Fig 2: Relative CSN1 expression in HCC and its clinical significance. (A) Tissue microarray immunohistochemical staining. Magnification, ×200. (B) Relative expression of CSN1 in HCC tissue (n=117) and paracancerous tissue samples (n=59). (C) CSN1 expression levels in cancer and adjacent tissue samples. n=59 in each group. (D and E) Kaplan-Meier curves for (D) overall survival or (E) disease-free survival in two groups defined by low and high expression of CSN1 in patients with HCC. (F) CSN1 protein levels in HCC cell lines compared with the normal human liver cell line MIHA. **P<0.01 and ***P<0.001. CSN1, constitutive photomorphogenesis 9 signalosome subunit 1; HCC, hepatocellular carcinoma.

Fig 3: CSN1 interacts with cyclin A2. (A) Representative western blots of CSN1, cyclin A2 and cell cycle-related proteins following CSN1 overexpression in MHCC-LM3 cells. Cells transfected with empty vectors were used as NC group. (B) Western blots of cyclin A2 protein levels in MHCC-LM3 cells transfected with NC or OE-CSN1 plasmids, with or without si-cyclin A2. (C) Proliferation (magnification, ×200), (D) wound healing (magnification, ×100) (E) and Transwell assay (magnification, ×100 and ×400) of MHCC-LM3 cells transfected with NC or OE-CSN1 plasmids, with or without si-cyclin A2. (F) Effect of OE-CSN1 on cyclin A2 mRNA levels. (G) Representative western blots of cyclin A2 turnover rate in OE-CSN1 MHCC-LM3 cells following CXH treatment. (H) Cyclin A2 protein levels after OE-CSN1 transfection, and CHX or ActD treatment in MHCC-LM3 cells. *P<0.05, **P<0.01 and ***P<0.001. CHX, cycloheximide; CSN1, constitutive photomorphogenesis 9 signalosome subunit 1; OE, overexpression; ActD, actinomycin D; CDK, cyclin-dependent kinase; si, small interfering; NC, negative control.

Fig 4: Effects of CSN1 on tumor growth in vivo. Nude mice were subcutaneously injected with CSN1-overexpressing MHCC-LM3 cells and NC cells. Tumor sizes were measured after sizeable tumor formation (day 8). On day 28, the tumors were excised for analysis. n=5. (A) Western blot images of CSN1 levels. (B) Macroscopic appearance of isolated tumors. (C) Tumor volume and (D) weights in CSN1 and NC xenograft nude mice. *P<0.05 and **P<0.01. CSN1, constitutive photomorphogenesis 9 signalosome subunit 1; NC, negative control.