PRESENCE OF A NOVEL HAMSTER ORAL PAPILLOMAVIRUS IN DYSPLASTIC LESIONSOF HAMSTER LINGUAL MUCOSA INDUCED BY APPLICATION OF DIMETHYLBENZANTHRACENE AND EXCISIONAL WOUNDING - MOLECULAR-CLONING AND COMPLETE NUCLEOTIDE-SEQUENCE

A combination of 9,10-dimethyl-1,2-benzanthracene (DMBA) application a nd excisional wounding on the lingual tips of Syrian Golden hamsters ( Mesocricetus auratus) induces dysplastic and malignant mucosal lesions . Papillomavirus genus-specific antigen and viral particles, measuring 55 nm in diameter, were demonstrated in the nuclei of squamous cells of dysplastic lesions showing koilocytotic change. In this study, we c loned a circular genome at a single KpnI site from one of these dyspla stic lesions. The genomic sequence of this clone, consisting of 7647 b p, was shown to be that of a novel papillomavirus with a conserved gen omic organization. We named the new virus hamster oral papillomavirus (HOPV). All dysplastic lesions induced by this combination of DMBA app lication and excisional wounding contained viral DNA. Although Souther n blot hybridization analysis could not detect the HOPV genome, PCR an alysis demonstrated the latent HOPV genome in the tongue and skin of a n untreated hamster. These results suggest that latently present HOPV genome is reactivated by the DMBA/wounding procedures. Lingual HOPV in fection may be an important model for gaining insight into the interac tions between papillomavirus infection, chemical carcinogens and physi cal irritations in carcinogenesis or malignant transformation.