Apo-2L induces apoptosis of HL-60, U937, and Jurkat cells.

Cells were exposed to the indicated concentrations of Apo-2L for 24 hours (A). Following this, the percentage of apoptotic cells were determined (see “Results”). Apo-2L induced the processing and down-regulation of caspase-8, Bid, caspase-9, caspase-3, and XIAP, as well as cytosolic accumulation of cyt c in Jurkat cells (B). Following exposure of Jurkat cells to 100 ng/mL of Apo-2L for 24 hours, cell lysates were obtained and Western analyses of the indicated proteins were performed (see “Results”). Western analyses of DR4, DR5, DcR2, cIAP-1, XIAP, I-FLICE (FLAME-1 or cFLIP), and survivin in HL-60, U937, and Jurkat cells (C).