MG-132 induces apoptosis in AML but not normal CD34⁺ cells.

Inhibitors of NF-κB induce apoptosis in AML but not in normal CD34⁺ hematopoietic cells. (A) Representative flow cytometric profile of primary AML cells (left panels) compared to normal cord blood cell (right panels) after a 6-hour treatment with or without 1 μM MG-132. Cells failing to label with annexin or the DNA dye 7-AAD represent viable cells (lower left). As apoptosis begins, cells start to label with annexin (lower right quadrant). As apoptosis proceeds, membrane integrity breaks down, and cells also label with 7-AAD (upper right quadrant). (B) Percent apoptotic cells in primary CD34⁺ AML cells (left panel, specimens 2, 4, and 6) compared to normal cord blood CD34⁺ cells (right panel) treated with 0.5 μM MG-132 (open bars), 1 μM MG-132 (hatched bars), or 1 μM MG-132 plus 5 mM sodium salicylate (dark bars).