title: MicroRNA profile: a promising ancillary tool for accurate renal cell tumour diagnosis.
abstract: BACKGROUND
  Renal cell tumours (RCTs) are clinically, morphologically and genetically heterogeneous. Accurate identification of renal cell carcinomas (RCCs) and its discrimination from normal tissue and benign tumours is mandatory. We, thus, aimed to define a panel of microRNAs that might aid in the diagnostic workup of RCTs.
  
  
  METHODS
  Fresh-frozen tissues from 120 RCTs (clear-cell RCC, papillary RCC, chromophobe RCC (chRCC) and oncocytomas: 30 cases each), 10 normal renal tissues and 60 cases of ex-vivo fine-needle aspiration biopsies from RCTs (15 of each subtype validation set) were collected. Expression levels of miR-21, miR-141, miR-155, miR-183 and miR-200b were assessed by quantitative reverse transcription-PCR. Receiver operator characteristic curves were constructed and the areas under the curve were calculated to assess diagnostic performance. Disease-specific survival curves and a Cox regression model comprising all significant variables were computed.
  
  
  RESULTS
  Renal cell tumours displayed significantly lower expression levels of miR-21, miR-141 and miR-200b compared with that of normal tissues, and expression levels of all miRs differed significantly between malignant and benign RCTs. Expression analysis of miR-141 or miR-200b accurately distinguished RCTs from normal renal tissues, oncocytoma from RCC and chRCC from oncocytoma. The diagnostic performance was confirmed in the validation set. Interestingly, miR-21, miR-141 and miR-155 expression levels showed prognostic significance in a univariate analysis.
  
  
  CONCLUSIONS
  The miR-141 or miR-200b panel accurately distinguishes RCC from normal kidney and oncocytoma in tissue samples, discriminating from normal kidney and oncocytoma, whereas miR-21, miR-141 and miR-155 convey prognostic information. This approach is feasible in fine-needle aspiration biopsies and might provide an ancillary tool for routine diagnosis.
authors.affiliation: 1] Cancer Epigenetics Group, Research Center of the Portuguese Oncology Institute, Rua Doutor António Bernardino Almeida, 4200-072 Porto, Portugal [2] Department of Genetics, Portuguese Oncology Institute, Porto, Portugal.
authors.forename: R M
authors.initials: RM
authors.lastname: Silva-Santos
authors.forename: P
authors.initials: P
authors.lastname: Costa-Pinheiro
authors.forename: A
authors.initials: A
authors.lastname: Luis
authors.forename: L
authors.initials: L
authors.lastname: Antunes
authors.forename: F
authors.initials: F
authors.lastname: Lobo
authors.forename: J
authors.initials: J
authors.lastname: Oliveira
authors.forename: R
authors.initials: R
authors.lastname: Henrique
authors.forename: C
authors.initials: C
authors.lastname: Jerónimo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics; D002292:Carcinoma, Renal Cell / Q000175:diagnosis* / Q000235:genetics; D055088:Early Detection of Cancer / Q000379:methods*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000175:diagnosis* / Q000235:genetics; D008297:Male; D035683:MicroRNAs / Q000502:physiology*; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D015203:Reproducibility of Results; D059467:Transcriptome; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D035683:MicroRNAs