FIG. 7.

PDB induces no death in human PBMC or HEC-1-A cells exposed continuously to the compound for 24 h. (A) A continuous 24-h exposure to PDB had no effect on the viability of resting or activated human PBMC. PBMC from healthy donors were either unstimulated (resting) or stimulated with PHA-P and IL-2 for 48 h (activated). Cells were then harvested, resuspended in fresh medium, and treated with 25 μM and 250 μM PDB for 24 h. Cell death was measured by annexin V staining and flow cytometry. Percentages in plots indicate the percent death. Annexin V and forward scatter (FSC) are shown. (B) Pooled data from 3 donors are shown. (C) A continuous 24-h exposure of HEC-1-A cells to PDB at concentrations of 25 μM and 250 μM had no effect on their viability. Viability was measured by an MTT assay. Pooled data from 3 experiments are shown.