FIGURE 9.
Knockdown of IQGAP1 abrogates resistance to the growth inhibitory effects of trastuzumab. Trastuzumab-sensitive (SkBR3) or trastuzumab-resistant (SkBR3TR) SkBR3 cells were transiently transfected with siRNA against renilla luciferase (siRen) or siRNAs against IQGAP1 (siIQ12 and siIQ14). 36 h after siRNA transfection, cells were serum-starved in the presence of vehicle (black bars) or 21 μg/ml trastuzumab (white bars) for 48 h. Cell growth was measured using sulforhodamine B staining. The data, expressed relative to the number of control cells in wells transfected with siRen and treated with vehicle, represent the mean ± S.E. (n = 5). *, significantly different from control cells transfected with siRen and treated with vehicle (p < 0.05); θ, significantly different from cells treated with vehicle (p < 0.05).