Epigenetic Regulation and Promising Therapies in Colorectal Cancer.

The recent developments in epigenetics have shown a very important role of epigenetic changes in cancer initiation, development, and progression. Some of the important histone modifications shown to occur are methylation, acetylation, phosphorylation, citrullination, sumoylation, ADP ribosylation, deamination, ubiquitination, formylation, O-GlcNAcylation, propionylation, butyrylation, proline isomerization, and crotonylation, but most of the studies in the past had limited their interest mainly on histone methylation, acetylation, and phosphorylation. Modification of DNA strands by hypermethylation and hypomethylation regulates genomic instability and promotes cancer. Colorectal cancer involves multiple changes in epigenetic marks present on histone residues and DNA, which in collaboration with genetic changes, leads to cancer progression. In this review paper, basic concepts of epigenetics relevant to cancer development are discussed, followed by its significance in understanding the mechanism of colon carcinogenesis. Some of the epigenetic target-based drugs are also discussed in the relevant sections to give an idea of the potential promises of epigenetics for colorectal cancer treatment.