To verify the methylation status of CDH1, DAPK, COX2, hMLH1 and CDKN2A genes and to evaluate their association with Helicobacter pylori (H. pylori)-cagA(+) and Epstein Barr virus (EBV) infections in gastric adenocarcinomas.
The first was characterized by hypermethylation of BRCA1 and younger age (<45 years old), and the second by hypermethylation of p14 and p16 genes, male predominance and Epstein-Barr virus infection.
Presence of EBV infection was detected by EBV early RNA in situ hybridization. p16(INK4A) gene deletion status was assessed by fluorescence in situ hybridization technique.
We have previously demonstrated that EBV-induced reactive oxygen is associated with hypermethylation of the tumor suppressor gene p16 in Burkitt lymphoma, and that p16 hypermethylation is nearly always associated with EBV infection in Burkitt lymphoma.