Zebularine, a cytidine analog, is a DNA methylation inhibitor that acts by forming a covalent complex with DNA methyltransferases (DNMTs). By stabilizing the binding of DNMTs to DNA, zebularine hinders methylation and decreases dissociation, trapping DNMT and preventing its turnover. Zebularine preferentially targets cancer cells in various human carcinoma cell lines demonstrating IC20 values of 20, 10, 20, and 5 μM for reducing proliferation of TK6, Jurkat, KG-1, and HCT116 cells, respectively. Zebularine exhibits low toxicity in mice even after prolonged administration (0.2 mg/mL drinking water for 113 days in a mouse intestinal cancer model).
