Properties of Rat Cells Transformed by DMA Plasmids Containing Adenovirus Type 12 E1 DNA or Specific Fragments of the E1 Region: Comparison of Transforming Frequencies1

In this paper, we describe for the first time the transformation of normal rat cells by DMA equivalent to adenovirus type 12 Early Region 1 (E1A). This DMA was 30-fold less efficient at transfor mation than DMA encoding the entire E1 region. Those estab lished lines expressing a full complement of adenovirus type 12 E1 proteins were phenotypically indistinguishable from adenovi rus type 12 virus-transformed cell lines. However, cell lines produced by plasmids carrying subgenomic fragments of E1 DMA and therefore not expressing E1B M, 52,000 protein took longer to establish and produced tumors only after a protracted latent period. A Giemsa-banding study showed that adenovirus transformation can occur without disruption of the normal rat karyotype.