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In the search for novel effective compounds to use in thyroid cancer (TC) unresponsive to current treatment, attention has recently focused on plant-derived compounds with anticancer activity. In this review, we discuss the preclinical studies demonstrating phytochemical activity against thyroid cancer cells. In particular, we describe their antiproliferative properties or ability to re-induce iodine retention, thus supporting their potential use as single agents or adjuvants in radioiodine-resistant thyroid cancer treatment.

Purpose: Several studies have shown that different tumour types sharing a driver gene mutation do not respond uniformly to the same targeted agent. Our aim was to use an unbiased network-based approach to investigate this fundamental issue using BRAF mutant tumours and the BRAF inhibitor vemurafenib. Methods: We applied SWIM, a software able to identify putative regulatory (switch) genes involved in drastic changes to the cell phenotype, to gene expression profiles of different BRAF mutant cancers and their normal counterparts in order to identify the switch genes that could potentially explain the heterogeneity of these tumours' responses to vemurafenib. Results: We identified lung adenocarcinoma as the tumour with the highest number of switch genes (298) compared to its normal counterpart. By looking for switch genes encoding for kinases with homology sequences similar to known vemurafenib targets, we found that thyroid cancer and lung adenocarcinoma have a similar number of putative targetable switch gene kinases (5 and 6, respectively) whereas colorectal cancer has just one. Conclusions: We are persuaded that our network analysis may aid in the comprehension of molecular mechanisms underlying the different responses to vemurafenib in BRAF mutant tumours.

Cancer stem-like cells (CSCs) have self-renewal abilities responsible for cancer progression, therapy resistance, and metastatic growth. The glioblastoma stem-like cells are the most studied among CSC populations. A recent study identified four transcription factors (SOX2, SALL2, OLIG2, and POU3F2) as the minimal core sufficient to reprogram differentiated glioblastoma (GBM) cells into stem-like cells. Transcriptomic data of GBM tissues and cell lines from two different datasets were then analyzed by the SWItch Miner (SWIM), a network-based software, and FOSL1 was identified as a putative regulator of the previously identified minimal core. Herein, we selected NTERA-2 and HEK293T cells to perform an in vitro study to investigate the role of FOSL1 in the reprogramming mechanisms. We transfected the two cell lines with a constitutive FOSL1 cDNA plasmid. We demonstrated that FOSL1 directly regulates the four transcription factors binding their promoter regions, is involved in the deregulation of several stemness markers, and reduces the cells’ ability to generate aggregates increasing the extracellular matrix component FN1. Although further experiments are necessary, our data suggest that FOSL1 reprograms the stemness by regulating the core of the four transcription factors.

Angiopoietin-like proteins, namely ANGPTL3-4-8, are known as regulators of lipid metabolism. However, recent evidence points towards their involvement in the regulation of adipose tissue function. Alteration of adipose tissue functions (also called adiposopathy) is considered the main inducer of metabolic syndrome (MS) and its related complications. In this review, we intended to analyze available evidence derived from experimental and human investigations highlighting the contribution of ANGPTLs in the regulation of adipocyte metabolism, as well as their potential role in common cardiometabolic alterations associated with adiposopathy. We finally propose a model of ANGPTLs-based adipose tissue dysfunction, possibly linking abnormalities in the angiopoietins to the induction of adiposopathy and its related disorders.

Whole exome sequencing (WES) was used to investigate two Italian siblings with wild-type RET genotype, who developed medullary thyroid cancers (MTCs) and, later, primary prostate and breast cancers, respectively. The proband's MTC harbored a p.Met918Thr RET mutation; his sister's MTC was RET/RAS wild-type. Both siblings had a germline mutation (p.Arg417Gln) in the extracellular Sema domain of the proto-oncogene MET. Experiments involving ectopic expression of MET p.Arg417Gln in MET-negative T47D breast cancer cells documented the mutant receptor's functionality and its ability to enhance cell migration and invasion. Our findings highlight a possible link between MET germline mutations and MTCs and suggest that MET p. Arg417Gln may promote an invasive malignant phenotype. The possibility that MTC can be driven/co-driven by a MET mutation has potential management implications, since the tyrosine-kinase inhibitor cabozantinib-approved for treating advanced MTCs-is a specific MET inhibitor.

Deciding whether patients with a cytologically indeterminate thyroid nodule should be referred for surgery or for active surveillance is an important challenge for clinicians. The aim of this study was to evaluate the performance of a novel dual-component molecular assay as an ancillary molecular method for resolving indeterminate thyroid nodule cytology. We selected 156 thyroid nodules from those that had undergone fine-needle aspiration processed by liquid-based cytology and surgical resection between June 2016 and December 2017. The sample set included 63 nodules cytologically classified as indeterminate, and 93 other nodules randomly selected from those with non-diagnostic, benign, suspicious, or malignant cytology. Nucleic acids from each nodule were subjected to next-generation sequencing analysis for mutation detection in 23 genes and to digital polymerase chain reaction (PCR) evaluation for miR-146b-5p expression levels. Used alone, mutation analysis in the indeterminate subset (cancer prevalence: 22.5%) displayed high sensitivity (89%) and NPV (96%). In contrast, the miR-146b-5p assay offered high specificity (93%) and PPV (93%). Combined use of both analyses improved panel performance by eliminating false-negative results. These preliminary data suggest that a dual-component molecular test can increase the diagnostic accuracy of thyroid cytology alone by reducing the number of nodules that will be classified as indeterminate and increasing those that can be reliably classified as benign. If these findings are confirmed, this test can be considered for use in clinical practice and is expected to reduce diagnostic surgery and health care costs, and to improve patient quality of life.

The identification of somatic mutations in cancer specimens enables detection of molecular markers for personalized treatment. We recently developed a novel molecular assay and evaluated its clinical performance as an ancillary molecular method for indeterminate thyroid nodule cytology. Herein we describe the analytical validation of the novel targeted next-generation sequencing (NGS) assay in thyroid samples from different sources. We present validation data of a novel NGS-based panel on 463 thyroid samples, including 310 fine-needle aspiration (FNA) specimens from different sources (FNA collected in preservative solution, liquid-based, and stained smears), 10 fresh frozen, and 143 formalin-fixed paraffin-embedded (FFPE) thyroid tissue specimens. Sequencing performance in the different samples was evaluated along with reproducibility, repeatability, minimum nucleic acid input to detect variants, and analytical sensitivity of the assay. All thyroid samples achieved high sequencing performance, with a mean base coverage depth ranging from 2228 × (in liquid-based FNA) to 3661 × (in FNA stained smears), and coverage uniformity ranging from 86% (in FFPE) to 95% (in FNA collected in preservative solution), with all target regions covered above the minimum depth required to call a variant (500×). The minimum nucleic acid input was 1 ng. Analytic sensitivity for mutation detection was 2–5% mutant allele frequency. This validation study of a novel NGS-based assay for thyroid nodules demonstrated that the assay can be reliably used on multiple thyroid sample types, including FNA from different sources and FF and FFPE thyroid samples, thus providing a robust and reliable assay to genotype thyroid nodules, which may improve thyroid cancer diagnosis and care.

Optimal management of patients with thyroid cancer requires the use of sensitive and specific biomarkers. For early diagnosis and effective follow-up, the currently available cytological and serum biomarkers, thyroglobulin and calcitonin, present severe limitations. Research on microRNA expression in thyroid tumors is providing new insights for the development of novel biomarkers that can be used to diagnose thyroid cancer and optimize its management. In this review, we will examine some of the methods commonly used to detect and quantify microRNA in biospecimens from patients with thyroid tumor, as well as the potential applications of these techniques for developing microRNA-based biomarkers for the diagnosis and prognostic evaluation of thyroid cancers.

H&uuml, rthle cell carcinomas (HCC) are rare differentiated thyroid cancers that display low avidity for radioactive iodine and respond poorly to kinase inhibitors. Here, using next-generation sequencing, we analyzed the mutational status of primary tissue and poorly differentiated metastatic tissue from two HCC patients. In both cases, metastatic tissues harbored a mutation of SETD2, each resulting in loss of the SRI and WW domains of SETD2, a methyltransferase that trimethylates H3K36 (H3K36me3) and also interacts with p53 to promote its stability. Functional studies of the novel p.D1890fs6* mutation (case 1) revealed significantly reduced H3K36me3 levels in SETD2-mutated tissue and primary cell cultures and decreased levels of the active form of p53. Restoration of SETD2-wildtype expression in the SETD2-mutant cells significantly reduced the expression of four well-known stemness markers (OCT-4, SOX2, IPF1, Goosecoid). These findings suggest potential roles for SETD2 loss-of-function mutations in HCC progression, possibly involving p53 destabilization and promotion of stemness. Their prevalence and potential treatment implications in thyroid cancer, especially HCC, require further study.

Mutations in TERT promoter have been detected in the more aggressive papillary thyroid cancers (PTCs). To elucidate the role of TERT as an eligible molecular target in these tumors, the expression of hTERT was analyzed in a series of PTCs and the effects of both pharmacological and RNA-interference-induced hTERT silencing were investigated in two human PTC cell lines (K1 and BCPAP). The expression levels of hTERT mRNA and protein were evaluated by real-time PCR and western blot assays, respectively. Effects of hTERT silencing on PTC cell lines were analyzed by MTT, migration and western blot assays. Pharmacological inhibition of hTERT was performed using two bromodomain and extra-terminal (BET) inhibitors, JQ1 and I-BET762. hTERT expression results increased in 20 out of 48 PTCs, including tumors either positive or negative for the presence of hTERT promoter and/or BRAF mutations. In K1 and BCPAP cells, hTERT silencing determined a reduction in cell viability (~50% for K1 and ~70%, for BCPAP, vs control) and migration properties that were associated with a decrease of AKT phosphorylation and β-Catenin expression. Moreover, hTERT mRNA levels were down-regulated by two BET inhibitors, JQ1 and I-BET762, which at the same dosage (0.5 and 5 µM) reduced the growth of these thyroid cancer cells. These findings demonstrate that hTERT may represent an excellent therapeutic target in subgroups of aggressive PTCs.

Background. Obesity has been hypothesized to contribute to the aggressiveness of thyroid cancer through the production of abnormal levels of serum adipokines. Leptin receptor (OB-R) expression has also been documented in papillary thyroid cancer (PTC). Aim. In this translational study, we analyzed in vitro the effects of leptin on the growth and migration of thyroid cancer cells (TPC-1 and K1), the molecular mechanisms underlying leptin’s action, and the influence of prolonged leptin exposure on cell response to a protein kinase inhibitor lenvatinib. The expression levels of OB-R mRNA and protein were also investigated in vivo in a series of aggressive PTCs divided into two groups based on the presence of the BRAF mutation. Results. In TPC-1 and K1 cells, prolonged treatment with leptin (500 ng/ml for 96 h) resulted in a mild increase in the proliferation (about 20% over control only in K1 cells, p<0.05) and in the migration of both cancer cell lines. Immunoblot analysis revealed a slight increase in the phosphorylation of AKT, but no effect on β-catenin and phospho-ERK expressions. The inhibitory effects of lenvatinib on the viability of both cell lines were not influenced by the leptin treatment. OB-R transcript (in fresh tissues) and proteins (in formalin-fixed and paraffin-embedded specimens) were expressed in all PTC tissues examined, with no significant differences between BRAF-mutated and BRAF-wild-type tumors. Conclusions. These results demonstrate leptin’s role in mildly increasing the aggressive phenotype of PTC cells but without influencing the action of lenvatinib. Further studies will clarify whether it is possible to target OB-R, expressed in all aggressive PTCs, as an adjuvant treatment approach for these malignancies.

A substantial proportion of patients with advanced thyroid carcinoma fail to respond to or at some point become refractory to conventional therapies. This resistance and the phenomena of thyroid cancer progression and metastasis themselves are thought to be related to tumor-cell sub-populations with stem-like properties. We isolated thyrospheres from four advanced thyroid carcinomas that were resistant to radioiodine therapy and analyzed their molecular profiles. ALDH activity and proteomic profile of main stem cell markers were used to assess stem cell properties. The TaqMan Low Density Array approach was used to evaluate the expression of several genes involved in the EMT process. The phosphorylation status of tyrosine kinase receptors (RTKs) was analyzed to identify potential markers for targeted therapies. We then investigated the effects of the EMT-inhibitor crizotinib on both cell proliferation and phosphorylation status of RTK targets. The cancer stem-like properties of a subset of cells from primary cultures of each tumor were demonstrated. A wide variability among thyrospheres arising from the four thyroid cancers in terms of ALDH activity, stem cell marker expression, and phosphoproteome profiling was present. Dysregulated expression of genes involved in the EMT was observed in all four thyrosphere lines. Treatment with crizotinib was ineffective in cancer stem-like cells, suggesting the presence of a mechanism of resistance in thyrospheres. Collectively, our data indicate that thyroid cancer stem-like populations vary markedly from tumor to tumor and require detailed molecular and biological characterization if they are to be used as the basis of "personalized" treatment of aggressive disease.

Synonymous mutations continue to be filtered out from most large-scale cancer genome studies, but several lines of evidence suggest they can play driver roles in neoplastic disease. We investigated a case of an aggressive, apparently sporadic medullary thyroid carcinoma (MTC) harboring a somatic RET p.Cys634Arg mutation (a known MTC driver). A germ-line RET substitution (p.Cys630=) had also been found but was considered clinically irrelevant because of its synonymous nature. Next generation sequencing (NGS) of the tumor tissues revealed that the RET mutations were in cis. There was no evidence of gene amplification. Expression analysis found an increase of RET transcript in p.Cys630=;p.Cys634Arg patient compared with that found in 7 MTCs harboring p.Cys634 mutations. Minigene expression assays demonstrated that the presence of the synonymous RET mutation was sufficient to explain the increased RET mRNA level. In silico analyses and RNA immunoprecipitation experiments showed that the p.Cys630 = variant created new exonic splicing enhancer motifs that enhanced SRp55 recruitment to the mutant allele, leading to more efficient maturation of its pre-mRNA and an increased abundance of mature mRNA encoding a constitutively active RET receptor. These findings document a novel mechanism by which synonymous mutations can contribute to cancer progression., Author summary Synonymous mutations—once considered “silent” because they do not alter the gene product’s amino-acid sequence—are now emerging as potential drivers of cancer. Our recent investigation of an aggressive medullary thyroid carcinoma (MTC) revealed a novel mechanism that could underlie such effects. The MTC analyzed harbored a somatic p.Cys634Arg mutation of the RET protooncogene (a well-known MTC driver). A second RET substitution (p.Cys630=) discovered in the germline had been considered clinically irrelevant because of its synonymous nature. Our next-generation sequencing analysis of the patient’s cancer tissues revealed that the RET mutations were in cis. We also found that RET mRNA levels in patient’s MTC were significantly higher than those found in seven other MTCs with various amino-acid substitutions at position 634 in RET. Subsequent experiments demonstrated that the presence of the synonymous mutation created new exonic splicing enhancer motifs in the mutant allele, which led to more efficient maturation of its transcript and increased expression of a constitutively active RET receptor.

MicroRNA (miRNA) expression is dysregulated in many human malignancies, and a growing number of studies are focused on their potential use as tumor biomarkers. To identify a miRNA signature for papillary thyroid carcinomas (PTC), we investigated miRNA expression profiles in two independent cohorts of PTCs, which included major histological subtypes [classical-type (PTC‑CT), follicular-variant (PTC‑FV), and tall-cell variant (PTC‑TCV)] and cases with low or intermediate risk of recurrence. Using TaqMan® Array Human MicroRNA A+B Cards v3.0, we first performed microRNA profiling of normal and neoplastic thyroid tissues from 29 PTC patients. Promising candidates were then investigated in a second, independent cohort of 76 PTCs using Custom TaqMan® Array MicroRNA Cards. We identified a molecular signature of 11 miRNAs that were significantly upregulated (miR‑146b-5p, miR‑146b-3p, miR‑221-3p, miR‑222‑5p, miR‑222‑3p) or downregulated (miR‑1179, miR‑486‑5p, miR‑204-5p, miR‑7-2-3p, miR‑144-5p, miR‑140-3p) in PTC tissues vs. normal thyroid tissue. Upregulation of miR‑146b-5p and miR‑222‑3p was also significantly associated with an increased risk of recurrence. Higher than normal expression of miR‑146b-5p and miR‑146b-3p characterized PTC‑CT and PTC‑TCV but not PTC‑FV, whereas miR‑21-5p was significantly upregulated only in PTC‑TCV. When PTC‑FV were subclassified as encapsulated (PTC‑EFV) or infiltrative (PTC‑IFV), miR‑204-5p was downregulated in all histological subtypes except PTC‑EFV, which displayed expression levels similar to those of normal thyroid tissues. These findings provide new insights into the molecular classification of PTC, showing that different miRNA expression profiles are associated with different histological types of PTC and different risks of recurrence.

Context: Trends toward more conservative management of papillary thyroid cancer (PTC) diminish the primacy of serum thyroglobulin (Tg) assays as a posttreatment surveillance tool. Objective: To identify thyroid tumor-associated microRNAs (miRNAs) in the serum with potential for development as unique biomarkers of PTC recurrence. Methods: We measured expression of 754 miRNAs in serum samples collected from 11 patients with PTC before and 30 days after thyroidectomy. Major candidates were then re-evaluated by absolute quantitative polymerase chain reaction analysis in an independent cohort of patients with PTC (n = 44) or benign nodules and 20 healthy controls (HCs). The 2 miRNAs most significantly associated with thyroid tumors were then assessed in matched serum samples (before and 30 days and 1 to 2 years after surgery) from the 20 PTC patients with complete follow-up datasets and results correlated with American Thyroid Association (ATA) responses to therapy. Results: Eight miRNAs (miR-221-3p, miR-222-3p, miR-146a-5p, miR-24-3p, miR-146b-5p, miR-191-5p, miR-103a-3p, and miR-28-3p) displayed levels in prethyroidectomy serum samples from patients with PTC that significantly exceeded those measured after thyroidectomy and those found in samples from HCs. The 2 most promising candidates—miR-146a-5p and miR-221-3p —were further analyzed in the 20 PTC patients mentioned earlier. Serum levels of both miRNAs after 1 to 2 years of follow-up were consistent with ATA responses to therapy in all patients, including 2 with structural evidence of disease whose Tg assays remained negative (, Precis: Analysis of miRNA levels in pre- and postoperative serum samples from PTC patients reveals possible associations between postoperative changes in miR-146a-5p and miR-221-3p and clinical outcome.

Advanced medullary thyroid cancers (MTCs) are now being treated with drugs that inhibit receptor tyrosine kinases, many of which involved in angiogenesis. Response rates vary widely, and toxic effects are common, so treatment should be reserved for MTCs likely to be responsive to these drugs.RETmutations are common in MTCs, but it is unclear how they influence the microvascularization of these tumors. We examined 45 MTCs with germ-line or somaticRETmutations (RETmut group) and 34 with wild-typeRET(RETwt). Taqman Low-Density Arrays were used to assess proangiogenic gene expression. Immunohistochemistry was used to assess intratumoral, peritumoral and nontumoral expression levels of VEGFR1, R2, R3, PDGFRa, PDGFB and NOTCH3. We also assessed microvessel density (MVD) and lymphatic vessel density (LVD) based on CD31-positive and podoplanin-positive vessel counts, respectively, and vascular pericyte density based on staining for a-smooth muscle actin (a-SMA), a pericyte marker. Compared withRETwt tumors,RETmut tumors exhibited upregulated expression of proangiogenic genes (mRNA and protein), especially VEGFR1, PDGFB and NOTCH3. MVDs and LVDs were similar in the two groups. However, microvessels inRETmut tumors were more likely to be a-SMA positive, indicating enhanced coverage by pericytes, which play key roles in vessel sprouting, maturation and stabilization. These data suggest that angiogenesis inRETmut MTCs may be more intense and complete than that found inRETwt tumors, a feature that might increase their susceptibility to antiangiogenic therapy. Given their increased vascular pericyte density,RETmut MTCs might also benefit from combined or preliminary treatment with PDGF inhibitors.

In this study we analyzed the expression levels of markers of epithelial-to-mesenchymal transition (EMT) in several papillary thyroid carcinomas (PTCs) and the relation with tumor genotypes and clinicopathological characteristics. The role of fibronectin-1 (FN1) was investigated by analyzing the effects of FN1 silencing in two human thyroid cancer cell lines. Most of EMT markers were significantly over-expressed in a group of 36 PTCs. In particular, FN1 mRNA levels were higher in tumor vs non-tumor tissue (117.3, p 0.001) and also in aggressive and BRAF(V600E) samples. Similar results were observed (and confirmed at the protein level) when FN1 expression was analyzed in a validation group of 50 PTCs and six lymph node (LN) metastases. Silencing of FN1 in TPC-1 and BCPAP thyroid cancer cells significantly reduced proliferation, adhesion, migration, and invasion in both cell lines. Collectively, our data indicate that FN1 overexpression is an important determinant of thyroid cancer aggressiveness.