Fig. 3
From: MT1-MMP directs force-producing proteolytic contacts that drive tumor cell invasion
Invadopodia assemble on the inner side of the curved collagen fibrils. a Tks5 (red) and F-actin (green) staining of MDA-MB-231 cells cultured on type I collagen (gray) for 60 min (same image as in Fig. 1c). The nucleus is stained with DAPI (blue). The cell contour is shown with a dashed line. Insets show higher magnification of the boxed region in separated channels. b ARPC2 (Arp2/3 complex, red) and cortactin (green) staining as in panel a. Scale bars, 10 µm; 5 µm (zoom-in). Same image as in panel a using inverted lookup tables (collagen fibers in blue, Tks5-positive invadopodia in red). c Averaged fluorescence intensity profiles for the indicated markers. Individual line-scans were recorded perpendicular to the curved collagen fibers and aligned relative to the longitudinal fiber axis corresponding to the maximum intensity of collagen fluorescence set to 100 (position ‘0’). Distance in µm, (−) corresponds to the inner (concave) side of curvature, ( + ) correspond to the outer (convex) side of curvature. (N), number of individual line-scans that were averaged from respectively 32 and 20 cells from two independent experiments. The distribution of invadopodial components in association with a collagen fiber relative to curvature is sketched out
