Figure 5
Efficacy of 3-drug combinations in 3D co-cultures with various fibroblast percentages. Metabolic activity of HCT116 (A), SW620 (B) and DLD1 (C) 3D co-cultures (3D-CC), consisting of tumor cells with 30%, 50% or 70% fibroblasts and an additinal 5% of endothelial cells, after treatment with 3-drug combinations of regorafenib, erlotinib and 5-fluorouracil at low dose (LD) or maximum plasma concentration (MPC). Treatment was performed for 72 h at day 2–5 or at day 4–7 after the start of spheroid formation. Error bars represent the standard error of the mean (SEM). Significance levels of *p < 0.05, **p < 0.01 and ***p < 0.001 were determined by a two-way ANOVA with post-hoc Sidak’s multiple comparison test.
