Silencing of Armadillo Repeat-Containing Protein 8 (ARMc8) Inhibits TGF-β-Induced EMT in Bladder Carcinoma UMUC3 Cells

Abstract

Armadillo repeat-containing protein 8 (ARMc8) is a key factor in regulating cell migration, proliferation, tissue maintenance, and tumorigenesis. However, its role in bladder cancer remains unknown. Thus, in this study we sought to investigate the effect of ARMc8 on the epithelial-to-mesenchymal transition (EMT) progress in bladder cancer cells induced by transforming growth factor-β1 (TGF-β1). Our results found that ARMc8 was highly expressed in bladder cancer cell lines. ARMc8 silencing inhibited the TGF-β1-induced migration and invasion and suppressed the EMT progress in bladder cancer cells. Furthermore, ARMc8 silencing inhibited the TGF-β1-induced expression of β-catenin, cyclin D1, and c-myc in bladder cancer cells. In conclusion, the present study demonstrates a novel function for ARMc8, which acts as a mediator for TGF-β1-induced cell migration/invasion through modulation of the Wnt/β-catenin signaling pathway in bladder cancer cells. This study suggests that ARMc8 may be a potential therapeutic target for the development of therapies for bladder cancer.

Figure 1

ARMc8 is highly expressed in bladder cancer cell lines. (A) The expression of ARMc8 mRNA was evaluated in bladder cancer cell lines and normal bladder epithelial cell line by qRT-PCR analysis. (B) The expression of ARMc8 protein was evaluated in bladder cancer cell lines and normal bladder epithelial cell line by Western blot analysis. *p < 0.05 versus SV-HUC-1 group.

Figure 2

ARMc8 silencing inhibits TGF-β1-induced EMT in bladder cancer cells. (A) The transfection efficiency was confirmed by Western blot analysis in UMUC3 cells after transfection with si-AMRc8. (B) UMUC3 cells transfected with si-AMRc8 or si-NC were treated with TGF-β1 (10 ng/ml) for 24 h. The protein expression levels of E-cadherin and N-cadherin were detected by Western blot analysis. Quantification analysis was performed using the Gel-Pro Analyzer version 4.0 software. *p < 0.05 versus control group, #p < 0.05 versus TGF-β1 + si-NC group.

Figure 3

ARMc8 silencing inhibits TGF-β1-induced migration and invasion in bladder cancer cells. UMUC3 cells transfected with si-AMRc8 or si-NC were treated with TGF-β1 (10 ng/ml) for 24 h. (A) Cell migration was detected by Transwell assay. (B) Cell invasion was detected by Transwell assay with Matrigel. *p < 0.05 versus control group, #p < 0.05 versus TGF-β1 + si-NC group.

Figure 4

ARMc8 silencing inhibits the activation of Wnt/β-catenin signaling pathway in bladder cancer cells induced by TGF-β1. (A) UMUC3 cells transfected with si-AMRc8 or si-NC were treated with TGF-β1 (10 ng/ml) for 30 min. The protein expression levels of β-catenin, cyclin D1, and c-myc were evaluated by Western blot analysis. (B) Quantification analysis was performed using the Gel-Pro Analyzer version 4.0 software. *p < 0.05 versus control group, #p < 0.05 versus TGF-β1 + si-NC group.