[Effect of interferon on mouse glioma]

Mouse interferon (IFN) induced in L 929 cells by Newcastle disease virus was examined for its effect on the growth of mouse brain tumor cell line. In this study, we used subcutaneously transplanted 203 Glioma model, which had been originally induced by methylcholanthrene in C 57 BL mice. After subcutaneous transplantation, intraperitoneal administration of IFN was started by following schedule; 5 X 10(3) IU twice a week, 5 X 10(4) IU twice a week, 2.5 X 10(5) IU twice a week, 5 X 10(3) IU every day and 2.5 X 10(4) IU every day. In all groups treated by IFN intraperitoneally, no inhibition of the tumor growth was seen. On the other hand, natural killer (NK) activity was augmented by IFN treatment. Therefore, we considered that augmentation of NK activity was not directly correlated with the antitumor effect of IFN. Then, local administration was examined. After subcutaneous tumor was recognized, 2.5 X 10(4) IU of IFN was injected intratumorally every day. About 20 days later, the tumor decreased its size less than that treated by local injection of saline. It was suggested that the local administration of IFN might be better than the systemic administration.