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Low level phosphorylation of histone H2AX on serine 139 (γH2AX) is not associated with DNA double-strand breaks
Phosphorylation of histone H2AX on serine 139 (γH2AX) is an early step in cellular response to a DNA double-strand break (DSB). γH2AX foci are generally regarded as markers of DSBs. A growing body of evidence demonstrates, however, that while induction of DSBs always brings about phosphorylation of...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Impact Journals LLC
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5226530/ https://www.ncbi.nlm.nih.gov/pubmed/27391338 http://dx.doi.org/10.18632/oncotarget.10411 |
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author | Rybak, Paulina Hoang, Agnieszka Bujnowicz, Lukasz Bernas, Tytus Berniak, Krzysztof Zarębski, Mirosław Darzynkiewicz, Zbigniew Dobrucki, Jerzy |
author_facet | Rybak, Paulina Hoang, Agnieszka Bujnowicz, Lukasz Bernas, Tytus Berniak, Krzysztof Zarębski, Mirosław Darzynkiewicz, Zbigniew Dobrucki, Jerzy |
author_sort | Rybak, Paulina |
collection | PubMed |
description | Phosphorylation of histone H2AX on serine 139 (γH2AX) is an early step in cellular response to a DNA double-strand break (DSB). γH2AX foci are generally regarded as markers of DSBs. A growing body of evidence demonstrates, however, that while induction of DSBs always brings about phosphorylation of histone H2AX, the reverse is not true - the presence of γH2AX foci should not be considered an unequivocal marker of DNA double-strand breaks. We studied DNA damage induced in A549 human lung adenocarcinoma cells by topoisomerase type I and II inhibitors (0.2 μM camptothecin, 10 μM etoposide or 0.2 μM mitoxantrone for 1 h), and using 3D high resolution quantitative confocal microscopy, assessed the number, size and the integrated intensity of immunofluorescence signals of individual γH2AX foci induced by these drugs. Also, investigated was spatial association between γH2AX foci and foci of 53BP1, the protein involved in DSB repair, both in relation to DNA replication sites (factories) as revealed by labeling nascent DNA with EdU. Extensive 3D and correlation data analysis demonstrated that γH2AX foci exhibit a wide range of sizes and levels of H2AX phosphorylation, and correlate differently with 53BP1 and DNA replication. This is the first report showing lack of a link between low level phosphorylation γH2AX sites and double-strand DNA breaks in cells exposed to topoisomerase I or II inhibitors. The data are discussed in terms of mechanisms that may be involved in formation of γH2AX sites of different sizes and intensities. |
format | Online Article Text |
id | pubmed-5226530 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | Impact Journals LLC |
record_format | MEDLINE/PubMed |
spelling | pubmed-52265302017-01-18 Low level phosphorylation of histone H2AX on serine 139 (γH2AX) is not associated with DNA double-strand breaks Rybak, Paulina Hoang, Agnieszka Bujnowicz, Lukasz Bernas, Tytus Berniak, Krzysztof Zarębski, Mirosław Darzynkiewicz, Zbigniew Dobrucki, Jerzy Oncotarget Research Paper Phosphorylation of histone H2AX on serine 139 (γH2AX) is an early step in cellular response to a DNA double-strand break (DSB). γH2AX foci are generally regarded as markers of DSBs. A growing body of evidence demonstrates, however, that while induction of DSBs always brings about phosphorylation of histone H2AX, the reverse is not true - the presence of γH2AX foci should not be considered an unequivocal marker of DNA double-strand breaks. We studied DNA damage induced in A549 human lung adenocarcinoma cells by topoisomerase type I and II inhibitors (0.2 μM camptothecin, 10 μM etoposide or 0.2 μM mitoxantrone for 1 h), and using 3D high resolution quantitative confocal microscopy, assessed the number, size and the integrated intensity of immunofluorescence signals of individual γH2AX foci induced by these drugs. Also, investigated was spatial association between γH2AX foci and foci of 53BP1, the protein involved in DSB repair, both in relation to DNA replication sites (factories) as revealed by labeling nascent DNA with EdU. Extensive 3D and correlation data analysis demonstrated that γH2AX foci exhibit a wide range of sizes and levels of H2AX phosphorylation, and correlate differently with 53BP1 and DNA replication. This is the first report showing lack of a link between low level phosphorylation γH2AX sites and double-strand DNA breaks in cells exposed to topoisomerase I or II inhibitors. The data are discussed in terms of mechanisms that may be involved in formation of γH2AX sites of different sizes and intensities. Impact Journals LLC 2016-07-06 /pmc/articles/PMC5226530/ /pubmed/27391338 http://dx.doi.org/10.18632/oncotarget.10411 Text en Copyright: © 2016 Rybak et al. http://creativecommons.org/licenses/by/2.5/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Paper Rybak, Paulina Hoang, Agnieszka Bujnowicz, Lukasz Bernas, Tytus Berniak, Krzysztof Zarębski, Mirosław Darzynkiewicz, Zbigniew Dobrucki, Jerzy Low level phosphorylation of histone H2AX on serine 139 (γH2AX) is not associated with DNA double-strand breaks |
title | Low level phosphorylation of histone H2AX on serine 139 (γH2AX) is not associated with DNA double-strand breaks |
title_full | Low level phosphorylation of histone H2AX on serine 139 (γH2AX) is not associated with DNA double-strand breaks |
title_fullStr | Low level phosphorylation of histone H2AX on serine 139 (γH2AX) is not associated with DNA double-strand breaks |
title_full_unstemmed | Low level phosphorylation of histone H2AX on serine 139 (γH2AX) is not associated with DNA double-strand breaks |
title_short | Low level phosphorylation of histone H2AX on serine 139 (γH2AX) is not associated with DNA double-strand breaks |
title_sort | low level phosphorylation of histone h2ax on serine 139 (γh2ax) is not associated with dna double-strand breaks |
topic | Research Paper |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5226530/ https://www.ncbi.nlm.nih.gov/pubmed/27391338 http://dx.doi.org/10.18632/oncotarget.10411 |
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