PURPOSE: We tried to elucidate antitumor effect of interleukin-2 containing miscrospheres (IL-2 MS) against intrahepatic challenge of parental cancer cells, which is clinically relevant tumor model. MATERIALS AND METHODS: Using a model of liver metastasis by intrahepatic challenge of CT-26 murine colon carcinoma cells to syngeneic BALB/c mice, IL-2 MS were given with parental tumor cells, or intratumorally in animals with established tumors. Tumor volume and survivals were determined. RESULTS: Animals receiving IL-2 MS showed significant tumor suppression effect and systemic protection against the hepatic challenge of parental tumor cells after concomitant challenge with parental CT-26. In animals with established hepatic tumors, significant prolongation in survival was noted. CONCLUSION: IL-2 MS was effective for the protection of host agaisnt the metastatic hepatic tumor when administered with tumor cells. Its efficacy against the established tumor was also significant as in protection. Locally administered IL-2 MS can obviate the high- efficiency gene transfer technique and ex vivo culture of autologous tumor cells in gene transduced autologous tumor vaccine. It can also provide support for the specific immuno- therapy for the metastatic liver cancer.
Animals ; Colon ; Gene Transfer Techniques ; Humans ; Immunotherapy* ; Interleukin-2 ; Interleukins* ; Liver Neoplasms* ; Liver* ; Mice ; Microspheres* ; Neoplasm Metastasis ; Parents ; Tumor Burden