Comparison of expression of MITF-M, SOX10, and selected pigmentation-associated genes in different drug-naïve patient-derived melanoma cell lines. (a) Representative Western blot images showing MITF-M and SOX10 levels. GAPDH was used as loading control. The proteins were visualized by using ChemiDoc Imaging System (Biorad). ((b)-(c)) Basal expression level of MITF-M (b) and MLANA, PMEL, TYR, and DCT (c) determined by qRT-PCR. Gene expression levels in each melanoma cell line are shown relative to the median value of all seven populations. Bars represent mean values ± SD. (d) Representative flow cytometry density plots and percentages of Melan-A-positive (black frames) and Ki-67-positive (red frames) cells are shown. Percentages of Melan-A-positive cells and Ki-67-positive cells are indicated. DMBC, patient-derived cell lines obtained in Department of Molecular Biology of Cancer.