BRAF(V600E) mutation and expression of proangiogenic molecular markers in papillary thyroid carcinomas

A new molecular subclassification and in silico predictions for diagnosis and prognosis of papillary thyroid cancer by alternative splicing profile

Introduction: Papillary thyroid cancer (PTC) is the most common endocrine malignancy. However, different PTC variants reveal high heterogeneity at histological, cytological, molecular and clinicopathological levels, which complicates the precise diagnosis and management of PTC. Alternative splicing (AS) has been reported to be potential cancer biomarkers and therapeutic targets. Method: Here, we aim to find a more sophisticated molecular subclassification and characterization for PTC by integrating AS profiling. Based on six differentially expressed alternative splicing (DEAS) events, a new molecular subclassification was proposed to reclassify PTC into three new groups named as Cluster0, Cluster1 and Cluster2 respectively. Results: An in silico prediction was performed for accurate recognition of new groups with the average accuracy of 91.2%. Moreover, series of analyses were implemented to explore the differences of clinicopathology, molecular and immune characteristics across them. It suggests that there are remarkable differences among them, but Cluster2 was characterized by poor prognosis, higher immune heterogeneity and more sensitive to anti-PD1 therapy. The splicing correlation networks proved the complicated regulation relationships between AS events and splicing factors (SFs). An independent prognostic indicator for PTC overall survival (OS) was established. Finally, three compounds (orantinib, tyrphostin-AG-1295 and AG-370) were discovered to be the potential therapeutic agents. Discussion: Overall, the six DEAS events are not only potential biomarkers for precise diagnosis of PTC, but also the probable prognostic predictors. This research would be expected to highlight the effect of AS events on PTC characterization and also provide new insights into refining precise subclassification and improving medical therapy for PTC patients.

Poorly Differentiated Thyroid Carcinoma: Single Centre Experience and Review of the Literature

There is controversy in the literature regarding a distinct subset of thyroid carcinoma whose histologically classification falls between well-differentiated and anaplastic carcinomas, previously identified as ‘poorly differentiated thyroid carcinoma’ (PDTC), or ‘insular carcinoma’, in view of the peculiar morphological characteristics of the cell groupings. The correct diagnosis and treatment of this entity have important prognostic and therapeutic significance. In this review, we describe the epidemiology, diagnosis, and management of PDTC and report our single centre experience to add to the limited evidence existing in the literature.

Prognostic factors in patients with advanced differentiated thyroid cancer treated with multikinase inhibitors - a single Brazilian center experience

OBJECTIVE

The aim of this study was to describe the real-world experience multikinase inhibitors (MKI) in the treatment advanced differentiated thyroid carcinoma (DTC) refractory to radioactive iodine (RAIR) therapy.

METHODS

We reviewed the records of all patients with MKI-treated DTC from 2010 to 2018. Progression free survival (PFS), response rates (RR) and adverse events (AE) profiles were assessed. Clinical parameters were compared between groups with different outcomes (disease progression and death) to identify possible prognostic factors and benefit from treatment.

RESULTS

Forty-four patients received MKI for progressive RAIR DTC. Median PFS was 24 months (10.2-37.7) and median overall survival (OS) was 31 months. Best overall response was complete response in one patient (4.5%), partial response in nine (20.4%), stable disease in twenty-two (50%), and progressive disease (PD) in twelve (27.3%). Seventy-two point 7 percent patients had clinical benefit and AE were mild in most cases (82.7%). Progressive patients were more likely to have FDG positive target lesion than those who did not progress (p = 0.033) and higher maximum SUV on target lesions (p = 0.042). Presence of lung-only metastasis and lower thyroglobulin (Tg) during treatment was associated with stable disease (p = 0.015 and 0,049, respectively). Patients with shorter survival had larger primary tumor size (p = 0.015) and higher maximum SUV on target lesions (p = 0.023).

CONCLUSION

Our findings demonstrate safety and effectiveness of MKI in patients with advanced RAIR DTC. We were able to identify as possible prognostic markers of better outcomes: absence of FDG uptake on target lesions, lower maximum SUV on PET-CT, presence of lung-only metastasis and lower Tg during treatment.

The evolution of acquired resistance to BRAF inhibitor is sustained by IGF1-driven tumor vascular remodeling

As hallmark of cancer, angiogenesis plays a pivotal role in carcinogenesis. The correlation between angiogenesis and evolution of BRAF inhibitor acquired resistance is, however, still poorly understood. Here, we reported that the molecular signatures of angiogenesis were enriched in early on-treated biopsies but not in disease progressed biopsies. The process of drug resistance development was accompanied by remodeling of vascular morphology, which was potentially manipulated by tumor-secreted pro-angiogenic factors. Further transcriptomic dissection indicated that tumor-secreted IGF1 drove the vascular remodeling through activating IGF1/IGF1R axis on endothelial cells, and sustained the prompt re-growth of resistant tumor. Blockade of IGF1R with small molecules at early stage of response disrupted vascular reconstruction, and subsequently delayed tumor relapse. Our findings not only demonstrated the correlation between IGF1-mediated tumor vascular remodeling and the development of acquired resistance to BRAFi but also provided a potential therapeutic strategy for the prevention of tumor relapse in clinical application.

Identification of Potential BRAF Inhibitor Joint Therapy Targets in PTC based on WGCAN and DCGA

As the most common mutation in papillary thyroid cancer (PTC), B-type Raf kinase V600E mutation (BRAFV600E ) has become an important target for the clinical treatment of PTC. However, the clinical application still faces the problem of resistance to BRAF inhibitors (BRAFi). Therefore, exploring BRAFV600E-associated prognostic factors to providing potential joint targets is important for combined targeted therapy with BRAFi. In this study, we combined transcript data and clinical information from 199 BRAF wild-type (BRAFWT ) patients and 283 BRAFV600E mutant patients collected from The Cancer Genome Atlas (TCGA), and screened 455 BRAFV600E- associated genes through differential analysis and weighted gene co-expression network analysis. Based on these BRAFV600E -associated genes, we performed functional enrichment analysis and co-expression differential analysis and constructed a core co-expression network. Next, genes in the differential co-expression network were used to predict drugs for therapy in the crowd extracted expression of differential signatures (CREEDS) database, and the key genes were selected based on the hub co-expression network through survival analyses and receiver operating characteristic (ROC) curve analyses. Finally, we obtained eight BRAFV600E -associated biomarkers with both prognostic and diagnostic values as potential BRAFi joint targets, including FN1, MET, SLC34A2, NGEF, TBC1D2, PLCD3, PROS1, and NECTIN4. Among these genes, FN1, MET, PROS1, and TBC1D2 were validated through GEO database. Two novel biomarkers, PROS1 and TBC1D2, were further validated by qRT-PCR experiment. Besides, we obtained four potential targeted drugs that could be used in combination with BRAFi to treat PTC, including MET inhibitor, ERBB3 inhibitor, anti-NaPi2b antibody-drug conjugate, and carboplatin through literature review. The study provided potential drug targets for combination therapy with BRAFi for PTC to overcome the drug resistance for BRAFi.

Does the Site of Origin of the Microcarcinoma with Respect to the Thyroid Surface Matter? A Multicenter Pathologic and Clinical Study for Risk Stratification

It is unclear whether the site of origin of papillary thyroid microcarcinoma (mPTC) with respect to the thyroid surface has an influence on clinicopathologic parameters. The objectives of the study were to: (i) Accurately measure the mPTC distance from the thyroid surface; (ii) analyze whether this distance correlates with relevant clinicopathologic parameters; and (iii) investigate the impact of the site of origin of the mPTC on risk stratification. Clinicopathologic features and BRAF mutational status were analyzed and correlated with the site of origin of the mPTC in a multicenter cohort of 298 mPTCs from six Italian medical institutions. Tumors arise at a median distance of 3.5 mm below the surface of the thyroid gland. Statistical analysis identified four distinct clusters. Group A, mPTC: size ≥ 5 mm and distance of the edge of the tumor from the thyroid capsule = 0 mm; group B, mPTC: size ≥ 5 mm and distance of the edge of the tumor from the thyroid capsule > 0 mm; group C, mPTC: size < 5 mm and distance of the edge of the tumor from the thyroid capsule = 0 mm; and group D, mPTC: size < 5 mm and distance of the edge of the tumor from the thyroid capsule > 0 mm. Univariate analysis demonstrates significant differences between the groups: Group A shows the most aggressive features, and group D the most indolent ones. By multivariate analysis, group A tumors are characterized by tall cell histotype, BRAF V600E mutation, tumor fibrosis, aggressive growth with invasive features, vascular invasion, lymph node metastases, and intermediate ATA risk. The mPTC clinicopathologic features vary according to the tumor size and distance from the thyroid surface. A four-group model may be useful for risk stratification and to refine the selection of nodules to be targeted for fine needle aspiration.

Adjuvant bevacizumab for melanoma patients at high risk of recurrence: survival analysis of the AVAST-M trial

Background

Bevacizumab is a recombinant humanised monoclonal antibody to vascular endothelial growth factor shown to improve survival in advanced solid cancers. We evaluated the role of adjuvant bevacizumab in melanoma patients at high risk of recurrence.

Patients and methods

Patients with resected AJCC stage IIB, IIC and III cutaneous melanoma were randomised to receive either adjuvant bevacizumab (7.5 mg/kg i.v. 3 weekly for 1 year) or standard observation. The primary end point was detection of an 8% difference in 5-year overall survival (OS) rate; secondary end points included disease-free interval (DFI) and distant metastasis-free interval (DMFI). Tumour and blood were analysed for prognostic and predictive markers.

Results

Patients (n=1343) recruited between 2007 and 2012 were predominantly stage III (73%), with median age 56 years (range 18–88 years). With 6.4-year median follow-up, 515 (38%) patients had died [254 (38%) bevacizumab; 261 (39%) observation]; 707 (53%) patients had disease recurrence [336 (50%) bevacizumab, 371 (55%) observation]. OS at 5 years was 64% for both groups [hazard ratio (HR) 0.98; 95% confidence interval (CI) 0.82–1.16, P = 0.78). At 5 years, 51% were disease free on bevacizumab versus 45% on observation (HR 0.85; 95% CI 0.74–0.99, P = 0.03), 58% were distant metastasis free on bevacizumab versus 54% on observation (HR 0.91; 95% CI 0.78–1.07, P = 0.25). Forty four percent of 682 melanomas assessed had a BRAF^V600 mutation. In the observation arm, BRAF mutant patients had a trend towards poorer OS compared with BRAF wild-type patients (P = 0.06). BRAF mutation positivity trended towards better OS with bevacizumab (P = 0.21).

Conclusions

Adjuvant bevacizumab after resection of high-risk melanoma improves DFI, but not OS. BRAF mutation status may predict for poorer OS untreated and potential benefit from bevacizumab.

Clinical Trial Information

ISRCTN 81261306; EudraCT Number: 2006-005505-64

Lenvatinib for thyroid cancer treatment: discovery, pre-clinical development and clinical application

Introduction: About one third of patients affected with thyroid cancer present with recurrent disease. Unresectability, advanced disease and radioiodine refractoriness are considered poor prognostic factors. Treatment with small molecules inhibiting molecular signaling can be considered for patients with progressive disease, when other therapeutic strategies cannot be applied. Lenvatinib is a tyrosine kinase inhibitor targeting multiple molecular factors involved in angiogenesis and tumor progression. Preclinical studies have demonstrated the utility of lenvatinib as a targeted therapy for different tumors, including both differentiated and anaplastic thyroid cancer.Areas covered: The authors provide an overview of the preclinical development of lenvatinib in the treatment of thyroid cancer and review its clinical application. They also provide their expert opinion on its development.Expert opinion: Preclinical studies have helped in the understanding of the mechanisms of thyroid carcinogenesis and in the development of a targeted therapy. These findings have represented the rationale for the use of lenvatinib in clinical trials, which have confirmed its utility but yet failed to prove a clear benefit in overall survival. The decision to start a systemic treatment with lenvatinib must be personalized for each patient evaluating the risk/benefits ratio. Treatment emergent adverse events must be considered and reasonably managed by a multidisciplinary approach.

Detection of BRAF V600E Mutations With Next-Generation Sequencing in Infarcted Thyroid Carcinomas After Fine-Needle Aspiration

OBJECTIVES

Fine-needle aspiration (FNA) of thyroid lesions may result in infarction and diagnostic difficulties on subsequent thyroidectomy specimens. Next-generation sequencing (NGS) methods for detection of hallmark driver BRAF V600E mutations may help characterize such tumors in which histologic alterations preclude definitive tissue diagnosis.

METHODS

Thyroidectomy specimens with both malignant FNA diagnoses and resultant infarction were identified from our institutional database. NGS methods were used to detect BRAF V600E mutations in the infarcted thyroid carcinomas.

RESULTS

Nine thyroid carcinomas with infarction were characterized as BRAF-like papillary thyroid carcinoma based on molecular driver categorization and histologic diagnosis. BRAF V600E mutations were detected in the infarcted tissue in four (67%) of six lesions.

CONCLUSIONS

We demonstrate detection of hallmark BRAF V600E mutations by NGS within infarcted tissue of thyroid carcinomas after FNA. This suggests a potential ancillary method of characterizing infarcted thyroid carcinomas whose altered histology may be nondiagnostic.

Treatment of refractory thyroid cancer

Distant metastases from thyroid cancer of follicular origin are uncommon. Treatment includes levothyroxine administration, focal treatment modalities with surgery, external radiation therapy and thermal ablation, and radioiodine in patients with uptake of ¹³¹I in their metastases. Two-thirds of distant metastases become refractory to radioiodine at some point, and when there is a significant tumor burden and documented progression on imaging, a treatment with a kinase inhibitor may provide benefits.

VEGF blockade enhances the antitumor effect of BRAFV600E inhibition

The development of resistance remains a major obstacle to long‐term disease control in cancer patients treated with targeted therapies. In BRAF‐mutant mouse models, we demonstrate that although targeted inhibition of either BRAF or VEGF initially suppresses the growth of BRAF‐mutant tumors, combined inhibition of both pathways results in apoptosis, long‐lasting tumor responses, reduction in lung colonization, and delayed onset of acquired resistance to the BRAF inhibitor PLX4720. As well as inducing tumor vascular normalization and ameliorating hypoxia, this approach induces remodeling of the extracellular matrix, infiltration of macrophages with an M1‐like phenotype, and reduction in cancer‐associated fibroblasts. At the molecular level, this therapeutic regimen results in a de novo transcriptional signature, which sustains and explains the observed efficacy with regard to cancer progression. Collectively, our findings offer new biological rationales for the management of clinical resistance to BRAF inhibitors based on the combination between BRAF^V600E inhibitors with anti‐angiogenic regimens.

VEGF-C Is a Thyroid Marker of Malignancy Superior to VEGF-A in the Differential Diagnostics of Thyroid Lesions

Introduction

Thyroid nodular goiter is one of the most common medical conditions affecting even over a half of adult population. The risk of malignancy is rather small but noticeable–estimated by numerous studies to be about 3–10%. The definite differentiation between benign and malignant ones is a vital issue in endocrine practice. The aim of the current study was to assess the expression of vascular endothelial growth factor A (VEGF-A) and VEGF-C on the mRNA level in FNAB washouts in case of benign and malignant thyroid nodules and to evaluate the diagnostic value of these markers of malignancy.

Materials and Methods

Patients undergoing fine-needle aspiration biopsy (FNAB) in our department between January 2013 and May 2014 were included. In case of all patients who gave the written consent, after ultrasonography (US) and fine-needle aspiration biopsy (FNAB) performed as routine medical procedure the needle was flushed with RNA Later solution, the washouts were frozen in -80 Celsius degrees. Expression of VEGF-A and VEGF-C and GADPH (reference gene) was assessed in washouts on the mRNA level using the real-time PCR technique. Probes of patients who underwent subsequent thyroidectomy and were diagnosed with differentiated thyroid cancer (DTC; proved by post-surgical histopathology) were analyzed. Similar number of patients with benign cytology were randomly selected to be a control group.

Results

Thirty one DTCs and 28 benign thyroid lesions were analyzed. Expression of VEGF-A was insignificantly higher in patients with DTCs (p = 0.13). Expression of VEGF-C was significantly higher in patients with DTC. The relative expression of VEGF-C (in comparison with GAPDH) was 0.0049 for DTCs and 0.00070 for benign lesions, medians – 0.0036 and 0.000024 respectively (p<0.0001).

Conclusions

Measurement of expression VEGF-C on the mRNA level in washouts from FNAB is more useful than more commonly investigated VEGF-A. Measurement of VEGF-C in FNAB washouts do not allow for fully reliable differentiation of benign and malignant thyroid nodules and should be interpreted carefully. Further studies on larger groups are indicated. However, measurement of VEGF-C on mRNA level can bring important information without exposing patient for additional risk and invasive procedures.

PDE5 expression in human thyroid tumors and effects of PDE5 inhibitors on growth and migration of cancer cells

Recent studies have revealed in normal thyroid tissue the presence of the transcript of several phosphodiesterases (PDEs), enzymes responsible for the hydrolysis of cyclic nucleotides. In this work, we analyzed the expression of PDE5 in a series of human papillary thyroid carcinomas (PTCs) presenting or not BRAF V600E mutation and classified according to ATA risk criteria. Furthermore, we tested the effects of two PDE5 inhibitors (sildenafil, tadalafil) against human thyroid cancer cells. PDE5 gene and protein expression were analyzed in two different cohorts of PTCs by real-time PCR using a TaqMan micro-fluid card system and Western blot. MTT and migration assay were used to evaluate the effects of PDE5 inhibitors on proliferation and migration of TPC-1, BCPAP, and 8505C cells. In a first series of 36 PTCs, we found higher expression levels of PDE5A in tumors versus non-tumor (normal) tissues. PTCs with BRAF mutation showed higher levels of mRNA compared with those without mutation. No significant differences were detected between subgroups with low and intermediate ATA risk. Upregulation of PDE5 was also detected in tumor tissue proteins. Similar results were obtained analyzing the second cohort of 50 PTCs. Moreover, all tumor tissues with high PDE5 levels showed reduction of Thyroglobulin, TSH receptor, Thyroperoxidase, and NIS transcripts. In thyroid cancer cells in vitro, sildenafil and tadalafil determined a reduction of proliferation and cellular migration. Our findings demonstrate for the first time an overexpression of PDE5 in PTCs, and the ability of PDE5 inhibitors to block the proliferation of thyroid cancer cells in culture, therefore, suggesting that specific inhibition of PDE5 may be proposed for the treatment of these tumors.

BRAF V600E and risk stratification of thyroid microcarcinoma: a multicenter pathological and clinical study

Studies from single institutions have analyzed BRAF in papillary microcarcinomas, sometimes with contradictory results. Most of them have provided limited integration of histological and clinical data. To obtain a comprehensive picture of BRAF V600E-mutated microcarcinomas and to evaluate the role of BRAF testing in risk stratification we performed a retrospective multicenter analysis integrating microscopical, pathological, and clinical information. Three hundred and sixty-five samples from 300 patients treated at six medical institutions covering different geographical regions of Italy were analyzed with central review of all cases. BRAF V600E statistical analysis was conducted on 298 microcarcinomas from 264 patients after exclusion of those that did not meet the required criteria. BRAF V600E was identified in 145/298 tumors (49%) including the following subtypes: 35/37 (95%, P<0.0001) tall cell and 72/114 (64%, P<0.0001) classic; conversely 94/129 follicular variant papillary microcarcinomas (73%, P<0.0001) were BRAF wild type. BRAF V600E-mutated microcarcinomas were characterized by markedly infiltrative contours (P<0.0001) with elongated strings of neoplastic cells departing from the tumor, and by intraglandular tumor spread (P<0.0001), typically within 5 mm of the tumor border. Multivariate analysis correlated BRAF V600E with specific microscopic features (nuclear grooves, optically clear nuclei, tall cells within the tumor, and tumor fibrosis), aggressive growth pattern (infiltrative tumor border, extension into extrathyroidal tissues, and intraglandular tumor spread), higher American Thyroid Association recurrence risk group, and non-incidental tumor discovery. The following showed the strongest link to BRAF V600E: tall cell subtype, many neoplastic cells with nuclear grooves or with optically clear nuclei, infiltrative growth, intraglandular tumor spread, and a tumor discovery that was non-incidental. BRAF V600E-mutated microcarcinomas represent a distinct biological subtype. The mutation is associated with conventional clinico-pathological features considered to be adverse prognostic factors for papillary microcarcinoma, for which it could be regarded as a surrogate marker. BRAF analysis may be useful to identify tumors (BRAF wild type) that have negligible clinical risk.

VEGF-D and A Preoperative Serum Levels Predict Nodal and Distant Metastases in Differentiated Thyroid Cancer Patients

BACKGROUND

Preoperative tumor aggressiveness biomarkers may help surgeons decide the extent of an operation. However, whether serum angiogenetic factors can be used to predict the prognosis of patients with differentiated thyroid cancer is still unclear.

METHODS

Seventy-six DTC patients were prospectively recruited. Preoperative serum samples were collected and measured for Tie-2, Ang-1, Ang-2, VEGF-A, and VEGF-D levels. The potential correlations between their serum levels and clinicopathologic features as well as their prognoses were analyzed.

RESULTS

Older age (>45 years old) and higher VEGF-A serum levels were independent predictors of extrathyroidal extension. The VEGF-D serum level was an independent factor for lymph node metastases and VEGF-A was an independent factor for distant metastases. None of these serum angiogenetic factors were significantly different between patients who were disease free and those with recurrences. The presence of lymph node metastases was the only independent factor for recurrence over the 2-year follow-up.

CONCLUSION

Preoperative serum VEGF-A and VEGF-D levels were significantly elevated in DTC patients with distant and lymph node metastases. These findings, when combined with other clinicopathological factors, may help in surgical decisions.

Targeting vascular endothelial growth factor (VEGF) pathway in iodine-refractory differentiated thyroid carcinoma (DTC): from bench to bedside

Thyroid cancer is the most common endocrine malignancy, representing 1% of all human malignancies; its incidence has been escalating worldwide during the last decades. In recent years important molecular pathways contributing to tumor progression and worse survival rates have been identified in iodine-refractory differentiated thyroid carcinoma (DTC) with the consequent development of molecular therapeutics to target these specific oncogenic pathways. For example, a positive correlation has been found between expression of vascular endothelial growth factor (VEGF) and a more aggressive phenotype of DTC. This has led to the widespread adoption of VEGF-targeted therapeutics in the preclinical and clinical settings. In this review we will provide an overview of the different aspects of the use of VEGF-pathway-oriented treatments in iodine-refractory DTC with particular focus on future prospects.

Perioperative care in elderly patients undergoing thyroid surgery

The features of western world population are rapidly changing. The increment geriatric population obliges clinicians to implement specific recommendations and guidelines to manage these patients. In the field of thyroid surgery, when indications are represented by benign conditions, surgeons and endocrinologists tent to avoid surgery for the increased perioperative risks in the over 70 year old population. We reviewed our experience in thyroid surgery in geriatric patients within the environment of a "week surgery unit". This unit was conceived to offer a highly specialized setting for thyroid patients needing short stay after surgery. Results showed that the surgical outcomes were comparable to the ones from third surgery in young patients. The week surgery approach is the best and safest formula to offer to the geriatric population needing thyroid surgery.

Shifted termination assay (STA) fragment analysis to detect BRAF V600 mutations in papillary thyroid carcinomas

Background

BRAF mutation is an important diagnostic and prognostic marker in patients with papillary thyroid carcinoma (PTC). To be applicable in clinical laboratories with limited equipment, diverse testing methods are required to detect BRAF mutation.

Methods

A shifted termination assay (STA) fragment analysis was used to detect common V600 BRAF mutations in 159 PTCs with DNAs extracted from formalin-fixed paraffin-embedded tumor tissue. The results of STA fragment analysis were compared to those of direct sequencing. Serial dilutions of BRAF mutant cell line (SNU-790) were used to calculate limit of detection (LOD).

Results

BRAF mutations were detected in 119 (74.8%) PTCs by STA fragment analysis. In direct sequencing, BRAF mutations were observed in 118 (74.2%) cases. The results of STA fragment analysis had high correlation with those of direct sequencing (p < 0.00001, κ = 0.98). The LOD of STA fragment analysis and direct sequencing was 6% and 12.5%, respectively. In PTCs with pT3/T4 stages, BRAF mutation was observed in 83.8% of cases. In pT1/T2 carcinomas, BRAF mutation was detected in 65.9% and this difference was statistically significant (p = 0.007). Moreover, BRAF mutation was more frequent in PTCs with extrathyroidal invasion than tumors without extrathyroidal invasion (84.7% versus 62.2%, p = 0.001). To prepare and run the reactions, direct sequencing required 450 minutes while STA fragment analysis needed 290 minutes.

Conclusions

STA fragment analysis is a simple and sensitive method to detect BRAF V600 mutations in formalin-fixed paraffin-embedded clinical samples.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5684057089135749

Increased expression of pro-angiogenic factors and vascularization in thyroid hyperfunctioning adenomas with and without TSH receptor activating mutations

Autonomously functioning thyroid nodules (AFTN) are known to receive an increased blood influx necessary to sustain their high rate of growth and hormone production. Here, we investigated the expression of hematic and lymphatic vases in a series of 20 AFTN compared with the contralateral non-tumor tissues of the same patients, and the transcript levels of proteins involved in the control of vascular proliferation, including the vascular endothelial growth factor (VEGF) and platelet-derived growth factors (PDGF) and their receptors and the endothelial nitric oxide synthase (eNOS). In parallel, the expression of the differentiation markers sodium/iodide symporter (NIS), thyroperoxidase (TPO), thyroglobulin (Tg), and TSH receptor (TSHR) was also investigated. The data were further analyzed comparing subgroups of tumors with or without mutations in the TSHR gene. Analysis by means of CD31 and D2-40 immunostaining showed in AFTN an increased number of hematic, but not lymphatic, vessels in parallel with an enhanced proliferation rate shown by increased Ki67 staining. Quantitative RT-PCR analysis revealed an increase of VEGF, VEGFR1 and 2, PDGF-A, PDGF-B, and eNOS expression in tumor versus normal tissues. Also, higher transcript levels of NIS, TPO, and Tg were detected. Comparison of the two subgroups of samples revealed only few differences in the expression of the genes examined. In conclusion, these data demonstrate an increased expression of angiogenesis-related factors associated with an enhanced proliferation of hematic, but not lymphatic, vessels in AFTNs. In this context, the presence of TSHR mutations may only slightly influence the expression of pro-angiogenic growth factors.

Combinational usage of next generation sequencing and qPCR for the analysis of tumor samples

The combination of multiple techniques especially those adding complementary information have proven to be beneficial in terms of data consistency. The employment of quantitative PCR (qPCR) prior to next generation sequencing (NGS) methods such as RNA-Seq and mutational analysis presented here does not only enhance data in terms of CNV integration and sample choice, but also allows a faster and more efficient workflow. Correct analysis of libraries prior to sequencing has proven to be a vital step for specific assumption and to some extent for a more parallel testing. By illustrating the combination of qPCR and NGS in oncological examples, the potential of this approach is presented.

Cyclic AMP-response element modulator inhibits the promoter activity of the sodium iodide symporter gene in thyroid cancer cells

BACKGROUND

Comprehension of the regulatory mechanism involved in the sodium iodide symporter (NIS) expression is of great relevance for thyroid cancer. In fact, restoration of NIS expression would be a strategy to treat undifferentiated thyroid cancer. Previous in vitro findings suggest that the cyclic AMP-response element (CRE) modulator (CREM) is involved in control of NIS expression. In this work, we examined the expression of CREM in a series of thyroid cancer tissues and its action on NIS promoter in human thyroid cancer cells.

METHODS

Expression of mRNA levels for CREM, PAX8 and NIS was measured by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) in 6 normal thyroid tissues, 22 papillary, 12 follicular and 4 anaplastic thyroid cancers. The effect of CREM on transcriptional activity of the NIS promoter was investigated by transient transfection of human thyroid cell lines.

RESULTS

Compared to normal tissues, NIS and PAX8 mRNA levels were significantly reduced in all types of thyroid cancer. As expected, the maximal decrease was detected in anaplastic thyroid cancer. Conversely, CREM mRNA levels were increased in all types of thyroid cancer, reaching statistical significance for follicular and anaplastic thyroid carcinoma (p=0.0157 and 0.0045, respectively). Transfection experiments showed an inhibitory effect of CREM on NIS promoter activity in various thyroid cancer cell lines.

CONCLUSIONS

These data demonstrate that CREM expression is increased in thyroid cancer tissue and may play a role in the downregulation of NIS expression in thyroid cancer acting at the transcriptional level.