N6-methyladenosine in DNA promotes genome stability

Brooke A Conti1, Leo Novikov1, Deyan Tong2

  • 1Centers for Therapeutic Innovation, Emerging Sciences and Innovation, Pfizer, New York, United States.

Elife
|April 7, 2025
PubMed

Insights

Researchers discovered that METTL3 and its product 6mA are crucial for repairing DNA damage caused by agents like floxuridine. This finding highlights their role in maintaining genome stability in mammalian cells.

Area of Science:

  • Molecular Biology
  • Genetics
  • Biochemistry

Background:

  • DNA base lesions, including uracil incorporation and mismatches, pose risks to cellular replication and genome integrity.
  • Chemotherapeutic agents like floxuridine can introduce uracil into DNA, leading to cytotoxicity.

Purpose of the Study:

  • To identify factors involved in the repair of genomic uracil lesions.
  • To investigate the role of METTL3 and its product 6mA in DNA damage response.

Main Methods:

  • Conducted a CRISPR knockout screen using floxuridine to identify essential repair factors.
  • Utilized immunofluorescence to visualize N6-methyladenosine (6mA) foci.
  • Employed liquid chromatography-tandem mass spectrometry for orthogonal confirmation of 6mA in DNA.

Main Results:

  • Identified known (UNG) and novel factors, including METTL3, essential for overcoming floxuridine-induced cytotoxicity.
  • Observed nuclear foci of 6mA in floxuridine-treated cells, confirming its presence in DNA.
  • Demonstrated that METTL3 and 6mA are required for repairing lesions induced by various DNA-damaging agents (raltitrexed, gemcitabine, hydroxyurea).

Conclusions:

  • Established a significant role for METTL3 and DNA 6mA in promoting mammalian genome stability.
  • Highlighted the importance of the METTL3-6mA pathway in cellular response to base damage.

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