Androgen Androgen Receptor Research Articles

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

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

Oncolytic adenovirus-mediated therapy for prostate cancer.

Prostate cancer is a leading cause of cancer-related death and morbidity in men in the Western world. Tumor progression is dependent on functioning androgen receptor signaling, and initial administration of antiandrogens and hormone therapy (androgen-deprivation therapy) prevent growth and spread. Tumors frequently develop escape mechanisms to androgen-deprivation therapy and progress to castration-resistant late-stage metastatic disease that, in turn, inevitably leads to resistance to all current therapeutics, including chemotherapy. In spite of the recent development of more effective inhibitors of androgen–androgen receptor signaling such as enzalutamide and abiraterone, patient survival benefits are still limited. Oncolytic adenoviruses have proven efficacy in prostate cancer cells and cause regression of tumors in preclinical models of numerous drug-resistant cancers. Data from clinical trials demonstrate that adenoviral mutants have limited toxicity to normal tissues and are safe when administered to patients with various solid cancers, including prostate cancer. While efficacy in response to adenovirus administration alone is marginal, findings from early-phase trials targeting local-ized and metastatic prostate cancer suggest improved efficacy in combination with cytotoxic drugs and radiation therapy. Here, we review recent progress in the development of multimodal oncolytic adenoviruses as biological therapeutics to improve on tumor elimination in prostate cancer patients. These optimized mutants target cancer cells by several mechanisms including viral lysis and by expression of cytotoxic transgenes and immune-stimulatory factors that activate the host immune system to destroy both infected and noninfected prostate cancer cells. Additional modifications of the viral capsid proteins may support future systemic delivery of oncolytic adenoviruses.

Effects of Tribulus terrestris saponins on exercise performance in overtraining rats and the underlying mechanisms.

The objective of this study was to determine the effects of Tribulus terrestris L. (TT) saponins on exercise performance and the underlying mechanisms. A rat overtraining model was established and animals were treated with TT extracts (120 mg/kg body mass) 30 min before each training session. Serum levels of testosterone and corticosterone and levels of androgen receptor (AR) and insulin growth factor-1 receptor (IGF-1R) in the liver, gastrocnemius, and soleus were determined by ELISA and Western blot. Treatment of rats with TT saponins significantly improved the performance of the overtraining rats, reflected by the extension of time to exhaustion, with a concomitant increase in body mass, relative mass, and protein levels of gastrocnemius. Overtraining alone induced a significant decrease in the serum level of testosterone. In contrast, treatment with TT saponins dramatically increased the serum level of testosterone in overtraining rats to about 150% of control and 216% of overtraining groups, respectively. In addition, TT saponins resulted in a further significant increase in AR in gastrocnemius and significantly suppressed the overtraining-induced increase in IGF-1R in the liver. These results indicated that TT saponins increased performance, body mass, and gastrocnemius mass of rats undergoing overtraining, which might be attributed to the changes in androgen-AR axis and IGF-1R signaling.

Long noncoding RNA DANCR promotes invasion of prostate cancer through epigenetically silencing expression of TIMP2/3.

LncRNA DANCR suppresses differentiation of epithelial cells, however, its function in prostate cancer development is still unknown. In the present study, we found the expression of DANCR increases in prostate cancer tissues and cells compared to normal prostate tissues and cells, moreover, DANCR promotes invasion and migration of prostate cancer cells in vitro and metastasis of tumor xenografts in nude mice. Mechanistically, we found that TIMP2/3, which are critical metastasis inhibitor of prostate cancer, were down-regulated by DANCR synergistically with EZH2 through epigenetically silencing their promoter by chromatin immunoprecipitation assay. In addition, we further investigated whether DANCR is regulated by the differentiation-promoting androgen-androgen receptor (AR) pathway and found that DANCR expression is repressed by androgen-AR; furthermore, DANCR impedes the upregulation of TIMP2/3 and the suppression of invasion and migration by androgen-AR. On the other hand, interestingly, we found that in prostate cancer cells DANCR knockdown decreased the promotion of invasion and migration by the treatment of enzalutamide, which is an AR inhibitor. In summary, our results indicate that DANCR promotes prostate cancer invasion and metastasis through repressing the expression of TIMP2/3, and suggest that DANCR could be a potential target for preventing prostate cancer metastasis, and knockdown DANCR may lessen the potential side effect of AR inhibitor.

Androgen/androgen receptor axis maintains and promotes cancer cell stemness through direct activation of Nanog transcription in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common and malignant cancers. The HCC incidence gets a strong sexual dimorphism as men are the major sufferers in this disaster. Although several studies have uncovered the presentative correlation between the axis of androgen/androgen receptor (AR) and HCC incidence, the mechanism is still largely unknown. Cancer stem cells (CSCs) are a small subgroup of cancer cells contributing to multiple tumors malignant behaviors, which play an important role in oncogenesis of various cancers including HCC. However, whether androgen/AR axis involves in regulation of HCC cells stemness remains unclear. Our previous study had identified that the pluripotency factor Nanog is not only a stemness biomarker, but also a potent regulator of CSCs in HCC. In this study, we revealed androgen/AR axis can promote HCC cells stemness by transcriptional activation of Nanog expression through directly binding to its promoter. In HCC tissues, we found that AR expression was abnormal high and got correlation with Nanog. Then, by labeling cellular endogenous Nanog with green fluorescent protein (GFP) through CRISPR/Cas9 system, it verified the co-localization of AR and Nanog in HCC cells. With in vitro experiments, we demonstrated the axis can promote HCC cells stemness, which effect is in a Nanog-dependent manner and through activating its transcription. And the xenografted tumor experiments confirmed the axis effect on tumorigenesis facilitation in vivo. Above all, we revealed a new sight of androgen/AR axis roles in HCC and provided a potential way for suppressing the axis in HCC therapy.

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

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.

Androgen-glucocorticoid interactions in the era of novel prostate cancer therapy.

Great strides have been made in the treatment of castration-resistant prostate cancer (CRPC) with the development of new antiandrogens (enzalutamide) and more potent androgen synthesis inhibitors (abiraterone) that have both improved patient outcomes. These new drugs have also helped unravel the complex biology of androgen-androgen receptor driven prostate cancer and brought into prominence various mechanisms triggering the development of drug resistance and tumour cell survival despite use of androgen deprivation therapy (ADT). The complex role of glucocorticoids in the treatment, management and progression of patients with CRPC is integral to these advances. Historically, glucocorticoid treatment has resulted in both subjective and objective responses in patients with advanced-stage prostate cancer. With the use of these new therapeutic agents, however, unexpected glucocorticoid-related mechanisms that can cause iatrogenic stimulation of prostate cancer growth have emerged, which might contribute to drug resistance and disease progression despite optimal ADT. For example, the upregulation of glucocorticoid receptors (GRs) during enzalutamide therapy results in glucocorticoid-GR-mediated regulation of androgen target genes, leading to escape from enzalutamide blockade. Thus, understanding the biological role of glucocorticoids in patients with prostate cancer is of major importance in the era of new and evolving antiandrogen therapies.

Editorial: Prostate Cancer: What We Know and What We Would Like to Know.

Cancer research has undergone radical changes over the last few years. The issue today is no longer the amount of molecular, cellular, and clinical information available, but how to handle it. Systems biology is the latest in a series of innovative strategies driven by technological advances that have provided us with a suite of “omics” (1). Technology advancements have enabled comprehensive characterization of genomic, epigenomic, transcriptomic, proteomic, and metabolomic alterations in tumor specimens (2). Despite this continuous progress, prostate cancer remains a major public health problem throughout the world (3). Among men, cancers of the prostate, lung and bronchus, and colon–rectum will account for about 50% of all newly diagnosed cancer (4). Prostate-specific antigen (PSA) is one of the most widely used tumor markers. Although its possible use in early diagnosis or screening PSA has various drawbacks mainly due to its low specificity (5) considering that more than half of the men with PSA over 4.0 ng/ml are negative on initial biopsy (6). A new generation of biomarkers is emerging, consisting of genomic-, serum-, urine-, and tissue-based assays that may supplement PSA testing, or replace it over time (7–9). Although the identification and development of more specific diagnostic biomarkers are considered important, the major focus in translational prostate cancer research is the identification of potential “quantitative variables” to detect clinically significant prostate cancers. As reported by Vlaeminck-Giullem et al. (10), the current dilemma is to specifically distinguish among all prostate tumors the very aggressive high-grade cancers that will become life threatening by developing extra-prostatic invasion and metastatic potential from the indolent cancers that will never modify a patient’s life expectancy. At molecular level, Src and other members of the Src kinase family have been proposed as potential candidates (10). Recently, it has been shown that the activation of Src-dependent intracellular pathways is frequently observed in clinically significant prostate cancer (11). The proto-oncogene tyrosine-protein kinase Src influences some of most important events that accompany tumor progression, including cell proliferation, cell motility, invasion, epithelial-to-mesenchymal transition, resistance to apoptosis, angiogenesis, neuroendocrine differentiation, and metastatic diffusion (11). The particularity of the Src oncogenic action in prostate carcinogenesis is its ability to interfere with the androgen pathway. Through both direct and indirect interaction with the androgen receptor (AR), Src reinforce the proliferative and anti-apoptotic actions of the AR, even in the absence of specific ligands. These molecular mechanisms constitute a solid rationale in favor of the use of Src inhibitors in managing patients with prostate cancer (10, 12). On the other hands, decades of research are now leading to therapeutics that target the molecular mechanisms of the cancer-specific immune response (13). These therapeutics include tumor antigen vaccines, dendritic cell activators, adjuvants that activate innate immunity, adoptive cellular therapy, and checkpoint blockade (13). Another major effort has been in prostate cancer prevention, where blockade of the testosterone metabolism pathway may be a major focus. However, the results of two large randomized, placebo-controlled trials: the prostate cancer prevention trial (PCPT) with finasteride and the reduction by dutasteride of prostate cancer events (REDUCE) trial have fueled controversies on the use of 5α-reductase inhibitors (5-ARI). Finasteride and dutasteride are among the agents used to target the androgen–AR axis to prevent the development and/or progression of prostate cancer, as summarized by Kosaka et al. (14). In particular, 5-ARIs have been shown to play a potential role in preventing clinical progression among men with low-risk prostate cancer on active surveillance. However, in light of the US Food and Drug Administration recommendation against 5-ARIs for primary chemoprevention, these findings should be interpreted with caution (3, 15).

Abstract 612: Endostatin is a novel inhibitor of androgen receptor function in prostate cancer

Abstract Abnormalities in androgen-androgen receptor (AR) axis have long been recognized for their roles in promoting prostate tumor growth and metastasis. Conventional therapies targeting androgen ablation show transient tumor regression, however, when the tumor recurs during castration-refractory metastatic stage, the current treatment options are very limited. Although the precise mechanism by which prostate cancer (PCa) cells circumvent the androgen deprivation is unclear, recurring tumors have been shown to retain AR activity and upregulation of AR-target gene expression such as prostate specific antigen (PSA), suggesting that targeting AR remains a key component of developing novel therapeutic strategies. Here, we show a profound effect of endostatin, an endogenous angiogenesis inhibitor, on proliferation and invasion of AR-positive PCa cells by targeting AR function. The present study identified that intracellular trafficking of endostatin and direct interaction with AR disrupts AR nuclear translocation and the consequent transcriptional activation of PSA gene. In addition, our structural modeling and site-directed mutagenesis studies suggest that the binding mechanism may include the interaction of bulky side chains (F31 and F34) present in endostatin with the co-activator binding interface (AF-2) in AR ligand-binding domain (LBD). Regarding drug resistance to the second-generation androgen antagonists in patients with metastatic PCa, recent studies revealed that a missense mutation in AR LBD (F876L) and the consequential antagonist-to-agonist switch confers continued AR activity. In this context, our study suggests that endostatin can be recognized as an endogenous AR inhibitor where its molecular interaction with AR may prevent from agonistic switch of AR function by fully masking the AF-2 subdomain. Overall, the current finding provides new insights into endostatin whose anti-cancer activity is not only limited to inhibiting angiogenesis, but can also be expanded to suppressing AR-mediated PCa progression by disrupting AR transactivation. Citation Format: Joo Hyoung Lee, Tatyana Isayeva, Matthew Larson, Diptiman Chanda, Igor Chesnokov, Selvarangan Ponnazhagan. Endostatin is a novel inhibitor of androgen receptor function in prostate cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 612. doi:10.1158/1538-7445.AM2014-612

Abstract 617: Repression of cell proliferation and androgen receptor activity by 2’-hydroxyflavanone in prostate cancer cells

Abstract Background: Since androgen-androgen receptor (AR) axis is the main stream for development and progression of prostate cancer, androgen-deprivation therapy (ADT) is conducted as a first line hormonal therapy using medical castration, such as LH-RH agonists, LH-RH antagonist, and antiandrogen for advanced PCa. After an initial response to ADT, however, PCa eventually loses responsiveness to ADT and progresses into castration-resistant prostate cancer (CRPC). Prevention of the development of castration-resistant from hormone-naïve prostate cancer is an important issue in maintaining the quality of life of the patients. We explored the effect of 2’-hydroxyflavanone on proliferation and androgen responsiveness using prostate cancer cell lines. Materials and Methods: To investigate the effect of 2’ -hydroxyflavanone on proliferation, prostate cancer cells were treated with 2’-hydroxyflavanone. Androgen-responsiveness in LNCaP cells was confirmed by luciferase assay after transfection of luciferase reporter driven by prostate specific antigen promoter. To detect androgen receptor (AR) expression, reverse transcriptase polymerase chain reaction and western blot analysis were conducted. Results: 2’ -Hydroxyflavanone inhibited the proliferation of PC-3 and DU145 cells by induction of apoptosis. 2’ -Hydroxyflavanone inhibited the proliferation of LNCaP cells stimulated by androgens and attenuated androgen-responsiveness through down-regulation of AR protein. Conclusion: 2’ -Hydroxyflavanone not only inhibited proliferation of prostate cancer cells, but also repressed androgen-responsiveness, suggesting that it might be an useful agent in preventing recurrence of prostate cancer. Citation Format: Atsushi Mizokami, Mitsuo Ofude, Misako Kumaki, Kouji Izumi, Hiroyuki Konaka, Yoshifumi Kadono, Minkyoung Shin, Jian Zhang, Evan T. Keller, Mikio Namiki. Repression of cell proliferation and androgen receptor activity by 2’-hydroxyflavanone in prostate cancer cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 617. doi:10.1158/1538-7445.AM2014-617

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

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

Androgenic regulation of beta-defensins in the mouse epididymis.

BackgroundThe majority of beta-defensin family members are exclusively expressed in the epididymis, and some members have been shown to play essential roles in sperm maturation and fertility in rats, mice and humans. Therefore, beta-defensins are hypothesized to be potential targets for contraception and infertility diagnosis and treatment. Clarifying the regulatory mechanisms for the expression of these genes is necessary. Androgen/androgen receptor (AR) signaling plays an important regulatory role in epididymal structure and function. However, very little is known about the androgenic regulation on the production and secretion of the epididymal beta-defensins.MethodsThe expression of beta-defensins was detected by quantitative RT-PCR. The androgen dependence of beta-defensins was determined by bilateral orchiectomy and androgen supplementation. The androgen response elements (AREs) in the promoters of beta-defensins were identified using the MatInspector software. The binding of AR to AREs was assayed by ChIP-PCR/qPCR.ResultsWe demonstrated that 23 mouse caput epididymal beta-defensins were differentially regulated by androgen/androgen receptor. Six genes, Defb18, 19, 20, 39, 41, and 42, showed full regulation by androgens. Ten genes, Defb15, 30, 34, 37, 40, 45, 51, 52, 22 and Spag11a, were partially regulated by androgens. Defb15, 18, 19, 20, 30, 34, 37, 39, 41, 42, 22 and Spag11a were associated with androgen receptor binding sites in their promoter or intronic regions, indicating direct regulation of AR. Six genes, Defb1, 12, 13, 29, 35, and spag11b/c, exhibited an androgen-independent expression pattern. One gene, Defb25, was highly dependent on testicular factors rather on androgens.ConclusionsThe present study provides novel insights into the mechanisms of androgen regulation on epididymal beta-defensins, enabling a better understanding of the function of beta-defensins in sperm maturation and fertility.

PMA induces androgen receptor downregulation and cellular apoptosis in prostate cancer cells.

Phorbol 12-myristate 13-acetate (PMA) induces cellular apoptosis in prostate cancer cells, the growth of which is governed by androgen/androgen receptor (AR) signaling, but the mechanism by which PMA exerts this effect remains unknown. Therefore, in this study, we investigated the mechanistic action of PMA in prostate cancer cells with regard to AR. We showed that PMA decreased E2F1 as well as AR expression in androgen-dependent prostate cancer LNCaP cells. Furthermore, PMA activated JNK and p53 signaling, resulting in the induction of cellular apoptosis. In LNCaP cells, androgen deprivation and a novel anti-androgen enzalutamide (MDV3100) augmented cellular apoptosis induced by PMA. Moreover, castration-resistant prostate cancer (CRPC) C4-2 cells were more sensitive to PMA compared with LNCaP cells and were sensitized to PMA by enzalutamide. Finally, the expression of PKC, E2F1, and AR was diminished in PMA-resistant cells, indicating that the gain of independence from PKC, E2F1, and AR functions leads to PMA resistance. In conclusion, PMA exerted its anti-cancer effects via the activation of pro-apoptotic JNK/p53 and inhibition of pro-proliferative E2F1/AR in prostate cancer cells including CRPC cells. The therapeutic effects of PMA were augmented by androgen deletion and enzalutamide in androgen-dependent prostate cancer cells, as well as by enzalutamide in castration-resistant cells. Taken together, PMA derivatives may be promising therapeutic agents for treating prostate cancer patients including CRPC patients.

Minoxidil may suppress androgen receptor-related functions.

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.

Androgen receptor roles in hepatocellular carcinoma, fatty liver, cirrhosis and hepatitis

Androgen/androgen receptor (AR) signaling plays important roles in normal liver function and in progression of liver diseases. In studies of noncancerous 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-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.

Serum Testosterone Levels and Androgen Receptor CAG Polymorphism Correlate with Hepatitis B Virus (HBV)-Related Acute Liver Failure in Male HBV Carriers

BackgroundAugmentation of androgen/androgen receptor (AR) pathway may influence chronic hepatitis B (CHB) more likely in males. AR activity is modulated by a polymorphic CAG repeat sequence in AR exon 1. This study aimed to investigate the relationship between serum testosterone levels, CAG repeat numbers and hepatitis B virus (HBV)-related acute liver failure (ALF).MethodsThree hundred and seventy eight male CHB patients with ALF and 441 asymptomatic HBV carriers (AsCs) were recruited. AR CAG repeats numbers were analyzed. The serum testosterone levels of AsCs, ALFs and patients with hepatitis B flare groups, and sequential serum samples, were assessed quantitatively.ResultsThe median CAG repeat (M-CAG) frequency was significantly higher in ALF patients than AsCs (P<0.001). Patients with M-CAG alleles (P<0.001, OR 3.0, 95% CI 2.1–4.2) had the highest risk for ALF. Serum testosterone levels were significantly higher (P<0.001) at hepatitis flare point (8.2±3.0 ng/mL) than inactive phase (6.4±2.0 ng/mL). CHB (8.30±2.71 ng/mL, P = 7.6×10−6) and ALF group (2.61±1.83 ng/mL, P = 1.7×10−17) had significantly different levels of testosterone in comparison with AsCs group (6.56±2.36 ng/mL). The serum testosterone levels sharply decreased from hepatitis flare phase to liver failure phase, and tended to be normal at the recovery phase. Male AsCs with M-CAG alleles had significantly lower serum testosterone levels (P<0.05).ConclusionsThere was a serum testosterone fluctuation during hepatitis B flare and HBV-related ALF, and the median CAG repeats in AR gene exon 1 were associated with lower serum testosterone levels in asymptomatic HBV carriers and an increased susceptibility to HBV-related ALF.

An Androgen Receptor-MicroRNA-29a Regulatory Circuitry in Mouse Epididymis

MicroRNAs are involved in a number of cellular processes; thus, their deregulation is usually apt to the occurrence of diverse diseases. Previous studies indicate that abnormally up-regulated miR-29a is associated with several diseases, such as human acute myeloid leukemia and diabetes; therefore, the proper level of miR-29a is critical for homeostasis. Herein, we observed that miR-29a was repressed by androgen/androgen receptor signaling in mouse epididymis by targeting a conserved androgen response element located 8 kb upstream of miR-29b1a loci. It is well known that multiple regulatory programs often form a complicated network. Here, we found that miR-29a reversibly suppressed androgen receptor and its target genes by targeting IGF1 and p53 pathways. miR-29b1a-overexpressing transgenic mice displayed epididymis hypoplasia partially similar to the phenotype of those mice with an impaired androgen-androgen receptor signal system. Taken together, the results demonstrated that there is a regulatory circuitry between the androgen signaling pathway and miR-29a in mouse epididymis that may be vital for epididymal development and functions.

Bisphenol a (BPA) induces abnormal androgen accumulation via androgen-androgen receptor (AR) mdiated cyp19a1 transcription inhibition in granulosa cells (GCs)

Bisphenol a (BPA) induces abnormal androgen accumulation via androgen-androgen receptor (AR) mdiated cyp19a1 transcription inhibition in granulosa cells (GCs)

Abstract 3559: FKBP5 is an androgen-responsive gene in thyroid cancer cells.

Abstract There has been a steady increase in the incidence thyroid cancer in the United States, with over 56,000 cases predicted for 2012. The increased aggressiveness of the disease and poorer clinical outcome in men and postmenopausal women may be due to androgen/androgen receptor (AR) related functions. FK506 binding protein 51 (FKBP5) is a member of the immunophilin family and plays a role in steroid receptor function. Further, FKBP5 regulates the NFkB and AKT pathways and is thought to be relevant to the neoplastic process. Immunohistochemical analysis of 38 papillary thyroid cancer (PTC) specimens indicated that androgen receptor is expressed in both normal and cancerous epithelial cells, in both men and women. Analysis of AR expression in thyroid cell lines indicated that the normal thyroid cell line, Nthy-ori 3-1 and PTC cell lines BCPAP and TPC-1 expressed very low levels of AR, as measured by qRT-PCR and western blotting (&amp;gt;1000 fold less than the prostate cancer cell line, LNCaP). In contrast, PTC/anaplastic 8505C cells expressed higher levels of AR protein (approximately one third the level expressed in LNCaP cells). Upon addition of androgen, AR in 8505C translocated into the nucleus (as determined by immunocytochemistry) and upregulated transcription of both AR (∼1.7 fold) and FKBP5 (∼1.8 fold). To more fully understand the function of androgen/AR in thyroid cells, the AR cDNA from pSG5-AR was subcloned into the pcDNA3.1+ expression vector and stably transfected into thyroid cell lines. Primers for qRT-PCR of the endogenous or the transfected gene were designed. The 84E7 clone of transfected 8505C cells expressed 68 fold higher levels of AR mRNA than 8505C and 16 fold higher AR protein expression (∼5 fold higher AR protein expression than LNCaP). Upon addition of DHT to clone 84E7, AR translocated into the nucleus, and increased AR and FKBP5 mRNA expression (∼3 fold and ∼13 fold, respectively). The association between androgens/AR and upregulation of FKBP5 in thyroid cancer cells suggests that FKBP5 may play a role in thyroid cancer etiology and the different clinical presentation and outcomes between young women and men/postmenopausal women. Citation Format: Melanie E. MacEwan, Ken Wong, Ismatun Swati, Suqing Xie, Mohammad Rasul, Olena Ardacheva, Joseph Buchsbaum, Edward Shin, Augustine Moscatello, Stimson Schantz, Raj K. Tiwari, Jan Geliebter. FKBP5 is an androgen-responsive gene in thyroid cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3559. doi:10.1158/1538-7445.AM2013-3559

Abstract 4087: Androgen receptor splice variants in mouse prostate cancer cell lines: altered distribution in lines derived from castration-resistant tumors relative to those primary tumors.

Abstract Prostate cancer is sensitive to androgen deprivation at the primary androgen-dependent growth stage (ADCa). However, it invariably acquires resistance to androgen withdrawal leading to the recurrence of the castration-resistant prostate cancer (CRPC). Androgen receptor (AR) activity that is necessary for the normal prostate development remains active through both phases of the disease. Even at castrate levels of androgen AR remains functional, possibly through several non-mutually exclusive mechanisms including expression of constitutively active AR variants (ARVs). The full-length of AR (ARFL) is a 110 KDa nuclear hormone receptor composed of an N-terminal domain (NTD, exon1), DNA-binding domain (DBD, exon 2 and 3), a hinge region (exon 4), and the C-terminal ligand binding domain (LBD, exon 4-8). To date up to 15 different ARVs lacking LBD have been identified in human prostate cancer cell lines or specimens. It is thought that the altered biological properties of these ARVs may be, in part, correlated to the development of castration resistance. ARVs remain understudied in mouse prostate cancer cell lines; detection of only two ARVs was reported in a mouse cell line. A better definition of ARVs in distinct phases of this cancer in an appropriate mouse model should be valuable for insights into the role of ARVs in therapy and disease progression. To this end, by using cell lines established from the conditional Pten deletion mouse model of prostate adenocarcinoma, we detected low molecular weight AR protein species (∼50 kDa - 80 kDa) besides the presence of the 110 kDa full-length. We performed 3’RACE and subsequent Sanger sequencing on cell lines derived from both ADCa (E-series) and CRPC stages (cE-series) and identified three different ARVs which we named as mARV-abc. Structurally, mARVa is analogous to the previously reported mAR-V4 and the human ARV567es which only lacks LBD domain retaining exon 1-4 followed by the inclusion of a cryptic exon 4 from intron 4 at the 3’-terminal sequence. More interestingly, we identified two novel ARV isoforms (mARV-b and -c) which merely contains the NTD encoded by exon 1 before the addition of specific sequences from different positions of intron 1. Although these mARVs occur in all the murine cell lines tested, their proportion appears to vary with respect to the stage of the disease from which the cell lines originated. In cE-series established from a CRPC tumor, novel ARVb and ARVc are more abundant than that in E-series from an ADCa tumor; in parallel, ARVa displays an opposite expression profile. These new findings together with the results of ongoing experiments, including the single cell expression analysis and on their biological activities of the splice variants will be discussed. Citation Format: Mengmeng Liang, Helty A. Adisetiyo, Xiuqing Li, Ren Liu, Parkash S. Gill, Pradip Roy-Burman. Androgen receptor splice variants in mouse prostate cancer cell lines: altered distribution in lines derived from castration-resistant tumors relative to those primary tumors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4087. doi:10.1158/1538-7445.AM2013-4087