Small molecule stabilisation of the p53 – 14-3-3σ interaction as a therapeutic modality for cancer

Abstract

The p53/p21 pathway is the principal way in which cells trigger senescence and apoptosis. In the last years, numerous studies have focused on targeting the p53 pathway, as this protein prevents proliferation of cells with a damaged genome and has many roles in the cell cycle. Therefore, it is also known as the guardian of the genome. Nowadays, great results have been achieved using small molecules which modulate the interaction between p53 and its negative regulator MDM2. Inhibiting their interaction, p53 functions can be restored. Despite this success, another strategy is emerging, and it consists of the stabilization of p53 interaction with its positive regulator. In this experimental project, a compound called Fusicoccin A (FC-A) will be tested in cancer cells, as it seems to interact both with p53 and one of its positive regulators, called 14-3-3σ. Experiments where performed in which different concentrations of the compound (10 μM, 1 μM, 0.1 μM, 0.01 μM and 0.001 μM ) were used to treat the cells. Cells were collected at the beginning, middle and end of the experiment to measure cell senescence with a Senescence-Associated β-Galactosidase Activity Detection Assay and Western Blots to look at the expression levels of specific senescence markers. Two replicates were done per each experiment. Based on the results obtained with the experiments, FC-A is not increasing the binding affinity of p53 and 14-3-3σ but it is not toxic for the cells either. The same drug is going to be tested in other cell lines and other FC-A analogues will be synthetized to increase the stabilization between p53 and 14-3-3σ. Moreover, these compounds will be tested in association to see if there is a synergistic effect and if the cells get stimulated enough not only to become senescent but to undergo apoptosis.