Fig. 1
From: MT1-MMP directs force-producing proteolytic contacts that drive tumor cell invasion
Collagen fiber bending and remodeling by matrix-degradative invadopodia. a MDA-MB-231 cells expressing Tks5GFP (green) cultured on a thin collagen layer (gray) were stained for GFP (green), cleaved collagen neoepitope (Col1-¾C, red) and DAPI (blue). Fluorescence intensity profiles along the white line are showed in the inset. b GM6001-treated cells (40 µM) analyzed as in panel a. Scale bars, 10 µm; 5 µm (zoom-in). c Tks5 staining of MDA-MB-231 cells cultured on type I collagen for 60 min. Inverted lookup tables are used (collagen fibers in blue, Tks5-positive invadopodia in red). The cell contour is shown with a dashed line. Empty arrowheads point to curved invadopodia/fiber ensembles. Full arrowheads depict bundles of collagen fibers at the cell periphery. Scale bar, 10 µm. d Quantification of collagen fiber curvature (in µm−1) in association with Tks5-positive invadopodia (Inv. + ) or for invadopodia-free regions (Inv. -) underneath control (siNT-treated) cells, or in randomly selected regions of collagen fibers underneath siTks5- or siMT1-MMP-treated cells. Data are presented as box and whisker plots with black lines indicating medians and whiskers representing the 25th and 75th percentiles. n: number of fibers analyzed; (n): number of independent experiments. Statistical significance was determined by Kruskal–Wallis tests. e Box plots show the average pore cross sections between fibers quantified by confocal optical xy sections of fluorescently labeled rat tail collagen layer underneath the indicated cells. Medians and 25th and 75th percentiles are presented. n, number of cells analyzed; (n): number of independent experiments. Statistical significance was determined by Kruskal–Wallis tests. ** P < 0.01, **** P < 0.0001, ns not significant
