Molecular markers of aggressiveness of thyroid cancer

Extracellular Vesicles as Signal Carriers in Malignant Thyroid Tumors?

Extracellular vesicles (EVs) are small, membranous structures involved in intercellular communication. Here, we analyzed the effects of thyroid cancer-derived EVs on the properties of normal thyroid cells and cells contributing to the tumor microenvironment. EVs isolated from thyroid cancer cell lines (CGTH, FTC-133, 8505c, TPC-1 and BcPAP) were used for treatment of normal thyroid cells (NTHY), as well as monocytes and endothelial cells (HUVEC). EVs' size/number were analyzed by flow cytometry and confocal microscopy. Gene expression, protein level and localization were investigated by qRT-PCR, WB and ICC/IF, respectively. Proliferation, migration and tube formation were analyzed. When compared with NTHY, CGTH and BcPAP secreted significantly more EVs. Treatment of NTHY with cancer-derived EVs changed the expression of tetraspanin genes, but did not affect proliferation and migration. Cancer-derived EVs suppressed tube formation by endothelial cells and did not affect the phagocytic index of monocytes. The number of 6 μm size fraction of cancer-derived EVs correlated negatively with the CD63 and CD81 expression in NTHY cells, as well as positively with angiogenesis in vitro. Thyroid cancer-derived EVs can affect the expression of tetraspanins in normal thyroid cells. It is possible that 6 μm EVs contribute to the regulation of NTHY gene expression and angiogenesis.

New Insights into the Link between Melanoma and Thyroid Cancer: Role of Nucleocytoplasmic Trafficking

Cancer remains a major public health concern, mainly because of the incompletely understood dynamics of molecular mechanisms for progression and resistance to treatments. The link between melanoma and thyroid cancer (TC) has been noted in numerous patients. Nucleocytoplasmic transport of oncogenes and tumor suppressor proteins is a common mechanism in melanoma and TC that promotes tumorigenesis and tumor aggressiveness. However, this mechanism remains poorly understood. Papillary TC (PTC) patients have a 1.8-fold higher risk for developing cutaneous malignant melanoma than healthy patients. Our group and others showed that patients with melanoma have a 2.15 to 2.3-fold increased risk of being diagnosed with PTC. The BRAF V600E mutation has been reported as a biological marker for aggressiveness and a potential genetic link between malignant melanoma and TC. The main mechanistic factor in the connection between these two cancer types is the alteration of the RAS-RAF-MEK-ERK signaling pathway activation and translocation. The mechanisms of nucleocytoplasmic trafficking associated with RAS, RAF, and Wnt signaling pathways in melanoma and TC are reviewed. In addition, we discuss the roles of tumor suppressor proteins such as p53, p27, forkhead O transcription factors (FOXO), and NF-_KB within the nuclear and cytoplasmic cellular compartments and their association with tumor aggressiveness. A meticulous English-language literature analysis was performed using the PubMed Central database. Search parameters included articles published up to 2021 with keyword search terms melanoma and thyroid cancer, BRAF mutation, and nucleocytoplasmic transport in cancer.

Molecular Heterogeneity of Papillary Thyroid Cancer: Comparison of Primary Tumors and Synchronous Metastases in Regional Lymph Nodes by Mass Spectrometry Imaging

Intra-tumor heterogeneity results from both genetic heterogeneity of cancer (sub)clones and phenotypic plasticity of cancer cells that could be induced by different local microenvironments. Here, we used mass spectrometry imaging (MSI) to compare molecular profiles of primary tumors located in the thyroid gland and their synchronous metastases in regional lymph nodes to analyze phenotypic heterogeneity in papillary thyroid cancer. Two types of cancerous (primary tumor and metastasis) and two types of not cancerous (thyroid gland and lymph node) regions of interest (ROIs) were delineated in postoperative material from 11 patients, then the distribution of tryptic peptides (spectral components) was analyzed by MSI in all tissue regions. Moreover, tryptic peptides identified by shotgun proteomics in corresponding tissue lysates were matched to components detected by MSI to enable their hypothetical protein annotation. Unsupervised segmentation of all cancer ROIs revealed that different clusters dominated in tumor ROIs and metastasis ROIs. The intra-patient similarity between thyroid and tumor ROIs was higher than the intra-patient similarity between tumor and metastasis ROIs. Moreover, the similarity between tumor and its metastasis from the same patients was lower than similarities among tumors and among metastases from different patients (inter-patient similarity was higher for metastasis ROIs than for tumor ROIs). Components differentiating between tumor and its metastases were annotated as proteins involved in the organization of the cytoskeleton and chromatin, as well as proteins involved in immunity-related functions. We concluded that phenotypical heterogeneity between primary tumor and lymph node metastases from the same patient was higher than inter-tumor heterogeneity between primary tumors from different patients.

PSMA expression level predicts differentiated thyroid cancer aggressiveness and patient outcome

Background

Prostate-specific membrane antigen (PSMA) is overexpressed on the endothelial cells of tumor neo-vessels of several solid malignancies, including differentiated thyroid cancer (DTC). We aimed to test the potential role of PSMA as a biomarker for DTC aggressiveness and outcome prediction.

We retrospectively screened all patients who underwent thyroidectomy between 1 January 2010 and 31 December 2017 in our institution. Applying the inclusion (histological diagnosis of thyroid cancer and tissue availability) and exclusion criteria (no clinical or follow-up data or diagnosis of medullary thyroid cancer), a cohort of 59 patients was selected. The monoclonal mouse anti-human PSMA antibody was used to stain tissue sections. A 3-point scale was used to score PSMA positivity: 0–5% expression was considered as negative (score 0), 6–50% as moderately positive (score 1), and 51–100% as highly positive (score 2). A cumulative score (0–10%, 11–79%, and 80–100%) was also explored. Univariate and multivariate logistic regression analyses were performed to predict the presence of distant metastases, chosen as endpoint of aggressiveness. The area under the curve (AUC) was calculated. Cox models were built to predict patient outcome in terms of recurrence, iodine refractoriness, and status at last follow-up, which were calculated using the Kaplan-Meier failure function.

Results

At immunostaining, 12, 25, and 22 patients had scores of 0, 1, and 2, respectively. According to the cumulative score, PSMA expression was ≤ 10% in 17 cases, 11–79% in 31 cases, and ≥ 80% in 11 cases. At multivariate analysis, age, sex, histotype, vascular invasion, T and N parameters, and PSMA positivity were significant predictors of distant metastases. The AUC was 0.92. Recurrence or progression occurred in 19/59 patients. Twelve patients developed radioiodine (RAI) refractoriness, after a median time of 17 months (range 2–32). One patient died of DTC; 46 of the 58 patients alive at last follow-up were disease free. Median DFS was 23 months (range 3–82). The final multivariate model to predict RAI refractoriness included as covariates the stage, high PSMA expression (≥ 80%), and the interaction between moderate PSMA expression (11–79%) and stage.

Conclusions

PSMA, a marker of neovasculature formation expressed by DTC, contributes in the prediction of tumor aggressiveness and patient outcome.

Electronic supplementary material

The online version of this article (10.1186/s13550-019-0559-9) contains supplementary material, which is available to authorized users.

Extensive lymphatic spread of papillary thyroid microcarcinoma is associated with an increase in expression of genes involved in epithelial-mesenchymal transition and cancer stem cell-like properties

Background

Active surveillance is an alternative management for patents with low‐risk papillary thyroid microcarcinoma (PTMC); however, there is an absence of specific molecular markers that predict its progression. We compared gene expression patterns between PTMC with lateral neck‐node metastasis (N1b) and PTMC‐lacking nodal metastasis (N0).

Methods

We performed oligonucleotide microarray analysis in three PTMCs without cervical lymph‐node metastases (N0), and five PTMCs with lateral neck‐node metastasis (N1b) at initial diagnosis, using an Illumina HumanHT‐12 v4.0 Expression BeadChip. Quantitative real‐time PCR (qPCR) and western blot analysis confirmed microarray data. We performed immunohistochemistry (IHC) to confirm protein overexpression in samples from 20 N0 and 24 N1b PTMC patients who underwent thyroidectomy.

Results

Microarray analyses identified 52 probes corresponding to 45 genes. Expression of these genes differed significantly between the two PTMC groups. Forty genes were significantly upregulated and five genes were downregulated in N1b PTMC compared to N0. Four genes related to epithelial‐to‐mesenchymal transition (EMT) and stem cell markers, including ALDH1A3, TM4SF1, PROM1, and CAV1 were significantly upregulated in N1b PTMCs. Real‐time qPCR confirmed this expression and western blot analysis confirmed higher expression of ALDH1A3, TM4SF1, PROM1, and CAV1 in N1b than in N0 PTMCs. IHC indicated overexpression of ALDH1A3 and CAV1 in N1b compared to N0 PTMCs.

Conclusions

Genes related to EMT and thyroid cancer stem cell‐like properties are upregulated in early extensive lymphatic spread of PTMC.

Evaluation of the diagnostic value of emerin and CD56 in papillary thyroid carcinoma - an immunohistochemical study

Papillary thyroid carcinoma (PTC) is diagnosed in both cytological and histological specimens on the basis of distinct nuclear morphology. These features may not be prominent in some PTC variants and may be seen in some benign conditions. It is necessary to differentiate PTC from other neoplastic and nonneoplastic lesions since it affects treatment strategy and patients' fate. Emerin is a type II integral membrane protein of the inner nuclear membrane that has a characteristic staining pattern in PTC. CD56 is a homophilic membrane glycoprotein that is expressed in thyroid follicular epithelial cells and adrenal glands. The aim of this study was to evaluate the diagnostic value of emerin (positivity, percentage, and highlighting nuclear features) and CD56 (positive versus negative) both singly and in combination for differentiation of PTC from other neoplastic and nonneoplastic mimics. This study was performed on 50 cases of PTC, 9 cases of follicular adenoma (FA), and 12 cases of nonneoplastic thyroid lesions using immunohistochemistry for detection of emerin and CD56. Positive emerin expression was seen in 82% of PTC and in 16.7% of nonneoplastic cases with an absence of expression in FA. CD56 was expressed in 88.9% of FA, 91.7% of nonneoplastic cases and in a minority of PTC cases (6%). Positive emerin revealed 82% sensitivity and 90% specificity, while emerin-highlighted nuclear changes was more specific (95%). Negative CD56 expression revealed 84% sensitivity and 90% specificity. Combined positive emerin (including highlighting nuclear changes) and negative CD56 showed 72% sensitivity and 100% specificity. Positive emerin expression (moderate/strong) and its highlighting nuclear changes combined with negative CD56 could be a very helpful procedure in difficult and overlapping cases with high diagnostic validity (high specificity and positive predictive value).

Current Advances in Thyroid Cancer Management. Are We Ready for the Epidemic Rise of Diagnoses?

A rising incidence of thyroid cancers (TCs) mainly small tumors, observed during recent years, lead to many controversies regarding treatment strategies. TCs represent a distinct molecular background and clinical outcome. Although in most cases TCs are characterized by a good prognosis, there are some aggressive forms, which do not respond to standard treatment. There are still some questions, which have to be resolved to avoid dangerous simplifications in the clinical management. In this article, we focused on the current advantages in preoperative molecular diagnostic tests and histopathological examination including noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). We discussed the controversies regarding the extent of thyroid surgery and adjuvant radioiodine therapy, as well as new treatment modalities for radioiodine-refractory differentiated thyroid cancer (RR-DTC). Considering medullary thyroid cancer (MTC), we analyzed a clinical management based on histopathology and RET (ret proto-oncogene) mutation genotype, disease follow-up with a special attention to serum calcitonin doubling time as an important prognostic marker, and targeted therapy applied in advanced MTC. In addition, we provided some data regarding anaplastic thyroid cancer (ATC), a highly lethal neoplasm, which lead to death in nearly 100% of patients due to the lack of effective treatment options.

Repositioning therapy for thyroid cancer: new insights on established medications

Repositioning of established non-cancer pharmacotherapeutic agents with well-known activity and side-effect profiles is a promising avenue for the development of new treatment modalities for multiple cancer types. We have analyzed some of the medications with mechanism of action that may have relevance to thyroid cancer (TC). Experimental in vitro and in vivo evidences, as well as results of clinical studies, have indicated that molecular targets for medications currently available for the treatment of mood disorders, sexually transmitted diseases, metabolic disorders, and diabetes may be active and relevant in TC. For instance, the derivatives of cannabis and an anti-diabetic agent, metformin, both are able to inhibit ERK, which is commonly activated in TC cells. We present here several examples of well-known medications that have the potential to become new therapeutics for patients with TC. Repositioning of established medications for the treatment of TC could broaden the scope of current therapeutic strategies. These diverse treatment choices could allow physicians to provide an individualized approach to optimize treatment for patients with TC.

BRAF activates and physically interacts with PAK to regulate cell motility

Increased p21-activated kinase (PAK) signaling and expression have been identified in the invasive fronts of aggressive papillary thyroid cancers (PTCs), including those with RET/PTC, BRAFV600E, and mutant RAS expression. Functionally, thyroid cancer cell motility in vitro is dependent on group 1 PAKs, particularly PAK1. In this study, we hypothesize that BRAF, a central kinase in PTC tumorigenesis and invasion, regulates thyroid cancer cell motility in part through PAK activation. Using three well-characterized human thyroid cancer cell lines, we demonstrated in all cell lines that BRAF knockdown reduced PAK phosphorylation of direct downstream targets. In contrast, inhibition of MEK activity either pharmacologically or with siRNA did not reduce PAK activity, indicating MEK is dispensable for PAK activity. Inhibition of cell migration through BRAF loss is rescued by overexpression of either constitutive active MEK1 or PAK1, demonstrating that both signaling pathways are involved in BRAF-regulated cell motility. To further characterize BRAF-PAK signaling, immunofluorescence and immunoprecipitation demonstrated that both exogenously overexpressed and endogenous PAK1 and BRAF co-localize and physically interact, and that this interaction was enhanced in mitosis. Finally, we demonstrated that acute induction of BRAFV600E expression in vivo in murine thyroid glands results in increased PAK expression and activity confirming a positive signaling relationship in vivo. In conclusion, we have identified a signaling pathway in thyroid cancer cells which BRAF activates and physically interacts with PAK and regulates cell motility.

Potential diagnostic utility of CD56 and claudin-1 in papillary thyroid carcinoma and solitary follicular thyroid nodules

BACKGROUND AND AIM

The pathological diagnosis of papillary thyroid carcinoma (PTC) is usually easily achieved. However distinguishing the follicular variant of papillary carcinoma (FVPC) from other follicular thyroid lesions is an area of controversy. In this study we investigated the role of CD56 and claudin-1 in discriminating the FVPCs from other solitary follicular patterned nodules. We also evaluated the application of these two markers in reclassifying the controversial cases of the well differentiated tumors of unknown malignant potential (WDTs-UMP).

MATERIALS AND METHODS

The immunohistochemical expression of CD56 and claudin-1 was evaluated in 86 samples of thyroid lesions together with 10 samples of normal thyroid tissue. Thyroid lesions included: 29 PTCs [classic papillary carcinoma (n = 13) and FVPC (n = 16)], 47 solitary follicular patterned nodules [follicular adenomas (n = 12), hyperplastic nodules (n = 32) and follicular tumor of unknown malignant potential (n = 3)] and 10 WDTs-UMP.

RESULTS

The statistical analysis showed significantly different expressions of each of CD56 and claudin-1 in the FVPCs versus other solitary follicular patterned nodules. Claudin-1 sensitivity (100%) was higher than CD56 sensitivity (81.3%). However claudin-1 specificity (80.9%) was < CD56 specificity (89.4%). The combined use of CD56 and claudin-1(claudin-1 + /CD56-) showed specificity (100%), positive predictive value (100%) and sensitivity (81.3%) in the differentiation between the FVPCs and other follicular nodules. In the light of this statistical outcome, 5/10 cases of WDTs-UMP expressing the (claudin-1 + /CD56-) panel could be rediagnosed as PTC.

CONCLUSION

Combined utility of CD56 and claudin-1 is helpful in diagnosing the FVPC and its differentiation from other follicular patterned nodules. Application of these two markers may greatly aid in the reevaluation of the WDTs-UMP and interpretation of their expected behavior.

Expression of the proliferation marker Ki-67 associates with tumour staging and clinical outcome in differentiated thyroid carcinomas

OBJECTIVE

Although the prognosis of differentiated thyroid carcinoma (DTC) is excellent, with 10-year survival rates of about 90%, about one-third of patients experiences recurrent disease. We aimed to identify novel histological prognostic factors to optimize treatment and follow-up of patients at risks.

DESIGN

Retrospective analysis of patients diagnosed from January 1990 to March 2004.

SUBJECTS

A total of 93 patients diagnosed with DTC of which 67 with papillary and 26 with follicular histology.

MEASUREMENTS

Analysis of immunohistochemical expression of somatostatin receptor (sst) subtypes 1-5, glucose transporter-1 (GLUT-1), receptor tyrosine kinase c-KIT, oestrogen and progesterone receptors, and proliferation marker Ki-67 and correlation with the patients' clinical outcome.

RESULTS

DTC showed immunohistochemical expression of GLUT-1, C-KIT and progesterone receptor in a high percentage of cases (range: 57-80%). In contrast, the oestrogen receptor as well as the sst subtypes 1-5 was less frequently detected (range: 15-29%). Mean staining of the proliferation marker Ki-67 was 6% positive cells (range 0-20%). Ki-67 expression was significantly associated with tumour staging (ρ = 0·2076, P = 0·0459), whereas the other histopathological markers were not associated with gender, age, tumour entity, or tumour classification. Tumour staging and expression of Ki-67, oestrogen receptor and sst2, but of none of the other histopathological factors, independently predicted the clinical outcome 5 years after definitive treatment (P < 0·0001, P < 0·0001, P = 0·0004 and P = 0·0206, respectively).

CONCLUSIONS

In patients with DTC, Ki-67 expression associates with tumour staging and clinical outcome.

Metastatic dormancy and progression in thyroid cancer: targeting cells in the metastatic frontier

BACKGROUND

Metastatic dormancy, or the ability of cancer cells to survive but not progress in metastatic environments, is now recognized to be a common occurrence in cancer.

SUMMARY

From a clinical perspective, this phenomenon is common in metastatic well-differentiated thyroid cancer, whereby patients often present with distant metastases that remain stable for years after removal of the primary tumor and subsequent treatment. Experimental data suggest that metastases can develop throughout the life of a cancer and that progression in the distant environment depends on the biology of the cancer cells that metastasize as well as that of the various microenvironments they encounter. A firm understanding of how thyroid cancer cell progression is regulated in different metastatic environments is necessary to devise effective therapies targeting progressive metastatic thyroid cancer.

CONCLUSION

In this review, current models of metastatic progression and factors that regulate late-stage metastatic progression that are particularly relevant for thyroid cancer are discussed.

Dedifferentiation of differentiated thyroid carcinoma cell line FTC-133 is enhanced by 131I pretreatment

INTRODUCTION

Differentiated thyroid carcinoma (DTC) usually has a high iodine uptake. However, dedifferentiation of DTC with decreased or no radioiodine ((131)I) uptake is observed in clinical practice, with poor prognosis. The aim of this study was to investigate the effects of (131)I radiation on radioiodine uptake (RAIU) and the expression of thyroid-specific molecules.

METHODS

FTC-133 cells were treated with (131)I, the dosage dictated by methylthiazol tetrazolium test results and preliminary experiments. The experimental cell group was incubated with (131)I for 48 h and then cultured for 3 months in (131)I-free medium. The control group was set without (131)I. Primary cells were defined as the blank group. Following treatment, RAIU was measured with a gamma counter as the counts/cell number. Na(+)/I(-) symporter (NIS), thyroid-stimulating hormone receptor (TSHR), thyroid peroxidase (TPO) and thyroglobulin (Tg) levels were detected by Western blotting and radioimmunoassay, and their mRNAs were detected by real-time polymerase chain reaction.

RESULTS

RAIU of FTC-133 cells decreased gradually after coincubation with (131)I and did not recover even if (131)I was removed. The relative RAIU of the control and experimental groups was 0.567 and 0.182, respectively, a statistically significant difference (P<.01). Expression of NIS, TSHR, TPO and Tg decreased in the experimental group to a statistically significant degree compared to that of controls (P<.05).

CONCLUSION

Changes in the mRNA levels were in accordance with the expression of thyroid-specific proteins. Thus, FTC-133 cells undergo dedifferentiation during long-term culture in vitro, and (131)I may promote this progress.

Molecular analyses of thyroid tumors for diagnosis of malignancy on fine-needle aspiration biopsies and for prognosis of invasiveness on surgical specimens

High throughput genetic and genomic analyses have allowed the identification of series of genes exhibiting either distinct expression profiles or a particular mutational status in the different types or subtypes of thyroid tumors. The use of molecular data to improve the preoperative diagnosis of thyroid cancer on materiel from fine-needle aspiration biopsy (FNAB) is in the course of validation by numerous teams throughout the world. We have proposed a molecular test based on the expression level of a series of 19 genes, capable of discriminating malignant from benign tumors [15]. A prospective study aiming at the clinical validation of the molecular test has been performed on a cohort of 730 patients with a thyroid nodule. In patients subjected to tumor resection (≈ 220), the preoperative molecular diagnosis (generated on FNAB material from analyses of the expression level of the 19 genes) was compared to the postoperative diagnosis given by the pathologist (used as reference). Treatment and follow-up of the serious forms of thyroid cancer should benefit by the early identification of tumors with a metastatic potential using molecular characteristics differentiating invasive and non-invasive thyroid carcinomas. We have performed genetic and genomic analyses on a series of 200 papillary thyroid carcinomas (non-invasive or NI-PTC, 50%; invasive or I-PTC, 50%). BRAF(V600E) mutation or/and RET/PTC gene rearrangement have been detected in less than 25% of NI-PTC but in more than 75% of I-PTC. Pan-genomic analyses (Agilent microarray) revealed that 1373 genes are differentially expressed (fold change greater than 2) in NI-PTC as compared to I-PTC samples. The majority of genes (≈ 1200) are overexpressed in I-PTC. Data related to the two domains: diagnosis and prognosis of thyroid cancer will be presented at 2011 International H.P. KLOTZ conference on Clinical Endocrinology.

Group I p21-activated kinases regulate thyroid cancer cell migration and are overexpressed and activated in thyroid cancer invasion

p21-activated kinases (PAKs) are a family of serine/threonine kinases that regulate cytoskeletal dynamics and cell motility. PAKs are subdivided into group I (PAKs 1-3) and group II (PAKs 4-6) on the basis of structural and functional characteristics. Based on prior gene expression data that predicted enhanced PAK signaling in the invasive fronts of aggressive papillary thyroid cancers (PTCs), we hypothesized that PAKs functionally regulate thyroid cancer cell motility and are activated in PTC invasive fronts. We examined PAK isoform expression in six human thyroid cancer cell lines (BCPAP, KTC1, TPC1, FTC133, C643, and SW1746) by quantitative reverse transcription-PCR and western blot. All cell lines expressed PAKs 1-4 and PAK6 mRNA and PAKs 1-4 protein; PAK6 protein was variably expressed. Samples from normal and malignant thyroid tissues also expressed PAKs 1-4 and PAK6 mRNA; transfection with the group I (PAKs 1-3) PAK-specific p21 inhibitory domain molecular inhibitor reduced transwell filter migration by ∼50% without altering viability in all cell lines (P<0.05). BCPAP and FTC133 cells were transfected with PAK1, PAK2, or PAK3-specific small interfering RNA (siRNA); only PAK1 siRNA reduced migration significantly for both cell lines. Immunohistochemical analysis of seven invasive PTCs demonstrated an increase in PAK1 and pPAK immunoactivity in the invasive fronts versus the tumor center. In conclusion, PAK isoforms are expressed in human thyroid tissues and cell lines. PAK1 regulates thyroid cancer cell motility, and PAK1 and pPAK levels are increased in PTC invasive fronts. These data implicate PAKs as regulators of thyroid cancer invasion.