miR-21 regulates proliferation and invasion of hilar cholangiocarcinoma cells

Previous studies demonstrated difference of micro-RNA expression between hilar cholangiocarcinoma and normal tissues. Further, miR-21 was reported to be overexpressed in hilar cholangiocarcinoma cells. Thus, our study aimed to elucidate association between miR-21 and cell behaviors of hilar cholangiocarcinoma and explore potential mechanisms. miR-21 activator and miR-21 inhibitor were designed and synthesized according to miR-21 sequence. RBE cell line was purchased for cell model. Three groups were prepared for different intervention, including activator group, inhibitor group, and control group. Transient expression model was established with transfection of miR-21 activator or miR-21 inhibitor, respectively. Cell proliferation was analyzed with CCK-8 examination. Cellular migration was examined with cell wound scratch assay. Transwell assay was performed to examine effect of miR-21 on tumor invasion. PTEN expression was determined with Western blot. Compared with control group, miR-21 activator group showed significantly increased proliferation, migration, and invasion (P<0.05), while miR-21 inhibitor group demonstrated reduced proliferation, migration, and invasion (P<0.05). Moreover, PTEN expression group was remarkedly inhibited after miR-21 activator transfection, but enhanced after miR-21 inhibitor transfection (P<0.05). miR-21 could influence proliferation, migration, and invasion of hilar cholangiocarcinoma cells via regulating PTEN expression.