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SiR-DNA/SiR-Hoechst-induced chromosome entanglement generates severe anaphase bridges and DNA damage

Girish Rajendraprasad1, Sergi Rodriguez-Calado2, Marin Barisic3,4

  • 1Cell Division and Cytoskeleton, Danish Cancer Institute, Copenhagen, Denmark girish@cancer.dk.

Life Science Alliance
|September 19, 2023
PubMed

Insights

SiR-DNA probes, used in live-cell imaging, can cause DNA damage and chromosome entanglement during mitosis when exposed to light. This highlights the need for alternative methods to study late mitotic events and DNA damage.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Genetics

Background:

  • SiR-DNA is a widely used far-red fluorescent probe for live-cell imaging of DNA.
  • Previous reports suggest SiR-DNA may induce DNA damage, but its use is extensive in mitosis and cancer research.

Purpose of the Study:

  • To comprehensively analyze the effects of SiR-DNA on mitosis in human cell lines.
  • To investigate the dose-, time-, and light-dependent impact of SiR-DNA on chromosome segregation and genome integrity.

Main Methods:

  • Live-cell imaging of four human cell lines (RPE-1, DLD-1, HeLa, U2OS).
  • Analysis of chromosome segregation, spindle elongation, and DNA damage.
  • Dose, time, and light exposure variations were assessed.

Main Results:

  • SiR-DNA induces dose-, time-, and light-dependent chromosome entanglement at non-centromeric regions.
  • Impaired sister chromatid segregation and spindle elongation during anaphase were observed.
  • Induced DNA damage was inherited by subsequent cell cycles, affecting genome integrity.

Conclusions:

  • SiR-DNA, under light exposure during imaging, causes significant mitotic aberrations and DNA damage.
  • The findings caution against using SiR-DNA for studying late mitotic events and DNA damage response.
  • Alternative labeling strategies are recommended for accurate investigation of these processes.

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