KRASG12V enhances migrating and invasive capacity of colon adenocarcinoma cells through Cdc42 activation. (A) GST-pull down assay for Cdc42 activation in a panel of cell lines and quantification. (B) Fascin confocal staining illustrates filopodia formation (upper panel) and western blot analysis for expression of fascin and quantification (lower panel). (C) Caco-2 and Caco-K15 cells were treated for 48 hours with 160 pmol of a negative control siRNA sequence (siCtr) or with Cdc42-specific siRNA analyzed by western blot (upper panel). Assesment of cell migration and invasion in Caco-2 and Caco-K15 cells following siRNA against Cdc42 for 48 hours (lower panel). (D) Confocal images of Fascin in Caco-K cells after treatment with siRNA against Cdc42. (E) GST pull-down assay for Cdc42 activation in Caco-2 and Caco-K15 cells following treatment for 30 minutes with 1 μM PI3K inhibitor wortmanin. Results of migration and invasion assays were consistent between 3 independent experiments performed in triplicates. ***: P ≤ 0,001 as determined with Student t-test.