Effect of OK-432 for Prevention of Spontaneous Metastasis in the Liver

C57BL/6 murine reticulum cell sarcoma M5076 was injected into the left footpad to induce spontaneous metastasis in the liver and other organs. The preventive effect of OK-432 was assessed with this spontaneous metastasis model. Hepatic colony incidence and number were reduced in OK-432-treated mice compared with untreated. In LATA, spleen cells obtained from treated mice showed significantly higher antitumor effects than those from untreated. The survival time of treated mice was significantly longer than that of untreated. These findings suggested that the treatment by intrasplenic administration with OK-432 had cytotoxicity against metastatic tumor cells in the liver.