Fig. 8

MDA-MB-468 cells acquire resistance to PI3K inhibition. A MDA-MB-468 cells were seeded and cultivated in phenol red-free RPMI 1640 for 24 h. On the following day, cells were treated with LY294002 (40 µM) for 48 h. Control cells were treated with DMSO. Subsequently, cells were lysed and proteins were separated by SDS-PAGE. After Western blotting, membranes were stained with specific antibodies against (p)Y Gab1, Gab1, (p)T/Y ERK1/2, ERK1/2, (p)S Akt, Akt, (p)Y STAT3, STAT3 and tubulin. Vertical bars indicate removed lanes on the same blot. A representative result of n = 3 independent experiments is shown. The results from (A) were quantified. The diagrams show the ratios of B (p)Y Gab1 to Gab1, C (p)T/Y ERK1/2 to ERK1/2, D (p)S Akt to Akt, and E (p)Y STAT3 to STAT3. Gab1, ERK1/2, Akt and STAT3 phosphorylation in DMSO-treated cells was normalised to 100% in each independent repetition of the experiment. Data are given as mean of two to three independent experiments ± SD. Student’s t-test: n.s. = non-significant, * = p < 0.05, ** = p < 0.01, *** = p < 0.001