Article
Combined treatment with ONC201/TIC10 and ABT-263 results in a synergistic anti-medulloblastoma activity in vitro
Die kombinierte Behandlung mit ONC201/TIC10 und ABT-263 führt zu einer synergistischen anti-neoplastischen Aktivität im Medulloblastomin vitro
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Authors
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Antonia Spilz
- Universitätsklinikum Ulm, Neurochirurgie, Ulm, Deutschland
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Annika Dwucet
- Universitätsklinikum Ulm, Neurochirurgie, Ulm, Deutschland
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Felix Seyfried
- Universitätsklinikum Ulm, Kinder- und Jugendmedizin, Ulm, Deutschland
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Aurelia Peraud
- Universitätsklinikum Ulm, Neurochirurgie, Ulm, Deutschland
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Varun V. Prabhu
- Chimerix, Durham, NC, Vereinigte Staaten
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Joshua E. Allen
- Chimerix, Durham, NC, Vereinigte Staaten
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Mike-Andrew Westhoff
- Universitätsklinikum Ulm, Kinder- und Jugendmedizin, Ulm, Deutschland
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Markus David Siegelin
- Columbia University, Department of Pathology and Cell Biology, New York, NY, Vereinigte Staaten
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Christian Rainer Wirtz
- Universitätsklinikum Ulm, Neurochirurgie, Ulm, Deutschland
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Georg Karpel-Massler
- Universitätsklinikum Ulm, Neurochirurgie, Ulm, Deutschland
| Published: | May 25, 2022 |
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Outline
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Objective: Medulloblastoma represents one of the most common brain tumors in children. We previously showed that the impipridone ONC201/TIC10 has a strong anti-neoplastic activity against medulloblastoma cells. In this study, we performed preclinical testing of a combined treatment with ONC201/TIC10 and the Bcl-xL/Bcl-2 inhibitor ABT-263 in vitro.
Methods: The combination therapy was tested on established, primary cultured and stem-like medulloblastoma cells using MTT assays. Isobolograms were calculated for evaluation of the nature of the drug-drug interaction. Spheroids were used to examine the effects of the combination therapy in a 3-dimensional setting. AnnexinV/PI staining followed by flowcytometric analysis was used to detect pro-apoptotic effects. Western blot analyses and knockdown experiments with siRNA were performed for molecular analysis. Extracellular flux analyses served at examining effects on the tumor cell metabolism.
Results: Combined treatment with ONC201/TIC10 and ABT-263 led to a synergistic anti-proliferative effect on established (D425, D458, DAOY, HD-MB03), primary cultured (PC322) and stem-like (SC322) medulloblastoma cells. The nature of the response towards the combination therapy was independent of baseline c-myc expression. In the 3-dimensional setting, combined treatment with ONC201/TIC10 and ABT-263 resulted in a significantly enhanced inhibitory effect on medulloblastoma spheroids. On the molecular level, treatment with ONC201/TIC10 led to a dose-dependent decrease of the expression of the anti-apoptotic Bcl-2 family member, Mcl-1. Moreover, combined treatment with ONC201/TIC10 and ABT-263 caused enhanced cleavage of caspases 9 and 3. On the metabolic level, the combination therapy led to a reduction in both, oxidative phosphorylation and the glycolytic rate in PC322 cells. In line with this finding, a reduced expression of respiratory chain proteins was found.
Conclusion: Combined treatment with ONC201/TIC10 and ABT-263 had a synergistic inhibitory effect on the cell viability of a broad panel of medulloblastoma cells. On the molecular level, this effect was associated with downregulation of Mcl-1. Moreover, the combination treatment resulted in a metabolic reprogramming which likely creates a state of energy deprivation. Further studies are warranted.
