血管形成抑制因子HIAF-1在昆虫细胞中的高效表达和活性研究

背景与目的：大肠杆菌表达的人抑制血管生成因子－1（human inhibiting angiogenesis factor-1,HIAF-1）可抑制肿瘤血管的形成。本研究在昆虫细胞中表达HIAF－1,并研究其生物活性。方法：用DNA重组技术,构建了重组杆状病毒表达载体pAcuW51-HIAF-1,用Cellfectin将其与线性病毒DNA共转染昆虫细胞sf9,获得重组病毒。用SDS－PAGE电泳和Western blot鉴定重组病毒感染的昆虫细胞中重组HIAF－1重组蛋白的表达。重组蛋白经亲和层析纯化后,在体外用MTT法检测其对内皮细胞的作用,用食管癌移植瘤研究其体内抑瘤活性。结果：在昆虫细胞中高效表达了分子量为26kDa的HIAF－1重组蛋白,其表达量可达昆虫可溶性蛋白的5％－10％。重组HIAF－1蛋白不仅在体外显著抑制内皮细胞的生长,IC50值为3．1μg/ml,而且显著抑制食管癌移植瘤的生长。结论：在昆虫细胞中高效表达了分子量为26kDa的HIAF－1重组蛋白,其表达量可达昆虫可溶性蛋白的5％－10％。重组HIAF－1蛋白不仅在体外显著抑制内皮细胞的生长,IC50值为3．1μg/ml,而且显著抑制食管癌移植瘤的生长。结论：在昆虫细胞中高效表达了HIAF－1重组蛋白;HIAF－1重组蛋白的生物活性优于相应的原核重组蛋白。

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

BACKGROUND & OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: The recombinant HIAF-1 with better activity was successfully expressed in insect cells and establish a base for clinical application.