5-Azacytidine

5-Azacytidine, a chemical analogue of the DNA and RNA nucleoside cytidine, is an inhibitor of DNA methyltransferases, potentially serving to reverse epigenetic changes.{17258} It reduces hypermethylation associated with certain diseases, including myelodysplastic syndromes (IC50s = 2.4 and 2.6 ?M for in vitro anti-myeloma activity) and cancer (IC50s ~ 0.4 ?M for inhibiting proliferation of various cancer cell lines).{18356,18373,17257} 5-Azacytidine has a reported half-life of 17 hours and is considerably cytotoxic; it must be incorporated into DNA to covalently trap DNA methyltransferases.{17258}