Activating p53^Y220C with a Mutant-Specific Small Molecule

Area of Science:

• Oncology
• Molecular Biology
• Drug Discovery

Background:

• The TP53 gene is the most frequently mutated gene in human cancers.
• Mutant p53 proteins often lose their tumor suppressor functions and are difficult to therapeutically target.
• Restoring p53 function is a key goal in cancer therapy.

Purpose of the Study:

• To discover and characterize a small molecule that can reactivate mutant p53.
• To investigate the mechanism of action for this novel compound.
• To evaluate the therapeutic potential of reactivating mutant p53 in cancer models.

Main Methods:

• Discovery of a small molecule chemical inducer of proximity, named TRanscriptional Activator of p53 (TRAP-1).
• Characterization of TRAP-1's ability to form a ternary complex with mutant p53 and BRD4.
• Treatment of p53Y220C-expressing pancreatic cancer cell lines with TRAP-1.
• Analysis of p53 target gene transcription (e.g., p21) and cell growth inhibition.
• Use of control compounds lacking ternary complex formation capability.

Main Results:

• TRAP-1 successfully engages mutant p53 and BRD4, forming a ternary complex.
• This complex formation potently activates mutant p53 and induces robust transcription of p53 target genes.
• TRAP-1 treatment led to rapid upregulation of p21 and other target genes in p53Y220C-expressing cells.
• TRAP-1 inhibited the growth of these specific cancer cell lines.
• Control compounds without ternary complex formation ability did not yield similar results.

Conclusions:

• Chemically induced proximity is a viable strategy for reactivating mutant tumor suppressor proteins like p53.
• TRAP-1 demonstrates the potential of this approach to restore lost tumor suppressor functions in cancer.
• This discovery opens new avenues for developing therapies against cancers with TP53 mutations.