Epigenetics involves changes in gene activity that are not directly caused by DNA sequence alterations. Instead, gene expression is activated or inhibited through regulatory changes such as chromatin remodeling, which can involve post-translational modifications of histone proteins, or the addition of methyl or alkyl groups to DNA nucleotides. Methylation or acetylation of histones can have profound changes on the state of the chromatin and its likelihood of transcription.
Similarly, hypermethylation of DNA sequences in the promoter region of a gene can prevent transcription of the gene product. Targeting epigenetic modifiers such as histone deacetylases, histone methyltransferases, and DNA methyltransferases shows potential for therapeutic benefit in the treatment of a variety of cancers.
Epigenetic modifiers typically influence the following proteins: