Fig. 1

Constitutive signalling in breast cancer cell lines. A MCF7, T-47D, SKBR3, MDA-MB-468, UACC-3199, MDA-MB-231 and Hs 578T cells were seeded and cultivated in phenol red-free RPMI 1640 for 24 h. On the following day, cells were lysed and proteins were separated by SDS-PAGE. After Western blotting, membranes were stained with specific antibodies against vimentin, E-cadherin, (p)Y EGFR, EGFR, (p)Y Gab1, Gab1, (p)T/Y ERK1/2, ERK1/2, (p)S Akt, Akt, (p)Y STAT3, STAT3 and tubulin. A representative result of n = 3 independent experiments is shown. B Expression or phosphorylation of (p)Y EGFR, EGFR, (p)Y Gab1, Gab1, (p)T/Y ERK1/2, (p)S Akt and (p)Y STAT3 from n = 3 independent experiments were quantified and normalised to tubulin expression. The highest phosphorylation or expression among the cell lines analysed was set to 100%. High expression or phosphorylation is visualised in dark red. For each cell type the normalised phosphorylation and expression strengths of all analysed entities are summed up and depicted in blue. C MDA-MB-468 or MDA-MB-231 cells were seeded on poly-L-lysine-coated glass cover slips and cultivated in phenol red-free RPMI 1640. After 24 h, cells were transfected with an expression vector for murine Gab1-GFP. On the following day, cells were placed into the incubation chamber of a laser scanning microscope. Imaging was performed after 30 min equilibration. Representative results of n = 3 independent experiments are shown