Overexpression of human NOX1 complex induces genome instability in mammalian cells

Federica Chiera, Ettore Meccia, Paolo Degan, Gabriele Aquilina, Donatella Pietraforte, Maurizio Minetti, David Lambeth, Margherita Bignami

Research output: Contribution to journalArticlepeer-review


The production of reactive oxygen species (ROS) in mammalian cells is tightly regulated because of their potential to damage macromolecules, including DNA. To investigate possible links between high ROS levels, oxidative DNA damage, and genomic instability in mammalian cells, we established a novel model of chronic oxidative stress by coexpressing the NADPH oxidase human (h) NOX1 gene together with its cofactors NOXO1 and NOXA1. Transfectants of mismatch repair (MMR)-proficient HeLa cells or MMR-defective Msh2-/- mouse embryo fibroblasts overexpressing the hNOX1 complex displayed increased intracellular ROS levels. In one HeLa clone in which ROS were particularly elevated, reactive nitrogen species were also increased and nitrated proteins were identified with an anti-3-nitrotyrosine antibody. Overexpression of the hNOX1 complex increased the steady-state levels of DNA 8-oxo-7,8-dihydroguanine and caused a threefold increase in the HPRT mutation rate in HeLa cells. In contrast, additional oxidatively generated damage did not affect the constitutive mutator phenotype of the Msh2-/- fibroblasts. Because no significant changes in the expression of several DNA repair enzymes for oxidative DNA damage were identified, we suggest that chronic oxidative stress can saturate the cell's DNA repair capacity and cause significant genomic instability.

Original languageEnglish
Pages (from-to)332-342
Number of pages11
JournalFree Radical Biology and Medicine
Issue number3
Publication statusPublished - Feb 1 2008


  • 8-OxoGua
  • DNA repair
  • Free radicals
  • Genetic instability
  • hNOX1
  • Reactive oxygen species

ASJC Scopus subject areas

  • Clinical Biochemistry
  • Medicine(all)
  • Toxicology


Dive into the research topics of 'Overexpression of human NOX1 complex induces genome instability in mammalian cells'. Together they form a unique fingerprint.

Cite this