Fig. 3

Spheroid immunohistochemistry and invadopodia formation. a Summary of the protocol for generation of spheroid and data analysis. b Representative images of sectioned MDA-MB-231 spheroid stained with Hematoxylin and eosin imaged with light-microscopy (40× magnification). The adjacent spheroid section was incubated for antibodies targeting cortactin (red), Tks5 (dark blue), and MMP-14 (green) and counter-stained with DAPI (light blue) and images using super-resolution (c). d MDA-MB-231 tumor spheroids were stained with cortactin (Red), Tks5 (blue) and MMP-14 (green) and imaged using confocal microscopy. Top images represent a collective area of invasion and the bottom panel shows single cells extending away from the spheroid (arrows). Images are representative of 3 repetitions. Scale bar, 10 μm. Panels (e-g) are representative areas of MMP14 accumulation at the extracellular space, invadopodia and cell periphery respectively. Graphs show the pixel intensity distribution over the dashed lines shown on the left panels