Abstract 5259: Fatty acid oxidation represents a metabolic vulnerability in glioblastoma in nutrient-deprived conditions

Abstract

Glioblastoma represents an aggressive, primary brain tumor with limited treatment options. We performed an integrative, cross-platform analysis coupling global metabolomics and gene expression profiling in >100 patient-derived gliomas to begin to understand the diverse metabolic programs driving the aggressive phenotype of this malignancy. Alterations in fatty acid β-oxidation (FAO) emerged as a key metabolic node differentiating glioblastoma from low-grade astrocytoma, as demonstrated by an accumulation of acylcarnitines. Metabolic heterogeneity was observed within glioblastoma that could further define tumors as FAO ‘high’ and ‘low’. Integrative analyses identified these metabolic subtypes to be enriched with mesenchymal (MES) and proneural (PN) glioblastoma subtypes, respectively. These findings were metabolomically and functionally recapitulated in molecular subtype-specific preclinical models. Analysis of gene expression profiles from these lines uncovered an orchestrated transcriptional program designed to promote fatty acid uptake, activation, and mitochondrial oxidation. Studies designed to determine the biologic consequence of enhanced FAO in glioblastoma only identified a role in glucose-deprived conditions, where it served as a vital, alternate source for ATP synthesis. Based on these findings, we tested the hypothesis that dual targeting of glycolysis and FAO would elicit energetic stress-mediated cell death in glioblastoma. Accordingly, the glycolysis inhibitor 2DG and the FAO inhibitor etomoxir only demonstrated anti-proliferative activity in MES glioblastoma cell lines when used as single agents in vitro, while the combination resulted in robust, necroptosis-mediated cell death. Synergistic anti-tumor activity was observed following combined glycolysis and FAO inhibition when extended in vivo in an orthotopic model. Collectively, our findings suggest FAO provides metabolic plasticity in MES glioblastoma, allowing these cells to adapt to nutrient-deprived microenvironments. Combinatorial strategies designed to inhibit glycolysis and FAO represents an attractive therapeutic approach in glioblastoma. Citation Format: Shiva Kant, Antony Dayalan, Pravin Kesarwani, Prakash Chinnaiyan. Fatty acid oxidation represents a metabolic vulnerability in glioblastoma in nutrient-deprived conditions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5259.