title: Cell-Free microRNA-214 From Urine as a Biomarker for Non-Muscle-Invasive Bladder Cancer.
abstract: OBJECTIVE
  MicroRNAs are small noncoding RNAs and microRNA-214 (miR-214) has been associated with the inhibition of cancer cell growth, migration, and invasion. The aim of this study was to investigate whether cell-free miR-214 isolated from urine could be used as a biomarker for non-muscle-invasive bladder cancer (NMIBC).
  
  
  METHODS
  A total of 138 patients with primary NMIBC and 144 healthy normal controls were enrolled in this study. By use of quantitative polymerase chain reaction (PCR), the urinary levels of cell-free miR-214 were measured and the clinicopathological parameters of patients with NMIBC were compared with those of the controls.
  
  
  RESULTS
  The urinary levels of cell-free miR-214 were significantly higher in the NMIBC patients than in the controls (20.08±3.21 vs. 18.96±2.68, p=0.002). However, the urinary levels of cell-free miR-214 were neither graded nor staged for the NMIBC patients (p>0.05, each). When we compared the urinary levels of cell-free miR-214 according to clinical outcomes, patients with recurrence had lower levels of miR-214 than did those with no recurrence (19.24±2.67 vs. 20.41±3.41, p=0.023). By contrast, there were no significant differences in the urinary level of cell-free miR-214 between the NMIBC patients showing progression and those showing no progression (p=0.919). Multivariate Cox regression analysis revealed that urinary levels of cell-free miR-214 were an independent predictor of NMIBC recurrence (hazard ratio, 2.011; 95% confidence interval, 1.027 to 3.937; p=0.041).
  
  
  CONCLUSIONS
  Urinary levels of cell-free miR-214 could be an independent prognostic parameter for NMIBC recurrence. Thus, urinary cell-free microRNA-214 might be a useful prognostic marker for NMI BC.
authors.affiliation: Department of Urology, Chungbuk National University College of Medicine, Cheongju, Korea.
authors.forename: Sung Min
authors.initials: SM
authors.lastname: Kim
authors.forename: Ho Won
authors.initials: HW
authors.lastname: Kang
authors.forename: Won Tae
authors.initials: WT
authors.lastname: Kim
authors.forename: Yong-June
authors.initials: YJ
authors.lastname: Kim
authors.forename: Seok Joong
authors.initials: SJ
authors.lastname: Yun
authors.forename: Sang-Cheol
authors.initials: SC
authors.lastname: Lee
authors.forename: Wun-Jae
authors.initials: WJ
authors.lastname: Kim
keywords: MicroRNAs; Neoplasms; Recurrence; Urinary bladder