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Pretreatment but not subsequent coincubation with midazolam reduces the cytotoxicity of temozolomide in neuroblastoma cells
BACKGROUND: Temozolomide (TMZ) induces a G2/M cell cycle arrest and is used for treatment of paediatric tumours, especially neuroblastomas. Patients treated with TMZ frequently receive midazolam for sedation prior to surgery and other interventions. Previous studies suggested both cytoprotective and...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
BioMed Central
2015
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4609078/ https://www.ncbi.nlm.nih.gov/pubmed/26475338 http://dx.doi.org/10.1186/s12871-015-0135-4 |
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author | Braun, Sebastian Bauer, Inge Pannen, Benedikt Werdehausen, Robert |
author_facet | Braun, Sebastian Bauer, Inge Pannen, Benedikt Werdehausen, Robert |
author_sort | Braun, Sebastian |
collection | PubMed |
description | BACKGROUND: Temozolomide (TMZ) induces a G2/M cell cycle arrest and is used for treatment of paediatric tumours, especially neuroblastomas. Patients treated with TMZ frequently receive midazolam for sedation prior to surgery and other interventions. Previous studies suggested both cytoprotective and apoptosis-inducing properties of midazolam. Therefore, the impact of midazolam on TMZ-induced cytotoxicity was investigated in vitro. METHODS: Human neuroblastoma cells were incubated with midazolam alone, as a pretreatment prior to incubation with TMZ or a coincubation of both. Cell viability and proliferation was analysed (XTT and BrdU assay) after 24 h and flowcytometric cell cycle analysis was performed after 24 and 48 h. RESULTS: Midazolam alone increased cell viability at lower concentrations (2, 4, 8, 16 μM), whereas higher concentrations (128, 256, 512 μM) reduced cell viability. Pretreatment with midazolam 6 h prior to TMZ incubation reduced cytotoxic effects (IC(25) 1005 ± 197 μM; IC(50) 1676 ± 557 μM; P < 0.05) compared to incubation with TMZ alone (IC(25) 449 ± 304 μM; IC(50) 925 ± 196 μM) and reduced the antiproliferative effect of TMZ (1000 μM) by 43.9 % (P < 0.05). In contrast, cytotoxic effects of TMZ were increased (IC(75) 1175 ± 221 μM vs. 2764 ± 307 μM; P < 0.05) when midazolam pretreatment was followed by coincubation of midazolam and TMZ. Cell cycle analysis revealed increased fractions of cells in G2/M phase after TMZ treatment (100 μM; 48 h), irrespective of midazolam pretreatment. CONCLUSION: Midazolam causes a hormetic dose–response relationship in human neuroblastoma cells. Pretreatment with midazolam reduces the cytotoxic and antiproliferative effects of TMZ without interfering with G2/M cell cycle arrest. In contrast, subsequent midazolam coincubation increases overall cytotoxicity. |
format | Online Article Text |
id | pubmed-4609078 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-46090782015-10-18 Pretreatment but not subsequent coincubation with midazolam reduces the cytotoxicity of temozolomide in neuroblastoma cells Braun, Sebastian Bauer, Inge Pannen, Benedikt Werdehausen, Robert BMC Anesthesiol Research Article BACKGROUND: Temozolomide (TMZ) induces a G2/M cell cycle arrest and is used for treatment of paediatric tumours, especially neuroblastomas. Patients treated with TMZ frequently receive midazolam for sedation prior to surgery and other interventions. Previous studies suggested both cytoprotective and apoptosis-inducing properties of midazolam. Therefore, the impact of midazolam on TMZ-induced cytotoxicity was investigated in vitro. METHODS: Human neuroblastoma cells were incubated with midazolam alone, as a pretreatment prior to incubation with TMZ or a coincubation of both. Cell viability and proliferation was analysed (XTT and BrdU assay) after 24 h and flowcytometric cell cycle analysis was performed after 24 and 48 h. RESULTS: Midazolam alone increased cell viability at lower concentrations (2, 4, 8, 16 μM), whereas higher concentrations (128, 256, 512 μM) reduced cell viability. Pretreatment with midazolam 6 h prior to TMZ incubation reduced cytotoxic effects (IC(25) 1005 ± 197 μM; IC(50) 1676 ± 557 μM; P < 0.05) compared to incubation with TMZ alone (IC(25) 449 ± 304 μM; IC(50) 925 ± 196 μM) and reduced the antiproliferative effect of TMZ (1000 μM) by 43.9 % (P < 0.05). In contrast, cytotoxic effects of TMZ were increased (IC(75) 1175 ± 221 μM vs. 2764 ± 307 μM; P < 0.05) when midazolam pretreatment was followed by coincubation of midazolam and TMZ. Cell cycle analysis revealed increased fractions of cells in G2/M phase after TMZ treatment (100 μM; 48 h), irrespective of midazolam pretreatment. CONCLUSION: Midazolam causes a hormetic dose–response relationship in human neuroblastoma cells. Pretreatment with midazolam reduces the cytotoxic and antiproliferative effects of TMZ without interfering with G2/M cell cycle arrest. In contrast, subsequent midazolam coincubation increases overall cytotoxicity. BioMed Central 2015-10-17 /pmc/articles/PMC4609078/ /pubmed/26475338 http://dx.doi.org/10.1186/s12871-015-0135-4 Text en © Braun et al. 2015 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. |
spellingShingle | Research Article Braun, Sebastian Bauer, Inge Pannen, Benedikt Werdehausen, Robert Pretreatment but not subsequent coincubation with midazolam reduces the cytotoxicity of temozolomide in neuroblastoma cells |
title | Pretreatment but not subsequent coincubation with midazolam reduces the cytotoxicity of temozolomide in neuroblastoma cells |
title_full | Pretreatment but not subsequent coincubation with midazolam reduces the cytotoxicity of temozolomide in neuroblastoma cells |
title_fullStr | Pretreatment but not subsequent coincubation with midazolam reduces the cytotoxicity of temozolomide in neuroblastoma cells |
title_full_unstemmed | Pretreatment but not subsequent coincubation with midazolam reduces the cytotoxicity of temozolomide in neuroblastoma cells |
title_short | Pretreatment but not subsequent coincubation with midazolam reduces the cytotoxicity of temozolomide in neuroblastoma cells |
title_sort | pretreatment but not subsequent coincubation with midazolam reduces the cytotoxicity of temozolomide in neuroblastoma cells |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4609078/ https://www.ncbi.nlm.nih.gov/pubmed/26475338 http://dx.doi.org/10.1186/s12871-015-0135-4 |
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