title: Cell-free urinary microRNA-99a and microRNA-125b are diagnostic markers for the non-invasive screening of bladder cancer.
abstract: BACKGROUND
  Evidence implicated the diagnostic significance of microRNAs in whole urine/urine sediments in urothelial carcinoma of the bladder (UCB). However, the contaminated blood cells in patients with haematouria significantly altered the expression profiles of urinary microRNA, influencing the test accuracy.
  
  
  METHODS
  MicroRNA profiles of the urine supernatants of UCB patients and controls without any malignancy and profiles of malignant and corresponding normal mucosa tissues from the patients were determined by microRNA microarray and compared to identify differentially expressed microRNAs. The differential expression was verified in the tissues of an independent patient cohort by RT-qPCR. The diagnostic significance of selected microRNAs as biomarkers in the urine supernatant was investigated in the expanded cohorts.
  
  
  RESULTS
  MicroRNA-99a and microRNA-125b were down-regulated in the urine supernatants of UCB patients. The degree of down-regulation was associated with the tumor grade. A diagnostic model was developed using a combined index of the levels of microRNA-99a and microRNA-125b in the urine supernatant with a sensitivity of 86.7%, a specificity of 81.1% and a positive predicted value (PPV) of 91.8%. Discriminating between high- and low-grade UCB, the model using the level of microRNA-125b alone exhibited a sensitivity of 81.4%, a specificity of 87.0% and a PPV of 93.4%.
  
  
  CONCLUSIONS
  The results revealed a unique microRNA expression signature in the urine supernatants of UCB patients for the development of molecular diagnostic tests. An effective cell-free urinary microRNA-based model was developed using a combined index of the levels of microRNA-99a and microRNA-125b to detect UCB with good discriminating power, high sensitivity and high specificity.
authors.affiliation: Division of Urology, Department of Surgery, The Chinese University of Hong Kong, Hong Kong SAR, China.
authors.forename: Ding-Zuan
authors.initials: DZ
authors.lastname: Zhang
authors.affiliation: Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong SAR, China.
authors.forename: Kin-Mang
authors.initials: KM
authors.lastname: Lau
authors.affiliation: Division of Urology, Department of Surgery, The Chinese University of Hong Kong, Hong Kong SAR, China.
authors.forename: Eddie S Y
authors.initials: ES
authors.lastname: Chan
authors.affiliation: Division of Nephrology, Department of Medicine and Therapeutic, The Chinese University of Hong Kong, Hong Kong SAR, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Wang
authors.affiliation: Division of Nephrology, Department of Medicine and Therapeutic, The Chinese University of Hong Kong, Hong Kong SAR, China.
authors.forename: Cheuk-Chun
authors.initials: CC
authors.lastname: Szeto
authors.affiliation: Department of Obstetrics & Gynaecology, The Chinese University of Hong Kong, Hong Kong SAR, China.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Wong
authors.affiliation: Department of Obstetrics & Gynaecology, The Chinese University of Hong Kong, Hong Kong SAR, China.
authors.forename: Richard K W
authors.initials: RK
authors.lastname: Choy
authors.affiliation: Division of Urology, Department of Surgery, The Chinese University of Hong Kong, Hong Kong SAR, China.
authors.forename: Chi-Fai
authors.initials: CF
authors.lastname: Ng
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000652:urine*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000652:urine*; D008875:Middle Aged; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis* / Q000652:urine*
chemical_list: D014408:Biomarkers, Tumor; C531888:MIRN125 microRNA, human; C561679:MIRN99 microRNA, human; D035683:MicroRNAs