Repair Pathway Choices and Consequences at the Double-Strand Break

Trends Cell Biol. 2016 Jan;26(1):52-64. doi: 10.1016/j.tcb.2015.07.009. Epub 2015 Oct 1.


DNA double-strand breaks (DSBs) are cytotoxic lesions that threaten genomic integrity. Failure to repair a DSB has deleterious consequences, including genomic instability and cell death. Indeed, misrepair of DSBs can lead to inappropriate end-joining events, which commonly underlie oncogenic transformation due to chromosomal translocations. Typically, cells employ two main mechanisms to repair DSBs: homologous recombination (HR) and classical nonhomologous end joining (C-NHEJ). In addition, alternative error-prone DSB repair pathways, namely alternative end joining (alt-EJ) and single-strand annealing (SSA), have been recently shown to operate in many different conditions and to contribute to genome rearrangements and oncogenic transformation. Here, we review the mechanisms regulating DSB repair pathway choice, together with the potential interconnections between HR and the annealing-dependent error-prone DSB repair pathways.

Keywords: DNA repair; Polθ; alternative end joining; homologous recombination; synthetic lethality.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Cell Survival
  • DNA Breaks, Double-Stranded*
  • DNA Repair*
  • Genomic Instability
  • Humans
  • Mutation