title: Deregulated expression of c-myc by murine erythroleukaemia cells prevents differentiation.
abstract: Friend murine erythroleukaemia (F-MEL) cells are a permanent line of primitive erythroid precursors originally derived from the spleens of mice infected with the Friend strain of murine leukaemia virus. F-MEL cells differentiate in vitro in response to various chemical inducers. Concomitantly with induction, a biphasic regulation of c-myc oncogene transcripts is observed. Within one hour of the addition of dimethyl sulphoxide (DMSO) or hypoxanthine (Hyp), the levels of c-myc transcripts fall dramatically and remain virtually undetectable for the next few hours. Between 8 and 24 hours after induction, c-myc transcripts return to pre-induction levels and then decline again between 3 and 5 days as most of the cells undergo terminal differentiation. To explore the potential relationship between c-myc expression and F-MEL terminal differentiation, we have investigated here whether reversing the early fluctuations in c-myc transcript levels affects the ability of F-MEL cells to differentiate. We therefore constructed an amplifiable plasmid vector containing a full-length mouse c-myc complementary DNA and introduced it stably into recipient F-MEL cells. The exogenous c-myc sequences are transcribed in F-MEL cells and the transcript levels do not change significantly in response to inducing agents. The net result is continued c-myc expression following DMSO or Hyp induction and a complete or partial inhibition of F-MEL differentiation.
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D005622:Friend murine leukemia virus; D005786:Gene Expression Regulation / Q000187:drug effects; D004915:Leukemia, Erythroblastic, Acute / Q000235:genetics*; D051379:Mice; D009857:Oncogenes; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis* / Q000235:genetics; D016271:Proto-Oncogene Proteins c-myc; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D014162:Transfection
chemical_list: D011518:Proto-Oncogene Proteins; D016271:Proto-Oncogene Proteins c-myc; D011994:Recombinant Proteins; D004121:Dimethyl Sulfoxide