title: Retinoic acid activates interferon regulatory factor-1 gene expression in myeloid cells.
abstract: All-trans-retinoic acid (ATRA) is the drug of choice in the treatment of acute promyelocytic leukemia (APL). ATRA induces both in vitro and in vivo differentiation of APL cells into mature granulocytes. However, the molecular mechanisms involved in ATRA-dependent growth inhibition and cellular differentiation are not presently understood. The NB4 cell line, which is derived from the bone marrow of a patient with APL during relapse, can be used as a model system to study the growth and differentiation of APL cells. Because interferon (IFN) regulatory factors (IRF-1 and IRF-2) and other IFN-inducible gene products regulate cell growth, we analyzed the effects of ATRA on the expression of these genes. We show that ATRA directly activates IRF-1 gene expression, followed by activation of IRF-2 and 2'-5' oligoadenylate synthetase (OAS) gene expression with slower kinetics. In addition to NB4 cells, ATRA also activated IRF-1 gene expression in HL-60, U937, and THP-1 cells, which all respond to ATRA by growth inhibition. A more than additive increase in IRF-1 gene expression was seen with ATRA and IFN-gamma in NB4 cells. ATRA did not activate nuclear factor kappa B or signal transducer and activator of transcription (STAT) activation pathways, suggesting that an alternate mechanism is involved in IRF-1 gene activation. The ATRA-induced expression of IRF-1, an activator of transcription and repressor of transformation, may be one of the molecular mechanisms of ATRA-induced growth inhibition, and the basis for the synergistic actions of ATRA and IFNs in myeloid leukemia cells.
authors.affiliation: Molecular Biology Programme, National Public Health Institute, Helsinki, Finland.
authors.forename: S
authors.initials: S
authors.lastname: Matikainen
authors.forename: T
authors.initials: T
authors.lastname: Ronni
authors.forename: M
authors.initials: M
authors.lastname: Hurme
authors.forename: R
authors.initials: R
authors.lastname: Pine
authors.forename: I
authors.initials: I
authors.lastname: Julkunen
mesh_terms: D015088:2',5'-Oligoadenylate Synthetase / Q000096:biosynthesis; D001483:Base Sequence; D002454:Cell Differentiation; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D004357:Drug Synergism; D004790:Enzyme Induction; D005786:Gene Expression Regulation; D018922:HL-60 Cells / Q000187:drug effects; D006801:Humans; D050856:Interferon Regulatory Factor-1; D050836:Interferon Regulatory Factor-2; D007371:Interferon-gamma / Q000494:pharmacology; D007948:Leukemia, Monocytic, Acute / Q000473:pathology; D016403:Lymphoma, Large B-Cell, Diffuse / Q000473:pathology; D008264:Macrophages / Q000187:drug effects* / Q000201:enzymology; D008969:Molecular Sequence Data; D009000:Monocytes / Q000187:drug effects* / Q000201:enzymology; D016328:NF-kappa B / Q000378:metabolism; D010750:Phosphoproteins / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D012097:Repressor Proteins; D050796:STAT3 Transcription Factor; D015398:Signal Transduction; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D004268:DNA-Binding Proteins; C494257:IRF1 protein, human; C494229:IRF2 protein, human; D050856:Interferon Regulatory Factor-1; D050836:Interferon Regulatory Factor-2; D016328:NF-kappa B; D010750:Phosphoproteins; D012333:RNA, Messenger; D012097:Repressor Proteins; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D015534:Trans-Activators; D014157:Transcription Factors; D014212:Tretinoin; D007371:Interferon-gamma; D004247:DNA; D015088:2',5'-Oligoadenylate Synthetase