Direct observation of DNA alterations induced by a DNA disruptor

Area of Science:

• Molecular Biology
• Genomics
• Biophysics

Background:

• DNA alterations, including base modifications and mutations, are critical for understanding transcription factor activity and cell functions.
• Detecting DNA alterations caused by exogenous molecules, like cancer therapeutics, is vital for drug development and diagnostics.
• Direct evidence linking DNA modifications, transcription factor binding, and cell function has been limited.

Purpose of the Study:

• To directly observe DNA alterations in transcription factor binding motifs after exposure to trifluridine (FTD).
• To evaluate the impact of FTD-induced DNA alterations on transcriptional activity in cancer cells.
• To demonstrate the utility of single-molecule electrical detection for studying DNA sequence changes.

Main Methods:

• Utilized a single-molecule electrical detection method.
• Exposed cancer cell lines to the nucleic acid analogue trifluridine (FTD).
• Analyzed DNA alterations within transcription factor p53 binding regions and assessed p53 binding affinity.

Main Results:

• Observed approximately 10% FTD incorporation within p53 binding regions in cancer cells after 5 months of exposure.
• Found reduced p53 binding to DNA containing FTD in these regions.
• Inferred that FTD incorporation weakens the binding affinity of p53 to its DNA motifs.

Conclusions:

• Single-molecule electrical detection is an effective method for observing DNA sequence alterations.
• FTD incorporation into DNA can directly impair transcription factor binding, affecting gene regulation.
• This methodology aids in understanding the functional consequences of DNA modifications in cellular processes.