Coadministration of PD184352 and UCN-01 potently induces loss of viability and clonogenic survival in MM cells

. 8226, H929, and U266 MM cells were exposed to either 1 μM As₂O₃ or 10 μM PD184352 + 150 nM UCN-01 for 24 or 48 hours, after which the extent of morphological apoptosis (A) or loss of viability, reflected by MTS dye reduction (B), was determined as described in “Materials and methods.” Alternatively, cells were washed free of drug and clonogenic assays performed as described in “Materials and methods” (C). Values represent the means ± SD for 3 separate experiments performed in triplicate. For all panels: ▪ indicates 8226: PD + UCN; ■, 8226: As₂O₃; ▾, H929: PD + UCN; ▿, H929: As₂O₃; ●, U266: PD + UCN; ○, U266: As₂O₃.