OBJECTIVETo investigate the effect of G4PAMAM/VEGFASODN compound on expression of VEGF and VEGF mRNA in MDA-MB-231 breast cancer cells and the growth inhibition of vascular endothelial cells.

METHODSThe diameter of G4PAMAM/VEGFASODN granule was measured by transmission electron microscopy, and its stability under different pH was also observed. The efficiency of transfection in vitro was detected by flow cytometer and the positively transfected cells were detected by laser scanning confocal microscope. The survival rate and the inhibitory rate of vascular endothelial cells were determined by MTT assay. The expression of protein VEGF was detected by immunohistochemical method and the expression of VEGF mRNA was detected by RT-PCR.

RESULTThe diameter of G4PAMAM/VEGFASODN granules was about 10 nm and it arranged as homogeneous netlike. Under pH 5-10 G4PAMAM/VEGFASODN presented highly stable and no dissociation was observed with different charge ratios. The 48-hour transfection rate of G4PAMAM/VEGFASODN in charge ratio of 1:40 was significantly higher than that of the lipofectamine group. None of the transfection products in each group showed cell toxicity. The staining of VEGF protein in the cytoplasm of MDA-MB-231 cells after G4PAMAM/ASODN transfection weakened markedly, and the positive expression rate decreased. Meanwhile, the VEGF mRNA expression was also decreased.

CONCLUSIONWith good stability and transfection rate, compound G4PAMAM/VEGFASODN can be a promising new nanometer vector of gene transfer system. The G4PAMAM/VEGFASODN can inhibit the expression of VEGF gene specifically and efficiently, which may be used for in vivo animal experiment.