Discovery of an Indole-Based p53-Y220C Reactivator with In Vivo Antitumor Activity via Structure-Guided Design

The oncogenic Y220C mutation destabilizes the p53 DNA-binding domain by creating a druggable surface crevice. Although the clinical advancement of PC14586 validates this target, the scarcity of structurally distinct correctors limits exploration of this chemical space. Using a structure-guided design strategy, we identified D2 as an indole-based p53-Y220C stabilizer that engages the mutation-induced cavity. D2 significantly enhanced the thermodynamic stability of the mutant protein (ΔT_m = +3.7 °C) and restored p53-dependent transcriptional activity, primarily inducing cell cycle arrest rather than acute apoptosis. Despite rapid metabolic clearance and the need for intraperitoneal dosing, D2 achieved 59.2% tumor growth inhibition in a xenograft model. Although further pharmacokinetic optimization is required, D2 serves as an alternative structural template for future medicinal chemistry efforts.