title: The microRNA spectrum in 12 body fluids.
abstract: BACKGROUND
  MicroRNAs (miRNAs) are small, noncoding RNAs that play an important role in regulating various biological processes through their interaction with cellular messenger RNAs. Extracellular miRNAs in serum, plasma, saliva, and urine have recently been shown to be associated with various pathological conditions including cancer.
  
  
  METHODS
  With the goal of assessing the distribution of miRNAs and demonstrating the potential use of miRNAs as biomarkers, we examined the presence of miRNAs in 12 human body fluids and urine samples from women in different stages of pregnancy or patients with different urothelial cancers. Using quantitative PCR, we conducted a global survey of the miRNA distribution in these fluids.
  
  
  RESULTS
  miRNAs were present in all fluids tested and showed distinct compositions in different fluid types. Several of the highly abundant miRNAs in these fluids were common among multiple fluid types, and some of the miRNAs were enriched in specific fluids. We also observed distinct miRNA patterns in the urine samples obtained from individuals with different physiopathological conditions.
  
  
  CONCLUSIONS
  MicroRNAs are ubiquitous in all the body fluid types tested. Fluid type-specific miRNAs may have functional roles associated with the surrounding tissues. In addition, the changes in miRNA spectra observed in the urine samples from patients with different urothelial conditions demonstrates the potential for using concentrations of specific miRNAs in body fluids as biomarkers for detecting and monitoring various physiopathological conditions.
authors.affiliation: Institute for Systems Biology, 1441 North 34th St., Seattle, WA 98103, USA.
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Weber
authors.forename: David H
authors.initials: DH
authors.lastname: Baxter
authors.forename: Shile
authors.initials: S
authors.lastname: Zhang
authors.forename: David Y
authors.initials: DY
authors.lastname: Huang
authors.forename: Kuo How
authors.initials: KH
authors.lastname: Huang
authors.forename: Ming Jen
authors.initials: MJ
authors.lastname: Lee
authors.forename: David J
authors.initials: DJ
authors.lastname: Galas
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
mesh_terms: D015415:Biomarkers / Q000032:analysis; D001826:Body Fluids / Q000737:chemistry*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000652:urine; D035683:MicroRNAs / Q000032:analysis*; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011264:Pregnancy Trimesters / Q000652:urine; D012016:Reference Values; D001749:Urinary Bladder Neoplasms / Q000652:urine
chemical_list: D015415:Biomarkers; D035683:MicroRNAs