Abstract
This study examines the antitumor effects of recombinant interferon-γ (ReIFN-γ), by comparing various routes for its administration in nude mice transplanted with human cervical tumor cells. Daily intratumoral injection of ReIFN-γ showed the best inhibitory effect, although intramuscular daily administration of this IFN also showed a significant antitumor effect. Furthermore, the earlier treatment was initiated after tumor inoculation, the better was the antitumor effect of the IFN. Histologic examination of the transplanted tumors after treatment with ReIFN-γ showed a sparse or reticular arrangement of the tumor cells, and very large multinucleated giant cells. Unlike the original tumor, 'pearl' formation and isolated cell keratinization were frequently observed in the transplanted tumors obtained from IFN-treat-ed groups.