Potent inhibition of angiogenesis and liver tumor growth by administration of an aerosol containing a transferrin-liposome-endostatin complex

To obtain an efficient delivery system for transporting endostatin gene to mouse liver tumor xenografts by administration of aerosol. Recombinant plasmid pcDNA3.0/endostatin containing human endostatin gene together with signal peptide from alkaline phosphatase were transferred into human umbilical vein endothelial cell (HUVEC) by transferrin(TF)-liposome-endostatin complex. Western blot was used to detect the expression of human endostatin in transfected HUVEC cells and its medium. After the tumor-bearing mice were administrated with TF-liposome-endostatin complex, the lung tissue was analyzed by immunohistochemical method for expression of endostatin and the tumors were treated with CD-31 antibody to detect the density of microvessels in tumor tissues. The inhibition of tumor growth was estimated by the weight of tumors from groups treated with different doses of TF-liposome-endostatin complex. DNA fragmentation assay was used to detect the apoptosis of the cells from primary liver tumor. Western blot analysis and immunohistochemical method confirmed the expression of endostatin protein in vitro and in vivo. After the tumor sections were treated with CD-31 antibody, the positive reaction cells appeared brown while the negative cells were colorless. The positively stained area of the TF-liposome-endostatin treated group was significantly smaller (P