In vitro immune interferon induction during tumor evolution

In a syngeneic C3H mammary adenocarcinoma model we studied gamma-interferon (gamma IFN) production during tumor evolution. The IFN production was induced by soluble tumor extracts on spleen cell cultures from tumor-bearing mice. A low level of IFN production was found in culture supernatants from small tumor-bearing mice (tumor diameter less than 10 mm, 12-15 days of tumor evolution). In advanced stages of tumor growth (diameter more than 15 mm, 20 days or more of tumor evolution), this ability was lost.