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Tightly Focused Femtosecond Laser Radiation Induces DNA Double-Strand Breaks in Human Tumor Cells

Yu A Fedotov1,2, A D Zalessky1, E I Yashkina1,2

  • 1N. N. Semenov Federal Research Center of Chemical Physics, Russian Academy of Sciences, Moscow, Russia.

Bulletin of Experimental Biology and Medicine
|May 2, 2022
PubMed

Insights

Femtosecond laser pulses induce DNA double-strand breaks (DNA DSB) in lung cancer cells. Researchers observed specific protein markers (phospho-ATM and γH2AX) at laser-irradiated sites, confirming DNA DSB formation.

Area of Science:

  • Biophysics
  • Molecular Biology
  • Cell Biology

Background:

  • Femtosecond laser radiation is a tool for precise cellular manipulation.
  • Understanding laser-induced DNA damage is crucial for applications in biology and medicine.
  • Phosphorylated ATM kinase (phospho-ATM) and γH2AX are key markers for DNA double-strand breaks (DNA DSB).

Purpose of the Study:

  • To investigate the formation of DNA DSB in A549 human lung adenocarcinoma cells induced by femtosecond laser radiation.
  • To analyze the colocalization of phospho-ATM and γH2AX protein tracks after laser irradiation.

Main Methods:

  • Immunocytochemical staining was employed to detect phospho-ATM protein tracks.
  • Colocalization analysis of phospho-ATM and γH2AX protein tracks was performed.
  • A549 cells were irradiated with femtosecond infrared laser pulses at varying energies (1 and 2 nJ).

Main Results:

  • Tracks of phospho-ATM and γH2AX proteins were observed in cell nuclei at laser beam path sites 30 minutes post-irradiation.
  • The formation of these protein tracks was confirmed at radiation power densities of 2×1011 and 4×1011 W×cm-2.
  • Significant colocalization of phospho-ATM and γH2AX tracks was evident.

Conclusions:

  • Focused femtosecond infrared laser radiation with pulse energy of 1-2 nJ induces DNA DSB in A549 cells.
  • The observed colocalization of phospho-ATM and γH2AX proteins confirms laser-induced DNA DSB.
  • This study validates femtosecond laser as a method for inducing targeted DNA DSB.
Keywords:
double-strand DNA breaksfemtosecond laser radiationphospho-ATMtumor cellsγH2AX

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