Epigenetics

Epigenetics is the study of heritable changes in gene expression without a change in DNA sequence. The best understood Epigenetic mechanism, DNA methylation, refers to the addition of a methyl group by the enzyme DNA Methyltransferase to the 5-carbon of cytosine in a CpG dinucleotide. Methylation in regulatory regions adjacent to genes generally acts to suppress gene expression and/or regulation potentially having an impact on cellular function. Once a cell has an established DNA Methylation pattern, methlyated sites are inherited by daughter cells which have important implications in cellular function. Epigenetic research has demonstrated that aberrant DNA methylation is present in several disease states including cancer, in addition to other genetic diseases. Carcinogenesis can occur when DNA methylation acts to silence tumor suppressor genes, leading to heritable alterations of these genes.