A MONOCLONAL-ANTIBODY TO HUMAN ANGIOGENIN SUPPRESSES TUMOR-GROWTH IN ATHYMIC MICE

Human angiogenin, a potent inducer of neovascularization, is secreted by HT-29 colon adenocarcinoma cells. mu g doses of a monoclonal antibody that neutralizes the in vitro and in vivo activities of angiogenin prevent or delay the appearance of s.c. HT-29 tumors in athymic mice in a statistically significant, dose-dependent manner. The antibody is not cytotoxic to tumor cells irt vitro, which indicates that inhibition of tumor grow th most likely occurs by neutralization of the activity of angiogenin in vivo and further implies a critical role for angiogenin in the early development of HT-29 tumors. The results suggest a therapeutically useful approach to the treatment of angiogenin-dependent malignancy.