Lack of XPC leads to a shift between respiratory complexes I and II but sensitizes cells to mitochondrial stress.
Sci Rep
; 7(1): 155, 2017 03 13.
Article
em En
| MEDLINE
| ID: mdl-28273955
ABSTRACT
Genomic instability drives tumorigenesis and DNA repair defects are associated with elevated cancer. Metabolic alterations are also observed during tumorigenesis, although a causal relationship between these has not been clearly established. Xeroderma pigmentosum (XP) is a DNA repair disease characterized by early cancer. Cells with reduced expression of the XPC protein display a metabolic shift from OXPHOS to glycolysis, which was linked to accumulation of nuclear DNA damage and oxidants generation via NOX-1. Using XP-C cells, we show that mitochondrial respiratory complex I (CI) is impaired in the absence of XPC, while complex II (CII) is upregulated in XP-C cells. The CI/CII metabolic shift was dependent on XPC, as XPC complementation reverted the phenotype. We demonstrate that mitochondria are the primary source of H2O2 and glutathione peroxidase activity is compromised. Moreover, mtDNA is irreversibly damaged and accumulates deletions. XP-C cells were more sensitive to the mitochondrial inhibitor antimycin A, an effect also prevented in XPC-corrected cells. Our results show that XPC deficiency leads to alterations in mitochondrial redox balance with a CI/CII shift as a possible adaptation to lower CI activity, but at the cost of sensitizing XP-C cells to mitochondrial oxidative stress.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Xeroderma Pigmentoso
/
Complexo I de Transporte de Elétrons
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Complexo II de Transporte de Elétrons
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Proteínas de Ligação a DNA
/
Mitocôndrias
Limite:
Humans
Idioma:
En
Revista:
Sci Rep
Ano de publicação:
2017
Tipo de documento:
Article