Development of a high-content screening method for chemicals modulating DNA damage response

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• The cellular DNA damage response (DDR) is a critical target for cancer therapy.
• Histone H2AX phosphorylation (γH2AX) serves as a sensitive biomarker for DNA damage.
• Quantitative assessment of DDR is crucial for drug discovery.

Purpose of the Study:

• To develop a quantitative, cell-based, high-content screening system for measuring the DNA damage response (DDR).
• To validate the utility of γH2AX foci quantification for large-scale screening applications.
• To identify novel inhibitors of DDR for potential anticancer drug development.

Main Methods:

• Developed a high-content screening system to quantify DNA damage-induced γH2AX nuclear foci using an automated cell imager.
• Correlated the total area of γH2AX foci per cell with the concentration of DNA damage-inducing agents.
• Validated the system by quantifying known DNA damage inhibitors and screening a chemical library.

Main Results:

• The total area of γH2AX foci per cell showed a strong correlation with DNA damage agent concentration.
• The system successfully quantified the effects of known DNA damage inhibitors.
• Screening a chemical library identified compounds inhibiting both early DDR signaling and later DNA repair.

Conclusions:

• The developed γH2AX foci-measuring system is a suitable method for quantitative, high-content screening of DDR.
• This system can effectively identify inhibitors of DNA damage response pathways.
• The approach holds potential for the discovery of novel anticancer therapeutics targeting DDR.