OBJECTIVETo study the effect of adenovirus vector-mediated siRNA targeting vascular endothelial growth factor(VEGF) on apoptosis and the expression of survivin in K562 cells.

METHODSK562 cells were infected with recombinant adenovirus Ad5-VEGFsi for 72 hours as experimental group (K562/Ad5-VEGFsi), and empty vector group (K562/Ad5) and blank control group (K562) as controls. VEGF mRNA and survivin mRNA expression were determined by RT-PCR. The protein levels of VEGF and survivin were measured by ELISA and Western blot, respectively. The apoptosis of K562 cells was detected by flow cytometry.

RESULTSThe levels of VEGF and survivin mRNA expression in experimental group cells were significantly decreased (P < 0.01). The protein concentration of VEGF in experimental group supernatant was (1121 +/- 15) pg/ml, being lower than that in empty vector group \[(1290 +/- 28) pg/ml\] and black control group \[(1303 +/- 28) pg/ml\] (P < 0.01), and the level of survivin protein in experimental group (0.26 +/- 0.11) was significantly reduced compared with that in blank control group (0.74 +/- 0.10) (P < 0.01). The apoptosis rate of K562/Ad5-VEGFsi cells (16.45 +/- 0.14)% was higher than those of K562/Ad5 cells (3.54 +/- 0.17)% and K562 cells (2.56 +/- 0.20)% (P < 0.01).

CONCLUSIONSVEGF can up-regulate the expression of survivin. After inhibition of VEGF by RNAi, the expression of survivin is decreased subsequently and the rates of cell apoptosis are increased.