Growth regulated expression of B-myb in fibroblasts and hematopoietic cells

J Cell Physiol. 1991 Sep;148(3):338-43. doi: 10.1002/jcp.1041480303.


The B-myb cDNA has extensive sequence similarities to the c-myb proto-oncogene, but, at variance with c-myb, it is expressed in cells other than hematopoietic cells. In this paper, we show that (1) B-myb is expressed in mouse, human, and hamster fibroblasts; (2) B-myb mRNA levels are growth-regulated in both fibroblasts and peripheral blood mononuclear cells; (3) by its mode of growth regulation (peak of expression, behavior in G1-specific temperature sensitive (ts) mutants and in the presence of cycloheximide), B-myb can be classified, like c-myb, thymidine kinase, PCNA, and others, as a late growth-regulated gene; (4) B-myb mRNA levels decrease when HL-60 cells are induced to differentiate; and (5) the increase in mRNA levels in serum-stimulated cells is only partially explained by an increase in rate of transcription. The possibility that the B-myb gene may be the equivalent in fibroblasts and epithelial cells of the c-myb proto-oncogene of hematopoietic cells is discussed.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cell Cycle*
  • Cell Differentiation
  • Cell Division*
  • Cell Line
  • Fibroblasts / cytology
  • Fibroblasts / physiology
  • Gene Expression Regulation
  • Gene Expression Regulation, Neoplastic
  • Hematopoietic Stem Cells / cytology
  • Hematopoietic Stem Cells / physiology*
  • Humans
  • Lymphocytes / physiology
  • Oncogenes*
  • Plasmids
  • RNA / genetics
  • RNA / isolation & purification
  • RNA, Messenger / genetics
  • Transcription, Genetic*


  • RNA, Messenger
  • RNA