Selective therapeutic strategy for p53-deficient cancer by targeting dysregulation in DNA repair

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Mutations in the tumor suppressor p53 are common in breast cancer.
• Targeting mutant p53 has historically been challenging.
• p53 mutant cancers exhibit distinct genomic and repair pathway characteristics.

Purpose of the Study:

• To develop a selective combination therapy for p53 mutant breast cancers.
• To investigate the role of the Base-Excision Repair (BER) pathway in p53 mutant cells.
• To evaluate the efficacy of combining deoxyuridine analogues with PARP inhibitors.

Main Methods:

• Genomic data analysis to identify cancer-specific vulnerabilities.
• Experimental testing of DNA damage accumulation in p53 mutant cells.
• Inhibition of poly (ADP-ribose) polymerase (PARP) and assessment of cellular response.
• Preclinical animal studies to evaluate combination therapy efficacy.

Main Results:

• p53 mutant cancers show high replication activity and dysregulated BER.
• Deoxyuridine analogues induce DNA damage accumulation in p53 mutant cells.
• PARP inhibition significantly enhances the anti-cancer effect of deoxyuridine analogues.
• The combination therapy demonstrated superior anti-neoplastic efficacy compared to monotherapy in preclinical models.

Conclusions:

• A selective combination therapy strategy targeting p53 mutant cancers has been identified.
• Exploiting BER pathway defects in p53 mutant cells offers a therapeutic window.
• This approach holds potential to improve treatment outcomes for breast cancer patients with p53 mutations.