Effect of microbubble contrast agent on expression of plasmid EGFP in hepatocellular carcinoma of mice with exposure to low-frequency ultrasound / 中华超声影像学杂志

ABSTRACT

Objective To explore the optimal dose-effect relationship of gene transfer according to the expression of pEGFP in tumor cells under different parameters mediated by microbubble contrast agent and ultrasound in vivo.Methods C57BL/6J mice were inoculated subcutaneously in the middle of the right flank with hepal-6 tumor cells.The mixture of SonoVue and enhanced green fluorescent protein(EGFP)plasmid was injected into the tail vein of each mouse, groups were randomly established according to different output intensity( 1 W/cm2, 2 W/cm2, 3 W/cm2 ), exposure time ( 1 min, 5 min, 10 min) and volume of SonoVue(30 μl,60 μl,90 μl), the expression of EGFP in tumor cells under different parameter was examined by flow cytometry and fluorescence microscopy.Results The expression of pEGFP in tumor cells was significantly higher with the increase of exposure time,output intensity and volume of SonoVue (1 min vs 5 min, P＜0.05; 1 W/cm2 vs 2 W/cm2, P＜0.05 ; 30/μl vs 60 μl, P＜0.05).However, the transfection efficiency of EGFP can not be enhanced continuously with the increasing exposure time,output intensity and volume of SonoVue (5 min vs 10 min, P＞0.05; 2 W/cm2 vs 3 W/cm2, P＞0.05; 60 μl vs 90 μl, P＞0.05).The highest transfection effieieney was achieved under intensities was 2 W/cm2 [(21.02±1.45)%]with 5 min[(23.22±1.91)%] exposed to ultrasound, and 60 /μl SonoVue [ (21.02±1.45) % ].Conclusions Gene transfeetion efficiency changded with the difference parameters.2 W/cm2,5 min and 60 μl SonoVue led to the optimum dose-effect relationship of gene transfer in vivo .