Characterization of ATC Cell Lines

FRO (purchased from the European Collection of Cell Cultures, Salisbury, United Kingdom) and SW1736 (obtained from Cell Lines Service GmbH, Eppelheim, Germany) are human cell lines derived from ATC, both harboring a BRAF V600E mutation (Pilli et al. 2009 (link); Schweppe et al. 2008 (link)). Both cell lines have been tested for being mycoplasma-free and authenticated by STR analysis to be appropriate cell lines of thyroid cancer origin. FRO and SW1736 were grown in DMEM medium (EuroClone, Milan, Italy) and RPMI 1640 medium (EuroClone) respectively, supplemented with 10% fetal bovine serum (Gibco Invitrogen, Milan, Italy), 2 mM L-glutamine (EuroClone) and 50 mg/ml gentamicin (Gibco Invitrogen), in a humidified incubator (5% CO₂ in air at 37°C). Cultured cells were treated with vehicle (DMSO, Sigma Aldrich, Saint Louis, MO, USA) or the following agents: JQ1 (50 nM–10 μM in DMSO) (Cayman Chemical, Ann Arbor, MI, USA) and I-BET762 (50 nM –10 μM in DMSO) (Merck Millipore, Darmstadt, Germany). T4888M and T3531L are ATC cell lines derived from tumors developed by [Pten, Tp53]^thyr−/− mice (Antico Arciuch et al. 2011 (link)). Cells were grown in DMEM supplemented with 10% FBS.