Myeloblastin is an Myb target gene: mechanisms of regulation in myeloid leukemia cells growth-arrested by retinoic acid.
A pivotal role has been assigned to Myb in the control of myeloid cell growth. Although Myb is a target of retinoic acid, little is known about the mechanisms by which it may contribute to induced growth arrest in leukemia cells. Indeed, few Myb target genes are known to be linked to proliferation. Myeloblastin is involved in the control of proliferation in myeloid leukemia cells. It is expressed early during hematopoiesis and is a granulocyte colony-stimulating factor-responsive gene. Myeloblastin can confer factor-independent growth to hematopoietic cells, an early step in leukemia transformation. The myeloblastin promoter contains PU.1, C/EBP, and Myb binding sites, each of which are critical for constitutive expression in myeloid cells. Inhibition of myeloblastin expression in leukemia cells growth-arrested by retinoic acid is demonstrated to depend on Myb down-regulation. Myb is shown to induce myeloblastin expression and abolish its down-regulation by retinoic acid. Altogether, the data offer a clue as to how a myeloid-specific transcriptional machinery can be accessible to regulation by retinoic acid and point to myeloblastin as a novel target of Myb. This link between Myb and myeloblastin suggests a previously nonidentified Myb pathway through which growth arrest is induced by retinoic acid in myeloid leukemia cells.
Lutz
P G
PG
Unité INSERM U417, Hôpital Saint Antoine, Paris, France.
Houzel-Charavel
A
A
Moog-Lutz
C
C
Cayre
Y E
YE
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001483:Base Sequence; D001665:Binding Sites; D022763:CCAAT-Enhancer-Binding Protein-alpha / Q000378:metabolism; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000378:metabolism; D051743:CCAAT-Enhancer-Binding Protein-delta; D022762:CCAAT-Enhancer-Binding Proteins / Q000378:metabolism; D019556:COS Cells; D002455:Cell Division / Q000187:drug effects; D002522:Chlorocebus aethiops; D015973:Gene Expression Regulation, Leukemic / Q000187:drug effects*; D020570:Genes, myb; D008969:Molecular Sequence Data; D053146:Myeloblastin; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D020598:Proto-Oncogene Proteins c-myb / Q000096:biosynthesis / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017384:Sequence Deletion; D012697:Serine Endopeptidases / Q000235:genetics*; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors; D014158:Transcription, Genetic; D014162:Transfection; D014212:Tretinoin / Q000494:pharmacology*; D000099232:Proto-Oncogene Protein Spi-1
D000970:Antineoplastic Agents; D022763:CCAAT-Enhancer-Binding Protein-alpha; D022782:CCAAT-Enhancer-Binding Protein-beta; D051743:CCAAT-Enhancer-Binding Protein-delta; D022762:CCAAT-Enhancer-Binding Proteins; D053146:Myeloblastin; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D020598:Proto-Oncogene Proteins c-myb; D011993:Recombinant Fusion Proteins; D012697:Serine Endopeptidases; D015534:Trans-Activators; D014157:Transcription Factors; D014212:Tretinoin; D000099232:Proto-Oncogene Protein Spi-1