Epithelial dysplasia produced by carcinogen pretreatment and subsequent wounding

Tumorigenesis of the Oral Mucosa and Skin in Athymic Nude Mice: DMBA, Trp-P-2 and ENU Applications

“…However, lingual carcinoma could not be produced in any of the Groups. These results suggest that athymic nude mice are relatively similar in carcinogen sensitivity to conventional hamsters that were used in the previ-ous studies (11)(12)(13)(14)(15)(16), and are in agreement with some studies (8,9) which suggest that there are no differences in chemical carcinogenesis for either conventional or nude mice.…”

“…In regard to experimental lingual carcinogenesis, some studies have shown that DMBA is a potent chemical carcinogen for in vivo tongue carcinogenesis (11)(12)(13). Previous studies also indicated that a combination of trauma and applications of chemical carcinogens such as DMBA, Trp-P-2 (3-amino-1-methyl-5H-pyrido [3,4-b] indole) and ENU (N-ethyl-N-nitrosourea) to hamster tongues or rat tooth germs led to the development of lingual carcinomas (14,15), lingual epithelial dysplasia (16) and odontogenic tumors (17), respectively. Therefore, it is predicted that the combination of immunodeficiency, trauma and carcinogens may lead to a higher incidence and a shortening of induction time of tumor in athymic nude mice.…”

DNA Vaccine against Hamster Oral Papillomavirus-associated Oral Cancer

“…1 Histologically, these lesions showed pathognomonic changes indicative of papillomavirus infection, including koilocytosis of dysplastic cells, and the nuclei of some of the dysplastic or cancerous cells were positive for papillomavirus genus-specific antigen. 2 Furthermore, viral particles resembling papillomavirus, 50 -55 nm in diameter, were detected in the nuclei of these cells. 3 Using the same animal model, we also demonstrated the presence of a novel hamster papillomavirus by molecular cloning and sequencing of the viral genome.…”

Presence of a novel hamster oral papillomavirus in dysplastic lesions of hamster lingual mucosa induced by application of dimethylbenzanthracene and excisional wounding: molecular cloning and complete nucleotide sequence.

“…We induced the dysplastic lingual lesions by a previously described protocol which has been reviewed and approved by the animal use committee (Maeda et al, 1989). The lingual tips of 3-week-old outbred Syrian Golden hamsters were painted three times a week with DMBA (0n5 % solution in acetone) for 4 weeks.…”

“…In this model, dysplastic or malignant mucosal lesions are observed only around the site of excision and DMBA application. Histologically, these lesions exhibit koilocytosis indicative of papillomavirus infection, and the nuclei of some dysplastic cells are positive for papillomavirus genus-specific antigen (GSA) (Maeda et al, 1989). Furthermore, viral particles resembling papillomavirus, measuring 50-55 nm in diameter, have been detected in the nuclei (Suzuki, 1986).…”