evaluation of the effect of temperature on androgen receptor binding of [3H]testosterone allowed estimation of several thermodynamic parameters, including activation energies of association and dissociation (delta H congruent to 14 kcal/mol), the apparent free energy (delta G congruent to -12 kcal/mol), enthalpy (delta H congruent to -2.5 kcal/mol), and entropy (delta S congruent to 35 cal col-1 K-1). Optimum receptor binding occurred at a pH of 8. Receptor stability was greatly enhanced when bound with androgen. Receptor specificity for testosterone and dihydrotestosterone was demonstrated by competitive binding assays. The potent synthetic androgen, 7 alpha, 17 alpha-dimethyl-19-nortestosterone, inhibited binding of [3H] testosterone or [3H] dihydrotesterone nearly as well as testosterone and dihydrotestosterone while larger amounts of 5 alpha-androstane-3alpha, 17 beta-diol and nonandrogenic steroids were required. Sedimentation coefficients of androgen receptors in all unfractionated supernatants were 4 and 5 to 8 S

  17. Protein phosphatase 1 suppresses androgen receptor ubiquitylation and degradation.

    PubMed

    Liu, Xiaming; Han, Weiwei; Gulla, Sarah; Simon, Nicholas I; Gao, Yanfei; Cai, Changmeng; Yang, Hongmei; Zhang, Xiaoping; Liu, Jihong; Balk, Steven P; Chen, Shaoyong

    2016-01-12

    The phosphoprotein phosphatases are emerging as important androgen receptor (AR) regulators in prostate cancer (PCa). We reported previously that the protein phosphatase 1 catalytic subunit (PP1α) can enhance AR activity by dephosphorylating a site in the AR hinge region (Ser650) and thereby decrease AR nuclear export. In this study we show that PP1α increases the expression of wildtype as well as an S650A mutant AR, indicating that it is acting through one or more additional mechanisms. We next show that PP1α binds primarily to the AR ligand binding domain and decreases its ubiquitylation and degradation. Moreover, we find that the PP1α inhibitor tautomycin increases phosphorylation of AR ubiquitin ligases including SKP2 and MDM2 at sites that enhance their activity, providing a mechanism by which PP1α may suppress AR degradation. Significantly, the tautomycin mediated decrease in AR expression was most pronounced at low androgen levels or in the presence of the AR antagonist enzalutamide. Consistent with this finding, the sensitivity of LNCaP and C4-2 PCa cells to tautomycin, as assessed by PSA synthesis and proliferation, was enhanced at low androgen levels or by treatment with enzalutamide. Together these results indicate that PP1α may contribute to stabilizing AR protein after androgen deprivation therapies, and that targeting PP1α or the AR-PP1α interaction may be effective in castration-resistant prostate cancer (CRPC). PMID:26636645

  18. Cloning and expression analysis of androgen receptor gene in chicken embryogenesis.

    PubMed

    Katoh, Hironori; Ogino, Yukiko; Yamada, Gen

    2006-03-01

    We cloned a full-length androgen receptor (AR) cDNA from chicken (Gallus gallus) gonads. The cDNA sequence has an open reading frame of 2109 bp encoding 703 amino acids. The chicken AR (cAR) shares high homology with ARs from other species in its amino acid sequences, in particular DNA binding domain (DBD) and ligand binding domain (LBD). RT-PCR analysis revealed that cAR mRNA is expressed in several embryonic tissues of both sexes, and relatively higher expression was observed in left ovary compared with testis. The immunoreactive signal of AR was co-localized within the ovarian cell nucleus, while such nuclear localization was not detected in those of testis. To get insight on the possible role of androgen-AR signaling during gonadal development, non-steroidal AR antagonist, flutamide, was administrated in ovo. The treatment induced the disorganization of sex cords in ovarian cortex at day 12 of incubation. The effect was restored by testosterone co-treatment, implying the possibility that AR mediated signaling may be involved in ovarian morphogenesis. Furthermore, co-treatment of flutamide with estradiol-17beta (E2) also restored the phenotype, suggesting androgen-AR signaling might activate aromatase expression that is necessary for estrogen synthesis. These findings suggest androgen-AR signaling might contribute to chicken embryonic ovarian development. PMID:16480982

  19. Single amino acid substitutions at 2 of 14 positions in an ultra-conserved region of the androgen receptor yield an androgen-binding domain that is reversibly thermolabile

    SciTech Connect

    Vasiliou, M.; Lumbroso, R.; Alvarado, C.

    1994-09-01

    The stereochemistry of the androgen receptor (AR) that is responsible for androgen-specific binding and for its contribution to the transregulatory attributes of an androgen-receptor complex are unknown. Our objective is to define structure-function relations of the human AR by correlating germline missense mutations at its X-linked locus with its resultant misbehavior. Subjects with Arg773Cys have complete androgen insensitivity. We and several other laboratories have reported that their genital skin fibroblasts (GSF) have negligible androgen-binding activity at 37{degrees}. We have found that Phe763Leu also causes CAI, but with approximately 10 fmol/mg protein androgen-binding activity at 37{degrees} (R-deficient). Within COS-1 cells transfected with each mutant AR cDNA, Phe763Leu and Arg773Cys androgen-binding activities are reversibly thermolabile, by a factor of 2, at 37{degrees} versus 22{degrees}, only in the presence of androgen; in the absence of androgen they are thermostable at 37{degrees}. We have discovered that (for a reason yet unknown) the GSF from a third family with Arg773Cys (and no other coding sequence mutation) have 20-40 mol/mg protein of androgen-binding activity at 37{degrees} when measured with 3-6 nFM androgen. This activity reversibly doubles at 22{degrees}. The reversible thermolability of an AR with Arg773Cys (and probably with Phe763Leu) is demonstrable within GSF. Ligand-dependence of this thermolability implies that ligand induces these mutant AR to undergo a deviant conformational change in, or near, a 14-aa region that shares 90% identity/similarity with its closest receptor relatives.

  20. The liver X receptor agonist T0901317 acts as androgen receptor antagonist in human prostate cancer cells

    SciTech Connect

    Chuu, Chih-pin; Chen, Rou-Yu; Hiipakka, Richard A.; Kokontis, John M.; Warner, Karen V.; Xiang, Jialing; Liao, Shutsung . E-mail: sliao@uchicago.edu

    2007-06-01

    T0901317 is a potent non-steroidal synthetic liver X receptor (LXR) agonist. T0901317 blocked androgenic stimulation of the proliferation of androgen-dependent LNCaP 104-S cells and androgenic suppression of the proliferation of androgen-independent LNCaP 104-R2 cells, inhibited the transcriptional activation of an androgen-dependent reporter gene by androgen, and suppressed gene and protein expression of prostate specific antigen (PSA), a target gene of androgen receptor (AR) without affecting gene and protein expression of AR. T0901317 also inhibited binding of a radiolabeled androgen to AR, but inhibition was much weaker compared to the effect of the antiandrogens, bicalutamide and hydroxyflutamide. The LXR agonist T0901317, therefore, acts as an antiandrogen in human prostate cancer cells.

  1. Complete androgen insensitivity syndrome caused by a deep intronic pseudoexon-activating mutation in the androgen receptor gene.

    PubMed

    Känsäkoski, Johanna; Jääskeläinen, Jarmo; Jääskeläinen, Tiina; Tommiska, Johanna; Saarinen, Lilli; Lehtonen, Rainer; Hautaniemi, Sampsa; Frilander, Mikko J; Palvimo, Jorma J; Toppari, Jorma; Raivio, Taneli

    2016-01-01

    Mutations in the X-linked androgen receptor (AR) gene underlie complete androgen insensitivity syndrome (CAIS), the most common cause of 46,XY sex reversal. Molecular genetic diagnosis of CAIS, however, remains uncertain in patients who show normal coding region of AR. Here, we describe a novel mechanism of AR disruption leading to CAIS in two 46,XY sisters. We analyzed whole-genome sequencing data of the patients for pathogenic variants outside the AR coding region. Patient fibroblasts from the genital area were used for AR cDNA analysis and protein quantification. Analysis of the cDNA revealed aberrant splicing of the mRNA caused by a deep intronic mutation (c.2450-118A>G) in the intron 6 of AR. The mutation creates a de novo 5' splice site and a putative exonic splicing enhancer motif, which leads to the preferential formation of two aberrantly spliced mRNAs (predicted to include a premature stop codon). Patient fibroblasts contained no detectable AR protein. Our results show that patients with CAIS and normal AR coding region need to be examined for deep intronic mutations that can lead to pseudoexon activation. PMID:27609317

  2. Complete androgen insensitivity syndrome caused by a deep intronic pseudoexon-activating mutation in the androgen receptor gene

    PubMed Central

    Känsäkoski, Johanna; Jääskeläinen, Jarmo; Jääskeläinen, Tiina; Tommiska, Johanna; Saarinen, Lilli; Lehtonen, Rainer; Hautaniemi, Sampsa; Frilander, Mikko J.; Palvimo, Jorma J.; Toppari, Jorma; Raivio, Taneli

    2016-01-01

    Mutations in the X-linked androgen receptor (AR) gene underlie complete androgen insensitivity syndrome (CAIS), the most common cause of 46,XY sex reversal. Molecular genetic diagnosis of CAIS, however, remains uncertain in patients who show normal coding region of AR. Here, we describe a novel mechanism of AR disruption leading to CAIS in two 46,XY sisters. We analyzed whole-genome sequencing data of the patients for pathogenic variants outside the AR coding region. Patient fibroblasts from the genital area were used for AR cDNA analysis and protein quantification. Analysis of the cDNA revealed aberrant splicing of the mRNA caused by a deep intronic mutation (c.2450-118A>G) in the intron 6 of AR. The mutation creates a de novo 5′ splice site and a putative exonic splicing enhancer motif, which leads to the preferential formation of two aberrantly spliced mRNAs (predicted to include a premature stop codon). Patient fibroblasts contained no detectable AR protein. Our results show that patients with CAIS and normal AR coding region need to be examined for deep intronic mutations that can lead to pseudoexon activation. PMID:27609317

  3. Nonneural Androgen Receptors Affect Sexual Differentiation of Brain and Behavior.

    PubMed

    Swift-Gallant, Ashlyn; Coome, Lindsay A; Ramzan, Firyal; Monks, D Ashley

    2016-02-01

    Testosterone, acting via estrogenic and androgenic pathways, is the major endocrine mechanism promoting sexual differentiation of the mammalian nervous system and behavior, but we have an incomplete knowledge of which cells and tissues mediate these effects. To distinguish between neural and nonneural actions of androgens in sexual differentiation of brain and behavior, we generated a loxP-based transgenic mouse, which overexpresses androgen receptors (ARs) when activated by Cre. We used this transgene to overexpress AR globally in all tissues using a cytomegalovirus (CMV)-Cre driver (CMV-AR), and we used a Nestin-Cre driver to overexpress AR only in neural tissue (Nes-AR). We then examined whether neural or global AR overexpression can affect socio-sexual behaviors using a resident-intruder paradigm. We found that both neural and global AR overexpression resulted in decreased aggressive behaviors and increased thrusting during mounting of intruders, consistent with a neural site of action. Global, but not neural, AR overexpression in males led to an increase in same-sex anogenital investigation. Together, these results suggest novel roles for nonneural AR in sexual differentiation of mice, and indicate that excess AR can lead to a paradoxical reduction of male-typical behavior. PMID:26636184

  4. Expression of androgen receptor splice variants in clinical breast cancers

    PubMed Central

    Dvinge, Heidi; Tarulli, Gerard A.; Hanson, Adrienne R.; Ryan, Natalie K.; Pickering, Marie A.; Birrell, Stephen N.; Hu, Dong Gui; Mackenzie, Peter I.; Russell, Roslin; Caldas, Carlos; Raj, Ganesh V.; Dehm, Scott M.; Plymate, Stephen R.; Bradley, Robert K.; Tilley, Wayne D.; Selth, Luke A.

    2015-01-01

    The importance of androgen receptor (AR) signaling is increasingly being recognized in breast cancer, which has elicited clinical trials aimed at assessing the efficacy of androgen deprivation therapy (ADT) for metastatic disease. In prostate cancer, resistance to ADT is frequently associated with the emergence of androgen-independent splice variants of the AR (AR variants, AR-Vs) that lack the LBD and are constitutively active. Women with breast cancer may be prone to a similar phenomenon. Herein, we show that in addition to the prototypical transcript, the AR gene produces a diverse range of AR-V transcripts in primary breast tumors. The most frequently and highly expressed variant was AR-V7 (exons 1/2/3/CE3), which was detectable at the mRNA level in > 50% of all breast cancers and at the protein level in a subset of ERα-negative tumors. Functionally, AR-V7 is a constitutively active and ADT-resistant transcription factor that promotes growth and regulates a transcriptional program distinct from AR in ERα-negative breast cancer cells. Importantly, we provide ex vivo evidence that AR-V7 is upregulated by the AR antagonist enzalutamide in primary breast tumors. These findings have implications for treatment response in the ongoing clinical trials of ADT in breast cancer. PMID:26554309

  5. Expression of androgen receptor splice variants in clinical breast cancers.

    PubMed

    Hickey, Theresa E; Irvine, Connie M; Dvinge, Heidi; Tarulli, Gerard A; Hanson, Adrienne R; Ryan, Natalie K; Pickering, Marie A; Birrell, Stephen N; Hu, Dong Gui; Mackenzie, Peter I; Russell, Roslin; Caldas, Carlos; Raj, Ganesh V; Dehm, Scott M; Plymate, Stephen R; Bradley, Robert K; Tilley, Wayne D; Selth, Luke A

    2015-12-29

    The importance of androgen receptor (AR) signaling is increasingly being recognized in breast cancer, which has elicited clinical trials aimed at assessing the efficacy of androgen deprivation therapy (ADT) for metastatic disease. In prostate cancer, resistance to ADT is frequently associated with the emergence of androgen-independent splice variants of the AR (AR variants, AR-Vs) that lack the LBD and are constitutively active. Women with breast cancer may be prone to a similar phenomenon. Herein, we show that in addition to the prototypical transcript, the AR gene produces a diverse range of AR-V transcripts in primary breast tumors. The most frequently and highly expressed variant was AR-V7 (exons 1/2/3/CE3), which was detectable at the mRNA level in > 50% of all breast cancers and at the protein level in a subset of ERα-negative tumors. Functionally, AR-V7 is a constitutively active and ADT-resistant transcription factor that promotes growth and regulates a transcriptional program distinct from AR in ERα-negative breast cancer cells. Importantly, we provide ex vivo evidence that AR-V7 is upregulated by the AR antagonist enzalutamide in primary breast tumors. These findings have implications for treatment response in the ongoing clinical trials of ADT in breast cancer. PMID:26554309

  6. Minoxidil may suppress androgen receptor-related functions

    PubMed Central

    Hsu, Cheng-Lung; Liu, Jai-Shin; Lin, An-Chi; Yang, Chih-Hsun; Chung, Wen-Hung; Wu, Wen-Guey

    2014-01-01

    Although minoxidil has been used for more than two decades to treat androgenetic alopecia (AGA), an androgen-androgen receptor (AR) pathway-dominant disease, its precise mechanism of action remains elusive. We hypothesized that minoxidil may influence the AR or its downstream signaling. These tests revealed that minoxidil suppressed AR-related functions, decreasing AR transcriptional activity in reporter assays, reducing expression of AR targets at the protein level, and suppressing AR-positive LNCaP cell growth. Dissecting the underlying mechanisms, we found that minoxidil interfered with AR-peptide, AR-coregulator, and AR N/C-terminal interactions, as well as AR protein stability. Furthermore, a crystallographic analysis using the AR ligand-binding domain (LBD) revealed direct binding of minoxidil to the AR in a minoxidil-AR-LBD co-crystal model, and surface plasmon resonance assays demonstrated that minoxidil directly bound the AR with a Kd value of 2.6 μM. Minoxidil also suppressed AR-responsive reporter activity and decreased AR protein stability in human hair dermal papilla cells. The current findings provide evidence that minoxidil could be used to treat both cancer and age-related disease, and open a new avenue for applications of minoxidil in treating androgen-AR pathway-related diseases. PMID:24742982

  7. Minoxidil may suppress androgen receptor-related functions.

    PubMed

    Hsu, Cheng-Lung; Liu, Jai-Shin; Lin, An-Chi; Yang, Chih-Hsun; Chung, Wen-Hung; Wu, Wen-Guey

    2014-04-30

    Although minoxidil has been used for more than two decades to treat androgenetic alopecia (AGA), an androgen-androgen receptor (AR) pathway-dominant disease, its precise mechanism of action remains elusive. We hypothesized that minoxidil may influence the AR or its downstream signaling. These tests revealed that minoxidil suppressed AR-related functions, decreasing AR transcriptional activity in reporter assays, reducing expression of AR targets at the protein level, and suppressing AR-positive LNCaP cell growth. Dissecting the underlying mechanisms, we found that minoxidil interfered with AR-peptide, AR-coregulator, and AR N/C-terminal interactions, as well as AR protein stability. Furthermore, a crystallographic analysis using the AR ligand-binding domain (LBD) revealed direct binding of minoxidil to the AR in a minoxidil-AR-LBD co-crystal model, and surface plasmon resonance assays demonstrated that minoxidil directly bound the AR with a K(d) value of 2.6 µM. Minoxidil also suppressed AR-responsive reporter activity and decreased AR protein stability in human hair dermal papilla cells. The current findings provide evidence that minoxidil could be used to treat both cancer and age-related disease, and open a new avenue for applications of minoxidil in treating androgen-AR pathway-related diseases. PMID:24742982

  8. Androgens.

    PubMed

    Iyer, Rakesh; Handelsman, David J

    2016-01-01

    Androgen abuse is the most potent and prevalent form of sports doping detected. It originated from the early years of the Cold War as an epidemic confined to drug cheating within elite power sports. In the decades following the end of the Cold War, it has become disseminated into an endemic based within the illicit drug subcultures serving recreational abusers seeking cosmetic body sculpting effects. Within sports, both direct androgen abuse (administration of androgens), as well as indirect androgen abuse (administration of nonandrogenic drugs to increase endogenous testosterone), is mostly readily detectable with mass spectrometry-based anti-doping urine tests. The ongoing temptation of fame and fortune and the effectiveness of androgen abuse in power sports continue to entice cheating via renewed approaches aiming to exploit androgens. These require ongoing vigilance, inventiveness in anti-doping science, and targeting coaches as well as athletes in order to build resilience against doping and maintain fairness in elite sport. The challenge of androgen abuse in the community among recreational abusers has barely been recognized and effective approaches remain to be developed. PMID:27347677

  9. Protein kinase D1 (PKD1) influences androgen receptor (AR) function in prostate cancer cells

    SciTech Connect

    Mak, Paul; Jaggi, Meena; Chauhan, Subhash C.; Balaji, K.C.

    2008-09-05

    Protein kinase D1 (PKD1), founding member of PKD protein family, is down-regulated in advanced prostate cancer (PCa). We demonstrate that PKD1 and androgen receptor (AR) are present as a protein complex in PCa cells. PKD1 is associated with a transcriptional complex which contains AR and promoter sequence of the Prostate Specific Antigen (PSA) gene. Ectopic expression of wild type PKD1 and the kinase dead mutant PKD1 (K628W) attenuated the ligand-dependent transcriptional activation of AR in prostate cancer cells and yeast cells indicating that PKD1 can affect AR transcription activity, whereas knocking down PKD1 enhanced the ligand-dependent transcriptional activation of AR. Co-expression of kinase dead mutant with AR significantly inhibited androgen-mediated cell proliferation in both LNCaP and DU145 PC cells. Our data demonstrate for the first time that PKD1 can influence AR function in PCa cells.

  10. Molecular cloning and characterization of a nuclear androgen receptor activated by 11-ketotestosterone

    PubMed Central

    Olsson, Per-Erik; Berg, A Håkan; von Hofsten, Jonas; Grahn, Birgitta; Hellqvist, Anna; Larsson, Anders; Karlsson, Johnny; Modig, Carina; Borg, Bertil; Thomas, Peter

    2005-01-01

    Although 11-ketotestosterone is a potent androgen and induces male secondary sex characteristics in many teleosts, androgen receptors with high binding affinity for 11-ketotestosterone or preferential activation by 11-ketotestosterone have not been identified. So, the mechanism by which 11-ketotestosterone exhibits such high potency remains unclear. Recently we cloned the cDNA of an 11-ketotestosterone regulated protein, spiggin, from three-spined stickleback renal tissue. As spiggin is the only identified gene product regulated by 11-ketotestosterone, the stickleback kidney is ideal for determination of the mechanism of 11-ketotestosterone gene regulation. A single androgen receptor gene with two splicing variants, belonging to the androgen receptor-β subfamily was cloned from stickleback kidney. A high affinity, saturable, single class of androgen specific binding sites, with the characteristics of an androgen receptor, was identified in renal cytosolic and nuclear fractions. Measurement of ligand binding moieties in the cytosolic and nuclear fractions as well as to the recombinant receptor revealed lower affinity for 11-ketotestosterone than for dihydrotestosterone. Treatment with different androgens did not up-regulate androgen receptor mRNA level or increase receptor abundance, suggesting that auto-regulation is not involved in differential ligand activation. However, comparison of the trans-activation potential of the stickleback androgen receptor with the human androgen receptor, in both human HepG2 cells and zebrafish ZFL cells, revealed preferential activation by 11-ketotestosterone of the stickleback receptor, but not of the human receptor. These findings demonstrate the presence of a receptor preferentially activated by 11-ketotestosterone in the three-spined stickleback, so far the only one known in any animal. PMID:16107211

  11. Association of androgen receptor GGN repeat length polymorphism and male infertility in Khuzestan, Iran

    PubMed Central

    Moghadam, Mohamad; Khatami, Saied Reza; Galehdari, Hamid

    2015-01-01

    Background: Androgens play critical role in secondary sexual and male gonads differentiations such as spermatogenesis, via androgen receptor. The human androgen receptor (AR) encoding gene contains two regions with three nucleotide polymorphic repeats (CAG and GGN) in the first exon. Unlike the CAG repeats, the GGN has been less studied because of technical difficulties, so the functional role of these polymorphic repeats is still unclear. Objective: The goal of this study was to investigate any relationship between GGN repeat length in the first exon of AR gene and idiopathic male infertility in southwest of Iran. Materials and Methods: This is the first study on GGN repeat of AR gene in infertile male in Khuzestan, Iran. We used polymerase chain reaction (PCR) and polyacrylamide gel electrophoresis to categorize GGN repeat lengths in 72 infertile and 72 fertile men. Afterwards we sequenced the PCR products to determine the exact length of GGN repeat in each category. Our samples included 36 azoospermic and 36 oligozoospermic men as cases and 72 fertile men as control group. Results: We found that the numbers of repeats in the cases range from 18 to 25, while in the controls this range is from 20 to 28. The results showed a significant relation between the length of GGN repeat and fertility (p=0.015). The most frequent alleles were alleles with 24 and 25 repeats respectively in case and control groups. On the other hand no significant differences were found between Arab and non-Arab cases by considering GGN repeat lengths (p=0.234). Conclusion: Due to our results, there is a significant association between the presence of allele with 24 repeats and susceptibility to male infertility. Therefore this polymorphism should be considered in future studies to clarify etiology of disorders related to androgen receptor activity. PMID:26221130

  12. Molecular cloning, characterization, and expression profiles of androgen receptors in spotted scat (Scatophagus argus).

    PubMed

    Chen, H P; Deng, S P; Dai, M L; Zhu, C H; Li, G L

    2016-01-01

    Androgen plays critical roles in vertebrate reproductive systems via androgen receptors (ARs). In the present study, the full-length spotted scat (Scatophagus argus) androgen receptor (sAR) cDNA sequence was cloned from testis. The sAR cDNA measured 2448 bp in length with an open-reading frame of 2289 bp, encoding 763 amino acids. Amino acid alignment analyses showed that the sARs exhibited highly evolutionary conserved functional domains. Phylogenetically, the sARs clustered within the ARβ common vertebrate group. Real-time polymerase chain reaction (RT-PCR) revealed that sAR expression varied in level and distribution throughout the tissues of both females and males. sAR expression was detected during testicular development by quantitative RT-PCR. The results showed that the highest transcription of sARs was observed in the mid-testicular stage, and remained at a high expression level until the late-testicular stage. In addition, the effects of 17α-methyltestosterone (MT) and estrogen (E2) on the expression of sARs in ovaries were determined using quantitative RT-PCR. sAR expression increased at 12 and 24 h post-MT treatment and decreased with E2 treatment. The present study provides preliminary evidence indicating gonadal plasticity of spotted scat under exogenous steroidal hormone treatments. It also provides a theoretical basis for sex reversal and production of artificial pseudo-males for female monosex breeding. PMID:27173207

  13. Contributions of sex, testosterone, and androgen receptor CAG repeat number to virtual Morris water maze performance.

    PubMed

    Nowak, Nicole T; Diamond, Michael P; Land, Susan J; Moffat, Scott D

    2014-03-01

    The possibility that androgens contribute to the male advantage typically found on measures of spatial cognition has been investigated using a variety of approaches. To date, evidence to support the notion that androgens affect spatial cognition in healthy young adults is somewhat equivocal. The present study sought to clarify the association between testosterone (T) and spatial performance by extending measurements of androgenicity to include both measures of circulating T as well as an androgen receptor-specific genetic marker. The aims of this study were to assess the contributions of sex, T, and androgen receptor CAG repeat number (CAGr) on virtual Morris water task (vMWT) performance in a group of healthy young men and women. The hypothesis that men would outperform women on vMWT outcomes was supported. Results indicate that CAGr may interact with T to impact navigation performance and suggest that consideration of androgen receptor sensitivity is an important consideration in evaluating hormone-behavior relationships. PMID:24495604

  14. Androgen receptor targeted therapies in castration-resistant prostate cancer: Bench to clinic.

    PubMed

    Imamura, Yusuke; Sadar, Marianne D

    2016-08-01

    The androgen receptor is a transcription factor and validated therapeutic target for prostate cancer. Androgen deprivation therapy remains the gold standard treatment, but it is not curative, and eventually the disease will return as lethal castration-resistant prostate cancer. There have been improvements in the therapeutic landscape with new agents approved, such as abiraterone acetate, enzalutamide, sipuleucel-T, cabazitaxel and Ra-223, in the past 5 years. New insight into the mechanisms of resistance to treatments in advanced disease is being and has been elucidated. All current androgen receptor-targeting therapies inhibit the growth of prostate cancer by blocking the ligand-binding domain, where androgen binds to activate the receptor. Persuasive evidence supports the concept that constitutively active androgen receptor splice variants lacking the ligand-binding domain are one of the resistant mechanisms underlying advanced disease. Transcriptional activity of the androgen receptor requires a functional AF-1 region in its N-terminal domain. Preclinical evidence proved that this domain is a druggable target to forecast a potential paradigm shift in the management of advanced prostate cancer. This review presents an overview of androgen receptor-related mechanisms of resistance as well as novel therapeutic agents to overcome resistance that is linked to the expression of androgen receptor splice variants in castration-resistant prostate cancer. PMID:27302572

  15. Advantages and Limitations of Androgen Receptor-Based Methods for Detecting Anabolic Androgenic Steroid Abuse as Performance Enhancing Drugs.

    PubMed

    Bailey, Kathy; Yazdi, Tahmineh; Masharani, Umesh; Tyrrell, Blake; Butch, Anthony; Schaufele, Fred

    2016-01-01

    Testosterone (T) and related androgens are performance enhancing drugs (PEDs) abused by some athletes to gain competitive advantage. To monitor unauthorized androgen abuse, doping control programs use mass spectrometry (MS) to detect androgens, synthetic anabolic-androgenic steroids (AASs) and their metabolites in an athlete's urine. AASs of unknown composition will not be detected by these procedures. Since AASs achieve their anabolic effects by activating the Androgen Receptor (AR), cell-based bioassays that measure the effect of a urine sample on AR activity are under investigation as complementary, pan-androgen detection methods. We evaluated an AR BioAssay as a monitor for androgen activity in urine pre-treated with glucuronidase, which releases T from the inactive T-glucuronide that predominates in urine. AR BioAssay activity levels were expressed as 'T-equivalent' concentrations by comparison to a T dose response curve. The T-equivalent concentrations of androgens in the urine of hypogonadal participants supplemented with T (in whom all androgenic activity should arise from T) were quantitatively identical to the T measurements conducted by MS at the UCLA Olympic Analytical Laboratory (0.96 ± 0.22). All 17 AASs studied were active in the AR BioAssay; other steroids were inactive. 12 metabolites of 10 commonly abused AASs, which are used for MS monitoring of AAS doping because of their prolonged presence in urine, had reduced or no AR BioAssay activity. Thus, the AR BioAssay can accurately and inexpensively monitor T, but its ability to monitor urinary AASs will be limited to a period immediately following doping in which the active AASs remain intact. PMID:26998755

  16. Advantages and Limitations of Androgen Receptor-Based Methods for Detecting Anabolic Androgenic Steroid Abuse as Performance Enhancing Drugs

    PubMed Central

    Bailey, Kathy; Yazdi, Tahmineh; Masharani, Umesh; Tyrrell, Blake; Butch, Anthony; Schaufele, Fred

    2016-01-01

    Testosterone (T) and related androgens are performance enhancing drugs (PEDs) abused by some athletes to gain competitive advantage. To monitor unauthorized androgen abuse, doping control programs use mass spectrometry (MS) to detect androgens, synthetic anabolic-androgenic steroids (AASs) and their metabolites in an athlete’s urine. AASs of unknown composition will not be detected by these procedures. Since AASs achieve their anabolic effects by activating the Androgen Receptor (AR), cell-based bioassays that measure the effect of a urine sample on AR activity are under investigation as complementary, pan-androgen detection methods. We evaluated an AR BioAssay as a monitor for androgen activity in urine pre-treated with glucuronidase, which releases T from the inactive T-glucuronide that predominates in urine. AR BioAssay activity levels were expressed as ‘T-equivalent’ concentrations by comparison to a T dose response curve. The T-equivalent concentrations of androgens in the urine of hypogonadal participants supplemented with T (in whom all androgenic activity should arise from T) were quantitatively identical to the T measurements conducted by MS at the UCLA Olympic Analytical Laboratory (0.96 ± 0.22). All 17 AASs studied were active in the AR BioAssay; other steroids were inactive. 12 metabolites of 10 commonly abused AASs, which are used for MS monitoring of AAS doping because of their prolonged presence in urine, had reduced or no AR BioAssay activity. Thus, the AR BioAssay can accurately and inexpensively monitor T, but its ability to monitor urinary AASs will be limited to a period immediately following doping in which the active AASs remain intact. PMID:26998755

  17. Androgen receptor functions in castration-resistant prostate cancer and mechanisms of resistance to new agents targeting the androgen axis

    PubMed Central

    Yuan, X; Cai, C; Chen, S; Chen, S; Yu, Z; Balk, SP

    2016-01-01

    The metabolic functions of androgen receptor (AR) in normal prostate are circumvented in prostate cancer (PCa) to drive tumor growth, and the AR also can acquire new growth-promoting functions during PCa development and progression through genetic and epigenetic mechanisms. Androgen deprivation therapy (ADT, surgical or medical castration) is the standard treatment for metastatic PCa, but patients invariably relapse despite castrate androgen levels (castration-resistant PCa, CRPC). Early studies from many groups had shown that AR was highly expressed and transcriptionally active in CRPC, and indicated that steroids from the adrenal glands were contributing to this AR activity. More recent studies showed that CRPC cells had increased expression of enzymes mediating androgen synthesis from adrenal steroids, and could synthesize androgens de novo from cholesterol. Phase III clinical trials showing a survival advantage in CRPC for treatment with abiraterone (inhibitor of the enzyme CYP17A1 required for androgen synthesis that markedly reduces androgens and precursor steroids) and for enzalutamide (new AR antagonist) have now confirmed that AR activity driven by residual androgens makes a major contribution to CRPC, and led to the recent Food and Drug Administration approval of both agents. Unfortunately, patients treated with these agents for advanced CRPC generally relapse within a year and AR appears to be active in the relapsed tumors, but the molecular mechanisms mediating intrinsic or acquired resistance to these AR-targeted therapies remain to be defined. This review outlines AR functions that contribute to PCa development and progression, the roles of intratumoral androgen synthesis and AR structural alterations in driving AR activity in CRPC, mechanisms of action for abiraterone and enzalutamide, and possible mechanisms of resistance to these agents. PMID:23752196

  18. STANDARDIZATION AND VALIDATION OF PROPOSED PROTOCOLS FOR IN VITRO SCREENING ASSAYS AND QSAR FOR ESTROGEN RECEPTOR AND ANDROGEN RECEPTOR

    EPA Science Inventory

    Screening EDCs for androgenic and antiandrogenic activities was recommended by the EDSTAC Committee in it Final Report. This research will develop in vitro approaches to assess estrogen receptor binding, develop cell lines that stably express estrogen receptor for screening EDC...

  19. Modulation of the cytosolic androgen receptor in striated muscle by sex steroids

    NASA Technical Reports Server (NTRS)

    Rance, N. E.; Max, S. E.

    1982-01-01

    The influence of orchiectomy (GDX) and steroid administration on the level of the cytosolic androgen receptor in the rat levator ani muscle and in rat skeletal muscles (tibialis anterior and extensor digitorum longus) was studied. Androgen receptor binding to muscle cytosol was measured using H-3 methyltrienolone (R1881) as ligand, 100 fold molar excess unlabeled R1881 to assess nonspecific binding, and 500 fold molar excess of triamcinolone acetonide to prevent binding to glucocorticoid and progestin receptors. Results demonstrate that modification of the levels of sex steroids can alter the content of androgen receptors of rat striated muscle. Data suggest that: (1) cytosolic androgen receptor levels increase after orchiectomy in both levator ani muscle and skeletal muscle; (2) the acute increase in receptor levels is blocked by an inhibitor of protein synthesis; and (3) administration of estradiol-17 beta to castrated animals increases receptor binding in levator ani muscle but not in skeletal muscle.

  20. Androgen-androgen receptor system improves chronic inflammatory conditions by suppressing monocyte chemoattractant protein-1 gene expression in adipocytes via transcriptional regulation.

    PubMed

    Morooka, Nobukatsu; Ueguri, Kei; Yee, Karen Kar Lye; Yanase, Toshihiko; Sato, Takashi

    2016-09-01

    Age-related decreases in sex hormones are closely related to chronic inflammation in obesity and metabolic diseases. Particularly, the molecular basis of androgen activity in regulating inflammation and controlling metabolism remains largely unknown. Obese adipocytes secrete monocyte chemoattractant protein-1 (MCP-1), a key chemokine that promotes the infiltration of monocytes/macrophages into adipose tissue, thereby leading to metabolic disorders. Here, we studied the role of androgen-androgen receptor (AR) action in regulating MCP-1 expression in adipose tissue. We observed the induction of Mcp-1 expression in 3T3-L1 adipocytes co-cultured with RAW264.7 macrophages. Additionally, Mcp-1 expression was upregulated by culturing in conditioned medium derived from inflammatory macrophages (M1-Mφ) containing tumor necrosis factor-alpha (TNF-α). We found that sex hormones downregulated TNF-α-induced Mcp-1 and interleukin (Il)-6 expression in 3T3-L1 adipocytes. Furthermore, luciferase-reporter analysis indicated that MCP-1 promoter activity was predominantly suppressed by dihydrotestosterone (DHT)-AR interactions through functional canonical nuclear factor-kappa B (NF-κB) sites, whereas non-canonical NF-κB site containing important flanking sequences exhibited minor contributions to DHT-AR transcriptional repression. These findings suggested that androgen-AR suppressed obesity-induced chronic inflammation in adipose tissue. PMID:27392713

  1. Selective androgen receptor modulator activity of a steroidal antiandrogen TSAA-291 and its cofactor recruitment profile.

    PubMed

    Hikichi, Yukiko; Yamaoka, Masuo; Kusaka, Masami; Hara, Takahito

    2015-10-15

    Selective androgen receptor modulators (SARMs) specifically bind to the androgen receptor and exert agonistic or antagonistic effects on target organs. In this study, we investigated the SARM activity of TSAA-291, previously known as a steroidal antiandrogen, in mice because TSAA-291 was found to possess partial androgen receptor agonist activity in reporter assays. In addition, to clarify the mechanism underlying its tissue selectivity, we performed comprehensive cofactor recruitment analysis of androgen receptor using TSAA-291 and dihydrotestosterone (DHT), an endogenous androgen. The androgen receptor agonistic activity of TSAA-291 was more obvious in reporter assays using skeletal muscle cells than in those using prostate cells. In castrated mice, TSAA-291 increased the weight of the levator ani muscle without increasing the weight of the prostate and seminal vesicle. Comprehensive cofactor recruitment analysis via mammalian two-hybrid methods revealed that among a total of 112 cofactors, 12 cofactors including the protein inhibitor of activated STAT 1 (PIAS1) were differently recruited to androgen receptor in the presence of TSAA-291 and DHT. Prostate displayed higher PIAS1 expression than skeletal muscle. Forced expression of the PIAS1 augmented the transcriptional activity of the androgen receptor, and silencing of PIAS1 by siRNAs suppressed the secretion of prostate-specific antigen, an androgen responsive marker. Our results demonstrate that TSAA-291 has SARM activity and suggest that TSAA-291 may induce different conformational changes of the androgen receptor and recruitment profiles of cofactors such as PIAS1, compared with DHT, to exert tissue-specific activity. PMID:26335395

  2. Bisphenol A affects androgen receptor function via multiple mechanisms.

    PubMed

    Teng, Christina; Goodwin, Bonnie; Shockley, Keith; Xia, Menghang; Huang, Ruili; Norris, John; Merrick, B Alex; Jetten, Anton M; Austin, Christopher P; Tice, Raymond R

    2013-05-25

    Bisphenol A (BPA), is a well-known endocrine disruptor compound (EDC) that affects the normal development and function of the female and male reproductive system, however the mechanisms of action remain unclear. To investigate the molecular mechanisms of how BPA may affect ten different nuclear receptors, stable cell lines containing individual nuclear receptor ligand binding domain (LBD)-linked to the β-Gal reporter were examined by a quantitative high throughput screening (qHTS) format in the Tox21 Screening Program of the NIH. The results showed that two receptors, estrogen receptor alpha (ERα) and androgen receptor (AR), are affected by BPA in opposite direction. To confirm the observed effects of BPA on ERα and AR, we performed transient transfection experiments with full-length receptors and their corresponding response elements linked to luciferase reporters. We also included in this study two BPA analogs, bisphenol AF (BPAF) and bisphenol S (BPS). As seen in African green monkey kidney CV1 cells, the present study confirmed that BPA and BPAF act as ERα agonists (half maximal effective concentration EC50 of 10-100 nM) and as AR antagonists (half maximal inhibitory concentration IC50 of 1-2 μM). Both BPA and BPAF antagonized AR function via competitive inhibition of the action of synthetic androgen R1881. BPS with lower estrogenic activity (EC50 of 2.2 μM), did not compete with R1881 for AR binding, when tested at 30 μM. Finally, the effects of BPA were also evaluated in a nuclear translocation assays using EGPF-tagged receptors. Similar to 17β-estradiol (E2) which was used as control, BPA was able to enhance ERα nuclear foci formation but at a 100-fold higher concentration. Although BPA was able to bind AR, the nuclear translocation was reduced. Furthermore, BPA was unable to induce functional foci in the nuclei and is consistent with the transient transfection study that BPA is unable to activate AR. PMID:23562765

  3. Bisphenol A affects androgen receptor function via multiple mechanisms

    PubMed Central

    Teng, Christina; Goodwin, Bonnie; Shockley, Keith; Xia, Menghang; Huang, Ruili; Norris, John; Merrick, B. Alex; Jetten, Anton M.; Austin, Christopher, P.; Tice, Raymond R.

    2013-01-01

    Bisphenol A (BPA), is a well-known endocrine disruptor compound (EDC) that affects the normal development and function of the female and male reproductive system, however the mechanisms of action remain unclear. To investigate the molecular mechanisms of how BPA may affect ten different nuclear receptors, stable cell lines containing individual nuclear receptor ligand binding domain (LBD)-linked to the β-Gal reporter were examined by a quantitative high throughput screening (qHTS) format in the Tox21 Screening Program of the NIH. The results showed that two receptors, estrogen receptor alpha (ERα) and androgen receptor (AR), are affected by BPA in opposite direction. To confirm the observed effects of BPA on ERα and AR, we performed transient transfection experiments with full-length receptors and their corresponding response elements linked to luciferase reporters. We also included in this study two BPA analogs, bisphenol AF (BPAF) and bisphenol S (BPS). As seen in African green monkey kidney CV1 cells, the present study confirmed that BPA and BPAF act as ERα agonists (half maximal effective concentration EC50 of 10-100 nM) and as AR antagonists (half maximal inhibitory concentration IC50 of 1-2 μM). Both BPA and BPAF antagonized AR function via competitive inhibition of the action of synthetic androgen R1881. BPS with lower estrogenic activity (EC50 of 2.2 μM), did not compete with R1881 for AR binding, when tested at 30 μM. Finally, the effects of BPA were also evaluated in a nuclear translocation assays using EGPF-tagged receptors. Similar to 17β-estradiol (E2) which was used as control, BPA was able to enhance ERα nuclear foci formation but at a 100-fold higher concentration. Although BPA was able to bind AR, the nuclear translocation was reduced. Furthermore, BPA was unable to induce functional foci in the nuclei and is consistent with the transient transfection study that BPA is unable to activate AR. PMID:23562765

  4. The PPAR{gamma} ligand ciglitazone regulates androgen receptor activation differently in androgen-dependent versus androgen-independent human prostate cancer cells

    SciTech Connect

    Moss, Patrice E.; Lyles, Besstina E.; Stewart, LaMonica V.

    2010-12-10

    The androgen receptor (AR) regulates growth and progression of androgen-dependent as well as androgen-independent prostate cancer cells. Peroxisome proliferator-activated receptor gamma (PPAR{gamma}) agonists have been reported to reduce AR activation in androgen-dependent LNCaP prostate cancer cells. To determine whether PPAR{gamma} ligands are equally effective at inhibiting AR activity in androgen-independent prostate cancer, we examined the effect of the PPAR{gamma} ligands ciglitazone and rosiglitazone on C4-2 cells, an androgen- independent derivative of the LNCaP cell line. Luciferase-based reporter assays and Western blot analysis demonstrated that PPAR{gamma} ligand reduced dihydrotestosterone (DHT)-induced increases in AR activity in LNCaP cells. However, in C4-2 cells, these compounds increased DHT-induced AR driven luciferase activity. In addition, ciglitazone did not significantly alter DHT-mediated increases in prostate specific antigen (PSA) protein or mRNA levels within C4-2 cells. siRNA-based experiments demonstrated that the ciglitazone-induced regulation of AR activity observed in C4-2 cells was dependent on the presence of PPAR{gamma}. Furthermore, overexpression of the AR corepressor cyclin D1 inhibited the ability of ciglitazone to induce AR luciferase activity in C4-2 cells. Thus, our data suggest that both PPAR{gamma} and cyclin D1 levels influence the ability of ciglitazone to differentially regulate AR signaling in androgen-independent C4-2 prostate cancer cells.

  5. Steroid-induced androgen receptor-oestradiol receptor beta-Src complex triggers prostate cancer cell proliferation.

    PubMed

    Migliaccio, A; Castoria, G; Di Domenico, M; de Falco, A; Bilancio, A; Lombardi, M; Barone, M V; Ametrano, D; Zannini, M S; Abbondanza, C; Auricchio, F

    2000-10-16

    Treatment of human prostate carcinoma-derived LNCaP cells with androgen or oestradiol triggers simultaneous association of androgen receptor and oestradiol receptor beta with Src, activates the Src/Raf-1/Erk-2 pathway and stimulates cell proliferation. Surprisingly, either androgen or oestradiol action on each of these steps is inhibited by both anti-androgens and anti-oestrogens. Similar findings for oestradiol receptor alpha were observed in MCF-7 or T47D cells stimulated by either oestradiol or androgens. Microinjection of LNCaP, MCF-7 and T47D cells with SrcK(-) abolishes steroid-stimulated S-phase entry. Data from transfected Cos cells confirm and extend the findings from these cells. Hormone-stimulated Src interaction with the androgen receptor and oestradiol receptor alpha or beta is detected using glutathione S:-transferase fusion constructs. Src SH2 interacts with phosphotyrosine 537 of oestradiol receptor alpha and the Src SH3 domain with a proline-rich stretch of the androgen receptor. The role of this phosphotyrosine is stressed by its requirement for association of oestradiol receptor alpha with Src and consequent activation of Src in intact Cos cells. PMID:11032808

  6. Promoter-dependent activity on androgen receptor N-terminal domain mutations in androgen insensitivity syndrome.

    PubMed

    Tadokoro-Cuccaro, Rieko; Davies, John; Mongan, Nigel P; Bunch, Trevor; Brown, Rosalind S; Audi, Laura; Watt, Kate; McEwan, Iain J; Hughes, Ieuan A

    2014-01-01

    Androgen receptor (AR) mutations are associated with androgen insensitivity syndrome (AIS). Missense mutations identified in the AR-N-terminal domain (AR-NTD) are rare, and clinical phenotypes are typically mild. We investigated 7 missense mutations and 2 insertion/deletions located in the AR-NTD. This study aimed to elucidate the pathogenic role of AR-NTD mutants in AIS and to use this knowledge to further define AR-NTD function. AR-NTD mutations (Q120E, A159T, G216R, N235K, G248V, L272F, and P380R) were introduced into AR-expression plasmids. Stably expressing cell lines were established for del57L and ins58L. Transactivation was measured using luciferase reporter constructs under the control of GRE and Pem promoters. Intrinsic fluorescence spectroscopy and partial proteolysis studies were performed for mutations which showed reduced activities by using a purified AR-AF1 protein. Pem-luciferase reporter activation was reduced for A159T, N235K, and G248V but not the GRE-luciferase reporter. Protein structure analysis detected no significant change in the AR-AF1 region for these mutations. Reduced cellular expression and transactivation activity were observed for ins58L. The mutations Q120E, G216R, L272F, P380R, and del57L showed small or no detectable changes in function. Thus, clinical and experimental analyses have identified novel AR-signalling defects associated with mutations in the structurally disordered AR-NTD domain in patients with AIS. PMID:25500996

  7. Androgen receptor repression of gonadotropin-releasing hormone gene transcription via enhancer 1.

    PubMed

    Brayman, Melissa J; Pepa, Patricia A; Mellon, Pamela L

    2012-11-01

    Gonadotropin-releasing hormone (GnRH) plays a major role in the hypothalamic-pituitary-gonadal (HPG) axis, and synthesis and secretion of GnRH are regulated by gonadal steroid hormones. Disruptions in androgen levels are involved in a number of reproductive defects, including hypogonadotropic hypogonadism and polycystic ovarian syndrome. Androgens down-regulate GnRH mRNA synthesis in vivo and in vitro via an androgen receptor (AR)-dependent mechanism. Methyltrienolone (R1881), a synthetic AR agonist, represses GnRH expression through multiple sites in the proximal promoter. In this study, we show AR also represses GnRH transcription via the major enhancer (GnRH-E1). A multimer of the -1800/-1766 region was repressed by R1881 treatment. Mutation of two bases, -1792 and -1791, resulted in decreased basal activity and a loss of AR-mediated repression. AR bound to the -1796/-1791 sequence in electrophoretic mobility shift assays, indicating a direct interaction with DNA or other transcription factors in this region. We conclude that AR repression of GnRH-E1 acts via multiple AR-responsive regions, including the site at -1792/-1791. PMID:22877652

  8. Identification of the functional domains of ANT-1, a novel coactivator of the androgen receptor

    SciTech Connect

    Fan Shuli; Goto, Kiminobu; Chen Guangchun; Morinaga, Hidetaka; Nomura, Masatoshi; Okabe, Taijiro; Nawata, Hajime; Yanase, Toshihiko . E-mail: yanase@intmed3.med.kyushu-u.ac.jp

    2006-03-03

    Previously, we identified a transcriptional coactivator for the activation function-1 (AF-1) domain of the human androgen receptor (AR) and designated it androgen receptor N-terminal domain transactivating protein-1 (ANT-1). This coactivator, which contains multiple tetratricopeptide repeat (TPR) motifs from amino acid (aa) 294, is identical to a component of U5 small nuclear ribonucleoprotein particles and binds specifically to the AR or glucocorticoid receptor. Here, we identified four distinct functional domains. The AR-AF-1-binding domain, which bound to either aa 180-360 or 360-532 in AR-AF-1, clearly overlapped with TAU-1 and TAU-5. This domain and the subnuclear speckle formation domain in ANT-1 were assigned within the TPR motifs, while the transactivating and nuclear localization signal domains resided within the N-terminal sequence. The existence of these functional domains may further support the idea that ANT-1 can function as an AR-AF-1-specific coactivator while mediating a transcription-splicing coupling.

  9. Quantitative Proteomic Profiles of Androgen Receptor Signaling in the Liver of Fathead Minnows Pimephalus promelas

    EPA Science Inventory

    Androgenic chemicals are present in the environment at concentrations that impair reproductive processes in fish. The objective of this experiment was to identify proteins altered by an androgen receptor agonist (17â-trenbolone) and antagonist (flutamide) in the liver. Female fa...

  10. Targeting of androgen receptor in bone reveals a lack of androgen anabolic action and inhibition of osteogenesis A model for compartment-specific androgen action in the skeleton

    PubMed Central

    Wiren, Kristine M.; Semirale, Anthony A.; Zhang, Xiao-Wei; Woo, Adrian; Tommasini, Steven M.; Price, Christopher; Schaffler, Mitchell B.; Jepsen, Karl J.

    2008-01-01

    Androgens are anabolic hormones that affect many tissues, including bone. However, an anabolic effect of androgen treatment on bone in eugonadal subjects has not been observed and clinical trials have been disappointing. The androgen receptor (AR) mediates biological responses to androgens. In bone tissue, both AR and the estrogen receptor (ER) are expressed. Since androgens can be converted into estrogen, the specific role of the AR in maintenance of skeletal homoeostasis remains controversial. The goal of this study was to use skeletally targeted overexpression of AR in differentiated osteoblasts as a means of elucidating the specific role(s) for AR transactivation in the mature bone compartment. Transgenic mice overexpressing AR under the control of the 2.3-kb α1(I)-collagen promoter fragment showed no difference in body composition, testosterone, or 17β-estradiol levels. However, transgenic males have reduced serum osteocalcin, CTx and TRAPC5b levels, and a bone phenotype was observed. In cortical bone, high-resolution micro-computed tomography revealed no difference in periosteal perimeter but a significant reduction in cortical bone area due to an enlarged marrow cavity. Endocortical bone formation rate was also significantly inhibited. Biomechanical analyses showed decreased whole bone strength and quality, with significant reductions in all parameters tested. Trabecular morphology was altered, with increased bone volume comprised of more trabeculae that were closer together but not thicker. Expression of genes involved in bone formation and bone resorption was significantly reduced. The consequences of androgen action are compartment-specific; anabolic effects are exhibited exclusively at periosteal surfaces, but in mature osteoblasts androgens inhibited osteogenesis with detrimental effects on matrix quality, bone fragility and whole bone strength. Thus, the present data demonstrate that enhanced androgen signaling targeted to bone results in low bone

  11. Recognition and Accommodation at the Androgen Receptor Coactivator Binding Interface

    PubMed Central

    Hur, Eugene; Pfaff, Samuel J; Payne, E. Sturgis; Grøn, Hanne; Buehrer, Benjamin M

    2004-01-01

    Prostate cancer is a leading killer of men in the industrialized world. Underlying this disease is the aberrant action of the androgen receptor (AR). AR is distinguished from other nuclear receptors in that after hormone binding, it preferentially responds to a specialized set of coactivators bearing aromatic-rich motifs, while responding poorly to coactivators bearing the leucine-rich “NR box” motifs favored by other nuclear receptors. Under normal conditions, interactions with these AR-specific coactivators through aromatic-rich motifs underlie targeted gene transcription. However, during prostate cancer, abnormal association with such coactivators, as well as with coactivators containing canonical leucine-rich motifs, promotes disease progression. To understand the paradox of this unusual selectivity, we have derived a complete set of peptide motifs that interact with AR using phage display. Binding affinities were measured for a selected set of these peptides and their interactions with AR determined by X-ray crystallography. Structures of AR in complex with FxxLF, LxxLL, FxxLW, WxxLF, WxxVW, FxxFF, and FxxYF motifs reveal a changing surface of the AR coactivator binding interface that permits accommodation of both AR-specific aromatic-rich motifs and canonical leucine-rich motifs. Induced fit provides perfect mating of the motifs representing the known family of AR coactivators and suggests a framework for the design of AR coactivator antagonists. PMID:15328534

  12. Choline Kinase Alpha as an Androgen Receptor Chaperone and Prostate Cancer Therapeutic Target

    PubMed Central

    Asim, Mohammad; Massie, Charles E.; Orafidiya, Folake; Pértega-Gomes, Nelma; Warren, Anne Y.; Esmaeili, Mohsen; Selth, Luke A.; Zecchini, Heather I.; Luko, Katarina; Qureshi, Arham; Baridi, Ajoeb; Menon, Suraj; Madhu, Basetti; Escriu, Carlos; Lyons, Scott; Vowler, Sarah L.; Zecchini, Vincent R.; Shaw, Greg; Hessenkemper, Wiebke; Russell, Roslin; Mohammed, Hisham; Stefanos, Niki; Lynch, Andy G.; Grigorenko, Elena; D’Santos, Clive; Taylor, Chris; Lamb, Alastair; Sriranjan, Rouchelle; Yang, Jiali; Stark, Rory; Dehm, Scott M.; Rennie, Paul S.; Carroll, Jason S.; Griffiths, John R.; Tavaré, Simon; Mills, Ian G.; McEwan, Iain J.; Baniahmad, Aria; Tilley, Wayne D.; Neal, David E.

    2016-01-01

    Background: The androgen receptor (AR) is a major drug target in prostate cancer (PCa). We profiled the AR-regulated kinome to identify clinically relevant and druggable effectors of AR signaling. Methods: Using genome-wide approaches, we interrogated all AR regulated kinases. Among these, choline kinase alpha (CHKA) expression was evaluated in benign (n = 195), prostatic intraepithelial neoplasia (PIN) (n = 153) and prostate cancer (PCa) lesions (n = 359). We interrogated how CHKA regulates AR signaling using biochemical assays and investigated androgen regulation of CHKA expression in men with PCa, both untreated (n = 20) and treated with an androgen biosynthesis inhibitor degarelix (n = 27). We studied the effect of CHKA inhibition on the PCa transcriptome using RNA sequencing and tested the effect of CHKA inhibition on cell growth, clonogenic survival and invasion. Tumor xenografts (n = 6 per group) were generated in mice using genetically engineered prostate cancer cells with inducible CHKA knockdown. Data were analyzed with χ2 tests, Cox regression analysis, and Kaplan-Meier methods. All statistical tests were two-sided. Results: CHKA expression was shown to be androgen regulated in cell lines, xenografts, and human tissue (log fold change from 6.75 to 6.59, P = .002) and was positively associated with tumor stage. CHKA binds directly to the ligand-binding domain (LBD) of AR, enhancing its stability. As such, CHKA is the first kinase identified as an AR chaperone. Inhibition of CHKA repressed the AR transcriptional program including pathways enriched for regulation of protein folding, decreased AR protein levels, and inhibited the growth of PCa cell lines, human PCa explants, and tumor xenografts. Conclusions: CHKA can act as an AR chaperone, providing, to our knowledge, the first evidence for kinases as molecular chaperones, making CHKA both a marker of tumor progression and a potential therapeutic target for PCa. PMID:26657335

  13. Localization of androgen receptors and estrogen receptors in the same cells of the songbird brain

    SciTech Connect

    Gahr, M. )

    1990-12-01

    Estrogens and androgens each have unique effects but act together for the neural differentiation and control of sexual behaviors in male vertebrates, such as the canary. The neuronal basis for these synergistic effects is elusive because the spatial relation between estrogen target cells and androgen target cells is unknown. This study localized estrogen receptor (ER)-containing cells by using immunocytochemistry and androgen receptor (AR)-containing cells by using autoradiography in the same sections of the male canary brain. Three cell types, those containing only ER, those containing only AR, and those containing both ER and AR, were found in tissue-specific frequencies. The midbrain nucleus intercollicularis exhibited the highest number of cells expressing both ER and AR, whereas ER and AR are expressed only in disjunctive cell populations in the forebrain nucleus hyperstriatalis ventrale, pars caudale. Synergistic effects of androgens and estrogens for the neural behavorial control could result from cells containing both ER and AR (intracellular) and from neural circuits containing ER and AR in different cells (intercellular).

  14. Regulators of Androgen Action Resource: a one-stop shop for the comprehensive study of androgen receptor action.

    PubMed

    DePriest, Adam D; Fiandalo, Michael V; Schlanger, Simon; Heemers, Frederike; Mohler, James L; Liu, Song; Heemers, Hannelore V

    2016-01-01

    Androgen receptor (AR) is a ligand-activated transcription factor that is the main target for treatment of non-organ-confined prostate cancer (CaP). Failure of life-prolonging AR-targeting androgen deprivation therapy is due to flexibility in steroidogenic pathways that control intracrine androgen levels and variability in the AR transcriptional output. Androgen biosynthesis enzymes, androgen transporters and AR-associated coregulators are attractive novel CaP treatment targets. These proteins, however, are characterized by multiple transcript variants and isoforms, are subject to genomic alterations, and are differentially expressed among CaPs. Determining their therapeutic potential requires evaluation of extensive, diverse datasets that are dispersed over multiple databases, websites and literature reports. Mining and integrating these datasets are cumbersome, time-consuming tasks and provide only snapshots of relevant information. To overcome this impediment to effective, efficient study of AR and potential drug targets, we developed the Regulators of Androgen Action Resource (RAAR), a non-redundant, curated and user-friendly searchable web interface. RAAR centralizes information on gene function, clinical relevance, and resources for 55 genes that encode proteins involved in biosynthesis, metabolism and transport of androgens and for 274 AR-associated coregulator genes. Data in RAAR are organized in two levels: (i) Information pertaining to production of androgens is contained in a 'pre-receptor level' database, and coregulator gene information is provided in a 'post-receptor level' database, and (ii) an 'other resources' database contains links to additional databases that are complementary to and useful to pursue further the information provided in RAAR. For each of its 329 entries, RAAR provides access to more than 20 well-curated publicly available databases, and thus, access to thousands of data points. Hyperlinks provide direct access to gene

  15. Regulators of Androgen Action Resource: a one-stop shop for the comprehensive study of androgen receptor action

    PubMed Central

    Fiandalo, Michael V.; Schlanger, Simon; Heemers, Frederike; Mohler, James L.; Liu, Song; Heemers, Hannelore V.

    2016-01-01

    Androgen receptor (AR) is a ligand-activated transcription factor that is the main target for treatment of non-organ-confined prostate cancer (CaP). Failure of life-prolonging AR-targeting androgen deprivation therapy is due to flexibility in steroidogenic pathways that control intracrine androgen levels and variability in the AR transcriptional output. Androgen biosynthesis enzymes, androgen transporters and AR-associated coregulators are attractive novel CaP treatment targets. These proteins, however, are characterized by multiple transcript variants and isoforms, are subject to genomic alterations, and are differentially expressed among CaPs. Determining their therapeutic potential requires evaluation of extensive, diverse datasets that are dispersed over multiple databases, websites and literature reports. Mining and integrating these datasets are cumbersome, time-consuming tasks and provide only snapshots of relevant information. To overcome this impediment to effective, efficient study of AR and potential drug targets, we developed the Regulators of Androgen Action Resource (RAAR), a non-redundant, curated and user-friendly searchable web interface. RAAR centralizes information on gene function, clinical relevance, and resources for 55 genes that encode proteins involved in biosynthesis, metabolism and transport of androgens and for 274 AR-associated coregulator genes. Data in RAAR are organized in two levels: (i) Information pertaining to production of androgens is contained in a ‘pre-receptor level’ database, and coregulator gene information is provided in a ‘post-receptor level’ database, and (ii) an ‘other resources’ database contains links to additional databases that are complementary to and useful to pursue further the information provided in RAAR. For each of its 329 entries, RAAR provides access to more than 20 well-curated publicly available databases, and thus, access to thousands of data points. Hyperlinks provide direct access to

  16. Antiandrogens Act as Selective Androgen Receptor Modulators at the Proteome Level in Prostate Cancer Cells*

    PubMed Central

    Brooke, Greg N.; Gamble, Simon C.; Hough, Michael A.; Begum, Shajna; Dart, D. Alwyn; Odontiadis, Michael; Powell, Sue M.; Fioretti, Flavia M.; Bryan, Rosie A.; Waxman, Jonathan; Wait, Robin; Bevan, Charlotte L.

    2015-01-01

    Current therapies for prostate cancer include antiandrogens, inhibitory ligands of the androgen receptor, which repress androgen-stimulated growth. These include the selective androgen receptor modulators cyproterone acetate and hydroxyflutamide and the complete antagonist bicalutamide. Their activity is partly dictated by the presence of androgen receptor mutations, which are commonly detected in patients who relapse while receiving antiandrogens, i.e. in castrate-resistant prostate cancer. To characterize the early proteomic response to these antiandrogens we used the LNCaP prostate cancer cell line, which harbors the androgen receptor mutation most commonly detected in castrate-resistant tumors (T877A), analyzing alterations in the proteome, and comparing these to the effect of these therapeutics upon androgen receptor activity and cell proliferation. The majority are regulated post-transcriptionally, possibly via nongenomic androgen receptor signaling. Differences detected between the exposure groups demonstrate subtle changes in the biological response to each specific ligand, suggesting a spectrum of agonistic and antagonistic effects dependent on the ligand used. Analysis of the crystal structures of the AR in the presence of cyproterone acetate, hydroxyflutamide, and DHT identified important differences in the orientation of key residues located in the AF-2 and BF-3 protein interaction surfaces. This further implies that although there is commonality in the growth responses between androgens and those antiandrogens that stimulate growth in the presence of a mutation, there may also be influential differences in the growth pathways stimulated by the different ligands. This therefore has implications for prostate cancer treatment because tumors may respond differently dependent upon which mutation is present and which ligand is activating growth, also for the design of selective androgen receptor modulators, which aim to elicit differential proteomic

  17. Prostate cancer stem cells: the role of androgen and estrogen receptors.

    PubMed

    Di Zazzo, Erika; Galasso, Giovanni; Giovannelli, Pia; Di Donato, Marzia; Di Santi, Annalisa; Cernera, Gustavo; Rossi, Valentina; Abbondanza, Ciro; Moncharmont, Bruno; Sinisi, Antonio Agostino; Castoria, Gabriella; Migliaccio, Antimo

    2016-01-01

    Prostate cancer is one of the most commonly diagnosed cancers in men, and androgen deprivation therapy still represents the primary treatment for prostate cancer patients. This approach, however, frequently fails and patients develop castration-resistant prostate cancer, which is almost untreatable.Cancer cells are characterized by a hierarchical organization, and stem/progenitor cells are endowed with tumor-initiating activity. Accumulating evidence indicates that prostate cancer stem cells lack the androgen receptor and are, indeed, resistant to androgen deprivation therapy. In contrast, these cells express classical (α and/or β) and novel (GPR30) estrogen receptors, which may represent new putative targets in prostate cancer treatment.In the present review, we discuss the still-debated mechanisms, both genomic and non-genomic, by which androgen and estradiol receptors (classical and novel) mediate the hormonal control of prostate cell stemness, transformation, and the continued growth of prostate cancer. Recent preclinical and clinical findings obtained using new androgen receptor antagonists, anti-estrogens, or compounds such as enhancers of androgen receptor degradation and peptides inhibiting non-genomic androgen functions are also presented. These new drugs will likely lead to significant advances in prostate cancer therapy. PMID:26506594

  18. Prostate cancer stem cells: the role of androgen and estrogen receptors

    PubMed Central

    Di Zazzo, Erika; Galasso, Giovanni; Giovannelli, Pia; Di Donato, Marzia; Di Santi, Annalisa; Cernera, Gustavo; Rossi, Valentina; Abbondanza, Ciro; Moncharmont, Bruno; Sinisi, Antonio Agostino; Castoria, Gabriella; Migliaccio, Antimo

    2016-01-01

    Prostate cancer is one of the most commonly diagnosed cancers in men, and androgen deprivation therapy still represents the primary treatment for prostate cancer patients. This approach, however, frequently fails and patients develop castration-resistant prostate cancer, which is almost untreatable. Cancer cells are characterized by a hierarchical organization, and stem/progenitor cells are endowed with tumor-initiating activity. Accumulating evidence indicates that prostate cancer stem cells lack the androgen receptor and are, indeed, resistant to androgen deprivation therapy. In contrast, these cells express classical (α and/or β) and novel (GPR30) estrogen receptors, which may represent new putative targets in prostate cancer treatment. In the present review, we discuss the still-debated mechanisms, both genomic and non-genomic, by which androgen and estradiol receptors (classical and novel) mediate the hormonal control of prostate cell stemness, transformation, and the continued growth of prostate cancer. Recent preclinical and clinical findings obtained using new androgen receptor antagonists, anti-estrogens, or compounds such as enhancers of androgen receptor degradation and peptides inhibiting non-genomic androgen functions are also presented. These new drugs will likely lead to significant advances in prostate cancer therapy. PMID:26506594

  19. Common molecular weight of the androgen receptor monomer in different target tissues

    SciTech Connect

    Johnson, M.P.; Young, C.Y.F.; Rowley, D.R.; Tindall, D.J.

    1987-06-02

    Previously reported molecular weights for the monomeric steroid binding subunit of the androgen receptor protein have ranged from 25,000 to 167,000. The molecular weight appeared to vary among different species and target organs, as well as between different investigators. This study has examined androgen receptors from a diverse group of organs and species to determine whether these tissues share a common monomeric form. Gel filtration revealed peaks of specific (/sup 3/H)dihydrotestosterone binding activity corresponding to Stokes radii of 54, 33, and 20 A in cytosols from several tissues. Phosphocellulose chromatography diminished the appearance of the smaller androgen receptor forms and facilitated the appearance of the larger 54-A form. Mixing experiments suggested that phosphocellulose was stabilizing the 54-A form by binding putative proteases which cleave this larger form. Methods were developed to generate homogeneous preparations of a given androgen receptor size for comparative study. Sucrose density gradient analysis showed sedimentation coefficients of 4.5-5.0, 3.5-4.0, and 2.5-3.0 S, respectively. The corresponding calculated molecular weights were 109,000-121,000, 52,000-59,000, and 22,000-27,000. Scatchard analysis of each of these androgen receptor forms demonstrated very similar affinity for (/sup 3/H)dihydrotestosterone. Extensively purified preparations of androgen receptor from R3327 tumor contained varying amounts of the three receptor forms even though molybdate and phosphocellulose were used to stabilize the androgen receptor protein during purification. It is concluded that androgen receptors from a variety of tissues share a common monomeric subunit and that stabilization is necessary during analytical and purification procedures to prevent cleavage of the monomer by endogenous proteases.

  20. Identification and Characterization of the Androgen Receptor From the American Alligator, Alligator mississippiensis.

    PubMed

    Miyagawa, Shinichi; Yatsu, Ryohei; Kohno, Satomi; Doheny, Brenna M; Ogino, Yukiko; Ishibashi, Hiroshi; Katsu, Yoshinao; Ohta, Yasuhiko; Guillette, Louis J; Iguchi, Taisen

    2015-08-01

    Androgens are essential for the development, reproduction, and health throughout the life span of vertebrates, particularly during the initiation and maintenance of male sexual characteristics. Androgen signaling is mediated by the androgen receptor (AR), a member of the steroid nuclear receptor superfamily. Mounting evidence suggests that environmental factors, such as exogenous hormones or contaminants that mimic hormones, can disrupt endocrine signaling and function. The American alligator (Alligator mississippiensis), a unique model for ecological research in that it exhibits environment-dependent sex determination, is oviparous and long lived. Alligators from a contaminated environment exhibit low reproductive success and morphological disorders of the testis and phallus in neonates and juveniles, both associated with androgen signaling; thus, the alterations are hypothesized to be related to disrupted androgen signaling. However, this line of research has been limited because of a lack of information on the alligator AR gene. Here, we isolated A mississippiensis AR homologs (AmAR) and evaluated receptor-hormone/chemical interactions using a transactivation assay. We showed that AmAR responded to all natural androgens and their effects were inhibited by cotreatment with antiandrogens, such as flutamide, p,p'-dichlorodiphenyldichloroethylene, and vinclozolin. Intriguingly, we found a spliced form of the AR from alligator cDNA, which lacks seven amino acids within the ligand-binding domain that shows no response to androgens. Finally, we have initial data on a possible dominant-negative function of the spliced form of the AR against androgen-induced AmAR. PMID:25974402

  1. Identification and Characterization of the Androgen Receptor From the American Alligator, Alligator mississippiensis

    PubMed Central

    Miyagawa, Shinichi; Yatsu, Ryohei; Kohno, Satomi; Doheny, Brenna M.; Ogino, Yukiko; Ishibashi, Hiroshi; Katsu, Yoshinao; Ohta, Yasuhiko; Guillette, Louis J.

    2015-01-01

    Androgens are essential for the development, reproduction, and health throughout the life span of vertebrates, particularly during the initiation and maintenance of male sexual characteristics. Androgen signaling is mediated by the androgen receptor (AR), a member of the steroid nuclear receptor superfamily. Mounting evidence suggests that environmental factors, such as exogenous hormones or contaminants that mimic hormones, can disrupt endocrine signaling and function. The American alligator (Alligator mississippiensis), a unique model for ecological research in that it exhibits environment-dependent sex determination, is oviparous and long lived. Alligators from a contaminated environment exhibit low reproductive success and morphological disorders of the testis and phallus in neonates and juveniles, both associated with androgen signaling; thus, the alterations are hypothesized to be related to disrupted androgen signaling. However, this line of research has been limited because of a lack of information on the alligator AR gene. Here, we isolated A mississippiensis AR homologs (AmAR) and evaluated receptor-hormone/chemical interactions using a transactivation assay. We showed that AmAR responded to all natural androgens and their effects were inhibited by cotreatment with antiandrogens, such as flutamide, p,p′-dichlorodiphenyldichloroethylene, and vinclozolin. Intriguingly, we found a spliced form of the AR from alligator cDNA, which lacks seven amino acids within the ligand-binding domain that shows no response to androgens. Finally, we have initial data on a possible dominant-negative function of the spliced form of the AR against androgen-induced AmAR. PMID:25974402

  2. INTERACTION OF ORGANOPHOSPHATE PESTICIDES AND RELATED COMPOUNDS WITH THE ANDROGEN RECEPTOR

    EPA Science Inventory

    Identification of several environmental chemicals capable of binding to the androgen receptor (AR) and interfering with its normal function has heightened concern for adverse effects across a broad spectrum of environmental chemicals. We previously demonstrated AR antagonist act...

  3. Homology-modeled ligand-binding domains of medaka estrogen receptors and androgen receptors: A model system for the study of reproduction

    SciTech Connect

    Cui Jianzhou Shen Xueyan; Yan Zuowei; Zhao Haobin; Nagahama, Yoshitaka

    2009-02-27

    Estrogen and androgen and their receptors play critical roles in physiological processes such as sexual differentiation and development. Using the available structural models for the human estrogen receptors alpha and beta and androgen receptor as templates, we designed in silico agonist and antagonist models of medaka estrogen receptor (meER) alpha, beta-1, and beta-2, and androgen receptor (meAR) alpha and beta. Using these models, we studied (1) the structural relationship between the ligand-binding domains (LBDs) of ERs and ARs of human and medaka, and (2) whether medaka ER and AR can be potential models for studying the ligand-binding activities of various agonists and antagonists of these receptors by docking analysis. A high level of conservation was observed between the sequences of the ligand-binding domains of meER{alpha} and huER{alpha}, meER{beta}1 and huER{beta}, meER{beta}2, and huER{beta} with 62.8%, 66.4%, and 65.1% identity, respectively. The sequence conservation between meAR{alpha} and huAR, meAR{beta}, and huAR was found with 70.1% and 61.0% of identity, respectively. Thirty-three selected endocrine disrupting chemicals (EDCs), including both agonists and antagonists, were docked into the LBD of ER and AR, and the corresponding docking score for medaka models and human templates were calculated. In order to confirm the conservation of the overall geometry and the binding pocket, the backbone root mean square deviation (RMSD) for C{alpha} atoms was derived from the structure superposition of all 10 medaka homology models to the six human templates. Our results suggested conformational conservation between the ERs and ARs of medaka and human, Thus, medaka could be highly useful as a model system for studies involving estrogen and androgen interaction with their receptors.

  4. Honokiol Inhibits Androgen Receptor Activity in Prostate Cancer Cells

    PubMed Central

    Hahm, Eun-Ryeong; Karlsson, A. Isabella; Bonner, Michael Y.; Arbiser, Jack L.; Singh, Shivendra V.

    2014-01-01

    BACKGROUND We have shown previously that honokiol (HNK), a bioactive component of the medicinal plant Magnolia officinalis, inhibits growth of human prostate cancer cells in vitro and in vivo. However, the effect of HNK on androgen receptor (AR) signaling is not known. METHODS LNCaP, C4-2, and TRAMP-C1 cells were used for various assays. Trypan blue dye exclusion assay or clonogenic assay was performed for determination of cell viability. The effects of HNK and/or its analogs on protein levels of AR and its target gene product prostate specific antigen (PSA) were determined by western blotting. RNA interference of p53 was achieved by transient transfection. Reverse transcription-polymerase chain reaction was performed for mRNA expression of AR. Nuclear translocation of AR was visualized by microscopy. Apoptosis was quantified by DNA fragmentation assay or flow cytometry after Annexin V-propidium iodide staining. RESULTS HNK and its dichloroacetate analog (HDCA) were relatively more effective in suppressing cell viability and AR protein level than honokiol epoxide or biseugenol. Nuclear translocation of AR stimulated by a synthetic androgen (R1881) was markedly suppressed in the presence of HNK. Downregulation of AR protein resulting from HNK exposure was attributable to transcriptional repression as well as proteasomal degradation. HNK-mediated suppression of AR protein was maintained in LNCaP cells after knockdown of p53 protein. HNK-induced apoptosis was not affected by R1881 treatment. CONCLUSIONS The present study demonstrates, for the first time, that HNK inhibits activity of AR in prostate cancer cells regardless of the p53 status. PMID:24338950

  5. The androgen receptor mediates antiapoptotic function in myometrial cells.

    PubMed

    Li, H; Li, Y; Morin, D; Plymate, S; Lye, S; Dong, X

    2014-01-01

    During pregnancy, myometrial phenotype is programmed into three characteristic stages referred to as the early proliferative, the midterm hypertrophic, and the late contractile stage. Increased myometrial growth in the early and midterm of pregnancy involves a complex process of cell proliferation, antiapoptosis and differentiation. We have previously demonstrated that the androgen receptor (AR) is required for myometrial cell proliferation by modulating IGF-1 signaling during early pregnancy. Here, we report that AR also exerts its antiapoptotic function in human myometrial cells. Enhanced AR expression protects, whereas AR silencing sensitizes myometrial cells to both intrinsic and extrinsic apoptotic stimuli. AR agonist inhibits, whereas AR antagonist induces myometrial cells to undergo apoptotic cell death. Gene microarray analysis confirms that the central functions of AR in myometrial cells are to regulate cell cycling and apoptosis through three major gene groups involving the epidermal growth factor (EGF) signaling, RNA splicing and DNA repair processes. AR mediates its antiapoptotic function through two distinct pathways. In the receptor-dependent pathway, AR is required for the expression of several protein factors within the EGF signaling pathway. Through the PI3K/Akt pathway, AR enhances the expression of the antiapoptotic protein Mcl-1. In the ligand-dependent pathway, AR agonist triggers the activation of Src kinase, which in turn phosphorylates STAT3 to increase Mcl-1 expression. We conclude from these results that the AR signaling exerts antiapoptotic function in myometrial cells, further supporting its key role in programming of myometrial phenotype. PMID:25032861

  6. Involvement of the Androgen and Glucocorticoid Receptors in Bladder Cancer

    PubMed Central

    McBeth, Lucien; Grabnar, Maria; Selman, Steven; Hinds, Terry D.

    2015-01-01

    Bladder cancer is encountered worldwide having been associated with a host of environmental and lifestyle risk factors. The disease has a male to female prevalence of 3 : 1. This disparity has raised the possibility of the androgen receptor (AR) pathway being involved in the genesis of the disease; indeed, research has shown that AR is involved in and is likely a driver of bladder cancer. Similarly, an inflammatory response has been implicated as a major player in bladder carcinogenesis. Consistent with this concept, recent work on anti-inflammatory glucocorticoid signaling points to a pathway that may impact bladder cancer. The glucocorticoid receptor- (GR-) α isoform has an important role in suppressing inflammatory processes, which may be attenuated by AR in the development of bladder cancer. In addition, a GR isoform that is inhibitory to GRα, GRβ, is proinflammatory and has been shown to induce cancer growth. In this paper, we review the evidence of inflammatory mediators and the relationship of AR and GR isoforms as they relate to the propensity for bladder cancer. PMID:26347776

  7. Dominant-Negative Androgen Receptor Inhibition of Intracrine Androgen-Dependent Growth of Castration-Recurrent Prostate Cancer

    PubMed Central

    Kantor, Boris; Li, Xiangping; Haack, Karin; Moore, Dominic T.; Wilson, Elizabeth M.

    2012-01-01

    Background Prostate cancer (CaP) is the second leading cause of cancer death in American men. Androgen deprivation therapy is initially effective in CaP treatment, but CaP recurs despite castrate levels of circulating androgen. Continued expression of the androgen receptor (AR) and its ligands has been linked to castration-recurrent CaP growth. Principal Finding In this report, the ligand-dependent dominant-negative ARΔ142–337 (ARΔTR) was expressed in castration-recurrent CWR-R1 cell and tumor models to elucidate the role of AR signaling. Expression of ARΔTR decreased CWR-R1 tumor growth in the presence and absence of exogenous testosterone (T) and improved survival in the presence of exogenous T. There was evidence for negative selection of ARΔTR transgene in T-treated mice. Mass spectrometry revealed castration-recurrent CaP dihydrotestosterone (DHT) levels sufficient to activate AR and ARΔTR. In the absence of exogenous testosterone, CWR-R1-ARΔTR and control cells exhibited altered androgen profiles that implicated epithelial CaP cells as a source of intratumoral AR ligands. Conclusion The study provides in vivo evidence that activation of AR signaling by intratumoral AR ligands is required for castration-recurrent CaP growth and that epithelial CaP cells produce sufficient active androgens for CaP recurrence during androgen deprivation therapy. Targeting intracrine T and DHT synthesis should provide a mechanism to inhibit AR and growth of castration-recurrent CaP. PMID:22272301

  8. Abiraterone Treatment in Castration-Resistant Prostate Cancer Selects for Progesterone Responsive Mutant Androgen Receptors

    PubMed Central

    Chen, Eddy J.; Sowalsky, Adam G.; Gao, Shuai; Cai, Changmeng; Voznesensky, Olga; Schaefer, Rachel; Loda, Massimo; True, Lawrence D.; Ye, Huihui; Troncoso, Patricia; Lis, Rosina L.; Kantoff, Philip W.; Montgomery, Robert B.; Nelson, Peter S.; Bubley, Glenn J.; Balk, Steven P.; Taplin, Mary-Ellen

    2014-01-01

    Purpose The CYP17A1 inhibitor abiraterone markedly reduces androgen precursors and is thereby effective in castration-resistant prostate cancer (CRPC). However, abiraterone increases progesterone, which can activate certain mutant androgen receptors (ARs) identified previously in flutamide-resistant tumors. Therefore, we sought to determine if CYP17A1 inhibitor treatment selects for progesterone activated mutant ARs. Experimental Design AR was examined by targeted sequencing in metastatic tumor biopsies from 18 CRPC patients who were progressing on a CYP17A1 inhibitor (17 on abiraterone, 1 on ketoconazole), alone or in combination with dutasteride, and by whole exome sequencing in residual tumor in one patient treated with neoadjuvant leuprolide plus abiraterone. Results The progesterone-activated T878A mutant AR was present at high allele frequency in 3 of the 18 CRPC cases. It was also present in one focus of resistant tumor in the neoadjuvant treated patient, but not in a second clonally related resistant focus which instead had lost one copy of PTEN and both copies of CHD1. The T878A mutation appeared to be less common in the subset of CRPC patients treated with abiraterone plus dutasteride, and transfection studies showed that dutasteride was a more potent direct antagonist of the T878A versus the wildtype AR. Conclusions These findings indicate that selection for tumor cells expressing progesterone-activated mutant ARs is a mechanism of resistance to CYP17A1 inhibition. PMID:25320358

  9. Crosstalk between RON and androgen receptor signaling in the development of castration resistant prostate cancer

    PubMed Central

    Batth, Izhar; Yun, Huiyoung; Hussain, Suleman; Meng, Peng; Osumulski, Powel; Huang, Tim Hui-Ming; Bedolla, Roble; Profit, Amanda; Reddick, Robert; Kumar, Addanki

    2016-01-01

    Castrate-resistant prostate cancer (CRPC) is the fatal form of prostate cancer. Although reactivation of androgen receptor (AR) occurs following androgen deprivation, the precise mechanism involved is unclear. Here we show that the receptor tyrosine kinase, RON alters mechanical properties of cells to influence epithelial to mesenchymal transition and functions as a transcription factor to differentially regulate AR signaling. RON inhibits AR activation and subset of AR-regulated transcripts in androgen responsive LNCaP cells. However in C4-2B, a castrate-resistant sub-line of LNCaP and AR-negative androgen independent DU145 cells, RON activates subset of AR-regulated transcripts. Expression of AR in PC-3 cells leads to activation of RON under androgen deprivation but not under androgen proficient conditions implicating a role for RON in androgen independence. Consistently, RON expression is significantly elevated in castrate resistant prostate tumors. Taken together our results suggest that RON activation could aid in promoting androgen independence and that inhibition of RON in combination with AR antagonist(s) merits serious consideration as a therapeutic option during hormone deprivation therapy. PMID:26872377

  10. In Silico and In Vitro Investigation of the Piperine's Male Contraceptive Effect: Docking and Molecular Dynamics Simulation Studies in Androgen-Binding Protein and Androgen Receptor.

    PubMed

    Chinta, Gopichand; Ramya Chandar Charles, Mariasoosai; Klopčič, Ivana; Sollner Dolenc, Marija; Periyasamy, Latha; Selvaraj Coumar, Mohane

    2015-07-01

    Understanding the molecular mechanism of action of traditional medicines is an important step towards developing marketable drugs from them. Piperine, an active constituent present in the Piper species, is used extensively in Ayurvedic medicines (practiced on the Indian subcontinent). Among others, piperine is known to possess a male contraceptive effect; however, the molecular mechanism of action for this effect is not very clear. In this regard, detailed docking and molecular dynamics simulation studies of piperine with the androgen-binding protein and androgen receptors were carried out. Androgen receptors control male sexual behavior and fertility, while the androgen-binding protein binds testosterone and maintains its concentration at optimal levels to stimulate spermatogenesis in the testis. It was found that piperine docks to the androgen-binding protein, similar to dihydrotestosterone, and to androgen receptors, similar to cyproterone acetate (antagonist). Also, the piperine-androgen-binding protein and piperine-androgen receptors interactions were found to be stable throughout 30 ns of molecular dynamics simulation. Further, two independent simulations for 10 ns each also confirmed the stability of these interactions. Detailed analysis of the piperine-androgen-binding protein interactions shows that piperine interacts with Ser42 of the androgen-binding protein and could block the binding with its natural ligands dihydrotestosterone/testosterone. Moreover, piperine interacts with Thr577 of the androgen receptors in a manner similar to the antagonist cyproterone acetate. Based on the in silico results, piperine was tested in the MDA-kb2 cell line using the luciferase reporter gene assay and was found to antagonize the effect of dihydrotestosterone at nanomolar concentrations. Further detailed biochemical experiments could help to develop piperine as an effective male contraceptive agent in the future. PMID:26039262

  11. Androgen receptor mutations in carcinoma of the prostate: significance for endocrine therapy.

    PubMed

    Culig, Z; Klocker, H; Bartsch, G; Hobisch, A

    2001-01-01

    Endocrine therapy for advanced prostate cancer involves androgen ablation (orchiectomy or application of luteinizing hormone releasing hormone analogs) and/or blockade of the androgen receptor (AR) with either steroidal (cyproterone acetate) or nonsteroidal (hydroxyflutamide, bicalutamide and nilutamide) antiandrogens. These antagonists prevent androgen-induced conformational change and activation of the AR. During long term androgen ablation, the AR adapts to an environment with low androgen concentrations and becomes hypersensitive to low concentrations of androgens, either alone or in combination with various cellular regulators. Bicalutamide can switch from antagonist to agonist during long-term androgen withdrawal, as shown in prostate cancer LNCaP cells. AR point mutations were detected in metastatic lesions from human prostate cancer more frequently than in primary tumors. Although functional characterization of only some mutant AR detected in prostate cancer tissue has been performed, data available suggest that they are activated by dihydrotestosterone, its precursors and metabolites, synthetic androgens, estrogenic and progestagenic steroids and hydroxyflutamide. A direct association between AR mutations and endocrine withdrawal syndrome has been investigated in only one study thus far. There is no evidence at present that activation of any of the mutant AR genes detected in prostate cancer is enhanced in the presence of a nonsteroidal AR stimulator. Coactivators of the AR are proteins that associate with the receptor, possess histone acetylase activity and facilitate AR activation. The coregulatory proteins ARA70 and ARA160 differentially affected the activity of the mutated AR Glu(231)-->Gly, which was discovered in a mouse authochthonous prostate tumor. ARA70 enhanced receptor activation by both androgen and estradiol, whereas ARA160 augmented only androgen-induced AR activity. Novel experimental therapies that down-regulate AR expression have been

  12. Androgen Receptor Roles in Insulin Resistance and Obesity in Males: The Linkage of Androgen-Deprivation Therapy to Metabolic Syndrome

    PubMed Central

    Yu, I-Chen; Lin, Hung-Yun; Sparks, Janet D.; Yeh, Shuyuan

    2014-01-01

    Prostate cancer (PCa) is one of the most frequently diagnosed malignancies in men. Androgen-deprivation therapy (ADT) is the first-line treatment and fundamental management for men with advanced PCa to suppress functions of androgen/androgen receptor (AR) signaling. ADT is effective at improving cancer symptoms and prolonging survival. However, epidemiological and clinical studies support the notion that testosterone deficiency in men leads to the development of metabolic syndrome that increases cardiovascular disease risk. The underlying mechanisms by which androgen/AR signaling regulates metabolic homeostasis in men are complex, and in this review, we discuss molecular mechanisms mediated by AR signaling that link ADT to metabolic syndrome. Results derived from various AR knockout mouse models reveal tissue-specific AR signaling that is involved in regulation of metabolism. These data suggest that steps be taken early to manage metabolic complications associated with PCa patients receiving ADT, which could be accomplished using tissue-selective modulation of AR signaling and by treatment with insulin-sensitizing agents. PMID:25249645

  13. Molecular cloning of canine co-chaperone small glutamine-rich tetratricopeptide repeat-containing protein α (SGTA) and investigation of its ability to suppress androgen receptor signalling in androgen-independent prostate cancer.

    PubMed

    Kato, Yuiko; Ochiai, Kazuhiko; Michishita, Masaki; Azakami, Daigo; Nakahira, Rei; Morimatsu, Masami; Ishiguro-Oonuma, Toshina; Yoshikawa, Yasunaga; Kobayashi, Masato; Bonkobara, Makoto; Kobayashi, Masanori; Takahashi, Kimimasa; Watanabe, Masami; Omi, Toshinori

    2015-11-01

    Although the morbidity of canine prostate cancer is low, the majority of cases present with resistance to androgen therapy and poor clinical outcomes. These pathological conditions are similar to the signs of the terminal stage of human androgen-independent prostate cancer. The co-chaperone small glutamine-rich tetratricopeptide repeat-containing protein α (SGTA) is known to be overexpressed in human androgen-independent prostate cancer. However, there is little information about the structure and function of canine SGTA. In this study, canine SGTA was cloned and analysed for its ability to suppress androgen receptor signalling. The full-length open reading frame (ORF) of the canine SGTA gene was amplified by RT-PCR using primers designed from canine-expressed sequence tags that were homologous to human SGTA. The canine SGTA ORF has high homology with the corresponding human (89%) and mouse (81%) sequences. SGTA dimerisation region and tetratricopeptide repeat (TPR) domains are conserved across the three species. The ability of canine SGTA to undergo homodimerisation was demonstrated by a mammalian two-hybrid system and a pull-down assay. The negative impact of canine SGTA on androgen receptor (AR) signalling was demonstrated using a reporter assay in androgen-independent human prostate cancer cell lines. Pathological analysis showed overexpression of SGTA in canine prostate cancer, but not in hyperplasia. A reporter assay in prostate cells demonstrated suppression of AR signalling by canine SGTA. Altogether, these results suggest that canine SGTA may play an important role in the acquisition of androgen independence by canine prostate cancer cells. PMID:26346258

  14. Increased cytosolic androgen receptor binding in rat striated muscle following denervation and disuse

    NASA Technical Reports Server (NTRS)

    Bernard, P. A.; Fishman, P. S.; Max, S. R.; Rance, N. E.

    1984-01-01

    The effects of denervation and disuse on cytosolic androgen receptor binding by rat striated muscle are investigated. Denervation of the extensor digitorum longus and tibialis anterior muscles caused by a 40-50-percent increase in cytosolic androgen receptor concentration with no change in apparent binding affinity. This effect was evident at 6 h postdenervation, maximal at 24 h, and declined to 120 percent of the control level 72 h after denervation. A 40-percent increase in cytosolic androgen receptor concentration was also noted 24 hr after denervation of the hormone-sensitive levator ani muscle. The effect of denervation on androgen receptors was blocked by in vivo injection of cycloheximide; therefore, de novo receptor synthesis probably is not involved in the observed increase. Disuse, produced by subperineurial injection of tetrodotoxin into the tibial and common peroneal branches of the sciatic nerve, mimicked the effect of denervation on androgen receptor binding, suggesting that neuromuscular activity is important in regulation of receptor concentration. Possible mechanisms subserving this effect are discussed.

  15. Androgen receptor and monoamine oxidase polymorphism in wild bonobos.

    PubMed

    Garai, Cintia; Furuichi, Takeshi; Kawamoto, Yoshi; Ryu, Heungjin; Inoue-Murayama, Miho

    2014-12-01

    Androgen receptor gene (AR), monoamine oxidase A gene (MAOA) and monoamine oxidase B gene (MAOB) have been found to have associations with behavioral traits, such as aggressiveness, and disorders in humans. However, the extent to which similar genetic effects might influence the behavior of wild apes is unclear. We examined the loci AR glutamine repeat (ARQ), AR glycine repeat (ARG), MAOA intron 2 dinucleotide repeat (MAin2) and MAOB intron 2 dinucleotide repeat (MBin2) in 32 wild bonobos, Pan paniscus, and compared them with those of chimpanzees, Pan troglodytes, and humans. We found that bonobos were polymorphic on the four loci examined. Both loci MAin2 and MBin2 in bonobos showed a higher diversity than in chimpanzees. Because monoamine oxidase influences aggressiveness, the differences between the polymorphisms of MAin2 and MBin2 in bonobos and chimpanzees may be associated with the differences in aggression between the two species. In order to understand the evolution of these loci and AR, MAOA and MAOB in humans and non-human primates, it would be useful to conduct future studies focusing on the potential association between aggressiveness, and other personality traits, and polymorphisms documented in bonobos. PMID:25606465

  16. Molecular Cloning and Characterization of Estrogen, Androgen, and Progesterone Nuclear Receptors from a Freshwater Turtle (Pseudemys nelsoni)

    PubMed Central

    Katsu, Yoshinao; Ichikawa, Rie; Ikeuchi, Toshitaka; Kohno, Satomi; Guillette, Louis J.; Iguchi, Taisen

    2008-01-01

    Steroid hormones are essential for the normal function of many organ systems in vertebrates. Reproductive activity in females and males, such as the differentiation, growth, and maintenance of the reproductive system, requires signaling by the sex steroids. Although extensively studied in mammals and a few fish, amphibians, and bird species, the molecular mechanisms of sex steroid hormone (estrogens, androgens, and progestins) action are poorly understood in reptiles. Here we evaluate hormone receptor ligand interactions in a freshwater turtle, the red-belly slider (Pseudemys nelsoni), after the isolation of cDNAs encoding an estrogen receptor alpha (ERα), an androgen receptor (AR), and a progesterone receptor (PR). The full-length red-belly slider turtle (t)ERα, tAR, and tPR cDNAs were obtained using 5′ and 3′ rapid amplification cDNA ends. The deduced amino acid sequences showed high identity to the chicken orthologs (tERα, 90%; tAR, 71%; tPR, 71%). Using transient transfection assays of mammalian cells, tERα protein displayed estrogen-dependent activation of transcription from an estrogen-responsive element-containing promoter. The other receptor proteins, tAR and tPR, also displayed androgen- or progestin-dependent activation of transcription from androgen- and progestin-responsive murine mammary tumor virus promoters. We further examined the transactivation of tERα, tAR and tPR by ligands using a modified GAL4-transactivation system. We found that the GAL4-transactivation system was not suitable for the measurement of tAR and tPR transactivations. This is the first report of the full coding regions of a reptilian AR and PR and the examination of their transactivation by steroid hormones. PMID:17916628

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

    PubMed

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

    2016-09-01

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

  18. BTG2 is an LXXLL-dependent co-repressor for androgen receptor transcriptional activity

    SciTech Connect

    Hu, Xu-Dong; Meng, Qing-Hui; Xu, Jia-Ying; Jiao, Yang; Ge, Chun-Min; Jacob, Asha; Wang, Ping; Rosen, Eliot M; Fan, Saijun

    2011-01-28

    Research highlights: {yields} BTG2 associates with AR, androgen causes an increase of the interaction. {yields} BTG2 as a co-repressor inhibits the AR-mediated transcription activity. {yields} BTG2 inhibits the transcription activity and expression of PSA. {yields} An intact {sup 92}LxxLL{sup 96} motif is essential and necessary for these activities of BTG2, while the {sup 20}LxxLL{sup 24} motif is not required. {yields} Ectopic expression of BTG2 reduces proliferation of prostate cancer cells. -- Abstract: The tumor suppressor gene, BTG2 has been down-regulated in prostate cancer and the ectopic expression of this gene has been shown to inhibit prostate cancer cell growth. Sequence analysis revealed that the BTG2 protein contains two leucine-rich motifs ({sup 20}LxxLL{sup 24} and {sup 92}LxxLL{sup 96}), which are usually found in nuclear receptor co-factors. Based on this, we postulated that there will be an association between BTG2 and AR. In this study, we discovered that BTG2 directly bound to the androgen receptor (AR) in the absence of 5{alpha}-dihydrotestosterone (DHT), and in the presence of the androgen, this interaction was increased. BTG2 bearing the mutant {sup 20}LxxLL{sup 24} motif bound to AR equally efficient as the wild-type BTG2, while BTG2 bearing the mutant {sup 92}LxxLL{sup 96} motif failed to interact with AR. Functional studies indicated that ectopic expression of BTG2 caused a significant inhibition of AR-mediated transcriptional activity and a decreased growth of prostate cancer cells. Androgen-induced promoter activation and expression of prostate-specific antigen (PSA) are significantly attenuated by BTG2. The intact {sup 92}LxxLL{sup 96} motif is required for these activities. These findings, for the first time, demonstrate that BTG2 complexes with AR via an LxxLL-dependent mechanism and may play a role in prostate cancer via modulating the AR signaling pathway.

  19. [The mechanism of progression without androgen receptor interaction in prostate cancer].

    PubMed

    Matsuyama, Hideyasu; Matsumoto, Hiroaki

    2016-01-01

    Recently, new generation androgen receptor (AK) targeted agents enzautamide or abiraterone etc.) has been clinically utilized in patients with castration-resistant prostate cancer (CRPC). However, metastatic CRPC has also AR-independent survival pathway which leads to lethal phenotype by either adaptation or clonal selection resistant mechanism after AR targeted therapy. There are many studies regarding the progression mechanisms without AR signal transduction, such as growth factor, anti-apoptotic factor, and PTEN/mTOR pathway and so on. Also, cancer microenvironment and cancer stem cell is a hot research area for CRPC. It is very important to repress both AR-dependent and -independent signaling pathway to improve the clinical outcome in CRPC patients. Application of the new technology, such as next generation sequencing, would be developing for the prostate cancer research, providing pre-clinical proof-of-principle as a promising approach in CRPC. PMID:26793881

  20. Agonist and antagonist switch DNA motifs recognized by human androgen receptor in prostate cancer

    PubMed Central

    Chen, Zhong; Lan, Xun; Thomas-Ahner, Jennifer M; Wu, Dayong; Liu, Xiangtao; Ye, Zhenqing; Wang, Liguo; Sunkel, Benjamin; Grenade, Cassandra; Chen, Junsheng; Zynger, Debra L; Yan, Pearlly S; Huang, Jiaoti; Nephew, Kenneth P; Huang, Tim H-M; Lin, Shili; Clinton, Steven K; Li, Wei; Jin, Victor X; Wang, Qianben

    2015-01-01

    Human transcription factors recognize specific DNA sequence motifs to regulate transcription. It is unknown whether a single transcription factor is able to bind to distinctly different motifs on chromatin, and if so, what determines the usage of specific motifs. By using a motif-resolution chromatin immunoprecipitation-exonuclease (ChIP-exo) approach, we find that agonist-liganded human androgen receptor (AR) and antagonist-liganded AR bind to two distinctly different motifs, leading to distinct transcriptional outcomes in prostate cancer cells. Further analysis on clinical prostate tissues reveals that the binding of AR to these two distinct motifs is involved in prostate carcinogenesis. Together, these results suggest that unique ligands may switch DNA motifs recognized by ligand-dependent transcription factors in vivo. Our findings also provide a broad mechanistic foundation for understanding ligand-specific induction of gene expression profiles. PMID:25535248

  1. Agonist and antagonist switch DNA motifs recognized by human androgen receptor in prostate cancer.

    PubMed

    Chen, Zhong; Lan, Xun; Thomas-Ahner, Jennifer M; Wu, Dayong; Liu, Xiangtao; Ye, Zhenqing; Wang, Liguo; Sunkel, Benjamin; Grenade, Cassandra; Chen, Junsheng; Zynger, Debra L; Yan, Pearlly S; Huang, Jiaoti; Nephew, Kenneth P; Huang, Tim H-M; Lin, Shili; Clinton, Steven K; Li, Wei; Jin, Victor X; Wang, Qianben

    2015-02-12

    Human transcription factors recognize specific DNA sequence motifs to regulate transcription. It is unknown whether a single transcription factor is able to bind to distinctly different motifs on chromatin, and if so, what determines the usage of specific motifs. By using a motif-resolution chromatin immunoprecipitation-exonuclease (ChIP-exo) approach, we find that agonist-liganded human androgen receptor (AR) and antagonist-liganded AR bind to two distinctly different motifs, leading to distinct transcriptional outcomes in prostate cancer cells. Further analysis on clinical prostate tissues reveals that the binding of AR to these two distinct motifs is involved in prostate carcinogenesis. Together, these results suggest that unique ligands may switch DNA motifs recognized by ligand-dependent transcription factors in vivo. Our findings also provide a broad mechanistic foundation for understanding ligand-specific induction of gene expression profiles. PMID:25535248

  2. Androgen receptor transcriptionally regulates μ-opioid receptor expression in rat trigeminal ganglia.

    PubMed

    Lee, Ki Seok; Zhang, Youping; Asgar, Jamila; Auh, Q-Schick; Chung, Man-Kyo; Ro, Jin Y

    2016-09-01

    The involvement of testosterone in pain, inflammation, and analgesia has been reported, but the role of androgen receptor (AR), a steroid receptor for testosterone, is not well understood. We have previously shown that peripheral inflammation upregulates μ-opioid receptor (MOR) in rat trigeminal ganglia (TG) in a testosterone-dependent manner. In this study, we hypothesized that testosterone regulates MOR expression via transcriptional activities of AR in TG. We first examined whether AR is co-expressed with MOR in TG neurons. Our immunohistochemical experiment revealed that AR staining is detected in neurons of all sizes in TG and that a subset of AR is expressed in MOR as well as in TRPV1-positive neurons. We identified the promoter region of the rat MOR gene contains putative AR binding sites. Using chromatin immunoprecipitation assay, we demonstrated that AR directly binds to these sites in TG extracts. We confirmed with luciferase reporter assay that AR activated the MOR promoter in response to androgens in a human neuroblastoma cell line (5H-5YSY). These data demonstrated that AR functions as a transcriptional regulator of the MOR gene activity. Finally, we showed that flutamide, a specific AR antagonist, prevents complete Freund's adjuvant (CFA)-induced upregulation of MOR mRNA in TG, and that flutamide dose-dependently blocks the efficacy of DAMGO, a specific MOR agonist, on CFA-induced mechanical hypersensitivity. Our results expand the knowledge regarding the role of androgens and their receptor in pain and analgesia and have important clinical implications, particularly for inflammatory pain patients with low or compromised plasma testosterone levels. PMID:27320211

  3. Research Resource: Androgen Receptor Activity Is Regulated Through the Mobilization of Cell Surface Receptor Networks

    PubMed Central

    Hsiao, Jordy J.; Ng, Brandon H.; Smits, Melinda M.; Martinez, Harryl D.; Jasavala, Rohini J.; Hinkson, Izumi V.; Fermin, Damian; Eng, Jimmy K.; Nesvizhskii, Alexey I.

    2015-01-01

    The aberrant expression of androgen receptor (AR)-dependent transcriptional programs is a defining pathology of the development and progression of prostate cancers. Transcriptional cofactors that bind AR are critical determinants of prostate tumorigenesis. To gain a deeper understanding of the proteins linked to AR-dependent gene transcription, we performed a DNA-affinity chromatography-based proteomic screen designed to identify proteins involved in AR-mediated gene transcription in prostate tumor cells. Functional experiments validated the coregulator roles of known AR-binding proteins in AR-mediated transcription in prostate tumor cells. More importantly, novel coregulatory functions were detected in components of well-established cell surface receptor-dependent signal transduction pathways. Further experimentation demonstrated that components of the TNF, TGF-β, IL receptor, and epidermal growth factor signaling pathways modulated AR-dependent gene transcription and androgen-dependent proliferation in prostate tumor cells. Collectively, our proteomic dataset demonstrates that the cell surface receptor- and AR-dependent pathways are highly integrated, and provides a molecular framework for understanding how disparate signal-transduction pathways can influence AR-dependent transcriptional programs linked to the development and progression of human prostate cancers. PMID:26181434

  4. Identification of androgen receptors in normal human osteoblast-like cells

    SciTech Connect

    Colvard, D.S.; Eriksen, E.F.; Keeting, P.E.; Riggs, B.L.; Spelsberg, T.C. ); Wilson, E.M.; Lubahn, D.B.; French, F.S. )

    1989-02-01

    The sex steroids, androgens and estrogens, are major regulators of bone metabolism. However, whether these hormones act on bone cells through direct or indirect mechanisms has remained unclear. A nuclear binding assay recently used to demonstrate estrogen receptors in bone was used to identify specific nuclear binding of a tritiated synthetic androgen, ({sup 3}H)R1881 (methyltrienolone), in 21 of 25 (84%) human osteoblast-like cell strains and a concentration of bound steroid receptors of 821 {plus minus} 140 molecules per cell nucleus. Binding was saturable and steroid-specific. Androgen receptor gene expression in osteoblasts was confirmed by RNA blot analysis. Relative concentrations of androgen and estrogen receptors were compared by measuring specific nuclear estrogen binding. Nuclear binding of ({sup 3}H)estradiol was observed in 27 of 30 (90%) cell strains; the concentration of bound estradiol receptor was 1537 {plus minus} 221 molecules per cell nucleus. The concentrations of nuclear binding sites were similar in males and females for both ({sup 3}H)R1881 and ({sup 3}H)estradiol. The authors conclude that both androgens and estrogens act directly on human bone cells through their respective receptor-mediated mechanisms.

  5. Restoration of spermatogenesis and male fertility using an androgen receptor transgene.

    PubMed

    Walker, William H; Easton, Evan; Moreci, Rebecca S; Toocheck, Corey; Anamthathmakula, Prashanth; Jeyasuria, Pancharatnam

    2015-01-01

    Androgens signal through the androgen receptor (AR) to regulate male secondary sexual characteristics, reproductive tract development, prostate function, sperm production, bone and muscle mass as well as body hair growth among other functions. We developed a transgenic mouse model in which endogenous AR expression was replaced by a functionally modified AR transgene. A bacterial artificial chromosome (BAC) was constructed containing all AR exons and introns plus 40 kb each of 5' and 3' regulatory sequence. Insertion of an internal ribosome entry site and the EGFP gene 3' to AR allowed co-expression of AR and EGFP. Pronuclear injection of the BAC resulted in six founder mice that displayed EGFP production in appropriate AR expressing tissues. The six founder mice were mated into a Sertoli cell specific AR knockout (SCARKO) background in which spermatogenesis is blocked at the meiosis stage of germ cell development. The AR-EGFP transgene was expressed in a cyclical manner similar to that of endogenous AR in Sertoli cells and fertility was restored as offspring were produced in the absence of Sertoli cell AR. Thus, the AR-EGFP transgene under the control of AR regulatory elements is capable of rescuing AR function in a cell selective, AR-null background. These initial studies provide proof of principle that a strategy employing the AR-EGFP transgene can be used to understand AR functions. Transgenic mice expressing selective modifications of the AR-EGFP transgene may provide crucial information needed to elicit the molecular mechanisms by which AR acts in the testis and other androgen responsive tissues. PMID:25803277

  6. Identification of an anabolic selective androgen receptor modulator that actively induces death of androgen-independent prostate cancer cells.

    PubMed

    Schmidt, Azriel; Meissner, Robert S; Gentile, Michael A; Chisamore, Michael J; Opas, Evan E; Scafonas, Angela; Cusick, Tara E; Gambone, Carlo; Pennypacker, Brenda; Hodor, Paul; Perkins, James J; Bai, Chang; Ferraro, Damien; Bettoun, David J; Wilkinson, Hilary A; Alves, Stephen E; Flores, Osvaldo; Ray, William J

    2014-09-01

    Prostate cancer (PCa) initially responds to inhibition of androgen receptor (AR) signaling, but inevitably progresses to hormone ablation-resistant disease. Much effort is focused on optimizing this androgen deprivation strategy by improving hormone depletion and AR antagonism. However we found that bicalutamide, a clinically used antiandrogen, actually resembles a selective AR modulator (SARM), as it partially regulates 24% of endogenously 5α-dihydrotestosterone (DHT)-responsive genes in AR(+) MDA-MB-453 breast cancer cells. These data suggested that passive blocking of all AR functions is not required for PCa therapy. Hence, we adopted an active strategy that calls for the development of novel SARMs, which induce a unique gene expression profile that is intolerable to PCa cells. Therefore, we screened 3000 SARMs for the ability to arrest the androgen-independent growth of AR(+) 22Rv1 and LNCaP PCa cells but not AR(-) PC3 or DU145 cells. We identified only one such compound; the 4-aza-steroid, MK-4541, a potent and selective SARM. MK-4541 induces caspase-3 activity and cell death in both androgen-independent, AR(+) PCa cell lines but spares AR(-) cells or AR(+) non-PCa cells. This activity correlates with its promoter context- and cell-type dependent transcriptional effects. In rats, MK-4541 inhibits the trophic effects of DHT on the prostate, but not the levator ani muscle, and triggers an anabolic response in the periosteal compartment of bone. Therefore, MK-4541 has the potential to effectively manage prostatic hypertrophic diseases owing to its antitumor SARM-like mechanism, while simultaneously maintaining the anabolic benefits of natural androgens. PMID:24565564

  7. Androgen receptor and immune inflammation in benign prostatic hyperplasia and prostate cancer

    PubMed Central

    Izumi, Kouji; Li, Lei; Chang, Chawnshang

    2014-01-01

    Both benign prostatic hyperplasia (BPH) and prostate cancer (PCa) are frequent diseases in middle-aged to elderly men worldwide. While both diseases are linked to abnormal growth of the prostate, the epidemiological and pathological features of these two prostate diseases are different. BPH nodules typically arise from the transitional zone, and, in contrast, PCa arises from the peripheral zone. Androgen deprivation therapy alone may not be sufficient to cure these two prostatic diseases due to its undesirable side effects. The alteration of androgen receptor-mediated inflammatory signals from infiltrating immune cells and prostate stromal/epithelial cells may play key roles in those unwanted events. Herein, this review will focus on the roles of androgen/androgen receptor signals in the inflammation-induced progression of BPH and PCa. PMID:26594314

  8. The neural androgen receptor: a therapeutic target for myelin repair in chronic demyelination.

    PubMed

    Hussain, Rashad; Ghoumari, Abdel M; Bielecki, Bartosz; Steibel, Jérôme; Boehm, Nelly; Liere, Philippe; Macklin, Wendy B; Kumar, Narender; Habert, René; Mhaouty-Kodja, Sakina; Tronche, François; Sitruk-Ware, Regine; Schumacher, Michael; Ghandour, M Said

    2013-01-01

    Myelin regeneration is a major therapeutic goal in demyelinating diseases, and the failure to remyelinate rapidly has profound consequences for the health of axons and for brain function. However, there is no efficient treatment for stimulating myelin repair, and current therapies are limited to anti-inflammatory agents. Males are less likely to develop multiple sclerosis than females, but often have a more severe disease course and reach disability milestones at an earlier age than females, and these observations have spurred interest in the potential protective effects of androgens. Here, we demonstrate that testosterone treatment efficiently stimulates the formation of new myelin and reverses myelin damage in chronic demyelinated brain lesions, resulting from the long-term administration of cuprizone, which is toxic for oligodendrocytes. In addition to the strong effect of testosterone on myelin repair, the number of activated astrocytes and microglial cells returned to low control levels, indicating a reduction of neuroinflammatory responses. We also identify the neural androgen receptor as a novel therapeutic target for myelin recovery. After the acute demyelination of cerebellar slices in organotypic culture, the remyelinating actions of testosterone could be mimicked by 5α-dihydrotestosterone, a metabolite that is not converted to oestrogens, and blocked by the androgen receptor antagonist flutamide. Testosterone treatment also failed to promote remyelination after chronic cuprizone-induced demyelination in mice with a non-functional androgen receptor. Importantly, testosterone did not stimulate the formation of new myelin sheaths after specific knockout of the androgen receptor in neurons and macroglial cells. Thus, the neural brain androgen receptor is required for the remyelination effect of testosterone, whereas the presence of the receptor in microglia and in peripheral tissues is not sufficient to enhance remyelination. The potent synthetic

  9. Androgen receptor co-activator Hic-5/ARA55 as a molecular regulator of androgen sensitivity in dermal papilla cells of human hair follicles.

    PubMed

    Inui, Shigeki; Fukuzato, Yoko; Nakajima, Takeshi; Kurata, Sotaro; Itami, Satoshi

    2007-10-01

    Androgen site-specifically affects human hair growth after puberty through androgen receptors in the dermal papilla, which transactivate target genes acting in conjunction with co-activators. To examine the regulation of androgen sensitivity in hair follicles, we focused on androgen receptor co-activator Hic-5/ARA55. Its interaction with transfected androgen receptor in beard dermal papilla cells was confirmed with mammalian two-hybrid assays. The semiquantitative reverse transcriptase-polymerase chain reaction showed that Hic-5/ARA55 mRNA expression was high in dermal papilla cells from the beard and bald frontal scalp but low in cells from the occipital scalp. To determine whether Hic-5/ARA55 mRNA level correlates with its endogenous activity, we studied the effect of dominant negative Hic-5/ARA55 on transfected androgen receptor transactivation induced by R1881 using mouse mammary tumor virus-luciferase assays. We found that it suppressed the transactivation by 64.5 and 71.4% in dermal papilla cells from the beard and bald frontal scalp, respectively, whereas it showed no significant effect in cells from the occipital scalp. Our findings suggest that Hic-5/ARA55 is a molecular regulator for androgen sensitivity in human hair follicles. PMID:17508020

  10. Impaired spermatogenesis is not an obligate expression of receptor-defective androgen resistance.

    PubMed

    Pinsky, L; Kaufman, M; Killinger, D W

    1989-01-01

    We are studying a man who presented at age 21 years with severe extragenital subvirilization despite high-normal to above-normal levels of plasma testosterone for at least 5 years. At puberty, his penis, scrotum, and testes matured normally, and he did not develop gynecomastia; however, his voice, muscularity, and facial, sexual, and body hair remained immature. A 2.5-ml ejaculate yielded normal results for sperm density, morphology, and motility. Because persistent undervirilization was emotionally disabling, he has received pharmacologic doses of testosterone enanthate intramuscularly for 3.5 years. The treatment has improved his virilization and masculine self-image substantially, and his semen analysis has remained well within the normal range. The androgen receptor in his genital skin fibroblasts has a distinctively mutant phenotype: it has a low affinity (increased apparent equilibrium dissociation constant, Kd) for 5 alpha-dihydrotestosterone and two synthetic androgens, mibolerone (MB) and methyltrienolone (MT), and its binding capacity (Bmax) is normal for the other two ligands, but questionably low for MT. In addition, it up-regulates its activity normally in response to prolonged incubation with androgen, and its androgen-receptor complexes are not thermolabile. Our study of this man permits two conclusions: impaired spermatogenesis is not the irreducible expression of receptor-defective androgen resistance in man; and androgen pharmacotherapy may be remedial for those in whom extragenital subvirilization is emotionally costly and subnormal spermatogenesis is not an inevitable side effect of such therapy. PMID:2705470

  11. Targeting Alternative Sites on the Androgen Receptor to Treat Castration-Resistant Prostate Cancer

    PubMed Central

    Lallous, Nada; Dalal, Kush; Cherkasov, Artem; Rennie, Paul S.

    2013-01-01

    Recurrent, metastatic prostate cancer continues to be a leading cause of cancer-death in men. The androgen receptor (AR) is a modular, ligand-inducible transcription factor that regulates the expression of genes that can drive the progression of this disease, and as a consequence, this receptor is a key therapeutic target for controlling prostate cancer. The current drugs designed to directly inhibit the AR are called anti-androgens, and all act by competing with androgens for binding to the androgen/ligand binding site. Unfortunately, with the inevitable progression of the cancer to castration resistance, many of these drugs become ineffective. However, there are numerous other regulatory sites on this protein that have not been exploited therapeutically. The regulation of AR activity involves a cascade of complex interactions with numerous chaperones, co-factors and co-regulatory proteins, leading ultimately to direct binding of AR dimers to specific DNA androgen response elements within the promoter and enhancers of androgen-regulated genes. As part of the family of nuclear receptors, the AR is organized into modular structural and functional domains with specialized roles in facilitating their inter-molecular interactions. These regions of the AR present attractive, yet largely unexploited, drug target sites for reducing or eliminating androgen signaling in prostate cancers. The design of small molecule inhibitors targeting these specific AR domains is only now being realized and is the culmination of decades of work, including crystallographic and biochemistry approaches to map the shape and accessibility of the AR surfaces and cavities. Here, we review the structure of the AR protein and describe recent advancements in inhibiting its activity with small molecules specifically designed to target areas distinct from the receptor’s androgen binding site. It is anticipated that these new classes of anti-AR drugs will provide an additional arsenal to treat

  12. An Integrated Network of Androgen Receptor, Polycomb, and TMPRSS2-ERG Gene Fusions in Prostate Cancer Progression

    PubMed Central

    Yu, Jindan; Yu, Jianjun; Mani, Ram-Shankar; Cao, Qi; Brenner, Chad J.; Cao, Xuhong; Wang, George X.; Wu, Longtao; Li, James; Hu, Ming; Gong, Yusong; Cheng, Hong; Laxman, Bharathi; Vellaichamy, Adaikkalam; Shankar, Sunita; Li, Yong; Dhanasekaran, Saravana M.; Morey, Roger; Barrette, Terrence; Lonigro, Robert J.; Tomlins, Scott A.; Varambally, Sooryanarayana; Qin, Zhaohui S.; Chinnaiyan, Arul M.

    2010-01-01

    SUMMARY While chromosomal rearrangements fusing the androgen-regulated gene TMPRSS2 to the oncogenic ETS transcription factor ERG occur in approximately 50% of prostate cancers, how the fusion products regulate prostate cancer remains unclear. Using chromatin immunoprecipitation coupled with massively parallel sequencing (ChIP-Seq), we found that ERG disrupts androgen receptor (AR) signaling by inhibiting AR expression, binding to and inhibiting AR activity at gene-specific loci, and inducing repressive epigenetic programs via direct activation of the H3K27 methyltransferase EZH2, a Polycomb group protein. These findings provide a working model in which TMPRSS2-ERG plays a critical role in cancer progression by disrupting lineage-specific differentiation of the prostate and potentiating the EZH2-mediated de-differentiation program. PMID:20478527

  13. Mechanistic relationship between androgen receptor polyglutamine tract truncation and androgen-dependent transcriptional hyperactivity in prostate cancer cells.

    PubMed

    Wang, Qianben; Udayakumar, T S; Vasaitis, Tadas S; Brodie, Angela M; Fondell, Joseph D

    2004-04-23

    Androgen receptor (AR) signaling pathways mediate critical events in normal and neoplastic prostate growth. Shortening of the polymorphic N-terminal polyglutamine (poly(Q)) tract of the AR gene leads to transcriptional hyperactivity and has been correlated with an increased risk of prostate cancer. The underlying mechanisms for these effects are poorly understood. We show here that androgen-dependent cellular proliferation and transcription in prostate cancer cells is inversely correlated to the length of the AR poly(Q) region. We further show that AR proteins containing a shortened poly(Q) region functionally respond to lower concentrations of androgens than wild type AR. Whereas DNA binding activity is relatively unaffected by AR poly(Q) variation, we found that ligand binding affinity and the ligand-induced NH(2)- to COOH-terminal intramolecular interaction is enhanced when the poly(Q) region is shortened. Importantly, we show that AR proteins containing a shortened poly(Q) region associate in vivo with higher levels of specific p160 coactivators and components of the SWI/SNF chromatin remodeling complex as compared with the wild type AR. Collectively, our findings suggest that the AR transcriptional hyperactivity associated with shortened poly(Q) length stems from altered ligand-induced conformational changes that enhance coactivator recruitment. PMID:14966121

  14. Camptothecin disrupts androgen receptor signaling and suppresses prostate cancer cell growth

    SciTech Connect

    Liu, Shicheng; Yuan, Yiming; Okumura, Yutaka; Shinkai, Norihiro; Yamauchi, Hitoshi

    2010-04-02

    The androgen receptor (AR) is the main therapeutic target for treatment of metastatic prostate cancers. The present study demonstrates that the topoisomerase I inhibitor camptothecin selectively inhibits androgen-responsive growth of prostate cancer cells. Camptothecin strikingly inhibited mutated and wild-type AR protein expression in LNCaP and PC-3/AR cells. This inhibition coincided with decreased androgen-mediated AR phosphorylation at Ser{sup 81} and reduced androgen-mediated AR transcriptional activity in a dose-dependent manner. Additionally, camptothecin disrupted the association between AR and heat shock protein 90 and impeded binding of the synthetic androgen [{sup 3}H]R1881 to AR in LNCaP cells. Camptothecin also blocked androgen-induced AR nuclear translocation, leading to downregulation of the AR target gene PSA. In addition to decreasing the intracellular and secreted prostate-specific antigen (PSA) levels, camptothecin markedly inhibited androgen-stimulated PSA promoter activity. Collectively, our data reveal that camptothecin not only serves as a traditional genotoxic agent but, by virtue of its ability to target and disrupt AR, may also be a novel candidate for the treatment of prostate cancer.

  15. Molecular processes leading to aberrant androgen receptor signaling and castration resistance in prostate cancer

    PubMed Central

    Hu, Rong; Denmeade, Samuel R; Luo, Jun

    2011-01-01

    Hormone therapies targeting androgen receptor signaling are the mainstay of treatment for patients with advanced prostate cancer. The length of clinical remission induced by hormone therapies varies substantially among treated patients. Why some patients progress rapidly after treatment while others benefit with prolonged remission is a question that remains unsolved. The androgen receptor signaling pathway is the key molecular determinant of castration resistance, and a key target for prostate cancer drug design. Recent advances in characterizing molecular processes leading to the development of castration-resistant prostate cancer, including the discovery of multiple androgen receptor splicing variants, offer opportunities for rational development of new clinical tools or approaches to predict, monitor or control/prevent prostate cancer progression in the castrate setting. PMID:21318111

  16. GATA2 facilitates steroid receptor coactivator recruitment to the androgen receptor complex

    PubMed Central

    He, Bin; Lanz, Rainer B.; Fiskus, Warren; Geng, Chuandong; Yi, Ping; Hartig, Sean M.; Rajapakshe, Kimal; Shou, John; Wei, Liping; Shah, Shrijal S.; Foley, Christopher; Chew, Sue Anne; Eedunuri, Vijay K.; Bedoya, Diego J.; Feng, Qin; Minami, Takashi; Mitsiades, Constantine S.; Frolov, Anna; Weigel, Nancy L.; Hilsenbeck, Susan G.; Rosen, Daniel G.; Palzkill, Timothy; Ittmann, Michael M.; Song, Yongcheng; Coarfa, Cristian; O’Malley, Bert W.; Mitsiades, Nicholas

    2014-01-01

    The androgen receptor (AR) is a key driver of prostate cancer (PC), even in the state of castration-resistant PC (CRPC) and frequently even after treatment with second-line hormonal therapies such as abiraterone and enzalutamide. The persistence of AR activity via both ligand-dependent and ligand-independent mechanisms (including constitutively active AR splice variants) highlights the unmet need for alternative approaches to block AR signaling in CRPC. We investigated the transcription factor GATA-binding protein 2 (GATA2) as a regulator of AR signaling and an actionable therapeutic target in PC. We demonstrate that GATA2 directly promotes expression of both full-length and splice-variant AR, resulting in a strong positive correlation between GATA2 and AR expression in both PC cell lines and patient specimens. Conversely, GATA2 expression is repressed by androgen and AR, suggesting a negative feedback regulatory loop that, upon androgen deprivation, derepresses GATA2 to contribute to AR overexpression in CRPC. Simultaneously, GATA2 is necessary for optimal transcriptional activity of both full-length and splice-variant AR. GATA2 colocalizes with AR and Forkhead box protein A1 on chromatin to enhance recruitment of steroid receptor coactivators and formation of the transcriptional holocomplex. In agreement with these important functions, high GATA2 expression and transcriptional activity predicted worse clinical outcome in PC patients. A GATA2 small molecule inhibitor suppressed the expression and transcriptional function of both full-length and splice-variant AR and exerted potent anticancer activity against PC cell lines. We propose pharmacological inhibition of GATA2 as a first-in-field approach to target AR expression and function and improve outcomes in CRPC. PMID:25489091

  17. A New Trick of an Old Molecule: Androgen Receptor Splice Variants Taking the Stage?!

    PubMed Central

    Guo, Zhiyong; Qiu, Yun

    2011-01-01

    Prostate cancer is the second leading cause of cancer-related death in American men. Although most prostate cancers are initially androgen-dependent and respond to androgen ablation therapy, majority of them eventually relapse and progress into incurable castration-resistant (or hormone refractory) prostate cancer. The underlying mechanisms are the focus of intensive investigation for development of more effective treatment. Mounting evidence from both clinical and basic research has demonstrated that the activity of the androgen receptor (AR) is still required for castration-resistant prostate cancer. Multiple mechanisms by which AR is re-activated under androgen-depleted conditions may be involved in the development of castration resistance. The recent identification of AR splicing variants may add another layer of complexity in AR biology. The present review summarizes recent progress in study of AR splicing variants in prostate cancer. PMID:21750650

  18. Accessory Scrotum With Perineal Lipoma: Pathologic Evaluation Including Androgen Receptor Expression

    PubMed Central

    Iida, Keitaro; Mizuno, Kentaro; Nishio, Hidenori; Moritoki, Yoshinobu; Kamisawa, Hideyuki; Kurokawa, Satoshi; Kohri, Kenjiro; Hayashi, Yutaro

    2014-01-01

    Accessory scrotum is an unusual developmental anomaly defined as additional scrotal tissue in addition to a normally developed scrotum. The accessory scrotum arises posterior to the normally located scrotum and does not contain a testis. We report a case of an 18-month-old boy with an accessory scrotum attached to a perineal lipoma. We resected both and determined histologically that they were of the same tissue as the scrotum, including the presence of androgen receptor expression. To the best of our knowledge, this is the first case to assess androgen receptor expression in an accessory scrotum using immunostaining. PMID:26958486

  19. High abundance androgen receptor in goldfish brain: characteristics and seasonal changes

    SciTech Connect

    Pasmanik, M.; Callard, G.V.

    1988-08-01

    Testosterone (T) exerts its actions in brain directly via androgen receptors or, after aromatization to estradiol, via estrogen receptors. Brain aromatase activity in teleost fish is 100-1000 times greater than in mammals and would be expected to significantly reduce the quantity of androgen available for receptor binding. Experiments were carried out on the goldfish Carassius auratus to determine if androgen receptors are present in teleost brain and whether their physicochemical properties reflect elevated aromatase. Cytosolic and nuclear extracts were assayed with the use of (/sup 3/H)T and charcoal, Sephadex LH-20, or DNA-cellulose chromatography to separate bound and free steroids. Binding activity was saturable and had an equally high affinity for T and 5 alpha-dihydrotestosterone. Although mibolerone was a relatively weak competitor, the putative teleost androgen 11-ketotestosterone, methyltrienolone (R1881), estradiol, progesterone, and cortisol were poor ligands. Characteristics that distinguish this receptor from a steroid-binding protein in goldfish serum are the presence of binding activity in both nuclear and cytosolic extracts, a low rate of ligand-receptor dissociation, electrophoretic mobility, sedimentation properties in low vs. high salt, and tissue distribution. DNA cellulose-adhering and nonadhering forms were detected, but these did not differ in other variables measured. Although goldfish androgen receptors resembled those of mammals in all important physicochemical characteristics, they were unusually abundant compared to levels in rat brain, but comparable to levels in prostate and other male sex hormone target organs. Moreover, there were seasonal variations in total receptors, with a peak at spawning (April) 4- to 5-fold higher than values in reproductively inactive fish.

  20. Drug Insight: testosterone and selective androgen receptor modulators as anabolic therapies for chronic illness and aging

    PubMed Central

    Bhasin, Shalender; Calof, Olga M; Storer, Thomas W; Lee, Martin L; Mazer, Norman A; Jasuja, Ravi; Montori, Victor M; Gao, Wenqing; Dalton, James T

    2007-01-01

    SUMMARY Several regulatory concerns have hindered development of androgens as anabolic therapies, despite unequivocal evidence that testosterone supplementation increases muscle mass and strength in men; it induces hypertrophy of type I and II muscle fibers, and increases myonuclear and satellite cell number. Androgens promote differentiation of mesenchymal multipotent cells into the myogenic lineage and inhibit their adipogenic differentiation, by facilitating association of androgen receptors with β-catenin and activating T-cell factor 4. Meta-analyses indicate that testosterone supplementation increases fat-free mass and muscle strength in HIV-positive men with weight loss, glucocorticoid-treated men, and older men with low or low-normal testosterone levels. The effects of testosterone on physical function and outcomes important to patients have not, however, been studied. In older men, increased hematocrit and increased risk of prostate biopsy and detection of prostate events are the most frequent, testosterone-related adverse events. Concerns about long-term risks have restrained enthusiasm for testosterone use as anabolic therapy. Selective androgen-receptor modulators that are preferentially anabolic and that spare the prostate hold promise as anabolic therapies. We need more studies to determine whether testosterone or selective androgen-receptor modulators can induce meaningful improvements in physical function and patient-important outcomes in patients with physical dysfunction associated with chronic illness or aging. PMID:16932274

  1. Cross-species sensitivity to a novel androgen receptor agonist of potential environmental concern, spironolactone.

    PubMed

    LaLone, Carlie A; Villeneuve, Daniel L; Cavallin, Jenna E; Kahl, Michael D; Durhan, Elizabeth J; Makynen, Elizabeth A; Jensen, Kathleen M; Stevens, Kyle E; Severson, Megan N; Blanksma, Chad A; Flynn, Kevin M; Hartig, Philip C; Woodard, Jonne S; Berninger, Jason P; Norberg-King, Teresa J; Johnson, Rodney D; Ankley, Gerald T

    2013-11-01

    Spironolactone is a pharmaceutical that in humans is used to treat conditions like hirsutism, various dermatologic afflictions, and female-pattern hair loss through antagonism of the androgen receptor. Although not routinely monitored in the environment, spironolactone has been detected downstream of a pharmaceutical manufacturer, indicating a potential for exposure of aquatic species. Furthermore, spironolactone has been reported to cause masculinization of female western mosquitofish, a response indicative of androgen receptor activation. Predictive methods to identify homologous proteins to the human and western mosquitofish androgen receptor suggest that vertebrates would be more susceptible to adverse effects mediated by chemicals like spironolactone that target the androgen receptor compared with invertebrate species that lack a relevant homolog. In addition, an adverse outcome pathway previously developed for activation of the androgen receptor suggests that androgen mimics can lead to reproductive toxicity in fish. To assess this, 21-d reproduction studies were conducted with 2 fish species, fathead minnow and Japanese medaka, and the invertebrate Daphnia magna. Spironolactone significantly reduced the fecundity of medaka and fathead minnows at 50 μg/L, whereas daphnia reproduction was not affected by concentrations as large as 500 μg/L. Phenotypic masculinization of females of both fish species was observed at 5 μg/L as evidenced by formation of tubercles in fathead minnows and papillary processes in Japanese medaka. Effects in fish occurred at concentrations below those reported in the environment. These results demonstrate how a priori knowledge of an adverse outcome pathway and the conservation of a key molecular target across vertebrates can be utilized to identify potential chemicals of concern in terms of monitoring and highlight potentially sensitive species and endpoints for testing. PMID:23881739

  2. Androgen action.

    PubMed

    Werner, Ralf; Holterhus, Paul-Martin

    2014-01-01

    Androgens are important for male sex development and physiology. Their actions are mediated by the androgen receptor (AR), a ligand-dependent nuclear transcription factor. The activity of the AR is controlled at multiple stages due to ligand binding and induced structural changes assisted by the foldosome, compartmentalization, recruitment of coregulators, posttranslational modifications and chromatin remodeling, leading to subsequent transcription of androgen-responsive target genes. Beside these short-term androgen actions, there is phenomenological and experimental evidence of long-term androgen programming in mammals and in the human during sensitive programming time windows, both pre- and postnatally. At the molecular level, research into androgen insensitivity syndrome has unmasked androgen programming at the transcriptome level, in genital fibroblasts and peripheral blood mononuclear cells, and at the epigenome level. Androgens are crucial for male sex development and physiology during embryogenesis, at puberty and in adult life. Testosterone and its more potent metabolite, dihydrotestosterone, which is converted from testosterone within the target cell by 5α-reductase II, are the main androgens involved in male sex differentiation. Androgen action is mediated by a single AR. The AR belongs to the nuclear receptor 3 group C, composed of the glucocorticoid receptor (NR3C1), mineralocorticoid receptor (NR3C2), progesterone receptor (NR3C3) and AR (NR3C4), and acts as a ligand-dependent transcription factor. PMID:25247642

  3. Epidermal growth factor receptor-dependent stimulation of amphiregulin expression in androgen-stimulated human prostate cancer cells.

    PubMed Central

    Sehgal, I; Bailey, J; Hitzemann, K; Pittelkow, M R; Maihle, N J

    1994-01-01

    Amphiregulin is a heparin-binding epidermal growth factor (EGF)-related peptide that binds to the EGF receptor (EGF-R) with high affinity. In this study, we report a role for amphiregulin in androgen-stimulated regulation of prostate cancer cell growth. Androgen is known to enhance EGF-R expression in the androgen-sensitive LNCaP human prostate carcinoma cell line, and it has been suggested that androgenic stimuli may regulate proliferation, in part, through autocrine mechanisms involving the EGF-R. In this study, we demonstrate that LNCaP cells express amphiregulin mRNA and peptide and that this expression is elevated by androgenic stimulation. We also show that ligand-dependent EGF-R stimulation induces amphiregulin expression and that androgenic effects on amphiregulin synthesis are mediated through this EGF-R pathway. Parallel studies using the estrogen-responsive breast carcinoma cell line, MCF-7, suggest that regulation of amphiregulin by estrogen may also be mediated via an EGF-R pathway. In addition, heparin treatment of LNCaP cells inhibits androgen-stimulated cell growth further suggesting that amphiregulin can mediate androgen-stimulated LNCaP proliferation. Together, these results implicate an androgen-regulated autocrine loop composed of amphiregulin and its receptor in prostate cancer cell growth and suggest that the mechanism of steroid hormone regulation of amphiregulin synthesis may occur through androgen upregulation of the EGF-R and subsequent receptor-dependent pathways. Images PMID:8049525

  4. A Novel Mutation in Human Androgen Receptor Gene Causing Partial Androgen Insensitivity Syndrome in a Patient Presenting with Gynecomastia at Puberty.

    PubMed

    Koçyiğit, Cemil; Sarıtaş, Serdar; Çatlı, Gönül; Onay, Hüseyin; Dündar, Bumin Nuri

    2016-06-01

    Partial androgen insensitivity syndrome (PAIS) typically presents with micropenis, perineoscrotal hypospadias, and a bifid scrotum with descending or undescending testes and gynecomastia at puberty. It is an X-linked recessive disorder resulting from mutations in the androgen receptor (AR) gene. However, AR gene mutations are found in less than a third of PAIS cases. A 16-year-old boy was admitted with complaints of gynecomastia and sparse facial hair. Family history revealed male relatives from maternal side with similar clinical phenotype. His external genitalia were phenotypically male with pubic hair Tanner stage IV, penoscrotal hypospadias, and a bifid scrotum with bilateral atrophic testes. He had elevated gonadotropins with a normal testosterone level. Chromosome analysis revealed a 46,XY karyotype. Due to the family history suggesting a disorder of X-linked trait, PAIS was considered and molecular analysis of AR gene was performed. DNA sequence analysis revealed a novel hemizygous mutation p.T576I (c.1727C>T) in the AR gene. The diagnosis of PAIS is based upon clinical phenotype and laboratory findings and can be confirmed by detection of a defect in the AR gene. An accurate approach including a detailed family history suggesting an X-linked trait is an important clue for a quick diagnosis. PMID:27087292

  5. Dose-dependent effects of small-molecule antagonists on the genomic landscape of androgen receptor binding

    PubMed Central

    2012-01-01

    Background The androgen receptor plays a critical role throughout the progression of prostate cancer and is an important drug target for this disease. While chromatin immunoprecipitation coupled with massively parallel sequencing (ChIP-Seq) is becoming an essential tool for studying transcription and chromatin modification factors, it has rarely been employed in the context of drug discovery. Results Here we report changes in the genome-wide AR binding landscape due to dose-dependent inhibition by drug-like small molecules using ChIP-Seq. Integration of sequence analysis, transcriptome profiling, cell viability assays and xenograft tumor growth inhibition studies enabled us to establish a direct cistrome-activity relationship for two novel potent AR antagonists. By selectively occupying the strongest binding sites, AR signaling remains active even when androgen levels are low, as is characteristic of first-line androgen ablation therapy. Coupled cistrome and transcriptome profiling upon small molecule antagonism led to the identification of a core set of AR direct effector genes that are most likely to mediate the activities of targeted agents: unbiased pathway mapping revealed that AR is a key modulator of steroid metabolism by forming a tightly controlled feedback loop with other nuclear receptor family members and this oncogenic effect can be relieved by antagonist treatment. Furthermore, we found that AR also has an extensive role in negative gene regulation, with estrogen (related) receptor likely mediating its function as a transcriptional repressor. Conclusions Our study provides a global and dynamic view of AR’s regulatory program upon antagonism, which may serve as a molecular basis for deciphering and developing AR therapeutics. PMID:22849360

  6. Steroid-induced androgen receptor–oestradiol receptor β–Src complex triggers prostate cancer cell proliferation

    PubMed Central

    Migliaccio, Antimo; Castoria, Gabriella; Di Domenico, Marina; de Falco, Antonietta; Bilancio, Antonio; Lombardi, Maria; Barone, Maria Vittoria; Ametrano, Donatella; Zannini, Maria Stella; Abbondanza, Ciro; Auricchio, Ferdinando

    2000-01-01

    Treatment of human prostate carcinoma-derived LNCaP cells with androgen or oestradiol triggers simultaneous association of androgen receptor and oestradiol receptor β with Src, activates the Src/Raf-1/Erk-2 pathway and stimulates cell proliferation. Surprisingly, either androgen or oestradiol action on each of these steps is inhibited by both anti-androgens and anti-oestrogens. Similar findings for oestradiol receptor α were observed in MCF-7 or T47D cells stimulated by either oestradiol or androgens. Microinjection of LNCaP, MCF-7 and T47D cells with SrcK– abolishes steroid-stimulated S-phase entry. Data from transfected Cos cells confirm and extend the findings from these cells. Hormone-stimulated Src interaction with the androgen receptor and oestradiol receptor α or β is detected using glutathione S-transferase fusion constructs. Src SH2 interacts with phosphotyrosine 537 of oestradiol receptor α and the Src SH3 domain with a proline-rich stretch of the androgen receptor. The role of this phosphotyrosine is stressed by its requirement for association of oestradiol receptor α with Src and consequent activation of Src in intact Cos cells. PMID:11032808

  7. Compartmentalization of androgen receptor protein–protein interactions in living cells

    PubMed Central

    van Royen, Martin E.; Cunha, Sónia M.; Brink, Maartje C.; Mattern, Karin A.; Nigg, Alex L.; Dubbink, Hendrikus J.; Verschure, Pernette J.; Trapman, Jan; Houtsmuller, Adriaan B.

    2007-01-01

    Steroid receptors regulate gene expression in a ligand-dependent manner by binding specific DNA sequences. Ligand binding also changes the conformation of the ligand binding domain (LBD), allowing interaction with coregulators via LxxLL motifs. Androgen receptors (ARs) preferentially interact with coregulators containing LxxLL-related FxxLF motifs. The AR is regulated at an extra level by interaction of an FQNLF motif in the N-terminal domain with the C-terminal LBD (N/C interaction). Although it is generally recognized that AR coregulator and N/C interactions are essential for transcription regulation, their spatiotemporal organization is largely unknown. We performed simultaneous fluorescence resonance energy transfer and fluorescence redistribution after photobleaching measurements in living cells expressing ARs double tagged with yellow and cyan fluorescent proteins. We provide evidence that AR N/C interactions occur predominantly when ARs are mobile, possibly to prevent unfavorable or untimely cofactor interactions. N/C interactions are largely lost when AR transiently binds to DNA, predominantly in foci partly overlapping transcription sites. AR coregulator interactions occur preferentially when ARs are bound to DNA. PMID:17420290

  8. Radiation-inactivation size of transformed and non-transformed androgen receptors.

    PubMed Central

    Turcotte, G; Beauregard, G; Potier, M; Chevalier, S

    1991-01-01

    The nucleic acid sequence of the androgen receptor (AR) gene predicts that the protein structure possesses DNA- and steroid-binding domains that show high degrees of sequence similarity with those of other steroid receptors. Since the steroid-binding domain of the AR corresponds to a 30 kDa portion of the protein, and the AR structure may be monomeric or hetero-oligomeric depending on its transformation state, we have herein determined the AR radiation-inactivation size (RIS) in relation to the molecular structure whose binding activity toward methyltrienolone (R1881) is abolished by a radiation 'hit'. Soluble fractions from whole canine prostatic tissue were used as a source of non-transformed AR. The AR transformation was induced by the addition of 0.6 M-KCl, and these preparations were used together with high-salt nuclear extracts as a source of transformed AR. To maximize the binding activity, molybdate and dithiothreitol were included during AR extraction. Receptor transformation was verified by modifications of both the sedimentation coefficients (from 7.5 S to 4.1 S on sucrose gradients) and molecular masses (from 260 kDa to 115 kDa by gel filtration). The RIS values of the non-transformed and transformed ARs were not statistically different: 92 +/- 19 kDa and 110 +/- 25 kDa respectively. In addition, the inactivation of AR binding activity by radiation was attributed to a loss of binding sites, with no significant change in the Kd. When benzoic acid, a free-electron scavenger, was added together with dithiothreitol before and after irradiation, no change in the RIS value was observed. Thus, in the canine prostate, the RIS value of the AR represents the monomeric protein, independently of its association with other proteins, and this value corresponds to that predicted by cloning studies and photoaffinity-labelling of AR. PMID:2018483

  9. Beyond aggression: Androgen-receptor blockade modulates social interaction in wild meerkats.

    PubMed

    delBarco-Trillo, Javier; Greene, Lydia K; Goncalves, Ines Braga; Fenkes, Miriam; Wisse, Jillian H; Drewe, Julian A; Manser, Marta B; Clutton-Brock, Tim; Drea, Christine M

    2016-02-01

    In male vertebrates, androgens are inextricably linked to reproduction, social dominance, and aggression, often at the cost of paternal investment or prosociality. Testosterone is invoked to explain rank-related reproductive differences, but its role within a status class, particularly among subordinates, is underappreciated. Recent evidence, especially for monogamous and cooperatively breeding species, suggests broader androgenic mediation of adult social interaction. We explored the actions of androgens in subordinate, male members of a cooperatively breeding species, the meerkat (Suricata suricatta). Although male meerkats show no rank-related testosterone differences, subordinate helpers rarely reproduce. We blocked androgen receptors, in the field, by treating subordinate males with the antiandrogen, flutamide. We monitored androgen concentrations (via baseline serum and time-sequential fecal sampling) and recorded behavior within their groups (via focal observation). Relative to controls, flutamide-treated animals initiated less and received more high-intensity aggression (biting, threatening, feeding competition), engaged in more prosocial behavior (social sniffing, grooming, huddling), and less frequently initiated play or assumed a 'dominant' role during play, revealing significant androgenic effects across a broad range of social behavior. By contrast, guarding or vigilance and measures of olfactory and vocal communication in subordinate males appeared unaffected by flutamide treatment. Thus, androgens in male meerkat helpers are aligned with the traditional trade-off between promoting reproductive and aggressive behavior at a cost to affiliation. Our findings, based on rare endocrine manipulation in wild mammals, show a more pervasive role for androgens in adult social behavior than is often recognized, with possible relevance for understanding tradeoffs in cooperative systems. PMID:26545817

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

    EPA Science Inventory

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

  11. A Time-course Study with the Androgen Receptor Antagonist Flutamide in Fish

    EPA Science Inventory

    Flutamide, a drug registered to treat some types of prostate cancer in humans, has been used for many years as a model androgen receptor (AR) antagonist in studies aimed at characterizing disruption of the vertebrate hypothalamic-pituitary-gonadal (HPG) axis. Various studies hav...

  12. Cross species sensitivity to a novel androgen receptor agonist of potential environmental concern, spironolactone

    EPA Science Inventory

    Spironolactone (SPL) is a pharmaceutical that is used in humans as an androgen receptor (AR) antagonist to treat conditions like hirsutism, various dermatologic afflictions, and female pattern hair loss, in addition to its common usage as a diuretic to treat hypertension. Althoug...

  13. Stilbenes inhibit androgen receptor expression in 22Rv1 castrate-resistant prostate cancer cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Androgen receptor (AR) signaling plays an important role in the development and progression of prostate cancer (PCa). Importantly, AR continues to be expressed in advanced stages of castrate-resistant PCa (CRPC), where it can have ligand- independent activity. Identification of naturally occurring s...

  14. AOP description: Androgen receptor agonism leading to reproductive dysfunction (in fish)

    EPA Science Inventory

    This adverse outcome pathway details the linkage between binding and activation of androgen receptor as a nuclear transcription factor in females and the adverse effect of reduced cumulative fecundity in repeat-spawning fish species. Cumulative fecundity is the most apical endpoi...

  15. [Epigenetic Regulation by Androgen Receptor and Possible Function in Bone Metabolism].

    PubMed

    Imai, Yuuki

    2016-07-01

    Epigenetic regulation underlying AR(Androgen receptor)mediated transcription is important component to understand pathophysiology of osteoporosis in men. In this commentary, it is reported recent findings related to epigenetic landscape governed by AR and its cofactors including lysine-specific demethylase 1 (LSD1), and possible implication for bone metabolism. PMID:27346313

  16. Testosterone and Androgen Receptor Sensitivity in Relation to Hyperactivity Symptoms in Boys with Autism Spectrum Disorders

    PubMed Central

    2016-01-01

    Introduction Autism spectrum disorders (ASD) and hyperactivity symptoms exhibit an incidence that is male-biased. Thus androgen activity can be considered a plausible biological risk factor for these disorders. However, there is insufficient information about the association between increased androgen activity and hyperactivity symptoms in children with ASD. Methods In the present study, the relationship between parameters of androgenicity (plasmatic testosterone levels and androgen receptor sensitivity) and hyperactivity in 60 boys (age 3–15) with ASD is investigated. Given well documented differences in parent and trained examiners ratings of symptom severity, we employed a standardized parent`s questionnaire (Nisonger Child Behavior Rating Form) as well as a direct examiner`s rating (Autism diagnostic observation schedule) for assessment of hyperactivity symptoms. Results Although it was found there was no significant association between actual plasmatic testosterone levels and hyperactivity symptoms, the number of CAG triplets was significantly negatively correlated with hyperactivity symptoms (R2 = 0.118, p = 0.007) in the sample, indicating increased androgen receptor sensitivity in association with hyperactivity symptoms. Direct trained examiner´s assessment appeared to be a relevant method for evaluating of behavioral problems in the investigation of biological underpinnings of these problems in our study. Conclusions A potential ASD subtype characterized by increased rates of hyperactivity symptoms might have distinct etiopathogenesis and require a specific behavioral and pharmacological approach. We propose an increase of androgen receptor sensitivity as a biomarker for a specific ASD subtype accompanied with hyperactivity symptoms. Findings are discussed in terms of their implications for practice and future research. PMID:26910733

  17. Selectivity in progesterone and androgen receptor binding of progestagens used in oral contraceptives

    SciTech Connect

    Kloosterboer, H.J.; Vonk-Noordegraaf, C.A.; Turpijn, E.W.

    1988-09-01

    The relative binding affinities (RBAs) of four progestational compounds (norethisterone, levonorgestrel, 3-keto-desogestrel and gestodene) for the human progesterone and androgen receptors were measured in MCF-7 cytosol and intact MCF-7 cells. For the binding to the progesterone receptor, both Org 2058 and Org 3236 (or 3-keto-desogestrel) were used as labelled ligands. The following ranking (low to high) for the RBA of the nuclear (intact cells) progesterone receptor irrespective of the ligand used is found: norethisterone much less than levonorgestrel less than 3-keto-destogestrel less than gestodene. The difference between the various progestagens is significant with the exception of that between 3-keto-desogestrel and gestodene, when Org 2058 is used as ligand. For the cytosolic progesterone receptor, the same order is found with the exception that similar RBAs are found for gestodene and 3-keto-desogestrel. The four progestagens clearly differ with respect to binding to the androgen receptor using dihydrotestosterone as labelled ligand in intact cells; the ranking (low to high) is: norethisterone less than 3 keto-desogestrel less than levonorgestrel and gestodene. The difference between 3-keto-desogestrel and levonorgestrel or gestodene is significant. The selectivity indices (ratio of the mean RBA for the progesterone receptor to that of androgen receptor) in intact cells are significantly higher for 3-keto-desogestrel and gestodene than for levonorgestrel and norethisterone. From these results we conclude that the introduction of the 18-methyl in norethisterone (levonorgestel) increases both the binding to the progesterone and androgen receptors.

  18. Androgen receptors beyond prostate cancer: an old marker as a new target

    PubMed Central

    Kurzrock, Razelle

    2015-01-01

    Androgen receptors (ARs) play a critical role in the development of prostate cancer. Targeting ARs results in important salutary effects in this malignancy. Despite mounting evidence that ARs also participate in the pathogenesis and/or progression of diverse tumors, exploring the impact of hormonal manipulation of these receptors has not been widely pursued beyond prostate cancer. This review describes patterns of AR expression in a spectrum of cancers, and the potential to exploit this knowledge in the clinical therapeutic setting. PMID:25595907

  19. Distribution of androgen receptor in microdissected brain areas of the female baboon (Papio cynocephalus).

    PubMed

    Handa, R J; Roselli, C E; Resko, J A

    1988-03-29

    We measured androgen receptors in the brain and pituitary of 4 female baboons (Papio cynocephalus) by the in vitro binding of methyltrienolone (R1881) to cytosols from 17 brain subregions as well as anterior and posterior pituitaries. High levels of AR were detected in anterior (22.1 +/- 7.1 (S.E.M.) fmol/mg protein) and posterior pituitary (12.6 +/- 3.3 fmol/mg protein). In brain tissue, the highest androgen receptor levels were found in the infundibular nucleus/median eminence (9.4 +/- 2.3 fmol/mg protein), ventromedial nucleus (6.3 +/- 1.7 fmol/mg protein) and periventricular area (4.9 +/- 1.3 fmol/mg protein). Saturation analysis of anterior pituitary and brain tissue (pool of hypothalamic, preoptic area, amygdala and septum remaining after microdissection of brain nuclei) showed that [3H]R1881 binds to the androgen receptor with high specificity and affinity (Kd = 1.25 x 10(-10) M, 0.45 x 10(-10) M, in anterior pituitary and HPA cytosol, respectively). Serum testosterone levels were low in all animals (0.59 +/- 0.26 ng/ml). With these data we described the quantitative distribution of androgen receptor in the pituitary and in specific brain nuclei in a species of nonhuman primate. The distribution is similar in many respects to that described in the male rat and the data suggest a conservation of androgen receptor distribution across species. PMID:3259151

  20. Androgen receptor blockade using flutamide skewed sex ratio of litters in mice

    PubMed Central

    Gharagozlou, Faramarz; Youssefi, Reza; Vojgani, Mehdi; Akbarinejad, Vahid; Rafiee, Ghazaleh

    2016-01-01

    Maternal testosterone has been indicated to affect sex ratio of offspring. The present study was conducted to elucidate the role of androgen receptor in this regard by blockade of androgen receptor using flutamide in female mice. Mice were randomly assigned to two experimental groups. Mice in the control (n = 20) and treatment (n = 20) groups received 8 IU equine chorionic gonadotropin (eCG) followed by human chorionic gonadotropin (hCG) injection (8 IU) 47 hr later. In addition, mice in the control and treatment groups received four injections of ethanol-saline vehicle and flutamide solution (2.50 mg), respectively, started from 1 hr before eCG injection until hCG injection at 12-hr intervals. Conception rate was not different between the treatment (18/20: 90.00%) and control (19/20: 95.00%) groups (p > 0.05). Litter size was higher in the treatment (8.22 ± 0.26) than control (7.21 ± 0.28) group (p < 0.05). Male sex ratio was lower in the flutamide-treated mice (67/148: 45.30%) as compared with the untreated ones (80/137: 58.40%; odds ratio = 1.69; p < 0.05). In conclusion, the results showed that androgen receptor blockade could skew sex ratio of offspring toward females implying that the effect of testosterone on sex ratio might be through binding to androgen receptor. In addition, the blockade of androgen receptor using flutamide appeared to enhance litter size. PMID:27482363

  1. Androgen receptor blockade using flutamide skewed sex ratio of litters in mice.

    PubMed

    Gharagozlou, Faramarz; Youssefi, Reza; Vojgani, Mehdi; Akbarinejad, Vahid; Rafiee, Ghazaleh

    2016-01-01

    Maternal testosterone has been indicated to affect sex ratio of offspring. The present study was conducted to elucidate the role of androgen receptor in this regard by blockade of androgen receptor using flutamide in female mice. Mice were randomly assigned to two experimental groups. Mice in the control (n = 20) and treatment (n = 20) groups received 8 IU equine chorionic gonadotropin (eCG) followed by human chorionic gonadotropin (hCG) injection (8 IU) 47 hr later. In addition, mice in the control and treatment groups received four injections of ethanol-saline vehicle and flutamide solution (2.50 mg), respectively, started from 1 hr before eCG injection until hCG injection at 12-hr intervals. Conception rate was not different between the treatment (18/20: 90.00%) and control (19/20: 95.00%) groups (p > 0.05). Litter size was higher in the treatment (8.22 ± 0.26) than control (7.21 ± 0.28) group (p < 0.05). Male sex ratio was lower in the flutamide-treated mice (67/148: 45.30%) as compared with the untreated ones (80/137: 58.40%; odds ratio = 1.69; p < 0.05). In conclusion, the results showed that androgen receptor blockade could skew sex ratio of offspring toward females implying that the effect of testosterone on sex ratio might be through binding to androgen receptor. In addition, the blockade of androgen receptor using flutamide appeared to enhance litter size. PMID:27482363

  2. Androgen receptors and experimental bone loss - an in vivo and in vitro study.

    PubMed

    Steffens, Joao Paulo; Coimbra, Leila Santana; Rossa, Carlos; Kantarci, Alpdogan; Van Dyke, Thomas E; Spolidorio, Luis Carlos

    2015-12-01

    Testosterone is a sex hormone that exhibits many functions beyond reproduction; one such function is the regulation of bone metabolism. The role played by androgen receptors during testosterone-mediated biological processes associated with bone metabolism is largely unknown. This study aims to use a periodontal disease model in vivo in order to assess the involvement of androgen receptors on microbial-induced inflammation and alveolar bone resorption in experimental bone loss. The impact of hormone deprivation was tested through both orchiectomy and chemical blockage of androgen receptor using flutamide (FLU). Additionally, the direct effect of exogenous testosterone, and the role of the androgen receptor, on osteoclastogenesis were investigated. Thirty male adult rats (n=10/group) were subjected to: 1-orchiectomy (OCX); 2-OCX sham surgery; or 3-OCX sham surgery plus FLU, four weeks before the induction of experimental bone loss. Ten OCX sham-operated rats were not subjected to experimental bone loss and served as healthy controls. The rats were euthanized two weeks later, so as to assess bone resorption and the production of inflammatory cytokines in the gingival tissue and serum. In order to study the in vitro impact of testosterone, osteoclasts were differentiated from RAW264.7 cells and testosterone was added at increasing concentrations. Both OCX and FLU increased bone resorption, but OCX alone was observed to increase osteoclast count. IL-1β production was increased only in the gingival tissue of OCX animals, whereas FLU-treated animals presented a decreased expression of IL-6. Testosterone reduced the osteoclast formation in a dose-dependent manner, and significantly impacted the production of TNF-α; FLU partially reversed these actions. When taken together, our results indicate that testosterone modulates experimental bone loss, and that this action is mediated, at least in part, via the androgen receptor. PMID:26450018

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

    PubMed

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

    2014-08-01

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

  4. CLONING, EXPRESSION AND CHARACTERIZATION OF THE ANDROGEN RECEPTOR AND ISOLATION OF ESTROGEN RECEPTOR ALPHA FROM THE FATHEAD MINNOW (PIMEPHALES PROMELAS)

    EPA Science Inventory

    In vitro screening assays designed to identify hormone mimics or antagonists, including those recommended for use in the EPA's Tier 1 screening battery, typically use mammalian estrogen (ER) and androgen receptors (AR) such as rat or human. Although we know that the amino acid s...

  5. Anabolic-androgenic steroid interaction with rat androgen receptor in vivo and in vitro: a comparative study.

    PubMed

    Feldkoren, Boris I; Andersson, Stefan

    2005-04-01

    Anabolic steroids are synthetic derivatives of testosterone and are characterized by their ability to cause nitrogen retention and positive protein metabolism, thereby leading to increased protein synthesis and muscle mass. There are disagreements in the literature in regards to the interaction of anabolic steroids with the androgen receptor (AR) as revealed by competitive ligand binding assays in vitro using cytosolic preparations from prostate and skeletal muscle. By use of tissue extracts, it has been shown that some anabolic steroids have binding affinities for the AR that are higher than that of the natural androgen testosterone, while others such as stanozolol and methanedienone have significantly lower affinities as compared with testosterone. In this study we show that stanozolol and methanedienone are low affinity ligands of the rat recombinant AR as revealed by a ligand binding assay in vitro, however, based on a cell-based AR-dependent transactivation assay, they are potent activators of the AR. We also show that a single injection of stanozolol and methanedienone causes a rapid cytosolic depletion of AR in rat skeletal muscle. Based on these results, we conclude that anabolic steroids with low affinity to AR in vitro, can in fact in vivo act on the AR to cause biological responses. PMID:15876413

  6. [Transdisciplinary Approach for Sarcopenia. Appication of selective androgen receptor modulator to the therapy of sarcopenia].

    PubMed

    Yanase, Toshihiko; Tanabe, Makito; Nomiyama, Takashi

    2014-10-01

    The research to develop a drug, so called selective androgen receptor modulator (SARM) , which shows beneficial androgenic action on bone and muscle, but hardly possesses the stimulatory action on prostate has been making a progress. However, no drug is available in the market at present. Most of such drugs are developed, aiming at the application to age-related muscle reduction (sarcopenia) and osteoporosis. Recently, in a clinical trial of SARM (enbosarm) administration to healthy elderly men, a promising data showing the increase of lean body mass and physical function has been reported. Future clinical applications of SARMs are expected. PMID:25266096

  7. Blockade of androgen receptor in the medial amygdala inhibits noncontact erections in male rats.

    PubMed

    Bialy, Michal; Nikolaev-Diak, Anna; Kalata, Urszula; Nikolaev, Evgeni

    2011-06-01

    Our previous work demonstrated that androgens in the medial amygdala (MeA) of castrated male rats maintained noncontact erections (NCEs), which occur during exposure to an inaccessible receptive female, for one week after implantation. The present experiments investigated the effects of implantation into the MeA of either flutamide (F), a blocker of androgen receptors, or of 1,4,6-androstatrien-3,17-dione (ATD), which blocks aromatization of testosterone. One day after implantation of F, fewer males displayed NCEs, and had longer latencies to the first NCE and fewer NCEs, and spent less total time in genital grooming, compared to the control group. ATD had only weak facilitative effects on some measures of NCEs. These results suggest that androgen receptors in the MeA play a major role in the regulation of NCEs and that the MeA is one of the neuronal structures that regulate male sexual arousal. Furthermore, it is sensitive to relatively fast changes in the level of androgen receptors stimulation. PMID:21315100

  8. Equol inhibits prostate cancer growth through degradation of androgen receptor by S-phase kinase-associated protein 2.

    PubMed

    Itsumi, Momoe; Shiota, Masaki; Takeuchi, Ario; Kashiwagi, Eiji; Inokuchi, Junichi; Tatsugami, Katsunori; Kajioka, Shunichi; Uchiumi, Takeshi; Naito, Seiji; Eto, Masatoshi; Yokomizo, Akira

    2016-07-01

    Chemopreventive and potential therapeutic effects of soy isoflavones have been shown to be effective in numerous preclinical studies as well as clinical studies in prostate cancer. Although the inhibition of androgen receptor signaling has been supposed as one mechanism underlying their effects, the precise mechanism of androgen receptor inhibition remains unclear. Thus, this study aimed to clarify their mechanism. Among soy isoflavones, equol suppressed androgen receptor as well as prostate-specific antigen expression most potently in androgen-dependent LNCaP cells. However, the inhibitory effect on androgen receptor expression and activity was less prominent in castration-resistant CxR and 22Rv1 cells. Consistently, cell proliferation was suppressed and cellular apoptosis was induced by equol in LNCaP cells, but less so in CxR and 22Rv1 cells. We revealed that the proteasome pathway through S-phase kinase-associated protein 2 (Skp2) was responsible for androgen receptor suppression. Taken together, soy isoflavones, especially equol, appear to be promising as chemopreventive and therapeutic agents for prostate cancer based on the fact that equol augments Skp2-mediated androgen receptor degradation. Moreover, because Skp2 expression was indicated to be crucial for the effect of soy isoflavones, soy isoflavones may be applicable for precancerous and cancerous prostates. PMID:27088761

  9. Restoration of the cellular secretory milieu overrides androgen dependence of in vivo generated castration resistant prostate cancer cells overexpressing the androgen receptor.

    PubMed

    Patki, Mugdha; Huang, Yanfang; Ratnam, Manohar

    2016-07-22

    It is believed that growth of castration resistant prostate cancer (CRPC) cells is enabled by sensitization to minimal residual post-castrate androgen due to overexpression of the androgen receptor (AR). Evidence is derived from androgen-induced colony formation in the absence of cell-secreted factors or from studies involving forced AR overexpression in hormone-dependent cells. On the other hand, standard cell line models established from CRPC patient tumors (e.g., LNCaP and VCaP) are hormone-dependent and require selection pressure in castrated mice to re-emerge as CRPC cells and the resulting tumors then tend to be insensitive to the androgen antagonist enzalutamide. Therefore, we examined established CRPC model cells produced by castration of mice bearing hormone-dependent cell line xenografts including CRPC cells overexpressing full-length AR (C4-2) or co-expressing wtAR and splice-variant AR-V7 that is incapable of ligand binding (22Rv1). In standard colony formation assays, C4-2 cells were shown to be androgen-dependent and sensitive to enzalutamide whereas 22Rv1 cells were incapable of colony formation under identical conditions. However, both C4-2 and 22Rv1 cells formed colonies in conditioned media derived from the same cells or from HEK293 fibroblasts that were proven to lack androgenic activity. This effect was (i) not enhanced by androgen, (ii) insensitive to enzalutamide, (iii) dependent on AR (in C4-2) and on AR-V7 and wtAR (in 22Rv1) and (iv) sensitive to inhibitors of several signaling pathways, similar to androgen-stimulation. Therefore, during progression to CRPC in vivo, coordinate cellular changes accompanying overexpression of AR may enable cooperation between hormone-independent activity of AR and actions of cellular secretory factors to completely override androgen-dependence and sensitivity to drugs targeting hormonal factors. PMID:27179779

  10. AB46. Screening and identification for the target genes of androgen receptor in mouse Sertoli cells

    PubMed Central

    Gui, Yaoting; Mou, Lisha; Zhang, Qiaoxia; Yang, Lihua; Wang, Yadong; Cai, Zhiming

    2014-01-01

    Androgen and androgen receptor (AR) play important roles in spermatogenesis, yet detailed androgen/AR signals in Sertoli cells remain unclear. To identify AR target genes in Sertoli cells, we analyzed the gene expression profiles of testis between mice lacking AR in Sertoli cells (S-AR) and their littermate wild-type (WT) mice. Digital gene expression analysis identified 2,276 genes downregulated and 2,865 genes upregulated in the S-AR mice testis compared to WT ones. To further nail down the difference within Sertoli cells, we first constructed Sertoli cell line TM4 with stably transfected AR (named as TM4/AR) and found androgens failed to transactivate AR in Sertoli TM4 and TM4/AR cells. Interestingly, additional transient transfection of AR-cDNA resulted in significant androgen responsiveness with TM4/AR cells showing ten times more androgen sensitivity than TM4 cells. In the condition where maximal androgen response was demonstrated, we then analyzed gene expression and found the expression levels of 2313 genes were changed more than twofold by transient transfection of AR-cDNA in the presence of testosterone. Among these genes, 603 androgen-/AR-regulated genes, including 164 up-regulated and 439 down-regulated, were found in both S-AR mice testis and TM4/AR cells. Ubiquitin-conjugating enzyme E2B (Ube2b) is one of the regulated genes from the digital gene expression analysis. The expression of UBE2B was decreased in the testes of the S-AR mice analyzed by quantitative RT-PCR (qRT-PCR) and immunofluorescence. The up-regulation of Ube2b gene by testosterone was further demonstrated by Western blot and qRT-PCR in TM4 cells. Moreover, luciferase assay, electrophoretic mobility shift assay, and chromatin immunoprecipitation assay validated that the ligand-bound AR activated Ube2b transcription via directly binding to the androgen-responsive element of the Ube2b promoter. In vitro analyses showed that testosterone increased UBE2B expression and activated H2A

  11. Androgen Receptor as a Driver of Therapeutic Resistance in Advanced Prostate Cancer

    PubMed Central

    Kahn, Barbara; Collazo, Joanne; Kyprianou, Natasha

    2014-01-01

    The role of the androgen receptor (AR) signaling axis in the progression of prostate cancer is a cornerstone to our understanding of the molecular mechanisms causing castration-resistant prostate cancer (CRPC). Resistance of advanced prostate cancer to available treatment options makes it a clinical challenge that results in approximately 30,000 deaths of American men every year. Since the historic discovery by Dr. Huggins more than 70 years ago, androgen deprivation therapy (ADT) has been the principal treatment for advanced prostate cancer. Initially, ADT induces apoptosis of androgen-dependent prostate cancer epithelial cells and regression of androgen-dependent tumors. However, the majority of patients with advanced prostate cancer progress and become refractory to ADT due to emergence of androgen-independent prostate cancer cells driven by aberrant AR activation. Microtubule-targeting agents such as taxanes, docetaxel and paclitaxel, have enjoyed success in the treatment of metastatic prostate cancer; although new, recently designed mitosis-specific agents, such as the polo-kinase and kinesin-inhibitors, have yielded clinically disappointing results. Docetaxel, as a first-line chemotherapy, improves prostate cancer patient survival by months, but tumor resistance to these therapeutic agents inevitably develops. On a molecular level, progression to CRPC is characterized by aberrant AR expression, de novo intraprostatic androgen production, and cross talk with other oncogenic pathways. Emerging evidence suggests that reactivation of epithelial-mesenchymal-transition (EMT) processes may facilitate the development of not only prostate cancer but also prostate cancer metastases. EMT is characterized by gain of mesenchymal characteristics and invasiveness accompanied by loss of cell polarity, with an increasing number of studies focusing on the direct involvement of androgen-AR signaling axis in EMT, tumor progression, and therapeutic resistance. In this article, we

  12. Mental rotation in intellectually gifted boys is affected by the androgen receptor CAG repeat polymorphism.

    PubMed

    Durdiaková, Jaroslava; Lakatošová, Silvia; Kubranská, Aneta; Laznibatová, Jolana; Ficek, Andrej; Ostatníková, Daniela; Celec, Peter

    2013-08-01

    Testosterone was shown to organize brain and modulate cognitive functions. It is currently unknown whether mental rotation is also associated with prenatal testosterone exposure and testosterone-related genetic polymorphisms. The aim of our study was to analyze associations between mental rotation performance, the actual testosterone levels, the prenatal testosterone level (expressed as 2D:4D ratio) and the androgen receptor CAG repeat polymorphism in intellectually gifted boys. One hundred forty-seven boys aged 10-18 years with IQ>130 were enrolled. Saliva samples were collected and used for ELISA of actual levels of salivary testosterone. The 2D:4D finger length ratio as an indicator of prenatal testosterone was measured on both hands and averaged. Amthauer mental rotation test was used for the assessment of this spatial ability. The CAG repeat polymorphism in the androgen receptor gene was analyzed using PCR and capillary electrophoresis. Linear regression revealed that 2D:4D finger length ratio and the number of CAG repeats in the androgen receptor gene were associated with mental rotation. Actual levels of testosterone did not correlate significantly with mental rotation. Multivariate analysis of covariance revealed that after adjustment of age as a confounding variable, only the effect of the genetic polymorphism was significant. The results are in line with our previous genetic analysis of intellectually gifted boys showing the importance of CAG repeat polymorphism in the androgen receptor gene. Details of the interactions between androgen signaling, testosterone levels and its metabolism especially during the prenatal development of brain function remain to be elucidated. PMID:23727571

  13. Targeting the androgen receptor in prostate and breast cancer – several new agents in development

    PubMed Central

    Proverbs-Singh, Tracy; Feldman, Jarett L.; Morris, Michael J.; Autio, Karen A.; Traina, Tiffany A.

    2016-01-01

    Prostate cancer and breast cancer share similarities as hormone-sensitive cancers with a wide heterogeneity of both phenotype and biology. The androgen receptor (AR) is a hormone receptor involved in both benign and malignant processes. Targeting androgen synthesis and the AR pathway has been and remains central to prostate cancer therapy. Recently, there is increased interest in the role of the AR in breast cancer development and growth, with data suggesting AR co-expression with estrogen, progesterone and human epidermal growth factor receptors, across all intrinsic subtypes of breast cancer. Targeting the AR axis is an evolving field with novel therapies in development which may ultimately be applicable for both tumor types. In this review, we offer an overview of available agents which target the AR axis in both prostate and breast cancer and provide insight into the novel drugs in development for targeting this signaling pathway. PMID:25722318

  14. Green tea polyphenol EGCG blunts androgen receptor function in prostate cancer

    PubMed Central

    Siddiqui, Imtiaz A.; Asim, Mohammad; Hafeez, Bilal B.; Adhami, Vaqar M.; Tarapore, Rohinton S.; Mukhtar, Hasan

    2011-01-01

    Androgen deprivation therapy is the major treatment for advanced prostate cancer (PCa). However, it is a temporary remission, and the patients almost inevitably develop hormone refractory prostate cancer (HRPC). HRPC is almost incurable, although most HRPC cells still express androgen receptor (AR) and depend on the AR for growth, making AR a prime drug target. Here, we provide evidence that epigallocatechin-3-gallate (EGCG), the major polyphenol in green tea, is a direct antagonist of androgen action. In silico modeling and FRET-based competition assay showed that EGCG physically interacts with the ligand-binding domain of AR by replacing a high-affinity labeled ligand (IC50 0.4 μM). The functional consequence of this interaction was a decrease in AR-mediated transcriptional activation, which was due to EGCG mediated inhibition of interdomain N-C termini interaction of AR. Treatment with EGCG also repressed the transcriptional activation by a hotspot mutant AR (T877A) expressed ectopically as well as the endogenous AR mutant. As the physiological consequence of AR antagonism, EGCG repressed R1881-induced PCa cell growth. In a xenograft model, EGCG was found to inhibit AR nuclear translocation and protein expression. We also observed a significant down-regulation of androgen-regulated miRNA-21 and up-regulation of a tumor suppressor, miRNA-330, in tumors of mice treated with EGCG. Taken together, we provide evidence that EGCG functionally antagonizes androgen action at multiple levels, resulting in inhibition of PCa growth.—Siddiqui, I. A., Asim, M., Hafeez, B. B., Adhami, V. M., Tarapore, R. S., Mukhtar, H. Green tea polyphenol EGCG blunts androgen receptor function in prostate cancer. PMID:21177307

  15. A novel selective androgen receptor modulator, NEP28, is efficacious in muscle and brain without serious side effects on prostate.

    PubMed

    Akita, Kazumasa; Harada, Koichiro; Ichihara, Junji; Takata, Naoko; Takahashi, Yasuhiko; Saito, Koichi

    2013-11-15

    Age-related androgen depletion is known to be a risk factor for various diseases, such as osteoporosis and sarcopenia. Furthermore, recent studies have demonstrated that age-related androgen depletion results in accumulation of β-amyloid protein and thereby acts as a risk factor for the development of Alzheimer's disease. Supplemental androgen therapy has been shown to be efficacious in treating osteoporosis and sarcopenia. In addition, studies in animals have demonstrated that androgens can play a protective role against Alzheimer's disease. However, androgen therapy is not used routinely for these indications, because of side effects. Selective androgen receptor modulators (SARMs) are a new class of compounds. SARMs maintain the beneficial effects of androgens on bone and muscle while reducing unwanted side effects. NEP28 is a new SARM exhibiting high selectivity for androgen receptor. To investigate the pharmacological effects of NEP28, we compared the effects on muscle, prostate, and brain with mice that were androgen depleted by orchidectomy and then treated with either placebo, NEP28, dihydrotestosterone, or methyltestosterone. We demonstrated that NEP28 showed tissue-selective effect equivalent to or higher than existing SARMs. In addition, the administration of NEP28 increased the activity of neprilysin, a known Aβ-degrading enzyme. These results indicate that SARM is efficacious for the treatment of not only osteoporosis and sarcopenia, but also Alzheimer's disease. PMID:24177288

  16. Androgen receptor (CAG)n polymorphisms and breast cancer risk in a Han Chinese population.

    PubMed

    Dang, J; Peng, L; Zhong, H J; Huo, Z H

    2015-01-01

    The androgen receptor (AR) is involved in the differentiation and growth of breast cancer. Genetic markers in the AR gene have a plausible role in modulating the risk of breast cancer. In this study, we studied the association of breast cancer and the trinucleotide repeat polymorphism (CAG)n in exon 1 of the AR gene in 202 patients with breast cancer and 183 healthy controls from our hospital (Yinchuan, China). Repeat lengths were determined by fluorescent DNA fragment analysis using the ABI GeneScan software and DNA sequencing. We detected 17 short tandem repeat alleles in exon 1 in the Han population of Ningxia Province, China. The CAG repeat number ranged from 14 to 31 and the frequency ranged from 0.339 to 24.460%. Generally, (CAG)n repeat lengths <22 were classified as short (S), and those >22 were classified as long (L). No association was found between breast cancer and the S/L (CAG) variants. However, the frequency of the (CAG)25 repeats in the breast cancer group was significantly higher than that in the control group (P = 0.033, odds ratio = 1.790, 95% confidence interval = 1.044-3.069). These findings indicate a role for AR gene (CAG)n variations in breast cancer and might be informative for future genetic or biological studies on breast cancer, although these findings need replication in other populations. PMID:26345963

  17. Testosterone signaling through internalizable surface receptors in androgen receptor-free macrophages.

    PubMed

    Benten, W P; Lieberherr, M; Stamm, O; Wrehlke, C; Guo, Z; Wunderlich, F

    1999-10-01

    Testosterone acts on cells through intracellular transcription-regulating androgen receptors (ARs). Here, we show that mouse IC-21 macrophages lack the classical AR yet exhibit specific nongenomic responses to testosterone. These manifest themselves as testosterone-induced rapid increase in intracellular free [Ca(2+)], which is due to release of Ca(2+) from intracellular Ca(2+) stores. This Ca(2+) mobilization is also inducible by plasma membrane-impermeable testosterone-BSA. It is not affected by the AR blockers cyproterone and flutamide, whereas it is completely inhibited by the phospholipase C inhibitor U-73122 and pertussis toxin. Binding sites for testosterone are detectable on the surface of intact IC-21 cells, which become selectively internalized independent on caveolae and clathrin-coated vesicles upon agonist stimulation. Internalization is dependent on temperature, ATP, cytoskeletal elements, phospholipase C, and G-proteins. Collectively, our data provide evidence for the existence of G-protein-coupled, agonist-sequestrable receptors for testosterone in plasma membranes, which initiate a transcription-independent signaling pathway of testosterone. PMID:10512854

  18. Testosterone Signaling through Internalizable Surface Receptors in Androgen Receptor-free Macrophages

    PubMed Central

    Benten, W. Peter M.; Lieberherr, Michèle; Stamm, Olaf; Wrehlke, Christian; Guo, Zhiyong; Wunderlich, Frank

    1999-01-01

    Testosterone acts on cells through intracellular transcription-regulating androgen receptors (ARs). Here, we show that mouse IC-21 macrophages lack the classical AR yet exhibit specific nongenomic responses to testosterone. These manifest themselves as testosterone-induced rapid increase in intracellular free [Ca2+], which is due to release of Ca2+ from intracellular Ca2+ stores. This Ca2+ mobilization is also inducible by plasma membrane-impermeable testosterone-BSA. It is not affected by the AR blockers cyproterone and flutamide, whereas it is completely inhibited by the phospholipase C inhibitor U-73122 and pertussis toxin. Binding sites for testosterone are detectable on the surface of intact IC-21 cells, which become selectively internalized independent on caveolae and clathrin-coated vesicles upon agonist stimulation. Internalization is dependent on temperature, ATP, cytoskeletal elements, phospholipase C, and G-proteins. Collectively, our data provide evidence for the existence of G-protein-coupled, agonist-sequestrable receptors for testosterone in plasma membranes, which initiate a transcription-independent signaling pathway of testosterone. PMID:10512854

  19. Tissue-specific pioneer factors associate with androgen receptor cistromes and transcription programs

    PubMed Central

    Pihlajamaa, Päivi; Sahu, Biswajyoti; Lyly, Lauri; Aittomäki, Viljami; Hautaniemi, Sampsa; Jänne, Olli A

    2014-01-01

    Androgen receptor (AR) binds male sex steroids and mediates physiological androgen actions in target tissues. ChIP-seq analyses of AR-binding events in murine prostate, kidney and epididymis show that in vivo AR cistromes and their respective androgen-dependent transcription programs are highly tissue specific mediating distinct biological pathways. This high order of tissue specificity is achieved by the use of exclusive collaborating factors in the three androgen-responsive tissues. We find two novel collaborating factors for AR signaling in vivo—Hnf4α (hepatocyte nuclear factor 4α) in mouse kidney and AP-2α (activating enhancer binding protein 2α) in mouse epididymis—that define tissue-specific AR recruitment. In mouse prostate, FoxA1 serves for the same purpose. FoxA1, Hnf4α and AP-2α motifs are over-represented within unique AR-binding loci, and the cistromes of these factors show substantial overlap with AR-binding events distinct to each tissue type. These licensing or pioneering factors are constitutively bound to chromatin and guide AR to specific genomic loci upon hormone exposure. Collectively, liganded receptor and its DNA-response elements are required but not sufficient for establishment of tissue-specific transcription programs. PMID:24451200

  20. Effect of Small Molecules Modulating Androgen Receptor (SARMs) in Human Prostate Cancer Models

    PubMed Central

    Tesei, Anna; Leonetti, Carlo; Di Donato, Marzia; Gabucci, Elisa; Porru, Manuela; Varchi, Greta; Guerrini, Andrea; Amadori, Dino; Arienti, Chiara; Pignatta, Sara; Paganelli, Giulia; Caraglia, Michele; Castoria, Gabriella; Zoli, Wainer

    2013-01-01

    The management of hormone-refractory prostate cancer represents a major challenge in the therapy of this tumor, and identification of novel androgen receptor antagonists is needed to render treatment more effective. We analyzed the activity of two novel androgen receptor antagonists, (S)-11 and (R)-9, in in vitro and in vivo experimental models of hormone-sensitive or castration-resistant prostate cancer (CRPC). In vitro experiments were performed on LNCaP, LNCaP-AR, LNCaP-Rbic and VCaP human prostate cancer cells. Cytotoxic activity was assessed by SRB and BrdU uptake, AR transactivation by luciferase reporter assay and PSA levels by Real Time RT-PCR and ELISA assays. Cell cycle progression-related markers were evaluated by western blot. In vivo experiments were performed on SCID mice xenografted with cells with different sensitivity to hormonal treatment. In hormone-sensitive LNCaP and LNCaP-AR cells, the latter expressing high androgen receptor levels, (R)-9 and (S)-11 exhibited a higher cytotoxic effect compared to that of the reference compound ((R)-bicalutamide), also in the presence of the synthetic androgen R1881. Furthermore, the cytotoxic effect produced by (R)-9 was higher than that of (S)-11 in the two hormone-resistant LNCaP-AR and VCaP cells. A significant reduction in PSA levels was observed after exposure to both molecules. Moreover, (S)-11 and (R)-9 inhibited DNA synthesis by blocking the androgen-induced increase in cyclin D1 protein levels. In vivo studies on the toxicological profile of (R)-9 did not reveal the presence of adverse events. Furthermore, (R)-9 inhibited tumor growth in various in vivo models, especially LNCaP-Rbic xenografts, representative of recurrent disease. Our in vitro results highlight the antitumor activity of the two novel molecules (R)-9 and (S)-11, making them a potentially attractive option for the treatment of CRPC. PMID:23667504

  1. Pharmacological characterization of an imidazolopyrazole as novel selective androgen receptor modulator.

    PubMed

    Zhang, Xuqing; Allan, George F; Tannenbaum, Pamela; Sbriscia, Tifanie; Linton, Olivia; Lai, Muh-Tsann; Haynes-Johnson, Donna; Bhattacharjee, Sheela; Lundeen, Scott G; Sui, Zhihua

    2013-03-01

    Selective androgen receptor modulators (SARMs) are androgens with tissue-selective activity. SARMs that have anabolic activity on muscle while having minimal stimulatory activity on prostate are classified as SARM agonists. They can be used to prevent the loss of lean body mass that is associated with cancer, immunodeficiency, renal disease and aging. They may also have anabolic activity on bone; thus, unlike estrogens, they may reverse the loss of bone strength associated with aging or hypogonadism. Our in-house effort on SARM program discovers a nonsteroidal androgen receptor ligand with a unique imidazolopyrazole moiety in its structure. In vitro, this compound is a weak androgen receptor binder and a weak androgen agonist. Despite this, in orchidectomized mature rats it is an effective SARM agonist, with an ED(50) on levator ani muscle of 3.3mg/kg and an ED(50) on ventral prostate of >30mg/kg. It has its maximal effect on muscle at the dose of 10mg/kg. In addition, this compound has mixed agonistic and antagonistic activities on prostate, reducing the weight of that tissue in intact rats by 22% at 10mg/kg. The compound does not have significant effect on gonadotropin levels or testosterone levels in both orchidectomized and intact male rats. It does not have notable progestin, estrogen or glucocorticoid agonistic or antagonistic activity in rats. In a female sexual behavior model, it improves the sexual desire of ovariectomized female rats for sexually mature intact males over nonsexually ovariectomized females. Overall, the imidazolopyrazole is a potent prostate-sparing candidate for development as a SARM agonist with an appropriate pharmacological profile for clinical benefit in muscle-wasting conditions and female sexual function disorders. PMID:23098693

  2. Evolutionary Fate of the Androgen Receptor-Signaling Pathway in Ray-Finned Fishes with a Special Focus on Cichlids.

    PubMed

    Lorin, Thibault; Salzburger, Walter; Böhne, Astrid

    2015-11-01

    The emergence of the steroid system is coupled to the evolution of multicellular animals. In vertebrates in particular, the steroid receptor repertoire has been shaped by genome duplications characteristic to this lineage. Here, we investigate for the first time the composition of the androgen receptor-signaling pathway in ray-finned fish genomes by focusing in particular on duplicates that emerged from the teleost-specific whole-genome duplication. We trace lineage- and species-specific duplications and gene losses for the genomic and nongenomic pathway of androgen signaling and subsequently investigate the sequence evolution of these genes. In one particular fish lineage, the cichlids, we find evidence for differing selection pressures acting on teleost-specific whole-genome duplication paralogs at a derived evolutionary stage. We then look into the expression of these duplicated genes in four cichlid species from Lake Tanganyika indicating, once more, rapid changes in expression patterns in closely related fish species. We focus on a particular case, the cichlid specific duplication of the rac1 GTPase, which shows possible signs of a neofunctionalization event. PMID:26333839

  3. Structure of the ligand-binding domain (LBD) of human androgen receptor in complex with a selective modulator LGD2226

    SciTech Connect

    Wang, Feng; Liu, Xiao-qin; Li, He; Liang, Kai-ni; Miner, Jeffrey N.; Hong, Mei; Kallel, E. Adam; Oeveren, Arjan van; Zhi, Lin; Jiang, Tao

    2006-11-01

    Crystal structure of the ligand-binding domain of androgen receptor in complex with LGD2226. The androgen receptor (AR) is a ligand-inducible steroid hormone receptor that mediates androgen action, determining male sexual phenotypes and promoting spermatogenesis. As the androgens play a dominant role in male sexual development and function, steroidal androgen agonists have been used clinically for some years. However, there is a risk of potential side effects and most steroidal androgens cannot be dosed orally, which limits the use of these substances. 1,2-Dihydro-6-N,N-bis(2,2,2-trifluoroethyl) amino-4-trifluoromethyl-2-quinolinone (LGD2226) is a synthetic nonsteroidal ligand and a novel selective AR modulator. The crystal structure of the complex of LGD2226 with the androgen receptor ligand-binding domain (AR LBD) at 2.1 Å was solved and compared with the structure of the AR LBD–R1881 complex. It is hoped that this will aid in further explaining the selectivity of LGD2226 observed in in vitro and in vivo assays and in developing more selective and effective therapeutic agents.

  4. Androgen Receptors in a Cichlid Fish, Astatotilapia burtoni: Structure, Localization, and Expression Levels

    PubMed Central

    HARBOTT, LENE K.; BURMEISTER, SABRINA S.; WHITE, RICHARD B.; VAGELL, MIKE; FERNALD, RUSSELL D.

    2009-01-01

    Androgens are an important output of the hypothalamic-pituitary-gonadal (HPG) axis that controls reproduction in all vertebrates. In male teleosts two androgens, testosterone and 11-ketotestosterone, control sexual differentiation and development in juveniles and reproductive behavior in adults. Androgenic signals provide feedback at many levels of the HPG axis, including the hypothalamic neurons that synthesize and release gonadotropin-releasing hormone 1 (GnRH1), but the precise cellular site of androgen action in the brain is not known. Here we describe two androgen receptor subtypes, ARα and ARβ, in the cichlid Astatotilapia burtoni and show that these subtypes are differentially located throughout the adult brain in nuclei known to function in the control of reproduction. ARα was expressed in the ventral part of the ventral telencephalon, the preoptic area (POA) of the hypothalamus and the ventral hypothalamus, whereas ARβ was more widely expressed in the dorsal and ventral telencephalon, the POA, and the ventral and dorsal hypothalamus. We provide the first evidence in any vertebrate that the GnRH1-releasing neurons, which serve as the central control point of the HPG axis, express both subtypes of AR. Using quantitative real-time PCR, we show that A. burtoni AR subtypes have different expression levels in adult tissue, with ARα showing significantly higher expression than ARβ in the pituitary, and ARβ expressed at a higher level than ARα in the anterior and middle brain. These data provide important insight into the role of androgens in regulating the vertebrate reproductive axis. PMID:17614300

  5. Androgen Receptor Coactivators in Regulation of Growth and Differentiation in Prostate Cancer.

    PubMed

    Culig, Zoran

    2016-02-01

    Androgen receptor (AR) is a key factor in regulation of growth and differentiation in normal and malignant prostate. Endocrine therapies for prostate cancer include inhibition of androgen production either by analogs of luteinizing hormone releasing hormone or abiraterone acetate and/or use of anti-androgens such as hydroxyflutamide, bicalutamide, and enzalutamide. Castration therapy-resistant cancer develops inevitably in patients who undergo treatment. AR coactivators are proteins which interact with one or more regions of the AR thus enhancing its function. Although several functions of AR coactivators may be redundant, specific functions have been identified and analyzed. The p160 group of coactivators, SRC-1, -2, and -3 not only potentiate the activation of the AR, but are also implicated in potentiation of function of insulin-like growth factor-I and activation of the Akt pathway. Transcriptional integrators p300 and CBP are up-regulated by androgen ablation and may influence antagonist/agonist balance of non-steroidal anti-androgens. A therapy approach designed to target p300 in prostate cancer revealed its role in regulation of proliferation of migration of androgen-sensitive and -insensitive prostate cancer cells. Coactivators p300 and SRC-1 are required for AR activation by interleukin-6 (IL-6), a cytokine that is overexpressed in castration therapy-resistant prostate cancer. Some coactivators, such as Vav3, are involved in regulation of transcriptional activity of truncated AR, which emerge during endocrine thrapy. Stimulation of cellular migration and invasion by AR coactivators has also been described. Translational studies with aim to introduce anti-AR coactivator therapy have not been successfully implemented in the clinic so far. PMID:26201947

  6. Structural Stereochemistry of Androstene Hormones Determines Interactions with Human Androgen, Estrogen, and Glucocorticoid Receptors

    PubMed Central

    Shaak, Thomas L.; Wijesinghe, Dayanjan S.; Chalfant, Charles E.; Diegelmann, Robert F.; Ward, Kevin R.; Loria, Roger M.

    2013-01-01

    DHEA, 17α-AED, 17β-AED, and 17β-AET exhibit strong biological activity that has been attributed to androgenic, estrogenic, or antiglucocorticoid activity in vivo and in vitro. This study compared DHEA, 17α-AED, 17β-AED, and 17β-AET for their ability to activate the human AR, ER, and GR and determine the relative androgenicity, estrogenicity, and glucocorticoid activity. The results show that, at the receptor level, these androstene hormones are weak AR and even weaker ER activators. Direct androstene hormone activation of the human AR, ERα, and ERβ may not be essential for their biological function. Similarly, these hormones indirectly activated the human GR, only in the presence of high dexamethasone concentrations. These results underscore the major difference between androstene hormone interactions with these nuclear receptors and their biological effects. PMID:24729874

  7. Synthesis and biological evaluation of novel selective androgen receptor modulators (SARMs). Part I.

    PubMed

    Aikawa, Katsuji; Miyawaki, Toshio; Hitaka, Takenori; Imai, Yumi N; Hara, Takahito; Miyazaki, Junichi; Yamaoka, Masuo; Kusaka, Masami; Kanzaki, Naoyuki; Tasaka, Akihiro; Shiraishi, Mitsuru; Yamamoto, Satoshi

    2015-05-15

    To develop effective drugs for hypogonadism, sarcopenia, and cachexia, we designed, synthesized, and evaluated selective androgen receptor modulators (SARMs) that exhibit not only anabolic effects on organs such as muscles and the central nervous system (CNS) but also neutral or antagonistic effects on the prostate. Based on the information obtained from a docking model with androgen receptor (AR), we modified a hit compound A identified through high-throughput screening. Among the prepared compounds, 1-(4-cyano-1-naphthyl)-2,3-disubstituted pyrrolidine derivatives 17h, 17m, and 17j had highly potent AR agonistic activities in vitro and good tissue selectivity in vivo. These derivatives increased the weight of the levator ani muscle without influencing the prostate and seminal vesicle. In addition, these compounds induced sexual behavior in castrated rats, indicating that the compounds could also act as agonists on the CNS. PMID:25862209

  8. Androgen receptor antagonists compromise T cell response against prostate cancer leading to early tumor relapse.

    PubMed

    Pu, Yang; Xu, Meng; Liang, Yong; Yang, Kaiting; Guo, Yajun; Yang, Xuanming; Fu, Yang-Xin

    2016-04-01

    Surgical and medical androgen deprivation therapy (ADT) is a cornerstone for prostate cancer treatment, but relapse usually occurs. We herein show that orchiectomy synergizes with immunotherapy, whereas the more widely used treatment of medical ADT involving androgen receptor (AR) antagonists suppresses immunotherapy. Furthermore, we observed that the use of medical ADT could unexpectedly impair the adaptive immune responses through interference with initial T cell priming rather than in the reactivation or expansion phases. Mechanistically, we have revealed that inadvertent immunosuppression might be potentially mediated by a receptor shared with γ-aminobutyric acid. Our data demonstrate that the timing and dosing of antiandrogens are critical to maximizing the antitumor effects of combination therapy. This study highlights an underappreciated mechanism of AR antagonist-mediated immunosuppression and provides a new strategy to enhance immune response and prevent the relapse of advanced prostate cancer. PMID:27053771

  9. N-Aryl-oxazolidin-2-imine Muscle Selective Androgen Receptor Modulators Enhance Potency through Pharmacophore Reorientation

    SciTech Connect

    Nirschl, Alexandra A.; Zou, Yan; Krystek, Jr., Stanley R.; Sutton, James C.; Simpkins, Ligaya M.; Lupisella, John A.; Kuhns, Joyce E.; Seethala, Ramakrishna; Golla, Rajasree; Sleph, Paul G.; Beehler, Blake C.; Grover, Gary J.; Egan, Donald; Fura, Aberra; Vyas, Viral P.; Li, Yi-Xin; Sack, John S.; Kish, Kevin F.; An, Yongmi; Bryson, James A.; Gougoutas, Jack Z.; DiMarco, John; Zahler, Robert; Ostrowski, Jacek; Hamann, Lawrence G.

    2010-11-09

    A novel selective androgen receptor modulator (SARM) scaffold was discovered as a byproduct obtained during synthesis of our earlier series of imidazolidin-2-ones. The resulting oxazolidin-2-imines are among the most potent SARMs known, with many analogues exhibiting sub-nM in vitro potency in binding and functional assays. Despite the potential for hydrolytic instability at gut pH, compounds of the present class showed good oral bioavailability and were highly active in a standard rodent pharmacological model.

  10. Utility of novel androgen receptor therapies in the real world: A nuanced approach.

    PubMed

    Dhawan, Mallika; Ryan, Charles J

    2016-08-01

    Abiraterone and enzalutamide are in widespread clinical use because of their favorable safety and efficacy. Nonetheless, even with newer agents, resistance develops overtime. In this review, we discuss mechanisms of resistance to these newer agents as well as novel therapeutic agents. We also review the literature to help clinicians decide which agent to begin with and when to stop or switch androgen receptor agents. PMID:27450893

  11. Androgen receptor-mediated non-genomic regulation of prostate cancer cell proliferation

    PubMed Central

    Liao, Ross S.; Ma, Shihong; Miao, Lu; Li, Rui; Yin, Yi

    2013-01-01

    Androgen receptor (AR)-mediated signaling is necessary for prostate cancer cell proliferation and an important target for therapeutic drug development. Canonically, AR signals through a genomic or transcriptional pathway, involving the translocation of androgen-bound AR to the nucleus, its binding to cognate androgen response elements on promoter, with ensuing modulation of target gene expression, leading to cell proliferation. However, prostate cancer cells can show dose-dependent proliferation responses to androgen within minutes, without the need for genomic AR signaling. This proliferation response known as the non-genomic AR signaling is mediated by cytoplasmic AR, which facilitates the activation of kinase-signaling cascades, including the Ras-Raf-1, phosphatidyl-inositol 3-kinase (PI3K)/Akt and protein kinase C (PKC), which in turn converge on mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) activation, leading to cell proliferation. Further, since activated ERK may also phosphorylate AR and its coactivators, the non-genomic AR signaling may enhance AR genomic activity. Non-genomic AR signaling may occur in an ERK-independent manner, via activation of mammalian target of rapamycin (mTOR) pathway, or modulation of intracellular Ca2+ concentration through plasma membrane G protein-coupled receptors (GPCRs). These data suggest that therapeutic strategies aimed at preventing AR nuclear translocation and genomic AR signaling alone may not completely abrogate AR signaling. Thus, elucidation of mechanisms that underlie non-genomic AR signaling may identify potential mechanisms of resistance to current anti-androgens and help developing novel therapies that abolish all AR signaling in prostate cancer. PMID:26816736

  12. Differential ligand selectivity of androgen receptors α and β from Murray-Darling rainbowfish (Melanotaenia fluviatilis).

    PubMed

    Bain, Peter A; Ogino, Yukiko; Miyagawa, Shinichi; Iguchi, Taisen; Kumar, Anupama

    2015-02-01

    Androgen receptors (ARs) mediate the physiological effects of androgens in vertebrates. In fishes, AR-mediated pathways can be modulated by aquatic contaminants, resulting in the masculinisation of female fish or diminished secondary sex characteristics in males. The Murray-Darling rainbowfish (Melanotaenia fluviatilis) is a small-bodied freshwater teleost used in Australia as a test species for environmental toxicology research. We determined concentration-response profiles for selected agonists and antagonists of rainbowfish ARα and ARβ using transient transactivation assays. For both ARα and ARβ, the order of potency of natural agonists was 11-ketotestosterone (11-KT)>5α-dihydrotestosterone>testosterone>androstenedione. Methyltestosterone was a highly potent agonist of both receptors relative to 11-KT. The relative potency of the veterinary growth-promoting androgen, 17β-trenbolone, varied by more than a factor of 5 between ARα and ARβ. The non-steroidal anti-androgen bicalutamide exhibited high inhibitory potency relative to the structurally related model anti-androgen, flutamide. The inhibitory potency of the agricultural fungicide, vinclozolin, was approximately 1.7-fold relative to flutamide for ARα, but over 20-fold in the case of ARβ. Fluorescent protein tagging of ARs showed that the rainbowfish ARα subtype is constitutively localised to the nucleus, while ARβ is cytoplasmic in the absence of ligand, an observation which agrees with the reported subcellular localisation of AR subtypes from other teleost species. Collectively, these data suggest that M. fluviatilis ARα and ARβ respond differently to environmental AR modulators and that in vivo sensitivity to contaminants may depend on the tissue distribution of the AR subtypes at the time of exposure. PMID:25644213

  13. Role of androgen and vitamin D receptors in endothelial cells from benign and malignant human prostate

    PubMed Central

    Chung, Ivy; Montecinos, Viviana P.; Buttyan, Ralph; Johnson, Candace S.; Smith, Gary J.

    2013-01-01

    Forty years ago, Judah Folkman (Folkman. N Engl J Med 285: 1182–1186, 1971) proposed that tumor growth might be controlled by limiting formation of new blood vessels (angiogenesis) needed to supply a growing tumor with oxygen and nutrients. To this end, numerous “antiangiogenic” agents have been developed and tested for therapeutic efficacy in cancer patients, including prostate cancer (CaP) patients, with limited success. Despite the lack of clinical efficacy of lead anti-angiogenic therapeutics in CaP patients, recent published evidence continues to support the idea that prostate tumor vasculature provides a reasonable target for development of new therapeutics. Particularly relevant to antiangiogenic therapies targeted to the prostate is the observation that specific hormones can affect the survival and vascular function of prostate endothelial cells within normal and malignant prostate tissues. Here, we review the evidence demonstrating that both androgen(s) and vitamin D significantly impact the growth and survival of endothelial cells residing within prostate cancer and that systemic changes in circulating androgen or vitamin D drastically affect blood flow and vascularity of prostate tissue. Furthermore, recent evidence will be discussed about the expression of the receptors for both androgen and vitamin D in prostate endothelial cells that argues for direct effects of these hormone-activated receptors on the biology of endothelial cells. Based on this literature, we propose that prostate tumor vasculature represents an unexplored target for modulation of tumor growth. A better understanding of androgen and vitamin D effects on prostate endothelial cells will support development of more effective angiogenesis-targeting therapeutics for CaP patients. PMID:23548616

  14. The androgen receptor confers protection against diet-induced atherosclerosis, obesity, and dyslipidemia in female mice

    PubMed Central

    Fagman, Johan B.; Wilhelmson, Anna S.; Motta, Benedetta M.; Pirazzi, Carlo; Alexanderson, Camilla; De Gendt, Karel; Verhoeven, Guido; Holmäng, Agneta; Anesten, Fredrik; Jansson, John-Olov; Levin, Malin; Borén, Jan; Ohlsson, Claes; Krettek, Alexandra; Romeo, Stefano; Tivesten, Åsa

    2015-01-01

    Androgens have important cardiometabolic actions in males, but their metabolic role in females is unclear. To determine the physiologic androgen receptor (AR)–dependent actions of androgens on atherogenesis in female mice, we generated female AR-knockout (ARKO) mice on an atherosclerosis-prone apolipoprotein E (apoE)–deficient background. After 8 weeks on a high-fat diet, but not on a normal chow diet, atherosclerosis in aorta was increased in ARKO females (+59% vs. control apoE-deficient mice with intact AR gene). They also displayed increased body weight (+18%), body fat percentage (+62%), and hepatic triglyceride levels, reduced insulin sensitivity, and a marked atherogenic dyslipidemia (serum cholesterol, +52%). Differences in atherosclerosis, body weight, and lipid levels between ARKO and control mice were abolished in mice that were ovariectomized before puberty, consistent with a protective action of ovarian androgens mediated via the AR. Furthermore, the AR agonist dihydrotestosterone reduced atherosclerosis (−41%; thoracic aorta), subcutaneous fat mass (−44%), and cholesterol levels (−35%) in ovariectomized mice, reduced hepatocyte lipid accumulation in hepatoma cells in vitro, and regulated mRNA expression of hepatic genes pivotal for lipid homeostasis. In conclusion, we demonstrate that the AR protects against diet-induced atherosclerosis in female mice and propose that this is mediated by modulation of body composition and lipid metabolism.—Fagman, J. B., Wilhelmson, A. S., Motta, B. M., Pirazzi, C., Alexanderson, C., De Gendt, K., Verhoeven, G., Holmäng, A., Anesten, F., Jansson, J.-O., Levin, M., Borén, J., Ohlsson, C., Krettek, A., Romeo, S., Tivesten, A. The androgen receptor confers protection against diet-induced atherosclerosis, obesity, and dyslipidemia in female mice. PMID:25550469

  15. Enobosarm (GTx-024) Modulates Adult Skeletal Muscle Mass Independently of the Androgen Receptor in the Satellite Cell Lineage.

    PubMed

    Dubois, Vanessa; Simitsidellis, Ioannis; Laurent, Michaël R; Jardi, Ferran; Saunders, Philippa T K; Vanderschueren, Dirk; Claessens, Frank

    2015-12-01

    Androgens increase skeletal muscle mass, but their clinical use is hampered by a lack of tissue selectivity and subsequent side effects. Selective androgen receptor modulators elicit muscle-anabolic effects while only sparingly affecting reproductive tissues. The selective androgen receptor modulator, GTx-024 (enobosarm), is being investigated for cancer cachexia, sarcopenia, and muscle wasting diseases. Here we investigate the role of muscle androgen receptor (AR) in the anabolic effect of GTx-024. In mice lacking AR in the satellite cell lineage (satARKO), the weight of the androgen-sensitive levator ani muscle was lower but was decreased further upon orchidectomy. GTx-024 was as effective as DHT in restoring levator ani weights to sham levels. Expression of the muscle-specific, androgen-responsive genes S-adenosylmethionine decarboxylase and myostatin was decreased by orchidectomy and restored by GTx-024 and DHT in control mice, whereas the expression was low and unaffected by androgen status in satARKO. In contrast, insulin-like growth factor 1Ea expression was not different between satARKO and control muscle, decreased upon castration, and was restored by DHT and GTx-024 in both genotypes. These data indicate that GTx-024 does not selectively modulate AR in the satellite cell lineage and that cells outside this lineage remain androgen responsive in satARKO muscle. Indeed, residual AR-positive cells were present in satARKO muscle, coexpressing the fibroblast-lineage marker vimentin. AR positive, muscle-resident fibroblasts could therefore be involved in the indirect effects of androgens on muscle. In conclusion, both DHT and GTx-024 target AR pathways in the satellite cell lineage, but cells outside this lineage also contribute to the anabolic effects of androgens. PMID:26393303

  16. Identification of androgen receptor antagonists: In vitro investigation and classification methodology for flavonoid.

    PubMed

    Wu, Yang; Doering, Jon A; Ma, Zhiyuan; Tang, Song; Liu, Hongling; Zhang, Xiaowei; Wang, Xiaoxiang; Yu, Hongxia

    2016-09-01

    A tremendous gap exists between the number of potential endocrine disrupting chemicals (EDCs) possibly in the environment and the limitation of traditional regulatory testing. In this study, the anti-androgenic potencies of 21 flavonoids were analyzed in vitro, and another 32 flavonoids from the literature were selected as additional chemicals. Molecular dynamic simulations were employed to obtain four different separation approaches based on the different behaviors of ligands and receptors during the process of interaction. Specifically, ligand-receptor complex which highlighted the discriminating features of ligand escape or retention via "mousetrap" mechanism, hydrogen bonds formed during simulation times, ligand stability and the stability of the helix-12 of the receptor were investigated. Together, a methodology was generated that 87.5% of flavonoids could be discriminated as active versus inactive antagonists, and over 90% inactive antagonists could be filtered out before QSAR study. This methodology could be used as a "proof of concept" to identify inactive anti-androgenic flavonoids, as well could be beneficial for rapid risk assessment and regulation of multiple new chemicals for androgenicity. PMID:27258897

  17. Selective activity of deguelin identifies therapeutic targets for androgen receptor-positive breast cancer.

    PubMed

    Robles, Andrew J; Cai, Shengxin; Cichewicz, Robert H; Mooberry, Susan L

    2016-06-01

    Triple-negative breast cancers (TNBC) are aggressive malignancies with no effective targeted therapies. Recent gene expression profiling of these heterogeneous cancers and the classification of cell line models now allows for the identification of compounds with selective activities against molecular subtypes of TNBC. The natural product deguelin was found to have selective activity against MDA-MB-453 and SUM-185PE cell lines, which both model the luminal androgen receptor (LAR) subtype of TNBC. Deguelin potently inhibited proliferation of these cells with GI50 values of 30 and 61 nM, in MDA-MB-453 and SUM-185PE cells, respectively. Deguelin had exceptionally high selectivity, 197 to 566-fold, for these cell lines compared to cell lines representing other TNBC subtypes. Deguelin's mechanisms of action were investigated to determine how it produced these potent and selective effects. Our results show that deguelin has dual activities, inhibiting PI3K/Akt/mTOR signaling, and decreasing androgen receptor levels and nuclear localization. Based on these data, we hypothesized that the combination of the mTOR inhibitor rapamycin and the antiandrogen enzalutamide would have efficacy in LAR models. Rapamycin and enzalutamide showed additive effects in MDA-MB-453 cells, and both drugs had potent antitumor efficacy in a LAR xenograft model. These results suggest that the combination of antiandrogens and mTOR inhibitors might be an effective strategy for the treatment of androgen receptor-expressing TNBC. PMID:27255535

  18. Modulation of androgen receptor protein by culture conditions of human skin fibroblasts.

    PubMed

    Palma, Marcela M; Fernandez, Mireya; Vivanco, Ximena; Pino, Ana M

    2002-10-01

    Cultures of skin fibroblasts show variation of androgen binding with culture conditions; binding variations are usually avoided by using confluent cultures. In this work, we analysed the effect of cell density and mitogenic agents on the level of androgen receptor (AR) of cultured human skin fibroblasts. Results demonstrated that in cultures of human skin fibroblasts, cellular binding of dihydrotestosterone was higher in cells grown at low than at high cell density. The reduction in binding resulted from a decrease in the number of high affinity receptors and not from a change in receptor affinity. Immunocytochemistry for AR showed greater staining intensity in cells grown at low than at high cell density. Additionally, immunoblot analysis demonstrated more AR protein in low cell density cultures. On the other hand, it was observed that cells grown at low cell density showed diminished androgen binding capacity after 24 h of treatment with insulin-like growth factor (IGF-l), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), or granulocyte-colony stimulating factor (G-CSF); this effect of growth factors was not observed in cells grown at high cell density. In conclusion, we found that cell density of cultures and mitogenic agents can regulate AR binding activity in human fibroblasts. While we do not yet know how changes in cell density affect the amount of AR, we conclude that the mechanism could be mediated by activation of the tyrosine kinase pathway, as the effect was reproduced by mitogens. PMID:12270026

  19. Stromal androgen receptor roles in the development of normal prostate, benign prostate hyperplasia, and prostate cancer.

    PubMed

    Wen, Simeng; Chang, Hong-Chiang; Tian, Jing; Shang, Zhiqun; Niu, Yuanjie; Chang, Chawnshang

    2015-02-01

    The prostate is an androgen-sensitive organ that needs proper androgen/androgen receptor (AR) signals for normal development. The progression of prostate diseases, including benign prostate hyperplasia (BPH) and prostate cancer (PCa), also needs proper androgen/AR signals. Tissue recombination studies report that stromal, but not epithelial, AR plays more critical roles via the mesenchymal-epithelial interactions to influence the early process of prostate development. However, in BPH and PCa, much more attention has been focused on epithelial AR roles. However, accumulating evidence indicates that stromal AR is also irreplaceable and plays critical roles in prostate disease progression. Herein, we summarize the roles of stromal AR in the development of normal prostate, BPH, and PCa, with evidence from the recent results of in vitro cell line studies, tissue recombination experiments, and AR knockout animal models. Current evidence suggests that stromal AR may play positive roles to promote BPH and PCa progression, and targeting stromal AR selectively with AR degradation enhancer, ASC-J9, may allow development of better therapies with fewer adverse effects to battle BPH and PCa. PMID:25432062

  20. Stromal Androgen Receptor Roles in the Development of Normal Prostate, Benign Prostate Hyperplasia, and Prostate Cancer

    PubMed Central

    Wen, Simeng; Chang, Hong-Chiang; Tian, Jing; Shang, Zhiqun; Niu, Yuanjie; Chang, Chawnshang

    2016-01-01

    The prostate is an androgen-sensitive organ that needs proper androgen/androgen receptor (AR) signals for normal development. The progression of prostate diseases, including benign prostate hyperplasia (BPH) and prostate cancer (PCa), also needs proper androgen/AR signals. Tissue recombination studies report that stromal, but not epithelial, AR plays more critical roles via the mesenchymal-epithelial interactions to influence the early process of prostate development. However, in BPH and PCa, much more attention has been focused on epithelial AR roles. However, accumulating evidence indicates that stromal AR is also irreplaceable and plays critical roles in prostate disease progression. Herein, we summarize the roles of stromal AR in the development of normal prostate, BPH, and PCa, with evidence from the recent results of in vitro cell line studies, tissue recombination experiments, and AR knockout animal models. Current evidence suggests that stromal AR may play positive roles to promote BPH and PCa progression, and targeting stromal AR selectively with AR degradation enhancer, ASC-J9, may allow development of better therapies with fewer adverse effects to battle BPH and PCa. PMID:25432062

  1. Occurrence of androgen and estrogen receptor mRNAs in the harderian gland: a comparative survey.

    PubMed

    Varriale, B

    1996-06-01

    In Rana esculenta the presence of an androgen receptor in both the male and female Harderian gland (HG) has been demonstrated. Hybridization analysis has evidenced a high degree of homology between the rat androgen receptor cDNA and the frog androgen receptor mRNA (fARmRNA). Correspondingly the molecular size of fARmRNA is similar to those described in mammals (9.4 kb). In in vivo experiments testosterone (T) increases the levels of fARmRNA. The use of the antiandrogen alone or in combination with T prevents the increase of fARmRNA. In the control animals a loss of fARmRNA has been observed. In primary cultures of HG cells, the steady-state levels of fARmRNA increase in the cells exposed to T. These results suggest that T exerts an autoinduction on its own receptor, increasing the levels of fARmRNA. In Xenopus laevis the HG shows a sexual dimorphism of the protein pattern. The female shows two major proteins (210 and 180 kDa). Administration of estradiol to the male shifts the protein pattern into the female one. In this respect an estrogen receptor mRNA (ERmRNA) has been found in the female gland and can be induced in the male one. No ARmRNA has been detected in either sexes. A similar sex dimorphism has been found in Gallus domesticus. The female pattern is characterised by a protein fraction of about 210 kDa, the male one by a protein fraction of about 180 kDa. In 4-day-old chicks no sex differences have been found. An ERmRNA is expressed in the female, while no ARmRNA has been detected in both sexes. Neither AR nor ER mRNAs have been detected in the chick HG. Among mammals the HG or the hamster (Mesocricetus auratus) shows an androgen-dependent sex dimorphism. In in vitro experiments T 10(-12) M induces a onefold increase of ARm-RNA with respect to unexposed cells. This effect reaches its maximum (4.4-fold) when cells are exposed to T 10(-8) M. The size of the hamster ARmRNA is similar to that observed in other mammals (9.5 kb). The above results suggest that

  2. A novel insA2933 causes premature termination of translation and is accompanied by overexpression of truncated androgen receptor gene in a patient with complete androgen insensitivity syndrome.

    PubMed

    Turek-Plewa, J; Starzyk, J B; Trzeciak, W H

    2015-11-01

    A patient with a female phenotype, 46,XY karyotype, and a diagnosis of complete androgen insensitivity syndrome (CAIS) was examined. Her mother and three 46,XX sisters were also included in the study. Sequence analysis of the androgen receptor gene (AR) revealed a novel A2933 insertion that alters the Tyr codon to a termination codon (Y857X), resulting in a truncated form of the receptor. Computer simulation revealed major conformational changes in the hydrophobic pocket that accommodates the hormone. An insA2933 results in a truncated receptor incapable of binding the ligand and is responsible for the clinical symptoms of CAIS in the patient. The levels of the AR transcript in peripheral blood leukocytes were higher in the patient than in her heterozygous mother and her heterozygous sister, as well as in the two healthy sisters. It is hypothesized that elevated levels of the AR transcript in the patient might be caused by the inability of the truncated receptor to react with IFI-16, which functions in complex with AR to inhibit the expression of the AR gene. PMID:25997614

  3. Molecular and biochemical effects of a kola nut extract on androgen receptor-mediated pathways.

    PubMed

    Solipuram, Rajasree; Koppula, Sowmya; Hurst, Angela; Harris, Kinesha; Naragoni, Srivatcha; Fontenot, Krystal; Gray, Wesley

    2009-01-01

    The low incidence of prostate cancer in Asians has been attributed to chemopreventative properties of certain chemicals found in their diet. This study characterized the androgenic and chemopreventative properties of the Jamaican bush tea "Bizzy," using androgen receptor positive and negative cell lines. Exposure of prostate cells to Biz-2 resulted in a growth inhibition (GI(50)) of 15 ppm in LNCaP cells and 3.6 ppm in DU145 cells. Biz-2 elicited a 2-fold increase in the mRNA of the anti-apoptotic gene Bcl2, with a 10-fold increase in that of the proapoptotic gene Bax. We observed a 2.4- to 7.5-fold change in apoptotic cells in both cell lines. Biz-2 at 10 ppm elicited a time- and dose-dependent stimulation of both the protein and mRNA levels of several androgen-regulated genes. Biz-2 caused a 36% decrease in PSA secretion and a significant increase in PSA mRNA. The relative binding affinity (IC(50)) of Biz-2 for AR was 2- to 5-fold lower than that of the synthetic androgen R1881. Biz-2 was found to be a specific ligand for the AR in that the natural ligand, DHT, and the anti-androgen, flutamide, displaced Biz-2 bound to AR and inhibited Biz-2-induced transcription and PSA secretion. This study provided evidence that Biz-2 extract possesses the ability to modulate prostate cancer cell biology in an AR-dependent manner. PMID:20107586

  4. Cryptorchidism in Mice with an Androgen Receptor Ablation in Gubernaculum Testis

    PubMed Central

    Kaftanovskaya, Elena M.; Huang, Zaohua; Barbara, Agustin M.; De Gendt, Karel; Verhoeven, Guido; Gorlov, Ivan P.

    2012-01-01

    Androgens play a critical role in the development of the male reproductive system, including the positioning of the gonads. It is not clear, however, which developmental processes are influenced by androgens and what are the target tissues and cells mediating androgen signaling during testicular descent. Using a Cre-loxP approach, we have produced male mice (GU-ARKO) with conditional inactivation of the androgen receptor (Ar) gene in the gubernacular ligament connecting the epididymis to the caudal abdominal wall. The GU-ARKO males had normal testosterone levels but developed cryptorchidism with the testes located in a suprascrotal position. Although initially subfertile, the GU-ARKO males became sterile with age. We have shown that during development, the mutant gubernaculum failed to undergo eversion, a process giving rise to the processus vaginalis, a peritoneal outpouching inside the scrotum. As a result, the cremasteric sac did not form properly, and the testes remained in the low abdominal position. Abnormal development of the cremaster muscles in the GU-ARKO males suggested the participation of androgens in myogenic differentiation; however, males with conditional AR inactivation in the striated or smooth muscle cells had a normal testicular descent. Gene expression analysis showed that AR deficiency in GU-ARKO males led to the misexpression of genes involved in muscle differentiation, cell signaling, and extracellular space remodeling. We therefore conclude that AR signaling in gubernacular cells is required for gubernaculum eversion and outgrowth. The GU-ARKO mice provide a valuable model of isolated cryptorchidism, one of the most common birth defects in newborn boys. PMID:22322597

  5. Androgen receptor- and PIAS1-regulated gene programs in molecular apocrine breast cancer cells.

    PubMed

    Malinen, Marjo; Toropainen, Sari; Jääskeläinen, Tiina; Sahu, Biswajyoti; Jänne, Olli A; Palvimo, Jorma J

    2015-10-15

    We have analyzed androgen receptor (AR) chromatin binding sites (ARBs) and androgen-regulated transcriptome in estrogen receptor negative molecular apocrine breast cancer cells. These analyses revealed that 42% of ARBs and 39% androgen-regulated transcripts in MDA-MB453 cells have counterparts in VCaP prostate cancer cells. Pathway analyses showed a similar enrichment of molecular and cellular functions among AR targets in both breast and prostate cancer cells, with cellular growth and proliferation being among the most enriched functions. Silencing of the coregulator SUMO ligase PIAS1 in MDA-MB453 cells influenced AR function in a target-selective fashion. An anti-apoptotic effect of the silencing suggests involvement of the PIAS1 in the regulation of cell death and survival pathways. In sum, apocrine breast cancer and prostate cancer cells share a core AR cistrome and target gene signature linked to cancer cell growth, and PIAS1 plays a similar coregulatory role for AR in both cancer cell types. PMID:26219822

  6. Ethnic variation in allele distribution of the androgen receptor (AR) (CAG)n repeat.

    PubMed

    Ackerman, Christine M; Lowe, Lynn P; Lee, Hoon; Hayes, M Geoffrey; Dyer, Alan R; Metzger, Boyd E; Lowe, William L; Urbanek, Margrit

    2012-01-01

    The androgen receptor (AR) is important in reproductive organ development, as well as tissue homeostasis of the pancreas, liver, and skeletal muscle in adulthood. The trinucleotide (CAG)(n) repeat polymorphism in exon 1 of the AR gene is thought to regulate AR activity, with longer alleles conferring reduced receptor activity. Therefore, the evaluation of the allelic distribution of the AR (CAG)(n) repeat in various ethnic groups is crucial in understanding the interindividual variability in AR activity. We evaluated ethnic variation of this AR polymorphism by genotyping individuals from the multiethnic Hyperglycemia and Adverse Pregnancy Outcome study cohort. We genotyped 4421 Caucasian mothers and 3365 offspring of European ancestry; 1494 Thai mothers and 1742 offspring; 1119 Afro-Caribbean mothers and 1142 offspring; and 780 Hispanic mothers and 770 offspring of Mexican ancestry from Bellflower, California. The distributions of (CAG)(n) alleles among all 4 ethnic groups are significantly different (P < .0001). Pairwise tests confirmed significant differences between each pair of ethnicities tested (P < 10(-28)). The relative AR (CAG)(n) repeat length in the different groups was as follows: Afro-Caribbean (shortest repeat lengths and greatest predicted AR activity) < Caucasian < Hispanic < Thai (longest repeat length and lowest predicted AR activity). Significant interethnic differences in the allele frequencies of the AR exon 1 (CAG)(n) polymorphism exist. Our results suggest that there may be potential ethnic differences in androgenic pathway activity and androgen sensitivity. PMID:21597087

  7. Androgen Receptor Targeted Conjugate for Bimodal Photodynamic Therapy of Prostate Cancer in Vitro.

    PubMed

    Rapozzi, Valentina; Ragno, Daniele; Guerrini, Andrea; Ferroni, Claudia; della Pietra, Emilia; Cesselli, Daniela; Castoria, Gabriella; Di Donato, Marzia; Saracino, Emanuela; Benfenati, Valentina; Varchi, Greta

    2015-08-19

    Prostate cancer (PC) represents the most common type of cancer among males and is the second leading cause of cancer death in men in Western society. Current options for PC therapy remain unsatisfactory, since they often produce uncomfortable long-term side effects, such as impotence (70%) and incontinence (5-20%) even in the first stages of the disease. Light-triggered therapies, such as photodynamic therapy, have the potential to provide important advances in the treatment of localized and partially metastasized prostate cancer. We have designed a novel molecular conjugate (DR2) constituted of a photosensitizer (pheophorbide a, Pba), connected to a nonsteroidal anti-androgen molecule through a small pegylated linker. This study aims at investigating whether DR2 represents a valuable approach for PC treatment based on light-induced production of single oxygen and nitric oxide (NO) in vitro. Besides being able to efficiently bind the androgen receptor (AR), the 2-trifluoromethylnitrobenzene ring on the DR2 backbone is able to release cytotoxic NO under the exclusive control of light, thus augmenting the general photodynamic effect. Although DR2 is similarly internalized in cells expressing different levels of androgen receptor, the AR ligand prevents its efflux through the ABCG2-pump. In vitro phototoxicity experiments demonstrated the ability of DR2 to kill cancer cells more efficiently than Pba, while no dark toxicity was observed. Overall, the presented approach is very promising for further development of AR-photosensitizer conjugates in the multimodal photodynamic treatment of prostate cancer. PMID:26108715

  8. Novel and next-generation androgen receptor-directed therapies for prostate cancer: Beyond abiraterone and enzalutamide.

    PubMed

    Bambury, Richard M; Rathkopf, Dana E

    2016-08-01

    The approval of abiraterone and enzalutamide for the treatment of advanced castration-resistant prostate cancer heralded a paradigm shift in the management of this disease. Nevertheless, new and improved treatments are needed since the disease remains incurable for the majority of these patients. In this article, we review the biology of castration-resistant disease as well as emerging therapeutic compounds directed at the androgen receptor, including galeterone, VT-464, ARN-509, and ODM-201. Mechanisms of action, early clinical data, and ongoing clinical studies for these compounds are all reviewed. The need to find optimal sequencing and combination strategies as well as the need for predictive biomarkers of response to these agents is discussed. PMID:26162486

  9. BAY 1024767 blocks androgen receptor mutants found in castration-resistant prostate cancer patients.

    PubMed

    Sugawara, Tatsuo; Lejeune, Pascale; Köhr, Silke; Neuhaus, Roland; Faus, Hortensia; Gelato, Kathy A; Busemann, Matthias; Cleve, Arwed; Lücking, Ulrich; von Nussbaum, Franz; Brands, Michael; Mumberg, Dominik; Jung, Klaus; Stephan, Carsten; Haendler, Bernard

    2016-02-01

    Androgen receptor (AR) mutations arise in patients developing resistance to hormone deprivation therapies. Here we describe BAY 1024767, a thiohydantoin derivative with strong antagonistic activity against nine AR variants with mutations located in the AR ligand-binding domain (LBD), and against wild-type AR. Antagonism was maintained, though reduced, at increased androgen levels. Anti-tumor efficacy was evidenced in vivo in the KuCaP-1 prostate cancer model which bears the W741C bicalutamide resistance mutation and in the syngeneic prostate cancer rat model Dunning R3327-G. The prevalence of six selected AR mutations was determined in plasma DNA originating from 100 resistant patients and found to be at least 12%. Altogether the results show BAY 1024767 to be a strong antagonist for several AR mutants linked to therapy resistance, which opens the door for next-generation compounds that can benefit patients based on their mutation profile. PMID:26760770

  10. ODM-201: a new-generation androgen receptor inhibitor in castration-resistant prostate cancer.

    PubMed

    Fizazi, Karim; Albiges, Laurence; Loriot, Yohann; Massard, Christophe

    2015-01-01

    Androgen deprivation therapy is the standard of care for patients with advanced hormone-sensitive prostate cancer. Despite an initial response, most patients progress to castration-resistant prostate cancer (CRPC). The realization that CRPC remains driven by androgen receptor (AR) signaling has formed the basis for a new generation of agents targeting the AR axis. Two of these agents, abiraterone acetate and enzalutamide, have been shown to prolong overall survival in patients with CRPC. Several other AR inhibitors are currently in development for the treatment of CRPC. The present article reviews ODM-201, a new-generation AR inhibitor with a unique molecular structure, in the treatment of CRPC. The design of an ongoing Phase III trial (ARAMIS) of ODM-201 in men with non-metastatic CRPC is also discussed, at a disease stage for which there is currently no approved treatment. PMID:26313416

  11. BAY 1024767 blocks androgen receptor mutants found in castration-resistant prostate cancer patients

    PubMed Central

    Sugawara, Tatsuo; Lejeune, Pascale; Köhr, Silke; Neuhaus, Roland; Faus, Hortensia; Gelato, Kathy A.; Busemann, Matthias; Cleve, Arwed; Lücking, Ulrich; von Nussbaum, Franz; Brands, Michael; Mumberg, Dominik; Jung, Klaus; Stephan, Carsten; Haendler, Bernard

    2016-01-01

    Androgen receptor (AR) mutations arise in patients developing resistance to hormone deprivation therapies. Here we describe BAY 1024767, a thiohydantoin derivative with strong antagonistic activity against nine AR variants with mutations located in the AR ligand-binding domain (LBD), and against wild-type AR. Antagonism was maintained, though reduced, at increased androgen levels. Anti-tumor efficacy was evidenced in vivo in the KuCaP-1 prostate cancer model which bears the W741C bicalutamide resistance mutation and in the syngeneic prostate cancer rat model Dunning R3327-G. The prevalence of six selected AR mutations was determined in plasma DNA originating from 100 resistant patients and found to be at least 12%. Altogether the results show BAY 1024767 to be a strong antagonist for several AR mutants linked to therapy resistance, which opens the door for next-generation compounds that can benefit patients based on their mutation profile. PMID:26760770

  12. ODM-201: a new-generation androgen receptor inhibitor in castration-resistant prostate cancer

    PubMed Central

    Fizazi, Karim; Albiges, Laurence; Loriot, Yohann; Massard, Christophe

    2015-01-01

    Androgen deprivation therapy is the standard of care for patients with advanced hormone-sensitive prostate cancer. Despite an initial response, most patients progress to castration-resistant prostate cancer (CRPC). The realization that CRPC remains driven by androgen receptor (AR) signaling has formed the basis for a new generation of agents targeting the AR axis. Two of these agents, abiraterone acetate and enzalutamide, have been shown to prolong overall survival in patients with CRPC. Several other AR inhibitors are currently in development for the treatment of CRPC. The present article reviews ODM-201, a new-generation AR inhibitor with a unique molecular structure, in the treatment of CRPC. The design of an ongoing Phase III trial (ARAMIS) of ODM-201 in men with non-metastatic CRPC is also discussed, at a disease stage for which there is currently no approved treatment. PMID:26313416

  13. Cross-talk between androgen receptor/filamin A and TrkA regulates neurite outgrowth in PC12 cells

    PubMed Central

    Di Donato, Marzia; Bilancio, Antonio; D'Amato, Loredana; Claudiani, Pamela; Oliviero, Maria Antonietta; Barone, Maria Vittoria; Auricchio, Alberto; Appella, Ettore; Migliaccio, Antimo; Auricchio, Ferdinando; Castoria, Gabriella

    2015-01-01

    Steroids and growth factors control neuronal development through their receptors under physiological and pathological conditions. We show that PC12 cells harbor endogenous androgen receptor (AR), whose inhibition or silencing strongly interferes with neuritogenesis stimulated by the nonaromatizable synthetic androgen R1881 or NGF. This implies a role for AR not only in androgen signaling, but also in NGF signaling. In turn, a pharmacological TrkA inhibitor interferes with NGF- or androgen-induced neuritogenesis. In addition, androgen or NGF triggers AR association with TrkA, TrkA interaction with PI3-K δ, and downstream activation of PI3-K δ and Rac in PC12 cells. Once associated with AR, filamin A (FlnA) contributes to androgen or NGF neuritogenesis, likely through its interaction with signaling effectors, such as Rac. This study thus identifies a previously unrecognized reciprocal cross-talk between AR and TrkA, which is controlled by β1 integrin. The contribution of FlnA/AR complex and PI3-K δ to neuronal differentiation by androgens and NGF is also novel. This is the first description of AR function in PC12 cells. PMID:26063730

  14. Positive association of the androgen receptor CAG repeat length polymorphism with the risk of prostate cancer.

    PubMed

    Paz-Y-Miño, César; Robles, Paulo; Salazar, Carolina; Leone, Paola E; García-Cárdenas, Jennyfer M; Naranjo, Manuel; López-Cortés, Andrés

    2016-08-01

    Prostate cancer (PC) is the most frequently diagnosed cancer in Ecuador (15.6%). The androgen receptor gene codes for a protein that has an androgen‑binding domain, DNA‑binding domain and N‑terminal domain, which contains two polymorphic trinucleotide repeats (CAG and GGC). The aim of the present study was to determine whether variations in the number of repetitions of CAG and GGC are associated with the pathological features and the risk of developing PC. The polymorphic CAG and GGC repeat lengths in 108 mestizo patients with PC, 148 healthy mestizo individuals, and 78 healthy indigenous individuals were examined via a retrospective case‑control study. Genotypes were determined by genomic sequencing. The results demonstrated that patients with ≤21 CAG repeats have an increased risk of developing PC [odds ratio (OR)=2.99, 95% confidence interval (CI) =1.79‑5.01; P<0.001]. The presence of ≤21 CAG repeats was also associated with a tumor stage ≥T2c (OR=4.75; 95% CI=1.77‑12.72; P<0.005) and a Gleason score ≥7 (OR=2.9; 95% CI=1.1‑7.66; P=0.03). In addition, the combination of ≤21 CAG and ≥17 GGC repeats was associated with the risk of developing PC (OR=2.42; 95% CI=1.38‑4.25; P=0.002) and with tumor stage ≥T2c (OR=2.77; 95% CI=1.13‑6.79; P=0.02). In conclusion, the histopathological characteristics and PC risk in Ecuadorian indigenous and mestizo populations differs in association with the CAG repeats, and the combination of CAG and GGC repeats. PMID:27357524

  15. Concordance of phenotypic expression and gender identity in a large kindred with a mutation in the androgen receptor.

    PubMed

    Hooper, H T; Figueiredo, B C; Pavan-Senn, C C; De Lacerda, L; Sandrini, R; Mengarelli, J K; Japp, K; Karaviti, L P

    2004-03-01

    A 14-year-old female presented to the Pediatric Endocrine Clinic, Universidade Federal o Parana Curitiba, Brazil, for obesity. A few years later, despite normal breast development, the patient had failed to menstruate and lacked pubic and axillary hair. Laboratory analyses revealed high levels of testosterone. Karyotype analysis was XY. Direct sequencing of her genomic DNA showed a G to T transition at nucleotide 2089 at exon 2 in the androgen receptor gene, resulting in a substitution of Phe for Cys at position 576. This mutation disrupts the first Zn finger critical to DNA binding and transcriptional activity and results in complete androgen-insensitivity syndrome (CAIS). This individual was part of 700-member multigenerational kindred of German origin living in small villages in Southern Brazil. Family members who gave informed consent were screened using a polymerase chain reaction-based method. Nineteen CAIS-affected individuals and carriers were identified. All presented with infertility and lack of or sparse pubic hair. The prevalence of common AIS within the kindred greatly exceeds that of the general population and is due in part to their isolated familial and community structures. All individuals are genuinely feminine in their appearance, sex behavior, gender identity, and integration within their communities. We conclude that CAIS leads to complete feminization of XY individuals and results in individuals who are psychologically and socially established and integrated as women within the familial and cultural contexts of their communities. PMID:14756668

  16. Androgen receptor and miRNA-126* axis controls follicle-stimulating hormone receptor expression in porcine ovarian granulosa cells.

    PubMed

    Du, Xing; Li, Qiqi; Pan, Zengxiang; Li, Qifa

    2016-08-01

    Androgen, which acts via the androgen receptor (AR), plays crucial roles in mammalian ovarian function. Recent studies showed that androgen/AR signaling regulates follicle-stimulating hormone receptor (FSHR) expression in follicles; however, the detailed mechanism underlying this regulation remained unknown. Here, we demonstrate that AR and miR-126* cooperate to inhibit FSHR expression and function in pig follicular granulosa cells (pGCs). In pGCs, overexpression of AR decreased, whereas knockdown increased, FSHR mRNA and protein expression; however, neither manipulation affected FSHR promoter activity. Using a dual-luciferase reporter assay, we found that the FSHR gene is a direct target of miR-126*, which inhibits FSHR expression and increases the rate of AR-induced apoptosis in pGCs. Collectively, our data show for the first time that the AR/miR-126* axis exerts synergetic effects in the regulation of FSHR expression and apoptosis in pGCs. Our findings thus define a novel pathway, AR/miR-126*/FSHR, that regulates mammalian GC functions. PMID:27222597

  17. Androgen receptor expression and morphology of forebrain and neuromuscular systems in male green anoles displaying individual differences in sexual behavior

    PubMed Central

    Neal, Jennifer K.; Wade, Juli

    2010-01-01

    Investigating individual differences in sexual performance in unmanipulated males is important for understanding natural relationships between behavior and morphology, and the mechanisms regulating them. Among male green anole lizards, some court and copulate frequently (studs) and others do not (duds). To evaluate potential factors underlying differences in the level of these behaviors, morphology and androgen receptor expression in neuromuscular courtship and copulatory structures, as well as in the preoptic area and amygdala, were compared in males displaying varying degrees of sexual function. This study revealed that individual differences in behavior among unmanipulated males, in particular the extension of a throat fan (dewlap) used during courtship, were positively correlated with the size of fibers in the associated muscle and with soma size in the amygdala. The physiological response to testosterone, as indicated by the height of cells in an androgen-sensitive portion of the kidney, was also correlated with male sexual behavior, and predicted it better than plasma androgen levels. Androgen receptor expression was not related to the display of courtship or copulation in any of the tissues examined. The present data indicate that higher levels of male courtship behavior result in (or are the result of) enhanced courtship muscle and amygdala morphology, and that androgen-sensitive tissue in studs may be more responsive to testosterone than duds. However, some mechanism(s) other than androgen receptor expression likely confer this difference in responsiveness. PMID:17531996

  18. Androgen receptor expression and morphology of forebrain and neuromuscular systems in male green anoles displaying individual differences in sexual behavior.

    PubMed

    Neal, Jennifer K; Wade, Juli

    2007-08-01

    Investigating individual differences in sexual performance in unmanipulated males is important for understanding natural relationships between behavior and morphology, and the mechanisms regulating them. Among male green anole lizards, some court and copulate frequently (studs) and others do not (duds). To evaluate potential factors underlying differences in the level of these behaviors, morphology and androgen receptor expression in neuromuscular courtship and copulatory structures, as well as in the preoptic area and amygdala, were compared in males displaying varying degrees of sexual function. This study revealed that individual differences in behavior among unmanipulated males, in particular the extension of a throat fan (dewlap) used during courtship, were positively correlated with the size of fibers in the associated muscle and with soma size in the amygdala. The physiological response to testosterone, as indicated by the height of cells in an androgen-sensitive portion of the kidney, was also correlated with male sexual behavior, and predicted it better than plasma androgen levels. Androgen receptor expression was not related to the display of courtship or copulation in any of the tissues examined. The present data indicate that higher levels of male courtship behavior result in (or are the result of) enhanced courtship muscle and amygdala morphology, and that androgen-sensitive tissue in studs may be more responsive to testosterone than duds. However, some mechanism(s) other than androgen receptor expression likely confer this difference in responsiveness. PMID:17531996

  19. Female predominance in meningiomas can not be explained by differences in progesterone, estrogen, or androgen receptor expression.

    PubMed

    Korhonen, Katariina; Salminen, Tiina; Raitanen, Jani; Auvinen, Anssi; Isola, Jorma; Haapasalo, Hannu

    2006-10-01

    The female predominance in meningioma incidence and association between meningioma and breast cancer suggest that growth of meningiomas is hormone-dependent. There are several discrepancies in literature about the proliferative effect of sex hormones on meningiomas. This study aims to evaluate the hormone receptor status of meningiomas and assess its relation to age, sex, histological grade, recurrence, and proliferation activity. The material was based on consecutive patients operated for meningioma at Tampere University Hospital in 1989-1999. The occurrence of progesterone, estrogen and androgen receptor in patients with primary and recurrent meningiomas was studied immunohistochemically by using specific monoclonal antibodies. Hormonal status was determined in 510 tumor samples. 443 samples were from primary meningiomas and 67 from recurrent tumors. Of the samples, 455 were benign (WHO grade I), 49 atypical (grade II), and 6 malignant (grade III). Of the primary tumor samples, 88% were progesterone receptor positive, 40% were positive for estrogen and 39% for androgen receptors. Grade I meningiomas had significantly higher incidence for estrogen and androgen receptors than higher grade meningiomas. Estrogen positive tumor samples had significantly higher proliferation index than estrogen negative samples. No difference in expression of sex hormone receptors was observed by sexes or age group. Estrogen and androgen receptors may have more influence on the pathogenesis of meningiomas than earlier thought. The higher incidence of meningiomas in women can not be explained by differences of sex hormone receptor expression. PMID:16703453

  20. Tissue- and cell-specific functions of the androgen receptor revealed through conditional knockout models in mice.

    PubMed

    De Gendt, Karel; Verhoeven, Guido

    2012-04-16

    This review aims to evaluate the contribution of individual cell-selective knockout models to our current understanding of androgen action. Cre/loxP technology has allowed the generation of cell-selective knockout models targeting the androgen receptor (AR) in distinct putative target cells in a wide variety of organs and tissues including: testis, ovary, accessory sex tissues, muscle, bone, fat, liver, skin and myeloid tissue. In some androgen-regulated processes such as spermatogenesis and folliculogenesis this approach has lead to the identification of a key cellular mediator of androgen action (Sertoli and granulosa cells, respectively). In many target tissues, however, the final response to androgens appears to be more complex. Here, cell-selective knockout technology offers a platform upon which we can begin to unravel the more complex interplay and signaling pathways of androgens. A prototypic example is the analysis of mesenchymal-epithelial interactions in many accessory sex glands. Furthermore, for some actions of testosterone, in which part of the effect is mediated by the active metabolite 17β-estradiol, conditional knockout technology offers a novel strategy to study the relative contribution of AR and estrogen receptor-mediated signaling. The latter approach has already resulted in a better understanding of androgen action in brain and bone. Finally, cell-selective knockout technology has generated valuable models to search for AR-controlled molecular mediators of androgen action, a strategy that has successfully been applied to the study of androgen action in the testis and in the epididymis. Although some conditional knockout models have provided clear answers to physiologic questions, it should be noted that others have pointed to unexpected complexities or technical limitations confounding interpretation of the results. PMID:21871526

  1. An examination of the characteristics, concentration, and distribution of androgen receptor in rat testis during sexual maturation

    SciTech Connect

    Buzek, S.W.

    1989-01-01

    In these studies a nuclear exchange assay was established in rat testis in which exchange after 86 hours at 4{degree}C was greater than 85% complete and receptor was stable. Receptor concentration per DNA measured by exchange declined between 15 and 25 days of age in the rat testis, then increased 4-fold during sexual maturation. Proliferation of germ cells which had low receptor concentration appeared to account for the early decline in testicular receptor concentration, whereas increase in receptor number per Sertoli cell between 25 and 35 days of age contributed to the later increase. Detailed studies showed that other possible explanations for changes in receptor number were not likely. Androgen receptor dynamics in testicular cells showed rapid, specific uptake of ({sup 3}H)-testosterone that was easily blocked by unlabeled testosterone, and medroxyprogesterone acetate, but not as well as by the anti-androgens cyproterone acetate and hydroxyflutamide.

  2. The AhR Ligand, TCDD, Regulates Androgen Receptor Activity Differently in Androgen-Sensitive versus Castration-Resistant Human Prostate Cancer Cells.

    PubMed

    Ghotbaddini, Maryam; Powell, Joann B

    2015-07-01

    The reported biological effects of TCDD include induction of drug metabolizing enzymes, wasting syndrome and tumor promotion. TCDD elicits most of its effects through binding the aryl hydrocarbon receptor (AhR). TCDD induced degradation of AhR has been widely reported and requires ubiquitination of the protein. The rapid depletion of AhR following TCDD activation serves as a mechanism to modulate AhR mediated gene induction. In addition to inducing AhR degradation, TCDD has been reported to induce degradation of hormone receptors. The studies reported here, evaluate the effect of TCDD exposure on androgen receptor (AR) expression and activity in androgen-sensitive LNCaP and castration-resistant C4-2 prostate cancer cells. Our results show that TCDD exposure does not induce AhR or AR degradation in C4-2 cells. However, both AhR and AR are degraded in LNCaP cells following TCDD exposure. In addition, TCDD enhances AR phosphorylation and induces expression of AR responsive genes in LNCaP cells. Our data reveals that TCDD effect on AR expression and activity differs in androgen-sensitive and castration-resistant prostate cancer cell models. PMID:26154658

  3. The AhR Ligand, TCDD, Regulates Androgen Receptor Activity Differently in Androgen-Sensitive versus Castration-Resistant Human Prostate Cancer Cells

    PubMed Central

    Ghotbaddini, Maryam; Powell, Joann B.

    2015-01-01

    The reported biological effects of TCDD include induction of drug metabolizing enzymes, wasting syndrome and tumor promotion. TCDD elicits most of its effects through binding the aryl hydrocarbon receptor (AhR). TCDD induced degradation of AhR has been widely reported and requires ubiquitination of the protein. The rapid depletion of AhR following TCDD activation serves as a mechanism to modulate AhR mediated gene induction. In addition to inducing AhR degradation, TCDD has been reported to induce degradation of hormone receptors. The studies reported here, evaluate the effect of TCDD exposure on androgen receptor (AR) expression and activity in androgen-sensitive LNCaP and castration-resistant C4-2 prostate cancer cells. Our results show that TCDD exposure does not induce AhR or AR degradation in C4-2 cells. However, both AhR and AR are degraded in LNCaP cells following TCDD exposure. In addition, TCDD enhances AR phosphorylation and induces expression of AR responsive genes in LNCaP cells. Our data reveals that TCDD effect on AR expression and activity differs in androgen-sensitive and castration-resistant prostate cancer cell models. PMID:26154658

  4. Identification of Androgen Receptor Splice Variants in the Pten Deficient Murine Prostate Cancer Model.

    PubMed

    Liang, Mengmeng; Adisetiyo, Helty; Li, Xiuqing; Liu, Xiuqing; Liu, Ren; Gill, Parkash; Roy-Burman, Pradip; Jones, Jeremy O; Mulholland, David J

    2015-01-01

    Androgen receptor (AR) variants are associated with resistance to anti androgen therapy both in human prostate cancer cell lines and clinical samples. These observations support the hypothesis that AR isoform accumulation is a consequence of selective therapeutic pressure on the full length AR. The Pten deficient prostate cancer model proceeds with well-defined kinetics including progression to castration resistant prostate cancer (CRPC). While surgical castration and enzalutamide treatments yield an initial therapeutic response, Pten-/-epithelia continue to proliferate yielding locally invasive primary tumor pathology. That most epithelium remains AR positive, but ligand independent, suggests the presence of oncogenic AR variants. To address this hypothesis, we have used a panel of recently described Pten-/- tumor cell lines derived from both from hormone intact (E4, E8) and castrated Pten mutants (cE1, cE2) followed by RACE PCR to identify and characterize three novel truncated, amino terminus containing AR variants (mAR-Va, b, c). Variants appear not only conserved throughout progression but are correlated with nearly complete loss of full length AR (AR-FL) at castrate androgen levels. The overexpression of variants leads to enhanced transcriptional activity of AR while knock down studies show reduced transcriptional output. Collectively, the identification of truncated AR variants in the conditional PTEN deletion model supports a role for maintaining the CRPC phenotype and provides further therapeutic applications of this preclinical model. PMID:26196517

  5. Pituitary Androgen Receptor Signalling Regulates Prolactin but Not Gonadotrophins in the Male Mouse

    PubMed Central

    O’Hara, Laura; Curley, Michael; Tedim Ferreira, Maria; Cruickshanks, Lyndsey; Milne, Laura; Smith, Lee B.

    2015-01-01

    Production of the androgen testosterone is controlled by a negative feedback loop within the hypothalamic-pituitary-gonadal (HPG) axis. Stimulation of testicular Leydig cells by pituitary luteinising hormone (LH) is under the control of hypothalamic gonadotrophin releasing hormone (GnRH), while suppression of LH secretion by the pituitary is controlled by circulating testosterone. Exactly how androgens exert their feedback control of gonadotrophin secretion (and whether this is at the level of the pituitary), as well as the role of AR in other pituitary cell types remains unclear. To investigate these questions, we exploited a transgenic mouse line (Foxg1Cre/+; ARfl/y) which lacks androgen receptor in the pituitary gland. Both circulating testosterone and gonadotrophins are unchanged in adulthood, demonstrating that AR signalling is dispensable in the male mouse pituitary for testosterone-dependent regulation of LH secretion. In contrast, Foxg1Cre/+; ARfl/y males have a significant increase in circulating prolactin, suggesting that, rather than controlling gonadotrophins, AR-signalling in the pituitary acts to suppress aberrant prolactin production in males. PMID:25799562

  6. Enhancer RNAs participate in androgen receptor-driven looping that selectively enhances gene activation.

    PubMed

    Hsieh, Chen-Lin; Fei, Teng; Chen, Yiwen; Li, Tiantian; Gao, Yanfei; Wang, Xiaodong; Sun, Tong; Sweeney, Christopher J; Lee, Gwo-Shu Mary; Chen, Shaoyong; Balk, Steven P; Liu, Xiaole Shirley; Brown, Myles; Kantoff, Philip W

    2014-05-20

    The androgen receptor (AR) is a key factor that regulates the behavior and fate of prostate cancer cells. The AR-regulated network is activated when AR binds enhancer elements and modulates specific enhancer-promoter looping. Kallikrein-related peptidase 3 (KLK3), which codes for prostate-specific antigen (PSA), is a well-known AR-regulated gene and its upstream enhancers produce bidirectional enhancer RNAs (eRNAs), termed KLK3e. Here, we demonstrate that KLK3e facilitates the spatial interaction of the KLK3 enhancer and the KLK2 promoter and enhances long-distance KLK2 transcriptional activation. KLK3e carries the core enhancer element derived from the androgen response element III (ARE III), which is required for the interaction of AR and Mediator 1 (Med1). Furthermore, we show that KLK3e processes RNA-dependent enhancer activity depending on the integrity of core enhancer elements. The transcription of KLK3e was detectable and its expression is significantly correlated with KLK3 (R(2) = 0.6213, P < 5 × 10(-11)) and KLK2 (R(2) = 0.5893, P < 5 × 10(-10)) in human prostate tissues. Interestingly, RNAi silencing of KLK3e resulted in a modest negative effect on prostate cancer cell proliferation. Accordingly, we report that an androgen-induced eRNA scaffolds the AR-associated protein complex that modulates chromosomal architecture and selectively enhances AR-dependent gene expression. PMID:24778216

  7. Effects of testosterone on synaptic plasticity mediated by androgen receptors in male SAMP8 mice.

    PubMed

    Jia, Jian-Xin; Cui, Cheng-Li; Yan, Xu-Sheng; Zhang, Bai-Feng; Song, Wei; Huo, Dong-Sheng; Wang, He; Yang, Zhan-Jun

    2016-01-01

    Synaptic changes are closely associated with cognitive deficits. In addition, testosterone (T) is known to exert regulative effects on synaptic plasticity. T may improve cognitive deficits in Alzheimer's disease (AD) patients, but the underlying mechanisms of androgenic action on cognitive performance remain unclear. The aim of this study was thus to examine the protective mechanism attributed to T on cognitive performance in an AD senescence, accelerated mouse prone 8 (SAMP8) animal model. Using Golgi staining to quantify the dendritic spine density in hippocampal CA1 region, molecular biomarkers of synapse function were analyzed using immunohistochemistry and western blot. T significantly increased the dendritic spine density in hippocampal CA1 region, while flutamide (F) inhibited these T-mediated effects. Immunohistochemistry and western blot analysis showed that the expression levels of brain derived neurotrophic factor (BDNF), postsynaptic density 95 (PSD-95), and p-cyclic-AMP response element binding protein (CREB)/CREB levels were significantly elevated in the T group, but F reduced the T-induced effects in these biomarkers to control levels. There were no significant differences in the expression levels of PSD-95, BDNF, and p-CREB/CREB between C and F. These findings indicate that the effects of T on improvement in synaptic plasticity were mediated via androgen receptor (AR). It is conceivable that new treatments targeted toward preventing synaptic pathology in AD may involve the use of androgen-acting drugs. PMID:27599230

  8. Adaptive responses of androgen receptor signaling in castration-resistant prostate cancer

    PubMed Central

    2015-01-01

    Prostate Cancer (PCa) is an important age-related disease being the most common cancer malignancy and the second leading cause of cancer mortality in men in Western countries. Initially, PCa progression is androgen receptor (AR)- and androgen-dependent. Eventually advanced PCa reaches the stage of Castration-Resistant Prostate Cancer (CRPC), but remains dependent on AR, which indicates the importance of AR activity also for CRPC. Here, we discuss various pathways that influence the AR activity in CRPC, which indicates an adaptation of the AR signaling in PCa to overcome the treatment of PCa. The adaptation pathways include interferences of the normal regulation of the AR protein level, the expression of AR variants, the crosstalk of the AR with cytokine tyrosine kinases, the Src-Akt-, the MAPK-signaling pathways and AR corepressors. Furthermore, we summarize the current treatment options with regard to the underlying molecular basis of the common adaptation processes of AR signaling that may arise after the treatment with AR antagonists, androgen deprivation therapy (ADT) as well as for CRPC, and point towards novel therapeutic strategies. The understanding of individualized adaptation processes in PCa will lead to individualized treatment options in the future. PMID:26325261

  9. Regulation of androgen receptor splice variant AR3 by PCGEM1

    PubMed Central

    Zhang, Ziqiang; Zhou, Nanjiang; Huang, Jianguo; Ho, Tsui-Ting; Zhu, Zhuxian; Qiu, Zhongmin; Zhou, Xinchun; Bai, Chunxue; Wu, Fangting; Xu, Min; Mo, Yin-Yuan

    2016-01-01

    The androgen receptor (AR) is required for prostate development and is also a major driver of prostate cancer pathogenesis. Thus androgen deprivation therapy (ADT) is the mainstay of treatment for advanced prostate cancer. However, castration resistance due to expression of constitutively active AR splice variants is a significant challenge to prostate cancer therapy; little is known why effectiveness of ADT can only last for a relatively short time. In the present study, we show that PCGEM1 interacts with splicing factors heterogeneous nuclear ribonucleoprotein (hnRNP) A1 and U2AF65, as determined by RNA precipitation and Western blot, suggesting a role for PCGEM1 in alternative splicing. In support of this possibility, PCGEM1 is correlated with AR3, a predominant and clinically important form of AR splice variants in prostate cancer. Moreover, androgen deprivation (AD) induces PCGEM1 and causes its accumulation in nuclear speckles. Finally, we show that the AD-induced PCGEM1 regulates the competition between hnRNP A1 and U2AF65 for AR pre-mRNA. AD promotes PCGEM1 to interact with both hnRNP A1 and U2AF65 with different consequences. While the interaction of PCGEM1 with hnRNP A1 suppresses AR3 by exon skipping, its interaction with U2AF65 promotes AR3 by exonization. Together, we demonstrate an AD-mediated AR3 expression involving PCGEM1 and splicing factors. PMID:26848868

  10. Variable expressivity and mutation databases: The androgen receptor gene mutations database.

    PubMed

    Gottlieb, B; Beitel, L K; Trifiro, M A

    2001-05-01

    For over 50 years genetics has presumed that variations in phenotypic expression have, for the most part, been the result of alterations in genotype. The importance and value of mutation databases has been based on the premise that the same gene or allelic variation in a specific gene that has been proven to determine a specific phenotype, will always produce the same phenotype. However, recent evidence has shown that so called "simple" Mendelian disorders or monogenic traits are often far from simple, exhibiting phenotypic variation (variable expressivity) that cannot be explained solely by a gene or allelic alteration. The AR gene mutations database now lists 25 cases where different degrees of androgen insensitivity are caused by identical mutations in the androgen receptor gene. In five of these cases the phenotypic variability is due to somatic mosaicism, that is, somatic mutations that occur in only certain cells of androgen-sensitive tissue. Recently, a number of other cases of variable expressivity have also been linked to somatic mosaicism. The impact of variable expressivity due to somatic mutations and mosaicism on mutation databases is discussed. In particular, the effect of an organism exhibiting genetic heterogeneity within its tissues, and the possibility of an organism's genotype changing over its lifetime, are considered to have important implications for mutation databases in the future. PMID:11317353