Restore of miR-541 resensitizes pancreatic cancer cells to gemcitabine-induced apoptosis through suppression of HAX-1

Abstract

Background: MiR-541 acts as a tumor suppressor in some cancers. However, the role of miR-541 in regulating the chemosensitivity to cancer cells is still unclear. The aim of this study is to explore the effect of miR-541 on chemoresistance of pancreatic cancer (PCa) cells to gemcitabine-induced apoptosis.Methods: Gemcitabine-resistant Panc-1 and Capan-2 PCa cell lines (Panc-1/R and Capan-2/R) were established through long term exposure to gemcitabine. Effect of miR-541 on changing the sensitivity of Panc-1/R and Capan-2/R to gemcitabine-induced cytotoxicity was evaluated by MTT assays. Regulation of miR-541 on HAX-1 was confirmed by bioinformatics, western blot analysis and luciferase reporter assays. Cell apoptosis and mitochondrial membrane potential (MMP) was measured by flow cytometry analysis.Results: Comparison with Panc-1 and Capan-2, downregulation of miR-541 was observed in Panc-1/R and Capan-2/R cells. Overexpression of miR-541 was found to increase the cytotoxicity of gemcitabine to Panc-1/R and Capan-2/R cells. However, transfection with HAX-1 plasmid can abolish the effect of miR-541 on gemcitabine-induced cytotoxicity against Panc-1/R and Capan-2/R.Conclusion: Downregulation of miR-541 is responsible for development of gemcitabine resistance in PCa. Overexpression of miR-541 may represent a potential strategy to reverse the chemoresistance of PCa.