Figure 8.

DU-145 uridine auxotrophs are markedly resistant to TFN-induced apoptosis. (A) Representative PI (DNA) histograms for PWR-1E cells exposed to Me₂SO (control) or to 50, 100, or 200 µM TFN for 48 hours. The gated cells detected below approximately 300 fluorescence units of PI on the linear x-axis of the representative histograms are designated the hypoploid apoptotic cell population. (B) A summary of the hypoploid PWR-1E cells observed after the 24- or 48-hour treatments described in panel (A). *P < .01 compared with the 24-hour control; **P < .01 compared with the 48-hour control. (C) The parental DU-145 cells and their ρ^o clones were treated for 24, 48, or 72 hours with 200 µM TFN or with an equal volume of the vehicle Me₂SO (control). *P < .01 compared with the 24- or 48-hour DU-145 control; #P < .05 compared with the 48-hour DU-145 ρ^o control; **P < .001 compared with the 72-hour DU-145 control.