Bmscs

Chronic myeloid leukaemia cell line, LAMA84, was obtained from DSMZ (Braunschweig, Germany); human primary CD34⁺ cells and bone marrow primary stromal cells (BMSCs) were obtained from Lonza (Basel, Switzerland). LAMA84 cells were cultured in RPMI 1640 medium, supplemented with 10% foetal bovine serum (FBS), 2 mM L‐glutamine, 100 U/ml penicillin and 100 μg/ml streptomycin (Euroclone, UK). CD34⁺ cells were cultured in IMDM medium, supplemented with 15% FBS, 2 mM L‐glutamine, 100 U/ml penicillin and 100 mg/ml streptomycin (Euroclone, UK). BMSCs were cultured in MyeloCult H5100 (STEMCELL Technologies Inc., Vancouver, BC, Canada). Gefitinib or Erlotinib (Cayman Chemical, Ann Arbor, MI, USA) was solubilized at 10‐mM stock solution in DMSO and stored at −20°C. Neutralizing antibody anti‐AREG (R&D Systems, Abingdon, UK) was reconstituted at 0.2 mg/ml in sterile PBS, aliquoted and stored at −20°C. Recombinant Areg (R&D Systems, Abingdon, UK) was reconstituted at 0.1 mg/ml in sterile PBS, aliquoted and stored at −20°C. Working dilutions, where necessary, were prepared in medium. All other reagents were purchased from Sigma‐Aldrich (St. Louis, MO, USA), if not cited otherwise.