title: DNA double strand break repair: a radiation perspective.
abstract: CONCLUSIONS
  Ionizing radiation (IR) can induce a wide range of unique deoxyribonucleic acid (DNA) lesions due to the spatiotemporal correlation of the ionization produced. Of these, DNA double strand breaks (DSBs) play a key role. Complex mechanisms and sophisticated pathways are available within cells to restore the integrity and sequence of the damaged DNA molecules.
  
  
  BACKGROUND
  Here we review the main aspects of the DNA DSB repair mechanisms with emphasis on the molecular pathways, radiation-induced lesions, and their significance for cellular processes.
  
  
  RESULTS
  Although the main characteristics and proteins involved in the two DNA DSB repair processes present in eukaryotic cells (homologous recombination and nonhomologous end-joining) are reasonably well established, there are still uncertainties regarding the primary sensing event and their dependency on the complexity, location, and time of the damage. Interactions and overlaps between the different pathways play a critical role in defining the repair efficiency and determining the cellular functional behavior due to unrepaired/miss-repaired DNA lesions. The repair pathways involved in repairing lesions induced by soluble factors released from directly irradiated cells may also differ from the established response mechanisms.
  
  
  CONCLUSIONS
  An improved understanding of the molecular pathways involved in sensing and repairing damaged DNA molecules and the role of DSBs is crucial for the development of novel classes of drugs to treat human diseases and to exploit characteristics of IR and alterations in tumor cells for successful radiotherapy applications.
authors: Centre for Cancer Research & Cell Biology, Queen's University Belfast, Belfast, United Kingdom.
authors: Joy N
authors: JN
authors: Kavanagh
authors: Kelly M
authors: KM
authors: Redmond
authors: Giuseppe
authors: G
authors: Schettino
authors: Kevin M
authors: KM
authors: Prise
mesh_terms: D000818:Animals; D024201:Bystander Effect; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair / Q000528:radiation effects*; D004261:DNA Replication / Q000528:radiation effects; D006801:Humans; D009369:Neoplasms / Q000532:radiotherapy; D018384:Oxidative Stress; D011832:Radiation Injuries / Q000235:genetics*