title: Identification of differentially expressed microRNA in parathyroid tumors.
abstract: BACKGROUND
  The molecular factors that control parathyroid tumorigenesis are poorly understood. In the absence of local invasion or metastasis, distinguishing benign from malignant parathyroid neoplasm is difficult on histologic examination. We studied the microRNA (miRNA) profile in normal, hyperplastic, and benign and malignant parathyroid tumors to better understand the molecular factors that may play a role in parathyroid tumorigenesis and that may serve as diagnostic markers for parathyroid carcinoma.
  
  
  METHODS
  miRNA arrays containing 825 human microRNAs with four duplicate probes per miRNA were used to profile parathyroid tumor (12 adenomas, 9 carcinomas, and 15 hyperplastic) samples normalized to four reference normal parathyroid glands. Differentially expressed miRNA were validated by real-time quantitative TaqMan polymerase chain reaction (PCR).
  
  
  RESULTS
  One hundred fifty-six miRNAs in parathyroid hyperplasia, 277 microRNAs in parathyroid adenoma, and 167 microRNAs in parathyroid carcinomas were significantly dysregulated as compared with normal parathyroid glands [false discovery rate (FDR) < 0.05]. By supervised clustering analysis, all parathyroid carcinomas clustered together. Three miRNAs (miR-26b, miR-30b, and miR-126*) were significantly dysregulated between parathyroid carcinoma and parathyroid adenoma. Receiver-operating characteristic curve analysis showed mir-126* was the best diagnostic marker, with area under the curve of 0.776.
  
  
  CONCLUSIONS
  Most miRNAs are downregulated in parathyroid carcinoma, while in parathyroid hyperplasia most miRNAs are upregulated. miRNA profiling shows distinct differentially expressed miRNAs by tumor type which may serve as helpful adjunct to distinguish parathyroid adenoma from carcinoma.
authors.affiliation: Endocrine Oncology Section, Surgery Branch, National Cancer Institute, Bethesda, MD, USA.
authors.forename: Reza
authors.initials: R
authors.lastname: Rahbari
authors.forename: Alisha K
authors.initials: AK
authors.lastname: Holloway
authors.forename: Mei
authors.initials: M
authors.lastname: He
authors.forename: Elham
authors.initials: E
authors.lastname: Khanafshar
authors.forename: Orlo H
authors.initials: OH
authors.lastname: Clark
authors.forename: Electron
authors.initials: E
authors.lastname: Kebebew
mesh_terms: D000236:Adenoma / Q000235:genetics* / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D006965:Hyperplasia / Q000378:metabolism* / Q000473:pathology; D035683:MicroRNAs / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D010280:Parathyroid Glands / Q000378:metabolism* / Q000473:pathology; D010282:Parathyroid Neoplasms / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D012372:ROC Curve; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D014408:Biomarkers, Tumor; D035683:MicroRNAs; D012333:RNA, Messenger