Fig. 2

Effect of collagen I on MMP-2 and -9 activities in supernatant of kidney cancer spheroid cultures. Activities of pro-MMP-9 in 786-O (A) or WT-CLS1 (C) spheroids cultured in absence or presence of collagen I measured in a zymogram assay. Zymogram analysis of MMP-2 activity in 786-O (B) or WT-CLS1 (D) spheroids cultured in absence or presence of collagen I. One to five spheroids were pooled and cultured for 24 h. For each independent experiment, pro-MMP-9 (92 kDa) and active MMP-2 (62 kDa) band intensities were quantified using Fiji software and normalized to the corresponding condition without collagen I. Data are presented as the mean +/- SEM of 4 to 5 independent experiments (n = 5 for 786-O and n = 4 for WT-CLS1 spheroid cultures). *p < 0.05 and **p < 0.01, Wilcoxon-Mann-Whitney test