Auy922

Human K562 CML cell line was obtained from American Type Culture Collection (Manassas, VA). CD44^high K562 cells were established during isolation of imatinib-resistant K562 cells after treatment with increasing concentrations of imatinib, and were stable in complete medium without imatinib. The profile of cell surface CD44 expression was carried out on both cells and gated using mouse anti-human CD44-FITC (BD Biosciences, San Jose, CA, USA).We also used CD44⁺ HCT-15 cells with high CD44 expression and CD44^- HCT-15 cells with low CD44 expression isolated from human colon cancer cell line HCT-15 29 (link). Cells were maintained in RPMI medium (Invitrogen, Carlsbad, CA, USA) supplemented with 10% (v⁄v) heat-inactivated FBS (Gibco BRL, Life Technologies, Carlsbad, CA, USA), 100 U⁄ml penicillin and 100 mg⁄ml streptomycin (Sigma-Aldrich, St.Louis, MO, USA) in a 5% CO₂ humidified incubator at 37°C. 17-AAG and AUY922 were purchased from Enzo Life Sciences Inc. (Farmingdale, New York, USA) and Selleck Chemicals (Houston, TX, USA), respectively. EX527 was purchased from BioVision Inc. (Milpitas, CA, USA). Amurensin G, a natural SIRT1 inhibitor, was supplied Dr. Oh (Seoul National University, Seoul, Korea) as described previously 30 (link).