title: Association between STAT1 activity and BRAF mutations in papillary thyroid carcinomas.
abstract: BACKGROUND
  Signal transducer and activator of transcription-1 (STAT1) plays a critical role in tumorigenesis by controlling several functions in both tumor cells and the immune system, and is considered to be a tumor suppressor. The present study evaluated the activity of STAT1 in human papillary thyroid carcinomas (PTC).
  
  
  METHODS
  STAT1 activity was measured in nuclear extracts of tumor tissues from 35 PTC patients using an ELISA-based kit.
  
  
  RESULTS
  STAT1 activity was significantly lower in tumors than in the surrounding normal thyroid tissues (P < 0.01). The association between STAT1 activity and clinicopathologic factors was analyzed in PTC tissues. STAT1 activity was significantly lower in tumors that measured 2 cm or more than in tumors that measured 2 cm or less (P = 0.044). Moreover, tumor size was inversely correlated with STAT1 activity (Spearman's rank correlation coefficient (rho) = -0.34, P = 0.048). In addition, tumors with BRAF mutations showed lower STAT1 activity than wild-type BRAF tumors [0.064 (0.056-0.124) vs. 0.108 (0.073-0.153) arbitrary units, P = 0.048].
  
  
  CONCLUSIONS
  STAT1 activity is suppressed in PTCs (as measured by DNA-binding activities). The tumor with T1799A BRAF mutation and tumor sizes of 2 cm or more were clinicopathologic parameters associated with lower STAT1 activity. STAT1 activity of tumor might be one of potential biomarkers for PTC's.
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Ji Hye
authors.initials: JH
authors.lastname: Yim
authors.forename: Eun Sook
authors.initials: ES
authors.lastname: Kim
authors.forename: Hyun-Jung
authors.initials: HJ
authors.lastname: Choi
authors.forename: Min Ji
authors.initials: MJ
authors.lastname: Jeon
authors.forename: Ji Min
authors.initials: JM
authors.lastname: Han
authors.forename: Won Gu
authors.initials: WG
authors.lastname: Kim
authors.forename: Tae Yong
authors.initials: TY
authors.lastname: Kim
authors.forename: Gyungub
authors.initials: G
authors.lastname: Gong
authors.forename: Sang Yoon
authors.initials: SY
authors.lastname: Kim
authors.forename: Won Bae
authors.initials: WB
authors.lastname: Kim
authors.forename: Young Kee
authors.initials: YK
authors.lastname: Shong
mesh_terms: D000328:Adult; D002277:Carcinoma / Q000175:diagnosis / Q000235:genetics* / Q000378:metabolism; D002291:Carcinoma, Papillary; D004247:DNA / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011379:Prognosis; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D011933:Reagent Kits, Diagnostic; D050794:STAT1 Transcription Factor / Q000378:metabolism*; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000378:metabolism
chemical_list: D011933:Reagent Kits, Diagnostic; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D004247:DNA; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf