CD133 siRNA knockdown sensitizes BAK and STU melanoma cells to targeted therapies. qRT-PCR and RT-PCR of RNA derived from BAK (a) and STU (f) cells after siRNA knockdown of CD133 expression. (b) Immunoblot analysis of CD133, ABCG2, and Î²-actin following siRNA-mediated CD133 knockdown in BAK cells. (c, g) Cell viability (%) of CD133-depleted siRNA knockdown BAK (c) and STU (g) cells compared to scrambled control after exposure to D, T, and the combination treatment. (d, h) IC50s were calculated for BAK or STU cells, respectively. (e) Immunoblot analysis of MEK, and phospho-MEK, following siRNA-mediated CD133 knockdown and exposure to T or D at the indicated doses.