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Background: In the field of gene therapy, viral vectors as delivery tools have a number of disadvantages for medical application. This study aimed to explore a novel nonviral vector as a vehicle for gene therapy., Methods: Transvector-rpE-MPP and EGFP (enhanced green fluorescent protein) were used as the gene transfer carrier and the reporter gene, respectively. Polyplexes which integrate transvector-rpE-MPP, the object gene, and EGFP were formed. The optimal charge ratio, stability, and transduction capacity of the polyplexes in mouse hepatocytes in vitro and in mouse liver in vivo were investigated. The polyplexes of transvector-rpE-MPP and pcDNA(3)-EGFP, with charge ratios of 0, 0.25, 0.5, 0.75, 1 and 1.5 were compared to determine the optimal charge ratio., Results: Polyplexes with charge ratios of 1:1 were most stable; pcDNA(3)-EGFP in these complexes resisted digestion by DNase I and blood plasma. On the other hand, pcDNA(3)-EGFP alone was digested. Fluorescence analysis indicated that transvector-rpE-MPP successfully delivered the reporter gene EGFP into hepatocytes and that EGFP expression was detected in hepatocyte cultures and in liver tissue., Conclusion: These results have laid a foundation for further study of a novel nonviral gene delivery system.

Background: The proliferation and metastasis of cancers depend on angiogenesis. This property provides the feasibility for the treatment of cancer by inhibition of angiogenesis, and many angiogenic inhibitors have been demonstrated to effectively inhibit angiogenesis and consequently the growth of solid cancer. As for the newly identified angiogenesis inhibitor, arresten, some studies have found its high activity on restrainting tumor vessel. This study was to assess the anti-angiogenic activity of arresten., Methods: The arresten gene was obtained from a healthy puerperal's placenta tissue by the reverse transcriptase-polymerase chain reaction (RT-PCR) method, and molecular cloning to prokaryotic expression plasmid pBV220 by recombination strategy. The prokaryotic expression plasmid pBV220/arr was identified by restriction enzyme digestion and sequenced. The pBV220/arr was transformed into E. coli JM109, DH5alpha, BL21 and BL21 (DE3) by the CaCl2 transformation method. The arresten expression level was detected by SDS-PAGE. The expressed product was purified, re-naturalized and detected for its biological activity of inhibiting the angiogenesis of chorioallantoic membrane (CAM)., Results: The arresten gene was cloned and pBV220/arr was constructed. The arresten expression level of protein was highly increased after pBV220/arr was transformed into E. coli BL21 (DE3). SDS-PAGE showed that the expressed arresten proteins were mainly inclusion bodies and had a molecular weight of 26 kDa. The expressed arresten protein showed evident biological activities., Conclusions: The successful construction of recombinant plasmid pBV220/arr and the effective expression in E.coli have laid a foundation for further study of its anti-angiogenic function and may pave the way for future anti-tumor application.

Background: The development of a harmless and efficient nonviral gene delivery system that can facilitate the penetration of nucleic acids through the plasma membrane is a key to successful gene therapy. The aim of this study was to test a nonviral gene transferring vector's function of delivering DNA into liver cells to provide an important clue for gene transfer in liver gene therapy., Methods: The complex of DNA and DNA delivering protein was injected into mice through their tail veins. Then the mice were killed and their liver tissue was sectioned. The gene transferring results were detected using a confocal laser scanning microscope., Results: Fluorescence analysis indicated that both DNA-membrane penetrating peptide (MPP) complex and DNA- hepatocyte specific receptor binding domain (HSRBD)-MPP complex could go into liver cells. The fluorescence value of liver cells in the DNA- HSRBD-MPP group was higher than that in the DNA-MPP group., Conclusions: MPP can successfully deliver DNA and protein into cells, and MPP with a HSRBD can specifically deliver DNA into liver cells. These have laid a foundation for further study on the nonviral liver cell gene delivering system.