title: Expression differences of circulating microRNAs in metastatic castration resistant prostate cancer and low-risk, localized prostate cancer.
abstract: BACKGROUND
  Recent studies show that microRNAs (miRNAs), small non-coding RNAs that negatively regulate gene expression, may have potential for monitoring cancer status. We investigated circulating miRNAs in prostate cancer that may be associated with the progression of hormone-sensitive primary tumors to metastatic castration resistant prostate cancer (CRPC) after androgen deprivation therapy.
  
  
  METHODS
  Using genome-wide expression profiling by TaqMan Human MicroRNA Arrays (Applied Biosystems) and/or quantitative real-time polymerase chain reaction, we compared the expression levels of miRNAs in serum samples from 28 patients of low-risk localized disease, 30 of high-risk localized disease and 26 of metastatic CRPC.
  
  
  RESULTS
  We demonstrated that serum samples from patients of low risk, localized prostate cancer and metastatic CRPC patients exhibit distinct circulating miRNA signatures. MiR-375, miR-378*, and miR-141 were significantly over-expressed in serum from CRPC patients compared with serum from low-risk localized patients, while miR-409-3p was significantly under-expressed. In prostate primary tumor samples, miR-375 and miR-141 also had significantly higher expression levels compared with those in normal prostate tissue.
  
  
  CONCLUSIONS
  Circulating miRNAs, particularly miR-375, miR-141, miR-378*, and miR-409-3p, are differentially expressed in serum samples from prostate cancer patients. In the search for improved minimally invasive methods to follow cancer pathogenesis, the correlation of disease status with the expression patterns of circulating miRNAs may indicate the potential importance of circulating miRNAs as prognostic markers for prostate cancer progression.
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02215, USA.
authors.forename: Han Christine Ngoc
authors.initials: HC
authors.lastname: Nguyen
authors.forename: Wanling
authors.initials: W
authors.lastname: Xie
authors.forename: Ming
authors.initials: M
authors.lastname: Yang
authors.forename: Chen-Lin
authors.initials: CL
authors.lastname: Hsieh
authors.forename: Sarah
authors.initials: S
authors.lastname: Drouin
authors.forename: Gwo-Shu Mary
authors.initials: GS
authors.lastname: Lee
authors.forename: Philip W
authors.initials: PW
authors.lastname: Kantoff
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000096:biosynthesis* / Q000097:blood* / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000096:biosynthesis* / Q000097:blood* / Q000235:genetics; D008875:Middle Aged; D009919:Orchiectomy; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000235:genetics; D012307:Risk Factors
chemical_list: D014408:Biomarkers, Tumor; D035683:MicroRNAs