Identification of circulating miRNAs as novel prognostic biomarkers for bladder cancer

MicroRNAs (miRNAs) are a type of ncRNAs with 18-25 nucleotides in length and reported to play crucial roles in human cancers. Bladder cancer is one of the most common causes of cancer-related death. The discovery of new early biomarkers for BC may improve the patients' response to the treatment thus obtaining higher outcomes. The present study identified 7 miRNAs were up-regulated in bladder serum cancer samples compared to normal samples, including hsa-miR-185-5p, hsa-miR-663a, hsa-miR-30c-5p, hsa-miR-3648, hsa-miR-1270, hsa-miR-200c-3p, and hsa-miR-29c-5p. The dysregulation of these miRNAs were correlated to advanced stage and overall survival time in bladder cancer patients. Moreover, we identified a predictive model to predict the prognosis of bladder cancer. Kaplan-Meier survival curve analyses showed that bladder cancer patients with high-risk scores had significantly worse overall survival time than bladder patients with lower risk scores. Furthermore, we constructed a miRNA-mRNA regulating network. Bioinformatics analysis showed these miRNAs were involved in regulating sarcomere organization, positive regulation of multicellular organism growth, phosphorylation, phosphatidylinositol-mediated signaling, and peroxisome proliferator activated receptor signaling pathway. We thought this study could provide novel noninvasive early biomarkers for bladder cancer.