Liver metastasis of colon 26 cells implanted into the superior mesenteric vein in mice.

The intraportal implantation of mouse transplantable colon adenocarcinoma 26 was investigated as an experimental liver metastasis model of colorectal cancer. CDF1 male mice (5 weeks old) were laparotomized under pentobarbital sodium anesthesia, and colon 26 tumor cells (1 X 10, 1 X 10(3), or 1 X 10(5) cells) were inoculated into the superior mesenteric vein. On day 21 after inoculation, mice inoculated with 1 X 10(3) tumor cells showed five to 12 colonies of liver metastasis (mean, 9.2 colonies; n = 6). The survival time was 27 to 36 days (median, 27 days; n = 5) in these mice. When mitomycin C (MMC) was administered into the superior mesenteric vein 15 min after the inoculation of tumor cells, the number of metastatic foci in the liver was strongly inhibited; 81.1% and 100% inhibitions were observed in the groups given 4 mg/kg and 6 mg/kg of MMC, respectively. The mouse colon 26 model seems to be one of the more useful experimental models for evaluating treatments for the prevention of liver metastases from colorectal cancer.