Influence of p53 on the progression of irradiated cells through the S-phase

  • Friedo Zölzer


Objectives: Many pathways seem to be involved in the regulation of the intra-S-phase checkpoint after exposure to ionizing radiation, but the role of p53 has proven to be rather elusive. Here we have a closer look at the progression of irradiated cells through S-phase in dependence of their p53 status.

Materials and methods: Three pairs of cell lines were used, each consisting of one p53 functional and one p53 non-functional line. Cells were labelled with BrdU immediately after irradiation, they were then incubated in label-free medium, and at different times afterwards their position within the S-phase was determined flow cytometrically.

Results: While in the p53 deficient cells progression through S-phase was slowed significantly over at least a few hours, it was halted for just about an hour in the p53 proficient cells and then proceeded without further delay or even at a slightly accelerated pace.

Conclusions: It is clear from the experiments presented here that p53 does play a role for the progress of cells through the S-phase after X-ray exposure, but the exact mechanisms by which replicon initiation and elongation is controlled in irradiated cells remain to be elucidated.

Author Biography

Friedo Zölzer
Head Department of Radiology, Toxicology, and Civil Protection Faculty of Health and Social Studies University of South Bohemia in České Budějovice
How to Cite
Zölzer, F. (2014). Influence of p53 on the progression of irradiated cells through the S-phase. Radiology and Oncology, 48(4). Retrieved from
Experimental radiology