Androgens suppress TGF-β responses in the prostate through mechanisms that are not fully explored. We have recently reported that <em>5α</em>-dihydrotestosterone (<em>DHT</em>) suppresses the ability of TGF-β to inhibit proliferation and induce apoptosis of prostatic epithelial cells and provided evidence that such suppression was fueled by transcriptional down-regulation of TGF-β receptor II (ΤβRII). We now show that androgen receptor (AR) activated by <em>DHT</em> suppresses the TGF-β-induced phosphorylation of Sma- and Mad-related protein (Smad)3 in LNCaP cells overexpressing TβRII under the control of a cytomegalovirus promoter, which is not regulated by <em>DHT</em>, suggesting that transcriptional repression of TβRII alone does not fully account for the impact of <em>DHT</em> on TGF-β responses. Instead, we demonstrate that such suppression occurs through loss of total Smad3, resulting from transcriptional suppression of Smad3. We provide evidence that <em>DHT</em> down-regulates the promoter activity of Smad3 in various prostate cancer cell lines, including NRP-154+AR, DU145+AR, LNCaP, and VCaP, at least partly through androgen-dependent inactivation of Sp1. Moreover, we show that overexpression of Smad3 reverses the ability of <em>DHT</em> to protect against TGF-β-induced apoptosis in NRP-154+AR, supporting our model that loss of Smad3 by <em>DHT</em> is involved in the protection against TGF-β-induced apoptosis. Together, these findings suggest that deregulated/enhanced expression and activation of AR in prostate carcinomas may intercept the tumor suppressor function of TGF-β through transcriptional suppression of Smad3, thereby providing new mechanistic insight into the development of castration-resistant prostate cancer.

Sexual neurosteroids (SN), namely 17β-estradiol (E2) and <em>5α</em>-dehydrotestosterone (<em>DHT</em>), are synthesized in the hippocampus, where they induce circuit modifications by changing the number of excitatory spine synapses in a paracrine and sex-specific manner. The mechanisms of this sex-specific synapse turnover, which are likely to affect cognitive functions, are poorly understood. We found that hippocampal neurons synthesize estradiol, which maintains LTP and synapses in females but not in males. In females, inhibition of estradiol synthesis results in impairment of LTP and synapse loss. These effects were not seen in males. The essential role of local estrogen on the stability and maintenance of connectivity in the hippocampus is consistent with age-related cognitive decline in women after menopause. In male animals the regulation of synaptic stability and plasticity by locally synthesized sexual steroids remains to be clarified. This article is part of a Special Issue entitled SI: Brain and Memory.

We investigated thoroughly the effect of lncRNA PART1 on prostate cancer cells proliferation and apoptosis, through regulating toll-like receptor (TLR) pathways. LncRNA PART1 expression was also examined by quantitative real-time polymerase chain reactions (qRT-PCR) in human tissues and the cells lines LNCaP and PC3. After transfection with si-PART1 or control constructs, the cell viability was measured by MTS and colony formation assays. In addition, the apoptosis rate of the prostate cancer cells was validated by TUNEL staining. Relationships between lncRNA PART1 expression and TLR pathway genes were demonstrated by qRT-PCR and Western blotting. High levels of lncRNA PART1 expression were correlated with advanced cancer stage and predication of poor survival. LncRNA PART1 levels was increased in PCa cells treated with <em>5α</em>-dihydrotestosterone (<em>DHT</em>), confirming PART1 was directly induced by androgen. Moreover, down-regulation of lncRNA PART1 inhibited prostate cancer cell proliferation and accelerated cell apoptosis. In addition, lncRNA PART1 induced downstream genes expression in TLR pathways including TLR3, TNFSF10 and CXCL13 to further influence prostate cancer cells, indicating its carcinogenesis on prostate cancer. LncRNA PART1 promoted cell proliferation ability and apoptosis via the inhibition of TLR pathways in prostate cancer. LncRNA PART1 could hence be considered as a new target in the treatment of prostate cancer.

Prostate cancer is the second leading cause of cancer death in the United States. Treatment of localized high-risk disease and de novo metastatic disease frequently leads to relapse. These metastatic castration resistant prostate cancers (mCRPC) claim a high mortality rate, despite the extended survival afforded by the growing armamentarium of androgen deprivation, radiation and immunotherapies. Here, we review two studies of neoadjuvant treatment of high-risk localized prostate cancer prior to prostatectomy, the total androgen pathway suppression (TAPS) trial and the neoadjuvant abiraterone acetate (AA) trial. These two trials assessed the efficacy of the non-specific P450c17 inhibitor, ketoconazole and the specific P450c17 inhibitor, AA, to inhibit tissue and serum androgen levels. Furthermore, a novel and validated stable isotope dilution liquid chromatography electrospray ionization selected reaction monitoring mass spectrometry assay was used to accurately quantify adrenal and gonadal androgens in circulation during the course of these trials. The adrenal androgens, Δ(4)-androstene-3,17-dione, dehydroepiandrosterone and dehydroepiandrosterone sulfate were significantly reduced in the patients receiving ketoconazole or AA compared to those who did not. However, in both trials, a significant amount of DHEA-S (∼20 μg/dL) persists and thus may serve as a depot for intratumoral conversion to the potent androgen receptor ligands, testosterone (T) and <em>5α</em>-dihydrotestosterone (<em>DHT</em>). The final step in conversion of Δ(4)-androstene-3,17-dione and <em>5α</em>-androstanedione to T and <em>DHT</em>, respectively, is catalyzed by AKR1C3. We therefore present the case that in the context of the DHEA-S depot, P450c17 and AKR1C3 inhibition may be an effective combinatorial treatment strategy.

BACKGROUND

The polycystic ovary syndrome (PCOS) is a complex and heterogeneous endocrine condition characterized by hyperandrogenism, hyperinsulinemia, insulin resistance and chronic anovulation. Regulation and interaction of a multitude of genes required for follicular development are found to be altered in PCOS. MicroRNAs (miRNAs) mediate posttranscriptional gene regulation by binding to the 3´ untranslated region of mRNAs to either inhibit or enhance translation. However, the extent and regulation of miRNA expression in PCOS is poorly understood and the current study is the first to describe altered expression of miRNAs in PCOS.

METHODS

A chronically androgenized [<em>5α</em>-dihydrotestosterone (<em>DHT</em>)-treated] rat model which recapitulates many of the phenotypes of human PCOS, and miRNA PCR array was used to investigate the expression of 349 miRNAs in <em>DHT</em> treated rat ovaries. The ovarian expression of several selected miRNAs was also analyzed by in situ localization experiment.

RESULTS

DHT-treated rats exhibit increased body weight, disrupted estrus cyclicity, decreased insulin sensitivity and decreased ovarian weight, with the latter phenomenon readily rescued by gonadotropin treatment in vivo. In general, 24% of the 349 miRNAs investigated were found to be differentially expressed between DHT-treated and control rats. Most of the differentially expressed miRNAs were found to be predominantly localized in the theca cells of the follicles. In silico analysis of the potential target genes of dysregulated miRNAs revealed their possible involvement in various pathways in the regulation of ovarian function.

CONCLUSIONS

Our current findings suggest that miRNAs are differentially regulated in hyperandrogenism, a condition possibly involved in the dysregulation of steroid hormone receptors and intra-ovarian factors, and that miRNAs may be involved in the etiology of PCOS.

Adrenal C19 steroids, dehydroepiandrostenedione (DHEA(S)) and androstenedione (A4), play a critical role in castration resistant prostate cancer (CRPC) as they are metabolised to dihydrotestosterone (<em>DHT</em>), via testosterone (T), or via the alternate <em>5α</em>-dione pathway, bypassing T. Adrenal 11OHA4 metabolism in CRPC is, however, unknown. We present a novel pathway for 11OHA4 metabolism in CRPC leading to the production of 11ketoT (11KT) and novel <em>5α</em>-reduced C19 steroids - 11OH-<em>5α</em>-androstanedione, 11keto-<em>5α</em>-androstanedione, 11OH<em>DHT</em> and 11keto<em>DHT</em> (11K<em>DHT</em>). The pathway was validated in the androgen-dependent prostate cancer cell line, LNCaP. Androgen receptor (AR) transactivation studies showed that while 11KT and 11OH<em>DHT</em> act as a partial AR agonists, 11K<em>DHT</em> is a full AR agonist exhibiting similar activity to <em>DHT</em> at 1nM. Our data demonstrates that, while 11OHA4 has negligible androgenic activity, its metabolism to 11KT and 11K<em>DHT</em> yields androgenic compounds which may be implicated, together with A4 and DHEA(S), in driving CRPC in the absence of testicular T.

Androgens are important regulators of bone mass but the relative importance of testosterone (T) versus dihydrotestosterone (<em>DHT</em>) for the activation of the androgen receptor (AR) in bone is unknown. <em>5α</em>-reductase is responsible for the irreversible conversion of T to the more potent AR activator <em>DHT</em>. There are two well established isoenzymes of <em>5α</em>-reductase (type 1 and type 2), encoded by separate genes (Srd5a1 and Srd5a2). <em>5α</em>-reductase type 2 is predominantly expressed in male reproductive tissues whereas <em>5α</em>-reductase type 1 is highly expressed in liver and moderately expressed in several other tissues including bone. The aim of the present study was to investigate the role of <em>5α</em>-reductase type 1 for bone mass using Srd5a1⁻/⁻ mice. Four-month-old male Srd5a1⁻/⁻ mice had reduced trabecular bone mineral density (-36%, p<0.05) and cortical bone mineral content (-15%, p<0.05) but unchanged serum androgen levels compared with wild type (WT) mice. The cortical bone dimensions were reduced in the male Srd5a1⁻/⁻ mice as a result of a reduced cortical periosteal circumference compared with WT mice. T treatment increased the cortical periosteal circumference (p<0.05) in orchidectomized WT mice but not in orchidectomized Srd5a1⁻/⁻ mice. Male Srd5a1⁻/⁻ mice demonstrated a reduced forelimb muscle grip strength compared with WT mice (p<0.05). Female Srd5a1⁻/⁻ mice had slightly increased cortical bone mass associated with elevated circulating levels of androgens. In conclusion, <em>5α</em>-reductase type 1 inactivated male mice have reduced bone mass and forelimb muscle grip strength and we propose that these effects are due to lack of <em>5α</em>-reductase type 1 expression in bone and muscle. In contrast, the increased cortical bone mass in female Srd5a1⁻/⁻ mice, is an indirect effect mediated by elevated circulating androgen levels.

BACKGROUND

Several important functions for a successful spermatogenesis are dependent on Sertoli cells (SCs). Besides their unique characteristics as support cells, they produce essential cofactors and metabolites, and are responsible for nurturing the developing germ cells. The continuous production of lipids, phospholipids and proteins by germ cells must require high amounts of metabolic precursors. Thus, we hypothesized that hSCs could produce acetate in a hormonally-regulated manner.

METHODS

hSC-enriched primary cultures were maintained in the absence of insulin or in the presence of 17β-estradiol (E2) or <em>5α</em>-dihydrotestosterone (<em>DHT</em>). Acetate production was determined by 1H-NMR. mRNA gene expression levels of Acetyl CoA hydrolase (ACoA Hyd) and Acetyl CoA synthase (ACoA Synt) were determined by RT-PCR.

RESULTS

hSCs produced high amounts of acetate suggesting that this metabolite should play a key role on the progression of spermatogenesis, namely as a metabolic precursor for the synthesis of cellular constituents. In addition, acetate metabolism proved to be under strict hormonal regulation. In the presence of E2 or DHT, hSCs produced different amounts of acetate. While E2 treatment increased acetate production, increasing ACoA Hyd gene transcript levels, DHT-treated cells showed decreased acetate production, differently modulating the ratio ACoA Hyd/ACoA Synt. Surprisingly, insulin-deprivation completely suppressed acetate production/export and significantly decreased the ACoA Hyd gene transcript levels.

CONCLUSIONS

Taken together, these results suggest that, although hSCs are primarily described as lactate producers, the elevated production of acetate deserves special attention, in order to clarify the mechanisms behind its hormonal regulation and its role on a successful spermatogenesis.

Sertoli cells actively metabolize glucose that is converted into lactate, which is used by developing germ cells for their energy metabolism. Androgens and oestrogens have general metabolic roles that reach far beyond reproductive processes. Hence, the main purpose of this study was to examine the effect of sex hormones on metabolite secretion/consumption in primary cultures of rat Sertoli cells. Sertoli cell-enriched cultures were maintained in a defined medium for 50 h. Glucose and pyruvate consumption, and lactate and alanine secretion were determined, by 1H-NMR (proton NMR) spectra analysis, in the presence or absence of 100 nM E2 (17β-oestradiol) or 100 nM <em>5α</em>-<em>DHT</em> (dihydrotestosterone). Cells cultured in the absence (control) or presence of E2 consumed the same amount of glucose (29±2 pmol/cell) at similar rates during the 50 h. After 25 h of treatment with <em>DHT</em>, glucose consumption and glucose consumption rate significantly increased. Control and E2-treated cells secreted similar amounts of lactate during the 50 h, while the amount of lactate secreted by <em>DHT</em>-treated cells was significantly lower. Such a decrease was concomitant with a significant decrease in LDH A [LDH (lactate dehydrogenase) chain A] and MCT4 [MCT (monocarboxylate transporter) isoform 4] mRNA levels after 50 h treatment in hormonally treated groups, being more pronounced in <em>DHT</em>-treated groups. Finally, alanine production was significantly increased in E2-treated cells after 25 h treatment, which indicated a lower redox/higher oxidative state for the cells in those conditions. Together, these results support the existence of a relation between sex hormones action and energy metabolism, providing an important assessment of androgens and oestrogens as metabolic modulators in rat Sertoli cells.

Polycystic ovarian syndrome (PCOS) is a heterogeneous syndrome associated with follicle growth arrest, minimal granulosa cell proliferation, dysregulated sex hormone profile, hyperthecosis, and insulin resistance. Using a <em>5α</em>-dihydrotestosterone (<em>DHT</em>)-induced rat model that recapitulates the reproductive and metabolic phenotypes of human PCOS, we have examined the steroidogenic capability of granulosa cells from <em>DHT</em>-treated rats. Gene expression of several key steroidogenic enzymes including p450 side-chain cleavage enzyme (p450scc), aromatase, steroidogenic acute regulatory protein, hydroxysteroid dehydrogenase-17β, and hydroxysteroid dehydrogenase-3β were markedly lower in <em>DHT</em>-treated rats than the controls, although the responsiveness of their granulosa cells to FSH was higher. Expression of the adipokine chemerin and its receptor, chemokine receptor-like 1, was evident in control and <em>DHT</em>-treated rats, with significantly higher ovarian mRNA abundances and protein contents of chemerin and its receptor. Recombinant chemerin decreases basal estradiol secretion in granulosa cells from <em>DHT</em>-treated rats. When the inhibitory role of chemerin on steroidogenesis was further examined in vitro, chemerin suppressed FSH-induced progesterone and estradiol secretion in cultured preantral follicles and granulosa cells. Chemerin also inhibits FSH-induced aromatase and p450scc expression in granulosa cells. Overexpression of nuclear receptors NR5a1 and NR5a2 promotes p450scc and aromatase expression, respectively, which is suppressed by chemerin. These findings suggest that chemerin is a novel negative regulator of FSH-induced follicular steroidogenesis and may contribute to the pathogenesis of PCOS.

Survival of mice after Klebsiella pneumoniae infection and phagocytosis by alveolar macrophages (AMs), in the presence or absence of ozone (O(3)) exposure prior to infection, is sex dependent. The objective of this work was to study the role of gonadal hormones, <em>5α</em>-dihydrotestosterone (<em>DHT</em>) and 17β-estradiol (E(2)), on mouse survival after filtered air (FA) or O(3) exposure. Gonadectomized female (G×F) and male (G×M) mice implanted with control or hormone pellets (<em>DHT</em> in G×F, or E(2) in G×M), exposed to O(3) (2 ppm, 3h) or FA, and infected with K. pneumoniae were monitored for survival. Survival in G×F was identical after FA or O(3) exposure; in G×M O(3) exposure resulted in lower survival compared to FA. In O(3)-exposed females, gonadectomy resulted in increased survival compared to intact females or to G×M+E(2). A similar effect was observed in G×F+<em>DHT</em>. The combined negative effect of oxidative stress and hormone on survival was higher for E(2). Gonadectomy eliminated (females) or minimized (males) the previously observed sex differences in survival in response to oxidative stress, and hormone treatment restored them. These findings indicate that gonadal hormones and/or oxidative stress have a significant effect on mouse survival.

A sensitive rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS/MS) method, combined with solid-phase extraction, ultrasonic extraction and silica gel cartridge cleanup, was developed for 28 steroids including 4 estrogens (estrone (E1), 17β-estradiol (E2), 17α-ethynyl estradiol (EE2), diethylstilbestrol (DES)), 14 androgens (androsta-1,4-diene-3,17-dione (ADD), 17α-trenbolone, 17β-trenbolone, 4-androstene-3,17-dione, 19-nortestoserone, 17β-boldenone, 17α-boldenone, testosterone (T), epi-androsterone (EADR), methyltestosterone (MT), 4-hydroxy-androst-4-ene-17-dione (4-OHA), <em>5α</em>-dihydrotestosterone (<em>5α</em>-<em>DHT</em>), androsterone (ADR), stanozolol (S)), 5 progestagens (progesterone (P), ethynyl testosterone (ET), 19-norethindrone, norgestrel, medroxyprogesterone (MP)), and 5 glucocorticoids (cortisol, cortisone, prednisone, prednisolone, dexamethasone) in surface water, wastewater and sludge samples. The recoveries of surface water, influents, effluents and sludge samples were 90.6-119.0% (except <em>5α</em>-<em>DHT</em> was 143%), 44.0-200%, 60.7-123% and 62.6-138%, respectively. The method detection limits for the 28 analytes in surface water, influents, effluents and freeze-dried sludge samples were 0.01-0.24 ng/L, 0.02-1.44 ng/L, 0.01-0.49 ng/L and 0.08-2.06 ng/g, respectively. This method was applied in the determination of the residual steroidal hormones in two surface water of Danshui River, 12 wastewater and 8 sludge samples from two wastewater treatment plants (Meihu and Huiyang WWTPs) in Guangdong (China). Ten analytes were detected in surface water samples with concentrations ranging between 0.4 ng/L (17β-boldenone) and 55.3 ng/L (<em>5α</em>-<em>DHT</em>); twenty analytes in the wastewater samples with concentrations ranging between 0.3 ng/L (P) and 621 ng/L (<em>5α</em>-<em>DHT</em>); and 12 analytes in the sludge samples with concentrations ranging between 1.6 ng/g (E1) and 372 ng/g (EADR).

Benefits associated with lowered serum <em>DHT</em> levels after <em>5α</em>-reductase inhibitor (5AR-I) therapy in men have contributed to a misconception that circulating <em>DHT</em> levels are an important stimulus for androgenic action in target tissues (e.g., prostate). Yet evidence from clinical studies indicates that intracellular concentrations of androgens (particularly in androgen-sensitive tissues) are essentially independent of circulating levels. To assess the clinical significance of modest elevations in serum <em>DHT</em> and the <em>DHT</em>/testosterone (T) ratio observed in response to common T replacement therapy, a comprehensive review of the published literature was performed to identify relevant data. Although the primary focus of this review is about <em>DHT</em> in men, we also provide a brief overview of <em>DHT</em> in women. The available published data are limited by the lack of large, well-controlled studies of long duration that are sufficiently powered to expose subtle safety signals. Nonetheless, the preponderance of available clinical data indicates that modest elevations in circulating levels of <em>DHT</em> in response to androgen therapy should not be of concern in clinical practice. Elevated <em>DHT</em> has not been associated with increased risk of prostate disease (e.g., cancer or benign hyperplasia) nor does it appear to have any systemic effects on cardiovascular disease safety parameters (including increased risk of polycythemia) beyond those commonly observed with available T preparations. Well-controlled, long-term studies of transdermal <em>DHT</em> preparations have failed to identify safety signals unique to markedly elevated circulating <em>DHT</em> concentrations or signals materially different from T.

Sertoli cells (SCs) glucose metabolism is crucial for spermatogenesis since developing germ cells consume lactate produced by SCs as their main energy source. Recently, androgens and estrogens have been implicated in SCs energy metabolism modulation, although the molecular mechanisms remained undisclosed. Here, we report the effect of sex steroid hormones on key points of cultured rat SCs glycolytic pathway. We used primary cultures of immature rat SCs treated with 17β-estradiol (E2) or <em>5α</em>-dihydrotestosterone (<em>DHT</em>). The transcript levels of glucose transporters (GLUTs), phosphofructokinase 1 (PFK-1) and lactate dehydrogenase C (LDH C) were analyzed after 25 and 50 h of culture by qPCR. Protein levels of GLUTs, PFK-1, LDH and monocarboxylate transporter 4 (MCT4) after 25 and 50 h were determined by western blot and LDH activity was also assessed. Our results show that both E2 and <em>DHT</em> downregulated the transcript levels of PFK-1, GLUT1 and GLUT3 after 50 h. However, only <em>DHT</em>-treated cells presented a downregulation of LDH C transcript levels. Interestingly, the protein levels of these enzymes and transporters remained unaltered except in <em>DHT</em>-treated cells that presented a significant decrease on GLUT1 protein levels evidencing a possible site for the regulation of SCs glucose metabolism by androgens. Taken together, our results provide evidence that sex steroid hormones action in SCs energy metabolism is mediated through modulation in glycolysis-related transporters and enzymes, particularly at the transcriptional level. <em>DHT</em> decreased GLUT1 protein levels and increased LDH activity after 25 h, evidencing key points for this hormone action in the regulation of SCs metabolism.

Testosterone acts directly at androgen receptors and also exerts potent actions following <em>5α</em>-reduction to dihydrotestosterone (<em>DHT</em>). Finasteride (type II <em>5α</em>-reductase inhibitor) lowers <em>DHT</em> and is used to treat benign prostatic hyperplasia. However, it is unknown whether elevated <em>DHT</em> mediates either beneficial musculoskeletal effects or prostate enlargement resulting from higher-than-replacement doses of testosterone. Our purpose was to determine whether administration of testosterone plus finasteride to older hypogonadal men could produce musculoskeletal benefits without prostate enlargement. Sixty men aged ≥60 yr with a serum testosterone concentration of ≤300 ng/dl or bioavailable testosterone ≤70 ng/dl received 52 wk of treatment with testosterone enanthate (TE; 125 mg/wk) vs. vehicle, paired with finasteride (5 mg/day) vs. placebo using a 2 × 2 factorial design. Over the course of 12 mo, TE increased upper and lower body muscle strength by 8-14% (P = 0.015 to <0.001), fat-free mass 4.04 kg (P = 0.032), lumbar spine bone mineral density (BMD) 4.19% (P < 0.001), and total hip BMD 1.96% (P = 0.024) while reducing total body fat -3.87 kg (P < 0.001) and trunk fat -1.88 kg (P = 0.0051). In the first 3 mo, testosterone increased hematocrit 4.13% (P < 0.001). Coadministration of finasteride did not alter any of these effects. Over 12 mo, testosterone also increased prostate volume 11.4 cm(3) (P = 0.0051), an effect that was completely prevented by finasteride (P = 0.0027). We conclude that a higher-than-replacement TE combined with finasteride significantly increases muscle strength and BMD and reduces body fat without causing prostate enlargement. These results demonstrate that elevated <em>DHT</em> mediates testosterone-induced prostate enlargement but is not required for benefits in musculoskeletal or adipose tissue.

OBJECTIVE

Intratumoral androgen synthesis in prostate cancer contributes to the development of castration-resistant prostate cancer (CRPC). Several enzymes responsible for androgen biosynthesis have been shown to be overexpressed in CRPC, thus contributing to CRPC in a castrated environment. The TMPRSS2-ERG transcription factor has been shown to be present in primary prostate cancer tumors as well as CRPC tumors. We hypothesize that TMPRSS2-ERG fusions regulate androgen biosynthetic enzyme (ABE) gene expression and the production of androgens, which contributes to the development of CRPC.

METHODS

We used a panel of assays, including lentivirus transduction, gene expression, chromatin immunoprecipitation and sequencing, liquid chromatography-mass spectrometric quantitation, immunocytochemistry, immunohistochemistry, and bioinformatics analysis of gene microarray databases, to determine ERG regulation of androgen synthesis.

RESULTS

We found that ERG regulated the expression of the ABE AKR1C3 in prostate cancer cells via direct binding to the AKR1C3 gene. Knockdown of ERG resulted in reduced AKR1C3 expression, which caused a reduction in both <em>DHT</em> synthesis and PSA expression in VCaP prostate cancer cells treated with <em>5α</em>-androstanedione (<em>5α</em>-Adione), a <em>DHT</em> precursor metabolite. Immunohistochemical staining revealed that ERG was coexpressed with AKR1C3 in prostate cancer tissue samples.

CONCLUSIONS

These data suggest that AKR1C3 catalyzes the biochemical reduction of <em>5α</em>-Adione to <em>DHT</em> in prostate cancer cells, and that ERG regulates this step through upregulation of AKR1C3 expression. Elucidation of ERG regulation of ABEs in CRPC may help to stratify TMPRSS2-ERG fusion-positive prostate cancer patients in the clinic for anti-androgen receptor-driven therapies; and AKR1C3 may serve as a valuable therapeutic target in the treatment of CRPC.

Sertoli cells metabolize glucose, converting it to lactate that is used by developing germ cells for their energy metabolism. Androgens and oestrogens have metabolic roles that reach far beyond reproductive processes. So, the main purpose of this study was to examine the effect of sex steroid hormones on metabolite secretion/consumption in human Sertoli cells. Human Sertoli cell-enriched primary cultures were maintained in a defined medium for 50 h and glucose, pyruvate, lactate and alanine variations were determined using (1) H-NMR spectra analysis, in the absence or presence of 100 nm 17β-estradiol (E(2) ) or 100 nm <em>5α</em>-dihydrotestosterone (<em>DHT</em>). The mRNA expression levels of glucose transporters, lactate dehydrogenase and monocarboxylate transporters were also determined using semi-quantitative RT-PCR. Cells cultured in the absence (control) or presence of E(2) consumed the same amounts of glucose at similar rates during the 50 h. During the first 15 h of treatment with <em>DHT</em>, glucose consumption and glucose consumption rate were significantly higher. Nevertheless, <em>DHT</em>-treated cells secreted a significantly lower amount of lactate than control and E(2) -treated cells. Such a decrease was concomitant with a significant decrease in lactate dehydrogenase A mRNA levels after 50 h treatment in <em>DHT</em>-treated groups. Finally, alanine production was significantly increased in E(2) -treated cells after 25 h treatment, which indicated a lower redox/higher oxidative state for the cells on those conditions. These results support the existence of a relationship between sex steroid hormones action and energy metabolism, providing the first assessment of androgens and oestrogens as metabolic modulators of human Sertoli cells.

BACKGROUND

Androgenic alopecia (AGA) is the major type of scalp hair loss affecting 60 - 70% of the population worldwide. It is caused by two potent androgens, namely testosterone (T) and <em>5α</em>-dihydrotestosterone (<em>5α</em>-<em>DHT</em>). Till date, only two FDA-approved synthetic drugs, minoxidil and finasteride, are used to cure AGA with only 35 and 48% success, respectively; therefore, a search for new drug based on the mechanism of androgens action is still needed.

METHODS

Relevant literature was reviewed to identify current therapeutic targets and treatments for AGA. The potential targets are classified into three categories: i) <em>5α</em>-reductase; ii) androgen receptor and iii) growth-factor-producing genes related to hair growth.

CONCLUSIONS

Relevant assay systems using the right targets are required in order to obtain specific and effective drugs for AGA treatment. It is unlikely that single targeted agents will be sufficient for treating AGA, and therefore, it would be a challenge to obtain compounds with multiple activities.

Masculinization of the external genitalia in humans is dependent on formation of <em>5α</em>-dihydrotestosterone (<em>DHT</em>) through both the canonical androgenic pathway and an alternative (backdoor) pathway. The fetal testes are essential for canonical androgen production, but little is known about the synthesis of backdoor androgens, despite their known critical role in masculinization. In this study, we have measured plasma and tissue levels of endogenous steroids in second trimester human fetuses using multidimensional and high-resolution mass spectrometry. Results show that androsterone is the principal backdoor androgen in the male fetal circulation and that <em>DHT</em> is undetectable (<1 ng/mL), while in female fetuses, there are significantly lower levels of androsterone and testosterone. In the male, intermediates in the backdoor pathway are found primarily in the placenta and fetal liver, with significant androsterone levels also in the fetal adrenal. Backdoor intermediates, including androsterone, are only present at very low levels in the fetal testes. This is consistent with transcript levels of enzymes involved in the alternate pathway (steroid <em>5α</em>-reductase type 1 [SRD5A1], aldo-keto reductase type 1C2 [AKR1C2], aldo-keto reductase type 1C4 [AKR1C4], cytochrome P450 17A1 [CYP17A1]), as measured by quantitative PCR (qPCR). These data identify androsterone as the predominant backdoor androgen in the human fetus and show that circulating levels are sex dependent, but also that there is little de novo synthesis in the testis. Instead, the data indicate that placental progesterone acts as substrate for synthesis of backdoor androgens, which occurs across several tissues. Masculinization of the human fetus depends, therefore, on testosterone and androsterone synthesis by both the fetal testes and nongonadal tissues, leading to <em>DHT</em> formation at the genital tubercle. Our findings also provide a solid basis to explain why placental insufficiency is associated with disorders of sex development in humans.

Labelled <em>5α</em>-dihydrotestosterone (<em>DHT</em>) binding experiments have shown that expression levels of (yet unidentified) membrane androgen receptors (mAR) are elevated in prostate cancer and correlate with a negative prognosis. However, activation of these receptors which mediate a rapid androgen response can counteract several cancer hallmark functions such as unlimited proliferation, enhanced migration, adhesion and invasion and the inability to induce apoptosis. Here, we investigate the downstream signaling pathways of mAR and identify rapid <em>DHT</em> induced activation of store-operated Ca2+ entry (SOCE) in primary cultures of human prostate epithelial cells (hPEC) from non-tumorous tissue. Consequently, down-regulation of Orai1, the main molecular component of Ca2+ release-activated Ca2+ (CRAC) channels results in an almost complete loss of <em>DHT</em> induced SOCE. We demonstrate that this <em>DHT</em> induced Ca2+ influx via Orai1 is important for rapid androgen triggered prostate specific antigen (PSA) release. We furthermore identified alterations of the molecular components of CRAC channels in prostate cancer. Three lines of evidence indicate that prostate cancer cells down-regulate expression of the Orai1 homolog Orai3: First, Orai3 mRNA expression levels are significantly reduced in tumorous tissue when compared to non-tumorous tissue from prostate cancer patients. Second, mRNA expression levels of Orai3 are decreased in prostate cancer cell lines LNCaP and DU145 when compared to hPEC from healthy tissue. Third, the pharmacological profile of CRAC channels in prostate cancer cell lines and hPEC differ and siRNA based knock-down experiments indicate changed Orai3 levels are underlying the altered pharmacological profile. The cancer-specific composition and pharmacology of CRAC channels identifies CRAC channels as putative targets in prostate cancer therapy.

Apoptosis is an important regulatory event in testicular homeostasis and optimization of sperm production. Sertoli cells (SCs) form the blood-testis barrier creating a special microenvironment where germ cells develop and are under strict hormonal control. Estrogens and androgens are known to play critical roles in SCs functioning, improving their in vitro survival by preventing apoptotic progression. Herein, we studied the influence of 17β-estradiol (E2) and <em>5α</em>-dihydrotestosterone (<em>DHT</em>) on the apoptotic signaling pathways of immature rat cultured SCs. For that we chose key points of the apoptotic pathway that interact with the mitochondria and evaluated the mRNA expression and/or protein levels of several apoptotic markers such as p53, the anti-apoptotic protein Bcl2, the pro-apoptotic Bcl2 family member Bax, the apoptosis-inducing factor (AIF) and caspase-3 and 9. Caspase-3 activity and DNA fragmentation were also evaluated as endpoint markers of apoptosis. E2 and <em>DHT</em> down-regulated the mRNA transcript levels of p53, Bax, caspase-9 and caspase-3. The protein levels of AIF were reduced after <em>DHT</em> treatment while E2-treated cells presented decreased levels of cleaved caspase-9 protein. Moreover, Bax/Bcl2 ratio was significantly decreased in E2-treated cells. The apoptotic endpoints caspase-3 activity and DNA fragmentation presented significant decreased levels after hormonal treatment. Taken together, these results show that E2 and <em>DHT</em> act as apoptotic signaling modulators in in vitro immature rat SCs suggesting that androgens and estrogens may be capable of modulating independent pathways of the apoptotic event by regulating different pro-apoptotic factors.

Although glioblastoma multiforme (GBM) is the most malignant primary human brain cancer with surprisingly high incidence rate in adult men than in women, the exact mechanism underlying this pronounced epidemiology is unclear. Here, we showed significant upregulated androgen receptor (AR) expression in the GBM tissue compared to the periphery normal brain tissue in patients. An expression of AR was further detected in all eight examined human GBM cell lines. To figure out whether AR signaling may play a role in GBM, we used high AR-expressing U87-MG GBM line for further study. We found that activation of transforming growth factor β (TGFβ) receptor signaling by TGFβ1 in GBM significantly inhibited cell growth and increased apoptosis. Moreover, application of active AR ligand <em>5α</em>-dihydrotestosterone (<em>DHT</em>) significantly decreased the effect of TGFβ1 on GBM growth and apoptosis, suggesting that AR signaling pathway may contradict the effect of TGFβ receptor signaling in GBM. However, neither total protein nor the phosphorylated protein of SMAD3, a major TGFβ receptor signaling downstream effector in GBM, was affected by <em>DHT</em>, suggesting that AR activation may not affect the SMAD3 protein production or phosphorylation of TGFβ receptor and SMAD3. Finally, immunoprecipitation followed by immunoblot confirmed binding of pAR to pSMAD3, which may prevent the DNA binding of pSMAD3 and subsequently prevent its effect on cell growth in GBM. Taken together, our study suggests that AR signaling may promote tumorigenesis of GBM in adult men by inhibiting TGFβ receptor signaling.

Androgenetic alopecia (AGA) is the most common type of hair loss in men and women. This continuous process results in a type of alopecia that follows a definite pattern in those individuals who are genetically predisposed. At present the predisposing genes are unknown but the relatively strong concordance of the degree of baldness in fathers and sons is not consistent with a simple Mendelian trait and a polygenic basis is therefore most likely. AGA can be defined as a <em>DHT</em>-dependent process with continuous miniaturization of sensitive HF. Today we do not understand the molecular steps involved in androgen-dependent beard growth versus androgen-dependent hair loss in AGA. However, recent experimental and clinical advances enable us to explain some pathogenetic steps leading to androgenetic hair loss. Among other steroidogenic isoenzymes such as 17b- and 3b- hydroxysteroid dehydrogenases, the type 2 <em>5a</em>-reductase within the dermal papilla plays a central role by the intrafollicular conversion of T to <em>DHT</em>.

Androgens play important roles during the first trimester of intrauterine life, coinciding with genital tract differentiation, during virilization and maintenance of secondary male characteristics, and during initiation of spermatogenesis. Little is known about the impact of inappropriate exposure to excess androgens during fetal development on male sexual maturation and reproduction. The objectives of this study were to determine the effects of prenatal <em>5α</em>-dihydrotestosterone (<em>DHT</em>) and testosterone treatment during ovine sexual differentiation on post-pubertal testicular formation and subsequent potential for fertility as assessed by epididymal sperm characteristics. Rams prenatally treated with testosterone exhibited increased testicular weight relative to age-matched controls and prenatal <em>DHT</em>-treated rams (P<0.05), as well as elevated total and free testosterone concentrations compared with <em>DHT</em>-treated rams (P=0.07 and P<0.05 respectively). The percentage of progressively motile sperm from the epididymis was significantly reduced in prenatal <em>DHT</em>-treated but not testosterone-treated rams compared with control rams (P<0.05). The testosterone-treated rams had a greater number of germ cell layers than <em>DHT</em>-treated rams, but comparable to the controls. Prenatal testosterone-treated rams had significantly larger seminiferous tubule diameter and lumen diameter compared with prenatal <em>DHT</em>-treated (P<0.05). Significantly, more prenatal <em>DHT</em>- and testosterone-treated rams (P<0.05) had occluded tubule lumen than control rams. Findings from this study demonstrate that exposure to excess testosterone/<em>DHT</em> during male fetal sexual differentiation have differential effects on post-pubertal testicular size, seminiferous tubule size and function, sperm motility, and testosterone concentrations.