Imatinib

K562 cells were treated with 20 μM etoposide (Sigma-Aldrich, St Louis, MO, USA), 10 μg/ml camptothecin (Sigma-Aldrich), 5 μM staurosporine (Sigma-Aldrich).
The KCL22-S and KCL22-R cell lines were incubated in the presence of either 5 μM imatinib, 400 nM nilotinib (Novartis Pharma), or 3 nM dasatinib (Bristol-Myers Squibb Company Princeton, New Jersey, USA).
To inhibit different signaling pathways, K562 cells were treated with either 1 μM imatinib (Novartis Pharma), 30 μM LY294002 (Calbiochem, Merck KgaA, Darmstadt, Germany), 10 μM NVP-BEZ235 (Novartis Pharma), 50 ng/ml rapamycin (Cell Signalling Technology, Beverly, MA, USA) or 1 μM everolimus (Sigma-Aldrich). To investigate ZNF224 mRNA stability, cells were treated with 4 μg/ml actinomycin D (Sigma-Aldrich).

The donor of the study specimen was a 12-year-old female NF1 patient, diagnosed according to the modified National Institutes of Health criteria [18] (link). A parent of the patient gave informed written consent in addition to assent from the patient. The Institutional Review Board approved the study (OB-061/05). Her PNF was operated at the Department of Maxillofacial Surgery, University Hospital Hamburg-Eppendorf. A part of the tumor was kept in Hanks buffered saline and delivered into the laboratory for cell culture and for xenografting. Schwann cells from the PNF were cultured and identified as previously described [16] (link).
After ensuring purity of 85%, PNF-derived Schwann cells were treated with nilotinib and imatinib (Novartis Pharma AG, Switzerland), each at 0, 5, 10, 15 and 20 µM for 10 days. Cell proliferation and viability assays were performed as previously described [16] (link).