, Cramlington, UK) and MAPK inhibitor detected using a CCD-UVIprochemin system (UVItec Ltd., Cambridge, UK).

MK-0518 Co-immunoprecipitation samples were prepared as follows: cell lysate of the protein of interest was probed with primary antibody (1:100 dilution) and placed on a rotating wheel for 2 hour allowing Claudin-5 antibody to bind to their targets. One hundred microlitres of conjugated A/G protein agarose beads (Santa-Cruz Biotechnologies Inc., USA) were added to each sample to make the antibody-protein complex insoluble, followed by overnight incubation on the rotation wheel. The supernatant was discarded and the pellet was washed in 200 μl of lysis buffer and resuspended in 200 μl of 2X Lamelli sample buffer concentrate (Sigma-Aldrich, Dorset, UK), then denatured for 5 minutes by boiling at 100°C. Two Claudin-5 antibodies were used to prevent cross-reactivity with N-WASP and ROCK antibodies. Trans-epithelial resistance (TER) Cells were seeded into 0.4 μm transparent pore size inserts (Greiner bio-one, Stonehouse, UK) at a density of 50,000

cells in 200 μl of ordinary medium within 24 well plates, grown to confluence, the medium removed and replaced with fresh Dulbecco’s Modified Eagle’s medium containing 15 Mm Hepes, L-Glutamine ( Lonza Laboratories, Verviers, Belgium). Medium alone was added to the base of the wells (control) or with 50 ng/ml HGF [22]. Resistance across the layer JPH203 of MDA-MB-231 cells was measured using an EVON volt-ohmmeter (EVON, World Precision Instruments, Aston, Herts, UK), equipped with static electrodes (WPI, FL, USA) for a period of 4 h. In vitro cell growth assay MDA-MB-231 cells were seeded into a 96 well plate at a density of 3,000 cells/well to obtain density readings after 4 hours (day 0), 1 day, 3 days and 4 days. Within each experiment Rebamipide four duplicates were set up. After appropriate incubation periods, cells were fixed in 4% formaldehyde in BSS for 5-10 minutes before staining for 10 minutes with 0.5% (w/v) crystal violet in distilled water. The crystal violet was then extracted from

the cells using 10% acetic acid. Absorbance was determined at a wavelength of 540 nm on a plate reading spectrophotometer. In vitro cell matrix adhesion assay The cell-matrix attachment was carried out as previously described method [24]. Briefly, 45,000 cells were seeded onto the Matrigel basement (10 μg/well) membrane in 200 μl of normal medium and incubated at 37°C with 5% CO2 for 40 minutes. After the incubation period, the medium was aspirated and the membrane washed 5 times with 150 μl of BSS to remove the non-attached cells, then fixed in 4% formaldehyde (v/v) in BSS for 10minutes before being stained in 0.5% crystal violet (w/v) in distilled water. The number of adherent cells were counted from 5 random fields per well and 5 duplicate wells per sample, under a microscope.