Inhibitory effect of methylation inhibitor 5-aza-2-deoxycytidine on bile duct cancer cell line in vivo and in vitro

BACKGROUND: Since the resection rate is low for bile duct cancer and the drugs used for chemotherapy are less effective, we studied the inhibitory effects of 5-aza-2-deo- xycytidine (ZdCyd) on bile duct cancer cell line QBC-939 in vivo and in vitro and its possibility in clinical treatment. METHODS: The survival and apoptosis rates of QBC939 af- ter treatment with different dose of ZdCyd were detected by methyl thiazoy tetrazolium (MTT) and flow cytome- try. The cooperative effect of ZdCyd with other chemo- therapeutic drugs was also studied with MTT. The cancer cells were transplanted into nude mice, which were pre- treated with ZdCyd after tumor occurrence. RESULTS: ZdCyd decreased the cell survival rate, blocked the cell cycle at G1 phase, and increased the apoptosis rate. These effects were dose- and time-dependent. ZdCyd also increased the anti-tumor effects of other chemotherapeutic drugs when used in combination. The tumor occurrence rate was lower in the ZdCyd pre-treated cells than in the untreated cells in nude mice, and ZdCyd was found to in- hibit tumor growth. CONCLUSION: ZdCyd can inhibit the growth of QBC939 in vivo and in vitro through induction of cell apoptosis and has the cooperative effect on bile duct cancer cell when it is ’ used with other chemotherapeutic drugs.