Figure 1
Correlation between endogenous podoplanin expression and invadopodia formation in human SCC cell lines. (a) Endogenous podoplanin expression in subconfluent SCC cell cultures by western blot. Two different exposure times are shown (upper panel 15 s; lower panel 40 s). The molecular mass variability observed between the different cell lines arises from the presence of O-linked carbohydrates on its extracellular domain as previously reported.21, 26, 54 (b) Determination of active invadopodia formation in SCC cells by gelatin-degradation assays. The different SCC cell lines were cultured on glass coverslips covered with crosslinked TRITC-gelatin for 18 h. Representative confocal images of SCC cells are shown. Insets show zoomed areas of individual invadopodia. Bar=10 μm. (c) Quantification of active invadopodia formation in SCC cells (left and middle) and degradation area per cell (right) by gelatin-degradation assay. The results shown are the means±s.e.m. of n⩾100 cells (left graph) or n⩾10 cells-100 invadopodia (middle and right graphs) for each condition over three independent experiments.
