Fig. 3

EphA2 co-localize with f-actin and FVIIa stimulation potentiates ephrin-A1-induced cell rounding and retraction fiber formation in MDA-MB-231 cells. a EphA2 co-localizes with the actin cytoskeleton in MDA-MB-231 cells. Confocal micrographs showing EphA2 (red signal) and actin fibers stained by phalloidin (green signal). Blue signal represents DAPI-stained DNA. b MDA-MB-231 cells were plated on collagen IV and treated with 10 nM FVIIa for 1 h prior to stimulation with 1 μg/ml ephrin-A1 for 10, 30 and 60 min. Cells were fixed and stained with FITC-conjugated phalloidin and micrographs generated by epifluorescence microscopy. Ephrin-A1 treatment induced cell rounding and retraction fiber formation, which was potentiated by FVIIa to 49.7 ± 4.4 % vs 29.3 ± 4.1 % at 10 min (p =0.009), 30.9 ± 8.9 % vs 16.2 ± 1.6 % at 30 min (p = 0.08) and 25.4 ± 7.5 % vs 13.3 ± 2.9 % at 60 min (p = 0.010). FVIIa alone did not increase cell rounding and retraction fiber formation compared to untreated cells (7.3 ± 4.5 % vs 5.2 ± 2 %, p = 0.49). N = 3, results are expressed as means ± SD of the percentage of rounded cells with retraction fibers. Representative images are shown