Fig. 4

Ex vivo metabolic differences between the PTX-sensitive and PTX-resistant tumors. PCA scatter plot of the metabolite profile of positive ionization mode showing the separation between the OV and OV_PTX groups (A). OPLS-DA analysis showing a good discrimination between the OV and OV_PTX groups, with R2 = 0.97, Q2 = -0.46 (B, C). Data was screened using VIP ≥ 1, fold change ≥ 2 or ≤ 0.5, and P < 0.05. Volcano plot showing differential metabolites between the OV and OV_PTX groups (D). Hierarchical clustering heat map analysis of differential metabolites between the OV and OV_PTX groups (E). Each column depicts a sample and each row represents a metabolite. The colour of each section corresponds to a normalized concentration value of each metabolite. PCA principal component analysis, OPLS-DA orthogonal partial least squares discriminant analysis