Abstract: Objective We intend to investigate the expression profile of miRNAs down-regualted in human extrahepatic and intrahepatic cholangiocarcinoma tissues and probe the effect on cell growth of four of these miRNAs in QBC939 cell line. Methods Down-regulated miRNAs in extrahepatic or intrahepatic cholangiocarcinoma tissues were analyzed by using miRNA-microarray, which was confirmed by using miRNA Real-Time PCR analysis. Based on these findings, four of these down-regulated miNRAs were chosen to perform function investigation. The miRNAs mimics were transfected into QBC939 cells and cell proliferation assay was performed by using MTT, which would demonstrate the relationship between down-regulated miRNAs and cholangiocarcinoma cell growth. Results 25 miRNAs and 15 miRNAs were down-regulated in extrahepatic cholangiocarcinoma and intrahepatic cholangiocarcinoma, respectively. There were 6 miRNAs down-regulated both in two types of cholangiocarcinoma. miR-181a, miR-596, miR-492, and miR-602 were overexpressed in QBC939 cells, which indicated a significant inhibitory effect on cell growth. Conclusion The miRNAs expression patterns in human extrahepatic and intrahepatic cholangiocarcinoma tissues are different and Down-regulated miRNAs act as suppressors on cholangiocarcinoma cell growth.

Key words: cholangiocarcinoma, microRNAs, cell growth