ANTITUMOR ACTION OF BOVINE SEMINAL RIBONUCLEASE

Unlike the bovine pancreatic ribonuclease (RNAase A), bovine seminal r ibonuclease (BS RNAase) displays various biological activities includi ng antitumor cytotoxicity. To learn more about its antitumor activity, we investigated BS RNAase effect on athymic nude mice bearing various tumors. BS RNAase (250 mu g per mouse per day) was administered to th e mice with prostate carcinoma for three weeks by three different rout es (intraperitoneally - i.p., subcutaneously - s.c., and intratumorall y - i.t.). Administration i.p. was ineffective, while s.c. administrat ion reduced significantly size of tumors and i.t. administration aboli shed half of the tumors in treated mice. The i.t. administration of BS RNase to nude mice bearing melanoma showed even better results. Eight y % of mice were without tumors and in the other mice the tumors were significantly diminished. The best antitumor effect was obtained in ca se of seminoma. All mice bearing this tumor were cured after ten doses of BS RNAase.