A review of the chemistry, biological action, and clinical applications of anabolic-androgenic steroids

BACKGROUND

Since its discovery in 1935, numerous derivatives of testosterone have been synthesized, with the goals of prolonging its biological activity in vivo, producing orally active androgens, and developing products, commonly referred to as anabolic-androgenic steroids (AAS), that are more anabolic and less androgenic than the parent molecule.

OBJECTIVE

This article reviews the structure, biotransformation, and mechanism of action of testosterone and some of the most commonly used AAS. Clinical applications of the AAS are discussed, and guidelines and therapeutic maneuvers for minimizing their side effects are outlined.

METHODS

Literature for inclusion in this review was identified using the libraries of the University of Wisconsin Medical School and School of Pharmacy, the author's files, and searches of MEDLINE, Science Citation Index, Biological Abstracts, and Chemical Abstracts.

RESULTS

The myotrophic action of testosterone and its derivatives and their stimulatory effects on the brain have led to widespread use of AAS by athletes and "recreational" drug users. Consequently, all AAS were classified as class III controlled substances in 1991. Nonetheless, AAS have shown benefit in a variety of human disorders, including HIV-related muscle wasting and other catabolic conditions such as chronic obstructive pulmonary disease, severe burn injuries, and alcoholic hepatitis. Because of their diverse biological actions, AAS have been used to treat a variety of other conditions, including bone marrow failure syndromes, constitutional growth retardation in children, and hereditary angioedema. AAS therapy is associated with various side effects that are generally dose related; therefore, illicit use of megadoses of AAS for the purpose of bodybuilding and enhancement of athletic performance can lead to serious and irreversible organ damage. The most common side effects of AAS are some degree of masculinization in women and children, behavioral changes (eg, aggression), hepatotoxicity, and alteration of blood lipid levels and coagulation factors.

CONCLUSIONS

To minimize or avoid serious toxicities with AAS therapy, close medical supervision and periodic monitoring are important, with dose adjustment as appropriate to achieve the minimum effective dose. Given the biological effects and potential adverse effects of AAS, administration of these agents should be avoided in pregnant women, women with breast cancer or hypercalcemia, men with carcinoma of the prostate or breast, and patients with nephrotic syndromes or significant liver dysfunction.

An androgen response element in a far upstream enhancer region is essential for high, androgen-regulated activity of the prostate-specific antigen promoter

Prostate-specific antigen (PSA) is expressed at a high level in the luminal epithelial cells of the prostate and is absent or expressed at very low levels in other tissues. PSA expression can be regulated by androgens. Previously, two functional androgen-response elements were identified in the proximal promoter of the PSA gene. To detect additional, more distal control elements, DNasel-hypersensitive sites (DHSs) upstream of the PSA gene were mapped in chromatin from the prostate-derived cell line LNCaP grown in the presence and absence of the synthetic androgen R1881. In a region 4.8 to 3.8 kb upstream of the transcription start site of the PSA gene, a cluster of three DHSs was detected. The middle DNAseI-hypersensitive site (DHSII, at approximately -4.2 kb) showed strong androgen responsiveness in LNCaP cells and was absent in chromatin from HeLa cells. Further analysis of the region encompassing DHSII provided evidence for the presence of a complex, androgen-responsive and cell-specific enhancer. In transient transfected LNCaP cells, PSA promoter constructs containing this upstream enhancer region showed approximately 3000-fold higher activity in the presence than in the absence of R1881. The core region of the enhancer could be mapped within a 440-bp fragment. The enhancer showed synergistic cooperation with the proximal PSA promoter and was found to be composed of at least three separate regulatory regions. In the center, a functionally active, high-affinity androgen receptor binding site (GGAACATATTGTATC) could be identified. Mutation of this element almost completely abolished PSA promoter activity. Transfection experiments in prostate and nonprostate cell lines showed largely LNCaP cell specificity of the upstream enhancer region, although some activity was found in the T47D mammary tumor cell line.

Species differences in prostatic steroid 5 alpha-reductases of rat, dog, and human

The conversion of testosterone to 5 alpha-dihydrotestosterone by prostate particulates from rats, dogs, and humans was investigated, and significant species differences were found with their pH profiles, affinities for 4-azasteroidal inhibitors, and sensitivities to mercuric sulfhydryl reagents. The pH optima for the rat (pH 7), the dog (pH 6), and the human (pH 5) enzyme are significantly different. Mersalyl acid and p-hydroxymercuribenzoate inactivate only the rat 5 alpha-reductase, but not the human or dog enzyme. The rank orders of potencies of 24 3-oxo-4-azasteroids to inhibit 5 alpha-reductases of the rat, dog, and human prostate are different. The variation of the 17 beta-functional groups of the inhibitors demonstrates clearly the species differences. Those inhibitors with a 17 beta-diethylcarbamoyl, 17 beta-diisopropylcarbamoyl, 17 beta-t-butylcarbamoyl, or 17 beta-secbutylcarbonyl functional group are approximately equipotent as inhibitors of the rat and human enzymes, whereas they are only 0.1-15% as potent as inhibitors of the dog enzyme. On the other hand, those inhibitors with a 17 beta-spiroether functional group are most potent as inhibitors of the rat enzyme, are 15-50% as potent as inhibitors of the dog enzyme, and are 0.2-0.4% as potent as inhibitors of the human enzyme. Those inhibitors with a 17 beta-n-octylcarbamoyl, 17 beta-(1-carboxyethyl), or 17 beta-(1-carboxy-3-butyl) functional group are 2-3 orders of magnitude less potent as inhibitors of the dog and human enzymes than as inhibitors of the rat enzyme. These results suggest that prostatic 5 alpha-reductases of rats, dogs, and humans are significantly different. In spite of the significant species differences in inhibitor affinities, where determined, inhibition of the rat, dog and human enzymes by these compounds is competitive with testosterone. These 3-oxo-4-azasteroids have a similar rank order of potency as inhibitors of 5 alpha-reductase in human normal, benign hyperplastic, and cancerous prostates, indicating that the inhibitor-binding sites of 5 alpha-reductase in the prostate in different pathological states are similar. The affinities of the 3-oxo-4-azasteroids for rat prostatic cytosol receptor were determined. Five of these 5 alpha-reductase inhibitors have no significant affinity for the androgen receptor, whereas others do have an affinity for the receptor.

Balding hair follicle dermal papilla cells contain higher levels of androgen receptors than those from non-balding scalp

Androgens can gradually transform large scalp hair follicles to smaller vellus ones, causing balding. The mechanisms involved are unclear, although androgens are believed to act on the epithelial hair follicle via the mesenchyme-derived dermal papilla. This study investigates whether the levels and type of androgen receptors in primary lines of cultured dermal papilla cells derived from balding scalp hair follicles differ from those of follicles from non-balding scalp. Androgen receptor content was measured by saturation analysis using the non-metabolisable androgen, [3H]mibolerone (0.05-10 nM) in a 9-10 point assay. Pubic dermal fibroblasts and Shionogi cells were examined as positive controls. Repetitive assays of Shionogi cells showed good precision in the levels of androgen receptor content (coefficient of variation = 3.7%). Specific, high affinity, low capacity androgen receptors were detected in dermal papilla cells from both balding and non-balding follicles. Balding cells contained significantly (P < 0.01) greater levels of androgen receptors (Bmax = 0.06 +/- 0.01 fmol/10(4) cells (mean +/- S.E.M.)) than those from non-balding scalp (0.04 +/- 0.001). Competition studies with a range of steroids showed no differences in receptor binding specificity in the two cell types. The higher levels of androgen receptors in cells from balding scalp hair follicles with similar properties to those from non-balding scalp concur with the expectations from their in vivo responses to androgens. This supports the hypothesis that androgens act via the dermal papilla and suggests that cultured dermal papilla cells may offer a model system for studying androgen action in androgenetic alopecia.

Androgen-inducible TGF-beta1 from balding dermal papilla cells inhibits epithelial cell growth: a clue to understand paradoxical effects of androgen on human hair growth

We attempted establishing an in vitro coculture system by using human dermal papilla cells (DPCs) from androgenetic alopecia (AGA) and keratinocytes (KCs) to explore the role of androgens in hair growth regulation. Androgen showed no significant effect on the growth of KCs when they were cocultured with DPCs from AGA. Because the expressions of mRNA of androgen receptor (AR) decreased during subcultivation of DPCs in vitro, we transiently transfected the AR expression vector into the DPCs and cocultured them with KCs. In this modified coculture, androgen significantly suppressed the growth of KCs by approximately 50%, indicating that overexpression of AR can restore the responsiveness of the DPCs to androgen in vivo. We found that androgen stimulated the expression of TGF-beta1 mRNA in the cocultured DPCs. ELISA assays demonstrated that androgen treatment increased the secretion of both total and active TGF-beta1 in the conditioned medium. Moreover, the neutralizing anti-TGF-beta1 antibody reversed the androgen-elicited growth inhibition of KCs in a dose-dependent manner. These findings suggest that androgen-inducible TGF-beta1 derived from DPCs of AGA is involved in epithelial cell growth suppression in our coculture system, providing the clue to understand the paradoxical effects of androgens for human hair growth.

Androgen increases androgen receptor protein while decreasing receptor mRNA in LNCaP cells

We have examined the effect of androgen treatment on androgen receptor mRNA and protein expression in the LNCaP human prostate carcinoma cell line. Incubation with androgen caused a decrease in cellular androgen receptor mRNA content that was concentration and time dependent. Maximal suppression to approximately 35% of control level was observed after 49 h of exposure to androgen. By contrast, incubation of LNCaP cells with androgen resulted in a 2-fold increase in the cellular content of androgen receptor protein at 24 h. At 49 h androgen receptor protein increased 30% as assayed by immunoblots and 79% as assayed by ligand binding. These results suggest that ligand-induced changes in androgen receptor stability and/or the translational efficiency of androgen receptor mRNA account for the phenomenon of androgen receptor upregulation observed in cultured LNCaP cells. Furthermore, the suppression of androgen mRNA and protein that is caused by prolonged incubation with androgen is incomplete and is reversible upon removal of ligand.

Plant-derived 3,3'-Diindolylmethane is a strong androgen antagonist in human prostate cancer cells

3,3'-Diindolylmethane (DIM) is a major digestive product of indole-3-carbinol, a potential anticancer component of cruciferous vegetables. Our results indicate that DIM exhibits potent antiproliferative and antiandrogenic properties in androgen-dependent human prostate cancer cells. DIM suppresses cell proliferation of LNCaP cells and inhibits dihydrotestosterone (DHT) stimulation of DNA synthesis. These activities were not produced in androgen-independent PC-3 cells. Moreover, DIM inhibited endogenous PSA transcription and reduced intracellular and secreted PSA protein levels induced by DHT in LNCaP cells. Also, DIM inhibited, in a concentration-dependent manner, the DHT-induced expression of a prostate-specific antigen promoter-regulated reporter gene construct in transiently transfected LNCaP cells. Similar effects of DIM were observed in PC-3 cells only when these cells were co-transfected with a wild-type androgen receptor expression plasmid. Using fluorescence imaging with green fluorescent protein androgen receptor and Western blot analysis, we demonstrated that DIM inhibited androgen-induced androgen receptor (AR) translocation into the nucleus. Results of receptor binding assays indicated further that DIM is a strong competitive inhibitor of DHT binding to the AR. Results of structural modeling studies showed that DIM is remarkably similar in conformational geometry and surface charge distribution to an established synthetic AR antagonist, although the atomic compositions of the two substances are quite different. Taken together with our published reports of the estrogen agonist activities of DIM, the present results establish DIM as a unique bifunctional hormone disrupter. To our knowledge, DIM is the first example of a pure androgen receptor antagonist from plants.

Transcriptional programs activated by exposure of human prostate cancer cells to androgen

BACKGROUND

Androgens are required for both normal prostate development and prostate carcinogenesis. We used DNA microarrays, representing approximately 18,000 genes, to examine the temporal program of gene expression following treatment of the human prostate cancer cell line LNCaP with a synthetic androgen.

RESULTS

We observed statistically significant changes in levels of transcripts of more than 500 genes. Many of these genes were previously reported androgen targets, but most were not previously known to be regulated by androgens. The androgen-induced expression programs in three additional androgen-responsive human prostate cancer cell lines, and in four androgen-independent subclones derived from LNCaP, shared many features with those observed in LNCaP, but some differences were observed. A remarkable fraction of the genes induced by androgen appeared to be related to production of seminal fluid and these genes included many with roles in protein folding, trafficking, and secretion.

CONCLUSIONS

Prostate cancer cell lines retain features of androgen responsiveness that reflect normal prostatic physiology. These results provide a broad view of the effect of androgen signaling on the transcriptional program in these cancer cells, and a foundation for further studies of androgen action.

AKT-independent protection of prostate cancer cells from apoptosis mediated through complex formation between the androgen receptor and FKHR

Recent studies suggested that the protection of cell apoptosis by AKT involves phosphorylation and inhibition of FKHR and related FOXO forkhead transcription factors and that androgens provide an AKT-independent cell survival signal in prostate cancer cells. Here, we report receptor-dependent repression of FKHR function by androgens in prostate cancer cells. Transcriptional analysis demonstrated that activation of the androgen receptor caused an inhibition of both wild-type FKHR and a mutant in which all three known AKT sites were mutated to alanines, showing that the repression is AKT independent. In vivo and in vitro coprecipitation studies demonstrated that the repression is mediated through protein-protein interaction between FKHR and the androgen receptor. Mapping analysis localized the interacting domains to the carboxyl terminus between amino acids 350 and 655 of FKHR and to the amino-terminal A/B region and the ligand binding domain of the receptor. Further analysis demonstrated that the activated androgen receptor blocked FKHR's DNA binding activity and impaired its ability to induce Fas ligand expression and prostate cancer cell apoptosis and cell cycle arrest. These studies identify a new mechanism for androgen-mediated prostate cancer cell survival that appears to be independent of the activity of the receptor on androgen response element-mediated transcription and establish FKHR and related FOXO forkhead proteins as important nuclear targets for both AKT-dependent and -independent survival signals in prostate cancer cells.

Distinguishing androgen receptor agonists and antagonists: distinct mechanisms of activation by medroxyprogesterone acetate and dihydrotestosterone

Natural and pharmacological androgen receptor (AR) ligands were tested for their ability to induce the AR NH2-terminal and carboxyl-terminal (N/C) interaction in a two-hybrid protein assay to determine whether N/C complex formation distinguishes in vivo AR agonists from antagonists. High-affinity agonists such as dihydrotestosterone, mibolerone, testosterone, and methyltrienolone at concentrations between 0.1 and 1 nM induce the N/C interaction more than 40-fold. The lower affinity anabolic steroids, oxandrolone and fluoxymesterone, require concentrations of 10-100 nM for up to 23-fold induction of the N/C interaction. However no N/C interaction was detected in the presence of the antagonists, hydroxyflutamide, cyproterone acetate, or RU56187, at concentrations up to 1 microM, or with 1 microM estradiol, progesterone, or medroxyprogesterone acetate; each of these steroids at 1-500 nM inhibited the dihydrotestosterone-induced N/C interaction, with medroxyprogesterone acetate being the most effective. In transient and stable cotransfection assays using the mouse mammary tumor virus reporter vector, all ligands displayed concentration-dependent AR agonist activity that paralleled induction of the N/C interaction, with antagonists and weaker agonists failing to induce the N/C interaction. AR dimerization and DNA binding in mobility shift assays and AR stabilization reflected, but were not dependent on, the N/C interaction. The results indicate that the N/C interaction facilitates agonist potency at low physiological ligand concentrations as detected in transcription, dimerization/DNA binding, and stabilization assays. However the N/C interaction is not required for agonist activity at sufficiently high ligand concentrations, nor does its inhibition imply antagonist activity.

Altered transcriptional regulation in cells expressing the expanded polyglutamine androgen receptor

Kennedy's disease is a degenerative disease of motor neurons in which the causative mutation is expansion of a CAG/polyglutamine tract near the 5' end of the androgen receptor gene. The mutant protein misfolds, aggregates, and interacts abnormally with other proteins, leading to a novel, toxic gain of function and an alteration of normal function. We used a cell culture model to explore the mechanisms underlying the alterations in androgen receptor function conferred by the mutation. Here we show that cells expressing the wild-type androgen receptor with 24 CAG repeats respond to ligand by showing trophic effects including prolonged survival in low serum, whereas cells expressing the mutant receptor with 65 CAG repeats do not show a robust trophic response. This partial loss of function correlates with decreased levels of the mutant protein due to its preferential degradation by the ubiquitin-proteasome pathway. Expression analysis using oligonucleotide arrays confirms that the mutant receptor has undergone a partial loss of function, and fails to regulate a subset of genes whose expression is normally affected by ligand activation of the wild-type receptor. The mutant receptor has also undergone several functionally important post-translational modifications in the absence of ligand that the wild-type receptor undergoes in the presence of ligand, including acetylation and phosphorylation. These modifications correlate with a ligand-independent gain of function exhibited by the mutant receptor in expression analysis. Our findings suggest that polyglutamine expansion alters androgen receptor function by promoting its degradation and by modifying its activity as a transcription factor.

AGR2, an androgen-inducible secretory protein overexpressed in prostate cancer

AGR2, the human homologue of Xenopus anterior gradient 2 (XAG2), was identified by a suppression subtractive hybridization-based technique as an androgen-inducible gene. There are two AGR2 transcripts, which encode the same secretory protein of 175 amino acids. The androgen induction was time- and dose-dependent, with more than a 10-fold increase in the level of AGR2 mRNA after 48 hr of treatment with 10(-9) M R1881. Expression of AGR2 mRNA was specifically detected in limited human tissue rich in epithelial cells, including the prostate gland. Analysis of 46 microdissected primary prostate adenocarcinoma samples showed that AGR2 mRNA expression was markedly elevated in the majority of tumors as compared to matched adjacent benign tissues. Androgen-induced AGR2 protein expression was demonstrated in LNCaP cells by Western blot analysis with an anti-AGR2 antibody. Immunohistochemistry analysis indicated that AGR2 protein expression was highly restricted to the secretory epithelial cells in the prostate gland. In tissue sections from radical prostatectomy specimens, immunohistochemical staining of AGR2 showed markedly increased expression in high-grade prostatic intraepithelial neoplasia and Gleason pattern 3-4 prostatic adenocarcinoma. Therefore, the androgen-induced secretory protein AGR2 may serve as a potential therapeutic target and/or molecular marker for prostate cancer.

Testosterone supplementation for hypogonadal impotence: assessment of biochemical measures and therapeutic outcomes

PURPOSE

Although hypogonadism is a rare cause of erectile failure, impotent men are frequently treated with supplemental androgens. The results of such treatment and the individual merits of available formulations remain controversial. A series of hypogonadal men participated in a trial of oral testosterone undecanoate to assess the effectiveness of the medication, and use of biochemical and clinical outcome measures.

MATERIALS AND METHODS

A consecutive sample of 23 hypogonadal impotent men received testosterone undecanoate orally for no less than 60 days. Serum levels of gonadotropins, testosterone, estrogens and sex hormone-binding globulin were measured before, during and after the trial. Sexual response and feeling of well-being were measured by daily diaries and visual analogue scales.

RESULTS

Testosterone undecanoate produced restoration of plasma testosterone levels in all patients but a measurable improvement in sexual attitudes and performance in only 61%. Visual analogue scores were effective discriminants of the therapeutic response but none of the conventional biochemical measures predicted or correlated with clinical outcome.

CONCLUSIONS

Testosterone undecanoate is an effective agent for treating hypogonadism. In hypogonadal impotent patients the most appropriate outcome measure for androgen supplementation is individual response to therapy, while conventional biochemical hormone determinations lack predictive value and fail to correlate with response.

Androgen induction of cyclin-dependent kinase inhibitor p21 gene: role of androgen receptor and transcription factor Sp1 complex

Previous studies have shown that androgen up-regulates expression of the p21 (WAF1, CIP1, SDI1, CAP20) gene, which contains a canonical androgen response element (ARE) in its proximal promoter region. We undertook the current studies to determine whether elements in the p21 promoter other than the ARE mediate androgen action. We found that deletion of the ARE did not completely abolish the promoter responsiveness to androgen, suggesting that additional cis-regulatory elements within the p21 core promoter may also be involved in androgen responsiveness. The p21 core promoter is GC-rich and contains six binding sites for transcription factor Sp1. We determined whether one or more of these Sp1 sites mediate androgen responsiveness of the p21 promoter. To do so, we used a transient transfection assay with p21 promoter-luciferase reporter constructs. The reporter activity of a construct lacking the ARE but containing all six Sp1 sites was induced approximately 3-fold by androgen. Mutation of Sp1-3 nearly eliminated basal promoter activity as well as androgen responsiveness, whereas deletion of Sp1-1 and Sp1-2 sites and mutation of Sp1-4, Sp1-5, and Sp1-6 sites had relatively little effect. We also used the mammalian one-hybrid assay and coimmunoprecipitation assay to show that androgen receptor (AR) and transcription factor Sp1 interact with one another. The current studies suggest a model in which AR and transcription factor Sp1 not only bind to their respective consensus sites within the p21 promoter, but also complex with one another, thereby recruiting coactivators and general transcription factors and inducing p21 transcription.

A novel androgen-regulated gene, PMEPA1, located on chromosome 20q13 exhibits high level expression in prostate

Biologic effects of androgen on target cells are mediated in part by transcriptional regulation of androgen-regulated genes (ARGs) by androgen receptor. Using serial analysis of gene expression (SAGE), we have identified a comprehensive repertoire of ARGs in LNCaP cells. One of the SAGE-derived tags exhibiting homology to an expressed sequence tag was maximally induced in response to synthetic androgen R1881 treatment. The open reading frame of the androgen-induced RNA (PMEPA1) was characterized as a 759-bp nucleotide sequence coding for a 252-amino-acid protein. The analysis of PMEPA1 protein sequence indicated the existence of a type Ib transmembrane domain between residues 9 and 25. Analysis of multiple-tissue Northern blots revealed the highest level of PMEPA1 expression in prostate tissue. PMEPA1 expression was predominately detected in glandular epithelial cells of prostate by in situ hybridization analysis. The expression of PMEPA1 in LNCaP cells was induced by androgen in a time- and dose-specific manner. Evaluation of PMEPA1 expression in androgen-dependent/independent tumors of the CWR22 xenograft model revealed that PMEPA1 was overexpressed in three of four androgen-independent tumor tissues. These observations define PMEPA1 as a novel androgen-regulated gene exhibiting abundant expression in prostate tissue. The increased expression of PMEPA1 in relapsed tumors of the CWR22 model suggests activation of androgen signaling in hormone refractory disease. PMEPA1, along with other highly androgen-induced prostate-specific genes, has potential to serve as an androgen signaling read-out biomarker in prostate tissue.

Repressors of androgen and progesterone receptor action

Androgen and progesterone receptors (AR and PR) are two determining factors in gonadal differentiation that are highly expressed in developing and mature gonads. Loss of AR results in XY sex reversal and mutations causing reduced AR activity lead to varying degrees of defects in masculinization. Female PR knockout mice are infertile due to ovarian defects. While much has been discovered about positive regulation of these receptors by coactivators little is known about repression of the transcriptional activity of AR and PR in the presence of agonists. In this study we assessed the effect of SMRT and DAX-1 on AR and PR activity in the presence of both agonists and partial antagonists. We show that SMRT and DAX-1 repress agonist-dependent activity of both receptors, and the mechanism of repression includes disruption of the receptor dimer interactions rather than recruitment of histone deacetylases. We demonstrate that endogenous agonist-bound PR and DAX-1 in T47D breast cancer cells and endogenous AR and DAX-1 in LNCaP prostate cancer cells can be coimmunoprecipitated suggesting that the interaction is physiological. Surprisingly, although DAX-1 represses partial antagonist activity of AR, it was ineffective in repressing partial antagonist induced activity of PR. In contrast to most reported repressors, the expression of DAX-1 is restricted. We found that although DAX-1 is expressed in normal human prostate, its expression is strongly reduced in benign prostatic hyperplasia suggesting that DAX-1 plays a role in limiting AR activity in prostate.

Multiple mechanisms for regulation of 3 beta-hydroxysteroid dehydrogenase/delta 5----delta 4-isomerase, 17 alpha-hydroxylase/C17-20 lyase cytochrome P450, and cholesterol side-chain cleavage cytochrome P450 messenger ribonucleic acid levels in primary cultures of mouse Leydig cells

The regulation of mRNA levels for delta 5-3 beta-hydroxysteroid dehydrogenase/delta 5----delta 4-isomerase (3 beta HSD), 17 alpha-hydroxylase/C17-20 lyase cytochrome P450 (P450(17 alpha] and cholesterol side-chain cleavage cytochrome P450 (P450scc) was studied in primary cultures of mouse Leydig cells. Treatment of Leydig cells with 8-bromo-cAMP (cAMP) was essential for expression of P450(17 alpha) mRNA, but not for 3 beta HSD. Treatment with cAMP caused a decrease in basal levels of 3 beta HSD mRNA. The addition of aminoglutethimide (AG), an inhibitor of cholesterol metabolism, to the cAMP-treated cultures resulted in increased expression of both 3 beta HSD and P450(17 alpha) mRNA levels. The addition of testosterone or the androgen agonist mibolerone to cAMP- plus AG-treated cultures reduced 3 beta HSD and P450(17 alpha) mRNA to levels comparable to those observed when cells were treated with cAMP only. The glucocorticoid dexamethasone reduced both basal and cAMP- plus AG-induced increases in 3 beta HSD mRNA, but not in P450(17 alpha) mRNA. Estradiol at a concentration of 1 microM had no effect on cAMP- plus AG-induced 3 beta HSD or P450(17 alpha) mRNA levels. The role of protein synthesis in mediating the cAMP induction of 3 beta HSD, P450(17 alpha), and P450scc was investigated. The addition of cycloheximide (10 micrograms/ml) to cAMP-treated cultures for 24 h completely suppressed both constitutive and cAMP-induced 3 beta HSD mRNA levels. Cycloheximide also repressed cAMP-induced levels of P450(17 alpha) to 12% of levels observed in the absence of cycloheximide. In sharp contrast, 24-h treatment with cycloheximide did not suppress cAMP induction of P450scc mRNA, but reduced basal levels by approximately 50%. A time course of induction by cAMP (50 microM) of P450(17 alpha) and P450scc mRNA showed very similar rates of increase in P450(17 alpha) and P450scc mRNA, with the greatest increase occurring between 12 and 24 h of treatment. The results of the study demonstrate that in normal mouse Leydig cells steady state levels of mRNA for 3 beta HSD, P450(17 alpha), and P450scc are differentially regulated. cAMP is required for maximal levels of all three mRNAs. There is high constitutive expression of 3 beta HSD and P450scc mRNA, while expression of P450(17 alpha) mRNA is absolutely dependent on cAMP stimulation. Endogenously produced testosterone negatively regulates the expression of cAMP-induced P450(17 alpha) and 3 beta HSD, while the glucocorticoid dexamethasone negatively regulates 3 beta HSD and P450scc.(ABSTRACT TRUNCATED AT 400 WORDS)

Androgens markedly stimulate the accumulation of neutral lipids in the human prostatic adenocarcinoma cell line LNCaP

Microscopic evaluation of LNCaP cells stained with the lipophilic dye Oil red O revealed that androgens induce a marked stimulation of lipid droplet accumulation. As determined by quantitative analysis of the Oil red O extracted from the stained cells, stimulatory effects of the synthetic androgen R1881 became apparent at concentrations as low as 10(-11) M. Maximal induction (15-fold) was reached at 10(-8) M. Increases were observed 2 days after hormone addition and were maximal 1 day later. Accumulation of lipid droplets was also induced by mibolerone (another synthetic androgen) and by the natural androgens testosterone and dihydrotestosterone. In agreement with the aberrant ligand specificity of the mutated androgen receptor in LNCaP cells, stimulation of lipid accumulation was also apparent after treatment with progesterone and estradiol. Cortisol and the synthetic glucocorticoid dexamethasone were ineffective. The androgen antagonist Casodex (bicalutamide) abolished the stimulatory effect of R1881, further supporting the involvement of the androgen receptor. In agreement with this conclusion, no changes in lipid accumulation were observed after androgen treatment of the androgen receptor-negative prostate tumor lines PC-3 and DU-145. To investigate the nature of the lipids affected by androgens, lipid extracts were analyzed by TLC, complemented with enzymatic lipid analyses. Androgens were shown to have major effects on the content of triglycerides and cholesterol esters (33- and 7-fold stimulation, respectively), the two main classes of lipids stained by Oil red O. Phospholipid and cholesterol contents were increased by a factor of 2. Incorporation studies with [2-14C]acetate revealed that androgens caused a major stimulation of 2-14C incorporation into triglycerides and cholesterol esters (11- and 13-fold, respectively), suggesting that androgens act at least in part at the level of lipid synthesis. Taken together, these findings indicate that androgens, besides affecting proliferation and protein secretion, also markedly stimulate the production and accumulation of neutral lipids, revealing a novel interesting aspect of androgen regulation of LNCaP cells.

Risk factors for anabolic-androgenic steroid use among weightlifters: a case-control study

Anabolic-androgenic steroid (AAS) use represents a major public health problem in the United States, but the risk factors for this form of drug use are little studied. We evaluated 48 men who had used AAS for at least 2 months and 45 men who had never used AAS, using a verbal interview and a battery of questionnaires covering hypothesized demographic, familial, and psychosocial risk factors for AAS use. All subjects in both groups were experienced weightlifters; thus, differences between groups were likely to be associated specifically with AAS use, rather than with weightlifting in general. The AAS users and non-users generally described similar childhood and family experiences, but users reported significantly poorer relationships with their fathers and greater childhood conduct disorder than non-users. At the time that they first started lifting weights, AAS users and non-users were similar in their perceived physical, social, and sexual status, but users were significantly less confident about their body appearance. AAS users displayed much higher rates of other illicit substance use, abuse, or dependence than non-users, with use of other illicit substances almost always preceding first use of AAS. These findings suggest that AAS use may be most likely to occur in men with high levels of antisocial traits and low levels of body esteem.

Steroid receptor profiling of vinclozolin and its primary metabolites

Several pesticides and fungicides commonly used to control agricultural and indoor pests are highly suspected to display endocrine-disrupting effects in animals and humans. Endocrine disruption is mainly caused by the interference of chemicals at the level of steroid receptors: it is now well known that many of these chemicals can display estrogenic effects and/or anti-androgenic effects, but much less is known about the interaction of these compounds with other steroid receptors. Vinclozolin, a dicarboximide fungicide, like its primary metabolites 2-[[(3,5-dichlorophenyl)-carbamoyl]oxy]-2-methyl-3-butenoic acid (M1), and 3',5'-dichloro-2-hydroxy-2-methylbut-3-enanilide (M2), is known to bind androgen receptor (AR). Although vinclozolin and its metabolites were characterized as anti-androgens, relatively little is known about their effects on the function of the progesterone (PR), glucocorticoid (GR), mineralocorticoid (MR) or estrogen receptors (ERalpha and ERbeta). Objectives of the study were to determine the ability of vinclozolin and its two primary metabolites to activate AR, PR, GR, MR and ER. For this purpose, we used reporter cell lines bearing luciferase gene under the control of wild type or chimeric Gal4 fusion AR, PR, GR, MR or ERs. We confirmed that all three were antagonists for AR, whereas only M2 was found a partial agonist. Interestingly, M2 was also a PR, GR and MR antagonist (MR>>PR>GR) while vinclozolin was an MR and PR antagonist. Vinclozolin, M1 and M2 were agonists for both ERs with a lower affinity for ERbeta. Although the potencies of the fungicide and its metabolites are low when compared to natural ligands, their ability to act via more than one mechanism and the potential for additive or synergistic effect must be taken into consideration in the risk assessment process.

Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show?

Supplementing with creatine is very popular amongst athletes and exercising individuals for improving muscle mass, performance and recovery. Accumulating evidence also suggests that creatine supplementation produces a variety of beneficial effects in older and patient populations. Furthermore, evidence-based research shows that creatine supplementation is relatively well tolerated, especially at recommended dosages (i.e. 3-5 g/day or 0.1 g/kg of body mass/day). Although there are over 500 peer-refereed publications involving creatine supplementation, it is somewhat surprising that questions regarding the efficacy and safety of creatine still remain. These include, but are not limited to: 1. Does creatine lead to water retention? 2. Is creatine an anabolic steroid? 3. Does creatine cause kidney damage/renal dysfunction? 4. Does creatine cause hair loss / baldness? 5. Does creatine lead to dehydration and muscle cramping? 6. Is creatine harmful for children and adolescents? 7. Does creatine increase fat mass? 8. Is a creatine 'loading-phase' required? 9. Is creatine beneficial for older adults? 10. Is creatine only useful for resistance / power type activities? 11. Is creatine only effective for males? 12. Are other forms of creatine similar or superior to monohydrate and is creatine stable in solutions/beverages? To answer these questions, an internationally renowned team of research experts was formed to perform an evidence-based scientific evaluation of the literature regarding creatine supplementation.

Silymarin inhibits function of the androgen receptor by reducing nuclear localization of the receptor in the human prostate cancer cell line LNCaP

A number of reports have shown that the polyphenolic flavonoid silymarin (SM) is an effective anticancer agent. Agents with novel mechanisms of blocking androgen receptor (AR) function may be useful for prostate cancer prevention and therapy. Previous studies showed that silibinin (SB), the major active component of SM, could inhibit cell proliferation of a human prostate cancer cell line, LNCaP, by arresting the cell cycle at the G(1) phase without causing cell death. This study further delineates the potential molecular mechanism by which SM and SB exhibit antiproliferative effects on androgen-responsive prostate cancer cells by inhibiting function of the AR. We observed that SM and SB inhibited androgen-stimulated cell proliferation as well as androgen-stimulated secretion of both prostate-specific antigen (PSA) and human glandular kallikrein (hK2). Additionally, for the first time, we show that an immunophilin, FKBP51, is androgen regulated and that this up-regulation is suppressed by SM and SB. We further demonstrate that transactivation activity of the AR was diminished by SM and SB using gene transfer of PSA promoter and hK2 androgen-responsive element constructs. However, expression and steroid-binding ability of total AR were not affected by SM in western blotting and ligand-binding assays. Intriguingly, we found that nuclear AR levels are significantly reduced by SM and SB in the presence of androgens using western blotting assay and immunocytochemical staining. This study provides a new insight into how SM and SB negatively modulate androgen action in prostate cancer cells.

Androgen stimulates matrix metalloproteinase-2 expression in human prostate cancer

Prostate growth and differentiation is androgen dependent, and increased expression of matrix metalloproteinase 2 (MMP-2) has been found in more aggressive prostate cancers. As part of our efforts to elucidate the mechanisms responsible for prostate cancer progression, we evaluated the MMP-2 expression after androgen stimulation in human prostate cancer LNCaP and LAPC-4 cells, which express a functional androgen receptor. Treatment of the cells with a synthetic androgen R1881 resulted in an increase of pro-MMP-2 expression assessed by Western blot and gelatinolytic zymography in both cell lines. R1881-stimulated pro-MMP-2 expression occurred in a dose-dependent manner, which was completely abrogated in the presence of the nonsteroid androgen antagonist bicalutamide. In accordance with the protein expression, MMP-2 promoter activity was also increased by R1881 in a cell-based luciferase reporter assay. However, R1881 treatment did not significantly affect either the pro-MMP-9 expression or its promoter activity. Although we observed an appearance of active form of MMP-2, its activator MT1-MMP was not changed after R1881 treatment. Pretreatment of the cells with inhibitors of RNA transcription, actinomycin D, or protein translation, cycloheximide, significantly suppressed R1881-induced pro-MMP-2 expression in LNCaP cells, indicating that androgen stimulates pro-MMP-2 gene expression. In addition, phosphatidylinositol 3'-kinase inhibitor, LY294002 or wortmannin, strongly inhibited R1881-induced pro-MMP-2 expression. Finally, R1881-enhanced LNCaP cell migration was clearly suppressed by LY294002 or the MMP-2 inhibitor OA-Hy in an in vitro migration assay. In conclusion, our data demonstrated that androgen stimulates pro-MMP-2 expression in LNCaP cells via phosphatidylinositol 3'-kinase-dependent androgen receptor transactivation.