Abstract:Objective ：To investigate the selective killing effect of MDA/IL-24 on human hepatocellular carcinoma line HepG2 in vitro and provide a theoretical basis for gene therapy of hepatocellular carcinoma. Methods ：The MDA-7/IL-24 gene was transfected into human hepatocullular carcinoma cell line HepG2 and normal liver cell line L02 with a replication-incompetent adenovirus vector. The mRNA and protein expression of MDA7/IL-24 in HepG2 and L02 cells was examined by RT-PCR and ELISA assay respectively. MTT assay and flow cytometry were used to study tumor cell proliferation and cell cycle in vitro. Hoechst and Annexin-V and PI staining were studied to indicate the apoptosis.Results ：RT-PCR confirmed that the exogenous MDA-7/IL-24 gene was expressed in HepG2 and L02 cells. The protein product was confirmed by assay of the supernatant with ELISA. MTT and apoptosis test indicated MDA-7/IL-24 induced growth suppression and cell apoptosis of the HepG2 cell in vitro but not in cell line L02, and cell cycle test revealed MDA-7/IL-24 could block HepG2 cell in G2/M but not in L02. Conclusions ：MDA-7/IL-24 selectively induces growth suppression and apoptosis in lines HepG2 in vitro but not in L02 cell, which indicates that adenovirus mediated MDA-7/IL-24 can be an excellent tool for gene therapy in hepatocellular carcinoma.