Epigenetic Targets and their Inhibitors in Cancer Therapy.

Epigenetics is defined as the stable and heritable alternations in gene expression without changing the DNA nucleotide sequence. The initiation and progression of cancer result from not only genetic mutation, but also aberrant epigenetic regulation, such as DNA methylation and histones acetylation. Although Genetic alternations cannot be reversed, epigenetic modification is a dynamic and reversible process. Over the past few decades, much progress has been made in the research of epigenetic medications and a variety of drugs have been developed targeting at epigenetic regulatory proteins, which are capable of restoring malignant cancer cells to the normal state. The epigenetic drugs currently approved for cancer treatment mainly target at DNA methylation and histones acetylation. In addition, there are a great many epigenetic drugs in clinical trials for cancer therapy, such as inhibitors of DNA methyltransferases, histone deacetylases, histone methyltransferases, lysine specific demethylases, and BET (bromodomain and extra-terminal domain) family proteins. We will discuss the latest developments of these inhibitors and their applications in cancer therapy.