Fig. 1

Proteasome inhibition decreases the AGR2 expression. a Kaplan–Meier survival curves of lung adenocarcinoma patients are plotted for AGR2. The survival rate of the patients in the AGR2-lower group was significantly higher than that of patients in the AGR2-higher group (log-rank test, p= 0.02). b The baseline expression of AGR2 in several lung cancer cell lines. GAPDH served as a loading control. **p < 0.01 and ***p < 0.001 compared with the HBE cells. c The expression change of AGR2 in MG132-treated A549 cells was estimated by western blotting analysis. d MTT assay and e annexin staining was used to evaluate the effect of MG132 on A549 cells at 24 h. All values are expressed as the means ± SD of three independent experiments. f The levels of p53, p27, and AGR2 were measured by western blotting with 5 μM MG132 or 10 μM bortezomib for indicated time. g QRT-PCR analysis of AGR2 mRNA levels with 5 μM MG132 for 24 h. **p < 0.01 compared with the negative control. h The AGR2 promoter (0.5 or 1.4 kb) reporter constructs were transfected into A549 cells for 24 h, and then cells were treated with 5 μM MG132 for another 24 h. Luciferase activity was determined and was normalized to Renilla luciferase activity. ***p < 0.001 compared with the basic reporter