Selected Alu methylation levels in the gastric carcinogenesis cascade

Background: Genome-wide hypomethylation, a common epigenetic change that occurs during cancer development, primarily affects repetitive elements, such as Alu repeats. Consequently, Alu repeats can be used as a surrogate marker of genomic hypomethylation. Methods: In this study, we aimed to investigate the correlation between Alu methylation levels and the multistage course of gastric carcinogenesis. Results: We found that the Alu methylation levels in gastric cancer tissue decreased compared with those in normal gastric tissue, with the change in methylation levels and pattern being most significant between chronic gastritis and intestinal metaplasia. Moreover, Alu methylation levels were not associated with Helicobacter pylori or Epstein–Barr virus infection. Conclusions: Finally, our sensitivity and specificity analyses suggested that Alu methylation level can be used to distinguish gastric cancer tissue from normal tissue. Thus, Alu methylation level shows promise as biomarker for gastric cancer diagnosis.