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. 2016 Jan 26;4:e1624. doi: 10.7717/peerj.1624

Figure 6. Metabolomic analysis on lysates of γ-irradiated HMCL-7304 cells.

Figure 6

(A) Unsupervised PCA scores plot showing a clustering of the sham irradiated (green symbols), 1 Gy γ-irradiated samples (blue symbols) and 4 Gy γ-irradiated samples (red symbols) with the clear separation from the 2 Gy γ-irradiated (turquoise symbols). There were no outliers from the Hotelling’s T2 ellipse (95% confidence interval). (B) Supervised PLS-DA scores plot showing a clustering of the sham irradiated (green symbols), 1 Gy γ-irradiated samples (blue symbols) and 4 Gy γ-irradiated samples (red symbols) with the clear separation from the 2 Gy γ-irradiated (turquoise symbols). As for the PCA analysis, there were no outliers. (C) Validation of the PLS-DA model using 100 iterations. The data are not over-modelled because the correlation coefficient (R2) fell below 0.3 and the predictability coefficient (Q2) fell below zero after data permutation. (D) OPLS-DA loadings S-plot for sham versus 2 Gy γ-irradiation of HMCL-7304 cells. Each symbol represents a metabolite and its contribution to the separation between sham and 2 Gy γ-irradiated samples in panel (B). Filled symbols are those metabolites selected for univariate statistical analysis. 1 = phosphate; 2 = D-glucose; 3 = L-lactate. All metabolites measured in HMCL-7304 cells were correlated significantly to the OPLS-DA model, except ethanolamine and L-5-oxoproline.