DNA methylation machinery

The DNA methylation machinery is a fundamental epigenetic system composed of enzymes and proteins that regulate gene expression by adding or removing methyl groups at the 5-position of cytosine residues, typically within CpG islands. The primary components include DNA methyltransferases (DNMT1, DNMT3A, DNMT3B), which establish and maintain methylation patterns, and Ten-eleven translocation (TET) enzymes, which facilitate DNA demethylation (NIH, 2023). This machinery plays a critical role in biological processes such as genomic imprinting, X-chromosome inactivation, and the suppression of transposable elements (PubMed, 2022). In many diseases, particularly cancer, the machinery becomes dysregulated, leading to the silencing of tumor suppressor genes through hypermethylation or genomic instability through global hypomethylation (UniProt, 2024). Pharmacological intervention typically involves DNA methyltransferase inhibitors (DNMTis), such as azacitidine and decitabine, which act as nucleoside analogs that trap DNMT enzymes on DNA, leading to their degradation and subsequent DNA hypomethylation (PubChem, 2024). While effective in treating certain hematologic malignancies like myelodysplastic syndromes, these therapies face challenges regarding their lack of sequence specificity and potential for systemic toxicity (StatPearls, 2023).

Other names

DNA methylation machinery and associated signaling pathwaysDNA methylation systemEpigenetic methylation machineryDNMT/TET pathwayCpG methylation machinery

Inhibition of DNA methyltransferases (DNMTs) leading to DNA hypomethylation and reactivation of epigenetically silenced genes.