Fig. 5: PSMD2 regulates β-catenin stability in breast cancer cells.

A Western blotting analysis of β-catenin and RACK1 expression in PSMD2-silenced breast cancer cells. B Western blotting analysis of β-catenin expression in control and PSMD2-silenced breast cancer cells treated with 50 μg/mL of CHX. The relative levels of β-catenin were quantified and are shown in the right panel. C Knockdown of PSMD2 increased the levels of ubiquitinated β-catenin. Cell lysates were immunoprecipitated with anti-β-catenin antibodies, and then analyzed by Western blotting with anti-HA-ubiquitin antibodies. D Western blotting analysis of β-catenin expression in PSMD2 overexpressing MDA-231 and BT549 cells. The relative expression levels of β-catenin are shown in the right panel. E Western blotting analysis of β-catenin expression in control and PSMD2-overexpressing cells treated with 50 μg/mL of CHX. The relative levels of β-catenin were quantified and are shown in the right panel. F Western blotting analysis of PSMD2 and β-catenin expression in RACK1-silenced breast cancer cells. G Western blotting analysis of PSMD2 and RACK1 expression in β-catenin-silenced breast cancer cells. H Western blotting analysis of β-catenin expression in RACK1-silenced and RACK1 and PSMD2 dual-silenced breast cancer cells. The relative levels of β-catenin were quantified and are shown in the right panel. All data are expressed as the mean ± SD; *p < 0.05. **p < 0.01, ***p < 0.001, ****p < 0.0001 and ns p > 0.05 versus control, N = 3.