Fig. 1: Nutrient levels in plasma, CSF and tissue interstitial fluid from mice.
From: Nutrient requirements of organ-specific metastasis in breast cancer
a, Schematic of plasma, CSF and tissue interstitial fluid (IF) isolation from female NSG or B6 mice. Metabolites were quantified by liquid chromatography–mass spectrometry alongside a dilution series of chemical standards; 124 metabolites were quantified. TCA, tricarboxylic acid. Created in BioRender. Abbott, K. (2025) https://BioRender.com/tp4l6fd. b,c, PCA (b) and hierarchical clustering (c) of metabolites measured in plasma, CSF or tissue IF samples from NSG mice. Data represent n = 10 (plasma, liver IF, lung IF and pancreas IF), n = 6 (kidney IF and MFP IF) or n = 4 (CSF) biologically independent samples. Metabolite measurements were performed twice for plasma, liver, lung and pancreas IF samples and once for the remaining tissues; data from repeated measurements were pooled for analysis. Columns of the heatmap were z-score normalized. d, Bar plot showing the number of metabolites with significantly lower (depleted) or higher (elevated) levels in IF or CSF relative to plasma. Significance was determined by Welch’s t-test (two-sided, unequal variance) with fold change > 2 and P < 0.05. e, Loadings plot presenting the contribution of individual metabolite classes to the PCA components in b. The colours indicate pathway assignment in a. f–k, log2 fold change of selected metabolites in tissue IF or CSF relative to plasma. Data are mean ± s.e.m., with n values as in b,c. l–n, Heatmaps of average log2 fold change (FC) in metabolite concentrations relative to plasma. Scale bars indicate value ranges. o, Area under the curve (AUC) values from proliferation assays of MDA-MB-231 control (Ctrl) or indicated knockout (KO) cells cultured ± relevant rescue metabolites (Extended Data Fig. 6a–f). AUC values were normalized to control + rescue. Data are mean ± s.d.; n = 3 biologically independent samples. Representative plots are shown from one of two independent experiments with similar results. Statistical analysis was done by a Kruskal–Wallis test with Dunn’s multiple comparisons (two-sided). Arg, arginine; Cit, citrulline; Hx, hypoxanthine; Pro, proline; Ser, serine; Urd, uridine. PYCR denotes PYCR1/2/3 triple knockout.
