Fig. 4

Determination of the proportion of metabolically active cells in patient and control fibroblasts after camptothecin treatment. A Patient- and control-derived fibroblasts were treated with camptothecin (CPT) at a concentration of 0.75 µM, 1 µM, 2.5 µM, or 5 µM or with an equal volume of DMSO for 72 h. The graph shows the proportion of metabolically active cells in patient (P1, P2) and control (C2-C4) fibroblasts following treatment with the indicated concentrations of CPT for 72 h relative to DMSO-treated cells. The mean ± SD of three individual experiments is shown (n = 3), each performed in triplicate. B Two-way ANOVA followed by Dunnett’s post hoc test was used for statistical analysis to compare the proportion of metabolically active fibroblasts from patients 1 and 2 separately with that of fibroblasts from controls 2–4. *p ≤ 0.05; **p ≤ 0.01; ***p ≤ 0.001; ****p ≤ 0.0001. n.s. not significant