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，我们提出了 ¹³C-SpaceM，这是一种空间单细胞同位素示踪方法，它扩展了之前发表的 SpaceM 方法，可检测酯化脂肪酸中的 ¹³C₆-葡萄糖衍生碳。我们在空间异质性模型上使用经受常氧缺氧或 ATP 柠檬酸裂解酶耗竭的肝癌细胞验证了 ¹³个 C-SpaceM。这揭示了脂肪生成乙酰辅酶 A 库的标记以及隐藏在批量分析中的相对脂肪酸摄取与合成方面存在很大的单细胞异质性。分析喂食含 ¹³C₆-葡萄糖饮食的小鼠的荷瘤脑组织，我们发现与健康大脑相比，肿瘤中饱和脂肪酸的葡萄糖依赖性合成更高，必需脂肪酸的伸长率更高。此外，我们的分析揭示了肿瘤中脂肪生成乙酰辅酶 A 库标记的空间异质性。我们的方法增强了对单细胞和组织中代谢活动的空间探测，为顺势稳态和疾病中的脂肪酸代谢提供了见解。