title: c-myb but not c-myc suppresses the hemin-induced nonterminal expression of hemoglobin by murine erythroleukemia cells.
abstract: Clonal lines of Friend murine erythroleukemia (F-MEL) cells have been generated following transfection with c-myc or c-myb expression plasmids. These clones produce high levels of abnormally regulated proto-oncogene transcripts and fail to terminally differentiate in the presence of dimethyl sulfoxide. To determine the relative levels at which the two proto-oncogenes might exert their inhibitory effects, we asked whether these clones could express differentiated functions in the absence of terminal differentiation. It was found that exposure of c-myc-transfected cells to hemin allows for the induction of hemoglobin, whereas c-myb-transfected cells were refractory to hemin induction. It thus appears that c-myb exerts a more globally suppressive effect on F-MEL-differentiated functions than does c-myc and may prevent the expression of those events that can otherwise be dissociated from the terminally differentiated state.
authors.affiliation: University of Michigan, Ann Arbor 48109.
authors.forename: E V
authors.initials: EV
authors.lastname: Prochownik
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D002454:Cell Differentiation / Q000187:drug effects; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004920:Erythropoiesis; D005786:Gene Expression Regulation / Q000187:drug effects; D005914:Globins / Q000235:genetics; D006418:Heme / Q000031:analogs & derivatives*; D006427:Hemin / Q000494:pharmacology*; D006454:Hemoglobins / Q000235:genetics*; D004915:Leukemia, Erythroblastic, Acute / Q000473:pathology; D051379:Mice; D011518:Proto-Oncogene Proteins / Q000502:physiology*; D020598:Proto-Oncogene Proteins c-myb; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger / Q000235:genetics; D014407:Tumor Cells, Cultured
chemical_list: D006454:Hemoglobins; D011518:Proto-Oncogene Proteins; D020598:Proto-Oncogene Proteins c-myb; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D006418:Heme; D006427:Hemin; D005914:Globins; D004121:Dimethyl Sulfoxide