title: Redox modulation of FAK controls melanoma survival--role of NOX4.
abstract: Studies have demonstrated that reactive oxygen species (ROS) generated by NADPH oxidase are essential for melanoma proliferation and survival. However, the mechanisms by which NADPH oxidase regulates these effects are still unclear. In this work, we investigate the role of NADPH oxidase-derived ROS in the signaling events that coordinate melanoma cell survival. Using the highly metastatic human melanoma cell line MV3, we observed that pharmacological NADPH oxidase inhibition reduced melanoma viability and induced dramatic cellular shape changes. These effects were accompanied by actin cytoskeleton rearrangement, diminished FAKY397 phosphorylation, and decrease of FAK-actin and FAK-cSrc association, indicating disassembly of focal adhesion processes, a phenomenon that often results in anoikis. Accordingly, NADPH oxidase inhibition also enhanced hypodiploid DNA content, and caspase-3 activation, suggesting activation of the apoptotic machinery. NOX4 is likely to be involved in these effects, since silencing of NOX4 significantly inhibited basal ROS production, reduced FAKY397 phosphorylation and decreased tumor cell viability. Altogether, the results suggest that intracellular ROS generated by the NADPH oxidase, most likely NOX4, transmits cell survival signals on melanoma cells through the FAK pathway, maintaining adhesion contacts and cell viability.
authors.affiliation: Laboratory of Cellular and Molecular Pharmacology, Department of Cell Biology, IBRAG, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Cristiane
authors.initials: C
authors.lastname: Ribeiro-Pereira
authors.affiliation: Laboratory of Cellular and Molecular Pharmacology, Department of Cell Biology, IBRAG, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: João Alfredo
authors.initials: JA
authors.lastname: Moraes
authors.affiliation: Laboratory of Cellular and Molecular Pharmacology, Department of Cell Biology, IBRAG, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Mariele de Jesus
authors.initials: Mde J
authors.lastname: Souza
authors.affiliation: Laboratory of Vascular Biology, Instituto do Coração, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Francisco R
authors.initials: FR
authors.lastname: Laurindo
authors.affiliation: Laboratory of Cellular and Molecular Pharmacology, Department of Cell Biology, IBRAG, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Vice-Diretoria de Ensino, Pesquisa e Inovação, Farmanguinhos, Fiocruz, Rio de Janeiro, RJ, Brazil.
authors.forename: Maria Augusta
authors.initials: MA
authors.lastname: Arruda
authors.affiliation: Laboratory of Cellular and Molecular Pharmacology, Department of Cell Biology, IBRAG, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Christina
authors.initials: C
authors.lastname: Barja-Fidalgo
mesh_terms: D000199:Actins / Q000378:metabolism; D017209:Apoptosis; D000081247:CSK Tyrosine-Protein Kinase; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D002470:Cell Survival; D004789:Enzyme Activation; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism*; D020868:Gene Silencing; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D008545:Melanoma / Q000378:metabolism* / Q000401:mortality*; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism; D010084:Oxidation-Reduction; D010766:Phosphorylation; D017382:Reactive Oxygen Species / Q000378:metabolism; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: D000199:Actins; D017382:Reactive Oxygen Species; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C498910:NOX4 protein, human; D000081247:CSK Tyrosine-Protein Kinase; D051416:Focal Adhesion Protein-Tyrosine Kinases; D019061:src-Family Kinases; C000631346:CSK protein, human