Adenovirus vector expressing MDA-7/IL-24 selectively induces growth arrests and apoptosis in human hepatocellular carcinoma cell lines independent of the state of p53 gene

Objective To investigate the effect of melanoma differentiation associated gene-7/interleukin 24 (MDA/IL-24) on human hepatocellular carcinoma cell lines HepG2, MHCC97L and Hep3B and normal liver cell line L02 with a different p53 state. Methods The MDA-7/IL-24 gene was transfected into human hepatocellular carcinoma cell lines HepG2, MHCC97L and Hep3B and hepatocyte line L02 with a replication-incompetent adenovirus vector. The mRNA expression of MDA7/IL-24 in HepG2, MHCC97L, Hep3B and L02 cells was confirmed using RT-PCR. Protein expression was confirmed using ELISA assay. MTT assay and flow cytometry were used to study tumor cell proliferation and cell cycle in vitro. Hoecnst and flow cytometry assay after annexin-V and PI staining were performed to indicate the apoptosis effect. Results Exogenous MDA-7/IL-24 gene was expressed in HepG2, MHCC97L, Hep3B and L02 cells. The protein product of MDA-7/IL-24 was confirmed in the supernatant. MTT assay and apoptosis test indicated MDA-7/IL-24 could induce growth suppression and apoptosis of HepG2, MHCC97L and Hep3B but could not in L02. Cell cycle test revealed MDA-7/IL-24 could block those cancer cells in G2/M but not in the normal cell L02. Conclusion M0A-7/IL-24 selectively induces growth suppression and apoptosis in hepatocellular carcinoma lines HepG2, MHCC97L and Hep3B in vitro independent of the state of p53 gene but not in normal liver cell L02. This indicates MDA-7/IL-24 can be a perfect gene for gene therapy in hepatocellular carcinoma.