Down‐regulation of c‐Myc expression inhibits the invasion of bile duct carcinoma cells

Cholangiocarcinoma is the second most common primary hepatic tumour originating from biliary tract epithelial cells with poor prognosis. Enhanced c‐Myc protein expression contributes to many aspects of tumour cell biology. Although the ability of c‐Myc to drive unrestricted cell proliferation and to inhibit cell differentiation had been well recognized, whether down‐regulated c‐Myc expression can inhibit tumour cell invasion still remains to be explored. The c‐Myc ASODN (antisense oligodeoxyribonucleotide) and NSODN (nonsense oligodeoxyribonucleotide) were designed, synthesized and transfected into human QBC939 bile duct carcinoma cells using the Lipofectamine 2000 reagent. The protein expression of c‐Myc was detected by Western blot. A transwell experiment was applied to evaluate the invasive capacity of the QBC939 cells. c‐Myc ASODN could significantly suppress the c‐Myc protein expression (P<0.05) and the invasion (P<0.01) of QBC939 cells transfected with c‐Myc ASODN compared with that in the control and c‐Myc NSODN‐transfected group. Thus in the present study we show that down‐regulation of c‐Myc expression can inhibit the invasion of QBC939 cells in vitro.