Fig. 6.

Reducing PDK4 expression partially restores sensitivity to antiestrogen in tamoxifen resistant breast cancer cells. a TamR-MCF-7 cells were transfected with siRNA targeted to PDK4 or a non-specific control siRNA. The next day, they were treated with 1 nm dexamethasone in media containing fetal bovine serum. Two days later, total RNA was collected, and PDK4 and β-actin mRNA expression was measured by qPCR as described. The average ratio of PDK4 mRNA to b-actin mRNA is shown; error bars indicate one standard deviation (n = 3 biological replicates). b MCF-7L and TamR-MCF-7 cells were transfected with PDK4 or control siRNA. The next day, cells were treated with the indicated doses of ICI or vehicle control. After 4 days, cellular mass was measured by sulforhodamine B staining. The average SRB staining is shown relative to vehicle treated samples; error bars indicate one standard deviation (n = 4). Different letters indicate statistically significant differences determined by ANOVA and Tukey–Kramer honest significant differences comparisons