OBJECTIVETo evaluate the antiangiogenic property of pigment epithelium-derived factor(PEDF) in heptocarcinoma cell lines and explore its possible application in the gene therapy of human hepatocellular carcinoma (HCC).

METHODSThe gene encoding human PEDF was subcloned into lentiviral vector to generate the recombinant plasmid pLenti-PEDF. The plasmid pLenti-PEDF and two other packaging plasmids were cotransfected to 293T cells by calcium phosphate. Then HepG2 was infected with recombinant lentivirus and the expression efficiency of PEDF was analyzed by western blot. Proliferation and migration assay of human umbilical vein endothelial cells (HUVEC) was used to evaluate the biological activity of PEDF in vitro. Murine subcutaneous tumor model was established to investigate the therapeutic effects of Lenti-PEDF on HCC, and the expression of PEDF mRNA in tumor tissues was analyzed by RT-PCR.

RESULTSRestriction enzyme digestion and DNA sequencing demonstrated that the recombinant plasmid pLenti-PEDF was constructed successfully. HepG2 secreted PEDF in the media effectively after infected with the recombinant lentivirus and this protein exhibited strong inhibitory effects on proliferation and migration of human umbilical vein endothelial cells (P less than 0.01). Intratumoral injection of Lenti-PEDF caused significant inhibition of tumor growth (P less than 0.01), and high level expression of PEDF mRNA was detected in tumor tissues by RT-PCR.

CONCLUSIONSOur data suggest that PEDF may exert an inhibitory effect on tumor angiogenesis and PEDF gene therapy may provide a new approach for the treatment of HCC.