Figure 4

Inhibition of Rho GTPases, Rac, or Cdc42 in migration of the high metastatic MDA-MB-435α6HG6 cell variant. (a) MDA-MB-435α6HG6 cells were treated with vehicle or 2 ng/ml toxin B for 24 h and subjected to a basement membrane haptotaxis assay. Cells migrating to the underside of the membrane were stained with propidium iodide and counted under 400× Magnification. (b) MDA-MB-435α6HG6 cells transiently expressing vector alone or myc-Cdc42(T17N) were subjected to a basement membrane haptotaxis assay. Cells migrating to the underside of the membrane were stained with propidium iodide and counted under 400× Magnification. Equal loading was confirmed by a total actin blot, ectopic myc-Cdc42(T17N) expression confirmed by western blotting with anti-Cdc42 or anti-myc. (c) MDA-MB-435α6HG6 cells transiently expressing vector alone, myc-Rac1(T17N), or myc-Rac3(T17N) were subjected to a basement membrane haptotaxis assay. Bars represent ±SEM; equal loading was confirmed by total actin blot. Myc-Rac1(T17N) and myc-Rac3(T17N) expression were confirmed by western blotting with anti-Rac or anti-myc. Data are expressed as mean ±SEM of three independent experiments. A star denotes statistical significance from control (P < 0.05, calculated from paired t-tests).