Induction of apoptosis by salicylate on B-CLL cells. (A) Effect of salicylate on DNA fragmentation in B-CLL cells. Cells from patients no. 3 and 4 were incubated for 24 hours with 5 and 10 mmol/L sodium salicylate (NaSal). DNA was extracted and subjected to agarose gel electrophoresis as described in the Materials and Methods. (B) Effect of salicylate on PARP cleavage. Cells from patients no. 3 and 4 were incubated for 48 hours with 5 and 10 mmol/L sodium salicylate (NaSal). PARP cleavage was analyzed on protein extracts from these cells by Western blot as described in the Materials and Methods. The position of the native PARP (116 kD) and the proteolytic fragment (85 kD) is indicated.