Fig. 3.

Downregulation of USP15 decreases the apoptosis of CML cells by lowering the level of Caspase-6 protein. (a) K562 cells were transfected with si-USP15,si-NC, pcDNA3.1-USP15 and pcDNA3.1-vector, respectively. Western blot analysis was performed to test protein levels of USP15 and Caspase-6. (b) Co-immunoprecipitation (CoIP) assays were performed to detect the interaction between USP15 and Caspase-6. (c) K562 cells were stained with anti-USP15 antibody (red) and anti-Caspase-6 antibody (green). Immunofluorescence stains analyzed the co-localization of USP15 protein and Caspase-6 protein in K562 cells. Scale bar = 64 μm. (d) K562 cells were transfected with si-NC or si-USP15 for 24 h then treated with MG132 for 6 h or not. USP15 and Caspase-6 protein level was detected by Western blot analysis. (e) K562 cells were transfected with pcDNA3.1-USP15 or si-Caspase-6, respectively, or co-transfected with pcDNA3.1-USP15 and si-Caspase-6 together. Cell apoptosis were evaluated by Annexin V-FITC/PI staining. Below panel shows the analysis of apoptosis rate. *P < 0.05 vs. corresponding control