Fig. 1

VB1 blocks the proliferation of melanoma cells. a Chemical structure of VB1. b A375 and Sk-Mel-28 cells were prepared in 96-well plates. The cells were treated with VB1 for various times and dosages as indicated, and cell viability was tested by CCK-8 as described in the Methods. The data from multiple experiments are expressed as the mean (n = 6) ± S.D. Significant differences were evaluated using one-way ANOVA, and an asterisk (*) indicates a significant difference (p < 0.05). c The IC50 values of VB1 in A375 and Sk-Mel-28 were automatically calculated by GraphPad Prism software as described in the Materials and Methods. d A375 and Sk-Mel-28 cells were seeded into 6-well plates, and then treated with various dosages of VB1 as indicated for 24 h. After 10–14 days, the number of colonies was assessed and quantified by crystal violet staining as described in the Methods. The data represent the mean (n = 4) ± SD of each group, and an asterisk (*) indicates a significant difference evaluated using one-way ANOVA (p < 0.05). e Nontumorigenic HaCaT and JB6 cells were treated with VB1 for different times and dosages as indicated. Cell viability was determined by the CCK-8 assay. The data from multiple experiments are expressed as the mean (n = 6) ± S.D. Significant differences were evaluated using one-way ANOVA, and an asterisk (*) indicates a significant difference (p < 0.05)