DNA methylation analysis of cancer-related genes from cell-free DNA of patients with cancer

DNA methylation is a very important mechanism for regulating gene expression in normal development and cell differentiation. However, DNA methylation, when acting on the promoter region of a tumor suppressor gene, suppresses transcription and is one of the major epigenetic modifications involved in the development and progression of many cancers (Wajed et al., 2001; Morris and Chan 2015). In our laboratory, we have carried out methylation analysis of 14 different tumor suppressor genes in cell-free DNA from the peripheral blood of over 1400 cancer patients, and have detected more than a total of 1900 methylations. We performed an analysis of DNA methylations of 14 different tumor suppressor genes, by type of cancer, stage of cancer, function of tumor suppressor genes, and their correlation to genetic mutations.