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Updated: Jul 24, 2025
Analysis of DNA Double-strand Break DSB Repair in Mammalian Cells
Published on: September 8, 2010
Detection of endogenous translesion DNA synthesis in single mammalian cells
Tom Egger1, Antoine Aze1, Domenico Maiorano1
1Institut de Génétique Humaine (IGH) CNRS UMR9002, Université de Montpellier, Molecular Bases of Human Pathologies Department, "Genome Surveillance and Stability" Laboratory, 34396 Cedex 5 Montpellier, France.
Abstract:
Translesion DNA synthesis (TLS) is an evolutionarily conserved process that cells activate to tolerate DNA damage. TLS facilitates proliferation under DNA damage conditions and is exploited by cancer cells to gain therapy resistance. It has been so far challenging to analyze endogenous TLS factors such as PCNAmUb and TLS DNA polymerases in single mammalian cells due to a lack of suitable detection tools. We have adapted a flow cytometry-based quantitative method allowing detection of endogenous, chromatin-bound TLS factors in single mammalian cells, either untreated or exposed to DNA-damaging agents. This high-throughput procedure is quantitative, accurate, and allows unbiased analysis of TLS factors' recruitment to chromatin, as well as occurrence of DNA lesions with respect to the cell cycle. We also demonstrate detection of endogenous TLS factors by immunofluorescence microscopy and provide insights into TLS dynamics upon DNA replication forks stalled by UV-C-induced DNA damage.
Insights
Researchers developed a new method to detect translesion DNA synthesis (TLS) factors in single cells. This technique enables quantitative analysis of DNA damage tolerance mechanisms and cancer therapy resistance.
Area of Science:
- Molecular Biology
- Cell Biology
- Genetics
Background:
- Translesion DNA synthesis (TLS) is crucial for cells to tolerate DNA damage and maintain proliferation.
- Cancer cells exploit TLS for therapy resistance, making it a key target for drug development.
- Analyzing endogenous TLS factors in single cells has been limited by a lack of suitable detection tools.
Purpose of the Study:
- To develop and validate a quantitative method for detecting endogenous, chromatin-bound TLS factors in single mammalian cells.
- To enable high-throughput, cell cycle-resolved analysis of TLS factor recruitment and DNA lesion occurrence.
- To gain insights into TLS dynamics at stalled replication forks.
Main Methods:
- Adaptation of a flow cytometry-based quantitative method.
- Detection of endogenous, chromatin-bound TLS factors (e.g., PCNAmUb, TLS DNA polymerases).
- Analysis of cells under various conditions, including exposure to DNA-damaging agents (e.g., UV-C).
- Immunofluorescence microscopy for TLS factor detection and dynamics studies.
Main Results:
- A quantitative, accurate, and high-throughput method for detecting endogenous TLS factors in single cells was established.
- The method allows unbiased analysis of TLS factor recruitment to chromatin and DNA lesion occurrence across the cell cycle.
- Insights into TLS dynamics at UV-C-stalled replication forks were obtained.
Conclusions:
- The developed flow cytometry method significantly advances the ability to study DNA damage tolerance in single cells.
- This tool facilitates research into cancer therapy resistance mechanisms.
- The findings provide a foundation for further investigation of TLS dynamics and regulation.
