Disease stage-specific role of the mitochondrial pyruvate carrier suppresses differentiation in temozolomide and radiation-treated glioblastoma

Abstract

Background: The mitochondrial pyruvate carrier (MPC), a central metabolic conduit linking glycolysis and mitochondrial metabolism, is instrumental in energy production. However, the role of the MPC in cancer is controversial. In particular, the importance of the MPC in glioblastoma (GBM) disease progression following standard temozolomide (TMZ) and radiation therapy (RT) remains unexplored.

Methods: Leveraging in vitro and in vivo patient-derived models of TMZ-RT treatment in GBM, we characterize the temporal dynamics of MPC abundance and downstream metabolic consequences using state-of-the-art molecular, metabolic, and functional assays.

Results: Our findings unveil a disease stage-specific role for the MPC, where in posttreatment GBM, but not therapy-naïve tumors, the MPC acts as a central metabolic regulator that suppresses differentiation. Temporal profiling reveals a dynamic metabolic rewiring where a steady increase in MPC abundance favors a shift towards enhanced mitochondrial metabolic activity across patient GBM samples. Intriguingly, while overall mitochondrial metabolism is increased, acetyl-CoA production is reduced in posttreatment GBM cells, hindering histone acetylation and silencing neural differentiation genes in an MPC-dependent manner. Finally, the therapeutic translations of these findings are highlighted by the successful pre-clinical patient-derived orthotopic xenograft trials utilizing a blood-brain-barrier permeable MPC inhibitor, MSDC-0160, which augments standard TMZ-RT therapy to mitigate disease relapse and prolong animal survival.

Conclusion: Our findings demonstrate the critical role of the MPC in mediating GBM aggressiveness and molecular evolution following standard TMZ-RT treatment, illuminating a therapeutically-relevant metabolic vulnerability to potentially improve survival outcomes for GBM patients.

Keywords: differentiation; glioblastoma; metabolism; mitochondrial pyruvate carrier; tumor recurrence.