title: The Gag-Myb-Ets fusion oncogene alters the apoptotic response and growth factor dependence of interleukin-3 dependent murine cells.
abstract: Expression of the avian E26-derived Gag-Myb-Ets fusion oncogene in interleukin-3(IL3)-dependent murine hematopoietic cell lines results in a pattern of cell line dependent changes in growth factor-induced proliferation and apoptosis. A drug-selectable retrovirus expressing p135Gag-Myb-Ets induced an erythropoietin(Epo)-responsive phenotype in the cell lines FDC-P2, BaF3 and 32Dc123. Gag-Myb-Ets expression alone did not increase expression of GATA-1 or the Epo receptor(EpoR) in the presence of IL3, and infected cell lines express increased GATA-1 and EpoR only when IL3 was replaced by Epo in the culture media. Indicative of Epo-induced erythroid differentiation, these cells also began to express beta-globin after 3-5 days growth in Epo. Unlike control cells, infected FDC-P2 cells failed to undergo programmed cell death (apoptosis) when transferred from IL3- to Epo-containing media, although a fraction of the cells failed to proliferate following the media shift. Three other IL3-dependent cell lines showed no changes in growth behavior when induced to express the fusion oncogene. Our data shows that Gag-Myb-Ets can have different affects on growth factor pathways depending on the cell background, suggesting a model in which the p135gag-myb-ets fusion oncogene promotes these different responses through its affect on apoptosis.
authors.affiliation: Laboratory of Cellular Biochemistry, SAIC Frederick, Maryland, USA.
authors.forename: M
authors.initials: M
authors.lastname: Athanasiou
authors.forename: G J
authors.initials: GJ
authors.lastname: Mavrothalassitis
authors.forename: C C
authors.initials: CC
authors.lastname: Yuan
authors.forename: D G
authors.initials: DG
authors.lastname: Blair
mesh_terms: D016475:3T3 Cells; D000818:Animals; D017209:Apoptosis; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D004921:Erythropoietin / Q000494:pharmacology; D015683:Gene Products, gag / Q000235:genetics*; D007377:Interleukin-3 / Q000494:pharmacology*; D051379:Mice; D008969:Molecular Sequence Data; D009857:Oncogenes; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D050783:Proto-Oncogene Proteins c-ets; D020598:Proto-Oncogene Proteins c-myb; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D015683:Gene Products, gag; D007377:Interleukin-3; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D020598:Proto-Oncogene Proteins c-myb; D014157:Transcription Factors; D004921:Erythropoietin