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Downregulation of LRRC8A protects human ovarian and alveolar carcinoma cells against Cisplatin-induced expression of p53, MDM2, p21(Waf1/Cip1), and Caspase-9/-3 activation

The leucine-rich repeat containing 8A (LRRC8A) protein is an essential component of the volume-sensitive organic anion channel (VSOAC), and using pharmacological anion channel inhibitors (NS3728, DIDS) and LRRC8A siRNA we have investigated its role in development of Cisplatin resistance in human ova...

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Autores principales: Sørensen, Belinda Halling, Nielsen, Dorthe, Thorsteinsdottir, Unnur Arna, Hoffmann, Else Kay, Lambert, Ian Henry
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Physiological Society 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4935196/
https://www.ncbi.nlm.nih.gov/pubmed/26984736
http://dx.doi.org/10.1152/ajpcell.00256.2015
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author Sørensen, Belinda Halling
Nielsen, Dorthe
Thorsteinsdottir, Unnur Arna
Hoffmann, Else Kay
Lambert, Ian Henry
author_facet Sørensen, Belinda Halling
Nielsen, Dorthe
Thorsteinsdottir, Unnur Arna
Hoffmann, Else Kay
Lambert, Ian Henry
author_sort Sørensen, Belinda Halling
collection PubMed
description The leucine-rich repeat containing 8A (LRRC8A) protein is an essential component of the volume-sensitive organic anion channel (VSOAC), and using pharmacological anion channel inhibitors (NS3728, DIDS) and LRRC8A siRNA we have investigated its role in development of Cisplatin resistance in human ovarian (A2780) and alveolar (A549) carcinoma cells. In Cisplatin-sensitive cells Cisplatin treatment increases p53-protein level as well as downstream signaling, e.g., expression of p21(Waf1/Cip1), Bax, Noxa, MDM2, and activation of Caspase-9/-3. In contrast, Cisplatin-resistant cells do not enter apoptosis, i.e., their p53 and downstream signaling are reduced and caspase activity unaltered following Cisplatin exposure. Reduced LRRC8A expression and VSOAC activity are previously shown to correlate with Cisplatin resistance, and here we demonstrate that pharmacological inhibition and transient knockdown of LRRC8A reduce the protein level of p53, MDM2, and p21(Waf1/Cip1) as well as Caspase-9/-3 activation in Cisplatin-sensitive cells. Cisplatin resistance is accompanied by reduction in total LRRC8A expression (A2780) or LRRC8A expression in the plasma membrane (A549). Activation of Caspase-3 dependent apoptosis by TNFα-exposure or hyperosmotic cell shrinkage is almost unaffected by pharmacological anion channel inhibition. Our data indicate 1) that expression/activity of LRRC8A is essential for Cisplatin-induced increase in p53 protein level and its downstream signaling, i.e., Caspase-9/-3 activation, expression of p21(Waf1/Cip1) and MDM2; and 2) that downregulation of LRRC8A-dependent osmolyte transporters contributes to acquirement of Cisplatin resistance in ovarian and lung carcinoma cells. Activation of LRRC8A-containing channels is upstream to apoptotic volume decrease as hypertonic cell shrinkage induces apoptosis independent of the presence of LRRC8A.
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spelling pubmed-49351962016-07-15 Downregulation of LRRC8A protects human ovarian and alveolar carcinoma cells against Cisplatin-induced expression of p53, MDM2, p21(Waf1/Cip1), and Caspase-9/-3 activation Sørensen, Belinda Halling Nielsen, Dorthe Thorsteinsdottir, Unnur Arna Hoffmann, Else Kay Lambert, Ian Henry Am J Physiol Cell Physiol Call for Papers The leucine-rich repeat containing 8A (LRRC8A) protein is an essential component of the volume-sensitive organic anion channel (VSOAC), and using pharmacological anion channel inhibitors (NS3728, DIDS) and LRRC8A siRNA we have investigated its role in development of Cisplatin resistance in human ovarian (A2780) and alveolar (A549) carcinoma cells. In Cisplatin-sensitive cells Cisplatin treatment increases p53-protein level as well as downstream signaling, e.g., expression of p21(Waf1/Cip1), Bax, Noxa, MDM2, and activation of Caspase-9/-3. In contrast, Cisplatin-resistant cells do not enter apoptosis, i.e., their p53 and downstream signaling are reduced and caspase activity unaltered following Cisplatin exposure. Reduced LRRC8A expression and VSOAC activity are previously shown to correlate with Cisplatin resistance, and here we demonstrate that pharmacological inhibition and transient knockdown of LRRC8A reduce the protein level of p53, MDM2, and p21(Waf1/Cip1) as well as Caspase-9/-3 activation in Cisplatin-sensitive cells. Cisplatin resistance is accompanied by reduction in total LRRC8A expression (A2780) or LRRC8A expression in the plasma membrane (A549). Activation of Caspase-3 dependent apoptosis by TNFα-exposure or hyperosmotic cell shrinkage is almost unaffected by pharmacological anion channel inhibition. Our data indicate 1) that expression/activity of LRRC8A is essential for Cisplatin-induced increase in p53 protein level and its downstream signaling, i.e., Caspase-9/-3 activation, expression of p21(Waf1/Cip1) and MDM2; and 2) that downregulation of LRRC8A-dependent osmolyte transporters contributes to acquirement of Cisplatin resistance in ovarian and lung carcinoma cells. Activation of LRRC8A-containing channels is upstream to apoptotic volume decrease as hypertonic cell shrinkage induces apoptosis independent of the presence of LRRC8A. American Physiological Society 2016-03-16 2016-06-01 /pmc/articles/PMC4935196/ /pubmed/26984736 http://dx.doi.org/10.1152/ajpcell.00256.2015 Text en Copyright © 2016 the American Physiological Society Licensed under Creative Commons Attribution CC-BY 3.0 (http://creativecommons.org/licenses/by/3.0/deed.en_US) : © the American Physiological Society.
spellingShingle Call for Papers
Sørensen, Belinda Halling
Nielsen, Dorthe
Thorsteinsdottir, Unnur Arna
Hoffmann, Else Kay
Lambert, Ian Henry
Downregulation of LRRC8A protects human ovarian and alveolar carcinoma cells against Cisplatin-induced expression of p53, MDM2, p21(Waf1/Cip1), and Caspase-9/-3 activation
title Downregulation of LRRC8A protects human ovarian and alveolar carcinoma cells against Cisplatin-induced expression of p53, MDM2, p21(Waf1/Cip1), and Caspase-9/-3 activation
title_full Downregulation of LRRC8A protects human ovarian and alveolar carcinoma cells against Cisplatin-induced expression of p53, MDM2, p21(Waf1/Cip1), and Caspase-9/-3 activation
title_fullStr Downregulation of LRRC8A protects human ovarian and alveolar carcinoma cells against Cisplatin-induced expression of p53, MDM2, p21(Waf1/Cip1), and Caspase-9/-3 activation
title_full_unstemmed Downregulation of LRRC8A protects human ovarian and alveolar carcinoma cells against Cisplatin-induced expression of p53, MDM2, p21(Waf1/Cip1), and Caspase-9/-3 activation
title_short Downregulation of LRRC8A protects human ovarian and alveolar carcinoma cells against Cisplatin-induced expression of p53, MDM2, p21(Waf1/Cip1), and Caspase-9/-3 activation
title_sort downregulation of lrrc8a protects human ovarian and alveolar carcinoma cells against cisplatin-induced expression of p53, mdm2, p21(waf1/cip1), and caspase-9/-3 activation
topic Call for Papers
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4935196/
https://www.ncbi.nlm.nih.gov/pubmed/26984736
http://dx.doi.org/10.1152/ajpcell.00256.2015
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