Figure 6

Cell viability assay for treatment of curcumin with PKB inhibitor or SKP2 SiRNA. (A) Wortmannin alters curcumin response in MCF-7 and MDA-MB-231 cells. MCF-7 and MDA-MB-231 cells were treated with 1 μM concentration of wortmannin for 1 h prior to treatment with curcumin (40 μM) for 12 h and WST-1 assay was performed as described in the “Materials and methods”. Each bar represents the mean ± SD of three independent experiments. *,P <0.05; **,P <0.01, compared with control (DMSO). (B) Silencing of SKP2 increases cellular sensitivity to curcumin in MCF-7 and MDA-MB-231 cells. Cells were seeded at a density of 5000 cells/well in 96-well plate and cultured overnight. Then the medium was replaced by 1%(V/V) FBS, 20nM SKP2-SiRNA and control-SiRNA was added to indicated wells and cells were cultured for 48 h. SKP2-SiRNA transfection cells and control-SiRNA transfection cells were obtained. Cells were treated with 40 μM curcumin for 12 h and WST-1 assay was performed to detect viability of cells. One-way ANOVA was studied, followed by Student’s t test. Each bar represents the mean ± SD of three independent experiments. *,P <0.05; **,P <0.01, compared with control (DMSO).