title: Nox1-dependent superoxide production controls colon adenocarcinoma cell migration.
abstract: Reactive oxygen species are well-known mediators of various biological responses. Recently, new homologues of the catalytic subunit of NADPH oxidase have been discovered in non-phagocytic cells. These new homologues (Nox1-Nox5) produce low levels of superoxides compared to the phagocytic homologue Nox2/gp91phox. Using Nox1 siRNA, we show that Nox1-dependent superoxide production affects the migration of HT29-D4 colonic adenocarcinoma cells on collagen-I. Nox1 inhibition or down-regulation led to a decrease of superoxide production and alpha 2 beta 1 integrin membrane availability. An addition of arachidonic acid stimulated Nox1-dependent superoxide production and HT29-D4 cell migration. Pharmacological evidences using phospholipase A2, lipoxygenases and protein kinase C inhibitors show that upstream regulation of Nox1 relies on arachidonic acid metabolism. Inhibition of 12-lipoxygenase decreased basal and arachidonic acid induced Nox1-dependent superoxide production and cell migration. Migration and ROS production inhibited by a 12-lipoxygenase inhibitor were restored by the addition of 12(S)-HETE, a downstream product of 12-lipoxygenase. Protein kinase C delta inhibition by rottlerin (and also GO6983) prevented Nox1-dependent superoxide production and inhibited cell migration, while other protein kinase C inhibitors were ineffective. We conclude that Nox1 activation by arachidonic acid metabolism occurs through 12-lipoxygenase and protein kinase C delta, and controls cell migration by affecting integrin alpha 2 subunit turn-over.
authors.affiliation: CNRS FRE 2737, Cytosquelette et Intégration des Signaux du Microenvironnement Tumoral, Aix-Marseille Université, France.
authors.forename: Amine
authors.initials: A
authors.lastname: Sadok
authors.forename: Véronique
authors.initials: V
authors.lastname: Bourgarel-Rey
authors.forename: Florence
authors.initials: F
authors.lastname: Gattacceca
authors.forename: Claude
authors.initials: C
authors.lastname: Penel
authors.forename: Maxime
authors.initials: M
authors.lastname: Lehmann
authors.forename: Hervé
authors.initials: H
authors.lastname: Kovacic
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology*; D001092:Arachidonate 12-Lipoxygenase / Q000378:metabolism; D001095:Arachidonic Acids / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D002465:Cell Movement / Q000187:drug effects; D003110:Colonic Neoplasms / Q000378:metabolism* / Q000473:pathology*; D019073:HT29 Cells; D006801:Humans; D038982:Integrin alpha2beta1 / Q000378:metabolism; D000074624:NADPH Oxidase 1; D019255:NADPH Oxidases / Q000378:metabolism*; D051745:Protein Kinase C-delta / Q000378:metabolism; D013481:Superoxides / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D001095:Arachidonic Acids; D038982:Integrin alpha2beta1; D013481:Superoxides; D001092:Arachidonate 12-Lipoxygenase; D000074624:NADPH Oxidase 1; D019255:NADPH Oxidases; C402799:NOX1 protein, human; D051745:Protein Kinase C-delta