MicroRNA-621 inhibits cell proliferation and metastasis in bladder cancer by suppressing Wnt/β-catenin signaling.

Increasing evidence has shown that dysregulation of microRNA-621 (miR-621) is demonstrated to be associated with several cancers. However, the role of miR-621 in bladder cancer (BCa) remains unclear. Herein, we aimed to study the expression pattern, biological function, and molecular mechanism of miR-621 in BCa. First, we demonstrated that miR-621 was frequently downregulated in BCa tissues and cell lines compared with the adjacent normal BCa tissues and non-cancerous immortalized urothelial cell line. In addition, the expression of miR-621 was negatively correlated with overall survival of BCa patients. Functional experiments suggessted that miR-621 inhibited the proliferation and metastasis of BCa cells. Notably, dual-luciferase assay showed that miR-621 directly targeted the 3' UTR of TRIM29, which was frequently upregulated in BCa tissues and displayed inverse correlation with miR-621 expression. Furthermore, we demonstrated that miR-621 inhibited the proliferation and metastasis of BCa cells via Wnt/β-catenin signaling pathway by targeting TRIM29. Our study suggested that the miR-621/TRIM29 axis inhibits the proliferation and metastasis of BCa cells via Wnt/β-catenin signaling pathway and may have potential applications for development of BCa diagnosis or treatment.