<abstract xmlns="http://www.w3.org/1999/xhtml"> Background. 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 tumour cell lines were used, each consisting of one p53 functional and one p53 non-functional line. Cells were labelled with bromodeoxyuridine(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 by means of flow cytometry. 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.</abstract>

Background. 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 tumour cell lines were used, each consisting of one p53 functional and one p53 non-functional line. Cells were labelled with bromodeoxyuridine(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 by means of flow cytometry. 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.

Differential S-phase progression after irradiation of p53 functional versus non-functional tumour cells

Institute of Medical Radiobiology, Medical Faculty, University Duisburg-Essen, Germany / Department of Radiology, Toxicology and Civil Protection, Faculty of Health and Social Studies, University of South Bohemia in České Budějovice, Czech Republic

Institute of Medical Radiobiology, Medical Faculty, University Duisburg-Essen, Germany

Radiology and Oncology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Background. 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...

Differential S-phase progression after irradiation of p53 functional versus non-functional tumour cells

Published Online: Nov 05, 2014

Page range: 354 - 360

Received: Apr 24, 2014

Accepted: Jul 24, 2014

DOI: https://doi.org/10.2478/raon-2014-0032

Keywords
x-rays, intra-S-phase checkpoint, flow cytometry, relative movement

© by Friedo Zölzer

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Differential S-phase progression after irradiation of p53 functional versus non-functional tumour cells

Published Online: Nov 05, 2014

Page range: 354 - 360

Received: Apr 24, 2014

Accepted: Jul 24, 2014

DOI: https://doi.org/10.2478/raon-2014-0032

Keywordsx-rays, intra-S-phase checkpoint, flow cytometry, relative movement

© by Friedo Zölzer

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
x-rays, intra-S-phase checkpoint, flow cytometry, relative movement