An overview of epigenetics and cancer

Epigenetics mechanisms are implicated in multiple diseases, and they have shaped the way we understand complex diseases such as cancer and its development and progression. Epigenetic mechanisms play a role in regulating both normal and cancer cells. The three epigenetic mechanisms, DNA methylation, histone modification, and chromatin remodeling in general, ensure proper gene regulation both in normal and cancer cells either through the silencing of tumor suppressor genes or by activation of oncogenes. In addition, there is growing evidence that there are crosstalks among this mechanism especially between DNA methylation and histone modifications, adding extra layers of complexity in how the genes are epigenetically dysregulations in cancer. Further, noncoding RNAs, particularly microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), regulate the expression of protein-coding genes either acting as suppressor genes or oncogenes which further serve as potential diagnostic markers and therapeutic targets. With the new innovations and technologies in studying epigenetic mechanisms, new epigenetic diagnostic and therapeutic targets are being introduced. Thus, epigenetic therapies such as DNA methyltransferase, histone methyl transferase, and histone deacetylase inhibitors are emerging as promising therapies to reestablish normal epigenetic patterns and inhibit or slow down cancer progression.