Galectin-3 expression in papillary microcarcinoma of the thyroid.
OBJECTIVE
Galectin-3 is a beta-galactoside binding protein, recently recognized as a promising molecular marker of thyroid malignancy. As reported in several studies, galectin-3 is highly expressed in papillary thyroid carcinoma, but its expression has not been investigated in papillary microcarcinoma, which is a variant of papillary thyroid carcinoma.


RESULTS
Using a monoclonal antibody to galectin-3 and the avidin-biotin-peroxidase complex (ABC) immunohistochemical technique, we analysed galectin-3 expression in 63 cases of papillary microcarcinoma. The results showed immunohistochemical reactivity for galectin-3 in 51 (80.9%) cases. Intensity of staining varied from strong or moderate to weak. Galectin-3 localization was mostly cytoplasmic, but also membranous or nuclear in some cells. Immunohistochemical expression of galectin-3 was not found in 12 (19.1%) cases. Most galectin-3 negative microcarcinomas (10/12) were of the non-classical type, i.e. without papillary architecture. Neither the frequency nor the intensity of a positive reaction was related to tumour size.


CONCLUSIONS
Galectin-3 gene is expressed at the protein level in most papillary microcarcinomas, although with slightly lower frequency than that reported for clinically evident papillary thyroid carcinoma. The presence of galectin-3 in clinically silent microcarcinomas may indicate that galectin-3 is not related to growth or aggressiveness of papillary thyroid microcarcinomas but rather plays some other role in thyroid tumour biology.
Cvejic
D
D
Institute for the Application of Nuclear Energy, INEP, University of Belgrade, Zumun, Belgrade, Serbia. dubravka@inep.co.yu
Savin
S
S
Petrovic
I
I
Paunovic
I
I
Tatic
S
S
Krgovic
K
K
Havelka
M
M
D000328:Adult; D000368:Aged; D002291:Carcinoma, Papillary / Q000378:metabolism / Q000473:pathology*; D005260:Female; D037502:Galectin 3 / Q000096:biosynthesis*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D013964:Thyroid Neoplasms / Q000378:metabolism / Q000473:pathology*
D037502:Galectin 3