Figure 4.

Cisplatin resistance in CD44(+) and CD44(−) cells. A, Viabilities of CD44(+) and CD44(−) MKN45 cells after treatment with cisplatin (2 or 2.5 μg/mL) as measured by MTS assay. Values shown represent averages of relative control cell viabilities; each treatment was carried out in triplicate (*P < .05). B, CD44(+) and CD44(−) MKN45 cells were treated with cisplatin (3 μg/mL) for 24 h and then stained with annexin V and propidium iodide. Values shown represent average rates of apoptosis after cisplatin treatment of CD44(+) and CD44(−) MKN45 cells. Each treatment was carried out in triplicate (*P < .05). CDDP, cisplatin