Multifunctional metallochaperone modifications for targeting subsite cavities in mutant p53-Y220C

• Published in: Journal of inorganic biochemistry 2023-05, Vol.242, p.112164-112164, Article 112164
• Main Authors: Miller, Jessica J., Kwan, Kalvin, Blanchet, Anaïs, Orvain, Christophe, Mellitzer, Georg, Smith, Jason, Lento, Cristina, Nouchikian, Lucienne, Omoregbee-Leichnitz, Sabrina, Sabatou, Marie, Wilson, Derek, Gaiddon, Christian, Storr, Tim
• Format: Article
• Language: English
• Subjects: Cell Line, Tumor; Chemical Sciences; Cytotoxicity; Life Sciences; Ligand design; Ligands; Metallochaperones; Metallochaperones - metabolism; p53 protein; Protein Domains; ROS; Tumor Suppressor Protein p53 - genetics; Tumor Suppressor Protein p53 - metabolism; Zinc
• ISSN: 0162-0134; 1873-3344
• DOI: 10.1016/j.jinorgbio.2023.112164

The p53 protein, known as the ‘guardian of the genome’, plays an important role in cancer prevention. Unfortunately, p53 mutations result in compromised activity with over 50% of cancers resulting from point mutations to p53. There is considerable interest in mutant p53 reactivation, with the development of small-molecule reactivators showing promise. We have focused our efforts on the common p53 mutation Y220C, which causes protein unfolding, aggregation, and can result in the loss of a structural Zn from the DNA-binding domain. In addition, the Y220C mutant creates a surface pocket that can be stabilized using small molecules. We previously reported the bifunctional ligand L5 as a Zn metallochaperone and reactivator of the p53-Y220C mutant. Herein we report two new ligands L5-P and L5-O that are designed to act as Zn metallochaperones and non-covalent binders in the Y220C mutant pocket. For L5-P the distance between the Zn-binding di-(2-picolyl)amine function and the pocket-binding diiodophenol was extended in comparison to L5, while for L5-O we extended the pocket-binding moiety via attachment of an alkyne function. While both new ligands displayed similar Zn-binding affinity to L5, neither acted as efficient Zn-metallochaperones. However, the new ligands exhibited significant cytotoxicity in the NCI-60 cell line screen as well as in the NUGC3 Y220C mutant cell line. We identified that the primary mode of cytotoxicity is likely reactive oxygen species (ROS) generation for L5-P and L5-O, in comparison to mutant p53 reactivation for L5, demonstrating that subtle changes to the ligand scaffold can change the toxicity pathway. The use of multifunctional metallochaperones to stabilize mutant p53 protein results in a number of different cytotoxicity mechanisms. [Display omitted] •We explore the influence of structural modifications to a lead multifunctional metallochaperone.•The new cytotoxic compounds are not efficient Zn metallochaperones, despite similar Zn affinities to previously studied compounds.•The primary mode of cytotoxicity for the new derivatives is via reactive oxygen species generation, and not p53 reactivation, New highlight: Subtle structural changes to the ligand scaffold can change the toxicity pathway for these compounds.