title: Expression profile analysis of microRNAs in prostate cancer by next-generation sequencing.
abstract: BACKGROUND
  Prostate cancer (PCa) is the second leading cause of tumor mortality among males in western societies. In China, the diagnostic and fatality rate of PCa is increasing yearly.
  
  
  METHODS
  To characterize underlying molecular mechanisms, the microRNA (miRNA) profile of high-grade PCa, low-grade PCa, and benign prostate hyperplasia (BPH) were compared using high-throughput Illumina sequencing and quantitative real-time PCR (qRT-PCR) methods. Moreover, a variety of biological information softwares and databases were applied to predict the target genes of miRNA, molecular functions, and signal pathways.
  
  
  RESULTS
  Eighteen miRNAs were differentially expressed (fold change ≥ 2, P < 0.05), of which thirteen were upregulated and five were downregulated by sequencing. This was confirmed by qRT-PCR in more clinical tissue samples. In the tumors, miRNAs (miR-125b-5p, miR-126-5p, miR-151a-5p, miR-221-3p, and miR-222-3p) were significantly upregulated with downregulation of miR-486-5p. In addition, 13 novel miRNAs were identified from three prostate tissue libraries, with 12 of them assayed in 21 human normal tissues by qRT-PCR. Multiple databases indicated target genes for these differentially expressed miRNAs. Function annotation of target genes indicated that most of them tend to target genes involved in signal transduction and cell communication, especially cancer-related PI3K-Akt and p53 signaling pathway.
  
  
  CONCLUSIONS
  The small RNA transcriptomes obtained in this study uncovers six differentially expressed miRNAs and 12 novel miRNAs, and provides a better understanding of the expression and function of miRNAs in the development of PCa and reveals several miRNAs in PCa that may have biomarker and therapeutic potentials.
authors.affiliation: Medical Research Center, Shaoxing people's Hospital, Shaoxing, China.
authors.forename: Chunjiao
authors.initials: C
authors.lastname: Song
authors.forename: Huan
authors.initials: H
authors.lastname: Chen
authors.forename: Tingzhang
authors.initials: T
authors.lastname: Wang
authors.forename: Weiguang
authors.initials: W
authors.lastname: Zhang
authors.forename: Guomei
authors.initials: G
authors.lastname: Ru
authors.forename: Juan
authors.initials: J
authors.lastname: Lang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002681:China; D019295:Computational Biology; D020869:Gene Expression Profiling; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D035683:MicroRNAs
keywords: microRNA; next-generation sequencing; pathway enrichment analysis; prostate cancer