Study on X-ray-induced apoptosis and chromosomal damage in G2 human lymphocytes in the presence of pifithrin-α, an inhibitor of p53.

The aim of this study is to investigate the role of the cell-cycle phase in cells exposed to radiation and chemicals in relation to the cellular response. The analysis was focused on the G2 cell-cycle phase, exploring the impact of p53 inhibition in human lymphocytes irradiated with X-rays in the presence or absence of pifithrin-α (PFT-α), a p53-specific inhibitor. Lymphocytes, 44h after stimulation to proliferate, were X-irradiated with 0.

Relation between DNA repair, apoptosis and chromosomal aberrations in presence of pifithrin-alpha, an inhibitor of p53.

The aim of this study was to investigate the impact of inhibition of p53 in X-irradiated human peripheral blood lymphocytes (HPBL) in the G0 phase of the cell cycle in the presence or absence of pifithrin-alpha (PFT-alpha), a specific inhibitor of p53, on repair of DNA damage or induced apoptosis. Lymphocyte (HPBL) cultures were X-irradiated with 3 Gy in the absence or presence of PFT-alpha. In order to distinguish the effects of PFT-alpha either on DNA repair or on apoptosis, PFT-alpha was added to the cultures employing different protocols namely, a) "continuous treatment", where PFT-alpha was added four hours before X-irradiation and left until the end of the experiment, b) "pre-treatment", where PFT-alpha was added four hours before X-irradiation and removed by washing the cells with phosphate buffered saline (PBS) four hours after irradiation and c) "post-treatment", where PFT-alpha was added four hours after irradiation and left in the medium until the harvest.