[High expression of human angiogenesis inhibitor HIAF-1 in insect cells and biological activity]

Human inhibiting angiogenesis factor-1(HIAF-1) expressed in E coli. shown the activity of inhibiting the angiogenesis of tumors. This study was designed to investigate the expression of HIAF-1 in insect cells and to elucidate its biological activity.

Recombinant baculovirus expression vector pAcuW51-HIAF-1 was constructed by recombinant DNA technique and cotransfected with linearized baculovirus DNA into sf9 cells to produce recombinant virus. The expression of recombinant HIAF-1 in insect cells infected by recombinant virus was detected by SDS-PAGE and Western blot. The recombinant protein was purified by affinity chromatography. In vitro endothelial proliferation inhibiting activity of recombinant HIAF-1 was examined by MTT method, its antitumor activity in vivo was studied in human esophageal cancer transplanted in nude mice.

HIAF-1 was effectively expressed in insect cells as 26 KD fusing protein and its expression level was about 5-10% of insect cellular total soluble proteins. Recombinant HIAF-1 protein could inhibit endothelial cell proliferation in vitro with IC50 value of 3.1 micrograms/ml and inhibited remarkably growth of human esophageal cancer transplanted in nude mice.

The recombinant HIAF-1 with better activity was successfully expressed in insect cells and establish a base for clinical application.