Análise do perfil de metilação dos genes THBS1, GPX3 e COX2 e identificação de H. pylori em amostras de câncer gástrico.

• Ano de defesa: 2013
• Autor(a) principal: Melo, Cynthia Farias Vieira de
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraí­ba; Brasil; Biologia Celular e Molecular; Programa de Pós-Graduação em Biologia Celular e Molecular; UFPB
• Palavras-chave em Português: Câncer de estômago; Gastric cancer; Methylation; Gene TBBS1; Gene COX2; Gene GPX3; H. pylori; CIENCIAS BIOLOGICAS::BIOLOGIA GERAL
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/tede/3645

Cancer is a disease with a high mortality rate in Brazil, including, stomach cancer is currently the fourth most common type of cancer worldwide, responsible for countless deaths. Its etiology is multifactorial, because studies suggest associations to various factors such as dietary habits, environmental factors, genetic and epigenetic factors and gastric infection by Helicobacter pylori. Epigenetic changes such as methylation of the promoter regions of genes involved in cellular homeostasis may contribute to gastric carcinogenesis. To verify the methylation status of THBS1, GPX3 and COX2 genes and to evaluate their association with H. pylori in gastric adenocarcinomas, Methylation-Sensitive Restriction Enzyme PCR (MSRE-PCR) assay was performed in 39 gastric carcinomas (intestinal and diffuse types) and 15 normal stomach tissue samples. The presence of H. pylori was performed by amplification of the fragment of the 16S rRNA. Statistical analysies were performed using Fisher s exact test. The hypermethylation of GPX3, THBS1 and COX2 occurred in 18% (n = 7), 5% (n = 2) 36% (n = 14) of gastric cancer samples, respectively, whereas in normal samples was found in 13%, 7% and 67%. The presence of H. pylori was detected in 67% of gastric cancer samples and 67% in normal gastric samples. No correlation was found between the methylation profile of the studied samples and clinicopathological variables and the presence of H. pylori (P ≥ 0,05). The presence of H. pylori in gastric cancer samples and normal was not associated with clinicopathologic variables analyzed (P> 0.05).