title: Granulocyte-macrophage colony-stimulating factor, phorbol ester, and sodium butyrate induce the CD11c integrin gene promoter activity during myeloid cell differentiation.
abstract: To analyze the activity of the CD11c promoter during myeloid differentiation without the limitations of transient expression systems, we have stably transfected the myeloid U937 cell line with the pCD11C361-Luc plasmid, in which the expression of the firefly luciferase cDNA is driven by the CD11c promoter region -361/+43, previously shown to confer myeloid specificity to reporter genes. The stable transfectants (U937-C361) retained the ability to differentiate in response to phorbol-ester (PMA), sodium butyrate (SB), granulocyte-macrophage colony-stimulating factor (GM-CSF), and other differentiating agents. U937-C361 differentiation correlated with increased cellular luciferase levels, showing the inducibility of the CD11c promoter during myeloid differentiation and establishing the U937-C361 cells as a suitable system for studying the myeloid differentiation-inducing capacity of cytokines, growth, factors, and other biological response modifiers. Unexpectedly, the inducibility of the CD11c gene promoter showed distinct kinetics and magnitude on the PMA-, SB-, GM-CSF-triggered differentiation. Moreover, SB synergized with either PMA or GM-CSF in enhancing both the CD11c promoter activity and the cell surface expression of p150,95 on differentiating U937 cells. Furthermore, we showed the existence of a c-Myb-binding site at -85, the importance of the -99/-61 region in the CD11c promoter inducibility during PMA- or SB-triggered differentiation, and the dependency of the GM-CSF and PMA responsiveness of the CD11c promoter on an intact AP-1-binding site located at -60. These results, together with the lack of functional effect of mutations disrupting the Sp1-and Myb-binding sites within the proximal region of the CD11c promoter, indicate that the myeloid differentiation pathways indicated by SB and phorbol esters (or GM-CSF) activate a distinct set of transcription factors and show that the myeloid differentiation-inducibility of the CD11c gene maps to the -99/-53 proximal region of the promoter.
authors.affiliation: Hospital de la Princesa, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.
authors.forename: M A
authors.initials: MA
authors.lastname: Rubio
authors.forename: C
authors.initials: C
authors.lastname: Lopez-Rodriguez
authors.forename: A
authors.initials: A
authors.lastname: Nueda
authors.forename: P
authors.initials: P
authors.lastname: Aller
authors.forename: A L
authors.initials: AL
authors.lastname: Armesilla
authors.forename: M A
authors.initials: MA
authors.lastname: Vega
authors.forename: A L
authors.initials: AL
authors.lastname: Corbí
mesh_terms: D001483:Base Sequence; D002087:Butyrates / Q000494:pharmacology*; D020148:Butyric Acid; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000235:genetics; D004357:Drug Synergism; D005786:Gene Expression Regulation / Q000187:drug effects*; D017930:Genes, Reporter; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D006412:Hematopoietic Stem Cells / Q000187:drug effects* / Q000378:metabolism; D016167:Integrin alphaXbeta2 / Q000096:biosynthesis / Q000235:genetics*; D008156:Luciferases / Q000096:biosynthesis; D016403:Lymphoma, Large B-Cell, Diffuse / Q000473:pathology; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000187:drug effects*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D002087:Butyrates; D016167:Integrin alphaXbeta2; D011993:Recombinant Fusion Proteins; D020148:Butyric Acid; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D008156:Luciferases; D013755:Tetradecanoylphorbol Acetate