Inhibition of Akt, mTOR, and IGF-1R induces cell death in BR cells. (A) 8226.wt and 8226.BR cells were exposed to the indicated concentrations of NVP-BEZ-235 for 24 hours, and viability was assessed using the WST-1 reagent. Data shown are representative of 3 independent experiments, and errors bars denote ± SD. (B) RPMI 8226.wt and 8226.BR cells were treated with increasing concentrations of PPP with (right) or without (left) simultaneous addition of 10nM bortezomib for 24 hours, and assessed by WST-1. Data points are representative from triplicate experiments, and error bars indicate SD. (C) The effect of PPP on Akt kinase activity was determined using RPMI 8226 and OPM-2 drug-naive and BR cell lines treated with 1μM PPP for 24 hours. After each experiment, cell lysates were prepared, and 25 mg of protein from each was probed for the levels of phospho-Akt in duplicate using an ELISA. Data shown are the mean of 2 experiments performed in duplicate ± SD. (D) CD138⁺ plasmacytes from patients were treated with increasing concentrations of PPP without (left) or with (right) simultaneous addition of 10nM bortezomib. Viable cell populations were evaluated using the WST-1 assay (*P < .05, **P < .01). All data points are the mean of experiments performed in triplicate ± SD.