Methylated DNA marker (MDM)

Methylated DNA markers (MDMs) are epigenetic signatures characterized by the covalent addition of a methyl group to cytosine residues within CpG islands of the genome. These markers function as fundamental regulators of gene transcription, where hypermethylation of promoter regions typically results in gene silencing and hypomethylation facilitates gene expression (NIH, 2023). In clinical oncology, MDMs serve as vital diagnostic and prognostic biomarkers because aberrant methylation patterns, such as the silencing of tumor suppressor genes, are early and stable events in carcinogenesis (PubMed, 2022). While MDMs are not direct therapeutic targets like receptors or enzymes, they are the biological indicators and products of DNA methyltransferase (DNMT) activity. Therapeutic intervention involves the use of DNMT inhibitors, such as azacitidine and decitabine, which aim to erase these methylated markers to reactivate silenced genes (PubChem, 2024). Consequently, MDMs are extensively used in non-invasive screening tests, such as liquid biopsies for colorectal and lung cancers, to detect disease at early stages (FDA, 2014).

Other names

DNA methylationCpG methylation5-methylcytosineEpigenetic DNA marker

Inhibition of DNA methyltransferase (DNMT) enzymes, leading to the depletion of methyl groups from DNA (hypomethylation) and the subsequent reactivation of silenced tumor suppressor genes.