Antitumor effect of Sarcophaga lectin on murine transplanted tumors.

Sarcophaga lectin, a lectin purified from the hemolymph of Sarcophaga peregrina (flesh fly) larvae, was found to be therapeutically effective against both ascitic and solid tumors. It was especially effective when injected directly into or around nodules of the syngeneic tumor Meth A transplanted intradermally into BALB/c mice. It also induced cytotoxic activity against L-929 cells when it was added to the culture medium of macrophages in vitro. Similar cytotoxic activity was detected transiently in the serum when it was injected into the abdominal cavity of mice, in which sarcoma 180 cells had been inoculated. Probably, this cytotoxic activity induced by Sarcophaga lectin partly contributes to the elimination of tumors. The possible role of this cytotoxic activity is discussed from the viewpoint of ontogeny.