Partial transformation of human tumor cell lines showing defective interaction between unusual p53 gene product and SV40 large-T antigen.
Stable SV40 transformation of the human osteosarcoma cell line HOS yielded SV-HOS cells with high levels of large-T and quasi-original levels of p53. The latter kept its former intermediate metabolic stability, was found to be uncomplexed with SV40 large-T, however coimmunopurified with a 70 kDa protein. Upon comparison with HOS, SV40-HOS cells showed decreased serum-dependence and increased colony-forming efficiency in soft agar. SV-HOS cells were non-invasive in an in vitro assay in contrast with SV40-transformed human cells exhibiting a classical large-T-p53 complex. Both SV40-transformed human cell types were poorly tumorigenic in athymic mice in contrast with transformed HOS cells, expressing activated v-ras or met oncogenes. The p53 molecules from HOS cells and any of the HOS derivatives were underphosphorylated and showed unusual methionine- and phosphate-containing peptide fingerprints when compared with 'normal' human p53, which can associate with SV40 large-T. The structural and biological features of the HOS p53 molecules are discussed in relationship to analogous human and murine molecules in experimental and natural systems.
Van Roy
F
F
Laboratory of Molecular Biology, State University of Ghent, Belgium.
Liebaut
G
G
Mareel
M
M
Fiers
W
W
D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000032:analysis*; D002472:Cell Transformation, Viral; D002642:Chick Embryo; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007231:Infant, Newborn; D051379:Mice; D015513:Oncogene Proteins / Q000032:analysis* / Q000378:metabolism; D010750:Phosphoproteins / Q000032:analysis* / Q000378:metabolism; D010766:Phosphorylation; D013539:Simian virus 40 / Q000235:genetics; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53
D000952:Antigens, Polyomavirus Transforming; D015513:Oncogene Proteins; D010750:Phosphoproteins; D016159:Tumor Suppressor Protein p53