Redox modulation of FAK controls melanoma survival--role of NOX4

PLoS One. 2014 Jun 9;9(6):e99481. doi: 10.1371/journal.pone.0099481. eCollection 2014.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • Apoptosis
  • CSK Tyrosine-Protein Kinase
  • Cell Adhesion
  • Cell Line, Tumor
  • Cell Survival
  • Enzyme Activation
  • Focal Adhesion Protein-Tyrosine Kinases / metabolism*
  • Gene Silencing
  • Humans
  • Intracellular Space / metabolism
  • Melanoma / metabolism*
  • Melanoma / mortality*
  • NADPH Oxidase 4
  • NADPH Oxidases / genetics
  • NADPH Oxidases / metabolism
  • Oxidation-Reduction*
  • Phosphorylation
  • Reactive Oxygen Species / metabolism
  • src-Family Kinases / metabolism

Substances

  • Actins
  • Reactive Oxygen Species
  • NADPH Oxidase 4
  • NADPH Oxidases
  • NOX4 protein, human
  • CSK Tyrosine-Protein Kinase
  • Focal Adhesion Protein-Tyrosine Kinases
  • src-Family Kinases
  • CSK protein, human

Grants and funding

This work was supported by CNPq (www.cnpq.br), CAPES (www.capes.gov.br), FAPERJ (www.faperj.br) and Sub-reitoria de Pós-Graduação e Pesquisa (SR-2/UERJ - www.sr2.uerj.br). M.A. Arruda is a L′Oréal-UNESCO-ABC For Women In Science National Fellowship – 2008 awardee. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.