Clinical significance of E-cadherin expression in thyroid neoplasms

The Correlation between Proliferative Immunohistochemical Markers and Papillary Thyroid Carcinoma Aggressiveness

Background and Objectives: Papillary thyroid carcinoma (PTC) is one of the most common malignancies of the endocrine system. In order to improve the ability to predict tumor behavior, several studies have been conducted to search for surrogate prognostic immunohistochemical tumor markers. Objective: To evaluate the correlation between the intensity of different immunohistochemical marker staining in PTC and the risk for extrathyroidal extension and metastases. Materials and Methods: The study comprised patients who underwent hemi- or total thyroidectomy. Thyroid tissues were immunohistochemically stained for different tumor proliferative markers: Minichromosome maintenance proteins 2 (MCM2), Ki-67 labeling index, E-Cadherin, Neuropilin-1 and Metallothionein. The correlation between the intensity of each marker staining and the final diagnosis (benign neoplasm and PTC) and the correlation between the intensity of each staining and tumor extrathyroidal extension and metastases were evaluated. Results: The study included 66 patients. Staining for Metallothionein, E-Cadherin and MCM2 significantly differed between benign neoplasm (n = 22) and thyroid-confined PTC (n = 21) (p = 0.002, 0.004 and 0.005, respectively), between benign neoplasm and PTC with extrathyroidal extension (n = 11) (p = 0.001, 0.006 and 0.01, respectively), and between benign neoplasm and PTC with metastases (n = 12) (p = 0.01, <0.001 and 0.037, respectively). No staining correlated with extrathyroidal extension. The intensity of E-Cadherin staining was significantly lower in PTC with metastases than thyroid confined PTC and PTC with extrathyroidal extension (p = 0.028 and 0.021, respectively). Conclusions: Immunohistochemical staining for Metallothionein, E-Cadherin and MCM2 significantly distinguished between benign thyroid tumor and PTC. E-Cadherin staining significantly and inversely correlated with the presence of metastases.

Papillary thyroid cancer with Hashimoto’s thyroiditis attenuates the tumour aggressiveness through the up-regulation of E-cadherin and TGF-β expression

Human papillary thyroid cancer (PTC) is often associated with Hashimoto’s thyroiditis (HT), and their coexistence improves the prognosis of PTC. Aim of the study. The objective of our study is to investigate the expression of cadherins and TGF-β which are regulators in the tumour aggressiveness with metastatic spread in PTC patients and its relationship with HT. The expression of E-cadherin and N-cadherin was measured in thyroid tissues of healthy volunteers and PTC patients with HT (PTC/HT) or without. The E-cadherin expression was also determined in thyroid cancer cells (TPC1, SNU373, SNU790, 8505C, CAL62, and FTC133). Cell migration was measured by wound healing assay. The expression of N-cadherin, ICAM1, and TGF-β was measured in thyroid tissues and plasma. The E-cadherin expression was significantly increased in PTC/HT patients compared with PTC alone. Meanwhile, the N-cadherin expression was significantly decreased in PTC/HT patients. The E-cadherin expression was only observed in FTC cells, and the overexpression of E-cadherin inhibited cancer cell migration. The TGF-β expression was significantly increased in PTC/HT patients, and the plasma levels were higher in PTC/HT patients than in PTC alone. The expression of N-cadherin and ICAM-1 was significantly decreased in PTC/HT patients. Our results indicate that the expression of E-cadherin and TGF-β was higher in PTC/HT patients than in PTC alone. This suggests that the presence of PTC with HT may attenuate the tumour aggressiveness and metastasis through the up-regulation of E-cadherin and TGF-β expression.

Vitamin D Receptor Expression and its Clinical Significance in Papillary Thyroid Cancer

Objective: This study aimed to evaluate the association between vitamin D receptor (an essential component in the vitamin D signaling pathway) and serum vitamin D as well as its clinical significance in papillary thyroid cancer. Methods: This prospective cohort study comprised patients with thyroid tumors who visited our hospital, from 2017 to 2018. The level of vitamin D receptor expression from thyroid tissue was measured in patients with thyroid tumor and evaluated for correlation with serum vitamin D levels and clinicopathologic characteristics of papillary thyroid cancer. Data from 501 patients with papillary thyroid cancer from The Cancer Genome Atlas database were analyzed. Results: Increased vitamin D receptor protein and mRNA expression were observed in papillary thyroid cancer compared to those in normal and benign tissues. Lower vitamin D receptor protein expression was associated with high TNM stage papillary thyroid cancer and low p21 protein expression. Lower relative vitamin D receptor mRNA expression in papillary thyroid cancer was associated with low serum 25-hydroxyvitamin D level. The Cancer Genome Atlas database showed a positive correlation among mRNA expression of vitamin D receptor, CYP24A1, and p21. Conclusions: An association between decreased vitamin D receptor protein expression and advanced stage papillary thyroid cancer, and a correlation between low vitamin D receptor mRNA expression with low serum 25-hydroxyvitamin D level was observed. Low vitamin D receptor expression in papillary thyroid cancer was shown to positively correlate with low serum vitamin D level and disease aggressiveness.

Clinical, pathological and prognostic implications of USP22, SIRT1 and E-cadherin expression in papillary thyroid cancer (PTC) and adjacent non-neoplastic tissue

Introduction

Ubiquitin-specific peptidase 22 (USP22) is described as a stem cell (CSC) marker which is involved in many biological processes, including cancer development, cellular growth and differentiation. Sirtuin 1 (SIRT1) controls a set of biologic processes that range from metabolic homeostasis to cancer. E-cadherin is a calcium-dependent intercellular adhesion molecule. Clinically, USP22, SIRT1 and E-cadherin have been studied to predict prognosis of a variety of cancers but the detailed roles of their expression in papillary thyroid cancer (PTC) and their relation to cancer invasion, metastases and recurrence are still not fully explained.

Aim of the study

To evaluate the expression of USP22, SIRT1 & E-cadherin in PTC tissues and adjacent non-neoplastic thyroid tissue and to correlate their expression with histopathology, clinical, pathological and prognostic parameters of PTC patients.

Methods

We have assessed USP22, SIRT1 & E-cadherin expression using immunohistochemistry in 40 cases with PTC in both malignant tissue and adjacent non-neoplastic tissue, analyzed the relationships between their levels of expression, clinic-pathological parameters, prognosis and survival of patients.

Results

High protein expression levels of both USP22, SIRT1 in addition to low E-cadherin expression in PTC were associated with larger tumors, extra-thyroidal extension, vascular invasion, lymphatic spread (p < 0.001), existence of distant metastases (p = 0.005 & 0.012 respectively), higher stage of the disease (p = 0.012 & 0.042 respectively) and worse five-years overall survival rates (p < 0.001).

Conclusion

Patients having advanced PTC with unfavorable prognosis had high levels of both USP22, SIRT1 in addition to low E-cadherin expression.

E-cadherin expression is associated with susceptibility and clinicopathological characteristics of thyroid cancer: A PRISMA-compliant meta-analysis

BACKGROUND

Recently, many studies have been carried out to investigate the clinicopathological significance of E-cadherin expression in thyroid cancer. However, the results remained inconsistent. In the present study, we performed a meta-analysis to evaluate the associations of E-cadherin expression with susceptibility and clinicopathological characteristics of thyroid cancer.

METHODS

Eligible studies were searched from Medicine, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), and Wanfang databases. The strength of associations between E-cadherin expression and susceptibility and clinicopathological features of thyroid cancer were assessed by pooled odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Forty-six studies with 1700 controls and 2298 thyroid cancer patients were included for this meta-analysis. Pooled results indicated that E-cadherin expression was significantly associated with susceptibility of papillary cancer and follicular cancer (papillary cancer, ORs = 14.31, 95% CIs = 3.42-59.90; follicular cancer, ORs = 10.14, 95% CI = 4.52-22.75). Significant association between E-cadherin expression and thyroid cancer risk was also observed in the subgroup analysis based on control group (normal thyroid tissue, ORs = 28.28, 95% CI = 8.36-95.63; adjacent thyroid tissue, ORs = 8.83, 95% CI = 3.27-23.85; benign thyroid tissue, ORs = 43.96, 95% CI = 9.91-194.95). In addition, E-cadherin expression was significantly correlated with lymph node metastasis, differentiation, and tumor-node-metastasis (TNM) stage of thyroid cancer (lymph node metastasis, ORs = 3.21, 95% CI = 1.98-5.20; differentiation, ORs = 0.25, 95% CI = 0.07-0.82; TNM stage, ORs = 4.85, 95% CI = 2.86-8.25).

CONCLUSIONS

The present study showed that E-cadherin expression was significantly associated with susceptibility and clinicopathological characteristics of thyroid cancer, which suggested that E-cadherin expression might be a potential predictive factor for clinical progression of thyroid cancer.

Cdc6 expression is induced by HPV16 E6 and E7 oncogenes and represses E-cadherin expression

Cervical cancer is one of the most common cancers in women worldwide, and its development is related to two viral oncoproteins E6 and E7 from high-risk human papillomaviruses. Aberrant expression of E-cadherin is associated with epithelial-to-mesenchymal transition (EMT), and it is frequently seen in cervical cancer. However, the underlying mechanisms involved in E-cadherin suppression in cervical cancer are not clear. We studied the effects of human papillomavirus 16 (HPV16) E6 and E7 on E-cadherin and Cdc6 (cell division cycle 6) expression in the HCT-116 cell line. We also assessed the relationship between Cdc6 and E-cadherin expression in cells expressing HPV16 E6 and E7 proteins. The results showed that HPV16 E6 and E7 proteins reduce E-cadherin expression, and HPV16 E6-expressing cells undergo a more profound suppression of E-cadherin compared with cells expressing HPV16 E7. Our results also revealed that HPV16 E6 and E7 oncoproteins induce Cdc6 expression, whereas suppression of Cdc6 protein by short hairpin RNA restores E-cadherin expression. Induction of Cdc6 expression in HCT-116 cells was greater with E6 than with E7, a finding that was consistent with the corresponding changes in E-cadherin expression. These observations suggest that Cdc6 overexpression is an important factor for E-cadherin reduction in cells expressing HPV16 E6 and E7 proteins and may have an important role in the metastasis of HPV-associated cancers.Cancer Gene Therapy advance online publication, 11 November 2016; doi:10.1038/cgt.2016.51.

Expression of Tenascin C, EGFR, E-Cadherin, and TTF-1 in Medullary Thyroid Carcinoma and the Correlation with RET Mutation Status

Tenascin C expression correlates with tumor grade and indicates worse prognosis in several tumors. Epidermal growth factor receptor (EGFR) plays an important role in driving proliferation in many tumors. Loss of E-cadherin function is associated with tumor invasion and metastasis. Thyroid transcription factor-1 (TTF-1) is involved in rearranged during transfection (RET) transcription in Hirschsprung’s disease. Tenascin C, EGFR, E-cadherin, TTF-1-expression, and their correlations with RET mutation status were investigated in 30 patients with medullary thyroid carcinoma (MTC) (n = 26) or C-cell hyperplasia (n = 4). Tenascin C was found in all, EGFR in 4/26, E-cadherin in 23/26, and TTF-1 in 25/26 MTC. Tenascin C correlated significantly with tumor proliferation (overall, r = 0.61, p < 0.005; RET-mutated, r = 0.81, p < 0.01). E-cadherin showed weak correlation, whereas EGFR and TTF-1 showed no significant correlation with tumor proliferation. EGFR, E-cadherin, and TTF-1 showed weak correlation with proliferation of RET-mutated tumors. Correlation between TTF-1 and tenascin C, E-cadherin, and EGFR was r = −0.10, 0.37, and 0.21, respectively. In conclusion, MTC express tenascin C, E-cadherin, and TTF-1. Tenascin C correlates significantly with tumor proliferation, especially in RET-mutated tumors. EGFR is low, and tumors expressing EGFR do not exhibit higher proliferation. TTF-1 does not correlate with RET mutation status and has a weak correlation with tenascin C, E-cadherin, and EGFR expression.

Proteomics of thyroid tumours provides new insights into their molecular composition and changes associated with malignancy

Around 5% of the general population have palpable thyroid nodules. Although most thyroid tumours are benign, thyroid cancer represents the most common malignancy of the endocrine system, comprising mainly follicular and papillary thyroid carcinomas. Previous studies have shed some light on the molecular pathogenesis of thyroid cancer but there have not been any comprehensive mass spectrometry-based proteomic studies of large scale to reveal protein expression differences between thyroid tumours and the molecular alterations associated with tumour malignancy. We applied data-independent acquisition mass spectrometry which enabled quantitative expression analysis of over 1,600 proteins from 32 specimens to compare normal thyroid tissue with the three most common tumours of the thyroid gland: follicular adenoma, follicular carcinoma and papillary carcinoma. In follicular tumours, we found marked reduction of the tumour suppressor and therapeutic target extracellular protein decorin. We made the novel observation that TGFβ-induced protein ig-h3 (TGFBI) was found frequently overexpressed in follicular carcinoma compared with follicular adenoma. Proteomic pathway analysis showed changes in papillary carcinoma were associated with disruption of cell contacts (loss of E-cadherin), actin cytoskeleton dynamics and loss of differentiation markers, all hallmarks of an invasive phenotype.

Inflammatory mediators drive metastasis and drug resistance in head and neck squamous cell carcinoma

OBJECTIVES/HYPOTHESIS

The presence of regional metastases in head and neck squamous cell carcinoma (HNSCC) patients is a common and adverse event associated with poor prognosis. Understanding the molecular mechanisms that mediate HNSCC metastasis may enable identification of novel therapeutic targets. E-cadherin plays a key role in epithelial intercellular adhesion; its downregulation is a hallmark of the epithelial-to-mesenchymal transition (EMT) (an essential process during tumor progression); and it is associated with invasion, metastasis, and decreased survival. Inflammatory cytokines have been implicated in the progression of HNSCC. Herein, the mechanisms by which the inflammatory mediator, Interleukin-1β (IL-1β), might contribute to EMT in HNSCC is investigated. The pathways involved in E-cadherin regulation in HNSCC had not previously been defined. It is hypothesized that 1) inflammatory mediators upregulate cyclooxygenase-2/prostaglandin E2 (COX-2/PGE2), which then in turn regulate E-cadherin expression in HNSCC; and 2) PGE2 downregulates E-cadherin via transcriptional repressors of E-cadherin (such as Snail) in HNSCC. The outcome of the proposed research will allow us to define how resistance to epidermal growth factor receptor (EGFR)-selective tyrosine kinase inhibitors is mediated and whether the benefits of combination therapy are due to the capacity of COX-2 inhibitors to increase E-cadherin expression and thus create a more sensitive target for EGFR TK inhibition.

STUDY DESIGN

Basic science, molecular biology, animal model, immunohistochemistry.

METHODS

We evaluated the effect of IL-1β on the molecular events of EMT in surgical specimens and HNSCC cell lines. We examined the correlation with tumor histologic features, and a severely compromised immunodeficient (SCID) xenograft model was used to assess the effects in vivo.

RESULTS

COX-2-dependent pathways contribute to the modulation of E-cadherin expression in HNSCC. An inverse relationship between COX-2 and E-cadherin was demonstrated in situ by double immunohistochemical staining of human HNSCC tissue sections. Treatment of HNSCC cells with IL-1β caused the downregulation of E-cadherin expression and upregulation of COX-2 expression. This effect was blocked in the presence of COX-2 small hairpin RNA (shRNA). IL-1β -treated HNSCC cell lines demonstrated a significant decrease in E-cadherin messenger RNA (mRNA) and an increase in the mRNA expression of the transcriptional repressor Snail. IL-1β exposure led to enhanced Snail binding at the chromatin level. ShRNA-mediated knockdown of Snail interrupted the capacity of IL-1β to downregulate E-cadherin. Snail overexpression in normal oral keratinocytes and HNSCC cells is sufficient to drive EMT and confers resistance to erlotinib. In a SCID xenograft model, HNSCC Snail overexpressing cells demonstrated significantly increased primary and metastatic tumor burdens.

CONCLUSIONS

The inflammatory mediator IL-1β modulates Snail and thereby regulates COX-2-dependent E-cadherin expression in HNSCC. This is the first report indicating the role of Snail in the inflammation-induced promotion of EMT in HNSCC. This newly defined pathway for transcriptional regulation of E-cadherin in HNSCC has important implications for targeted chemoprevention and therapy.

LEVEL OF EVIDENCE

N/A.

Loss of Heterozygosities in Five Tumor Suppressor Genes (FHIT Gene, p16, pRb, E-Cadherin and p53) in Thyroid Tumors

Objectives

To evaluate the loss of heterozygosities (LOH) of chromosomes 3p14 (FHIT gene), 9p21 (p16), 13q21 (pRb), 6q22 (E-cadherin) and 17p13 (p53) in various thyroid tumors.

Methods

Eighty thyroid tumor cases (20 follicular adenomas, 10 follicular carcinomas, and 50 papillary carcinomas) have been analyzed for the presence of LOH in chromosomes 3p14, 9p21, 13q21, 6q22, and 17p13 allelic loss, using microsatellite markers and DNA obtained from formalin-fixed paraffin-embedded archival tissues.

Results

LOH on 3p14 was found in 10.5%, 33.3%, and 30.4% of follicular adenomas, follicular carcinomas, and papillary carcinomas, respectively. LOH on 9p21 was detected in 6%, 44.4%, and 47.8%, respectively. LOH on pRb gene was found in 5.3%, 20.0%, and 35.4%, respectively. LOH on E-cadherin gene was found in 5.3%, 22.2%, and 43.8%, respectively. LOH on 17p13 was detected in 0%, 40%, and 45.8%, respectively. LOH in FHIT gene, p16, pRb, E-cadherin, and p53 genes were more frequently identified in follicular carcinoma and papillary carcinoma than in follicular adenoma.

Conclusion

LOH results of the five tumor suppressor genes (FHIT gene, p16, pRb, E-cadherin, and p53) showed statistical differences between benign tumor and malignant tumor. Among papillary carcinoma, LOH in p16, E-cadherin and p53 genes well correlated with poorly differentiated grade, and LOH of E-cadherin was associated with lymph node metastasis.

E-cadherin expression and cell proliferation in the primary tumor and metastatic lymph nodes of papillary thyroid microcarcinoma

Although papillary thyroid microcarcinoma (PTMC) has an excellent prognosis, certain cases exhibit aggressive clinical manifestations. In this study, we assessed the expression of E-cadherin and Ki-67 in primary PTMC tumors and metastatic lymph nodes, in order to investigate the mechanism underlying the mainly indolent but potentially malignant nature of PTMC. A total of 93 PTMC patients treated in our institute were included in this study. All primary tumors and 57 metastatic lymph nodes were immunohistochemically stained and a total of 73 tumors (78.5%) were positive for E-cadherin. E-cadherin expression was significantly less common at the invasive front (58.1%, P<0.01) compared to that at the center of the tumor. Tumors that had lost E-cadherin expression at the invasive front frequently presented with lymph node metastasis (70.6%). Small tumors (≤5 mm diameter) expressed E-cadherin significantly more frequently compared with larger tumors (P=0.04); however, no other particular characteristic was found to correlate with the status of E-cadherin expression in the primary tumors. E-cadherin expression was detected in 49 (86.0%) of the 57 metastatic foci and correlated significantly with the expression status at the invasive front of the tumor (P=0.02). The Ki-67 index was universally low and was not correlated with the clinicopathological characteristics or the E-cadherin expression of the tumors. These results suggested that cancer cells in the metastatic lymph nodes exhibit indolent characteristics, similar to those of the primary PTMC. However, the metastatic cancer cells may have already completed the process of epithelial-to-mesenchymal transition (EMT) and mesenchymal-to-epithelial transition (MET), suggesting an innate malignant potential.

Transcriptional repression of E-cadherin by human papillomavirus type 16 E6

There is increasing evidence supporting DNA virus regulation of the cell adhesion and tumour suppressor protein, E-cadherin. We previously reported that loss of E-cadherin in human papillomavirus (HPV) type 16-infected epidermis is contributed to by the major viral proto-oncogene E6 and is associated with reduced Langerhans cells density, potentially regulating the immune response. The focus of this study is determining how the HPV16 E6 protein mediates E-cadherin repression. We found that the E-cadherin promoter is repressed in cells expressing E6, resulting in fewer E-cadherin transcripts. On exploring the mechanism for this, repression by increased histone deacetylase activity or by increased binding of trans-repressors to the E-cadherin promoter Epal element was discounted. In contrast, DNA methyltransferase (DNMT) activity was increased in E6 expressing cells. Upon inhibiting DNMT activity using 5-Aza-2'-deoxycytidine, E-cadherin transcription was restored in the presence of HPV16 E6. The E-cadherin promoter was not directly methylated, however a mutational analysis showed general promoter repression and reduced binding of the transactivators Sp1 and AML1 and the repressor Slug. Expression of E7 with E6 resulted in a further reduction in surface E-cadherin levels. This is the first report of HPV16 E6-mediated transcriptional repression of this adhesion molecule and tumour suppressor protein.

Signaling pathways in follicular cell-derived thyroid carcinomas (review)

Thyroid carcinoma is the most common malignant endocrine neoplasia. Differentiated thyroid carcinomas (DTCs) represent more than 90% of all thyroid carcinomas and comprise the papillary and follicular thyroid carcinoma subtypes. Anaplastic thyroid carcinomas correspond to less than 1% of all thyroid tumors and can arise de novo or by dedifferentiation of a differentiated tumor. The etiology of DTCs is not fully understood. Several genetic events have been implicated in thyroid tumorigenesis. Point mutations in the BRAF or RAS genes or rearranged in transformation (RET)/papillary thyroid carcinoma (PTC) gene rearrangements are observed in approximately 70% of papillary cancer cases. Follicular carcinomas commonly harbor RAS mutations and paired box gene 8 (PAX8)-peroxisome proliferator-activated receptor γ (PPARγ) rearrangements. Anaplastic carcinomas may have a wide set of genetic alterations, that include gene effectors in the mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K) and/or β-catenin signaling pathways. These distinct genetic alterations constitutively activate the MAPK, PI3K and β-catenin signaling pathways, which have been implicated in thyroid cancer development and progression. In this context, the evaluation of specific genes, as well as the knowledge of their effects on thyroid carcinogenesis may provide important information on disease presentation, prognosis and therapy, through the development of specific tyrosine kinase targets. In this review, we aimed to present an updated and comprehensive review of the recent advances in the understanding of the genetic basis of follicular cell-derived thyroid carcinomas, as well as the molecular mechanisms involved in tumor development and progression.

Correlation of E-cadherin, VEGF, COX-2 expression to prognostic parameters in papillary thyroid carcinoma

Thyroid cancer represents approximately 1% of all human malignancies. papillary thyroid carcinoma (PTC) is the most common malignant tumor of the thyroid gland, accounting for 70-80% of all thyroid cancers. In the US, the incidence of thyroid cancer is 4 per 100,000 individuals. It is two to four times as frequent in women as in men. The development of PTC is influenced by many factors including genetic alterations, growth factors, and physical agents such as radiation. In order to recognize the prognosis for PTC, a lot of clinic and pathological parameters such as; age, tumor size, extra-thyroid tumor spread, lymph node, distant metastases, gender, tumor stage are used. As most of these parameters are subjective, more objective and useful prognostic factors are needed for determining biologic behavior, providing an initial assessment. In this study, we aimed to compare the expressions of COX-2, E-cadherin, VEGF to classical prognostic factors, and to investigate the correlation with prognosis. Operation records from 79 PTC cases were examined retrospectively. In the study, we aimed to investigate the whole tissue by means of stereology method, which is an impartial one, and we indicated the expression COX-2, VEGF, E-cadherin immunohistochemically in 79 resection diagnosed with PTC. We determined correlations between the expressions of COX-2 and VEGF, E-cadherin, and age, gender, and stage.

Cellular cohesiveness in benign and malignant thyroid follicular tumours varies significantly, but the difference is not useful in diagnosis of individual cases

INTRODUCTION

The aim of our study was to search for new, readily available and statistically reliable cytological markers for differentiating benign and malignant follicular thyroid neoplasms pre-operatively.

METHODS

Cohesiveness of tumour cells in cytology slides from a series of 58 follicular tumours diagnosed between 1998 and 2004 inclusive was studied, including 48 follicular adenomas, and eight minimally invasive and two widely invasive follicular carcinomas. Photomicrographs of the cytology slides were taken and the digital images were analysed using computer image analysis software. We evaluated the relative proportions of cells arranged in groups of various sizes. The cohesiveness of the cells in cytological smears was then correlated with the immunohistochemical expression of E-cadherin in corresponding histological slides.

RESULTS

Cases from 15 men (26%) and 43 women (74%) with a mean age of 50 years (range, 19-79) were analysed. In follicular adenomas and carcinomas, respectively, isolated cells were seen in 16.8% and 24.7% (P = 0.028), groups of two to five cells in 9.7% and 11.5% (P = 0.145) and groups of more than five cells in 73.5% and 63.8% (P = 0.041). The mean cell count in groups with more than five cells was 46.5 and 27.0 in adenomas and carcinomas, respectively (P < 0.001). Cell cohesiveness, either as percentage of cells in groups of more than five (R(2) = 0.026) or as mean cell count per group of more than five (R(2) = 0.005), was not found to be dependent on the expression of E-cadherin. Using a threshold of 13% isolated tumour cells in cytological smears, follicular adenomas and carcinomas could be distinguished with 90% sensitivity and 41% specificity.

CONCLUSIONS

Although we demonstrated a statistically significant difference in cell cohesion between follicular adenomas and carcinomas, these could not be distinguished in the clinical setting by evaluation of the percentage of isolated cells in cytological smears because the specificity was too low. The absence of correlation of cellular cohesiveness with E-cadherin expression indicates that other factors are probably responsible for the loss of cohesiveness observed in follicular thyroid malignancy.

The Immunocytochemistry Is a Valuable Tool in the Diagnosis of Papillary Thyroid Cancer in FNA's Using Liquid-Based Cytology

Introduction. Papillary thyroid carcinoma (PTC) is the most common malignancy of the thyroid. An accurate cytological diagnosis is based on distinctive cytological features in combination with immunocytochemistry. Methods. A number of 83 fine needle aspirations, positive for papillary thyroid cancer (44 from thyroid nodules and 39 from cervical lymph nodes), were studied using Thin Layer Cytology. A panel of the immunomarkers Cytokeratin-19, Galectin-3, HBME1, CD-44, CD-56, and E-Cadherin was performed. Results. Positive expression of CK-19 was observed in 77 cases (92.7%), of Galectin-3 in 74 cases (89.1%), of HBME1 in 65 (78.3%), and of CD-44 in 72 cases (86.7%). Loss of expression of CD-56 was observed in 80 cases (96.4%) and of E-cadherin in 78 (93.9%). Conclusions. Our data suggest that Thin Layer Cytology increases the diagnostic accuracy in papillary carcinoma and seems to be a promising technique for further investigation of thyroid lesions permitting the possibility to use archive material. Positive immunoexpression of CK-19, Galectin-3, HBME-1, and CD-44 improves the diagnostic accuracy of papillary thyroid cancer. Furthermore, loss of E-cadherin and of CD-56 expression is a feature of malignancy.

Relation between proinflammatory mediators and epithelial-mesenchymal transition in head and neck squamous cell carcinoma

Increasing evidence suggests that the tumor microenvironment plays an important role in tumor progression and oncogenesis. Various proinflammatory mediators contribute to tumor proliferation, neoangiogenesis, invasion, metastasis, and resistance to cancer therapy such as hormonal therapy and chemotherapy. The major causes of death related to head and neck squamous cell carcinoma (HNSCC) include cervical node and distant metastases. Epithelial-mesenchymal transition (EMT) has been identified to play a key role in mediating the tumor invasion and metastasis of carcinomas. Herein, the relationship between proinflammatory mediators and EMT in HNSCC was investigated. Immunohistochemical expression of interleukin-1 β (IL-1β), cyclooxygenase-2 (COX-2), Slug and E-cadherin in relationship to histologic differentiation, clinical stage and nodal status was evaluated in 146 surgical specimens of HNSCC. A correlation was noted between increased expression of IL-1β and nodal status, as well as increased expression of COX-2 and histologic differentiation, clinical stage and nodal status. Increased Slug expression was correlated with histologic differentiation and clinical stage. Decreased E-cadherin expression was correlated with histologic differentiation and nodal status. A significant relationship was observed between IL-1β and COX-2. However, a significant inverse correlation was noted between Slug and E-cadherin. A significant relationship was observed between increased proinflammatory mediator IL-1β/COX-2 expression and increased EMT marker Slug/E-cadherin expression. These results indicate that proinflammatory mediators IL-1β and COX-2 may induce EMT through an increase in Slug and a decrease in E-cadherin. The present findings suggest that various anti-inflammatory agents could be used as an adjuvant treatment modality with anti-cancer chemotherapeutic drugs in HNSCC.

Inhibitory effects of retinoic acid on invasiveness of human thyroid carcinoma cell lines in vitro

BACKGROUND

The prognosis of patients with metastasized thyroid carcinoma is not optimistic, necessitating the search for new treatment options.

AIM

Beneficial effects of retinoic acid (RA) have been suggested in thyroid cancer differentiation and the present study was performed to investigate the anti-metastatic potential of RA in respect of important determinants of metastatic behavior in thyroid carcinoma, focusing on the role of invasion-associated proteins.

MATERIALS AND METHODS

Differentiated thyroid carcinoma cell lines FTC- 133 and XTC.UC1, and anaplastic thyroid cancer cell lines C643 and HTH74 were studied. All cell lines were cultured with alltrans- RA (ATRA) or the solvent ethanol. Invasion and adhesion potency in vitro was studied by transwell experiment and short-term adhesion assay. The involvement of invasion-associated proteins, urokinase type plasminogen activator (uPA), uPA receptor (uPAR), matrix metalloproteinase-2 (MMP-2) and E-cadherin, were investigated by semi-quantitative RT-PCR and Western blot.

RESULTS

In vitro invasion assay revealed that ATRA treatment could reduce the invasive potency in all the thyroid cancer cell lines, with the most significant effect in anaplastic cancer cells. Short-term adhesion assay suggested that ATRA increases cancer cell adhesion to extracellular matrix (ECM) in C643, HTH74 and XTC.UC1, probably through a transcriptional and translational regulation of some attachment molecules. RT-PCR andWestern blot both revealed diminished expression of uPAR in all four carcinoma cell lines. In C643 and HTH74 cell lines, the expression of uPA was reduced and the expression of E-cadherin was increased, whereas the MMP-2 expression was not significantly down-regulated in ATRA-treated group. In ATRA-treated FTC-133 and XTC.UC1 cell lines, MMP-2 expression was decreased, but no significant changes in uPA and E-cadherin expression were observed.

CONCLUSIONS

The present study demonstrates the influence of ATRA on both important determinants of metastatic behavior ("de-adhesion" and proteolysis) in thyroid carcinoma cell lines, especially in anaplastic cancer cells. These findings may add to the explanations for beneficial effects of RA in the treatment of metastatic thyroid carcinomas.

Proinflammatory mediators upregulate snail in head and neck squamous cell carcinoma

PURPOSE

Inflammatory cytokines have been implicated in the progression of head and neck squamous cell carcinoma (HNSCC). Herein we investigate the mechanisms by which interleukin-1beta (IL-1beta) might contribute to Epithelial-Mesenchymal Transition (EMT) in HNSCC.

EXPERIMENTAL DESIGN

We evaluated the effect of IL-1beta on the molecular events of EMT in surgical specimens and HNSCC cell lines. We examined the correlation with tumor histologic features, and a SCID xenograft model was used to assess the effects of Snail overexpression.

RESULTS

Cyclooxygenase-2 (COX-2)-dependent pathways contribute to the modulation of E-cadherin expression in HNSCC. An inverse relationship between COX-2 and E-cadherin was shown in situ by double immunohistochemical staining of human HNSCC tissue sections. Treatment of HNSCC cells with IL-1beta caused the downregulation of E-cadherin expression and upregulation of COX-2 expression. This effect was blocked in the presence of COX-2 small hairpin RNA. IL-1beta-treated HNSCC cell lines showed a significant decrease in E-cadherin mRNA and an increase in the mRNA expression of the transcriptional repressor Snail. IL-1beta exposure led to enhanced Snail binding at the chromatin level. Small hairpin RNA-mediated knockdown of Snail interrupted the capacity of IL-1beta to downregulate E-cadherin. In a SCID xenograft model, HNSCC Snail-overexpressing cells showed significantly increased primary and metastatic tumor burdens.

CONCLUSIONS

IL-1beta modulates Snail and thereby regulates COX-2-dependent E-cadherin expression in HNSCC. This is the first report indicating the role of Snail in the inflammation-induced promotion of EMT in HNSCC. This newly defined pathway for transcriptional regulation of E-cadherin in HNSCC has important implications for targeted chemoprevention and therapy.

Snail family transcription factors are implicated in thyroid carcinogenesis

E-Cadherin (CDH1) expression is reduced in thyroid carcinomas by primarily unknown mechanisms. In several tissues, SNAIL (SNAI1) and SLUG (SNAI2) induce epithelial-mesenchymal transition by altering target gene transcription, including CDH1 repression, but these transcription factors have not been studied in thyroid carcinoma. Recently, our group has provided direct evidence that ectopic SNAI1 expression induces epithelial and mesenchymal mouse tumors. SNAI1, SNAI2, and CDH1 expression were analyzed in thyroid-derived cell lines and samples of human follicular and papillary thyroid carcinoma by reverse transcriptase-polymerase chain reaction, Western blotting, and immunohistochemistry. The effect of SNAI1 expression on CDH1 transcription was analyzed by reverse transcriptase-polymerase chain reaction and Western blotting in ori-3 cells. Thyroid carcinoma development was analyzed in CombitTA-Snail mice, in which SNAI1 levels are up-regulated. SNAI1 and SNAI2 were not expressed in cells derived from normal thyroid tissue, or in normal human thyroid samples, but were highly expressed in cell lines derived from thyroid carcinomas, in human thyroid carcinoma samples, and their metastases. SNAI1 expression in ori-3 cells repressed CDH1 transcription. Combi-TA mice developed papillary thyroid carcinomas, the incidence of which was increased by concomitant radiotherapy. In conclusion, SNAI1 and SNAI2 are ectopically expressed in thyroid carcinomas, and aberrant expression in mice is associated with papillary carcinoma development.

Molecular mechanisms involved in differentiated thyroid cancer invasion and metastasis

PURPOSE OF REVIEW

The majority of patients with thyroid cancer have an excellent prognosis, however patients with extensive local invasion and distant metastasis frequently do not respond to standard treatments and have worsened prognosis. Understanding the specific mechanisms involved in thyroid cancer invasion and metastasis is critical in order to develop new treatments specifically targeted for these patients.

RECENT FINDINGS

The genetic basis for thyroid cancer initiation and development is well characterized, with the majority of studies implicating activation of the RAS-RAF-ERK and PI3K/PDK1/Akt signaling pathways. Over the last several years, data from a concerted effort to define the pathways involved in invasion and metastasis suggest that reactivation of embryonic pathways involved in cell movement, to include epithelial to mesenchymal transition and collective cell migration, may be involved in cancer cell migration and invasion. The previously identified thyroid oncogenes, BRAF, RET/PTC and Ras, appear to be important regulators of this process.

SUMMARY

The molecular mechanisms that control cell migration during embryological development, such as epithelial to mesenchymal transition, appear to be reactivated in invading thyroid cancer cells. Elucidation of the signal-transduction networks and molecules that are involved in thyroid cancer invasion may lead to novel therapeutic targets.

Derangement of the E-cadherin/catenin complex is involved in transformation of differentiated to anaplastic thyroid carcinoma

BACKGROUND

Anaplastic thyroid cancer arises, or transforms, from pre-existing differentiated thyroid cancer. E-cadherin functions as a cell-cell adhesion molecule that complexes with catenin proteins for function. The objective of this study was to evaluate the change in E-cadherin/beta-catenin expression in the transformation of differentiated to anaplastic thyroid carcinoma.

METHODS

A tissue microarray was constructed from 12 anaplastic thyroid tumors and their adjacent associated differentiated foci. Immunohistochemistry was used to evaluate tumor expression of E-cadherin and beta-catenin.

RESULTS

There was decreased expression of E-cadherin and beta-catenin by the anaplastic tumors when compared with the differentiated thyroid tumors from which they evolved. The expression of E-cadherin and beta-catenin was 92% and 67%, respectively, by the differentiated thyroid carcinoma, and 17% and 50%, respectively, by the anaplastic tumors.

CONCLUSIONS

This report shows that derangement of the E-cadherin/catenin complex is associated with the transformation of differentiated into anaplastic thyroid carcinoma.

Aerodigestive Tract Invasion by Well-Differentiated Thyroid Carcinoma: Diagnosis, Management, Prognosis, and Biology

OBJECTIVES/HYPOTHESIS

1) To describe the clinical entity invasive well-differentiated thyroid carcinoma (IWDTC), 2) to determine prognostic factors for survival in patients with IWDTC, 3) to describe and compare types of surgical resection to determine treatment efficacy, 4) to offer a staging system and surgical algorithm for management of patients with IWDTC, 5) to examine alterations in expression of E-cadherin and beta-catenin adhesion molecules in three groups of thyroid tissue and propose a cellular mechanism for invasion of the aerodigestive tract.

STUDY DESIGN

Basic science: quantification of expression of E-cadherin and beta-catenin in three groups of thyroid tissue. Clinical: retrospective review of patients with IWDTC surgically treated and followed over a 45-year time period.

METHODS

Basic science: immunohistochemical staining was used with antibodies against E-cadherin and beta-catenin in three groups of tissue: group 1, normal control thyroid tissue (n = 10); group 2, conventional papillary thyroid carcinoma (n = 20); group 3, IWDTC (n = 12). Intensity scores were given on the basis of protocol. One-way analysis of variance (ANOVA) was used to evaluate differences between groups. Post hoc ANOVA testing was completed. P < .05 was significant. Clinical: patients were divided into three surgical groups within the laryngotracheal subset: group 1, complete resection of gross disease (n = 34); group 2, shave excision (n = 75); group 3, incomplete excision (n = 15). Cox regression analysis was used to determine significance of prognostic factors. Kaplan-Meier plots were used to evaluate survival. P < .05 was significant.

RESULTS

Basic science: a significant difference between the three thyroid tissue groups for E-cadherin expression was demonstrated on one-way ANOVA testing. When controls were compared with either experimental group in post hoc ANOVA testing, differences between all groups were demonstrated (P < .001). For beta-catenin, the intensities of the three groups were not different by one-way ANOVA testing. Similar nonsignificant results were found on post hoc ANOVA testing. Clinical: there was a statistically significant difference in survival for patients with and without involvement of any portion of the endolarynx or trachea (P < .01). There was a significant difference among all three surgical groups when compared (P < .001). When complete and shave groups were compared with gross residual group there was a significant decrease in survival in incomplete resection group (P < .01). Cox regression analysis demonstrated invasion of larynx and trachea were significant prognostic factors for poor outcome. The type of initial resection was significant on multivariate analysis. Removal of all gross disease is a major factor for survival.

CONCLUSIONS

Basic science: there is a decrease in membrane expression of E-cadherin in IWDTC, and loss of this tumor suppressor adhesion molecule may contribute to the invasive nature of well-differentiated thyroid carcinomas. Clinical: laryngotracheal invasion is a significant independent prognostic factor for survival. Patients undergoing shave excision had similar survival when compared with those undergoing radical tumor resection if gross tumor did not remain. Gross intraluminal tumor should be resected completely. Shave excision is adequate for minimal invasion not involving the intraluminal surfaces of the aerodigestive tract.

Prognostic value of E-cadherin expression in thyroid follicular carcinoma

AIMS

To evaluate the expression of E-cadherin, its association with various clinicopathological features and its possible relation with distant metastasis-free survival (DMFS) in follicular carcinoma of the thyroid.

METHODS

E-cadherin expression was assessed immunohistochemically in sections from paraffin embedded tissues in a group of 54 patients with follicular carcinoma and its variants who were followed for a median of 7.25 years.

RESULTS

Reduced E-cadherin expression, defined as <90% of cells showing membrane positivity, was found in 15 tumours and was significantly associated with widely invasive growth, insular morphology and lesser degree of differentiation, but was not related to patient sex and age or tumour size. In univariate analysis, DMFS was significantly worse in male patients (P<0.03), widely invasive tumours (P=0.0002), moderately/poorly differentiated tumours (P<0.05) and tumours showing reduced E-cadherin expression (P=0.0001). In multivariate analysis, the degree of invasiveness and E-cadherin expression were the only independent prognostic factors. Among widely invasive cases, those with reduced E-cadherin expression had significantly worse DMFS than those with preserved expression.

CONCLUSIONS

Our findings suggest that E-cadherin expression could be used as a prognostic marker in widely invasive follicular carcinomas of the thyroid. Larger studies are needed to assess its prognostic value in the group of minimally invasive carcinomas.

Reduced E-cadherin expression contributes to the loss of p27kip1-mediated mechanism of contact inhibition in thyroid anaplastic carcinomas

In the present study, we have characterized several human thyroid cancer cell lines of different histotypes for their responsiveness to contact inhibition. We found that cells derived from differentiated carcinoma (TPC-1, WRO) arrest in G(1) phase at confluence, whereas cells derived from anaplastic carcinoma (ARO, FRO and FB1) continue to grow after reaching confluence. Furthermore, we provide experimental evidence that the axis, E-cadherin/beta-catenin/p27(Kip1), represents an integral part of the regulatory mechanism that controls proliferation at a high cell density, whose disruption may play a key role in determining the clinical behaviour of thyroid cancer. This conclusion derives from the finding that: (i) the expression of p27(Kip1) is enhanced at high cell density only in cells responsive to contact inhibition (TPC-1, WRO), but not in contact-inhibition resistant cells (ARO, FRO or FB1 cells); (ii) the increase in p27(Kip1) also resulted in increased levels of p27(Kip1) bound to cyclin E-Cdk2 complex, a reduction in cyclin E-Cdk2 activity and dephosphorylation of the retinoblastoma protein; (iii) antisense inhibition of p27(Kip1) upregulation at high cell density in confluent-sensitive cells completely prevents the confluence-induced growth arrest; (iv) proper expression and/or membrane localization of E-cadherin is observed only in cells responsive to contact inhibition (TPC-1, NPA, WRO) but not in unresponsive cells (ARO, FRO or FB1); (v) disruption of E-cadherin-mediated cell-cell contacts at high cell density induced by an anti-E-cadherin neutralizing antibody, inhibits the induction of p27(kip1) and restores proliferation in contact-inhibited cells; (vi) re-expression of E-cadherin into cells unresponsive to contact inhibition (ARO, FB1) induces a p27(kip1) expression and growth arrest. In summary, our data indicate that the altered response to contact inhibition exhibited by thyroid anaplastic cancer cells is due to the failure to upregulate p27(Kip1) in response to cell-cell interactions.

Expression profiles of 39 HOX genes in normal human adult organs and anaplastic thyroid cancer cell lines by quantitative real-time RT-PCR system

HOX genes are well known as master control genes in embryonic morphogenesis. We hypothesized that HOX genes give cells spatial information to maintain tissue- or organ-specificity in adult body and that the deregulated expression of HOX genes results in tumor development. We established a comprehensive analysis system to quantify expression of 39 human HOX genes based on the real-time reverse transcription PCR (RT-PCR) method. Analysis of 39 HOX genes of 20 normal adult organs by this system revealed that 5' HOX genes were expressed in organs in the caudal parts of the body, and that the more caudal regions the more numbers of HOX genes were expressed. It was also found that the expression patterns of HOX genes were more similar in the adjacent genes on the same cluster rather than in those belonging to the same paralogs. Compared with normal thyroid tissues, thyroid cancer cell lines showed the altered expression of some HOX genes, especially Abd-B homeobox family genes. Our results showed that HOX genes were organ-specifically expressed in adult body and that the deregulated expressions of Abd-B family genes were implicated in thyroid tumor development.

Molecular pathogenesis of thyroid cancer

A number of molecular abnormalities have been described in association with the progression from normal thyroid tissue to benign adenomas to well-differentiated and finally anaplastic epithelial thyroid cancer. These include upregulation of proliferative factors, such as growth hormones and oncogenes, downregulation of apoptotic and cell-cycle inhibitory factors, such as tumor suppressors, disruption of normal cell-to-cell interactions, and cellular immortalization. The progression model for thyroid carcinoma has not been proven, but evidence suggests that an evolutionary molecular process is involved, especially in the development of follicular thyroid cancers for which there are distinct intermediate phenotypes. We present a comprehensive evaluation of factors involved in thyroid tumorigenesis and attempt to describe preliminary attributes of a progression model. The organization of this model should also provide a template for the incorporation of new information as it is derived from large-scale genomic studies.

Real-time quantitative analysis of E-cadherin expression in ret/PTC-1-activated thyroid neoplasms

Papillary thyroid carcinoma (PTC), the most common variety of thyroid cancer, is found in a variety of morphologic variants, usually grows slowly, and is clinically indolent, although rare, aggressive forms, with local invasion or distant metastases, occur. Our group has previously demonstrated an association between Hashimoto thyroiditis and ret/PTC-1 activation, and have hypothesised that c-ret activation might be implicated in immune reaction to thyroid epithelium. The objective of this study was to examine expression of the cellular adhesion molecule, E-cadherin, in various thyroid tumor types and Hashimoto thyroiditis in the context of ret/PTC-1 positivity by using laser capture microdissection and TaqMan reverse transcription-polymerase chain reaction (RT-PCR). Variable down-regulation of E-cadherin among carcinomas was demonstrated, with anaplastic carcinomas showing little or no expression. Follicular thyroid carcinomas consistently had significantly decreased E-cadherin expression compared with papillary thyroid carcinomas. The ret/PTC-1-positive papillary thyroid carcinoma (PTCret+) and Hashimoto thyroiditis cases had consistently lower E-cadherin expression levels than the corresponding ret/PTC-1-negative papillary carcinomas (PTCret-), suggesting not only an association between ret activation and the loss of cellular adhesion but also, more significantly, an association between papillary thyroid carcinoma and Hashimoto thyroiditis.