Discovery of Nanomolar-Affinity Pharmacological Chaperones Stabilizing the Oncogenic p53 Mutant Y220C

Abstract

The tumor suppressor protein p53 is inactivated in the majority of human cancers and remains a prime target for developing new drugs to reactivate its tumor suppressing activity for anticancer therapies. The oncogenic p53 mutant Y220C accounts for approximately 125,000 new cancer cases per annum and is one of the most prevalent p53 mutants overall. It harbors a narrow, mutationally induced pocket at the surface of the DNA-binding domain that destabilizes p53, leading to its rapid denaturation and aggregation. Here, we present the structure-guided development of high-affinity small molecules stabilizing p53-Y220C in vitro, along with the synthetic routes developed in the process, in vitro structure− activity relationship data, and confirmation of their binding mode by protein X-ray crystallography. We disclose two new chemical probes displaying sub-micromolar binding affinity in vitro, marking an important milestone since the discovery of the first small-molecule ligand of Y220C in 2008. New chemical probe JC744 displayed a K d = 320 nM, along with potent in vitro protein stabilization. This study, therefore, represents a significant advance toward highaffinity Y220C ligands for clinical evaluation.

2-Sulfonylpyrimidines: Reactivity Adjustable Agents for Cysteine Arylation

“…The cancer associated mutant p53-Y220C is a particularly well-suited test case. 34 In the unmodified protein, cysteine residues C182/C229/C275/C277 are solvent exposed and freely accessible, while C124/135/141/176/238/242 are sterically hindered and/or involved in structural Zn(II) coordination. The cancer specific C220 lies at the bottom of a mutationally induced hydrophobic pocket at the surface of the p53 DNA-binding domain (DBD, 25kDa) and is also sterically hindered.…”

Identification of necroptosis-related subtypes, development of a novel signature, and characterization of immune infiltration in colorectal cancer

“…APC and TP53 are the most widespread and representative mutations in colorectal cancer, and detecting the mutation status of these genes can help improve the accuracy of diagnosis and guide individualized treatment. Moreover, several studies have focused on reactivating TP53 function to exert its anti-tumor effects ( 29 , 30 ). Among the mutated genes, the mutation rate of KRAS was significantly higher in the high-risk group than that in the low-risk group (51% vs. 37%, P = 0.009).…”

Plant-derived natural products and combination therapy in liver cancer

“…Taking p53 mutant Y220C as the core, Joseph et al studied the structure-guided development of highaffinity small molecules stabilizing p53-Y220C in vitro and the synthetic route developed in the process. They found two new chemical probes with submicromolar binding affinity in vitro, which represents an important step toward the novel and effective Y220C ligand in the clinical evaluation of tumors (85). Cryptotanshinone significantly inhibited the cell viability of HepG2 cells with an IC 50 of 93.73 mmol/L and induced ferroptosis by ROS accumulation via reducing glutathione (GSH) level and the expression of cystine/glutamate antiporter system light chain (xCT) and glutathione peroxidase 4 (GPX4) (86).…”