Urinary androgens excretion patterns and prostate cancer in Mexican men.

Epidemiological studies related to androgens and prostate cancer (PC) have focused on serum determination of testosterone, androstenedione (A4), and DHEA, with inconsistent results. Herein, we hypothesized that differences in androgen biosynthetic and metabolic pathways, rather than differences in specific androgen concentrations, are associated with prostatic carcinogenesis. Therefore, spot urine samples from 111 incident PC cases with Gleason score at diagnosis and 227 healthy population controls, were analyzed. Urinary androgen concentrations (nanograms/milligrams of creatinine) were determined by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS). Using a factor analysis, we identified three androgen urinary excretion patterns. In a subsample, we evaluated a modification effect of the androgen receptor (AR) CAG polymorphism. Pattern I, characterized by A4 and testosterone hydroxylated metabolites (11ß-OHT; 2ß-OHT; 15ß-OHT; 2α-OHT; 6ß-OHT), was associated with high PC odds among carriers of AR gene (CAG)>19 repeats (OR: 3.67 95% CI: 1.23-11.0; P for interaction= 0.009). Conversely, higher testosterone excretion (pattern III), was marginally associated with lower (OR: 0.35 95% CI: 0.12-1.00, P for trend= 0.08) poorly differentiated PC (Gleason ≥8). No clear association was observed with pattern II (DHEA; 16α and 16ß-OHT). Our results were consistent with the previous evidence which suggests that the C11-oxy backdoor pathway is important for prostatic carcinogenesis. Androgen urine excretion analysis could be useful for PC diagnosis, treatment, and prognosis; however, further studies with a larger number of samples and the urinary determination of 11-ketoandrogens are necessary.

Vitamin A deficiency in K14E7HPV expressing transgenic mice facilitates the formation of malignant cervical lesions.

Infection with high-risk human papillomavirus (HR-HPV) is the main cause of cervical cancer (CC), but viral infection alone does not guarantee the development of this malignancy. Indeed, deficiencies of dietary micronutrients could favor cervical cancer development in individuals that harbor HR-HPV infections. The status of retinoid levels, natural and synthetic derivatives of vitamin A, is important in maintaining cellular differentiation of the cervical epithelium. Moreover, many studies show a link between deficient intake of retinoids or alteration of the retinoid receptors and CC development. In spite of this, the effect of vitamin A deficiency (VAD) in presence of HR-HPV oncoproteins on cervical carcinogenesis in vivo has not been reported. Transgenic mice expressing E6 or E7 oncoproteins (K14E6 or K14E7 mice, respectively) were used to evaluate the possible role of VAD in the development of malignant cervical lesions. The survival of the mice in VAD condition was studied, and histopathological analysis and immunohistochemical detection of molecular cancer markers such as the tumor suppressor retinoic acid receptor beta (RARß), proliferating cell nuclear antigen (PCNA), cleaved caspase 3, and the tumor suppressor protein p16INK4A (inhibitor of CDK4) were performed. Our results show that K14E6/VAD mice showed moderate cervical dysplasia; notably, K14E7/VAD mice developed severe cervical dysplasia and cervical in situ carcinoma at an early age. VAD synergizes with HPV16E7 oncoprotein expression favoring cervical carcinogenesis in vivo.

Analysis of testosterone-hydroxylated metabolites in human urine by ultra high performance liquid chromatography-Mass Spectrometry.

Testosterone regulates the male reproductive system and acts directly or indirectly on nearly all systems during fetal, pubertal and adult life. Testosterone homeostasis depends on its synthesis and degradation. The major biotransformation reactions are hydroxylation by different cytochrome P450 (CYP) isoforms. There are no described methods to determine the profile of testosterone-hydroxylated metabolites in human urine. The aim of this study was to develop an analytical method to determine testosterone-hydroxylated metabolites in human urine using UPLC-MS. Seven testosterone-hydroxylated metabolites, androstenedione, and testosterone, were identified by comparison of their tret and positive electrospray ionization (ESI+) data, with those of analytical standards. The method developed is sensitive, specific, repeatable, and precise. Limits of detection and quantitation for all compounds ranged from 1.360 to 13.054 ng/ml and 4.234-39.679 ng/ml, respectively. The percentages of recovery were between 81.2 and 128.8%. The applicability of the analytical method was confirmed by analysis of urine samples obtained from two groups of healthy men (25-30 and 50-75 years old). All analytes were identified with slightly different metabolites profiles in both groups. In conclusion, the UPLC-MS method developed here was validated for the analysis of testosterone-hydroxylated metabolites in human urine.

Analysis of 3',5'-dichloro-2,3,4-trihydroxy-2-methylbutylanilide (DTMBA) as a new potential biomarker of exposure to vinclozolin in urine.

Vinclozolin (V) is a fungicide with anti-androgenic properties whose metabolism is not fully understood, and data on urinary elimination of either V or its metabolites are limited. Therefore the kinetics of urinary elimination of V and its metabolites, after an oral dose in adult male rats were investigated. A single oral dose of V (100 mg/kg) suspended in corn oil was administered to male adult Wistar rats, and urine was collected at different times after dosing. V and its metabolites were extracted from urine, then enzymatically hydrolyzed using ß-glucuronidase/sulfatase of H. pomatia, and analyzed by HPLC/DAD. Urinary pharmacokinetic parameters were calculated using the analyte concentrations adjusted by creatinine levels. V and its metabolites 3',5'-dichloro-2,3,4-trihydroxy-2-methylbutylanilide (DTMBA, formerly denoted as M5), 2-[[(3,5-dichlorophenyl)-carbamoyl]oxy]-2-methyl-3-butenoic acid (M1), 3,5-dichloroaniline (M3), and 3',5'-dichloro-2-hydroxy-2-methylbut-3-enanilide (M2) were efficiently detected. The mean urine concentrations of V and M1 metabolite were fitted to a two-compartmental model for pharmacokinetic analysis. DTMBA approximately represented 88% of the total excreted metabolites, it was easily detected up to 168 h after dosing and its half-lives were 21.5 and 74.1 h, respectively. M1 was the second most abundant metabolite and was detected up to 144 h after being void. V and M3 were detected before 48 h, and M2 exhibited the lowest levels during the first 8 h after dosing. DTMBA, the most abundant V metabolite is quickly eliminated by urine, it is chemically stable, specific and could represent a useful alternative to be used as a biomarker of exposure to V.

Vinclozolin modulates hepatic cytochrome P450 isoforms during pregnancy.

Vinclozolin (V) is classified as a potent endocrine disruptor. The aim of the present study was to determine the effects of V on rat liver CYP regulation and on serum levels of testosterone and estradiol during pregnancy. Pregnancy decreased the liver total CYP content by 65%, enzyme activities of MROD, PROD, and PNPH, and testosterone hydroxylation activities, as well as the protein content of CYP2A and 3A. V exposure remarkably induced the protein content and enzyme activities of CYP1A, 2A, 2B and 3A subfamilies. Testosterone and estradiol were affected in an opposite manner, provoking a 3.5-fold increase in the estradiol/testosterone ratio. These results suggest that V could regulate the hepatic CYP expression through interaction with receptors and coactivators involved in its expression and may play an important role in hormonal balance during pregnancy. In addition, the results may also contribute to understanding the toxicity of V by in utero exposure.