Figure 1. UBC9 expression is up-regulated by E₂ in MCF-7 cells.

(A) UBC9 and (B) ER-α mRNA expression after treatment of MCF-7 cells with 10 nM E₂ for 12, 24, 48 and 72 hours. Where indicated, 100 nM ICI was also added to the culture medium. Total RNA was isolated and analyzed by real-time RT-PCR. Expression levels were normalized to GAPDH expression and relative to expression in untreated cells, which was arbitrarily set to 1. The data refer to results obtained in four separate experiments performed in triplicate. Bars represent the standard deviation (SD). (C) Up-regulation of UBC9 protein levels after induction with E₂. Total protein was extracted and analyzed by Western blotting. Actin was used as an internal protein loading control.