MicroRNA-340 Inhibits Bladder Cancer Cell Growth by Downregulating Glucose Transporter-1

Abstract

Background: MicroRNA (miRNA)-340 is emerging as a critical regulator for the development and progression of various cancers, such as oral squamous cell carcinoma and prostate cancer. However, little was known about the role of miR-340 in bladder cancer. Methods: Bladder cancer and adjacent non-tumor tissue samples were collected from thirty patients undergoing surgical resection at Shaoxing People's Hospital. The expression of miR-340 and Glut-1 were studied via real-time quantitative PCR (RT-qPCR) or western blots. Bladder cancer T24 cells were transfected with miR-340 mimics to explore cell proliferation and apoptosis via MTT assay, flow cytometer, RT-qPCR and western blots. Results: Compared with that of normal tissues, miR-340 expression was significantly lower, while both mRNA and protein expression of Glut-1 were higher in bladder cancer tissues. The miR-340 could negatively regulate Glut-1 expression in bladder cells. Moreover, bladder cell proliferation could be inhibited by miR-340 and the corresponding antitumor effect could partially reverse by the overexpression of Glut-1. In view of the complexity of gene networks, some other multiple pathways might also confer to miR-340 inducing bladder cell apoptosis, including downregulating PCNA, upregulating Bax and decreasing the phosphorylation levels of PI3K and AKT.Conclusion: This work suggested an inverse correlation between miR-340 and glucose transporter-1 (Glut-1) expression in bladder cancer. miR-340/Glut-1 axis might be a potential and novel therapeutic target for the treatment of bladder cancer. More investigations need to further explore the applications of miR-340 in bladder cancer.