Efficacy of the combination of a PARP inhibitor and UVC on cancer cells as imaged by focus formation by the DNA repair-related protein 53BP1 linked to green fluorescent protein

Shuuya Yano, Kiyoto Takehara, Shinji Miwa, Hiroyuki Kishimoto, Hiroshi Tazawa, Yasuo Urata, Shunsuke Kagawa, Michael Bouvet, Toshiyoshi Fujiwara, Robert M. Hoffman

Research output: Contribution to journalArticle

1 Citation (Scopus)


Background: The ability to image DNA repair in cancer cells after irradiation, as well as its inhibition by potential therapeutic agents, is important for the further development of effective cancer therapy. 53BP1 is a DNA repair protein that is overexpressed and forms foci when doublestranded DNA breaks occur in DNA. Materials and Methods: The re-localization of green fluorescent protein (GFP) fused to the chromatin-binding domain of 53BP1 to form foci was imaged after UVC irradiation of breast and pancreatic cancer cells expressing 53BP1-GFP using confocal microscopy. Results: During live-cell imaging, 53BP1-GFP focus formation was observed within 10 minutes after UVC irradiation. Most 53BP1 foci resolved by 100 minutes. To block UVC-induced double-strand break repair in cancer cells, poly(ADP-ribose) polymerase (PARP) was targeted with ABT-888 (veliparib). PARP inhibition markedly enhanced UVC-irradiation-induced persistence of 53BP1-foci, even beyond 100 minutes after UVC irradiation, and reduced proliferation of breast and pancreatic cancer cells. Conclusion: Confocal microscopy of 53BP1-GFP is a powerful method for imaging UVC-induced DNA damage and repair, as well as inhibition of repair.

Original languageEnglish
Pages (from-to)3821-3826
Number of pages6
JournalAnticancer Research
Issue number8
Publication statusPublished - Aug 1 2016
Externally publishedYes



  • 53BP-1
  • ABT888
  • Confocal microscopy
  • DNA damage
  • DNA repair
  • Focus formation
  • Green fluorescent protein
  • Inhibition
  • PARP
  • Real-time imaging

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

Cite this