Focal adhesion kinase inhibitors reduce synovial fibroblast invasion in vitro . Human rheumatoid synovial fibroblasts were treated with focal adhesion kinase (FAK) inhibitors for 30 minutes or 5 hours. Cells were lysed and subjected to Western blot analysis for total FAK and FAK phosphorylated at tyrosine 397 (pY397). Bands were quantified by densitometry. Representative blot is shown in (A). (B) Graph depicts phosphorylated FAK divided by total FAK (n = 3 independent experiments using cell lines from two different patients). (C) Rheumatoid synovial fibroblasts were treated with PF-562,271, PF-573,228 or dimethyl sulfoxide (DMSO) as the vehicle control and allowed to invade for 24 hours in Matrigel invasion chambers. Graph shows the number of invaded cells per microscopic field at 100× magnification (n = 4 replicates using cell lines from three different patients). All graphs show average ± standard error of the mean (SEM) data with *P < 0.05 and ****P < 0.0001 by one-way analysis of variance.