Comparison of comet-based approaches to assess base excision repair

Congying Zheng, Sergey Shaposhnikov, Andrew Collins, Gunnar Brunborg, Florin Oancea, Frederik-Jan Van Schooten, Roger Godschalk*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

DNA repair plays an essential role in maintaining genomic stability, and can be assessed by various comet assay-based approaches, including the cellular repair assay and the in vitro repair assay. In the cellular repair assay, cells are challenged with a DNA-damaging compound and DNA damage removal over time is assessed. In the in vitro repair assay, an early step in the repair process is assessed as the ability of a cellular extract to recognize and incise damaged DNA in substrate nucleoids from cells treated with a DNA-damaging compound. Our direct comparison of both assays in eight cell lines and human peripheral blood lymphocytes indicated no significant relationship between these DNA repair assays (R-2 = 0.084, P = 0.52). The DNA incision activity of test cells measured with the in vitro repair assay correlated with the background level of DNA damage in the untreated test cells (R-2 = 0.621, P = 0.012). When extracts were prepared from cells exposed to DNA-damaging agents (10 mM KBrO3 or 1 & mu;M Ro 19-8022 plus light), the incision activity was significantly increased, which is in line with the notion that base excision repair is inducible. The data presented suggest that the two assays do not measure the same endpoint of DNA repair and should be considered as complementary.
Original languageEnglish
Pages (from-to)2273-2281
Number of pages9
JournalArchives of Toxicology
Volume97
Issue number8
Early online date1 Jun 2023
DOIs
Publication statusPublished - 1 Aug 2023

Keywords

  • DNA repair
  • Comet assay
  • Genotoxicity
  • In vitro repair assay
  • Cellular repair assay
  • INDUCED DNA-DAMAGE
  • IN-VITRO REPAIR
  • ASSAY
  • VALIDATION

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