Research Paper Volume 11, Issue 21 pp 9643—9660

Oncogenic USP22 supports gastric cancer growth and metastasis by activating c-Myc/NAMPT/SIRT1-dependent FOXO1 and YAP signaling

Figure 5. USP22 promotes in vitro GC progression via c-Myc/NAMPT/ SIRT1-dependent FOXO1 and YAP signaling pathways. (A) Representative images show the levels of USP22, c-Myc, NAMPT, and SIRT1 proteins in BGC-823 and HGC-27 cells transfected with 100 nM siNC or siUSP22-1. The cells were analyzed at 24 h after transfection. β-actin was used as an endogenous control. (B) ChIP assay analysis shows binding efficiency of c-Myc in the promoter region of NAMPT in BGC-823 and HGC-27 cells that were transfected with 100 nM sic-Myc or siNC. (C) Representative images show the levels of c-Myc and NAMPT proteins in BGC-823 and HGC-27 cells that were transfected with 100 nM sic-Myc or siNC. β-actin was used as endogenous control. (D) ChIP assay analysis shows binding efficiency of NAMPT in the promoter region of SIRT1 in BGC-823 and HGC-27 cells that were transfected with 100 nM siNAMPT or siNC. (E) Representative images show the levels of NAMPT and SIRT1 protein in BGC-823 and HGC-27 cells were transfected with 100 nM siNAMPT or siNC. β-actin was used as endogenous control. (FG) Representative images show the levels of (F) Sirt1, FOXO1, Ki67, Cyclin D1, Bax, and Bcl-2, and (G) Sirt1, YAP, MMP-2, and MMP-9 proteins in BGC-823 and HGC-27 cells transfected with 100 nM siSirt1 or siNC, or cells treated with 100 μM EX527, a Sirt1 inhibitor. β-actin was used as an endogenous control.