Effects of VEGF down regulation by small interfering RNA on chemosensitivity and Akt signal pathway of human pancreatic cancer cell

Objective To study the effects VEGF small interfering RNA (siRNA) on chemosinsitivity of human BxPC3 cell and its mechanism. Methods BxPC3 cells were divided into single BxPC3 cell group,lipofection group, scrambled siRNA transfection (200 nmol/L) group, VEGF siRNA transfection group.VEGF siRNA (5, 10, 20, 100,200 nmol/L) was used to transfect BxPC3 cells. Expressions of VEGF mRNA and protein were determined by real-time PGR and ELISA assay, respectively. MTT was performed to examine the inhibitory effects of gemcitabine on BxPC3 cells of each group. The phosphorylated-Akt protein was evaluated by Western blotting. Results After VEGF siRNA transfection, the expression of VEGF mRNA and protein in BxPC3 cells was down-regulated in a dose-and time-dependent manner, but there was no effect on BxPC3 cells proliferation. After 0. 2 μmol/L of gemcitabine treatment for 48 h, the inhibitory rates were ( 16.9 ±0.3)%, (17.3 ±0.3)%, (28.8 ±0.4)%, (52.2 ±0.3)%, (75.4 ±0.4)% in BxPC3 cell group,lipofection group, 5,10,20 nmol/L VEGF siRNA transfection group, and the inhibitory effects were correlated with siRNA concentration ( r = 0. 928 ). The phosphorylated-Akt protein was reduced significantly in siRNA transfected cells. Conclusions VEGF gene plays an important role in BxPC3 cells resistence to chemotherapy through inhibiting Akt phosphorylation. Key words: Pancreatic neoplasms;  Vascular endothelial growth factor;  RNA, small interfering; Chemosensitivity ;  Akt