Reaction of Electrons with DNA: Radiation Damage to Radiosensitization

Int J Mol Sci. 2019 Aug 16;20(16):3998. doi: 10.3390/ijms20163998.

Abstract

This review article provides a concise overview of electron involvement in DNA radiation damage. The review begins with the various states of radiation-produced electrons: Secondary electrons (SE), low energy electrons (LEE), electrons at near zero kinetic energy in water (quasi-free electrons, (e-qf)) electrons in the process of solvation in water (presolvated electrons, e-pre), and fully solvated electrons (e-aq). A current summary of the structure of e-aq, and its reactions with DNA-model systems is presented. Theoretical works on reduction potentials of DNA-bases were found to be in agreement with experiments. This review points out the proposed role of LEE-induced frank DNA-strand breaks in ion-beam irradiated DNA. The final section presents radiation-produced electron-mediated site-specific formation of oxidative neutral aminyl radicals from azidonucleosides and the evidence of radiosensitization provided by these aminyl radicals in azidonucleoside-incorporated breast cancer cells.

Keywords: ion-beam radiation; low energy electrons; quasi-free electron; radiosensitization; solvated electron.

Publication types

  • Review

MeSH terms

  • Animals
  • DNA / chemistry
  • DNA / genetics*
  • DNA Damage / radiation effects*
  • Electrons / adverse effects*
  • Humans
  • Models, Chemical
  • Models, Molecular
  • Pyrimidine Nucleosides / chemistry
  • Pyrimidine Nucleosides / genetics
  • Radiation, Ionizing

Substances

  • Pyrimidine Nucleosides
  • DNA