130P - Restoration of the mutant p53 protein upon treatment with small molecule modulators

Background

The p53 protein is a transcription factor that preserves the integrity of the genome and activates downstream genes the products of which are involved in cell cycle arrest, apoptosis, and DNA repair. The TP53 gene is the most frequently mutated gene in human cancer. Missense mutations in the DNA-binding domain lead to protein destabilization and denaturation. This results in impaired transcriptional activity, uncontrolled proliferation, inhibition of apoptosis, and resistance to anticancer therapies. Reactivation of mutant p53 protein using small molecules is a highly promising strategy for therapeutic treatment of cancer. In this work we aimed to evaluate the effectiveness of indazole derivatives as modulators of p53^R248W, p53^R273H, and p53^R248Q mutants.

Methods

SNB-19 p53^R273H, MiaPaca-2 p53^R248W, Ovcar-3 p53^R248Q, and A549 p53^wt cells were treated with compounds in the concentration range of 0-200 μM. The cytotoxicity of the compound was assessed using colorimetric MTS assay. The data were processed in the GraphPad Prism: the dependence of cell viability (%) on the logarithm of the compound concentrations was plotted. The p53 and p21 expression levels were evaluated using immunoblotting.

Results

IC50 values for the compounds could only be determined for p53-mutated cell lines at a concentration range of 40-150 μM. The expression levels of p53 protein in the same cell lines were also higher than in A549 (wild-type cell line), as evidenced by the results of immunoblotting analysis. We also observed increase in p21 protein levels upon treatment with the compounds.

Conclusions

The results showed that the compounds exhibit a specific effect on p53 mutant cell lines, and lead to increased expression of p53 target proteins associated with cell cycle arrest. The work was funded by the RSF grant 22-24-20034 and supported by the Kazan Federal University Strategic Academic Leadership Program (PRIORITY-2030).

Legal entity responsible for the study

The authors.

Funding

The work was funded by the RSF grant 22-24-20034 and supported by the Kazan Federal University Strategic Academic Leadership Program (PRIORITY-2030).

Disclosure

All authors have declared no conflicts of interest.