抑制肿瘤生长活性的内皮生长抑制剂EDI-8t

Endothelial genesis inhibitor-8t(EDI-8t) against tumor growth

对内源性的内皮生长抑制剂的序列来源分析后,用RT-PCR方法从人脐带中获得了417bp的cDNA,并克隆到毕赤酵母表达载体pPIC9,然后转化毕赤酵母GS115获得重组表达菌株。表达菌株通过甲醇诱导表达后,将发酵液通过分离纯化获得重组蛋白纯品,命名为EDI-8t。体外实验结果表明,这个胶原蛋白VIII来源的rhEDI-8t蛋白能特异性地抑制牛主动脉内皮细胞的增殖和迁移,并能引起内皮细胞的凋亡。动物体内实验结果表明,rhEDI-8t蛋白样品可有效抑制裸鼠皮下肝癌肿瘤的生长,抑制效果和参照品endostatin相同。但在小鼠黑色素瘤肺转移模型中,rhEDI-8t显示了高于参照品的抑癌效果。

On the basis of the origin comparison of known endothelial genesis inhibitors,a 417-bp cDNA fragment was amplified from umbilical cord by RT-PCR and cloned into the expression vector pPIC9,followed by transformation into Pichia pastoris GS115.The resulted yeast was induced with methanol to express recombinant protein.The resulted protein was purified from culture broth and designated as EDI-8t.The in vitro study showed that EDI-8t,originated from collagen VIII,could specifically inhibit the growth and migration of bovine aortic endothelial cells（BAEC） stimulated by basic fibroblast growth factor（bFGF）.The protein also exhibited the activity to cause cell apoptosis.In vivo EDI-8t showed the identical activity comparing with endostatin to inhibit the growth of liver tumor transplanted into nude mice.Interestingly,EDI-8t showed higher activity than endostatin to inhibit tumor growth in metastatic model of melanoma mice.