[Transforming genes of human papillomaviruses and cancer].

The human papillomaviruses (HPVs) are epitheliotropic viruses that induce epithelial hyperproliferation including cutaneous warts and condylomas in cervical and vaginal epithelia. Certain types of HPVs, such as HPV 16, 18 are closely associated with cervical cancer, penile cancer and skin cancer of EV (epidermodysplasia verruciformis) patient. Experimental studies in cultured cell lines provide strong support for the idea that HPV 16 and 18 have transforming genes and are involved in the development of above cancers. However, their transforming genes are unable to induce malignant transformation of primary cultured cells originated from rodent, human for skin and cervical epithelial cells. For the carcinogenesis by HPVs, alteration of some additional factor(s) is thought to be necessary. It is the aim of this review to summarize recent knowledge about transforming genes of HPVs and their additional factors associated with carcinogenesis focused on cervical cancer.