RhoG mediates HGF-induced invasion. A) SNB19 glioblastoma cells were transfected with siRNAs directed against luciferase (control, 20 nM), RhoG-2 (10 nM) or Rac1-1 (20 nM). Two days after transfection, cells were serum starved overnight and processed for the Matrigel invasion assay as described in Materials and Methods. All invaded cells on the bottom of the filter were counted using an inverted microscope. Data were normalized to those of control cells. The results shown represent the means +/− SEM of 4 independent experiments, performed in duplicate (* = p < 0.0005, two-tailed t test). B) Western blot demonstrating depletion of RhoG and Rac1.