[The study on in vitro transformation by human papillomavirus type 16 E6/E7 region].
A NIH3T3-derived cell clone (NA7) in which human papillomavirus (HPV) 16 early region E6/E7 was inducible by dexamethasone (DXM) under the control of mouse mammary tumor virus long terminal repeat was established. A transforming function for HPV 16 E6/E7 region was analyzed by this established clone. Northern blot hybridization demonstrated that the increased expression of PCNA/cyclin and c-myc at the confluent state in accordance with the induced expression of E6/E7 region by DXM. Although complete transformation was not observed, the saturation density of NA7 was increased by the addition of DXM. The transfection assay using NA7 showed that adenovirus type 5 E1B (Ad5E1B) could cooperate with E6/E7. Furthermore, it was indicated that E7 could also cooperate with adenovirus type 5 E1B as well as with EJ-ras in transforming primary rat embryonal cells. However, E6/E7 could not cooperate with Ad12E1B in both cell systems. In this study, HPV 16 E6/E7 was assumed to have the growth-stimulatory activity in association with some cellular genes and transforming activity by cooperation with some transforming genes. These results suggest that E6/E7 seems to play a major role in the process of human cervical cell carcinogenesis.
Kato
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Department of Obstetrics and Gynecology, Hokkaido University School of Medicine, Sapporo, Japan.
D000818:Animals; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D002999:Clone Cells; D005260:Female; D009857:Oncogenes; D027383:Papillomaviridae / Q000235:genetics*; D010957:Plasmids; D051381:Rats; D011916:Rats, Inbred F344; D014162:Transfection; D002583:Uterine Cervical Neoplasms