Abstract:Objective ：To investigate the possibility of XIAP inhibition by RNA interference (RNAi) vectors, and the chemotherapeutic sensitivity change of pancreatic carcinoma cells of SW1990 after XIAP inhibition. Methods ：RNA interference vectors against XIAP was constructed and transfected into the pancreatic carcinoma cell line SW1990, the expression of XIAP was determined by RT-PCR and Western blot, while flow cytometry and Hoechst 33258 stain were employed to examine the apoptosis index of SW1990 induced by gemcitabine. The relationship between XIAP and apoptosis index was analyzed by linear regression. Results ：Four RNAi vectors against XIAP were constructed, two of the four RNAi vectors could instantaneous inhibit XIAP expression more than 50%, The sensitivity of SW1990 to gemcitabine increased after XIAP was inhibited ( P <0.05), and the expression level of XIAP was negatively related to the apoptosis index ( P <0.05). Conclusions ：RNAi vectors could effectively suppress the expression of XIAP, and enhance the sensitivety of pancreatic cancer cells to chemtherapentic drygs.