Progress in studies of angio-statin and its anti-tumor effects

Angiostatin is a 38 ku circulating angiogenesis inhibitor purified from the serum and urine of mice bearing a murine Lewis lung carcinoma. It is regarded as an internal fragment of plasminogen containing the first 4 Kringle structures. In vitro, angiostatin specifically inhibits endothe-lial cell proliferation. In vivo, it inhibits angiogenesis and suppresses the growth of such primary tumors as Lewis lung carcinoma and hemangioendotheliolma in mice.