Figure 3. Overexpression of SHP2 in CAL27 cells, which express low levels of endogenous SHP2, increases invadopodia formation in the cells.
A. The levels of SHP2 protein were analyzed by immunoblotting with the indicated antibody in SAS and CAL27 cells. B. An equal amounts of whole cell lysates from CAL27 cells stably overexpressing FLAG-SHP2 (clones #1, #2 and #3) was analyzed by immunoblotting with the indicated antibody. Values (means) are from three independent experiments. C. Cells (4 × 105) were seeded onto Alexa Fluor 546-conjugated gelatin-coated coverslips for 4 h. The cells were fixed and then stained for F-actin, cortactin and DAPI. Scale bar, 10 μm. D. Quantitative results for invadopodia formation. The number of invadopodia per cell was determined (n > 150). The data are expressed as fold relative to the control CAL27 cells. Values (means ± s.d.) are from three independent experiments; *P < 0.05; **P < 0.001. E. Quantitative results for the matrix degradation assay. The data are expressed as fold relative to the control CAL27 cells. Values (means ± s.d.) are from three independent experiments; *P < 0.05; **P < 0.001.