Abstract
This investigation was carried out to study tumorigenesis in the tongue of athymic nude mice by painting with carcinogens such as DMBA, Trp-P-2 and ENU after mechanical scratching. Tumorigenesis in the skin of the same animals was also investigated by painting with the above-mentioned carcinogens. In athymic nude mice, severe dysplasia of the tongue was induced by a combination of mechanical trauma and applications of DMBA, and the expression pattern for PCNA indicated that dysplastic cells were more proliferative and of a higher malignant potential than those induced by applications of Trp-P-2 or ENU. Squamous cell carcinoma was produced in the skin of the same athymic nude mice by application of DMBA only, indicating that the skin of nude mice was more sensitive than the tongue to DMBA. Our results indicated that the mechanical trauma was very significant in producing oral epithelial dysplasia after application of carcinogens.
