A synthetic nucleoside analogue of deoxycytidine. Dihydro-5-azacytidine inhibits DNA methyltransferase, thereby interfering with abnormal DNA methylation patterns that are associated with genetic instability in some tumor cells. Inhibition of this enzyme may restore expression of tumor-suppressor genes and result in antitumor activity. Check for active clinical trials using this agent. (NCI Thesaurus)