Role of the uridine/cytidine kinase 2 mutation in cellular sensitiveness toward 3′-ethynylcytidine treatment of human cancer cells

A nucleosidic medicine, 1-(3-C-ethynyl-β-D-ribo-pentofuranosyl)cytosine [3′-ethynylcytidine (ECyd)], is a potent inhibitor of RNA polymerase I and shows anticancer activity to various human solid tumors in vitro and in vivo. ECyd is phosphorylated to 3′-ethyntlcytidine 5′-monophosphate by uridine/cy