Differentiation of mouse erythroleukemia cells is blocked by late up-regulation of a c-myb transgene.

AUTOR(ES)

McClinton, D

RESUMO

During chemically induced differentiation of Friend virus-infected mouse erythroleukemia (MEL) cell lines, there is a biphasic down-regulation of the c-myb proto-oncogene. A plasmid containing a murine c-myb cDNA controlled by a mouse metallothionein I promoter was transfected into the C19 MEL cell line. For six transfected clones, it was found that expression of the exogenous c-myb mRNA could be up-regulated by the addition of 120 microM ZnCl2 and that the N,N'-hexamethylenebisacetamide-induced differentiation of these transfectants was inhibited in proportion to the level of exogenous c-myb mRNA expression. By adding or removing ZnCl2 at different times during the induction process, it was possible to show that up-regulation of exogenous c-myb limited to the first 2 days of induction had little or no effect on differentiation. In contrast, continuous expression of exogenous c-myb beginning at any time during the period of induction blocked further differentiation. These results suggest that during HMBA induction of MEL cells, the early down-regulation of c-myb mRNA is not necessary for terminal differentiation, whereas the down-regulation of c-myb at a later time is necessary.

Documentos Relacionados

• Constitutive expression of a c-myb cDNA blocks Friend murine erythroleukemia cell differentiation.
• Down-regulation of c-myb gene expression is a prerequisite for erythropoietin-induced erythroid differentiation.
• Regulation of c-myb expression in human neuroblastoma cells during retinoic acid-induced differentiation.
• Developmental regulation of c-myb in normal myeloid progenitor cells.
• Developmental regulation of c-myb in normal myeloid progenitor cells