Role of DNA methylation in cancer development and its clinical applications

methyltransferase gene (DNA) methylation is a key process in epigenetic modification. This transformation leads to genomic instability that creates an impact on gene expression. DNA methylation is also involved in several mutations of tumour suppressor genes (TSGs) or proto-oncogenes, resulting in cancer (hypermethylation and hypomethylation). Hypermethylation of promoter segments in TSGs causes transcriptional silencing, whereas hypomethylation of regulatory sequence activates proto-oncogenes and retrotransposons. DNA methylation regulated by DNA methyltransferases is one of the essential epigenetic mechanisms that controls the cell cycle, cell proliferation, differentiation, apoptosis and transformation in eukaryotes, leading to genetic instability of tumour cells. Recent scientific research has highlighted that DNA methylation is a vital cancer biomarker source of several parts of body fluids that allow primary-stage cancer cell detection during clinical screening. Nowadays, epigenetic biomarkers have been introduced as a decision maker with the potential to improve cancer prognosis. DNA methylation profiling helps to determine cancer at the deep genetic level, and create high impactful cancer screening approach in the future.