[Epigenome Diagnosis of Cancer-Focusing on Genome-Wide DNA Methylation Diagnosis of Colorectal Cancer for Predicting Sensitivity of Anti-EGFR Antibody Treatment].

Epigenetic regulation mechanisms such as DNA methylation and histone acetylation are important for controlling various biological phenomena by regulating gene expression at the genome level. They are reversible systems that change depending on environmental factors. Epigenetic abnormalities are associated with the onset of various diseases, including developmental and aging abnormalities, neurological disorders, and malignant tumors. Aberrant DNA methylation is an important epigenetic change in the development and progression of colorectal cancer. DNA methylation in tumor tissues occurs mainly in CpG islands in the promoter regions of genes and inactivates gene functions by negatively suppressing transcription. CpG island methylator phenotype(CIMP)is an important carcinogenic mechanism of colorectal cancer related to DNA methylation and is involved in approximately 20% of all colorectal cancers. CIMP is generally judged to be positive when a certain percentage or more of the marker gene set is methylated, and many CIMP markers have been reported so far. However, no established marker has been set to classify colorectal cancer by genome-wide DNA methylation. We developed a new method to assess genome-wide DNA methylation status and obtained pharmaceutical approval as a new in vitro diagnostic drug to predict sensitivity to anti-EGFR antibody drugs in colorectal cancer.