Effect of anticancer drugs on the release of interferon gamma in vitro.

Some conventional and experimental anti-cancer drugs were tested for their effect on concanavalin-A-induced interferon gamma release from rat splenocytes in vitro. When 2.5 x 10(6) rat splenocytes/ml, stimulated with 1 microgram/ml concanavalin A, were incubated with various non-cytotoxic doses of the vinca alkaloid vincristine, there was an inhibition of the release of interferon gamma in culture supernatants. The antitumour antibiotics bleomycin and Adriamycin, alkylating agents 4-hydroperoxycyclophosphamide and mafosfamide, and the immunoactive peptides FK156 and FK565 did not affect the release of interferon gamma under similar conditions. However, cyclosporin A, in similar experiments, markedly inhibited the release of interferon gamma.