A–C: Western blot analysis of the effect of sodium selenite on cleavage of PARP and selected pro-caspases after 24 h exposure to increasing concentrations of sodium selenite (0, 1, 2.5, 5, and 10 μmol/l) in A) LNCaP cells, B) BPH-1 cells, and C) PC-3 cells. D) Agarose (1.5%) gel electrophoretic detection of nucleosomal DNA fragmentation (laddering) in LNCaP (left 5 lanes) and BPH-1 cells (right 5 lanes) after 72 h exposure to increasing concentrations of sodium selenite. The middle lane, which is indicated as MM, was loaded with 100-bp DNA size markers. TR, thioredoxin reductase; CI, cleaved; PAR-4, Prostate apoptosis response-4.