Abstract:Objective: To investigate the miR-519d expression in pancreatic cancer cells, and its actions. Methods: The miR-519d expressions in pancreatic cancer cell lines AsPC-1, BxPC-3, Capan-2 and Panc-1 as well as in normal pancreatic duct epithelial cell line HPDE6-C7 were detected by qRT-PCR. The Panc-1 cells were transfected with miR-519d over-expression plasmid (miR-519d group) and negative plasmid (negative control group) respectively, with untreated Panc-1 cells as blank control group. After that, the proliferative and invasion abilities, apoptosis and expression of X-linked inhibitor of apoptosis protein (XIAP) were determined by MTT assay, Transwell assay, flow cytometry and Western blot analysis, respectively. Results: The relative expression level of miR-519d in each pancreatic cancer cell line was significantly lower than that in normal pancreatic duct epithelial HPDE6-C7 cells (all P<0.05). In cells of miR-519d group compared with blank control group, the proliferative ability was reduced (significantly reduced after 72-h culture), the apoptosis rate was significantly increased, the invasion ability was significantly decreased and the expression level of XIAP protein was significantly down-regulated (all P<0.05). All the differences of the observed parameters in negative control group and blank control group showed no statistical significance (all P>0.05). Conclusion: The miR-519d expression is down-regulated in pancreatic cancer cells. Down-regulation of miR-519d expression can enhance the proliferative and invasion abilities, and decrease apoptosis in pancreatic cancer cell lines, and these actions may be associated with its regulating XIAP protein expression.