[Expression of angiogenin in COS-7 cells and analysis of its biological activity]

This study was purposed to investigate the angiogenin (ANG) expression in COS-7 cells and its biological activity. The gene of angiogenin was obtained from mononuclear cells of peripheral blood by using RT-PCR and inserted into eukaryotic expression vector of pcDNA3.1. After being transfected into COS-7 cells, the recombinant ANG was identified by Western blot assay. The function of promoting proliferation of ANG to ECV304 cells was detected by MTT method, and its activity of vascularization was analyzed by chick embryo chorioallantois treated by the culture supernatant after transfection with pcDNA3.1-ang. The result showed that recombinant ANG was expressed in COS-7 cells after transfection for 24 to 36 hours. It could specifically react with monoclonal antibody against ANG. The recombinant ANG could obviously promote the proliferation of ECV304 cells. In contrast with the control group, the culture supernatant of pcDNA3.1-ang transfected group could stimulate the angiogenesis in embryo chorioallantois. It is concluded that the ang transiently expresses in COS-7 cells, and its expression product obviously stimulates the cell proliferation and angiogenesis.