ATR-p53 Restricts Homologous Recombination in Response to Replicative Stress but Does Not Limit DNA Interstrand Crosslink Repair in Lung Cancer Cells
2011

p53's Role in DNA Repair and Cancer

publication 10 minutes Evidence: moderate

Author Information

Author(s): Sirbu Bianca M., Lachmayer Sarah J., Wülfing Verena, Marten Lara M., Clarkson Katie E., Lee Linda W., Gheorghiu Liliana, Zou Lee, Powell Simon N., Dahm-Daphi Jochen, Willers Henning

Primary Institution: Massachusetts General Hospital Cancer Center

Hypothesis

How does p53 regulate homologous recombination in response to replicative stress?

Conclusion

p53 downregulates homologous recombination in response to replicative stress but does not impair the repair of DNA double-strand breaks induced by cytotoxic agents.

Supporting Evidence

  • p53 downregulates RAD51 foci formation in response to replication stress.
  • Transactivation-impaired p53 mutants still suppress homologous recombination.
  • p53's suppression of homologous recombination is dependent on ATR but not ATM.
  • Cells expressing mutant p53 show increased resistance to DNA crosslinking agents.

Takeaway

p53 helps fix DNA when it's broken, but sometimes it slows down the repair process to prevent mistakes that could lead to cancer.

Methodology

The study used various cell lines to analyze the effects of p53 on homologous recombination and DNA repair mechanisms under different stress conditions.

Potential Biases

Potential bias due to the use of specific cell lines which may not represent all cancer types.

Limitations

The study's findings may not be generalizable across all cell lines and the foci studies do not directly measure protein activities at replication forks.

Participant Demographics

The study primarily involved lung cancer cell lines.

Statistical Information

P-Value

p<0.01

Statistical Significance

p<0.01

Digital Object Identifier (DOI)

10.1371/journal.pone.0023053

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