Experimental studies on apoptosis of human hepatocellular carcinoma cell induced by VEGFP-CDglyTK system / 解放军医学杂志

ABSTRACT

Objective To study the effects of suicide gene system mediated by adenovirus containing the CD-TK fusion gene controlled by human vascular endothelial growth factor(VEGF)promoter on apoptosis of human hepatocellular carcinoma cells HepG2 in vitro.Methods The VEGF-expressing HepG2 cells were infected by adenovirus vector containing CD-TK fusion gene controlled by the VEGF promoter(Ad-VEGFP-CDglyTK).The infection efficiencies in HepG2 cells were observed under a fluorescence microscope.The toxic effect of 5-fluorocytosine(5-FC)and ganciclovic(GCV)on infected cells was determined by light microscopy,electron-microscopy and flow cytometry(FCM).Results The transfection efficiency in HepG2 cells increased with the increasing adenoviral titer.The pro-drug(5-FC and GCV)could induce apoptosis of HepG2 cells in certain range of dosage(the doses of GCV+5-FC1mg/L + 20mg/L,10mg/L + 40mg/L,100mg/L + 60mg/L)at the multiplicity of infection(MOI)of 100.The effect showed a time-dependent manner.HepG2 cells showed typical morphologic changes of apoptosis after administration of the pro-drug(GCV10mg/L,5-FC40mg/L)for 72 hourschromatin condensation and disposition along nuclear membrane.Karyopyknosis and karyoklasis were seen under electron microscopy(?10 000).Apoptotic peak was also shown in HepG2 cells treated with the pro-drug(5-FC and GCV)by flow cytometry.The cell apoptosis rate was increased accordingly as the concentration of pro-drug(5-FC and GCV)increased.The apoptosis was increased obviously in comparison with the negative control group(P