PRDX1 and MTH1 cooperate to prevent ROS-mediated inhibition of telomerase

Genes Dev. 2018 May 1;32(9-10):658-669. doi: 10.1101/gad.313460.118. Epub 2018 May 17.


Telomerase counteracts telomere shortening and cellular senescence in germ, stem, and cancer cells by adding repetitive DNA sequences to the ends of chromosomes. Telomeres are susceptible to damage by reactive oxygen species (ROS), but the consequences of oxidation of telomeres on telomere length and the mechanisms that protect from ROS-mediated telomere damage are not well understood. In particular, 8-oxoguanine nucleotides at 3' ends of telomeric substrates inhibit telomerase in vitro, whereas, at internal positions, they suppress G-quadruplex formation and were therefore proposed to promote telomerase activity. Here, we disrupt the peroxiredoxin 1 (PRDX1) and 7,8-dihydro-8-oxoguanine triphosphatase (MTH1) genes in cancer cells and demonstrate that PRDX1 and MTH1 cooperate to prevent accumulation of oxidized guanine in the genome. Concomitant disruption of PRDX1 and MTH1 leads to ROS concentration-dependent continuous shortening of telomeres, which is due to efficient inhibition of telomere extension by telomerase. Our results identify antioxidant systems that are required to protect telomeres from oxidation and are necessary to allow telomere maintenance by telomerase conferring immortality to cancer cells.

Keywords: MTH1; PRDX1; aging; cellular senescence; oxidative stress; telomerase; telomeres.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA Damage / genetics
  • DNA Repair Enzymes / genetics
  • DNA Repair Enzymes / metabolism*
  • Enzyme Activation / genetics
  • Gene Knockout Techniques
  • Genome
  • Guanine / metabolism
  • HCT116 Cells
  • Humans
  • Oxidation-Reduction
  • Oxidative Stress / genetics
  • Peroxiredoxins / metabolism*
  • Phosphoric Monoester Hydrolases / genetics
  • Phosphoric Monoester Hydrolases / metabolism*
  • Reactive Oxygen Species / metabolism*
  • Telomerase / antagonists & inhibitors
  • Telomerase / metabolism*
  • Telomere Homeostasis / genetics
  • Telomere Shortening / genetics*


  • Reactive Oxygen Species
  • Guanine
  • PRDX1 protein, human
  • Peroxiredoxins
  • Telomerase
  • Phosphoric Monoester Hydrolases
  • 8-oxodGTPase
  • DNA Repair Enzymes