Fig. 3

MCF-7 cell lines that express high levels of MT1-MMP demonstrated widespread ECM degradation (a) MCF-7, MT1-MMP cell lines, and MDA-MB 231 breast cancer cells were incubated on Alexa488 gelatin-coated coverslips for 24 h and processed for immunofluorescence to examine cytoplasmic MT1-MMP protein and ECM degradation. Representative fields of view are shown at 20× (top panels) and 60× (bottom panels) magnification. Panels are composed of an overlay showing the nuclei, F-actin, and Alexa488 gelatin signal (top) and the MT1-MMP signal with an inset of the Alexa488 gelatin channel (bottom). White arrows indicate cells that have degraded the underlying gelatin but are devoid of MT1-MMP signal. Scale bars = 100 μm. Cells in each sample positive for cytoplasmic MT1-MMP protein signal (MT1-MMP +) or devoid of underneath Alexa488 gelatin signal (Gelatin -) were quantified per 20× fields of view and are shown as mean percentage of total cells per field of view ± SEM