Aging related methylation influences the gene expression of key control genes in colorectal cancer and adenoma

AIM: To analyze colorectal carcinogenesis and age-related DNA methylation alterations of gene sequences associated with epigenetic clock(definition) CpG sites. METHODS: ) promoter methylation was further investigated in colonic tissue from 8 healthy adults, 19 normal children, 20 adenoma and 8 CRC patients using bisulfite-specific PCR followed by methylation-specific high resolution melting (MS-HRM) analysis. mRNA expression of age-related "epigenetic clock" genes was studied using Affymetrix HGU133 Plus2.0 whole transcriptome data of 153 colonic biopsy samples (49 healthy adult, 49 adenoma, 49 CRC, 6 healthy children) (GEO accession numbers: GSE37364, GSE10714, GSE4183, GSE37267). Whole promoter methylation analysis of genes showing inverse DNA methylation-gene expression data was performed on 30 colonic samples using methyl capture sequencing. RESULTS: ., MGP). CONCLUSION: Several age-related DNA methylation alterations can be observed during CRC development and progression affecting the mRNA expression of certain CRC- and adenoma-related key control genes.