Fig. 5. Enhancement of HMM species with proteasome inhibitors. Cells were treated with 500 μM DPTA (D), 10 μM bortezomib (Bort), 20 μM MG-132 (MG), or the indicated combinations for 2 hours. (A) Representative Western blot image of HMM species with respective treatments. (B) Quantification of CYP2A6 protein activity. (C) Quantification of CYP2A6 protein concentration data. (D) Quantification of HMM signal, with control levels arbitrarily set to 1. Individual data from three independent experiments are shown, as well as means and 95% confidence intervals for each group. Repeated measures one-way ANOVA (with treatment as a within-subjects factor) and Šídák’s test were used to test for differences among treatment groups. In (B and C), a = significantly different from control (CON), b = significantly different from DPTA alone; P < 0.05. In (D), a = significantly different from DPTA alone, b = significantly different from bortezomib alone (Bort), c = significantly different from MG132 alone (MG); P < 0.05. MW, molecular weight.