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Fractionated γ-irradiation renders tumour cells more responsive to apoptotic signals through CD95

Signals through the CD95 surface receptor can specifically induce apoptosis. Some tumour cell lines are sensitive to CD95 signals, and insensitive cells can be converted to a sensitive phenotype if given appropriate treatment. To determine whether the apoptotic response of tumour cells to signalling...

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Autores principales: Sheard, M A, Krammer, P H, Zaloudik, J
Formato: Texto
Lenguaje:English
Publicado: Nature Publishing Group 1999
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2363128/
https://www.ncbi.nlm.nih.gov/pubmed/10468284
http://dx.doi.org/10.1038/sj.bjc.6690585
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author Sheard, M A
Krammer, P H
Zaloudik, J
author_facet Sheard, M A
Krammer, P H
Zaloudik, J
author_sort Sheard, M A
collection PubMed
description Signals through the CD95 surface receptor can specifically induce apoptosis. Some tumour cell lines are sensitive to CD95 signals, and insensitive cells can be converted to a sensitive phenotype if given appropriate treatment. To determine whether the apoptotic response of tumour cells to signalling through CD95 might be enhanced by ionizing irradiation, carcinoma cells were treated with either single-dose or fractionated γ-irradiation. The response to treatment with an agonist anti-CD95 antibody was enhanced by pretreatment with either a single large dose or daily fractionated radiation. Fractionated irradiation induced cumulative and prolonged up-regulation of CD95 expression in cell lines bearing functional p53. Since two of four cell lines exhibiting heightened responsiveness to CD95-mediated signals following fractionated irradiation express mutant p53 and displayed little or no up-regulation of CD95, enhanced responsiveness did not correlate with p53 status and CD95 up-regulation. Continuous inhibition of CD95/CD95–ligand interactions during fractionated irradiation provided no protective effect to cells, arguing that autologous CD95/CD95–ligand interactions did not contribute to the direct lethal effect of irradiation. We conclude that fractionated γ-irradiation provides an extended period of time when carcinoma cells are more responsive to CD95-mediated signals in vitro. © 1999 Cancer Research Campaign
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spelling pubmed-23631282009-09-10 Fractionated γ-irradiation renders tumour cells more responsive to apoptotic signals through CD95 Sheard, M A Krammer, P H Zaloudik, J Br J Cancer Regular Article Signals through the CD95 surface receptor can specifically induce apoptosis. Some tumour cell lines are sensitive to CD95 signals, and insensitive cells can be converted to a sensitive phenotype if given appropriate treatment. To determine whether the apoptotic response of tumour cells to signalling through CD95 might be enhanced by ionizing irradiation, carcinoma cells were treated with either single-dose or fractionated γ-irradiation. The response to treatment with an agonist anti-CD95 antibody was enhanced by pretreatment with either a single large dose or daily fractionated radiation. Fractionated irradiation induced cumulative and prolonged up-regulation of CD95 expression in cell lines bearing functional p53. Since two of four cell lines exhibiting heightened responsiveness to CD95-mediated signals following fractionated irradiation express mutant p53 and displayed little or no up-regulation of CD95, enhanced responsiveness did not correlate with p53 status and CD95 up-regulation. Continuous inhibition of CD95/CD95–ligand interactions during fractionated irradiation provided no protective effect to cells, arguing that autologous CD95/CD95–ligand interactions did not contribute to the direct lethal effect of irradiation. We conclude that fractionated γ-irradiation provides an extended period of time when carcinoma cells are more responsive to CD95-mediated signals in vitro. © 1999 Cancer Research Campaign Nature Publishing Group 1999-08 /pmc/articles/PMC2363128/ /pubmed/10468284 http://dx.doi.org/10.1038/sj.bjc.6690585 Text en Copyright © 1999 Cancer Research Campaign https://creativecommons.org/licenses/by/4.0/This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material.If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit https://creativecommons.org/licenses/by/4.0/.
spellingShingle Regular Article
Sheard, M A
Krammer, P H
Zaloudik, J
Fractionated γ-irradiation renders tumour cells more responsive to apoptotic signals through CD95
title Fractionated γ-irradiation renders tumour cells more responsive to apoptotic signals through CD95
title_full Fractionated γ-irradiation renders tumour cells more responsive to apoptotic signals through CD95
title_fullStr Fractionated γ-irradiation renders tumour cells more responsive to apoptotic signals through CD95
title_full_unstemmed Fractionated γ-irradiation renders tumour cells more responsive to apoptotic signals through CD95
title_short Fractionated γ-irradiation renders tumour cells more responsive to apoptotic signals through CD95
title_sort fractionated γ-irradiation renders tumour cells more responsive to apoptotic signals through cd95
topic Regular Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2363128/
https://www.ncbi.nlm.nih.gov/pubmed/10468284
http://dx.doi.org/10.1038/sj.bjc.6690585
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