Fig. 4: S63845 combined with ABT-263 or A-1331852 killed the resistant heterogeneous MIC population and inhibited the self-renewability.

a, b Melanoma cells were subjected to the primary sphere assay. Spheres were treated with indicated compounds either alone, or in combination, for 48 h, and were then analyzed by bright field microscopy (a) and the number of primary spheres quantified (b). c, d The combination treatment also inhibited the formation of secondary spheres (c) and quantified data for the number of secondary spheres is expressed as bar graph in (d). In all melanoma lines, the combination treatment significantly inhibited sphere maintainence/formation compared with all other treatments (DMSO or single drug). For visual clarity, we marked only the combinational treatments that were significantly different from comparisons with the DMSO and the single-drug treatments. Within each significant combination treatment, we only showed the most significant p-value of the comparisons. *Indicates p < 0.05; **indicates p < 0.01; ***indicates p < 0.001. Scale bar = 100 μm. Error bars represent ± SEM.