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Calpastatin phosphorylation regulates radiation-induced calpain activity in glioblastoma
Glioblastoma (GBM) is an aggressive, malignant brain tumor that inevitably develops resistance to conventional chemotherapy and radiation treatments. In order to identify signaling pathways involved in the development of radiation resistance, we performed mass spectrometry-based phospho-proteomic pr...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Impact Journals LLC
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5865692/ https://www.ncbi.nlm.nih.gov/pubmed/29581866 http://dx.doi.org/10.18632/oncotarget.24523 |
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author | Bassett, Emily A. Palanichamy, Kamalakannan Pearson, Mitchell McElroy, Joseph P. Haque, Saikh Jaharul Bell, Erica Hlavin Chakravarti, Arnab |
author_facet | Bassett, Emily A. Palanichamy, Kamalakannan Pearson, Mitchell McElroy, Joseph P. Haque, Saikh Jaharul Bell, Erica Hlavin Chakravarti, Arnab |
author_sort | Bassett, Emily A. |
collection | PubMed |
description | Glioblastoma (GBM) is an aggressive, malignant brain tumor that inevitably develops resistance to conventional chemotherapy and radiation treatments. In order to identify signaling pathways involved in the development of radiation resistance, we performed mass spectrometry-based phospho-proteomic profiling of GBM cell lines and normal human astrocytes before and after radiation treatment. We found radiation induced phosphorylation of a number of proteins including calpastatin, specifically in GBM stem cells (GSCs). Herein, we focused on calpastatin, an endogenous inhibitor of calpain proteases. Radiation-induced phosphorylation of calpastatin at Ser-633 within the inhibitory domain was validated with a phospho-specific antibody. In order to test the functional significance of phosphorylated calpastatin, we utilized site-directed mutagenesis to generate phospho-inactive (Ser633Ala) and phospho-mimetic (Ser633Glu) mutant calpastatin. GBM cell lines stably expressing the mutant calpastatin showed that phosphorylation was necessary for radiation-induced calpain activation. We also showed that casein kinase 2, a pro-survival kinase overexpressed in many cancer types, phosphorylated calpastatin at Ser-633. Our results indicate that calpastatin phosphorylation promotes radiation resistance in GBM cells by increasing the activity of calpain proteases, which are known to promote survival and invasion in cancer. |
format | Online Article Text |
id | pubmed-5865692 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | Impact Journals LLC |
record_format | MEDLINE/PubMed |
spelling | pubmed-58656922018-03-26 Calpastatin phosphorylation regulates radiation-induced calpain activity in glioblastoma Bassett, Emily A. Palanichamy, Kamalakannan Pearson, Mitchell McElroy, Joseph P. Haque, Saikh Jaharul Bell, Erica Hlavin Chakravarti, Arnab Oncotarget Research Paper Glioblastoma (GBM) is an aggressive, malignant brain tumor that inevitably develops resistance to conventional chemotherapy and radiation treatments. In order to identify signaling pathways involved in the development of radiation resistance, we performed mass spectrometry-based phospho-proteomic profiling of GBM cell lines and normal human astrocytes before and after radiation treatment. We found radiation induced phosphorylation of a number of proteins including calpastatin, specifically in GBM stem cells (GSCs). Herein, we focused on calpastatin, an endogenous inhibitor of calpain proteases. Radiation-induced phosphorylation of calpastatin at Ser-633 within the inhibitory domain was validated with a phospho-specific antibody. In order to test the functional significance of phosphorylated calpastatin, we utilized site-directed mutagenesis to generate phospho-inactive (Ser633Ala) and phospho-mimetic (Ser633Glu) mutant calpastatin. GBM cell lines stably expressing the mutant calpastatin showed that phosphorylation was necessary for radiation-induced calpain activation. We also showed that casein kinase 2, a pro-survival kinase overexpressed in many cancer types, phosphorylated calpastatin at Ser-633. Our results indicate that calpastatin phosphorylation promotes radiation resistance in GBM cells by increasing the activity of calpain proteases, which are known to promote survival and invasion in cancer. Impact Journals LLC 2018-02-19 /pmc/articles/PMC5865692/ /pubmed/29581866 http://dx.doi.org/10.18632/oncotarget.24523 Text en Copyright: © 2018 Bassett et al. http://creativecommons.org/licenses/by/3.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License 3.0 (http://creativecommons.org/licenses/by/3.0/) (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Paper Bassett, Emily A. Palanichamy, Kamalakannan Pearson, Mitchell McElroy, Joseph P. Haque, Saikh Jaharul Bell, Erica Hlavin Chakravarti, Arnab Calpastatin phosphorylation regulates radiation-induced calpain activity in glioblastoma |
title | Calpastatin phosphorylation regulates radiation-induced calpain activity in glioblastoma |
title_full | Calpastatin phosphorylation regulates radiation-induced calpain activity in glioblastoma |
title_fullStr | Calpastatin phosphorylation regulates radiation-induced calpain activity in glioblastoma |
title_full_unstemmed | Calpastatin phosphorylation regulates radiation-induced calpain activity in glioblastoma |
title_short | Calpastatin phosphorylation regulates radiation-induced calpain activity in glioblastoma |
title_sort | calpastatin phosphorylation regulates radiation-induced calpain activity in glioblastoma |
topic | Research Paper |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5865692/ https://www.ncbi.nlm.nih.gov/pubmed/29581866 http://dx.doi.org/10.18632/oncotarget.24523 |
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