Epigenetic Alterations in Carcinogenesis: Role of DNA Methylation and Histone Modifications

Epigenetic alterations, particularly DNA methylation and histone modifications, play a crucial role in the initiation, progression, and metastasis of cancer. Unlike genetic mutations, which involve changes in the DNA sequence, epigenetic modifications are reversible and can be influenced by environmental factors, lifestyle, and age. DNA methylation, the addition of a methyl group to the 5’ position of cytosine residues, typically leads to gene silencing and has been associated with the inactivation of tumor suppressor genes. On the other hand, histone modifications, including acetylation, methylation, and phosphorylation, influence chromatin structure and gene expression. These modifications can either promote or inhibit the expression of oncogenes and tumor suppressor genes, depending on the specific modification and context. This paper reviews the roles of DNA methylation and histone modifications in carcinogenesis, exploring their impact on gene expression regulation, tumor progression, and potential for therapeutic intervention. A comprehensive understanding of these epigenetic mechanisms may open new avenues for early detection, targeted therapy, and the development of epigenetic drugs in cancer treatment.