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Updated: Oct 8, 2025
Author Spotlight: Developing Novel Anticancer Therapeutics Targeting the DNA Damage Response
Published on: June 14, 2024
Assessing kinetics and recruitment of DNA repair factors using high content screens
Barbara Martinez-Pastor1, Giorgia G Silveira2, Thomas L Clarke2
1The Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA 02114, USA; Molecular Oncology Program, Spanish National Cancer Research Center (CNIO), Madrid 28029, Spain.
Abstract:
Repair of genetic damage is coordinated in the context of chromatin, so cells dynamically modulate accessibility at DNA breaks for the recruitment of DNA damage response (DDR) factors. The identification of chromatin factors with roles in DDR has mostly relied on loss-of-function screens while lacking robust high-throughput systems to study DNA repair. In this study, we have developed two high-throughput systems that allow the study of DNA repair kinetics and the recruitment of factors to double-strand breaks in a 384-well plate format. Using a customized gain-of-function open-reading frame library ("ChromORFeome" library), we identify chromatin factors with putative roles in the DDR. Among these, we find the PHF20 factor is excluded from DNA breaks, affecting DNA repair by competing with 53BP1 recruitment. Adaptable for genetic perturbations, small-molecule screens, and large-scale analysis of DNA repair, these resources can aid our understanding and manipulation of DNA repair.
Insights
Scientists developed high-throughput systems to study DNA repair. They identified PHF20 as a factor that hinders DNA repair by preventing 53BP1 recruitment to double-strand breaks.
Area of Science:
- Molecular Biology
- Genetics
- Cell Biology
Background:
- DNA repair is crucial for maintaining genomic stability and is tightly regulated by chromatin.
- Current methods for identifying DNA repair factors, such as loss-of-function screens, are limited.
- High-throughput systems are needed to study DNA repair kinetics and factor recruitment.
Purpose of the Study:
- To develop novel high-throughput systems for studying DNA repair.
- To identify novel chromatin factors involved in the DNA damage response (DDR).
- To investigate the role of PHF20 in DNA double-strand break repair.
Main Methods:
- Development of two high-throughput systems in a 384-well plate format to analyze DNA repair kinetics.
- Utilized a customized gain-of-function open-reading frame library (ChromORFeome) for factor screening.
- Investigated the recruitment of chromatin factors to DNA breaks and their impact on repair.
Main Results:
- Successfully established high-throughput systems for studying DNA repair and factor recruitment.
- Identified several chromatin factors with putative roles in the DDR.
- Discovered that PHF20 is excluded from DNA breaks and impairs DNA repair by competing with 53BP1 recruitment.
Conclusions:
- The developed high-throughput systems provide robust tools for DNA repair research.
- PHF20 plays an inhibitory role in DNA double-strand break repair.
- These resources facilitate the understanding and manipulation of DNA repair pathways.
