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

Zölzer F, Mußfeldt T, Streffer C - Radiol Oncol (2014)

Bottom Line: 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.Three pairs of tumour cell lines were used, each consisting of one p53 functional and one p53 non-functional line.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.

View Article: PubMed Central - PubMed

Affiliation: 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.

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.

No MeSH data available.


Related in: MedlinePlus

Examples of scattergrams of control cultures and cultures exposed to 4 Gy of X-rays, labelled with BrdU and kept in BrdU-free medium for the times indicated (MeWo) (FL1-H: BrdU incorporation (FITC), FL3-H: DNA content (PI))
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f1-rado-48-04-354: Examples of scattergrams of control cultures and cultures exposed to 4 Gy of X-rays, labelled with BrdU and kept in BrdU-free medium for the times indicated (MeWo) (FL1-H: BrdU incorporation (FITC), FL3-H: DNA content (PI))

Mentions: Relative movement (RM) values were calculated as the mean DNA fluorescence of the BrdU labelled undivided cells (those that had not yet passed through mitosis, Figure 1) less the DNA fluorescence of the cells in G1 divided by the difference in DNA fluorescence of the cells in G1and G247, 49:RM=Flab−FG1FG2−FG1


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

Zölzer F, Mußfeldt T, Streffer C - Radiol Oncol (2014)

Examples of scattergrams of control cultures and cultures exposed to 4 Gy of X-rays, labelled with BrdU and kept in BrdU-free medium for the times indicated (MeWo) (FL1-H: BrdU incorporation (FITC), FL3-H: DNA content (PI))
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4230555&req=5

f1-rado-48-04-354: Examples of scattergrams of control cultures and cultures exposed to 4 Gy of X-rays, labelled with BrdU and kept in BrdU-free medium for the times indicated (MeWo) (FL1-H: BrdU incorporation (FITC), FL3-H: DNA content (PI))
Mentions: Relative movement (RM) values were calculated as the mean DNA fluorescence of the BrdU labelled undivided cells (those that had not yet passed through mitosis, Figure 1) less the DNA fluorescence of the cells in G1 divided by the difference in DNA fluorescence of the cells in G1and G247, 49:RM=Flab−FG1FG2−FG1

Bottom Line: 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.Three pairs of tumour cell lines were used, each consisting of one p53 functional and one p53 non-functional line.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.

View Article: PubMed Central - PubMed

Affiliation: 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.

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.

No MeSH data available.


Related in: MedlinePlus