Vemurafenib

All cancer cell lines were purchased from American Type Culture Collection (ATCC; Manassas, VA) between February 2013 and July 2014. As indicated in the provided information, all cell lines were authenticated by their karyotypes, images and detailed gene expression. The cells were preserved and passaged in accordance with ATCC protocols for a maximum of 2 months and tested weekly for mycoplasma infection by PCR method. Cells were cultured in DMEM (Gibco-BRL, NY) supplemented with 10% FBS (Corning, NY) and 1% penicillin/streptomycin at 37 °C in a humidified 5% CO₂ incubator. Dr. Joon Kim (Korea Advanced Institute of Science and Technology, Daejeon, Korea) provided the parental WM3248 melanoma cells and vemurafenib-resistant WM3248 melanoma cells^{6 (link)}. The parental WM3248 cells and vemurafenib-resistant WM3248 cells were grown in MEM (Gibco-BRL) supplemented with 10% FBS; vemurafenib-resistant WM3248 cells were maintained in the presence of 2 μM vemurafenib (Adooq Bioscience, CA). Before the experiments, cell number and viability were measured using a Luna II automated cell counter (Logos Biosystems, Anyang, Korea).

Vemurafenib was acquired from Adooq Bioscience (Irvine, CA, USA), dabrafenib from AbMole BioScience (Housten, TX, USA), trametinib from Selleckchem (Housten, TX, USA), and cobimetinib from Roche (Basel, Switzerland). BRAF and MEK inhibitors were diluted according to the manufacturers’ instructions with DMSO (Life Technologies, Darmstadt, Germany). Final concentrations of the inhibitors are shown in Table 1.