Coordinate regulation of myelomonocytic phenotype by v-myb and v-myc.
Both avian myeloblastosis virus (by the action of v-myb) and avian myelocytomatosis virus MC29 (by the action of v-myc) transform cells of the myelomonocytic lineage. Whereas avian myeloblastosis virus elicits a relatively immature phenotype, cells transformed by MC29 resemble mature macrophages. When cells previously transformed by v-myb were superinfected with MC29, their phenotype was rapidly altered to that of a more mature cell. These superinfected cells expressed both v-myb (at a level similar to that found before superinfection) and v-myc. It therefore appears that the expression of v-myc can elicit certain properties of a more differentiated phenotype. In addition, unlike cells transformed by v-myb alone, the cells expressing both v-myb and v-myc could not be induced by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate to differentiate to fully mature macrophages. Cells with a morphology similar to that of the superinfected cells were elicited by simultaneously infecting yolk sac macrophages with avian myeloblastosis virus and MC29. Such cells expressed both v-myb and v-myc. These results indicate that expression of v-myb and v-myc in infected cells coordinately regulates myelomonocytic phenotype and that the two viral oncogenes vary in their ability to interfere with tumor promoter-induced differentiation. Our findings also sustain previous suggestions that the oncogenes v-myb and v-myc may not transform target cells by simply blocking differentiation.
D000818:Animals; D001354:Avian Leukosis Virus / Q000235:genetics*; D009189:Avian Myeloblastosis Virus / Q000235:genetics*; D001358:Avian Sarcoma Viruses / Q000235:genetics*; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D002642:Chick Embryo; D005814:Genes, Viral; D009857:Oncogenes; D010641:Phenotype; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D013755:Tetradecanoylphorbol Acetate