Figure 7
Effect of proton irradiation on the metabolic activity of chondrosarcoma cells. (a) Principal Component Analysis (PCA) and (Orthogonal) Partial Least Squares Discriminant Analysis ((O)-PLS-DA) of cell culture supernatants 1 h, 4 h, and 24 h after 4 Gy proton IR versus non-IR control conditions (n = 3). (b) Reduced NMR spectra reveal altered metabolites in normalized cell culture supernatants at 1 h (left) and 4 h (right). Positive covariance corresponds to metabolites present at increased concentrations, whereas negative covariance corresponds to decreased metabolite concentrations in supernatants of irradiated samples compared to the corresponding control samples. Predictivity of the model is represented by R2. 1…lactate, 2…glutamine, 3…glutamate, 4…glucose. (c) shows the alteration in the normalized concentrations of lactate, glucose, glutamine, and glutamate without (−) and with (+) 4 Gy proton IR.
