Cloning, expression, and in vitro activity of human endostatin

Endostatin, a 20 kDa C-terminal fragment of collagen XVIII, is a specific i nhibitor of endothelial cell proliferation and angiogenesis, In the present study, we have expressed human endostatin in a yeast expression system (10 mg/L). The recombinant protein was expressed in a soluble form and purifie d to homogeneity. It specifically inhibited the proliferation and migration of endothelial cells. In addition, we report for the first time that endos tatin caused G(1) arrest of endothelial cells. Also, we show that endostati n treatment resulted in apoptosis of HUVE and HMVE cells and that all of th ese effects do not occur in nonendothelial cells. Collectively, these findi ngs demonstrate the expression of a biologically active form of human endos tatin in yeast and provide important mechanistic insight into endostatin ac tion on endothelial cells. (C) 1999 Academic Press.