Abstract C152: Characterizing rhabdomyosarcoma and osteosarcoma cellular metabolism.

Abstract

Abstract Sarcomas represent a diverse group of malignancies with distinct molecular and pathological features. A better understanding of the alterations associated with specific sarcoma subtypes is critically important to improve sarcoma treatment. A renewed interest in the metabolic properties of cancer cells, as well as the recognition of altered cellular metabolism as a critical hallmark of cancer, has led to an exploration of targeting metabolic dependencies of cancer cells as a therapeutic strategy. In this study, we have characterized key bioenergetic properties of human rhabdomyosarcoma and osteosarcoma cell lines in order to identify potential differences in sarcoma subtypes. We have also investigated the effects of compounds that inhibit glycolysis or mitochondrial respiration, either alone or in combination, and examined relationships between bioenergetic parameters and sensitivity to metabolic inhibitors. Glycolytic and mitochondrial bioenergetic profiles were generated using Seahorse extracellular flux analysis to measure extracellular acidification rates and oxygen consumption rates, and significant differences in glycolytic and respiratory bioenergetics between rhabdomyosarcoma and osteosarcoma cell lines were identified. Using 2-deoxy-D-glucose (2-DG), a competitive inhibitor of glycolysis, oligomycin, an inhibitor of mitochondrial ATP synthase, and metformin, a widely-used diabetes drug and inhibitor of complex I of the mitochondrial respiratory chain, we evaluated the effects of metabolic inhibition on sarcoma cell growth and bioenergetic function. Inhibition of glycolysis by 2-DG effectively reduced the viability of alveolar rhabdomyosarcoma cells versus embryonal rhabdomyosarcoma, osteosarcoma, and normal cells, whereas inhibition of mitochondrial respiration by oligomycin or metformin did not significantly affect viability. Combined inhibition of glycolysis and respiration decreased cell growth more effectively than either treatment alone in all sarcoma lines tested. Additionally, inhibition of glycolysis significantly reduced intracellular ATP levels in all sarcoma lines tested, and sensitivity to 2-DG-induced growth inhibition was related to respiratory rates and glycolytic dependency. Our findings suggest that inhibition of metabolic pathways in sarcomas should be further investigated as a potential therapeutic strategy. Funded by NCI Contract No. HHSN261200800001E. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C152. Citation Format: Sameer Issaq, Beverly Teicher, Anne Monks. Characterizing rhabdomyosarcoma and osteosarcoma cellular metabolism. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C152.