Bortezomib treatment decreases ERα and cohesin expression. (A) MCF7 cells were treated with vehicle (ethanol, Cont) or 50 nM bortezomib (Bort) for 2, 6 or 24 h. Total mRNA was harvested and reverse-transcribed. The expression levels of ESR1, SMC3, SMC1A, STAG1, RAD21 and MED12 genes were normalized to 28S ribosomal mRNA and graphed as in (A); mean values + SD, n =2. (B) MCF7 cells were treated with either vehicle (ethanol, Cont), 10 nM 17β-Estradiol (E2) or 50 nM bortezomib (Bort) for 24 h. SMC3 and ERα protein levels were analyzed by Western blot analysis. β-Actin is shown as loading control.