Abstract: Objective To study the Antiangiogenic potency of BAI1 in vivo and the therapeutic effect on human glioblastoma. Method The COS-TPC method was used to construct recombinant adenovirus carrying the human BAI1 cDNA or LacZ(Mock). BAI1 mRNA and protein were detected using Northern Blotting and Western Blotting respectively. Dorsal skinfold transparent chamber analysis was used to evaluate the antiangiogenesis effect of BAI1. Observations were performed using intravital microscopy and a S-VHS video tape recorder. Immunohistochemical staining using anti-von Willebrand factor antibody was used to show the stained endothelia inside tumor. Blood vessels were counted under microscope. U373MG cells were inoculated into mice subcutaneously. After the tumors grew up to a size of 0.5～1.0 cm in diameter. AdeBAI1, or AdeMock, or Medium were injected intra-tumorly, this injection was repeated 5 times every three days. The tumor size was observed and recorded every other day. Result The results of Northern Blotting and Western Blotting showed that BAI1 mRNA and protein was expressed only in those transduced with AdeBAI1. In mice injected with DMEM or AdeMock tumors, blood vessels were infiltrated into the tumor tissue. On the other hand, angiogenesis was completely inhibited in dorsal skinfold chamber of SCID mice transplanted with AdBAI1-transduced cells at day 12 after the transplantation. Immunohistochemical staining using anti-von Willebrand factor antibody showed decreased vascularization was evident in the xenografts of AdBAI1-transduced U373MG cells compared with AdeMock-transduced or nontransduced U373MG cells in SCID mice. The mean tumor sizes of SCID mice treated with AdeBAI1 were significantly small than that of those treated with AdeMock, or Medium.Conclusion BAI1 has antiangiogenesis effect. Intratumor injection of AdeBAI1 can inhibit the tumor growth. BAI1 was one of the potent candidate genes for gene therapy of brain tumors, particularly human glioblastomas.

Key words: BAI1, adenovirus, glioblastoma, genetherapy