Epigenetics: DNA Methylation Analysis in Esophageal Adenocarcinoma.

The aberrant DNA methylation has been noted to occur at promoter of tumor suppressor, cell adhesion, DNA repair, and other growth regulating genes during the progression of nonneoplastic esophageal mucosa to Barrett esophagus to esophageal adenocarcinoma. Methylation-mediated silencing of individual gene or concurrent loss of a number of genes plays crucial roles in dysplasia-metaplasia-neoplasia sequence of esophageal adenocarcinoma. In addition, promoter methylation of genes had shown significant prognostic potential in patients with esophageal adenocarcinoma. Thus, determination of methylation status of genes of interest can be used as a molecular marker for risk stratification and/or better prognosis of patients with esophageal adenocarcinoma. There are a number of methods including bead array, PCR and sequencing, pyrosequencing, methylation-specific PCR, and PCR with high-resolution melt curve available to determine the methylation status of particular gene of interest. Herein, we describe the polymerase chain reaction followed by sequencing-based protocol for identifying DNA methylation status in esophageal adenocarcinoma.