DNA methylation regulates gene expression in normal and malignant cells. RG-108 is a non-nucleoside DNA methyltransferase inhibitor (IC50 = 115 nM in vitro). It significantly reduces the methylation of genomic DNA in cells at 10 μM without detectable toxicity, distinguishing it from nucleoside-based inhibitors like 5-azacytidine. Further, RG-108 inhibits DNA methyltransferase activity by blocking the enzyme active site. Through these actions, RG-108 demethylates and reactivates epigenetically silenced tumor suppressor genes.
