Targeting mitochondrial protease in diffuse gliomas.

Area of Science:

• Biochemistry
• Molecular Biology
• Oncology

Background:

• The mitochondrial ClpXP protease, including caseinolytic protease (ClpP), degrades damaged proteins to maintain cellular homeostasis.
• Small molecule activators of ClpP (ClpP agonists) are emerging as potential therapeutics for metabolically active cancers.

Purpose of the Study:

• To evaluate the efficacy and mechanism of TR107, a novel ClpP activator, against glioma cells.
• To compare TR107 with the FDA-approved ClpP agonist ONC201.
• To investigate the preferential activity of TR107 against IDH-mutant gliomas.

Main Methods:

• In vitro, ex vivo, and in vivo studies using patient-derived and isogenic glioma models.
• Assessment of TR107 cytotoxicity, ClpP-dependency, and mitochondrial function (protein degradation, oxidative phosphorylation, mtDNA copy number, ATP levels).
• Analysis of cell cycle arrest, apoptosis, and signaling pathways (mTOR/AKT/4EBP1).

Main Results:

• TR107 demonstrated potent and selective cytotoxicity against glioma cells at nanomolar concentrations.
• TR107 induced ClpP-dependent mitochondrial dysfunction, including protein degradation, impaired OxPhos, reduced mtDNA, and ATP depletion.
• TR107 exhibited greater efficacy than ONC201 and showed preferential anti-tumor activity in IDH-mutant glioma models.

Conclusions:

• TR107 is a potent ClpP activator with significant anti-glioma activity.
• TR107 induces severe mitochondrial dysfunction, particularly in IDH-mutant glioma cells.
• TR107 represents a promising targeted therapeutic candidate for IDH-mutant gliomas.