Restin Expressed in vivo Suppresses the Growth of Tumors in Nude Mice

XU Ren, XIN Li, ZHANG Jing-Mei, LI Zai-Ping, GAN Ren-Bao
( Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, ª¤
the Chinese Academy of Science, Shanghai 200031, China )

Abstract    Restin, a homologous protein of endostatin (62% homology), is the NC domain of collagen XV at C-terminal. The recombinant restin expressed in E. coli had the ability to suppress the proliferation of bovin aortic endothelial cells and cause apoptosis. In this report, mouse restin gene was fused with a sequence ofª©human plasminogen signal peptide by PCR and cloned into eukaryotic expression vector pCDNA3. The plasmid containing restin gene was named pCDNAXV and was transfected into human hepatoma cell line Bel7404. Stable transfected clones were screened and expression of restin was confirmed by RT-PCR and Western blot. The proliferated cells were injected subcutaneusly into nude mice. The growth of tumors formed by cells transfected with restin gene was much slower than that of control group. These results indicated that the expressed restin in vivo could suppress the growth of tumor, and this suppression might be achieved by restraining angiogenesis since the restin had no effect on the proliferation of tumor cells. At the same time, this report provided a new method to investigate the effect of anti-angiogenetic proteins on the tumor growth.
Key words restin; tumor; angiogensis; stable transfection

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