Activation of the gene for the PDGF receptor beta1 (PDGFRbeta) in interleukin-3-dependent myeloid cells by retroviral insertional mutagenesis: implications for the transforming potential of PDGFRbeta.
Retroviral insertional mutagenesis has proven to be a powerful tool to identify genetic lesions disrupting normal hematopoiesis. The gene encoding the beta receptor for platelet-derived growth factor (PDGFRbeta) was identified as a target of retroviral mutagenesis in mutants selected for interleukin-3 (IL3)-independent growth. Expression of PDGFRbeta in the parental cells using a retroviral vector increased the frequency of factor-independent growth, confirming the significance of the retroviral integration site. Significantly, however, expression of the receptor did not induce IL3-independent growth in one step. In contrast, TEL-PDGFRbeta, the fusion protein generated by the t(5;12) translocation associated with chronic myelomonocytic leukemia, induced factor-independent growth in all transductants, demonstrating that the TEL-PDGFRbeta fusion protein is a more potent mitogenic signal. Nevertheless PDGFRbeta overexpression is sufficient to give a selective advantage to IL3-dependent cells under adverse conditions, allowing the selection of secondary mutations that impart IL3-independent growth. These results underline the power of insertional mutagenesis to identify subtle but initiating mutations that synergize with other lesions in oncogenic transformation.
Meyer
Johann
J
Department of Cell- and Virus-Genetics, Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie, Martinistrasse 52, D-20251 Hamburg, Germany.
Laker
Christine
C
Janzir
Nadia
N
Franz
Marie-Joseé
MJ
Bergholz
Ursula
U
Ostertag
Wolfram
W
Stocking
Carol
C
D016475:3T3 Cells; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D015153:Blotting, Western; D002455:Cell Division; D004591:Electrophoresis, Polyacrylamide Gel; D007377:Interleukin-3 / Q000378:metabolism*; D016173:Macrophage Colony-Stimulating Factor / Q000378:metabolism; D051379:Mice; D008957:Models, Genetic; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009154:Mutation; D020033:Protein Isoforms; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012190:Retroviridae / Q000235:genetics*; D013997:Time Factors; D015533:Transcriptional Activation; D014178:Translocation, Genetic; D014407:Tumor Cells, Cultured
D007377:Interleukin-3; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins; D016173:Macrophage Colony-Stimulating Factor; D020797:Receptor, Platelet-Derived Growth Factor beta