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Updated: Jan 23, 2026
Isolation, Enrichment, and Maintenance of Medulloblastoma Stem Cells
Published on: September 1, 2010
Neuronal differentiation and cell-cycle programs mediate response to BET-bromodomain inhibition in MYC-driven
Pratiti Bandopadhayay1,2,3, Federica Piccioni2, Ryan O'Rourke1,2
1Dana-Farber/Boston Children's Cancer and Blood Disorders Center, Boston, USA.
Abstract:
BET-bromodomain inhibition (BETi) has shown pre-clinical promise for MYC-amplified medulloblastoma. However, the mechanisms for its action, and ultimately for resistance, have not been fully defined. Here, using a combination of expression profiling, genome-scale CRISPR/Cas9-mediated loss of function and ORF/cDNA driven rescue screens, and cell-based models of spontaneous resistance, we identify bHLH/homeobox transcription factors and cell-cycle regulators as key genes mediating BETi's response and resistance. Cells that acquire drug tolerance exhibit a more neuronally differentiated cell-state and expression of lineage-specific bHLH/homeobox transcription factors. However, they do not terminally differentiate, maintain expression of CCND2, and continue to cycle through S-phase. Moreover, CDK4/CDK6 inhibition delays acquisition of resistance. Therefore, our data provide insights about the mechanisms underlying BETi effects and the appearance of resistance and support the therapeutic use of combined cell-cycle inhibitors with BETi in MYC-amplified medulloblastoma.
Insights
BET-bromodomain inhibitors show promise for MYC-amplified medulloblastoma. Resistance involves neuronal differentiation and cell-cycle regulators, suggesting combination therapy with cell-cycle inhibitors.
Area of Science:
- Oncology
- Genetics
- Molecular Biology
Background:
- BET-bromodomain inhibition (BETi) is a promising pre-clinical strategy for MYC-amplified medulloblastoma.
- The precise mechanisms of BETi action and resistance in this context remain incompletely understood.
Purpose of the Study:
- To elucidate the molecular mechanisms underlying BETi response and resistance in MYC-amplified medulloblastoma.
- To identify key genetic factors mediating drug sensitivity and tolerance.
Main Methods:
- Genome-scale CRISPR/Cas9 loss-of-function and rescue screens.
- Expression profiling and cell-based models of spontaneous drug resistance.
- Analysis of bHLH/homeobox transcription factors and cell-cycle regulators.
Main Results:
- Acquired drug tolerance is associated with a more differentiated neuronal cell-state and expression of bHLH/homeobox transcription factors.
- Resistant cells maintain CCND2 expression and continue cell cycling through S-phase.
- Inhibition of CDK4/CDK6 delays the onset of BETi resistance.
Conclusions:
- BETi efficacy and resistance are mediated by bHLH/homeobox transcription factors and cell-cycle regulators.
- Combined therapeutic strategies involving BET inhibitors and cell-cycle inhibitors show potential for treating MYC-amplified medulloblastoma.
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