APOPTOSIS OF VEGF-siRNA-INDUCED MCF-7 AND ITS MECHANISM

Objective To investigate the effect of small interfering RNA(siRNA) targeting vascular endothelial growth factor(VEGF) on apoptosis and apoptosis-related gene survivin when it reduced VEGF expression in human breast cancer MCF-7 cells. Methods siRNA targeting VEGF was designed and synthesized in vitro,and transfected into MCF-7 cells.There were blank group,lipofectamine group,negative control SCR group and three siRNA concentration gradient groups(50,100,and 200 nmol/L).At 24 hours after transfection,apoptosis was examined by FCM essay;RT-PCR and immunocytochemistry were used to examine the expression of survivin mRNA,before and after transfection. Results Compared with the blank control,the early and advanced stage apoptosis of MCF cells in the three small-dose-siRNA groups was increased with a significant difference among them(F=35.81,30.12;q=6.08-56.53;P0.05,0.01),and the expressions of both survivin mRNA and survivin protein were down-regulated(F=21.59,35.64;q=11.56-273.20;P0.05,0.01).The differences among the blank control,lipofectamine group and negative control group were not significant regarding the expressions of survivin mRNA and protein(P0.05). Conclusion siRNA targeting VEGF gene transfected in MCF-7 cells can induce apoptosis of the cells,which is correlated with the dose of transfection.Its molecular mechanism is related to the expression of survivin.