Reduced survival of MM cell lines in the presence of celecoxib or DMC. Various MM cell lines were treated with different drugs, and cell growth and survival was determined after 48 hours by MTT assay. The top 3 panels show the results with the use of RPMI8226 cells and several drug-resistant variants as indicated. The bottom panels show the results with the cell pair MM1.S and MM1.R. Note that all cell lines are similarly inhibited by celecoxib (left panels) and by DMC (middle panels). As a control to verify drug resistance of these lines, the cells were treated with various drugs, as shown in the right panels. For example, 8226/Dox40 cells demonstrate clear resistance to killing by doxorubicin and paclitaxel, whereas the parental RPMI8226 cells are effectively growth inhibited and killed by these drugs (top right panel). Similarly, the proliferation of MM1.R cells is not affected by dexamethasone up to 100 μM, whereas MM1.S cells are sensitive to concentrations of 5 μM and below (bottom right panel). Shown are the mean values of n equal to 8 plus or minus SE.