Irreversible EGFR inhibitor EKB-569 targets low-LET γ-radiation-triggered rel orchestration and potentiates cell death in squamous cell carcinoma.
EKB-569 (Pelitinib), an irreversible EGFR tyrosine kinase inhibitor has shown potential therapeutic efficiency in solid tumors. However, cell-killing potential in combination with radiotherapy and its underlying molecular orchestration remain to be explored. The objective of this study was to determ...
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Public Library of Science (PLoS)
2011-01-01
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Series: | PLoS ONE |
Online Access: | http://europepmc.org/articles/PMC3248439?pdf=render |
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author | Natarajan Aravindan Charles R Thomas Sheeja Aravindan Aswathi S Mohan Jamunarani Veeraraghavan Mohan Natarajan |
author_facet | Natarajan Aravindan Charles R Thomas Sheeja Aravindan Aswathi S Mohan Jamunarani Veeraraghavan Mohan Natarajan |
author_sort | Natarajan Aravindan |
collection | DOAJ |
description | EKB-569 (Pelitinib), an irreversible EGFR tyrosine kinase inhibitor has shown potential therapeutic efficiency in solid tumors. However, cell-killing potential in combination with radiotherapy and its underlying molecular orchestration remain to be explored. The objective of this study was to determine the effect of EKB-569 on ionizing radiation (IR)-associated NFκB-dependent cell death. SCC-4 and SCC-9 cells exposed to IR (2Gy) with and without EKB-569 treatment were analyzed for transactivation of 88 NFκB pathway molecules, NFκB DNA-binding activity, translation of the NFκB downstream mediators, Birc1, 2 and 5, cell viability, metabolic activity and apoptosis. Selective targeting of IR-induced NFκB by EKB-569 and its influence on cell-fate were assessed by overexpressing (p50/p65) and silencing (ΔIκBα) NFκB. QPCR profiling after IR exposure revealed a significant induction of 74 NFκB signal transduction molecules. Of those, 72 were suppressed with EKB-569. EMSA revealed a dose dependent inhibition of NFκB by EKB-569. More importantly, EKB-569 inhibited IR-induced NFκB in a dose-dependent manner, and this inhibition was sustained up to at least 72 h. Immunoblotting revealed a significant suppression of IR-induced Birc1, 2 and 5 by EKB-569. We observed a dose-dependent inhibition of cell viability, metabolic activity and apoptosis with EKB-569. EKB-569 significantly enhanced IR-induced cell death and apoptosis. Blocking NFκB improved IR-induced cell death. Conversely, NFκB overexpression negates EKB-569 -induced cell-killing. Together, these pre-clinical data suggest that EKB-569 is a radiosensitizer of squamous cell carcinoma and may mechanistically involve selective targeting of IR-induced NFκB-dependent survival signaling. Further pre-clinical in-vivo studies are warranted. |
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spelling | doaj.art-867f269632e7440c8f43f7a77b98db1e2022-12-21T18:10:15ZengPublic Library of Science (PLoS)PLoS ONE1932-62032011-01-01612e2970510.1371/journal.pone.0029705Irreversible EGFR inhibitor EKB-569 targets low-LET γ-radiation-triggered rel orchestration and potentiates cell death in squamous cell carcinoma.Natarajan AravindanCharles R ThomasSheeja AravindanAswathi S MohanJamunarani VeeraraghavanMohan NatarajanEKB-569 (Pelitinib), an irreversible EGFR tyrosine kinase inhibitor has shown potential therapeutic efficiency in solid tumors. However, cell-killing potential in combination with radiotherapy and its underlying molecular orchestration remain to be explored. The objective of this study was to determine the effect of EKB-569 on ionizing radiation (IR)-associated NFκB-dependent cell death. SCC-4 and SCC-9 cells exposed to IR (2Gy) with and without EKB-569 treatment were analyzed for transactivation of 88 NFκB pathway molecules, NFκB DNA-binding activity, translation of the NFκB downstream mediators, Birc1, 2 and 5, cell viability, metabolic activity and apoptosis. Selective targeting of IR-induced NFκB by EKB-569 and its influence on cell-fate were assessed by overexpressing (p50/p65) and silencing (ΔIκBα) NFκB. QPCR profiling after IR exposure revealed a significant induction of 74 NFκB signal transduction molecules. Of those, 72 were suppressed with EKB-569. EMSA revealed a dose dependent inhibition of NFκB by EKB-569. More importantly, EKB-569 inhibited IR-induced NFκB in a dose-dependent manner, and this inhibition was sustained up to at least 72 h. Immunoblotting revealed a significant suppression of IR-induced Birc1, 2 and 5 by EKB-569. We observed a dose-dependent inhibition of cell viability, metabolic activity and apoptosis with EKB-569. EKB-569 significantly enhanced IR-induced cell death and apoptosis. Blocking NFκB improved IR-induced cell death. Conversely, NFκB overexpression negates EKB-569 -induced cell-killing. Together, these pre-clinical data suggest that EKB-569 is a radiosensitizer of squamous cell carcinoma and may mechanistically involve selective targeting of IR-induced NFκB-dependent survival signaling. Further pre-clinical in-vivo studies are warranted.http://europepmc.org/articles/PMC3248439?pdf=render |
spellingShingle | Natarajan Aravindan Charles R Thomas Sheeja Aravindan Aswathi S Mohan Jamunarani Veeraraghavan Mohan Natarajan Irreversible EGFR inhibitor EKB-569 targets low-LET γ-radiation-triggered rel orchestration and potentiates cell death in squamous cell carcinoma. PLoS ONE |
title | Irreversible EGFR inhibitor EKB-569 targets low-LET γ-radiation-triggered rel orchestration and potentiates cell death in squamous cell carcinoma. |
title_full | Irreversible EGFR inhibitor EKB-569 targets low-LET γ-radiation-triggered rel orchestration and potentiates cell death in squamous cell carcinoma. |
title_fullStr | Irreversible EGFR inhibitor EKB-569 targets low-LET γ-radiation-triggered rel orchestration and potentiates cell death in squamous cell carcinoma. |
title_full_unstemmed | Irreversible EGFR inhibitor EKB-569 targets low-LET γ-radiation-triggered rel orchestration and potentiates cell death in squamous cell carcinoma. |
title_short | Irreversible EGFR inhibitor EKB-569 targets low-LET γ-radiation-triggered rel orchestration and potentiates cell death in squamous cell carcinoma. |
title_sort | irreversible egfr inhibitor ekb 569 targets low let γ radiation triggered rel orchestration and potentiates cell death in squamous cell carcinoma |
url | http://europepmc.org/articles/PMC3248439?pdf=render |
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