Bladder cancer is a common cancer in the Western world. The current 
prognosticators such as tumor grade, stage, size, and multifocality do not 
accurately reflect the clinical outcome. It is of clinical interest to identify 
biomarkers that could improve diagnostic and/or prognostic predictions. The 
objectives of this study were to identify deregulated miRNAs in bladder cancer 
samples and evaluate their potential as diagnostic and prognostic biomarkers. We 
screened 723 miRNAs by microarray and selected a subset of 15 distinctively 
deregulated miRNAs for further validation by real-time quantitative RT-(q)PCR. 
Seven miRNAs (miR-20a, miR-106b, miR-130b, miR-141, miR-200a, miR-200a*, and 
miR-205) were found to be up-regulated and eight miRNAs (miR-100, miR-125b, 
miR-130a, miR-139-5p, miR-145*, miR-199a-3p, miR-214, and miR-222) were found to 
be down-regulated in malignant bladder tissue samples compared to healthy 
tissue. Four miRNAs that have already been described in the literature (miR-141, 
miR-199a-3p, miR-205, and miR-214) were significantly differentially expressed 
between nonmuscle-invasive and muscle-invasive bladder cancer. Furthermore, 
real-time RT-qPCR of all miRNAs provided high overall correct classification 
(>75%) of bladder cancer diagnosis. Two miRNAs (miR-141 and miR-205) were 
associated with overall survival time. The verification of tumor-specific miRNA 
expression profile, together with the observed association of miR-141 and 
miR-205 expression with overall survival, underline the potential of miRNAs to 
function as diagnostic and/or prognostic markers of bladder cancer.