Figure 3.

Knockdown of SOX2 reduces number and self-renewal of ALDH^high melanoma stem cells. (a) Quantification of the fraction of ALDH^high cells, determined by Aldefluor assay in SSM2c, M26c, M5 and A375 melanoma cells transduced with LV-c, LV-shSOX2-1 or LV-shSOX2-2. Significant reduction in the number of ALDH^high cells after silencing of SOX2 in all the four cell types is shown. (b, c) Number (b) and size (c) of secondary spheres in ALDH^high and ALDH^low SSM2c and M26c cells after silencing of SOX2 with shSOX2-1. (d, e) Quantification of BrdU incorporation (d) and of the fraction of early (Annexin V⁺/7-AAD⁻) and late (Annexin V⁺/7-AAD⁺) apoptotic cells (e) in ALDH^high and ALDH^low SSM2c and M26c secondary spheres transduced with LV-c and LV-shSOX2-1. Data shown are the mean±s.e.m. of at least three independent experiments. *P⩽0.05; **P⩽0.01.