Figure 3.

The effect of the MEK inhibitor PD184161 on the proliferation of four human HCC cell lines (Hep3B, HepG2, PLC, and SKHep). Actively dividing cells were treated for 24, 48, or 72 hours with concentrations of PD184161 varying from 1.0 to 20 µM. A colorimetric proliferation assay was used to determine proliferation relative to control dimethyl sulfoxide-treated cells. Data are expressed as percentage of control. Each point on the graph represents the mean of triplicate samples, and error bars represent SEM. Similar results were obtained in at least two independent experiments.