The Roles of epigenetic machanisms in cancer formation

Neoplasias have a distinct pattern of disrupted pathways, which are the results not only of genetic alterations but also of heritable patterns of disrupted gene expression. Epigenetics refers to these changes in patterns of gene expression that are mediated by mechanisms that do not alter the primary DNA sequence. Epigenetic changes in tumors mostly result in inappropriate gene silencing. The transcriptionally silenced state is the consequence of alterations in chromatin sructure, including DNA hypermethylation and histone modifications. Therefore, epigenetic changes are the results of the two processes. A better understanding of the epigenetic mechanisms that cause transcriptional repression has allowed researchers to find new agents that open new possibilities for cancer therapies.