Chloroquine and SAHA increase the expression and alter the subcellular localization of cathepsin D and reduce the levels of its substrate thioredoxin (Trx). (A) Drug-induced modulation of cathepsin-D and Trx expression. K562 and LAMA 84 CML cells were treated with 25 μM CQ, 2 μM SAHA, or the combination for 24 hours. Immunoblotting was used to evaluate cathepsin-D and Trx expression. Actin was used as a loading control. (B-C) Subcellular localization of cathepsin D. K562 (B) and LAMA 84 (C) cells were treated with 25 μM CQ, 2 μM SAHA, or the combination for 18 hours. Cells were centrifuged at 150g onto glass slides and stained with anti–cathepsin-D and anti–LAMP-2 (lysosomal marker) antibodies as described in Confocal Microscopy in “Patients, materials, and methods.” Cells were visualized by confocal microscopy. Magnification, × 40.