Effect of natural substances from tea on G-quadruplexes and binding and transactivation properties of p53 protein

The tumor suppressor protein p53 belongs to the most important regulator of the cell cycle in case of DNA damage. Apart from stopping the cell cycle and inducing apoptosis, protein p53 interacts with other proteins and DNA. Mutation of the TP53 gene encoding the protein p53 are a common feature of human cancer. This Bachelor thesis investigates natural substances from tea which could play a positive role in the activation of protein p53 in cancer and be used to support the treatment of these diseases. In the theoretical part of the Bachelor thesis, the secondary structures of DNA were described, specifically the structure and properties of G-quadruplexes, as well as protein p53 and its binding activity to the secondary structure of DNA. Selected natural substances found in tea and food were described – gallic acid and apigenin. The aim of the experimental part of this work was to verify the ability of these substances to interact with G-quadruplexes in vitro and thus to stabilize them in the yeast model and to assess the subsequent effect on measuring the effect of protein p53 transactivation. The interaction of quaternary structures with G4 ligands was verified in vitro by using the ThT fluorescence assay and the luciferase reporter assay. It was found that G4 ligands at 30 M concentration after 20 hours of incubation did not show a significant effect on the tested yeast cultures. At a 60 M concentration of G4 ligands, an increase in protein p53 production was observed due to cellular stress caused by the presence of G4 ligands