| 1. |
- Karger, Stefan, et al.
(författare)
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FOXO3a : a novel player in thyroid carcinogenesis?
- 2009
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Ingår i: Endocrine-Related Cancer. - 1351-0088 .- 1479-6821. ; 16:1, s. 189-99
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Tidskriftsartikel (refereegranskat)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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| 2. |
- Krause, Kerstin, et al.
(författare)
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Characterisation of DEHAL1 expression in thyroid pathologies.
- 2007
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Ingår i: European Journal of Endocrinology. - 0804-4643 .- 1479-683X. ; 156:3, s. 295-301
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Tidskriftsartikel (refereegranskat)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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| 3. |
- Krause, Kerstin, et al.
(författare)
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Evidence for a role of the amyloid precursor protein in thyroid carcinogenesis.
- 2008
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Ingår i: The Journal of endocrinology. - 1479-6805. ; 198:2, s. 291-9
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Tidskriftsartikel (refereegranskat)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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| 4. |
- Krause, Kerstin, et al.
(författare)
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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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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 93:4, s. 1390-3
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Tidskriftsartikel (refereegranskat)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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| 5. |
- Maksymowych, Walter P., et al.
(författare)
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Development of draft validation criteria for a soluble biomarker to be regarded as a valid biomarker reflecting structural damage endpoints in rheumatoid arthritis and spondyloarthritis clinical trials
- 2007
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Ingår i: Journal of Rheumatology. - 0315-162X. ; 34:3, s. 634-640
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Recent work has shown that several soluble biomarkers, detectable in peripheral blood, synovial fluid, and/or urine, reflect remodeling of joint tissues and may therefore constitute outcome measures that reflect joint damage. Consequently, it is now desirable to begin the process of developing criteria for validation of a soluble biomarker as an outcome measure reflecting structural damage progression in trials of disease-modifying therapies for rheumatoid arthritis (RA) and spondyloarthritis (SpA). Our objective was to develop validation criteria for a soluble biomarker to be regarded as a valid biomarker reflecting radiological endpoints in RA and SpA clinical trials. Methods. A special interest group was established comprising investigators with expertise in soluble biomarker assay development as well as in outcomes research. This project was initiated by means of a Delphi consensus exercise. A list of draft criteria was first generated following a review of a US National Institutes of Health (NIH) 2000 white paper (available at: http://www.niams.nih.gov/ne/oi/ oabiomarwhipap.htm) that focused on biomarkers in OA, and these were organized under subject headings relevant to the OMERACT filter: truth, discrimination, and feasibility. Additional criteria were solicited from the working group. This was followed by 3 rounds of voting. Results. A list of 31 criteria was generated prior to voting. The first 2 rounds of voting resulted in cumulative agreement that 19 criteria be retained and 4 discarded, while discrepancies were recorded for 8 criteria. In the third round of voting, cumulative agreement was achieved to retain 5 of the 8 discrepant criteria, so that the final list included 24 criteria. Conclusion. A draft set of criteria for validation of a soluble biomarker to be regarded as reflecting radiological damage endpoints in clinical trials has been proposed on the basis of consensus.
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