Development Of Thyroid Tumors Research Articles

Atrophic changes in thyroid tumors are strong indicators of underlying DICER1 mutations: a bi-institutional genotype–phenotype correlation study

Somatic and biallelic DICER1 mutations are reported in subsets of thyroid tumors, supporting the role of this gene in thyroid tumor development. As recent studies have brought attention to macrofollicular patterns, atrophic changes, and papillary structures as being associated with DICER1 mutations, we sought to explore these observations in a bi-institutional cohort. A total of 61 thyroid lesions (54 tumors and 7 cases of thyroid follicular nodular disease; TFND), including 26 DICER1 mutated and 35 DICER1 wildtype controls were subjected to histological re-investigation and clinical follow-up. DICER1-mutated lesions showed a statistically significant association with younger age at surgery (29.2 ± 12.5 versus 51.3 ± 18.8, p = 0.0001), a predominant macrofollicular growth pattern (20/26 mutated cases versus 18/35 wildtype; p = 0.01) and atrophic changes (20/26 mutated cases versus 2/35 wildtype; p = 0.0001). Similar results were obtained when excluding TFND cases. We also present clinical and histological triaging criteria for DICER1 sequencing of thyroid lesions, which led to the identification of DICER1 variants in 16 out of 26 cases (62%) when followed. Among these, 3 out of 12 cases with available data were found to carry a constitutional DICER1 mutation. This observation suggests that the majority of DICER1 mutations are somatic—however implies that sequencing of constitutional tissues could be clinically motivated. We conclude that DICER1 mutations are amassed in younger patients with macrofollicular-patterned tumors and, most strikingly, atrophic changes. Given the rate of constitutional involvement, our findings could be of clinical value, allowing the pathologist to triage cases for genetic testing based on histological findings.

Prevalence, Molecular Landscape, and Clinical Impact of DICER1 and DGCR8 Mutated Follicular-Patterned Thyroid Nodules.

Mutations in micro-RNA (miRNA) regulators DICER1 and DGCR8 have recently been uncovered, revealing a potential novel mechanism driving thyroid tumor development. However, the true frequency of these hotspot mutations in follicular-patterned thyroid tumors (FTs) and their relation to established driver gene events remain elusive. A total of 440 FTs from 2 institutions were interrogated for DICER1, DGCR8, and RAS family hotspot mutations using Sanger sequencing. Whole-exome sequencing was also performed to identify additional driver gene aberrations in DICER1/DGCR8-mutant cases. Subsets of cases were further analyzed using miRNA expression profiling, and key dysregulated miRNAs were validated as markers of DICER1 mutations using quantitative RT-PCR analysis. The Cancer Genome Atlas (TCGA) database was also probed for DICER1/DGCR8 mutations and miRNA dysregulation. Fourteen (3.2%) and 4 (1%) FTs harbored DICER1 and DGCR8 hotspot mutations, respectively, in the combined cohort, and no cases with normal tissue available were found to exhibit a constitutional variant. Two DGCR8-mutant cases also harbored oncogenic RAS mutations. Whole-exome sequencing analysis did not identify additional driver gene events in DICER1/DGCR8-positive cases. Comprehensive miRNA expression profiling revealed a unique pattern of dysregulated miRNAs in DICER1/DGCR8-mutant cases compared with wild-type lesions. Moreover, DICER1-mutant cases showed a remarkable reduction of 5' arm miRNAs, findings corroborated in the TCGA cohort. DICER1 and DGCR8 hotspot mutations are rare in unselected cohorts of FTs, and mutated cases exhibit a specific miRNA profile. Although DGCR8 mutations may coexist with established RAS gene alterations, FTs with DICER1 variants were devoid of other driver gene events.

Cancer-associated fibroblast-derived periostin promotes papillary thyroid tumor growth through integrin-FAK-STAT3 signaling.

Background: Periostin (POSTN) is a critical extracellular matrix protein in various tumor microenvironments. However, the function of POSTN in thyroid cancer progression remains largely unknown. Methods: Postn and Rag1 knock-out mice and orthotopic mouse models were used to determine the role of POSTN on papillary thyroid tumor progression. Immunofluorescence, cell co-culture, fluorescence in situ hybridization, chromatin immunoprecipitation assay, recombinant protein and inhibitor treatment were performed to explore the underlying mechanisms of POSTN-promoted papillary thyroid tumor growth. Results: POSTN is up-regulated in papillary thyroid tumors and negatively correlates with the overall survival of patients with thyroid cancer. Cancer-associated fibroblast (CAF)-derived POSTN promotes papillary thyroid tumor growth in vivo and in vitro. POSTN deficiency in CAFs significantly impairs CAF-promoted papillary thyroid tumor growth. POSTN promotes papillary thyroid tumor cell proliferation and IL-4 expression through integrin-FAK-STAT3 signaling. In turn, tumor cell-derived IL-4 induces the activation of CAFs and stimulates POSTN expression by activating STAT6. We reveal the crucial role of CAF-derived POSTN and tumor cell-derived IL-4 in driving the development of papillary thyroid tumors through the POSTN-integrin-FAK-STAT3-IL-4 pathway in tumor cells and IL-4-STAT6-POSTN signaling in CAFs. Conclusion: Our findings underscore the significance of POSTN and IL-4 as critical molecular mediators in the dynamic interplay between CAFs and tumor cells, ultimately supporting the growth of papillary thyroid tumors.

Organochlorine pesticides induce thyroid tumors through oxidative stress; an in vivo and in silico study.

Thyroid disease is one of the most common endocrine problems around the world. Among the numerous factors, exposure to environmental elements such as pesticides is associated with an increase in the incidence of thyroid disorders. The aim of the present study was to investigate the role of organochlorine pesticides (OCPs) in induction of oxidative stress (OS) and development of thyroid tumors. This case-control study was conducted on 61 patients with papillary thyroid carcinoma (PTC), 70 patients with benign thyroid nodules (BTN), and 73 healthy individuals as control. Seven derived OCPs residues measured by gas chromatography (GC), and enzyme activities of acetylcholinesterase (AChE), superoxide dismutase3 (SOD3), catalase (CAT), glutathione peroxidase3 (GPx3) and paraoxonase1 (PON1) and also, non-enzymatic antioxidant including; malondialdehyde (MDA), total antioxidant capacity (TAC), protein carbonyl (PC), and nitric oxide (NO) biomarkers in all participants were investigated. Furthermore, all of the above enzymes were docked against measured OCPs. The results revealed that β-HCH, γ-HCH, 2,4 DDE, 4,4 DDE, 2,4-DDT, and 4,4-DDT levels along with MDA, NO, and PC levels were elevated, while AChE, SOD3, GPx3, CAT, and PON1 activities and TAC levels were decreased in the PTC and BTN groups compared with the control group. Therefore, OCPs might play a role in the development of thyroid tumors through several mechanisms including generation of OS. Importantly, in silico analysis confirmed the in vivo findings.

Adrenomedullin2 stimulates progression of thyroid cancer in mice and humans under nutrient excess conditions.

Thyroid cancer is associated with genetic alterations, e.g. BRAFV600E , which may cause carcinomatous changes in hormone-secreting epithelial cells. Epidemiological studies have shown that overnutrition is related to the development and progression of cancer. In this study, we attempted to identify the cell nonautonomous factor responsible for the progression of BRAFV600E thyroid cancer under overnutrition conditions. We developed a mouse model for inducible thyrocyte-specific activation of BRAFV600E , which showed features similar to those of human papillary thyroid cancer. LSL-BrafV600E ;TgCreERT2 showed thyroid tumour development in the entire thyroid, and the tumour showed more abnormal cellular features with mitochondrial abnormalities in mice fed a high-fat diet (HFD). Transcriptomics revealed that adrenomedullin2 (Adm2) was increased in LSL-BrafV600E ;TgCreERT2 mice fed HFD. ADM2 was upregulated on the addition of a mitochondrial complex I inhibitor or palmitic acid with integrated stress response (ISR) in cancer cells. ADM2 stimulated protein kinase A and extracellular signal-regulated kinase in vitro. The knockdown of ADM2 suppressed the proliferation and migration of thyroid cancer cells. We searched The Cancer Genome Atlas and Genotype-Tissue Expression databases and found that increased ADM2 expression was associated with ISR and poor overall survival. Consistently, upregulated ADM2 expression in tumour cells and circulating ADM2 molecules were associated with aggressive clinicopathological parameters, including body mass index, in thyroid cancer patients. Collectively, we identified that ADM2 is released from cancer cells under mitochondrial stress resulting from overnutrition and acts as a secretory factor determining the progressive properties of thyroid cancer. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

RB depletion is required for the continuous growth of tumors initiated by loss of RB.

The retinoblastoma (RB) tumor suppressor is functionally inactivated in a wide range of human tumors where this inactivation promotes tumorigenesis in part by allowing uncontrolled proliferation. RB has been extensively studied, but its mechanisms of action in normal and cancer cells remain only partly understood. Here, we describe a new mouse model to investigate the consequences of RB depletion and its re-activation in vivo. In these mice, induction of shRNA molecules targeting RB for knock-down results in the development of phenotypes similar to Rb knock-out mice, including the development of pituitary and thyroid tumors. Re-expression of RB leads to cell cycle arrest in cancer cells and repression of transcriptional programs driven by E2F activity. Thus, continuous RB loss is required for the maintenance of tumor phenotypes initiated by loss of RB, and this new mouse model will provide a new platform to investigate RB function in vivo.

High Prevalence of DICER1 Mutations and Low Frequency of Gene Fusions in Pediatric Follicular-Patterned Tumors of the Thyroid.

Follicular-patterned tumors of the thyroid in the adult population frequently harbor RAS mutations or PAX8-PPARG rearrangement, but little is known about molecular profiles in the pediatric patients with thyroid tumors, which is rare. To identify the molecular profile of pediatric follicular-patterned tumors, we enrolled 41 pediatric patients with follicular-patterned tumors from two institutions. We did next-generation sequencing using a mutation panel targeting 49 thyroid-tumor-related genes and a fusion panel targeting 88 types of thyroid-related gene fusions. We identified nonsynonymous mutations in at least one target gene in most of the tumors (28/41, 68%). Somatic DICER1 mutations (22%, n = 9) were the most common genetic alteration, followed by mutations of NRAS (15%), FGFR3 (15%), PTEN (12%), and STK11 (10%). Infrequent genetic alterations (≤ 5% of all cases) included mutations of HRAS, APC, TSHR, CTNNB1, TP53, EIF1AX, FGFR4, GNAS, RET, and SOS1, and gene fusion of THADA-IGF2BP3. DICER1 and RAS mutations were mutually exclusive. No patients had tumors related to the DICER1 syndrome or the Cowden syndrome. There was no significant difference in total mutation burden or distribution between follicular adenoma and follicular carcinoma. In the literature, the DICER1 mutation has been reported in 20 to 53% of pediatric patients with follicular-patterned tumors. In conclusion, our study reinforces the role of the DICER1 mutation in the development of pediatric thyroid tumors. Gene fusions rarely occur in pediatric follicular-patterned tumors. Mutation or gene fusion alone could not distinguish benign from malignant follicular-patterned tumors in pediatric patients.

Targeting the Sonic Hedgehog Pathway to Suppress the Expression of the Cancer Stem Cell (CSC)-Related Transcription Factors and CSC-Driven Thyroid Tumor Growth.

Simple SummaryPoorly differentiated and anaplastic thyroid cancers respond poorly to surgery, radiation, and hormone therapy. Cancer stem cells play an important role in tumor growth, drug resistance, and recurrence. This study focuses on how the sonic hedgehog (Shh) pathway maintains thyroid cancer stem cell self-renewal and whether it can be targeted for anticancer therapy. The authors report that the Shh pathway regulates the expression of BMI1 and SOX2, two genes involved in stem cell self-renewal, and that targeting the Shh pathway has little effect on thyroid tumor xenografts but can inhibit the growth of tumor xenografts derived from thyroid cancer stem cells. This study advances the knowledge on how thyroid cancer stem cells regenerate and highlights the potential therapeutic values of targeting the Shh pathway. The sonic hedgehog (Shh) pathway plays important roles in tumorigenesis, tumor growth, drug resistance, and metastasis. We and others have reported earlier that this pathway is highly activated in thyroid cancer. However, its role in thyroid cancer stem cell (CSC) self-renewal and tumor development remains incompletely understood. B lymphoma Mo-MLV insertion region 1 homolog (BMI1) and SRY-Box Transcription Factor 2 (SOX2) are two CSC-related transcription factors that have been implicated in promoting CSC self-renewal. The objective of our current investigation was to determine the role of the Shh pathway in regulating BMI1 and SOX2 expression in thyroid cancer and promoting thyroid tumor growth and development. Here we report that inhibition of the Shh pathway by Gli1 siRNA or by cyclopamine and GANT61 reduced BMI1 and SOX2 expression in SW1736 and KAT-18 cells, two anaplastic thyroid cancer cell lines. The opposite results were obtained in cells overexpressing Gli1 or its downstream transcription factor Snail. The Shh pathway regulated SOX2 and BMI1 expression at a transcriptional and post-transcriptional level, respectively. GANT61 treatment suppressed the growth of SW1736 CSC-derived tumor xenografts but did not significantly inhibit the growth of tumors grown from bulk tumor cells. Clinicopathological analyses of thyroid tumor specimens by immunohistochemical (IHC) staining revealed that BMI1 and SOX2 were highly expressed in thyroid cancer and correlated with Gli1 expression. Our study provides evidence that activation of the Shh pathway leads to increased BMI1 and SOX2 expression in thyroid cancer and promotes thyroid CSC-driven tumor initiation. Targeting the Shh pathway may have therapeutic value for treating thyroid cancer and preventing recurrence.

Study of BRAF and RAS Mutations in Thyroid Nodules with Indeterminate Cytology and Papillary Thyroid Cancer

OBJECTIVES Thyroid cancer Treatment decision-making is often guided by tumor tissue molecular analysis. The aim of this study was the detection of BRAF, NRAS and HRAS mutations in Georgian patients with thyroid cancer and determination of the frequency of these mutations in the respective populations. SETTING Diagnostic molecular laboratory located in Tbilisi, Georgia. PARTICIPANTS 116 patients with thyroid cancer participated in the study. PRIMARY AND SECONDARY OUTCOME MEASURES Genetic change is the main force of thyroid tumor development, based on new methods of managing thyroid cancer. The latest significant genetic discovery in thyroid cancer is the BRAF-T1799A (V600E) transformation (the gene for B-type RAF kinase, BRAF). Since the initial report of this breakthrough in thyroid cancer years ago, rapid progress has been made. The BRAF mutation is the most common genetic change in thyroid cancer. BRAF and NRAS mutations are frequent genetic alterations found in thyroid nodules. These molecular markers establish a differential diagnosis and facilitate clinical decision-making. Prevalence of thyroid nodule-associated mutations has not been studied in Georgia. We evaluated BRAF, NRAS and HRAS mutations in Georgian patients with indeterminate cytology or diagnosed with papillary thyroid cancer (PTC). RESULTS BRAF (V600E), NRAS (G12C, G12D, Q61R, and Q61K) and HRAS (G12C, G13R, and Q61R) were determined in the DNA extracted from fine needle aspirate specimens. In total, 116 patient samples were analyzed using competitive-specificTaqMan PCR (Cast PCR TM). In these samples, 36 were diagnosed as papillary thyroid carcinoma, and 80 were indeterminate by Bethesda system for reporting thyroid cytopathology (BSRTC III-V). BRAF (V600E) mutation was the most frequent genetic alteration found in 31% of all analyzed samples. Specifically, this mutation was present in 61% of PTC cases and 18% of cases classified as indeterminate (BSRTC III-V). NRAS mutations were present in 16% of PTC and 30% of indeterminate cytology samples. NRAS G12D and Q61R were most prevalent at 36.6% and 40% of all NRAS mutations. BSRTC IV category of indeterminate cytology had the highest frequency of NRAS mutations at 43%. From analyzed samples, HRAS (Q61R) mutation was present in only one PTC case.

MiR-144-3p Contributes to the Development of Thyroid Tumors Through the PTEN/PI3K/AKT Pathway.

PurposeTo explore the expression and related mechanism of miR-144-3p and PTEN in thyroid cancer (TC).Patients and MethodsFrom February 2018 to November 2019, 62 patients with TC who received treatment in Chengwu Hospital Affiliated to Shandong First Medical University were collected. TC cells and human normal thyroid HTori-3 cells were purchased. The miR-144-3p-inhibitor, miR-144-3p-mimics, empty vector plasmid (miRNA-NC), si-PTEN and sh-PTEN were transfected into B-CPAP and HTh-7 cells. The expressions of miR-144-3p and PTEN in the specimens were tested by qRT-PCR (qP). WB was used to detect the expression of Bcl-2, APR3, N-cadherin, Slug and Bax proteins in the cells. The cell proliferation was detected by MTT, and the cell invasion was tested by Transwell. The apoptosis was detected by flow cytometry (FC).ResultsmiR-144-3p was highly expressed and PTEN was weakly expressed in the patients’ tissues. The AUC of miR-144-3p and PTEN was >0.8. miR-144-3p and PTEN were related to TNM stage, lymph node metastasis and differentiation degree of TC patients. The B-CPAP and HTh-7 with the greatest expression differences were selected for transfection. The expression of miR-144-3p in miR-144-3p-inhibitor group was significantly lower than that in NC group (P<0.01), and that in miR-144-3p-mimics group was significantly higher than that in NC group (p < 0.01). The expression of PTEN in si-PTEN group was significantly lower than that in NC group (P<0.01), while that in sh-PTEN group was significantly higher than that in NC group (P<0.01). Silencing miR-144-3p and overexpressing PTEN could inhibit cell proliferation, invasion and promote apoptosis. WB detection uncovered that silencing the miR-144-3p expression and overexpressing PTEN could inhibit the PI3K, Akt, p-AKT, Bcl-2, APR3 and cyclinD1 proteins and promote the up-regulation of Bax expression. Rescue experiments revealed that the cell proliferation, invasion and apoptosis were not different from NC after co-transfection of miR-144-3p-mimics+sh-PTEN and miR-144-3p-inhibitor+si-PTEN into B-CPAP and HTh-7.ConclusionInhibition of miR-144-3p expression can up-regulate PTEN and affect cell proliferation, invasion and apoptosis, which may be a potential therapeutic target for TC.

157P Search for new markers of thyroid carcinogenesis associated with ER, AR and PR receptor status

In recent years a plethora of new investigating methods have appeared, which allows us to fully and thoroughly observe thyroid diseases. Though, final diagnosis at the pre-operative stage remains to be difficult. Fine-needle aspiration biopsy used for pre-surgical diagnosis doesn't distinguish benign follicular tumors (adenoma) from malignant ones (carcinoma). It is known that thyroid cancer is more common in women (approximately 1: 3), but more aggressive forms of thyroid cancer are common in men. This indicates that estrogen, progesterone and androgen receptors (ER, PR and AR) can play an important role in carcinogenesis of the thyroid gland. Also miRNAs, which role in thyroid cancerogenesis processes is being actively studied, are in interest. However, certain attempts to connect disruptions in receptor expression with disruptions in miRNA expression during thyroid cancerogenesis haven’t been made yet. The expression of the miRNAs and their target-genes was analyzed by RT-PCR in 90 samples of thyroid neoplasms (TN). To find new thyroid cancer markers, we analyzed the expression levels of ER, PR, AR, miRNAs for which these receptors are targets, as well as other target genes of selected miRNAs (ID4, FOXE1, VEGFA, BCL2, ITGB3, SLC24A4, TSHR) in TN. The results has shown that benign TN can be distinguished from malignant ones by expression levels of miRNA-181a, miRNA-205 and their target genes – PR, VEGFA, BCL2, TSHR. Markers, that allow to distinguish follicular variant of papillary thyroid cancer from follicular and papillary carcinomas, have been identified as well. Moreover, it has been shown that miRNA-22 can be marker for lymph node metastases: miRNA level is reduced in patients with metastases. Furthermore, based on the results, it can be assumed that there is a relationship between miRNA-222, miRNA-19b, miRNA-22, miRNA-193b, miRNA-205, miRNA-181a, miRNA-378a levels and ER, PR, AR expression levels during thyroid tumor development. Markers that distinguish between different types of thyroid tumors have been identified (miRNA-181a, miRNA-205, PR, VEGFA, BCL2 and TSHR). The miRNA-22 level was shown to be associated with N stage.

Progress of risk factors for thyroid tumors

In recent years, both benign and malignant thyroid tumors have grown rapidly in the world, and have become one of the most common tumors in the endocrine system. At present, the pathogenesis of thyroid tumor is still unclear, but more and more studies have found that certain factors are related to the occurrence and development of thyroid tumors. It is of great significance to summarize and analyze these risk factors. This article reviews the research progress of its risk factors reported in recent years, so as to provide a basis for the accuracy and scientific prevention and control of thyroid tumors.

Diagnostic significance of DNA methylation of PTEN and DAPK in thyroid tumors.

DNA Methylation of the tumour suppressor gene leading to gene silencing plays an important role in thyroid tumour development. The purpose was to determine the DNA methylation status of phosphatase and tensin homolog (PTEN) and death-associated protein kinase (DAPK) in patients with thyroid nodules and to explore whether they can be used as molecular diagnostic tools to differentiate benign and malignant thyroid nodules. Thyroid tissue and blood samples were obtained from normal healthy individuals (controls) and patients suffering from clinically diagnosed thyroid nodular disease [papillary thyroid carcinoma (PTC), adenoma and nodular goitre]. DNA methylation level, mRNA expression and protein expression of PTEN and DAPK in the thyroid tissues and peripheral blood were detected using methylation-specific PCR, semi-quantitative reverse transcription PCR and Western blot, respectively. Diagnostic sensitivity, specific and accuracy of detection were evaluated between blood and thyroid tissue. There was a significant increase in the level of DNA methylation of PTEN and DAPK in PTC (P<.05) compared with controls and other types of thyroid nodules. Levels of the mRNA of both PTEN and DAPK were lower in PTC in both peripheral blood and tissue samples compared with controls, while there was concomitant decrease of both PTEN and DAPK protein expression in PTC tissues (P<.05). There was no significant difference in diagnostic specificity, sensitivity and accuracy between blood sample and thyroid tissues. Hypermethylated status of both PTEN and DAPK in peripheral blood and tissue samples can be useful biomarkers for clinical diagnosis and, distinguishing of benign and malignant thyroid nodules.

Effect of single-nucleotide polymorphism in TERT promoter on follicular thyroid tumor development.

Follicular thyroid neoplasm is a common tumor, and consists of follicular thyroid adenoma (FTA) and carcinoma (FTC). The mechanisms of tumor development of FTA and FTC are not well-understood. Single-nucleotide polymorphisms (SNPs) and point mutations in the telomerase reverse transcriptase (TERT) promoter have been associated with tumor development of many cancers. In order to clarify the significance of TERT promoter SNPs and mutations, including rs2853669 (-245T>C), C228T, and C250T, we analyzed 59 FTA patients and 19 FTC patients. Rs2853669 was found in 67.8% (40/59) and 57.9% (11/19) of FTAs and FTCs, respectively, and homozygous rs2853669 (CC) was more frequently found in FTC than in FTA. Furthermore, in FTA, rs2853669 was significantly associated with tumor size greater than 2.0 cm (P < 0.05). C228T was found in 5.1% and 36.8% of FTAs and FTCs, respectively. Frequencies of rs2853669 or/and C228T mutation were 71.2% in FTAs and 73.7%, in FTCs, and were significantly associated with larger tumor sizes in FTAs (P < 0.05). Rs2853669 is considered to be associated with tumor development in FTA and FTC.

Long Non-coding RNA Expression in Anaplastic Thyroid Carcinomas.

Long non-coding RNAs (lncRNAs) participate in transcription and in epigenetic or post-transcriptional regulation of gene expression. They also have roles in epithelial to mesenchymal transition and in carcinogenesis. Because lncRNAs may also have a role in thyroid cancer progression, we examined a group of thyroid tumors which included papillary thyroid carcinomas and anaplastic thyroid carcinomas to determine the specific lncRNAs that were upregulated during thyroid tumor progression. An RT2 Profiler PCR Array Human Cancer Pathway Finder consisting of 84 lncRNAs (Qiagen) and fresh tissues of normal thyroid, PTCs, and ATCs with gene expression profiling was used to determine genes upregulated and downregulated in ATCs. Two of the most highly upregulated genes, prostate cancer antigen 3 (PCA3) and HOX antisense intergenic RNA myeloid 1 (HOTAIRM1 or HAM-1), were selected for further studies using a thyroid tissue microarray(TMA) with formalin-fixed paraffin-embedded tissues of normal thyroid (NT, n= 10), nodular goiters (NG, n= 10), follicular adenoma (FA, n= 32), follicular carcinoma (FCA, n= 28), papillary thyroid carcinoma (PTC, n= 28), follicular variant of papillary thyroid carcinoma (FVPTC, n = 28), and anaplastic thyroid carcinoma (ATC, n= 10). TMA sections were analyzed by in situ hybridization (ISH) using RNAscope technology. The results of ISH analyses were imaged with Vectra imaging technology and quantified with Nuance® and inForm® software. The TMA analysis was validated by qRT-PCR using FFPE tissues for RNA preparation. Cultured thyroid carcinoma cell lines (n= 7) were also used to analyze for lncRNAs by qRT-PCR. The results showed 11 lncRNAs upregulated and 7 downregulated lncRNAs more than twofold in the ATCS compared with PTCs. Two of the upregulated lncRNAs, PCA3 and HAM-1, were analyzed on a thyroid carcinoma TMA. There was increased expression of both lncRNAs in ATCs and PTCs compared with NT after TMA analysis. qRT-PCR analyses showed increased expression of both lncRNAs in ATCs compared with NT and PTCs. Analyses of these lncRNAs from cultured thyroid carcinoma cell lines by qRT-PCR showed the highest levels of lncRNA expression in ATCs. TGF-β treatment of cultured PTC and ATC cells for 21days led to increased expression of PCA3 lncRNA in both cell lines by day 14. These results show that the lncRNAs PCA3 and HAM-1 are upregulated during thyroid tumor development and progression and may function as oncogenes during tumor progression.

Association of –634 G > C VEGF-A polymorphism in thyroid cancer patients in North West of Iran

Thyroid tumors with prevalence of 10–67% in the world are common among adults. Before the tumor can grow >1–2 mm, it needs blood vessels to supply nutrients and oxygen. The producing of vascular endothelial growing factor by the tumor, stimulates the angiogenesis pathway and producing new blood vessels around the tumor. It is therefore considered as a factor in the prognosis and development of thyroid tumors. The present study investigated VEGF (− 634G > C) gene polymorphism with thyroid tumors susceptibility in the northwest of Iran. This study was performed on 112 patients with thyroid tumors and 132 normal control subjects from Iranian-Azeri population in a case-control study. Genomic DNA was extracted from peripheral blood by salting out method. The genotypes were also determined by PCR-RFLP method. The Alibaba and RNA secondary structure analysis were used to predict that how the binding of some transcription factors affected by this polymorphism. This study indicated that VEGF (− 634G > C) polymorphism in over dominant model (P = .002) was significantly associated with increased risk of thyroid tumors. Moreover, the recessive model of this polymorphism (P = .002) had a protective effect against thyroid tumors. It was found that the sp1 transcription factor binding to −634 position was influenced in presence of G and C alleles of this polymorphism. The results of this study showed that the VEGF −634G > C SNP may be associated with the susceptibility to thyroid tumors in the northwest of Iran. It is also found that how G allele of this polymorphism can be increase the VEGF translation. If these results are confirmed in larger studies, the analysis of the VEGF (−634G > C) (rs2010963) gene polymorphism can be useful in determining the relative risk of tumor development.

Mouse Model of Thyroid Cancer Progression and Dedifferentiation Driven by STRN-ALK Expression and Loss of p53: Evidence for the Existence of Two Types of Poorly Differentiated Carcinoma.

Background: Thyroid tumor progression from well-differentiated cancer to poorly differentiated thyroid carcinoma (PDTC) and anaplastic thyroid carcinoma (ATC) involves step-wise dedifferentiation associated with loss of iodine avidity and poor outcomes. ALK fusions, typically STRN-ALK, are found with higher incidence in human PDTC compared with well-differentiated cancer and, as previously shown, can drive the development of murine PDTC. The aim of this study was to evaluate thyroid cancer initiation and progression in mice with concomitant expression of STRN-ALK and inactivation of the tumor suppressor p53 (Trp53) in thyroid follicular cells. Methods: Transgenic mice with thyroid-specific expression of STRN-ALK and biallelic p53 loss were generated and aged on a regular diet or with methimazole and sodium perchlorate goitrogen treatment. Development and progression of thyroid tumors were monitored by using ultrasound imaging, followed by detailed histological and immunohistochemical evaluation. Gene expression analysis was performed on selected tumor samples by using RNA-Seq and quantitative RT-PCR. Results: In mice treated with goitrogen, the first thyroid cancers appeared at 6 months of age, reaching 86% penetrance by the age of 12 months, while a similar rate (71%) of tumor occurrence in mice on regular diet was observed by 18 months of age. Histological examination revealed well-differentiated papillary thyroid carcinomas (PTC) (n = 26), PDTC (n = 21), and ATC (n = 8) that frequently coexisted in the same thyroid gland. The tumors were frequently lethal and associated with the development of lung metastasis in 24% of cases. Histological and immunohistochemical characteristics of these cancers recapitulated tumors seen in humans. Detailed analysis of PDTC revealed two tumor types with distinct cell morphology and immunohistochemical characteristics, designated as PDTC type 1 (PDTC1) and type 2 (PDTC2). Gene expression analysis showed that PDTC1 tumors retained higher expression of thyroid differentiation genes including Tg and Slc5a5 (Nis) as compared with PDTC2 tumors. Conclusions: In this study, we generated a new mouse model of multistep thyroid cancer dedifferentiation with evidence of progression from PTC to PDTC and ATC. Further, PDTC in these mice showed two distinct histologic appearances correlated with levels of expression of thyroid differentiation and iodine metabolism genes, suggesting a possibility of existence of two PDTC types with different functional characteristics and potential implication for therapeutic approaches to these tumors.

Vitamin C kills thyroid cancer cells through ROS-dependent inhibition of MAPK/ERK and PI3K/AKT pathways via distinct mechanisms.

Background: Vitamin C has been demonstrated to kill BRAF mutant colorectal cancer cells selectively. BRAF mutation is the most common genetic alteration in thyroid tumor development and progression; however, the antitumor efficacy of vitamin C in thyroid cancer remains to be explored.Methods: The effect of vitamin C on thyroid cancer cell proliferation and apoptosis was assessed by the MTT assay and flow cytometry. Xenograft and transgenic mouse models were used to determine its in vivo antitumor activity of vitamin C. Molecular and biochemical methods were used to elucidate the underlying mechanisms of anticancer activity of vitamin C in thyroid cancer.Results: Pharmaceutical concentration of vitamin C significantly inhibited thyroid cancer cell proliferation and induced cell apoptosis regardless of BRAF mutation status. We demonstrated that the elevated level of Vitamin C in the plasma following a high dose of intraperitoneal injection dramatically inhibited the growth of xenograft tumors. Similar results were obtained in the transgenic mouse model. Mechanistically, vitamin C eradicated BRAF wild-type thyroid cancer cells through ROS-mediated decrease in the activity of EGF/EGFR-MAPK/ERK signaling and an increase in AKT ubiquitination and degradation. On the other hand, vitamin C exerted its antitumor activity in BRAF mutant thyroid cancer cells by inhibiting the activity of ATP-dependent MAPK/ERK signaling and inducing proteasome degradation of AKT via the ROS-dependent pathway.Conclusions: Our data demonstrate that vitamin C kills thyroid cancer cells by inhibiting MAPK/ERK and PI3K/AKT pathways via a ROS-dependent mechanism and suggest that pharmaceutical concentration of vitamin C has potential clinical use in thyroid cancer therapy.

Reception of Sex Steroid Hormones in Thyroid Papillary Cancer Tissue and Relationship with Expression and Content of Transcription Factors Brn-3α and TRIM16.

We studied reception of sex steroid hormones in the tissues of thyroid papillary cancer and benign tumor. Enhanced expression of AR and ERβ mRNA reflected malignant tumor growth. Nuclear factors Brn-3α and TRIM16 modulating expression of steroid hormones play an important role in the development of thyroid tumors. It was found that the level of TRIM16 mRNA is associated with the expression of ERβ, which seems to be mediated by its antiestrogen effect.

Epstein-Barr virus and thyroid cancer: The role of viral expressed proteins.

Thyroid cancer is a common endocrine malignancy whose incidence has increased in recent years. Several internal and external risk factors are involved in the development of this cancer, such as infectious agents. Evidence supporting the role of viral infection as an etiology for the invasiveness of thyroid cancer is increasing. The aim of this study was to determine the presence of the Epstein-Barr virus (EBV) and the association between viral gene products and thyroid tumor development. Fifty-seven thyroid cancer specimens were collected from the same number of patients as well as 18 samples from healthy controls. The presence of the EBV genome and the genotyping was examined by polymerase chain reaction (PCR). Also, an enzyme-linked immunosorbent assayand real-time PCR were used to measure the expression levels of viral and cellular genes. The EBV DNA was detected in 71.9% of the samples, and it was also found that the presence of the EBV was associated with increasing development of thyroid tumor. Our results demonstrated that EBV infection may play a role in the development of thyroid tumor.