Melanoma Cell Line Authentication and Drug Treatment

A375 (CRL-1619) and Mewo (HTB-65) melanoma cells were purchased at American Type Culture Collection (Manassas, VA, USA) and normal human epidermal melanocytes at PromoCell (Heidelberg, Germany). SK-Mel-2, SK-Mel-5 and SK-Mel-28 melanoma cells were kindly provided by Dr Laura Poliseno (CRL-ITT, Pisa, Italy). Cell lines were authenticated by short tandem repeat profiling. Human melanoma samples (Supplementary Table S1) were obtained after approved protocols by the local Ethics Committee, and processed as previously described.^{7 (link), 8 (link)} Patient-derived SSM2c, M26c, M33x melanoma cells were already described^{8 (link)} and M51 cells were derived from a subcutaneous melanoma metastasis. Lentiviruses were produced in HEK-293T cells as already described.^{58 (link)} Cells were periodically tested for Mycoplasma contamination by 4’,6-diamidino-2-phenylindole inspection and PCR. CI-1040 and SCH772984 (Sigma, St Louis, MO, USA) were used for 16 h, respectively, at 1 μM and 0.5 μM, and transduced cells were selected with puromycin (2 μg/ml) (Sigma).