Fig. 5

MAME co-cultures of MCF10.DCIS:CAF40TKi show expression of the cysteine protease cathepsin B at sites of proteolysis of matrix. a Representative confocal image obtained from the equatorial plane, showing live cell proteolysis via degraded DQ-collagen IV (dDQ-Col.IV). Fluorescent signal intensity correlates with degree of proteolysis. b Immunofluorescent staining for cathepsin B (red) in the equatorial plane. c Fluorescent overlay of dDQ-Col.IV (green) and cathepsin B immunostaining (red). Scale bar, 200 μm. Quantification of dDQ-Col.IV fluorescent intensity in MAME co-cultures treated with cell permeable inhibitors E64d (pan-cysteine protease inhibitor) (d) or the cathepsin B selective inhibitor CA074-Me (e). *P < 0.05, Student’s t-test; mean ± SD