Two Steps Methylation Specific PCR for Assessment of APC Promoter Methylation in Gastric Adenocarcinoma

Gastric Cancer (GC) is the second most common cancer in the world and a leading cause of cancer-related mortality. Methylation of promoter CpG islands (CGIs) belonging to tumor suppressor genes causes transcriptional silencing of their corresponding genes leading to carcinogenesis and other disorders. Adenomatous Polyposis Coli (APC) a tumor suppressor gene is inactivated by methylation of promoter region in CpG islands. In current study, methylation of CGIs in the promoter of APC was analyzed using two steps Methylation Specific PCR in 36 tumor tissue samples together with an equal number of normal tissues belonging to patients with confirmed diagnosis of gastric carcinoma. Methylation specific PCR (MSP) was positive for 28 out of 36 (77.77%) of the tumors. No correlation was found between APC hypermethylation and the age of patients regardless of the relevant cofactors in aberrant methylation. Our study showed that hypermethylation of the APC gene was frequent among our patients with gastric cancer. Although the APC hypermethylation has been proposed to be involved in the early stages of gastric carcinogenesis, but the APC gene alone, does not seem to be a reliable marker for the different stages of cancer prognosis. Thus, it is recommended to use a panel of genes for evaluating the CpG Island methylator phenotype (CIMP) phenomena as an early event in gastric cancer, both for tumor and serum samples.