AIM: To investigate the inhibitory effects of endostatinvascular endothelial growth inhibitor (VEGI151) recombinant adenoviruses on neovascularization.METHODS: We used recombinant adenoviruses to treat human vascular endothelial cell line ECV304, human hepatocellular carcinoma cell line HepG2, and murine fibroblast cell line L929, in order to study the chimeric gene expression in these cell lines. Chick choriallantic membrane (CAM) model, rabbit inflammatory ceal neovascularization (CNV) model, and liver cancer-bearing nude mice model were employed to investigate the negative biological effect of fusion molecules on neovascularizationin vivo.RESULTS: West blot showed that the molecular weight of fusion protein was about 41kD after infection of ECV304,HepG2 and L929 cells with supematant of AdhENDO-VEGI151.The fusion protein showed a specific inhibitory effect on the proliferation of ECV304 cells, but no inhibitory effect on the growth of HepG2 and L929 cells (F=13112.13,P=0.0001). In the chick choriallantic membrane (CAM)assay, the expressed fusion protein significantly inhibited neovascularization. Rabbit inflammatory ceal neovascularization (CNV) induced by intrastromal sutures resulted in a uniform neovascular response. In this model, direct subconjunctival injection of AdhENDO-VEGI151 expressed the fusion proteinin vivo and suppressed the development of CNV. Topical application of AdhENDO-VEGI151 led to a significant suppression of CNV (F= 1413.11, P=0.0001),as compared with the control group of AdLacZ. Immunohistochemical staining showed the fusion protein dominantly expressed in ceal epithelium. Compared with the control group of AdLacZ (4075.9±1849.9 mm3), the average tumor size of group AdhENDO-VEGI151 reduced in size (487.7±241.2 mm3) (F=14.80, P=0.0085), with an inhibition rate of 88.03%. Immunohistochemical staining showed the adenoviruses carried the fusion gene expressed on liver cancer cell membrane. MVD decreased more significantly in treated mice (30.75±3.31%) than in AdLacZ control (50.25±8.65%) (F=17.72, P=0.0056) with an inhibition rate of 39%.CONCLUSION: Fusion protein expressed by recombinant adenoviruses has a significant inhibitory effect on neovascularization.