FIGURE 2.

Establishment of drug-resistant cancer cell lines. A, comparison of drug sensitivity between SNU387 and SNU387^R cells. Each cell line was treated with various concentrations of each drug for 24 h. Cell numbers were determined by MTT assays. Each value represents an average of three independent experiments, and each experiment was performed in triplicate. B, comparison of drug sensitivity between Malme3M and Malme3M^R. C, comparison of caspase-3 activity in response to drugs between SNU387 and SNU387^R cells. D, comparison of caspase-3 activity was made between Malme3M and Malme3M^R. S denotes drug-sensitive, and R denotes drug-resistant. A.U., arbitrary units.