Multifunctional Compounds for Activation of the p53‐Y220C Mutant in Cancer

Abstract

The p53 protein plays a major role in cancer prevention, and over 50 % of cancer diagnoses can be attributed to p53 malfunction. The common p53 mutation Y220C causes local protein unfolding, aggregation, and can result in a loss of Zn in the DNA-binding domain. Structural analysis has shown that this mutant creates a surface site that can be stabilized using small molecules, and herein a multifunctional approach to restore function to p53-Y220C is reported. A series of compounds has been designed that contain iodinated phenols aimed for interaction and stabilization of the p53-Y220C surface cavity, and Zn-binding fragments for metallochaperone activity. Their Zn-binding affinity was characterized using spectroscopic methods and demonstrate the ability of compounds L4 and L5 to increase intracellular levels of Zn in a p53-Y220C-mutant cell line. The in vitro cytotoxicity of our compounds was initially screened by the National Cancer Institute (NCI-60), followed by testing in three stomach cancer cell lines with varying p53 status', including AGS (WTp53), MKN1 (V143A), and NUGC3 (Y220C). Our most promising ligand, L5, is nearly 3-fold more cytotoxic than cisplatin in a large number of cell lines. The impressive cytotoxicity of L5 is further maintained in a NUGC3 3D spheroid model. L5 also induces Y220C-specific apoptosis in a cleaved caspase-3 assay, reduces levels of unfolded mutant p53, and recovers p53 transcriptional function in the NUGC3 cell line. These results show that these multifunctional scaffolds have the potential to restore wild-type function in mutant p53-Y220C.

A Structure-Guided Molecular Chaperone Approach for Restoring the Transcriptional Activity of the p53 Cancer Mutant Y220C

“…In addition, alkylating agents, such as PRIMA-1 Met /APR-246 and 2-sulfonylpryrimidines, that modify exposed cysteine residues have been shown to induce cell death in p53-compromised cells through a combination of p53 protein stabilization and an increase in reactive oxygen species levels via alkylation of other cellular targets [17–19]. Another rescue strategy targets the zinc-binding deficient R175H mutant with metallochaperones [20], and more recently, multifunctional compounds combining a small-molecule stabilizer with a metallochaperone have been suggested for targeting thermolabile mutants [21].…”

Dibromine Promoted Transmetalation of an Organomercurial by Fe(CO)5: Synthesis, Properties, and Cytotoxicity of Bis(2-C6H4-2′-py-κC,N)dicarbonyliron(II)

“…The cytotoxic activity of 1 was tested in the stomach cancer cell lines. Gastric cancer is a particularly aggressive cancer, with only 25% of the patient surviving after 5 years . The median survival is below 12 months.…”

“…Gastric cancer is a particularly aggressive cancer, with only 25% of the patient surviving after 5 years. 56 The median survival is below 12 months. These clinical facts highlight the necessity to find novel therapeutic approach for gastric cancers.…”

Follow the Mutations: Toward Class-Specific, Small-Molecule Reactivation of p53

“…Miller et al took a creative approach by combining ZMC and cavity-binding functionalities in a single molecule [58]. A Zn 2+ -chelating pyridylmethyl moiety was mated to the Y220C-binding iodophenol core to create compound L5 (Figure 3).…”