Expression of matrix metalloproteinases and their specific inhibitors in normal and different human thyroid tumor cell lines

Role of Matrix Metalloproteinases and Their Inhibitors in Locally Invasive Papillary Thyroid Cancer

Locally invasive papillary thyroid carcinoma (PTC) protrudes beyond the thyroid capsule and invades local structures. Matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) are implicated in local invasion and metastasis in PTC. The aim of our study was to determine expression levels of MMP-1, MMP-2, MMP-9, TIMP-1, and TIMP-2 in tissue specimens of invasive and non-invasive PTC. Our hypothesis was that expression levels of these biomarkers correlate with the development of locally invasive PTC. In our single-center study we retrospectively investigated MMP and TIMP expression levels in 50 samples of thyroid tissue diagnosed as locally invasive papillary carcinoma (study group) and 30 samples of thyroid tissue diagnosed as non-invasive, non-metastatic papillary carcinoma (control group). Tissue specimens were immunohistochemically stained with primary monoclonal antibodies against MMP-1, MMP-2, MMP-9, TIMP-1, and TIMP-2. When correlating expression levels of MMPs and TIMPs in thyroid tissue, statistically significant differences were found for MMP-1 and TIMP-1 expression (p < 0.001; Mann−Whitney U test) with the highest levels of expression in the invasive PTC group. Although expression of MMP-9 and TIMP-2 was higher in invasive PTC, the differences were not statistically significant. Elevated expression of MMP-1 and TIMP-1 in tumor tissue can predict invasiveness for PTC.

In Vitro and In Vivo Effects of the Urokinase Plasminogen Activator Inhibitor WX-340 on Anaplastic Thyroid Cancer Cell Lines

Increased expression of the urokinase-type plasminogen activator (uPA) system is associated with tumor invasion, neo-angiogenesis, and metastatic spread, and has been shown to positively correlate with a poor prognosis in several cancer types, including thyroid carcinomas. In recent years, several uPA inhibitors were found to have anticancer effects in preclinical studies and in some phase II clinical trials, which prompted us to evaluate uPA as a potential therapeutic target for the treatment of patients affected by the most aggressive form of thyroid cancer, the anaplastic thyroid carcinoma (ATC). In this study, we evaluated the in vitro and in vivo effects of WX-340, a highly specific and selective uPA inhibitor, on two ATC-derived cell lines, CAL-62 and BHT-101. The results obtained indicated that WX-340 was able to reduce cell adhesion and invasiveness in a dose-dependent manner in both cell lines. In addition, WX-340 increased uPA receptor (uPAR) protein levels without affecting its plasma membrane concentration. However, this compound was unable to significantly reduce ATC growth in a xenograft model, indicating that uPA inhibition alone may not have the expected therapeutic effects.

TNRC6C Functions as a Tumor Suppressor and Is Frequently Downregulated in Papillary Thyroid Cancer

Our previous study found that trinucleotide repeat containing adaptor 6C (TNRC6C) may act as a tumor suppressor in papillary thyroid cancer (PTC). In this study, we aimed to confirm the effect of TNRC6C on PTC and investigate the underlying molecular mechanism. The difference of mRNA level of TNRC6C between PTC tissue and noncancerous thyroid tissue and the association of expression level of TNRC6C with clinicopathological features of PTC were analyzed using TCGA data. Immunohistochemical assay was performed to detect the protein expression of TNRC6C in PTC and its adjacent noncancerous tissue. Cell proliferation, migration, invasion, and apoptosis were analyzed after knockdown or overexpression of TNRC6C in BCPAP cells. RNA-sequencing was performed to find the target genes of TNRC6C, and potential targets were validated in BCPAP and TPC1 cells. Our results showed that TNRC6C was downregulated in PTC, and lower expression level of TNRC6C was associated with worse clinicopathological features. Overexpression of TNRC6C significantly inhibited proliferation, migration, and invasion of BCPAP cells and promoted its apoptosis, while knockdown of TNRC6C acted the opposite role. By analyzing RNA-sequencing data and TCGA data, 12 genes (SCD, CRLF1, APCDD1L, CTHRC1, PTPRU, ALDH1A3, VCAN, TNC, ECE1, COL1A1, CAMK2N2, and MMP14) were considered as potential target genes of TNRC6C, and most of them were associated with clinicopathological features of PTC in TCGA. All of them except CAMK2N2 were significantly downregulated after overexpressing TNRC6C. Our study demonstrated that TNRC6C functions as a tumor suppressor in PTC and may serve as a useful therapeutic target and prognostic marker for PTC patients.

Membrane type 1 matrix metalloproteinase regulates anaplastic thyroid carcinoma cell growth and invasion into the collagen matrix

Anaplastic thyroid carcinoma (ATC) is one of the most aggressive cancer types; however, the molecular mechanism contributing to the aggressive characteristics remain unclear. Membrane type 1 matrix metalloproteinase (MT1-MMP) plays an important role in cancer invasion and has been associated with a poor prognosis in various malignant neoplasms. In this study, we investigated the relationship between MT1-MMP expression and the proliferation and invasion of ATC cells, along with the association with clinicopathologic factors in patients with ATC. Suppression of MT1-MMP reduced the proliferation and invasion of ATC cells, and suppressed ERK activity, indicating a role in cancer cell proliferation in collagen matrix culture conditions. The expression of MT1-MMP was detected in 29 of 34 (85.3%) surgical specimens from ATC patients. In addition, the expression of MT1-MMP in the tumor lesion was higher than that of normal and stromal tissues. Collectively, these results suggest that elevated MT1-MMP expression plays a role in the pathogenesis of ATC, which may promote its aggressive characteristics such as proliferation and invasion, highlighting a potential new therapeutic target.

Molecular mechanisms of long non-coding RNAs in anaplastic thyroid cancer: a systematic review

BACKGROUND

anaplastic thyroid cancer (ATC) is one of the most lethal and aggressive cancers. Evidence has shown that the tumorigenesis of ATC is a multistep process involving the accumulation of genetic and epigenetic changes. Several studies have suggested that long non-coding RNAs (lncRNAs) may play an important role in the development and progression of ATC. In this article, we have collected the published reports about the role of lncRNAs in ATC.

METHODS

"Scopus", "Web of Science", "PubMed", "Embase", etc. were systematically searched for articles published since 1990 to 2020 in English language, using the predefined keywords.

RESULTS

961 papers were reviewed and finally 33 papers which fulfilled the inclusion and exclusion criteria were selected. Based on this systematic review, among a lot of evidences on examining the function of lncRNAs in thyroid cancer, there are only a small number of studies about the role of lncRNAs and their molecular mechanisms in the pathogenesis of ATC.

CONCLUSIONS

lncRNAs play a crucial role in regulation of different processes involved in the development and progression of ATC. Currently, just a few lncRNAs have been identified in ATC that may serve as prognosis markers such as GAS5, MIR22HG, and CASC2. Also, because of the dysregulation of Klhl14-AS, HOTAIRM1, and PCA3 during ATC development and progression, they may act as therapeutic targets. However, for most lncRNAs, only a single experiment has evaluated the expression profile in ATC tissues/cells. Therefore, further functional studies and expression profiling is needed to resolve this limitation and identify novel and valid biomarkers.

Role of matrix metalloproteinases and their inhibitors in the development of cervical metastases in papillary thyroid cancer

OBJECTIVE

To investigate the role of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) in the development of cervical metastases in papillary thyroid cancer. Our hypothesis is that level of expression of MMPs and TIMPs is associated with the development of cervical metastases and the pattern of metastatic process in papillary thyroid cancer.

DESIGN

This research retrospectively investigates the expression of MMP-1, -2 and -9 as well as TIMP-1 and -2 in papillary thyroid carcinoma tissue. Tissue specimens were immunohistochemically treated with primary monoclonal antibodies against MMP-1, MMP-2, MMP-9, TIMP-1 and TIMP-2.

SETTING

Single-centre study.

PARTICIPANTS

In total, samples of 159 patients were analysed. In all patients, total thyroidectomy was performed, whereas 102 patients underwent selective neck dissection of either central (level VI) or lateral neck (level II-V). Subjects were divided into four groups.

MAIN OUTCOME MEASURES

Matrix metalloproteinases and TIMPs expression values were analysed in each group, and groups were compared to each other.

RESULTS

Total number of patients was 159, of which 125 were women and 34 men. Comparing expression levels of MMPs and TIMPs in metastatic (study groups) and non-metastatic (control group), papillary thyroid carcinomas yielded significant differences in MMP-1 and TIMP-1 expression levels, where the highest expression values were found in the group with metastasis in lateral neck. Expression levels of MMP-2, MMP-9 and TIMP-2 did not differ statistically significant among the groups.

CONCLUSION

Elevated expression of MMP-1 and TIMP-1 in tumour tissue can be considered a predictive factor for the development of metastases.

Transcription Factor Prospero Homeobox 1 (PROX1) as a Potential Angiogenic Regulator of Follicular Thyroid Cancer Dissemination

It is well known that Prospero homeobox 1 (PROX1) is a crucial regulator of lymphangiogenesis, that reprograms blood endothelial cells to lymphatic phenotype. However, the role of PROX1 in tumor progression, especially in angiogenesis remains controversial. Herein, we studied the role of PROX1 in angiogenesis in cell lines derived from follicular thyroid cancer (FTC: FTC-133) and squamous cell carcinoma of the thyroid gland (SCT: CGTH-W-1) upon PROX1 knockdown. The genes involved in angiogenesis were selected by RNA-seq, and the impact of PROX1 on vascularization potential was investigated using human umbilical vein endothelial cells (HUVECs) cultured in conditioned medium collected from FTC- or SCT-derived cancer cell lines after PROX1 silencing. The angiogenic phenotype was examined in connection with the analysis of focal adhesion and correlated with fibroblast growth factor 2 (FGF2) levels. Additionally, the expression of selected genes involved in angiogenesis was detected in human FTC tissues. As a result, we demonstrated that PROX1 knockdown resulted in upregulation of factors associated with vascularization, such as metalloproteinases (MMP1 and 3), FGF2, vascular endothelial growth factors C (VEGFC), BAI1 associated protein 2 (BAIAP2), nudix hydrolase 6 (NUDT6), angiopoietin 1 (ANGPT1), and vascular endothelial growth factor receptor 2 (KDR). The observed molecular changes resulted in the enhanced formation of capillary-like structures by HUVECs and upregulated focal adhesion in FTC-133 and CGTH-W-1 cells. The signature of selected angiogenic genes' expression in a series of FTC specimens varied depending on the case. Interestingly, PROX1 and FGF2 showed opposing expression levels in FTC tissues and seven thyroid tumor-derived cell lines. In summary, our data revealed that PROX1 is involved in the spreading of thyroid cancer cells by regulation of angiogenesis.

The role of matrix metalloproteinase-9 as a prognostic biomarker in papillary thyroid cancer

BACKGROUND

The aim of the present study was to investigate the association between matrix metalloproteinase-9 (MMP-9) expression with BRAF V600E mutation and clinicopathological features, in Iranian papillary thyroid cancer (PTC) patients.

METHODS

In total, 90 participants including 60 PTC patients (15 males and 45 females) and 30 individuals with benign multinodular goiter (MNG) (5 males and 25 females) which were confirmed by surgical pathology, were investigated. MMP-9 was evaluated at both mRNA and protein levels, using SYBR-Green Real-Time PCR and enzyme-linked immune sorbent assay (ELISA), respectively. BRAF V600E mutation was detected by sequencing.

RESULTS

Mean age of PTC and MNG patients was 37.6 ± 12.6 and 48.1 ± 13.3 years, respectively (P = 0.001). BRAF V600E mutation was found in 24 of the 60 (40%) PTC cases, with mean tumor size of 1.59 ± 1.20 cm. MMP-9 mRNA levels were elevated in tumoral compared to the adjacent non-tumoral tissues (P = 0.039); moreover, this rise was also observed in PTC patients compared to MNG patients (P = 0.001). The mRNA levels of MMP-9 increased in patients aged≥45 years (P = 0.015), those with lymphovascular invasion (P = 0.003), and higher tumor stages (III and IV) (P = 0.011). The protein level of MMP-9 increased in tumoral compared to adjacent non-tumoral tissues (P < 0.001); this increase was also found in PTC patients compared to MNG participants (P = 0.004). MMP-9 protein level was higher in patients aged≥45 years (P = 0.001), those with lymphovascular invasion (P = 0.036) and higher TNM stages (III and IV) (P = 0.001). Area under the ROC curve (AUC) was 0.70 (95%CI: 0.57-0.83, P = 0.003), with 91.4% sensitivity and 51.9% specificity at the cutoff value of 0.50.

CONCLUSION

The mRNA and protein levels of MMP-9 had no association with BRAF V600E mutation in Iranian PTC patients. These levels were associated with age, TNM stages, and lymphovascular invasion, being defined as malignant factors. Thus, elevated levels of MMP-9 in PTC patients compared to MNG participants illustrated that it can be used as a potential biomarker to differentiate PTC patients from those with MNG.

Long Noncoding RNA LINC003121 Inhibits Proliferation and Invasion of Thyroid Cancer Cells by Suppression of the Phosphatidylinositol-3-Kinase (PI3K)/Akt Signaling Pathway

BACKGROUND The aim of this study was to explore the potential effects of long noncoding RNA (lncRNA) LINC003121 on thyroid cancer (TC) cell proliferation and invasion and to explore their possible mechanisms with the involvement of the PI3K/Akt signaling pathway. MATERIAL AND METHODS We enrolled 211 thyroid cancer tissues and 70 adjacent normal tissues in this study. TC cell lines K1, SW579, and 8505C and the human thyroid follicular cell line Nthy-ori3-1 were selected and assigned into blank, control vectors, LINC00312 vectors, si-control, and si-LINC00312 groups. Quantitative real-time PCR was used to determine the levels of LINC003121 and Western blotting was used to detect the protein expression of MMP-9, PI3K, t-Akt, and p-Akt. Cell proliferation was assessed by CCK8 assay and EdU incorporation assay, and cell invasion was assessed by Transwell assay. RESULTS The expression of LINC00312 was significantly decreased in TC tissues and cell lines. In an in vitro experiment, si-LINC00312 significantly promoted the invasion and proliferation of TC cells. Conversely, overexpression of LINC00312 decreased cell proliferation and invasion in vitro, and decreased tumorigenicity in TC xenograft models in nude mice. LINC00312-mediated tumor suppression in TC cells may occur via suppression of activation of the PI3K/Akt signaling pathway and expression of MMP-9, and the role of MMP-9 expression induced by overexpressed LINC00312 or si-LINC00312 could be weakened by LY294002 (PI3K inhibitor). CONCLUSIONS LINC00312 can act as a tumor-suppressor in TC by attenuating the PI3K/Akt signaling pathway, and LINC00312 could be a novel diagnosis biomarker and a promising therapeutic target for TC patients.

New perspectives in the diagnosis of thyroid follicular lesions

Thyroid nodules are very common, affecting 19%-67% of the adult population. However, about 10% of them harbor a malignant lesion. Consequently, the first aim in their clinical evaluation is to exclude malignancy. Fine-needle aspiration cytology (FNAC) represents the main diagnostic tool for the evaluation of thyroid nodules. However, FNAC has a main diagnostic limit, namely cellular atypias of indeterminate significance, which require surgical excision and histological examination to differentiate benign from malignant lesions. Histology reports show that approximately 80% of these patients harbor a benign lesion. Therefore, in order to reduce unnecessary thyroidectomy, over the last years, the cytological classification of thyroid nodules has been revised and a number of new instrumental and molecular approaches have been proposed. In the present article, we will attempt to summarize the most recent cytological, molecular and echographic strategies to enhance the diagnostic accuracy of preoperative thyroid follicular lesions. In particular, we will discuss the new cytological classifications from the Bethesda System for Reporting Thyroid Cytopathology (BSRTC), the British Thyroid Association-Royal College of Pathologists (PTA-RCPath) and the new Italian Society for Anatomic Pathology and Cytology (SIAPEC 2014. We will review molecular tests evaluated to ameliorate follicular lesion diagnosis as well as the clinical utility of the new echographic Thyroid Imaging Reporting and Data System (TI-RADS) score.

Estrogen receptor subtype expression and regulation is altered in papillary thyroid cancer after menopause

BACKGROUND

Estrogen receptors can regulate growth in papillary thyroid cancer and may affect prognosis after menopause. This study examines changes of estrogen receptor subtype ratio expression in papillary thyroid cancer cell lines derived from pre- and postmenopausal women.

METHODS

Cells were harvested from papillary thyroid cancer and non-papillary thyroid cancer thyroid tissue (control) from pre- (n = 9) and postmenopausal women (n = 11). Protein expression of estrogen receptor α, estrogen receptor β, and phosphorylated extracellular signal-regulated kinase and protein kinase B were analyzed. Matrix metalloproteinase-2 activity was determined as a measure of tumor invasiveness. Mitochondrial retrograde signaling was altered with ethidium bromide to determine its effect on estrogen receptor α protein expression.

RESULTS

Estrogen receptor α expression was increased in postmenopausal papillary thyroid cancer cells compared with controls but was unchanged in premenopausal papillary thyroid cancer. Estrogen receptor β expression did not change in either group. Increased matrix metalloproteinase-2 activity was observed only in postmenopausal papillary thyroid cancer. Premenopausal papillary thyroid cancer cells demonstrated increased extracellular signal-regulated kinase and unchanged protein kinase B activation. Conversely, postmenopausal papillary thyroid cancer cells had decreased extracellular signal-regulated kinase and increased protein kinase B activation. Ethidium bromide treatment resulted in increased estrogen receptor α protein expression only in premenopausal papillary thyroid cancer cells.

CONCLUSION

Increased estrogen receptor α expression may be involved in papillary thyroid cancer aggressiveness after menopause. This process may be regulated by differential activation of intracellular pathways and differing sensitivities to mitochondrial signaling regulation.

Nodular thyroid disease in the elderly: novel molecular approaches for the diagnosis of malignancy

Epithelial thyroid cancers (TC) comprise two differentiated histotypes (DTC), the papillary (PTC) and the follicular (FTC) thyroid carcinomas which, following dedifferentiation, are assumed to give rise to the poorly differentiated thyroid carcinomas and the rare, but highly aggressive and invariably fatal, anaplastic thyroid carcinomas. Although thyroid cancer mortality has not been changed, its annual incidence has increased over the last two decades, mainly because of the improved ability to diagnose malignant transformation in small non-palpable thyroid nodules. Despite DTC patients have a favorable prognosis, aggressive disease is more frequently observed in the elderly showing a higher disease-specific mortality. Of relevance is the high prevalence of nodular thyroid disease in aged patients being higher than 90%, in women older than 60 year, and 60% in men older than 80 year. This implies a careful evaluation of thyroid nodules in this group of patients in order to exclude malignancy. In fact, despite the tremendous progress in the comprehension of the underlying molecular mechanisms deregulated in DTC progression, several aspects of their clinical management remain to be solved and novel diagnostic strategies are sorely needed. Here, we will attempt to review new molecular approaches, which are currently being exploited in order to ameliorate the diagnosis of thyroid nodules.

Transient Receptor Potential Canonical 1 (TRPC1) Channels as Regulators of Sphingolipid and VEGF Receptor Expression: IMPLICATIONS FOR THYROID CANCER CELL MIGRATION AND PROLIFERATION

The identity of calcium channels in the thyroid is unclear. In human follicular thyroid ML-1 cancer cells, sphingolipid sphingosine 1-phosphate (S1P), through S1P receptors 1 and 3 (S1P1/S1P3), and VEGF receptor 2 (VEGFR2) stimulates migration. We show that human thyroid cells express several forms of transient receptor potential canonical (TRPC) channels, including TRPC1. In TRPC1 knockdown (TRPC1-KD) ML-1 cells, the basal and S1P-evoked invasion and migration was attenuated. Furthermore, the expression of S1P3 and VEGFR2 was significantly down-regulated. Transfecting wild-type ML-1 cells with a nonconducting TRPC1 mutant decreased S1P3 and VEGFR2 expression. In TRPC1-KD cells, receptor-operated calcium entry was decreased. To investigate whether the decreased receptor expression was due to attenuated calcium entry, cells were incubated with the calcium chelator BAPTA-AM (1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid). In these cells, and in cells where calmodulin and calmodulin-dependent kinase were blocked pharmacologically, S1P3 and VEGFR2 expression was decreased. In TRPC1-KD cells, both hypoxia-inducible factor 1α expression and the secretion and activity of MMP2 and MMP9 were attenuated, and proliferation was decreased in TRPC1-KD cells. This was due to a prolonged G1 phase of the cell cycle, a significant increase in the expression of the cyclin-dependent kinase inhibitors p21 and p27, and a decrease in the expression of cyclin D2, cyclin D3, and CDK6. Transfecting TRPC1 to TRPC1-KD cells rescued receptor expression, migration, and proliferation. Thus, the expression of S1P3 and VEGFR2 is mediated by a calcium-dependent mechanism. TRPC1 has a crucial role in this process. This regulation is important for the invasion, migration, and proliferation of thyroid cancer cells.

Gene expression profile analyze the molecular mechanism of CXCR7 regulating papillary thyroid carcinoma growth and metastasis

Background

To detect genetic expression profile alterations after papillary thyroid carcinoma (PTC) cells transfected with chemokine receptor CXCR7 gene by gene microarray, and gain insights into molecular mechanisms of how CXCR7 regulating PTC growth and metastasis.

Methods

The Human OneArray microarray was used for a complete genome-wide transcript profiling of CXCR7 transfected PTCs (K1-CXCR7 cells), defined as experimental group. Non CXCR7 transfected PTCs (K1 cells) were used as control group. Differential analysis for per gene was performed with a random variance model and t test, p values were adjusted to control the false discovery rate. Gene ontology (GO) on differentially expressed genes to identify the biological processes in modulating the progression of papillary thyroid carcinoma. Pathway analysis was used to evaluate the signaling pathway that differentially expressed genes were involved in. In addition, quantitative real-time polymerase chain reaction (q-PCR) and Western blot were used to verify the top differentially expression genes.

Results

Comparative analysis revealed that the expression level of 1149 genes was changed in response to CXCR7 transfection. After unsupervised hierarchical clustering analysis, 270 differentially expressed genes were filtered, of them 156 genes were up-regulated whereas 114 genes were down-regulated in K1-CXCR7 cells. GO enrichment analysis revealed the differentially expressed genes were mainly involved in biopolymer metabolic process, signal transduction and protein metabolism. Pathway enrichment analysis revealed differentially expressed genes were mainly involved in ECM-receptor interaction, Focal adhesion, MAPK signaling pathway and Cytokine-cytokine receptor interaction pathway. More importantly, the expression level of genes closely associated with tumor growth and metastasis was altered significantly in K1-CXCR7 cells, including up-regulated genes FN1, COL1A1, COL4A1, PDGFRB, LTB, CXCL12, MMP-11, MT1-MMP and down-regulated genes ITGA7, and Notch-1.

Conclusions

Gene expression profiling analysis of papillary thyroid carcinoma can further delineate the mechanistic insights on how CXCR7 regulating papillary thyroid carcinoma growth and metastasis. CXCR7 may regulate growth and metastasis of papillary thyroid carcinoma via the activation of PI3K/AKT pathway and its downstream NF-κB signaling, as well as the down-regulation of Notch signaling.

A new aurora in anaplastic thyroid cancer therapy

Anaplastic thyroid cancers (ATC) are among the most aggressive human neoplasms with a dire prognosis and a median survival time of few months from the diagnosis. The complete absence of effective therapies for ATC renders the identification of novel therapeutic approaches sorely needed. Chromosomal instability, a feature of all human cancers, is thought to represent a major driving force in thyroid cancer progression and a number of mitotic kinases showing a deregulated expression in malignant thyroid tissues are now held responsible for thyroid tumor aneuploidy. These include the three members of the Aurora family (Aurora-A, Aurora-B, and Aurora-C), serine/threonine kinases that regulate multiple aspects of chromosome segregation and cytokinesis. Over the last few years, several small molecule inhibitors targeting Aurora kinases were developed, which showed promising antitumor effects against a variety of human cancers, including ATC, in preclinical studies. Several of these molecules are now being evaluated in phase I/II clinical trials against advanced solid and hematological malignancies. In the present review we will describe the structure, expression, and mitotic functions of the Aurora kinases, their implications in human cancer progression, with particular regard to ATC, and the effects of their functional inhibition on malignant cell proliferation.

Curcumin inhibits invasion and metastasis in K1 papillary thyroid cancer cells

Curcumin, the active constituent of dietary spice turmeric, possesses a strong potential for cancer prevention and treatment. However, there is no study to address the effects of curcumin on invasion and metastasis of thyroid cancers. Thyroid cancer is the most common malignancy of endocrine organs, and its incidence rates have steadily increased over recent decades. Although most indolent tumours can be effectively managed, metastatic tumours at distant secondary sites behave aggressively and currently there is no effective form of treatment. Here, for the first time it has been reported that curcumin inhibit multiple metastasis steps of K1 papillary thyroid cancer cells. Curcumin dose-dependently suppressed viability of K1 cells as well as its cell attachment, spreading, migration and invasion abilities. Moreover, curcumin could also down-regulate the expression and activity of matrix metalloproteinase-9 (MMP-9). The findings showed that curcumin might be an effective tumouristatic agent for the treatment of aggressive papillary thyroid carcinomas.

Molecular photoacoustic imaging of follicular thyroid carcinoma

PURPOSE

To evaluate the potential of targeted photoacoustic imaging as a noninvasive method for detection of follicular thyroid carcinoma.

EXPERIMENTAL DESIGN

We determined the presence and activity of two members of matrix metalloproteinase family (MMP), MMP-2 and MMP-9, suggested as biomarkers for malignant thyroid lesions, in FTC133 thyroid tumors subcutaneously implanted in nude mice. The imaging agent used to visualize tumors was MMP-activatable photoacoustic probe, Alexa750-CXeeeeXPLGLAGrrrrrXK-BHQ3. Cleavage of the MMP-activatable agent was imaged after intratumoral and intravenous injections in living mice optically, observing the increase in Alexa750 fluorescence, and photoacoustically, using a dual-wavelength imaging method.

RESULTS

Active forms of both MMP-2 and MMP-9 enzymes were found in FTC133 tumor homogenates, with MMP-9 detected in greater amounts. The molecular imaging agent was determined to be activated by both enzymes in vitro, with MMP-9 being more efficient in this regard. Both optical and photoacoustic imaging showed significantly higher signal in tumors of mice injected with the active agent than in tumors injected with the control, nonactivatable, agent.

CONCLUSIONS

With the combination of high spatial resolution and signal specificity, targeted photoacoustic imaging holds great promise as a noninvasive method for early diagnosis of follicular thyroid carcinomas.

Matrix metalloproteinase-9 and the Cu/Zn ratio as ancillary diagnostic tools in distinguishing between the classical and follicular variants of papillary thyroid carcinoma

The most common histological variants of papillary thyroid carcinoma (PTC), classical (CPTC) and follicular (FPTC), have different diagnostic features, molecular biology, and prognosis. Matrix metalloproteinase-9 (MMP-9) endopeptidase which degrades the components of the extracellular matrix is essential in the invasive growth and metastasizing of malignant tumors. The serum copper (Cu)/zinc (Zn) ratios are sensitive diagnostic and prognostic indicators in oncology since Cu- and Zn-dependent enzymes play important roles in the genesis and the progression of tumors. The aim of this study was to examine the expressions of MMP-9 in tissues of CPTC and FPTC, as well as to determine the Cu/Zn ratios in the same samples. MMP-9 was determined immunohistochemically, and the concentrations of copper and zinc in thyroid tissue were determined by means of flame atomic absorption spectrometry. The results obtained revealed significantly higher expressions of MMP-9 in CPTC in comparison with FPTC, as well as higher Cu/Zn ratios in CPTC than in FPTC. Thus, determining MMP-9 activities and the Cu/Zn ratios could improve the accuracy of the standard histopathological diagnosis of these two types of PTC.

Overexpression of pro-inflammatory genes and down-regulation of SOCS-1 in human PTC and in hypoxic BCPAP cells

Hypoxia-inducible factor-1α (HIF-1α) is frequently overexpressed and activated in many cancer types. However, its regulation and function in thyroid carcinomas are only partially known. Aim of our study was to demonstrate that adaptation to the hypoxic micro-environment by human papillary thyroid carcinoma (PTC) cells, in the absence of leukocyte infiltrate, induces a "molecular inflammation" process characterized by the expression of a large set of genes normally involved in inflammation. To address this, tumor, peritumor or normal host tissue from eleven human PTC surgical samples, were separated by laser capture microdissection (LCMD) and studied by real-time quantitative PCR and Western blot. In such condition, we observed an increased expression and activation of HIF-1α, NF-kB and pro-inflammatory genes only in tumor tissues. Importantly, an anti-inflammatory gene such as SOCS-1 was markedly down-regulated in tumor tissue compared to surrounding normal host tissue. Similar results were found in fine-needle aspiration biopsy (FNAB)-derived specimens from PTC and in hypoxic human papillary thyroid tumor cell line, BCPAP. Moreover, we also detected an elevated expression of metalloproteinase-9 (MMP9) both in solid tumor and in hypoxic-treated BCPAP cells. Our findings reveal that, in human PTC tumor, hypoxic conditions are accompanied by up-regulation of pro-inflammatory genes, down-regulation of anti-inflammatory genes and increased expression of MMP9. We propose that a better understanding of the pro- and anti-inflammatory pathways involved in the "molecular inflammation" process even in the absence of leukocyte, may help to clarify progression toward malignancy and may prove useful for new anti-tumor strategy.

Extra- and intracellular imaging of human matrix metalloprotease 11 (hMMP-11) with a cell-penetrating FRET substrate

Matrix metalloprotease 11 (MMP-11), a protease associated with invasion and aggressiveness of cancerous tissue, was postulated as a prognostic marker for pancreatic, breast, and colon cancer patients. Expression analysis, however, did not reveal localization and regulation of this protease. Thus, cellular tools for the visualization of MMP-11 are highly desirable to monitor presence and activity and to elucidate the functional role of MMP-11. Therefore, fluorescein-Dabcyl-labeled Foerster resonance energy transfer (FRET) substrates were developed. The design focused on enhanced peptide binding to human MMP-11, employing an unusual amino acid for the specificity pocket P1'. The addition of several arginines resulted in a cell-permeable FRET substrate SM-P124 (Ac-GRRRK(Dabcyl)-GGAANC(MeOBn)RMGG-fluorescein). In vitro evaluation of SM-P124 with human MMP-11 showed a 25-fold increase of affinity (k(cat)/K(m) = 9.16 × 10(3) m(-1) s(-1), K(m) = 8 μm) compared with previously published substrates. Incubation of pancreatic adenocarcinoma cell line MIA PaCa-2 and mamma adenocarcinoma cell line MCF-7 with the substrate SM-P124 (5 μm) indicated intra- and extracellular MMP-11 activity. A negative control cell line (Jurkat) showed no fluorescent signal either intra- or extracellularly. Negative control FRET substrate SM-P123 produced only insignificant extracellular fluorescence without any intracellular fluorescence. SM-P124 therefore enabled intra- and extracellular tracking of MMP-11-overexpressing cancers such as pancreatic and breast adenocarcinoma and might contribute to the understanding of the activation pathways leading to MMP-11-mediated invasive processes.

The insulin and igf-I pathway in endocrine glands carcinogenesis

Endocrine cancers are a heterogeneous group of diseases that may arise from endocrine cells in any gland of the endocrine system. These malignancies may show an aggressive behavior and resistance to the common anticancer therapies. The etiopathogenesis of these tumors remains mostly unknown. The normal embryological development and differentiation of several endocrine glands are regulated by specific pituitary tropins, which, in adult life, control the function and trophism of the endocrine gland. Pituitary tropins act in concert with peptide growth factors, including the insulin-like growth factors (IGFs), which are considered key regulators of cell growth, proliferation, and apoptosis. While pituitary TSH is regarded as tumor-promoting factor for metastatic thyroid cancer, the role of other pituitary hormones in endocrine cancers is uncertain. However, multiple molecular abnormalities of the IGF system frequently occur in endocrine cancers and may have a role in tumorigenesis as well as in tumor progression and resistance to therapies. Herein, we will review studies indicating a role of IGF system dysregulation in endocrine cancers and will discuss the possible implications of these findings for tumor prevention and treatment, with a major focus on cancers from the thyroid, adrenal, and ovary, which are the most extensively studied.

Multifaceted suppression of aggressive behavior of thyroid carcinoma by all-trans retinoic acid induced re-differentiation

Since all-trans retinoic acid (ATRA) has shown promising results in differentiation therapy, the present study was designed to investigate the effects of ATRA on thyroid carcinoma and to evaluate the effectiveness of ATRA in redifferentiation induction of thyroid carcinoma. Therefore, we investigated cell growth rate, morphological and nuclear: cytoplasmic ratio, adherent-dependent growth, response to chemotherapy drug following differentiation, T3 and T4 measurement, and critical genes expression pattern. Papillary cell line showed more growth inhibition by ATRA, in addition, mesenchymal and spindle-shape of 8305C cells changed to polygonal. Additionally, high nuclear: cytoplasmic ratio of anaplastic decreased significantly. Redifferentiation significantly suppressed the anchorage-dependent growth in the both cell lines in a dose-dependent manner, potentiated the arsenic trioxide (ATO) effects in anaplastic and papillary cell lines. Furthermore, reduction in the expression of stemness, and invasion related genes was observed in the both cell lines. Altogether, ATRA treatment could hold the aggressive behavior of thyroid carcinoma in restraint and/or potentiate the effect of chemotherapy drug ATO.

BRAFV600E mutation, TIMP-1 upregulation, and NF-κB activation: closing the loop on the papillary thyroid cancer trilogy

BRAF(V600E) is the most common mutation found in papillary thyroid carcinoma (PTC). Tissue inhibitor of metalloproteinases (TIMP-1) and nuclear factor (NF)-κB have been shown to play an important role in thyroid cancer. In particular, TIMP-1 binds its receptor CD63 on cell surface membrane and activates Akt signaling pathway, which is eventually responsible for its anti-apoptotic activity. The aim of our study was to evaluate whether interplay among these three factors exists and exerts a functional role in PTCs. To this purpose, 56 PTC specimens were analyzed for BRAF(V600E) mutation, TIMP-1 expression, and NF-κB activation. We found that BRAF(V600E) mutation occurs selectively in PTC nodules and is associated with hyperactivation of NF-κB and upregulation of both TIMP-1 and its receptor CD63. To assess the functional relationship among these factors, we first silenced BRAF gene in BCPAP cells, harboring BRAF(V600E) mutation. We found that silencing causes a marked decrease in TIMP-1 expression and NF-κB binding activity, as well as decreased invasiveness. After treatment with specific inhibitors of MAPK pathway, we found that only sorafenib was able to increase IκB-α and reduce both TIMP-1 expression and Akt phosphorylation in BCPAP cells, indicating that BRAF(V600E) activates NF-κB and this pathway is MEK-independent. Taken together, our findings demonstrate that BRAF(V600E) causes upregulation of TIMP-1 via NF-κB. TIMP-1 binds then its surface receptor CD63, leading eventually to Akt activation, which in turn confers antiapoptotic behavior and promotion of cell invasion. The recognition of this functional trilogy provides insight on how BRAF(V600E) determines cancer initiation, progression, and invasiveness in PTC, also identifying new therapeutic targets for the treatment of highly aggressive forms.

Down-regulation of matrix metalloproteinase-7 inhibits metastasis of human anaplastic thyroid cancer cell line

Epigenetic drugs such as histone deacetylase inhibitors (HDACIs) possess anticancer properties due to its ability to regulate genes associated with tumor growth, differentiation, apoptosis and metastasis. In addition to its apoptotic effect, phenylbutyrate (PB), a carboxylic acid HDACI, inhibited an anaplastic (ATC) thyroid cancer cell line ARO from penetrating a matrigel coated transwell with concomitant suppression of a metastasis-associated gene, matrix metalloproteinase-7 (MMP-7) and stimulation of a transformation suppressor protein, reversion-inducing- cysteine-rich protein with Kazal motifs without affecting MMP-2 expression levels. Direct evidence suggesting MMP-7 down-regulated cancer metastasis came from the observation of a decreased pulmonary metastasis in SCID mice xeno-transplanted with MMP-7-knocked-down ARO cells. In addition, H-89, a protein kinase A inhibitor, remarkably restored the down-regulaed MMP-7 level treated by PB. Thus, the suppressive effect of PB on MMP-7 was partially carried out through H3 phosphoacetylation. To conclude, our findings suggest PB inhibits MMP-7 expression epigenetically through phosphoacetylation of histone proteins, and thereby, reduced invasive ability of an ATC thyroid cancer cell line.

Inhibition of uPAR and uPA reduces invasion in papillary thyroid carcinoma cells

OBJECTIVES/HYPOTHESIS

We analyzed the expression of urokinase plasminogen activator (uPA) and its receptor (uPAR) in papillary thyroid carcinoma (PTC) and normal thyroid tissue and examined in vitro how uPA and uPAR contribute to an invasive/metastatic phenotype, and the functional consequences of inhibiting this system.

STUDY DESIGN

Retrospective chart review of PTC patients, followed by prospective study using previously obtained patient tissue and PTC cellular models.

METHODS

uPA and uPAR RNA and protein levels were analyzed in PTC patient tissue samples, PTC and normal thyroid tissue culture cells, and conditioned media (CM) using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and/or Western blotting. The plasminogen-activating ability of CM was examined using dark-quenched casein fluorimetry and casein-plasminogen gel zymography. The invasive potentials of the PTC and normal thyroid epithelial cell lines were assessed using an in vitro cellular invasion/migration system.

RESULTS

uPA and uPAR RNA and protein levels were increased in PTC patient samples and PTC cells relative to controls. uPA and uPAR RNA were also significantly higher in patients with metastatic disease. Casein-plasminogen zymography and Western blotting demonstrated increased active uPA secreted by PTC cells compared with normal thyroid cells. Fluorimetric assays revealed that the PTC cells' CM was able to activate plasminogen, resulting in measurable casein hydrolysis. This casein hydrolysis was prevented by the addition of several specific uPA inhibitors. Finally, the in vitro invasion phenotypes of PTC cells were augmented by the addition of plasminogen, and this augmentation was reversed by inhibitory anti-uPA and anti-uPAR antibodies.

CONCLUSIONS

These data provide new functional evidence of the uPA/uPAR system's role in PTC invasion/metastasis and demonstrate the attractiveness of uPA and uPAR as molecular biomarkers and therapeutic targets.

Expression of MMP-1 in invasive well-differentiated thyroid carcinoma

The objective of this study is to examine the expression of matrix metalloproteinase 1 (MMP-1) in invasive well-differentiated thyroid carcinoma (WDTC) and its relation to clinicopathological features. This retrospective case study group included 26 patients with invasive WDTC who were treated at our center between January 1985 and May 2007. Clinical data were collected from the medical files. MMP-1 expression was tested in samples from paraffin-embedded tumor by immunohistochemical staining. MMP-1 expression correlated with laryngotracheal invasion (p = 0.032), multifocality of the tumor (p = 0.044), and presence of regional (p = 0.034) and distant metastases (p = 0.048). In conclusion, the expression of MMP-1 in invasive WDTC is consistent with tumor aggressiveness, manifested by laryngotracheal invasion, multifocality, and regional and distant metastases. MMP-1 expression may serve as a prognostic marker and an indicator for the need for more aggressive surgical treatment.

Inhibition of nuclear factor-kappa B differentially affects thyroid cancer cell growth, apoptosis, and invasion

Background

Nuclear factor-κB (NF-κB) is constitutively activated in many cancers and plays a key role in promoting cell proliferation, survival, and invasion. Our understanding of NF-κB signaling in thyroid cancer, however, is limited. In this study, we have investigated the role of NF-κB signaling in thyroid cancer cell proliferation, invasion, and apoptosis using selective genetic inhibition of NF-κB in advanced thyroid cancer cell lines.

Results

Three pharmacologic inhibitors of NF-κB differentially inhibited growth in a panel of advanced thyroid cancer cell lines, suggesting that these NF-κB inhibitors may have off-target effects. We therefore used a selective genetic approach to inhibit NF-κB signaling by overexpression of a dominant-negative IκBα (mIκBα). These studies revealed decreased cell growth in only one of five thyroid cancer cell lines (8505C), which occurred through a block in the S-G2/M transition. Resistance to TNFα-induced apoptosis was observed in all cell lines, likely through an NF-κB-dependent mechanism. Inhibition of NF-κB by mIκBα sensitized a subset of cell lines to TNFα-induced apoptosis. Sensitive cell lines displayed sustained activation of the stress-activated protein kinase/c-Jun NH2-terminal kinase (SAPK/JNK) pathway, defining a potential mechanism of response. Finally, NF-κB inhibition by mIκBα expression differentially reduced thyroid cancer cell invasion in these thyroid cancer cell lines. Sensitive cell lines demonstrated approximately a two-fold decrease in invasion, which was associated with differential expression of MMP-13. MMP-9 was reduced by mIκBα expression in all cell lines tested.

Conclusions

These data indicate that selective inhibition of NF-κB represents an attractive therapeutic target for the treatment of advanced thyroid. However, it is apparent that global regulation of thyroid cancer cell growth and invasion is not achieved by NF-κB signaling alone. Instead, our findings suggest that other important molecular processes play a critical role in defining the extent of NF-κB function within cancer cells.

Expression of membrane type 1 matrix metalloproteinase in medullary thyroid carcinoma: prognostic implications

BACKGROUND

Clinical and pathologic examinations cannot always provide a prognosis for patients with medullary thyroid carcinoma. Membrane type 1 matrix metalloproteinase (MT1-MMP) can act directly on carcinogenesis and takes part in 1 of the processes of metalloproteinase 2 activation, an enzyme related to prognostic impairment of patients with such tumor.

METHODS

Thirty-five patients who were submitted to surgery were followed up for an average of 74 months. Postoperative and final medical conditions were characterized for comparison with MT1-MMP immunostainings, performed in surgical paraffin blocks. A value of p < .05 was considered statistically significant.

RESULTS

Proposed index (association of proportion and intensity of immunostaining) and proportion of immunostained cells in primary specimens were correlated with cure or persistence after initial operations (p = .0216 and p = .0098, respectively).

CONCLUSION

MT1-MMP immunostaining in primary tumor specimens is a new and complementary prognostic predictor in patients with medullary thyroid carcinomas.

Diagnostic markers and prognostic factors in thyroid cancer

There has been considerable progress identifying biomarkers in thyroid tumors that improve the accuracy of fine-needle aspiration biopsy and also help predict tumor aggressiveness or behavior. In this review we address both the clinical potential of molecular biomarkers and their usefulness, based on the most recent literature. We describe the current best clinical staging systems and the common somatic mutations in thyroid cancer. The BRAF mutation is the most common mutation in papillary thyroid cancer and has recently been reported to be associated with disease aggressiveness; it is also an independent predictor of tumor behavior. Combined testing of RET/PTC, NTRK, RAS and PAX8–PPARγ, which are mutually exclusive mutations, helps improve the accuracy of fine-needle aspiration biopsy. Gene-expression profiling studies have identified a variety of potential molecular markers to help distinguish benign from malignant thyroid neoplasms. Expression analysis of differentially expressed microRNAs also appears to be a promising diagnostic approach for distinguishing benign from malignant thyroid neoplasm. It is especially useful for indeterminate nodules by fine-needle aspiration biopsy.

Higher serum TSH in thyroid cancer patients occurs independent of age and correlates with extrathyroidal extension

BACKGROUND

It has previously been shown that higher serum TSH is associated with increased thyroid cancer incidence and advanced-stage disease. In the healthy adult population, mean TSH increases with age. As age over 45 years is a known prognostic indicator for thyroid cancer, it is important to know whether higher TSH in patients with thyroid cancer occurs independent of age.

OBJECTIVE

To determine the relationship between higher TSH, cancer and age.

DESIGN

A retrospective cohort study.

PATIENTS AND METHODS

A total of 1361 patients underwent thyroid surgery between May 1994 and December 2007 at a single institution. Of these patients, 954 had pathological data, preoperative TSH and complete surgical history available. Data were analysed in relation to age and TSH.

RESULTS

Mean TSH was significantly higher in cancer patients regardless of age < 45 years or >or= 45 years (P = 0.046 and P = 0.027, respectively). When examining age groups < 20, 20-44, 45-59 and >or= 60 years, there was a trend of rising mean TSH with age. Despite the rise in the benign subgroups, mean TSH was consistently higher in those with cancer vs. those without. On multivariate analysis, higher TSH was independently associated with cancer (P = 0.039) and pathological features of Hashimoto's thyroiditis (P = 0.001) but not with age (P = 0.557). On multivariate analysis of high-risk features associated with poor prognosis, there was a significant association between higher TSH and extrathyroidal extension (P = 0.002), whereas there was no clear relationship with age, tumour size > 4 cm, and distant metastases.

CONCLUSION

Independent of age, thyroid cancer incidence correlates with higher TSH. Higher TSH is associated with extrathyroidal extension of disease.

Expression of matrix metalloproteinase 2 (MMP-2) and tissue inhibitor of metalloproteinase 2 (TIMP-2) in medullary thyroid carcinoma: prognostic implications

BACKGROUND

Metalloproteinase 2 (MMP-2) and tissue inhibitor of metalloproteinase 2 (TIMP-2) participate in the degeneration of the extracellular matrix and are associated with carcinogenesis. MMP-2 is one of the main metalloproteinases active in neoplasia and is a marker of the malignant phenotype. Since the biological behavior of medullary thyroid carcinoma (MTC) varies widely, the present study was undertaken to determine if there is a correlation between the clinical evolution of MTC and the immunohistochemically detected expression of these enzymes in thyroid surgical specimens containing MTC. If so, their expression would be a novel indicator of the prognosis of MTC.

METHODS

Thirty-seven patients with MTC who had undergone thyroid surgery were followed for an average of 73 months. Immunohistochemical staining for metalloproteinase-related enzymes was performed in surgical paraffin blocks. The clinical status of the patients after surgery and at the end of the study period was characterized to determine correlations between these and the immunohistochemical markers. A value of p < 0.05 was considered statistically significant.

RESULTS

At the end of the study period, 15 patients (40.5%) were alive and without evidence of MTC, 17 (45.9%) had persistent MTC, and 5 (13.5%) had a relapse of their neoplasia. Four patients (10.8%) died during the course of the study. There was a significant correlation (p = 0.0005) between the immunohistochemical staining for MMP-2 and the clinical condition of the patients at the end of the study period, and a correlation between the state of apparent cure compared to persistence of MTC after thyroid surgery (p = 0.0207). No significant correlations were observed between either TIMP-2 expression or immune marking of metastatic lymph nodes and the clinical variables studied.

CONCLUSION

Immunohistochemical expression of MMP-2 in thyroid surgical specimens from patients with MTC is a novel indicator of the prognosis of this cancer.

Conditional activation of RET/PTC3 and BRAFV600E in thyroid cells is associated with gene expression profiles that predict a preferential role of BRAF in extracellular matrix remodeling

Papillary thyroid cancers (PTC) are associated with nonoverlapping mutations of genes coding for mitogen-activated protein kinase signaling effectors (i.e., the TK receptors RET or NTRK and the signaling proteins RAS and BRAF). We examined the pattern of gene expression after activation of these oncoproteins in thyroid PCCL3 cells, with the goal of identifying pathways or gene subsets that may account for the phenotypic differences observed in human cancers. We hybridized cDNA from cells treated with or without doxycycline to induce expression of BRAF(V600E), RET/PTC3, or RET/PTC3 with small interfering RNA-mediated knockdown of BRAF, respectively, to slides arrayed with a rat 70-mer oligonucleotide library consisting of 27,342 oligos. Among the RET/PTC3-induced genes, 2,552 did not require BRAF as they were similarly regulated by RET/PTC3 with or without BRAF knockdown and not by expression of BRAF(V600E). Immune response and IFN-related genes were highly represented in this group. About 24% of RET/PTC3-regulated genes were BRAF dependent, as they were similarly modified by RET/PTC3 and BRAF(V600E) but not in cells expressing RET/PTC3 with knockdown of BRAF. A gene cluster coding for components of the mitochondrial electron transport chain pathway was down-regulated in this group, potentially altering regulation of cell viability. Metalloproteinases were also preferentially induced by BRAF, particularly matrix metalloproteinase 3 (MMP3), MMP9, and MMP13. Accordingly, conditional expression of BRAF was associated with markedly increased invasion into Matrigel compared with cells expressing RET/PTC3. The preferential induction of MMPs by BRAF could explain in part the more invasive behavior of thyroid cancers with BRAF mutations.

Differential expression of the components of the plasminogen activating system in human thyroid tumour derived cell lines and papillary carcinomas

We characterised the expression of the plasminogen activators (uPA and tPA), the uPA receptor (uPAR) and the PAs inhibitors (PAI-1 and PAI-2) in human thyroid cell lines derived from normal thyroid, follicular adenoma, follicular, papillary and anaplastic carcinomas. Urokinase PA activity was detected in the supernatant of normal thyrocytes and augmented in those of all tumour cells. Quantitative RT-PCR analysis showed that uPA, uPAR and PAI-1 mRNAs increased in all carcinoma cells. Similar results were found in 13 papillary thyroid carcinoma (PTC) tissues which were mirrored in Western blot experiments. A correlation was found between tumour size and uPA mRNA increase, and higher levels of uPA and uPAR mRNAs were found in metastatic PTC. In conclusion, thyroid carcinoma cell lines and PTC overexpress uPA, uPAR and PAI-1 and the correlation of uPA and its cognate receptor with tumour size and metastasis may suggest their potential prognostic relevance in thyroid cancer.

Expression of new human inorganic pyrophosphatase in thyroid diseases: its intimate association with hyperthyroidism

Inorganic pyrophosphatase (PPase) controls the level of inorganic pyrophosphate produced by biosynthesis of protein, RNA, and DNA. Thus, PPase is essential for life. PPase expression is unclear in the thyroid. We cloned a new human PPase, phospholysine phosphohistidine inorganic pyrophosphate phosphatase (LHPPase), and established a rabbit polyclonal anti-LHPPase antibody. This is the first study to determine the PPase expression by immunohistochemistry and Western blot. Intranuclear LHPPase expression of thyrocytes was enhanced most prominently in Graves' disease and autonomously functional thyroid nodule. To estimate a regulating factor of subcellular localization of LHPPase, we examined its expression of Graves' disease-derived thyrocytes in vitro with the disease-originated serum. Nuclear expression of LHPPase was lost in cultured thyrocytes even with the serum, while its cytoplasmic expression was retained. The data suggest that increased expression of LHPPase is associated with hyperthyroidism. Intranuclear expression of LHPPase may not be regulated by Graves' disease-derived serum factors.

Immunohistochemical separation of follicular variant of papillary thyroid carcinoma from follicular adenoma

The accurate diagnosis of differentiated thyroid tumors is very important for clinical management of patients. The histopathological distinction between some types of differentiated thyroid tumors can be very difficult even for experienced pathologists. We used immunohistochemical markers from published data obtained from DNA expression profiling, tissue microarray analysis, and immunohistochemistry to analyze a series of 157 thyroid tumors and 5 normal thyroids. These analyses showed that several antibodies were useful in distinguishing follicular adenomas from follicular variant of papillary thyroid carcinomas including HBME-1, CITED1, galectin-3, cytokeratin 19, and S100A4 (p < 0.0001). A combination of markers consisting of a panel of HBME-1, galectin-3, and CK19 or a panel of HBME-1, CITED1, and galectin-3 was usually most effective in distinguishing follicular adenoma from follicular variant of papillary thyroid carcinoma. Because individual tumors may not express some of these markers, the use of a panel of antibodies is recommended. These results indicate that some individual antibodies or a panel of antibodies combined with histopathological analysis can be useful in separating follicular adenoma (FA) from follicular variant of papillary thyroid carcinoma (FVPTC).

Expression of N-acetyl transferase human and human Arrest defective 1 proteins in thyroid neoplasms

Protein acetylation is an important posttranslational modification regulating oncogenesis, apoptosis and cell cycle. NATH (N-acetyl transferase human) is overexpressed at the mRNA level in papillary thyroid carcinomas relative to non-neoplastic thyroid tissue. The NATH protein has recently been demonstrated to be the partner of hARD1 (human Arrest defective 1) and this complex acetylates the N-termini of proteins. ARD1 has also been implicated in the destabilization of the transcription factor HIF-1alpha (hypoxia inducible factor-1alpha). Using human thyroid papillary carcinoma biopsies and NATH- and hARD1-specific antibodies, we examined the levels of endogenous NATH and hARD1 proteins in 27 patients. We demonstrate that NATH protein level is upregulated in neoplastic versus non-neoplastic tissue in good accordance with our previous mRNA findings. In all tumors in which NATH was downregulated compared to non-neoplastic tissue, the hARD1 protein level was concomitantly reduced. SiRNA-mediated knockdown of NATH resulted in decreased levels of hARD1 protein. Taken together, these results suggest that NATH positively affects the level of hARD1 protein both in vivo and in cell cultures.