A designed inhibitor of p53 aggregation rescues p53 tumor-suppression in ovarian carcinomas

Half of all human cancers lose p53 function by missense mutations, with an unknown fraction of these containing p53 in a self-aggregated, amyloid-like state. Here we show that a cell-penetrating peptide, ReACp53, designed to inhibit p53 amyloid formation, rescues p53 function in cancer cell lines and in organoids derived from high-grade serous ovarian carcinomas (HGSOC), an aggressive cancer characterized by ubiquitous p53 mutations. Rescued p53 behaves similarly to its wild-type counterpart in regulating target genes, reducing cell proliferation and increasing cell death. Intraperitoneal administration decreases tumor proliferation and shrinks xenografts in vivo. Our data show the effectiveness of targeting a specific aggregation defect of p53 and its potential applicability to HGSOCs. Overall design: Vehicle vs. ReACp53 treatment in 4 different samples: 2 cell lines (MCF7 w/ WT p53 as negative control and OVCAR3 w/ R248Q p53) and 2 clinical specimens (primary cells from patient #8 w/ WT p53 as negative control and primary cells from patient #1 w/ R248Q p53)

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Soragni A, Janzen DM, Johnson LM, Lindgren AG, Thai-Quynh Nguyen A, Tiourin E, Soriaga AB, Lu J, Jiang L, Faull KF, Pellegrini M, Memarzadeh S, Eisenberg DS