In this study,mouse models of benign prostatic hyperplasia induced by subcutaneous injection of testosterone propionate was used to investigate the therapeutic effect and mechanism of Urtica hyperborean( UW) extracts on prostate hyperplasia in mice. The effects of UW extracts on prostate index,serum epidermal growth factor( EGF) and dihydrotestosterone( DHT) in model mice were observed,and the EGF and anti-apoptotic factor( Bcl-2) mRNA expression levels were detected as well as pathological changes in prostate tissue. The results showed that the ethyl acetate extraction and alcohol soluble fraction of the UW could significantly reduce the prostate index,reduce the serum DHT and EGF levels( P<0. 01),and significantly decrease the EGF and Bcl-2 mRNA expression( P<0. 01),significantly improved the morphological structure of prostate tissue. The above results confirmed that ethyl acetate extract and alcohol-soluble parts of UW have a good preventive effect on mice prostatic hyperplasia model,and its mechanism may be to reduce androgen levels by regulating polypeptide growth factors and/or inhibiting cell hyperproliferation and promoting apoptosis. This study laid the foundation for the further research on UW.
Animals ; Dihydrotestosterone ; blood ; Epidermal Growth Factor ; blood ; Male ; Medicine, Tibetan Traditional ; Mice ; Plant Extracts ; pharmacology ; Prostatic Hyperplasia ; chemically induced ; drug therapy ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Testosterone Propionate ; Urticaceae ; chemistry

As men grow older, circulating testosterone declines while the incidence of cardiovascular disease increases. Thus, the role of sex hormones as biomarkers, and possibly contributing factors to clinical manifestations of cardiovascular disease in the increasing demographic of aging men, has attracted considerable interest. This review focuses on observational studies of endogenous androgens, namely circulating testosterone and dihydrotestosterone, which have examined their associations with cardiovascular events such as myocardial infarction and stroke. Studies which have examined the associations of endogenous estrogens, namely circulating estradiol, with these outcomes are also discussed. In large prospective cohort studies of predominantly middle-aged and older men, lower circulating testosterone consistently predicts higher incidence of cardiovascular events. Of note, both lower circulating testosterone and lower dihydrotestosterone are associated with higher incidence of stroke. These associations are less apparent when myocardial infarction is considered as the outcome. Results for estradiol are inconsistent. Lower circulating testosterone has been shown to predict higher cardiovascular disease-related mortality, as has lower circulating dihydrotestosterone. It is possible that the relationship of circulating androgens to cardiovascular events or mortality outcomes may be U-shaped rather than linear, with an optimal range defining men at lowest risk. Epidemiological studies are observational in nature and do not prove causality. Associations observed in studies of endogenous androgens need not necessarily translate into similar effects of exogenous androgens. Rigorous randomized controlled trials are needed to clarify the effects of testosterone treatment on cardiovascular risk in men.
Cardiovascular Diseases/mortality* ; Dihydrotestosterone/metabolism* ; Estradiol/metabolism* ; Humans ; Incidence ; Male ; Mortality ; Myocardial Infarction/metabolism* ; Stroke/metabolism* ; Testosterone/metabolism*

In men, obesity and metabolic complications are associated with lower serum testosterone (T) and dihydrotestosterone (DHT) and an increased risk of, and mortality from, multiple chronic diseases in addition to cardiovascular disease (CVD). The causal interrelationships between these factors remain a matter of debate. In men with untreated congenital and lifelong forms of hypogonadotropic hypogonadism, there appears to be no increased risk. Men with Klinefelter's syndrome have an increased risk of various types of cancers, as well as CVD, which persist despite T therapy. In the absence of pathology of the hypothalamic-pituitary-gonadal axis, the effect of modest reductions in serum T in aging men is unclear. The prevalence of low serum T concentrations is high in men with cancer, renal disease, and respiratory disease and is likely to be an indicator of severity of systemic disease, not hypogonadism. Some population-based studies have found low serum T to be associated with a higher risk of deaths attributed to cancer, renal disease, and respiratory disease, while others have not. Although a meta-analysis of longitudinal studies has shown an association between low serum T and all-cause mortality, marked heterogeneity between studies limited a firm conclusion. Therefore, while a decrease in T particularly occurring later in life may be associated with an increase in all-cause and specific types of mortality in men, the differential effects, if any, of T and other sex steroids as compared to health and lifestyle factors are unknown at the current time.
Age Factors ; Cardiovascular Diseases/metabolism* ; Cause of Death ; Dihydrotestosterone/metabolism* ; Humans ; Hypogonadism/metabolism* ; Klinefelter Syndrome/metabolism* ; Male ; Mortality ; Obesity/metabolism* ; Testosterone/metabolism*

Epidemiological studies hint at a beneficial influence of endogenous circulating testosterone (T), or its metabolite dihydrotestosterone (DHT), such that men with lower concentrations of T or DHT appear to have poorer health outcomes including frailty, diabetes, cardiovascular disease, and mortality. Small interventional studies of T have shown favorable effects on surrogate outcome measures, but a large randomized controlled trial (RCT) with the prespecified outcome of cardiovascular events has not been performed and would be logistically demanding. In the absence of such a definitive RCT, there is a controversy about the cardiovascular risks of T-therapy fuelled by contradictory findings from retrospective analyses of insurance databases of men prescribed T. The US Testosterone Trials (T-Trials) are the largest published RCTs of T-therapy in older men with symptoms or signs of hypogonadism and circulating T <9.54 nmol l⁻¹ at baseline. The T-Trials showed a modest benefit of T-therapy over a 12-month period on sexual function, a significant benefit in bone density and for anemia and neutral effect on cognition. The T-Trials cardiovascular sub-study was designed to determine the effects of T in these older men, and there was a statistically significant difference in the increase in noncalcified plaque volume in the T-treated group compared to placebo, but it is difficult to interpret these results due to differences in baseline coronary plaque burden (>50% difference) between the treatment and placebo arms of the subset involved. Therefore, there continues to be ongoing uncertainty over the effect of T-therapy on the cardiovascular system in men.
Age Factors ; Androgens/therapeutic use* ; Cardiovascular Diseases/metabolism* ; Dihydrotestosterone/metabolism* ; Hormone Replacement Therapy ; Humans ; Hypogonadism/metabolism* ; Male ; Protective Factors ; Risk Factors ; Testosterone/therapeutic use*

OBJECTIVETo determine the expression of Skp2 in different prostate cancer (PCa) cell lines and tissues, and explore its influence on the androgen receptor (AR) signaling pathway and development of castration-resistant prostate cancer (CRPC).

METHODSThe expression levels of Skp2 and AR in different PCa cell lines were detected by Western blot. After knockdown of Skp2 in the C4-2 and 22RV1 cells transfected with shRNA, the expressions of AR and P27 were determined and the activity of ARR3-Luc measured by dual-luciferase reporter gene assay following treatment with dihydrotestosterone (DHT). The expressions of AR and Skp2 in human naïve PCa or CRPC specimens were detected by immunohistochemical staining followed by analysis of their differences and correlation.

RESULTSThe Skp2 protein expression level was significantly higher in the C4-2 or 22RV1 cells than in the LNCaP cells. DHT treatment increased the expression of Skp2 in the C4-2 cells, but knock-down of Skp2 significantly up-regulated the expression of the well-known downstream protein P27 and down-regulated that of AR. Consistently, DHT treatment increased the activity of ARR3-Luc, while knockdown of Skp2 remarkably decreased it in the C4-2 and 22RV1 cells (P < 0.05). In addition, significantly higher expressions of Skp2 and AR were observed in the CRPC than in the naïve specimens (P < 0.05), with a positive correlation between the two proteins (r = 0.658 1, P < 0.05).

CONCLUSIONSkp2 can enhance the expression and transcription activity of the AR protein in CRPC cells or tissues and is promising to be a critical molecular therapeutic target.

Androgens ; pharmacology ; Cell Line, Tumor ; Dihydrotestosterone ; pharmacology ; Disease Progression ; Gene Knockdown Techniques ; Humans ; Male ; Neoplasm Proteins ; genetics ; metabolism ; Prostatic Neoplasms, Castration-Resistant ; metabolism ; Receptors, Androgen ; genetics ; metabolism ; S-Phase Kinase-Associated Proteins ; physiology ; Transcriptional Activation ; Up-Regulation

PURPOSE: Steroid 5-alpha reductase type 2 (SRD5A2) modifies testosterone to dihydrotestosterone (DHT) in the prostate. Single-nucleotide polymorphisms (SNPs) of the SRD5A2 gene might affect DHT. We sought to understand the relationship of SRD5A2 SNPs to prostate cancer in the Korean population. MATERIALS AND METHODS: Twenty-six common SNPs in the SRD5A2 gene were assessed in 272 prostate cancer cases and 173 controls. Single-locus analyses were conducted by using conditional logistic regression. Additionally, we performed a haplotype analysis for the SRD5A2 SNPs tested. RESULTS: Among the 20 SNPs and 4 haplotypes, there were no statistically significant results in the prostate cancer patients and the controls. In the logistic analysis of SRD5A2 polymorphisms with prostate-specific antigen (PSA) criteria, two SNPs (rs508562, rs11675297) and haplotype 1 displayed significant results (odds ratio [OR], 1.76; p=0.05; OR, 1.88-2.02; p=0.01-0.04; OR, 0.59; p=0.02, respectively). rs508562, rs11675297, rs2208532, and haplotype 1 (OR, 1.49; p=0.05; OR, 2.02; p=0.05; OR, 2.01; p=0.04; OR, 0.56-0.64, p=0.03-0.04, respectively) had significant associations with Gleason score. rs508562, rs11675297, and haplotype 1 (OR, 1.41-2.34; p=0.004-0.05; OR, 1.74-1.82; p=0.03-0.05; OR, 0.42-0.67; p=0.0005-0.03, respectively) were significantly associated with clinical stage. CONCLUSIONS: We conclude that there was no significant association between SRD5A2 SNPs and the risk of prostate cancer in the Korean population. However, we found that some SNPs and 1 haplotype influenced PSA level, Gleason score, and clinical stage.
3-Oxo-5-alpha-Steroid 4-Dehydrogenase/*genetics ; Aged ; Case-Control Studies ; Dihydrotestosterone/metabolism ; Genetic Predisposition to Disease ; Genotype ; Haplotypes ; Humans ; Logistic Models ; Male ; Membrane Proteins/*genetics ; Middle Aged ; Neoplasm Grading ; Neoplasm Staging ; Odds Ratio ; Polymorphism, Single Nucleotide ; Prostate-Specific Antigen/blood ; Prostatic Neoplasms/epidemiology/*genetics ; Republic of Korea/epidemiology ; Risk Factors ; Testosterone/genetics

OBJECTIVETo explore the molecular mechanism of dutasteride inhibiting fertility by studying its effects on the expressions of the epididymal epithelial junction proteins Claudin1 and β-catenin in rats.

METHODSSixteen 3-month-old SD male rats were equally divided into an experimental and a negative control group to be treated intragastrically with dutasteride at 40 mg/kg per day and the same dose of solvent, respectively, for 14 consecutive days. Then, the sperm motility and morphology of the rats were detected by computer-assisted sperm analysis, the serum levels of testosterone (T) and dihydrotestosterone (DHT) measured by ELISA, changes in the tight junction of epididymal cells observed under the transmission electron microscope, the protein and gene expressions of Claudin1 and β-catenin determined by RT-PCR and immunohistochemistry, and the conception rate of the mated female rats calculated.

RESULTSDutasteride significantly suppressed the serum DHT level, sperm motility, and fertility of the rats (P <0.05). Interspaces between epididymal epithelial cell tight junctions were observed, the volume of epididymal fluid obviously increased, and the expressions of Claudin1 and β-catenin gene and protein remarkably downregulated in the experimental rats (P <0.05).

CONCLUSIONDutasteride can significantly inhibit the fertility of male rats by reducing the serum DHT level, suppressing Claudin1 and β-catenin expressions, and damaging epididymal epithelial cell junctions.

Animals ; Azasteroids ; pharmacology ; Claudin-1 ; metabolism ; Dihydrotestosterone ; blood ; Dutasteride ; Epididymis ; drug effects ; metabolism ; Female ; Fertility ; drug effects ; Humans ; Intercellular Junctions ; drug effects ; Male ; Rats ; Rats, Sprague-Dawley ; Sperm Motility ; drug effects ; Testosterone ; blood ; Urological Agents ; pharmacology ; beta Catenin ; metabolism

BACKGROUND5α-Reductase inhibitors (5α-RI) act by inhibiting the conversion of testosterone to dihydrotestosterone (DHT), thereby preventing DHT induced benign prostatic hyperplasia. The existing 5α-RIs can be classified into two types: competitive and noncompetitive. Currently, limited evidence is available concerning the effect differences between the two types of 5α-RI on androgens. The purpose of this study was to assess the effects of competitive and noncompetitive 5α-RIs on serum and intra-prostatic androgens in beagle dogs.

METHODSTwenty beagles with spontaneous benign prostatic hyperplasia were randomly allocated into two groups: epristeride group (n = 10) in which beagles were treated with epristeride at 1 mg/kg once a day for 3 months, and finasteride group (n = 10) in which beagles were treated with finasteride at 1 mg/kg once a day for 3 months. The levels of intra-prostatic testosterone and DHT were measured before treatment and on day one after three months medication. Serum levels of testosterone and DHT were measured at the same time points. Changes in androgen levels before and after treatment were analyzed, and comparisons were made within each treatment group and between treatment groups.

RESULTSAfter 3-month treatment, serum and intra-prostatic DHT levels all decreased significantly in both the epristeride and finasteride groups. The change of DHT in serum was significantly higher in the finasteride group (-14% and -43% in epristeride and finasteride groups respectively, with P < 0.001); however there was no significant difference in the changes of intra-prostatic DHT between the two groups (-47% and -51% in epristeride and finasteride groups, respectively, P = 0.304). The decreases in DHT levels were accompanied by reciprocal increases in serum and intra-prostatic testosterone levels. Changes of testosterone were significantly higher in finasteride group both in serum (20% and 42% in epristeride and finasteride groups, respectively, P < 0.001) and in prostate tissue (18% and 29% in epristeride and finasteride groups, respectively, P = 0.004).

CONCLUSIONSTwo types of 5α-RI have similar effects in reducing DHT in prostate tissue in beagles. Competitive 5α-RI may reduce serum DHT to a greater scale, and significantly increase testosterone in beagle serum and prostate.

5-alpha Reductase Inhibitors ; pharmacology ; Androgens ; blood ; metabolism ; Androstadienes ; pharmacology ; Animals ; Dihydrotestosterone ; blood ; metabolism ; Dogs ; Finasteride ; pharmacology ; Male ; Prostate ; drug effects ; metabolism

The steroidal enzyme cytochrome P45017alpha catalyzes the conversion of progesterone and pregnenolone into androgens, androstenedione and dehydroepiandrosterone, respectively, the direct precursors of estrogens and testosterone. Dihydrotestosterone is the principal active androgen in the prostate, testosterone is also an active stimulant of the growth of prostatic cancer tissue. Inhibition of this enzyme as a mechanism for inhibiting androgen biosynthesis could be a worthwhile therapeutic strategy for the treatment of PCA. In this paper, four categories of steroidal inhibitors of cytochrome P45017alpha will be reviewed, a diverse range of steroidal inhibitors had been synthesized and shown to be potent inhibitors of P45017alpha.
Androstenedione ; biosynthesis ; Androstenes ; Androstenols ; chemical synthesis ; chemistry ; pharmacology ; Animals ; Antineoplastic Agents ; chemical synthesis ; chemistry ; pharmacology ; Dehydroepiandrosterone ; biosynthesis ; Dihydrotestosterone ; metabolism ; Enzyme Inhibitors ; chemical synthesis ; chemistry ; pharmacology ; Humans ; Male ; Molecular Structure ; Pregnenolone ; metabolism ; Progesterone ; metabolism ; Prostatic Neoplasms ; pathology ; Steroid 17-alpha-Hydroxylase ; antagonists & inhibitors ; Testosterone ; biosynthesis

Post-translational degradation of protein plays an important role in cell life. We employed chimeric molecules (dihydrotestosterone-based proteolysis-targeting chimeric molecule [DHT-PROTAC]) to facilitate androgen receptor (AR) degradation via the ubiquitin-proteasome pathway (UPP) and to investigate the role of AR in cell proliferation and viability in androgen-sensitive prostate cancer cells. Western blot analysis and immunohistochemistry were applied to analyse AR levels in LNCaP cells after DHT-PROTAC treatment. Cell counting and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) cell viability assay were used to evaluate cell proliferation and viability after AR elimination in both LNCaP and PC-3 cells. AR was tagged for elimination via the UPP by DHT-PROTAC, and this could be blocked by proteasome inhibitors. Degradation of AR depended on DHT-PROTAC concentration, and either DHT or an ALAPYIP-(arg)(8) peptide could compete with DHT-PROTAC. Inhibition of cell proliferation and decreased viability were observed in LNCaP cells, but not in PC-3 or 786-O cells after DHT-PROTAC treatment. These data indicate that AR elimination is facilitated via the UPP by DHT-PROTAC, and that the growth of LNCaP cells is repressed after AR degradation.
Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Dihydrotestosterone ; pharmacology ; Dose-Response Relationship, Drug ; Humans ; Male ; Prostatic Neoplasms ; drug therapy ; metabolism ; pathology ; Proteasome Endopeptidase Complex ; metabolism ; Receptors, Androgen ; metabolism ; Recombinant Fusion Proteins ; pharmacology ; therapeutic use ; Signal Transduction ; drug effects ; Ubiquitin ; metabolism