Abstract: Objective To investigate the expression profile of miR-21 in human cholangiocarcinoma tissues and QBC939 cell line and probe the function of miR-21 in cholangiocarcinogenesis. Methods MiR-21 expression in human cholangiocarcinoma tissues and QBC939 cell line is measured by using Real-Time PCR and Northern Blot, respectively. Cell growth and apoptosis was analyzed in QBC939 after transfected with Anti-miR-21. Specific target analysis is performed by using dual-reporter gene assay and FACS. In Vitro invasion assay is performed to probe the effect of miR-21 on QBC939 invasiveness. Results Expression analysis reveals that miR-21 levels depicted a significant up-regulation as compared to the matched normal bile duct and miR-21 levels are augmented approximately 3.4-fold in QBC939 cells. Silencing of miR-21 in QBC939 by using anti-miR-21 decreases cell growth and induces cell apoptosis. RECK is identified as a direct effector of miR-21 and miR-21 promotes QBC939 cell invasion in vitro through negatively regulating miR-21-RECK program. Conclusion Increased miR-21 expression is a frequent event in human cholangiocarcinoma. Augmented miR-21 promotes cell growth and dampens cell apoptosis. The invasiveness is enhanced by miR-21 through inhibiting RECK expression.

Key words: miR-21, Cholangiocarcinoma, RECK, Invasion