Figure 5. Disorazole C₁ causes irreversible growth inhibition.

A549 cells were treated for 1 h with 10 nM disorazole C₁, 1 μM nocodazole or DMSO vehicle followed by either washout of compound (wash) or continuous exposure to compound (contin) for 1, 24, 48, 72 and 144 h. Live cells were counted by trypan blue exclusion. The number of viable cells (trypan blue negative) is graphed as the percentage of viable cells/ml normalized to the DMSO control. Data are representative of two independent experiments. (B) A549 cells were incubated with doxorubicin (50 nM) or disorazole C₁ (2 or 10 nM) for 24 h (open bars) or 48 h (black bars) and apoptosis determined with a TUNEL assay. N=3, bars are SEM.