Real-time fluorescence imaging of the DNA damage repair response during mitosis

J Cell Biochem. 2015 Apr;116(4):661-6. doi: 10.1002/jcb.25021.

Abstract

The response to DNA damage during mitosis was visualized using real-time fluorescence imaging of focus formation by the DNA-damage repair (DDR) response protein 53BP1 linked to green fluorescent protein (GFP) (53BP1-GFP) in the MiaPaCa-2(Tet-On) pancreatic cancer cell line. To observe 53BP1-GFP foci during mitosis, MiaPaCa-2(Tet-On) 53BP1-GFP cells were imaged every 30 min by confocal microscopy. Time-lapse imaging demonstrated that 11.4 ± 2.1% of the mitotic MiaPaCa-2(Tet-On) 53BP1-GFP cells had increased focus formation over time. Non-mitotic cells did not have an increase in 53BP1-GFP focus formation over time. Some of the mitotic MiaPaCa-2(Tet-On) 53BP1-GFP cells with focus formation became apoptotic. The results of the present report suggest that DNA strand breaks occur during mitosis and undergo repair, which may cause some of the mitotic cells to enter apoptosis in a phenomenon possibly related to mitotic catastrophe.

Keywords: 53BP1; APOPTOSIS; DNA DAMAGE; DNA REPAIR RESPONSE; FOCUS FORMATION; FUSION GENE; GFP; MITOSIS; MITOTIC CATASTROPHE; TIME-LAPSE CONFOCAL IMAGING.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Cell Line, Tumor
  • DNA Damage
  • DNA Repair
  • Green Fluorescent Proteins
  • Humans
  • Intracellular Signaling Peptides and Proteins / chemistry*
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Microscopy, Confocal
  • Mitosis*
  • Optical Imaging / methods*
  • Time-Lapse Imaging
  • Tumor Suppressor p53-Binding Protein 1

Substances

  • Intracellular Signaling Peptides and Proteins
  • TP53BP1 protein, human
  • Tumor Suppressor p53-Binding Protein 1
  • Green Fluorescent Proteins