title: Nox1 downstream of 12-lipoxygenase controls cell proliferation but not cell spreading of colon cancer cells.
abstract: The catalytic subunit of the NADPH oxidase complex, Nox1 (homologue of gp91phox/Nox2), expressed mainly in intestinal epithelial and vascular smooth muscle cells, functions in innate immune defense and cell proliferation. The molecular mechanisms underlying these functions, however, are not completely understood. We measured Nox1-dependent O2- production during cell spreading on Collagen IV (Coll IV) in colon carcinoma cell lines. Knocking down Nox1 by shRNA, we showed that Nox1-dependent O2- production is activated during cell spreading after 4 hr of adhesion on Collagen IV. Nox1 activation during cell spreading relies on Rac1 activation and arachidonic metabolism. Our results showed that manoalide (a secreted phospholipase A2 inhibitor) and cinnamyl-3,4-dihydroxy-alpha-cyanocinnamate (a 12-lipoxygenase inhibitor) inhibit O2- production, cell spreading and cell proliferation in these colonic epithelial cells. 12-Lipoxygenase inhibition of ROS production and cell spreading can be reversed by adding 12-HETE, a 12-lipoxygenase product, supporting the specific effect observed with cinnamyl-3,4-dihydroxy-alpha-cyanocinnamate. In contrast, Nox1 shRNA and DPI (NADPH oxidase inhibitor) weakly affect cell spreading while inhibiting O2- production and cell proliferation. These results suggest that the 12-lipoxygenase pathway is upstream of Nox1 activation and controls cell spreading and proliferation, while Nox1 specifically affects cell proliferation.
authors: CNRS FRE 2737, Cytosquelette et Intégration des Signaux du Microenvironnement Tumoral (CISMET), Aix-Marseille Université, France.
authors: Daniela D
authors: DD
authors: de Carvalho
authors: Amine
authors: A
authors: Sadok
authors: Véronique
authors: V
authors: Bourgarel-Rey
authors: Florence
authors: F
authors: Gattacceca
authors: Claude
authors: C
authors: Penel
authors: Maxime
authors: M
authors: Lehmann
authors: Hervé
authors: H
authors: Kovacic
mesh_terms: D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid / Q000494:pharmacology; D001092:Arachidonate 12-Lipoxygenase / Q000378:metabolism*; D015153:Blotting, Western; D002109:Caffeic Acids / Q000494:pharmacology; D002277:Carcinoma / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D003110:Colonic Neoplasms / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology*; D004789:Enzyme Activation; D006801:Humans; D016859:Lipoxygenase Inhibitors; D000074624:NADPH Oxidase 1; D019255:NADPH Oxidases / Q000378:metabolism*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D064801:Phospholipase A2 Inhibitors; D012313:RNA / Q000302:isolation & purification; D017382:Reactive Oxygen Species / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013729:Terpenes / Q000494:pharmacology
chemical_list: D002109:Caffeic Acids; D016859:Lipoxygenase Inhibitors; D010726:Phosphodiesterase Inhibitors; D064801:Phospholipase A2 Inhibitors; D017382:Reactive Oxygen Species; D013729:Terpenes; C099255:cinnamyl-3,4-dihydroxycyanocinnamate; D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D012313:RNA; C045673:manoalide; D001092:Arachidonate 12-Lipoxygenase; D000074624:NADPH Oxidase 1; D019255:NADPH Oxidases; C402799:NOX1 protein, human