Downregulation of miR-138-5p is associated with poor prognosis in human bladder cancer

Accumulating evidence suggested that microRNA (miRNA) plays an important role in the carcinogenesis of bladder cancer. MicroRNA-138-5p (miR-138-5p) was dysregulated in human cancers including bladder cancer. However, its clinical significance remains unclear. We recruited 126 patients with bladder cancer in the study. Real-time quantitative polymerase chain reaction (RT-qPCR) was conducted for detection of miR-138-5p levels in tumor tissues and paired normal tissues. The prognostic significance of miR-138-5p in bladder cancer was further analyzed. MiR-138-5p levels were significantly decreased in the tumor tissues compared with the non-cancerous tissues. In addition, low levels of miR-138-5p were strongly associated with various clinicopathological parameters including TNM stage and histological grade as well as Ki-67 staining intensity. Bladder cancer patients with lower miR-138-5p levels had worse 5 year overall survival and recurrence free survival rates. Finally, multivariate analysis demonstrated that miR-138-5p was an independent prognostic factor for bladder cancer. Overall, our study indicated that miR-138-5p might serve as a useful prognostic biomarker for patients with bladder cancer.