Figure 4.

RhoC knock-down decreases EGF-stimulated Akt and GSK-3β^ser9 phosphorylation. (A) Expression of RhoC in HNSCC cells transfected with siRhoC. Plasmid expressing either control siRNA (siNon-target) or RhoC-specific siRNA (siRhoC) was transfected into UM-SCC-6 cells as described in the Materials and Methods. The cells were then simulated with 100 ng/ml EGF. RhoA and RhoC expression were confirmed by immunoblot analysis with GAPDH serving as a loading control. (B) At 72 hours following transfection with either siNon-target or siRhoC, UM-SCC-6 cells were stimulated with 100 ng/ml EGF or vehicle control for 5 minutes. Whole cell lysates were then blotted with phospho-ERK, phospho-GSK-3β^ser9 and phospho-AKT antibodies followed by total ERK, AKT and GSK-3β^ser9 antibodies, respectively.