Plasticity of Drug-Naïve and Vemurafenib- or Trametinib-Resistant Melanoma Cells in Execution of Differentiation/Pigmentation Program
Figure 4
Changes in expression levels of pigmentation-associated genes following acute treatment of melanoma cells with vemurafenib (PLX) or trametinib (TRA). (a) Transcript levels of MLANA, PMEL, TYR, and DCT were assessed by qRT-PCR and expressed relative to control. They are presented as mean ± SD from three independent experiments. Statistically significant differences are indicated: p<0.05. Comparison of expression levels of pigmentation-associated genes in melanoma cell line treated either with vemurafenib or with trametinib shown relative to the median values of all six drug-treated lines (right panels of (a)). (b) DCT protein levels assessed by immunoblotting. GAPDH was used as loading control. The proteins were visualized by using ChemiDoc Imaging System (Biorad). The images are cropped, which is indicated by white spaces. (c) Drug influence on percentages of Melan-A-positive and Ki-67-positive cells shown as representative density plots along with quantification (below). Data are presented as mean ± SD. Statistically significant differences are indicated: p<0.05. (d) Drug-induced changes in transcript levels of pigmentation-related genes after 22 h and 44 h of treatment with either vemurafenib or trametinib. qRT-PCR data were normalized to the expression of a reference gene RPS17.