title: Expression and regulation of the mu opioid peptide receptor in TPA-differentiated HL-60 promyelocytic leukemia cells.
abstract: Cellular differentiation of immune cells involves an array of molecular events responsible for their commitment to cellular maturation. Treatment of HL-60 promyelocytic leukemia cells with 12-o-tetradecanoyl-phorbol-13-acetate (TPA) induces the cells to differentiate into monocyte/macrophage-like cells. In this study, following TPA treatment, there was a significant increase in mu opioid peptide receptor (MOPR) mRNA levels in the differentiated HL-60 cells as measured by quantitative-competitive RT-PCR (QC-RT-PCR) and real-time RT-PCR. Morphine's inhibition of forskolin-induced intracellular cAMP confirmed the functionality of the MOPR. TPA-induced differentiation also significantly enhanced the binding activities of two transcriptional factors, AP-1 and NFkB. Prolonged treatment of the TPA-differentiated HL-60 cells with morphine down-regulated MOPR mRNA expression and decreased the binding activities of AP-1 and NFkB, both of which were naloxone reversible. Thus, the direct correlation between AP-1 and NFkB binding activities and MOPR expression in HL-60 cells following TPA-induced differentiation as well as in TPA-differentiated HL-60 cells given prolonged treatment with morphine suggests that transcriptional factors, such as AP-1 and NFkB, may play a role in the molecular mechanisms underlying regulation of MOPR expression in immune cells.
authors.affiliation: Department of Biology, Seton Hall University, McNulty Hall, Room 215, South Orange, NJ 07079, USA.
authors.forename: Jose A
authors.initials: JA
authors.lastname: Beltran
authors.forename: Jennifer
authors.initials: J
authors.lastname: Peek
authors.forename: Sulie L
authors.initials: SL
authors.lastname: Chang
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D015973:Gene Expression Regulation, Leukemic / Q000187:drug effects*; D018922:HL-60 Cells; D006801:Humans; D009020:Morphine / Q000494:pharmacology; D016328:NF-kappa B / Q000378:metabolism; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017450:Receptors, Opioid, mu / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D018808:Transcription Factor AP-1 / Q000378:metabolism
chemical_list: D000701:Analgesics, Opioid; D016328:NF-kappa B; D009292:Narcotic Antagonists; D012333:RNA, Messenger; D017450:Receptors, Opioid, mu; D018808:Transcription Factor AP-1; D005576:Colforsin; D009270:Naloxone; D009020:Morphine; D000242:Cyclic AMP; D013755:Tetradecanoylphorbol Acetate