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Sample records for active androgen receptor

  1. Spongian diterpenoids inhibit androgen receptor activity

    PubMed Central

    Yang, Yu Chi; Meimetis, Labros G; Tien, Amy H; Mawji, Nasrin R; Carr, Gavin; Wang, Jun; Andersen, Raymond J; Sadar, Marianne D

    2013-01-01

    Androgen receptor (AR) is a ligand-activated transcription factor and a validated drug target for all stages of prostate cancer. Antiandrogens compete with physiological ligands for AR ligand-binding domain (LBD). High-throughput screening of a marine natural product library for small molecules that inhibit AR transcriptional activity yielded the furanoditerpenoid spongia-13(16),-14-dien-19-oic acid, designated terpene 1 (T1). Characterization of T1 and the structurally related semi-synthetic analogues (T2 and T3) revealed that these diterpenoids have antiandrogen properties that include inhibition of both androgen-dependent proliferation and AR transcriptional activity by a mechanism that involved competing with androgen for AR LBD and blocking essential N/C interactions required for androgen-induced AR transcriptional activity. Structure activity relationship analyses revealed some chemical features of T1 that are associated with activity and yielded T3 as the most potent analogue. In vivo, T3 significantly reduced the weight of seminal vesicles, which are an androgen-dependent tissue, thereby confirming T3’s on-target activity. The ability to create analogues of diterpenoids that have varying antiandrogen activity represents a novel class of chemical compounds for the analysis of AR ligand-binding properties and therapeutic development. PMID:23443807

  2. Modulators of androgen and estrogen receptor activity.

    PubMed

    Clarke, Bart L; Khosla, Sundeep

    2010-01-01

    This review focuses on significant recent findings regarding modulators of androgen and estrogen receptor activity. Selective androgen receptor modulators (SARMs) interact with androgen receptors (ARs), and selective estrogen receptor modulators (SERMs) interact with estrogen receptors (ERs), with variable tissue selectivity. SERMs, which interact with both ERб and ERв in a tissue-specific manner to produce diverse outcomes in multiple tissues, continue to generate significant interest for clinical application. Development of SARMs for clinical application has been slower to date because of potential adverse effects, but these diverse compounds continue to be investigated for use in disorders in which modulation of the AR is important. SARMs have been investigated mostly at the basic and preclinical level to date, with few human clinical trials published. These compounds have been evaluated mostly for application in different stages of prostate cancer to date, but they hold promise for multiple other applications. Publication of the large STAR and RUTH clinical trials demonstrated that the SERMs tamoxifen and raloxifene have interesting similarities and differences in tissues that contain ERs. Lasofoxifene, bazedoxifene, and arzoxifene are newer SERMs that have been demonstrated in clinical trials to more potently increase bone mineral density and lower serum cholesterol values than tamoxifen or raloxifene. Both SARMs and SERMs hold great promise for therapeutic use in multiple disorders in which tissue-specific effects are mediated by their respective receptors.

  3. Androgen receptor antagonists (antiandrogens): structure-activity relationships.

    PubMed

    Singh, S M; Gauthier, S; Labrie, F

    2000-02-01

    Prostate cancer, acne, seborrhea, hirsutism, and androgenic alopecia are well recognized to depend upon an excess or increased sensitivity to androgens or to be at least sensitive to androgens. It thus seems logical to use antiandrogens as therapeutic agents to prevent androgens from binding to the androgen receptor. The two predominant naturally occurring androgens are testosterone (T) and dihydrotestosterone (DHT). DHT is the more potent androgen in vivo and in vitro. All androgen-responsive genes are activated by androgen receptor (AR) bound to either T or DHT and it is believed that AR is more transcriptionally active when bound to DHT than T. The two classes of antiandrogens, presently available, are the steroidal derivatives, all of which possess mixed agonistic and antagonistic activities, and the pure non-steroidal antiandrogens of the class of flutamide and its derivatives. The intrinsic androgenic, estrogenic and glucocorticoid activities of steroidal derivatives have limited their use in the treatment of prostate cancer. The non-steroidal flutamide and its derivatives display pure antiandrogenic activity, without exerting agonistic or any other hormonal activity. Flutamide (89) and its derivatives, Casodex (108) and Anandron (114), are highly effective in the treatment of prostate cancer. The combination of flutamide and Anandron with castration has shown prolongation of life in prostate cancer. Furthermore, combined androgen blockade in association with radical prostatectomy or radiotherapy are very effective in the treatment of localized prostate cancer. Such an approach certainly raises the hope of a further improvement in prostate cancer therapy. However, all antiandrogens, developed so-far display moderate affinity for the androgen receptor, and thus moderate efficacy in vitro and in vivo. There is thus a need for next-generation antiandrogens, which could display an equal or even higher affinity for AR compared to the natural androgens, and at the

  4. 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

  5. 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

  6. Structural characteristics of anabolic androgenic steroids contributing to binding to the androgen receptor and to their anabolic and androgenic activities. Applied modifications in the steroidal structure.

    PubMed

    Fragkaki, A G; Angelis, Y S; Koupparis, M; Tsantili-Kakoulidou, A; Kokotos, G; Georgakopoulos, C

    2009-02-01

    Anabolic androgenic steroids (AAS) are synthetic derivatives of testosterone introduced for therapeutic purposes providing enhanced anabolic potency with reduced androgenic effects. Androgens mediate their action through their binding to the androgen receptor (AR) which is mainly expressed in androgen target tissues, such as the prostate, skeletal muscle, liver and central nervous system. This paper reviews some of the wide spectrum of testosterone and synthetic AAS structure modifications related to the intended enhancement in anabolic activity. The structural features of steroids necessary for effective binding to the AR and those which contribute to the stipulation of the androgenic and anabolic activities are also presented.

  7. Activation of two mutant androgen receptors from human prostatic carcinoma by adrenal androgens and metabolic derivatives of testosterone.

    PubMed

    Culig, Z; Stober, J; Gast, A; Peterziel, H; Hobisch, A; Radmayr, C; Hittmair, A; Bartsch, G; Cato, A C; Klocker, H

    1996-01-01

    The androgen receptor (AR) plays a central regulatory role in prostatic carcinoma and is a target of androgen ablation therapy. Recent detection of mutant receptors in tumor specimens suggest a contribution of AR alterations to progression towards androgen independence. In a specimen derived from metastatic prostate cancer we have reported a point mutation in the AR gene that leads to a single amino acid exchange in the ligand binding domain of the receptor. Another amino acid exchange resulting from a point mutation was also identified 15 amino acids away from our mutation. This mutation was detected in the AR gene isolated from an organ-confined prostatic tumor. Here we report the functional characterization of the two mutant receptors in the presence of adrenal androgens and testosterone metabolites. These studies were performed by cotransfecting androgen-responsive reporter genes and either the wild-type or mutant AR expression vectors into receptor negative DU-145 and CV-1 cells. The indicator genes used consisted of the promoter of the androgen-inducible prostate-specific antigen gene or the C' Delta9 enhancer fragment from the promoter of the mouse sex-limited protein driving the expression of the bacterial chloramphenicol acetyl transferase gene. Cotransfection-transactivation assays revealed that the adrenal androgen androstenedione and two products of testosterone metabolism, androsterone and androstandiol, induced reporter gene activity more efficiently in the presence of the mutant receptors than in the presence of the wild-type receptor. No difference between wild-type and mutant receptors was observed in the presence of the metabolite androstandione. The interaction of receptor-hormone complexes with target DNA was studied in vitro by electrophoretic mobility shift assays (EMSA). Dihydrotestosterone and the synthetic androgen mibolerone induced a faster migrating complex with all receptors, whereas the androgen metabolite androstandione induced this

  8. Negative Modulation of Androgen Receptor Transcriptional Activity by Daxx

    PubMed Central

    Lin, Ding-Yen; Fang, Hsin-I; Ma, Ai-Hong; Huang, Yen-Sung; Pu, Yeong-Shiau; Jenster, Guido; Kung, Hsing-Jien; Shih, Hsiu-Ming

    2004-01-01

    The transcriptional activity of the androgen receptor (AR) modulated by positive or negative regulators plays a critical role in controlling the growth and survival of prostate cancer cells. Although numerous positive regulators have been identified, negative regulators of AR are less well understood. We report here that Daxx functions as a negative AR coregulator through direct protein-protein interactions. Overexpression of Daxx suppressed AR-mediated promoter activity in COS-1 and LNCaP cells and AR-mediated prostate-specific antigen expression in LNCaP cells. Conversely, downregulation of endogenous Daxx expression by RNA interference enhances androgen-induced prostate-specific antigen expression in LNCaP cells. In vitro and in vivo interaction studies revealed that Daxx binds to both the amino-terminal and the DNA-binding domain of the AR. Daxx proteins interfere with the AR DNA-binding activity both in vitro and in vivo. Moreover, sumoylation of AR at its amino-terminal domain is involved in Daxx interaction and trans-repression. Together, these findings not only provide a novel role of Daxx in controlling AR transactivation activity but also uncover the mechanism underlying sumoylation-dependent transcriptional repression of the AR. PMID:15572661

  9. 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.

  10. Androgen receptors, sex behavior, and aggression.

    PubMed

    Cunningham, Rebecca L; Lumia, Augustus R; McGinnis, Marilyn Y

    2012-01-01

    Androgens are intricately involved in reproductive and aggressive behaviors, but the role of the androgen receptor in mediating these behaviors is less defined. Further, activity of the hypothalamic-pituitary-gonadal axis and hypothalamic-pituitary-adrenal axis can influence each other at the level of the androgen receptor. Knowledge of the mechanisms for androgens' effects on behaviors through the androgen receptor will guide future studies in elucidating male reproductive and aggressive behavior repertoires.

  11. 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.

  12. 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...

  13. A physiological role for androgen actions in the absence of androgen receptor DNA binding activity.

    PubMed

    Pang, Tammy P S; Clarke, Michele V; Ghasem-Zadeh, Ali; Lee, Nicole K L; Davey, Rachel A; MacLean, Helen E

    2012-01-01

    We tested the hypothesis that androgens have physiological actions via non-DNA binding-dependent androgen receptor (AR) signaling pathways in males, using our genetically modified mice that express a mutant AR with deletion of the 2nd zinc finger of the DNA binding domain (AR(ΔZF2)) that cannot bind DNA. In cultured genital skin fibroblasts, the mutant AR(ΔZF2) has normal ligand binding ability, phosphorylates ERK-1/2 in response to 1 min DHT treatment (blocked by the AR antagonist bicalutamide), but has reduced androgen-dependent nuclear localization compared to wildtype (WT). AR(ΔZF2) males have normal baseline ERK-1/2 phosphorylation, with a 1.5-fold increase in Akt phosphorylation in AR(ΔZF2) muscle vs WT. To identify physiological actions of non-DNA binding-dependent AR signaling, AR(ΔZF2) males were treated for 6 weeks with dihydrotestosterone (DHT). Cortical bone growth was suppressed by DHT in AR(ΔZF2) mice (6% decrease in periosteal and 7% decrease in medullary circumference vs untreated AR(ΔZF2) males). In conclusion, these data suggest that non-DNA binding dependent AR actions suppress cortical bone growth, which may provide a mechanism to fine-tune the response to androgens in bone.

  14. The Deubiquitinating Enzyme USP7 Regulates Androgen Receptor Activity by Modulating Its Binding to Chromatin*

    PubMed Central

    Chen, Shu-Ting; Okada, Maiko; Nakato, Ryuichiro; Izumi, Kosuke; Bando, Masashige; Shirahige, Katsuhiko

    2015-01-01

    The androgen receptor (AR), a nuclear receptor superfamily transcription factor, plays a key role in prostate cancer. AR signaling is the principal target for prostate cancer treatment, but current androgen-deprivation therapies cannot completely abolish AR signaling because of the heterogeneity of prostate cancers. Therefore, unraveling the mechanism of AR reactivation in androgen-depleted conditions can identify effective prostate cancer therapeutic targets. Increasing evidence indicates that AR activity is mediated by the interplay of modifying/demodifying enzymatic co-regulators. To better understand the mechanism of AR transcriptional activity regulation, we used antibodies against AR for affinity purification and identified the deubiquitinating enzyme ubiquitin-specific protease 7, USP7 as a novel AR co-regulator in prostate cancer cells. We showed that USP7 associates with AR in an androgen-dependent manner and mediates AR deubiquitination. Sequential ChIP assays indicated that USP7 forms a complex with AR on androgen-responsive elements of target genes upon stimulation with the androgen 5α-dihydrotestosterone. Further investigation indicated that USP7 is necessary to facilitate androgen-activated AR binding to chromatin. Transcriptome profile analysis of USP7-knockdown LNCaP cells also revealed the essential role of USP7 in the expression of a subset of androgen-responsive genes. Hence, inhibition of USP7 represents a compelling therapeutic strategy for the treatment of prostate cancer. PMID:26175158

  15. Analytical methodology for the profiling and characterization of androgen receptor active compounds in human placenta.

    PubMed

    Indiveri, Paolo; Horwood, Julia; Abdul-Sada, Alaa; Arrebola, Juan P; Olea, Nicolas; Hill, Elizabeth M

    2014-08-01

    The exposure to endocrine disrupting chemicals during foetal development has been proposed to cause reproductive dysfunctions in the neonate or later life. In order to support such studies, an analytical method was developed to profile the receptor mediated (anti)androgenic activities present in extracts of placenta samples. Placenta samples from women giving birth to healthy male neonates were extracted and fractionated by HPLC. Fractions containing androgen receptor (AR) activity were detected using an in vitro yeast-based human androgen receptor transcription screen. GC-MS analyses of receptor active fractions resulted in detection of chemical contaminants including antimicrobial and cosmetic compounds which exhibited AR antagonist activity in the yeast screen, and endogenously derived steroids which contributed to both the agonist and antagonistic activity in the samples. The bioassay-directed fractionation methodology developed in this study revealed the potential to identify mixtures of chemical contaminants that should be investigated for potential effects on the reproductive system.

  16. 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

  17. Human androgen receptor expressed in HeLa cells activates transcription in vitro.

    PubMed Central

    De Vos, P; Schmitt, J; Verhoeven, G; Stunnenberg, H G

    1994-01-01

    The androgen receptor (AR) is a ligand-responsive transcription factor, belonging to the class of steroid receptors. AR mutations have been associated with various X-linked diseases, characterized by complete or partial resistance to androgens. To further analyse the molecular mechanism of action of the AR, we have produced the human AR in HeLa cells with a Vaccinia virus expression system. Binding studies on infected HeLa cells demonstrate that the recombinant AR interacts specifically and with high affinity with natural and synthetic androgens. In a gel retardation assay the partially purified AR specifically recognizes an androgen response element of the rat prostatic binding protein gene. Moreover, the recombinant AR activates transcription in vitro from a synthetic promoter construct containing glucocorticoid response elements (GRE). Images PMID:8165128

  18. Synthesis, structure-activity relationships, and characterization of novel nonsteroidal and selective androgen receptor modulators.

    PubMed

    Schlienger, Nathalie; Lund, Birgitte W; Pawlas, Jan; Badalassi, Fabrizio; Bertozzi, Fabio; Lewinsky, Rasmus; Fejzic, Alma; Thygesen, Mikkel B; Tabatabaei, Ali; Bradley, Stefania Risso; Gardell, Luis R; Piu, Fabrice; Olsson, Roger

    2009-11-26

    Herein we describe the discovery of ACP-105 (1), a novel and potent nonsteroidal selective androgen receptor modulator (SARM) with partial agonist activity relative to the natural androgen testosterone. Compound 1 was developed from a series of compounds found in a HTS screen using the receptor selection and amplification technology (R-SAT). In vivo, 1 improved anabolic parameters in a 2-week chronic study in castrated male rats. In addition to compound 1, a number of potent antiandrogens were discovered from the same series of compounds whereof one compound, 13, had antagonist activity at the AR T877A mutant involved in prostate cancer.

  19. 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

  20. SUMOylation modulates the transcriptional activity of androgen receptor in a target gene and pathway selective manner.

    PubMed

    Sutinen, Päivi; Malinen, Marjo; Heikkinen, Sami; Palvimo, Jorma J

    2014-07-01

    Androgen receptor (AR) plays an important regulatory role in prostate cancer. AR's transcriptional activity is regulated by androgenic ligands, but also by post-translational modifications, such as SUMOylation. To study the role of AR SUMOylation in genuine chromatin environment, we compared androgen-regulated gene expression and AR chromatin occupancy in PC-3 prostate cancer cell lines stably expressing wild-type (wt) or doubly SUMOylation site-mutated AR (AR-K386R,K520R). Our genome-wide gene expression analyses reveal that the SUMOylation modulates the AR function in a target gene and pathway selective manner. The transcripts that are differentially regulated by androgen and SUMOylation are linked to cellular movement, cell death, cellular proliferation, cellular development and cell cycle. Fittingly, SUMOylation mutant AR cells proliferate faster and are more sensitive to apoptosis. Moreover, ChIP-seq analyses show that the SUMOylation can modulate the chromatin occupancy of AR on many loci in a fashion that parallels their differential androgen-regulated expression. De novo motif analyses reveal that FOXA1, C/EBP and AP-1 motifs are differentially enriched at the wtAR- and the AR-K386R,K520R-preferred genomic binding positions. Taken together, our data indicate that SUMOylation does not simply repress the AR activity, but it regulates AR's interaction with the chromatin and the receptor's target gene selection.

  1. Identification of Anabolic Selective Androgen Receptor Modulators with Reduced Activities in Reproductive Tissues and Sebaceous Glands

    PubMed Central

    Schmidt, Azriel; Harada, Shun-Ichi; Kimmel, Donald B.; Bai, Chang; Chen, Fang; Rutledge, Su Jane; Vogel, Robert L.; Scafonas, Angela; Gentile, Michael A.; Nantermet, Pascale V.; McElwee-Witmer, Sheila; Pennypacker, Brenda; Masarachia, Patricia; Sahoo, Soumya P.; Kim, Yuntae; Meissner, Robert S.; Hartman, George D.; Duggan, Mark E.; Rodan, Gideon A.; Towler, Dwight A.; Ray, William J.

    2009-01-01

    Androgen replacement therapy is a promising strategy for the treatment of frailty; however, androgens pose risks for unwanted effects including virilization and hypertrophy of reproductive organs. Selective Androgen Receptor Modulators (SARMs) retain the anabolic properties of androgens in bone and muscle while having reduced effects in other tissues. We describe two structurally similar 4-aza-steroidal androgen receptor (AR) ligands, Cl-4AS-1, a full agonist, and TFM-4AS-1, which is a SARM. TFM-4AS-1 is a potent AR ligand (IC50, 38 nm) that partially activates an AR-dependent MMTV promoter (55% of maximal response) while antagonizing the N-terminal/C-terminal interaction within AR that is required for full receptor activation. Microarray analyses of MDA-MB-453 cells show that whereas Cl-4AS-1 behaves like 5α-dihydrotestosterone (DHT), TFM-4AS-1 acts as a gene-selective agonist, inducing some genes as effectively as DHT and others to a lesser extent or not at all. This gene-selective agonism manifests as tissue-selectivity: in ovariectomized rats, Cl-4AS-1 mimics DHT while TFM-4AS-1 promotes the accrual of bone and muscle mass while having reduced effects on reproductive organs and sebaceous glands. Moreover, TFM-4AS-1 does not promote prostate growth and antagonizes DHT in seminal vesicles. To confirm that the biochemical properties of TFM-4AS-1 confer tissue selectivity, we identified a structurally unrelated compound, FTBU-1, with partial agonist activity coupled with antagonism of the N-terminal/C-terminal interaction and found that it also behaves as a SARM. TFM-4AS-1 and FTBU-1 represent two new classes of SARMs and will allow for comparative studies aimed at understanding the biophysical and physiological basis of tissue-selective effects of nuclear receptor ligands. PMID:19846549

  2. Identification of anabolic selective androgen receptor modulators with reduced activities in reproductive tissues and sebaceous glands.

    PubMed

    Schmidt, Azriel; Harada, Shun-Ichi; Kimmel, Donald B; Bai, Chang; Chen, Fang; Rutledge, Su Jane; Vogel, Robert L; Scafonas, Angela; Gentile, Michael A; Nantermet, Pascale V; McElwee-Witmer, Sheila; Pennypacker, Brenda; Masarachia, Patricia; Sahoo, Soumya P; Kim, Yuntae; Meissner, Robert S; Hartman, George D; Duggan, Mark E; Rodan, Gideon A; Towler, Dwight A; Ray, William J

    2009-12-25

    Androgen replacement therapy is a promising strategy for the treatment of frailty; however, androgens pose risks for unwanted effects including virilization and hypertrophy of reproductive organs. Selective Androgen Receptor Modulators (SARMs) retain the anabolic properties of androgens in bone and muscle while having reduced effects in other tissues. We describe two structurally similar 4-aza-steroidal androgen receptor (AR) ligands, Cl-4AS-1, a full agonist, and TFM-4AS-1, which is a SARM. TFM-4AS-1 is a potent AR ligand (IC(50), 38 nm) that partially activates an AR-dependent MMTV promoter (55% of maximal response) while antagonizing the N-terminal/C-terminal interaction within AR that is required for full receptor activation. Microarray analyses of MDA-MB-453 cells show that whereas Cl-4AS-1 behaves like 5alpha-dihydrotestosterone (DHT), TFM-4AS-1 acts as a gene-selective agonist, inducing some genes as effectively as DHT and others to a lesser extent or not at all. This gene-selective agonism manifests as tissue-selectivity: in ovariectomized rats, Cl-4AS-1 mimics DHT while TFM-4AS-1 promotes the accrual of bone and muscle mass while having reduced effects on reproductive organs and sebaceous glands. Moreover, TFM-4AS-1 does not promote prostate growth and antagonizes DHT in seminal vesicles. To confirm that the biochemical properties of TFM-4AS-1 confer tissue selectivity, we identified a structurally unrelated compound, FTBU-1, with partial agonist activity coupled with antagonism of the N-terminal/C-terminal interaction and found that it also behaves as a SARM. TFM-4AS-1 and FTBU-1 represent two new classes of SARMs and will allow for comparative studies aimed at understanding the biophysical and physiological basis of tissue-selective effects of nuclear receptor ligands.

  3. 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

  4. The CXCL12/CXCR4 axis promotes ligand-independent activation of the androgen receptor.

    PubMed

    Kasina, Sathish; Macoska, Jill A

    2012-04-01

    The molecular mechanisms responsible for the transition of some prostate cancers from androgen ligand-dependent to androgen ligand-independent are incompletely established. Molecules that are ligands for G protein coupled receptors (GPCRs) have been implicated in ligand-independent androgen receptor (AR) activation. The purpose of this study was to examine whether CXCL12, the ligand for the GPCR, CXCR4, might mediate prostate cancer cell proliferation through AR-dependent mechanisms involving functional transactivation of the AR in the absence of androgen. The results of these studies showed that activation of the CXCL12/CXCR4 axis promoted: The nuclear accumulation of both wild-type and mutant AR in several prostate epithelial cell lines; AR-dependent proliferative responses; nuclear accumulation of the AR co-regulator SRC-1 protein; SRC-1:AR protein:protein association; co-localization of AR and SRC-1 on the promoters of AR-regulated genes; AR- and SRC-1 dependent transcription of AR-regulated genes; AR-dependent secretion of the AR-regulated PSA protein; P13K-dependent phosphorylation of AR; MAPK-dependent phosphorylation of SRC-1, and both MAPK- and P13K-dependent secretion of the PSA protein, in the absence of androgen. Taken together, these studies identify CXCL12 as a novel, non-steroidal growth factor that promotes the growth of prostate epithelial cells through AR-dependent mechanisms in the absence of steroid hormones. These findings support the development of novel therapeutics targeting the CXCL12/CXCR4 axis as an ancillary to those targeting the androgen/AR axis to effectively treat castration resistant/recurrent prostate tumors.

  5. 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

  6. 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

  7. 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

  8. Hydrazinobenzoylcurcumin inhibits androgen receptor activity and growth of castration-resistant prostate cancer in mice

    PubMed Central

    Wu, Min; Kim, Sahn-Ho; Datta, Indrani; Levin, Albert; Dyson, Gregory; Li, Jing; Kaypee, Stephanie; Swamy, M. Mahadeva; Gupta, Nilesh; Kwon, Ho Jeong; Menon, Mani; Kundu, Tapas K.; Reddy, G. Prem-Veer

    2015-01-01

    There is a critical need for therapeutic agents that can target the amino-terminal domain (NTD) of androgen receptor (AR) for the treatment of castration-resistant prostate cancer (CRPC). Calmodulin (CaM) binds to the AR NTD and regulates AR activity. We discovered that Hydrazinobenzoylcurcumin (HBC), which binds exclusively to CaM, inhibited AR activity. HBC abrogated AR interaction with CaM, suppressed phosphorylation of AR Serine81, and blocked the binding of AR to androgen-response elements. RNA-Seq analysis identified 57 androgen-regulated genes whose expression was significantly (p ≤ 0.002) altered in HBC treated cells as compared to controls. Oncomine analysis revealed that genes repressed by HBC are those that are usually overexpressed in prostate cancer (PCa) and genes stimulated by HBC are those that are often down-regulated in PCa, suggesting a reversing effect of HBC on androgen-regulated gene expression associated with PCa. Ingenuity Pathway Analysis revealed a role of HBC affected genes in cellular functions associated with proliferation and survival. HBC was readily absorbed into the systemic circulation and inhibited the growth of xenografted CRPC tumors in nude mice. These observations demonstrate that HBC inhibits AR activity by targeting the AR NTD and suggest potential usefulness of HBC for effective treatment of CRPC. PMID:25704883

  9. Lysine Specific Demethylase 1 has Dual Functions as a Major Regulator of Androgen Receptor Transcriptional Activity

    PubMed Central

    Cai, Changmeng; He, Housheng Hansen; Gao, Shuai; Chen, Sen; Yu, Ziyang; Gao, Yanfei; Chen, Shaoyong; Chen, Mei Wei; Zhang, Jesse; Ahmed, Musaddeque; Wang, Yang; Metzger, Eric; Schüle, Roland; Liu, X. Shirley; Brown, Myles; Balk, Steven P.

    2014-01-01

    SUMMARY Lysine Specific Demethylase 1 (LSD1, KDM1A) functions as a transcriptional corepressor through demethylation of histone 3 lysine 4 (H3K4), but has coactivator function on some genes through unclear mechanisms. We show that LSD1, interacting with CoREST, associates with and coactivates androgen receptor (AR) on a large fraction of androgen-stimulated genes. A subset of these AR/LSD1-associated enhancer sites have histone 3 threonine 6 phosphorylation (H3T6ph), and these sites are further enriched for androgen-stimulated genes. Significantly, despite its coactivator activity, LSD1 still mediates H3K4me2 demethylation at these androgen-stimulated enhancers. FOXA1 is also associated with LSD1 at AR regulated enhancer sites, and a FOXA1 interaction with LSD1 enhances binding of both proteins at these sites. These findings show LSD1 functions broadly as a regulator of AR function, that it maintains a transcriptional repression function at AR-regulated enhancers through H3K4 demethylation, and has a distinct AR-linked coactivator function mediated by demethylation of other substrates. PMID:25482560

  10. Glucocorticoid Receptor Activity Contributes to Resistance to Androgen-Targeted Therapy in Prostate Cancer

    PubMed Central

    Isikbay, Masis; Otto, Kristen; Kregel, Steven; Kach, Jacob; Cai, Yi; Vander Griend, Donald J.; Conzen, Suzanne D.

    2015-01-01

    Despite new treatments for castrate-resistant prostate cancer (CRPC), the prognosis of patients with CRPC remains bleak due to acquired resistance to androgen receptor (AR)-directed therapy. The glucocorticoid receptor (GR) and AR share several transcriptional targets, including the anti-apoptotic genes serum and glucocorticoid-regulated kinase 1 (SGK1) and Map kinase phosphatase 1 (MKP1)/dual specificity phosphatase 1 (DUSP1). Because GR expression increases in a subset of primary prostate cancer (PC) following androgen deprivation therapy, we sought to determine whether GR activation can contribute to resistance to AR-directed therapy. We studied CWR-22Rv1 and LAPC4 AR/GR-expressing PC cell lines following treatment with combinations of the androgen R1881, AR antagonist MDV3100, GR agonist dexamethasone, GR antagonists mifepristone and CORT 122928, or the SGK1 inhibitor GSK650394. Cell lines stably expressing GR (NR3C1)-targeted shRNA or ectopic SGK1-Flag were also studied in vivo. GR activation diminished the effects of the AR antagonist MDV3100 on tumor cell viability. In addition, GR activation increased prostate-specific antigen (PSA) secretion and induced SGKI and MKP1/DUSP gene expression. Glucocorticoid-mediated cell viability was diminished by a GR antagonist or by co-treatment with the SGK1 inhibitor GSK650394. In vivo, GR depletion delayed castrate-resistant tumor formation, while SGK1-Flag-overexpressing PC xenografts displayed accelerated castrate-resistant tumor initiation, supporting a role for SGK1 in GR-mediated CRPC progression. We studied several PC models before and following treatment with androgen blockade and found that increased GR expression and activity contributed to tumor-promoting PC cell viability. Increased GR-regulated SGK1 expression appears, at least in part, to mediate enhanced PC cell survival. Therefore, GR and/or SGK1 inhibition may be useful adjuncts to AR blockade for treating CRPC. PMID:24615402

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

    PubMed

    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; Wright, Michael E

    2015-08-01

    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.

  12. 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

  13. Bioluminescence Microscopy as a Method to Measure Single Cell Androgen Receptor Activity Heterogeneous Responses to Antiandrogens

    PubMed Central

    Jain, Pallavi; Neveu, Bertrand; Velot, Lauriane; Wu, Lily; Fradet, Yves; Pouliot, Frédéric

    2016-01-01

    Cancer cell heterogeneity is well-documented. Therefore, techniques to monitor single cell heterogeneous responses to treatment are needed. We developed a highly translational and quantitative bioluminescence microscopy method to measure single cell androgen receptor (AR) activity modulation by antiandrogens from fluid biopsies. We showed that this assay can detect heterogeneous cellular response to drug treatment and that the sum of single cell AR activity can mirror the response in the whole cell population. This method may thus be used to monitor heterogeneous dynamic treatment responses in cancer cells. PMID:27678181

  14. 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

  15. Enhancement of gene transactivation activity of androgen receptor by hepatitis B virus X protein

    SciTech Connect

    Zheng Yanyan; Chen Wenling; Ma, W.-L. Maverick; Chang Chawnshang; Ou, J.-H. James . E-mail: jamesou@hsc.usc.edu

    2007-07-05

    Hepatitis B virus (HBV) X protein (HBx) is a regulatory protein that is required for efficient replication of HBV in its natural host. In this report, we demonstrate by co-immunoprecipitation experiments that HBx can physically bind to the androgen receptor (AR), which is a nuclear hormone receptor that is expressed in many different tissues including the liver. This observation is further supported by confocal microscopy, which reveals that HBx can alter the subcellular localization of the AR both in the presence and in the absence of dihydrotestosterone (DHT). Further studies indicate that HBx can enhance the gene transactivation activity of AR by enhancing its DNA binding activity in a DHT-dependent manner. However, HBx does not remain associated with AR on the DNA. As AR can regulate the expression of a number of cellular genes, our results raise the possibility that HBV pathogenesis may be mediated in part via the interaction between HBx and AR.

  16. The androgen receptor gene mutations database.

    PubMed

    Patterson, M N; Hughes, I A; Gottlieb, B; Pinsky, L

    1994-09-01

    The androgen receptor gene mutations database is a comprehensive listing of mutations published in journals and meetings proceedings. The majority of mutations are point mutations identified in patients with androgen insensitivity syndrome. Information is included regarding the phenotype, the nature and location of the mutations, as well as the effects of the mutations on the androgen binding activity of the receptor. The current version of the database contains 149 entries, of which 114 are unique mutations. The database is available from EMBL (NetServ@EMBL-Heidelberg.DE) or as a Macintosh Filemaker file (mc33001@musica.mcgill.ca).

  17. Modulation of Androgen Receptor Activation Function 2 by Testosterone and Dihydrotestosterone*

    PubMed Central

    Askew, Emily B.; Gampe, Robert T.; Stanley, Thomas B.; Faggart, Jonathan L.; Wilson, Elizabeth M.

    2014-01-01

    The androgen receptor (AR) is transcriptionally activated by high affinity binding of testosterone (T) or its 5α-reduced metabolite, dihydrotestosterone (DHT), a more potent androgen required for male reproductive tract development. The molecular basis for the weaker activity of T was investigated by determining T-bound ligand binding domain crystal structures of wild-type AR and a prostate cancer somatic mutant complexed with the AR FXXLF or coactivator LXXLL peptide. Nearly identical interactions of T and DHT in the AR ligand binding pocket correlate with similar rates of dissociation from an AR fragment containing the ligand binding domain. However, T induces weaker AR FXXLF and coactivator LXXLL motif interactions at activation function 2 (AF2). Less effective FXXLF motif binding to AF2 accounts for faster T dissociation from full-length AR. T can nevertheless acquire DHT-like activity through an AR helix-10 H874Y prostate cancer mutation. The Tyr-874 mutant side chain mediates a new hydrogen bonding scheme from exterior helix-10 to backbone protein core helix-4 residue Tyr-739 to rescue T-induced AR activity by improving AF2 binding of FXXLF and LXXLL motifs. Greater AR AF2 activity by improved core helix interactions is supported by the effects of melanoma antigen gene protein-11, an AR coregulator that binds the AR FXXLF motif and targets AF2 for activation. We conclude that T is a weaker androgen than DHT because of less favorable T-dependent AR FXXLF and coactivator LXXLL motif interactions at AF2. PMID:17591767

  18. An imaging agent to detect androgen receptor and its active splice variants in prostate cancer

    PubMed Central

    Imamura, Yusuke; Tien, Amy H.; Pan, Jinhe; Leung, Jacky K.; Banuelos, Carmen A.; Jian, Kunzhong; Wang, Jun; Mawji, Nasrin R.; Fernandez, Javier Garcia; Lin, Kuo-Shyan; Andersen, Raymond J.; Sadar, Marianne D.

    2016-01-01

    Constitutively active splice variants of androgen receptor (AR-Vs) lacking ligand-binding domain (LBD) are a mechanism of resistance to androgen receptor LBD–targeted (AR LBD–targeted) therapies for metastatic castration-resistant prostate cancer (CRPC). There is a strong unmet clinical need to identify prostate cancer patients with AR-V–positive lesions to determine whether they will benefit from further AR LBD–targeting therapies or should receive taxanes or investigational drugs like EPI-506 or galeterone. Both EPI-506 (NCT02606123) and galeterone (NCT02438007) are in clinical trials and are proposed to have efficacy against lesions that are positive for AR-Vs. AR activation function-1 (AF-1) is common to the N-terminal domains of full-length AR and AR-Vs. Here, we provide proof of concept for developing imaging compounds that directly bind AR AF-1 to detect both AR-Vs and full-length AR. 123I-EPI-002 had specific binding to AR AF-1, which enabled direct visualization of CRPC xenografts that express full-length AR and AR-Vs. Our findings highlight the potential of 123I-EPI-002 as an imaging agent for the detection of full-length AR and AR-Vs in CRPC. PMID:27525313

  19. Androgen receptor serine 81 phosphorylation mediates chromatin binding and transcriptional activation.

    PubMed

    Chen, Shaoyong; Gulla, Sarah; Cai, Changmeng; Balk, Steven P

    2012-03-01

    Our previous findings indicated that androgen receptor (AR) phosphorylation at serine 81 is stimulated by the mitotic cyclin-dependent kinase 1 (CDK1). In this report, we extended our previous study and confirmed that Ser-81 phosphorylation increases during mitosis, coincident with CDK1 activation. We further showed blocking cell cycle at G(1) or S phase did not disrupt androgen-induced Ser-81 phosphorylation and AR-dependent transcription, consistent with a recent report that AR was phosphorylated at Ser-81 and activated by the transcriptional CDK9. To assess the function of Ser-81 phosphorylation in prostate cancer (PCa) cells expressing endogenous AR, we developed a ligand switch strategy using a ligand-binding domain mutation (W741C) that renders AR responsive to the antagonist bicalutamide. An S81A/W741C double mutant AR stably expressed in PCa cells failed to transactivate the endogenous AR-regulated PSA or TMPRSS2 genes. ChIP showed that the S81A mutation prevented ligand-induced AR recruitment to these genes, and cellular fractionation revealed that the S81A mutation globally abrogated chromatin binding. Conversely, the AR fraction rapidly recruited to chromatin after androgen stimulation was highly enriched for Ser-81 phosphorylation. Finally, inhibition of CDK1 and CDK9 decreased AR Ser-81 phosphorylation, chromatin binding, and transcriptional activity. These findings indicate that Ser-81 phosphorylation by CDK9 stabilizes AR chromatin binding for transcription and suggest that CDK1-mediated Ser-81 phosphorylation during mitosis provides a pool of Ser-81 phosphorylation AR that can be readily recruited to chromatin for gene reactivation and may enhance AR activity in PCa.

  20. Transcriptional network of androgen receptor in prostate cancer progression.

    PubMed

    Takayama, Ken-ichi; Inoue, Satoshi

    2013-08-01

    The androgen receptor belongs to the nuclear receptor superfamily and functions as a ligand-dependent transcription factor. It binds to the androgen responsive element and recruits coregulatory factors to modulate gene transcription. In addition, the androgen receptor interacts with other transcription factors, such as forkhead box A1, and other oncogenic signaling pathway molecules that bind deoxyribonucleic acid and regulate transcription. Androgen receptor signaling plays an important role in the development of prostate cancer. Prostate cancer cells proliferate in an androgen-dependent manner, and androgen receptor blockade is effective in prostate cancer therapy. However, patients often progress to castration-resistant prostate cancer with elevated androgen receptor expression and hypersensitivity to androgen. Recently, comprehensive analysis tools, such as complementary DNA microarray, chromatin immunoprecipitation-on-chip and chromatin immunoprecipitation-sequence, have described the androgen-mediated diverse transcriptional program and gene networks in prostate cancer. Furthermore, functional and clinical studies have shown that some of the androgen receptor-regulated genes could be prognostic markers and potential therapeutic targets for the treatment of prostate cancer, particularly castration-resistant prostate cancer. Thus, identifying androgen receptor downstream signaling events and investigating the regulation of androgen receptor activity is critical for understanding the mechanism of carcinogenesis and progression to castration-resistant prostate cancer.

  1. Cholesterol synthesis inhibitor RO 48-8071 suppresses transcriptional activity of human estrogen and androgen receptor.

    PubMed

    Mafuvadze, Benford; Liang, Yayun; Hyder, Salman M

    2014-10-01

    Breast cancer cells express enzymes that convert cholesterol, the synthetic precursor of steroid hormones, into estrogens and androgens, which then drive breast cancer cell proliferation. In the present study, we sought to determine whether oxidosqualene cyclase (OSC), an enzyme in the cholesterol biosynthetic pathway, may be targeted to suppress progression of breast cancer cells. In previous studies, we showed that the OSC inhibitor RO 48-8071 (RO) may be a ligand which could potentially be used to control the progression of estrogen receptor-α (ERα)-positive breast cancer cells. Herein, we showed, by real-time PCR analysis of mRNA from human breast cancer biopsies, no significant differences in OSC expression at various stages of disease, or between tumor and normal mammary cells. Since the growth of hormone-responsive tumors is ERα-dependent, we conducted experiments to determine whether RO affects ERα. Using mammalian cells engineered to express human ERα or ERβ protein, together with an ER-responsive luciferase promoter, we found that RO dose-dependently inhibited 17β-estradiol (E2)-induced ERα responsive luciferase activity (IC50 value, ~10 µM), under conditions that were non-toxic to the cells. RO was less effective against ERβ-induced luciferase activity. Androgen receptor (AR) mediated transcriptional activity was also reduced by RO. Notably, while ERα activity was reduced by atorvastatin, the HMG-CoA reductase inhibitor did not influence AR activity, showing that RO possesses broader antitumor properties. Treatment of human BT-474 breast cancer cells with RO reduced levels of estrogen-induced PR protein, confirming that RO blocks ERα activity in tumor cells. Our findings demonstrate that an important means by which RO suppresses hormone-dependent growth of breast cancer cells is through its ability to arrest the biological activity of ERα. This warrants further investigation of RO as a potential therapeutic agent for use against hormone

  2. Global analysis of transcription in castration-resistant prostate cancer cells uncovers active enhancers and direct androgen receptor targets

    PubMed Central

    Toropainen, Sari; Niskanen, Einari A.; Malinen, Marjo; Sutinen, Päivi; Kaikkonen, Minna U.; Palvimo, Jorma J.

    2016-01-01

    Androgen receptor (AR) is a male sex steroid-activated transcription factor (TF) that plays a critical role in prostate cancers, including castration-resistant prostate cancers (CRPC) that typically express amplified levels of the AR. CRPC-derived VCaP cells display an excessive number of chromatin AR-binding sites (ARBs) most of which localize to distal inter- or intragenic regions. Here, we analyzed direct transcription programs of the AR in VCaP cells using global nuclear run-on sequencing (GRO-seq) and integrated the GRO-seq data with the ARB and VCaP cell-specific TF-binding data. Androgen immediately activated transcription of hundreds of protein-coding genes, including IGF-1 receptor and EGF receptor. Androgen also simultaneously repressed transcription of a large number of genes, including MYC. As functional enhancers have been postulated to produce enhancer-templated non-coding RNAs (eRNAs), we also analyzed the eRNAs, which revealed that only a fraction of the ARBs reside at functional enhancers. Activation of these enhancers was most pronounced at the sites that also bound PIAS1, ERG and HDAC3, whereas binding of HDAC3 and PIAS1 decreased at androgen-repressed enhancers. In summary, our genome-wide data of androgen-regulated enhancers and primary target genes provide new insights how the AR can directly regulate cellular growth and control signaling pathways in CPRC cells. PMID:27641228

  3. Global analysis of transcription in castration-resistant prostate cancer cells uncovers active enhancers and direct androgen receptor targets.

    PubMed

    Toropainen, Sari; Niskanen, Einari A; Malinen, Marjo; Sutinen, Päivi; Kaikkonen, Minna U; Palvimo, Jorma J

    2016-01-01

    Androgen receptor (AR) is a male sex steroid-activated transcription factor (TF) that plays a critical role in prostate cancers, including castration-resistant prostate cancers (CRPC) that typically express amplified levels of the AR. CRPC-derived VCaP cells display an excessive number of chromatin AR-binding sites (ARBs) most of which localize to distal inter- or intragenic regions. Here, we analyzed direct transcription programs of the AR in VCaP cells using global nuclear run-on sequencing (GRO-seq) and integrated the GRO-seq data with the ARB and VCaP cell-specific TF-binding data. Androgen immediately activated transcription of hundreds of protein-coding genes, including IGF-1 receptor and EGF receptor. Androgen also simultaneously repressed transcription of a large number of genes, including MYC. As functional enhancers have been postulated to produce enhancer-templated non-coding RNAs (eRNAs), we also analyzed the eRNAs, which revealed that only a fraction of the ARBs reside at functional enhancers. Activation of these enhancers was most pronounced at the sites that also bound PIAS1, ERG and HDAC3, whereas binding of HDAC3 and PIAS1 decreased at androgen-repressed enhancers. In summary, our genome-wide data of androgen-regulated enhancers and primary target genes provide new insights how the AR can directly regulate cellular growth and control signaling pathways in CPRC cells. PMID:27641228

  4. Antagonism effects of cypermethrin on interleukin-6-induced androgen receptor activation.

    PubMed

    Wang, Qi; Xu, Li-Fang; Zhou, Ji-Long; Zhou, Xiao-Long; Wang, Hui; Ju, Qiang; Pan, Chen; Zhang, Jin-Peng; Zhang, Mei-Rong; Yu, Hong-Min; Xu, Li-Chun

    2015-07-01

    To identify whether androgen receptor (AR) antagonism by cypermethrin involves interleukin-6 (IL-6)-induced ligand-independent AR signaling, we have developed the AR reporter gene assay. The reporter gene plasmid pMMTV-chloramphenicol transferase (CAT) was transfected into LNCaP cells. IL-6 increased expression of MMTV-CAT significantly (P<0.05). Cypermethrin decreased CAT reporter expression induced by IL-6 (50 ng/ml), and the significant inhibition was detected at 10(-5)M (P<0.05). IL-6 induces ligand-independent activation of AR. Cypermethrin exhibits inhibitory effects on IL-6-induced ligand-independent AR signaling. We provide a novel insight into cypermethrin-mediated antagonism of the IL-6-mediated ligand-independent activation of the AR.

  5. Identification of SRC3/AIB1 as a Preferred Coactivator for Hormone-activated Androgen Receptor

    SciTech Connect

    Zhou, X. Edward; Suino-Powell, Kelly M.; Li, Jun; He, Yuanzheng; MacKeigan, Jeffrey P.; Melcher, Karsten; Yong, Eu-Leong; Xu, H.Eric

    2010-09-17

    Transcription activation by androgen receptor (AR), which depends on recruitment of coactivators, is required for the initiation and progression of prostate cancer, yet the mechanisms of how hormone-activated AR interacts with coactivators remain unclear. This is because AR, unlike any other nuclear receptor, prefers its own N-terminal FXXLF motif to the canonical LXXLL motifs of coactivators. Through biochemical and crystallographic studies, we identify that steroid receptor coactivator-3 (SRC3) (also named as amplified in breast cancer-1 or AIB1) interacts strongly with AR via synergistic binding of its first and third LXXLL motifs. Mutagenesis and functional studies confirm that SRC3 is a preferred coactivator for hormone-activated AR. Importantly, AR mutations found in prostate cancer patients correlate with their binding potency to SRC3, corroborating with the emerging role of SRC3 as a prostate cancer oncogene. These results provide a molecular mechanism for the selective utilization of SRC3 by hormone-activated AR, and they link the functional relationship between AR and SRC3 to the development and growth of prostate cancer.

  6. Interleukin-6 regulates androgen receptor activity and prostate cancer cell growth.

    PubMed

    Culig, Zoran; Bartsch, Georg; Hobisch, Alfred

    2002-11-29

    Interleukin-6 (IL-6) is a multifunctional cytokine which is involved in regulation of growth of various malignant tumors. IL-6 binds to its receptor, which is composed of a ligand-binding and a signal-transducing subunit and activates pathways of signal transducers and activators of transcription and mitogen-activated protein kinases (MAPKs). In prostate cancer cells, IL-6 induces divergent proliferative responses. Serum levels of IL-6 are elevated in patients with therapy-resistant carcinoma of the prostate. We have investigated whether IL-6 interacts with the androgen signaling pathway in prostate cancer cells. In DU-145 cells, transiently transfected with androgen receptor (AR) cDNA, IL-6 caused ligand-independent and synergistic activation of the AR. Nonsteroidal antagonists of the AR down-regulated AR activity induced by IL-6. In LNCaP cells, IL-6-induced expression of the AR-regulated prostate-specific antigen gene. Inhibitors of protein kinase A and C and MAPK down-regulated IL-6-induced AR activity. IL-6 expression in human prostate tissue was studied by immunohistochemistry. In benign prostatic tissue, IL-6 immunoreactivity was confined to basal cells. In prostate intraepithelial neoplasia and in cancer tissue, atypical intraluminal and cancer cells expressed IL-6. The expression of IL-6 receptor was demonstrated in benign and malignant tissue in both epithelium and stroma. In the authors' laboratory, IL-6-inhibited proliferation of parental LNCaP cells. A new LNCaP subline was generated to investigate changes in signal transduction which might occur after prolonged treatment with IL-6. In the subline LNCaP-IL-6+, IL-6 neither reduced a number of cells nor caused G1 growth arrest. IL-6 receptor expression declined during long-term IL-6 treatment. However, IL-6-up-regulated AR expression and was capable of inducing AR activity in LNCaP-IL-6+ cells. Parental LNCaP cells do not express IL-6. In contrast, IL-6 mRNA and protein expression were detectable in

  7. Selective androgen receptor modulators: in pursuit of tissue-selective androgens.

    PubMed

    Omwancha, Josephat; Brown, Terry R

    2006-10-01

    The androgen receptor mediates the androgenic and anabolic activity of the endogenous steroids testosterone and 5alpha-dihydrotestosterone. Current knowledge of the androgen receptor protein structure, and the molecular mechanisms surrounding the binding properties and activities of agonists and antagonists has led to the design and development of novel nonsteroidal ligands with selected tissue-specific androgen receptor agonist and antagonist activities. The activity of these compounds, termed selective androgen receptor modulators (SARMs), is directed toward the maintenance or enhancement of anabolic effects on bone and muscle with minimal androgenic effects on prostate growth. SARMs are of potential therapeutic value in the treatment of male hypogonadism, osteoporosis, frailty and muscle wasting, burn injury and would healing, anemia, mood and depression, benign prostatic hyperplasia and prostate cancer.

  8. 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.

  9. Comparative study on transcriptional activity of 17 parabens mediated by estrogen receptor α and β and androgen receptor.

    PubMed

    Watanabe, Yoko; Kojima, Hiroyuki; Takeuchi, Shinji; Uramaru, Naoto; Ohta, Shigeru; Kitamura, Shigeyuki

    2013-07-01

    The structure-activity relationships of parabens which are widely used as preservatives for transcriptional activities mediated by human estrogen receptor α (hERα), hERβ and androgen receptor (hAR) were investigated. Fourteen of 17 parabens exhibited hERα and/or hERβ agonistic activity at concentrations of ≤ 1 × 10(-5)M, whereas none of the 17 parabens showed AR agonistic or antagonistic activity. Among 12 parabens with linear alkyl chains ranging in length from C₁ to C₁₂, heptylparaben (C₇) and pentylparaben (C₅) showed the most potent ERα and ERβ agonistic activity in the order of 10(-7)M and 10(-8)M, respectively, and the activities decreased in a stepwise manner as the alkyl chain was shortened to C₁ or lengthened to C₁₂. Most parabens showing estrogenic activity exhibited ERβ-agonistic activity at lower concentrations than those inducing ERα-agonistic activity. The estrogenic activity of butylparaben was markedly decreased by incubation with rat liver microsomes, and the decrease of activity was blocked by a carboxylesterase inhibitor. These results indicate that parabens are selective agonists for ERβ over ERα; their interactions with ERα/β are dependent on the size and bulkiness of the alkyl groups; and they are metabolized by carboxylesterases, leading to attenuation of their estrogenic activity.

  10. LncRNA-Dependent Mechanisms of Androgen Receptor-regulated Gene Activation Programs

    PubMed Central

    Jin, Chunyu; Yang, Joy C.; Tanasa, Bogdan; Li, Wenbo; Merkurjev, Daria; Ohgi, Kenneth A.; Meng, Da; Zhang, Jie; Evans, Christopher P.; Rosenfeld, Michael G.

    2014-01-01

    While recent studies indicated roles of long non-coding RNAs (lncRNAs) in physiologic aspects of cell-type determination and tissue homeostasis1 yet their potential involvement in regulated gene transcription programs remain rather poorly understood. Androgen receptor (AR) regulates a large repertoire of genes central to the identity and behavior of prostate cancer cells2, and functions in a ligand-independent fashion in many prostate cancers when they become hormone refractory after initial androgen deprivation therapy3. Here, we report that two lncRNAs highly overexpressed in aggressive prostate cancer, PRNCR1 and PCGEM1, bind successively to the AR and strongly enhance both ligand-dependent and ligand-independent AR-mediated gene activation programs and proliferation in prostate cancer cells. Binding of PRNCR1 to the C-terminally acetylated AR on enhancers and its association with DOT1L appear to be required for recruitment of the second lncRNA, PCGEM1, to the DOT1L-mediated methylated AR N-terminus. Unexpectedly, recognition of specific protein marks by PCGEM1-recruited Pygopus2 PHD domain proves to enhance selective looping of AR-bound enhancers to target gene promoters in these cells. In “resistant” prostate cancer cells, these overexpressed lncRNAs can interact with, and are required for, the robust activation of both truncated and full length AR, causing ligand-independent activation of the AR transcriptional program and cell proliferation. Conditionally-expressed short hairpin RNA (shRNA) targeting of these lncRNAs in castration-resistant prostate cancer (CRPC) cell lines strongly suppressed tumor xenograft growth in vivo. Together, these results suggest that these overexpressed lncRNAs can potentially serve as a required component of castration-resistance in prostatic tumors. PMID:23945587

  11. Androgen receptor modulators: a marriage of chemistry and biology.

    PubMed

    McEwan, Iain J

    2013-06-01

    Androgenic steroids are important for male development in utero and secondary sexual characteristics at puberty. In addition, androgens play a role in non-reproductive tissues, such as bone and muscle in both sexes. The actions of the androgens testosterone and dihydrotestosterone are mediated by a single receptor protein, the androgen receptor. Over the last 60-70 years there has been considerable research interest in the development of inhibitors of androgen receptor for the management of diseases such as prostate cancer. However, more recently, there is also a growing appreciation of the need for selective androgen modulators that would demonstrate tissue-selective agonist or antagonist activity. The chemistry and biology of selective agonists, antagonists and selective androgen receptor modulators will be discussed in this review.

  12. Estrogen and androgen receptor activities of hydraulic fracturing chemicals and surface and ground water in a drilling-dense region

    USGS Publications Warehouse

    Kassotis, Christopher D.; Tillitt, Donald E.; Davis, J. Wade; Hormann, Anette M.; Nagel, Susan C.

    2014-01-01

    The rapid rise in natural gas extraction using hydraulic fracturing increases the potential for contamination of surface and ground water from chemicals used throughout the process. Hundreds of products containing more than 750 chemicals and components are potentially used throughout the extraction process, including more than 100 known or suspected endocrine-disrupting chemicals. We hypothesized thataselected subset of chemicalsusedin natural gas drilling operationsandalso surface and ground water samples collected in a drilling-dense region of Garfield County, Colorado, would exhibit estrogen and androgen receptor activities. Water samples were collected, solid-phase extracted, and measured for estrogen and androgen receptor activities using reporter gene assays in human cell lines. Of the 39 unique water samples, 89%, 41%, 12%, and 46% exhibited estrogenic, antiestrogenic, androgenic, and antiandrogenic activities, respectively. Testing of a subset of natural gas drilling chemicals revealed novel antiestrogenic, novel antiandrogenic, and limited estrogenic activities. The Colorado River, the drainage basin for this region, exhibited moderate levels of estrogenic, antiestrogenic, and antiandrogenic activities, suggesting that higher localized activity at sites with known natural gas–related spills surrounding the river might be contributing to the multiple receptor activities observed in this water source. The majority of water samples collected from sites in a drilling-dense region of Colorado exhibited more estrogenic, antiestrogenic, or antiandrogenic activities than reference sites with limited nearby drilling operations. Our data suggest that natural gas drilling operationsmayresult in elevated endocrine-disrupting chemical activity in surface and ground water.

  13. Estrogen and androgen receptor activities of hydraulic fracturing chemicals and surface and ground water in a drilling-dense region.

    PubMed

    Kassotis, Christopher D; Tillitt, Donald E; Davis, J Wade; Hormann, Annette M; Nagel, Susan C

    2014-03-01

    The rapid rise in natural gas extraction using hydraulic fracturing increases the potential for contamination of surface and ground water from chemicals used throughout the process. Hundreds of products containing more than 750 chemicals and components are potentially used throughout the extraction process, including more than 100 known or suspected endocrine-disrupting chemicals. We hypothesized that a selected subset of chemicals used in natural gas drilling operations and also surface and ground water samples collected in a drilling-dense region of Garfield County, Colorado, would exhibit estrogen and androgen receptor activities. Water samples were collected, solid-phase extracted, and measured for estrogen and androgen receptor activities using reporter gene assays in human cell lines. Of the 39 unique water samples, 89%, 41%, 12%, and 46% exhibited estrogenic, antiestrogenic, androgenic, and antiandrogenic activities, respectively. Testing of a subset of natural gas drilling chemicals revealed novel antiestrogenic, novel antiandrogenic, and limited estrogenic activities. The Colorado River, the drainage basin for this region, exhibited moderate levels of estrogenic, antiestrogenic, and antiandrogenic activities, suggesting that higher localized activity at sites with known natural gas-related spills surrounding the river might be contributing to the multiple receptor activities observed in this water source. The majority of water samples collected from sites in a drilling-dense region of Colorado exhibited more estrogenic, antiestrogenic, or antiandrogenic activities than reference sites with limited nearby drilling operations. Our data suggest that natural gas drilling operations may result in elevated endocrine-disrupting chemical activity in surface and ground water.

  14. A selective androgen receptor modulator with minimal prostate hypertrophic activity restores lean body mass in aged orchidectomized male rats.

    PubMed

    Allan, George; Sbriscia, Tifanie; Linton, Olivia; Lai, Muh-Tsann; Haynes-Johnson, Donna; Bhattacharjee, Sheela; Ng, Raymond; Sui, Zhihua; Lundeen, Scott

    2008-06-01

    Androgens are required for the maintenance of normal sexual activity in adulthood and for enhancing muscle growth and lean body mass in adolescents and adults. Androgen receptor (AR) ligands with tissue selectivity (selective androgen receptor modulators, or SARMs) have potential for treating muscle wasting, hypogonadism of aging, osteoporosis, female sexual dysfunction, and other indications. JNJ-37654032 is a nonsteroidal AR ligand with mixed agonist and antagonist activity in androgen-responsive cell-based assays. It is an orally active SARM with muscle selectivity in orchidectomized rat models. It stimulated growth of the levator ani muscle with ED(50) 0.8 mg/kg, stimulating maximal growth at a dose of 3mg/kg. In contrast, it stimulated ventral prostate growth to 21% of its full size at 3mg/kg. At the same time, JNJ-37654032 reduced prostate weight in intact rats by 47% at 3mg/kg, while having no inhibitory effect on muscle. Using magnetic resonance imaging to monitor body composition, JNJ-37654032 restored about 20% of the lean body mass lost following orchidectomy in aged rats. JNJ-37654032 reduced follicle-stimulating hormone levels in orchidectomized rats and reduced testis size in intact rats. JNJ-37654032 is a potent prostate-sparing SARM with the potential for clinical benefit in muscle-wasting diseases.

  15. A Combined Quantitative Structure-Activity Relationship Research of Quinolinone Derivatives as Androgen Receptor Antagonists.

    PubMed

    Wang, Yuwei; Bai, Fang; Cao, Hong; Li, Jiazhong; Liu, Huanxiang; Gramatica, Paola

    2015-01-01

    Antiandrogens bicalutamide, flutamide and enzalutamide etc. have been used in clinical trials to treat prostate cancer by binding to and antagonizing androgen receptor (AR). Although initially effective, the drug resistance problem will emerge eventually, which results in a high medical need for novel AR antagonist exploitation. Here in this work, to facilitate the rational design of novel AR antagonists, we studied the structure-activity relationships of a series of 2-quinolinone derivatives and investigated the structural requirements for their antiandrogenic activities. Different modeling methods, including 2D MLR, 3D CoMFA and CoMSIA, were implemented to evolve QSAR models. All these models, thoroughly validated, demonstrated satisfactory results especially for the good predictive abilities. The contour maps from 3D CoMFA and CoMSIA models provide visualized explanation of key structural characteristics relevant to the antiandrogenic activities, which is summarized to a position-specific conclusion at the end. The obtained results from this research are practically useful for rational design and screening of promising chemicals with high antiandrogenic activities.

  16. In Silico Discovery of Androgen Receptor Antagonists with Activity in Castration Resistant Prostate Cancer

    PubMed Central

    Shen, Howard C.; Shanmugasundaram, Kumaran; Simon, Nicholas I.; Cai, Changmeng; Wang, Hongyun; Chen, Sen; Rigby, Alan C.

    2012-01-01

    Previously available androgen receptor (AR) antagonists (bicalutamide, flutamide, and nilutamide) have limited activity against AR in prostate cancers that relapse after castration [castration resistant prostate cancer (CRPC)]. However, recent AR competitive antagonists such as MDV3100, generated through chemical modifications to the current AR ligands, appear to have increased activity in CRPC and have novel mechanisms of action. Using pharmacophore models and a refined homology model of the antagonist-liganded AR ligand binding domain, we carried out in silico screens of small molecule libraries and report here on the identification of a series of structurally distinct nonsteroidal small molecule competitive AR antagonists. Despite their unique chemical architectures, compounds representing each of six chemotypes functioned in vitro as pure AR antagonists. Moreover, similarly to MDV3100 and in contrast to previous AR antagonists, these compounds all prevented AR binding to chromatin, consistent with each of the six chemotypes stabilizing a similar AR antagonist conformation. Additional studies with the lead chemotype (chemotype A) showed enhanced AR protein degradation, which was dependent on helix 12 in the AR ligand binding domain. Significantly, chemotype A compounds functioned as AR antagonists in vivo in normal male mice and suppressed AR activity and tumor cell proliferation in human CRPC xenografts. These data indicate that certain ligand-induced structural alterations in the AR ligand binding domain may both impair AR chromatin binding and enhance AR degradation and support continued efforts to develop AR antagonists with unique mechanisms of action and efficacy in CRPC. PMID:23023563

  17. β-Catenin Binds to the Activation Function 2 Region of the Androgen Receptor and Modulates the Effects of the N-Terminal Domain and TIF2 on Ligand-Dependent Transcription

    PubMed Central

    Song, Liang-Nian; Herrell, Roger; Byers, Stephen; Shah, Salimuddin; Wilson, Elizabeth M.; Gelmann, Edward P.

    2003-01-01

    β-Catenin is a multifunctional molecule that is activated by signaling through WNT receptors. β-Catenin can also enhance the transcriptional activity of some steroid hormone receptors such as the androgen receptor and retinoic acid receptor α. Androgens can affect nuclear translocation of β-catenin and influence its subcellular distribution. Using mammalian two-hybrid binding assays, analysis of reporter gene transcription, and coimmunoprecipitation, we now show that β-catenin binds to the androgen receptor ligand-binding domain (LBD) and modulates the transcriptional effects of TIF2 and the androgen receptor N-terminal domain (NTD). In functional assays, β-catenin bound to androgen receptor only in the presence of ligand agonists, not antagonists. β-Catenin binding to the androgen receptor LBD was independent of and cooperative with the androgen receptor NTD and the p160 coactivator TIF2, both of which bind to the activation function 2 (AF-2) region of the androgen receptor. Different mutations of androgen receptor helix 3 amino acids disrupted binding of androgen receptor NTD and β-catenin. β-Catenin, androgen receptor NTD, and TIF2 binding to the androgen receptor LBD were affected similarly by a subset of helix 12 mutations, but disruption of two sites on helix 12 affected only binding of β-catenin and not of TIF2 or the androgen receptor NTD. Mutational disruption of each of five LXXLL peptide motifs in the β-catenin armadillo repeats did not disrupt either binding to androgen receptor or transcriptional coactivation. ICAT, an inhibitor of T-cell factor 4 (TCF-4), and E-cadherin binding to β-catenin also blocked binding of the androgen receptor LBD. We also demonstrated cross talk between the WNT and androgen receptor signaling pathways because excess androgen receptor could interfere with WNT signaling and excess TCF-4 inhibited the interaction of β-catenin and androgen receptor. Taken together, the data show that β-catenin can bind to the

  18. A Snapshot of the Expression Signature of Androgen Receptor Splicing Variants and Their Distinctive Transcriptional Activities

    PubMed Central

    Hu, Rong; Isaacs, William B.; Luo, Jun

    2012-01-01

    BACKGROUND The diversity and complexity of the human androgen receptor (AR) splicing variants are well appreciated but not fully understood. The goal of this study is to generate a comprehensive expression signature of AR variants in castration-resistant prostate cancer (CRPC), and to address the relative importance of the individual variants in conferring the castration-resistant phenotype. METHODS A modified RNA amplification method, termed selective linear amplification of sense RNA, was developed to amplify all AR transcripts containing AR exon 3 in CRPC specimens, which were profiled using tiling expression microarrays. Coding sequences for the AR variants were cloned into expression vectors and assessed for their transcriptional activities. Quantitative RT-PCR was used to determine their in vivo expression patterns in an expanded set of clinical specimens. RESULTS In addition to expression peaks in AR intron 3, a novel AR exon, termed exon 9, was discovered. Exon 9 was spliced into multiple novel AR variants. Different AR splicing variants were functionally distinctive, with some demonstrating constitutive activity while others were conditionally active. Conditionally active AR-Vs may activate AR signaling depending on the cellular context. Importantly, AR variant functions did not appear to depend on the full-length AR. CONCLUSIONS This study provided the first unbiased snapshot of the AR variant signature consisting of multiple AR variants with distinctive functional properties, directly in CRPC specimens. Study findings suggest that the aggregate function of multiple AR variants may confer a castration-resistant phenotype independent of the full-length AR. PMID:21446008

  19. Expanding the therapeutic use of androgens via selective androgen receptor modulators (SARMs).

    PubMed

    Gao, Wenqing; Dalton, James T

    2007-03-01

    Selective androgen receptor modulators (SARMs) are a novel class of androgen receptor (AR) ligands that might change the future of androgen therapy dramatically. With improved pharmacokinetic characteristics and tissue-selective pharmacological activities, SARMs are expected to greatly extend the clinical applications of androgens to osteoporosis, muscle wasting, male contraception and diseases of the prostate. Mechanistic studies with currently available SARMs will help to define the contributions of differential tissue distribution, tissue-specific expression of 5alpha-reductase, ligand-specific regulation of gene expression and AR interactions with tissue-specific coactivators to their observed tissue selectivity, and lead to even greater expansion of selective anabolic therapies.

  20. Masculinization of female mosquitofish in Kraft mill effluent-contaminated Fenholloway River water is associated with androgen receptor agonist activity.

    PubMed

    Parks, L G; Lambright, C S; Orlando, E F; Guillette, L J; Ankley, G T; Gray, L E

    2001-08-01

    Female mosquitofish (Gambusia affinis holbrooki) downstream from Kraft paper mills in Florida display masculinization of the anal fin, an androgen-dependent trait. The current investigation was designed to determine if water contaminated with pulp-mill effluent (PME) from the Fenholloway River in Florida displayed androgenic activity in vitro and to relate this activity to the reproductive status of female mosquitofish taken from this river. We tested water samples for androgenic activity from a reference site upstream of a Kraft pulp and paper mill on the Fenholloway River, from 3 sites downstream from the mill, and from another reference site on the Econfina River, also in Florida, where there is no paper mill. We also examined anal fin ray morphology in mosquitofish from these rivers for evidence of masculinization. Eighty percent of the female mosquitofish from the Fenholloway River were partially masculinized while another 10% were completely masculinized, based upon the numbers of segments in the longest anal fin ray (18.0 +/- 0.4 vs. 28.1 +/- 0.9 [p < 0.001]) in the Econfina River vs. the Fenholloway River, respectively). In a COS whole cell-binding assay, all 3 PME samples displayed affinity for human androgen receptor (hAR) (p < 0.001). In addition, PME induced androgen-dependent gene expression in CV-1 cells (cotransfected with pCMV hAR and MMTV luciferase reporter), which was inhibited by about 50% by coadministration of hydroxyflutamide (1 microM), an AR antagonist. Water samples collected upstream of the Kraft mill or from the Econfina River did not bind hAR or induce luciferase expression. When CV-1 cells were transfected with human glucocorticoid receptor (hGR) rather than hAR, PME failed to significantly induce MMTV-luciferase expression. Further evidence of the androgenicity was observed using a COS cell AR nuclear-translocalization assay. PME bound hAR and induced translocalization of AR into the nucleus. In contrast, AR remained perinuclear when

  1. Disruption of androgen and estrogen receptor activity in prostate cancer by a novel dietary diterpene carnosol: implications for chemoprevention

    PubMed Central

    Johnson, Jeremy J.; Syed, Deeba N.; Suh, Yewseok; Heren, Chenelle R.; Saleem, Mohammad; Siddiqui, Imtiaz A.; Mukhtar, Hasan

    2010-01-01

    Emerging data is suggesting that estrogens, in addition to androgens, may also be contributing to the development of prostate cancer (PCa). In view of this notion agents that target estrogens, in addition to androgens, may be a novel approach for PCa chemoprevention and treatment. Thus, the identification and development of non-toxic dietary agents capable of disrupting androgen receptor (AR) in addition to estrogen receptor (ER) could be extremely useful in the management of PCa. Through molecular modeling we found carnosol, a dietary diterpene fits within the ligand binding domain of both AR and ER-α. Using a TR-FRET assay we found that carnosol interacts with both AR and ER-α and additional experiments confirmed that it functions as a receptor antagonist with no agonist effects. LNCaP, 22Rv1, and MCF7 cells treated with carnosol (20–40 µM) showed decreased protein expression of AR and ER-α. Oral administration of carnosol at 30 mg/kg five days weekly for 28 days to 22Rv1 PCa xenografted mice suppressed tumor growth by 36% (p = 0.028) and was associated with a decrease in serum PSA by 26% (p=0.0042). These properties make carnosol unique to any known anti-androgen or anti-estrogen investigated so far for the simultaneous disruption of AR and ER-α. We suggest that carnosol may be developed or chemically modified through more rigorous structure activity relationship studies for a new class of investigational agents - a dual AR/ER modulator. PMID:20736335

  2. Androgen receptor (AR) in cardiovascular diseases.

    PubMed

    Huang, Chiung-Kuei; Lee, Soo Ok; Chang, Eugene; Pang, Haiyan; Chang, Chawnshang

    2016-04-01

    Cardiovascular diseases (CVDs) are still the highest leading cause of death worldwide. Several risk factors have been linked to CVDs, including smoking, diabetes, hyperlipidemia, and gender among others. Sex hormones, especially the androgen and its receptor, androgen receptor (AR), have been linked to many diseases with a clear gender difference. Here, we summarize the effects of androgen/AR on CVDs, including hypertension, stroke, atherosclerosis, abdominal aortic aneurysm (AAA), myocardial hypertrophy, and heart failure, as well as the metabolic syndrome/diabetes and their impacts on CVDs. Androgen/AR signaling exacerbates hypertension, and anti-androgens may suppress hypertension. Androgen/AR signaling plays dual roles in strokes, depending on different kinds of factors; however, generally males have a higher incidence of strokes than females. Androgen and AR differentially modulate atherosclerosis. Androgen deficiency causes elevated lipid accumulation to enhance atherosclerosis; however, targeting AR in selective cells without altering serum androgen levels would suppress atherosclerosis progression. Androgen/AR signaling is crucial in AAA development and progression, and targeting androgen/AR profoundly restricts AAA progression. Men have increased cardiac hypertrophy compared with age-matched women that may be due to androgens. Finally, androgen/AR plays important roles in contributing to obesity and insulin/leptin resistance to increase the metabolic syndrome.

  3. 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

  4. Androgen Receptor Expression in Prostate Cancer Cells Is Suppressed by Activation of Epidermal Growth Factor Receptor and ErbB2

    PubMed Central

    Cai, Changmeng; Portnoy, David C.; Wang, Hongyun; Jiang, Xinnong; Chen, Shaoyong; Balk, Steven P.

    2016-01-01

    Prostate cancers (PCa) that relapse after androgen deprivation therapies [castration-resistant PCa (CRPC)] express high levels of androgen receptor (AR) and androgen-regulated genes, and evidence from several groups indicates that ErbB family receptor tyrosine kinases [epidermal growth factor (EGF) receptor (EGFR) and ErbB2] may contribute to enhancing this AR activity. We found that activation of these kinases with EGF and heregulin-β1 rapidly (within 8 hours) decreased expression of endogenous AR and androgen-regulated PSA in LNCaP PCa cells. AR expression was similarly decreased in LAPC4 and C4-2 cells, but not in the CWR22Rv1 PCa cell line. The rapid decrease in AR was not due to increased AR protein degradation and was not blocked by phosphatidylinositol 3-kinase (LY294002) or MEK (UO126) inhibitors. Significantly, AR mRNA levels in LNCaP cells were markedly decreased by EGF and heregulin-β1, and experiments with actinomycin D to block new mRNA synthesis showed that AR mRNA degradation was increased. AR mRNA levels were still markedly decreased by EGF and heregulin-β1 in LNCaP cells adapted to growth in androgen-depleted medium, although AR protein levels did not decline due to increased AR protein stability. These findings show that EGFR and ErbB2 can negatively regulate AR mRNA and may provide an approach to suppress AR expression in CRPC. PMID:19491261

  5. Proline-Directed Androgen Receptor Phosphorylation

    PubMed Central

    Gao, Yanfei; Chen, Shaoyong

    2015-01-01

    The androgen receptor (AR) has been identified for decades and mediates essential steroid functions. Like most of biological molecules, AR functional activities are modulated by post-translational modifications. This review is focused on the reported activities and significance of AR phosphorylation, with particular emphasis on proline-directed serine/threonine phosphorylation that occurs predominantly on the receptor. The marked enrichment of AR phosphorylation in the most diverse N-terminal domain suggests that targeting AR phosphorylation can be synergistic to antagonizing the C-terminal domain by clinical antiandrogens. PMID:25866551

  6. EPI-001 is a selective peroxisome proliferator-activated receptor-gamma modulator with inhibitory effects on androgen receptor expression and activity in prostate cancer

    PubMed Central

    Brand, Lucas J.; Olson, Margaret E.; Ravindranathan, Preethi; Guo, Hong; Kempema, Aaron M.; Andrews, Timothy E.; Chen, Xiaoli; Raj, Ganesh V.; Harki, Daniel A.; Dehm, Scott M.

    2015-01-01

    The androgen receptor (AR) is a driver of prostate cancer (PCa) cell growth and disease progression. Therapies for advanced PCa exploit AR dependence by blocking the production or action of androgens, but these interventions inevitably fail via multiple mechanisms including mutation or deletion of the AR ligand binding domain (LBD). Thus, the development of new inhibitors which act through non-LBD interfaces is an unmet clinical need. EPI-001 is a bisphenol A-derived compound shown to bind covalently and inhibit the AR NH2-terminal domain (NTD). Here, we demonstrate that EPI-001 has general thiol alkylating activity, resulting in multilevel inhibitory effects on AR in PCa cell lines and tissues. At least one secondary mechanism of action associated with AR inhibition was found to be selective modulation of peroxisome proliferator activated receptor-gamma (PPARγ). These multi-level effects of EPI-001 resulted in inhibition of transcriptional activation units (TAUs) 1 and 5 of the AR NTD, and reduced AR expression. EPI-001 inhibited growth of AR-positive and AR-negative PCa cell lines, with the highest sensitivity observed in LNCaP cells. Overall, this study provides new mechanistic insights to the chemical biology of EPI-001, and raises key issues regarding the use of covalent inhibitors of the intrinsically unstructured AR NTD. PMID:25669987

  7. Development of selective androgen receptor modulators and their therapeutic applications.

    PubMed

    Chen, Fang; Rodan, Gideon A; Schmidt, Azi

    2002-01-01

    Androgens control a broad range of physiological functions. The androgen receptor (AR), a steroid receptor that mediates the diverse biological actions of androgens, is a ligand inducible transcription factor. Abnormalities in the androgen signaling system result in many disturbances ranging from changes in gender determination and sexual development to psychiatric and emotional disorders. Androgen replacement therapy can improve many clinical conditions including hypogonadism and osteoporosis, but is limited by the lack of efficacious and safe therapeutic agents with easy delivery options. Recent progress in the area of gene regulation by steroid receptors and by selective receptor modulators provides an opportunity to examine if selective androgen receptor modulators (SARMs) could address some of the problems associated with current androgen therapy. Since the composition of the transcriptional initiation complex recruited by liganded AR determines the specificity of gene regulation, synthetic ligands aimed at initiating transcription of tissue and promoter specific genes offers hope for developing better androgen therapy. Establishment of assays that predict synthetic ligand activity is critical for SARM development. Advancement in high throughput compound screening and gene fingerprinting technologies, such as microarrays and proteomics, will facilitate and accelerate identification of effective SARMs.

  8. SUMO-specific protease 1 modulates cadmium-augmented transcriptional activity of androgen receptor (AR) by reversing AR SUMOylation.

    PubMed

    Wu, Ruiqin; Cui, Yaxiong; Yuan, Xiaoyan; Yuan, Haitao; Wang, Yimei; He, Jun; Zhao, Jun; Peng, Shuangqing

    2014-09-01

    Cadmium is a potential prostate carcinogen and can mimic the effects of androgen by a mechanism that involves the hormone-binding domain of the androgen receptor (AR), which is a key transcriptional factor in prostate carcinogenesis. We focused on transcriptional activity of AR to investigate the toxicity of cadmium exposure on human prostate cell lines. Cadmium increased the proliferative index of LNCaP and the proliferative effect was obstructed significantly by AR blocking agent. In luciferase assay, cadmium activated the transcriptional activity of AR in 293T cells co-transfected with wild-type AR and an ARE (AR response elements)-luciferase reporter gene. Cadmium also increased expression of PSA, a downstream gene of AR, whereas the metal had no significant effect on AR amount. AR is regulated by multiple posttranslational modifications including SUMOylation. SUMOylated AR shows a lower transcriptional activity. SUMO-specific protease 1 (SENP1) decreases AR SUMOylation by deconjugating AR-SUMO covalent bond. We detected that cadmium increased the amount of SENP1 in a dose and time dependent manner. Knocking down of SENP1 by RNAi led to decrease of PSA expression and transcriptional activity of AR in luciferase assay. Furthermore, co-immunoprecipitation (Co-IP) results showed that SUMOylation level of AR was decreased after cadmium treatment. In conclusion, our results indicated that cadmium-induced SENP1 enhanced AR transcriptional activity by decreasing AR SUMOylation.

  9. Novel stably transfected human reporter cell line AIZ-AR as a tool for an assessment of human androgen receptor transcriptional activity.

    PubMed

    Bartonkova, Iveta; Novotna, Aneta; Dvorak, Zdenek

    2015-01-01

    Androgen receptor plays multiple physiological and pathological roles in human organism. In the current paper, we describe construction and characterization of a novel stably transfected human reporter cell line AIZ-AR for assessment of transcriptional activity of human androgen receptor. Cell line AIZ-AR is derived from human prostate carcinoma epithelial cell line 22Rv1 that was transfected with reporter plasmid containing 3 copies of androgen response regions (ARRs) followed by a single copy of androgen response element (ARE) from the promoter region of human prostate specific antigen (PSA) gene. AIZ-AR cells remained fully functional for more than 60 days and over 25 passages in the culture and even after cryopreservation. Time-course analyses showed that AIZ-AR cells allow detection of AR ligands as soon as after 8 hours of the treatment. We performed dose-response analyses with 23 steroids in 96-well plate format. We observed activation of AR by androgens, but not by estrogens and mineralocorticoids. Some glucocorticoids and progesterone also induced luciferase, but their potencies were 2-3 orders of magnitude weaker as compared to androgens. Taken together, we have developed a rapid, sensitive, selective, high-throughput and reproducible tool for detection of human AR ligands, with potential use in pharmacological and environmental applications.

  10. Histone H4 Lys 20 methyltransferase SET8 promotes androgen receptor-mediated transcription activation in prostate cancer

    SciTech Connect

    Yao, Lushuai; Li, Yanyan; Du, Fengxia; Han, Xiao; Li, Xiaohua; Niu, Yuanjie; Ren, Shancheng; Sun, Yingli

    2014-07-18

    Highlights: • Dihydrotestosterone stimulates H4K20me1 enrichment at the PSA promoter. • SET8 promotes AR-mediated transcription activation. • SET8 interacts with AR and promotes cell proliferation. - Abstract: Histone methylation status in different lysine residues has an important role in transcription regulation. The effect of H4K20 monomethylation (H4K20me1) on androgen receptor (AR)-mediated gene transcription remains unclear. Here we show that AR agonist stimulates the enrichment of H4K20me1 and SET8 at the promoter of AR target gene PSA in an AR dependent manner. Furthermore, SET8 is crucial for the transcription activation of PSA. Co-immunoprecipitation analyses demonstrate that SET8 interacts with AR. Therefore, we conclude that SET8 is involved in AR-mediated transcription activation, possibly through its interaction with AR and H4K20me1 modification.

  11. [Bone and Men's Health. Bone selective androgen receptor modulators].

    PubMed

    Furuya, Kazuyuki

    2010-02-01

    Androgen, one of the sex steroid hormones shows various biological activities on the corresponding various tissues. Many efforts to produce novel drug materials maintaining a desired biological activity with an adequate tissue selectivity, which is so-called selective androgen receptor modulators (SARMs) , are being performed. As one of such efforts, studies on SARMs against bone tissues which possess a significant potential to stimulate a bone formation with reducing undesirable androgenic virilizing activities are in progress all over the world. This review focuses on the research and development activities of such SARMs and discuses their usefulness for the treatment of osteoporosis.

  12. Androgen Receptor Exon 1 Mutation Causes Androgen Insensitivity by Creating Phosphorylation Site and Inhibiting Melanoma Antigen-A11 Activation of NH2- and Carboxyl-terminal Interaction-dependent Transactivation*

    PubMed Central

    Lagarde, William H.; Blackwelder, Amanda J.; Minges, John T.; Hnat, Andrew T.; French, Frank S.; Wilson, Elizabeth M.

    2012-01-01

    Naturally occurring germ line mutations in the X-linked human androgen receptor (AR) gene cause incomplete masculinization of the external genitalia by disrupting AR function in males with androgen insensitivity syndrome. Almost all AR missense mutations that cause androgen insensitivity syndrome are located in the highly structured DNA and ligand binding domains. In this report we investigate the functional defect associated with an AR exon 1 missense mutation, R405S, that caused partial androgen insensitivity. The 46,XX heterozygous maternal carrier had a wild-type Arg-405 CGC allele but transmitted an AGC mutant allele coding for Ser-405. At birth, the 46,XY proband had a bifid scrotum, hypospadias, and micropenis consistent with clinical stage 3 partial androgen insensitivity. Androgen-dependent transcriptional activity of AR-R405S expressed in CV1 cells was less than wild-type AR and refractory in androgen-dependent AR NH2- and carboxyl interaction transcription assays that depend on the coregulator effects of melanoma antigen-A11. This mutation created a Ser-405 phosphorylation site evident by the gel migration of an AR-R405S NH2-terminal fragment as a double band that converted to the wild-type single band after treatment with λ-phosphatase. Detrimental effects of the R405S mutation were related to the proximity of the AR WXXLF motif 433WHTLF437 required for melanoma antigen-A11 and p300 to stimulate transcriptional activity associated with the AR NH2- and carboxyl-terminal interaction. We conclude that the coregulator effects of melanoma antigen-A11 on the AR NH2- and carboxyl-terminal interaction amplify the androgen-dependent transcriptional response to p300 required for normal human male sex development in utero. PMID:22334658

  13. MDC1 functionally identified as an androgen receptor co-activator participates in suppression of prostate cancer

    PubMed Central

    Wang, Chunyu; Sun, Hongmiao; Zou, Renlong; Zhou, Tingting; Wang, Shengli; Sun, Shiying; Tong, Changci; Luo, Hao; Li, Yanshu; Li, Zhenhua; Wang, Enhua; Chen, Yuhua; Cao, Liu; Li, Feng; Zhao, Yue

    2015-01-01

    Mediator of DNA damage checkpoint protein 1 (MDC1) is essential for DNA damage response. However, the role of MDC1 in modulating gene transcription independently of DNA damage and the underlying mechanisms have not been fully defined. Androgen receptor (AR) is the central signaling pathway in prostate cancer (PCa) and its target genes are involved in both promotion and suppression of PCa. Here, we functionally identified MDC1 as a co-activator of AR. We demonstrate that MDC1 facilitates the association between AR and histone acetyltransferase GCN5, thereby increasing histone H3 acetylation level on cis-regulatory elements of AR target genes. MDC1 knockdown promotes PCa cells growth and migration. Moreover, depletion of MDC1 results in decreased expression of a subset of the endogenous androgen-induced target genes, including cell cycle negative regulator p21 and PCa metastasis inhibitor Vinculin, in AR positive PCa cell lines. Finally, the expression of MDC1 and p21 correlates negatively with aggressive phenotype of clinical PCa. These studies suggest that MDC1 as an epigenetic modifier regulates AR transcriptional activity and MDC1 may function as a tumor suppressor of PCa, and provide new insight into co-factor-AR-signaling pathway mechanism and a better understanding of the function of MDC1 on PCa. PMID:25934801

  14. Alterations Associated with Androgen Receptor Gene Activation in Salivary Duct Carcinoma (SDC) of Both Sexes: Potential Therapeutic Ramifications

    PubMed Central

    Mitani, Yoshitsugu; Rao, Pulivarthi H.; Maity, Sankar N.; Lee, Yu-Chen; Ferrarotto, Renata; Post, Julian C.; Licitra, Lisa; Lippman, Scott M.; Kies, Merrill S.; Weber, Randal S.; Caulin, Carlos; Lin, Sue-Hwa; El-Naggar, Adel K.

    2014-01-01

    Purpose To investigate the molecular events associated with the activation of androgen receptor (AR) as a potential therapeutic target in patients with salivary duct carcinoma (SDC). Experimental Design Comprehensive molecular and expression analysis of the AR gene in 35 tumor specimens (20 males and 15 females) and cell lines derived from SDC using Western blotting and RT-PCR, FISH analysis, and DNA sequencing were conducted. In vitro and in vivo animal studies were also performed. Results AR expression was detected in 70% of the tumors and was mainly nuclear and homogenous in both male and female SDCs, although variable cytoplasmic and/or nuclear localization was also found. We report the identification of Ligand-independent AR splice variants, mutations and extra AR gene copy in primary untreated SDC tumors. In contrast to prostate cancer, no AR gene amplification was observed. In vitro knockdown of AR in a female derived SDC cell line revealed marked growth inhibition in culture and in vivo androgen independent tumor growth. Conclusions Our study provides new detailed information on the molecular and structural alterations associated with AR gene activation in SDC and shed more light on the putative functional role of AR in SDC cells. Based on these data, we propose that patients with SDC (male and female) can be stratified for hormone-based therapy in future clinical trials. PMID:25316813

  15. Androgen receptor expression in gastrointestinal stromal tumor.

    PubMed

    Lopes, Lisandro F; Bacchi, Carlos E

    2009-03-01

    The aim of this study was to evaluate the expression of estrogen, progesterone, and androgen receptors in a large series of gastrointestinal stromal tumors. Clinical and pathologic data were reviewed in 427 cases of gastrointestinal stromal tumor and the expression of such hormone receptors was investigated by immunohistochemistry using tissue microarray technique. All tumors were negative for estrogen receptor expression. Progesterone and androgen receptors expression was observed in 5.4% and 17.6% of tumors, respectively. We found the higher average age at diagnosis, the lower frequency of tumors located in the small intestine, and the higher frequency of extragastrointestinal tumors to be statistically significant in the group of tumors with androgen receptor expression in contrast to the group showing no androgen receptor expression. There was no statistic difference between such groups regarding sex, tumor size, mitotic count, cell morphology, and risk of aggressive behavior. Considering that the expression of androgen receptors in gastrointestinal stromal tumors is not negligible, further studies are encouraged to establish the role of androgen deprivation therapy for gastrointestinal stromal tumors.

  16. 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

  17. Androgen receptor gene mutation, rearrangement, polymorphism.

    PubMed

    Eisermann, Kurtis; Wang, Dan; Jing, Yifeng; Pascal, Laura E; Wang, Zhou

    2013-09-01

    Genetic aberrations of the androgen receptor (AR) caused by mutations, rearrangements, and polymorphisms result in a mutant receptor that has varied functions compared to wild type AR. To date, over 1,000 mutations have been reported in the AR with most of these being associated with androgen insensitivity syndrome (AIS). While mutations of AR associated with prostate cancer occur less often in early stage localized disease, mutations in castration-resistant prostate cancer (CRPC) patients treated with anti-androgens occur more frequently with 10-30% of these patients having some form of mutation in the AR. Resistance to anti-androgen therapy usually results from gain-of-function mutations in the LBD such as is seen with bicalutamide and more recently with enzalutamide (MDV3100). Thus, it is crucial to investigate these new AR mutations arising from drug resistance to anti-androgens and other small molecule pharmacological agents.

  18. Androgen receptor in male breast cancer.

    PubMed

    Sas-Korczynska, Beata; Adamczyk, Aagnieszka; Niemiec, Joanna; Harazin-Lechowska, Agnieszka; Ambicka, Aleksandra; Jakubowicz, Jerzy

    2015-12-01

    We present the androgen receptor (AR) status in 32 breast cancers diagnosed in male patients. Androgen receptor expression was found in 62.5% tumors and it was more frequent (85% of cases) in estrogen-positive tumours. The analyses of its impact on treatment results showed that AR immmunopositivity is a prognostic factor for overall survival, and AR immunonegativity is also correlated with worse prognosis (distant metastases developed more frequently and earlier).

  19. Inhibition effect of cypermethrin mediated by co-regulators SRC-1 and SMRT in interleukin-6-induced androgen receptor activation.

    PubMed

    Wang, Qi; Zhou, Ji-Long; Wang, Hui; Ju, Qiang; Ding, Zhen; Zhou, Xiao-Long; Ge, Xing; Shi, Qiao-Mei; Pan, Chen; Zhang, Jin-Peng; Zhang, Mei-Rong; Yu, Hong-Min; Xu, Li-Chun

    2016-09-01

    It is hypothesized that the pesticide cypermethrin may induce androgen receptor (AR) antagonism via ligand-independent mechanisms. The Real-Time Cell Analysis (RTCA) iCELLigence system was used to investigate the inhibitory effect of cypermethrin on interleukin-6 (IL-6)-induced ligand-independent LNCaP cell growth. Then, the mammalian two-hybrid assays were applied to clarify whether the mechanism of IL-6-induced AR antagonism of cypermethrin was associated with the interactions of the AR and co-activator steroid receptor co-activator-1 (SRC-1) and co-repressor silencing mediator for retinoid and thyroid hormone receptors (SMRT). Cypermethrin inhibited the LNCaP cell growth induced by IL-6. The interactions of AR-SRC-1 and AR-SMRT mediated by IL-6 were suppressed by cypermethrin. The results indicate that the IL-6-mediated AR antagonism induced by cypermethrin is related to repress the recruitment of co-regulators SRC-1 and SMRT to the AR in a ligand-independent manner. Inhibition of the interactions of AR-SRC-1 and AR-SMRT mediated by IL-6 contributes to the AR antagonism induced by cypermethrin.

  20. Regulation of the transcriptional coactivator FHL2 licenses activation of the androgen receptor in castrate-resistant prostate cancer.

    PubMed

    McGrath, Meagan J; Binge, Lauren C; Sriratana, Absorn; Wang, Hong; Robinson, Paul A; Pook, David; Fedele, Clare G; Brown, Susan; Dyson, Jennifer M; Cottle, Denny L; Cowling, Belinda S; Niranjan, Birunthi; Risbridger, Gail P; Mitchell, Christina A

    2013-08-15

    It is now clear that progression from localized prostate cancer to incurable castrate-resistant prostate cancer (CRPC) is driven by continued androgen receptor (AR), signaling independently of androgen. Thus, there remains a strong rationale to suppress AR activity as the single most important therapeutic goal in CRPC treatment. Although the expression of ligand-independent AR splice variants confers resistance to AR-targeted therapy and progression to lethal castrate-resistant cancer, the molecular regulators of AR activity in CRPC remain unclear, in particular those pathways that potentiate the function of mutant AR in CRPC. Here, we identify FHL2 as a novel coactivator of ligand-independent AR variants that are important in CRPC. We show that the nuclear localization of FHL2 and coactivation of the AR is driven by calpain cleavage of the cytoskeletal protein filamin, a pathway that shows differential activation in prostate epithelial versus prostate cancer cell lines. We further identify a novel FHL2-AR-filamin transcription complex, revealing how deregulation of this axis promotes the constitutive, ligand-independent activation of AR variants, which are present in CRPC. Critically, the calpain-cleaved filamin fragment and FHL2 are present in the nucleus only in CRPC and not benign prostate tissue or localized prostate cancer. Thus, our work provides mechanistic insight into the enhanced AR activation, most notably of the recently identified AR variants, including AR-V7 that drives CRPC progression. Furthermore, our results identify the first disease-specific mechanism for deregulation of FHL2 nuclear localization during cancer progression. These results offer general import beyond prostate cancer, given that nuclear FHL2 is characteristic of other human cancers where oncogenic transcription factors that drive disease are activated like the AR in prostate cancer.

  1. A Recurrent Germline Mutation in the 5'UTR of the Androgen Receptor Causes Complete Androgen Insensitivity by Activating Aberrant uORF Translation.

    PubMed

    Hornig, Nadine C; de Beaufort, Carine; Denzer, Friederike; Cools, Martine; Wabitsch, Martin; Ukat, Martin; Kulle, Alexandra E; Schweikert, Hans-Udo; Werner, Ralf; Hiort, Olaf; Audi, Laura; Siebert, Reiner; Ammerpohl, Ole; Holterhus, Paul-Martin

    2016-01-01

    A subset of patients with monogenic disorders lacks disease causing mutations in the protein coding region of the corresponding gene. Here we describe a recurrent germline mutation found in two unrelated patients with complete androgen insensitivity syndrome (CAIS) generating an upstream open reading frame (uORF) in the 5' untranslated region (5'-UTR) of the androgen receptor (AR) gene. We show in patient derived primary genital skin fibroblasts as well as in cell-based reporter assays that this mutation severely impacts AR function by reducing AR protein levels without affecting AR mRNA levels. Importantly, the newly generated uORF translates into a polypeptide and the expression level of this polypeptide inversely correlates with protein translation from the primary ORF of the AR thereby providing a model for AR-5'UTR mediated translational repression. Our findings not only add a hitherto unrecognized genetic cause to complete androgen insensitivity but also underline the importance of 5'UTR mutations affecting uORFs for the pathogenesis of monogenic disorders in general.

  2. A Recurrent Germline Mutation in the 5’UTR of the Androgen Receptor Causes Complete Androgen Insensitivity by Activating Aberrant uORF Translation

    PubMed Central

    Hornig, Nadine C.; de Beaufort, Carine; Denzer, Friederike; Cools, Martine; Wabitsch, Martin; Ukat, Martin; Kulle, Alexandra E.; Schweikert, Hans-Udo; Werner, Ralf; Hiort, Olaf; Audi, Laura; Siebert, Reiner; Ammerpohl, Ole; Holterhus, Paul-Martin

    2016-01-01

    A subset of patients with monogenic disorders lacks disease causing mutations in the protein coding region of the corresponding gene. Here we describe a recurrent germline mutation found in two unrelated patients with complete androgen insensitivity syndrome (CAIS) generating an upstream open reading frame (uORF) in the 5’ untranslated region (5’-UTR) of the androgen receptor (AR) gene. We show in patient derived primary genital skin fibroblasts as well as in cell-based reporter assays that this mutation severely impacts AR function by reducing AR protein levels without affecting AR mRNA levels. Importantly, the newly generated uORF translates into a polypeptide and the expression level of this polypeptide inversely correlates with protein translation from the primary ORF of the AR thereby providing a model for AR-5′UTR mediated translational repression. Our findings not only add a hitherto unrecognized genetic cause to complete androgen insensitivity but also underline the importance of 5′UTR mutations affecting uORFs for the pathogenesis of monogenic disorders in general. PMID:27110943

  3. Down, But Not Out: Partial Elimination of Androgen Receptors in the Male Mouse Brain Does Not Affect Androgenic Regulation of Anxiety or HPA Activity.

    PubMed

    Chen, Chieh V; Brummet, Jennifer L; Jordan, Cynthia L; Breedlove, S Marc

    2016-02-01

    We previously found that androgen receptor (AR) activity mediates two effects of T in adult male mice: reduction of anxiety-like behaviors and dampening of the hypothalamic-pituitary-adrenal response to stress. To determine whether brain ARs mediate these effects, we used the Cre/loxP technology seeking to disable AR throughout the central nervous system (CNS). Female mice carrying the floxed AR allele (ARlox) were crossed with males carrying cre recombinase transgene controlled by the nestin promoter (NesCre), producing cre in developing neurons and glia. Among male offspring, four genotypes resulted: males carrying ARlox and NesCre (NesARko), and three control groups (wild types, NesCre, and ARlox). Reporter mice indicated ubiquitous Cre expression throughout the CNS. Nevertheless, AR immunocytochemistry in NesARko mice revealed efficient knockout (KO) of AR in some brain regions (hippocampus and medial prefrontal cortex [mPFC]), but not others. Substantial AR protein was seen in the amygdala and hypothalamus among other regions, whereas negligible AR remained in others like the bed nucleus of the stria terminalis and dorsal periaqueductal gray. This selective KO allowed for testing the role of AR in hippocampus and mPFC. Males were castrated and implanted with T at postnatal day 60 before testing on postnatal day 90-100. In contrast with males with global KO of AR, T still modulated anxiety-related behavior and hypothalamic-pituitary-adrenal activity in NesARko males. These results leave open the possibility that AR acting in the CNS mediates these effects of T, but demonstrate that AR is not required in the hippocampus or mPFC for T's anxiolytic effects.

  4. Role of the HSP90-associated cochaperone p23 in enhancing activity of the androgen receptor and significance for prostate cancer.

    PubMed

    Reebye, Vikash; Querol Cano, Laia; Lavery, Derek N; Brooke, Greg N; Powell, Sue M; Chotai, Deepa; Walker, Marjorie M; Whitaker, Hayley C; Wait, Robin; Hurst, Helen C; Bevan, Charlotte L

    2012-10-01

    Prostate tumor growth initially depends on androgens, which act via the androgen receptor (AR). Despite androgen ablation therapy, tumors eventually progress to a castrate-resistant stage in which the AR remains active. The mechanisms are poorly understood but it may be that changes in levels or activity of AR coregulators affect trafficking and activation of the receptor. A key stage in AR signaling occurs in the cytoplasm, where unliganded receptor is associated with the heat shock protein (HSP)90 foldosome complex. p23, a key component of this complex, is best characterized as a cochaperone for HSP90 but also has HSP90-independent activity and has been reported as having differential effects on the activity of different steroid receptors. Here we report that p23 increases activity of the AR, and this appears to involve steps both in the cytoplasm (increasing ligand-binding capacity, possibly via direct interaction with AR) and the nucleus (enhancing AR occupancy at target promoters). We show, for the first time, that AR and p23 can interact, perhaps directly, when HSP90 is not present in the same complex. The effects of p23 on AR activity are at least partly HSP90 independent because a mutant form of p23, unable to bind HSP90, nevertheless increases AR activity. In human prostate tumors, nuclear p23 was higher in malignant prostate cells compared with benign/normal cells, supporting the utility of p23 as a therapeutic target in prostate cancer.

  5. An Sp1 Modulated Regulatory Region Unique to Higher Primates Regulates Human Androgen Receptor Promoter Activity in Prostate Cancer Cells.

    PubMed

    Hay, Colin W; Hunter, Irene; MacKenzie, Alasdair; McEwan, Iain J

    2015-01-01

    Androgen receptor (AR) mediated signalling is necessary for normal development of the prostate gland and also drives prostate cancer (PCa) cell growth and survival, with many studies showing a correlation between increased receptor levels and therapy resistance with progression to fatal castrate recurrent PCa (CRPC). Although it has been held for some time that the transcription factor Sp1 is the main stimulator of AR gene transcription, comprehensive knowledge of the regulation of the AR gene remains incomplete. Here we describe and characterise in detail two novel active regulatory elements in the 5'UTR of the human AR gene. Both of these elements contain overlapping binding sites for the positive transcription factor Sp1 and the repressor protein pur-α. Aberrant cell signalling is characteristic of PCa and the transcriptional activity of the AR promoter in PCa cells is dependent upon the relative amounts of the two transcription factors. Together with our corroboration of the dominant role of Sp1, the findings support the rationale of targeting this transcription factor to inhibit tumour progression. This should be of particular therapeutic relevance in CRPC where the levels of the repressor pur-α are reduced. PMID:26448047

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

    PubMed

    Tan, M H 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

  8. Selective androgen receptor modulators based on a series of 7H-[1,4]oxazino[3,2-g]quinolin-7-ones with improved in vivo activity.

    PubMed

    Long, Yun Oliver; Higuchi, Robert I; Caferro, Thomas R; Lau, Thomas L S; Wu, Min; Cummings, Marquis L; Martinborough, Esther A; Marschke, Keith B; Chang, William Y; López, Francisco J; Karanewsky, Donald S; Zhi, Lin

    2008-05-01

    Modification on a lead series of [1,4]oxazino[3,2-g]quinolin-7-ones at the 2-position led to selective androgen receptor modulators with improved in vivo activity. The most potent analog (-)-33a exhibited full maintenance of levator ani muscle at 3mg/kg and reduced activity on ventral prostate weight in a 2-week orally-dosed and orchidectomized rat maintenance assay.

  9. The androgen receptor gene mutations database.

    PubMed

    Gottlieb, B; Trifiro, M; Lumbroso, R; Vasiliou, D M; Pinsky, L

    1996-01-01

    The current version of the androgen receptor (AR) gene mutations database is described. We have added (if available) data on the androgen binding phenotype of the mutant AR, the clinical phenotype of the affected persons, the family history and whether the pathogenicity of a mutation has been proven. Exonic mutations are now listed in 5'-->3' sequence regardless of type and single base pair changes are presented in codon context. Splice site and intronic mutations are listed separately. The database has allowed us to substantiate and amplify the observation of mutational hot spots within exons encoding the AR androgen binding domain. The database is available from EML (ftp://www.ebi.ac.uk/pub/databases/androgen) or as a Macintosh Filemaker file (MC33@musica.mcgill.ca).

  10. Anti-histone acetyltransferase activity from allspice extracts inhibits androgen receptor-dependent prostate cancer cell growth.

    PubMed

    Lee, Yoo-Hyun; Hong, Soon Won; Jun, Woojin; Cho, Hong Yon; Kim, Han-Cheon; Jung, Myung Gu; Wong, Jiemin; Kim, Ha-Il; Kim, Chang-Hoon; Yoon, Ho-Geun

    2007-11-01

    Histone acetylation depends on the activity of two enzyme families, histone acetyltransferase (HAT) and deacetylase (HDAC). In this study, we screened various plant extracts to find potent HAT inhibitors. Hot water extracts of allspice inhibited HAT activity, especially p300 and CBP (40% at 100 microg/ml). The mRNA levels of two androgen receptor (AR) regulated genes, PSA and TSC22, decreased with allspice treatment (100 microg/ml). Importantly, in IP western analysis, AR acetylation was dramatically decreased by allspice treatment.Furthermore, chromatin immunoprecipitation indicated that the acetylation of histone H3 in the PSA and B2M promoter regions was also repressed. Finally, allspice treatment reduced the growth of human prostate cancer cells, LNCaP (50% growth inhibition at 200 microg/ml). Taken together, our data indicate that the potent HAT inhibitory activity of allspice reduced AR and histone acetylation and led to decreased transcription of AR target genes, resulting in inhibition of prostate cancer cell growth.

  11. Theaflavin-3,3'-digallate and penta-O-galloyl-beta-D-glucose inhibit rat liver microsomal 5alpha-reductase activity and the expression of androgen receptor in LNCaP prostate cancer cells.

    PubMed

    Lee, Hung-Hsiao; Ho, Chi-Tang; Lin, Jen-Kun

    2004-07-01

    Androgens play a critical role in regulating the growth, differentiation and survival of epithelial cells in many androgen-responsive organs, such as prostate and skin. The enzyme steroid 5alpha-reductase (EC 1.3.99.5) catalyzes the conversion of testosterone (T) to a more active androgen, dihydrotestosterone (DHT). DHT then binds to androgen receptors (AR) and functions in the nucleus to regulate specific gene expression. Androgens via their cognate receptor may be involved in the development and progression of benign prostate hyperplasia, prostate cancer, hirsutism, male pattern alopecia and acne. The aim of this study was to determine whether theaflavin-3,3'-digallate (TF3) and penta-O-galloyl-beta-D-glucose (5GG) have inhibitory effects on androgen production and action. We found that TF3 and 5GG inhibit rat liver microsomal 5alpha-reductase activity. Furthermore, TF3 and 5GG significantly reduced androgen-responsive LNCaP prostate cancer cell growth, suppressed expression of the AR and lowered androgen-induced prostate-specific antigen secretion and fatty acid synthase protein level. In conclusion, our result suggests that TF3 and 5GG might be useful chemoprevention agents for prostate cancer through suppressing the function of androgen and its receptor. PMID:14963012

  12. 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

  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.

  14. Androgen Receptor Antagonists and Anti-Prostate Cancer Activities of Some Newly Synthesized Substituted Fused Pyrazolo-, Triazolo- and Thiazolo-Pyrimidine Derivatives

    PubMed Central

    Bahashwan, Saleh A.; Fayed, Ahmed A.; Ramadan, Mohamed A.; Amr, Abd El-Galil E.; Al-Harbi, Naif O.

    2014-01-01

    A series of substituted pyrazole, triazole and thiazole derivatives (2–13) were synthesized from 1-(naphtho[1,2-d]thiazol-2-yl)hydrazine as starting material and evaluated as androgen receptor antagonists and anti-prostate cancer agents. The newly synthesized compounds showed potent androgen receptor antagonists and anti-prostate cancer activities with low toxicity (lethal dose 50 (LD50)) comparable to Bicalutamide as reference drug. The structures of newly synthesized compounds were confirmed by IR, 1H-NMR, 13C-NMR, and MS spectral data and elemental analysis. The detailed synthesis, spectroscopic data, LD50 values and pharmacological activities of the synthesized compounds are reported. PMID:25421248

  15. 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%).

  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. Aberrant activation of the androgen receptor by NF-kappaB2/p52 in prostate cancer cells.

    PubMed

    Nadiminty, Nagalakshmi; Lou, Wei; Sun, Meng; Chen, Jun; Yue, Jiao; Kung, Hsing-Jien; Evans, Christopher P; Zhou, Qinghua; Gao, Allen C

    2010-04-15

    Prostate cancer initiation and progression are uniquely dependent on the androgen receptor (AR). Even when the cancer progresses to a castration-resistant stage, AR signaling remains active via a variety of mechanisms. In the present study, we showed that NF-kappaB/p52 can activate the AR, resulting in increased transactivation of AR-responsive genes, such as PSA and NKX3.1, in a ligand-independent manner. NF-kappaB2/p52 enhances nuclear translocation and activation of AR by interacting with its NH(2)-terminal domain and enhances the recruitment of coactivators such as p300 to the promoters of AR-dependent genes. These results were confirmed in three different prostate cancer cell lines: LAPC-4 (wild-type AR), LNCaP (mutant AR), and C4-2 (castration resistant). Transfection of p52 into LAPC-4 and LNCaP cells (which express low levels of p52) showed increased activation of the endogenous AR. Downregulation of endogenous p52 in C4-2 cells resulted in abrogation of AR constitutive activation. Comparison of the relative effects of p52 and p65 (RelA) showed that p52, but not p65, could activate the AR. Collectively, these findings, together with previous reports that the levels of NF-kappaB2/p52 are elevated in prostate cancer cells and that active NF-kappaB2/p52 promotes prostate cancer cell growth in vitro and in vivo, suggest that NF-kappaB2/p52 may play a critical role in the progression of castration-resistant prostate cancer.

  18. Corepressor effect on androgen receptor activity varies with the length of the CAG encoded polyglutamine repeat and is dependent on receptor/corepressor ratio in prostate cancer cells.

    PubMed

    Buchanan, Grant; Need, Eleanor F; Barrett, Jeffrey M; Bianco-Miotto, Tina; Thompson, Vanessa C; Butler, Lisa M; Marshall, Villis R; Tilley, Wayne D; Coetzee, Gerhard A

    2011-08-01

    The response of prostate cells to androgens reflects a combination of androgen receptor (AR) transactivation and transrepression, but how these two processes differ mechanistically and influence prostate cancer risk and disease outcome remain elusive. Given recent interest in targeting AR transrepressive processes, a better understanding of AR/corepressor interaction and responses is warranted. Here, we used transactivation and interaction assays with wild-type and mutant ARs, and deletion AR fragments, to dissect the relationship between AR and the corepressor, silencing mediator for retinoic acid and thyroid hormone receptors (SMRT). We additionally tested how these processes are influenced by AR agonist and antagonist ligands, as well as by variation in the polyglutamine tract in the AR amino terminal domain (NTD), which is encoded by a polymorphic CAG repeat in the gene. SMRT was recruited to the AR ligand binding domain by agonist ligand, and as determined by the effect of strategic mutations in activation function 2 (AF-2), requires a precise conformation of that domain. A distinct region of SMRT also mediated interaction with the AR-NTD via the transactivation unit 5 (TAU5; residues 315-538) region. The degree to which SMRT was able to repress AR increased from 17% to 56% as the AR polyglutamine repeat length was increased from 9 to 42 residues, but critically this effect could be abolished by increasing the SMRT:AR molar ratio. These data suggest that the extent to which the CAG encoded polyglutamine repeat influences AR activity represents a balance between corepressor and coactivator occupancy of the same ligand-dependent and independent AR interaction surfaces. Changes in the homeostatic relationship of AR to these molecules, including SMRT, may explain the variable penetrance of the CAG repeat and the loss of AR signaling flexibility in prostate cancer progression.

  19. Brachyury as a potential modulator of androgen receptor activity and a key player in therapy resistance in prostate cancer

    PubMed Central

    Pinto, Filipe; Pértega-Gomes, Nelma; Vizcaíno, José R.; Andrade, Raquel P.; Cárcano, Flavio M.; Reis, Rui Manuel

    2016-01-01

    Prostate cancer (PCa) is the most commonly diagnosed neoplasm and the second leading cause of cancer-related deaths in men. Acquisition of resistance to conventional therapy is a major problem for PCa patient management. Several mechanisms have been described to promote therapy resistance in PCa, such as androgen receptor (AR) activation, epithelial-to-mesenchymal transition (EMT), acquisition of stem cell properties and neuroendocrine transdifferentiation (NEtD). Recently, we identified Brachyury as a new biomarker of PCa aggressiveness and poor prognosis. In the present study we aimed to assess the role of Brachyury in PCa therapy resistance. We showed that Brachyury overexpression in prostate cancer cells lines increased resistance to docetaxel and cabazitaxel drugs, whereas Brachyury abrogation induced decrease in therapy resistance. Through ChiP-qPCR assays we further demonstrated that Brachyury is a direct regulator of AR expression as well as of the biomarker AMACR and the mesenchymal markers Snail and Fibronectin. Furthermore, in vitro Brachyury was also able to increase EMT and stem properties. By in silico analysis, clinically human Brachyury-positive PCa samples were associated with biomarkers of PCa aggressiveness and therapy resistance, including PTEN loss, and expression of NEtD markers, ERG and Bcl-2. Taken together, our results indicate that Brachyury contributes to tumor chemotherapy resistance, constituting an attractive target for advanced PCa patients. PMID:27049720

  20. Peroxisome proliferator-activated receptor gamma (PPARγ) in brown trout: Interference of estrogenic and androgenic inputs in primary hepatocytes.

    PubMed

    Lopes, Célia; Madureira, Tânia Vieira; Ferreira, Nádia; Pinheiro, Ivone; Castro, L Filipe C; Rocha, Eduardo

    2016-09-01

    Peroxisome proliferator-activated receptor gamma (PPARγ) is a pivotal regulator of lipid and glucose metabolism in vertebrates. Here, we isolated and characterized for the first time the PPARγ gene from brown trout (Salmo trutta f. fario). Hormones have been reported to interfere with the regulatory function of PPARγ in various organisms, albeit with little focus on fish. Thus, primary hepatocytes isolated from juveniles of brown trout were exposed to 1, 10 and 50μM of ethinylestradiol (EE2) or testosterone (T). A significant (3 fold) decrease was obtained in response to 50μM of EE2 and to 10 and 50μM of T (13 and 14 folds), while a 3 fold increase was observed at 1μM of EE2. Therefore, trout PPARγ seems a target for natural/synthetic compounds with estrogenic or androgenic properties and so, we advocate considering PPARγ as another alert sensor gene when assessing the effects of sex-steroid endocrine disruptors. PMID:27541269

  1. Synergic prodegradative activity of Bicalutamide and trehalose on the mutant androgen receptor responsible for spinal and bulbar muscular atrophy

    PubMed Central

    Giorgetti, Elisa; Rusmini, Paola; Crippa, Valeria; Cristofani, Riccardo; Boncoraglio, Alessandra; Cicardi, Maria E.; Galbiati, Mariarita; Poletti, Angelo

    2015-01-01

    Spinal and bulbar muscular atrophy (SBMA) is an X-linked motoneuron disease due to a CAG triplet-repeat expansion in the androgen receptor (AR) gene, which is translated into an elongated polyglutamine (polyQ) tract in AR protein (ARpolyQ). ARpolyQ toxicity is activated by the AR ligand testosterone (or dihydrotestosterone), and the polyQ triggers ARpolyQ misfolding and aggregation in spinal cord motoneurons and muscle cells. In motoneurons, testosterone triggers nuclear toxicity by inducing AR nuclear translocation. Thus, (i) prevention of ARpolyQ nuclear localization, combined with (ii) an increased ARpolyQ cytoplasmic clearance, should reduce its detrimental activity. Using the antiandrogen Bicalutamide (Casodex®), which slows down AR activation and nuclear translocation, and the disaccharide trehalose, an autophagy activator, we found that, in motoneurons, the two compounds together reduced ARpolyQ insoluble forms with higher efficiency than that obtained with single treatments. The ARpolyQ clearance was mediated by trehalose-induced autophagy combined with the longer cytoplasmic retention of ARpolyQ bound to Bicalutamide. This allows an increased recognition of misfolded species by the autophagic system prior to their migration into the nucleus. Interestingly, the combinatory use of trehalose and Bicalutamide was also efficient in the removal of insoluble species of AR with a very long polyQ (Q112) tract, which typically aggregates into the cell nuclei. Collectively, these data suggest that the combinatory use of Bicalutamide and trehalose is a novel approach to facilitate ARpolyQ clearance that has to be tested in other cell types target of SBMA (i.e. muscle cells) and in vivo in animal models of SBMA. PMID:25122660

  2. Synergic prodegradative activity of Bicalutamide and trehalose on the mutant androgen receptor responsible for spinal and bulbar muscular atrophy.

    PubMed

    Giorgetti, Elisa; Rusmini, Paola; Crippa, Valeria; Cristofani, Riccardo; Boncoraglio, Alessandra; Cicardi, Maria E; Galbiati, Mariarita; Poletti, Angelo

    2015-01-01

    Spinal and bulbar muscular atrophy (SBMA) is an X-linked motoneuron disease due to a CAG triplet-repeat expansion in the androgen receptor (AR) gene, which is translated into an elongated polyglutamine (polyQ) tract in AR protein (ARpolyQ). ARpolyQ toxicity is activated by the AR ligand testosterone (or dihydrotestosterone), and the polyQ triggers ARpolyQ misfolding and aggregation in spinal cord motoneurons and muscle cells. In motoneurons, testosterone triggers nuclear toxicity by inducing AR nuclear translocation. Thus, (i) prevention of ARpolyQ nuclear localization, combined with (ii) an increased ARpolyQ cytoplasmic clearance, should reduce its detrimental activity. Using the antiandrogen Bicalutamide (Casodex(®)), which slows down AR activation and nuclear translocation, and the disaccharide trehalose, an autophagy activator, we found that, in motoneurons, the two compounds together reduced ARpolyQ insoluble forms with higher efficiency than that obtained with single treatments. The ARpolyQ clearance was mediated by trehalose-induced autophagy combined with the longer cytoplasmic retention of ARpolyQ bound to Bicalutamide. This allows an increased recognition of misfolded species by the autophagic system prior to their migration into the nucleus. Interestingly, the combinatory use of trehalose and Bicalutamide was also efficient in the removal of insoluble species of AR with a very long polyQ (Q112) tract, which typically aggregates into the cell nuclei. Collectively, these data suggest that the combinatory use of Bicalutamide and trehalose is a novel approach to facilitate ARpolyQ clearance that has to be tested in other cell types target of SBMA (i.e. muscle cells) and in vivo in animal models of SBMA.

  3. The androgen receptor gene mutations database.

    PubMed

    Gottlieb, B; Trifiro, M; Lumbroso, R; Pinsky, L

    1997-01-01

    The current version of the androgen receptor (AR) gene mutations database is described. The total number of reported mutations has risen from 212 to 272. We have expanded the database: (i) by adding a large amount of new data on somatic mutations in prostatic cancer tissue; (ii) by defining a new constitutional phenotype, mild androgen insensitivity (MAI); (iii) by placing additional relevant information on an internet site (http://www.mcgill.ca/androgendb/ ). The database has allowed us to examine the contribution of CpG sites to the multiplicity of reports of the same mutation in different families. The database is also available from EMBL (ftp.ebi.ac.uk/pub/databases/androgen) or as a Macintosh Filemaker Pro or Word file (MC33@musica,mcgill.ca)

  4. Discovery AND Therapeutic Promise OF Selective Androgen Receptor Modulators

    PubMed Central

    Chen, Jiyun; Kim, Juhyun; Dalton, James T.

    2007-01-01

    Androgens are essential for male development and the maintenance of male secondary characteristics, such as bone mass, muscle mass, body composition, and spermatogenesis. The main disadvantages of steroidal androgens are their undesirable physicochemical and pharmacokinetic properties. The recent discovery of nonsteroidal selective androgen receptor modulators (SARMs) provides a promising alternative for testosterone replacement therapies with advantages including oral bioavailability, flexibility of structural modification, androgen receptor specificity, tissue selectivity, and the lack of steroid-related side effects. PMID:15994457

  5. Discovery and therapeutic promise of selective androgen receptor modulators.

    PubMed

    Chen, Jiyun; Kim, Juhyun; Dalton, James T

    2005-06-01

    Androgens are essential for male development and the maintenance of male secondary characteristics, such as bone mass, muscle mass, body composition, and spermatogenesis. The main disadvantages of steroidal androgens are their undesirable physicochemical and pharmacokinetic properties. The recent discovery of nonsteroidal selective androgen receptor modulators (SARMs) provides a promising alternative for testosterone replacement therapies with advantages including oral bioavailability, flexibility of structural modification, androgen receptor specificity, tissue selectivity, and the lack of steroid-related side effects.

  6. Environmental gestagens activate fathead minnow (Pimephales promelas) nuclear progesterone and androgen receptors in vitro

    EPA Science Inventory

    Gestagen is a collective term for endogenous and synthetic progesterone receptor (PR) ligands. In teleost fishes, 17á,20â-dihydroxy-4-pregnen-3-one (DHP) and17á,20â,21- trihydroxy-4-pregnen-3-one (20â-S) are the predominant progestogens, whereas in other vertebrates the major pro...

  7. Intratumoral de novo steroid synthesis activates androgen receptor in castration-resistant prostate cancer and is upregulated by treatment with CYP17A1 inhibitors.

    PubMed

    Cai, Changmeng; Chen, Sen; Ng, Patrick; Bubley, Glenn J; Nelson, Peter S; Mostaghel, Elahe A; Marck, Brett; Matsumoto, Alvin M; Simon, Nicholas I; Wang, Hongyun; Chen, Shaoyong; Balk, Steven P

    2011-10-15

    Relapse of castration-resistant prostate cancer (CRPC) that occurs after androgen deprivation therapy of primary prostate cancer can be mediated by reactivation of the androgen receptor (AR). One important mechanism mediating this AR reactivation is intratumoral conversion of the weak adrenal androgens DHEA and androstenedione into the AR ligands testosterone and dihydrotestosterone. DHEA and androstenedione are synthesized by the adrenals through the sequential actions of the cytochrome P450 enzymes CYP11A1 and CYP17A1, so that CYP17A1 inhibitors such as abiraterone are effective therapies for CRPC. However, the significance of intratumoral CYP17A1 and de novo androgen synthesis from cholesterol in CRPC, and the mechanisms contributing to CYP17A1 inhibitor resistance/relapse, remain to be determined. We report that AR activity in castration-resistant VCaP tumor xenografts can be restored through CYP17A1-dependent de novo androgen synthesis, and that abiraterone treatment of these xenografts imposes selective pressure for increased intratumoral expression of CYP17A1, thereby generating a mechanism for development of resistance to CYP17A1 inhibitors. Supporting the clinical relevance of this mechanism, we found that intratumoral expression of CYP17A1 was markedly increased in tumor biopsies from CRPC patients after CYP17A1 inhibitor therapy. We further show that CRPC cells expressing a progesterone responsive T877A mutant AR are not CYP17A1 dependent, but that AR activity in these cells is still steroid dependent and mediated by upstream CYP11A1-dependent intraturmoral pregnenolone/progesterone synthesis. Together, our results indicate that CRPCs resistant to CYP17A1 inhibition may remain steroid dependent and therefore responsive to therapies that can further suppress de novo intratumoral steroid synthesis.

  8. Human α(2)β(1)(HI) CD133(+VE) epithelial prostate stem cells express low levels of active androgen receptor.

    PubMed

    Williamson, Stuart C; Hepburn, Anastasia C; Wilson, Laura; Coffey, Kelly; Ryan-Munden, Claudia A; Pal, Deepali; Leung, Hing Y; Robson, Craig N; Heer, Rakesh

    2012-01-01

    Stem cells are thought to be the cell of origin in malignant transformation in many tissues, but their role in human prostate carcinogenesis continues to be debated. One of the conflicts with this model is that cancer stem cells have been described to lack androgen receptor (AR) expression, which is of established importance in prostate cancer initiation and progression. We re-examined the expression patterns of AR within adult prostate epithelial differentiation using an optimised sensitive and specific approach examining transcript, protein and AR regulated gene expression. Highly enriched populations were isolated consisting of stem (α(2)β(1)(HI) CD133(+VE)), transiently amplifying (α(2)β(1)(HI) CD133(-VE)) and terminally differentiated (α(2)β(1)(LOW) CD133(-VE)) cells. AR transcript and protein expression was confirmed in α(2)β(1)(HI) CD133(+VE) and CD133(-VE) progenitor cells. Flow cytometry confirmed that median (±SD) fraction of cells expressing AR were 77% (±6%) in α(2)β(1)(HI) CD133(+VE) stem cells and 68% (±12%) in α(2)β(1)(HI) CD133(-VE) transiently amplifying cells. However, 3-fold lower levels of total AR protein expression (peak and median immunofluorescence) were present in α(2)β(1)(HI) CD133(+VE) stem cells compared with differentiated cells. This finding was confirmed with dual immunostaining of prostate sections for AR and CD133, which again demonstrated low levels of AR within basal CD133(+VE) cells. Activity of the AR was confirmed in prostate progenitor cells by the expression of low levels of the AR regulated genes PSA, KLK2 and TMPRSS2. The confirmation of AR expression in prostate progenitor cells allows integration of the cancer stem cell theory with the established models of prostate cancer initiation based on a functional AR. Further study of specific AR functions in prostate stem and differentiated cells may highlight novel mechanisms of prostate homeostasis and insights into tumourigenesis.

  9. LINE-1 ORF-1p functions as a novel androgen receptor co-activator and promotes the growth of human prostatic carcinoma cells.

    PubMed

    Lu, Yinying; Feng, Fan; Yang, Yutao; Gao, Xudong; Cui, Jiajun; Zhang, Chuanfu; Zhang, Fan; Xu, Zhongxian; Qv, Jianhui; Wang, Chunping; Zeng, Zhen; Zhu, Yunfeng; Yang, Yongping

    2013-02-01

    Widespread interest in the mechanism of transcriptional regulation by the androgen receptor (AR) has been stimulated by the finding that AR signaling is critically important in the progression of human prostate cancers. Co-factors, the co-repressors, or the co-activators are responsible for the regulation of AR activation. The pro-oncogene human Long Interspersed Nucleotide acid Element-1 (LINE-1) encodes LINE-1 ORF-1p and plays important roles in the development and progression of several human carcinomas. In this study, the results showed that LINE-1 ORF-1p increased the AR transcriptional activity and in turn enhanced the expression of prostate specific antigen (PSA) in the presence of R1881. A physical protein-protein interaction between the AR signaling and the LINE-1 ORF-1p was identified by the immunoprecipitation assays and GST pull-down assays. Furthermore, LINE-1 ORF-1p would function as a novel AR positive co-regulator through modulating its cytoplasm/nucleus translocation and the recruitment to the androgen response element in the PSA gene promoter. Our date also showed that the LINE-1 ORF-1p promoted the proliferation and anchor-independent growth of LNCaP (ligand dependent) and PC-3 (ligand independent) human prostatic carcinoma cells. By investigating a novel role of the LINE-1 ORF-1p in the androgen/androgen receptor signaling pathway regulation, our study identifies that LINE-1 ORF-1p may be a novel AR co-regulator and molecular target for human prostate carcinoma therapy.

  10. A competitive inhibitor that reduces recruitment of androgen receptor to androgen-responsive genes.

    PubMed

    Cherian, Milu T; Wilson, Elizabeth M; Shapiro, David J

    2012-07-01

    The androgen receptor (AR) has a critical role in the growth and progression of androgen-dependent and castration-resistant prostate cancers. To identify novel inhibitors of AR transactivation that block growth of prostate cancer cells, a luciferase-based high-throughput screen of ~160,000 small molecules was performed in cells stably expressing AR and a prostate-specific antigen (PSA)-luciferase reporter. CPIC (1-(3-(2-chlorophenoxy) propyl)-1H-indole-3-carbonitrile) was identified as a small molecule that blocks AR transactivation to a greater extent than other steroid receptors. CPIC inhibited AR-mediated proliferation of androgen-sensitive prostate cancer cell lines, with minimal toxicity in AR-negative cell lines. CPIC treatment also reduced the anchorage-independent growth of LAPC-4 prostate cancer cells. CPIC functioned as a pure antagonist by inhibiting the expression of AR-regulated genes in LAPC-4 cells that express wild-type AR and exhibited weak agonist activity in LNCaP cells that express the mutant AR-T877A. CPIC treatment did not reduce AR levels or alter its nuclear localization. We used chromatin immunoprecipitation to identify the site of action of CPIC. CPIC inhibited recruitment of androgen-bound AR to the PSA promoter and enhancer sites to a greater extent than bicalutamide. CPIC is a new therapeutic inhibitor that targets AR-mediated gene activation with potential to arrest the growth of prostate cancer.

  11. Synthetic anabolic agents: steroids and nonsteroidal selective androgen receptor modulators.

    PubMed

    Thevis, Mario; Schänzer, Wilhelm

    2010-01-01

    The central role of testosterone in the development of male characteristics, as well as its beneficial effects on physical performance and muscle growth, has led to the search for synthetic alternatives with improved pharmacological profiles. Hundreds of steroidal analogs have been prepared with a superior oral bioavailability, which should also possess reduced undesirable effects. However, only a few entered the pharmaceutical market due to severe toxicological incidences that were mainly attributed to the lack of tissue selectivity. Prominent representatives of anabolic-androgenic steroids (AAS) are for instance methyltestosterone, metandienone and stanozolol, which are discussed as model compounds with regard to general pharmacological aspects of synthetic AAS. Recently, nonsteroidal alternatives to AAS have been developed that selectively activate the androgen receptor in either muscle tissue or bones. These so-called selective androgen receptor modulators (SARMs) are currently undergoing late clinical trials (IIb) and will be prohibited by the World Anti-Doping Agency from January 2008. Their entirely synthetic structures are barely related to steroids, but particular functional groups allow for the tissue-selective activation or inhibition of androgen receptors and, thus, the stimulation of muscle growth without the risk of severe undesirable effects commonly observed in steroid replacement therapies. Hence, these compounds possess a high potential for misuse in sports and will be the subject of future doping control assays.

  12. 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.

  13. Androgen receptor drives transcription of rat PACAP in gonadotrope cells.

    PubMed

    Grafer, Constance M; Halvorson, Lisa M

    2013-08-01

    Gonadotropin expression is precisely regulated within the hypothalamic-pituitary-gonadal axis through the complex interaction of neuropeptides, gonadal steroids. and both gonadal- and pituitary-derived peptides. In the anterior pituitary gland, the neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) modulates gonadotropin biosynthesis and secretion, acting both alone and in conjunction with GnRH. Steroid hormone feedback also influences gonadotropin expression via both direct and indirect mechanisms. Evidence from nonpituitary tissues suggests that PACAP may be a target for gonadal steroid regulation. In the present study, we show that androgen markedly stimulates rat (r) PACAP promoter-reporter activity in the LβT2 mature mouse gonadotrope cell line. 5'-Serial deletion analysis of reporter constructs identifies 2 regions of androgen responsiveness located at (-915 to -818) and (-308 to -242) of the rPACAP promoter. Androgen receptor (AR) binds directly to DNA cis-elements in each of these regions in vitro. Site-directed mutagenesis of 3 conserved hormone response element half-sites straddling the (-308 to -242) region dramatically blunts androgen-dependent PACAP promoter activity and prevents AR binding at the mutated promoter element. Chromatin immunoprecipitation demonstrates that endogenous AR binds the homologous region on mouse chromatin in LβT2 cells in both the presence and absence of androgen. These data demonstrate that androgen stimulates PACAP gene expression in the pituitary gonadotrope via direct binding of AR to a specific cluster of evolutionarily conserved hormone response elements in the proximal rPACAP gene promoter. Thus, androgen regulation of pituitary PACAP expression may provide an additional layer of control over gonadotropin expression within the hypothalamic-pituitary-gonadal axis.

  14. Differential regulation of metabolic pathways by androgen receptor (AR) and its constitutively active splice variant, AR-V7, in prostate cancer cells.

    PubMed

    Shafi, Ayesha A; Putluri, Vasanta; Arnold, James M; Tsouko, Efrosini; Maity, Suman; Roberts, Justin M; Coarfa, Cristian; Frigo, Daniel E; Putluri, Nagireddy; Sreekumar, Arun; Weigel, Nancy L

    2015-10-13

    Metastatic prostate cancer (PCa) is primarily an androgen-dependent disease, which is treated with androgen deprivation therapy (ADT). Tumors usually develop resistance (castration-resistant PCa [CRPC]), but remain androgen receptor (AR) dependent. Numerous mechanisms for AR-dependent resistance have been identified including expression of constitutively active AR splice variants lacking the hormone-binding domain. Recent clinical studies show that expression of the best-characterized AR variant, AR-V7, correlates with resistance to ADT and poor outcome. Whether AR-V7 is simply a constitutively active substitute for AR or has novel gene targets that cause unique downstream changes is unresolved. Several studies have shown that AR activation alters cell metabolism. Using LNCaP cells with inducible expression of AR-V7 as a model system, we found that AR-V7 stimulated growth, migration, and glycolysis measured by ECAR (extracellular acidification rate) similar to AR. However, further analyses using metabolomics and metabolic flux assays revealed several differences. Whereas AR increased citrate levels, AR-V7 reduced citrate mirroring metabolic shifts observed in CRPC patients. Flux analyses indicate that the low citrate is a result of enhanced utilization rather than a failure to synthesize citrate. Moreover, flux assays suggested that compared to AR, AR-V7 exhibits increased dependence on glutaminolysis and reductive carboxylation to produce some of the TCA (tricarboxylic acid cycle) metabolites. These findings suggest that these unique actions represent potential therapeutic targets.

  15. 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

  16. Beyond androgen deprivation: ancillary integrative strategies for targeting the androgen receptor addiction of prostate cancer.

    PubMed

    McCarty, Mark F; Hejazi, Jalal; Rastmanesh, Reza

    2014-09-01

    The large majority of clinical prostate cancers remain dependent on androgen receptor (AR) activity for proliferation even as they lose their responsiveness to androgen deprivation or antagonism. AR activity can be maintained in these circumstances by increased AR synthesis--often reflecting increased NF-κB activation; upregulation of signaling pathways that promote AR activity in the absence of androgens; and by emergence of AR mutations or splice variants lacking the ligand-binding domain, which render the AR constitutively active. Drugs targeting the N-terminal transactivating domain of the AR, some of which are now in preclinical development, can be expected to inhibit the activity not only of unmutated ARs but also of the mutant forms and splice variants selected for by androgen deprivation. Concurrent measures that suppress AR synthesis or boost AR turnover could be expected to complement the efficacy of such drugs. A number of nutraceuticals that show efficacy in prostate cancer xenograft models--including polyphenols from pomegranate, grape seed, and green tea, the crucifera metabolite diindolylmethane, and the hormone melatonin--have the potential to suppress AR synthesis via downregulation of NF-κB activity; clinical doses of salicylate may have analogous efficacy. The proteasomal turnover of the AR is abetted by diets with a high ratio of long-chain omega-3 to omega-6 fatty acids, which are beneficial in prostate cancer xenograft models; berberine and sulforaphane, by inhibiting AR's interaction with its chaperone Hsp90, likewise promote AR proteasomal degradation and retard growth of human prostate cancer in nude mice. Hinge region acetylation of the AR is required for optimal transactivational activity, and low micromolar concentrations of the catechin epigallocatechin-3-gallate (EGCG) can inhibit such acetylation--possibly explaining the ability of EGCG administration to suppress androgenic activity and cell proliferation in prostate cancer

  17. Androgen receptor gene polymorphism in zebra species.

    PubMed

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

    2015-09-01

    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

  18. The Androgen Receptor Gene Mutations Database.

    PubMed

    Gottlieb, B; Lehvaslaiho, H; Beitel, L K; Lumbroso, R; Pinsky, L; Trifiro, M

    1998-01-01

    The current version of the androgen receptor (AR) gene mutations database is described. The total number of reported mutations has risen from 272 to 309 in the past year. We have expanded the database: (i) by giving each entry an accession number; (ii) by adding information on the length of polymorphic polyglutamine (polyGln) and polyglycine (polyGly) tracts in exon 1; (iii) by adding information on large gene deletions; (iv) by providing a direct link with a completely searchable database (courtesy EMBL-European Bioinformatics Institute). The addition of the exon 1 polymorphisms is discussed in light of their possible relevance as markers for predisposition to prostate or breast cancer. The database is also available on the internet (http://www.mcgill. ca/androgendb/ ), from EMBL-European Bioinformatics Institute (ftp. ebi.ac.uk/pub/databases/androgen ), or as a Macintosh FilemakerPro or Word file (MC33@musica.mcgill.ca).

  19. A novel prostate cancer therapeutic strategy using icaritin-activated arylhydrocarbon-receptor to co-target androgen receptor and its splice variants

    PubMed Central

    Sun, Feng; Indran, Inthrani R.; Zhang, Zhi Wei; Tan, M.H.Eileen; Li, Yu; Lim, Z.L.Ryan; Hua, Rui; Yang, Chong; Soon, Fen-Fen; Li, Jun; Xu, H.Eric; Cheung, Edwin; Yong, Eu-Leong

    2015-01-01

    Persistent androgen receptor (AR) signaling is the key driving force behind progression and development of castration-resistant prostate cancer (CRPC). In many patients, AR COOH-terminal truncated splice variants (ARvs) play a critical role in contributing to the resistance against androgen depletion therapy. Unfortunately, clinically used antiandrogens like bicalutamide (BIC) and enzalutamide (MDV), which target the ligand binding domain, have failed to suppress these AR variants. Here, we report for the first time that a natural prenylflavonoid, icaritin (ICT), can co-target both persistent AR and ARvs. ICT was found to inhibit transcription of key AR-regulated genes, such as KLK3 [prostate-specific antigen (PSA)] and ARvs-regulated genes, such as UBE2C and induce apoptosis in AR-positive prostate cancer (PC) cells. Mechanistically, ICT promoted the degradation of both AR and ARvs by binding to arylhydrocarbon-receptor (AhR) to mediate ubiquitin-proteasomal degradation. Therefore, ICT impaired AR transactivation in PC cells. Knockdown of AhR gene restored AR stability and partially prevented ICT-induced growth suppression. In clinically relevant murine models orthotopically implanted with androgen-sensitive and CRPC cells, ICT was able to target AR and ARvs, to inhibit AR signaling and tumor growth with no apparent toxicity. Our results provide a mechanistic framework for the development of ICT, as a novel lead compound for AR-positive PC therapeutics, especially for those bearing AR splice variants. PMID:25908644

  20. Potent antiandrogen and androgen receptor activities of an Angelica gigas-containing herbal formulation: identification of decursin as a novel and active compound with implications for prevention and treatment of prostate cancer.

    PubMed

    Jiang, Cheng; Lee, Hyo-Jeong; Li, Guang-xun; Guo, Junming; Malewicz, Barbara; Zhao, Yan; Lee, Eun-Ok; Lee, Hyo-Jung; Lee, Jae-Ho; Kim, Min-Seok; Kim, Sung-Hoon; Lu, Junxuan

    2006-01-01

    Androgen and androgen receptor (AR)-mediated signaling are crucial for the development of prostate cancer. Identification of novel and naturally occurring phytochemicals that target androgen and AR signaling from Oriental medicinal herbs holds exciting promises for the chemoprevention of this disease. In this article, we report the discovery of strong and long-lasting antiandrogen and AR activities of the ethanol extract of a herbal formula (termed KMKKT) containing Korean Angelica gigas Nakai (AGN) root and nine other Oriental herbs in the androgen-dependent LNCaP human prostate cancer cell model. The functional biomarkers evaluated included a suppression of the expression of prostate-specific antigen (PSA) mRNA and protein (IC50, approximately 7 microg/mL, 48-hour exposure) and an inhibition of androgen-induced cell proliferation through G1 arrest and of the ability of androgen to suppress neuroendocrine differentiation at exposure concentrations that did not cause apoptosis. Through activity-guided fractionation, we identified decursin from AGN as a novel antiandrogen and AR compound with an IC50 of approximately 0.4 microg/mL (1.3 micromol/L, 48-hour exposure) for suppressing PSA expression. Decursin also recapitulated the neuroendocrine differentiation induction and G1 arrest actions of the AGN and KMKKT extracts. Mechanistically, decursin in its neat form or as a component of AGN or KMKKT extracts inhibited androgen-stimulated AR translocation to the nucleus and down-regulated AR protein abundance without affecting the AR mRNA level. The novel antiandrogen and AR activities of decursin and decursin-containing herbal extracts have significant implications for the chemoprevention and treatment of prostate cancer and other androgen-dependent diseases.

  1. Nonsteroidal selective androgen receptor modulators enhance female sexual motivation.

    PubMed

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

    2010-08-01

    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.

  2. p21-Activated kinase 6 (PAK6) inhibits prostate cancer growth via phosphorylation of androgen receptor and tumorigenic E3 ligase murine double minute-2 (Mdm2).

    PubMed

    Liu, Tong; Li, Yang; Gu, Hui; Zhu, Ge; Li, Jiabin; Cao, Liu; Li, Feng

    2013-02-01

    The androgen receptor (AR) signaling pathway plays a crucial role in the development and growth of prostate malignancies. Regulation of AR homeostasis in prostate tumorigenesis has not yet been fully characterized. In this study, we demonstrate that p21-activated kinase 6 (PAK6) inhibits prostate tumorigenesis by regulating AR homeostasis. First, we demonstrated that in normal prostate epithelium, AR co-localizes with PAK6 in the cytoplasm and translocates into the nucleus in malignant prostate. Furthermore, AR phosphorylation at Ser-578 by PAK6 promotes AR-E3 ligase murine double minute-2 (Mdm2) association, causing AR degradation upon androgen stimuli. We also showed that PAK6 phosphorylates Mdm2 on Thr-158 and Ser-186, which is critical for AR ubiquitin-mediated degradation. Moreover, we found that Thr-158 collaborates with Ser-186 for AR-Mdm2 association and AR ubiquitin-mediated degradation as it facilitates PAK6-mediated AR homeostasis. PAK6 knockdown promotes prostate tumor growth in vivo. Interestingly, we found a strong inverse correlation between PAK6 and AR expression in the cytoplasm of prostate cancer cells. These observations indicate that PAK6 may be important for the maintenance of androgen-induced AR signaling homeostasis and in prostate malignancy, as well as being a possible new therapeutic target for AR-positive and hormone-sensitive prostate cancer.

  3. Novel selective androgen receptor modulators: SAR studies on 6-bisalkylamino-2-quinolinones.

    PubMed

    van Oeveren, Arjan; Motamedi, Mehrnoush; Martinborough, Esther; Zhao, Shuo; Shen, Yixing; West, Sarah; Chang, William; Kallel, Adam; Marschke, Keith B; López, Francisco J; Negro-Vilar, Andrés; Zhi, Lin

    2007-03-15

    A series of selective androgen receptor modulators (SARMs) with a wide spectrum of receptor modulating activities was developed based on optimization of the 4-substituted 6-bisalkylamino-2-quinolinones (3). Significance of the trifluoromethyl group on the side chains and its interactions with amino acid residues within the androgen receptor (AR) ligand binding domain are discussed. A representative analog (9) was tested orally in a rodent model of hypogonadism and demonstrated desirable tissue selectivity.

  4. A satellite cell-specific knockout of the androgen receptor reveals myostatin as a direct androgen target in skeletal muscle.

    PubMed

    Dubois, Vanessa; Laurent, Michaël R; Sinnesael, Mieke; Cielen, Nele; Helsen, Christine; Clinckemalie, Liesbeth; Spans, Lien; Gayan-Ramirez, Ghislaine; Deldicque, Louise; Hespel, Peter; Carmeliet, Geert; Vanderschueren, Dirk; Claessens, Frank

    2014-07-01

    Androgens have well-established anabolic actions on skeletal muscle, although the direct effects of the androgen receptor (AR) in muscle remain unclear. We generated satellite cell-specific AR-knockout (satARKO) mice in which the AR is selectively ablated in satellite cells, the muscle precursor cells. Total-limb maximal grip strength is decreased by 7% in satARKO mice, with soleus muscles containing ∼10% more type I fibers and 10% less type IIa fibers than the corresponding control littermates. The weight of the perineal levator ani muscle is markedly reduced (-52%). Thus, muscle AR is involved in fiber-type distribution and force production of the limb muscles, while it is a major determinant of the perineal muscle mass. Surprisingly, myostatin (Mstn), a strong inhibitor of skeletal muscle growth, is one of the most androgen-responsive genes (6-fold reduction in satARKO) through direct transcription activation by the AR. Consequently, muscle hypertrophy in response to androgens is augmented in Mstn-knockout mice. Our finding that androgens induce Mstn signaling to restrain their own anabolic actions has implications for the treatment of muscle wasting disorders.-Dubois, V., Laurent, M. R., Sinnesael, M., Cielen, N., Helsen, C., Clinckemalie, L., Spans, L., Gayan-Ramirez, G., Deldicque, L., Hespel, P., Carmeliet, G., Vanderschueren, D., and Claessens, F. A satellite cell-specific knockout of the androgen receptor reveals myostatin as a direct androgen target in skeletal muscle.

  5. Novel Chemical Strategies for Labeling Small Molecule Ligands for Androgen, Progestin, and Peroxisome Proliferator-Activated Receptors for Imaging Prostate and Breast Cancer and the Heart

    SciTech Connect

    Katzenellenbogen, John, A.

    2007-04-19

    Summary of Progress The specific aims of this project can be summarized as follows: • Aim 1: Prepare and evaluate radiolabeled ligands for the peroxisome proliferator-activated receptor (PPAR), a new nuclear hormone receptor target for tumor imaging and hormone therapy. • Aim 2: Prepare steroids labeled with a cyclopentadienyl tricarbonyl technetium or rhenium unit. • Aim 3: Prepare and evaluate other organometallic systems of novel design as ligand mimics and halogenated ligands for nuclear hormone receptor-based tumor imaging. As is described in detail below, we made excellent progress on all three of these aims; the highlights of our progress are the following: • we have prepared the first fluorine-18 labeled analogs of ligands for the PPAR receptor and used these in tissue distribution studies in rats • we have developed three new methods for the synthesis of cyclopentadienyltricarbonyl rhenium and technetium (CpRe(CO)3 and CpTc(CO)3) systems and we have adapted these to the synthesis of steroids labeled with these metals, as well as ligands for other receptor systems • we have prepared a number of fluorine-18 labeled steroidal and non-steroidal androgens and measured their tissue distribution in rats • we have prepared iodine and bromine-labeled progestins with high progesterone receptor binding affinity • we have prepared inorganic metal tricarbonyl complexes and steroid receptor ligands in which the metal tricarbonyl unit is an integral part off the ligand core.

  6. 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.

  7. 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

  8. 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

  9. Selective androgen receptor modulators as improved androgen therapy for advanced breast cancer.

    PubMed

    Coss, Christopher C; Jones, Amanda; Dalton, James T

    2014-11-01

    Androgens were at one time a therapeutic mainstay in the treatment of advanced breast cancer. Despite comparable efficacy, SERMs and aromatase inhibitors eventually became the therapies of choice due to in part to preferred side-effect profiles. Molecular characterization of breast tumors has revealed an abundance of androgen receptor expression but the choice of an appropriate androgen receptor ligand (agonist or antagonist) has been confounded by multiple conflicting reports concerning the role of the receptor in the disease. Modern clinical efforts have almost exclusively utilized antagonists. However, the recent clinical development of selective androgen receptor modulators with greatly improved side-effect profiles has renewed interest in androgen agonist therapy for advanced breast cancer.

  10. 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

  11. 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

  12. 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. PMID:27471583

  13. Preliminary investigations into triazole derived androgen receptor antagonists.

    PubMed

    Altimari, Jarrad M; Niranjan, Birunthi; Risbridger, Gail P; Schweiker, Stephanie S; Lohning, Anna E; Henderson, Luke C

    2014-05-01

    A range of 1,4-substituted-1,2,3-N-phenyltriazoles were synthesized and evaluated as non-steroidal androgen receptor (AR) antagonists. The motivation for this study was to replace the N-phenyl amide portion of small molecule antiandrogens with a 1,2,3-triazole and determine effects, if any, on biological activity. The synthetic methodology presented herein is robust, high yielding and extremely rapid. Using this methodology a series of 17 N-aryl triazoles were synthesized from commercially available starting materials in less than 3h. After preliminary biological screening at 20 and 40 μM, the most promising three compounds were found to display IC50 values of 40-50 μM against androgen dependent (LNCaP) cells and serve as a starting point for further structure-activity investigations. All compounds in this work were the focus of an in silico study to dock the compounds into the human androgen receptor ligand binding domain (hARLBD) and compare their predicted binding affinity with known antiandrogens. A comparison of receptor-ligand interactions for the wild type and T877A mutant AR revealed two novel polar interactions. One with Q738 of the wild type site and the second with the mutated A877 residue.

  14. Expression of androgen and progesterone receptors in primary human meningiomas.

    PubMed

    Maxwell, M; Galanopoulos, T; Neville-Golden, J; Antoniades, H N

    1993-03-01

    Meningiomas are common brain tumors that show a predilection for females and become more aggressive during pregnancy and menses. The existence of gender-specific hormone receptors in meningiomas has long been a matter of controversy; the recent cloning of androgen, estrogen, and progesterone receptors has facilitated their direct evaluation. The authors have demonstrated the expression of androgen and progesterone receptor messenger ribonucleic acid and protein product in nine primary human meningiomas by Northern blot analysis. Cellular localization was achieved by in situ hybridization analysis. Estrogen receptor expression was not detected. Normal adult meninges were shown to express very low levels of both androgen and progesterone receptors.

  15. Pyridine analogues of curcumin exhibit high activity for inhibiting CWR-22Rv1 human prostate cancer cell growth and androgen receptor activation

    PubMed Central

    ZHOU, DAI-YING; ZHAO, SU-QING; DU, ZHI-YUN; ZHENG, XI; ZHANG, KUN

    2016-01-01

    The concentrations required for curcumin to exert its anticancer activity (IC50, 20 µM) are difficult to achieve in the blood plasma of patients, due to the low bioavailability of the compound. Therefore, much effort has been devoted to the development of curcumin analogues that exhibit stronger anticancer activity and a lower IC50 than curcumin. The present study investigated twelve pyridine analogues of curcumin, labeled as groups AN, BN, EN and FN, to determine their effects in CWR-22Rv1 human prostate cancer cells. The inhibitory effects of these compounds on testosterone (TT)-induced androgen receptor (AR) activity was determined by performing an AR-linked luciferase assay and by TT-induced expression of prostate-specific antigen. The results of the current study suggested that the FN group of analogues had the strongest inhibitory effect of growth on CWR-22Rv1 cultured cells, and were the most potent inhibitor of AR activity compared with curcumin, and the AN, BN and EN analogues. Thus, the results of the present study indicate the inhibition of the AR pathways as a potential mechanism for the anticancer effect of curcumin analogues in human prostate cancer cells. Furthermore, curcumin analogues with pyridine as a distal ring and tetrahydrothiopyran-4-one as a linker may be good candidates for the development of novel drugs for the treatment of prostate cancer, by targeting the AR signaling pathway. PMID:27313760

  16. 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).

  17. Screening for estrogen and androgen receptor activities in 200 pesticides by in vitro reporter gene assays using Chinese hamster ovary cells.

    PubMed Central

    Kojima, Hiroyuki; Katsura, Eiji; Takeuchi, Shinji; Niiyama, Kazuhito; Kobayashi, Kunihiko

    2004-01-01

    We tested 200 pesticides, including some of their isomers and metabolites, for agonism and antagonism to two human estrogen receptor (hER) subtypes, hERalpha and hERbeta, and a human androgen receptor (hAR) by highly sensitive transactivation assays using Chinese hamster ovary cells. The test compounds were classified into nine groups: organochlorines, diphenyl ethers, organophosphorus pesticides, pyrethroids, carbamates, acid amides, triazines, ureas, and others. These pesticides were tested at concentrations < 10-5 M. Of the 200 pesticides tested, 47 and 33 showed hER- and hERbeta-mediated estrogenic activities, respectively. Among them, 29 pesticides had both hERalpha and hERbeta agonistic activities, and the effects of the organochlorine insecticides beta-benzene hexachloride (BHC) and delta-BHC and the carbamate insecticide methiocarb were predominantly hERbeta rather than hERalpha agonistic. Weak antagonistic effects toward hERalpha and hERbeta were shown in five and two pesticides, respectively. On the other hand, none of tested pesticides showed hAR-mediated androgenic activity, but 66 of 200 pesticides exhibited inhibitory activity against the transcriptional activity induced by 5alpha-dihydrotestosterone. In particular, the antiandrogenic activities of two diphenyl ether herbicides, chlornitrofen and chlomethoxyfen, were higher than those of vinclozolin and p,p -dichlorodiphenyl dichloroethylene, known AR antagonists. The results of our ER and AR assays show that 34 pesticides possessed both estrogenic and antiandrogenic activities, indicating pleiotropic effects on hER and hAR. We also discussed chemical structures related to these activities. Taken together, our findings suggest that a variety of pesticides have estrogenic and/or antiandrogenic potential via ER and/or AR, and that numerous other manmade chemicals may also possess such estrogenic and antiandrogenic activities. PMID:15064155

  18. 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 ...

  19. 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...

  20. CUDC-101, a Novel Inhibitor of Full-Length Androgen Receptor (flAR) and Androgen Receptor Variant 7 (AR-V7) Activity: Mechanism of Action and In Vivo Efficacy.

    PubMed

    Sun, Huiying; Mediwala, Sanjay N; Szafran, Adam T; Mancini, Michael A; Marcelli, Marco

    2016-06-01

    Castration-resistant prostate cancer (CRPC) is an androgen receptor (AR)-dependent disease expected to cause the death of more than 27,000 Americans in 2015. There are only a few available treatments for CRPC, making the discovery of new drugs an urgent need. We report that CUDC-101 (an inhibitor od HER2/NEU, EGFR and HDAC) inhibits both the full length AR (flAR) and the AR variant AR-V7. This observation prompted experiments to discover which of the known activities of CUDC-101 is responsible for the inhibition of flAR/AR-V7 signaling. We used pharmacologic and genetic approaches, and found that the effect of CUDC-101 on flAR and AR-V7 was duplicated only by other HDAC inhibitors, or by silencing the HDAC isoforms HDAC5 and HDAC10. We observed that CUDC-101 treatment or AR-V7 silencing by RNAi equally reduced transcription of the AR-V7 target gene, PSA, without affecting viability of 22Rv1 cells. However, when cellular proliferation was used as an end point, CUDC-101 was more effective than AR-V7 silencing, raising the prospect that CUDC-101 has additional targets beside AR-V7. In support of this, we found that CUDC-101 increased the expression of the cyclin-dependent kinase inhibitor p21, and decreased that of the oncogene HER2/NEU. To determine if CUDC-101 reduces growth in a xenograft model of prostate cancer, this drug was given for 14 days to castrated male SCID mice inoculated with 22Rv1 cells. Compared to vehicle, CUDC-101 reduced xenograft growth in a statistically significant way, and without macroscopic side effects. These studies demonstrate that CUDC-101 inhibits wtAR and AR-V7 activity and growth of 22Rv1 cells in vitro and in vivo. These effects result from the ability of CUDC-101 to target not only HDAC signaling, which was associated with decreased flAR and AR-V7 activity, but multiple additional oncogenic pathways. These observations raise the possibility that treatment of CRPC may be achieved by using similarly multi-targeted approaches.

  1. Antiandrogens act as selective androgen receptor modulators at the proteome level in prostate cancer cells.

    PubMed

    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

    2015-05-01

    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

  2. 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

  3. Id-1 expression induces androgen-independent prostate cancer cell growth through activation of epidermal growth factor receptor (EGF-R).

    PubMed

    Ling, Ming-Tat; Wang, Xianghong; Lee, Davy T; Tam, P C; Tsao, Sai-Wah; Wong, Yong-Chuan

    2004-04-01

    The failure of prostate cancer treatment is largely due to the development of androgen independence, since the androgen depletion therapy remains the front-line option for this cancer. Previously, we reported that over-expression of the helix-loop-helix protein Id-1 was associated with progression of prostate cancer and ectopic expression of Id-1 induced serum-independent proliferation in prostate cancer cells. In the present study, we investigated if exogenous Id-1 expression in the androgen sensitive LNCaP cells had any effect on androgen-dependent cell growth and studied the molecular mechanisms involved. Using stable Id-1 transfectants, we found that expression of Id-1 was able to reduce androgen-stimulated growth and S phase fraction of the cell cycle in LNCaP cells, indicating that Id-1 may be involved in the development of androgen independence in these cells. The Id-1-induced androgen-independent prostate cancer cell growth was correlated with up-regulation of EGF-R (epidermal growth factor-receptor) and PSA (prostate specific antigen) expression, as confirmed by western blotting analysis and luciferase assays. In contrast, down-regulation of Id-1 in androgen-independent DU145 cells by its antisense oligonucleotides resulted in suppression of EGF-R expression at both transcriptional and protein levels. In addition, the results from immunohistochemistry study showed that Id-1 expression was significantly elevated in hormone refractory prostate cancer tissues when compared with the hormone-dependent tumours. Our results suggest that up-regulation of Id-1 in prostate cancer cells may be one of the mechanisms responsible for developing androgen independence and this process may be regulated through induction of EGF-R expression. Inactivation of Id-1 may provide a potential therapeutic strategy leading to inhibition of androgen-independent prostate cancer cell growth.

  4. Role of the Androgen-Androgen Receptor Axis in the Treatment Resistance of Advanced Prostate Cancer: From Androgen-Dependent to Castration Resistant and Further.

    PubMed

    Fujimoto, Naohiro

    2016-06-01

    After the introduction of prostate-specific antigen (PSA) screening, prostate cancer diagnosis has shifted to early and curative stages, although 10-20% of patients still present with metastatic and incurable cancer. Prostate cancer is androgen-dependent, and most patients with prostate cancer initially respond to androgen deprivation therapy (ADT). After 1-2 years of the treatment, advanced prostate cancer eventually progresses to castration resistant prostate cancer (CRPC). A variety of mechanisms of progression from androgen-dependent prostate cancer to CRPC under ADT have been postulated, and the key pathway is re-activation of the androgen-androgen receptor (AR) axis, for example, caused by AR mutation/overexpression/splice variants, altered expression of AR cofactors, and increased production of androgens. Recently approved new agents, such as the hormonal agents abiraterone and enzalutamide and the chemotherapeutic agent cabazitaxel, have demonstrated survival benefit in men with CRPC. However, the prolongation of survival times provided with these agents is limited because of the treatment resistance. Androgen-AR axis still plays a pivotal role in the resistance to the new agents for CRPC. To improve the prognosis of patients with CRPC, intensive research to identify effective agents, treatment strategies, and useful predictive biomarkers to select the patients who can benefit from such treatments are required. Additional clinical data, with a better understanding of the biology of CRPC, may provide better CRPC treatment outcomes. This article reviews the underlying mechanisms of treatment resistance and future direction of CRPC treatments.

  5. Discovery of diarylhydantoins as new selective androgen receptor modulators.

    PubMed

    Nique, François; Hebbe, Séverine; Peixoto, Christophe; Annoot, Denis; Lefrançois, Jean-Michel; Duval, Eric; Michoux, Laurence; Triballeau, Nicolas; Lemoullec, Jean-Michel; Mollat, Patrick; Thauvin, Maxime; Prangé, Thierry; Minet, Dominique; Clément-Lacroix, Philippe; Robin-Jagerschmidt, Catherine; Fleury, Damien; Guédin, Denis; Deprez, Pierre

    2012-10-11

    A novel selective androgen receptor modulator scaffold has been discovered through structural modifications of hydantoin antiandrogens. Several 4-(4-hydroxyphenyl)-N-arylhydantoins displayed partial agonism with nanomolar in vitro potency in transactivation experiments using androgen receptor (AR) transfected cells. In a standard castrated male rat model, several compounds showed good anabolic activity on levator ani muscle, dissociated from the androgenic activity on ventral prostate, after oral dosing at 30 mg/kg. (+)-4-[3,4-Dimethyl-2,5-dioxo-4-(4-hydroxyphenyl)imidazolidin-1-yl]-2-(trifluoromethyl)benzonitrile ((+)-11b) displayed anabolic potency with a strong dissociation between levator ani muscle and ventral prostate (A(50) = 0.5 mg/kg vs 70 mg/kg). The binding modes of two compounds, including (+)-11b, within the AR ligand-binding domain have been studied by cocrystallization experiments using a coactivator-like peptide. Both compounds bound to the same site, and the overall structures of the AR were very similar.

  6. 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

  7. Selective androgen receptor modulators in drug discovery: medicinal chemistry and therapeutic potential.

    PubMed

    Cadilla, Rodolfo; Turnbull, Philip

    2006-01-01

    Modulation of the androgen receptor has the potential to be an effective treatment for hypogonadism, andropause, and associated conditions such as sarcopenia, osteoporosis, benign prostatic hyperplasia, and sexual dysfunction. Side effects associated with classical anabolic steroid treatments have driven the quest for drugs that demonstrate improved therapeutic profiles. Novel, non-steroidal compounds that show tissue selective activity and improved pharmacokinetic properties have been developed. This review provides an overview of current advances in the development of selective androgen receptor modulators (SARMs).

  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. [Myoanabolic steroids and selective androgen receptor modulators: mechanism of action and perspectives].

    PubMed

    Tóth, Miklós

    2009-11-01

    Interest in anabolic steroids has been renewed in the last decade with the discovery of tissue-selective androgen receptor modulators exhibiting high myotropic and small androgenic activity. An explanation put forward by us in 1982 for the mechanism of the preferential myotropic effect of nandrolone (19-nortestosterone) exploits the fundamental difference between the 5alpha-reductase concentrations in skeletal muscle and androgenic target tissue. In androgenic tissue, testosterone is converted to the more potent 5alpha-dihydrotestosterone whereas nandrolone is converted to a less potent derivative. As 5alpha-reduction is negligible in skeletal muscle, this explains why nandrolone shows a greater myotropic to androgenic ratio when compared with testosterone. Anabolic steroids that do not undergo 5alpha-reduction exert myotropic-androgenic dissociation because their effect in androgenic tissues is not amplified by 5alpha-reduction. Tissue selectivity by receptor modulators may be achieved by inducing specific conformational changes of the androgen receptor that affect its interaction with transcriptional coregulators. Anabolic activity is mediated by the stimulation of ribosomal RNA synthesis therefore regulation of this synthesis by anabolic steroids would deserve detailed studies.

  10. Estren (4-estren-3alpha,17beta-diol) is a prohormone that regulates both androgenic and estrogenic transcriptional effects through the androgen receptor.

    PubMed

    Centrella, Michael; McCarthy, Thomas L; Chang, Wei-Zhong; Labaree, David C; Hochberg, Richard B

    2004-05-01

    Alternative mechanisms of steroid action, through both traditional nuclear receptors and indirect pathways of gene activation, are emerging. Recent studies suggest that the synthetic steroid, 4-estrene-3alpha,17beta-diol (estren), has nongenotropic as well as sex-nonspecific osteogenic effects in ovariectomized and orchidectomized mice. We found limited estrogen receptor-dependent effects by estren on gene expression in primary osteoblast cultures and showed that it binds poorly to estrogen and androgen receptors in vitro. However, estren potently regulated direct and indirect androgen receptor-dependent effects on gene expression by osteoblasts. Consistent with this, osteoblasts produced the potent androgen 19-nortestosterone from estren by way of a 3alpha-hydroxysteroid dehydrogenase-like activity. Moreover, recombinant 3alpha-hydroxysteroid dehydrogenase (AKR1C9) and osteoblast-derived cell lysate each effectively converted estren to 19-nortestosterone in vitro, and mRNA encoding this enzyme occurs in osteoblasts. In addition to its androgenic activity, estren potently stimulated androgen receptor-dependent effects on gene expression through conventional estrogen-sensitive transcriptional elements in osteoblasts. Therefore, through local metabolism, estren indirectly activates the androgen receptor to regulate both androgen- and estrogen-like transcriptional responses by bone-forming cells.

  11. 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

  12. 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

  13. 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

  14. 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

  15. Novel Role for p110β PI 3-Kinase in Male Fertility through Regulation of Androgen Receptor Activity in Sertoli Cells

    PubMed Central

    Guillermet-Guibert, Julie; Smith, Lee B.; Halet, Guillaume; Whitehead, Maria A.; Pearce, Wayne; Rebourcet, Diane; León, Kelly; Crépieux, Pascale; Nock, Gemma; Strömstedt, Maria; Enerback, Malin; Chelala, Claude; Graupera, Mariona; Carroll, John; Cosulich, Sabina; Saunders, Philippa T. K.; Huhtaniemi, Ilpo; Vanhaesebroeck, Bart

    2015-01-01

    The organismal roles of the ubiquitously expressed class I PI3K isoform p110β remain largely unknown. Using a new kinase-dead knockin mouse model that mimics constitutive pharmacological inactivation of p110β, we document that full inactivation of p110β leads to embryonic lethality in a substantial fraction of mice. Interestingly, the homozygous p110β kinase-dead mice that survive into adulthood (maximum ~26% on a mixed genetic background) have no apparent phenotypes, other than subfertility in females and complete infertility in males. Systemic inhibition of p110β results in a highly specific blockade in the maturation of spermatogonia to spermatocytes. p110β was previously suggested to signal downstream of the c-kit tyrosine kinase receptor in germ cells to regulate their proliferation and survival. We now report that p110β also plays a germ cell-extrinsic role in the Sertoli cells (SCs) that support the developing sperm, with p110β inactivation dampening expression of the SC-specific Androgen Receptor (AR) target gene Rhox5, a homeobox gene critical for spermatogenesis. All extragonadal androgen-dependent functions remain unaffected by global p110β inactivation. In line with a crucial role for p110β in SCs, selective inactivation of p110β in these cells results in male infertility. Our study is the first documentation of the involvement of a signalling enzyme, PI3K, in the regulation of AR activity during spermatogenesis. This developmental pathway may become active in prostate cancer where p110β and AR have previously been reported to functionally interact. PMID:26132308

  16. 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.

  17. 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

  18. 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

  19. Autoimmune anti-androgen-receptor antibodies in human serum.

    PubMed Central

    Liao, S; Witte, D

    1985-01-01

    Circulating autoantibodies to human and rat androgen receptors are present at high titers in the blood sera of some patients with prostate diseases. The antibodies from some serum samples were associated with a purified IgG fraction and interacted with the 3.8S cytosolic androgen-receptor complexes of rat ventral prostate to form 9- to 12S units. Other serum samples, however, formed 14- to 19S units, suggesting that other immunoglobulins might be involved. In the presence of an anti-human immunoglobulin as a second antibody, the androgen-receptor-antibody complexes could be immunoprecipitated. The antibodies interacted with the nuclear and the cytosolic androgen-receptor complexes, either the DNA-binding or the nonbinding form, but not with receptors for estradiol, progestin, or dexamethasone from a variety of sources. Human testosterone/estradiol-binding globulin, rat epididymal androgen-binding protein, or rat prostate alpha-protein (a nonreceptor steroid-binding protein) also did not interact with the antibodies to form immunoprecipitates. About 37% of male and 3% of female serum samples screened had significant antibody titer. The chance of finding serum with a high titer is much better in males older than 66 years than in the younger males or females at all ages. The presence of the high-titer antibodies may make it possible to prepare monoclonal antibodies to androgen receptors without purification of the receptors for immunization. PMID:3866227

  20. Estrogen-, androgen- and aryl hydrocarbon receptor mediated activities in passive and composite samples from municipal waste and surface waters.

    PubMed

    Jálová, V; Jarošová, B; Bláha, L; Giesy, J P; Ocelka, T; Grabic, R; Jurčíková, J; Vrana, B; Hilscherová, K

    2013-09-01

    Passive and composite sampling in combination with in vitro bioassays and identification and quantification of individual chemicals were applied to characterize pollution by compounds with several specific modes of action in urban area in the basin of two rivers, with 400,000 inhabitants and a variety of industrial activities. Two types of passive samplers, semipermeable membrane devices (SPMD) for hydrophobic contaminants and polar organic chemical integrative samplers (POCIS) for polar compounds such as pesticides and pharmaceuticals, were used to sample wastewater treatment plant (WWTP) influent and effluent as well as rivers upstream and downstream of the urban complex and the WWTP. Compounds with endocrine disruptive potency were detected in river water and WWTP influent and effluent. Year-round, monthly assessment of waste waters by bioassays documented estrogenic, androgenic and dioxin-like potency as well as cytotoxicity in influent waters of the WWTP and allowed characterization of seasonal variability of these biological potentials in waste waters. The WWTP effectively removed cytotoxic compounds, xenoestrogens and xenoandrogens. There was significant variability in treatment efficiency of dioxin-like potency. The study indicates that the WWTP, despite its up-to-date technology, can contribute endocrine disrupting compounds to the river. Riverine samples exhibited dioxin-like, antiestrogenic and antiandrogenic potencies. The study design enabled characterization of effects of the urban complex and the WWTP on the river. Concentrations of PAHs and contaminants and specific biological potencies sampled by POCIS decreased as a function of distance from the city.

  1. Examination of the in vitro (anti)estrogenic, (anti)androgenic and (anti)dioxin-like activities of tetralin, indane and isochroman derivatives using receptor-specific bioassays.

    PubMed

    Schreurs, Richard H M M; Sonneveld, Edwin; van der Saag, Paul T; van der Burg, Bart; Seinen, Willem

    2005-04-10

    Molecules derived from tetralin, indane and isochroman are often used in the synthesis of fragrance materials. The two polycyclic musk fragrances AHTN (6-acetyl-1,1,2,4,4,7-hexamethyltetralin), HHCB (1,2,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-gamma-2-benzopyran) and ADBI (4-acetyl-1,1-dimethyl-6-tert-butylindane) are derived from tetralin, isochroman and indane, respectively. In previous studies, AHTN and HHCB have been shown to antagonize estrogen receptors (ERs), both in vitro and in vivo. Here, we used two newly developed reporter gene assays, to examine the agonistic and antagonistic properties of several indane, tetralin and isochroman derivatives towards the human androgen receptor (AR) and aryl hydrocarbon receptor (AhR). Additionally, we also assessed (anti)estrogenicity of these compounds. A number of compounds showed weak estrogenic activity towards the human ER alpha. Several compounds showed (anti)estrogenic effects, starting at a concentration of 0.1 microM. Surprisingly, almost all compounds were found to be AR antagonists, starting at 0.1 microM. None of the compounds tested, showed either agonism or antagonism towards the AhR. Non-specific effects via crosstalk of the AhR and the ER or AR can therefore be ruled out. As far as we are aware, molecules derived from indane, tetralin and isochroman showing direct interaction with the ER and AR have not been reported previously.

  2. 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

  3. MASCULINIZATION OF FEMALE MOSQUITO FISH IN KRAFT MILL EFFLUENT -CONTAMINATED FENHOLLOWAY RIVER WATER IS ASSOCIATED WITH ANDROGEN RECEPTOR AGONIST ACTIVITY.

    EPA Science Inventory

    Female mosquitofish (Gambusia affinis holbrooki) downstream from Kraft paper mills in Florida display masculinization of the anal fin, an androgen-dependent trait. The current investigation was designed to determine if water contaminated with pulp-mill effluent (PME) from the Fen...

  4. MASCULINIZATION OF FEMALE MOSQUITOFISH IN KRAFT MILL EFFLUENT-CONTAMINATED FENHOLLOWAY RIVER WATER IS ASSOCIATED WITH ANDROGEN RECEPTOR AGONIST ACTIVITY

    EPA Science Inventory

    Female mosquitofish (Gambusia affinis holbrooki) downstream from Kraft paper mills in Florida display masculinization of the anal fin, an androgen-dependent trait. The current investigation was designed to determine if water contaminated with pulp mill effluent (PME) from the Fe...

  5. Selective androgen receptor modulators for frailty and osteoporosis.

    PubMed

    Kilbourne, Edward J; Moore, William J; Freedman, Leonard P; Nagpal, Sunil

    2007-10-01

    Androgens play an important role not only in male sexual differentiation, puberty, sexual behavior and spermatogenesis, but also in the maintenance of bone architecture and muscle mass and strength. For decades, steroidal androgens have been used by hypogonadal and aging men as hormone replacement therapy, and abused by prominent athletes as anabolic agents for enhancing physical performance. The use of steroidal androgens is associated with hepatotoxicity, potential for prostate stimulation, virilizing actions and other side effects resulting from their cross-reactivity to related steroid receptors. Therefore, to utilize the therapeutic potential of the androgen receptor for the treatment of indications such as osteoporosis and frailty, several pharmaceutical and biotechnology companies are developing non-steroidal tissue-selective androgen receptor modulators (SARMs) that retain the beneficial properties of natural androgens and exhibit better therapeutic indices. This article reviews the mechanism of androgen action, novel non-steroidal ligands under development and future directions of SARM research for the discovery of novel modulators for frailty and osteoporosis.

  6. Estrogen receptor ligands counteract cognitive deficits caused by androgen deprivation in male rats.

    PubMed

    Lagunas, Natalia; Calmarza-Font, Isabel; Grassi, Daniela; Garcia-Segura, Luis M

    2011-04-01

    Androgen deprivation causes impairment of cognitive tasks in rodents and humans, and this deficit can be reverted by androgen replacement therapy. Part of the effects of androgens in the male may be mediated by their local metabolism to estradiol or 3-alpha androstanediol within the brain and the consequent activation of estrogen receptors. In this study we have assessed whether the administration of estradiol benzoate, the estrogen receptor β selective agonist diarylpropionitrile or the estrogen receptor α selective agonist propyl pyrazole triol affect performance of androgen-deprived male Wistar rats in the cross-maze test. In addition, we tested the effect of raloxifene and tamoxifen, two selective estrogen receptor modulators used in clinical practice. The behavior of the rats was assessed 2 weeks after orchidectomy or sham surgery. Orchidectomy impaired acquisition in the cross-maze test. Estradiol benzoate and the selective estrogen receptor β agonist significantly improved acquisition in the cross-maze test compared to orchidectomized animals injected with vehicle. Raloxifene and tamoxifen at a dose of 1mg/kg, but not at doses of 0.5 or 2mg/kg, also improved acquisition of orchidectomized animals. Our findings suggest that estrogenic compounds with affinity for estrogen receptor β and selective estrogen receptor modulators, such as raloxifene and tamoxifen, may represent good candidates to promote cognitive performance in androgen-deprived males.

  7. 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.

  8. Toxic Identification and Evaluation of Androgen Receptor Antagonistic Activities in Acid-Treated Liver Extracts of High-Trophic Level Wild Animals from Japan.

    PubMed

    Misaki, Kentaro; Suzuki, Go; Tue, Nguyen Minh; Takahashi, Shin; Someya, Masayuki; Takigami, Hidetaka; Tajima, Yuko; Yamada, Tadasu K; Amano, Masao; Isobe, Tomohiko; Tanabe, Shinsuke

    2015-10-01

    Sulfuric acid-treated liver extracts of representative high-trophic level Japanese animals were analyzed by toxic identification and evaluation (TIE) with chemically activated luciferase expression (CALUX) and chemical analysis to elucidate androgen receptor (AR) antagonistic activities and potential contributions of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). The activities were detected in striped dolphins (n = 5), Stejneger's beaked whales (n = 6), golden eagle (n = 1), and Steller's sea eagle (n = 1) with CALUX-flutamide equivalents (FluEQs) as follow: 38 (20-52), 47 (21-96), 5.0, and 80 μg FluEQ/g-lipid, respectively. The AR antagonism was detected in limited number of specimens at lower levels for finless porpoise, raccoon dog, and common cormorant. Theoretical activities (Theo-FluEQs) were calculated using the concentration of OCPs and PCBs and their IC25-based relative potency (REP) values. These total contribution to CALUX-FluEQ was 126%, 84%, 53%, 55%, and 44% for striped dolphin, Steller's sea eagle, Stejneger's beaked whale, finless porpoise, and golden eagle, respectively, and the main contributor was p,p'-DDE. However, most of the activities for raccoon dog (7.6%) and common cormorant (17%) could not be explained by OCPs and PCBs. This suggests other unknown compounds could function as AR antagonists in these terrestrial species.

  9. Toxic Identification and Evaluation of Androgen Receptor Antagonistic Activities in Acid-Treated Liver Extracts of High-Trophic Level Wild Animals from Japan.

    PubMed

    Misaki, Kentaro; Suzuki, Go; Tue, Nguyen Minh; Takahashi, Shin; Someya, Masayuki; Takigami, Hidetaka; Tajima, Yuko; Yamada, Tadasu K; Amano, Masao; Isobe, Tomohiko; Tanabe, Shinsuke

    2015-10-01

    Sulfuric acid-treated liver extracts of representative high-trophic level Japanese animals were analyzed by toxic identification and evaluation (TIE) with chemically activated luciferase expression (CALUX) and chemical analysis to elucidate androgen receptor (AR) antagonistic activities and potential contributions of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). The activities were detected in striped dolphins (n = 5), Stejneger's beaked whales (n = 6), golden eagle (n = 1), and Steller's sea eagle (n = 1) with CALUX-flutamide equivalents (FluEQs) as follow: 38 (20-52), 47 (21-96), 5.0, and 80 μg FluEQ/g-lipid, respectively. The AR antagonism was detected in limited number of specimens at lower levels for finless porpoise, raccoon dog, and common cormorant. Theoretical activities (Theo-FluEQs) were calculated using the concentration of OCPs and PCBs and their IC25-based relative potency (REP) values. These total contribution to CALUX-FluEQ was 126%, 84%, 53%, 55%, and 44% for striped dolphin, Steller's sea eagle, Stejneger's beaked whale, finless porpoise, and golden eagle, respectively, and the main contributor was p,p'-DDE. However, most of the activities for raccoon dog (7.6%) and common cormorant (17%) could not be explained by OCPs and PCBs. This suggests other unknown compounds could function as AR antagonists in these terrestrial species. PMID:26321157

  10. Mass spectrometry of selective androgen receptor modulators.

    PubMed

    Thevis, Mario; Schänzer, Wilhelm

    2008-07-01

    Nonsteroidal selective androgen receptor modulators (SARMs) are an emerging class of drugs for treatment of various diseases including osteoporosis and muscle wasting as well as the correction of age-related functional decline such as muscle strength and power. Several SARMs, which have advanced to preclinical and clinical trials, are composed of diverse chemical structures including arylpropionamide-, bicyclic hydantoin-, quinoline-, and tetrahydroquinoline-derived nuclei. Since January 2008, SARMs have been categorized as anabolic agents and prohibited by the World Anti-Doping Agency (WADA). Suitable detection methods for these low-molecular weight drugs were based on mass spectrometric approaches, which necessitated the elucidation of dissociation pathways in order to characterize and identify the target analytes in doping control samples as well as potential metabolic products and synthetic analogs. Fragmentation patterns of representatives of each category of SARMs after electrospray ionization (ESI) and collision-induced dissociation (CID) as well as electron ionization (EI) are summarized. The complexity and structural heterogeneity of these drugs is a daunting challenge for detection methods.

  11. Ligand Binding to the Androgen Receptor Induces Conformational Changes That Regulate Phosphatase Interactions▿

    PubMed Central

    Yang, Chun-Song; Xin, Hong-Wu; Kelley, Joshua B.; Spencer, Adam; Brautigan, David L.; Paschal, Bryce M.

    2007-01-01

    We describe a mechanism for protein phosphatase 2A (PP2A) targeting to the androgen receptor (AR) and provide insight into the more general issue of kinase and phosphatase interactions with AR. Simian virus 40 (SV40) small t antigen (ST) binding to N-terminal HEAT repeats in the PP2A A subunit induces structural changes transduced to C-terminal HEAT repeats. This enables the C-terminal HEAT repeats in the PP2A A subunit, including HEAT repeat 13, to discriminate between androgen- and androgen antagonist-induced AR conformations. The PP2A-AR interaction was used to show that an AR mutant in prostate cancer cells (T877A) is activated by multiple ligands without acquiring the same conformation as that induced by androgen. The correlation between androgen binding to AR and increased phosphorylation of the activation function 1 (AF-1) region implies that changes in AR conformation or chaperone composition are causal to kinase access to phosphorylation sites. However, AF-1 phosphorylation sites are kinase accessible prior to androgen binding. This suggests that androgens can enhance the phosphorylation state of AR either by negatively regulating the ability of the ligand-binding domain to bind phosphatases or by inducing an AR conformation that is resistant to phosphatase action. SV40 ST subverts this mechanism by promoting the direct transfer of PP2A onto androgen-bound AR, resulting in multisite dephosphorylation. PMID:17325038

  12. CD147 modulates androgen receptor activity through the Akt/Gsk-3β/β-catenin/AR pathway in prostate cancer cells

    PubMed Central

    Fang, Fang; Qin, Yingxin; Hao, Feng; Li, Qiang; Zhang, Wei; Zhao, Chen; Chen, Shuang; Zhao, Liangzhong; Wang, Liguo; Cai, Jianhui

    2016-01-01

    The androgen signaling pathway serves an important role in the development of prostate cancer. β-Catenin is an androgen receptor (AR) cofactor and augments AR signaling. Glycogen synthase kinase-3β (GSK-3β), a target of phosphorylated serine/threonine protein kinase B (p-Akt), regulates β-catenin stability. In addition, β-catenin, a coregulator of AR, physically interacts with AR and enhances AR-mediated target gene transcription. The multifunctional glycoprotein cluster of differentiation (CD) 147 is highly expressed on the cell surface of the majority of cancer cells, and it promotes tumor invasion, metastasis and growth. In the present study, the molecular effects of CD147 on the Akt/GSK-3β/β-catenin/AR signaling network were investigated in LNCaP cells. Using short hairpin-mediated RNA knockdown of CD147 in LNCaP cells, it was demonstrated that downregulation of CD147 resulted in inhibitory phosphorylation of GSK-3β, and then promoted degeneration of β-catenin and reduced nuclear accumulation of β-catenin. In addition, immunoprecipitation studies demonstrated that CD147 downregulation decreased the formation of a complex between β-catenin and AR. It was shown that CD147 knockdown suppressed the expression of the AR target gene prostate-specific antigen and the growth of AR-positive LNCaP cells. Furthermore, inhibition of PI3K/Akt with LY294002 augmented CD147-mediated function. The present study indicates that the PI3K/Akt pathway may facilitate CD147-mediated activation of the AR pathway. PMID:27446405

  13. USP10 deubiquitylates the histone variant H2A.Z and both are required for androgen receptor-mediated gene activation.

    PubMed

    Draker, Ryan; Sarcinella, Elizabeth; Cheung, Peter

    2011-05-01

    H2A.Z, a variant of H2A, is found at the promoters of inducible genes in both yeast and higher eukaryotes. However, its role in transcriptional regulation is complex since it has been reported to function both as a repressor and activator. We have previously found that mono-ubiquitylation of H2A.Z is linked to transcriptional silencing. Here, we provide new evidence linking H2A.Z deubiquitylation to transcription activation. We found that H2A.Z and ubiquitin-specific protease 10 (USP10) are each required for transcriptional activation of the androgen receptor (AR)-regulated PSA and KLK3 genes. USP10 directly deubiquitylates H2A.Z in vitro and in vivo, and reducing USP10 expression in prostate cancer cells results in elevated steady-state levels of mono-ubiquitylated H2A.Z (H2A.Zub1). Moreover, knockdown of USP10 ablates hormone-induced deubiquitylation of chromatin proteins at the AR-regulated genes. Finally, by sequential ChIP assays, we found that H2A.Zub1 is enriched at the PSA and KLK3 regulatory regions, and loss of H2A.Zub1 is associated with transcriptional activation of these genes. Together, these data provide novel insights into how H2A.Z ubiquitylation/deubiquitylation and USP10 function in AR-regulated gene expression.

  14. JS-K, a glutathione/glutathione S-transferase-activated nitric oxide releasing prodrug inhibits androgen receptor and WNT-signaling in prostate cancer cells

    PubMed Central

    2012-01-01

    Background Nitric oxide (NO) and its oxidative reaction products have been repeatedly shown to block steroid receptor function via nitrosation of zinc finger structures in the DNA-binding domain (DBD). In consequence NO-donors could be of special interest for the treatment of deregulated androgen receptor(AR)-signaling in castration resistant prostate cancer (CRPC). Methods Prostate cancer (PCa) cells were treated with JS-K, a diazeniumdiolate derivate capable of generating large amounts of intracellular NO following activation by glutathione S-transferase. Generation of NO was determined indirectly by the detection of nitrate in tissue culture medium or by immunodetection of nitrotyrosine in the cytoplasm. Effects of JS-K on intracellular AR-levels were determined by western blotting. AR-dimerization was analyzed by mammalian two hybrid assay, nuclear translocation of the AR was visualized in PCa cells transfected with a green fluorescent AR-Eos fusion protein using fluorescence microscopy. Modulation of AR- and WNT-signalling by JS-K was investigated using reporter gene assays. Tumor cell proliferation following JS-K treatment was measured by MTT-Assay. Results The NO-releasing compound JS-K was shown to inhibit AR-mediated reporter gene activity in 22Rv1 CRPC cells. Inhibition of AR signaling was neither due to an inhibition of nuclear import nor to a reduction in AR-dimerization. In contrast to previously tested NO-donors, JS-K was able to reduce the intracellular concentration of functional AR. This could be attributed to the generation of extremely high intracellular levels of the free radical NO as demonstrated indirectly by high levels of nitrotyrosine in JS-K treated cells. Moreover, JS-K diminished WNT-signaling in AR-positive 22Rv1 cells. In line with these observations, castration resistant 22Rv1 cells were found to be more susceptible to the growth inhibitory effects of JS-K than the androgen dependent LNCaP which do not exhibit an active WNT

  15. Pharmacological characterization of AC-262536, a novel selective androgen receptor modulator.

    PubMed

    Piu, Fabrice; Gardell, Luis R; Son, Thomas; Schlienger, Nathalie; Lund, Birgitte W; Schiffer, Hans H; Vanover, Kim E; Davis, Robert E; Olsson, Roger; Bradley, Stefania Risso

    2008-03-01

    Because of the limitations and liabilities of current testosterone therapies, non-steroidal tissue-selective androgen receptor modulators may provide a clinically meaningful advance in therapy. Using a functional cell-based assay AC-262536 was identified as a potent and selective AR ligand, with partial agonist activity relative to the natural androgen testosterone. A 2-week chronic study in castrated male rats indicated that AC-262536 significantly improves anabolic parameters in these animals, especially in stimulating the growth of the levator ani and in suppressing elevated LH levels. In sharp contrast to testosterone, AC-262536 has weak androgenic effects, as measured by prostate and seminal vesicle weights. Thus, AC-262536 represents a novel class of selective androgen receptor modulators (SARMs) with beneficial anabolic effects.

  16. Inhibition of androgen receptor (AR) function by the reproductive orphan nuclear receptor DAX-1.

    PubMed

    Holter, Elin; Kotaja, Noora; Mäkela, Sari; Strauss, Leena; Kietz, Silke; Jänne, Olli A; Gustafsson, Jan-Ake; Palvimo, Jorma J; Treuter, Eckardt

    2002-03-01

    DAX-1 (NROB1) is an atypical member of the nuclear receptor family that is predominantly expressed in mammalian reproductive tissues. While a receptor function of DAX-1 remains enigmatic, previous work has indicated that DAX-1 inhibits the activity of the orphan receptor steroidogenic factor 1 and the estrogen receptors (ERs), presumably via direct occupation of the coactivator-binding surface and subsequent recruitment of additional corepressors. In vivo evidence points at a particular role of DAX-1 for the development and maintenance of male reproductive functions. In this study, we have identified the androgen receptor (AR) NR3C4 as a novel target for DAX-1. We show that DAX-1 potently inhibits ligand-dependent transcriptional activation as well as the interaction between the N- and C-terminal activation domains of AR. We provide evidence for direct interactions of the two receptors that involve the N-terminal repeat domain of DAX-1 and the C-terminal ligand-binding and activation domain of AR. Moreover, DAX-1, known to shuttle between the cytoplasm and the nucleus, is capable of relocalizing AR in both cellular compartments, suggesting that intracellular tethering is associated with DAX-1 inhibition. These results implicate novel inhibitory mechanisms of DAX-1 action with particular relevance for the modulation of androgen-dependent gene transcription in the male reproductive system. PMID:11875111

  17. Prevalent flucocorticoid and androgen activity in US water sources

    USGS Publications Warehouse

    Stavreva, Diana A.; George, Anuja A.; Klausmeyer, Paul; Varticovski, Lyuba; Sack, Daniel; Voss, Ty C.; Schiltz, R. Louis; Blazer, Vicki; Iwanowiczl, Luke R.; Hager, Gordon L.

    2012-01-01

    Contamination of the environment with endocrine disrupting chemicals (EDCs) is a major health concern. The presence of estrogenic compounds in water and their deleterious effect are well documented. However, detection and monitoring of other classes of EDCs is limited. Here we utilize a high-throughput live cell assay based on sub-cellular relocalization of GFP-tagged glucocorticoid and androgen receptors (GFP-GR and GFP-AR), in combination with gene transcription analysis, to screen for glucocorticoid and androgen activity in water samples. We report previously unrecognized glucocorticoid activity in 27%, and androgen activity in 35% of tested water sources from 14 states in the US. Steroids of both classes impact body development, metabolism, and interfere with reproductive, endocrine, and immune systems. This prevalent contamination could negatively affect wildlife and human populations.

  18. 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

  19. 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

  20. Androgen receptor accelerates premature senescence of human dermal papilla cells in association with DNA damage.

    PubMed

    Yang, Yi-Chien; Fu, Hung-Chun; Wu, Ching-Yuan; Wei, Kuo-Ting; Huang, Ko-En; Kang, Hong-Yo

    2013-01-01

    The dermal papilla, located in the hair follicle, expresses androgen receptor and plays an important role in hair growth. Androgen/Androgen receptor actions have been implicated in the pathogenesis of androgenetic alopecia, but the exact mechanism is not well known. Recent studies suggest that balding dermal papilla cells exhibit premature senescence, upregulation of p16(INK4a), and nuclear expression of DNA damage markers. To investigate whether androgen/AR signaling influences the premature senescence of dermal papilla cells, we first compared frontal scalp dermal papilla cells of androgenetic alopecia patients with matched normal controls and observed that premature senescence is more prominent in the dermal papilla cells of androgenetic alopecia patients. Exposure of androgen induced premature senescence in dermal papilla cells from non-balding frontal and transitional zone of balding scalp follicles but not in beard follicles. Overexpression of the AR promoted androgen-induced premature senescence in association with p16(INK4a) upregulation, whereas knockdown of the androgen receptor diminished the effects of androgen. An analysis of γ-H2AX expression in response to androgen/androgen receptor signaling suggested that DNA damage contributes to androgen/androgen receptor-accelerated premature senescence. These results define androgen/androgen receptor signaling as an accelerator of premature senescence in dermal papilla cells and suggest that the androgen/androgen receptor-mediated DNA damage-p16(INK4a) axis is a potential therapeutic target in the treatment of androgenetic alopecia.

  1. 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

  2. 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

  3. 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

  4. Cell-specific activation of the human skeletal alpha-actin by androgens.

    PubMed

    Hong, Mei Hua; Sun, Hong; Jin, Cheng He; Chapman, Mark; Hu, Junlian; Chang, William; Burnett, Kelven; Rosen, Jon; Negro-Vilar, Andres; Miner, Jeffrey N

    2008-03-01

    Although it is evident that androgens increase muscle mass and strength, little is known about the critical molecular targets of androgens in skeletal muscle. In rodents, the skeletal alpha-actin gene is a tissue-specific gene expressed only in the levator ani and other skeletal muscles but not in the prostate or preputial gland, the well-known androgen target tissue. We identified tissue-specific androgen-regulated genes in the skeletal muscle in rats after oral administration of androgens and focused on androgen-dependent up-regulation of the skeletal alpha-actin gene. To investigate the mechanism of action, an in vitro system with various cell lines and a series of deletion mutants of the alpha-actin promoter were used. The human skeletal alpha-actin promoter was activated by androgens in the muscle cell line C2C12 but not in the liver, prostate, or breast cancer cell lines in which exogenous human androgen receptor is expressed. The sequence of the promoter is sufficient for cell-specific androgen response, providing a model for the tissue specificity demonstrated in vivo. Using a series of deletion mutants, the androgen response can be maintained using just the proximal promoter region. The importance of androgen regulation of this small portion of the human skeletal alpha-actin promoter was demonstrated by the correlation between muscle and the alpha-actin promoter activity for an array of selective androgen receptor modulators (SARMs), including an orally active SARM LGD2226. Taken together, the results suggest that the regulation of skeletal alpha-actin by androgens/SARMs may represent an important model system for understanding androgen anabolic action in the muscle.

  5. Sintokamide A Is a Novel Antagonist of Androgen Receptor That Uniquely Binds Activation Function-1 in Its Amino-terminal Domain*

    PubMed Central

    Banuelos, Carmen A.; Tavakoli, Iran; Tien, Amy H.; Caley, Daniel P.; Mawji, Nasrin R.; Li, Zhenzhen; Wang, Jun; Yang, Yu Chi; Imamura, Yusuke; Yan, Luping; Wen, Jian Guo; Andersen, Raymond J.; Sadar, Marianne D.

    2016-01-01

    Androgen receptor (AR) is a validated drug target for all stages of prostate cancer including metastatic castration-resistant prostate cancer (CRPC). All current hormone therapies for CRPC target the C-terminal ligand-binding domain of AR and ultimately all fail with resumed AR transcriptional activity. Within the AR N-terminal domain (NTD) is activation function-1 (AF-1) that is essential for AR transcriptional activity. Inhibitors of AR AF-1 would potentially block most AR mechanisms of resistance including constitutively active AR splice variants that lack the ligand-binding domain. Here we provide evidence that sintokamide A (SINT1) binds AR AF-1 region to specifically inhibit transactivation of AR NTD. Consistent with SINT1 targeting AR AF-1, it attenuated transcriptional activities of both full-length AR and constitutively active AR splice variants, which correlated with inhibition of growth of enzalutamide-resistant prostate cancer cells expressing AR splice variants. In vivo, SINT1 caused regression of CRPC xenografts and reduced expression of prostate-specific antigen, a gene transcriptionally regulated by AR. Inhibition of AR activity by SINT1 was additive to EPI-002, a known AR AF-1 inhibitor that is in clinical trials (NCT02606123). This implies that SINT1 binds to a site on AF-1 that is unique from EPI. Consistent with this suggestion, these two compounds showed differences in blocking AR interaction with STAT3. This work provides evidence that the intrinsically disordered NTD of AR is druggable and that SINT1 analogs may provide a novel scaffold for drug development for the treatment of prostate cancer or other diseases of the AR axis. PMID:27576691

  6. Cyclin-dependent kinase 5 modulates STAT3 and androgen receptor activation through phosphorylation of Ser⁷²⁷ on STAT3 in prostate cancer cells.

    PubMed

    Hsu, Fu-Ning; Chen, Mei-Chih; Lin, Kuan-Chia; Peng, Yu-Ting; Li, Pei-Chi; Lin, Eugene; Chiang, Ming-Ching; Hsieh, Jer-Tsong; Lin, Ho

    2013-10-15

    Cyclin-dependent kinase 5 (Cdk5) is known to regulate prostate cancer metastasis. Our previous results indicated that Cdk5 activates androgen receptor (AR) and supports prostate cancer growth. We also found that STAT3 is a target of Cdk5 in promoting thyroid cancer cell growth, whereas STAT3 may play a role as a regulator to AR activation under cytokine control. In this study, we investigated the regulation of Cdk5 and its activator p35 on STAT3/AR signaling in prostate cancer cells. Our results show that Cdk5 biochemically interacts with STAT3 and that this interaction depends on Cdk5 activation in prostate cancer cells. The phosphorylation of STAT3 at Ser⁷²⁷ (p-Ser⁷²⁷-STAT3) is regulated by Cdk5 in cells and xenograft tumors. The mutant of STAT3 S727A reduces its interaction with Cdk5. We further show that the nuclear distribution of p-Ser⁷²⁷-STAT3 and the expression of STAT3-regulated genes (junB, c-fos, c-myc, and survivin) are regulated by Cdk5 activation. STAT3 mutant does not further decrease cell proliferation upon Cdk5 inhibition, which implies that the role of STAT3 regulated by Cdk5 correlates to cell proliferation control. Interestingly, Cdk5 may regulate the interaction between STAT3 and AR through phosphorylation of Ser⁷²⁷-STAT3 and therefore upregulate AR protein stability and transactivation. Correspondingly, clinical evidence shows that the level of p-Ser⁷²⁷-STAT3 is significantly correlated with Gleason score and the levels of upstream regulators (Cdk5 and p35) as well as downstream protein (AR). In conclusion, this study demonstrates that Cdk5 regulates STAT3 activation through Ser⁷²⁷ phosphorylation and further promotes AR activation by protein-protein interaction in prostate cancer cells.

  7. 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

  8. 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.

  9. 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

  10. 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...

  11. A new trick of an old molecule: androgen receptor splice variants taking the stage?!

    PubMed

    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.

  12. Novel series of potent, nonsteroidal, selective androgen receptor modulators based on 7H-[1,4]oxazino[3,2-g]quinolin-7-ones.

    PubMed

    Higuchi, Robert I; Arienti, Kristen L; López, Francisco J; Mani, Neelakhanda S; Mais, Dale E; Caferro, Thomas R; Long, Yun Oliver; Jones, Todd K; Edwards, James P; Zhi, Lin; Schrader, William T; Negro-Vilar, Andrés; Marschke, Keith B

    2007-05-17

    Recent interest in orally available androgens has fueled the search for new androgens for use in hormone replacement therapy and as anabolic agents. In pursuit of this, we have discovered a series of novel androgen receptor modulators derived from 7H-[1,4]oxazino[3,2-g]quinolin-7-ones. These compounds were synthesized and evaluated in competitive binding assays and an androgen receptor transcriptional activation assay. A number of compounds from the series demonstrated single-digit nanomolar agonist activity in vitro. In addition, lead compound (R)-16e was orally active in established rodent models that measure androgenic and anabolic properties of these agents. In this assay, (R)-16e demonstrated full efficacy in muscle and only partially stimulated the prostate at 100 mg/kg. These data suggest that these compounds may be utilized as selective androgen receptor modulators or SARMs. This series represents a novel class of compounds for use in androgen replacement therapy.

  13. DETECTION OF ANDROGENIC ACTIVITY IN EMISSIONS FROM DIESEL FUEL AND BIOMASS COMBUSTION

    EPA Science Inventory

    The present study evaluated both diesel fuel exhaust and biomass (wood) burn extracts for androgen receptor¿mediated activity using MDA-kb2 cells, which contain an androgen-responsive promoter-luciferase reporter gene construct. This assay and analytical fractionization of the sa...

  14. Androgen receptor non-nuclear regulation of prostate cancer cell invasion mediated by Src and matriptase.

    PubMed

    Zarif, Jelani C; Lamb, Laura E; Schulz, Veronique V; Nollet, Eric A; Miranti, Cindy K

    2015-03-30

    Castration-resistant prostate cancers still depend on nuclear androgen receptor (AR) function despite their lack of dependence on exogenous androgen. Second generation anti-androgen therapies are more efficient at blocking nuclear AR; however resistant tumors still develop. Recent studies indicate Src is highly active in these resistant tumors. By manipulating AR activity in several different prostate cancer cell lines through RNAi, drug treatment, and the use of a nuclear-deficient AR mutant, we demonstrate that androgen acting on cytoplasmic AR rapidly stimulates Src tyrosine kinase via a non-genomic mechanism. Cytoplasmic AR, acting through Src enhances laminin integrin-dependent invasion. Active Matriptase, which cleaves laminin, is elevated within minutes after androgen stimulation, and is subsequently shed into the medium. Matriptase activation and shedding induced by cytoplasmic AR is dependent on Src. Concomitantly, CDCP1/gp140, a Matriptase and Src substrate that controls integrin-based migration, is activated. However, only inhibition of Matriptase, but not CDCP1, suppresses the AR/Src-dependent increase in invasion. Matriptase, present in conditioned medium from AR-stimulated cells, is sufficient to enhance invasion in the absence of androgen. Thus, invasion is stimulated by a rapid but sustained increase in Src activity, mediated non-genomically by cytoplasmic AR, leading to rapid activation and shedding of the laminin protease Matriptase.

  15. Functional characterisation of a natural androgen receptor missense mutation (N771H) causing human androgen insensitivity syndrome.

    PubMed

    Cai, J; Cai, L-Q; Hong, Y; Zhu, Y-S

    2012-05-01

    Androgen insensitivity syndrome (AIS) is an X-linked disorder due to mutations of androgen receptor (AR) gene. Various AR mutations have been identified, and the characterisation of these mutations greatly facilitates our understanding of AR structure-function. In this study, we have analysed an AR missense mutation (N771H) identified in patients with AIS. Functional analysis of the mutant AR was performed by in vitro mutagenesis-cotransfection assays. Compared to the wild-type AR, the dose-response curve of dihydrotestosterone-induced transactivation activity in the mutant AR was greatly shifted to the right and significantly decreased. However, the maximal efficacy of transactivation activity in the mutant AR was similar to that of the wild type. Receptor binding assay indicated that the mutant AR had an approximately 2.5-fold lower binding affinity to dihydrotestosterone compared to the wild type. Western blot analysis showed that the size and the expression level of mutant AR in transfected cells were comparable to the wild type. These data underscore the importance of asparagine at amino acid position 771 of human AR in normal ligand binding and normal receptor function, and a mutation at this position results in androgen insensitivity in affected subjects.

  16. Constitutively-active androgen receptor variants function independently of the HSP90 chaperone but do not confer resistance to HSP90 inhibitors.

    PubMed

    Gillis, Joanna L; Selth, Luke A; Centenera, Margaret M; Townley, Scott L; Sun, Shihua; Plymate, Stephen R; Tilley, Wayne D; Butler, Lisa M

    2013-05-01

    The development of lethal, castration resistant prostate cancer is associated with adaptive changes to the androgen receptor (AR), including the emergence of mutant receptors and truncated, constitutively active AR variants. AR relies on the molecular chaperone HSP90 for its function in both normal and malignant prostate cells, but the requirement for HSP90 in environments with aberrant AR expression is largely unknown. Here, we investigated the efficacy of three HSP90 inhibitors, 17-AAG, HSP990 and AUY922, against clinically-relevant AR missense mutants and truncated variants. HSP90 inhibition effectively suppressed the signaling of wild-type AR and all AR missense mutants tested. By contrast, two truncated AR variants, AR-V7 and ARv567es, exhibited marked resistance to HSP90 inhibitors. Supporting this observation, nuclear localization of the truncated AR variants was not affected by HSP90 inhibition and AR variant:HSP90 complexes could not be detected in prostate cancer cells. Interestingly, HSP90 inhibition resulted in accumulation of AR-V7 and ARv567es in both cell lines and human tumor explants. Despite the apparent independence of AR variants from HSP90 and their treatment-associated induction, the growth of cell lines with endogenous or enforced expression of AR-V7 or ARv567es remained highly sensitive to AUY922. This study demonstrates that functional AR variant signaling does not confer resistance to HSP90 inhibition, yields insight into the interaction between AR and HSP90 and provides further impetus for the clinical application of HSP90 inhibitors in advanced prostate cancer.

  17. The primate thyroid gland contains receptors for androgens.

    PubMed

    Sheridan, P J; McGill, H C; Lissitzky, J C; Martin, P M

    1984-12-01

    The gonadal steroids have long been known to modulate thyroid function. Most studies suggest that the gonadal steroids act indirectly through the hypothalamic-pituitary axis to modulate thyroid function. The following studies were conducted to determine whether there are receptors for androgens in the thyroid itself. Cytosols from male and female euthyroid patients were analyzed for the presence of androgen with the synthetic analog methyltrienolone [( 3H]R1881). No evidence of androgen receptors was found in any of the cytosols prepared from female patients. In all males studied, androgen receptors were found in concentrations ranging from 100-150 fmol/10 mg DNA for the cytosols and from 690-2800 fmol/10 mg DNA for the nuclear extracts. The receptors had a dissociation constant (Kd) of approximately 5-10 X 10(-10) M for the cytosol and approximately 10-15 X 10(-10) M for the nuclear extracts. In addition to the human studies, studies in baboons were conducted to determine the possible cell type which might contain receptors for androgens. Male and female baboons were injected with [3H] dihydrotestosterone and killed between 1 and 1 1/2 h later. The thyroids were removed and processed for autoradiography. In autoradiograms from animals injected with [3H]dihydrotestosterone, nuclear localization of radioactivity was found in virtually all of the follicular cells. Also, label was found overlying the colloid, with heaviest labeling near the cells. These data suggest that there may be direct actions of androgens on follicular cells.

  18. 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.

  19. Androgen activates β-catenin signaling in bladder cancer cells.

    PubMed

    Li, Yi; Zheng, Yichun; Izumi, Koji; Ishiguro, Hitoshi; Ye, Bo; Li, Faqian; Miyamoto, Hiroshi

    2013-06-01

    Androgen receptor (AR) signals have been implicated in bladder carcinogenesis and tumor progression. Activation of Wnt/β-catenin signaling has also been reported to correlate with bladder cancer progression and poor patients' outcomes. However, cross talk between AR and β-catenin pathways in bladder cancer remains uncharacterized. In radical cystectomy specimens, we immunohistochemically confirmed aberrant expression of β-catenin especially in aggressive tumors. There was a strong association between nuclear expressions of AR and β-catenin in bladder tumors (P=0.0215). Kaplan-Meier and log-rank tests further revealed that reduced membranous β-catenin expression (P=0.0276), nuclear β-catenin expression (P=0.0802), and co-expression of nuclear AR and β-catenin (P=0.0043) correlated with tumor progression after cystectomy. We then assessed the effects of androgen on β-catenin in AR-positive and AR-negative bladder cancer cell lines. A synthetic androgen R1881 increased the expression of an active form of β-catenin and its downstream target c-myc only in AR-positive lines. R1881 also enhanced the activity of β-catenin-mediated transcription, which was abolished by an AR antagonist hydroxyflutamide. Using western blotting and immunofluorescence, R1881 was found to induce nuclear translocation of β-catenin when co-localized with AR. Finally, co-immunoprecipitation revealed androgen-induced associations of AR with β-catenin or T-cell factor (TCF) in bladder cancer cells. Thus, it was likely that androgen was able to activate β-catenin signaling through the AR pathway in bladder cancer cells. Our results also suggest that activation of β-catenin signaling possibly via formation of AR/β-catenin/TCF complex contributes to the progression of bladder cancer, which may enhance the feasibility of androgen deprivation as a potential therapeutic approach. PMID:23447569

  20. The Rec protein of HERV-K(HML-2) upregulates androgen receptor activity by binding to the human small glutamine-rich tetratricopeptide repeat protein (hSGT).

    PubMed

    Hanke, Kirsten; Chudak, Claudia; Kurth, Reinhard; Bannert, Norbert

    2013-02-01

    The expression of endogenous retroviruses of the HERV-K(HML-2) family is strongly upregulated in germ cell tumors and several other cancers. Although the accessory Rec protein of HERV-K(HML-2) has been shown to induce carcinoma in situ in transgenic mice, to increase the activity of c-myc and to interact with the androgen receptor (AR), whether or not Rec expression is indeed implicated causally in the initiation or progression of any human malignancies remains unclear. We used the yeast two-hybrid system involving the Rec protein of a recently integrated HERV-K(HML-2) element in an effort to identify potential Rec-related oncogenic mechanisms. This revealed the human small glutamine-rich tetratricopeptide repeat (TPR)-containing protein (hSGT) to be a cellular binding partner. The interaction of Rec with this known negative regulator of the AR was confirmed by coimmunoprecipitation, pull-down assays and colocalization studies. The interaction involves the TPR motif of hSGT and takes place in the cytoplasm and in the nucleoli. Using an AR-responsive promoter and gene we could demonstrate that Rec interference with hSGT resulted in an up to five-fold increase in the activity of AR. Furthermore, in AR positive cells, Rec was shown to act as transactivator by enhancing AR-mediated activation of the HERV-K(HML-2) LTR promoter. This is in line with previous observations of elevated HERV-K(HML-2) expression in steroid-regulated tissues. On the basis of our findings we propose a "vicious cycle" model of Rec-driven hyperactivation of the AR leading to increased cell proliferation, inhibition of apoptosis and eventually to tumor induction or promotion.

  1. The use of human skin fibroblasts to obtain potency estimates of drug binding to androgen receptors.

    PubMed

    Eil, C; Edelson, S K

    1984-07-01

    Although several drugs with antiandrogenic properties have been used to treat such conditions as prostatic carcinoma, precocious puberty, acne, and hirsutism, their relative strengths in human tissues are not known. Most of the compounds that are effective clinically in opposing androgen action interact with the androgen receptor in various assay systems. To determine in human cells the relative potencies of these agents as well as others with androgenic properties, we measured the abilities of various compounds to compete with [3H]dihydrotestosterone [( 3H]DHT) for androgen-binding sites in dispersed human genital skin fibroblasts at 22 degrees C. The concentrations of unlabeled DHT, methyltrienolone (a synthetic non- metabolizeable androgen), and testosterone required for 50% inhibition of [3H]DHT binding were similar, approximately 1 nM [0.87 +/- 0.12 (+/- SE), 1.18 +/- 0.18, and 1.01 +/- 0.20 nM, respectively]. The relative binding activities, defined by the ratio of the concentration of methyltrienolone to the concentration of competitor required for 50% displacement of [3H]DHT, were as follows: spironolactone greater than R2956 (a synthetic antiandrogen) greater than megestrol acetate greater than cyproterone acetate greater than estradiol greater than flutamide much greater than testolactone greater than cimetidine. Danazol, an androgen agonist that causes hirsutism, was nearly as effective as spironolactone in its ability to compete for the fibroblast androgen receptor, 50% inhibition of fibroblast [3H]DHT binding was achieved by 1.76 +/- 0.31 nM spironolactone and 2.85 +/- 0.50 nM danazol. Two other compounds that induce hirsutism, diphenylhydantoin and diazoxide, did not displace [3H]DHT. We conclude that 1) of the compounds tested, spironolactone, which is rapidly metabolized in vivo to a much less potent competitor, is the most potent antiandrogen in its ability to interact in vitro with human skin fibroblast androgen receptors; 2) estradiol is a

  2. Vocal area-related expression of the androgen receptor in the budgerigar (Melopsittacus undulatus) brain.

    PubMed

    Matsunaga, Eiji; Okanoya, Kazuo

    2008-05-01

    The androgen receptor is a steroid hormone receptor widely expressed in the vocal control nuclei in songbirds. Here, we analysed androgen receptor expression in the brains of juvenile and adult budgerigars. With a species-specific probe for budgerigar androgen receptor mRNA, we found that the androgen receptor was expressed in the vocal areas, such as the central nucleus of the lateral nidopallium, the anterior arcopallium, the oval nucleus of the mesopallium, the oval nucleus of the anterior nidopallium and the tracheosyringeal hypoglossal nucleus. With the present data, together with previous reports, it turned out that the androgen receptor expression in telencephalic vocal control areas is similar amongst three groups of vocal learners--songbirds, hummingbirds and parrots, suggesting the possibility that the androgen receptor might play a role in vocal development and that the molecular mechanism regulating the androgen receptor expression in the vocal areas might be important in the evolution of vocal learning.

  3. 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

  4. 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

  5. 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

  6. Androgen Receptor and Histone Lysine Demethylases in Ovine Placenta

    PubMed Central

    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

  7. Direct interaction between AR and PAK6 in androgen-stimulated PAK6 activation.

    PubMed

    Liu, Xia; Busby, Jennifer; John, Ciny; Wei, Jianning; Yuan, Xin; Lu, Michael L

    2013-01-01

    A p21-activated kinase 6 (PAK6) was previously identified to be an androgen receptor (AR) interacting protein through a yeast two-hybrid screening. We used hormone responsive prostate cancer LAPC4 and LNCap cell lines as models to study the signaling events associated with androgen stimulation and PAK6. An androgen-stimulated PAK6 kinase activation was observed in LAPC4 cells expressing endogenous PAK6 and in LNCap cells ectopically expressing a wild type PAK6. This activation was likely mediated through a direct interaction between AR and PAK6 since siRNA knock-down of AR in LAPC4 cells downregulated androgen-stimulated PAK6 activation. In addition, LNCap cells expressing a non-AR-interacting PAK6 mutant exhibited dampened androgen-stimulated kinase activation. As a consequence of androgen-stimulated activation, PAK6 was phosphorylated at multiple serine/threonine residues including the AR-interacting domain of PAK6. Furthermore, androgen-stimulation promoted prostate cancer cell motility and invasion were demonstrated in LNCap cells ectopically expressing PAK6-WT. In contrast, LNCap expressing non-AR-interacting mutant PAK6 did not respond to androgen stimulation with increased cell motility and invasion. Our results demonstrate that androgen-stimulated PAK6 activation is mediated through a direct interaction between AR and PAK6 and PAK6 activation promotes prostate cancer cells motility and invasion.

  8. 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...

  9. 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.

  10. 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...

  11. 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...

  12. Metabolite Profiling and a Transcriptional Activation Assay Provide Direct Evidence of Androgen Receptor Antagonism by Bisphenol A in Fish.

    EPA Science Inventory

    Widespread environmental contamination by bisphenol A (BPA) has created the need to fully define its potential toxic mechanisms of action (MOA) to properly assess human health and ecological risks from exposure. Although long recognized as an estrogen receptor (ER) agonist, some ...

  13. 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.

  14. Drug insight: Testosterone and selective androgen receptor modulators as anabolic therapies for chronic illness and aging.

    PubMed

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

    2006-03-01

    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 beta-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.

  15. Coregulator control of androgen receptor action by a novel nuclear receptor-binding motif.

    PubMed

    Jehle, Katja; Cato, Laura; Neeb, Antje; Muhle-Goll, Claudia; Jung, Nicole; Smith, Emmanuel W; Buzon, Victor; Carbó, Laia R; Estébanez-Perpiñá, Eva; Schmitz, Katja; Fruk, Ljiljana; Luy, Burkhard; Chen, Yu; Cox, Marc B; Bräse, Stefan; Brown, Myles; Cato, Andrew C B

    2014-03-28

    The androgen receptor (AR) is a ligand-activated transcription factor that is essential for prostate cancer development. It is activated by androgens through its ligand-binding domain (LBD), which consists predominantly of 11 α-helices. Upon ligand binding, the last helix is reorganized to an agonist conformation termed activator function-2 (AF-2) for coactivator binding. Several coactivators bind to the AF-2 pocket through conserved LXXLL or FXXLF sequences to enhance the activity of the receptor. Recently, a small compound-binding surface adjacent to AF-2 has been identified as an allosteric modulator of the AF-2 activity and is termed binding function-3 (BF-3). However, the role of BF-3 in vivo is currently unknown, and little is understood about what proteins can bind to it. Here we demonstrate that a duplicated GARRPR motif at the N terminus of the cochaperone Bag-1L functions through the BF-3 pocket. These findings are supported by the fact that a selective BF-3 inhibitor or mutations within the BF-3 pocket abolish the interaction between the GARRPR motif(s) and the BF-3. Conversely, amino acid exchanges in the two GARRPR motifs of Bag-1L can impair the interaction between Bag-1L and AR without altering the ability of Bag-1L to bind to chromatin. Furthermore, the mutant Bag-1L increases androgen-dependent activation of a subset of AR targets in a genome-wide transcriptome analysis, demonstrating a repressive function of the GARRPR/BF-3 interaction. We have therefore identified GARRPR as a novel BF-3 regulatory sequence important for fine-tuning the activity of the AR.

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

    PubMed Central

    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

    2015-01-01

    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

  17. The antiandrogenic effect of finasteride against a mutant androgen receptor.

    PubMed

    Wu, Yue; Chhipa, Rishi Raj; Zhang, Haitao; Ip, Clement

    2011-05-15

    Finasteride is known to inhibit Type 2 5α-reductase and thus block the conversion of testosterone to dihydrotestosterone (DHT). The structural similarity of finasteride to DHT raises the possibility that finasteride may also interfere with the function of the androgen receptor (AR). Experiments were carried out to evaluate the antiandrogenic effect of finasteride in LNCaP, C4-2 and VCaP human prostate cancer cells. Finasteride decreased DHT binding to AR, and DHT-stimulated AR activity and cell growth in LNCaP and C4-2 cells, but not in VCaP cells. LNCaP and C4-2 (derived from castration-resistant LNCaP) cells express the T877A mutant AR, while VCaP cells express the wild type AR. When PC-3 cells, which are AR-null, were transfected with either the wild type or the T877A mutant AR, only the mutant AR-expressing cells were sensitive to finasteride inhibition of DHT binding. Peroxiredoxin-1 (Prx1) is a novel endogenous facilitator of AR binding to DHT. In Prx1-rich LNCaP cells, the combination of Prx1 knockdown and finasteride was found to produce a greater inhibitory effect on AR activity and cell growth than either treatment alone. The observation suggests that cells with a low expression of Prx1 are likely to be more responsive to the antiandrogenic effect of finasteride. Additional studies showed that the efficacy of finasteride was comparable to that of bicalutamide (a widely used non-steroidal antiandrogen). The implication of the above findings is discussed in the context of developing strategies to improve the outcome of androgen deprivation therapy.

  18. Design, synthesis, and biological evaluation of 4-phenylpyrrole derivatives as novel androgen receptor antagonists.

    PubMed

    Yamamoto, Satoshi; Matsunaga, Nobuyuki; Hitaka, Takenori; Yamada, Masami; Hara, Takahito; Miyazaki, Junichi; Santou, Takashi; Kusaka, Masami; Yamaoka, Masuo; Kanzaki, Naoyuki; Furuya, Shuichi; Tasaka, Akihiro; Hamamura, Kazumasa; Ito, Mitsuhiro

    2012-01-01

    A series of 4-phenylpyrrole derivatives D were designed, synthesized, and evaluated for their potential as novel orally available androgen receptor antagonists therapeutically effective against castration-resistant prostate cancers. 4-Phenylpyrrole compound 1 exhibited androgen receptor (AR) antagonistic activity against T877A and W741C mutant-type ARs as well as wild-type AR. An arylmethyl group incorporated into compound 1 contributed to enhancement of antagonistic activity. Compound 4n, 1-{[6-chloro-5-(hydroxymethyl)pyridin-3-yl]methyl}-4-(4-cyanophenyl)-2,5-dimethyl-1H-pyrrole-3-carbonitrile exhibited inhibitory effects on tumor cell growth against the bicalutamide-resistant LNCaP-cxD2 cell line as well as the androgen receptor-dependent JDCaP cell line in a mouse xenograft model. These results demonstrate that this series of pyrrole compounds are novel androgen receptor antagonists with efficacy against prostate cancer cells, including castration-resistant prostate cancers such as bicalutamide-resistant prostate cancer.

  19. 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

  20. Andrographolide Targets Androgen Receptor Pathway in Castration-Resistant Prostate Cancer

    PubMed Central

    Liu, Chengfei; Nadiminty, Nagalakshmi; Tummala, Ramakumar; Chun, Jae Yeon; Lou, Wei; Zhu, Yezi; Sun, Meng; Evans, Christopher P.; Zhou, Qinghua; Gao, Allen C.

    2011-01-01

    Androgen receptor (AR) signaling not only plays a pivotal role in the development of androgen-dependent prostate cancer but is also important in the growth and survival of castration-resistant prostate cancer (CRPC). The first line of treatment of androgen-dependent prostate cancer is the use of androgen deprivation therapy. However, most patients will eventually relapse due to development of CRPC. Thus, development of a strategy to target AR for treatment of CRPC is urgently needed. The authors have previously identified andrographolide as an inhibitor of interleukin-6, which can suppress tumor growth of prostate cancer cells by screening compounds from the Prestwick Natural compound library. In this study, they identified that andrographolide can inhibit AR expression and prostate cancer cell growth and induce apoptosis. Andrographolide is able to down-regulate AR expression at both mRNA and protein levels, prevents its nuclear translocation, and inhibits transactivation of its target genes. Andrographolide prevents the binding of Hsp90 to AR, resulting in proteasome-mediated AR degradation. Furthermore, andrographolide inhibits castration-resistant C4-2 cell growth by reducing AR expression and activity. Thus, andrographolide can be developed as a potential therapeutic agent for prostate cancer by inhibition of androgen receptor signaling. PMID:21779488

  1. Design and synthesis of an array of selective androgen receptor modulators.

    PubMed

    Trump, Ryan P; Blanc, Jean-Baptiste E; Stewart, Eugene L; Brown, Peter J; Caivano, Matilde; Gray, David W; Hoekstra, William J; Willson, Timothy M; Han, Bajin; Turnbull, Philip

    2007-01-01

    We describe the design, using shape comparison and fast docking computer algorithms, and rapid parallel synthesis of a 1300 member array based on GSK7721, a 4-aminobenzonitrile androgen receptor (AR) antagonist identified by focused screening of the GSK compound collection. The array yielded 352 submicromolar and 17 subnanomolar AR agonists as measured by a cell-based reporter gene functional assay. The rapid synthesis of a large number of active compounds provided valuable information in the optimization of AR modulators, which may be useful in treating androgen deficiency in aging males.

  2. 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

  3. Regulation of brain androgen receptor immunoreactivity by androgen in prepubertal male ferrets.

    PubMed

    Kashon, M L; Hayes, M J; Shek, P P; Sisk, C L

    1995-05-01

    During pubertal maturation, there is an increase in the number of androgen receptor-immunoreactive (AR-IR) cells in the preoptic area (POA), arcuate nucleus (ARC), medial amygdala (mAMY), and ventromedial hypothalamic nucleus (VMH) of the male ferret brain. In contrast, the number of AR-IR cells in the bed nucleus of the stria terminalis (BNST) or lateral septum (ISEP) does not change with pubertal development. This experiment tested the hypothesis that the pubertal increase in AR-IR cells in certain brain regions is the result of the pubertal increase in circulating androgens. Prepubertal male ferrets were left intact or were castrated and treated daily (10 days) with s.c. injections of either oil, testosterone (T; 5 mg/kg), dihydrotestosterone (DHT; 5 mg/kg), or estradiol (E; 10 micrograms/kg). Brains were processed for AR immunocytochemistry, and the number of immunopositive cells was quantified in POA, ARC, mAMY, VMH, BNST, and ISEP. Overall, castration reduced the number of AR-IR cells below that seen in intact animals, and E administration did not restore AR-IR cell number. Treatment of castrates with androgens restored numbers of AR-IR cells to those of intact animals in the BNST, ISEP, and VMH. However, AR-IR cell numbers were significantly greater in androgen-treated castrates than in intact animals in POA, mAMY, and ARC. These data show that AR-IR cells in prepubertal male ferrets are sensitive to circulating levels of androgens, supporting the hypothesis that the pubertal rise in T is responsible for the pubertal increase in the number of AR-IR cells in the POA, mAMY, and ARC. PMID:7626721

  4. Androgen receptor regulates SRC expression through microRNA-203.

    PubMed

    Siu, Man Kit; Chen, Wei-Yu; Tsai, Hong-Yuan; Yeh, Hsiu-Lien; Yin, Juan Juan; Liu, Shih-Yang; Liu, Yen-Nien

    2016-05-01

    The SRC kinase has pivotal roles in multiple developmental processes and in tumor progression. An inverse relationship has been observed between androgen receptor (AR) activity and SRC signaling in advanced prostate cancer (PCa); however, the modulation of AR/SRC crosstalk that leads to metastatic PCa is unclear. Here, we showed that patients with high SRC levels displayed correspondingly low canonical AR gene signatures. Our results demonstrated that activated AR induced miR-203 and reduced SRC levels in PCa model systems. miR-203 directly binds to the 3' UTR of SRC and regulates the stability of SRC mRNA upon AR activation. Moreover, we found that progressive PCa cell migration and growth were associated with a decrease in AR-regulated miR-203 and an increase in SRC. Relationships among AR, miR-203, and SRC were also confirmed in clinical datasets and specimens. We suggest that the induction of SRC results in increased PCa metastasis that is linked to the dysregulation of the AR signaling pathway through the inactivation of miR-203.

  5. Androgen receptor regulates SRC expression through microRNA-203

    PubMed Central

    Tsai, Hong-Yuan; Yeh, Hsiu-Lien; Yin, Juan Juan; Liu, Shih-Yang; Liu, Yen-Nien

    2016-01-01

    The SRC kinase has pivotal roles in multiple developmental processes and in tumor progression. An inverse relationship has been observed between androgen receptor (AR) activity and SRC signaling in advanced prostate cancer (PCa); however, the modulation of AR/SRC crosstalk that leads to metastatic PCa is unclear. Here, we showed that patients with high SRC levels displayed correspondingly low canonical AR gene signatures. Our results demonstrated that activated AR induced miR-203 and reduced SRC levels in PCa model systems. miR-203 directly binds to the 3′ UTR of SRC and regulates the stability of SRC mRNA upon AR activation. Moreover, we found that progressive PCa cell migration and growth were associated with a decrease in AR-regulated miR-203 and an increase in SRC. Relationships among AR, miR-203, and SRC were also confirmed in clinical datasets and specimens. We suggest that the induction of SRC results in increased PCa metastasis that is linked to the dysregulation of the AR signaling pathway through the inactivation of miR-203. PMID:27028864

  6. Regulation of androgen receptor and 5 alpha-reductase in the skin of normal and hirsute women.

    PubMed

    Mauvais-Jarvis, P

    1986-05-01

    The hormonal activity of androgens is mediated in target cells, particularly in human skin, by two kinds of proteins: the androgen receptor and the enzyme 5 alpha-reductase. In well differentiated androgen target cells, 5 alpha-reductase achieves the transformation of testosterone (T) into dihydrotestosterone (DHT), a more active androgen than T, because of its higher affinity for the receptor. In other words, 5 alpha-reductase acts as an amplifier of the androgen signal but is not absolutely required for androgen action. Regarding the regulation of the androgen receptor, minimal information is available. However, in genital skin, the receptor seems to be predominantly localized in the cytosolic compartment before puberty in males and in the nuclear compartment after puberty. In hirsute patients, recent data on genital skin fibroblasts do not show significant differences between the binding capacity of fibroblasts from normal and hirsute women whereas there is no difference between normal men and women. 5 alpha-Reductase activity seems to be a very important step in the processes involved in androgen action. While 5 alpha-reductase activity present in the skin of external genitalia does not seem to be androgen dependent, this is not the case for the enzyme located in pubic skin. In this area, a sex difference between males and females may be observed both in skin homogenates and in cultured fibroblasts. In addition DHT added to a medium of pubic skin fibroblasts is capable of increasing 5 alpha-reductase activity. This increase is not observed when cyproterone acetate is added to the medium and in patients with testicular feminization syndrome without receptors. Pubic 5 alpha-reductase activity is an androgen receptor mediated phenomenon. In patients with hirsutism, and particularly idiopathic hirsutism, 5 alpha-reductase activity is high without an increase in circulating androgens. This may be observed both in pubic skin homogenates and in cultured fibroblasts

  7. Diastereomers of the Brominated Flame Retardant 1,2-Dibromo-4-(1,2 dibromoethyl)cyclohexane Induce Androgen Receptor Activation in the HepG2 Hepatocellular Carcinoma Cell Line and the LNCaP Prostate Cancer Cell Line

    PubMed Central

    Khalaf, Hazem; Larsson, Anders; Berg, Håkan; McCrindle, Robert; Arsenault, Gilles; Olsson, Per-Erik

    2009-01-01

    Background Reported incidences of prostate cancer and masculinization of animals indicate a release of compounds with androgenic properties into the environment. Large numbers of environmental pollutants have been screened to identify such compounds; however, not until recently was 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH) identified as the first potent activator of the human androgen receptor (hAR). TBECH has been found in beluga whales and bird eggs and has also been found to be maternally transferred in zebrafish. Objectives In the present study we investigated interaction energies between TBECH diastereomers (α, β, γ, and δ) and the hAR, and their ability to activate the receptor and induce prostate-specific antigen (PSA) expression in vitro. Methods We performed computational modeling to determine interaction energies between the ligand and the AR ligand-binding site, and measured in vitro competitive binding assays for AR by polarization fluorometry analysis. We used enzyme-linked immunosorbent assays to determine PSA activity in LNCaP and HepG2 cells. Results We found the γ and δ diastereomers to be more potent activators of hAR than the α and β diastereomers, which was confirmed in receptor binding studies. All TBECH diastereomers induced PSA expression in LNCaP cells even though the AR present in these cells is mutated (T877A). Modeling studies of LNCaP AR revealed that TBECH diastereomers bound to the receptor with a closer distance to the key amino acids in the ligand-binding domain, indicating stronger binding to the mutated receptor. Conclusions The present study demonstrates the ability of TBECH to activate the hAR, indicating that it is a potential endocrine disruptor. PMID:20049203

  8. Nonsteroidal selective androgen receptor modulator Ostarine in cancer cachexia.

    PubMed

    Zilbermint, Mihail F; Dobs, Adrian S

    2009-10-01

    Cancer cachexia is a complex syndrome, affecting up to 60% of the approximately 1.4 million patients diagnosed with cancer each year in the USA. This condition is characterized by progressive deterioration of a patient's nutritional status, weight loss, anorexia, diminished quality of life and increased mortality and morbidity. Current therapy with progestational, anti-inflammatory and anabolic agents is often ineffective and has a large number of undesirable effects. The newly developed nonsteroidal selective androgen receptor modulator Ostarine has demonstrated promising results in Phase I and II clinical trials, increasing total lean body mass, enhancing functional performance and decreasing total tissue percent fat. This selective androgen receptor modulator may have the ability to perform as a potent anabolic agent with minimal side effects on other organs (prostate and hair follicles), thus presenting a new strategy in managing cancer cachexia. However, more extensive data is required before its efficacy is confirmed.

  9. Targeting Androgen Receptor Aberrations in Castration-Resistant Prostate Cancer.

    PubMed

    Sharp, Adam; Welti, Jonathan; Blagg, Julian; de Bono, Johann S

    2016-09-01

    Androgen receptor (AR) splice variants (SV) have been implicated in the development of metastatic castration-resistant prostate cancer and resistance to AR targeting therapies, including abiraterone and enzalutamide. Agents targeting AR-SV are urgently needed to test this hypothesis and further improve the outcome of patients suffering from this lethal disease. Clin Cancer Res; 22(17); 4280-2. ©2016 AACRSee related article by Yang et al., p. 4466.

  10. 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.

  11. 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

  12. Molecular insight into the differential anti-androgenic activity of resveratrol and its natural analogs: in silico approach to understand biological actions.

    PubMed

    Chakraborty, Sandipan; Kumar, Avinash; Butt, Nasir A; Zhang, Liangfen; Williams, Raquema; Rimando, Agnes M; Biswas, Pradip K; Levenson, Anait S

    2016-05-01

    The androgen receptor (AR) is a therapeutic target for the treatment of prostate cancer. Androgen receptor reactivation during the androgen-independent stage of prostate cancer is mediated by numerous mechanisms including expression of AR mutants and splice variants that become non-responsive to conventional anti-androgenic agents. Resveratrol and its natural analogs exhibit varying degrees of anti-androgenic effects on tumor growth suppression in prostate cancer. However, the structural basis for the observed differential activity remains unknown. Here, anti-androgenic activities of resveratrol and its natural analogs, namely, pterostilbene, piceatannol and trimethoxy-resveratrol were studied in LNCaP cells expressing T877A mutant AR and atomistic simulations were employed to establish the structure activity relationship. Interestingly, essential hydrogen bonding contacts and the binding energies of resveratrol analogs with AR ligand binding domain (LBD), emerge as key differentiating factors for varying anti-androgenic action. Among all the analogs, pterostilbene exhibited strongest anti-androgenic activity and its binding energy and hydrogen bonding interactions pattern closely resembled pure anti-androgen, flutamide. Principal component analysis of our simulation studies revealed that androgenic compounds bind more strongly to AR LBD compared to anti-androgenic compounds and provide conformational stabilization of the receptor in essential subspace. The present study provides critical insight into the structure-activity relationship of the anti-androgenic action of resveratrol analogs, which can be translated further to design novel highly potent anti-androgenic stilbenes. PMID:27063447

  13. Classification and virtual screening of androgen receptor antagonists.

    PubMed

    Li, Jiazhong; Gramatica, Paola

    2010-05-24

    Computational tools, such as quantitative structure-activity relationship (QSAR), are highly useful as screening support for prioritization of substances of very high concern (SVHC). From the practical point of view, QSAR models should be effective to pick out more active rather than inactive compounds, expressed as sensitivity in classification works. This research investigates the classification of a big data set of endocrine-disrupting chemicals (EDCs)-androgen receptor (AR) antagonists, mainly aiming to improve the external sensitivity and to screen for potential AR binders. The kNN, lazy IB1, and ADTree methods and the consensus approach were used to build different models, which improve the sensitivity on external chemicals from 57.1% (literature) to 76.4%. Additionally, the models' predictive abilities were further validated on a blind collected data set (sensitivity: 85.7%). Then the proposed classifiers were used: (i) to distinguish a set of AR binders into antagonists and agonists; (ii) to screen a combined estrogen receptor binder database to find out possible chemicals that can bind to both AR and ER; and (iii) to virtually screen our in-house environmental chemical database. The in silico screening results suggest: (i) that some compounds can affect the normal endocrine system through a complex mechanism binding both to ER and AR; (ii) new EDCs, which are nonER binders, but can in silico bind to AR, are recognized; and (iii) about 20% of compounds in a big data set of environmental chemicals are predicted as new AR antagonists. The priority should be given to them to experimentally test the binding activities with AR.

  14. Androgen dependent mammary gland virilism in rats given the selective estrogen receptor modulator LY2066948 hydrochloride.

    PubMed

    Rudmann, Daniel G; Cohen, Ilene R; Robbins, Michelle R; Coutant, David E; Henck, Judith W

    2005-01-01

    A selective estrogen receptor modulator (SERM) is a nonsteroidal compound with tissue specific estrogen receptor (ER) agonist or antagonist activities. In animals, SERMs may produce morphologic changes in hormonally-sensitive tissues like the mammary gland. Mammary glands from female rats given the SERM LY2066948 hydrochloride (LY2066948) for 1 month at >or= 175 mg/kg had intralobular ducts and alveoli lined by multiple layers of vacuolated, hypertrophied epithelial cells, resembling in part the morphology of the normal male rat mammary gland. We hypothesized that these SERM-mediated changes represented an androgen-dependent virilism of the female rat mammary gland. To test this hypothesis, the androgen receptor antagonist flutamide was co-administered with LY2066948 (175 mg/kg) to female rats for 1 month. Female rats given SERM alone had hyperandrogenemia and the duct and alveolar changes described here. Flutamide cotreatment did not affect serum androgen levels but completely blocked the SERM-mediated mammary gland change. In the mouse, a species that does not have the sex-specific differences in the mammary gland observed in the rat, SERM treatment resulted in hyperandrogenemia but did not alter mammary gland morphology. These studies demonstrate that LY2066948 produces species-specific, androgen-dependent mammary gland virilism in the female rat.

  15. Targeted overexpression of androgen receptor with a liver-specific promoter in transgenic mice.

    PubMed Central

    Chatterjee, B; Song, C S; Jung, M H; Chen, S; Walter, C A; Herbert, D C; Weaker, F J; Mancini, M A; Roy, A K

    1996-01-01

    The rodent liver displays marked age- and sex-dependent changes in androgen sensitivity due to the sexually dimorphic and temporally programmed expression of the androgen receptor (AR) gene. We have altered this normal phenotype by constitutive overexpression of the rat AR transgene in the mouse liver by targeting it via the human phenylalanine hydroxylase (hPAH) gene promoter. These transgenic animals in their heterozygous state produce an approximately 30-fold higher level of the AR in the liver as compared with the nontransgenic control. Androgen inactivation via sulfonation of the hormone by dehydroepiandrosterone sulfotransferase (DST), an androgen-repressible enzyme, also contributes to the age- and sex-dependent regulation of hepatic androgen sensitivity. DST has a broad range of substrate specificity and is responsible for the age- and sex-specific activation of certain polycyclic aromatic hepatocarcinogens as well, by converting them to electrophilic sulfonated derivatives. In the transgenic female, the hepatic expression of DST was approximately 4-fold lower than in normal females, a level comparable to that in normal males. The hPAH-AR mice will serve as a valuable model for studying the sex- and age-invariant expression of liver-specific genes, particularly those involved in the activation of environmental hepatocarcinogens such as the aromatic hydrocarbons. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:8570624

  16. Reduced affinity of the androgen receptor for 5 alpha-dihydrotestosterone but not methyltrienolone in a form of partial androgen resistance. Studies on cultured genital skin fibroblasts.

    PubMed Central

    Pinsky, L; Kaufman, M; Chudley, A E

    1985-01-01

    We have studied a child with posterior labial fusion, clitoral phallus, female urethra, and a short, blind vagina born to a mother with decreased axillary and pubic hair. Her karyotype is 46,XY. At 2 yr of age, the child's basal level of plasma testosterone was less than 0.35 nM and after human chorionic gonadotropin stimulation, it rose to 2.6. Testis and epididymis histology were normal. Her cultured genital (labial) skin fibroblasts have normal testosterone 5 alpha-reductase activity, and metabolize 5 alpha-dihydrotestosterone (DHT) normally, but they do not augment (up-regulate) their basal androgen-receptor binding activity during prolonged incubation with DHT. With DHT, the androgen receptor in her genital skin fibroblasts has a normal binding capacity (maximum binding capacity = 25 fmol/mg protein), but an increased rate constant of dissociation (k = 11.6 X 10(-3) min-1; normal, 6 +/- 1.2 (+/- SD)), and a decreased apparent equilibrium binding affinity (Kd = 0.6 nM; normal, 0.22 +/- 0.09) that is evident in the results of 2-h assays but not of those lasting 0.5 h. With the synthetic androgen, methyltrienolone, all three binding properties of the receptor are normal, and her receptor activity up-regulates normally. We interpret these results to mean that the subject has a ligand-selective defect in the time-dependent transformation of initial, low-affinity androgen-receptor complexes to serial states of higher affinity, presumably as the result of a structural mutation at the X-linked locus that encodes the androgen receptor protein. PMID:3872888

  17. Androgen suppresses the proliferation of androgen receptor-positive castration-resistant prostate cancer cells via inhibition of Cdk2, CyclinA, and Skp2.

    PubMed

    Kokontis, John M; Lin, Hui-Ping; Jiang, Shih Sheng; Lin, Ching-Yu; Fukuchi, Junichi; Hiipakka, Richard A; Chung, Chi-Jung; Chan, Tzu-Min; Liao, Shutsung; Chang, Chung-Ho; Chuu, Chih-Pin

    2014-01-01

    The majority of prostate cancer (PCa) patient receiving androgen ablation therapy eventually develop castration-resistant prostate cancer (CRPC). We previously reported that androgen treatment suppresses Skp2 and c-Myc through androgen receptor (AR) and induced G1 cell cycle arrest in androgen-independent LNCaP 104-R2 cells, a late stage CRPC cell line model. However, the mechanism of androgenic regulation of Skp2 in CRPC cells was not fully understood. In this study, we investigated the androgenic regulation of Skp2 in two AR-positive CRPC cell line models, the LNCaP 104-R1 and PC-3AR Cells. The former one is an early stage androgen-independent LNCaP cells, while the later one is PC-3 cells re-expressing either wild type AR or mutant LNCaP AR. Proliferation of LNCaP 104-R1 and PC-3AR cells is not dependent on but is suppressed by androgen. We observed in this study that androgen treatment reduced protein expression of Cdk2, Cdk7, Cyclin A, cyclin H, Skp2, c-Myc, and E2F-1; lessened phosphorylation of Thr14, Tyr15, and Thr160 on Cdk2; decreased activity of Cdk2; induced protein level of p27(Kip1); and caused G1 cell cycle arrest in LNCaP 104-R1 cells and PC-3AR cells. Overexpression of Skp2 protein in LNCaP 104-R1 or PC-3AR cells partially blocked accumulation of p27(Kip1) and increased Cdk2 activity under androgen treatment, which partially blocked the androgenic suppressive effects on proliferation and cell cycle. Analyzing on-line gene array data of 214 normal and PCa samples indicated that gene expression of Skp2, Cdk2, and cyclin A positively correlates to each other, while Cdk7 negatively correlates to these genes. These observations suggested that androgen suppresses the proliferation of CRPC cells partially through inhibition of Cyclin A, Cdk2, and Skp2.

  18. 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

  19. Immunocytochemical detection of androgen receptor in human temporal cortex characterization and application of polyclonal androgen receptor antibodies in frozen and paraffin-embedded tissues.

    PubMed

    Puy, L; MacLusky, N J; Becker, L; Karsan, N; Trachtenberg, J; Brown, T J

    1995-11-01

    Immunocytochemical and biochemical studies have demonstrated the presence of androgen receptor protein in various regions of the rodent and non-human primate cortex. Localization of androgen receptor in the human brain has, however, not been studied as extensively, because of difficulties in obtaining suitable tissue samples. In the present study, we have localized androgen receptors in both frozen and paraffin-embedded temporal cortex from epileptic patients undergoing resection. Polyclonal antibodies were raised against fusion proteins containing fragments of the human androgen receptor protein. The antibodies were affinity-purified against the corresponding fusion protein. Immunoprecipitation and Western blotting using extracts from human cell lines demonstrated the specificity of the antibodies for the human androgen receptor and lack of cross-reactivity with other steroid hormone receptors. Immunocytochemistry was performed on frozen and paraffin sections of human temporal cortex and in paraffin-embedded benign hyperplastic prostates (BPH), as well as prostate and breast carcinomas, by the streptavidin-biotin-peroxidase method. Antigen-retrieval was performed in paraffin-embedded sections using microwave irradiation. Specific nuclear and cytoplasmic immunoreactivity for androgen receptor was detected in neurons, astrocytes, oligodendrocytes, and microglia cells of the temporal cortex. In contrast, only nuclear staining was observed in BPH, prostate and breast carcinomas. Immunoprecipitation of human temporal cortex lysate and subsequent Western blot analysis demonstrated the expression of a 98 kDa immunoreactive protein, slightly smaller than the reported molecular weight of the wild-type androgen receptor. These results provide further evidence for the expression of androgen receptor in the human temporal cortex. The use of these immunocytochemical techniques should enable the retrospective determination of possible changes in androgen receptor expression in

  20. Differential Effects of Genistein on Prostate Cancer Cells Depend on Mutational Status of the Androgen Receptor

    PubMed Central

    Mahmoud, Abeer M.; Zhu, Tian; Parray, Aijaz; Siddique, Hifzur R.; Yang, Wancai; Saleem, Mohammad; Bosland, Maarten C.

    2013-01-01

    Blocking the androgen receptor (AR) activity is the main goal of therapies for advanced prostate cancer (PCa). However, relapse with a more aggressive, hormone refractory PCa arises, which harbors restored AR activity. One mechanism of such reactivation occurs through acquisition of AR mutations that enable its activation by various steroidal and non-steroidal structures. Thus, natural and chemical compounds that contribute to inappropriate (androgen-independent) activation of the AR become an area of intensive research. Here, we demonstrate that genistein, a soy phytoestrogen binds to both the wild and the Thr877Ala (T877A) mutant types of AR competitively with androgen, nevertheless, it exerts a pleiotropic effect on PCa cell proliferation and AR activity depending on the mutational status of the AR. Genistein inhibited, in a dose-dependent way, cell proliferation and AR nuclear localization and expression in LAPC-4 cells that have wild AR. However, in LNCaP cells that express the T877A mutant AR, genistein induced a biphasic effect where physiological doses (0.5-5 µmol/L) stimulated cell growth and increased AR expression and transcriptional activity, and higher doses induced inhibitory effects. Similar biphasic results were achieved in PC-3 cells transfected with AR mutants; T877A, W741C and H874Y. These findings suggest that genistein, at physiological concentrations, potentially act as an agonist and activate the mutant AR that can be present in advanced PCa after androgen ablation therapy. PMID:24167630

  1. Differential effects of genistein on prostate cancer cells depend on mutational status of the androgen receptor.

    PubMed

    Mahmoud, Abeer M; Zhu, Tian; Parray, Aijaz; Siddique, Hifzur R; Yang, Wancai; Saleem, Mohammad; Bosland, Maarten C

    2013-01-01

    Blocking the androgen receptor (AR) activity is the main goal of therapies for advanced prostate cancer (PCa). However, relapse with a more aggressive, hormone refractory PCa arises, which harbors restored AR activity. One mechanism of such reactivation occurs through acquisition of AR mutations that enable its activation by various steroidal and non-steroidal structures. Thus, natural and chemical compounds that contribute to inappropriate (androgen-independent) activation of the AR become an area of intensive research. Here, we demonstrate that genistein, a soy phytoestrogen binds to both the wild and the Thr877Ala (T877A) mutant types of AR competitively with androgen, nevertheless, it exerts a pleiotropic effect on PCa cell proliferation and AR activity depending on the mutational status of the AR. Genistein inhibited, in a dose-dependent way, cell proliferation and AR nuclear localization and expression in LAPC-4 cells that have wild AR. However, in LNCaP cells that express the T877A mutant AR, genistein induced a biphasic effect where physiological doses (0.5-5 µmol/L) stimulated cell growth and increased AR expression and transcriptional activity, and higher doses induced inhibitory effects. Similar biphasic results were achieved in PC-3 cells transfected with AR mutants; T877A, W741C and H874Y. These findings suggest that genistein, at physiological concentrations, potentially act as an agonist and activate the mutant AR that can be present in advanced PCa after androgen ablation therapy.

  2. 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

  3. Testosterone modulates mitochondrial aconitase in the full-length human androgen receptor-transfected PC-3 prostatic carcinoma cells.

    PubMed

    Juang, H-H; Hsieh, M-L; Tsui, K-H

    2004-08-01

    In vitro studies indicated that dihydrotestosterone (DHT) stimulates the enzymatic activity of the mitochondrial aconitase (mACON) in androgen-sensitive prostatic carcinoma cells, LNCaP. Cell proliferation assay determined that DHT doubles the optimal proliferation response of LNCaP cells. The androgen-insensitive human prostatic carcinoma cells, PC-3, were overexpressed in the human androgen receptor to assess the involvement of the native androgen receptor in the regulation by DHT of mACON gene expression. A stable-transfected clone that expresses the full-length androgen receptor was selected and termed PCAR9. The results revealed that DHT-treated PCAR9 cells paradoxically not only reduced the enzymatic activity of mACON but also blocked the biosynthesis of intracellular ATP attenuating cell proliferation. Transient gene expression assay indicated that DHT divergently regulates the promoter activity of the mACON gene in LNCaP and PCAR9 cells. This study suggested that DHT regulates mACON gene expression and the proliferation of cells in a receptor-dependent model through modulation by unidentified non-receptor factors. PMID:15291747

  4. Update of the androgen receptor gene mutations database.

    PubMed

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

    1999-01-01

    The current version of the androgen receptor (AR) gene mutations database is described. The total number of reported mutations has risen from 309 to 374 during the past year. We have expanded the database by adding information on AR-interacting proteins; and we have improved the database by identifying those mutation entries that have been updated. Mutations of unknown significance have now been reported in both the 5' and 3' untranslated regions of the AR gene, and in individuals who are somatic mosaics constitutionally. In addition, single nucleotide polymorphisms, including silent mutations, have been discovered in normal individuals and in individuals with male infertility. A mutation hotspot associated with prostatic cancer has been identified in exon 5. The database is available on the internet (http://www.mcgill.ca/androgendb/), from EMBL-European Bioinformatics Institute (ftp.ebi.ac.uk/pub/databases/androgen), or as a Macintosh FilemakerPro or Word file (MC33@musica.mcgill.ca).

  5. The discovery of novel human androgen receptor antagonist chemotypes using a combined pharmacophore screening procedure.

    PubMed

    Voet, Arnout; Helsen, Christine; Zhang, Kam Y J; Claessens, Frank

    2013-04-01

    Unraveling the mechanisms involved in castration- and therapy-resistant prostate cancer has led to a renewed interest in androgen receptor (AR)-targeted therapeutics. Anti-androgens that block the activity of the AR therefore remain a valid therapeutic option. However, they must be more effective than, or display a distinct mechanism of action or binding mode from those of bicalutamide and hydroxyflutamide, which are currently in clinical use. For that reason, the second-generation anti-androgen MDV3100 was developed. MDV3100, however, shares its 4-cyano-3-(trifluoromethyl)phenyl group with bicalutamide and hydroxyflutamide required for binding to the AR. In this work, we used a combined strategy to find new antagonist structures distinct from the 4-cyano-3-(trifluoromethyl)phenyl group to avoid cross-resistance for these compounds and to find structures without agonist activity on mutant ARs (AR W741C and AR T877A). We found two novel chemotypes with AR-antagonistic activity (IC(50): 3-6 μM) by virtual screening and confirmed their biological activity in an androgen-responsive reporter assay. The design of our computational approach was validated by the observation of strongly decreased or absence of agonistic activity on the two mutant ARs. Further structural derivatization to optimize the potency of these compounds can render these chemotypes into very promising, alternative AR antagonists for prostate cancer therapy.

  6. 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

  7. N-aryl-oxazolidin-2-imine muscle selective androgen receptor modulators enhance potency through pharmacophore reorientation.

    PubMed

    Nirschl, Alexandra A; Zou, Yan; Krystek, 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

    2009-05-14

    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.

  8. 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.

  9. Critical role of androgen receptor in the postnatal period in male sexual behavior in rats.

    PubMed

    Yamada, Shunji; Ohoya, Miku; Takanami, Keiko; Matsuda, Ken Ichi; Kawata, Mitsuhiro

    2015-11-16

    Gonadal hormones have a developmental role in organization of the nervous system that regulates sexually dimorphic behavior. It is well known that androgen secreted from testes in the perinatal period is converted to estrogen by aromatase in rodent brain, and that estrogen and its receptor play a pivotal role in masculinization of brain structure and function. Treatment with flutamide, an androgen receptor (AR) antagonist, during the perinatal period inhibits development of malespecific brain structure and function, suggesting that androgen signaling via AR also influences brain masculinization. In this study, we investigated which stage during the postnatal period is critical for androgen signaling in brain masculinization. The postnatal period was designated as postnatal days (PD) 0-22, and divided into stages I (PD 0-7), II (PD 8-14), and III (PD 15-22). Newborn male rats were given flutamide subcutaneously in each stage. After adulthood, the effects of postnatal flutamide treatment on brain masculinization were evaluated byanalysis of male sexual behavior. Continuous inhibition of AR throughout stages I and II caused a robust reduction of the intromission ratio and ejaculation frequency compared with other groups. AR inhibition in stage I, II, or III did not cause any change. AR inhibition had no effect onmount behavior. These results show that stage-specific AR activation in the first two postnatal weeks may contribute to brain masculinization mediating male sexual behavior in adulthood.

  10. Critical role of androgen receptor in the postnatal period in male sexual behavior in rats.

    PubMed

    Yamada, Shunji; Ohoya, Miku; Takanami, Keiko; Matsuda, Ken Ichi; Kawata, Mitsuhiro

    2015-11-16

    Gonadal hormones have a developmental role in organization of the nervous system that regulates sexually dimorphic behavior. It is well known that androgen secreted from testes in the perinatal period is converted to estrogen by aromatase in rodent brain, and that estrogen and its receptor play a pivotal role in masculinization of brain structure and function. Treatment with flutamide, an androgen receptor (AR) antagonist, during the perinatal period inhibits development of malespecific brain structure and function, suggesting that androgen signaling via AR also influences brain masculinization. In this study, we investigated which stage during the postnatal period is critical for androgen signaling in brain masculinization. The postnatal period was designated as postnatal days (PD) 0-22, and divided into stages I (PD 0-7), II (PD 8-14), and III (PD 15-22). Newborn male rats were given flutamide subcutaneously in each stage. After adulthood, the effects of postnatal flutamide treatment on brain masculinization were evaluated byanalysis of male sexual behavior. Continuous inhibition of AR throughout stages I and II caused a robust reduction of the intromission ratio and ejaculation frequency compared with other groups. AR inhibition in stage I, II, or III did not cause any change. AR inhibition had no effect onmount behavior. These results show that stage-specific AR activation in the first two postnatal weeks may contribute to brain masculinization mediating male sexual behavior in adulthood. PMID:26493607

  11. The ubiquitin-specific protease USP10 modulates androgen receptor function.

    PubMed

    Faus, Hortensia; Meyer, Hellmuth-Alexander; Huber, Martina; Bahr, Inke; Haendler, Bernard

    2005-12-21

    The role of the ubiquitin/proteasome system in degrading nuclear hormone receptors and regulating their transcriptional function has emerged in the last few years. We identified the ubiquitin-specific protease USP10 as part of DNA-bound androgen receptor (AR) complexes purified from nuclear extracts of PC-3 cells stably expressing the AR. The interaction between USP10 and the AR was confirmed by GST pull-down assays. Fluorescence microscopy documented that USP10 was localised in the nucleus and the cytoplasm. Cell-based transactivation assays in PC-3/AR cells revealed that overexpression of wild-type USP10, but not of an enzymatically inactive form, stimulated AR activity mediated by reporter constructs harbouring selective androgen response elements (AREs), non-selective steroid response elements (SREs) or the mouse mammary tumour virus (MMTV) promoter. Conversely, USP10 expression knock-down by siRNAs impaired the MMTV response to androgen. In summary, the data indicate that USP10 is a new cofactor that binds to the AR and stimulates the androgen response of target promoters. This finding underlines the role of the ubiquitin/proteasome system in modulating the AR function.

  12. Phospho-kinase profile of triple negative breast cancer and androgen receptor signaling

    PubMed Central

    2014-01-01

    Background The androgen receptor (AR) plays a central role in the oncogenesis of different tumors, as is the case in prostate cancer. In triple negative breast cancer (TNBC) a gene expression classification has described different subgroups including a luminal androgen subtype. The AR can be controlled by several mechanisms like the activation of membrane tyrosine kinases and downstream signaling pathways. However little is known in TNBC about how the AR is modulated by these mechanisms and the potential therapeutic strategists to inhibit its expression. Methods We used human samples to evaluate the expression of AR by western-blot and phospho-proteomic kinase arrays that recognize membrane tyrosine kinase receptors and downstream mediators. Western-blots in human cell lines were carried out to analyze the expression and activation of individual proteins. Drugs against these kinases in different conditions were used to measure the expression of the androgen receptor. PCR experiments were performed to assess changes in the AR gene after therapeutic modulation of these pathways. Results AR is present in a subset of TNBC and its expression correlates with activated membrane receptor kinases-EGFR and PDGFRβ in human samples and cell lines. Inhibition of the PI3K/mTOR pathway in TNBC cell lines decreased notably the expression of the AR. Concomitant administration of the anti-androgen bicalutamide with the EGFR, PDGFRβ and Erk1/2 inhibitors, decreased the amount of AR compared to each agent given alone, and had an additive anti-proliferative effect. Administration of dihydrotestosterone augmented the expression of AR that was not modified by the inhibition of the PI3K/mTOR or Erk1/2 pathways. AR expression was posttranscriptionally regulated by PI3K or Erk1/2 inhibition. Conclusion Our results describe the expression of the AR in TNBC as a druggable target and further suggest the combination of bicalutamide with inhibitors of EGFR, PDGFRβ or Erk1/2 for future

  13. Recent developments in antiandrogens and selective androgen receptor modulators.

    PubMed

    Haendler, Bernard; Cleve, Arwed

    2012-04-16

    The androgens testosterone and dihydrotestosterone play an essential role in the development and maintenance of primary and secondary male characteristics. Androgens bind to a specific androgen receptor (AR), a ligand-dependent transcription factor which controls the expression of a large number of downstream target genes. The AR is an essential player in early and late prostate cancer, and may also be involved in some forms of breast cancer. It also represents a drug target for the treatment of hypogonadism. Recent studies furthermore indicate that targeting the AR in pathologies such as frailty syndrome, cachexia or polycystic ovary syndrome may have clinical benefit. Numerous AR ligands with very different pharmacological properties have been identified in the last 40 years and helped to treat several of these diseases. However, progress still needs to be made in order to find compounds with an improved profile with regard to efficacy, differentiation and side-effects. This will only be achieved through a better understanding of the mechanisms involved in normal and aberrant AR signaling.

  14. LncRNA HOTAIR Enhances the Androgen-Receptor-Mediated Transcriptional Program and Drives Castration-Resistant Prostate Cancer.

    PubMed

    Zhang, Ali; Zhao, Jonathan C; Kim, Jung; Fong, Ka-Wing; Yang, Yeqing Angela; Chakravarti, Debabrata; Mo, Yin-Yuan; Yu, Jindan

    2015-10-01

    Understanding the mechanisms of androgen receptor (AR) activation in the milieu of low androgen is critical to effective treatment of castration-resistant prostate cancer (CRPC). Here, we report HOTAIR as an androgen-repressed lncRNA, and, as such, it is markedly upregulated following androgen deprivation therapies and in CRPC. We further demonstrate a distinct mode of lncRNA-mediated gene regulation, wherein HOTAIR binds to the AR protein to block its interaction with the E3 ubiquitin ligase MDM2, thereby preventing AR ubiquitination and protein degradation. Consequently, HOTAIR expression is sufficient to induce androgen-independent AR activation and drive the AR-mediated transcriptional program in the absence of androgen. Functionally, HOTAIR overexpression increases, whereas HOTAIR knockdown decreases, prostate cancer cell growth and invasion. Taken together, our results provide compelling evidence of lncRNAs as drivers of androgen-independent AR activity and CRPC progression, and they support the potential of lncRNAs as therapeutic targets.

  15. Design, synthesis, and in vivo SAR of a novel series of pyrazolines as potent selective androgen receptor modulators.

    PubMed

    Zhang, Xuqing; Li, Xiaojie; Allan, George F; Sbriscia, Tifanie; Linton, Olivia; Lundeen, Scott G; Sui, Zhihua

    2007-08-01

    A novel series of pyrazolines 2 have been designed, synthesized, and evaluated by in vivo screening as tissue-selective androgen receptor modulators (SARMs). Structure-activity relationships (SAR) were investigated at the R1 to R6 positions as well as the core pyrazoline ring and the anilide linker. Overall, strong electron-withdrawing groups at the R1 and R2 positions and a small group at the R5 and R6 position are optimal for AR agonist activity. The (S)-isomer of 7c exhibits more potent AR agonist activity than the corresponding (R)-isomer. (S)-7c exhibited an overall partial androgenic effect but full anabolic effect via oral administration in castrated rats. It demonstrated a noticeable antiandrogenic effect on prostate in intact rats with endogenous testosterone. Thus, (S)-7c is a tissue-selective nonsteroidal androgen receptor modulator with agonist activity on muscle and mixed agonist and antagonist activity on prostate.

  16. 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.

  17. Interlaboratory comparison of four in vitro assays for assessing androgenic and antiandrogenic activity of environmental chemicals.

    PubMed Central

    Körner, Wolfgang; Vinggaard, Anne Marie; Térouanne, Béatrice; Ma, Risheng; Wieloch, Carise; Schlumpf, Margret; Sultan, Charles; Soto, Ana M

    2004-01-01

    We evaluated and compared four in vitro assays to detect androgen agonists and antagonists in an international interlaboratory study. Laboratory 1 used a cell proliferation assay (assay 1) with human mammary carcinoma cells stably transfected with human androgen receptor. The other laboratories used reporter gene assays, two based on stably transfected human prostate carcinoma cells (assay 2) or human mammary carcinoma cells (assay 4), and the third based on transient transfection of Chinese hamster ovary cells (assay 3). Four laboratories received four coded compounds and two controls: two steroidal androgens, two antiandrogens, an androgenic control, 5alpha-dihydrotestosterone (DHT), and an antiandrogenic control, bicalutamide (ICI 176,334). All laboratories correctly detected the androgenic activity of 4-androsten-3,17-dione and 17alpha-methyltestosterone. For both compounds, the calculated androgenic potencies relative to the positive control (RAPs) remained within one order of magnitude. However, laboratory 3 calculated a 50-fold higher RAP for 4-androsten-3,17-dione. All assays detected and quantified the antiandrogenic effect of vinclozolin [median inhibitory concentration (IC50) values ranging from 1.1 times symbol 10(-7) M to 4.7 times symbol 10(-7) M]. In assays 2 and 3, vinclozolin showed partial androgenic activity at the highest concentrations tested. For vinclozolin, calculated antiandrogenic potencies relative to bicalutamide (RAAPs) differed no more than a factor of 10, and IC50 values matched those of bicalutamide. Similarly, we found antiandrogenic activity for tris-(4-chlorophenyl)methanol. RAAP values were between 0.086 and 0.37. Three assays showed cytotoxicity for this compound at or above 1 times symbol 10(-5) M. In summary, all assays proved sensitive screening tools to detect and quantify androgen receptor-mediated androgenic and antiandrogenic effects of these chemicals accurately, with coefficients of variation between 8 and 90%. PMID

  18. The transcriptional programme of the androgen receptor (AR) in prostate cancer.

    PubMed

    Lamb, Alastair D; Massie, Charlie E; Neal, David E

    2014-03-01

    The androgen receptor (AR) is essential for normal prostate and prostate cancer cell growth. AR transcriptional activity is almost always maintained even in hormone relapsed prostate cancer (HRPC) in the absence of normal levels of circulating testosterone. Current molecular techniques, such as chromatin-immunoprecipitation sequencing (ChIP-seq), have permitted identification of direct AR-binding sites in cell lines and human tissue with a distinct coordinate network evident in HRPC. The effectiveness of novel agents, such as abiraterone acetate (suppresses adrenal androgens) or enzalutamide (MDV3100, potent AR antagonist), in treating advanced prostate cancer underlines the on-going critical role of the AR throughout all stages of the disease. Persistent AR activity in advanced disease regulates cell cycle activity, steroid biosynthesis and anabolic metabolism in conjunction with regulatory co-factors, such as the E2F family, c-Myc and signal transducer and activator of transcription (STAT) transcription factors. Further treatment approaches must target these other factors.

  19. 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.

  20. Design, synthesis, and biological characterization of metabolically stable selective androgen receptor modulators.

    PubMed

    Marhefka, Craig A; Gao, Wenqing; Chung, Kiwon; Kim, Juhyun; He, Yali; Yin, Donghua; Bohl, Casey; Dalton, James T; Miller, Duane D

    2004-02-12

    A series of nonsteroidal ligands were synthesized as second-generation agonists for the androgen receptor (AR). These ligands were designed to eliminate metabolic sites identified in one of our first-generation AR agonists, which was inactive in vivo due to its rapid metabolism to inactive constituents. The binding affinity of these compounds was evaluated using AR isolated from rat ventral prostate. These second-generation compounds bound the AR in a high affinity and stereoselective manner, with K(i) values ranging from about 4 to 130 nM. The ability of these ligands to stimulate AR-mediated transcriptional activation was examined in cells transfected with the human AR and a hormone-dependent luciferase reporter gene. Although some compounds were unable to stimulate AR-mediated transcription, several demonstrated activity similar to that of dihydrotestosterone (DHT, an endogenous steroidal ligand for the AR). We also evaluated the in vivo pharmacologic activity of selected compounds in castrated male rats. Three compounds were identified as selective androgen receptor modulators (SARMs), exhibiting significant anabolic activity while having only moderate to minimal androgenic activity in vivo.

  1. Muscle-specific androgen receptor deletion shows limited actions in myoblasts but not in myofibers in different muscles in vivo.

    PubMed

    Rana, Kesha; Chiu, Maria W S; Russell, Patricia K; Skinner, Jarrod P; Lee, Nicole K L; Fam, Barbara C; Zajac, Jeffrey D; MacLean, Helen E

    2016-08-01

    The aim of this study was to investigate the direct muscle cell-mediated actions of androgens by comparing two different mouse lines. The cre-loxP system was used to delete the DNA-binding activity of the androgen receptor (AR) in mature myofibers (MCK mAR(ΔZF2)) in one model and the DNA-binding activity of the AR in both proliferating myoblasts and myofibers (α-actin mAR(ΔZF2)) in another model. We found that hind-limb muscle mass was normal in MCK mAR(ΔZF2) mice and that relative mass of only some hind-limb muscles was reduced in α-actin mAR(ΔZF2) mice. This suggests that myoblasts and myofibers are not the major cellular targets mediating the anabolic actions of androgens on male muscle during growth and development. Levator ani muscle mass was decreased in both mouse lines, demonstrating that there is a myofiber-specific effect in this unique androgen-dependent muscle. We found that the pattern of expression of genes including c-myc, Fzd4 and Igf2 is associated with androgen-dependent changes in muscle mass; therefore, these genes are likely to be mediators of anabolic actions of androgens. Further research is required to identify the major targets of androgen actions in muscle, which are likely to include indirect actions via other tissues.

  2. Hydrogen sulfide represses androgen receptor transactivation by targeting at the second zinc finger module.

    PubMed

    Zhao, Kexin; Li, Shuangshuang; Wu, Lingyun; Lai, Christopher; Yang, Guangdong

    2014-07-25

    Androgen receptor (AR) signaling is indispensable for the development of prostate cancer from the initial androgen-dependent state to a later aggressive androgen-resistant state. This study examined the role of hydrogen sulfide (H(2)S), a novel gasotransmitter, in the regulation of AR signaling as well as its mediation in androgen-independent cell growth in prostate cancer cells. Here we found that H(2)S inhibits cell proliferation of both androgen-dependent (LNCaP) and antiandrogen-resistant prostate cancer cells (LNCaP-B), with more significance on the latter, which was established by long term treatment of parental LNCaP cells with bicalutamide. The expression of cystathionine γ-lyase (CSE), a major H(2)S producing enzyme in prostate tissue, was reduced in both human prostate cancer tissues and LNCaP-B cells. LNCaP-B cells were resistant to bicalutamide-induced cell growth inhibition, and CSE overexpression could rebuild the sensitivity of LNCaP-B cells to bicalutamide. H(2)S significantly repressed the expression of prostate-specific antigen (PSA) and TMPRSS2, two AR-targeted genes. In addition, H(2)S inhibited AR binding with PSA promoter and androgen-responsive element (ARE) luciferase activity. We further found that AR is post-translationally modified by H(2)S through S-sulfhydration. Mutation of cysteine 611 and cysteine 614 in the second zinc finger module of AR-DNA binding domain diminished the effects of H(2)S on AR S-sulfhydration and AR dimerization. These data suggest that reduced CSE/H2S signaling contributes to antiandrogen-resistant status, and sufficient level of H(2)S is able to inhibit AR transactivation and treat castration-resistant prostate cancer.

  3. L712V mutation in the androgen receptor gene causes complete androgen insensitivity syndrome due to severe loss of androgen function.

    PubMed

    Rajender, Singh; Gupta, Nalini J; Chakrabarty, Baidyanath; Singh, Lalji; Thangaraj, Kumarasamy

    2013-12-11

    Inability to respond to the circulating androgens is named as androgen insensitivity syndrome (AIS). Mutations in the androgen receptor (AR) gene are the most common cause of AIS. A cause and effect relationship between some of these mutations and the AIS phenotype has been proven by in vitro studies. Several other mutations have been identified, but need to be functionally validated for pathogenicity. Screening of the AR mutations upon presumptive diagnosis of AIS is recommended. We analyzed a case of complete androgen insensitivity syndrome (CAIS) for mutations in the AR gene. Sequencing of the entire coding region revealed C>G mutation (CTT-GTT) at codon 712 (position according to the NCBI database) in exon 4 of the gene, resulting in replacement of leucine with valine in the ligand-binding domain of the AR protein. No incidence of this mutation was observed in 230 normal male individuals analyzed for comparison. In vitro androgen binding and transactivation assays using mutant clone showed approximately 71% loss of ligand binding and about 76% loss of transactivation function. We conclude that CAIS in this individual was due to L712V substitution in the androgen receptor protein.

  4. 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.

  5. 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

  6. Stress and Androgen Activity During Fetal Development.

    PubMed

    Barrett, Emily S; Swan, Shanna H

    2015-10-01

    Prenatal stress is known to alter hypothalamic-pituitary-adrenal axis activity, and more recent evidence suggests that it may also affect androgen activity. In animal models, prenatal stress disrupts the normal surge of testosterone in the developing male, whereas in females, associations differ by species. In humans, studies show that (1) associations between prenatal stress and child outcomes are often sex-dependent, (2) prenatal stress predicts several disorders with notable sex differences in prevalence, and (3) prenatal exposure to stressful life events may be associated with masculinized reproductive tract development and play behavior in girls. In this minireview, we examine the existing literature on prenatal stress and androgenic activity and present new, preliminary data indicating that prenatal stress may also modify associations between prenatal exposure to diethylhexyl phthalate, (a synthetic, antiandrogenic chemical) and reproductive development in infant boys. Taken together, these data support the hypothesis that prenatal exposure to both chemical and nonchemical stressors may alter sex steroid pathways in the maternal-placental-fetal unit and ultimately alter hormone-dependent developmental endpoints. PMID:26241065

  7. Stress and Androgen Activity During Fetal Development

    PubMed Central

    Swan, Shanna H.

    2015-01-01

    Prenatal stress is known to alter hypothalamic-pituitary-adrenal axis activity, and more recent evidence suggests that it may also affect androgen activity. In animal models, prenatal stress disrupts the normal surge of testosterone in the developing male, whereas in females, associations differ by species. In humans, studies show that (1) associations between prenatal stress and child outcomes are often sex-dependent, (2) prenatal stress predicts several disorders with notable sex differences in prevalence, and (3) prenatal exposure to stressful life events may be associated with masculinized reproductive tract development and play behavior in girls. In this minireview, we examine the existing literature on prenatal stress and androgenic activity and present new, preliminary data indicating that prenatal stress may also modify associations between prenatal exposure to diethylhexyl phthalate, (a synthetic, antiandrogenic chemical) and reproductive development in infant boys. Taken together, these data support the hypothesis that prenatal exposure to both chemical and nonchemical stressors may alter sex steroid pathways in the maternal-placental-fetal unit and ultimately alter hormone-dependent developmental endpoints. PMID:26241065

  8. 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

  9. 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

  10. Substituted 6-(1-pyrrolidine)quinolin-2(1H)-ones as novel selective androgen receptor modulators.

    PubMed

    Martinborough, Esther; Shen, Yixing; Oeveren, Arjan van; Long, Yun Oliver; Lau, Thomas L S; Marschke, Keith B; Chang, William Y; López, Francisco J; Vajda, Eric G; Rix, Peter J; Viveros, O Humberto; Negro-Vilar, Andrés; Zhi, Lin

    2007-10-18

    The androgen receptor is a ligand inducible transcription factor that is involved in a broad range of physiological functions. Here we describe the discovery of a new class of orally available selective androgen receptor modulators. The lead compound, 6-[(2R,5R)-2-methyl-5-((R)-2,2,2-trifluoro-1-hydroxyethyl)pyrrolidin-1-yl]-4-trifluoromethylquinolin-2(1H)-one (6a), showed excellent anabolic activity in muscle with reduced effect on the prostate in a rat model of hypogonadism. The compound also improved bone strength in a rat model of post-menopausal osteoporosis.

  11. Androgen Receptor (AR) Promotes Abdominal Aortic Aneurysm (AAA) Development via Modulating Inflammatory IL1α and TGFβ1 Expression

    PubMed Central

    Huang, Chiung-Kuei; Luo, Jie; Lai, Kuo-Pao; Wang, Ronghao; Pang, Haiyan; Chang, Eugene; Yan, Chen; Sparks, Janet; Lee, Soo Ok; Cho, Joshua; Chang, Chawnshang

    2015-01-01

    Gender difference is a risk factor for abdominal aortic aneurism formation yet the reason for male predominance remains unclear. Androgen and the androgen receptor influence the male gender difference, indicating that androgen receptor signaling may affect abdominal aortic aneurism development. Using angiotensin II induced abdominal aortic aneurism in apolipoprotein E null mouse models (82.4% abdominal aortic aneurism incidence), we found that mice lacking androgen receptor failed to develop abdominal aortic aneurism and aorta had dramatically reduced macrophages infiltration and intact elastic fibers. These findings suggested that androgen receptor expression in endothelial cells, macrophages or smooth muscle cells might play a role in abdominal aortic aneurism development. Selective knockout of androgen receptor in each of these cell types further demonstrated that mice lacking androgen receptor in macrophages (20% abdominal aortic aneurism incidence) or smooth muscle cells (12.5% abdominal aortic aneurism incidence), but not in endothelial cells (71.4% abdominal aortic aneurism incidence) had suppressed abdominal aortic aneurism development. Mechanism dissection showed that androgen receptor functioned through modulation of interleukin 1α and transforming growth factor β1 signals and by targeting androgen receptor with androgen receptor degradation enhancer ASC-J9® led to significant suppression of abdominal aortic aneurism development. These results demonstrate the underlying mechanism by which androgen receptor influences abdominal aortic aneurism development through interleukin 1α and transforming growth factor β1, and provides a potential new therapy to suppress/prevent abdominal aortic aneurism by targeting androgen receptor with ASC-J9®. PMID:26324502

  12. The para substituent of S-3-(phenoxy)-2-hydroxy-2-methyl-N-(4-nitro-3-trifluoromethyl-phenyl)-propionamides is a major structural determinant of in vivo disposition and activity of selective androgen receptor modulators.

    PubMed

    Kim, Juhyun; Wu, Di; Hwang, Dong Jin; Miller, Duane D; Dalton, James T

    2005-10-01

    Selective androgen receptor modulators (SARMs) have many potential therapeutic applications, including male hypogonadism, osteoporosis, muscle-wasting diseases, sexual libido, and contraception. A series of S-3-(phenoxy)-2-hydroxy-2-methyl-N-(4-nitro-3-trifluoromethyl-phenyl)-propionamides bearing a four-halogen substituent in the B-ring that displayed in vivo activity were identified in our previous study. Interestingly, in vivo pharmacological activity was not correlated with in vitro androgen receptor (AR) binding affinity. In this study, analysis of the area under the concentration-time curve-response relationship demonstrated that the discrepancy between in vitro and in vivo pharmacological activity of these halogen-substituted SARMs was due to differences in systemic exposure rather than intrinsic pharmacological activity. Studies also suggested that two simple criteria (i.e., Ki < 10 nM and lower in vivo clearance) could be used to identify efficacious and potent SARMs. We tested this hypothesis using a series of four compounds incorporating either a nitro or cyano substituent at the para-position of the A- and B-aromatic rings. The S-3-(4-nitrophenoxy) and S-3-(4-cyanophenoxy) 2-hydroxy-2-methyl-N-(4-nitro-3-trifluromethylphenyl) propionamides (S-19 and S-20, respectively) and S-3-(4-nitrophenoxy) and S-3-(4-cyanophenoxy) 2-hydroxy-2-methyl-N-(4-cyano-3-trifluromethylphenyl) propionamides (S-21 and S-22, respectively) demonstrated high AR binding affinity, with Ki values ranging from 2.0 to 3.8 nM. Pharmacokinetic studies of selected compounds showed that the in vivo clearance of S-22 was the slowest followed sequentially by S-20, S-21, and S-19. The dose-response relationships for S-22 showed that S-22 exerted efficacious and selective activity in anabolic tissues at dose rates as low as 0.03 mg/day, indicative of the high potency of this compound in anabolic tissue (relative potency 4.41) and its potential for clinical use in androgen deficiency

  13. Inhibition of constitutive aryl hydrocarbon receptor (AhR) signaling attenuates androgen independent signaling and growth in (C4-2) prostate cancer cells

    PubMed Central

    Tran, Cindy; Richmond, Oliver; Aaron, LaTayia; Powell, Joann B.

    2013-01-01

    The aryl hydrocarbon receptor is a member of the basic-helix-loop-helix family of transcription factors. AhR mediates the biochemical and toxic effects of a number of polyaromatic hydrocarbons such as 2,3,7,8,-tetrachloro-dibenzo-p-dioxin (TCDD). AhR is widely known for regulating the transcription of drug metabolizing enzymes involved in the xenobiotic metabolism of carcinogens and therapeutic agents, such as cytochrome P450-1B1 (CYP1B1). Additionally, AhR has also been reported to interact with multiple signaling pathways during prostate development. Here we investigate the effect of sustained AhR signaling on androgen receptor function in prostate cancer cells. Immunoblot analysis shows that AhR expression is increased in androgen independent (C4-2) prostate cancer cells when compared to androgen sensitive (LNCaP) cells. RT-PCR studies revealed constitutive AhR signaling in C4-2 cells without the ligand induced activation required in LNCaP cells. A reduction of AhR activity by short RNA mediated silencing in C4-2 cells reduced expression of both AhR and androgen responsive genes. The decrease in androgen responsive genes correlates to a decrease in phosphorylated androgen receptor and androgen receptor expression in the nucleus. Furthermore, the forced decrease in AhR expression resulted in a 50% decline in the growth rate of C4-2 cells. These data indicates that AhR is required to maintain hormone independent signaling and growth by the androgen receptor in C4-2 cells. Collectively, these data provide evidence of a direct role for AhR in androgen independent signaling and provides insight into the molecular mechanisms responsible for sustained androgen receptor signaling in hormone refractory prostate cancer. PMID:23266674

  14. 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

  15. Variation in the androgen receptor gene exon 1 CAG repeat correlates with manifestations of autoimmunity in women with lupus.

    PubMed

    Olsen, Nancy J; Benko, Ann L; Kovacs, William J

    2014-01-01

    Clinical and experimental evidence support a role for gonadal steroids in modulating the expression and course of autoimmune diseases such as lupus. Whether or not inherited variation in sensitivity to circulating androgenic hormones could influence the manifestations of such disease is, however, unknown. We sought to determine whether differences in androgen sensitivity conferred by variation in the exon 1 CAG repeat region of the androgen receptor (AR) gene were associated with differences in the clinical or humoral immune manifestations of lupus in a cohort of female subjects. We found that shorter AR CAG repeat lengths in lupus subjects correlated with a higher Systemic Lupus Erythematosus Disease Activity Index score, higher ANA levels, and expression of a broader array of IgG autoantibodies. Our findings of more severe clinical manifestations and more exuberant humoral autoimmunity in women with a shorter AR exon 1 CAG repeat length suggest a role for genetically determined sensitivity to androgens as a modulator of autoimmune processes. PMID:24711544

  16. 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.

  17. ASSESSMENT OF IN VITRO ANDROGENIC ACTIVITY IN KRAFT MILL EFFLUENT

    EPA Science Inventory

    Detection of In Vitro Androgenic Activity in Feedlot Effluent. Lambright, CS 1 , Guillette, LJ, Jr.2, Gray, LE, Jr.1 , 1USEPA, NHEERL, RTP, NC, 2 University of Florida, Dept. of Zoology, Gainesville FL

    Recent studies have shown the presence of androgenic activity in water...

  18. 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

  19. Androgen receptor cofactors in prostate cancer: potential therapeutic targets of castration-resistant prostate cancer.

    PubMed

    Shiota, Masaki; Yokomizo, Akira; Fujimoto, Naohiro; Naito, Seiji

    2011-09-01

    Androgens, acting through the androgen receptor (AR), are responsible for many male reproductive and nonreproductive functions. Moreover, aberrant androgen/AR signaling plays a critical role in androgen-dependent prostate cancer (PCa) as well as castration-resistant prostate cancer (CRPC). The formation of a productive AR transcriptional complex requires AR cofactors that interact functionally and structurally with the AR. Since the discovery of the first such cofactor in 1995, an ever increasing number of proteins have been identified as AR coactivators or corepressors. The expression and function of several AR cofactors have been investigated in PCa, and a clear link between AR cofactors and the development and progression of PCa has been identified. Recently, AR splice variants in CRPC were reported, which display significant constitutive activity in the absence of ligand. Then, this discovery revolutionized the concept of AR cofactors in CRPC. The current review aims to provide an overview of AR cofactor proteins in the context of PCa. In addition, we discuss the potential of AR cofactors as novel therapeutic targets for PCa, particularly for CRPC.

  20. Development and exploitation of a novel mutant androgen receptor modelling strategy to identify new targets for advanced prostate cancer therapy.

    PubMed

    O'Neill, Daniel; Jones, Dominic; Wade, Mark; Grey, James; Nakjang, Sirintra; Guo, Wenrui; Cork, David; Davies, Barry R; Wedge, Steve R; Robson, Craig N; Gaughan, Luke

    2015-09-22

    The persistence of androgen receptor (AR) signalling in castrate-resistant prostate cancer (CRPC) highlights the unmet clinical need for the development of more effective AR targeting therapies. A key mechanism of therapy-resistance is by selection of AR mutations that convert anti-androgens to agonists enabling the retention of androgenic signalling in CRPC. To improve our understanding of these receptors in advanced disease we developed a physiologically-relevant model to analyse the global functionality of AR mutants in CRPC. Using the bicalutamide-activated AR(W741L/C) mutation as proof of concept, we demonstrate that this mutant confers an androgenic-like signalling programme and growth promoting phenotype in the presence of bicalutamide. Transcriptomic profiling of AR(W741L) highlighted key genes markedly up-regulated by the mutant receptor, including TIPARP, RASD1 and SGK1. Importantly, SGK1 expression was found to be highly expressed in the KUCaP xenograft model and a CRPC patient biopsy sample both of which express the bicalutamide-activated receptor mutant. Using an SGK1 inhibitor, AR(W741L) transcriptional and growth promoting activity was reduced indicating that exploiting functional distinctions between receptor isoforms in our model may provide new and effective therapies for CRPC patients.

  1. Both Estrogen and Androgen Modify the Response to Activation of Neurokinin-3 and κ-Opioid Receptors in Arcuate Kisspeptin Neurons From Male Mice.

    PubMed

    Ruka, Kristen A; Burger, Laura L; Moenter, Suzanne M

    2016-02-01

    Gonadal steroids regulate the pattern of GnRH secretion. Arcuate kisspeptin (kisspeptin, neurokinin B, and dynorphin [KNDy]) neurons may convey steroid feedback to GnRH neurons. KNDy neurons increase action potential firing upon the activation of neurokinin B receptors (neurokinin-3 receptor [NK3R]) and decrease firing upon the activation of dynorphin receptors (κ-opioid receptor [KOR]). In KNDy neurons from intact vs castrated male mice, NK3R-mediated stimulation is attenuated and KOR-mediated inhibition enhanced, suggesting gonadal secretions are involved. Estradiol suppresses spontaneous GnRH neuron firing in male mice, but the mediators of the effects on firing in KNDy neurons are unknown. We hypothesized the same gonadal steroids affecting GnRH firing pattern would regulate KNDy neuron response to NK3R and KOR agonists. To test this possibility, extracellular recordings were made from KNDy neurons in brain slices from intact, untreated castrated or castrated adult male mice treated in vivo with steroid receptor agonists. As observed previously, the stimulation of KNDy neurons by the NK3R agonist senktide was attenuated in intact vs castrated mice and suppression by dynorphin was enhanced. In contrast to observations of steroid effects on the GnRH neuron firing pattern, both estradiol and DHT suppressed senktide-induced KNDy neuron firing and enhanced the inhibition caused by dynorphin. An estrogen receptor-α agonist but not an estrogen receptor-β agonist mimicked the effects of estradiol on NK3R activation. These observations suggest the steroid modulation of responses to activation of NK3R and KOR as mechanisms for negative feedback in KNDy neurons and support the contribution of these neurons to steroid-sensitive elements of a GnRH pulse generator.

  2. Both Estrogen and Androgen Modify the Response to Activation of Neurokinin-3 and κ-Opioid Receptors in Arcuate Kisspeptin Neurons From Male Mice.

    PubMed

    Ruka, Kristen A; Burger, Laura L; Moenter, Suzanne M

    2016-02-01

    Gonadal steroids regulate the pattern of GnRH secretion. Arcuate kisspeptin (kisspeptin, neurokinin B, and dynorphin [KNDy]) neurons may convey steroid feedback to GnRH neurons. KNDy neurons increase action potential firing upon the activation of neurokinin B receptors (neurokinin-3 receptor [NK3R]) and decrease firing upon the activation of dynorphin receptors (κ-opioid receptor [KOR]). In KNDy neurons from intact vs castrated male mice, NK3R-mediated stimulation is attenuated and KOR-mediated inhibition enhanced, suggesting gonadal secretions are involved. Estradiol suppresses spontaneous GnRH neuron firing in male mice, but the mediators of the effects on firing in KNDy neurons are unknown. We hypothesized the same gonadal steroids affecting GnRH firing pattern would regulate KNDy neuron response to NK3R and KOR agonists. To test this possibility, extracellular recordings were made from KNDy neurons in brain slices from intact, untreated castrated or castrated adult male mice treated in vivo with steroid receptor agonists. As observed previously, the stimulation of KNDy neurons by the NK3R agonist senktide was attenuated in intact vs castrated mice and suppression by dynorphin was enhanced. In contrast to observations of steroid effects on the GnRH neuron firing pattern, both estradiol and DHT suppressed senktide-induced KNDy neuron firing and enhanced the inhibition caused by dynorphin. An estrogen receptor-α agonist but not an estrogen receptor-β agonist mimicked the effects of estradiol on NK3R activation. These observations suggest the steroid modulation of responses to activation of NK3R and KOR as mechanisms for negative feedback in KNDy neurons and support the contribution of these neurons to steroid-sensitive elements of a GnRH pulse generator. PMID:26562263

  3. Sulforaphane increases the efficacy of anti-androgens by rapidly decreasing androgen receptor levels in prostate cancer cells.

    PubMed

    Khurana, Namrata; Talwar, Sudha; Chandra, Partha K; Sharma, Pankaj; Abdel-Mageed, Asim B; Mondal, Debasis; Sikka, Suresh C

    2016-10-01

    Prostate cancer (PCa) cells utilize androgen for their growth. Hence, androgen deprivation therapy (ADT) using anti-androgens, e.g. bicalutamide (BIC) and enzalutamide (ENZ), is a mainstay of treatment. However, the outgrowth of castration resistant PCa (CRPC) cells remains a significant problem. These CRPC cells express androgen receptor (AR) and utilize the intratumoral androgen towards their continued growth and invasion. Sulforaphane (SFN), a naturally occurring isothiocyanate found in cruciferous vegetables, can decrease AR protein levels. In the present study, we tested the combined efficacy of anti-androgens and SFN in suppressing PCa cell growth, motility and clonogenic ability. Both androgen-dependent (LNCaP) and androgen-independent (C4-2B) cells were used to monitor the effects of BIC and ENZ, alone and in combination with SFN. Co-exposure to SFN significantly (p<0.005) enhanced the anti-proliferative effects of anti-androgens and downregulated expression of the AR-responsive gene, prostate specific antigen (PSA) (p<0.05). Exposure to SFN decreased AR protein levels in a time- and dose-dependent manner with almost no AR detected at 24 h with 15 µM SFN (p<0.005). This rapid and potent AR suppression by SFN occurred by both AR protein degradation, as suggested by cycloheximide (CHX) co-exposure studies, and by suppression of AR gene expression, as evident from quantitative RT-PCR experiments. Pre-exposure to SFN also reduced R1881-stimulated nuclear localization of AR, and combined treatment with SFN and anti-androgens abrogated the mitogenic effects of this AR-agonist (p<0.005). Wound-healing assays revealed that co-exposure to SFN and anti-androgens can significantly (p<0.005) reduce PCa cell migration. In addition, long-term exposures (14 days) to much lower concentrations of these agents, SFN (0.2 µM), BIC (1 µM) and/or ENZ (0.4 µM) significantly (p<0.005) decreased the number of colony forming units (CFUs). These findings clearly suggest that

  4. 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

  5. Nrf1 and Nrf2 Transcription Factors Regulate Androgen Receptor Transactivation in Prostate Cancer Cells

    PubMed Central

    Schultz, Michelle A.; Hagan, Sharika S.; Datta, Amrita; Zhang, Yiguo; Freeman, Michael L.; Sikka, Suresh C.; Abdel-Mageed, Asim B.; Mondal, Debasis

    2014-01-01

    Despite androgen deprivation therapy (ADT), persistent androgen receptor (AR) signaling enables outgrowth of castration resistant prostate cancer (CRPC). In prostate cancer (PCa) cells, ADT may enhance AR activity through induction of oxidative stress. Herein, we investigated the roles of Nrf1 and Nrf2, transcription factors that regulate antioxidant gene expression, on hormone-mediated AR transactivation using a syngeneic in vitro model of androgen dependent (LNCaP) and castration resistant (C4-2B) PCa cells. Dihydrotestosterone (DHT) stimulated transactivation of the androgen response element (ARE) was significantly greater in C4-2B cells than in LNCaP cells. DHT-induced AR transactivation was coupled with higher nuclear translocation of p65-Nrf1 in C4-2B cells, as compared to LNCaP cells. Conversely, DHT stimulation suppressed total Nrf2 levels in C4-2B cells but elevated total Nrf2 levels in LNCaP cells. Interestingly, siRNA mediated silencing of Nrf1 attenuated AR transactivation while p65-Nrf1 overexpression enhanced AR transactivation. Subsequent studies showed that Nrf1 physically interacts with AR and enhances AR’s DNA-binding activity, suggesting that the p65-Nrf1 isoform is a potential AR coactivator. In contrast, Nrf2 suppressed AR-mediated transactivation by stimulating the nuclear accumulation of the p120-Nrf1 which suppressed AR transactivation. Quantitative RT-PCR studies further validated the inductive effects of p65-Nrf1 isoform on the androgen regulated genes, PSA and TMPRSS2. Therefore, our findings implicate differential roles of Nrf1 and Nrf2 in regulating AR transactivation in PCa cells. Our findings also indicate that the DHT-stimulated increase in p65-Nrf1 and the simultaneous suppression of both Nrf2 and p120-Nrf1 ultimately facilitates AR transactivation in CRPC cells. PMID:24466341

  6. Myocytic androgen receptor controls the strength but not the mass of limb muscles.

    PubMed

    Chambon, Céline; Duteil, Delphine; Vignaud, Alban; Ferry, Arnaud; Messaddeq, Nadia; Malivindi, Rocco; Kato, Shigeaki; Chambon, Pierre; Metzger, Daniel

    2010-08-10

    The anabolic effects of androgens on skeletal muscles are thought to be mediated predominantly through the androgen receptor (AR), a member of the ligand-dependent nuclear receptor superfamily. However, despite numerous studies performed in men and in rodents, these effects remain poorly understood. To characterize androgen signaling in skeletal muscles, we generated mice in which the AR is selectively ablated in myofibers. We show that myocytic AR controls androgen-induced insulin-like growth factor IEa (IGF-IEa) expression in the highly androgen-sensitive perineal muscles and that it mediates androgen-stimulated postnatal hypertrophy of these muscles. In contrast, androgen-dependent postnatal hypertrophy of limb muscle fibers is independent of myocytic AR. Thus, androgens control perineal and limb muscle mass in male mice through myocytic AR-dependent and -independent pathways, respectively. Importantly, we also show that AR deficiency in limb myocytes impairs myofibrillar organization of sarcomeres and decreases muscle strength, thus demonstrating that myocytic AR controls key pathways required for maximum force production. These distinct androgen signaling pathways in perineal and limb muscles may allow the design of screens to identify selective androgen modulators of muscle strength.

  7. Polymorphism of CAG repeats in androgen receptor of carnivores.

    PubMed

    Wang, Qin; Zhang, Xiuyue; Wang, Xiaofang; Zeng, Bo; Jia, Xiaodong; Hou, Rong; Yue, Bisong

    2012-03-01

    Androgen effect is mediated by the androgen receptor (AR). The polymorphism of CAG triplet repeat (polyCAG), in the N-terminal transactivation domain of the AR protein, has been involved either in endocrine or neurological disorders in human. We obtained partial sequence of AR exon 1 in 10 carnivore species. In most carnivore species, polyglutamine length polymorphism presented in all three CAG repeat regions of AR, in contrast, only CAG-I site polymorphism presented in primate species, and CAG-I and CAG-III sites polymorphism presented in Canidae. Therefore, studies focusing on disease-associated polymorphism of poly(CAG) in carnivore species AR should investigate all three CAG repeats sites, and should not only consider CAG-I sites as the human disease studies. The trinucleotide repeat length in carnivore AR exon 1 had undergone from expansions to contractions during carnivores evolution, unlike a linear increase in primate species. Furthermore, the polymorphisms of the triplet-repeats in the same tissue (somatic mosaicism) were demonstrated in Moutain weasel, Eurasian lynx, Clouded leopard, Chinese tiger, Black leopard and Leopard AR. And, the abnormal stop codon was found in the exon 1 of three carnivore species AR (Moutain weasel, Eurasian lynx and Black leopard). It seemed to have a high frequency presence of tissue-specific somatic in carnivores AR genes. Thus the in vivo mechanism leading to such highly variable phenotypes of the described mutations, and their impact on these animals, are worthwhile to be further elucidated.

  8. 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.

  9. Predicting anti-androgenic activity of bisphenols using molecular docking and quantitative structure-activity relationships.

    PubMed

    Yang, Xianhai; Liu, Huihui; Yang, Qian; Liu, Jining; Chen, Jingwen; Shi, Lili

    2016-11-01

    Both in vivo and in vitro assay indicated that bisphenols can inhibit the androgen receptor. However, the underlying antagonistic mechanism is unclear. In this study, molecular docking was employed to probe the interaction mechanism between bisphenols and human androgen receptor (hAR). The binding pattern of ligands in hAR crystal structures was also analyzed. Results show that hydrogen bonding and hydrophobic interactions are the dominant interactions between the ligands and hAR. The critical amino acid residues involved in forming hydrogen bonding between bisphenols and hAR is Asn 705 and Gln 711. Furthermore, appropriate molecular structural descriptors were selected to characterize the non-bonded interactions. Stepwise multiple linear regressions (MLR) analysis was employed to develop quantitative structure-activity relationship (QSAR) models for predicting the anti-androgenic activity of bisphenols. Based on the QSAR development and validation guideline issued by OECD, the goodness-of-fit, robustness and predictive ability of constructed QSAR model were assessed. The model application domain was characterized by the Euclidean distance and Williams plot. The mechanisms of the constructed model were also interpreted based on the selected molecular descriptors i.e. the number of hydroxyl groups (nROH), the most positive values of the molecular surface potential (Vs,max) and the lowest unoccupied molecular orbital energy (ELUMO). Finally, based on the model developed, the data gap for other twenty-six bisphenols on their anti-androgenic activity was filled. The predicted results indicated that the anti-androgenic activity of seven bisphenols was higher than that of bisphenol A. PMID:27561732

  10. Androgen receptor-driven chromatin looping in prostate cancer.

    PubMed

    Wu, Dayong; Zhang, Chunpeng; Shen, Yanping; Nephew, Kenneth P; Wang, Qianben

    2011-12-01

    The androgen receptor (AR) is important for prostate cancer development and progression. Genome-wide mapping of AR binding sites in prostate cancer has found that the majority of AR binding sites are located within non-promoter regions. These distal AR binding regions regulate AR target genes (e.g. UBE2C) involved in prostate cancer growth through chromatin looping. In addition to long-distance gene regulation, looping has been shown to induce spatial proximity of two genes otherwise located far away along the genomic sequence and the formation of double-strand DNA breaks, resulting in aberrant gene fusions (e.g. TMPRSS2-ERG) that also contribute to prostate tumorigenesis. Elucidating the mechanisms of AR-driven chromatin looping will increase our understanding of prostate carcinogenesis and may lead to the identification of new therapeutic targets.

  11. 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...

  12. Discovery of the selective androgen receptor modulator MK-0773 using a rational development strategy based on differential transcriptional requirements for androgenic anabolism versus reproductive physiology.

    PubMed

    Schmidt, Azriel; Kimmel, Donald B; Bai, Chang; Scafonas, Angela; Rutledge, Sujane; Vogel, Robert L; McElwee-Witmer, Sheila; Chen, Fang; Nantermet, Pascale V; Kasparcova, Viera; Leu, Chih-Tai; Zhang, Hai-Zhuan; Duggan, Mark E; Gentile, Michael A; Hodor, Paul; Pennypacker, Brenda; Masarachia, Patricia; Opas, Evan E; Adamski, Sharon A; Cusick, Tara E; Wang, Jiabing; Mitchell, Helen J; Kim, Yuntae; Prueksaritanont, Thomayant; Perkins, James J; Meissner, Robert S; Hartman, George D; Freedman, Leonard P; Harada, Shun-ichi; Ray, William J

    2010-05-28

    Selective androgen receptor modulators (SARMs) are androgen receptor (AR) ligands that induce anabolism while having reduced effects in reproductive tissues. In various experimental contexts SARMs fully activate, partially activate, or even antagonize the AR, but how these complex activities translate into tissue selectivity is not known. Here, we probed receptor function using >1000 synthetic AR ligands. These compounds produced a spectrum of activities in each assay ranging from 0 to 100% of maximal response. By testing different classes of compounds in ovariectomized rats, we established that ligands that transactivated a model promoter 40-80% of an agonist, recruited the coactivator GRIP-1 <15%, and stabilized the N-/C-terminal interdomain interaction <7% induced bone formation with reduced effects in the uterus and in sebaceous glands. Using these criteria, multiple SARMs were synthesized including MK-0773, a 4-aza-steroid that exhibited tissue selectivity in humans. Thus, AR activated to moderate levels due to reduced cofactor recruitment, and N-/C-terminal interactions produce a fully anabolic response, whereas more complete receptor activation is required for reproductive effects. This bimodal activation provides a molecular basis for the development of SARMs.

  13. Discovery of the Selective Androgen Receptor Modulator MK-0773 Using a Rational Development Strategy Based on Differential Transcriptional Requirements for Androgenic Anabolism Versus Reproductive Physiology*

    PubMed Central

    Schmidt, Azriel; Kimmel, Donald B.; Bai, Chang; Scafonas, Angela; Rutledge, SuJane; Vogel, Robert L.; McElwee-Witmer, Sheila; Chen, Fang; Nantermet, Pascale V.; Kasparcova, Viera; Leu, Chih-tai; Zhang, Hai-Zhuan; Duggan, Mark E.; Gentile, Michael A.; Hodor, Paul; Pennypacker, Brenda; Masarachia, Patricia; Opas, Evan E.; Adamski, Sharon A.; Cusick, Tara E.; Wang, Jiabing; Mitchell, Helen J.; Kim, Yuntae; Prueksaritanont, Thomayant; Perkins, James J.; Meissner, Robert S.; Hartman, George D.; Freedman, Leonard P.; Harada, Shun-ichi; Ray, William J.

    2010-01-01

    Selective androgen receptor modulators (SARMs) are androgen receptor (AR) ligands that induce anabolism while having reduced effects in reproductive tissues. In various experimental contexts SARMs fully activate, partially activate, or even antagonize the AR, but how these complex activities translate into tissue selectivity is not known. Here, we probed receptor function using >1000 synthetic AR ligands. These compounds produced a spectrum of activities in each assay ranging from 0 to 100% of maximal response. By testing different classes of compounds in ovariectomized rats, we established that ligands that transactivated a model promoter 40–80% of an agonist, recruited the coactivator GRIP-1 <15%, and stabilized the N-/C-terminal interdomain interaction <7% induced bone formation with reduced effects in the uterus and in sebaceous glands. Using these criteria, multiple SARMs were synthesized including MK-0773, a 4-aza-steroid that exhibited tissue selectivity in humans. Thus, AR activated to moderate levels due to reduced cofactor recruitment, and N-/C-terminal interactions produce a fully anabolic response, whereas more complete receptor activation is required for reproductive effects. This bimodal activation provides a molecular basis for the development of SARMs. PMID:20356837

  14. Discovery of the selective androgen receptor modulator MK-0773 using a rational development strategy based on differential transcriptional requirements for androgenic anabolism versus reproductive physiology.

    PubMed

    Schmidt, Azriel; Kimmel, Donald B; Bai, Chang; Scafonas, Angela; Rutledge, Sujane; Vogel, Robert L; McElwee-Witmer, Sheila; Chen, Fang; Nantermet, Pascale V; Kasparcova, Viera; Leu, Chih-Tai; Zhang, Hai-Zhuan; Duggan, Mark E; Gentile, Michael A; Hodor, Paul; Pennypacker, Brenda; Masarachia, Patricia; Opas, Evan E; Adamski, Sharon A; Cusick, Tara E; Wang, Jiabing; Mitchell, Helen J; Kim, Yuntae; Prueksaritanont, Thomayant; Perkins, James J; Meissner, Robert S; Hartman, George D; Freedman, Leonard P; Harada, Shun-ichi; Ray, William J

    2010-05-28

    Selective androgen receptor modulators (SARMs) are androgen receptor (AR) ligands that induce anabolism while having reduced effects in reproductive tissues. In various experimental contexts SARMs fully activate, partially activate, or even antagonize the AR, but how these complex activities translate into tissue selectivity is not known. Here, we probed receptor function using >1000 synthetic AR ligands. These compounds produced a spectrum of activities in each assay ranging from 0 to 100% of maximal response. By testing different classes of compounds in ovariectomized rats, we established that ligands that transactivated a model promoter 40-80% of an agonist, recruited the coactivator GRIP-1 <15%, and stabilized the N-/C-terminal interdomain interaction <7% induced bone formation with reduced effects in the uterus and in sebaceous glands. Using these criteria, multiple SARMs were synthesized including MK-0773, a 4-aza-steroid that exhibited tissue selectivity in humans. Thus, AR activated to moderate levels due to reduced cofactor recruitment, and N-/C-terminal interactions produce a fully anabolic response, whereas more complete receptor activation is required for reproductive effects. This bimodal activation provides a molecular basis for the development of SARMs. PMID:20356837

  15. TALEN-engineered AR gene rearrangements reveal endocrine uncoupling of androgen receptor in prostate cancer.

    PubMed

    Nyquist, Michael D; Li, Yingming; Hwang, Tae Hyun; Manlove, Luke S; Vessella, Robert L; Silverstein, Kevin A T; Voytas, Daniel F; Dehm, Scott M

    2013-10-22

    Androgen receptor (AR) target genes direct development and survival of the prostate epithelial lineage, including prostate cancer (PCa). Thus, endocrine therapies that inhibit the AR ligand-binding domain (LBD) are effective in treating PCa. AR transcriptional reactivation is central to resistance, as evidenced by the efficacy of AR retargeting in castration-resistant PCa (CRPC) with next-generation endocrine therapies abiraterone and enzalutamide. However, resistance to abiraterone and enzalutamide limits this efficacy in most men, and PCa remains the second-leading cause of male cancer deaths. Here we show that AR gene rearrangements in CRPC tissues underlie a completely androgen-independent, yet AR-dependent, resistance mechanism. We discovered intragenic AR gene rearrangements in CRPC tissues, which we modeled using transcription activator-like effector nuclease (TALEN)-mediated genome engineering. This modeling revealed that these AR gene rearrangements blocked full-length AR synthesis, but promoted expression of truncated AR variant proteins lacking the AR ligand-binding domain. Furthermore, these AR variant proteins maintained the constitutive activity of the AR transcriptional program and a CRPC growth phenotype independent of full-length AR or androgens. These findings demonstrate that AR gene rearrangements are a unique resistance mechanism by which AR transcriptional activity can be uncoupled from endocrine regulation in CRPC.

  16. 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

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

    2008-09-01

    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 alpha1(I)-collagen promoter fragment showed no difference in body composition, testosterone, or 17ss-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

  17. The binding of 3H-labelled androgen-receptor complexes to hypothalamic chromatin of neonatal mice: effect of sex and androgenization.

    PubMed

    Ventanas, J; Garcia, C; López-Bote, C; López, A; Burgos, J

    1990-03-01

    The binding of 3H-labelled androgen-receptor complexes, prepared by (NH4)2SO4 precipitation from the 105,000 g supernatant of hypothalamic cytosol, to hypothalamic chromatin of neonatal mice covalently coupled to cellulose was measured in vitro. Saturation binding was also determined after extraction of histones and the masking of acidic proteins with high molarities of guanidine hydrochloride. This investigation showed the presence of high-affinity, low-capacity acceptor sites for [3H]-testosterone-receptor complexes in male hypothalamic chromatin (Kd value = 0.39 x 10(-10) M and binding sites of 41 fmol per mg of DNA). Acceptor activity seems to be associated with the acidic protein fraction of chromatin. No specific acceptor sites of similar nature were found in chromatin taken from the hypothalami of female mice. On the basis of these results, it is suggested that the androgen-unresponsiveness of female mice is related to the absence of acceptors for the androgen-receptor in female mice hypothalami.

  18. Photoperiod and testosterone regulate androgen receptor immunostaining in the Siberian hamster brain.

    PubMed

    Bittman, Eric L; Ehrlich, David A; Ogdahl, Justyne L; Jetton, Amy E

    2003-09-01

    Day length regulates the effects of gonadal steroids on gonadotropin secretion and behavior in seasonal breeders. To determine whether this influence of photoperiod results from changes in androgen receptor expression in Siberian hamster brain regions that regulate neuroendocrine function, androgen receptor immunostaining was examined in castrated animals given either no androgen replacement or one of three doses of testosterone (T) resulting in physiological serum concentrations. Half of the animals were housed under inhibitory photoperiod conditions, and immunostaining was quantified 11 days later. Measurement of serum gonadotropin and prolactin concentrations confirmed that androgen exerted graded effects on pituitary function but that the animals were killed before photoperiodic influences had fully developed. T significantly increased the numbers of androgen receptor-immunoreactive cells in every brain region examined. Photoperiod exerted no significant influence on androgen receptor-immunoreactive cell number in the arcuate nucleus, bed nucleus of the stria terminalis (BNST), medial preoptic nucleus, or in medial amygdala. An interaction between T and photoperiod was observed in the BNST and in the rostral and middle portions of the arcuate nucleus. Although increasing concentrations of T resulted in more intense cellular immunostaining in the BNST and arcuate, this effect was not influenced by day length. These results indicate that relatively short-duration (11 days) exposure to inhibitory photoperiod triggers localized and regionally specific changes in androgen receptor expression.

  19. Steroid Sulfatase Deficiency and Androgen Activation Before and After Puberty

    PubMed Central

    Idkowiak, Jan; Taylor, Angela E.; Subtil, Sandra; O'Neil, Donna M.; Vijzelaar, Raymon; Dias, Renuka P.; Amin, Rakesh; Barrett, Timothy G.; Shackleton, Cedric H. L.; Kirk, Jeremy M. W.; Moss, Celia

    2016-01-01

    Context: Steroid sulfatase (STS) cleaves the sulfate moiety off steroid sulfates, including dehydroepiandrosterone (DHEA) sulfate (DHEAS), the inactive sulfate ester of the adrenal androgen precursor DHEA. Deficient DHEA sulfation, the opposite enzymatic reaction to that catalyzed by STS, results in androgen excess by increased conversion of DHEA to active androgens. STS deficiency (STSD) due to deletions or inactivating mutations in the X-linked STS gene manifests with ichthyosis, but androgen synthesis and metabolism in STSD have not been studied in detail yet. Patients and Methods: We carried out a cross-sectional study in 30 males with STSD (age 6–27 y; 13 prepubertal, 5 peripubertal, and 12 postpubertal) and 38 age-, sex-, and Tanner stage-matched healthy controls. Serum and 24-hour urine steroid metabolome analysis was performed by mass spectrometry and genetic analysis of the STS gene by multiplex ligation-dependent probe amplification and Sanger sequencing. Results: Genetic analysis showed STS mutations in all patients, comprising 27 complete gene deletions, 1 intragenic deletion and 2 missense mutations. STSD patients had apparently normal pubertal development. Serum and 24-hour urinary DHEAS were increased in STSD, whereas serum DHEA and testosterone were decreased. However, total 24-hour urinary androgen excretion was similar to controls, with evidence of increased 5α-reductase activity in STSD. Prepubertal healthy controls showed a marked increase in the serum DHEA to DHEAS ratio that was absent in postpubertal controls and in STSD patients of any pubertal stage. Conclusions: In STSD patients, an increased 5α-reductase activity appears to compensate for a reduced rate of androgen generation by enhancing peripheral androgen activation in affected patients. In healthy controls, we discovered a prepubertal surge in the serum DHEA to DHEAS ratio that was absent in STSD, indicative of physiologically up-regulated STS activity before puberty. This may

  20. 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

  1. 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

  2. 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

  3. Androgen Receptor-Target Genes in African American Prostate Cancer Disparities

    PubMed Central

    Wang, Bi-Dar; Yang, Qi; Ceniccola, Kristin; Bianco, Fernando; Andrawis, Ramez; Jarrett, Thomas; Frazier, Harold; Patierno, Steven R.; Lee, Norman H.

    2013-01-01

    The incidence and mortality rates of prostate cancer (PCa) are higher in African American (AA) compared to Caucasian American (CA) men. To elucidate the molecular mechanisms underlying PCa disparities, we employed an integrative approach combining gene expression profiling and pathway and promoter analyses to investigate differential transcriptomes and deregulated signaling pathways in AA versus CA cancers. A comparison of AA and CA PCa specimens identified 1,188 differentially expressed genes. Interestingly, these transcriptional differences were overrepresented in signaling pathways that converged on the androgen receptor (AR), suggesting that the AR may be a unifying oncogenic theme in AA PCa. Gene promoter analysis revealed that 382 out of 1,188 genes contained cis-acting AR-binding sequences. Chromatin immunoprecipitation confirmed STAT1, RHOA, ITGB5, MAPKAPK2, CSNK2A,1 and PIK3CB genes as novel AR targets in PCa disparities. Moreover, functional screens revealed that androgen-stimulated AR binding and upregulation of RHOA, ITGB5, and PIK3CB genes were associated with increased invasive activity of AA PCa cells, as siRNA-mediated knockdown of each gene caused a loss of androgen-stimulated invasion. In summation, our findings demonstrate that transcriptional changes have preferentially occurred in multiple signaling pathways converging (“transcriptional convergence”) on AR signaling, thereby contributing to AR-target gene activation and PCa aggressiveness in AAs. PMID:23365759

  4. 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.

  5. 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...

  6. Training volume, androgen use and serum creatine kinase activity.

    PubMed

    Häkkinen, K; Alén, M

    1989-09-01

    Serum creatine kinase (CK) activities were investigated in elite male strength athletes (n = 20) during normal weight training and bodybuilding training (one training session per day), during high volume strength training (two sessions per day) and during strength training (one session per day) with the use of high dose synthetic androgens (five athletes in each subgroup). The findings demonstrated that the increase in serum CK was highest in the subgroup using androgens. These results suggest that strength training with the use of androgenic steroids leads to higher serum CK activities than normal strength training.

  7. Neural Androgen Receptor Deletion Impairs the Temporal Processing of Objects and Hippocampal CA1-Dependent Mechanisms.

    PubMed

    Picot, Marie; Billard, Jean-Marie; Dombret, Carlos; Albac, Christelle; Karameh, Nida; Daumas, Stéphanie; Hardin-Pouzet, Hélène; Mhaouty-Kodja, Sakina

    2016-01-01

    We studied the role of testosterone, mediated by the androgen receptor (AR), in modulating temporal order memory for visual objects. For this purpose, we used male mice lacking AR specifically in the nervous system. Control and mutant males were gonadectomized at adulthood and supplemented with equivalent amounts of testosterone in order to normalize their hormonal levels. We found that neural AR deletion selectively impaired the processing of temporal information for visual objects, without affecting classical object recognition or anxiety-like behavior and circulating corticosterone levels, which remained similar to those in control males. Thus, mutant males were unable to discriminate between the most recently seen object and previously seen objects, whereas their control littermates showed more interest in exploring previously seen objects. Because the hippocampal CA1 area has been associated with temporal memory for visual objects, we investigated whether neural AR deletion altered the functionality of this region. Electrophysiological analysis showed that neural AR deletion affected basal glutamate synaptic transmission and decreased the magnitude of N-methyl-D-aspartate receptor (NMDAR) activation and high-frequency stimulation-induced long-term potentiation. The impairment of NMDAR function was not due to changes in protein levels of receptor. These results provide the first evidence for the modulation of temporal processing of information for visual objects by androgens, via AR activation, possibly through regulation of NMDAR signaling in the CA1 area in male mice.

  8. 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.

  9. Drug-Discovery Pipeline for Novel Inhibitors of the Androgen Receptor.

    PubMed

    Dalal, Kush; Munuganti, Ravi; Morin, Hélène; Lallous, Nada; Rennie, Paul S; Cherkasov, Artem

    2016-01-01

    The androgen receptor (AR) is an important regulator of genes responsible for the development and recurrence of prostate cancer. Current therapies for this disease rely on small-molecule inhibitors that block the transcriptional activity of the AR. Recently, major advances in the development of novel AR inhibitors resulted from X-ray crystallographic information on the receptor and utilization of in silico drug design synergized with rigorous experimental testing.Herein, we describe a drug-discovery pipeline for in silico screening for small molecules that target an allosteric region on the AR termed the binding-function 3 (BF3) site. Following the identification of potential candidates, the compounds are tested in cell culture and biochemical assays for their ability to interact with and inhibit the AR. The described pipeline is readily accessible and could be applied in drug design efforts toward any surface-exposed region on the AR or other related steroid nuclear receptor. PMID:27246333

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

    PubMed

    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

  11. 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

  12. Peripheral androgen receptors sustain the acrobatics and fine motor skill of elaborate male courtship.

    PubMed

    Fuxjager, Matthew J; Longpre, Kristy M; Chew, Jennifer G; Fusani, Leonida; Schlinger, Barney A

    2013-09-01

    Androgenic hormones regulate many aspects of animal social behavior, including the elaborate display routines on which many species rely for advertisement and competition. One way that this might occur is through peripheral effects of androgens, particularly on skeletal muscles that control complex movements and postures of the body and its limbs. However, the specific contribution of peripheral androgen-muscle interactions to the performance of elaborate behavioral displays in the natural world has never been examined. We study this issue in one of the only natural physiological models of animal acrobatics: the golden-collared manakin (Manacus vitellinus). In this tropical bird, males compete with each other and court females by producing firecracker-like wing- snaps and by rapidly dancing among saplings over the forest floor. To test how activation of peripheral androgen receptors (AR) influences this display, we treat reproductively active adult male birds with the peripherally selective antiandrogen bicalutamide (BICAL) and observe the effects of this manipulation on male display performance. We not only validate the peripheral specificity of BICAL in this species, but we also show that BICAL treatment reduces the frequency with which adult male birds perform their acrobatic display maneuvers and disrupts the overall structure and fine-scale patterning of these birds' main complex wing-snap sonation. In addition, this manipulation has no effect on the behavioral metrics associated with male motivation to display. Together, our findings help differentiate the various effects of peripheral and central AR on the performance of a complex sociosexual behavioral phenotype by indicating that peripheral AR can optimize the motor skills necessary for the production of an elaborate animal display. PMID:23782945

  13. The Cochaperone SGTA (Small Glutamine-rich Tetratricopeptide Repeat-containing Protein Alpha) Demonstrates Regulatory Specificity for the Androgen, Glucocorticoid, and Progesterone Receptors*

    PubMed Central

    Paul, Atanu; Garcia, Yenni A.; Zierer, Bettina; Patwardhan, Chaitanya; Gutierrez, Omar; Hildenbrand, Zacariah; Harris, Diondra C.; Balsiger, Heather A.; Sivils, Jeffrey C.; Johnson, Jill L.; Buchner, Johannes; Chadli, Ahmed; Cox, Marc B.

    2014-01-01

    Steroid hormone receptors are ligand-dependent transcription factors that require the ordered assembly of multichaperone complexes for transcriptional activity. Although heat shock protein (Hsp) 90 and Hsp70 are key players in this process, multiple Hsp70- and Hsp90-associated cochaperones associate with receptor-chaperone complexes to regulate receptor folding and activation. Small glutamine-rich tetratricopeptide repeat-containing protein alpha (SGTA) was recently characterized as an Hsp70 and Hsp90-associated cochaperone that specifically regulates androgen receptor activity. However, the specificity of SGTA for additional members of the steroid hormone receptor superfamily and the mechanism by which SGTA regulates receptor activity remain unclear. Here we report that SGTA associates with and specifically regulates the androgen, glucocorticoid, and progesterone receptors and has no effect on the mineralocorticoid and estrogen receptors in both yeast and mammalian cell-based reporter assays. In both systems, SGTA knockdown/deletion enhances receptor activity, whereas SGTA overexpression suppresses receptor activity. We demonstrate that SGTA binds directly to Hsp70 and Hsp90 in vitro with similar affinities yet predominately precipitates with Hsp70 from cell lysates, suggesting a role for SGTA in early, Hsp70-mediated folding. Furthermore, SGTA expression completely abrogates the regulation of receptor function by FKBP52 (52-kDa FK506-binding protein), which acts at a later stage of the chaperone cycle. Taken together, our data suggest a role for SGTA at distinct steps in the chaperone-dependent modulation of androgen, glucocorticoid, and progesterone receptor activity. PMID:24753260

  14. 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

  15. 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.

  16. 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

  17. Mechanism of the tissue-specific action of the selective androgen receptor modulator S-101479.

    PubMed

    Furuya, Kazuyuki; Yamamoto, Noriko; Ohyabu, Yuki; Morikyu, Teruyuki; Ishige, Hirohide; Albers, Michael; Endo, Yasuhisa

    2013-01-01

    Selective androgen receptor modulators (SARMs) comprise a new class of molecules that induce anabolic effects with fewer side effects than those of other anabolic agents. We previously reported that the novel SARM S-101479 had a tissue-selective bone anabolic effect with diminished side effects in female animals. However, the mechanism of its tissue selectivity is not well known. In this report, we show that S-101479 increased alkaline phosphatase activity and androgen receptor (AR) transcriptional activity in osteoblastic cell lines in the same manner as the natural androgen ligand dihydrotestosterone (DHT); conversely, stimulation of AR dimerization was very low compared with that of DHT (34.4%). S-101479 increased bone mineral content in ovariectomized rats without promoting endometrial proliferation. Yeast two-hybrid interaction assays revealed that DHT promoted recruitment of numerous cofactors to AR such as TIF2, SRC1, β-catenin, NCoA3, gelsolin and PROX1 in a dose-dependent manner. SARMs induced recruitment of fewer cofactors than DHT; in particular, S-101479 failed to induce recruitment of canonical p160 coactivators such as SRC1, TIF2 and notably NCoA3 but only stimulated binding of AR to gelsolin and PROX1. The results suggest that a full capability of the AR to dimerize and to effectively and unselectively recruit all canonical cofactors is not a prerequisite for transcriptional activity in osteoblastic cells and resulting anabolic effects in bone tissues. Instead, few relevant cofactors might be sufficient to promote AR activity in these tissues.

  18. Evidence for age-dependent changes in Sertoli cell androgen receptor concentration.

    PubMed

    Buzek, S W; Caston, L A; Sanborn, B M

    1987-01-01

    Cytosol and nuclear receptor concentrations in Sertoli cells isolated from the testes of 15-, 25-, and 35-day-old rats were measured using hydroxylapatite separation procedures. In these cells the mean Kd of the cytosol receptor for methyltrienolone (3H-R1881) ranged between 2.3 and 2.9 nM, and the concentration of cytosol androgen receptor per mg Sertoli cell DNA increased over the 15-to 35-day age interval. However, when the data were expressed per mg cytosol protein, no increase was observed. The increase in receptor concentration per mg DNA paralleled the increase in cytosol protein/DNA ratio. The concentration of androgen receptor per mg DNA in nuclear extracts also increased with age. Consequently, total Sertoli cell androgen receptor increases over the time interval in which meiosis is first completed in the testis.

  19. 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 ...

  20. 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.

  1. Production of recombinant insulin-like androgenic gland hormones from three decapod species: In vitro testicular phosphorylation and activation of a newly identified tyrosine kinase receptor from the Eastern spiny lobster, Sagmariasus verreauxi.

    PubMed

    Aizen, Joseph; Chandler, Jennifer C; Fitzgibbon, Quinn P; Sagi, Amir; Battaglene, Stephen C; Elizur, Abigail; Ventura, Tomer

    2016-04-01

    In crustaceans the insulin-like androgenic gland hormone (IAG) is responsible for male sexual differentiation. To date, the biochemical pathways through which IAG exerts its effects are poorly understood and could be elucidated through the production of a functional recombinant IAG (rIAG). We have successfully expressed glycosylated, biologically active IAG using the Pichia pastoris yeast expression system. We co-expressed recombinant single-chain precursor molecules consisting of the B and A chains (the mature hormone) tethered by a flexible linker, producing rIAGs of the following commercially important species: Eastern spiny lobster Sagmariasus verreauxi (Sv), redclaw crayfish Cherax quadricarinatus (Cq) and giant freshwater prawn Macrobrachium rosenbergii (Mr). We then tested the biological activity of each, through the ability to increase phosphorylation in the testis; both Sv and Cq rIAGs significantly elevated phosphorylation specific to their species, and in a dose-dependent manner. Mr rIAG was tested on Macrobrachium australiense (Ma), eliciting a similar response. Moreover, using bioinformatics analyses of the de novo assembled spiny lobster transcriptome, we identified a spiny lobster tyrosine kinase insulin receptor (Sv-TKIR). We validated this discovery with a receptor activation assay in COS-7 cells expressing Sv-TKIR, using a reporter SRE-LUC system designed for RTKs, with each of the rIAG proteins acting as the activation ligand. Using recombinant proteins, we aim to develop specific tools to control sexual development through the administration of IAG within the critical sexual differentiation time window. The biologically active rIAGs generated might facilitate commercially feasible solutions for the long sought techniques for sex-change induction and monosex population culture in crustaceans and shed new light on the physiological mode of action of IAG in crustaceans.

  2. Production of recombinant insulin-like androgenic gland hormones from three decapod species: In vitro testicular phosphorylation and activation of a newly identified tyrosine kinase receptor from the Eastern spiny lobster, Sagmariasus verreauxi.

    PubMed

    Aizen, Joseph; Chandler, Jennifer C; Fitzgibbon, Quinn P; Sagi, Amir; Battaglene, Stephen C; Elizur, Abigail; Ventura, Tomer

    2016-04-01

    In crustaceans the insulin-like androgenic gland hormone (IAG) is responsible for male sexual differentiation. To date, the biochemical pathways through which IAG exerts its effects are poorly understood and could be elucidated through the production of a functional recombinant IAG (rIAG). We have successfully expressed glycosylated, biologically active IAG using the Pichia pastoris yeast expression system. We co-expressed recombinant single-chain precursor molecules consisting of the B and A chains (the mature hormone) tethered by a flexible linker, producing rIAGs of the following commercially important species: Eastern spiny lobster Sagmariasus verreauxi (Sv), redclaw crayfish Cherax quadricarinatus (Cq) and giant freshwater prawn Macrobrachium rosenbergii (Mr). We then tested the biological activity of each, through the ability to increase phosphorylation in the testis; both Sv and Cq rIAGs significantly elevated phosphorylation specific to their species, and in a dose-dependent manner. Mr rIAG was tested on Macrobrachium australiense (Ma), eliciting a similar response. Moreover, using bioinformatics analyses of the de novo assembled spiny lobster transcriptome, we identified a spiny lobster tyrosine kinase insulin receptor (Sv-TKIR). We validated this discovery with a receptor activation assay in COS-7 cells expressing Sv-TKIR, using a reporter SRE-LUC system designed for RTKs, with each of the rIAG proteins acting as the activation ligand. Using recombinant proteins, we aim to develop specific tools to control sexual development through the administration of IAG within the critical sexual differentiation time window. The biologically active rIAGs generated might facilitate commercially feasible solutions for the long sought techniques for sex-change induction and monosex population culture in crustaceans and shed new light on the physiological mode of action of IAG in crustaceans. PMID:26883686

  3. Testosterone-Dependent Interaction between Androgen Receptor and Aryl Hydrocarbon Receptor Induces Liver Receptor Homolog 1 Expression in Rat Granulosa Cells

    PubMed Central

    Wu, Yanguang; Baumgarten, Sarah C.; Zhou, Ping

    2013-01-01

    Androgens play a major role in the regulation of normal ovarian function; however, they are also involved in the development of ovarian pathologies. These contrasting effects may involve a differential response of granulosa cells to the androgens testosterone (T) and dihydrotestosterone (DHT). To determine the molecular pathways that mediate the distinct effects of T and DHT, we studied the expression of the liver receptor homolog 1 (LRH-1) gene, which is differentially regulated by these steroids. We found that although both T and DHT stimulate androgen receptor (AR) binding to the LRH-1 promoter, DHT prevents T-mediated stimulation of LRH-1 expression. T stimulated the expression of aryl hydrocarbon receptor (AHR) and its interaction with the AR. T also promoted the recruitment of the AR/AHR complex to the LRH-1 promoter. These effects were not mimicked by DHT. We also observed that the activation of extracellular regulated kinases by T is required for AR and AHR interaction. In summary, T, but not DHT, stimulates AHR expression and the interaction between AHR and AR, leading to the stimulation of LRH-1 expression. These findings could explain the distinct response of granulosa cells to T and DHT and provide a molecular mechanism by which DHT negatively affects ovarian function. PMID:23689136

  4. Polymorphism of the long polyglutamine tract in the human androgen receptor influences craving of men in alcohol withdrawal.

    PubMed

    Lenz, Bernd; Jacob, Claudia; Frieling, Helge; Jacobi, Andrea; Hillemacher, Thomas; Muschler, Marc; Watson, Kathryn; Kornhuber, Johannes; Bleich, Stefan

    2009-08-01

    Until recently, genetic mechanisms influencing craving in alcohol withdrawal were poorly understood. Studies show that alcoholism is associated with dysregulation of sexual hormones. The androgen receptor is encoded by the trinucleotide repeat CAG. Long repeat regions have been shown to inhibit interactions between the androgen receptor and different co-activators. The aim of the present study was to determine whether or not this trinucleotide repeat is involved in the pathogenesis of alcohol dependence, withdrawal and craving. We included 112 male inpatients who were admitted for detoxification treatment. To measure the extent of craving we used the Obsessive Compulsive Drinking Scale on the day of hospital admission. Regarding total and obsessive craving we found a significant negative correlation for the androgen receptor repeat length. No significant difference between the group of patients and the control group was found. We found that reduced length of the investigated trinucleotide repeat might aggravate craving symptoms. Moreover, an elevated number of repeats might be protective against severe craving. In summary, the presented data points to an underestimated role of the genetic regulation of androgens in the pathogenesis of alcohol dependence and related disorders.

  5. Estrogen receptor (ER) agonists and androgen receptor (AR) antagonists in effluents from Norwegian North Sea oil production platforms.

    PubMed

    Tollefsen, Knut-Erik; Harman, Christopher; Smith, Andy; Thomas, Kevin V

    2007-03-01

    The in vitro estrogen receptor (ER) agonist and androgen receptor (AR) antagonist potencies of offshore produced water effluents collected from the Norwegian Sector were determined using recombinant yeast estrogen and androgen screens. Solid phase extraction (SPE) concentrates of the effluents showed E2 agonist activities similar to those previously reported for the United Kingdom (UK) Continental Shelf (<0.1-4 ng E2 L(-1)). No activity was detected in the filtered oil droplets suggesting that produced water ER activity is primarily associated with the dissolved phase. Targeted analysis for methyl- to nonyl-substituted alkylphenol isomers show the occurrence of known ER agonists in the analysed samples. For the first time, AR antagonists were detected in both the dissolved and oil associated phase at concentrations of between 20 and 8000 microg of flutamide equivalents L(-1). The identity of the AR antagonists is unknown, however this represents a significant input into the marine environment of unknown compounds that exert a known biological effect. It is recommended that further analysis using techniques such as bioassay-directed analysis is performed to identify the compounds/groups of compounds that are responsible in order to improve the assessment of the risk posed by produced water discharges to the marine environment. PMID:17258235

  6. Photoperiodic regulation of androgen receptor and steroid receptor coactivator-1 in Siberian hamster brain.

    PubMed

    Tetel, Marc J; Ungar, Todd C; Hassan, Brett; Bittman, Eric L

    2004-11-24

    Seasonal changes in the neuroendocrine actions of gonadal steroid hormones are triggered by fluctuations in daylength. The mechanisms responsible for photoperiodic influences upon the feedback and behavioral effects of testosterone in Siberian hamsters are poorly understood. We hypothesized that daylength regulates the expression of androgen receptor (AR) and/or steroid receptor coactivator-1 (SRC-1) in specific forebrain regions. Hamsters were castrated and implanted with either oil-filled capsules or low doses of testosterone; half of the animals remained in 16L/8D and the rest were kept in 10L/14D for the ensuing 70 days. The number of AR-immunoreactive (AR-ir) cells was regulated by testosterone in medial amygdala and caudal arcuate, and by photoperiod in the medial preoptic nucleus and the posterodorsal medial amygdala. A significant interaction between photoperiod and androgen treatment was found in medial preoptic nucleus and posterodorsal medial amygdala. The molecular weight and distribution of SRC-1 were similar to reports in other rodent species, and short days reduced the number of SRC-1-ir cells in posteromedial bed nucleus of the stria terminalis (BNST) and posterodorsal medial amygdala. A significant interaction between androgen treatment and daylength in regulation of SRC-1-ir was found in anterior medial amygdala. The present results indicate that daylength-induced fluctuations in SRC-1 and AR expression may contribute to seasonally changing effects of testosterone.

  7. Nonmyocytic Androgen Receptor Regulates the Sexually Dimorphic Development of the Embryonic Bulbocavernosus Muscle

    PubMed Central

    Ipulan, Lerrie Ann; Suzuki, Kentaro; Sakamoto, Yuki; Murashima, Aki; Imai, Yuuki; Omori, Akiko; Nakagata, Naomi; Nishinakamura, Ryuichi; Valasek, Petr

    2014-01-01

    The bulbocavernosus (BC) is a sexually dimorphic muscle observed only in males. Androgen receptor knockout mouse studies show the loss of BC formation. This suggests that androgen signaling plays a vital role in its development. Androgen has been known to induce muscle hypertrophy through satellite cell activation and myonuclei accretion during muscle regeneration and growth. Whether the same mechanism is present during embryonic development is not yet elucidated. To identify the mechanism of sexual dimorphism during BC development, the timing of morphological differences was first established. It was revealed that the BC was morphologically different between male and female mice at embryonic day (E) 16.5. Differences in the myogenic process were detected at E15.5. The male BC possesses a higher number of proliferating undifferentiated myoblasts. To identify the role of androgen signaling in this process, muscle-specific androgen receptor (AR) mutation was introduced, which resulted in no observable phenotypes. Hence, the expression of AR in the BC was examined and found that the AR did not colocalize with any muscle markers such as Myogenic differentiation 1, Myogenin, and paired box transcription factor 7. It was revealed that the mesenchyme surrounding the BC expressed AR and the BC started to express AR at E15.5. AR mutation on the nonmyocytic cells using spalt-like transcription factor 1 (Sall1) Cre driver mouse was performed, which resulted in defective BC formation. It was revealed that the number of proliferating undifferentiated myoblasts was reduced in the Sall1 Cre:ARL−/Y mutant embryos, and the adult mutants were devoid of BC. The transition of myoblasts from proliferation to differentiation is mediated by cyclin-dependent kinase inhibitors. An increased expression of p21 was observed in the BC myoblast of the Sall1 Cre:ARL−/Y mutant and wild-type female. Altogether this study suggests that the nonmyocytic AR may paracrinely regulate the

  8. Nonmyocytic androgen receptor regulates the sexually dimorphic development of the embryonic bulbocavernosus muscle.

    PubMed

    Ipulan, Lerrie Ann; Suzuki, Kentaro; Sakamoto, Yuki; Murashima, Aki; Imai, Yuuki; Omori, Akiko; Nakagata, Naomi; Nishinakamura, Ryuichi; Valasek, Petr; Yamada, Gen

    2014-07-01

    The bulbocavernosus (BC) is a sexually dimorphic muscle observed only in males. Androgen receptor knockout mouse studies show the loss of BC formation. This suggests that androgen signaling plays a vital role in its development. Androgen has been known to induce muscle hypertrophy through satellite cell activation and myonuclei accretion during muscle regeneration and growth. Whether the same mechanism is present during embryonic development is not yet elucidated. To identify the mechanism of sexual dimorphism during BC development, the timing of morphological differences was first established. It was revealed that the BC was morphologically different between male and female mice at embryonic day (E) 16.5. Differences in the myogenic process were detected at E15.5. The male BC possesses a higher number of proliferating undifferentiated myoblasts. To identify the role of androgen signaling in this process, muscle-specific androgen receptor (AR) mutation was introduced, which resulted in no observable phenotypes. Hence, the expression of AR in the BC was examined and found that the AR did not colocalize with any muscle markers such as Myogenic differentiation 1, Myogenin, and paired box transcription factor 7. It was revealed that the mesenchyme surrounding the BC expressed AR and the BC started to express AR at E15.5. AR mutation on the nonmyocytic cells using spalt-like transcription factor 1 (Sall1) Cre driver mouse was performed, which resulted in defective BC formation. It was revealed that the number of proliferating undifferentiated myoblasts was reduced in the Sall1 Cre:AR(L-/Y) mutant embryos, and the adult mutants were devoid of BC. The transition of myoblasts from proliferation to differentiation is mediated by cyclin-dependent kinase inhibitors. An increased expression of p21 was observed in the BC myoblast of the Sall1 Cre:AR(L-/Y) mutant and wild-type female. Altogether this study suggests that the nonmyocytic AR may paracrinely regulate the

  9. Dissection of androgen receptor-promoter interactions: steroid receptors partition their interaction energetics in parallel with their phylogenetic divergence.

    PubMed

    De Angelis, Rolando W; Yang, Qin; Miura, Michael T; Bain, David L

    2013-11-15

    Steroid receptors comprise a homologous family of ligand-activated transcription factors. The members include androgen receptor (AR), estrogen receptor (ER), glucocorticoid receptor (GR), mineralocorticoid receptor (MR), and progesterone receptor (PR). Phylogenetic studies demonstrate that AR, GR, MR, and PR are most closely related, falling into subgroup 3C. ER is more distantly related, falling into subgroup 3A. To determine the quantitative basis by which receptors generate their unique transcriptional responses, we are systematically dissecting the promoter-binding energetics of all receptors under a single "standard state" condition. Here, we examine the self-assembly and promoter-binding energetics of full-length AR and a mutant associated with prostate cancer, T877A. We first demonstrate that both proteins exist only as monomers, showing no evidence of dimerization. Although this result contradicts the traditional understanding that steroid receptors dimerize in the absence of DNA, it is fully consistent with our previous work demonstrating that GR and two PR isoforms either do not dimerize or dimerize only weakly. Moreover, both AR proteins exhibit substantial cooperativity between binding sites, again as seen for GR and PR. In sharp contrast, the more distantly related ER-α dimerizes so strongly that energetics can only be measured indirectly, yet cooperativity is negligible. Thus, homologous receptors partition their promoter-binding energetics quite differently. Moreover, since receptors most closely related by phylogeny partition their energetics similarly, such partitioning appears to be evolutionarily conserved. We speculate that such differences in energetics, coupled with different promoter architectures, serve as the basis for generating receptor-specific promoter occupancy and thus function.

  10. Design and synthesis of tricyclic tetrahydroquinolines as a new series of nonsteroidal selective androgen receptor modulators (SARMs).

    PubMed

    Nagata, Naoya; Miyakawa, Motonori; Amano, Seiji; Furuya, Kazuyuki; Yamamoto, Noriko; Inoguchi, Kiyoshi

    2011-03-15

    Some tricyclic tetrahydroquinolines (THQs) were found to have the potential of a new series of nonsteroidal selective androgen receptor modulators (SARMs). Compound 5b was first designed and synthesized under our hypothesis based on a four-point pharmacophoric requirement of the 3-carbonyl, 18-methyl, 17-hydroxyl, and 13-quaternary carbon groups of dihydrotestosterone (DHT). It was revealed that this compound exhibits not only a strong androgen receptor (AR) agonistic activity (EC(50)=9.2 nM) but also the highest selectivity in binding affinity to AR among the steroid hormone receptors. Furthermore, this compound showed a weak virilizing effect with retention of the desired anabolic effect as compared with DHT in vivo.

  11. Androgen- and Estrogen-Receptor Content in Spontaneous and Experimentally Induced Canine Prostatic Hyperplasia

    PubMed Central

    Trachtenberg, John; Hicks, L. Louise; Walsh, Patrick C.

    1980-01-01

    To gain insight into the mechanism by which steroidal hormones influence the development of canine prostatic hyperplasia, nuclear and cytosolic androgen- and estrogen-receptor content, as measured under exchange conditions by the binding of [3H]R1881 (methyltrienolone) and [3H]estradiol, respectively, were quantitated in the prostates of purebred beagles of known age. In young dogs with spontaneously arising and experimentally induced (androstanediol plus estradiol treatment) prostatic hyperplasia, nuclear, but not cytosolic, prostatic androgen-receptor content was significantly greater than that determined in the normal prostates of age-matched dogs (3,452±222 and 4,035±274 fmol/mg DNA vs. 2,096±364 fmol/mg DNA, respectively). No differences were observed between the androgen-receptor content of the normal prostates of young dogs and the hyperplastic prostates of old dogs. The cytosolic and nuclear estrogen-receptor content of spontaneously arising prostatic hyperplasia in both young and old animals was similar to that found in normal prostates. The administration of estradiol plus androstanediol to castrate dogs significantly increased the prostatic nuclear androgen-receptor content over that found in dogs treated only with androstanediol. This estradiol-associated increase in nuclear androgen-receptor content was accompanied by the development of benign prostatic hyperplasia. Estradiol treatment of castrate dogs resulted in an increase in prostatic nuclear estrogen-receptor content, in the appearance of a putative prostatic cytosolic progesterone receptor, and in an alteration of the epithelium of the prostate to one characterized by squamous metaplasia. Treatment of castrate dogs with both estradiol and androstanediol resulted in a reduction in prostatic nuclear estrogen-receptor content, disappearance of the progesterone receptor, and loss of squamous metaplasia. An increase in nuclear androgen-receptor content, thus, appears to be an important event in the

  12. Effects of Sorafenib on C-Terminally Truncated Androgen Receptor Variants in Human Prostate Cancer Cells

    PubMed Central

    Zengerling, Friedemann; Streicher, Wolfgang; Schrader, Andres J.; Schrader, Mark; Nitzsche, Bianca; Cronauer, Marcus V.; Höpfner, Michael

    2012-01-01

    Recent evidence suggests that the development of castration resistant prostate cancer (CRPCa) is commonly associated with an aberrant, ligand-independent activation of the androgen receptor (AR). A putative mechanism allowing prostate cancer (PCa) cells to grow under low levels of androgens, is the expression of constitutively active, C-terminally truncated AR lacking the AR-ligand binding domain (LBD). Due to the absence of a LBD, these receptors, termed ARΔLBD, are unable to respond to any form of anti-hormonal therapies. In this study we demonstrate that the multikinase inhibitor sorafenib inhibits AR as well as ARΔLBD-signalling in CRPCa cells. This inhibition was paralleled by proteasomal degradation of the AR- and ARΔLBD-molecules. In line with these observations, maximal antiproliferative effects of sorafenib were achieved in AR and ARΔLBD-positive PCa cells. The present findings warrant further investigations on sorafenib as an option for the treatment of advanced AR-positive PCa. PMID:23109869

  13. Effects of sorafenib on C-terminally truncated androgen receptor variants in human prostate cancer cells.

    PubMed

    Zengerling, Friedemann; Streicher, Wolfgang; Schrader, Andres J; Schrader, Mark; Nitzsche, Bianca; Cronauer, Marcus V; Höpfner, Michael

    2012-01-01

    Recent evidence suggests that the development of castration resistant prostate cancer (CRPCa) is commonly associated with an aberrant, ligand-independent activation of the androgen receptor (AR). A putative mechanism allowing prostate cancer (PCa) cells to grow under low levels of androgens, is the expression of constitutively active, C-terminally truncated AR lacking the AR-ligand binding domain (LBD). Due to the absence of a LBD, these receptors, termed ARΔLBD, are unable to respond to any form of anti-hormonal therapies. In this study we demonstrate that the multikinase inhibitor sorafenib inhibits AR as well as ARΔLBD-signalling in CRPCa cells. This inhibition was paralleled by proteasomal degradation of the AR- and ARΔLBD-molecules. In line with these observations, maximal antiproliferative effects of sorafenib were achieved in AR and ARΔLBD-positive PCa cells. The present findings warrant further investigations on sorafenib as an option for the treatment of advanced AR-positive PCa. PMID:23109869

  14. The androgenic anabolic steroid tetrahydrogestrinone produces dioxin-like effects via the aryl hydrocarbon receptor.

    PubMed

    Moon, Hyo Youl; Kim, Sun-Hee; Ryu, Sung Ho; Suh, Pann-Ghill

    2012-10-01

    For a long time, athletes have used androgenic anabolic steroids (AASs) in an inappropriate and veiled manner with the aim of improving exercise performance or for cosmetic purposes. Abuse of AASs triggers adverse effects such as hepatocarcinogenesis, heart attacks, and aggressive behavior. However, AAS-induced toxicity is not completely understood at the molecular level. In the present study, we showed, by performing a dioxin response element (DRE)-luciferase reporter gene assay, that tetrahydrogestrinone (THG), a popular and potent androgen receptor agonist, has dioxin-like effects. In addition, we showed that THG increased cytochrome P-450 1A1 (CYP1A1) mRNA and protein levels, and enzyme activity. The gene encoding CYP1A1 is involved in phase 1 xenobiotic metabolism and a target gene of the aryl hydrocarbon receptor (AhR). Using the AhR antagonist CH-223191, we also examined whether the effects of THG on DRE activation depended on AhR. Our results suggest that synthetic anabolic steroids may have dioxin-like side effects that can disturb endocrine systems and may cause other side effects including cancer through AhR.

  15. Preclinical pharmacology of FL442, a novel nonsteroidal androgen receptor modulator.

    PubMed

    Poutiainen, Pekka K; Huhtala, Tuulia; Jääskeläinen, Tiina; Petsalo, Aleksanteri; Küblbeck, Jenni; Kaikkonen, Sanna; Palvimo, Jorma J; Raunio, Hannu; Närvänen, Ale; Peräkylä, Mikael; Juvonen, Risto O; Honkakoski, Paavo; Laatikainen, Reino; Pulkkinen, Juha T

    2014-04-25

    The preclinical profiles of two most potent compounds of our recently published cycloalkane[d]isoxazole pharmacophore-based androgen receptor (AR) modulators, FL442 (4-(3a,4,5,6,7,7a-hexahydro-benzo[d]isoxazol-3-yl)-2-(trifluoromethyl)benzonitrile) and its nitro analog FL425 (3-(4-nitro-3-(trifluoromethyl)phenyl)-3a,4,5,6,7,7a-hexahydrobenzo[d]isoxazole), were explored to evaluate their druggability for the treatment of AR dependent prostate cancer. The studies revealed that both compounds are selective to AR over other closely related steroid hormone receptors and that FL442 exhibits equal inhibition efficiency towards the androgen-responsive LNCaP prostate cancer cell line as the most widely used antiandrogen bicalutamide and the more recently discovered enzalutamide. Notably, FL442 maintains antiandrogenic activity with enzalutamide-activated AR mutant F876L. In contrast to bicalutamide, FL442 does not stimulate the VCaP prostate cancer cells which express elevated levels of the AR. Distribution analyses showed that [(14)CN]FL442 accumulates strongly in the mouse prostate. In spite of its low plasma concentration obtained by intraperitoneal administration, FL442 significantly inhibited LNCaP xenograft tumor growth. These findings provide a preclinical proof for FL442 as a promising AR targeted candidate for a further optimization.

  16. A NOVEL CELL LINE, MDA-KB2, THAT STABLY EXPRESSES AN ANDROGEN AND GLUCOCORTICOID RESPONSIVE REPORTER FOR THE DETECTION OF HORMONE RECEPTOR AGONISTS AND ANTAGONISTS

    EPA Science Inventory

    The U.S. Environmental Protection Agency has proposed that in vitro assays for estrogen receptor (ER) and androgen receptor (AR) mediated actions be included in a Tier I screening battery to detect hormonally active chemicals. Herein we describe the development of a novel stab...

  17. 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

  18. Loss of androgen receptor expression promotes a stem-like cell phenotype in prostate cancer through STAT3 signaling.

    PubMed

    Schroeder, Anne; Herrmann, Andreas; Cherryholmes, Gregory; Kowolik, Claudia; Buettner, Ralf; Pal, Sumanta; Yu, Hua; Müller-Newen, Gerhard; Jove, Richard

    2014-02-15

    Androgen receptor (AR) signaling is important for prostate cancer progression. However, androgen-deprivation and/or AR targeting-based therapies often lead to resistance. Here, we demonstrate that loss of AR expression results in STAT3 activation in prostate cancer cells. AR downregulation further leads to development of prostate cancer stem-like cells (CSC), which requires STAT3. In human prostate tumor tissues, elevated cancer stem-like cell markers coincide with those cells exhibiting high STAT3 activity and low AR expression. AR downregulation-induced STAT3 activation is mediated through increased interleukin (IL)-6 expression. Treating mice with soluble IL-6 receptor fusion protein or silencing STAT3 in tumor cells significantly reduced prostate tumor growth and CSCs. Together, these findings indicate an opposing role of AR and STAT3 in prostate CSC development.

  19. 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

  20. Enhanced sexual behaviors and androgen receptor immunoreactivity in the male progesterone receptor knockout mouse.

    PubMed

    Schneider, Johanna S; Burgess, Carly; Sleiter, Nicole C; DonCarlos, Lydia L; Lydon, John P; O'Malley, Bert; Levine, Jon E

    2005-10-01

    Reproductive and behavioral functions of progesterone receptors (PRs) in males were assessed by examining consequences of PR gene deletion. Basal hormone levels were measured in male progesterone receptor knockout (PRKO) mice and compared to wild-type (WT) counterparts. RIA of serum LH, testosterone, and progesterone levels revealed no significant differences. Levels of FSH were moderately but significantly lower and inhibin levels were higher in PRKOs; these differences were not accompanied by gross differences in testicular weight or morphology. PRKOs exhibited significant alterations in sexual behavior. In initial tests PRKOs exhibited reduced latency to mount, compared with WT. In second sessions, PRKOs again showed a significantly reduced latency to mount and increased likelihood of achieving ejaculation. RU486 treatment in WT produced increased mount and intromission frequency and decreased latency to intromission. In anxiety-related behavior tests, PRKO mice exhibited intermediate anxiety levels, compared with WT, suggesting that enhanced sexual behavior in PRKOs is not secondary to reduced anxiety. Immunohistochemical analysis revealed significantly enhanced androgen receptor expression in the medial preoptic nucleus and bed nucleus of the stria terminalis of PRKO. We conclude that testicular development and function and homeostatic regulation of the hypothalamic-pituitary testicular axis are altered to a lesser extent by PR gene deletion. In contrast, PR appears to play a substantial role in inhibiting the anticipatory/motivational components of male sexual behavior in the mouse. The biological significance of this inhibitory mechanism and the extent to which it is mediated by reduced androgen receptor expression remain to be clarified.

  1. Selective androgen receptor modulator RAD140 is neuroprotective in cultured neurons and kainate-lesioned male rats.

    PubMed

    Jayaraman, Anusha; Christensen, Amy; Moser, V Alexandra; Vest, Rebekah S; Miller, Chris P; Hattersley, Gary; Pike, Christian J

    2014-04-01

    The decline in testosterone levels in men during normal aging increases risks of dysfunction and disease in androgen-responsive tissues, including brain. The use of testosterone therapy has the potential to increase the risks for developing prostate cancer and or accelerating its progression. To overcome this limitation, novel compounds termed "selective androgen receptor modulators" (SARMs) have been developed that lack significant androgen action in prostate but exert agonist effects in select androgen-responsive tissues. The efficacy of SARMs in brain is largely unknown. In this study, we investigate the SARM RAD140 in cultured rat neurons and male rat brain for its ability to provide neuroprotection, an important neural action of endogenous androgens that is relevant to neural health and resilience to neurodegenerative diseases. In cultured hippocampal neurons, RAD140 was as effective as testosterone in reducing cell death induced by apoptotic insults. Mechanistically, RAD140 neuroprotection was dependent upon MAPK signaling, as evidenced by elevation of ERK phosphorylation and inhibition of protection by the MAPK kinase inhibitor U0126. Importantly, RAD140 was also neuroprotective in vivo using the rat kainate lesion model. In experiments with gonadectomized, adult male rats, RAD140 was shown to exhibit peripheral tissue-specific androgen action that largely spared prostate, neural efficacy as demonstrated by activation of androgenic gene regulation effects, and neuroprotection of hippocampal neurons against cell death caused by systemic administration of the excitotoxin kainate. These novel findings demonstrate initial preclinical efficacy of a SARM in neuroprotective actions relevant to Alzheimer's disease and related neurodegenerative diseases.

  2. Selective Androgen Receptor Modulator RAD140 Is Neuroprotective in Cultured Neurons and Kainate-Lesioned Male Rats

    PubMed Central

    Jayaraman, Anusha; Christensen, Amy; Moser, V. Alexandra; Vest, Rebekah S.; Miller, Chris P.; Hattersley, Gary

    2014-01-01

    The decline in testosterone levels in men during normal aging increases risks of dysfunction and disease in androgen-responsive tissues, including brain. The use of testosterone therapy has the potential to increase the risks for developing prostate cancer and or accelerating its progression. To overcome this limitation, novel compounds termed “selective androgen receptor modulators” (SARMs) have been developed that lack significant androgen action in prostate but exert agonist effects in select androgen-responsive tissues. The efficacy of SARMs in brain is largely unknown. In this study, we investigate the SARM RAD140 in cultured rat neurons and male rat brain for its ability to provide neuroprotection, an important neural action of endogenous androgens that is relevant to neural health and resilience to neurodegenerative diseases. In cultured hippocampal neurons, RAD140 was as effective as testosterone in reducing cell death induced by apoptotic insults. Mechanistically, RAD140 neuroprotection was dependent upon MAPK signaling, as evidenced by elevation of ERK phosphorylation and inhibition of protection by the MAPK kinase inhibitor U0126. Importantly, RAD140 was also neuroprotective in vivo using the rat kainate lesion model. In experiments with gonadectomized, adult male rats, RAD140 was shown to exhibit peripheral tissue-specific androgen action that largely spared prostate, neural efficacy as demonstrated by activation of androgenic gene regulation effects, and neuroprotection of hippocampal neurons against cell death caused by systemic administration of the excitotoxin kainate. These novel findings demonstrate initial preclinical efficacy of a SARM in neuroprotective actions relevant to Alzheimer's disease and related neurodegenerative diseases. PMID:24428527

  3. Steroidal androgens and nonsteroidal, tissue-selective androgen receptor modulator, S-22, regulate androgen receptor function through distinct genomic and nongenomic signaling pathways.

    PubMed

    Narayanan, Ramesh; Coss, Christopher C; Yepuru, Muralimohan; Kearbey, Jeffrey D; Miller, Duane D; Dalton, James T

    2008-11-01

    Androgen receptor (AR) ligands are important for the development and function of several tissues and organs. However, the poor oral bioavailability, pharmacokinetic properties, and receptor cross-reactivity of testosterone, coupled with side effects, place limits on its clinical use. Selective AR modulators (SARMs) elicit anabolic effects in muscle and bone, sparing reproductive organs like the prostate. However, molecular mechanisms underlying the tissue selectivity remain ambiguous. We performed a variety of in vitro studies to compare and define the molecular mechanisms of an aryl propionamide SARM, S-22, as compared with dihydrotestosterone (DHT). Studies indicated that S-22 increased levator ani muscle weight but decreased the size of prostate in rats. Analysis of the upstream intracellular signaling events indicated that S-22 and DHT mediated their actions through distinct pathways. Modulation of these pathways altered the recruitment of AR and its cofactors to the PSA enhancer in a ligand-dependent fashion. In addition, S-22 induced Xenopus laevis oocyte maturation and rapid phosphorylation of several kinases, through pathways distinct from steroids. These studies reveal novel differences in the molecular mechanisms by which S-22, a nonsteroidal SARM, and DHT mediate their pharmacological effects.

  4. Inhibiting androgen receptor nuclear entry in castration-resistant prostate cancer.

    PubMed

    Pollock, Julie A; Wardell, Suzanne E; Parent, Alexander A; Stagg, David B; Ellison, Stephanie J; Alley, Holly M; Chao, Christina A; Lawrence, Scott A; Stice, James P; Spasojevic, Ivan; Baker, Jennifer G; Kim, Sung Hoon; McDonnell, Donald P; Katzenellenbogen, John A; Norris, John D

    2016-10-01

    Clinical resistance to the second-generation antiandrogen enzalutamide in castration-resistant prostate cancer (CRPC), despite persistent androgen receptor (AR) activity in tumors, highlights an unmet medical need for next-generation antagonists. We have identified and characterized tetra-aryl cyclobutanes (CBs) as a new class of competitive AR antagonists that exhibit a unique mechanism of action. These CBs are structurally distinct from current antiandrogens (hydroxyflutamide, bicalutamide, and enzalutamide) and inhibit AR-mediated gene expression, cell proliferation, and tumor growth in several models of CRPC. Conformational profiling revealed that CBs stabilize an AR conformation resembling an unliganded receptor. Using a variety of techniques, it was determined that the AR-CB complex was not recruited to AR-regulated promoters and, like apo AR, remains sequestered in the cytoplasm, bound to heat shock proteins. Thus, we have identified third-generation AR antagonists whose unique mechanism of action suggests that they may have therapeutic potential in CRPC.

  5. Molecular cloning and characterization of estrogen, androgen, and progesterone nuclear receptors from a freshwater turtle (Pseudemys nelsoni).

    PubMed

    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 (ERalpha), an androgen receptor (AR), and a progesterone receptor (PR). The full-length red-belly slider turtle (t)ERalpha, 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 (tERalpha, 90%; tAR, 71%; tPR, 71%). Using transient transfection assays of mammalian cells, tERalpha 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 tERalpha, 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

  6. 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

  7. Lead evaluation of tetrahydroquinolines as nonsteroidal selective androgen receptor modulators for the treatment of osteoporosis.

    PubMed

    Nagata, Naoya; Furuya, Kazuyuki; Oguro, Nao; Nishiyama, Daisuke; Kawai, Kentaro; Yamamoto, Noriko; Ohyabu, Yuki; Satsukawa, Masahiro; Miyakawa, Motonori

    2014-01-01

    Tetrahydroquinoline (THQ) was deemed to be a suitable scaffold for our nonsteroidal selective androgen receptor modulator (SARM) concept. We adapted the strategy of switching the antagonist function of cyano-group-containing THQ (CN-THQ) to the agonist function and optimized CN-THQ as an orally available drug candidate with suitable pharmacological and ADME profiles. Based on binding mode analyses and synthetic accessibility, we designed and synthesized a compound that possesses a para-substituted aromatic ring attached through an amide linker. The long-tail THQ derivative 6-acetamido-N-(2-(8-cyano-3a,4,5,9b-tetrahydro-3H-cyclopenta[c]quinolin-4-yl)-2-methylpropyl)nicotinamide (1 d), which bears a para-acetamide-substituted aromatic group, showed an appropriate in vitro biological profile, as expected. We considered that the large conformational change at Trp741 of the androgen receptor (AR) and the hydrogen bond between 1 d and helix 12 of the AR could maintain the structure of the AR in its agonist form; indeed, 1 d displays strong AR agonistic activity. Furthermore, 1 d showed an appropriate in vivo profile for use as an orally available SARM, displaying clear tissue selectivity, with a separation between its desirable osteoanabolic effect on femoral bone mineral density and its undesirable virilizing effects on the uterus and clitoral gland in a female osteoporosis model. PMID:24273094

  8. Lead evaluation of tetrahydroquinolines as nonsteroidal selective androgen receptor modulators for the treatment of osteoporosis.

    PubMed

    Nagata, Naoya; Furuya, Kazuyuki; Oguro, Nao; Nishiyama, Daisuke; Kawai, Kentaro; Yamamoto, Noriko; Ohyabu, Yuki; Satsukawa, Masahiro; Miyakawa, Motonori

    2014-01-01

    Tetrahydroquinoline (THQ) was deemed to be a suitable scaffold for our nonsteroidal selective androgen receptor modulator (SARM) concept. We adapted the strategy of switching the antagonist function of cyano-group-containing THQ (CN-THQ) to the agonist function and optimized CN-THQ as an orally available drug candidate with suitable pharmacological and ADME profiles. Based on binding mode analyses and synthetic accessibility, we designed and synthesized a compound that possesses a para-substituted aromatic ring attached through an amide linker. The long-tail THQ derivative 6-acetamido-N-(2-(8-cyano-3a,4,5,9b-tetrahydro-3H-cyclopenta[c]quinolin-4-yl)-2-methylpropyl)nicotinamide (1 d), which bears a para-acetamide-substituted aromatic group, showed an appropriate in vitro biological profile, as expected. We considered that the large conformational change at Trp741 of the androgen receptor (AR) and the hydrogen bond between 1 d and helix 12 of the AR could maintain the structure of the AR in its agonist form; indeed, 1 d displays strong AR agonistic activity. Furthermore, 1 d showed an appropriate in vivo profile for use as an orally available SARM, displaying clear tissue selectivity, with a separation between its desirable osteoanabolic effect on femoral bone mineral density and its undesirable virilizing effects on the uterus and clitoral gland in a female osteoporosis model.

  9. Androgen receptor splice variants and polycystic ovary syndrome: cause or effect?

    PubMed Central

    Walters, Kirsty A; Handelsman, David J

    2016-01-01

    Androgen receptor (AR)-mediated androgen action provides not only a classical pivotal role in male development and functions but also a recently proven role in female reproductive physiology. Splice variants of AR are reported to occur in various androgen-sensitive cancers and now, a recent study by Wang et al. proposed that AR splice variants have an etiological role in polycystic ovary syndrome (PCOS). Although further investigations are required to fully appraise the significance of their discovery, these seminal findings have exciting and important implications for opening a new chapter in the understanding of the role of AR signaling in the origins and pathogenesis of PCOS. PMID:26306851

  10. Crystallization and preliminary X-ray analysis of the human androgen receptor ligand-binding domain with a coactivator-like peptide and selective androgen receptor modulators.

    PubMed

    Thauvin, Maxime; Robin-Jagerschmidt, Catherine; Nique, François; Mollat, Patrick; Fleury, Damien; Prangé, Thierry

    2008-12-01

    The ligand-binding domain of the human androgen receptor has been cloned, overproduced and crystallized in the presence of a coactivator-like 11-mer peptide and two different nonsteroidal ligands. The crystals of the two ternary complexes were isomorphous and belonged to space group P2(1)2(1)2(1), with one molecule in the asymmetric unit. They diffracted to 1.7 and 1.95 A resolution, respectively. Structure determination of these two complexes will help in understanding the mode of binding of selective nonsteroidal androgens versus endogenous steroidal ligands and possibly the origin of their tissue selectivity.

  11. 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

  12. ATM Inhibition Potentiates Death of Androgen Receptor-inactivated Prostate Cancer Cells with Telomere Dysfunction.

    PubMed

    Reddy, Vidyavathi; Wu, Min; Ciavattone, Nicholas; McKenty, Nathan; Menon, Mani; Barrack, Evelyn R; Reddy, G Prem-Veer; Kim, Sahn-Ho

    2015-10-16

    Androgen receptor (AR) plays a role in maintaining telomere stability in prostate cancer cells, as AR inactivation induces telomere dysfunction within 3 h. Since telomere dysfunction in other systems is known to activate ATM (ataxia telangiectasia mutated)-mediated DNA damage response (DDR) signaling pathways, we investigated the role of ATM-mediated DDR signaling in AR-inactivated prostate cancer cells. Indeed, the induction of telomere dysfunction in cells treated with AR-antagonists (Casodex or MDV3100) or AR-siRNA was associated with a dramatic increase in phosphorylation (activation) of ATM and its downstream effector Chk2 and the presenceof phosphorylated ATM at telomeres, indicating activation of DDR signaling at telomeres. Moreover, Casodex washout led to the reversal of telomere dysfunction, indicating repair of damaged telomeres. ATM inhibitor blocked ATM phosphorylation, induced PARP cleavage, abrogated cell cycle checkpoint activation and attenuated the formation of γH2AX foci at telomeres in AR-inactivated cells, suggesting that ATM inhibitor induces apoptosis in AR-inactivated cells by blocking the repair of damaged DNA at telomeres. Finally, colony formation assay revealed a dramatic decrease in the survival of cells co-treated with Casodex and ATM inhibitor as compared with those treated with either Casodex or ATM inhibitor alone. These observations indicate that inhibitors of DDR signaling pathways may offer a unique opportunity to enhance the potency of AR-targeted therapies for the treatment of androgen-sensitive as well as castration-resistant prostate cancer.

  13. Design, synthesis, and biological evaluation of 16-substituted 4-azasteroids as tissue-selective androgen receptor modulators (SARMs).

    PubMed

    Mitchell, Helen J; Dankulich, William P; Hartman, George D; Prueksaritanont, Thomayant; Schmidt, Azriel; Vogel, Robert L; Bai, Chang; McElwee-Witmer, Sheila; Zhang, Hai Z; Chen, Fang; Leu, Chih-Tai; Kimmel, Donald B; Ray, William J; Nantermet, Pascale; Gentile, Michael A; Duggan, Mark E; Meissner, Robert S

    2009-08-13

    A novel series of 16-substituted-4-azasteroids has been identified as potential tissue-selective androgen receptor modulators. These ligands display potent hAR binding and agonist activity, low virilizing potential, and good pharmacokinetic profiles in dogs. On the basis of its in vitro profile, 21 was evaluated in the OVX and ORX rat models and exhibited an osteoanabolic, tissue-selective profile.

  14. Ligand-dependent inhibition of beta-catenin/TCF signaling by androgen receptor.

    PubMed

    Chesire, Dennis R; Isaacs, William B

    2002-12-01

    Beta-catenin signaling may contribute to prostate cancer (CaP) progression. Although beta-catenin is known to upregulate T cell factor (TCF) target gene expression in CaP cells, recent evidence demonstrates its capacity to enhance ligand-dependent androgen receptor (AR) function. Thus, we wished to further understand the interaction between these two pathways. We find in both CaP cells (CWR22-Rv1, LAPC-4, DU145) and non-CaP cells (HEK-293, TSU, SW480, HCT-116) that beta-catenin/TCF-related transcription (CRT), as measured by activation of a synthetic promoter and that of cyclin D1, is inhibited by androgen treatment. This inhibition is AR-dependent, as it only occurs in cells expressing AR endogenously or transiently, and is abrogated by AR antagonists. Additional analyses convey that the ligand-dependent nature of CRT suppression depends on transactivation-competent AR in the nucleus, but not on indirect effects stemming from AR target gene expression. Given the recent work identifying an AR/beta-catenin interaction, and from our finding that liganded AR does not prompt gross changes in the constitutive nuclear localization of TCF4 or mutant beta-catenin, we hypothesized that transcription factor (i.e. AR and TCF) competition for beta-catenin recruitment may explain, in part, androgen-induced suppression of CRT. To address this idea, we expressed an AR mutant lacking its DNA-binding domain (DBD). This receptor could not orchestrate ligand-dependent CRT repression, thereby providing support for those recent data implicating the AR DBD/LBD as necessary for beta-catenin interaction. Further supporting this hypothesis, TCF/LEF over-expression counteracts androgen-induced suppression of CRT, and requires beta-catenin binding activity to do so. Interestingly, TCF4 over-expression potently antagonizes AR function; however, this inhibition may occur independently of beta-catenin/TCF4 interaction. These results from TCF4 over-expression analyses, taken together, provide

  15. Calpain-mediated androgen receptor breakdown in apoptotic prostate cancer cells.

    PubMed

    Yang, Huanjie; Murthy, Shalini; Sarkar, Fazlul H; Sheng, Shijie; Reddy, G Prem-Veer; Dou, Q Ping

    2008-12-01

    Since androgen receptor (AR) plays an important role in prostate cancer development and progression, androgen-ablation has been the frontline therapy for treatment of advanced prostate cancer even though it is rarely curative. A curative strategy should involve functional and structural elimination of AR from prostate cancer cells. We have previously reported that apoptosis induced by medicinal proteasome-inhibitory compound celastrol is associated with a decrease in AR protein levels. However celastrol-stimulated events contributing to this AR decrease have not been elucidated. Here, we report that a variety of chemotherapeutic agents, including proteasome inhibitors, a topoisomerase inhibitor, DNA-damaging agents and docetaxel that cause cell death, decrease AR levels in LNCaP prostate cancer cells. This decrease in AR protein levels was not due to the suppression of AR mRNA expression in these cells. We observed that a proteolytic activity residing in cytosol of prostate cancer cells is responsible for AR breakdown and that this proteolytic activity was stimulated upon induction of apoptosis. Interestingly, proteasome inhibitor celastrol- and chemotherapeutic drug VP-16-stimulated AR breakdown was attenuated by calpain inhibitors calpastatin and N-acetyl-L-leucyl-L-leucyl-L-methioninal. Furthermore, AR proteolytic activity pulled down by calmodulin-agarose beads from celastrol-treated PC-3 cells showed immunoreactivity to a calpain antibody. Taken together, these results demonstrate calpain involvement in proteasome inhibitor-induced AR breakdown, and suggest that AR degradation is intrinsic to the induction of apoptosis in prostate cancer cells.

  16. Potent anti-prostate cancer agents derived from a novel androgen receptor down-regulating agent.

    PubMed

    Purushottamachar, Puranik; Khandelwal, Aakanksha; Vasaitis, Tadas S; Bruno, Robert D; Gediya, Lalji K; Njar, Vincent C O

    2008-04-01

    The search for novel androgen receptor (AR) down-regulating agents by catalyst HipHop pharmacophore modeling led to the discovery of some lead molecules. Unexpectedly, the effect of these leads on human prostate cancer LNCaP cell viability did not correlate with the ability of the compounds to cause down-regulation of AR protein expression. Through rational synthetic optimization of the lead compound (BTB01434), we have discovered a series of novel substituted diaryl molecules as potent anti-prostate cancer agents. Some compounds (1-6) were shown to be extremely potent inhibitors of LNCaP cell viability with GI(50) values in the nanomolar range (1.45-83 nM). The most potent compound (4-methylphenyl)[(4-methylphenyl)sulfonyl]amine (5) with a GI(50) value of 1.45 nM is 27,000 times more potent than our lead compound BTB01434 (GI(50)=39.8 microM). In addition, some of the compounds exhibited modest anti-androgenic activities and one was also a potent inhibitor (GI(50)=850 nM) of PC-3 (AR-null) cell growth. A clear structure-activity relationship (SAR) has been established for activity against LNCaP cells, where potent molecules possess two substituted/unsubstituted aromatic rings connected through a sulfonamide linker. These novel compounds are strong candidates for development for the treatment of hormone-sensitive and importantly hormone-refractory prostate cancers in humans. PMID:18316193

  17. Potent anti-prostate cancer agents derived from a novel androgen receptor down-regulating agent.

    PubMed

    Purushottamachar, Puranik; Khandelwal, Aakanksha; Vasaitis, Tadas S; Bruno, Robert D; Gediya, Lalji K; Njar, Vincent C O

    2008-04-01

    The search for novel androgen receptor (AR) down-regulating agents by catalyst HipHop pharmacophore modeling led to the discovery of some lead molecules. Unexpectedly, the effect of these leads on human prostate cancer LNCaP cell viability did not correlate with the ability of the compounds to cause down-regulation of AR protein expression. Through rational synthetic optimization of the lead compound (BTB01434), we have discovered a series of novel substituted diaryl molecules as potent anti-prostate cancer agents. Some compounds (1-6) were shown to be extremely potent inhibitors of LNCaP cell viability with GI(50) values in the nanomolar range (1.45-83 nM). The most potent compound (4-methylphenyl)[(4-methylphenyl)sulfonyl]amine (5) with a GI(50) value of 1.45 nM is 27,000 times more potent than our lead compound BTB01434 (GI(50)=39.8 microM). In addition, some of the compounds exhibited modest anti-androgenic activities and one was also a potent inhibitor (GI(50)=850 nM) of PC-3 (AR-null) cell growth. A clear structure-activity relationship (SAR) has been established for activity against LNCaP cells, where potent molecules possess two substituted/unsubstituted aromatic rings connected through a sulfonamide linker. These novel compounds are strong candidates for development for the treatment of hormone-sensitive and importantly hormone-refractory prostate cancers in humans.

  18. 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.

  19. Androgen deprivation therapy sensitizes prostate cancer cells to T-cell killing through androgen receptor dependent modulation of the apoptotic pathway.

    PubMed

    Ardiani, Andressa; Gameiro, Sofia R; Kwilas, Anna R; Donahue, Renee N; Hodge, James W

    2014-10-15

    Despite recent advances in diagnosis and management, prostrate cancer remains the second most common cause of death from cancer in American men, after lung cancer. Failure of chemotherapies and hormone-deprivation therapies is the major cause of death in patients with castration-resistant prostate cancer (CRPC). Currently, the androgen inhibitors enzalutamide and abiraterone are approved for treatment of metastatic CRPC. Here we show for the first time that both enzalutamide and abiraterone render prostate tumor cells more sensitive to T cell-mediated lysis through immunogenic modulation, and that these immunomodulatory activities are androgen receptor (AR)-dependent. In studies reported here, the NAIP gene was significantly down-regulated in human prostate tumor cells treated in vitro and in vivo with enzalutamide. Functional analysis revealed that NAIP played a critical role in inducing CTL sensitivity. Amplification of AR is a major mechanism of resistance to androgen-deprivation therapy (ADT). Here, we show that enzalutamide enhances sensitivity to immune-mediated killing of prostate tumor cells that overexpress AR. The immunomodulatory properties of enzalutamide and abiraterone provide a rationale for their use in combination with immunotherapeutic agents in CRPC, especially for patients with minimal response to enzalutamide or abiraterone alone, or for patients who have developed resistance to ADT. PMID:25344864

  20. Bypass Mechanisms of the Androgen Receptor Pathway in Therapy-Resistant Prostate Cancer Cell Models

    PubMed Central

    Marques, Rute B.; Dits, Natasja F.; Erkens-Schulze, Sigrun; van Weerden, Wytske M.; Jenster, Guido

    2010-01-01

    Background Prostate cancer is initially dependent on androgens for survival and growth, making hormonal therapy the cornerstone treatment for late-stage tumors. However, despite initial remission, the cancer will inevitably recur. The present study was designed to investigate how androgen-dependent prostate cancer cells eventually survive and resume growth under androgen-deprived and antiandrogen supplemented conditions. As model system, we used the androgen-responsive PC346C cell line and its therapy-resistant sublines: PC346DCC, PC346Flu1 and PC346Flu2. Methodology/Principal Findings Microarray technology was used to analyze differences in gene expression between the androgen-responsive and therapy-resistant PC346 cell lines. Microarray analysis revealed 487 transcripts differentially-expressed between the androgen-responsive and the therapy-resistant cell lines. Most of these genes were common to all three therapy-resistant sublines and only a minority (∼5%) was androgen-regulated. Pathway analysis revealed enrichment in functions involving cellular movement, cell growth and cell death, as well as association with cancer and reproductive system disease. PC346DCC expressed residual levels of androgen receptor (AR) and showed significant down-regulation of androgen-regulated genes (p-value = 10−7). Up-regulation of VAV3 and TWIST1 oncogenes and repression of the DKK3 tumor-suppressor was observed in PC346DCC, suggesting a potential AR bypass mechanism. Subsequent validation of these three genes in patient samples confirmed that expression was deregulated during prostate cancer progression. Conclusions/Significance Therapy-resistant growth may result from adaptations in the AR pathway, but androgen-independence may also be achieved by alternative survival mechanisms. Here we identified TWIST1, VAV3 and DKK3 as potential players in the bypassing of the AR pathway, making them good candidates as biomarkers and novel therapeutical targets. PMID:20976069

  1. Androgen-activating enzymes in the central nervous system.

    PubMed

    Poletti, A; Martini, L

    1999-01-01

    In the rat brain, several steroids can be converted by specific enzymes to either more potent compounds or to derivatives showing new biological effects. One of the most studied enzyme is the 5alpha-reductase (5alpha-R), which acts on 3keto-delta4 steroids. In males, testosterone is the main substrate and gives rise to the most potent natural androgen dihydrotestosterone. In females, progesterone is reduced to dihydroprogesterone, a precursor of allopregnanolone, a natural anxiolytic/anesthetic steroid. Other substrates are some gluco- and minero-corticoids. Two isoforms of the 5alpha-R, with limited degree of homology, have been cloned: 5alpha-R type 1 and type 2. The 5alpha-R type 1 possesses low affinity for the various substrates and is widely distributed in the body, with the highest levels in the liver; in the brain, this isoform is expressed throughout life and does not appear to be controlled by androgens. 5Alpha-R type 1 in the rat brain is mainly concentrated in myelin membranes, where it might be involved in the catabolism of potentially neurotoxic steroids. The 5alpha-R type 2 shows high affinity for the various substrates, a peculiar pH optimum at acidic values and is localized in androgen-dependent structures. In the rat brain, the type 2 isoform is expressed at high levels only in the perinatal period and is controlled by androgens, at least in males. In adulthood, the type 2 gene appears to be specifically expressed in localised brain regions, like the hypothalamus and the hippocampus. The 5alpha-R type 2 is present in the GT1 cells, a model of LHRH-secreting neurons. These cells also contain the androgen receptor, which is probably involved in the central negative feedback effect exerted by androgens on the hypothalamic-pituitary-gonadal axis. The physiological significance of these and additional data will be discussed.

  2. The androgen receptor has no direct antiresorptive actions in mouse osteoclasts.

    PubMed

    Sinnesael, Mieke; Jardi, Ferran; Deboel, Ludo; Laurent, Michaël R; Dubois, Vanessa; Zajac, Jeffrey D; Davey, Rachel A; Carmeliet, Geert; Claessens, Frank; Vanderschueren, Dirk

    2015-08-15

    Androgen deficiency or androgen receptor knockout (ARKO) causes high-turnover osteopenia, but the target cells for this effect remain unclear. To examine whether AR in osteoclasts directly suppresses bone resorption, we crossed AR-floxed with cathepsin K-Cre mice. Osteoclast-specific ARKO (ocl-ARKO) mice showed no changes neither in osteoclast surface nor in bone microarchitecture nor in the response to orchidectomy and androgen replacement, indicating that the AR in osteoclasts is not critical for bone maintenance. In line with the lack of a bone phenotype, the levels of AR were very low in osteoclast-enriched cultures derived from bone marrow (BM) and undetectable in osteoclasts generated from spleen precursors. Since tibiae of ubiquitous ARKO mice displayed increased osteoclast counts, the role of AR was further explored using cell cultures from these animals. Osteoclast generation and activity in vitro were similar between ARKO and wildtype control (WT) mice. In co-culture experiments, BM stromal cells (BMSCs) were essential for the suppressive action of AR on osteoclastogenesis and osteoclast activity. Stimulation with 1,25(OH)2 vitamin D3 increased Rankl and decreased Tnfsf11 (osteoprotegerin, Opg) gene expression in BMSCs more than in osteoblasts. This increase in the Rankl/Opg ratio following 1,25(OH)2D3 stimulation was lower, not higher, in ARKO mice. Runx2 expression in BMSCs was however higher in ARKO vs. WT, suggesting that ARKO mice may more readily commit osteoprogenitor cells to osteoblastogenesis. In conclusion, the AR does not seem to suppress bone resorption through direct actions in osteoclasts. BMSCs may however represent an alternative AR target in the BM milieu.

  3. Mutation of androgen receptor N-terminal phosphorylation site Tyr-267 leads to inhibition of nuclear translocation and DNA binding.

    PubMed

    Karaca, Mehmet; Liu, Yuanbo; Zhang, Zhentao; De Silva, Dinuka; Parker, Joel S; Earp, H Shelton; Whang, Young E

    2015-01-01

    Reactivation of androgen receptor (AR) may drive recurrent prostate cancer in castrate patients. Ack1 tyrosine kinase is overexpressed in prostate cancer and promotes castrate resistant xenograft tumor growth and enhances androgen target gene expression and AR recruitment to enhancers. Ack1 phosphorylates AR at Tyr-267 and possibly Tyr-363, both in the N-terminal transactivation domain. In this study, the role of these phosphorylation sites was investigated by characterizing the phosphorylation site mutants in the context of full length and truncated AR lacking the ligand-binding domain. Y267F and Y363F mutants showed decreased transactivation of reporters. Expression of wild type full length and truncated AR in LNCaP cells increased cell proliferation in androgen-depleted conditions and increased colony formation. However, the Y267F mutant of full length and truncated AR was defective in stimulating cell proliferation. The Y363F mutant was less severely affected than the Y267F mutant. The full length AR Y267F mutant was defective in nuclear translocation induced by androgen or Ack1 kinase. The truncated AR was constitutively localized to the nucleus. Chromatin immunoprecipitation analysis showed that it was recruited to the target enhancers without androgen. The truncated Y267F AR mutant did not exhibit constitutive nuclear localization and androgen enhancer binding activity. These results support the concept that phosphorylation of Tyr-267, and to a lesser extent Tyr-363, is required for AR nuclear translocation and recruitment and DNA binding and provide a rationale for development of novel approaches to inhibit AR activity.

  4. Human sex hormone-binding globulin binding affinities of 125 structurally diverse chemicals and comparison with their binding to androgen receptor, estrogen receptor, and α-fetoprotein.

    PubMed

    Hong, Huixiao; Branham, William S; Ng, Hui Wen; Moland, Carrie L; Dial, Stacey L; Fang, Hong; Perkins, Roger; Sheehan, Daniel; Tong, Weida

    2015-02-01

    One endocrine disruption mechanism is through binding to nuclear receptors such as the androgen receptor (AR) and estrogen receptor (ER) in target cells. The concentration of a chemical in serum is important for its entry into the target cells to bind the receptors, which is regulated by the serum proteins. Human sex hormone-binding globulin (SHBG) is the major transport protein in serum that can bind androgens and estrogens and thus change a chemical's availability to enter the target cells. Sequestration of an androgen or estrogen in the serum can alter the chemical elicited AR- and ER-mediated responses. To better understand the chemical-induced endocrine activity, we developed a competitive binding assay using human pregnancy plasma and measured the binding to the human SHBG for 125 structurally diverse chemicals, most of which were known to bind AR and ER. Eighty seven chemicals were able to bind the human SHBG in the assay, whereas 38 chemicals were nonbinders. Binding data for human SHBG are compared with that for rat α-fetoprotein, ER and AR. Knowing the binding profiles between serum and nuclear receptors will improve assessment of a chemical's potential for endocrine disruption. The SHBG binding data reported here represent the largest data set of structurally diverse chemicals tested for human SHBG binding. Utilization of the SHBG binding data with AR and ER binding data could enable better evaluation of endocrine disrupting potential of chemicals through AR- and ER-mediated responses since sequestration in serum could be considered.

  5. Similarities and Distinctions in Actions of Surface-Directed and Classic Androgen Receptor Antagonists.

    PubMed

    Suh, Ji Ho; Chattopadhyay, Arundhati; Sieglaff, Douglas H; Storer Samaniego, Cheryl; Cox, Marc B; Webb, Paul

    2015-01-01

    The androgen receptor (AR) surface-directed antagonist MJC13 inhibits AR function and proliferation of prostate cancer (PC) cells. These effects are related to arrest of an AR/chaperone complex in the cytoplasm. Here, we compared MJC13 and classic AR antagonists such as flutamide and bicalutamide. Microarray analysis and confirmatory qRT-PCR reveals that MJC13 and flutamide inhibit dihydrotestosterone (DHT)-dependent genes in LNCaP PC cells. Both compounds are equally effective on a genome wide basis and as effective as second generation AR antagonists (MDV3100, ARN-509) at selected genes. MJC13 inhibits AR binding to the prostate specific antigen (PSA) promoter more strongly than flutamide, consistent with different mechanisms of action. Examination of efficacy of MJC13 in conditions that reflect aspects castrate resistant prostate cancer (CRPC) reveals that it inhibits flutamide activation of an AR mutant (ART877A) that emerges during flutamide withdrawal syndrome, but displays greatly restricted gene-specific activity in 22Rv1 cells that express a constitutively active truncated AR and is inactive against glucocorticoid receptor (GR), which can co-opt androgen-dependent signaling networks in CRPC. Importantly, MJC13 inhibits AR interactions with SRC2 and β-catenin in the nucleus and, unlike flutamide, strongly inhibits amplification of AR activity obtained with transfected SRC2 and β-catenin. MJC13 also inhibits DHT and β-catenin-enhanced cell division in LNCaP cells. Thus, a surface-directed antagonist can block AR activity in some conditions in which a classic antagonist fails and may display utility in particular forms of CRPC.

  6. Linking ligand-induced alterations in androgen receptor structure to differential gene expression: a first step in the rational design of selective androgen receptor modulators.

    PubMed

    Kazmin, Dmitri; Prytkova, Tatiana; Cook, C Edgar; Wolfinger, Russell; Chu, Tzu-Ming; Beratan, David; Norris, J D; Chang, Ching-yi; McDonnell, Donald P

    2006-06-01

    We have previously identified a family of novel androgen receptor (AR) ligands that, upon binding, enable AR to adopt structures distinct from that observed in the presence of canonical agonists. In this report, we describe the use of these compounds to establish a relationship between AR structure and biological activity with a view to defining a rational approach with which to identify useful selective AR modulators. To this end, we used combinatorial peptide phage display coupled with molecular dynamic structure analysis to identify the surfaces on AR that are exposed specifically in the presence of selected AR ligands. Subsequently, we used a DNA microarray analysis to demonstrate that differently conformed receptors facilitate distinct patterns of gene expression in LNCaP cells. Interestingly, we observed a complete overlap in the identity of genes expressed after treatment with mechanistically distinct AR ligands. However, it was differences in the kinetics of gene regulation that distinguished these compounds. Follow-up studies, in cell-based assays of AR action, confirmed the importance of these alterations in gene expression. Together, these studies demonstrate an important link between AR structure, gene expression, and biological outcome. This relationship provides a firm underpinning for mechanism-based screens aimed at identifying SARMs with useful clinical profiles.

  7. CACUL1 functions as a negative regulator of androgen receptor in prostate cancer cells.

    PubMed

    Choi, Hanbyeul; Lee, Sang Hyup; Um, Soo-Jong; Kim, Eun-Joo

    2016-07-01

    The androgen receptor (AR) plays a critical role in the initiation and progression of prostate cancer (PCa), and thus its regulation is an important tool in PCa therapy. Here, we report that CDK2-associated cullin 1 (CACUL1) directly associates with AR and suppresses AR transcriptional activity. In addition, CACUL1 represses histone demethylase LSD1-mediated AR transactivation by competing with LSD1 for AR binding. Depletion of CACUL1 enhances the LSD1 occupancy of the AR-target promoter, accompanied by decreased accumulation of H3K9me2, a repressive transcriptional marker. CACUL1 and LSD1 oppositely regulate CDX-induced cell death in AR-positive LNCaP and metastatic castrate-resistant LNCaP-LN3 cells. These data suggest that CACUL1 impairs LSD1-mediated activation of AR, thereby implicating it as a potential antitumor target in PCa. PMID:27085459

  8. A pp32-retinoblastoma protein complex modulates androgen receptor-mediated transcription and associates with components of the splicing machinery

    SciTech Connect

    Adegbola, Onikepe; Pasternack, Gary R. . E-mail: gpastern@jhmi.edu

    2005-08-26

    We have previously shown pp32 and the retinoblastoma protein interact. pp32 and the retinoblastoma protein are nuclear receptor transcriptional coregulators: the retinoblastoma protein is a coactivator for androgen receptor, the major regulator of prostate cancer growth, while pp32, which is highly expressed in prostate cancer, is a corepressor of the estrogen receptor. We now show pp32 increases androgen receptor-mediated transcription and the retinoblastoma protein modulates this activity. Using affinity purification and mass spectrometry, we identify members of the pp32-retinoblastoma protein complex as PSF and nonO/p54nrb, proteins implicated in coordinate regulation of nuclear receptor-mediated transcription and splicing. We show that the pp32-retinoblastoma protein complex is modulated during TPA-induced K562 differentiation. Present evidence suggests that nuclear receptors assemble multiprotein complexes to coordinately regulate transcription and mRNA processing. Our results suggest that pp32 and the retinoblastoma protein may be part of a multiprotein complex that coordinately regulates nuclear receptor-mediated transcription and mRNA processing.

  9. Interaction of organophosphate pesticides and related compounds with the androgen receptor.

    PubMed Central

    Tamura, Hiroto; Yoshikawa, Hiromichi; Gaido, Kevin W; Ross, Susan M; DeLisle, Robert K; Welsh, William J; Richard, Ann M

    2003-01-01

    Identification of several environmental chemicals capable of binding to the androgen receptor (AR) and interfering with its normal function has heightened concern about adverse effects across a broad spectrum of environmental chemicals. We previously demonstrated AR antagonist activity of the organophosphate (OP) pesticide fenitrothion. In this study, we characterized AR activity of analogues of fenitrothion to probe the structural requirements for AR activity among related chemicals. AR activity was measured using HepG2 human hepatoma cells transfected with human AR plus an androgen-responsive luciferase reporter gene, MMTV-luc. AR antagonist activity decreased as alkyl chain length of the phosphoester increased, whereas electron-donating properties of phenyl substituents of the tested compounds did not influence AR activity. Oxon derivatives of fenitrothion, which are more likely to undergo hydrolytic degradation, had no detectable AR antagonist activity. Molecular modeling results suggest that hydrogen-bond energies and the maximum achievable interatomic distance between two terminal H-bond capable sites may influence both the potential to interact with the AR and the nature of the interaction (agonist vs. antagonist) within this series of chemicals. This hypothesis is supported by the results of recent AR homology modeling and crystallographic studies relative to agonist- and antagonist-bound AR complexes. The present results are placed in the context of structure-activity knowledge derived from previous modeling studies as well as studies aimed toward designing nonsteroidal antiandrogen pharmaceuticals. Present results extend understanding of the structural requirements for AR activity to a new class of nonsteroidal, environmental, OP-related chemicals. PMID:12676613

  10. Minireview: The Androgen Receptor in Breast Tissues: Growth Inhibitor, Tumor Suppressor, Oncogene?

    PubMed Central

    Hickey, T. E.; Robinson, J. L. L.; Carroll, J. S.

    2012-01-01

    Androgen receptor (AR) signaling exerts an antiestrogenic, growth-inhibitory influence in normal breast tissue, and this role may be sustained in estrogen receptor α (ERα)-positive luminal breast cancers. Conversely, AR signaling may promote growth of a subset of ERα-negative, AR-positive breast cancers with a molecular apocrine phenotype. Understanding the molecular mechanisms whereby androgens can elicit distinct gene expression programs and opposing proliferative responses in these two breast cancer phenotypes is critical to the development of new therapeutic strategies to target the AR in breast cancer. PMID:22745190

  11. SUMO ligase PIAS1 functions as a target gene selective androgen receptor coregulator on prostate cancer cell chromatin

    PubMed Central

    Toropainen, Sari; Malinen, Marjo; Kaikkonen, Sanna; Rytinki, Miia; Jääskeläinen, Tiina; Sahu, Biswajyoti; Jänne, Olli A.; Palvimo, Jorma J.

    2015-01-01

    Androgen receptor (AR) is a ligand-activated transcription factor that plays a central role in the development and growth of prostate carcinoma. PIAS1 is an AR- and SUMO-interacting protein and a putative transcriptional coregulator overexpressed in prostate cancer. To study the importance of PIAS1 for the androgen-regulated transcriptome of VCaP prostate cancer cells, we silenced its expression by RNAi. Transcriptome analyses revealed that a subset of the AR-regulated genes is significantly influenced, either activated or repressed, by PIAS1 depletion. Interestingly, PIAS1 depletion also exposed a new set of genes to androgen regulation, suggesting that PIAS1 can mask distinct genomic loci from AR access. In keeping with gene expression data, silencing of PIAS1 attenuated VCaP cell proliferation. ChIP-seq analyses showed that PIAS1 interacts with AR at chromatin sites harboring also SUMO2/3 and surrounded by H3K4me2; androgen exposure increased the number of PIAS1-occupying sites, resulting in nearly complete overlap with AR chromatin binding events. PIAS1 interacted also with the pioneer factor FOXA1. Of note, PIAS1 depletion affected AR chromatin occupancy at binding sites enriched for HOXD13 and GATA motifs. Taken together, PIAS1 is a genuine chromatin-bound AR coregulator that functions in a target gene selective fashion to regulate prostate cancer cell growth. PMID:25552417

  12. Immunohistochemical localization of androgen and progesterone receptors in the uterus of the camel (Camelus dromedarius).

    PubMed

    Emam, Mahmoud Abdelghaffar

    2014-10-01

    Ten adult, cyclic female camels (Camelus dromedarius) were used to describe the distribution of androgen (AR) and progesterone (PR) receptors in the uterus using immunohistochemistry. Both AR and PR were distributed throughout the different compartments of the uterus with nuclear staining for AR and PR seen in the cells of epithelia (luminal and glandular), stroma and myometrial smooth muscles. AR immunostaining was not uniform in distribution and intensity; the surface epithelium and the glandular epithelium in the adluminal region of the endometrium showed lower AR immunoreactivity than other compartments of the uterus. PR immunostaining showed uniformity in both distribution and intensity strong PR immunostaining intensity in almost all cells of the different uterine compartments. The intensity and distribution of PR immunostaining in epithelia of lumen and glands in the adluminal regions of endometrium was higher (P<0.05) than that of AR. In conclusion, immunohistochemical localization of AR and PR in the uterus of the cyclic dromedary camel indicates the important roles of androgen and progesterone in controlling the uterine activity during the follicular phase.

  13. Androgen receptor gene polymorphisms lean mass and performance in young men.

    PubMed

    Guadalupe-Grau, Amelia; Rodríguez-González, F Germán; Dorado, Cecilia; Olmedillas, Hugo; Fuentes, Teresa; Pérez-Gómez, Jorge; Delgado-Guerra, Safira; Vicente-Rodríguez, Germán; Ara, Ignacio; Guerra, Borja; Arteaga-Ortiz, Rafael; Calbet, José A L; Díaz-Chico, B Nicolás

    2011-02-01

    The exon-1 of the androgen receptor (AR) gene contains two repeat length polymorphisms which modify either the amount of AR protein inside the cell (GGN(n), polyglycine) or its transcriptional activity (CAG(n), polyglutamine). Shorter CAG and/or GGN repeats provide stronger androgen signalling and vice versa. To test the hypothesis that CAG and GGN repeat AR polymorphisms affect muscle mass and various variables of muscular strength phenotype traits, the length of CAG and GGN repeats was determined by PCR and fragment analysis and confirmed by DNA sequencing of selected samples in 282 men (28.6 ± 7.6 years). Individuals were grouped as CAG short (CAG(S)) if harbouring repeat lengths of ≤ 21 and CAG long (CAG(L)) if CAG >21. GGN was considered short (GGN(S)) or long (GGN(L)) if GGN ≤ 23 or >23, respectively. No significant differences in lean body mass or fitness were observed between the CAG(S) and CAG(L) groups, or between GGN(S) and GGN(L) groups, but a trend for a correlation was found for the GGN repeat and lean mass of the extremities (r=-0.11, p=0.06). In summary, the lengths of CAG and GGN repeat of the AR gene do not appear to influence lean mass or fitness in young men.

  14. Immunohistochemical localization of androgen and progesterone receptors in the uterus of the camel (Camelus dromedarius).

    PubMed

    Emam, Mahmoud Abdelghaffar

    2014-10-01

    Ten adult, cyclic female camels (Camelus dromedarius) were used to describe the distribution of androgen (AR) and progesterone (PR) receptors in the uterus using immunohistochemistry. Both AR and PR were distributed throughout the different compartments of the uterus with nuclear staining for AR and PR seen in the cells of epithelia (luminal and glandular), stroma and myometrial smooth muscles. AR immunostaining was not uniform in distribution and intensity; the surface epithelium and the glandular epithelium in the adluminal region of the endometrium showed lower AR immunoreactivity than other compartments of the uterus. PR immunostaining showed uniformity in both distribution and intensity strong PR immunostaining intensity in almost all cells of the different uterine compartments. The intensity and distribution of PR immunostaining in epithelia of lumen and glands in the adluminal regions of endometrium was higher (P<0.05) than that of AR. In conclusion, immunohistochemical localization of AR and PR in the uterus of the cyclic dromedary camel indicates the important roles of androgen and progesterone in controlling the uterine activity during the follicular phase. PMID:25081941

  15. Non-Cell-Autonomous Regulation of Prostate Epithelial Homeostasis by Androgen Receptor.

    PubMed

    Zhang, Boyu; Kwon, Oh-Joon; Henry, Gervaise; Malewska, Alicia; Wei, Xing; Zhang, Li; Brinkley, William; Zhang, Yiqun; Castro, Patricia D; Titus, Mark; Chen, Rui; Sayeeduddin, Mohammad; Raj, Ganesh V; Mauck, Ryan; Roehrborn, Claus; Creighton, Chad J; Strand, Douglas W; Ittmann, Michael M; Xin, Li

    2016-09-15

    Prostate inflammation has been suggested as an etiology for benign prostatic hyperplasia (BPH). We show that decreased expression of the androgen receptor (AR) in luminal cells of human BPH specimens correlates with a higher degree of regional prostatic inflammation. However, the cause-and-effect relationship between the two events remains unclear. We investigated specifically whether attenuating AR activity in prostate luminal cells induces inflammation. Disrupting luminal cell AR signaling in mouse models promotes cytokine production cell-autonomously, impairs epithelial barrier function, and induces immune cell infiltration, which further augments local production of cytokines and chemokines including Il-1 and Ccl2. This inflammatory microenvironment promotes AR-independent prostatic epithelial proliferation, which can be abolished by ablating IL-1 signaling or depleting its major cellular source, the macrophages. This study demonstrates that disrupting luminal AR signaling promotes prostate inflammation, which may serve as a mechanism for resistance to androgen-targeted therapy for prostate-related diseases. PMID:27594448

  16. Hormone stimulation of androgen receptor mediates dynamic changes in DNA methylation patterns at regulatory elements

    PubMed Central

    Dhiman, Vineet K.; Attwood, Kristopher; Campbell, Moray J.; Smiraglia, Dominic J.

    2015-01-01

    DNA methylation is an epigenetic modification that contributes to stable gene silencing by interfering with the ability of transcriptional regulators to bind to DNA. Recent findings have revealed that hormone stimulation of certain nuclear receptors induces rapid, dynamic changes in DNA methylation patterns alongside transcriptional responses at a subset of target loci, over time. However, the ability of androgen receptor (AR) to dynamically regulate gene transcription is relatively under-studied and its role in the regulation of DNA methylation patterns remains to be elucidated. Here we demonstrate in normal prostate cells that hormone stimulated AR activity results in dynamic changes in the transcription rate and DNA methylation patterns at the AR target genes, TIPARP and SGK1. Time-resolved chromatin immunoprecipitation experiments on the SGK1 locus reveals dynamic recruitment of AR and RNA Polymerase II, as well as the recruitment of proteins involved in the DNA demethylation process, TET1 and TDG. Furthermore, the presence of DNA methylation at dynamic regions inhibits protein binding and transcriptional activity of SGK1. These findings establish AR activity as a contributing factor to the dynamic regulation of DNA methylation patterns at target genes in prostate biology and infer further complexity involved in nuclear receptor mediation of transcriptional regulation. PMID:26646795

  17. Differential expression of androgen, estrogen, and progesterone receptors in benign prostatic hyperplasia

    PubMed Central

    Song, Lingmin; Shen, Wenhao; Zhang, Heng; Wang, Qiwu; Wang, Yongquan; Zhou, Zhansong

    2016-01-01

    This study aimed to identify the differential expression levels of androgen receptor (AR), estrogen receptors (ERα, ERβ), and progesterone receptor (PGR) between normal prostate and benign prostatic hyperplasia (BPH). The combination of immunohistochemistry, quantitative real-time reverse transcription polymerase chain reaction, and Western blotting assay was used to identify the distribution and differential expression of these receptors at the immunoactive biomarker, transcriptional, and protein levels between 5 normal human prostate tissues and 40 BPH tissues. The results were then validated in a rat model of BPH induced by testosterone propionate and estradiol benzoate. In both human and rat prostate tissues, AR was localized mainly to epithelial and stromal cell nuclei; ERα was distributed mainly to stromal cells, but not exclusively; ERβ was interspersed in the basal layer of epithelium, but sporadically in epithelial and stromal cells; PGR was expressed abundantly in cytoplasm of epithelial and stromal cells. There were decreased expression of ERα and increased expression of PGR, but no difference in the expression of ERβ in the BPH compared to the normal prostate of both human and rat. Increased expression of AR in the BPH compared to the normal prostate of human was observed, however, the expression of AR in the rat prostate tissue was decreased. This study identified the activation of AR and PGR and repression of ERα in BPH, which indicate a promoting role of AR and PGR and an inhibitory role of ERα in the pathogenesis of BPH.

  18. Differential expression of androgen, estrogen, and progesterone receptors in benign prostatic hyperplasia.

    PubMed

    Song, Lingmin; Shen, Wenhao; Zhang, Heng; Wang, Qiwu; Wang, Yongquan; Zhou, Zhansong

    2016-07-01

    This study aimed to identify the differential expression levels of androgen receptor (AR), estrogen receptors (ERα, ERβ), and progesterone receptor (PGR) between normal prostate and benign prostatic hyperplasia (BPH). The combination of immunohistochemistry, quantitative real-time reverse transcription polymerase chain reaction, and Western blotting assay was used to identify the distribution and differential expression of these receptors at the immunoactive biomarker, transcriptional, and protein levels between 5 normal human prostate tissues and 40 BPH tissues. The results were then validated in a rat model of BPH induced by testosterone propionate and estradiol benzoate. In both human and rat prostate tissues, AR was localized mainly to epithelial and stromal cell nuclei; ERα was distributed mainly to stromal cells, but not exclusively; ERβ was interspersed in the basal layer of epithelium, but sporadically in epithelial and stromal cells; PGR was expressed abundantly in cytoplasm of epithelial and stromal cells. There were decreased expression of ERα and increased expression of PGR, but no difference in the expression of ERβ in the BPH compared to the normal prostate of both human and rat. Increased expression of AR in the BPH compared to the normal prostate of human was observed, however, the expression of AR in the rat prostate tissue was decreased. This study identified the activation of AR and PGR and repression of ERα in BPH, which indicate a promoting role of AR and PGR and an inhibitory role of ERα in the pathogenesis of BPH. PMID:27483178

  19. 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

  20. Selectively Targeting the DNA-binding Domain of the Androgen Receptor as a Prospective Therapy for Prostate Cancer*

    PubMed Central

    Dalal, Kush; Roshan-Moniri, Mani; Sharma, Aishwariya; Li, Huifang; Ban, Fuqiang; Hessein, Mohamed; Hsing, Michael; Singh, Kriti; LeBlanc, Eric; Dehm, Scott; Tomlinson Guns, Emma S.; Cherkasov, Artem; Rennie, Paul S.

    2014-01-01

    The androgen receptor (AR) is a transcription factor that has a pivotal role in the occurrence and progression of prostate cancer. The AR is activated by androgens that bind to its ligand-binding domain (LBD), causing the transcription factor to enter the nucleus and interact with genes via its conserved DNA-binding domain (DBD). Treatment for prostate cancer involves reducing androgen production or using anti-androgen drugs to block the interaction of hormones with the AR-LBD. Eventually the disease changes into a castration-resistant form of PCa where LBD mutations render anti-androgens ineffective or where constitutively active AR splice variants, lacking the LBD, become overexpressed. Recently, we identified a surfaced exposed pocket on the AR-DBD as an alternative drug-target site for AR inhibition. Here, we demonstrate that small molecules designed to selectively bind the pocket effectively block transcriptional activity of full-length and splice variant AR forms at low to sub-micromolar concentrations. The inhibition is lost when residues involved in drug interactions are mutated. Furthermore, the compounds did not impede nuclear localization of the AR and blocked interactions with chromatin, indicating the interference of DNA binding with the nuclear form of the transcription factor. Finally, we demonstrate the inhibition of gene expression and tumor volume in mouse xenografts. Our results indicate that the AR-DBD has a surface site that can be targeted to inhibit all forms of the AR, including enzalutamide-resistant and constitutively active splice variants and thus may serve as a potential avenue for the treatment of recurrent and metastatic prostate cancer. PMID:25086042

  1. Androgen Receptor Coactivator ARID4B Is Required for the Function of Sertoli Cells in Spermatogenesis

    PubMed Central

    Zeng, Yang; Pan, I-Wen

    2015-01-01

    Defects in spermatogenesis, a process that produces spermatozoa inside seminiferous tubules of the testis, result in male infertility. Spermatogenic progression is highly dependent on a microenvironment provided by Sertoli cells, the only somatic cells and epithelium of seminiferous tubules. However, genes that regulate such an important activity of Sertoli cells are poorly understood. Here, we found that AT-rich interactive domain 4B (ARID4B), is essential for the function of Sertoli cells to regulate spermatogenesis. Specifically, we generated Sertoli cell-specific Arid4b knockout (Arid4bSCKO) mice, and showed that the Arid4bSCKO male mice were completely infertile with impaired testis development and significantly reduced testis size. Importantly, severe structural defects accompanied by loss of germ cells and Sertoli cell-only phenotype were found in many seminiferous tubules of the Arid4bSCKO testes. In addition, maturation of Sertoli cells was significantly delayed in the Arid4bSCKO mice, associated with delayed onset of spermatogenesis. Spermatogenic progression was also defective, showing an arrest at the round spermatid stage in the Arid4bSCKO testes. Interestingly, we showed that ARID4B functions as a “coactivator” of androgen receptor and is required for optimal transcriptional activation of reproductive homeobox 5, an androgen receptor target gene specifically expressed in Sertoli cells and critical for spermatogenesis. Together, our study identified ARID4B to be a key regulator of Sertoli cell function important for male germ cell development. PMID:26258622

  2. Identification of a Novel Coregulator, SH3YL1, That Interacts With the Androgen Receptor N-Terminus

    PubMed Central

    Blessing, Alicia M.; Ganesan, Sathya; Rajapakshe, Kimal; Ying Sung, Ying; Reddy Bollu, Lakshmi; Shi, Yan; Cheung, Edwin; Coarfa, Cristian; Chang, Jeffrey T.; McDonnell, Donald P.

    2015-01-01

    Nuclear receptor (NR)-mediated transcriptional activity is a dynamic process that is regulated by the binding of ligands that induce distinct conformational changes in the NR. These structural alterations lead to the differential recruitment of coregulators (coactivators or corepressors) that control the expression of NR-regulated genes. Here, we show that a stretch of proline residues located within the N-terminus of androgen receptor (AR) is a bona fide coregulator binding surface, the disruption of which reduces the androgen-dependent proliferation and migration of prostate cancer (PCa) cells. Using T7 phage display, we identified a novel AR-interacting protein, Src homology 3 (SH3)-domain containing, Ysc84-like 1 (SH3YL1), whose interaction with the receptor is dependent upon this polyproline domain. As with mutations within the AR polyproline domain, knockdown of SH3YL1 attenuated androgen-mediated cell growth and migration. RNA expression analysis revealed that SH3YL1 was required for the induction of a subset of AR-modulated genes. Notable was the observation that ubinuclein 1 (UBN1), a key member of a histone H3.3 chaperone complex, was a transcriptional target of the AR/SH3YL1 complex, correlated with aggressive PCa in patients, and was necessary for the maximal androgen-mediated proliferation and migration of PCa cells. Collectively, these data highlight the importance of an amino-terminal activation domain, its associated coregulator, and downstream transcriptional targets in regulating cellular processes of pathological importance in PCa. PMID:26305679

  3. The Safety, Pharmacokinetics, and Effects of LGD-4033, a Novel Nonsteroidal Oral, Selective Androgen Receptor Modulator, in Healthy Young Men

    PubMed Central

    Basaria, Shehzad; Collins, Lauren; Dillon, E. Lichar; Orwoll, Katie; Storer, Thomas W.; Miciek, Renee; Ulloor, Jagadish; Zhang, Anqi; Eder, Richard; Zientek, Heather; Gordon, Gilad; Kazmi, Syed; Sheffield-Moore, Melinda

    2013-01-01

    Background. Concerns about potential adverse effects of testosterone on prostate have motivated the development of selective androgen receptor modulators that display tissue-selective activation of androgenic signaling. LGD-4033, a novel nonsteroidal, oral selective androgen receptor modulator, binds androgen receptor with high affinity and selectivity. Objectives. To evaluate the safety, tolerability, pharmacokinetics, and effects of ascending doses of LGD-4033 administered daily for 21 days on lean body mass, muscle strength, stair-climbing power, and sex hormones. Methods. In this placebo-controlled study, 76 healthy men (21–50 years) were randomized to placebo or 0.1, 0.3, or 1.0 mg LGD-4033 daily for 21 days. Blood counts, chemistries, lipids, prostate-specific antigen, electrocardiogram, hormones, lean and fat mass, and muscle strength were measured during and for 5 weeks after intervention. Results. LGD-4033 was well tolerated. There were no drug-related serious adverse events. Frequency of adverse events was similar between active and placebo groups. Hemoglobin, prostate-specific antigen, aspartate aminotransferase, alanine aminotransferase, or QT intervals did not change significantly at any dose. LGD-4033 had a long elimination half-life and dose-proportional accumulation upon multiple dosing. LGD-4033 administration was associated with dose-dependent suppression of total testosterone, sex hormone–binding globulin, high density lipoprotein cholesterol, and triglyceride levels. follicle-stimulating hormone and free testosterone showed significant suppression at 1.0-mg dose only. Lean body mass increased dose dependently, but fat mass did not change significantly. Hormone levels and lipids returned to baseline after treatment discontinuation. Conclusions. LGD-4033 was safe, had favorable pharmacokinetic profile, and increased lean body mass even during this short period without change in prostate-specific antigen. Longer randomized trials should

  4. Effect of B-ring substitution pattern on binding mode of propionamide selective androgen receptor modulators.

    PubMed

    Bohl, Casey E; Wu, Zengru; Chen, Jiyun; Mohler, Michael L; Yang, Jun; Hwang, Dong Jin; Mustafa, Suni; Miller, Duane D; Bell, Charles E; Dalton, James T

    2008-10-15

    Selective androgen receptor modulators (SARMs) are essentially prostate sparing androgens, which provide therapeutic potential in osteoporosis, male hormone replacement, and muscle wasting. Herein we report crystal structures of the androgen receptor (AR) ligand-binding domain (LBD) complexed to a series of potent synthetic nonsteroidal SARMs with a substituted pendant arene referred to as the B-ring. We found that hydrophilic B-ring para-substituted analogs exhibit an additional region of hydrogen bonding not seen with steroidal compounds and that multiple halogen substitutions affect the B-ring conformation and aromatic interactions with Trp741. This information elucidates interactions important for high AR binding affinity and provides new insight for structure-based drug design.

  5. Endostatin: A novel inhibitor of androgen receptor function in prostate cancer

    PubMed Central

    Lee, Joo Hyoung; Isayeva, Tatyana; Larson, Matthew R.; Sawant, Anandi; Cha, Ha-Ram; Chanda, Diptiman; Chesnokov, Igor N.; Ponnazhagan, Selvarangan

    2015-01-01

    Acquired resistance to androgen receptor (AR)-targeted therapies compels the development of novel treatment strategies for castration-resistant prostate cancer (CRPC). Here, we report a profound effect of endostatin on prostate cancer cells by efficient intracellular trafficking, direct interaction with AR, reduction of nuclear AR level, and down-regulation of AR-target gene transcription. Structural modeling followed by functional analyses further revealed that phenylalanine-rich α1-helix in endostatin—which shares structural similarity with noncanonical nuclear receptor box in AR—antagonizes AR transcriptional activity by occupying the activation function (AF)-2 binding interface for coactivators and N-terminal AR AF-1. Together, our data suggest that endostatin can be recognized as an endogenous AR inhibitor that impairs receptor function through protein–protein interaction. These findings provide new insights into endostatin whose antitumor effect is not limited to inhibiting angiogenesis, but can be translated to suppressing AR-mediated disease progression in CRPC. PMID:25605930

  6. Androgenic-anabolic activities of some new synthesized steroidal pyrane, pyridine and thiopyrimidine derivatives.

    PubMed

    Abdalla, Mohamed M; Amr, Abd El-Galil E; Al-Omar, Mohamed A; Hussain, Azza A; Amer, Mohamed S

    2014-01-01

    In continuation of our previous work, fused steroidal derivatives with pyrane, pyridine, pyrimidine moieties were synthesized and evaluated as androgenic-anabolic agents. Some of the newly synthesized compounds are exhibited pronounced androgenic-anabolic activities.

  7. Androgen receptors in a cichlid fish, Astatotilapia burtoni: structure, localization, and expression levels.

    PubMed

    Harbott, Lene K; Burmeister, Sabrina S; White, Richard B; Vagell, Mike; Fernald, Russell D

    2007-09-01

    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, ARalpha and ARbeta, 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. ARalpha was expressed in the ventral part of the ventral telencephalon, the preoptic area (POA) of the hypothalamus and the ventral hypothalamus, whereas ARbeta 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 ARalpha showing significantly higher expression than ARbeta in the pituitary, and ARbeta expressed at a higher level than ARalpha in the anterior and middle brain. These data provide important insight into the role of androgens in regulating the vertebrate reproductive axis.

  8. Estrogen receptor alpha and androgen receptor are commonly expressed in well-differentiated liposarcoma

    PubMed Central

    2014-01-01

    Background Liposarcoma (LS) is the second-most common type of soft-tissue sarcoma. Despite advances in knowledge and treatment of this disease, there remains a need for more effective LS therapy. Steroid hormone receptors regulate metabolism in adipocytes. Estrogen receptor alpha (ER), progesterone receptor (PR), and androgen receptor (AR) have been implicated in the pathophysiology of other cancer types. We sought to comprehensively determine temporal expression patterns of these receptors in LS. Methods We analyzed 561 histologically subtyped LS specimens from 354 patients for expression of ER, PR, and AR by immunohistochemistry (IHC) using diagnostic-grade reagents and protocols. The fractions of positively stained tumor cells were scored within each specimen. IHC scores were compared across LS subtypes using the Kruskal-Wallis test, and subtypes were compared using Dunn’s post-hoc test. Ages of patients with receptor-positive vs. -negative LS were compared by t-test. Genders and races were compared for hormone receptor positivity using Fisher’s exact test and Chi-square analysis, respectively. Recurrence-free survival was compared between receptor-positive and negative patients by log-rank test. p< 0.05 was considered significant. Results ER and AR were frequently expressed in LS, while few tumors expressed PR. Most of the ER + and AR + samples were of the well-differentiated LS subtype. A smaller fraction of de-differentiated LS expressed ER or AR, but expression was common within well-differentiated regions of tumors histologically classified as de-differentiated LS. In LS specimens from patients who underwent multiple surgeries over time, receptor expression frequently changed over time, which may be attributable in part to intratumor heterogeneity, varying degrees of de-differentiation, and biopsy bias. ER and AR were frequently co-expressed. Receptor status was not significantly associated with gender or race, but AR and PR expression were

  9. NKX3.1 Suppresses TMPRSS2-ERG Gene Rearrangement and Mediates Repair of Androgen Receptor-Induced DNA Damage

    PubMed Central

    Bowen, Cai; Zheng, Tian; Gelmann, Edward P.

    2015-01-01

    TMPRSS2 gene rearrangements occur at DNA breaks formed during androgen receptor-mediated transcription and activate expression of ETS transcription factors at the early stages of more than half of prostate cancers. NKX3.1, a prostate tumor suppressor that accelerates the DNA repair response, binds to androgen receptor at the ERG gene breakpoint and inhibits both the juxtaposition of the TMPRSS2 and ERG gene loci and also their recombination. NKX3.1 acts by accelerating DNA repair after androgen-induced transcriptional activation. NKX3.1 influences the recruitment of proteins that promote homology-directed DNA repair. Loss of NKX3.1 favors recruitment to the ERG gene breakpoint of proteins that promote error-prone nonhomologous end-joining. Analysis of prostate cancer tissues showed that the presence of a TMPRSS2-ERG rearrangement was highly correlated with lower levels of NKX3.1 expression consistent with the role of NKX3.1 as a suppressor of the pathogenic gene rearrangement. PMID:25977336

  10. 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.

  11. 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

  12. Tumoristatic effects of endostatin in prostate cancer is dependent on androgen receptor status

    PubMed Central

    Isayeva, Tatyana; Moore, Lakisha D.; Chanda, Diptiman; Chen, Dongquan; Ponnazhagan, Selvarangan

    2016-01-01

    Background Although antiangiogenic therapy is a promising new line of therapy for prostate cancer, we recently reported that stable expression of endostatin arrested the progression of prostate cancer to poorly differentiated state and distant metastasis in TRAMP mice. However, the same therapy failed to provide any benefit when given either during or after the onset of metastatic switch. The present study determined the possible mechanisms behind the selective advantage of endostatin therapy in early stage disease. Methods Angiogenesis-related gene expression analysis was performed to identify target genes and molecular pathways involved in the therapy effects. Based on the results from in vivo studies, and recapitulation of the in vivo data in vitro using tumorigenic and non-tumorigenic human prostate cancer cells that are either androgen-sensitive or androgen-independent, analyses of possible mechanisms of the selective advantage of early treatment were performed using assays for cell proliferation, apoptosis, migration and cell signaling. The identified mechanisms were further confirmed in vivo. Results Results indicated that cells with high androgen receptor (AR) expression were more sensitive to endostatin treatment than androgen-independent cells with low or no AR expression. Endostatin was found to significantly downregulate the expression of growth factors, receptor tyrosine kinases, proteases, and AR both in vitro and in vivo only when the cells express high levels of AR. Cell proliferation was not influenced by endostatin treatment but migration was significantly affected only in androgen-sensitive cells. Targeted downregulation of AR prior to endostatin treatment in androgen sensitive cells and overexpression of AR in androgen independent cells indicated that the effect of endostatin via AR downregulation is mediated by a non-genotropic mechanism on Ras and RhoA pathways, and independently of AR on MAPK/ERK pathway. Conclusions These data indicate that

  13. 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...

  14. 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...

  15. Synthesis of potent, substituted carbazoles as selective androgen receptor modulators (SARMs).

    PubMed

    Miller, Chris P; Bhaket, Pushpal; Muthukaman, Nagarajan; Lyttle, C Richard; Shomali, Maysoun; Gallacher, Kyla; Slocum, Connie; Hattersley, Gary

    2010-12-15

    The synthesis and in vitro binding affinity for a novel series of potent androgen receptor modulators is described. One of the more potent compounds (17, RAD35010) was further characterized in vivo where it restored levator ani weight in castrated male rats to near sham level while having no significant effect on prostate weight.

  16. [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

  17. 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...

  18. Timing of androgen receptor disruption and estrogen exposure underlies a spectrum of congenital penile anomalies.

    PubMed

    Zheng, Zhengui; Armfield, Brooke A; Cohn, Martin J

    2015-12-29

    Congenital penile anomalies (CPAs) are among the most common human birth defects. Reports of CPAs, which include hypospadias, chordee, micropenis, and ambiguous genitalia, have risen sharply in recent decades, but the causes of these malformations are rarely identified. Both genetic anomalies and environmental factors, such as antiandrogenic and estrogenic endocrine disrupting chemicals (EDCs), are suspected to cause CPAs; however, little is known about the temporal window(s) of sensitivity to EDCs, or the tissue-specific roles and downstream targets of the androgen receptor (AR) in external genitalia. Here, we show that the full spectrum of CPAs can be produced by disrupting AR at different developmental stages and in specific cell types in the mouse genital tubercle. Inactivation of AR during a narrow window of prenatal development results in hypospadias and chordee, whereas earlier disruptions cause ambiguous genitalia and later disruptions cause micropenis. The neonatal phase of penile development is controlled by the balance of AR to estrogen receptor α (ERα) activity; either inhibition of androgen or augmentation of estrogen signaling can induce micropenis. AR and ERα have opposite effects on cell division, apoptosis, and regulation of Hedgehog, fibroblast growth factor, bone morphogenetic protein, and Wnt signaling in the genital tubercle. We identify Indian hedgehog (Ihh) as a novel downstream target of AR in external genitalia and show that conditional deletion of Ihh inhibits penile masculinization. These studies reveal previously unidentified cellular and molecular mechanisms by which antiandrogenic and estrogenic signals induce penile malformations and demonstrate that the timing of endocrine disruption can determine the type of CPA.

  19. Timing of androgen receptor disruption and estrogen exposure underlies a spectrum of congenital penile anomalies

    PubMed Central

    Armfield, Brooke A.; Cohn, Martin J.

    2015-01-01

    Congenital penile anomalies (CPAs) are among the most common human birth defects. Reports of CPAs, which include hypospadias, chordee, micropenis, and ambiguous genitalia, have risen sharply in recent decades, but the causes of these malformations are rarely identified. Both genetic anomalies and environmental factors, such as antiandrogenic and estrogenic endocrine disrupting chemicals (EDCs), are suspected to cause CPAs; however, little is known about the temporal window(s) of sensitivity to EDCs, or the tissue-specific roles and downstream targets of the androgen receptor (AR) in external genitalia. Here, we show that the full spectrum of CPAs can be produced by disrupting AR at different developmental stages and in specific cell types in the mouse genital tubercle. Inactivation of AR during a narrow window of prenatal development results in hypospadias and chordee, whereas earlier disruptions cause ambiguous genitalia and later disruptions cause micropenis. The neonatal phase of penile development is controlled by the balance of AR to estrogen receptor α (ERα) activity; either inhibition of androgen or augmentation of estrogen signaling can induce micropenis. AR and ERα have opposite effects on cell division, apoptosis, and regulation of Hedgehog, fibroblast growth factor, bone morphogenetic protein, and Wnt signaling in the genital tubercle. We identify Indian hedgehog (Ihh) as a novel downstream target of AR in external genitalia and show that conditional deletion of Ihh inhibits penile masculinization. These studies reveal previously unidentified cellular and molecular mechanisms by which antiandrogenic and estrogenic signals induce penile malformations and demonstrate that the timing of endocrine disruption can determine the type of CPA. PMID:26598695

  20. Chronic Blockade of the Androgen Receptor Abolishes Age-Dependent Increases in Blood Pressure in Female Growth-Restricted Rats.

    PubMed

    Dasinger, John Henry; Intapad, Suttira; Rudsenske, Benjamin R; Davis, Gwendolyn K; Newsome, Ashley D; Alexander, Barbara T

    2016-06-01

    Intrauterine growth restriction induced via placental insufficiency programs a significant increase in blood pressure at 12 months of age in female growth-restricted rats that is associated with early cessation of estrous cyclicity, indicative of premature reproductive senescence. In addition, female growth-restricted rats at 12 months of age exhibit a significant increase in circulating testosterone with no change in circulating estradiol. Testosterone is positively associated with blood pressure after menopause in women. Thus, we tested the hypothesis that androgen receptor blockade would abolish the significant increase in blood pressure that develops with age in female growth-restricted rats. Mean arterial pressure was measured in animals pretreated with and without the androgen receptor antagonist, flutamide (8 mg/kg/day, SC for 2 weeks). Flutamide abolished the significant increase in blood pressure in growth-restricted rats relative to control at 12 months of age. To examine the mechanism(s) by which androgens contribute to increased blood pressure in growth-restricted rats, blood pressure was assessed in rats untreated or treated with enalapril (250 mg/L for 2 weeks). Enalapril eliminated the increase in blood pressure in growth-restricted relative to vehicle- and flutamide-treated controls. Furthermore, the increase in medullary angiotensin type 1 receptor mRNA expression was abolished in flutamide-treated growth-restricted relative to untreated counterparts and controls; cortical angiotensin-converting enzyme mRNA expression was reduced in flutamide-treated growth-restricted versus untreated counterparts. Thus, these data indicate that androgens, via activation of the renin-angiotensin system, are important mediators of increased blood pressure that develops by 12 months of age in female growth-restricted rats. PMID:27113045

  1. DEVELOPMENT OF TWO ANDROGEN RECEPTOR ASSAYS USING ADENOVIRAL TRANSDUCTION OF MMTV-LUC REPORTER AND/OR HAR FOR ENDOCRINE SCREENING

    EPA Science Inventory

    Abstract
    The discovery of xenobiotics which interfere with androgen activity has highlighted the need to assess chemicals for their ability to modulate dihydrotestosterone (DHT)-receptor binding. Previous test systems have used cells transfected with plasmid containing a rep...

  2. Effects of Androgen and Estrogen Receptor Signaling Pathways on Bladder Cancer Initiation and Progression

    PubMed Central

    Godoy, Guilherme; Gakis, Georgios; Smith, Carolyn L.; Fahmy, Omar

    2016-01-01

    Epidemiologic studies have long demonstrated clear differences in incidence and progression of bladder cancer between genders suggesting that the mechanisms of development and progression in these tumors have a strong association with steroid hormonal pathways. Such observations led to preclinical studies investigating the role of androgen and estrogen receptors, as well as their cognate hormones in bladder cancer initiation and progression. Using various in vitro cell line assays and in vivo mouse models, studies have elucidated different mechanisms and signaling pathways through which these steroid receptors may participate in this disease. More recently, RNA expression data from multiple studies revealed a luminal subtype of bladder cancer that exhibited an estrogen receptor signaling pathway, making it a strong candidate for further consideration of targeted therapies in the future. Despite the promising preclinical data demonstrating potential roles for both antiandrogen and antiestrogen strategies targeting these pathways in different stages of bladder cancer, only two clinical trials are currently active and accruing patients for such clinical studies. Targeted therapies in bladder cancer are a large unmet need and have the potential to change treatment paradigms and improve oncological outcomes of patients with bladder cancer. PMID:27376135

  3. Regulation of uterine progesterone receptors by the nonsteroidal anti-androgen hydroxyflutamide

    SciTech Connect

    Chandrasekhar, Y.; Armstrong, D.T. )

    1991-07-01

    The authors have recently reported that the anti-androgen hydroxyflutamide causes delayed implantation and exhibits antideciduogenic activity in the rat. The present experiments were conducted to examine whether hydroxyflutamide binds to the uterine progesterone receptors and/or alters the progesterone binding sites in the uterus. Cytosol and nuclear fractions from decidualized rat uterus were incubated with (3H)-R5020 without or with increasing concentrations of radioinert R5020, RU486, dihydrotestosterone, or hydroxyflutamide. From the log-dose inhibition curves, the relative binding affinity of both hydroxyflutamide and dihydrotestosterone was less than 0.1% and 2%, compared with R5020 (100%) for displacing (3H)-R5020 bound to uterine cytosol and nuclear fractions, respectively. Injection of estradiol-17 beta (1 microgram/rat) to ovariectomized prepubertal rats induced a 1.85-fold increase in uterine weight by 24 h. Hydroxyflutamide at 2.5 or 5.0 mg did not significantly alter the estrogen-induced increase in uterine weight. Compared to vehicle alone, estrogen induced an approximately 5-fold increase in uterine cytosolic progesterone binding sites. Hydroxyflutamide at both 2.5- and 5.0-mg doses significantly attenuated the estrogen-induced elevation in uterine progesterone binding sites. These studies demonstrate that hydroxyflutamide does not bind with high affinity to progesterone receptors, but suppresses the estrogen-induced elevation in progesterone receptor levels in the uterus.

  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. 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

  6. 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.

  7. Ockham's razor and selective androgen receptor modulators (SARMs): are we overlooking the role of 5alpha-reductase?

    PubMed

    Gao, Wenqing; Dalton, James T

    2007-02-01

    Selective Androgen Receptor Modulators (SARMs) are a novel class of AR ligands that possess tissue-selective pharmacological activities. SARMs of various chemical structures have been discovered and characterized, and lead compounds with much improved specificity for AR, in vivo pharmacokinetic profiles, and higher degree of tissue selectivity have entered clinical development, and are expected to dramatically expand the clinical applications of androgens. With the rapid progress in SARM discovery and increasing demand for mechanism-based drug design, more and more research efforts have been devoted to the mechanisms of action of the observed tissue selectivity of SARMs. There is increasing enthusiasm in adapting the molecular mechanisms of action from SERM research to the SARM field; however, is the SARM story really so complicated? The tissue-specific expression of 5alpha-reductase might provide a simple explanation for this puzzle.

  8. Antarlides: A New Type of Androgen Receptor (AR) Antagonist that Overcomes Resistance to AR-Targeted Therapy.

    PubMed

    Saito, Shun; Fujimaki, Takahiro; Panbangred, Watanalai; Igarashi, Yasuhiro; Imoto, Masaya

    2016-02-18

    Prostate cancer is treated with androgen receptor (AR) antagonists but most patients experience disease progression after long-term treatment with these compounds. Therefore, new AR antagonists are required for patient follow-up treatment. In the course of screening for a new AR antagonist, we isolated the novel compounds antarlides A-E (1-5) from Streptomyces sp. BB47. Antarlides are mutually isomeric with respect to the double bond and have a 22-membered-ring macrocyclic structure. The full stereostructure of 1 was established by chemical modifications, including methanolysis, the Trost method, acetonide formation, and the PGME method. 1-5 inhibited the binding of androgen to ARs in vitro. In addition, 2 inhibited the transcriptional activity of not only wild-type AR but also mutant ARs, which are seen in patients with acquired resistance to clinically used AR antagonists. Therefore, antarlides are a potent new generation of AR antagonists that overcome resistance.

  9. 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.

  10. 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

  11. 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

  12. [A potential of selective androgen receptor modulator(SARM)for the therapy of osteoporosis].

    PubMed

    Yanase, Toshihiko

    2016-07-01

    In recent years, the drugs, which show anabolic, effect on bone and muscle without stimulating prostate has been developed. They show tissue-specific selective androgen actions and called selective androgen receptor modulators(SARMs). The development of drug targeting bone and muscle in male is very promising as a treatment tool for osteoporosis and sarcopenia in the near future. The clinical study is under going especially in the field of cachexia associated with cancer, but unfortunately there is no drug in the current market at present. The current situation of the development of SARMs will be reviewed.

  13. Establishment of a novel immortalized human prostatic epithelial cell line stably expressing androgen receptor and its application for the functional screening of androgen receptor modulators

    SciTech Connect

    Yu, Shan; Wang, Ming-Wei; Yao, Xiaoqiang; Chan, F.L.

    2009-05-15

    In this study, we developed a human prostatic epithelial cell line BPH-1-AR stably expressing AR by lentiviral transduction. Characterization by immunoblot and RT-PCR showed that AR was stably expressed in all representative BPH-1-AR clones. Androgen treatment induced a secretory differentiation phenotype in BPH-1-AR cells but suppressed their cell proliferation. Treatments with AR agonists induced transactivation of a transfected PSA-gene promoter reporter in BPH-1-AR cells, whereas this transactivation was suppressed by an AR antagonist flutamide, indicating that the transduced AR in BPH-1-AR cells was functional. Finally, we utilized BPH-1-AR cells to evaluate the androgenic activities and growth effects of five newly developed non-steroidal compounds. Results showed that these compounds showed androgenic activities and growth-inhibitory effects on BPH-1-AR cells. Our results showed that BPH-1-AR cell line would be a valuable in vitro model for the study of androgen-regulated processes in prostatic epithelial cells and identification of compounds with AR-modulating activities.

  14. Targeting stromal androgen receptor suppresses prolactin-driven benign prostatic hyperplasia (BPH).

    PubMed

    Lai, Kuo-Pao; Huang, Chiung-Kuei; Fang, Lei-Ya; Izumi, Kouji; Lo, Chi-Wen; Wood, Ronald; Kindblom, Jon; Yeh, Shuyuan; Chang, Chawnshang

    2013-10-01

    Stromal-epithelial interaction plays a pivotal role to mediate the normal prostate growth, the pathogenesis of benign prostatic hyperplasia (BPH), and prostate cancer development. Until now, the stromal androgen receptor (AR) functions in the BPH development, and the underlying mechanisms remain largely unknown. Here we used a genetic knockout approach to ablate stromal fibromuscular (fibroblasts and smooth muscle cells) AR in a probasin promoter-driven prolactin transgenic mouse model (Pb-PRL tg mice) that could spontaneously develop prostate hyperplasia to partially mimic human BPH development. We found Pb-PRL tg mice lacking stromal fibromuscular AR developed smaller prostates, with more marked changes in the dorsolateral prostate lobes with less proliferation index. Mechanistically, prolactin mediated hyperplastic prostate growth involved epithelial-stromal interaction through epithelial prolactin/prolactin receptor signals to regulate granulocyte macrophage-colony stimulating factor expression to facilitate stromal cell growth via sustaining signal transducer and activator of transcription-3 activity. Importantly, the stromal fibromuscular AR could modulate such epithelial-stromal interacting signals. Targeting stromal fibromuscular AR with the AR degradation enhancer, ASC-J9(®), led to the reduction of prostate size, which could be used in future therapy.

  15. Detection of persistent organic pollutants binding modes with androgen receptor ligand binding domain by docking and molecular dynamics

    PubMed Central

    2013-01-01

    Background Persistent organic pollutants (POPs) are persistent in the environment after release from industrial compounds, combustion productions or pesticides. The exposure of POPs has been related to various reproductive disturbances, such as reduced semen quality, testicular cancer, and imbalanced sex ratio. Among POPs, dichlorodiphenyldichloroethylene (4,4’-DDE) and polychlorinated biphenyls (PCBs) are the most widespread and well-studied compounds. Recent studies have revealed that 4,4’-DDE is an antagonist of androgen receptor (AR). However, the mechanism of the inhibition remains elusive. CB-153 is the most common congener of PCBs, while the action of CB-153 on AR is still under debate. Results Molecular docking and molecular dynamics (MD) approaches have been employed to study binding modes and inhibition mechanism of 4,4’-DDE and CB-153 against AR ligand binding domain (LBD). Several potential binding sites have been detected and analyzed. One possible binding site is the same binding site of AR natural ligand androgen 5α-dihydrotestosterone (DHT). Another one is on the ligand-dependent transcriptional activation function (AF2) region, which is crucial for the co-activators recruitment. Besides, a novel possible binding site was observed for POPs with low binding free energy with the receptor. Detailed interactions between ligands and the receptor have been represented. The disrupting mechanism of POPs against AR has also been discussed. Conclusions POPs disrupt the function of AR through binding to three possible biding sites on AR/LBD. One of them shares the same binding site of natural ligand of AR. Another one is on AF2 region. The third one is in a cleft near N-terminal of the receptor. Significantly, values of binding free energy of POPs with AR/LBD are comparable to that of natural ligand androgen DHT. PMID:24053684

  16. Phosphorylation of the androgen receptor by PIM1 in hormone refractory prostate cancer.

    PubMed

    Ha, S; Iqbal, N J; Mita, P; Ruoff, R; Gerald, W L; Lepor, H; Taneja, S S; Lee, P; Melamed, J; Garabedian, M J; Logan, S K

    2013-08-22

    Integration of cellular signaling pathways with androgen receptor (AR) signaling can be achieved through phosphorylation of AR by cellular kinases. However, the kinases responsible for phosphorylating the AR at numerous sites and the functional consequences of AR phosphorylation are only partially understood. Bioinformatic analysis revealed AR serine 213 (S213) as a putative substrate for PIM1, a kinase overexpressed in prostate cancer. Therefore, phosphorylation of AR serine 213 by PIM1 was examined using a phosphorylation site-specific antibody. Wild-type PIM1, but not catalytically inactive PIM1, specifically phosphorylated AR but not an AR serine-to-alanine mutant (S213A). In vitro kinase assays confirmed that PIM1 can phosphorylate AR S213 in a ligand-independent manner and cell type-specific phosphorylation was observed in prostate cancer cell lines. Upon PIM1 overexpression, AR phosphorylation was observed in the absence of hormone and was further increased in the presence of hormone in LNCaP, LNCaP-abl and VCaP cells. Moreover, phosphorylation of AR was reduced in the presence of PIM kinase inhibitors. An examination of AR-mediated transcription showed that reporter gene activity was reduced in the presence of PIM1 and wild-type AR, but not S213A mutant AR. Androgen-mediated transcription of endogenous PSA, Nkx3.1 and IGFBP5 was also decreased in the presence of PIM1, whereas IL6, cyclin A1 and caveolin 2 were increased. Immunohistochemical analysis of prostate cancer tissue microarrays showed significant P-AR S213 expression that was associated with hormone refractory prostate cancers, likely identifying cells with catalytically active PIM1. In addition, prostate cancers expressing a high level of P-AR S213 were twice as likely to be from biochemically recurrent cancers. Thus, AR phosphorylation by PIM1 at S213 impacts gene transcription and is highly prevalent in aggressive prostate cancer.

  17. 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.

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

    PubMed

    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.

  19. Structural and functional association of androgen receptor with telomeres in prostate cancer cells

    PubMed Central

    Zhou, Junying; Richardson, Michelle; Reddy, Vidyavathi; Menon, Mani; Barrack, Evelyn R.; Reddy, G. Prem-Veer; Kim, Sahn-Ho

    2013-01-01

    Telomeres protect the ends of linear chromosomes from being recognized as damaged DNA, and telomere stability is required for genome stability. Here we demonstrate that telomere stability in androgen receptor (AR)-positive LNCaP human prostate cancer cells is dependent on AR and androgen, as AR inactivation by AR antagonist bicalutamide (Casodex), AR-knockdown, or androgen-depletion caused telomere dysfunction, and the effect of androgen-depletion or Casodex was blocked by the addition of androgen. Notably, neither actinomycin D nor cycloheximide blocked the DNA damage response to Casodex, indicating that the role of AR in telomere stability is independent of its role in transcription. We also demonstrate that AR is a component of telomeres, as AR-bound chromatin contains telomeric DNA, and telomeric chromatin contains AR. Importantly, AR inactivation by Casodex caused telomere aberrations, including multiple abnormal telomere signals, remindful of a fragile telomere phenotype that has been described previously to result from defective telomere DNA replication. We suggest that AR plays an important role in telomere stability and replication of telomere DNA in prostate cancer cells, and that AR inactivation-mediated telomere dysfunction may contribute to genomic instability and progression of prostate cancer cells. PMID:23363843

  20. Androgen receptor regulates Cdc6 in synchronized LNCaP cells progressing from G1 to S phase.

    PubMed

    Bai, V Uma; Cifuentes, Eugenia; Menon, Mani; Barrack, Evelyn R; Reddy, G Prem-Veer

    2005-08-01

    We have shown previously that androgen receptor (AR) activity is required for the progression of cells from G(1) to S phase. In an attempt to elucidate the mechanism of androgen- and androgen-receptor-mediated proliferation of prostate cancer cells, we studied the effect of anti-androgen bicalutamide (Casodex) on the expression of cell-cycle regulatory genes in synchronized LNCaP cells progressing from G(1) to S phase. LNCaP cells were synchronized by isoleucine-deprivation. Expression of cell-cycle regulatory genes in S phase control cells versus Casodex-treated cells that fail to enter S phase was studied using a microarray containing cDNA probes for 111 cell-cycle specific genes. RT-PCR and Western-blots were used to validate microarray data. Casodex blocked synchronized LNCaP cells from entering S phase. Microarrays revealed downregulation of eight genes in cells prevented from entering into S phase by Casodex. Of these eight genes, only Cdc6, cyclin A, and cyclin B were downregulated at both the mRNA and protein level in Casodex treated cells as compared to control cells. The mRNA and protein levels of Cdc6 increased as synchronized LNCaP cells progressed from G(1) to S phase, and were attenuated in Casodex-treated cells failed to enter S phase. Cyclins A and B were detected when cells entered S phase, but not when they were in G(1) phase. Like Cdc6, the levels of both cyclins A and B were attenuated in Casodex-treated cells. AR may play an important role in the onset of DNA synthesis in prostate cancer cells by regulating the expression and stability of Cdc6, which is critically required for the assembly of the pre-replication complex(pre-RC).

  1. Role of the alpha subunit in the modulation of GABA(A) receptors by anabolic androgenic steroids.

    PubMed

    Yang, Paul; Jones, Brian L; Henderson, Leslie P

    2005-09-01

    Neural transmission mediated by circuits expressing alpha2 subunit-containing gamma-aminobutyric acid type A (GABA(A)) receptors is critical for the expression of behaviors known to be altered by anabolic androgenic steroids (AAS). Here we show that micromolar concentrations of AAS, which reflect levels found in steroid abusers, induce positive modulation of currents from alpha2beta3 gamma2L recombinant receptors elicited by pulses of GABA that mimic synaptic conditions in a manner that is mechanistically distinct from modulation induced at alpha1beta3 gamma2L receptors. Specifically, at alpha2-containing receptors, the AAS, 17alpha-methyltestosterone (17alpha-MeT) enhanced peak current, slowed deactivation, diminished desensitization, and promoted entry of receptors into more distal states along the activation pathway. Analysis of GABA(A) receptor-mediated synaptic currents in primary cortical neurons followed by single cell real-time RT-PCR demonstrated that 17alpha-MeT enhancement of synaptic currents is proportional to the ratio of alpha2 to alpha1 subunit mRNA. Finally, we show that the modulation elicited by AAS is not comparable to that produced by micromolar concentrations of other positive allosteric modulators at alpha2-containing receptors. In sum, these data indicate that AAS elicit effects on GABA(A) receptor function that depend significantly on alpha subunit composition and that the mechanism of AAS modulation of GABA(A) receptors is distinct from that of other positive allosteric modulators.

  2. Behavioral performance of tfm mice supports the beneficial role of androgen receptors in spatial learning and memory.

    PubMed

    Rizk, Angela; Robertson, Jennifer; Raber, Jacob

    2005-02-01

    In adulthood, androgens and androgen receptors might contribute to the sexually dimorphic performance in spatial learning and memory, but their roles seem complex. To study the potential role of androgen receptors in spatial learning and memory, we tested adult 6-8-month-old mutant mice with a naturally occurring defect in the androgen receptor gene (testicular feminization mutant or tfm) and C57Bl/6J wild-type mice. Because the trait is X-linked, only tfm males are completely androgen insensitive while female tfm mice are heterozygous, carrying one wild-type and one tfm copy of the androgen receptor. Here we show that female tfm carrier mice outperform tfm male mice in the water maze, while there are no gender differences in water maze performance in wild-type mice. In tfm mice, there were no gender differences in measures of anxiety in the open field or plus maze or sensorimotor function, indicating that potential differences in these measures did not contribute to the differences observed in the water maze. There were no differences in tfm and wild-type female and male mice in emotional learning and memory in the passive avoidance test. These findings support a beneficial role for androgen receptors in spatial learning and memory.

  3. 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

  4. 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

  5. Sox2 Is an Androgen Receptor-Repressed Gene That Promotes Castration-Resistant Prostate Cancer

    PubMed Central

    Kregel, Steven; Kiriluk, Kyle J.; Rosen, Alex M.; Cai, Yi; Reyes, Edwin E.; Otto, Kristen B.; Tom, Westin; Paner, Gladell P.; Szmulewitz, Russell Z.; Vander Griend, Donald J.

    2013-01-01

    Despite advances in detection and therapy, castration-resistant prostate cancer continues to be a major clinical problem. The aberrant activity of stem cell pathways, and their regulation by the Androgen Receptor (AR), has the potential to provide insight into novel mechanisms and pathways to prevent and treat advanced, castrate-resistant prostate cancers. To this end, we investigated the role of the embryonic stem cell regulator Sox2 [SRY (sex determining region Y)-box 2] in normal and malignant prostate epithelial cells. In the normal prostate, Sox2 is expressed in a portion of basal epithelial cells. Prostate tumors were either Sox2-positive or Sox2-negative, with the percentage of Sox2-positive tumors increasing with Gleason Score and metastases. In the castration-resistant prostate cancer cell line CWR-R1, endogenous expression of Sox2 was repressed by AR signaling, and AR chromatin-IP shows that AR binds the enhancer element within the Sox2 promoter. Likewise, in normal prostate epithelial cells and human embryonic stem cells, increased AR signaling also decreases Sox2 expression. Resistance to the anti-androgen MDV3100 results in a marked increase in Sox2 expression within three prostate cancer cell lines, and in the castration-sensitive LAPC-4 prostate cancer cell line ectopic expression of Sox2 was sufficient to promote castration-resistant tumor formation. Loss of Sox2 expression in the castration-resistant CWR-R1 prostate cancer cell line inhibited cell growth. Up-regulation of Sox2 was not associated with increased CD133 expression but was associated with increased FGF5 (Fibroblast Growth Factor 5) expression. These data propose a model of elevated Sox2 expression due to loss of AR-mediated repression during castration, and consequent castration-resistance via mechanisms not involving induction of canonical embryonic stem cell pathways. PMID:23326489

  6. New Therapeutic Approach to Suppress Castration-Resistant Prostate Cancer Using ASC-J9 via Targeting Androgen Receptor in Selective Prostate Cells

    PubMed Central

    Lai, Kuo-Pao; Huang, Chiung-Kuei; Chang, Yu-Jia; Chung, Chin-Ying; Yamashita, Shinichi; Li, Lei; Lee, Soo Ok; Yeh, Shuyuan; Chang, Chawnshang

    2014-01-01

    Using androgen receptor (AR) knockout mice to determine AR functions in selective prostate cancer (PCa) cells, we determined that AR might play differential roles in various cell types, either to promote or suppress PCa development/progression. These observations partially explain the failure of current androgen deprivation therapy (ADT) to reduce/prevent androgen binding to AR in every cell. Herein, we identified the AR degradation enhancer ASC-J9, which selectively degrades AR protein via interruption of the AR-AR selective coregulator interaction. Such selective interruption could, therefore, suppress AR-mediated PCa growth in the androgen-sensitive stage before ADT and in the castration-resistant stage after ADT. Mechanistic dissection suggested that ASC-J9 could activate the proteasome-dependent pathway to promote AR degradation through the enhanced association of AR-Mdm2 complex. The consequences of ASC-J9-promoted AR degradation included reduced androgen binding to AR, AR N-C terminal interaction, and AR nuclear translocation. Such inhibitory regulation could then result in suppression of AR transactivation and AR-mediated cell growth in eight different mouse models, including intact or castrated nude mice xenografted with androgen-sensitive LNCaP cells or androgen-insensitive C81 cells and castrated nude mice xenografted with castration-resistant C4-2 and CWR22Rv1 cells, and TRAMP and Pten+/− mice. These results demonstrate that ASC-J9 could serve as an AR degradation enhancer that effectively suppresses PCa development/progression in the androgen-sensitive and castration-resistant stages. PMID:23219429

  7. A precisely substituted benzopyran targets androgen refractory prostate cancer cells through selective modulation of estrogen receptors.

    PubMed

    Kumar, Rajeev; Verma, Vikas; Sharma, Vikas; Jain, Ashish; Singh, Vishal; Sarswat, Amit; Maikhuri, Jagdamba P; Sharma, Vishnu L; Gupta, Gopal

    2015-03-15

    Dietary consumption of phytoestrogens like genistein has been linked with lower incidence of prostate cancer. The estradiol-like benzopyran core of genistein confers estrogen receptor-β (ER-β) selectivity that imparts weak anti-proliferative activity against prostate cancer cells. DL-2-[4-(2-piperidinoethoxy)phenyl]-3-phenyl-2H-1-benzopyran (BP), a SERM designed with benzopyran core, targeted androgen independent prostate cancer (PC-3) cells 14-times more potently than genistein, ~25% more efficiently than tamoxifen and 6.5-times more actively than ICI-182780, without forfeiting significant specificity in comparison to genistein. BP increased apoptosis (annexin-V and TUNEL labeling), arrested cell cycle, and significantly increased caspase-3 activity along with mRNA expressions of estrogen receptor (ER)-β and FasL (qPCR) in PC-3 cells. In classical ERE-luc reporter assay BP behaved as a potent ER-α antagonist and ER-β agonist. Accordingly, it decreased expression of ER-α target PS2 (P<0.01) and increased expression of ER-β target TNF-α (P<0.05) genes in PC-3. ER-β deficient PC-3 (siRNA-transfected) was resistant to apoptotic and anti-proliferative actions of SERMs, including stimulation of FasL expression by BP. BP significantly inhibited phosphorylation of Akt and ERK-1/2, JNK and p38 in PC-3 (immunoblotting), and thus adopted a multi-pathway mechanism to exert a more potent anti-proliferative activity against prostate cancer cells than natural and synthetic SERMs. Its precise ER-subtype specific activity presents a unique lead structure for further optimization.

  8. Castration induces up-regulation of intratumoral androgen biosynthesis and androgen receptor expression in an orthotopic VCaP human prostate cancer xenograft model.

    PubMed

    Knuuttila, Matias; Yatkin, Emrah; Kallio, Jenny; Savolainen, Saija; Laajala, Teemu D; Aittokallio, Tero; Oksala, Riikka; Häkkinen, Merja; Keski-Rahkonen, Pekka; Auriola, Seppo; Poutanen, Matti; Mäkelä, Sari

    2014-08-01

    Androgens are key factors involved in the development and progression of prostate cancer (PCa), and PCa growth can be suppressed by androgen deprivation therapy. In a considerable proportion of men receiving androgen deprivation therapy, however, PCa progresses to castration-resistant PCa (CRPC), making the development of efficient therapies challenging. We used an orthotopic VCaP human PCa xenograft model to study cellular and molecular changes in tumors after androgen deprivation therapy (castration). Tumor growth was monitored through weekly serum prostate-specific antigen measurements, and mice with recurrent tumors after castration were randomized to treatment groups. Serum prostate-specific antigen concentrations showed significant correlation with tumor volume. Castration-resistant tumors retained concentrations of intratumoral androgen (androstenedione, testosterone, and 5α-dihydrotestosterone) at levels similar to tumors growing in intact hosts. Accordingly, castration induced up-regulation of enzymes involved in androgen synthesis (CYP17A1, AKR1C3, and HSD17B6), as well as expression of full-length androgen receptor (AR) and AR splice variants (AR-V1 and AR-V7). Furthermore, AR target gene expression was maintained in castration-resistant xenografts. The AR antagonists enzalutamide (MDV3100) and ARN-509 suppressed PSA production of castration-resistant tumors, confirming the androgen dependency of these tumors. Taken together, the findings demonstrate that our VCaP xenograft model exhibits the key characteristics of clinical CRPC and thus provides a valuable tool for identifying druggable targets and for testing therapeutic strategies targeting AR signaling in CRPC.

  9. Protein arginine methyltransferase 6 enhances polyglutamine-expanded androgen receptor function and toxicity in spinal and bulbar muscular atrophy.

    PubMed

    Scaramuzzino, Chiara; Casci, Ian; Parodi, Sara; Lievens, Patricia M J; Polanco, Maria J; Milioto, Carmelo; Chivet, Mathilde; Monaghan, John; Mishra, Ashutosh; Badders, Nisha; Aggarwal, Tanya; Grunseich, Christopher; Sambataro, Fabio; Basso, Manuela; Fackelmayer, Frank O; Taylor, J Paul; Pandey, Udai Bhan; Pennuto, Maria

    2015-01-01

    Polyglutamine expansion in androgen receptor (AR) is responsible for spinobulbar muscular atrophy (SBMA) that leads to selective loss of lower motor neurons. Using SBMA as a model, we explored the relationship between protein structure/function and neurodegeneration in polyglutamine diseases. We show here that protein arginine methyltransferase 6 (PRMT6) is a specific co-activator of normal and mutant AR and that the interaction of PRMT6 with AR is significantly enhanced in the AR mutant. AR and PRMT6 interaction occurs through the PRMT6 steroid receptor interaction motif, LXXLL, and the AR activating function 2 surface. AR transactivation requires PRMT6 catalytic activity and involves methylation of arginine residues at Akt consensus site motifs, which is mutually exclusive with serine phosphorylation by Akt. The enhanced interaction of PRMT6 and mutant AR leads to neurodegeneration in cell and fly models of SBMA. These findings demonstrate a direct role of arginine methylation in polyglutamine disease pathogenesis.

  10. Pax6 represses androgen receptor-mediated transactivation by inhibiting recruitment of the coactivator SPBP.

    PubMed

    Elvenes, Julianne; Thomassen, Ernst Ivan Simon; Johnsen, Sylvia Sagen; Kaino, Katrine; Sjøttem, Eva; Johansen, Terje

    2011-01-01

    The androgen receptor (AR) has a central role in development and maintenance of the male reproductive system and in the etiology of prostate cancer. The transcription factor Pax6 has recently been reported to act as a repressor of AR and to be hypermethylated in prostate cancer cells. SPBP is a transcriptional regulator that previously has been shown to enhance the activity of Pax6. In this study we have identified SPBP to act as a transcriptional coactivator of AR. We also show that Pax6 inhibits SPBP-mediated enhancement of AR activity on the AR target gene probasin promoter, a repression that was partly reversed by increased expression of SPBP. Enhanced expression of Pax6 reduced the amount of SPBP associated with the probasin promoter when assayed by ChIP in HeLa cells. We mapped the interaction between both AR and SPBP, and AR and Pax6 to the DNA-binding domains of the involved proteins. Further binding studies revealed that Pax6 and SPBP compete for binding to AR. These results suggest that Pax6 represses AR activity by displacing and/or inhibiting recruitment of coactivators to AR target promoters. Understanding the mechanism for inhibition of AR coactivators can give rise to molecular targeted drugs for treatment of prostate cancer. PMID:21935435

  11. Pax6 Represses Androgen Receptor-Mediated Transactivation by Inhibiting Recruitment of the Coactivator SPBP

    PubMed Central

    Johnsen, Sylvia Sagen; Kaino, Katrine; Sjøttem, Eva; Johansen, Terje

    2011-01-01

    The androgen receptor (AR) has a central role in development and maintenance of the male reproductive system and in the etiology of prostate cancer. The transcription factor Pax6 has recently been reported to act as a repressor of AR and to be hypermethylated in prostate cancer cells. SPBP is a transcriptional regulator that previously has been shown to enhance the activity of Pax6. In this study we have identified SPBP to act as a transcriptional coactivator of AR. We also show that Pax6 inhibits SPBP-mediated enhancement of AR activity on the AR target gene probasin promoter, a repression that was partly reversed by increased expression of SPBP. Enhanced expression of Pax6 reduced the amount of SPBP associated with the probasin promoter when assayed by ChIP in HeLa cells. We mapped the interaction between both AR and SPBP, and AR and Pax6 to the DNA-binding domains of the involved proteins. Further binding studies revealed that Pax6 and SPBP compete for binding to AR. These results suggest that Pax6 represses AR activity by displacing and/or inhibiting recruitment of coactivators to AR target promoters. Understanding the mechanism for inhibition of AR coactivators can give rise to molecular targeted drugs for treatment of prostate cancer. PMID:21935435

  12. A novel nuclear role for the Vav3 nucleotide exchange factor in androgen receptor coactivation in prostate cancer.

    PubMed

    Rao, S; Lyons, L S; Fahrenholtz, C D; Wu, F; Farooq, A; Balkan, W; Burnstein, K L

    2012-02-01

    Increased androgen receptor (AR) transcriptional activity mediated by coactivator proteins may drive castration-resistant prostate cancer (CRPC) growth. Vav3, a Rho GTPase guanine nucleotide exchange factor (GEF), is overexpressed in human prostate cancers, particularly in models of CRPC progression. Vav3 coactivates AR in a Vav3 pleckstrin homology (PH) domain-dependent but GEF-independent manner. Ectopic expression of Vav3 in androgen-dependent human prostate cancer cells conferred robust castration-resistant xenograft tumor growth. Vav3 but not a Vav3 PH mutant greatly stimulated interaction between the AR amino and carboxyl termini (N-C interaction), which is required for maximal receptor transcriptional activity. Vav3 was distributed between the cytoplasm and nucleus with nuclear localization-dependent on the Vav3 PH domain. Membrane targeting of Vav3 abolished Vav3 potentiation of AR activity, whereas nuclear targeting of a Vav3 PH mutant rescued AR coactivation, suggesting that nuclear localization is an important function of the Vav3 PH domain. A nuclear role for Vav3 was further demonstrated by sequential chromatin immunoprecipitation assays, which revealed that Vav3 and AR were recruited to the same transcriptional complexes of an AR target gene enhancer. These data demonstrate the importance of Vav3 in CRPC and define a novel nuclear function of Vav3 in regulating AR activity.

  13. Fenofibrate down-regulates the expressions of androgen receptor (AR) and AR target genes and induces oxidative stress in the prostate cancer cell line LNCaP

    SciTech Connect

    Zhao, Hu; Zhu, Chen; Qin, Chao; Tao, Tao; Li, Jie; Cheng, Gong; Li, Pu; Cao, Qiang; Meng, Xiaoxin; Ju, Xiaobing; Shao, Pengfei; Hua, Lixin; Gu, Min; Yin, Changjun

    2013-03-08

    Highlights: ► Fenofibrate induces cell cycle arrest in G1 phase and apoptosis in LNCaP cells. ► Fenofibrate reduces the expressions of androgen receptor in LNCaP cells. ► Fenofibrate induces oxidative stress in the prostate cancer cell line LNCaP. -- Abstract: Fenofibrate, a peroxisome proliferator-androgen receptor-alpha agonist, is widely used in treating different forms of hyperlipidemia and hypercholesterolemia. Recent reports have indicated that fenofibrate exerts anti-proliferative and pro-apoptotic properties. This study aims to investigate the effects of fenofibrate on the prostate cancer (PCa) cell line LNCaP. The effects of fenofibrate on LNCaP cells were evaluated by flow cytometry, reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assays, Western blot analysis, and dual-luciferase reporter assay. Fenofibrate induces cell cycle arrest in G1 phase and apoptosis in LNCaP cells, reduces the expressions of androgen receptor (AR) and AR target genes (prostate-specific antigen and TMPRSS2), and inhibits Akt phosphorylation. Fenofibrate can induce the accumulation of intracellular reactive oxygen species and malondialdehyde, and decrease the activities of total anti-oxidant and superoxide dismutase in LNCaP cells. Fenofibrate exerts an anti-proliferative property by inhibiting the expression of AR and induces apoptosis by causing oxidative stress. Therefore, our data suggest fenofibrate may have beneficial effects in fenofibrate users by preventing prostate cancer growth through inhibition of androgen activation and expression.

  14. Androgen receptor and prostate-specific antigen gene polymorphisms and breast cancer in African-American women.

    PubMed

    Wang, Wei; John, Esther M; Ingles, Sue Ann

    2005-12-01

    Several previous studies have found the CAG repeat polymorphism in exon 1 of the androgen receptor (AR) gene to be associated with breast cancer risk among some groups of Caucasian and Asian women. In a population-based case-control study of 488 African-American women (239 cases and 249 controls), we examined this polymorphism along with a polymorphism (-158 G/A) in an androgen-regulated gene (PSA) whose expression has been correlated with breast cancer prognosis. Overall, we did not observe any significant association between the CAG repeat polymorphism and breast cancer risk. However, among women with a first-degree family history of breast cancer, longer CAG repeats were associated with a significantly increased risk. Women carrying at least one longer allele [(CAG)n > or = 22] had a 3-fold increased risk compared to those with two shorter alleles (odds ratio, 3.18; 95% confidence interval, 1.08-9.36). There was no significant association between the PSA gene polymorphism and breast cancer risk, nor was there significant gene-gene interaction. In summary, our results further support that shorter CAG repeats (stronger AR transactivation activity) may reduce the risk of breast cancer, at least among some groups of women. Our data, however, are unable to provide evidence that PSA is the pathway through which the protective effect of androgens operates.

  15. Phytoestrogens selective for the estrogen receptor beta exert anti-androgenic effects in castration resistant prostate cancer.

    PubMed

    Thelen, Paul; Wuttke, Wolfgang; Seidlová-Wuttke, Dana

    2014-01-01

    Prostate cancer is the leading cause of cancer death in men of the Western world. A castration-resistant prostate cancer (CRPC) eventually will arise when a local restricted prostate carcinoma was not cured duly by radical prostatectomy or radiation therapy. Although androgen ablation therapies are considered the gold standard for treatments of advanced prostate cancer there is no curative therapy available at present. In previous pre-clinical and clinical trials several phytoestrogens were investigated for their anticancer potential in various models for prostate cancer. Phytoestrogens feature tumour preventive characteristics and most probably are involved in the low incidence rate of hormone related cancers in Asian countries. Phytoestrogens such as isoflavones can have a marked impact on the most essential therapy target of CRPC i.e. the androgen receptor. Furthermore, functional analyses solidified the notion of such drugs as androgen antagonistic. Phytoestrogens commonly feature low toxicity combined with a potential of targeted therapy. Thus, these drugs qualify for conceivable implementation in prostate cancer patients under active surveillance. In addition, relapse prevention with these drugs after radical prostatectomy or radiation therapy might be considered. This article is part of a Special Issue entitled 'Phytoestrogens'.

  16. Discovery of BMS-641988, a Novel Androgen Receptor Antagonist for the Treatment of Prostate Cancer

    PubMed Central

    2015-01-01

    BMS-641988 (23) is a novel, nonsteroidal androgen receptor antagonist designed for the treatment of prostate cancer. The compound has high binding affinity for the AR and acts as a functional antagonist in vitro. BMS-641988 is efficacious in multiple human prostate cancer xenograft models, including CWR22-BMSLD1 where it displays superior efficacy relative to bicalutamide. Based on its promising preclinical profile, BMS-641988 was selected for clinical development. PMID:26288692

  17. 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

  18. 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