While heterogeneity is a key feature of cancer, understanding metabolic heterogeneity at the single-cell level remains a challenge. Here we present ¹³C-SpaceM, a method for spatial single-cell isotope tracing that extends the previously published SpaceM method with detection of ¹³C₆-glucose-derived carbons in esterified fatty acids. We validated ¹³C-SpaceM on spatially heterogeneous models using liver cancer cells subjected to either normoxia-hypoxia or ATP citrate lyase depletion. This revealed substantial single-cell heterogeneity in labelling of the lipogenic acetyl-CoA pool and in relative fatty acid uptake versus synthesis hidden in bulk analyses. Analysing tumour-bearing brain tissue from mice fed a ¹³C₆-glucose-containing diet, we found higher glucose-dependent synthesis of saturated fatty acids and increased elongation of essential fatty acids in tumours compared with healthy brains. Furthermore, our analysis uncovered spatial heterogeneity in lipogenic acetyl-CoA pool labelling in tumours. Our method enhances spatial probing of metabolic activities in single cells and tissues, providing insights into fatty acid metabolism in homoeostasis and disease.

虽然异质性是癌症的一个关键特征，但了解单细胞水平的代谢异质性仍然是一个挑战。在这里，我们介绍¹³ C-SpaceM，一种空间单细胞同位素示踪方法，该方法扩展了先前发表的 SpaceM 方法，可检测酯化脂肪酸中的¹³ C ₆ -葡萄糖衍生碳。我们使用常氧-缺氧或 ATP 柠檬酸裂解酶耗尽的肝癌细胞在空间异质模型上验证了¹³ C-SpaceM。这揭示了批量分析中隐藏的脂肪生成乙酰辅酶A池标记以及相对脂肪酸摄取与合成的显着单细胞异质性。通过分析喂食含¹³ C ₆ -葡萄糖饮食的小鼠的携带肿瘤的脑组织，我们发现与健康大脑相比，肿瘤中葡萄糖依赖性饱和脂肪酸的合成更高，并且必需脂肪酸的伸长增加。此外，我们的分析揭示了肿瘤中脂肪生成乙酰辅酶A池标记的空间异质性。我们的方法增强了对单个细胞和组织代谢活动的空间探测，为稳态和疾病中的脂肪酸代谢提供了见解。