Cancer Cell Int. 2025 Oct 24. 25(1):
374
BACKGROUND: Breast cancer is the most common cancer among women, and metastasis is the leading cause of mortality. It is still unknown how breast cancer cells metabolically adapt to successfully metastasize to different organs to survive adverse conditions, including varying nutrient availability. The purpose of this study is to elucidate the metabolic characteristics and glucose adaptation mechanisms of breast cancer cells that preferentially metastasize to the lungs or the liver.
METHODS: Using a Wnt-driven breast cancer model with preferential metastasis to lung (metM-WntLung) or liver (metM-WntLiver), we measured 14C-glucose uptake, 13C6-glucose metabolic flux, metabolic enzyme levels, and cell viability under normal (5 mM), high (25 mM), and low (1 or 0 mM) glucose conditions.
RESULTS: Under normal glucose conditions, metM-WntLung cells were more glycolytic, exhibiting greater flux of 13C6-glucose-derived carbons into glycolytic intermediates, such as pyruvate and lactate. In contrast, metM-WntLiver cells favored oxidative phosphorylation, with higher levels of 13C6-glucose-derived carbons in tricarboxylic acid (TCA) cycle metabolites such as oxaloacetate indicative of higher pyruvate carboxylase (PC) activity. Exposure to high glucose reduced metM-WntLiver cell viability, with no effect on metM-WntLung cells, suggesting better adaptability of metM-WntLung cells to glucose excess. This was accompanied by increased PC activity and oxidative phosphorylation in metM-WntLung cells, whereas metM-WntLiver cells shifted to a more glycolytic phenotype. Under glucose deprivation, metM-WntLung cells were more viable than metM-WntLiver cells, suggesting that metM-WntLung cells have better adaptability to glucose deprivation. Inhibiting phosphoenolpyruvate carboxykinase, a key enzyme in gluconeogenesis, reduced metM-WntLung cell viability compared to metM-WntLiver cells. Similarly, inhibiting catabolism of glutamine, a gluconeogenic substrate, decreased metM-WntLung cell viability compared to metM-WntLiver cells, indicating that metM-WntLung cells rely on more on gluconeogenesis and glutamine metabolism under glucose deprivation.
CONCLUSION: Our findings reveal that metM-WntLung cells exhibit greater metabolic flexibility to glucose than metM-WntLiver cells by shifting from glycolysis to oxidative phosphorylation under high glucose conditions while utilizing gluconeogenesis and glutamine under glucose deprivation conditions.
Keywords: Breast cancer; Glucose; Metabolic adaptation; Metastasis