Sensitivity of myeloma cells to rapamycin.

Wild-type ras–expressing control cells (♦) or mutated N-ras (▴) or K-ras (▪) cells were incubated for 48 hours with 0 to 500 nM rapamycin, and then MTT assays were performed. Data are means of 3 separate experiments (SDs were always less than 5% of the means). Rapamycin-induced inhibition was significantly greater (P < .05) for N-ras and K-ras cells compared with wild-type cells at concentrations of 1, 10, 100, and 500 nM.