title: Activation of matrix metalloproteinase-2 by overexpression of manganese superoxide dismutase in human breast cancer MCF-7 cells involves reactive oxygen species.
abstract: Matrix metalloproteinases (MMPs) participate in cell migration and remodeling processes by affecting the extracellular matrix. MMP-2 is thought to be involved in cancer cell invasiveness. It has been proposed that the activity of MMP-2 can be modulated by intracellular reactive oxygen species (ROS)/reactive nitrogen species. We hypothesized that manganese superoxide dismutase (MnSOD) could mediate MMP-2 activity by changing the intracellular ROS level and that nitric oxide ((.)NO) may be involved in this process. Human breast cancer MCF-7 cells were stably transfected with plasmids containing MnSOD cDNA. A 2-30-fold increase of MnSOD protein and activity was observed in four clones. Our data demonstrated that overexpression of MnSOD stimulated the activation of MMP-2 with a corresponding elevation of ROS. A decrease in ROS by ebselen, a glutathione peroxidase mimetic, or by transduction of adenovirus containing human catalase or glutathione peroxidase cDNA abolished the effect of MnSOD on MMP-2 activation. Treatment of MCF-7 cells with antimycin A or rotenone increased intracellular ROS production and MMP-2 activation simultaneously. Our data also showed a suppression of endothelial nitric-oxide synthase expression that was accompanied by decreased (.)NO production in MnSOD-overexpressing cells. However, the changes in endothelial nitric-oxide synthase and (.)NO did not correlate with the MnSOD activity. Corresponding changes of MMP-2 activity after the addition of a NOS inhibitor (N(G)-amino-l-arginine) or a (.)NO donor ((Z)-1-[(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate) to the cells suggested the possibility that (.)NO may be involved in the MnSOD-mediated MMP-2 activation pathway. These results indicate that MnSOD induces MMP-2 activity by regulation of intracellular ROS and imply that signaling pathways involving (.)NO may also be involved in the MnSOD mediation of MMP-2 activity.
authors.affiliation: Department of Exercise Science and Free Radical and Radiation Biology Program, Department of Radiation Oncology, University of Iowa, Iowa City, Iowa 52242, USA.
authors.forename: Hannah J
authors.initials: HJ
authors.lastname: Zhang
authors.forename: Weiling
authors.initials: W
authors.lastname: Zhao
authors.forename: Sujatha
authors.initials: S
authors.lastname: Venkataraman
authors.forename: Michael E C
authors.initials: ME
authors.lastname: Robbins
authors.forename: Garry R
authors.initials: GR
authors.lastname: Buettner
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Kregel
authors.forename: Larry W
authors.initials: LW
authors.lastname: Oberley
mesh_terms: D001943:Breast Neoplasms / Q000201:enzymology* / Q000473:pathology; D004789:Enzyme Activation; D006801:Humans; D009569:Nitric Oxide / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D013482:Superoxide Dismutase