Fig. 8

Effect of EGF on ERK pathway in WT-CLS1 cells cultured as monolayer or spheroids. p-ERK and ERK were analyzed in WT-CLS1 cells cultured as monolayer (A and B) or spheroids (C and D) and stimulated or not with EGF. Five spheroids were pooled and cultured for 24 h. p-ERK and ERK are shown as 42–44 kDa proteins (A and C). For each independent experiment, band intensities were quantified using Fiji software and normalized to the corresponding total ERK signal (B and D). Values in absence of collagen I were arbitrarily set to 1. Data are presented as the mean +/- SEM of 4 independent experiments, *p < 0.05, Wilcoxon-Mann-Whitney test. P-p44/42 ERK: p-ERK, p44/42 ERK: ERK. Panel (B) and ( D): for five spheroids and in presence of EGF for 15 (B) or 5 (D) min stimulation, one outlier data point altered the mean value upwards