Selective inhibition of BCL-XL increases sensitivity of pediatric tumour models to the anti-mitotic agent MLN8237

Jane Levesley, Lynette Steele, Anke Bruning-Richardson, Adam Davison, Jia Zhou, Sean Lawler, Susan C Short

Research output: Contribution to journalMeeting Abstract

Abstract

BACKGROUND: Small molecule inhibitors of the mitotic kinases, including the Aurora kinase inhibitor MLN8237, are being investigated as novel therapeutic agents for the treatment of solid cancers including malignant brain tumours. However, resistance has been observed and anti-apoptotic proteins of the BCL-2 family have been shown to promote cell survival following treatment. In this study, we investigated the effect of disrupting anti-apoptotic protein function in medulloblastoma and pediatric glioblastoma (pGBM) models using BH3-mimetics in combination with MLN8237. METHODS: The effects of single agent and combination treatment on cell viability were determined by MTT/WST-1 assays and flow cytometry. Effects on cell phenotype, cell cycle progression and cellular ploidy were determined by live cell imaging and DNA content analysis. Induction of apoptosis was monitored in real-time, by time-lapse microscopy, using a fluorescent, polarity-sensitive phosphatidylserine probe, and confirmed by measuring caspase-3/7 activity. Knockdown of BAX/BAK was used to confirm these effects. Results: ABT-263 in combination with MLN8237 reduced mitotic slippage and polyploidy, significantly reduced cell viability and promoted the elimination of mitotically defective cells. This occurred through a BAX/BAK-dependent, caspase-mediated apoptotic pathway. The BCL-xL antagonist, WEHI-539, which targets BCL-2, significantly augmented tumour cell killing when used in combination with MLN8237. It also sensitized resistant brain tumour cells to a novel BAX activator, SMBA1. In addition, siRNA mediated knockdown of BCL-xL sensitized pGBM and medulloblastoma cells to MLN8237, and mimicked the effect of combination drug treatment. CONCLUSION: Combination treatment using a pro-apoptotic agent enhanced the cytotoxicity of MLN8237 in paediatric tumours and may overcome an important resistance mechanism
LanguageEnglish
Pages94
Number of pages1
JournalNeuro-Oncology
Volume19
Issue numberS3
DOIs
Publication statusPublished - May 2017
Externally publishedYes
Event5th Quadrennial Meeting of the World Federation of Neuro-Oncology Societies - Zurich, Switzerland
Duration: 4 May 20177 May 2017
Conference number: 5
https://www.eano.eu/eanomeetings/past-meetings/wfnos-2017-meeting/welcome/ (Link to Conference Details)

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Pediatrics
Neoplasms
Cell Survival
Apoptosis Regulatory Proteins
Medulloblastoma
Glioblastoma
Brain Neoplasms
Aurora Kinases
Caspase 7
Polyploidy
Ploidies
Phosphatidylserines
Drug Combinations
Caspases
Caspase 3
Small Interfering RNA
MLN 8237
Microscopy
Cell Cycle
Flow Cytometry

Cite this

Levesley, Jane ; Steele, Lynette ; Bruning-Richardson, Anke ; Davison, Adam ; Zhou, Jia ; Lawler, Sean ; Short, Susan C. / Selective inhibition of BCL-XL increases sensitivity of pediatric tumour models to the anti-mitotic agent MLN8237. In: Neuro-Oncology. 2017 ; Vol. 19, No. S3. pp. 94.
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title = "Selective inhibition of BCL-XL increases sensitivity of pediatric tumour models to the anti-mitotic agent MLN8237",
abstract = "BACKGROUND: Small molecule inhibitors of the mitotic kinases, including the Aurora kinase inhibitor MLN8237, are being investigated as novel therapeutic agents for the treatment of solid cancers including malignant brain tumours. However, resistance has been observed and anti-apoptotic proteins of the BCL-2 family have been shown to promote cell survival following treatment. In this study, we investigated the effect of disrupting anti-apoptotic protein function in medulloblastoma and pediatric glioblastoma (pGBM) models using BH3-mimetics in combination with MLN8237. METHODS: The effects of single agent and combination treatment on cell viability were determined by MTT/WST-1 assays and flow cytometry. Effects on cell phenotype, cell cycle progression and cellular ploidy were determined by live cell imaging and DNA content analysis. Induction of apoptosis was monitored in real-time, by time-lapse microscopy, using a fluorescent, polarity-sensitive phosphatidylserine probe, and confirmed by measuring caspase-3/7 activity. Knockdown of BAX/BAK was used to confirm these effects. Results: ABT-263 in combination with MLN8237 reduced mitotic slippage and polyploidy, significantly reduced cell viability and promoted the elimination of mitotically defective cells. This occurred through a BAX/BAK-dependent, caspase-mediated apoptotic pathway. The BCL-xL antagonist, WEHI-539, which targets BCL-2, significantly augmented tumour cell killing when used in combination with MLN8237. It also sensitized resistant brain tumour cells to a novel BAX activator, SMBA1. In addition, siRNA mediated knockdown of BCL-xL sensitized pGBM and medulloblastoma cells to MLN8237, and mimicked the effect of combination drug treatment. CONCLUSION: Combination treatment using a pro-apoptotic agent enhanced the cytotoxicity of MLN8237 in paediatric tumours and may overcome an important resistance mechanism",
author = "Jane Levesley and Lynette Steele and Anke Bruning-Richardson and Adam Davison and Jia Zhou and Sean Lawler and Short, {Susan C}",
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doi = "10.1093/neuonc/nox036.358",
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Selective inhibition of BCL-XL increases sensitivity of pediatric tumour models to the anti-mitotic agent MLN8237. / Levesley, Jane; Steele, Lynette; Bruning-Richardson, Anke; Davison, Adam; Zhou, Jia; Lawler, Sean; Short, Susan C.

In: Neuro-Oncology, Vol. 19, No. S3, 05.2017, p. 94.

Research output: Contribution to journalMeeting Abstract

TY - JOUR

T1 - Selective inhibition of BCL-XL increases sensitivity of pediatric tumour models to the anti-mitotic agent MLN8237

AU - Levesley, Jane

AU - Steele, Lynette

AU - Bruning-Richardson, Anke

AU - Davison, Adam

AU - Zhou, Jia

AU - Lawler, Sean

AU - Short, Susan C

PY - 2017/5

Y1 - 2017/5

N2 - BACKGROUND: Small molecule inhibitors of the mitotic kinases, including the Aurora kinase inhibitor MLN8237, are being investigated as novel therapeutic agents for the treatment of solid cancers including malignant brain tumours. However, resistance has been observed and anti-apoptotic proteins of the BCL-2 family have been shown to promote cell survival following treatment. In this study, we investigated the effect of disrupting anti-apoptotic protein function in medulloblastoma and pediatric glioblastoma (pGBM) models using BH3-mimetics in combination with MLN8237. METHODS: The effects of single agent and combination treatment on cell viability were determined by MTT/WST-1 assays and flow cytometry. Effects on cell phenotype, cell cycle progression and cellular ploidy were determined by live cell imaging and DNA content analysis. Induction of apoptosis was monitored in real-time, by time-lapse microscopy, using a fluorescent, polarity-sensitive phosphatidylserine probe, and confirmed by measuring caspase-3/7 activity. Knockdown of BAX/BAK was used to confirm these effects. Results: ABT-263 in combination with MLN8237 reduced mitotic slippage and polyploidy, significantly reduced cell viability and promoted the elimination of mitotically defective cells. This occurred through a BAX/BAK-dependent, caspase-mediated apoptotic pathway. The BCL-xL antagonist, WEHI-539, which targets BCL-2, significantly augmented tumour cell killing when used in combination with MLN8237. It also sensitized resistant brain tumour cells to a novel BAX activator, SMBA1. In addition, siRNA mediated knockdown of BCL-xL sensitized pGBM and medulloblastoma cells to MLN8237, and mimicked the effect of combination drug treatment. CONCLUSION: Combination treatment using a pro-apoptotic agent enhanced the cytotoxicity of MLN8237 in paediatric tumours and may overcome an important resistance mechanism

AB - BACKGROUND: Small molecule inhibitors of the mitotic kinases, including the Aurora kinase inhibitor MLN8237, are being investigated as novel therapeutic agents for the treatment of solid cancers including malignant brain tumours. However, resistance has been observed and anti-apoptotic proteins of the BCL-2 family have been shown to promote cell survival following treatment. In this study, we investigated the effect of disrupting anti-apoptotic protein function in medulloblastoma and pediatric glioblastoma (pGBM) models using BH3-mimetics in combination with MLN8237. METHODS: The effects of single agent and combination treatment on cell viability were determined by MTT/WST-1 assays and flow cytometry. Effects on cell phenotype, cell cycle progression and cellular ploidy were determined by live cell imaging and DNA content analysis. Induction of apoptosis was monitored in real-time, by time-lapse microscopy, using a fluorescent, polarity-sensitive phosphatidylserine probe, and confirmed by measuring caspase-3/7 activity. Knockdown of BAX/BAK was used to confirm these effects. Results: ABT-263 in combination with MLN8237 reduced mitotic slippage and polyploidy, significantly reduced cell viability and promoted the elimination of mitotically defective cells. This occurred through a BAX/BAK-dependent, caspase-mediated apoptotic pathway. The BCL-xL antagonist, WEHI-539, which targets BCL-2, significantly augmented tumour cell killing when used in combination with MLN8237. It also sensitized resistant brain tumour cells to a novel BAX activator, SMBA1. In addition, siRNA mediated knockdown of BCL-xL sensitized pGBM and medulloblastoma cells to MLN8237, and mimicked the effect of combination drug treatment. CONCLUSION: Combination treatment using a pro-apoptotic agent enhanced the cytotoxicity of MLN8237 in paediatric tumours and may overcome an important resistance mechanism

U2 - 10.1093/neuonc/nox036.358

DO - 10.1093/neuonc/nox036.358

M3 - Meeting Abstract

VL - 19

SP - 94

JO - Neuro-Oncology

T2 - Neuro-Oncology

JF - Neuro-Oncology

SN - 1522-8517

IS - S3

ER -