The E6 gene of human papillomavirus type 16 is sufficient for transformation of baby rat kidney cells in cotransfection with activated Ha-ras.

The transforming potential of the E6 open reading frame (ORF) of the human papillomavirus type 16 was investigated with transformation assays in cotransfections with an activated ras gene. The E6 ORF driven by the heterologous CMV promoter could fully transform baby rat kidney cells (BRK) in cooperation with ras. The transformed cells grew in soft agar and induced tumors in athymic nude mice. The E6 ORF with mutations at the splicing donor site, which only encodes the full length E6 but not E6*s, could also fully transform the BRK cells at a similar efficiency as the wild-type E6 ORF, indicating that the full-length E6 was sufficient for the transformed phenotype.