title: Isoenzyme-specific cyclooxygenase inhibitors: a whole cell assay system using the human erythroleukemic cell line HEL and the human monocytic cell line Mono Mac 6.
abstract: NSAIDs inhibit the conversion of arachidonic acid into Prostaglandin G2 and Prostaglandin H2 which is catalyzed by the enzyme cyclooxygenase (COX). Two genetically distinct isoforms have been discovered, COX-1 and COX-2. While COX-1 is thought to account for homeostatic amounts of eicosanoids, COX-2 is induced during inflammation leading to pathologic amounts of eicosanoids. Since NSAIDs inhibit both COX isoforms, antiinflammatory drug research has refocused to discovering COX-2 inhibitors that do not inhibit COX-1. For this purpose, we have developed a whole cell assay system using the human erythroleukemic cell line HEL as a source for COX-1 and the human monocytic cell line Mono Mac 6 as a source for COX-2. Mono Mac 6 cells express high amounts of COX-2 upon stimulation with lipopolysaccharide (LPS) in the absence of any detectable COX-1 protein. On the other hand, we find HEL cells to naturally express COX-1 protein, but not COX-2. Testing of a panel of NSAIDs as well as some COX-2 specific inhibitors showed that this assay system is suitable for identifying compounds that selectively inhibit either COX-1 or COX-2. This test system offers the advantage of assessing COX-1 and COX-2 inhibitors within the human species, within a similar test set-up, and circumvents the need for tedious purification of either platelets or peripheral blood monocytes.
authors.affiliation: Department of Pharmacology, Topcro Pharma Research GmbH, Linz, Austria.
authors.forename: J
authors.initials: J
authors.lastname: Berg
authors.forename: T
authors.initials: T
authors.lastname: Christoph
authors.forename: M
authors.initials: M
authors.lastname: Widerna
authors.forename: A
authors.initials: A
authors.lastname: Bodenteich
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000633:toxicity*; D016718:Arachidonic Acid / Q000494:pharmacology; D015153:Blotting, Western; D002460:Cell Line; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000633:toxicity*; D004591:Electrophoresis, Polyacrylamide Gel; D004790:Enzyme Induction / Q000187:drug effects; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007527:Isoenzymes / Q000096:biosynthesis*; D004915:Leukemia, Erythroblastic, Acute; D008070:Lipopolysaccharides / Q000494:pharmacology; D008565:Membrane Proteins; D009000:Monocytes; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis*; D013929:Thromboxane B2 / Q000032:analysis; D014407:Tumor Cells, Cultured
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D007527:Isoenzymes; D008070:Lipopolysaccharides; D008565:Membrane Proteins; D016718:Arachidonic Acid; D013929:Thromboxane B2; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases