Fig. 1.

PCA score plots, PLS-DA 3D score plots, validation plots of metabolic analysis results between LUAD and LUAD post-operative and between LUAD and normal groups, and enrichment of pathways based on relevant metabolites. PCA score plots compared (A) LUAD and normal groups (D) LUAD and LUAD post-operative groups. (B) PLS-DA score plot (two latent variables, R²Y = 0.846, Q² = 0.817) and (C) the 200-permutation plot validated LUAD versus normal groups. All permuted R2 and Q2 values on the left were lower than the point on the right (R2 = 0.133, Q2 = −0.27). (E) PLS-DA score plot (two latent variables, R2Y = 0.358, Q2 = 0.127), and (F) the 200-permutation plot validated LUAD versus LUAD post-operative groups. All permuted R2 and Q2 values on the left were lower than the point on the right (R2 = 0.118, Q2 = −0.117). (G) Bar chart discriminating the components with significant increments (red bar, n = 30) or decrement (blue bar, n = 6) in LUAD versus normal groups. (H) Bar chart discriminating the components with significant increments (red bar, n = 17) or decrements (blue bar, n = 18) in LUAD versus LUAD post-operative groups. (I) A total of 18 metabolic pathways were detected by MetaboAnalyst using pathway enrichment with differential substances common to both groups (LUAD versus normal and LUAD versus post-LUAD surgery).