Transgenic Models for Papillomavirus-Associated Multistep Carcinogenesis

To investigate the physiological and pathological in vivo functions of molecularly cloned genes, the transgenic mouse is one of the most useful experimental animal systems. Many kinds of transgenic mice carrying papillomavirus genes have been produced, and the studies have revealed several new aspects in the field of papillomaviral oncology. Among these transgenic mice, the mechanism of skin carcinogenis in the bovine papillomavirus (BPV) transgenic mouse has been well characterized, demonstrating that numbers of genetic alterations in specific cellular genes were deeply involved in tumor progression as well as in the expression of transforming genes encoded by the viral genome. Comparable mechanisms were found in testicular tumorigenesis in the HPV 16 E6E7 transgenic mouse. Here we discuss the mechanism of testicular tumorigenesis in the HPV 16 E6E7 transgenic mouse together with that of skin carcinogenesis in the BPV transgenic mouse in order to clarify some part of papillomavirus-associated carcinogenesis.