Ubiquitin-Specific Peptidase 8 Modulates Cell Proliferation and Induces Cell Cycle Arrest and Apoptosis in Breast Cancer by Stabilizing Estrogen Receptor Alpha

Figure 5

USP8 depletion promotes estrogen signaling activity. (a–d) USP8 knockdown decreased ERα target genes (PS2, GREB1, CCND1, and PDZK1) and protein levels. GAPDH was utilized as the internal control. (e, f) USP8 depletion effect on ERα protein level. Cells were treated with either ethanol or 10 nM estradiol for 6 h. (g) In the presence of the proteasome inhibitor MG132, shUSP8 did not further decrease ERα protein levels. Cells with shUSP8 or shControl were treated with 10 μM MG132/vehicle for 6 h. The results are representative of three independent experiments. (h) USP8 depletion decreases ER αhalf-life in MCF7 and T47D cells. Cells were treated with 100 μM CHX/vehicle for the indicated times. The relative density of protein bands was measured using the ImageJ software. (i) USP8 and ERα were partially colocalized in MCF7 and T47D cells (400 × magnification).

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