The Inhibition of Hsp27 Chaperone Affects the Level of p53 Protein in Tumor Cells

The characteristics of p53 protein content in Jurkat and THP-1 tumor cell line, and mononuclear leukocytes were evaluated from in vitro studies with selective inhibition of the chaperone Hsp27. For the inhibition of Hsp27 KRIBB3 ((5-(5-ethyl-2-hydroxy-4-methoxyphenyl)-4-(4-methoxyphenyl)-isoxasole) was used. The p53 protein concentration was determined by Western blot analysis. The apoptoticly transformed cells with selective inhibitor Hsp27 were assessed by in vitro fluorescence microscopy using FITC-labeled annexin V and propidium iodide. The present study showed that the in vitro inhibition of the chaperone Hsp27 leads to an increase in p53 concentration in tumor cells and a growth of the amount of apoptotic cells in modified Jurkat and THP-1 cultures but revealed no such effects in the mononuclear leukocytes culture. Thus, Hsp27 appeared to play an important regulatory role in the activation of p53 protein of tumor cells.