[Transforming activity of human papillomavirus 16 DNA]

A HPV16DNA integrated in a human cancer cell line of the uterine cervix (QG-U) was isolated and cloned. Three kinds of cells (mouse Balb/3T3, Detroit 551 and human keratinocyte) were co-transfected with HPV16DNA and neo DNA with calcium phosphate co-precipitates. Selection of the Transformants and their characteristics were examined. Transformants of mouse Balb/3T3 cells were able to be obtained about 2 weeks after co-transfection. HPV16DNA was integrated in the transformants. The most characteristic change observed in the transformants was the ability to proliferate in serum-free medium. In contrast, two kinds of human diploid cells (Detroit 551 and human keratinocyte) were not transformed by transfection, and ceased growing at almost the same time as nontransfected cells. These results indicate that HPV-DNA transformants are easily selected in cell lines rodents but selection of transformants from human diploid cells is relatively difficult.