MUC1 small interfering RNA (siRNA) affects cell death in response to stress in MDA-MB-468, but not BT-20 cells. (a) Basal apoptosis is shown as the combined total of early (propidium iodide (PI)-/annexin V+) and late (PI+/annexin V+) apoptotic populations. Results reflect the averages of three independent experiments. (b) Apoptosis after trypsinization 24 hours post-transfection. Numbers in the quadrants reflect the percentage of cells in each. Representative flow cytometry results are shown for MDA-MB-468 and BT-20 cells transfected with siRNA. (c) Total cell death (sum of non-apoptotic cell death (PI+/annexin V-), and early and late apoptosis) is shown for MDA-MB-468 cells in response to a panel of cellular stresses (G418, trypsin, peroxide, celecoxib) and controls (control, DMSO). Representative results from three independent experiments are shown. (d) Western blots (IB) for total and active AKT (AKT, pAKT) and tubulin loading control, performed on whole cell lysates from siRNA transfected cells. The same exposure is shown for both cell lines to show the relative levels of protein between lines, rather than optimal exposure times for comparison within a single cell line (shown in Figure 3a).