Treatment of Obesity with Thyroid hormones in Europe. Data from the THESIS* Collaboration.

PURPOSE: The use of thyroid hormones (TH) to treat obesity is unsupported by evidence as reflected in international guidelines. We explored views about this practice, and associations with respondent characteristics among European thyroid specialists. METHODS: Specialists from 28 countries were invited to a survey via professional organisations. The relevant question was whether "Thyroid hormones may be indicated in biochemically euthyroid patients with obesity resistant to lifestyle interventions". RESULTS: Of 17,232 invitations 5695 responses were received (33% valid response rate; 65% women; 90% endocrinologists). Of these, 290 (5.1%) stated that TH may be indicated as treatment for obesity in euthyroid patients. This view was commoner among non-endocrinologists (8.7% vs. 4.7%, p < 0.01), private practice (6.5% vs. 4.5%, p < 0.01), and varied geographically (Eastern Europe, 7.3%; Southern Europe, 4.8%; Western Europe, 2.7%; and Northern Europe, 2.5%). Respondents from Northern and Western Europe were less likely to use TH than those from Eastern Europe (p < 0.01). Gross national income (GNI) correlated inversely with this view (OR 0.97, CI: 0.96-0.97; p < 0.001). Having national guidelines on hypothyroidism correlated negatively with treating obesity with TH (OR 0.71, CI: 0.55-0.91). CONCLUSIONS: Despite the lack of evidence, and contrary to guidelines' recommendations, about 5% of respondents stated that TH may be indicated as a treatment for obesity in euthyroid patients resistant to life-style interventions. This opinion was associated with (i) respondent characteristics: being non-endocrinologist, working in private practice, treating a small number of hypothyroid patients annually and (ii) national characteristics: prevalence of obesity, Eastern Europe, low GNI and lack of national hypothyroidism guidelines.

[Genetics of thyroid nodules and thyroid carcinoma]. / Genetik von Schilddrüsenknoten und Schilddrüsenkarzinomen.

Thyroid nodules are heterogeneous tumors with variable genetic signatures. Thyroid cancers are monoclonal lesions with a defined histomorphology that largely depends on the underlying somatic mutation. While the mutation rate is generally low in differentiated thyroid cancers, poorly differentiated and anaplastic thyroid cancers show a high mutation load. The identification of somatic mutations in fine needle aspirates can be helpful for the differential diagnostics of thyroid nodules; however, a prognostic contribution is less certain. The molecular pathology of thyroid tumors is helpful for the development of targeted therapies and may infer novel immuno-oncological concepts for advanced aggressive thyroid cancers.

[Molecular Pathogenesis of Thyroid Nodules: Relevance for Clinical Care]. / Molekulare Pathogenese von Schilddrüsenknoten ­ Bedeutung für die klinische Versorgung.

Thyroid nodules represent heterogeneous tumors with distinct molecular signatures. While benign thyroid nodules correspond to poly- or monoclonal tumors, thyroid carcinomas are monoclonal and thus "real" neoplasms. These are caused by somatic mutations that lead to the constitutive activation of specific signaling cascades and determine the corresponding histology and also partly the functional phenotype of the thyroid tumor. Dedifferentiation of thyroid carcinomas is accompanied by the occurrence of additional mutations in the tumors. The mutation load of thyroid carcinomas correlates with their biological behavior. In clinical practice, detection of somatic mutations can help in the cytological differential diagnosis. In the prognostic assessment of thyroid tumors, proof of classical oncogene mutations (BRAF, RAS) has little relevance. Other genetic alterations, especially TERT promoter mutations that occur with increasing frequency in advanced thyroid carcinomas, probably have a prognostic significance. The molecular signature, however, is of great relevance for the development and application of targeted therapies in advanced carcinomas (radioactive iodine-refractory DTC, PDTC and ATC, metastatic medullary carcinoma). For this, there is increasing evidence from clinical studies and case reports that underline the concept of "oncogene addiction" as a pathogenetically relevant mechanism of thyroid tumorigenesis and carcinogenesis.

The Transcriptional Regulation of FOXO Genes in Thyrocytes.

FOXO transcription factors are key regulators of DNA damage repair, proliferation and apoptosis in thyrocytes. Thyroid malignancies show impaired FOXO function. In this study, we investigated the transcriptional regulation of FOXO isoforms in thyroid epithelial cells. mRNA expression of FOXO isoforms (FOXO1, 3 and 4) was determined in FRTL-5 cells stimulated with different growth factors and H2O2. Furthermore, the impact of PI3K/AKT signalling on FOXO transcription was investigated in PI3K p110α mutant FRTL-5 cells and regulatory dependence of FOXO transcription on FOXO was studied in FRTL-5 cells with hFOXO3 overexpression. Finally, mRNA expression levels of FOXO isoforms were determined in human epithelial thyroid tumours. Growth factor deprivation induced transcription of FOXO1, 3 and 4, whereas insulin stimulation decreased FOXO1 and FOXO4 transcription in FRTL-5 cells. Inhibition of the PI3K/AKT cascade amplified FOXO1 and FOXO4 expression. In contrast, H2O2 and TSH did not influence FOXO transcription in thyrocytes. Overexpression of PI3K p110α inhibited FOXO3 and induced FOXO4 transcription. In human thyroid tumours, FOXO1 and FOXO3 mRNA levels were significantly downregulated in papillary thyroid carcinoma when compared to normal tissues. In contrast, follicular thyroid carcinomas showed significant upregulation of FOXO4 mRNA.In this paper, we demonstrate an influence of PI3K signalling on FOXO transcription in thyrocytes. Moreover, we show that thyroid cancers exhibit alterations in FOXO transcription besides the previously reported alterations in posttranslational FOXO3 regulation. These findings may add to the concept of targeting the PI3K pathway in advanced thyroid cancers.

Sunitinib Efficacy in Patients with Advanced pNET in Clinical Practice.

Sunitinib treatment leads to improvement in progression-free survival in patients with advanced pancreatic neuroendocrine tumours (pNETs). However, limited data exist regarding the effectiveness, safety and tolerability in clinical practice. We present the results of the first detailed pNET cohort analysis since sunitinib was approved. Patients with advanced, differentiated pNET treated with sunitinib were retrospectively analysed. All patients had progressive disease before start of sunitinib treatment. Twenty-one patients, with a median age of 64 years (range 28-78), were included in this study. Nineteen patients could be analysed for treatment effectiveness. Twelve (57%) patients exhibited either a partial response (1 patient) or stable disease (11 patients) according to the RECIST criteria. The median progression-free survival was 7.0 months (95% CI 3.0-12.0); the probability of being event-free at 6 months was 52.6% (95% CI 28.4-72.1). Potential influencing factors as Ki-67 index, age or duration of disease did not show significant correlations with the response to sunitinib therapy. Considering the differences in patients' characteristics, sunitinib in daily practice showed effectiveness parameters similar to the phase III trial.

Expression of the cAMP binding protein EPAC1 in thyroid tumors and growth regulation of thyroid cells and thyroid carcinoma cells by EPAC proteins.

The thyrotropin receptor-cAMP pathway is central in growth regulation of thyroid cells and thyroid tumorigenesis, and it regulates expression of thyroid specific genes. Recently, 2 new protein kinase A-independent cAMP effectors named EPAC1 and 2 were described that activate additional intracellular pathways. The aim of our study was to investigate the role of EPAC proteins in growth regulation of thyroid cells and thyroid carcinomas. EPAC1 expression was investigated immunohistochemically in tissues of various thyroid tumors. Utilizing MTT assay, the effect of EPAC stimulation on proliferation in thyroid carcinoma cells and in non-transformed rat FRTL5 cells was investigated. The activation of intracellular signaling pathways was examined by RAP pull-down assay and Western blots. EPAC1 expression was strong in non-oxyphilic follicular thyroid adenomas and carcinomas and in follicular papillary thyroid carcinomas. It was moderate in oxyphilic follicular tumors and classical and tall cell papillary carcinomas. In contrast, EPAC1 expression was low in poorly differentiated carcinomas and very low in anaplastic carcinomas. Thyroid carcinoma cell lines showed no or very weak EPAC1 expression and exhibited no growth-promoting effect after EPAC stimulation. Non-transformed rat FRTL5 cells were growth-stimulated by an EPAC-specific cAMP-analogue and showed EPAC-dependent activation of RAP, ERK, and p70S6 kinase. EPAC1 expression and cellular response to EPAC activation in rat FRTL5 cells reflect cellular responses to cAMP and TSH stimulation in non-transformed thyroid cells. In undifferentiated thyroid carcinomas, loss of EPAC1 expression may be in accordance with the loss of thyroid-specific functions and the loss of responsiveness of the TSHR-cAMP pathway.

[Clinical importance of thyroid gland cytology]. / Klinische Bedeutung der Schilddrüsenzytologie.

The cytological evaluation of fine needle biopsies (FNB) of the thyroid gland crucially depends on a close cooperation between clinicians and cytopathologists. Scintigraphy, sonography as well as clinical data and patient history are necessary for a correct interpretation of the indications for FNB; moreover, these data are of outstanding importance for cytopathologists for the correct interpretation of the cytomorphological findings. This overview describes the present standards in the acquisition, technical workup and cytopathological interpretation of thyroid gland tissue obtained by FNB, particularly focusing on the rapidly growing relevance of additional molecular pathological investigations to increase the diagnostic accuracy of thyroid FNB.

[Differentiated thyroid cancer]. / Differenzierte Schilddrüsenkarzinome.

Thyroid carcinoma is a rare and heterogeneous disease. Initial therapy and follow-up has to be adjusted to the individual risk for an excellent vs. poor prognosis. Differentiated thyroid cancer has a very high cure rate and is treated by surgery, usually followed by radioiodine ablation. Depending on the response to initial therapy the risk for persisting or recurrent disease should be re-evaluated. Continued TSH suppressive levothyroxine therapy is only recommended in high-risk patients. In contrast, metastatic radioiodine-refractory thyroid cancers have a poor prognosis and may benefit from multidisciplinary treatment concepts including tyrosine kinase inhibitors. Due to its complexity, management of thyroid cancer patients should be performed in close collaboration with a specialized thyroid cancer team.

[Medullary thyroid carcinoma]. / Das medulläre Schilddrüsenkarzinom.

Medullary thyroid carcinoma (MTC) is a very rare malignancy, which arises from parafollicular C cells and accounts for 3-5% of all thyroid cancers. MTC represents a neuroendocrine tumor with a biology that differs considerably from differentiated thyroid cancer. Presence of a RET proto-oncogene germline mutation indicates hereditary C cell disease in the context of multiple endocrine neoplasia type 2 and hence a special treatment algorithm is required. Cure of MTC is only possible through surgery. Calcitonin screening is advocated for early MTC diagnosis and preoperative MTC management stratification. In case of surgically incurable persistent MTC, estimation of calcitonin and CEA doubling time is crucial to assess tumor biology and is complemented by multimodal imaging to assess tumor burden. Treatment decisions in incurable MTC must be carefully balanced with treatment-related morbidity, since MTC may take an indolent course over years.

Diabetes insipidus as a rare cause of acute cognitive impairment in multiple sclerosis.

Multiple sclerosis (MS) is a complex neurodegenerative disease presenting with a diversity of clinical symptoms including palsy and cognitive impairment. We present a 59-year-old woman with a history of secondary progressive MS since 1987, who was referred to our department because of recent onset of confusion and polydipsia. Initial lab tests showed mildly elevated serum sodium levels and low urine osmolality. Under water deprivation, diuresis and low urine osmolality persisted and serum sodium levels rose above 150 mmol/l. Oral desmopressin resulted in normalisation of serum sodium as well as urine osmolarity, confirming a diagnosis of central diabetes insipidus. As drug-induced diabetes could be excluded, pituitary magnetic resonance imaging (MRI) was performed. A demyelinating lesion was detected in the hypothalamus. The patient was started on oral desmopressin treatment (0.2 mg/day). Fluid intake and serum sodium levels have since remained normal. In summary, we report the rare case of a patient presenting with diabetes insipidus due to progressive MS. Diabetes insipidus should be considered in MS patients who develop new onset of polydipsia.

[Hirsutism and multinodular goiter in a 40-year-old female watchmaker]. / Hirsutismus und Struma multinodosa bei einer 40-jährigen Uhrmacherin.

This article presents the case of a female patient with acromegaly caused by ectopic production of growth hormone-releasing hormone (GHRH) secretion. In the presence of typical clinical features of acromegaly but a lack of evidence for a pituitary adenoma the results of somatostatin receptor scintigraphy were indicative of a typical carcinoid of the lungs as the cause of the ectopic secretion of GHRH and the stimulation of pituitary gland growth hormone secretion resulting in acromegaly. Finally, the patient underwent curative surgical treatment.

[Diseases of the thyroid gland in men and women-Status quo and new research needs]. / Schilddrüsenerkrankungen bei Frauen und Männern ­ Status quo und neuer Forschungsbedarf.

"Diseases of the thyroid gland occur more frequently in women": this statement has been used in textbooks for decades; however, is this equally true for all thyroid gland diseases and can conclusions be derived from this for a different disease relevance and prognosis in men and women? Is possibly even a sex-specific treatment needed? These questions are taken up and subsequently the epidemiological data and studies that have investigated the influence of gender on the course of thyroid gland diseases are taken into consideration. It is shown that the data situation is much more restricted than is to be expected for frequent diseases in the general population.

ADM3, TFF3 and LGALS3 are discriminative molecular markers in fine-needle aspiration biopsies of benign and malignant thyroid tumours.

BACKGROUND: Previously, we reported a six-marker gene set, which allowed a molecular discrimination of benign and malignant thyroid tumours. Now, we evaluated these markers in fine-needle aspiration biopsies (FNAB) in a prospective, independent series of thyroid tumours with proven histological outcome. METHODS: Quantitative RT-PCR was performed (ADM3, HGD1, LGALS3, PLAB, TFF3, TG) in the needle wash-out of 156 FNAB of follicular adenoma (FA), adenomatous nodules, follicular and papillary thyroid cancers (TC) and normal thyroid tissues (NT). RESULTS: Significant expression differences were found for TFF3, HGD1, ADM3 and LGALS3 in FNAB of TC compared with benign thyroid nodules and NT. Using two-marker gene sets, a specific FNAB distinction of benign and malignant tumours was achieved with negative predictive values (NPV) up to 0.78 and positive predictive values (PPV) up to 0.84. Two FNAB marker gene combinations (ADM3/TFF3; ADM3/ACTB) allowed the distinction of FA and malignant follicular neoplasia with NPV up to 0.94 and PPV up to 0.86. CONCLUSION: We demonstrate that molecular FNAB diagnosis of benign and malignant thyroid tumours including follicular neoplasia is possible with recently identified marker gene combinations. We propose multi-centre FNAB studies on these markers to bring this promising diagnostic tool closer to clinical practice.

[Thyroid illness during pregnancy]. / Schilddrüsenerkrankungen und Schwangerschaft.

Pregnancy causes a number of physiological alterations in thyroid hormone metabolism that need to be distinguished from the pathophysiological states of thyroid dysfunction. Both hypothyroidism and thyrotoxicosis may impair the course of pregnancy and may negatively affect the fetus. In particular, maternal hypothyroidism may lead to irreparable and detrimental deficits in the neurocognitive development of the fetus. Autoimmune thyroid disease is the most common cause of thyroid dysfunction in pregnancy. Hashimoto's thyroiditis is associated with impaired fertility and miscarriage, and may first manifest in pregnancy due to the increased thyroid hormone requirement. Graves' disease often shows a characteristic course in pregnancy with amelioration of thyrotoxicosis in the second half of pregnancy and exacerbation after delivery. In addition transplacental passage of maternal TSH receptor antibodies may lead to thyrotoxicosis in the fetus and/or newborn.

Impact of pregnancy on prevalence of goitre and nodular thyroid disease in women living in a region of borderline sufficient iodine supply.

An interplay of genetic, epigenetic, and environmental factors contributes to thyroid disease. In a cross-sectional study, we aimed to determine the influence of parity in combination with other risk factors on the prevalence of goitre and nodular thyroid disease (NTD) in women living in a region of previous overt iodine deficiency, which experienced a continuous improvement in alimentary iodine supply in the last two decades. Thyroid ultrasonography (7.5 MHz; Merck Thyromobil) was performed by the same investigator in 736 women living in Thuringia and Saxony. Age and BMI were documented and a comprehensive history on pregnancies, family history of thyroid disease, and past or present smoking was obtained. Goitre prevalence was 19.1%. Solitary thyroid nodules were detected in 21.5%, and multiple nodules in 23.8% of women. In a multivariate analysis, neither age nor parity was positively correlated with goitre prevalence and NTD. A significant correlation was detected between BMI and goitre and multinodular disease. Goitre was found in 25.3% of women with a positive family history for thyroid disease, as opposed to 16.1% goitre in women with a negative family history. Neither goitre nor NTD were associated with a history of smoking in the whole study population. Thyroid nodules and/or goitre are present in up to 45% of women in an area of previous overt iodine deficiency. Whereas BMI and family history are positively correlated with the presence of NTD and goitre, no such correlation could be detected for pregnancy and smoking after processing our data with multivariate analyses.

High-efficient nonviral transfection of the rat thyroid cell line FRTL-5.

FRTL-5 cells are used in many laboratories as an in vitro system of thyroid follicular cells since they share many properties of human thyrocytes. However, the use of FRTL-5 cells for experimental modifications is limited by low transfection efficiencies of lipid-based transfections and the need for cumbersome viral transduction protocols. A new technology - nucleofection - has become available for cell lines that are difficult to transfect. Here, we report the application and optimization of this method in FRTL-5 cells. Using the green fluorescent protein (GFP) as a reporter gene, FRTL-5 cells were easily transfectable with efficiencies over 60%. In addition, the simultaneous transfer of siRNA against GFP was feasible and allowed suppression of GFP over at least 4 days. Furthermore nucleofection was successful for establishing stable FRTL-5 cell clones. In conclusion, this optimized fast and efficient nucleofection protocol offers new properties for the experimental use of FRTL-5 cells.

Somatostatin receptor subtype expression in human thyroid tumours.

Somatostatin receptors (SSTR) are expressed in various endocrine tumours. The expression of SSTR at the tumour cell surface confers the possibility for diagnostic imaging and therapy of tumours using radiolabeled somatostatin analogues. The majority of currently available somatostatin analogues show a higher binding affinity for the SSTR2 subtype. To date, the precise expression pattern of the SSTR subtypes 1-5 in thyroid epithelial tumours remains to be determined. We investigated the mRNA expression of SSTR1-5 in benign and malignant epithelial thyroid tumours [20 cold thyroid nodules (CTNs), 20 toxic thyroid nodules (TTNs), 20 papillary, 20 follicular, and 5 anaplastic carcinomas (PTCs, FTCs, ATCs, respectively)] and compared them to normal surrounding thyroid tissues. Four out of five SSTR subtypes were detected in malignant thyroid tumours, benign neoplasia, and normal surrounding tissue with a predominant expression of SSTR2 and SSTR5, and a weak expression of SSTR1 and SSTR3. Weak SSTR4 mRNA expression was detected in some PTCs. Compared to normal thyroid tissue, SSTR2 was significantly upregulated in PTC and ATC. In addition significant upregulation of SSTR3 was found in PTC. SSTR5 mRNA expression was increased in PTC and FTC and significantly decreased in CTN and TTN compared to normal thyroid tissue. SSTR2 is the predominant subtype in thyroid epithelial tumours with a high expression pattern, in particular, in PTC . Perspectively, the expression of distinct SSTR in thyroid epithelial tumours might represent a promising avenue for diagnostics and therapy of advanced thyroid cancer with somatostatin analogues.

Distinct regulation of intrinsic apoptosis in benign and malignant thyroid tumours.

Aberrations in the control of apoptosis represent a central feature of thyroid carcinogenesis. However, little is known about the regulation of components of the intrinsic apoptosis pathway in the thyroid. Using a real-time PCR approach we investigated the mRNA expression levels of Caspase3, Caspase3 s, xIAP, Bad, and beta-actin in a panel of 79 thyroid tumours. Additionally, we assessed the activation status of Caspase3 by immunohistochemistry. In the present study, we provide first evidence for a deregulation of the intrinsic apoptosis pathway on the transcriptional and post-transcriptional level. Thus, malignant thyroid tumours revealed a significant downregulation of the proapoptotic Bad. In contrast Caspase3 s, an alternative splice variant of Caspase3 with anti-apoptotic characteristics, was upregulated in follicular and anaplastic cancers. Moreover, papillary thyroid tumours revealed a significant upregulation of Caspase3 mRNA. On the post-translational level, thyroid malignancies featured an impairment in the activation of Caspase3, since activated Caspase3 accumulated exclusively in the cytoplasm of thyroid cancer cells, whereas follicular adenoma and normal thyroid tissues showed no cytoplasmatic but nuclear Caspase3 distribution. Further knowledge on apoptosis-deregulation during thyroid carcinogenesis might confer diagnostic and therapeutic benefits in the management of thyroid cancer.

[Benign thyroid nodule or thyroid cancer?]. / Benigner Schilddrüsenknoten oder Schilddrüsenmalignom?

Thyroid nodular disease is highly frequent and affects 20-23% of the adult population in Germany. Differential diagnosis of thyroid nodules is directed at exclusion of thyroid autonomy and thyroid cancer. In addition, large nodules/nodular goiters may cause oesophageal and/or tracheal compression. Besides the patient's history and clinical examination, laboratory investigations (TSH-level, calcitonin screening), functional (scintiscan) and morphological imaging (ultrasound, in rare cases also CT without contrast media and MRI), as well as fine needle aspiration biopsy are useful tools in the differential diagnosis. In the past years, major advances have been made in the understanding of the molecular pathogenesis of thyroid tumors. This has led to the possibility of a molecular classification of thyroid tumors and may have prognostic as well as therapeutic impact.