Identificação de perfis diferenciais de metilação do DNA na endometriose

Abstract

A endometriose constitui uma doença de etiologia incerta, caracterizada pela presença de tecido endometriótico fora da cavidade uterina. E uma causa comum de morbidade, atingindo 5 a 10% das mulheres em idade reprodutiva. A metilção anormal na região promotora de genes especificos e os niveis de expressão alterados das DNA metiltransferases (DNMTs) compoem 0 conjunto de evidencias recentes indicando a endometriose como uma doença epigenetica. 0 presente estudo propos a investigaçao do perfil diferencial de metilaçao do DNA na endometriose, utilizando uma abordagem genomica de alta resoluçao baseada na metodologia de microarrays. Para isso, foram coletadas amostras pareadas de endometrio eutópico e de endometriose intestinal profunda de 18 pacientes. Foram selecionadas dez amostras pareadas para a hibridação do DNA: cinco casos foram submetidos ao enriquecimento das sequencias não metiladas (digerido com a enzima de restrição dependente de metilação McrBC ) e nove ao enriquecimento das sequencias metiladas (digerido com 0 coquetel de enzimas sensiveis a metilação do DNA Acil, HinP11, HpyCH41Ve Hpall). Os ensaios foram realizados em duplicatas totalizando 28 hibridações independentes na plataforma disponivel comercialmente Human CpG Island ChIP-on-Chip Set 244K (Agilent Technologies). Este protocolo foi previamente padronizada utilizando-se 0 DNA das linhagens derivadas de carcinomas de c610n HCT116 e DKO (celulas HCT116 duplo knockout para as DNMT1 e DNMT3b) usando marcação reversa (dye swap). Os dados foram avaliados nos software Agilent Technologies Genomic Workbench (DNA Analytics 5.0) e GeneSpring 7.3 (Agilent Technologies). Estre os 925 genes que apresentaram metila9ao diferencial, 55 foram recorrentes em dois ou mais casos. Varios destes genes mostram-se interessantes por exercerem funções relacionadas a fatores de transcrição (MSX1, EMX2, HOXB13, HOXD8 e HOXD9)...

Endometriosis is a disease of unknown etiology characterized by the presence of endometrial tissue outside the uterine cavity. It is a common cause of morbidity, affecting 5-10% of women in reproductive ages. The aberrant methylation in the promoter region of specific genes and the higher expression levels of DNA methyltransferases (DNMTs) in comparison with normal endometrium have been reported as evidences indicating that endometriosis is an epigenetic disease. The present study investigated the differential profile of DNA methylation in endometriosis using a high-resolution microarray-based assay. There were collected paired samples of eutopic endometrium and deep intestinal endometriosis from 18 patients and, subsequently, it was selected ten pairs to the DNA hybridization: five matched samples were submitted to the enrichment of unmethylated sequences (digested with the methylation-dependent restriction enzyme McrBG) and ten to the enrichment of methylated sequences (digested with the cocktail of enzymes sensitive to DNA methylation AGII, HinP1/, HpyGH4/V and Hpa/I). The assays were performed in duplicates totalizing 28 independent hybridizations in the commercially available platform Human CpG Island ChIP-on-Chip Set 244K (Agilent Technologies). The protocol was previously standardized using the DNA from the colon carcinomas cell lines HCT116 and DKO (HCT116 cells double-knockout for DNMT1 and DNMT3b) using reverse labeling (dye swap). The data were evaluated using the software Genomic Workbench (DNA Analytics 5.0) and GeneSpring 7.3. Among the 925 genes showing differential methylation, 55 genes were detected in at least two cases. Several of these gene could be considered good candidates to molecular biomarkers of endometriosis since that they act as transcription factors (MSX1, EMX2, HOXB13, HOXDB e HOXD9) , chromatin remodeling (MAD1L 1, WDR5 e BGOR)... (Complete abstract click electronic access below)