Evaluation of miR-141, miR-200c, miR-30b Expression and Clinicopathological Features of Bladder Cancer

Bladder cancer (BC) ranks the second most common genitourinary tract malignant tumor with high mortality and 70% recurrence rate worldwide. MiRNAs expression has noticeable role in bladder tumorigenesis. The purpose of this study was to assess miR-200c, miR-30b and miR-141 in tissue samples of patients with BC and healthy adjacent tissue samples and their association with muscle invasion, grade and the size of the tumor. Transurethral resection tissue samples were collected from thirty- five newly diagnosed untreated patients with BC from 2013 to 2014. The control group consisted of adjacent normal urothelium. All samples, observed by two pathologists, were diagnosed transitional cell carcinomas (TCC) with the proportion of tumor cells greater than 80%. Total RNA including miRNAs was extracted from about 50 mg tissue samples by applying TRIzol reagent. 2(-ΔΔ CT) method was used to calculate relative quantification of miRNA expression. Two of 35 patients were females and the other 33 were males. Invasion to bladder muscle was observed in 23 (67%) cases. MiR-141, miR-200-c and miR30-b were up-regulated in 91%, 79% and 64% of malignant tissues, respectively. Down-regulation of miR-141 had a strong association with muscle invasion (P= 0.017). Significant inverse correlation between grading and miRNA-141 level was observed (P= 0.043).