Metabolic Profiling of Tumors, Sera, and Skeletal Muscles from an Orthotopic Murine Model of Gastric Cancer Associated-Cachexia

Cachexia is a complex metabolic derangement syndrome that affects approximately 50-80% of cancer patients. So far, few works have been reported to provide a global overview of gastric cancer cachexia (GCC)-related metabolic changes. We established a GCC murine model by orthotopicly implanting BGC823 cell line and conducted NMR-based metabolomic analysis of gastric tissues, sera, and gastrocnemius. The model with typical cachexia symptoms, confirmed by significant weight loss and muscle atrophy, showed distinctly distinguished metabolic profiles of tumors, sera, and gastrocnemius from sham mice. We identified 20 differential metabolites in tumors, 13 in sera, and 14 in gastrocnemius. Tumor extracts displayed increased pyruvate and lactate, and decreased hypoxanthine, inosine, and inosinate, indicating significantly altered glucose and nucleic acid metabolisms. Cachectic mice exhibited up-regulated serum lactate and glycerol, and down-regulated glucose, which were closely related to hyperlipidemia and hypoglycemia. Furthermore, gastrocnemius transcriptomic and metabolomic data revealed that GCC induced perturbed pathways mainly concentrated on carbohydrate and amino acid metabolism. Specifically, cachectic gastrocnemius exhibited increased α-ketoglutarate and decreased glucose. In vitro study indicated that α-ketoglutarate could prompt myoblasts proliferation and reduce glucose deficiency-induced myotubes atrophy. Overall, this work provides a global metabolic overview to understand the metabolic alterations associated with GCC-induced muscle atrophy.