Zg. Wu et al., SUPPRESSION OF TUMOR-GROWTH WITH RECOMBINANT MURINE ANGIOSTATIN, Biochemical and biophysical research communications, 236(3), 1997, pp. 651-654
Angiostatin, a 38 kDa internal fragment of plasminogen, is an antiangi
ogenic endothelial cell inhibitor. It regresses several primary and me
tastatic tumors in mice. To produce recombinant angiostatin for furthe
r structural and functional studies, the mouse angiostatin gene preced
ed by a sequence including a signal peptide of plasminogen was introdu
ced into baculovirus. Recombinant murine angiostatin was purified from
the culture medium of angiostatin baculovirus-infected insect cells (
yield = 1 mg/liter) with a single-step of lysine-Sepharose chromatogra
phy. The angiostatin baculovirus-infected insect cells expressed and s
ecreted a 52 kDa polypeptide that demonstrated all of the biological a
ctivities of angiostatin. A partial amino acid sequence of the NH2-ter
minus of the secreted protein revealed that the signal peptide was rec
ognized and properly cleaved in insect cells. The recombinant murine a
ngiostatin potently inhibited the proliferation of bovine capillary en
dothelial cells in vitro (half maximal inhibition = 50 ng/ml) and supp
ressed the growth of primary Lewis lung carcinoma in vivo (6 mg/ kg/da
y, T/C = 0.08). (C) 1997 Academic Press.