[Human papillomavirus type 16-gene functions relevant to molecular human carcinogenesis]

Human papillomavirus type 16 is a strong ethiologic agent of tumor development in human mucous epithelia such as uterine cervix. The virus two early genes, E6 and E7, have been characterized to be oncogenes that transform various cells and cell lines in vitro. Extensive analyses of E6 and E7 proteins revealed that these two oncoproteins interacted with cellular tumor suppressors, p53 and pRb, respectively. Thus, oncogenic potentials of the E6/E7-genes could be explained in part by the consequence of crosstalk of E6/E7-proteins and the cell cycle regulators. Furthermore, telomerase activation that protects telomere erosion appeared to by necessary for HPV16-oncogenesis and was demonstrated in HPV16-immortalized human epithelial cell lines. This line of evidence now enabled us to describe, but not fully, a scheme of an earlier process of human carcinogenesis induced by this virus type.