Abstract: | For the analysis of the mechanism of cancer metastasis, effects of anticancer agents on the NK activity of spleen cells and on the artificial metastasis of B-16 melanoma cells were comparatively studied. The inhibitory effect of these anticancer agents on the growth of B-16 melanoma inoculated to foot pad of C57/BL6 mice was also examined. The growth of B-16 melanoma was inhibited by intravenous administration of 6 mg/kg of MMC, 18 mg/kg of KW-2083 and 5 mg/kg of CDDP, but not of 6 mg/kg of KW-2083. The NK activities in spleen cells of C57/BL6 mice administered with 6 mg/kg of MMC and 18 mg/kg of KW-2083 were decreased, but they were not decreased in mice administered with 6 mg/kg of KW 2083 and 5 mg/kg of CDDP. Significant increases in the number of artificial pulmonary and liver metastasis were observed in mice administered with 6 mg/kg of MMC and 18 mg/kg of KW-2083. It is suggested that the depression of NK activity induced by anticancer agents results in the promotion of metastatic disease. |