Background: Because of low sensitivity and specificity of the currently available urine markers for bladder cancer (BC) detection and painful cystoscopy procedure, our study was aimed to evaluate expression of urinary exosomal microRNA (miR)-96 and miR-183 as probable noninvasive and accurate biomarkers for the diagnosis and follow up of BC.
Methods and results: Using quantitative real-time polymerase chain reaction; Expression of exosomal miR-96 and miR- 183 in the urine samples of 51 patients with BC, 21 patients with benign urinary bladder lesions and in 24 normal individuals as control group. Our study results showed higher expressions of both miR-96 and miR-183 in urine of BC patients in comparison with control group (P <0.001 for each). Analysis of receiver-operating characteristic curve demonstrated that each microRNA had good sensitivity and specificity for differentiating BC patients from non-BC patients (miR-96; 80.4% and 91.8%; and miR-183, 78.4% and 81.6% respectively) compared to cytology (37.3% and 100%). In addition, it was obvious that the sensitivity and specificity of combined miR-96 and miR-183 for the diagnosis of BC reached 88.2%% and 87.8%, respectively, which were higher than each one alone. We also found that expression of miR-96 and miR-183 with lymph node invasion, advancing grade, and pathological stage was significantly increased. After surgery, collected urine samples showed significantly lower expression of microRNA (miR-96: P < 0.001; and miR-183, P = 0.002).
Conclusion: In conclusion, miR-96 and miR-183 in urine are promising diagnostic tumor markers for BC; particularly, when they combined with each other or with urinary cytology.