Association of nuclear, cytoplasmic expression of galectin-3 with beta-catenin/Wnt-pathway activation in thyroid carcinoma.
OBJECTIVE
To characterize the localization of galectin-3 in benign and malignant thyroid neoplasms and to correlate this with alterations in beta-catenin and cyclin D1 expression.


METHODS
Immunohistochemical study of 116 paraffin-embedded archival specimens from 113 patients who had undergone thyroidectomy and tissue placed into a commercially available tissue microarray.


METHODS
Tertiary care hospital.


METHODS
Thyroid tissue microarrays were stained by standard immunohistochemical protocols with monoclonal antibodies against galectin-3, beta-catenin, and cyclin D1.


METHODS
Nuclear and cytoplasmic expression of galectin-3 was correlated with clinical parameters, beta-catenin, and cyclin D1 expression.


RESULTS
Both cytoplasmic (56%) and nuclear (42%) galectin-3 expression was observed in most malignant neoplasms but was absent in benign thyroid specimens (P<.001). Among carcinomas, cytoplasmic galectin-3 expression was observed in papillary thyroid carcinomas (82%) and follicular (33%) and medullary (9%) carcinomas but was absent in anaplastic carcinomas (P<.001). Galectin-3 nuclear expression was observed in papillary thyroid carcinomas (62%) and follicular carcinomas (33%) but was undetectable in medullary, anaplastic carcinomas (P<.001). Cytoplasmic but not nuclear galectin-3 was inversely correlated with American Joint Committee on Cancer TNM stage (P = .02). There was a strong correlation between cytoplasmic and nuclear beta-catenin expression and both nuclear (P = .04) and cytoplasmic (P = .003) galectin-3 expression. Similarly, there was a strong association between galectin-3 nuclear (P<.001) and cytoplasmic (P<.001) expression and cyclin D1 expression.


CONCLUSIONS
Cytoplasmic and nuclear galectin-3 expression seem to be associated with activation of the Wnt-signaling pathway in well-differentiated thyroid neoplasms, suggesting that galectin-3 plays a role in thyroid carcinogenesis.
Weinberger
Paul M
PM
Department of Otolaryngology, Medical College of Georgia, Augusta, GA 30912, USA.
Adam
Bao-Ling
BL
Gourin
Christine G
CG
Moretz
William H
WH
Bollag
Roni J
RJ
Wang
Beverly Y
BY
Liu
Zhongmin
Z
Lee
Jeffrey R
JR
Terris
David J
DJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D001798:Blood Proteins / Q000235:genetics* / Q000378:metabolism; D005260:Female; D037502:Galectin 3 / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000235:genetics*; D019940:Genes, bcl-1 / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D040081:Protein Array Analysis / Q000379:methods; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics* / Q000378:metabolism; D012680:Sensitivity and Specificity; D015398:Signal Transduction / Q000235:genetics*; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D051153:Wnt Proteins / Q000235:genetics* / Q000378:metabolism; D051176:beta Catenin / Q000235:genetics* / Q000378:metabolism
D001798:Blood Proteins; D037502:Galectin 3; D018160:Receptors, Cytoplasmic and Nuclear; D051153:Wnt Proteins; D051176:beta Catenin; C021001:cytoplasmic activator protein, human