title: ROS-generating NADPH oxidase NOX4 is a critical mediator in oncogenic H-Ras-induced DNA damage and subsequent senescence.
abstract: Activated Ras oncogene induces DNA-damage response by triggering reactive oxygen species (ROS) production and this is critical for oncogene-induced senescence. Until now, little connections between oncogene expression, ROS-generating NADPH oxidases and DNA-damage response have emerged from different studies. Here we report that H-RasV12 positively regulates the NADPH oxidase system NOX4-p22(phox) that produces H(2)O(2). Knocking down the NADPH oxidase with small interference RNA decreases H-RasV12-induced DNA-damage response detected by γ-H2A.X foci analysis. Using HyPer, a specific probe for H(2)O(2), we detected an increase in H(2)O(2) in the nucleus correlated with NOX4-p22(phox) perinuclear localization. DNA damage response can be caused not only by H-RasV12-driven accumulation of ROS but also by a replicative stress due to a sustained oncogenic signal. Interestingly, NOX4 downregulation by siRNA abrogated H-RasV12 regulation of CDC6 expression, an essential regulator of DNA replication. Moreover, senescence markers, such as senescence-associated heterochromatin foci, PML bodies, HP1β foci and p21 expression, induced under H-RasV12 activation were decreased with NOX4 inactivation. Taken together, our data indicate that NADPH oxidase NOX4 is a critical mediator in oncogenic H-RasV12-induced DNA-damage response and subsequent senescence.
authors.affiliation: University Paris-Sud, Orsay, France.
authors.forename: U
authors.initials: U
authors.lastname: Weyemi
authors.forename: O
authors.initials: O
authors.lastname: Lagente-Chevallier
authors.forename: M
authors.initials: M
authors.lastname: Boufraqech
authors.forename: F
authors.initials: F
authors.lastname: Prenois
authors.forename: F
authors.initials: F
authors.lastname: Courtin
authors.forename: B
authors.initials: B
authors.lastname: Caillou
authors.forename: M
authors.initials: M
authors.lastname: Talbot
authors.forename: M
authors.initials: M
authors.lastname: Dardalhon
authors.forename: A
authors.initials: A
authors.lastname: Al Ghuzlan
authors.forename: J-M
authors.initials: JM
authors.lastname: Bidart
authors.forename: M
authors.initials: M
authors.lastname: Schlumberger
authors.forename: C
authors.initials: C
authors.lastname: Dupuy
mesh_terms: D059447:Cell Cycle Checkpoints / Q000235:genetics; D016922:Cellular Senescence / Q000235:genetics*; D000090266:Chromobox Protein Homolog 5; D004249:DNA Damage; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism*; D010084:Oxidation-Reduction; D016283:Proto-Oncogene Proteins p21(ras) / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: C000715593:CBX1 protein, human; D017382:Reactive Oxygen Species; D000090266:Chromobox Protein Homolog 5; D006861:Hydrogen Peroxide; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C498910:NOX4 protein, human; D016283:Proto-Oncogene Proteins p21(ras)