Deep CRISPR mutagenesis characterizes the functional diversity of TP53 mutations

Area of Science:

• Genomics
• Cancer Biology
• Molecular Genetics

Background:

• The TP53 tumor suppressor gene is frequently mutated in human cancers.
• Understanding the functional impact of TP53 mutations is crucial for personalized medicine.
• Over 2,000 missense mutations in TP53 have been identified.

Purpose of the Study:

• To comprehensively map the functional impact of TP53 missense mutations.
• To distinguish benign from pathogenic TP53 variants.
• To identify TP53 mutants amenable to pharmacological reactivation.

Main Methods:

• Utilized saturation genome editing with CRISPR-mediated homology-directed repair.
• Engineered 9,225 TP53 variants in cancer cells.
• Covered 94.5% of all cancer-associated TP53 missense mutations.

Main Results:

• Precisely mapped the impact of individual TP53 mutations on tumor cell fitness.
• Distinguished benign from pathogenic variants with high resolution.
• Identified subtle loss-of-function phenotypes and potential targets for drug reactivation.
• Uncovered roles of splicing alterations and nonsense-mediated mRNA decay in TP53 dysfunction.

Conclusions:

• Saturation genome editing is a powerful tool for advancing TP53 variant interpretation.
• Findings support improved genetic counseling and personalized cancer therapy.
• Detailed functional mapping enhances understanding of TP53 mutation impact in cancer.