title: Effect of taxol and taxotere on gene expression in macrophages: induction of the prostaglandin H synthase-2 isoenzyme.
abstract: Induction of genes encoding cytokines or other, unidentified proteins may contribute to the pharmacological effects of taxol. We hypothesized that prostaglandin H synthase-2 (PGHS-2) was one of the unidentified genes induced by taxol. Taxol alone or taxol plus IFN-gamma increased PGE2 formation, PGHS-2 protein expression, and PGHS-2 mRNA expression in RAW 264.7 murine macrophages. The kinetics for mRNA induction, protein expression, and catalysis were self-consistent. A selective inhibitor of PGHS-2 blocked PGE2 formation by cells incubated with taxol; a selective inhibitor of PGHS-1 had no effect. A glucocorticoid blocked the induction of mRNA, the expression of PGHS-2 protein, and the formation of PGE2. Neither taxol alone nor taxol plus IFN-gamma altered the expression of the PGHS-1 isoenzyme in RAW 264.7 cells. Taxotere, an analogue that stabilizes microtubules as potently as taxol, did not alter the expression of PGHS-2, implying that its induction in RAW 264.7 murine macrophages did not originate from microtubule stabilization. Taxol and taxotere each induced PGHS-2 expression in human monocytes suspended in 10% human serum. However, human monocytes suspended in 10% bovine serum responded only to LPS, not to taxol or taxotere, implying that they act independently of the LPS-mimetic process that is prominent in mice. Taxol induced PGHS-2 in human and murine monocytes via a p38 mitogen-associated protein kinase pathway. The inclusion of PGHS-2 among the early response genes induced in leukocytes may be relevant to the beneficial and adverse effects encountered during taxol administration.
authors.affiliation: Department of Oncological Sciences, Huntsman Cancer Institute, Salt Lake City, UT 84108, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Moos
authors.forename: D T
authors.initials: DT
authors.lastname: Muskardin
authors.forename: F A
authors.initials: FA
authors.lastname: Fitzpatrick
mesh_terms: D000818:Animals; D002460:Cell Line; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D000077143:Docetaxel; D004357:Drug Synergism; D004789:Enzyme Activation / Q000187:drug effects / Q000276:immunology; D004790:Enzyme Induction / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000276:immunology; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D007527:Isoenzymes / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D008264:Macrophages / Q000187:drug effects* / Q000201:enzymology* / Q000378:metabolism; D008565:Membrane Proteins; D051379:Mice; D009000:Monocytes / Q000187:drug effects / Q000201:enzymology; D019001:Nitric Oxide Synthase / Q000378:metabolism; D017239:Paclitaxel / Q000031:analogs & derivatives* / Q000494:pharmacology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D012260:Ribonucleases / Q000378:metabolism; D043823:Taxoids
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D007527:Isoenzymes; D008565:Membrane Proteins; D012333:RNA, Messenger; D043823:Taxoids; D000077143:Docetaxel; D007371:Interferon-gamma; D019001:Nitric Oxide Synthase; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D012260:Ribonucleases; D017239:Paclitaxel