title: Expression of X-linked inhibitor of apoptosis protein in neoplastic thyroid disorder.
abstract: X-linked inhibitor of apoptosis protein (XIAP) is associated with tumor genesis, growth, progression and metastasis, and acts by blocking caspase-mediated apoptosis. In the present study, we sought to evaluate the expression patterns of XIAP in various neoplastic thyroid disorders and determine the association between XIAP expression and clinicopathologic factors. Expression of XIAP was evaluated with immunohistochemical staining using monoclonal anti-XIAP in 164 specimens of conventional papillary thyroid carcinoma (PTC) and 53 specimens of other malignant or benign thyroid tumors. XIAP positivity was observed in 128 (78%) of the 164 conventional PTC specimens. Positive rates of XIAP expression in follicular variant PTC, follicular, medullary, poorly differentiated, and anaplastic thyroid carcinoma specimens were 20%, 25%, 38%, 67%, and 38%, respectively. Six nodular hyperplasia specimens were negative and 1 of 7 follicular adenomas (8%) was positive for XIAP. Lateral neck lymph node metastases were more frequent in patients negative for XIAP expression (P = 0.01). Immunohistochemical staining for XIAP as a novel molecular marker may thus be helpful in the differential diagnosis of thyroid cancer. Moreover, high XIAP expression in conventional PTC is strongly associated with reduced risk of lateral neck lymph node metastasis.
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: Jong Ho
authors.initials: JH
authors.lastname: Yoon
authors.forename: Sun A
authors.initials: SA
authors.lastname: Kim
authors.forename: Won Gu
authors.initials: WG
authors.lastname: Kim
authors.forename: Min Ji
authors.initials: MJ
authors.lastname: Jeon
authors.forename: Ji Min
authors.initials: JM
authors.lastname: Han
authors.forename: Tae Yon
authors.initials: TY
authors.lastname: Sung
authors.forename: Tae Yong
authors.initials: TY
authors.lastname: Kim
authors.forename: Won Bae
authors.initials: WB
authors.lastname: Kim
authors.forename: Suck Joon
authors.initials: SJ
authors.lastname: Hong
authors.forename: Young Kee
authors.initials: YK
authors.lastname: Shong
authors.forename: Gyungyub
authors.initials: G
authors.lastname: Gong
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal / Q000276:immunology; D002277:Carcinoma; D002291:Carcinoma, Papillary; D003937:Diagnosis, Differential; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000453:epidemiology / Q000378:metabolism / Q000473:pathology*; D051636:X-Linked Inhibitor of Apoptosis Protein / Q000276:immunology / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D051636:X-Linked Inhibitor of Apoptosis Protein