MiR-301b promotes the proliferation, mobility, and epithelial-to-mesenchymal transition of bladder cancer cells by targeting EGR1.

We investigated the role of miR-301b in the modulation of the proliferation, migration, and invasion of bladder cancer (BLCA) cells. The expression of miR-301b and EGR1 (early growth response gene 1) mRNA were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). A dual-luciferase reporter gene system was used to identify the target relationship between miR-301b and EGR1. Cell proliferation, cell cycle, and apoptosis were analyzed by MTT assay, colony-forming assay, and flow cytometry, respectively. Cell motility and invasiveness were assessed by wound healing and Transwell assays. The expression of proteins involved in epithelial-to-mesenchymal transition (EMT) and EGR1 were determined by Western blot. Our results showed that miR-301b was up-regulated while EGR1 was down-regulated in BLCA tissues compared with adjacent normal tissues. The proliferation, migration, and invasiveness of T24 cells (a kind of human BLCA cell) were suppressed by decreasing miR-301b expression or increasing EGR1 expression. In addition, miR-301b promoted EMT signaling by influencing the expression of related proteins. In conclusion, miR-301b promotes the proliferation, migration, and aggressiveness of human BLCA cells by inhibiting the expression of EGR1.