Transformation of NIH 3T3 cells by cotransfection with c-src and nuclear oncogenes.
pp60c-src, the cellular homolog of the Rous sarcoma virus transforming protein, does not completely transform cells even when present at high levels, but has been shown to be involved in polyomavirus-induced transformation when activated by polyomavirus middle T (pmt)-antigen binding. Here we show that cotransfection, but not solo transfection, of expression plasmids for c-src and either adenovirus E1A, v-myc, c-myc, or the 5' half of polyomavirus large T (pltN) antigen into NIH 3T3 cells induces anchorage-independent growth, enhanced focus formation, and, for pltN cotransfection, tumorigenicity in adult NFS mice. Enhancement of transformation was not observed with polyomavirus small t (pst) antigen. Cotransfection of c-src with pltN induced modification of pp60c-src that altered its electrophoretic mobility and in vivo phosphorylation state and stimulated its in vitro kinase activity. Similar alterations were not seen after c-src-E1A cotransfection, suggesting that at least two different mechanisms of enhancement are involved.
D017456:Adenovirus Early Proteins; D000818:Animals; D002448:Cell Adhesion; D002455:Cell Division; D002460:Cell Line; D002467:Cell Nucleus / Q000502:physiology; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D005786:Gene Expression Regulation; D051379:Mice; D009687:Nuclear Proteins / Q000235:genetics*; D009856:Oncogene Proteins, Viral / Q000235:genetics*; D009857:Oncogenes; D011505:Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D016392:Proto-Oncogene Proteins pp60(c-src); D011519:Proto-Oncogenes; D014162:Transfection
D017456:Adenovirus Early Proteins; D009687:Nuclear Proteins; D009856:Oncogene Proteins, Viral; D011518:Proto-Oncogene Proteins; D011505:Protein-Tyrosine Kinases; D016392:Proto-Oncogene Proteins pp60(c-src)