Can vitamin C induce nucleotide excision repair? Support from in vitro evidence

Br J Nutr. 2010 Mar;103(5):686-95. doi: 10.1017/S0007114509992285. Epub 2009 Dec 10.

Abstract

Intracellular vitamin C acts to protect cells against oxidative stress by intercepting reactive oxygen species (ROS) and minimising DNA damage. However, rapid increases in intracellular vitamin C may induce ROS with subsequent DNA damage priming DNA repair processes. Herein, we examine the potential of vitamin C and the derivative ascorbate-2-phosphate (2-AP) to induce a nucleotide excision repair (NER) response to DNA damage in a model of peripheral blood mononuclear cells. Exposure of cells to elevated levels of vitamin C induced ROS activity, resulting in increased levels of deoxycytidine glyoxal (gdC) and 8-oxo-2'-deoxyguanosine (8-oxodG) adducts in DNA; a stress response was also induced by 2-AP, but was delayed in comparison to vitamin C. Evidence of gdC repair was also apparent. Measurement of cyclobutane thymine-thymine dimers (T < >T) in DNA and culture supernatant were included as a positive marker for NER activity; this was evidenced by a reduction in DNA and increases in culture supernatant levels of T < >T for vitamin C-treated cells. Genomics analysis fully supported these findings confirming that 2-AP, in particular, induced genes associated with stress response, cell cycle arrest, DNA repair and apoptosis, and additionally provided evidence for the involvement of vitamin C in the mobilisation of intracellular catalytic Fe.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 8-Hydroxy-2'-Deoxyguanosine
  • Apoptosis / drug effects
  • Ascorbic Acid / analogs & derivatives
  • Ascorbic Acid / pharmacology*
  • Cell Cycle / drug effects
  • Cell Line, Tumor
  • DNA / metabolism
  • DNA Damage / drug effects*
  • DNA Repair / drug effects*
  • Deoxyguanosine / analogs & derivatives
  • Deoxyguanosine / metabolism
  • Gene Expression / drug effects*
  • Genetic Markers
  • Genomics
  • Glyoxal / metabolism
  • Humans
  • Iron / metabolism
  • Leukocytes, Mononuclear / drug effects
  • Models, Biological
  • Pyrimidine Dimers / metabolism
  • Reactive Oxygen Species / metabolism*
  • Vitamins / pharmacology*

Substances

  • Genetic Markers
  • Pyrimidine Dimers
  • Reactive Oxygen Species
  • Vitamins
  • ascorbate-2-phosphate
  • Glyoxal
  • 8-Hydroxy-2'-Deoxyguanosine
  • DNA
  • Iron
  • Deoxyguanosine
  • Ascorbic Acid