Abstract： Objective To investigate the effects of insulin on the proliferation and invasion of human pancreatic cancer cells PANC1,and on its HIF-1α,VEGF expression.Methods PANC1 was pretreated with insulin of different concentrations (0.1,1,10,100 nmol/L).The proliferation of PANC1 was tested by MTTmethod,and transwell assay was used to test the invasion ability of PANC1.HIF-1α,VEGF and PCNA protein expression was assessed by Western blots,and HIF-1α,VEGF mRNA was detected by real-time PCR.Results Insulin could increase the proliferation of PANC1 in a dose-dependent manner (p ＜0.05 ),and increase the expression of HIF-1α,VEGF protein.After 100 nmol/L insulin treatment for4 d,the PCNA protein expression in the insulin group was significantly higher than that in the control group (1.196 ±0.014 vs 1.157 ±0.013,P ＜ 0.05).The cancer cells passed through the chamber in insulin group were much more than that in the control group ( 141.0 ± 2.1 vs 89.0 ± 1.4,P ＜0.05 ).The expression of HIF-1α protein was significantly increased (1.139 ±0.020 vs 0.598 ±0.013,P ＜0.05),while there was no significant change of HIF-1αmRNA expression.Both the expression of VEGF protein and mRNA were significantly increased (1.011 ± 0.023 vs 0.627 ± 0.013 0.970 ± 0.016 vs 0.350 ± 0.01 3,P ＜ 0.05 ).Conclusions High insulin microenvironment could enhance the proliferation and invasion of PANC1 cells by up-regulating the expression of HIF-1α and VEGF.