| 1. |
- Karger, Stefan, et al.
(author)
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Distinct pattern of oxidative DNA damage and DNA repair in follicular thyroid tumours.
- 2012
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In: Journal of molecular endocrinology. - 1479-6813. ; 48:3, s. 193-202
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Journal article (peer-reviewed)abstract
- Increased oxidative stress has been linked to thyroid carcinogenesis. In this paper, we investigate whether oxidative DNA damage and DNA repair differ in follicular adenoma (FA) and follicular thyroid carcinoma (FTC). 7,8-Dihydro-8-oxoguanine (8-OxoG) formation was analysed by immunohistochemistry in 46 FAs, 52 FTCs and 18 normal thyroid tissues (NTs). mRNA expression of DNA repair genes OGG1, Mut Y homologue (MUTYH) and endonuclease III (NTHL1) was analysed by real-time PCR in 19 FAs, 25 FTCs and 19 NTs. Induction and repair of oxidative DNA damage were studied in rat FRTL-5 cells after u.v. irradiation. Moreover, activation of DNA damage checkpoints (ataxia telangiectasia mutated (ATM) and H2A histone family, member X (H2AFX (H2AFX))) and proliferation index (MIB-1) were quantified in 28 non-oxyphilic and 24 oxyphilic FTCs. Increased nuclear and cytosolic 8-OxoG formation was detected in FTC compared with follicular adenoma, whereby cytosolic 8-OxoG formation was found to reflect RNA oxidation. Significant downregulation of DNA repair enzymes was detected in FTC compared with FA. In vitro experiments mirrored the findings in FTC with oxidative stress-induced DNA checkpoint activation and downregulation of OGG1, MUTYH and NTHL1 in FRTL-5 cells, an effect that, however, was reversible after 24 h. Further analysis of FTC variants showed decreased oxidative DNA damage, sustained checkpoint activation and decreased proliferation in oxyphilic vs non-oxyphilic FTC. Our data suggest a pathophysiological scenario of accumulating unrepaired DNA/RNA damage in FTC vs counterbalanced DNA/RNA damage and repair in FA. Furthermore, this study provides the first evidence for differences in oxidative stress defence in FTC variants with possible implications for therapeutic response and prognostic outcome.
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| 2. |
- Karger, Stefan, et al.
(author)
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FOXO3a : a novel player in thyroid carcinogenesis?
- 2009
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In: Endocrine-Related Cancer. - 1351-0088 .- 1479-6821. ; 16:1, s. 189-99
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Journal article (peer-reviewed)abstract
- The forkhead box transcription factor FOXO3a has recently been identified as central mediator of the cellular response to oxidative stress inducing cell cycle arrest or apoptosis. The aim of our study was to investigate the regulation of FOXO3a in the thyroid and to determine whether alterations in FOXO3a activity occur in thyroid carcinogenesis. In vitro, we demonstrate that FOXO3a activity is negatively regulated by the PI3K/Akt cascade promoting increased phosphorylation and cytoplasmatic accumulation of FOXO3a with decreased transcription of the target genes p27kip (CDKN1B) and Bim (BCL2L11), but increased expression of GADD45A. By contrast, we show that H(2)O(2) exposure activates FOXO3a in thyrocytes with JNK (MAPK8)-mediated nuclear accumulation of FOXO3a and increased expression of the cell cycle arrest genes p27kip and GADD45A. In vivo, we observed a marked cytoplasmatic accumulation of FOXO3a in differentiated thyroid cancers versus an exclusive nuclear accumulation in follicular adenoma and normal thyroid tissue. Moreover, this cytosolic accumulation of FOXO3a correlated with an increased phospho-Akt expression in thyroid malignancies and was accompanied by decreased expression of the FOXO targets p27kip and Bim and an increase in GADD45A mRNA expression in the thyroid cancers. Our data suggest FOXO3a as a novel player of cellular stress response in the thyroid, mediating the thyrocyte's fate either to survive or to undergo apoptosis. Furthermore, PI3K-dependent FOXO3a inactivation may be a novel pathomechanism for the escape from apoptosis in thyroid cancer cells, in particular in follicular thyroid carcinoma.
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| 3. |
- Krause, Kerstin, et al.
(author)
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Characterisation of DEHAL1 expression in thyroid pathologies.
- 2007
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In: European Journal of Endocrinology. - 0804-4643 .- 1479-683X. ; 156:3, s. 295-301
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Journal article (peer-reviewed)abstract
- UNLABELLED: Iodotyrosine dehalogenase 1 (DEHAL1) is a transmembrane protein involved in the recycling of iodide in the human thyroid. The aim of the present study was (I) to investigate whether DEHAL1 expression is different in differentially functioning thyroid pathologies and (II) to evaluate DEHAL1 as a possible marker of thyroid cell differentiation.DESIGN AND METHODS: Real-time PCR for DEHAL1 and its isoform DEHAL1B was performed in a series of 105 thyroid specimens, including toxic thyroid nodules (TTN), Graves' disease (GD) thyroids, benign cold thyroid nodules (CTN), normal thyroid tissues and thyroid cancers (follicular thyroid carcinomas (FTC), papillary thyroid carcinomas (PTC), partially differentiated thyroid cancers (PDTC) and anaplastic thyroid carcinomas (ATC)). In addition, DEHAL1 protein expression was studied by immunohistochemistry in 163 benign and malignant thyroid pathologies and normal thyroids.RESULTS: (I) The highest DEHAL1 mRNA levels were found in GD thyroids, while downregulation of DEHAL1 and DEHAL1B mRNA occurred in PTC and ATC (P<0.001 and <0.05 respectively); (II) DEHAL1 protein was overexpressed in TTNs and GD thyroids with predominant apical staining in all samples; (III) a weaker and patchy staining pattern was found in CTNs and normal thyroids; (IV) in differentiated thyroid cancers (FTC and PTC), a diffuse cytoplasmic DEHAL1 expression was found; and (V) in PDTC and ATC, DEHAL1 expression was faint or absent.CONCLUSION: Upregulation of DEHAL1 protein expression and sublocalisation of DEHAL1 at the apical cell pole in TTNs and GD thyroids is consistent with increased thyroid hormone turnover during thyrotoxicosis. Diffuse cytoplasmatic localisation or downregulation of DEHAL1 expression in thyroid cancers suggests alteration or loss of DEHAL1 function during thyroid cell dedifferentiation.
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| 4. |
- Krause, Kerstin, et al.
(author)
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Dissecting molecular events in thyroid neoplasia provides evidence for distinct evolution of follicular thyroid adenoma and carcinoma.
- 2011
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In: American Journal of Pathology. - : Elsevier BV. - 0002-9440 .- 1525-2191. ; 179:6, s. 3066-74
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Journal article (peer-reviewed)abstract
- Benign hypofunctional cold thyroid nodules (CTNs) are a frequent scintiscan finding and need to be distinguished from thyroid carcinomas. The origin of CTNs with follicular morphologic features is unresolved. The DNA damage response might act as a physiologic barrier, inhibiting the progression of preneoplastic lesions to neoplasia. We investigated the following in hypofunctional follicular adenoma (FA) and follicular thyroid cancer (FTC): i) the mutation rate of frequently activated oncogenes, ii) the activation of DNA damage response checkpoints, and iii) the differential proteomic pattern between FA and FTC. Both FTC and FA, which did not harbor RAS, phosphoinositide-3-kinase, or PAX/peroxisome proliferator activated receptor-γ mutations, express various proteins in common and others that are more distinctly expressed in FTC rather than in FA or normal thyroid tissue. This finding is in line with the finding of constitutive DNA damage checkpoint activation (p-Chk2, γ-H2AX) and evidence for replicative stress causing genomic instability (increased cyclin E, retinoblastoma, or E2F1 mRNA expression) in FTC but not FA. We discuss the findings of the increased expression of translationally controlled tumor protein, phosphatase 2A inhibitor, and DJ-1 in FTC compared with FA identified by proteomics and their potential implication in follicular thyroid carcinogenesis. Our present findings argue for the definition of FA as a truly benign entity and against progressive development of FA to FTC.
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| 5. |
- Krause, Kerstin, et al.
(author)
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Evidence for a role of the amyloid precursor protein in thyroid carcinogenesis.
- 2008
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In: The Journal of endocrinology. - 1479-6805. ; 198:2, s. 291-9
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Journal article (peer-reviewed)abstract
- We have recently found an increased expression of amyloid precursor protein (APP) in cold thyroid nodules that are difficult to classify as a truly benign thyroid neoplasm or a lesion with the potential for further dedifferentiation. Since differences in APP activity have been found in other human cancers, we asked whether thyroid carcinogenesis might be associated with an altered APP expression and function. APP regulation was studied in vitro in differentiated (FRTL-5) and dedifferentiated follicular thyroid carcinomas (FTC-133) thyroid cells after specific inhibition or activation of the cAMP-PKA, the PI3K/AKT or the protein kinase c (PKC) cascades. In vivo analysis of APP expression and downstream signalling was performed in benign and malignant thyroid tissues. We found that upregulation of APP expression and sAPP secretion is induced by TSH in differentiated thyroid cells and by insulin in thyroid cancer cells. PKC is a strong activator of APP cleavage and in FTC-133 confers prolonged release of the APP ectodomain. FTC-133 but not FRTL-5 cells show a prominent cell surface expression of the APP ectodomain, which has been suggested to function as an autocrine growth factor. Thyroid cancers are characterized by APP upregulation, increased membrane targeting of the APP ectodomain and significantly increased mRNA levels of the APP scaffold proteins JIP1, ShcA and Fe65.
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| 6. |
- Krause, Kerstin, et al.
(author)
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TFF3-based candidate gene discrimination of benign and malignant thyroid tumors in a region with borderline iodine deficiency.
- 2008
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In: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 93:4, s. 1390-3
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Journal article (peer-reviewed)abstract
- BACKGROUND: With the advent of microarray technology, increasing numbers of marker genes are proposed to distinguish benign and malignant thyroid lesions. However, most markers await confirmation through independent studies. In this paper, we re-evaluate the diagnostic potential of 10 proposed candidate genes in benign and malignant thyroid pathologies in a region with borderline iodine deficiency.METHODS: Quantitative real-time PCR was performed for CCND2, PLAB, PCSK2, HGD1, TFF3, B4GALT, LGALS3, ETS1, ADM3, and TG in 150 thyroid specimens, including 52 benign thyroid nodules (28 follicular adenoma and 24 adenomatous nodules), 52 corresponding normal thyroid tissues, 20 follicular carcinomas, 20 papillary carcinomas, and six undifferentiated carcinomas.RESULTS: On a single-gene basis, significant differences in mRNA expression were found for TFF3, PLAB, and ADM3 in benign thyroid nodules and thyroid malignancy. Using two-marker gene sets, we identified 11 combinations, which allowed both a distinction of benign and malignant thyroid nodules and a discrimination of follicular adenoma and carcinoma. However, for cancer prediction, analysis of a minimum of six genes per sample was necessary and allowed correct prediction of a benign thyroid lesion and thyroid cancer with 94% accuracy in the most discriminative set (TFF3/PLAB/TG/ADM3/HGD1/LGALS3).CONCLUSION: We confirm the applicability of a number of recently proposed marker genes for the distinction of benign and malignant thyroid tumor and suggest that their diagnostic usefulness is independent of the iodide supply. We propose that the most discriminative marker set identified in our validation study together with marker combinations proposed by other investigators should now be evaluated in multicenter trials.
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| 7. |
- Siegel, Sonja, et al.
(author)
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Coping strategies have a strong impact on quality of life, depression, and embitterment in patients with Cushing's disease
- 2016
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In: Pituitary. - : Springer Science and Business Media LLC. - 1386-341X .- 1573-7403. ; 19:6, s. 590-600
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Journal article (peer-reviewed)abstract
- Quality of life (QoL) and psychosocial well-being are substantially impaired in patients with Cushing's disease (CD), not only at the acute illness stage but also after therapy; however, the reason for these impairments remains unclear. In this cross-sectional, patient-reported outcome study, we conducted a postal survey on psychosocial impairment and coping strategies in patients after surgical treatment of CD in three large tertiary referral centers. In total, 176 patients with CD completed a compilation of self-assessment inventories pertaining to depression (Hospital Anxiety and Depression Scale, HADS), QoL (Short Form SF-36, Tuebingen CD; Tuebingen CD-25), coping style (Freiburg questionnaire on coping with illness, FKV-LIS), and embitterment (Bern Embitterment Inventory), on average 6.8 +/- 6.66 years after surgery. Regression analyses were performed to identify predictors of psychosocial impairment. At the time of the study, 21.8 % of patients suffered from anxiety, 18.7 % experienced an above-average feeling of embitterment, and 13.1 % suffered from depression. Maladaptive coping styles (FKV-LIS subscales depressive coping and minimizing importance) emerged as robust and strong predictors of psychosocial impairment in all inventories; while age, sex, and hydrocortisone intake failed to explain the variance in these measures. Similar to several studies in non-pituitary patient cohorts (e.g., patients with multiple sclerosis or lower back pain), our results indicate that psychosocial impairment in CD is significantly influenced by how the patient deals with the illness. Therefore, psychological training of positive coping styles could be a helpful complementary therapy in the overall treatment strategy of CD.
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