Pyrimidine Triones as Potential Activators of p53 Mutants

p53 is a crucial tumor suppressor in vertebrates that is frequently mutated in human cancers. Most mutations are missense mutations that render p53 inactive in suppressing tumor initiation and progression. Developing small molecule drugs to convert mutant p53 into an active, wild-type-like conformation is a significant focus for personalized cancer therapy. Prior research indicates that reactivating p53 suppresses cancer cell proliferation and tumor growth in animal models. Early clinical evidence with a compound selectively targeting p53 mutants with substitutions of tyrosine 220 suggests potential therapeutic benefits of reactivating p53 in patients. This study identifies and examines the UCI-1001 compound series as a potential corrector for several p53 mutations. The findings indicate that UCI-1001 treatment in p53 mutant cancer cell lines inhibits growth and reinstates wild-type p53 activities, including DNA binding, target gene activation, and induction of cell death. Cellular thermal shift assays, conformation-specific immunofluorescence staining, and differential scanning fluorometry suggest that UCI-1001 interacts with and alters the conformation of mutant p53 in cancer cells. These initial results identify pyrimidine trione derivatives of the UCI-1001 series as candidates for p53 corrector drug development. Overall design: RNA samples were extracted from TOV-112D cells treated with UCI- 250 1001, UCI-1014, and DMSO using the RNeasy kit (Qiagen). Library generation and sequencing 251 was performed by Novogene Corporation Inc. Sequencing reads were quantified and aligned to 252 the human genome GRCh38 using kallisto v0.48.0. Estimated counts of transcripts from the 253 same Ensembl gene ID were added together and the sums were converted to integers. Differential 254 expression analysis was performed using DESeq2 v1.38.3.