Validation of an immunoassay for anti-Müllerian hormone measurements and reference intervals in healthy Brazilian subjects.

BACKGROUND: Anti-Müllerian hormone is marker of ovarian and testicular reserve. The clinical use of this hormone requires proper standardization of reference intervals. The aims of this study were to validate the Anti-Müllerian hormone Gen II immunoassay, to establish Anti-Müllerian hormone reference intervals in healthy subjects, and to evaluate the influence of hormonal contraceptives, smoking, and body mass index on Anti-Müllerian hormone. METHODS: The validation of the Anti-Müllerian hormone Gen II assay (Beckman Coulter Company, TX, USA) was performed using a simplified protocol recommended by Clinical Laboratory Standard Institute. One-hundred and thirty-three healthy females and 120 males were prospectively selected for this study. RESULTS: The analytical and functional sensitivities of the Anti-Müllerian hormone Gen II immunoassay were 0.02 and 0.2 ng/mL, respectively. Intra-assay coefficients ranged from 5.2 to 9.0%, whereas inter-assay precision ranged from 4.6 to 7.8% at different concentrations. In females, Anti-Müllerian hormone showed progressive decline with increasing age (r=-0.4, p<0.001), whereas in males, age showed no influence on Anti-Müllerian hormone concentrations. In females, Anti-Müllerian hormone concentrations did not differ between users and non-users of hormonal contraceptives, smokers, and non-smokers and obese and lean individuals. However, there was a negative and significant correlation between Anti-Müllerian hormone and body mass index in males (r=-0.3, p=0.008). CONCLUSIONS: Anti-Müllerian hormone Gen II assay was reliable for determining serum Anti-Müllerian hormone concentrations. Anti-Müllerian hormone concentrations declined with aging and presented a wide inter-individual variability. The lack of influence of hormonal contraceptives, smoking, and obesity on Anti-Müllerian hormone in both sexes allowed us to refine the normative concentrations for the Brazilian population.

Importância da via do mevalonato nas neoplasias do córtex adrenal / Importance of mevalonate pathway in adrenocortical tumors

Introdução: A 3-hidroxi-3-metilglutaril coenzima A redutase (HMGCR) é a enzima limitante da via do mevalonato. Esta via, que tem como produto final o colesterol, gera inúmeros subprodutos, como os isoprenóides, essenciais para modificação pós-traducional de várias proteínas envolvidas em proliferação e crescimento celular. Em tecidos esteroidogênicos (por exemplo, córtex adrenal), a HMGCR pode desempenhar um papel tanto no controle do crescimento e proliferação celular quanto na esteroidogênese. HMGCR está hiperexpressa em várias formas de neoplasias humanas inclusive em tumores adrenocorticais (ACTs), mas a sua importância na biologia dos ACTS é desconhecida. Objetivos: Avaliar o padrão de expressão da HMGCR e outros genes que participam na economia de colesterol e esteroidogênese em ACTs adultos e pediátricos; avaliar o efeito do inibidor da HMGCR lovastatina na via proliferativa MAPK; e analisar os efeitos de vários inibidores da via mevalonato na viabilidade de células NCI-H295A. Casuística e métodos: Analisamos a expressão do RNAm por PCR em tempo real dos genes HMCGR, FDFT1, SCARB1, LDLR StAR, TSPO, CYP11A1, CYP11B1, CYP17A1, CYP21A1 e HSD3B1, em ACTs, incluindo 27 tumores de adultos: [17 adenomas (ACA) e 10 carcinomas (ACC)]; 21 tumores de crianças [13 adenomas (PAD) e 8 carcinomas (PAC)]. Um pool comercial de RNA poli A obtido de córtex adrenal normal humano foi utilizado como amostra referência. A fosforilação da proteína ERK 1/2 (efetor final da via MAPK) no extrato intracelular de células NCI-H295A após tratamento com lovastatina foi avaliada através de SDS-PAGE seguido por immunoblot com anticorpos específicos. A ação sob a viabilidade celular em células NCI-H295A dos inibidores da via mevalonato foi realizada por análise colorimétrica. Resultados: A maioria dos ACTs de adultos apresentou expressão diminuída de StAR, TSPO, CYP11A1, CYP11B1, CYP17A1, CYP21A1 e HSD3B1 e hiperexpressão da HMGCR. Neste grupo, a expressão relativa dos genes StAR,...

Introduction: 3-hydroxy-3-methylglutaryl coenzime A reductase (HMGCR) is the rate-limiting enzyme of the mevalonate pathway, which generates isoprenoids for both post-translational modification of several proteins involved in cell growth and proliferation and biosynthesis of cholesterol. Therefore, in steroidogenic tissues (e. g. adrenal cortex), HMGCR may play a role in both growth control and steroidogenesis. HMGCR is overexpressed in several forms of human neoplasms incluiding adrenocortical tumors (ACTs), but its importance in the biology of ACTs is unknown. Objective: To assess the expression pattern of HMGCR, and other genes involved in cholesterol economy and steroidogenesis in pediatric and adult ACTs. To evaluate the impact of a HMGCR inhibitor lovastatin on proliferative pathway- MAPK - of NCI-H295A cells; to evaluate the effects of various mevalonate pathway inhibitors in NCI-H295A cells viability. Methods: We analyzed HMGCR, FDFT1, LDLR, SCARB1, StAR, TSPO, CYP11A1, CYP11B1, CYP17A1, CYP21A1 and HSD3B1 mRNA expression by real-time RT-PCR in ACTs [Adult tumors: 14 adenomas (ACA) and 11 carcinomas (ACC); Pediatric tumors: 13 adenomas (PAD) and 8 carcinomas (PAC)]. A commercial pool of normal human adrenal cortex poly A RNA was used as reference sample. We assess ERK phosphorylation after treatment with lovastatin through SDS-PAGE of intracellular extract followed by immunoblotting with specific antibodies. Action of mevalonate pathway inhibitors on cellular viability was assessed by colorimetric assay. Results: Most adult ACTs showed decreased expression of StAR, TSPO, CYP11A1, CYP11B1, CYP17A1, CYP21A1 and HSD3B1 and overexpression of HMGCR. In this group, the relative expressions of TSPO, StAR, CYP11B1, CYP21A1 and HSD3B1 were significantly lower in the ACCs (P<0.02). LDLR was not differentially expressed in most of adults ACTs, while FDFT1 and SCARB1 were hypoexpressed in this group, independently of biological behavior. Cluster...