Genetics and Epigenetics of Colorectal Cancer: An Extensive Review

Abstract

One of the most prevalent and fatal malignancies in the world is colorectal cancer (CRC). Invasive adenocarcinoma develops thru a series of steps in which normal colonic epithelial cells progressively undergo genetic and epigenetic alterations. Chromosome destabilization (CIN), normal microsatellite instability (MSI) brought on by flaws in the DNA repair mismatch system, and, in a smaller percentage of cases, an abnormally mutated phenotype linked to alterations in the validation domains of POLE or POLD1 are the three main types of genomic instability that are primarily linked to colorectal cancer (CRC). Colorectal carcinogenesis is significantly influenced by epigenetic modifications in addition to these hereditary ones. Widespread DNA hypomethylation, aberrant hypermethylation of tumor-suppressor and mismatch-repair gene promoter regions, the CpG insula methylator phenotype (CIMP), changes in histone modifications, interference with chromatin-remodeling mechanisms, and aberrant regulation of non-coding RNAs are some of these. The onset, development, and biological variety of colorectal cancer are all influenced by these hereditary and epigenetic aberrations.