Fig. 2: Tissue metabolomic landscape of ESCC patients based on NMR-based metabolomics.

A–C OPLS-DA score plot based on ¹H-NMR tissue spectra from ESCC patients at different stages. Red: ESCC tumor; Blue: Normal mucosa; Yellow: Early-stage ESCC tissue; Orange: Advanced-stage ESCC tissue. D–F Statistical validation of the corresponding model by permutation analysis (200 times). The x-axis represents the permutation retention rate of the permutation test, and the dots in the upper right corner represent the R² (light blue) and Q² (dark blue) values of the original model when the permutation retention rate is 1. R² measures the goodness of fit, while Q² measures the predictive ability of the model. Light blue dots represent the R² values obtained from the permutation test, while dark blue dots represent the Q² values obtained from the permutation test. The two dashed lines represent the regression lines of R² and Q², respectively. G–I Metabolic pathway analysis. Relative betweenness centrality was the selected node importance measure for pathway topological analysis. All pathways are represented as bubbles. The color and size of each bubble correspond to its p-value and pathway impact value, respectively. In general, bubbles on the right side of the map have higher weights, while bubbles at the top have smaller p-values. The precise p-values for metabolic pathway analysis are provided in the Source Data without adjustments. J Multiple Volcano plot based on the same batch of samples, showing the comparison of differential metabolites between different groups (Tumor vs Normal; Early ESCC vs Normal; Early ESCC vs Advanced ESCC). P-values were determined by two-sided t-test without adjustments. Metabolites with p < 0.05 were visualized as solid circles on the plot, while those with p > 0.05 were not displayed. A log₁₀ transformation was applied to the p-values of each significantly differential metabolite to visualize their significance levels. K Statistical analysis of principal metabolic pathway disturbances in the evolution of ESCC. A pathway impact greater than 0.1 and p < 0.05 was used as the cut-off value for the statistical significance. (A, D, G, left panel) ESCC vs. normal mucosa patients; (B, E, H, middle panel) early-ESCC vs. normal mucosa patients; and (C, F, I, right panel) early-ESCC vs. advanced -ESCC patients. Source data are provided as a Source Data file.