Abstract

 

DNA methylation alterations play an important pathophysiological role in the development and progression of colorectal cancer. In this study, we extensively analyzed the DNA methylation patterns of 165 Korean patients diagnosed with colorectal cancer (CRC) using a comprehensive profiling approach. Our analysis revealed that the tumor samples included a multitude of hypomethylated probes and few hypermethylated probes. A larger proportion of hypermethylated probes were located in promoter-like and CpG island regions, whereas hypomethylated probes were primarily found within gene body regions. A CIMP-H group, which is one of three distinct CpG island methylator phenotypes, was also marked by a significant enrichment of microsatellite instability (MSI) status sites, especially MSI-H. Further, our data pointed to a compelling association between MLH1 methylation and MSI-H status. Furthermore, the CIMP-H group phenotype more frequently affected the right-side colon tissues and marginally older patients. Consequently. This methylome profile set is uniquely capable of correlating the clinical features of CRC in Korean patients given the paucity of existing reports on the methylome of Korean CRC patients. Despite limitations, such as the single-center design and small study population, our study successfully reflected general cancer characteristics, such as age, sex, tumor stage, and location, as outlined in other studies. We believe that the CRC methylome profile created in this study will facilitate CRC development by offering valuable insights into methylation patterns and may guide future endeavors in molecular characterization, discovery of potential biomarkers, and analysis of CRC treatment modalities.