OBJECTIVE:To explore the effects of recombinant adenovirus vector Adxsi-GFP-VP3 carrying apoptin gene VP3 on the apoptosis of human lung squamous carcinoma SK-MES-1 cell lines and human lung adenocarcinoma NCI-H1299 cell lines. METHODS:The exponential phase SK-MES-1 and NCI-H1299 cell lines were respectively divided into a recombinant adenovirus (Adxsi-GFP-VP3) group,a empty virus (Adxsi-GFP) group and a cell control (phosphate buffer) group,which were marked as group A,B and C respectively. Reverse transcription polymerase chain reaction and Western blot method were used to detect the ex-pressions of VP3 mRNA and Apoptin in the cells of groups A and B 48 and 72 h after transfection. The change in the ultrastructure of the cells in group A was observed under transmission electron microscope 72 h thereafter. MTT method was adopted to detect the cell proliferation activities of three groups 24,48,72 and 96 h thereafter and flow cytometry to determine the apoptosis rates and cell cycle changes 24,48 and 72 h thereafter. RESULTS:Compared to group B,group A demonstrated the expression of VP3 mRNA in SK-MES-1 and NCI-H1299 cell lines 48 h after transfection,and Apoptin expression and ultrastructure change for apopto-sis of SK-MES-1 and NCI-H1299 cell lines 72 h thereafter. Compared to groups B and C,group A showed lower proliferation activ-ities and higher apoptosis rates of SK-MES-1 and NCI-H1299 cell lines,which had a positive correlation with transfection time;and in the group A,there was a decrease in the proportion of the SK-MES-1 and NCI-H1299 cell lines in S phase and an increase in the proportion of those in G2/M phase,72 h after transfection. There was statistically difference (P<0.05). CONCLUSIONS:Adxsi-GFP-VP3 can effectively induce the apoptosis of SK-MES-1 and NCI-H1299 cell lines.