Stage-related proliferative activity determines c-myb functional requirements during normal human hematopoiesis.
To determine if MYB protein is preferentially required during specific stages of normal human hematopoiesis we incubated normal marrow mononuclear cells (MNC) with c-myb antisense oligodeoxynucleotides. Treated cells were cultured in semisolid medium under conditions designed to favor the growth of specific progenitor cell types. Compared with untreated controls, granulocyte-macrophage (GM) CFU-derived colonies decreased 77% when driven by recombinant human (rH) IL-3, and 85% when stimulated by rH GM colony-stimulating factor (CSF); erythroid burst-forming unit (BFU-E)- and CFU-E-derived colonies decreased 48 and 78%, respectively. In contrast, numbers of G-CSF-stimulated granulocyte colonies derived from antisense treated MNC were unchanged from controls, though the numbers of cells composing these colonies decreased approximately 90%. Similar results were obtained when MY10+ cells were exposed to c-myb antisense oligomers. When compared with untreated controls, numbers of CFU-GM and BFU-E colonies derived from MY10+ cells were unchanged, but the numbers of cells composing these colonies were reduced approximately 75 and greater than 90%, respectively, in comparison with controls. c-myc sense and antisense oligomers were without significant effect in these assays. Using the reverse transcription-polymerase chain reaction, c-myb mRNA was detected in developing hematopoietic cells on days 0-8. At day 14 c-myb expression was no longer detectable using this technique. These results suggest that c-myb is required for proliferation of intermediate-late myeloid and erythroid progenitors, but is less important for lineage commitment and early progenitor cell amplification.
Istituto di Medicina ed Oncologia Sperimentale, Sezione di Ematologia, Torino, Italy.
D
D
Caracciolo
D
D
Venturelli
M
M
Valtieri
C
C
Peschle
A M
AM
Gewirtz
B
B
Calabretta
D001483:Base Sequence; D002455:Cell Division; D003114:Colony-Forming Units Assay; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D016133:Polymerase Chain Reaction; D011505:Protein-Tyrosine Kinases / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000502:physiology*; D020598:Proto-Oncogene Proteins c-myb; D011519:Proto-Oncogenes; D012333:RNA, Messenger / Q000032:analysis; D012016:Reference Values; D014158:Transcription, Genetic
D015345:Oligonucleotide Probes; D011518:Proto-Oncogene Proteins; D020598:Proto-Oncogene Proteins c-myb; D012333:RNA, Messenger; D011505:Protein-Tyrosine Kinases