Fig. 4: Activation of Wnt/β-catenin signaling reduces proliferation and invasion in melanoma cells in vitro.

a A representative picture of the MAPK inhibitor-resistant melanoma patient-derived cell culture M11 in presence of DMSO (left side) or CHIR99021 (6 µM) for 24 h (right side) in the upper panel. In the bottom panel a representative picture of nssh (left side) and shSOX10 (right side) expressing M11 cell culture. b Relative inhibition of proliferation of M98 (sensitive to MAPK inhibitor), M11, and M12 (resistant) melanoma cell cultures after treatment with increasing concentrations of CHIR99021 at 72 h. Drug concentration is indicated in a logarithmic scale (n = 3). c Relative fold changes in invasion in vitro of MAPK inhibitor sensitive (M00) and resistant (M11, M12) human melanoma cell cultures treated with 6 µM CHIR99021 are shown compared with DMSO (ctrl) (n = 3). d Representative images of colony formation assay of MAPK inhibitor sensitive cell cultures (M00 and M98) and resistant cell culture (M11) in presence of 6 µM CHIR99021, 100 nM LY2090314, 10 µM AZD1080, and shSOX10-expressing, respectively (n = 3). e Relative quantification of colony formation assay. Data represent mean ± s.d. Statistical significance was determined by unpaired, two-tailed Student’s t test. *P < 0.05, **P < 0.01, ***P < 0.001. In each panel, n indicates the number of independent experiments performed.