Figure 4.

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