title: Identification and Validation of a Five MicroRNA Signature Predictive of Prostate Cancer Recurrence and Metastasis: A Cohort Study.
abstract: BACKGROUND
  MicroRNA (miRNA) have been shown to be important in regulating gene expression in prostate cancer. We used next generation miRNA sequencing to conduct a whole miRNome analysis to identify miRNAs associated with prostate cancer metastasis.
  
  
  METHODS
  We conducted discovery and validation analyses of miRNAs among a total of 546 men who underwent surgery for prostate cancer using the development of metastasis as an endpoint. Genome wide analysis was conducted among the discovery group (n=31) to identify new miRNAs associated with prostate cancer metastasis. Selected miRNAs were then analyzed using qPCR on prostatectomy specimens from an independent cohort (n=515) to determine whether their expression could predict the development of metastasis after surgery. To examine the biology underlying these associations, we created prostate cancer cell lines which overexpressed miR-301a for in vitro and in vivo functional assays.
  
  
  RESULTS
  We identified 33 miRNAs associated with prostate cancer metastasis and selected a panel comprising miRs-301a, 652, 454, 223 and 139 which strongly predicted metastasis (AUC=95.3%, 95%C.I.:84%-99%). Among the validation cohort, the 15-year metastasis-free survival was 77.5% (95% C.I.:63.9%-86.4%) for patients with a high miRNA panel score and 98.8% (95% C.I.:94.9%-99.7%, p<0.0001 for difference) for those with a low score. After adjusting for grade, stage, and PSA, the hazard ratio for metastasis was 4.3 (95% C.I.: 1.7-11.1, p=0.002) for patients with a high miRNA panel score, compared to those with a low score. Prostate cancer cell lines overexpressing miR-301a had in significantly higher tumor growth and metastasis in a xenograft mouse model.
  
  
  CONCLUSIONS
  A panel of miRNAs is associated with prostate cancer metastasis. These could be used as potential new prognostic factors in the surgical management of prostate cancer.
authors.affiliation: 1. Division of Urology, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Ave., Toronto, ON, M4N3M5, Canada.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Nam
authors.affiliation: 2. Department of Anatomic Pathology, Platform Biological Sciences, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Ave., Toronto, ON, M4N3M5, Canada.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Amemiya
authors.affiliation: 2. Department of Anatomic Pathology, Platform Biological Sciences, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Ave., Toronto, ON, M4N3M5, Canada.
authors.forename: Tania
authors.initials: T
authors.lastname: Benatar
authors.affiliation: 1. Division of Urology, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Ave., Toronto, ON, M4N3M5, Canada.
authors.forename: Christopher J D
authors.initials: CJ
authors.lastname: Wallis
authors.affiliation: 1. Division of Urology, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Ave., Toronto, ON, M4N3M5, Canada.
authors.forename: Jessica
authors.initials: J
authors.lastname: Stojcic-Bendavid
authors.affiliation: 2. Department of Anatomic Pathology, Platform Biological Sciences, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Ave., Toronto, ON, M4N3M5, Canada.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Bacopulos
authors.affiliation: 3. Department of Laboratory Medicine and Pathobiology, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Ave., Toronto, ON, M4N3M5, Canada.
authors.forename: Christopher
authors.initials: C
authors.lastname: Sherman
authors.affiliation: 3. Department of Laboratory Medicine and Pathobiology, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Ave., Toronto, ON, M4N3M5, Canada.
authors.forename: Linda
authors.initials: L
authors.lastname: Sugar
authors.affiliation: 3. Department of Laboratory Medicine and Pathobiology, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Ave., Toronto, ON, M4N3M5, Canada.
authors.forename: Magda
authors.initials: M
authors.lastname: Naeim
authors.affiliation: 2. Department of Anatomic Pathology, Platform Biological Sciences, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Ave., Toronto, ON, M4N3M5, Canada.
authors.forename: Wenyi
authors.initials: W
authors.lastname: Yang
authors.affiliation: 2. Department of Anatomic Pathology, Platform Biological Sciences, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Ave., Toronto, ON, M4N3M5, Canada.
authors.forename: Aiguo
authors.initials: A
authors.lastname: Zhang
authors.affiliation: 1. Division of Urology, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Ave., Toronto, ON, M4N3M5, Canada.
authors.forename: Laurence H
authors.initials: LH
authors.lastname: Klotz
authors.affiliation: 4. Department of Public Health Sciences, University of Toronto, 790 Bay St., Toronto, ON, M5G 1N8, Canada.
authors.forename: Steven A
authors.initials: SA
authors.lastname: Narod
authors.affiliation: 2. Department of Anatomic Pathology, Platform Biological Sciences, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Ave., Toronto, ON, M4N3M5, Canada.
authors.forename: Arun
authors.initials: A
authors.lastname: Seth
keywords: High-throughput nucleotide sequencing; MicroRNA; Prostatectomy; Prostatic neoplasms