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Chemosensitization by phenothiazines in human lung cancer cells: impaired resolution of γH2AX and increased oxidative stress elicit apoptosis associated with lysosomal expansion and intense vacuolation

Chemotherapy resistance poses severe limitations on the efficacy of anti-cancer medications. Recently, the notion of using novel combinations of ‘old' drugs for new indications has garnered significant interest. The potential of using phenothiazines as chemosensitizers has been suggested earlie...

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Autores principales: Zong, D, Hååg, P, Yakymovych, I, Lewensohn, R, Viktorsson, K
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3199719/
https://www.ncbi.nlm.nih.gov/pubmed/21776019
http://dx.doi.org/10.1038/cddis.2011.62
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author Zong, D
Hååg, P
Yakymovych, I
Lewensohn, R
Viktorsson, K
author_facet Zong, D
Hååg, P
Yakymovych, I
Lewensohn, R
Viktorsson, K
author_sort Zong, D
collection PubMed
description Chemotherapy resistance poses severe limitations on the efficacy of anti-cancer medications. Recently, the notion of using novel combinations of ‘old' drugs for new indications has garnered significant interest. The potential of using phenothiazines as chemosensitizers has been suggested earlier but so far our understanding of their molecular targets remains scant. The current study was designed to better define phenothiazine-sensitive cellular processes in relation to chemosensitivity. We found that phenothiazines shared the ability to delay γH2AX resolution in DNA-damaged human lung cancer cells. Accordingly, cells co-treated with chemotherapy and phenothiazines underwent protracted cell-cycle arrest followed by checkpoint escape that led to abnormal mitoses, secondary arrest and/or a form of apoptosis associated with increased endogenous oxidative stress and intense vacuolation. We provide evidence implicating lysosomal dysfunction as a key component of cell death in phenothiazine co-treated cells, which also exhibited more typical hallmarks of apoptosis including the activation of both caspase-dependent and -independent pathways. Finally, we demonstrated that vacuolation in phenothiazine co-treated cells could be reduced by ROS scavengers or the vacuolar ATPase inhibitor bafilomycin, leading to increased cell viability. Our data highlight the potential benefit of using phenothiazines as chemosensitizers in tumors that acquire molecular alterations rendering them insensitive to caspase-mediated apoptosis.
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spelling pubmed-31997192011-10-24 Chemosensitization by phenothiazines in human lung cancer cells: impaired resolution of γH2AX and increased oxidative stress elicit apoptosis associated with lysosomal expansion and intense vacuolation Zong, D Hååg, P Yakymovych, I Lewensohn, R Viktorsson, K Cell Death Dis Original Article Chemotherapy resistance poses severe limitations on the efficacy of anti-cancer medications. Recently, the notion of using novel combinations of ‘old' drugs for new indications has garnered significant interest. The potential of using phenothiazines as chemosensitizers has been suggested earlier but so far our understanding of their molecular targets remains scant. The current study was designed to better define phenothiazine-sensitive cellular processes in relation to chemosensitivity. We found that phenothiazines shared the ability to delay γH2AX resolution in DNA-damaged human lung cancer cells. Accordingly, cells co-treated with chemotherapy and phenothiazines underwent protracted cell-cycle arrest followed by checkpoint escape that led to abnormal mitoses, secondary arrest and/or a form of apoptosis associated with increased endogenous oxidative stress and intense vacuolation. We provide evidence implicating lysosomal dysfunction as a key component of cell death in phenothiazine co-treated cells, which also exhibited more typical hallmarks of apoptosis including the activation of both caspase-dependent and -independent pathways. Finally, we demonstrated that vacuolation in phenothiazine co-treated cells could be reduced by ROS scavengers or the vacuolar ATPase inhibitor bafilomycin, leading to increased cell viability. Our data highlight the potential benefit of using phenothiazines as chemosensitizers in tumors that acquire molecular alterations rendering them insensitive to caspase-mediated apoptosis. Nature Publishing Group 2011-07 2011-07-21 /pmc/articles/PMC3199719/ /pubmed/21776019 http://dx.doi.org/10.1038/cddis.2011.62 Text en Copyright © 2011 Macmillan Publishers Limited http://creativecommons.org/licenses/by-nc-nd/3.0/ This work is licensed under the Creative Commons Attribution-NonCommercial-No Derivative Works 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-nd/3.0/
spellingShingle Original Article
Zong, D
Hååg, P
Yakymovych, I
Lewensohn, R
Viktorsson, K
Chemosensitization by phenothiazines in human lung cancer cells: impaired resolution of γH2AX and increased oxidative stress elicit apoptosis associated with lysosomal expansion and intense vacuolation
title Chemosensitization by phenothiazines in human lung cancer cells: impaired resolution of γH2AX and increased oxidative stress elicit apoptosis associated with lysosomal expansion and intense vacuolation
title_full Chemosensitization by phenothiazines in human lung cancer cells: impaired resolution of γH2AX and increased oxidative stress elicit apoptosis associated with lysosomal expansion and intense vacuolation
title_fullStr Chemosensitization by phenothiazines in human lung cancer cells: impaired resolution of γH2AX and increased oxidative stress elicit apoptosis associated with lysosomal expansion and intense vacuolation
title_full_unstemmed Chemosensitization by phenothiazines in human lung cancer cells: impaired resolution of γH2AX and increased oxidative stress elicit apoptosis associated with lysosomal expansion and intense vacuolation
title_short Chemosensitization by phenothiazines in human lung cancer cells: impaired resolution of γH2AX and increased oxidative stress elicit apoptosis associated with lysosomal expansion and intense vacuolation
title_sort chemosensitization by phenothiazines in human lung cancer cells: impaired resolution of γh2ax and increased oxidative stress elicit apoptosis associated with lysosomal expansion and intense vacuolation
topic Original Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3199719/
https://www.ncbi.nlm.nih.gov/pubmed/21776019
http://dx.doi.org/10.1038/cddis.2011.62
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