A Mouse Model of Tongue Epithelial Precancer Induced by 4-nitroquinoline l-oxide in Drinking Water.

Objective: To establish the precancerous animal model which is similar to the human occurrence. Methods: Chemical carcinogen 4-nitroquinoline 1-oxide (4NQO) in drinking water was administered to 40 Balb/c mice of experimental group,10 mice were controled group. The mouse were killed and tongues were removed for histological assessment by the end of 16 or 20 weeks. Results: Gross changes included white changes and leukoplakia appearances on the posterior mucosa of the tongue dorsum were present during carcinogenesis. The histopathological changes ranged from hyperplasia are mild dysplasia and moderate dysplasia for 16weeks, moderate dysplasia and severe dysplasia are for 20 weeks. The total rate of precancer lesions is 100%. Conclusions: 4NQO can credibly cause mouse tongue precancer, which morphologically and histologically mimic human oral carcinnogenesis. The method by drinking water to cause mice oral precancer is natural and handy, and it is similar to the process of human oral precancer. The application of 0.001% 4NQO is the ideal period to precancer induction frome 16 to 20 weeks.