Fig. 3.

Verification of true ERα-regulated proteins through the dynamics of protein expression and competitive inhibition by 4-hydroxytamoxifen. Four biological replicates of MCF-7 cells were stimulated with 10 nm 17β-estradiol and grown for 3–72 h, or stimulated with 10 nm 17β-estradiol in the presence of increasing concentrations of 4-hydroxytamoxifen (4-OHT) and grown for 36 h. Relative abundances of estrogen-regulated, house-keeping and control proteins were measured by a multiplex SRM assay. C, control: Cells treated with vehicle control (0.1% ethanol) and grown for 36 h. *Cells treated with vehicle control (0.1% ethanol) and 10⁻⁶ m 4-hydroxytamoxifen.