Induction of hepatocellular carcinoma and highly metastatic squamous cell carcinomas in the forestomach of mice by feeding 2-amino-3,4-dimethylimidazo[4,5-f]quinoline.

2-Amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), a potent mutagen which was isolated from grilled sardines, was tested for carcinogenicity in CDF1 mice. Mice were given diet containing 0.04 or 0.01% MeIQ for 91 weeks. The incidences of liver tumors (hepatocellular carcinomas and hepatocellular adenomas) in female mice given 0.04 and 0.01% MeIQ were significantly higher than those in controls. The incidences of forestomach tumors (squamous cell carcinomas and papillomas) were also significantly higher in both sexes of mice given MeIQ. About 40% of the squamous cell carcinomas that developed in mice given diet containing 0.04% MeIQ metastasized to the liver.