Figure 4

Simultaneous inhibition of caspases and cathepsin B attenuates DTX-induced cell LMP and DNA fragmentation. A. PC3 cell cultures treated with DTX for 36 hours in the presence of cathepsin B inhibitor and stained with acridine orange (AO) appeared to have less detached yellow cells than cultures treated with DTX in the absence of inhibitor (compare with Fig. 3A). Images were acquired from fields that had both attached and detached cells: B. Cell cycle analysis of PC3 cells treated with DTX in the presence and absence of cathepisn B inhibitor for 48 h. Flow cytometric analysis of cells stained with propidium iodide was used to determine the percentage of subG1 cells. Error bars represent the standard deviation of at least three independent experiments (* p < 0.05, t-test). Representative DNA histograms for one of the experiments are shown: C. PC3 cell cultures treated with DTX for 36 hours in the presence of both Z-VAD-FMK and cathepsin B inhibitor, and stained with acridine orange, showed very few yellow detached cells, as compared with cultures treated with DTX in the absence of inhibitors (see Fig. 3A): D. Cell cycle analysis of PC3 cells treated with DTX in the presence and absence of Z-VAD-FMK and cathepisn B inhibitor for 48 h. Flow cytometric analysis of cells stained with propidium iodide was used to determine the percentage of subG1 cells. Error bars represent the standard deviation of at least three independent experiments (* p < 0.05, t-test). Representative DNA histograms for one of the experiments are shown.