Differential Susceptibility of Human Cells to Transformation by Murine and Avian Sarcoma Viruses

Abstract
The susceptibility to Kirsten murine sarcoma virus (Ki-MSV) and Schmidt-Ruppin strain of Rous sarcoma virus (RSV-SR) transformation of cultured skin fibroblasts derived from hereditary adenomatosis of the colon and rectum (ACR), its Gardner's syndrome (GS) variant, and unrelated age and sex-matched controls was examined. Human skin fibroblasts from ACR and GS individuals were highly susceptible to transformation by Ki-MSV but not susceptible to RSV-SR transformation. However, the human osteosarcoma (HOS) clonal cells (TE-85 clone F-5), known to be sensitive to Ki-MSV transformation, could also be readily transformed by RSV-SR. The RSV-SR-transformed cells formed large cell aggregates and grew in this aggregate form when suspended in liquid growth medium above an agar base, formed colonies in soft agar with high efficiency, and grew to high saturation densities while the uninfected cells did not. The transformed cells produced tumors when transplanted subcutaneously into nude mice. The morphologically altered cells produced neither infectious virus nor type C virus particles. However, they contained RSV-RS complement-fixing antigen, a RSV transformation-specific protein (p60src)-associated kinase activity, and a rescuable infectious virus.