Gene transfer of human ANGPTL4 mediated by recombinant retroviral vector inhibits the growth of liver cancer

Objective To construct recombinant retroviral vector containing human hepatocellular carcinoma-related gene ANGPTL4 ( angiopoietin-like 4) cDNA and to evaluate antitumor effect of recombinant retroviral vector-mediated human ANGPTL4 gene transfer. Methods ANGPTL4 cDNA was cloned in vitro from human liver cell lines HL-7702 and subcloned into plasmid vector pMSCV and sequenced. High-tiler recombinant retrovirus pMSCV-ANGPTLA and blank retrovirus pMSCV packaged under mediation of lipofectamine infected HepG2 cells in vitro, respectively. Flow cytometry and fluorescence microscopy detected expression of GFP (green fluorescence protein) in HepG2 cells. The expression of ANGPTL4 mRNA in HepG2 cells was determined. Results Recombinant retroviral vector pMSCV-ANGPTL4 was constructed successfully. Titer of recombinant retrovirus pMSCV-ANGPTL4 packaged is 1. 4 × 106 infective viral grains /ml. Titer of blank retrovirus pMSCV packaged was 1. 5 × 106 infective viral grains /ml. Positive cell rate of HepG2-ANGPTL4 cells group expressing GFP was 68.45% , and average intensity of fluorescence of HepG2-ANGPTL4 cells group was 31.67 -fold as that of HepG2 cells group. Positive cell rate of HepG2-pMSCV cells group expressing GFP was 77.72%, and average intensity of fluorescence of HepG2-pMSCV cells group was 64. 87 -fold as that of HepG2 cells group. The expression of ANGPTL4 mRNA in HepG2-ANGPTL4 cells group was higher than that in HepG2-pMSCV cells group (154%) and HepG2 cells group( 161%). The proliferation rate of HepG2-ANGPTL4 cells group in vitro was lower than HepG2-pMSCV cells group and HepG2 cells group (P0. 01). The mean volume and weight of tumors in HepG2 -ANGPTL4 cells bearing nude mice were lower than HepG2 cells group and HepG2-pMSCV cells group (P 0. 01). Conclusions A stable ANGPTL4-transfected human liver cancer cell line HepG2 -ANGPTLA was obtained and gene transfer of human ANGPTL4 mediated by retroviral vector is possibly effective against liver cancer.