Androgen receptor (AR) coregulators: an overview

Importance of the Androgen Receptor Signaling in Gene Transactivation and Transrepression for Pubertal Maturation of the Testis

Androgens are key for pubertal development of the mammalian testis, a phenomenon that is tightly linked to Sertoli cell maturation. In this review, we discuss how androgen signaling affects Sertoli cell function and morphology by concomitantly inhibiting some processes and promoting others that contribute jointly to the completion of spermatogenesis. We focus on the molecular mechanisms that underlie anti-Müllerian hormone (AMH) inhibition by androgens at puberty, as well as on the role androgens have on Sertoli cell tight junction formation and maintenance and, consequently, on its effect on proper germ cell differentiation and meiotic onset during spermatogenesis.

Novel associations between sex hormones and diabetic vascular complications in men and postmenopausal women: a cross-sectional study

Background

Associations between sex hormones and vascular remodeling have been extensively studied, but the results vary widely among different races and sex. We aimed to investigate whether total testosterone (TT), estrogen (E2), and dehydroepiandrosterone (DHEA) associate with macrovascular complications and diabetic kidney disease (DKD) among community-dwelling patients with diabetes.

Methods

A total of 4720 participants with type 2 diabetes were recruited from Shanghai, China. Common carotid artery (CCA) plaques and diameter were assessed by ultrasound. Cardiovascular disease (CVD) was defined by prior diagnosis of coronary heart disease, myocardial infarction or stroke. DKD was defined according to the ADA Guidelines.

Results

(1) In men, TT was negatively associated with CCA diameter (regression coefficient (β) − 0.044, 95% CI − 0.087, 0). E2 levels were positively associated with CVD and CCA plaque prevalence (OR 1.151, 95% CI 1.038, 1.277 and OR 1.13, 95% CI 1.017, 1.255, respectively). DHEA was negatively associated with CVD (OR 0.809, 95% CI 0.734, 0.893). In postmenopausal women, TT levels were negatively associated with CCA diameter (β − 0.046, 95% CI − 0.083, − 0.010) and positively associated with CVD (OR 1.154, 95% CI 1.038, 1.284). (2) In both men and postmenopausal women, TT levels were negatively associated with the albumin/creatinine ratio and DKD (β − 0.098, 95% CI − 0.154, − 0.043 and OR 0.887, 95% CI 0.790, 0.997 vs. β − 0.084, 95% CI − 0.137, − 0.031 and OR 0.822, 95% CI 0.731, 0.924, respectively) and DHEA levels were positively associated with DKD (OR 1.167, 95% CI 1.038, 1.313 vs. OR 1.251, 95% CI 1.104, 1.418, respectively).

Conclusions

Our study indicates that macrovascular complications were associated with low TT, DHEA and high E2 in men and with high TT in postmenopausal women. DKD was associated with low TT and high DHEA levels in both genders. Sex hormone replacement therapy requires careful and comprehensive consideration.

Trial registration ChiCTR1800017573, http://www.chictr.org.cn. Registered 04 August 2018

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0901-6) contains supplementary material, which is available to authorized users.

Revisiting the relationships of 2D:4D with androgen receptor (AR) gene and current testosterone levels: Replication study and meta-analyses

The relationships of digit ratio (2D:4D) with the length of AR (CAG)n, and testosterone levels from saliva and blood have been extensively debated over the years. This research including three studies further clarifies such controversies. To do so, we re-examined the relationships between the length of AR (CAG)n, 2D:4D, and current testosterone levels, through replication study and meta-analysis for each study. The results indicate: (a) the length of AR (CAG)n is not significantly associated with 2D:4D; (b) current testosterone levels are not significantly associated with the ratio; and (c) the length is not significantly associated with testosterone levels. Thus, AR (CAG)n and current testosterone levels are not significantly related to 2D:4D at individual level.

Elevated androgen levels induce hyperinsulinemia through increase in Ins1 transcription in pancreatic beta cells in female rats

Hyperandrogenism is associated with hyperinsulinemia and insulin resistance in adult females. We tested whether androgens dysregulate pancreatic beta cell function to induce hyperinsulinemia through transcriptional regulation of insulin gene (Ins) in the islets. Adult female Wistar rats implanted with dihydrotestosterone (DHT; 7.5-mg, 90-d release) or placebo pellets were examined after 10 weeks. DHT exposure increased plasma DHT levels by 2-fold similar to that in polycystic ovary syndrome in women. DHT exposure induced hyperinsulinemia with increased HOMA-IR index in fasting state and glucose intolerance and exaggerated insulin responses following glucose tolerance test. DHT females had no change in islet number, size and beta cell proliferation/apoptosis but exhibited significant mitochondrial dysfunction (higher ADP/ATP ratio, decreased mtDNA copy number, increased reactive oxygen production and downregulation of mitochondrial biogenesis) and enhanced glucose-stimulated insulin secretion. Ins expression was increased in DHT islets. In vitro incubation of control islets with DHT dose dependently stimulated Ins transcription. Analysis of Ins1 gene revealed a putative androgen responsive element in the promoter. Chromatin-immunoprecipitation assays showed that androgen receptors bind to this element in response to DHT stimulation. Furthermore, reporter assays showed that the promoter element is highly responsive to androgens. Insulin-stimulated glucose uptake in skeletal muscle was decreased with associated decrease in IRβ expression in DHT females. Our studies identified a novel androgen-mediated mechanism for the control of Ins expression via transcriptional regulation providing a molecular mechanism linking elevated androgens and hyperinsulemia. Decreased IRβ expression in the skeletal muscles may contribute, in part, to glucose intolerance in this model.

Androgen receptor signalling in the male adrenal facilitates X-zone regression, cell turnover and protects against adrenal degeneration during ageing

Androgens are known to be an essential regulator of male health. Androgen receptor (AR) is widely expressed throughout the adrenal cortex, yet the wider role for androgen signalling in the adrenal remains underexplored. To investigate AR-dependent and AR-independent androgen signalling in the adrenal, we used a novel mouse model with a specific ablation of androgen receptor in the adrenal cortex with or without reduction of circulating androgen levels by castration. Our results describe AR expression in the human and mouse adrenal and highlight that the mouse is a viable model to investigate androgen signalling in the adrenal cortex. We show androgen signalling via AR is required for X-zone regression during puberty. Furthermore, cortex measurements define differences in X-zone morphology depending on whether circulating androgens or AR have been removed. We show androgens promote both cortical cell differentiation and apoptosis but are dispensable for the formation of the definitive cortex. Additionally, investigation of aged mice with AR ablation reveals severe cortex disruption, spindle cell hyperplasia and X-zone expansion. The data described herein demonstrates AR-signalling is required to facilitate X-zone regression, cell clearance and to protect against adrenal degeneration during ageing.

Advances in understanding mechanisms of long-term sperm storage-the soft-shelled turtle model

Long-term sperm storage is a special reproductive strategy, which can extend the time window between mating and fertilization in some animal species. Spermatozoa of the soft-shelled turtle, Pelodiscus sinensis, can be stored in the epididymis and oviduct for at least six months and one year, respectively. How spermatozoa can be stored in vivo for such a prolonged period is yet to be explained. We analyze the mechanisms that contribute to long-term sperm storage in P. sinensis, and compare them with other species from three different perspectives: the spermatozoon itself, the storage microenvironment and the interaction between the spermatozoon and microenvironment. Characteristics of soft-shelled turtle spermatozoa itself, such as the huge cytoplasmic droplet with its content of several large lipid droplets (LDs) and onion-like mitochondira, facilitate long-term sperm storage. The microenvironment of reproductive tract, involving in the secretions, structural barriers, exosomes, androgen receptors, Toll-like receptors and survival factor Bcl-2, are important for the maintenance of spermatozoa long-term storage. Sperm heads are always embedded among the oviductal cilia and even intercalate into the apical hollowness of the ciliated cells, indicating that the ciliated cells support the stored spermatozoa. RNA seq is firstly used to detect the molecular mechanism of sperm storage, which shows that autophagy, apoptosis and immune take part in the long-term sperm storage in this species.

MicroRNA-381 suppresses proliferation and invasion of prostate cancer cells through downregulation of the androgen receptor

Prostate cancer (PCa) is the most frequently diagnosed malignancy in men and its incidence has increased rapidly worldwide. Notably, the molecular mechanisms underlying prostate tumorigenesis have not been fully identified. The levels of microRNA (miR)-381 have been explored in numerous types of malignancy; however, the expression levels and biological function of miR-381 in PCa remain largely unknown. In the present study, reverse-transcription polymerase chain reaction was used to detect the expression levels of miR-381 in PCa cells and normal prostate epithelial cells. Subsequently, miR-381 antisense oligonucleotides and mimics were transfected into LNCaP PCa cells. Bioinformatics analysis was performed to identify the potential target genes of miR-381. Protein expression analysis, dual-luciferase reporter assay and a rescue assay were used to confirm the target of miR-381. The data suggested that the expression levels of miR-381 were significantly decreased in PCa cells compared with in normal prostatic epithelial cells. Furthermore, transfection of LNCaP cells with miR-381 mimics suppressed their proliferation, migration and invasion. In addition, bioinformatics analysis suggested that the androgen receptor (AR) was a target gene of miR-381. miR-381 suppressed the expression levels of AR by directly binding to its 3'-untranslated region. Furthermore, transfection with an AR plasmid partially attenuated miR-381-induced inhibition of cell proliferation, migration and invasion. The results of the present study suggested that miR-381 may act as a tumor suppressor in PCa by directly targeting the AR.

New Insights into the Binding Mechanism of Co-regulator BUD31 to AR AF2 Site: Structural Determination and Analysis of the Mutation Effect

Introduction

Androgen Receptor (AR) plays a pivotal role in the development of male sex and contributes to prostate cancer growth. Different from other nuclear receptors that bind to the co-regulator LxxLL motif in coregulator peptide interaction, the AR Ligand Binding Domain (LBD) prefers to bind to the FxxLF motif. BUD31, a novel co-regulator with FxxLF motif, has been demonstrated to suppress wild-type and mutated AR-mediated prostate cancer growth.

Methods

To find out the interaction mechanisms of BUD31 with WT/T877A/W741L AR complex, molecular dynamics simulations were employed to study the complex BUD31 and WT/mutant ARs. The molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) results demonstrated that T877A and W741L point mutations can reduce the binding affinity between BUD31 and AR. The RMSF and dynamic cross-correlation analysis indicated that amino acid point mutations can affect the motions of loop residues in the AR structure.

Results

These results indicated that AR co-regulator binding site AF2 can serve as a target for drug discovery to solve the resistance problem.

Increase Paclitaxel Sensitivity to Better Suppress Serous Epithelial Ovarian Cancer via Ablating Androgen Receptor/Aryl Hydrocarbon Receptor-ABCG2 Axis

Background: Epithelial ovarian cancer (EOC) is one of the most lethal gynecological malignancies and presents chemoresistance after chemotherapy treatment. Androgen receptor (AR) has been known to participate in proliferation. Yet the mechanisms of the resistance of this drug and its linkage to the AR remains unclear. Methods: To elucidate AR-related paclitaxel sensitivity, co-IP, luciferase reporter assay and ChIP assay were performed to identify that AR direct-regulated ABCG2 expression under paclitaxel treatment. IHC staining by AR antibody presented higher AR expression in serous-type patients than other types. AR degradation enhancer (ASC-J9) was used to examine paclitaxel-associated and paclitaxel-resistant cytotoxicity in vitro and in vivo. Results: We found AR/aryl hydrocarbon receptor (AhR)-mediates ABCG2 expression and leads to a change in paclitaxel cytotoxicity/sensitivity in EOC serous subtype cell lines. Molecular mechanism study showed that paclitaxel activated AR transactivity and bound to alternative ARE in the ABCG2 proximal promoter region. To identify AR as a potential therapeutic target, the ASC-J9 was used to re-sensitize paclitaxel-resistant EOC tumors upon paclitaxel treatment in vitro and in vivo. Conclusion: The results demonstrated that activation of AR transactivity beyond the androgen-associated biological effect. This novel AR mechanism explains that degradation of AR is the most effective therapeutic strategy for treating AR-positive EOC serous subtype.

Testosterone-mediated activation of androgenic signalling sustains in vitro the transformed and radioresistant phenotype of rhabdomyosarcoma cell lines

PURPOSE

Rhabdomyosarcoma (RMS), the most common soft-tissue sarcoma in childhood, rarely affects adults, preferring male. RMS expresses the receptor for androgen (AR) and responds to androgen; however, the molecular action of androgens on RMS is unknown.

METHODS

Herein, testosterone (T) effects were tested in embryonal (ERMS) and alveolar (ARMS) RMS cell lines, by performing luciferase reporter assay, RT-PCR, and western blotting experiments. RNA interference experiments or bicalutamide treatment was performed to assess the specific role of AR. Radiation treatment was delivered to characterise the effects of T treatment on RMS intrinsic radioresistance.

RESULTS

Our study showed that RMS cells respond to sub-physiological levels of T stimulation, finally promoting AR-dependent genomic and non-genomic effects, such as the transcriptional regulation of several oncogenes, the phosphorylation-mediated post-transductional modifications of AR and the activation of ERK, p38 and AKT signal transduction pathway mediators that, by physically complexing or not with AR, participate in regulating its transcriptional activity and the expression of T-targeted genes. T chronic daily treatment, performed as for the hormone circadian rhythm, did not significantly affect RMS cell growth, but improved RMS clonogenic and radioresistant potential and increased AR mRNA both in ERMS and ARMS. AR protein accumulation was evident in ERMS, this further developing an intrinsic T-independent AR activity.

CONCLUSIONS

Our results suggest that androgens sustain and improve RMS transformed and radioresistant phenotype, and therefore, their therapeutic application should be avoided in RMS post puberal patients.

Metformin alters H2A.Z dynamics and regulates androgen dependent prostate cancer progression

Epigenetic mechanisms involved in prostate cancer include hypermethylation of tumor suppressor genes, general hypomethylation of the genome, and alterations in histone posttranslational modifications (PTMs). In addition, over expression of the histone variant H2A.Z as well as deregulated expression of Polycomb group proteins including EZH2 have been well-documented. Recent evidence supports a role for metformin in prostate cancer (PCa) treatment. However, the mechanism of action of metformin in PCa is poorly understood. We provide data showing that metformin epigenetically targets PCa by altering the levels and gene binding dynamics of histone variant H2A.Z. Moreover, we show that the increase in H2A.Z upon metformin treatment occurs preferentially due to H2A.Z.1 isoform. Chromatin immunoprecipitation (ChIP)-RT PCR analysis indicates that metformin treatment results in an increased H2A.Z occupancy on the androgen receptor (AR) and AR-regulated genes that is more prominent in the androgen dependent AR positive LNCaP cells. Repression of H2A.Z.1 gene by siRNA-mediated knock down identified this H2A.Z isoform to be responsible. Based on preliminary data with an EZH2-specific inhibitor, we suggest that the effects of metformin on the early stages of PCa may involve both EZH2 and H2A.Z through the alteration of different molecular pathways.

An active and selective molecular mechanism mediating the uptake of sex steroids by prostate cancer cells

Steroid hormones play important roles in normal physiological functions and diseases. Sex steroids hormones are important in the biology and treatment of sex hormone-related cancer such as prostate cancer and breast cancer. Cells may take up steroids using multiple mechanisms. The conventionally accepted hypothesis that steroids cross cell membrane through passive diffusion has not been tested rigorously. Experimental data suggested that cells may take up sex steroid using an active uptake mechanism. ³H-testosterone uptake by prostate cancer cells showed typical transporter-mediated uptake kinetic. Cells retained testosterone taken up from the medium. The uptake of testosterone was selective for certain steroid hormones but not others. Data also indicated that the active and selective uptake mechanism resided in cholesterol-rich membrane domains, and may involve ATP and membrane transporters. In summary, the present study provided strong evidence to support the existence of an active and selective molecular mechanism for sex steroid uptake.

Identification of SEPTIN12 as a novel target of the androgen and estrogen receptors in human testicular cells

SEPTIN12 (SEPT12) is a testis-enriched gene that is downregulated in the testis of infertile men with severe spermatogenic defects. While SEPT12 is involved in spermatogenic failure and sperm motility disorder, SEPT12 transcriptional regulation is still unknown. Here we report the promoter region of SEPT12 as a 245 bp segment upstream of the transcription start site. One androgen receptor (AR) and two estrogen receptor α (ERα) binding sites in this region were initially identified by bioinformatics prediction and confirmed by chromatin immunoprecipitation assay. Truncated ERα or AR binding sites decreased the promoter activity, which indicated that the ERα and AR are essential for the SEPT12 promoter. On the other hand, the promoter activity was enhanced by the treatment with 17β-estradiol (E2) and 5α-dihydrotestosterone (5α-DHT). Thus, one androgen and two estrogen hormone responsive elements located in the promoter of SEPT12 gene can regulate SEPT12 expression. Two single nucleotide polymorphisms (SNPs), rs759992 T > C and rs3827527 C > T, were observed in the SEPT12 gene promoter region and were able to decrease the promoter activity. In conclusion, the current work identified the promoter of the human SEPT12 gene and provided key evidence about its transcriptional regulation via E2 and 5α-DHT. Since SEPT12 has an important role in spermatogenesis, SEPT12 expression analysis can be developed as a potential tool for the assessment of environmental or food pollution by hormones or for the evaluation of the risk of endocrine-disrupting chemicals (EDCs) in general.

The high expression of FOXA1 is correlated with a favourable prognosis in salivary duct carcinomas: a study of 142 cases

AIMS

Salivary duct carcinoma (SDC) is an uncommon, aggressive tumour that, histologically, resembles high-grade mammary ductal carcinoma, and is characterised by the expression of androgen receptor (AR). The androgen signalling pathway, a potential therapeutic target, can be regulated by FOXA1. This study aimed to evaluate the clinicopathological implications of FOXA1 in SDC.

METHODS AND RESULTS

We examined the relationship between the immunoexpression of FOXA1 and FOXA1 mutations and clinicopathological factors, including the biomarker status and clinical outcome, in 142 SDCs. FOXA1 was expressed in 128 SDCs (90.1%); the immunoexpression was heterogeneous. SDCs with a higher FOXA1 labelling index (LI) (≥20%) more frequently showed less advanced tumors on T classification (P = 0.002). FOXA1 LI was correlated positively with the AR expression value (r = 0.430, P < 0.001). PI3K and p-mTOR positivity, and intact-PTEN, were associated with a higher FOXA1 LI. Twenty-two of 121 SDCs (18.2%) harboured FOXA1 gene mutations at the flanking regions in and around the forkhead DNA binding domain; however, the given gene mutation and the expression of FOXA1 were not significantly correlated. A multivariate analysis revealed that SDCs with a higher FOXA1 LI were associated with longer overall survival and progression-free survival (P = 0.029 and 0.016, respectively).

CONCLUSIONS

In SDC, FOXA1, which may biologically interact with the AR and PI3K signalling pathways, is a putative biomarker that may be associated with a favourable prognosis. Further studies are needed to apply the findings to the development of targeted personalised therapy for patients with SDC.

Sex differences in lipid and lipoprotein metabolism

BACKGROUND

Endogenous sex hormones are important for metabolic health in men and women. Before menopause, women are protected from atherosclerotic cardiovascular disease (ASCVD) relative to men. Women have fewer cardiovascular complications of obesity compared to men with obesity. Endogenous estrogens have been proposed as a mechanism that lessens ASCVD risk, as risk of glucose and lipid abnormalities increases when endogenous estrogens decline with menopause. While baseline risk is higher in males than females, endogenously produced androgens are also protective against fatty liver, diabetes and ASCVD, as risk goes up with androgen deprivation and with the decline in androgens with age.

SCOPE OF REVIEW

In this review, we discuss evidence of how endogenous sex hormones and hormone treatment approaches impact fatty acid, triglyceride, and cholesterol metabolism to influence metabolic and cardiovascular risk. We also discuss potential reasons for why treatment strategies with estrogens and androgens in older individuals fail to fully recapitulate the effects of endogenous sex hormones.

MAJOR CONCLUSIONS

The pathways that confer ASCVD protection for women are of potential therapeutic relevance. Despite protection relative to men, ASCVD is still the major cause of mortality in women. Additionally, diabetic women have similar ASCVD risk as diabetic men, suggesting that the presence of diabetes may offset the protective cardiovascular effects of being female through unknown mechanisms.

Complete Androgen Insensitivity Syndrome due to Mutations in the DNA-Binding Domain of the Human Androgen Receptor Gene

Androgen insensitivity syndrome (AIS) is an X-linked recessive disorder with a 46,XY karyotype caused by alterations in the androgen receptor (AR) gene. We have identified 2 mutations in the AR gene that resulted in complete androgen insensitivity syndrome (CAIS) in 2 unrelated cases. This study includes cytogenetics, hormonal, molecular, and bioinformatics analysis including sequencing of the SRY (sex-determining region Y) and AR genes. Mutational analysis in the first case of primary amenorrhea revealed a novel nucleotide substitution (IVS2-2A>G) in the second intron of the AR gene. The mutation is located in the acceptor splice site (2 nucleotides before exon 3) and caused skipping of exon 3 and formation of an abnormal protein. The second mutation (g. 98762_98764delTCT) was identified in a case of oligoamenorrhea and caused the deletion of 1 amino acid (p.∆Phe583). Both identified mutations were located in the conserved P-box region of the DNA-binding domain which is responsible for base-specific contacts with the DNA major groove. Furthermore, a hormonal imbalance was also noticed in both cases with high levels of gonadotropins like FSH and LH in both cases. The present study concluded that both identified AR mutations are predicted to either abolish or decrease the binding ability of the AR to androgen response elements of its downstream genes.

Transcriptome analysis reveals novel insights into the response of low-dose benzo(a)pyrene exposure in male tilapia

Despite a wide number of toxicological studies that describe benzo[a]pyrene (BaP) effects, the metabolic mechanisms that underlie these effects in fish are largely unknown. Of great concern is the presence of BaP in aquatic systems, especially those in close proximity to human activity leading to consumption of potentially contaminated foods. BaP is a known carcinogen and it has been reported to have adverse effects on the survival, development and reproduction of fish. The purpose of this study was to investigate if a low dose of BaP can alter genes and key metabolic pathways in the liver and testis in male adult tilapia, and whether these could be associated with biological endpoints disruption. We used both high-throughput RNA-Sequencing to assess whole genome gene expression following repeated intraperitoneal injections of 3 mg/kg of BaP (every 6 days for 26 days) and morphometric endpoints as indicators of general health. Condition factor (K) along with hepatosomatic and gonadosomatic indices (morphometric parameters) were significantly lower in BaP-treated fish than in controls. BaP exposure induced important changes in the gene expression pattern in liver and testis as revealed by both Pathway and Gene Ontology (GO) analyses. Alterations that were shared by both tissues included arachidonic acid metabolism, androgen receptor to prostate-specific antigen signaling, and insulin-associated effects on lipogenesis. The most salient liver-specific effects included: biological processes involved in detoxification, IL6-associated insulin resistance, mTOR hyperactivation, mitotic cytokinesis, spindle pole and microtubule binding. BaP effects that were confined to the testis included: immune system functions, inflammatory response, estrogen and androgen metabolic pathways. Taken together, gene expression and morphometric end point data indicate that the reproductive success of adult male tilapia could be compromised as a result of BaP exposure. These results constitute new insights on the mechanism of action of low dose BaP in a non-model organism (tilapia).

Berberine Improves Benign Prostatic Hyperplasia via Suppression of 5 Alpha Reductase and Extracellular Signal-Regulated Kinase in Vivo and in Vitro

Benign prostate hyperplasia (BPH) is a common disease in elderly men, characterized by proliferated prostate and urinary tract symptoms. The hormonal cascade starting by the action of 5-alpha-reductase (5AR) is known to be one of the pathways responsible for the pathogenesis of BPH. Present investigation evaluated the capacity of berberine (BBR), a nature-derived compound abundant in Coptis japonica, in testosterone-induced BPH rats. Experimental BPH was induced by inguinal injection with testosterone propionate (TP) for 4 weeks. BBR or finasteride, a 5AR inhibitor as positive control, was treated for 4 weeks during BPH. BPH induced by TP evoked weight gaining and histological changes of prostate and BBR treatment improved all the detrimental effects not only weight reduction and histological changes but also suppression of prostate-specific antigen (PSA), which is elevated during BPH. Additionally, BBR suppressed TP-associated increase of 5AR, androgen receptor (AR) and steroid coactivator-1 (SRC-1), the key factors in the pathogenesis of BPH. To evaluate the underlying molecular mechanisms responsible for beneficial effects of BBR, we investigated whether these effects were associated with the mitogen-activated protein kinase pathway. BPH induced by TP showed increased phosphorylation of extracellular signal-regulated kinase (ERK), whereas this was suppressed by BBR treatment. On the other hand, c-jun-N-terminal kinase (JNK) and p38 mitogen-activated protein kinase was not changed in BPH rats. In in vitro study using RWPE-1 cells, a human prostate epithelial cell line. TP increased cell proliferation and BPH-related key factors such as PSA, AR, and 5AR in RWPE-1 cells, and those factors were significantly decreased in the presence of BBR. Furthermore, these proliferative effects in RWPE-1cells were attenuated by treatment with U0126, an ERK inhibitor, confirming BBR can relieve overgrowth of prostate via ERK-dependent signaling. The cotreatment of U0126 and BBR did not affect the change of 5AR nor proliferation compared with U0126 alone, suggesting that the effect of BBR was dependent on the action of ERK. In conclusion, this study shows that BBR can be used as a therapeutic agent for BPH by controlling hyperplasia of prostate through suppression of ERK mechanism.

Identification of open chromosomal regions and key genes in prostate cancer via integrated analysis of DNase‑seq and RNA‑seq data

Prostate cancer is a type of adenocarcinoma arising from the peripheral zone of the prostate gland, and metastasized prostate cancer is incurable with the current available therapies. The present study aimed to identify open chromosomal regions and differentially expressed genes (DEGs) associated with prostate cancer development. The DNase sequencing data (GSE33216) and RNA sequencing data (GSE22260) were downloaded from the Gene Expression Omnibus database. DNase I hypersensitive sites were detected and analyzed. Subsequently, DEGs were identified and their potential functions were enriched. Finally, upstream regulatory elements of DEGs were predicted. In LNCaP cells, following androgen receptor activation, 244 upregulated and 486 downregulated open chromosomal regions were identified. However, only 1% of the open chromosomal regions were dynamically altered. The 41 genes with upregulated open chromosomal signals within their promoter regions were primarily enriched in biological processes. Additionally, 211 upregulated and 150 downregulated DEGs were identified in prostate cancer, including eight transcription factors (TFs). Finally, nine regulatory elements associated with prostate cancer were predicted. In particular, inhibitor of DNA binding 1 HLH protein (ID1) was the only significantly upregulated TF which exhibited motif enrichment in the promoter regions of upregulated genes. CCCTC‑binding factor (CTCF) and ELK1 ETS transcription factor (ELK1), enriched in the open promoter regions of downregulated genes, were potential upstream regulatory elements. Furthermore, reverse transcription‑quantitative polymerase chain reaction analysis confirmed that ID1 expression was significantly upregulated in LNCaP cells and 5α‑dihydrotestosterone (DHT)‑treated LNCaP cells compared with that in BPH1 cells, while CTCF and ELK1 expression was significantly downregulated in LNCaP cells and DHT‑treated LNCaP cells. In conclusion, ID1, CTCF and ELK1 may be associated with prostate cancer, and may be potential therapeutic targets for the treatment of this disease.

Role of androgens in energy metabolism affecting on body composition, metabolic syndrome, type 2 diabetes, cardiovascular disease, and longevity: lessons from a meta-analysis and rodent studies

Testosterone is a sex hormone produced by testicular Leydig cells in males. Blood testosterone concentrations increase at three time-periods in male life-fetal, neonatal (which can be separated into newborn and infant periods), and pubertal stages. After peaking in the early 20s, the blood bioactive testosterone level declines by 1-2% each year. It is increasingly apparent that a low testosterone level impairs general physical and mental health in men. Here, this review summarizes recent systematic reviews and meta-analyses of epidemiological studies in males (including cross-sectional, longitudinal, and androgen deprivation studies, and randomized controlled testosterone replacement trials) in relation to testosterone and obesity,  body composition, metabolic syndrome, type 2 diabetes, cardiovascular disease, and longevity. Furthermore, underlying mechanisms are discussed using data from rodent studies involving castration or androgen receptor knockout. This review provides an update understanding of the role of testosterone in energy metabolism. Abbreviations AR: androgen receptor; CV: cardiovascular; FDA: US Food and Drug Administration; HFD: high-fat diet; KO: knockout; MetS: metabolic syndrome; RCT: randomized controlled trial; SHBG: sex hormone binding globulin; SRMA: systematic review and meta-analysis; TRT: testosterone replacement therapy; T2DM:type 2 diabetes mellitus.

Peripheral sensitivity to steroids revisited

Resistance to steroid hormones presents a serious problem with respect to their mass use in therapy. It may be caused genetically by mutation of genes involved in hormonal signaling, not only steroid receptors, but also other players in the signaling cascade as co-regulators and other nuclear factors, mediating the hormone-born signal. Another possibility is acquired resistance which may develop under long-term steroid treatment, of which a particular case is down regulation of the receptors. In the review recent knowledge is summarized on the mechanism of main steroid hormone action, pointing to already proven or potential sites causing steroid resistance. We have attempted to address following questions: 1) What does stay behind differences among patients as to their response to the (anti)steroid treatment? 2) Why do various tissues/cells respond differently to the same steroid hormone though they contain the same receptors? 3) Are such differences genetically dependent? The main attention was devoted to glucocorticoids as the most frequently used steroid therapeutics. Further, androgen insensitivity is discussed with a particular attention to acquired resistance to androgen deprivation therapy of prostate cancer. Finally the potential causes are outlined of breast and related cancer(s) resistance to antiestrogen therapy.

Sex differences, endogenous sex-hormone hormones, sex-hormone binding globulin, and exogenous disruptors in diabetes and related metabolic outcomes

In assessing clinical and pathophysiological development of type 2 diabetes (T2D), the critical role of the sex steroids axis is underappreciated, particularly concerning the sex-specific relationships with many relevant cardiometabolic outcomes. In this issue of the Journal of Diabetes, we provide a comprehensive overview of these significant associations of germline variants in the genes governing the sex steroid pathways, plasma levels of steroid hormones, and sex hormone-binding globulin (SHBG) with T2D risk that have been observed in many clinical and high-quality large prospective cohorts of men and women across ethnic populations. Together, this body of evidence indicates that sex steroids and SHBG should be routinely incorporated into clinical characterization of T2D patients, particularly in screening prediabetic patients, such as those with metabolic syndrome, using plasma levels of SHBG. Given that several germline mutations in the SHBG gene have also been directly related to both plasma concentrations of SHBG and clinical manifestation of T2D, targeting signals in the sex steroid axis, particularly SHBG, may have significant utility in the prediction and treatment of T2D. Further, many of the environmental endocrine disrupting chemicals may exert their potential adverse effects on cardiometabolic outcomes via either estrogenic or androgenic signaling pathways, highlighting the importance of using the sex steroids and SHBG as important biochemical markers in both clinical and population studies in studying sex-specific mechanisms in the pathogenesis of T2D and its complications, as well as the need to equitably allocate resources in studying both men and women.

Development of selective androgen receptor modulators (SARMs)

The Androgen Receptor (AR), a member of the steroid hormone receptor family, plays important roles in the physiology and pathology of diverse tissues. AR ligands, which include circulating testosterone and locally synthesized dihydrotestosterone, bind to and activate the AR to elicit their effects. Ubiquitous expression of the AR, metabolism and cross reactivity with other receptors limit broad therapeutic utilization of steroidal androgens. However, the discovery of selective androgen receptor modulators (SARMs) and other tissue-selective nuclear hormone receptor modulators that activate their cognate receptors in a tissue-selective manner provides an opportunity to promote the beneficial effects of androgens and other hormones in target tissues with greatly reduced unwanted side-effects. In the last two decades, significant resources have been dedicated to the discovery and biological characterization of SARMs in an effort to harness the untapped potential of the AR. SARMs have been proposed as treatments of choice for various diseases, including muscle-wasting, breast cancer, and osteoporosis. This review provides insight into the evolution of SARMs from proof-of-concept agents to the cusp of therapeutic use in less than two decades, while covering contemporary views of their mechanisms of action and therapeutic benefits.

The role of androgen receptors in atherosclerosis

Male disadvantage in cardiovascular health is well recognised. However, the influence of androgens on atherosclerosis, one of the major causes of many life-threatening cardiovascular events, is not well understood. With the dramatic increase in clinical prescription of testosterone in the past decade, concerns about the cardiovascular side-effects of androgen supplementation or androgen deprivation therapy are increasing. Potential atheroprotective effects of testosterone could be secondary to (aromatase-mediated) conversion into oestradiol or, alternatively, to direct activation of androgen receptors (AR). Recent development of animal models with cell-specific AR knockout has indicated a complex role for androgen action in atherosclerosis. Most studies suggest androgens are atheroprotective but the precise role of AR remains unclear. Increased use of AR knockout models should clarify the role of AR in atherogenesis and, thus, lead to exploitation of this pathway as a therapeutic target.

Androgens and androgen receptor action in skin and hair follicles

Beyond sexual functions, androgens exert their action in skin physiology and pathophysiology. Skin cells are able to synthesize most active androgens from gonadal or adrenal precursors and the enzymes involved in skin steroidogenesis are implicated both in normal or pathological processes. Even when the role of androgens and androgen receptor (AR) in skin pathologies has been studied for decades, their molecular mechanisms in skin disorders remain largely unknown. Here, we analyze recent studies of androgens and AR roles in several skin-related disorders, focusing in the current understanding of their molecular mechanisms in androgenetic alopecia (AGA). We review the molecular pathophysiology of type 2 5α-reductase, AR coactivators, the paracrine factors deregulated in dermal papillae (such as TGF-β, IGF 1, WNTs and DKK-1) and the crosstalk between AR and Wnt signaling in order to shed some light on new promising treatments.

Role of Androgens in Female Genitourinary Tissue Structure and Function: Implications in the Genitourinary Syndrome of Menopause

INTRODUCTION

Genitourinary conditions in women increase in prevalence with age. Androgens are prerequisite hormones of estrogen biosynthesis, are produced in larger amounts than estrogens in women, and decrease throughout adulthood. However, research and treatment for genitourinary complaints have traditionally focused on estrogens to the exclusion of other potential hormonal influences.

AIM

To summarize and evaluate the evidence that androgens are important for maintaining genitourinary health in women and that lack of androgenic activity can contribute to the development of symptoms of the genitourinary syndrome of menopause.

METHODS

The role of androgens in the pathophysiology, diagnosis, and treatment of genitourinary syndrome of menopause was discussed by an international and multidisciplinary panel during a consensus conference organized by the International Society for the Study of Women's Sexual Health. A subgroup further examined publications from the PubMed database, giving preference to clinical studies or to basic science studies in human tissues.

MAIN OUTCOME MEASURES

Expert opinion evaluating trophic and functional effects of androgens, their differences from estrogenic effects, and regulation of androgen and estrogen receptor expression in female genitourinary tissues.

RESULTS

Androgen receptors have been detected throughout the genitourinary system using immunohistochemical, western blot, ligand binding, and gene expression analyses. Lower circulating testosterone and estradiol concentrations and various genitourinary conditions have been associated with differential expression of androgen and estrogen receptors. Supplementation of androgen and/or estrogen in postmenopausal women (local administration) or in ovariectomized animals (systemic administration) induces tissue-specific responses that include changes in androgen and estrogen receptor expression, cell growth, mucin production, collagen turnover, increased perfusion, and neurotransmitter synthesis.

CONCLUSION

Androgens contribute to the maintenance of genitourinary tissue structure and function. The effects of androgens can be distinct from those of estrogens or can complement estrogenic action. Androgen-mediated processes might be involved in the full or partial resolution of genitourinary syndrome of menopause symptoms in women. Traish AM, Vignozzi L, Simon JA, et al. Role of Androgens in Female Genitourinary Tissue Structure and Function: Implications in the Genitourinary Syndrome of Menopause. Sex Med Rev 2018;6:558-571.

Chrysophanic acid reduces testosterone-induced benign prostatic hyperplasia in rats by suppressing 5α-reductase and extracellular signal-regulated kinase

Benign prostatic hyperplasia (BPH) is one of the most common chronic diseases in male population, of which incidence increases gradually with age. In this study, we investigated the effect of chrysophanic acid (CA) on BPH. BPH was induced by a 4-week injection of testosterone propionate (TP). Four weeks of further injection with vehicle, TP, TP + CA, TP + finasteride was carried on. In the CA treatment group, the prostate weight was reduced and the TP-induced histological changes were restored as the normal control group. CA treatment suppressed the TP-elevated prostate specific antigen (PSA) expression. In addition, 5α-reductase, a crucial factor in BPH development, was suppressed to the normal level close to the control group by CA treatment. The elevated expressions of androgen receptor (AR), estrogen receptor α and steroid receptor coactivator 1 by TP administration were also inhibited in the CA group when compared to the TP-induced BPH group. Then we evaluated the changes in three major factors of the mitogen-activated protein kinase chain during prostatic hyperplasia; extracellular signal-regulated kinase (ERK), c-Jun-N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38). While ERK was elevated in the process of BPH, JNK and p38 was not changed. This up-regulated ERK was also reduced as normal by CA treatment. Further in vitro studies with RWPE-1 cells confirmed TP-induced proliferation and elevated AR, PSA and p-ERK were all reduced by CA treatment. Overall, these results suggest a potential pharmaceutical feature of CA in the treatment of BPH.

Constructing Bayesian networks by integrating gene expression and copy number data identifies NLGN4Y as a novel regulator of prostate cancer progression

To understand the heterogeneity of prostate cancer (PCa) and identify novel underlying drivers, we constructed integrative molecular Bayesian networks (IMBNs) for PCa by integrating gene expression and copy number alteration data from published datasets. After demonstrating such IMBNs with superior network accuracy, we identified multiple sub-networks within IMBNs related to biochemical recurrence (BCR) of PCa and inferred the corresponding key drivers. The key drivers regulated a set of common effectors including genes preferentially expressed in neuronal cells. NLGN4Y—a protein involved in synaptic adhesion in neurons—was ranked as the top gene closely linked to key drivers of myogenesis subnetworks. Lower expression of NLGN4Y was associated with higher grade PCa and an increased risk of BCR. We show that restoration of the protein expression of NLGN4Y in PC-3 cells leads to decreased cell proliferation, migration and inflammatory cytokine expression. Our results suggest that NLGN4Y is an important negative regulator in prostate cancer progression. More importantly, it highlights the value of IMBNs in generating biologically and clinically relevant hypotheses about prostate cancer that can be validated by independent studies.

Low-dose metformin exposure causes changes in expression of endocrine disruption-associated genes

The presence of intersex fish in watersheds around the world is a warning of the presence of anthropogenic endocrine-disrupting compounds (EDCs) being deposited into the aquatic environment. The anti-diabetic drug metformin is among the most prevalent and ubiquitous of the myriad pharmaceuticals found in wastewater effluent and watersheds worldwide. In addition to its prescription for type-2 diabetes, metformin is indicated as a treatment in cancers and the endocrine disorder polycystic ovarian syndrome (PCOS). Our previous research found evidence of endocrine-disruption following Pimephales promelas (fathead minnow) exposure to metformin at an environmentally relevant concentration. However, the mechanism of action leading to these impacts is unknown. Although metformin does not structurally resemble classical EDCs, there's an increasing recognition that endocrine disruption may occur by mechanisms other than classical endocrine receptor binding, and metformin's off-label use for treating endocrine-related disorders such as PCOS indicates its potential interaction with the endocrine system. To further explore metformin's mechanism of action as an EDC, we measured expression of numerous endocrine-related genes in male fathead minnows exposed to metformin at a low-dose similar to that found in wastewater effluent and the environment (40 μg L^-1) for a full year (early development to adulthood) and discovered significant upregulation of the AR (3.6 ± 0.9-fold), 3β-HSD (3.9 ± 0.8-fold), 17β-HSD (17 ± 4-fold), CYP19A1 (40 ± 20-fold), and SULT2A1 (2.3 ± 0.4-fold) genes in exposed male gonad. We also found a significant correlation between expression of 3β-HSD, 17β-HSD, and CYP19A1 in testis of metformin-treated male fish and the degree of intersex occurring in their gonads. These results provide additional evidence of the endocrine disrupting impact of the drug metformin and insight into the potential mechanisms by which metformin may influence the endocrine system in aquatic organisms.

Circular RNA expression is suppressed by androgen receptor (AR)-regulated adenosine deaminase that acts on RNA (ADAR1) in human hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a heterogeneous malignancy as a result of complex genetic and epigenetic alterations. HCC is characterized by a clear gender disparity for which there is lack of a clear mechanistic understanding. Androgen receptor (AR) is thought to be critical for such bias. Meanwhile, the potential function of circular RNA (circRNA), regulated by RNA editing enzyme, remained largely unknown in malignancy till now. By utilizing circRNA microarray survey coupled with in vitro analysis, we analyzed the influence of AR on circRNA expression in HCC. Our results indicated that AR could suppress circRNA expression by upregulating ADAR1 p110. Such effect is because AR served as a transcriptional activator of ADAR1 promoter. More significantly, data collected from our center strongly suggest that ADAR1 expression can effectively predict HCC patients' prognosis and an abnormal overexpression of ADAR1 is positively correlated with AR in HCC. In addition, we found CircARSP91 (hsa_circ_0085154), one of the circRNAs downregulated by AR in an ADAR1-dependent manner, could inhibit HCC tumor growth both in vitro and in vivo. These findings highlight the fact that AR as a contributing factor for gender disparity in HCC can cause complex consequences though regulation of circRNA expression. Better understanding of the roles of circRNA during HCC initiation and progression will provide a novel angle to develop potential HCC therapies.

Targeting AR Variant-Coactivator Interactions to Exploit Prostate Cancer Vulnerabilities

Castration-resistant prostate cancer (CRPC) progresses rapidly and is incurable. Constitutively active androgen receptor splice variants (AR-Vs) represent a well-established mechanism of therapeutic resistance and disease progression. These variants lack the AR ligand-binding domain and, as such, are not inhibited by androgen deprivation therapy (ADT), which is the standard systemic approach for advanced prostate cancer. Signaling by AR-Vs, including the clinically relevant AR-V7, is augmented by Vav3, an established AR coactivator in CRPC. Using mutational and biochemical studies, we demonstrated that the Vav3 Diffuse B-cell lymphoma homology (DH) domain interacted with the N-terminal region of AR-V7 (and full length AR). Expression of the Vav3 DH domain disrupted Vav3 interaction with and enhancement of AR-V7 activity. The Vav3 DH domain also disrupted AR-V7 interaction with other AR coactivators: Src1 and Vav2, which are overexpressed in PC. This Vav3 domain was used in proof-of-concept studies to evaluate the effects of disrupting the interaction between AR-V7 and its coactivators on CRPC cells. This disruption decreased CRPC cell proliferation and anchorage-independent growth, caused increased apoptosis, decreased migration, and resulted in the acquisition of morphological changes associated with a less aggressive phenotype. While disrupting the interaction between FL-AR and its coactivators decreased N-C terminal interaction, disrupting the interaction of AR-V7 with its coactivators decreased AR-V7 nuclear levels.Implications: This study demonstrates the potential therapeutic utility of inhibiting constitutively active AR-V signaling by disrupting coactivator binding. Such an approach is significant, as AR-Vs are emerging as important drivers of CRPC that are particularly recalcitrant to current therapies. Mol Cancer Res; 15(11); 1469-80. ©2017 AACR.

Transcriptional mechanisms coordinating tight junction assembly during epithelial differentiation

Epithelial tissues form a selective barrier via direct cell-cell interactions to separate and establish concentration gradients between the different compartments of the body. Proper function and formation of this barrier rely on the establishment of distinct intercellular junction complexes. These complexes include tight junctions, adherens junctions, desmosomes, and gap junctions. The tight junction is by far the most diverse junctional complex in the epithelial barrier. Its composition varies greatly across different epithelial tissues to confer various barrier properties. Thus, epithelial cells rely on tightly regulated transcriptional mechanisms to ensure proper formation of the epithelial barrier and to achieve tight junction diversity. Here, we review different transcriptional mechanisms utilized during embryogenesis and disease development to promote tight junction assembly and maintenance of intercellular barrier integrity. We focus particularly on the Grainyhead-like transcription factors and ligand-activated nuclear hormone receptors, two central families of proteins in epithelialization.

Vanillic acid attenuates testosterone-induced benign prostatic hyperplasia in rats and inhibits proliferation of prostatic epithelial cells

Benign prostatic hyperplasia (BPH) is a common disease in the male population, especially in elderly men. Vanillic acid (VA), a dihydroxybenzoic derivative used as a flavoring agent, is reported to have an anti-inflammatory effect. However, there are no reports of its effects on BPH to date. BPH was induced with a pre-4-week treatment of daily subcutaneous injections of testosterone propionate (TP), and the normal control group received injections of ethanol with corn oil instead. Six weeks of further injections were done with (a) ethanol with corn oil, (b) TP only, (c) TP + finasteride, and (d) TP + VA. Finasteride was used as a positive control group. VA had protective effects on the TP-induced BPH. In the VA treatment group, the prostate weight was reduced, and the histological changes including the epithelial thickness and lumen area were restored like in the normal control group. Furthermore, in the VA treatment group, two proliferation related factors, high molecular weight cytokeratin 34βE12 and α smooth muscle actin, were significantly down-regulated compared to the TP-induced BPH group. The expressions of dihydrotestosterone and 5α-reductase, the most crucial factors in BPH development, were suppressed by VA treatment. Expressions of the androgen receptor, estrogen receptor α and steroid receptor coactivator 1 were also significantly inhibited by VA compared to the TP-induced BPH group. In addition, we established an in vitro model for BPH by treating a normal human prostatic epithelial cell line RWPE-1 with TP. VA successfully inhibited proliferation and BPH-related factors in a concentration-dependent manner in this newly established model. These results suggest a new and potential pharmaceutical therapy of VA in the treatment of BPH.

Transcriptional role of androgen receptor in the expression of long non-coding RNA Sox2OT in neurogenesis

The complex architecture of adult brain derives from tightly regulated migration and differentiation of precursor cells generated during embryonic neurogenesis. Changes at transcriptional level of genes that regulate migration and differentiation may lead to neurodevelopmental disorders. Androgen receptor (AR) is a transcription factor that is already expressed during early embryonic days. However, AR role in the regulation of gene expression at early embryonic stage is yet to be determinate. Long non-coding RNA (lncRNA) Sox2 overlapping transcript (Sox2OT) plays a crucial role in gene expression control during development but its transcriptional regulation is still to be clearly defined. Here, using Bicalutamide in order to pharmacologically inactivated AR, we investigated whether AR participates in the regulation of the transcription of the lncRNASox2OTat early embryonic stage. We identified a new DNA binding region upstream of Sox2 locus containing three androgen response elements (ARE), and found that AR binds such a sequence in embryonic neural stem cells and in mouse embryonic brain. Our data suggest that through this binding, AR can promote the RNA polymerase II dependent transcription of Sox2OT. Our findings also suggest that AR participates in embryonic neurogenesis through transcriptional control of the long non-coding RNA Sox2OT.

Androgenic mechanisms of sexual differentiation of the nervous system and behavior

Testicular androgens are the major endocrine factor promoting masculine phenotypes in vertebrates, but androgen signaling is complex and operates via multiple signaling pathways and sites of action. Recently, selective androgen receptor mutants have been engineered to study androgenic mechanisms of sexual differentiation of the nervous system and behavior. The focus of these studies has been to evaluate androgenic mechanisms within the nervous system by manipulating androgen receptor conditionally in neural tissues. Here we review both the effects of neural loss of AR function as well as the effects of neural overexpression of AR in relation to global AR mutants. Although some studies have conformed to our expectations, others have proved challenging to assumptions underlying the dominant hypotheses. Notably, these studies have called into question both the primacy of direct, neural mechanisms and also the linearity of the relationship between androgenic dose and sexual differentiation of brain and behavior.

Sex differences in vascular physiology and pathophysiology: estrogen and androgen signaling in health and disease

Sex differences between women and men are often overlooked and underappreciated when studying the cardiovascular system. It has been long assumed that men and women are physiologically similar, and this notion has resulted in women being clinically evaluated and treated for cardiovascular pathophysiological complications as men. Currently, there is increased recognition of fundamental sex differences in cardiovascular function, anatomy, cell signaling, and pathophysiology. The National Institutes of Health have enacted guidelines expressly to gain knowledge about ways the sexes differ in both normal function and diseases at the various research levels (molecular, cellular, tissue, and organ system). Greater understanding of these sex differences will be used to steer future directions in the biomedical sciences and translational and clinical research. This review describes sex-based differences in the physiology and pathophysiology of the vasculature, with a special emphasis on sex steroid receptor (estrogen and androgen receptor) signaling and their potential impact on vascular function in health and diseases (e.g., atherosclerosis, hypertension, peripheral artery disease, abdominal aortic aneurysms, cerebral aneurysms, and stroke).

Characterization of a novel androgen receptor (AR) coregulator RIPK1 and related chemicals that suppress AR-mediated prostate cancer growth via peptide and chemical screening

Using bicalutamide-androgen receptor (AR) DNA binding domain-ligand binding domain as bait, we observed enrichment of FxxFY motif-containing peptides. Protein database searches revealed the presence of receptor-interacting protein kinase 1 (RIPK1) harboring one FxxFY motif. RIPK1 interacted directly with AR and suppressed AR transactivation in a dose-dependent manner. Domain mapping experiments showed that the FxxFY motif in RIPK1 is critical for interactions with AR and the death domain of RIPK1 plays a crucial role in its inhibitory effect on transactivation. In terms of tissue expression, RIPK1 levels were markedly higher in benign prostate hyperplasia and non-cancerous tissue regions relative to the tumor area. With the aid of computer modeling for screening of chemicals targeting activation function 2 (AF-2) of AR, we identified oxadiazole derivatives as good candidates and subsequently generated a small library of these compounds. A number of candidates could effectively suppress AR transactivation and AR-related functions in vitro and in vivo with tolerable toxicity via inhibiting AR-peptide, AR-coregulator and AR N-C interactions. Combination of these chemicals with antiandrogen had an additive suppressive effect on AR transcriptional activity. Our collective findings may pave the way in creating new strategies for the development and design of anti-AR drugs.

Androgen Receptor Could Be a Potential Therapeutic Target in Patients with Advanced Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a male-dominant disease with poor prognosis. Sorafenib is the only approved systemic chemotherapeutic drug for patients with advanced HCC. Previous studies have shown that androgen and androgen receptor (AR) are involved in human hepatocarcinogenesis and the development of HCC. Here, we discuss the recent data on AR and HCC, and the combination of sorafenib and inhibitors of AR for advanced-HCC patients. Androgen-dependent and androgen-independent AR activation exist in human hepatocarcinogenesis. AR could directly control hepatocarcinogenesis and regulate the innate immune system to influence HCC progression. Combination of sorafenib with AR inhibitors might represent a potential treatment for patients with advanced HCC.

Trichosanthes kirilowii Exerts Androgenic Activity via Regulation of PSA and KLK2 in 22Rv1 Prostate Cancer Cells

Background:

The androgen comprises a group of hormones that play roles in male reproductive activity as well as personal characteristics.

Objective:

We investigated the androgenic activity of various herbal medicines in human prostate cancer 22Rv1 cells.

Materials and Methods:

Herbal extracts of Trichosanthes kirilowii (TK), Asarum sieboldii (AS), Sanguisorba officinalis (SO), and Xanthium strumarium (XS) were selected to have androgenic effects based on a preliminary in vitro screening system.

Results:

TK, AS, SO, and XS enhanced the proliferation of 22Rv1 cells without having cytotoxic effects. All tested herbal extracts increased androgen receptor (AR)-induced transcriptional activity in the absence or presence of dihydrotestosterone (DHT). In an AR-binding assay, TK, but not AS, SO, or XS, produced a significant inhibition of AR binding activity, indicating it has androgenic activity. Additionally, TK treatment positively regulated mRNA expression of the AR-related molecular targets prostate-specific antigen (PSA) and kallikrein 2 (KLK2) compared with untreated control.

Conclusion:

Taken together, TK-enhanced AR-mediated transcriptional activity might be an attractive candidate drug for treating androgen-related diseases.

SUMMARY

Trichosantheskirilowii (TK), Asarumsieboldii (AS), Sanguisorbaofficinalis (SO), and Xanthium strumarium (XS) enhanced the proliferation of 22Rv1 cells without having cytotoxic effects.

TK, AS, SO, and XS increased androgen receptor (AR)-induced transcriptional activity.

TK, but not AS, SO, or XS, produced a significant inhibition against AR-binding activity.

TK treatment positively regulated mRNA expression of the AR-related molecular targets prostate-specific antigen and kallikrein 2.

Abbreviations used: BPH: benign prostatic hyperplasia; AR: androgen receptor; DHT: dihydrotestosterone; PSA: prostate-specific antigen; TK: Trichosanthes kirilowii; AS: Asarum sieboldii; SO: Sanguisorba officinalis; XS: Xanthium strumarium; ATCC: American Type Culture Collection; FBS: fetal bovine serum; PBS: phosphate-buffered saline; SD: standard deviation; ARE: androgenresponsive element; KLK: kallikrein

Food components and contaminants as (anti)androgenic molecules

Androgens, the main male sex steroids, are the critical factors responsible for the development of the male phenotype during embryogenesis and for the achievement of sexual maturation and puberty. In adulthood, androgens remain essential for the maintenance of male reproductive function and behavior. Androgens, acting through the androgen receptor (AR), regulate male sexual differentiation during development, sperm production beginning from puberty, and maintenance of prostate homeostasis. Several substances present in the environment, now classified as endocrine disruptors (EDCs), strongly interfere with androgen actions in reproductive and non-reproductive tissues. EDCs are a heterogeneous group of xenobiotics which include synthetic chemicals used as industrial solvents/lubricants, plasticizers, additives, agrochemicals, pharmaceutical agents, and polyphenols of plant origin. These compounds are even present in the food as components (polyphenols) or food/water contaminants (pesticides, plasticizers used as food packaging) rendering the diet as the main route of exposure to EDCs for humans. Although huge amount of literature reports the (anti)estrogenic effects of different EDCs, relatively scarce information is available on the (anti)androgenic effects of EDCs. Here, the effects and mechanism of action of phytochemicals and pesticides and plasticizers as possible modulators of AR activities will be reviewed taking into account that insight derived from principles of endocrinology are required to estimate EDC consequences on endocrine deregulation and disease.

A Tale of Two Signals: AR and WNT in Development and Tumorigenesis of Prostate and Mammary Gland

Prostate cancer (PCa) is one of the most common cancers and among the leading causes of cancer deaths for men in industrialized countries. It has long been recognized that the prostate is an androgen-dependent organ and PCa is an androgen-dependent disease. Androgen action is mediated by the androgen receptor (AR). Androgen deprivation therapy (ADT) is the standard treatment for metastatic PCa. However, almost all advanced PCa cases progress to castration-resistant prostate cancer (CRPC) after a period of ADT. A variety of mechanisms of progression from androgen-dependent PCa to CRPC under ADT have been postulated, but it remains largely unclear as to when and how castration resistance arises within prostate tumors. In addition, AR signaling may be modulated by extracellular factors among which are the cysteine-rich glycoproteins WNTs. The WNTs are capable of signaling through several pathways, the best-characterized being the canonical WNT/β-catenin/TCF-mediated canonical pathway. Recent studies from sequencing PCa genomes revealed that CRPC cells frequently harbor mutations in major components of the WNT/β-catenin pathway. Moreover, the finding of an interaction between β-catenin and AR suggests a possible mechanism of cross talk between WNT and androgen/AR signaling pathways. In this review, we discuss the current knowledge of both AR and WNT pathways in prostate development and tumorigenesis, and their interaction during development of CRPC. We also review the possible therapeutic application of drugs that target both AR and WNT/β-catenin pathways. Finally, we extend our review of AR and WNT signaling to the mammary gland system and breast cancer. We highlight that the role of AR signaling and its interaction with WNT signaling in these two hormone-related cancer types are highly context-dependent.

Transcriptional regulation of core autophagy and lysosomal genes by the androgen receptor promotes prostate cancer progression

AR (androgen receptor) signaling is crucial for the development and maintenance of the prostate as well as the initiation and progression of prostate cancer. Despite the AR's central role in prostate cancer progression, it is still unclear which AR-mediated processes drive the disease. Here, we identified 4 core autophagy genes: ATG4B, ATG4D, ULK1, and ULK2, in addition to the transcription factor TFEB, a master regulator of lysosomal biogenesis and function, as transcriptional targets of AR in prostate cancer. These findings were significant in light of our recent observation that androgens promoted prostate cancer cell growth in part through the induction of autophagy. Expression of these 5 genes was essential for maximal androgen-mediated autophagy and cell proliferation. In addition, expression of each of these 5 genes alone or in combination was sufficient to increase prostate cancer cell growth independent of AR activity. Further, bioinformatic analysis demonstrated that the expression of these genes correlated with disease progression in 3 separate clinical cohorts. Collectively, these findings demonstrate a functional role for increased autophagy in prostate cancer progression, provide a mechanism for how autophagy is augmented, and highlight the potential of targeting this process for the treatment of advanced prostate cancer.

Alanine and arginine rich domain containing protein, Aard, is directly regulated by androgen receptor in mouse Sertoli cells

Alanine and arginine rich domain containing protein (Aard) is specifically expressed in Sertoli cells (SCs) of mouse testis and the expression increases in an age‑dependent manner. A number of previous studies have indicated that androgen and androgen receptor (AR) signaling pathways are particularly important for spermatogenesis in mouse SCs, however, the association between Aard and AR remain to be elucidated. The present study identified Aard as a gene that is directly regulated by AR in mouse SCs, which is important in spermatogenesis. The expression of AARD was significantly downregulated in the testes of Sertoli cell‑selective AR knockout mice compared with wild‑type mice as analyzed by western blotting and immunofluorescence analyses. Quantitative polymerase chain reaction and western blotting indicated that AARD was predominantly expressed in adult mouse testis and its expression was increased in an age-dependent manner. In addition, AARD expression was upregulated by testosterone in primary SCs in vitro, which was confirmed by bioinformatics analysis and a dual‑luciferase reporter assay. Finally, chromatin immunoprecipitation and electrophoretic mobility shift assays indicated that the ligand‑bound AR activated Aard transcription via directly binding to the androgen‑responsive element of the Aard promoter. To the best of our knowledge, the present study is the first to document that Aard is directly regulated by AR in mouse Sertoli cells.

Androgen Receptor-Mediated Genomic Androgen Action Augments Ischemia-Induced Neovascularization

Increasing evidence indicates that androgens regulate ischemia-induced neovascularization. However, the role of genomic androgen action mediated by androgen receptor (AR), a ligand-activated nuclear transcription factor, remains poorly understood. Using an AR knockout (KO) mouse strain that contains a transcriptionally inactive AR (AR^Δex3KO), we examined the role of AR genomic function in modulating androgen-mediated augmentation of ischemia-induced neovascularization. Castrated wild-type (AR^WT) and AR^Δex3KO mice were implanted with 5α-dihydrotestosterone (DHT) or placebo pellets after hindlimb ischemia (HLI). DHT modulation of angiogenesis and vasculogenesis, key processes for vascular repair and regeneration, was examined. Laser Doppler perfusion imaging revealed that DHT enhanced blood flow recovery in AR^WT mice post-HLI. In AR^WT mice, DHT enhanced angiogenesis by down-regulating prolyl hydroxylase 2 and augmenting hypoxia-inducible factor-1α (HIF-1α) levels in the ischemic tissues post-HLI. DHT also enhanced the production and mobilization of Sca1+/CXCR4+ progenitor cells in the bone marrow (BM) and circulating blood, respectively, in AR^WT mice. By contrast, DHT-mediated enhancement of blood flow recovery was abrogated in AR^Δex3KO mice. DHT modulation of HIF-1α expression was attenuated in AR^Δex3KO mice. DHT-induced HIF-1α transcriptional activity and DHT-augmented paracrine-mediated endothelial cell tubule formation were attenuated in fibroblasts isolated from AR^Δex3KO mice in vitro. Furthermore, DHT-induced augmentation of Sca1+/CXCR4+ progenitor cell production and mobilization was absent in AR^Δex3KO mice post-HLI. BM transplantation revealed that ischemia-induced mobilization of circulating progenitor cells was abolished in recipients of AR^Δex3KO BM. Together, these results indicate that androgen-mediated augmentation of ischemia-induced neovascularization is dependent on genomic AR transcriptional activation.