title: Osteopontin levels in patients with papillary thyroid cancer according to the presence of Hashimoto's thyroiditis.
abstract: BACKGROUND
  Human papillary thyroid carcinoma (PTC) is often associated with Hashimoto's thyroiditis (HT); their coexistence improves PTC prognosis. Osteopontin, a secreted glycoprotein, plays a role in cell survival, immunity, and tumor progression, its expression being associated with a poor prognosis and metastasis in several malignancies. Osteopontin overexpression correlates with aggressive clinicopathological features in PTC. Lymph node metastases and large tumor size positively correlate with osteopontin positivity. This study aimed to: (1) confirm osteopontin overexpression in human PTC samples; (2) compare osteopontin expression levels in PTC cases with and without HT; and (3) identify correlations between tumor aggressiveness and osteopontin expression levels.
  
  
  METHODS
  Plasma osteopontin was assessed in 45 patients with PTC, 22 patients with PTC and HT, and 24 healthy controls by enzyme-linked immunosorbent assay. Thyroid tissue osteopontin mRNA and protein levels were analyzed by reverse transcription-polymerase chain reaction and Western blotting, respectively.
  
  
  RESULTS
  Plasma osteopontin levels were significantly higher in PTC patients than in healthy controls. Plasma osteopontin, tissue osteopontin mRNA, and tissue osteopontin protein levels were significantly lower in patients with PTC and HT than in those with PTC alone. In advanced disease stage cases, osteopontin mRNA and protein expression levels were lower in patients with PTC and HT than in those with PTC alone. However, the osteopontin expression level was not significantly associated with the TNM stage.
  
  
  CONCLUSIONS
  Plasma osteopontin, tissue osteopontin mRNA, and tissue osteopontin protein levels were significantly lower in patients with PTC and HT than in those with PTC alone, suggesting that HT attenuates PTC aggressiveness through negative regulation of osteopontin expression.
authors.affiliation: Department of Endocrinology, Ulsan University Hospital, Ulsan, Korea E-mail : endo10@daum.net.
authors.forename: So-Hyun
authors.initials: SH
authors.lastname: Park
authors.forename: Chan-Sung
authors.initials: CS
authors.lastname: Park
authors.forename: Young-Il
authors.initials: YI
authors.lastname: Kim
authors.forename: Il-Seong
authors.initials: IS
authors.lastname: Nam-Goong
authors.forename: Yon-Seon
authors.initials: YS
authors.lastname: Kim
authors.forename: Jong-Cheol
authors.initials: JC
authors.lastname: Lee
authors.forename: Jung-Il
authors.initials: JI
authors.lastname: Choi
authors.forename: Jeong-Woo
authors.initials: JW
authors.lastname: Park
authors.forename: Eun-Sook
authors.initials: ES
authors.lastname: Kim
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D002291:Carcinoma, Papillary / Q000209:etiology / Q000378:metabolism* / Q000556:secondary; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D050031:Hashimoto Disease / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D053495:Osteopontin / Q000235:genetics / Q000378:metabolism*; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013964:Thyroid Neoplasms / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D047368:Tumor Burden
chemical_list: D014408:Biomarkers, Tumor; D012333:RNA, Messenger; D053495:Osteopontin