Related Experiment Video
Updated: Jul 31, 2026
Characterization of the Effects of Migrastatic Inhibitors on 3D Tumor Spheroid Invasion by High-resolution Confocal Microscopy
Published on: September 16, 2019
Imipridones affect tumor bioenergetics and promote cell lineage differentiation in diffuse midline gliomas
Justyna M Przystal1, Chiara Cianciolo Cosentino1, Sridevi Yadavilli1,2
1Department of Oncology, Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland.
Background:
Pediatric diffuse midline gliomas (DMGs) are incurable childhood cancers. The imipridone ONC201 has shown early clinical efficacy in a subset of DMGs. However, the anticancer mechanisms of ONC201 and its derivative ONC206 have not been fully described in DMGs.
Methods:
DMG models including primary human in vitro (n = 18) and in vivo (murine and zebrafish) models, and patient (n = 20) frozen and FFPE specimens were used. Drug-target engagement was evaluated using in silico ChemPLP and in vitro thermal shift assay. Drug toxicity and neurotoxicity were assessed in zebrafish models. Seahorse XF Cell Mito Stress Test, MitoSOX and TMRM assays, and electron microscopy imaging were used to assess metabolic signatures. Cell lineage differentiation and drug-altered pathways were defined using bulk and single-cell RNA-seq.
Results:
ONC201 and ONC206 reduce viability of DMG cells in nM concentrations and extend survival of DMG PDX models (ONC201: 117 days, P = .01; ONC206: 113 days, P = .001). ONC206 is 10X more potent than ONC201 in vitro and combination treatment was the most efficacious at prolonging survival in vivo (125 days, P = .02). Thermal shift assay confirmed that both drugs bind to ClpP, with ONC206 exhibiting a higher binding affinity as assessed by in silico ChemPLP. ClpP activation by both drugs results in impaired tumor cell metabolism, mitochondrial damage, ROS production, activation of integrative stress response (ISR), and apoptosis in vitro and in vivo. Strikingly, imipridone treatment triggered a lineage shift from a proliferative, oligodendrocyte precursor-like state to a mature, astrocyte-like state.
Conclusion:
Targeting mitochondrial metabolism and ISR activation effectively impairs DMG tumorigenicity. These results supported the initiation of two pediatric clinical trials (NCT05009992, NCT04732065).
Insights
Pediatric diffuse midline gliomas (DMGs) are targeted by ONC201 and ONC206, which impair tumor cell metabolism and induce apoptosis. These imipridones show promise in preclinical models, leading to new clinical trials for this incurable childhood cancer.
Area of Science:
- Oncology
- Molecular Biology
- Pediatric Cancer Research
Background:
- Pediatric diffuse midline gliomas (DMGs) represent an incurable group of childhood cancers.
- The imipridone ONC201 has demonstrated preliminary clinical efficacy in a subset of DMGs.
- The precise anticancer mechanisms of ONC201 and its derivative ONC206 in DMGs remain incompletely understood.
Purpose of the Study:
- To elucidate the anticancer mechanisms of ONC201 and ONC206 in pediatric diffuse midline gliomas.
- To evaluate the efficacy and molecular effects of ONC201 and ONC206 in diverse DMG models.
- To investigate the impact of these drugs on tumor cell metabolism, mitochondrial function, and cell lineage.
Main Methods:
- Utilized primary human in vitro and in vivo (murine, zebrafish) DMG models, alongside patient-derived specimens.
- Assessed drug-target engagement using in silico ChemPLP and in vitro thermal shift assays.
- Analyzed metabolic signatures via Seahorse XF, MitoSOX, and TMRM assays, and electron microscopy; defined drug-altered pathways using RNA-seq.
Main Results:
- ONC201 and ONC206 significantly reduced DMG cell viability and extended survival in patient-derived xenograft models.
- ONC206 demonstrated superior in vitro potency compared to ONC201; combination therapy yielded the greatest survival benefit in vivo.
- Both drugs bind to ClpP, leading to impaired tumor cell metabolism, mitochondrial damage, ROS production, ISR activation, and apoptosis, with a notable lineage shift towards astrocyte-like cells.
Conclusions:
- Targeting mitochondrial metabolism and integrative stress response (ISR) activation is a viable strategy against DMG.
- ONC201 and ONC206 show significant therapeutic potential for pediatric diffuse midline gliomas.
- These findings support the initiation of pediatric clinical trials for ONC201 and ONC206 in DMGs.
