title: Galectin-3 and oncofetal-fibronectin expression in thyroid neoplasia as assessed by reverse transcription-polymerase chain reaction and immunochemistry in cytologic and pathologic specimens.
abstract: Oncofetal fibronectin (onfFN) and galectin-3 (Gale-3) have been proposed as possible tools for the preoperative diagnosis of thyroid carcinomas, based on the finding that the expression of both onfFN and Gale-3 are significantly increased in papillary and anaplastic carcinomas, compared to normal thyroid tissues and follicular adenomas. In this study we analyzed the expression of these markers by immunochemical and molecular analysis of benign and malignant thyroid tumors. Sixty-five thyroid nodules, consisting of 20 follicular adenomas (FAs) and 45 papillary thyroid carcinomas (PTCs) at final histology were examined. At the molecular level, among the 45 PTCs, 44 (97.8%) showed a variable level of onfFN mRNA, while 8 of the 20 (40%) adenomas expressed the same marker. Similar results have been found analyzing Gale-3 expression: 97.8% of PTC and 55% of FAs were positive for this marker. Immunohistochemistry (IHC) for Gale-3 was positive in 42 of 45 (93.3%) PTC tissues. Staining was invariably confined to the cytoplasm, with a homogeneous distribution in the large majority of the neoplastic cells. The 3 negative cases (6.7%) were represented by 2 classic variants of PTC and 1 follicular variant of PTC. Eighteen of the 20 (90.0%) adenomas stained negative for Gale-3. A significant association was found between positive staining and malignant phenotype (p < 0.0001). Gale-3 protein expression was also performed on samples obtained by ex vivo fine-needle aspiration (FNA) in 35 PTCs by immunocytochemistry (ICC). Immunoreactivity was present in 32 (91.0%) and negative in 3 (8.8%) cases. With the exception of 1 case (negative by ICC and positive by IHC), ICC and IHC were fully concordant. In conclusion, our results indicate that a search for Gale-3 protein overexpression by IIC or ICC, but not by reverse transcription-polymerase chain reaction (RT-PCR), may yield an additional marker of malignant potential of thyroid nodular lesions, and may be a useful adjunct to the currently available diagnostic tools for the preoperative diagnosis of malignant thyroid tumors.
authors.affiliation: Department of Oncology, University of Pisa, Pisa, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Giannini
authors.forename: Pinuccia
authors.initials: P
authors.lastname: Faviana
authors.forename: Tiziana
authors.initials: T
authors.lastname: Cavinato
authors.forename: Rossella
authors.initials: R
authors.lastname: Elisei
authors.forename: Furio
authors.initials: F
authors.lastname: Pacini
authors.forename: Piero
authors.initials: P
authors.lastname: Berti
authors.forename: Gabriella
authors.initials: G
authors.lastname: Fontanini
authors.forename: Clara
authors.initials: C
authors.lastname: Ugolini
authors.forename: Tiziano
authors.initials: T
authors.lastname: Camacci
authors.forename: Katia
authors.initials: K
authors.lastname: De Ieso
authors.forename: Paolo
authors.initials: P
authors.lastname: Miccoli
authors.forename: Aldo
authors.initials: A
authors.lastname: Pinchera
authors.forename: Fulvio
authors.initials: F
authors.lastname: Basolo
mesh_terms: D000236:Adenoma / Q000235:genetics / Q000473:pathology; D001483:Base Sequence; D014408:Biomarkers, Tumor / Q000032:analysis; D017931:DNA Primers; D005353:Fibronectins / Q000032:analysis / Q000235:genetics*; D037502:Galectin 3 / Q000032:analysis / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D011237:Predictive Value of Tests; D012333:RNA, Messenger / Q000235:genetics; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013954:Thyroglobulin / Q000235:genetics; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor; D017931:DNA Primers; D005353:Fibronectins; D037502:Galectin 3; D012333:RNA, Messenger; C121542:oncofetal fibronectin; D013954:Thyroglobulin