FIGURE 8.

Knockdown of mda-9/syntenin suppresses COL-I-induced activation of ERK1/2 and Rac1 as well as cell invasion and reorganization of actin cytoskeleton. A, MDA-MB-231 cells were allowed to adhere to COL-I-coated dishes for the indicated periods of time. Whole cell lysates were blotted with the indicated antibodies. B, MDA-MB-231 cells transfected with a control siRNA (Co) or mda-9/syntenin-targeted siRNA (Sy) were plated onto COL-I-coated dishes for 2 h. Whole cell lysates were blotted with the indicated antibodies. C, MDA-MB-231 cells transfected with a control vector or HA-tagged ILK (E359K) vector were plated onto COL-I-coated dishes for 2 h. Whole cell lysates were blotted with the indicated antibodies. D, MDA-MB-231 cells transfected with the indicated constructs were plated onto COL-I-coated dishes for 30 min, and then Rac1 activity was determined. Data represent the average of two independent experiments performed in triplicate; *, statistically significant (p < 0.01) versus the control. E, MDA-MB-231 cells transfected with a control siRNA or mda-9/syntenin-targeted siRNA were plated onto COL-I-coated coverslips for 30 min and stained with FITC-labeled phalloidin to detect of F-actin filaments. Bar, 10 μm. F, MDA-MB-231 cells were transfected with the indicated constructs. Cells that invade through the pores in the filter were fixed, stained, and counted in five random fields visualized by microscopy (×100). Data represent average of three independent experiments performed in triplicate; *, statistically significant (p < 0.01) versus the control. Con, control.