MiR-25 regulates cell proliferation and metastasis in bladder urothelial carcinoma

Background: Bladder urothelial carcinoma (BC) is a common malignant tumor with a high incidence. This study aims to explore the role of miR-25 in BC tumorigenesis. Material and Methods: The expression of miR-25 and PTEN were detected in clinical BC tissues. BC cell lines T24 and 5637 were used to transfect miR-25 mimics or inhibitors. Luciferase reporter gene detection confirmed the correlation between miR-25 and PTEN. CCK-8 method and flow cytometry were used to detect cell viability and apoptosis. Cell migration and invasion ability were examined by transwell assays. Western blotting detects the protein levels of PTEN, β-catenin, GSK-3β and p-GSK-3β. Results: MiR-25 and PTEN expression are found to be negatively correlated in BC tissues. Further research confirmed that PTEN is a direct target of miR-25. In addition, the overexpression of miR-25 down-regulates the expression of PTEN, induces cell survival and inhibits apoptosis, while the knockout of miR-25 leads to the opposite result. miR-25 also inhibits the phosphorylation of GSK-3β and β-catenin without changing the total level of GSK-3β. In vivo experiments confirmed that miR-25 plays an oncogene's role by regulating the PTEN and Wnt/β-catenin signaling pathways. Conclusion: Our research shows that miR-25 has a negative regulatory effect on the expression of PTEN in clinical specimens and in vitro. miR-25 can promote the proliferation of BC cells and induce cell invasion. Therefore, miR-25 may be used as a biomarker to predict the progression of BC.