Galectin-3 expression in papillary thyroid carcinoma: relation to histomorphologic growth pattern, lymph node metastasis, extrathyroid invasion, and tumor size

Immunohistochemical Biomarkers in Thyroid Pathology

The application of immunohistochemistry to the diagnosis of thyroid lesions has increased as new biomarkers have emerged. In this review, we discuss the biomarkers that are critical for accurate diagnosis, prognosis, and management. Immunohistochemical markers are used to confirm that an unusual tumor in the thyroid is indeed of thyroid origin, either of follicular epithelial or C-cell differentiation; the various mimics include nonthyroidal lesions such as parathyroid tumors, paragangliomas, thymic neoplasms, and metastatic malignancies. Tumors of thyroid follicular epithelial cells can be further subclassified using a number of immunohistochemical biomarkers that can distinguish follicular-derived from C-cell lesions and others that support malignancy in borderline cases. The use of mutation-specific antibodies can distinguish papillary carcinomas harboring a BRAF^V600E mutation from RAS-like neoplasms. Immunostains have been developed to further identify molecular alterations underlying tumor development, including some rearrangements. Altered expression of several biomarkers that are known to be epigenetically modified in thyroid cancer can be used to assist in predicting more aggressive behavior such as a propensity to develop locoregional lymphatic spread. Immunohistochemistry can assist in identifying lymphatic and vascular invasion. Biomarkers can be applied to determine dedifferentiation and to further classify poorly differentiated and anaplastic carcinomas. The rare tumors associated with genetic predisposition to endocrine neoplasia can also be identified using some immunohistochemical stains. The application of these ancillary tools allows more accurate diagnosis and better understanding of pathogenesis while improving prediction and prognosis for patients with thyroid neoplasms.

Small‑sized gold nanoparticles inhibit the proliferation and invasion of SW579 cells

The present study reported on an intrinsic property of gold nanoparticles (Au‑NPs), namely their ability to inhibit the proliferation and invasion of thyroid carcinoma cells. Au‑NPs of various sizes (5‑60 nm) were synthesized and their uptake into the SW579 human thyroid carcinoma cell line was verified using transmission electron microscopy (TEM). The viability, apoptosis, cell cycle distribution and invasive capacity of SW579 cells were assessed following treatment with Au‑NPs using a Cell Counting Kit‑8 assay, flow cytometric analysis and a Transwell as well as a fluorometric invasion assay. TEM demonstrated that all sizes of Au‑NPs could be taken up by the SW579 cells. The results showed that small‑sized Au‑NPs (5 and 10 nm) significantly suppressed the proliferation and invasion of SW579 cells and induced apoptosis as well as cell cycle arrest in G0/G1 phase, while larger‑sized gold nanoparticles (20‑60 nm) did not exert these effects, therefore suggesting that the effects of Au‑NPs on SW579 cells were highly associated with their particle size. The reduction of the invasive capacity of SW579 cells following treatment with Au‑NPs may be attributed to decreases in the expression of matrix metalloproteinase‑2 and ‑9, which were observed using western blot and reverse‑transcription quantitative polymerase chain reaction analyses. The present study was the first to demonstrate that small‑sized Au‑NPs inhibit the proliferation and invasion of thyroid carcinoma cells, which may contribute to the advancement of biomedical applications of Au‑NPs.

Serum Galectin-3: diagnostic value for papillary thyroid carcinoma

OBJECTIVE

Thyroid cancer constitutes approximately 1% of all cancers, approximately 90% of the endocrine malignancies, and is responsible for 0.4% of cancer-related deaths. Additional markers are required for the accurate diagnosis of thyroid malignancies. There is no marker that can accurately facilitate pre-operative benign-malignant differentiation of thyroid nodules. The present study aims to evaluate the diagnostic value of preoperative serum Galectin-3 levels in thyroid cancer and to avoid unnecessary aggressive interventions.

MATERIAL AND METHODS

Sixty-four patients who were operated between May 2009 and April 2011 were included in this study prospectively. Patients with toxic nodules and those with malignancies detected in preoperative fine needle aspiration biopsies (FNAB) were excluded. Patients with thyroid nodules of >3 cm in ultrasonography or having suspicious cytological findings in their preoperative FNABs regardless of the nodule size were included. Patients were divided into 2 groups, "control"and "cancer," according to the postoperative pathology results.

RESULTS

The control group included 50 and cancer group included 14 patients. The mean age of the control group was 44.84±13.17 (19-79), while it was 44.14±15.94 (25-72) in the cancer group. A statistically significant difference was found between Galectin-3 levels in the cancer and control groups (p<0.001).

CONCLUSION

In the present study, serum Galectin-3 levels in patients with malignant nodules were statistically significant.

Downregulation of galectin-3 causes a decrease in uPAR levels and inhibits the proliferation, migration and invasion of hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related mortality worldwide. Galectin-3 (Gal-3), a multifunctional β-galactoside-binding protein, is highly expressed and associated with the prognosis of HCC. However, the functions of Gal-3 in HCC cells are not fully understood. To address the function of Gal-3 in HCC cells, we used small interfering RNA (siRNA) to knock down Gal-3 expression in HepG2, an HCC cell line. We found that in vitro the silencing of Gal-3 decreased the proliferative activity, colony formation ability, migratory and invasive potential of HepG2 cells. The silencing of Gal-3 significantly decreased the mRNA and protein levels of urokinase-type plasminogen activator receptor (uPAR) as well as uPAR's downstream signaling transduction pathway, including phosphorylation of AKT. Furthermore, the downregulation of Gal-3 by siRNA resulted in significantly decreased activity of the MEK/ERK signaling pathway, and the treatment of HepG2 cells with MEK/ERK inhibitor U0126 significantly reduced the mRNA and protein levels of uPAR. Taken together, our results suggest that Gal-3 modulates uPAR expression via the MEK/ERK pathway, and that Gal-3 may be a potential therapeutic target for the treatment of HCC.

CXC chemokine receptor 4 immunodetection in the follicular variant of papillary thyroid carcinoma: comparison to galectin-3 and hector battifora mesothelial cell-1

BACKGROUND

The cytological discrimination between benign and malignant follicular-patterned lesions of the thyroid can represent a diagnostic challenge, even for experienced pathologists. We evaluated the diagnostic use of protein expression of CXC chemokine receptor 4 (CXCR4) and galectin-3 (gal-3) that were found to be upregulated in papillary thyroid carcinoma compared to normal thyroid and of mesothelial cell surface protein recognized by monoclonal antibody Hector Battifora Mesothelial cell (HBME)-1 in thyroid tumors.

METHODS

Expression of CXCR4, HBME-1, and gal-3 was examined immunohistochemically in total of 100 aspirates of thyroid lesions, categorized as benign (n = 22), indeterminate lesion (n = 43), suspicious of papillary thyroid carcinoma (n = 10), or malignant (n = 25) by preoperative cytology.

RESULTS

Expression of each individual marker was significantly associated with malignancy (p < 0.0001), although the sensitivity of detection ranged from 56% for gal-3 to 94% for HBME-1. When focusing on the indeterminate lesions, only CXCR4 and HBME-1 expression was associated with malignancy; moreover, these two markers either used individually or in combination showed good values of diagnostic accuracy (88.4% and 90.7%, respectively). Further, the combination of CXCR4 plus HBME-1 or the simultaneous use of all the three markers provided absolute value of sensitivity and negative predictive value in the same group of lesions.

CONCLUSIONS

An immunohistochemical panel, including CXCR4, could be useful in the differential diagnosis between benign and malignant well-differentiated follicular-patterned thyroid lesions.

Diagnostic utility of galectin-3 in thyroid cancer

Galectin-3 (Gal-3), which has received significant recent attention for its utility as a diagnostic marker for thyroid cancer, represents the most well-studied molecular candidate for thyroid cancer diagnosis. Gal-3 is a protein that binds to beta-galactosidase residues on cell surface glycoproteins and has also been identified in the cytoplasmic and nuclear compartment. This marker has been implicated in regulation of normal cellular proliferation and apoptosis, as well as malignant transformation and the metastasis of cancer cells. We here present a mechanistic review of Gal-3 and its role in cancer development and progression. Gal-3 expression studies in thyroid tissue and cytologic tumor specimens and their methodological considerations are also discussed in this article. Despite great variance in their methodology, the majority of immunohistochemical studies found that Gal-3 was differentially expressed in thyroid carcinoma compared with benign and normal thyroid specimens, suggesting that Gal-3 is a good diagnostic marker for thyroid cancer. Recent studies have also demonstrated improved methodological reliability. On the other hand, Gal-3 genomic expression studies have shown inconsistent results for diagnostic utility and are not recommended. Overall, the development of Gal-3 as a diagnostic marker for thyroid cancer represents a promising avenue for future study, and its clinical application could significantly reduce the number of diagnostic thyroid operations performed for cases of indeterminant fine needle aspiration biopsy cytology, and thus positively impact the current management of thyroid nodular disease.

A morpho-molecular diagnosis of papillary thyroid carcinoma: BRAF V600E detection as an important tool in preoperative evaluation of fine-needle aspirates

BACKGROUND

Although most thyroid nodule fine-needle aspiration (FNA) diagnoses are definitive or nearly definitive, about 30% of them are not read as definitively benign or malignant, the so-called indeterminate or suspicious FNA diagnosis. The prevalence of malignancy in FNA samples with these diagnoses varies from 10% to 52%. The first aim of this study was to determine if BRAF V600E analysis of thyroid FNA cytological smears could be performed with a relatively simple protocol. We also sought to determine if assessing the presence of BRAF gene mutations in preoperative FNA cytology slides would provide diagnostic information for FNA samples with a reading of indeterminate or suspicious thyroid lesions.

METHODS

DNA was extracted directly from FNA-stained smears of 111 patients with thyroid lesions having different cytological diagnoses. There was 1 cystic nodule, 20 microfollicular proliferations without atypia, 32 that were suspicious for papillary carcinoma, 56 papillary thyroid carcinomas (PTC), and 2 poorly differentiated carcinomas. The BRAF V600E mutational status was determined by sequencing analysis in all patients. The histopathological diagnosis was obtained in all cases.

RESULTS

We observed that 56/90 (62.3%) patients received a definitive diagnosis of PTC when only cytology was used. After molecular analysis, the BRAF V600E mutation was detected in 18/32 (56.2%) cases with a cytology of suspicious for papillary carcinoma and 41/56 (73.2%) with PTC. According to the morpho-molecular analysis (i.e., traditional cytology combined with BRAF V600E analysis) 74/90 (82.2%) patients could be assigned a definitive diagnosis of PTC. Therefore, the addition of molecular analysis yielded an increase of 20% in the sensitivity compared to cytology alone.

CONCLUSIONS

The method of molecular analysis of thyroid FNA smears described here can be easily performed after the FNA, thereby avoiding inconvenience and additional time during the FNA and permitting later analysis of samples having indeterminate cytology features. The increased sensitivity of this preoperative morpho-molecular analysis should provide information that is useful in deciding the extent of thyroid surgery for thyroid nodules that are indeterminate or suspicious on cytology.

Application of immunohistochemistry to thyroid neoplasms

CONTEXT

Thyroid lesions with nodular architecture and follicular pattern of growth often pose difficulties in accurate diagnosis during the assessment of cytologic and histologic specimens. The diagnosis of follicular neoplasm on cytology or of follicular tumor of uncertain malignant potential on histology is likely to cause confusion among clinicians and delay effective management of these lesions. Occasionally, thyroid tumors represent unusual or metastatic lesions and their accurate diagnosis requires immunohistochemical confirmation.

OBJECTIVE

To review the literature on the applications of immunohistochemistry in the differential diagnosis of thyroid tumors.

DATA SOURCES

Relevant articles indexed in PubMed (National Library of Medicine) between 1976 and 2006.

CONCLUSIONS

Our review supports the use of ancillary techniques involving a panel of antibodies suitable for immunohistochemistry and molecular analysis in the assessment of thyroid nodules. These tools can improve diagnostic accuracy when combined with standard morphologic criteria.

Controversies in thyroid pathology: the diagnosis of follicular neoplasms

Thyroid nodules are common; almost 20% of the population has a palpable thyroid nodule and approximately 70% has a nodule detected by ultrasound. Thyroid cancer is the most frequent endocrine malignancy, and incidence rates have steadily increased over the last decades. Papillary carcinoma (PTC) is the most common malignant neoplasm of the thyroid; the diagnosis of this most frequent type (85-90%) has been increasing, possibly due to changing recognition of morphologic criteria. PTC is defined histologically as a malignant tumor showing evidence of follicular epithelial differentiation and characterized by distinctive nuclear features. However, there are borderline lesions that do not completely fulfill these criteria, making the diagnosis difficult. The use of immunohistochemical and molecular markers adds objective criteria to this confusing and controversial area of pathology. We review the differential diagnosis of well-differentiated follicular thyroid neoplasms and the ancillary techniques and molecular characteristics that have been proposed for application in the diagnosis of PTC.

Galectin-3 expression in tumor progression and metastasis of papillary thyroid carcinoma

Galectin-3 plays important roles in cell adhesion, cell proliferation, apoptosis, neoplastic transformation, and metastasis. Galectin-3 expression has been evaluated in various malignant neoplasms to determine its effectiveness in differential diagnosis from benign lesions and its effects on carcinogenesis. There are few and somewhat controversial results regarding its changes through cancer progression in thyroid malignancies. We studied the presence of galectin-3 expression immunohistochemically and its relation with tumor invasiveness and lymph node metastasis in 89 cases of papillary carcinoma of the thyroid. Galectin overexpression was less frequent in cases with lymph node metastases compared with cases without lymph node metastasis (P = 0.001). Metastatic foci in lymph nodes showed a lower degree of galectin-3 overexpression than their primary lesions (P = 0.001). Degree of galectin-3 overexpression was also lower in larger tumors (P = 0.009). Additionally, a decreased level of galectin-3 overexpression was observed at the invasive edges of the tumors (P = 0.001). Galectin-3 overexpression is more profound in early stages of papillary carcinoma, and its expression intensity decreases during tumor progression. This finding is consistent with roles for galectin-3 in cell adhesion to other tumor cells and the matrix.

Molecular Profiling of Matched Samples Identifies Biomarkers of Papillary Thyroid Carcinoma Lymph Node Metastasis

Biomarkers of papillary thyroid carcinoma (PTC) metastasis can accurately identify metastatic cells and aggressive tumor behavior. To find new markers, serial analysis of gene expression (SAGE) was done on three samples from the same patient: normal thyroid tissue, primary PTC, and a PTC lymph node metastasis. This genomewide expression analysis identified 31 genes expressed in lymph node metastasis, but not in the primary tumor. Eleven genes were evaluated by quantitative real-time reverse transcription-PCR (qPCR) on independent sets of matched samples to find genes that were consistently different between the tumor and metastatic samples. LIMD2 and PTPRC (CD45) showed a statistically significant difference in expression between tumor and metastatic samples (P < 0.0045), and an additional gene (LTB) had borderline significance. PTPRC and LTB were tested by immunohistochemistry in an independent set of paired samples, with both markers showing a difference in protein expression. All 20 metastases from 6 patients showed expression in both markers, with little or no expression in primary tumor. Some of these markers could provide an improved means to detect metastatic PTC cells during initial staging of a newly diagnosed carcinoma and/or to rule out recurrence. The functional role of these genes may also provide insight into mechanisms of thyroid cancer metastasis.