| 1. |
- Johansson, Ellen, et al.
(författare)
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Revising the embryonic origin of thyroid C cells in mice and humans
- 2015
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Ingår i: Development (Cambridge, England). - : The Company of Biologists. - 1477-9129 .- 0950-1991. ; 142:20, s. 3519-3528
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Tidskriftsartikel (refereegranskat)abstract
- Current understanding infers a neural crest origin of thyroid C cells, the major source of calcitonin in mammals and ancestors to neuroendocrine thyroid tumors. The concept is primarily based on investigations in quail-chick chimeras involving fate-mapping of neural crest cells to the ultimobranchial glands that regulate Ca(2+) homeostasis in birds, reptiles, amphibians and fishes, but whether mammalian C cell development implicates a homologous ontogenetic trajectory has not been experimentally verified. With lineage tracing we now provide direct evidence that Sox17+ anterior endoderm is the only source of differentiated C cells and their progenitors in mice. In similarity with many gut endoderm derivatives embryonic C cells were found to co-express pioneer factors forkhead box (Fox) a1 and Foxa2 before neuroendocrine differentiation takes place. In the ultimobranchial body epithelium emerging from pharyngeal pouch endoderm in early organogenesis differential Foxa1/Foxa2 expression distinguished two spatially separated pools of C cell precursors with different growth properties. A similar expression pattern was recapitulated in medullary thyroid carcinoma cells in vivo consistent with a growth-promoting role of Foxa1. Contrasting embryonic precursor cells, C cell-derived tumor cells invading the stromal compartment down-regulated Foxa2 foregoing epithelial-mesenchymal transition designated by loss of E-cadherin; both Foxa2 and E-cadherin were re-expressed at metastatic sites. These findings revise mammalian C cell ontogeny, expand the neuroendocrine repertoire of endoderm, and redefine the boundaries of neural crest diversification. The data further underpin distinct functions of Foxa1 and Foxa2 in both embryonic and tumor development.
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| 2. |
- Lyckesvärd, Madeleine Nordén, et al.
(författare)
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Linking loss of sodium-iodide symporter expression to DNA damage
- 2016
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Ingår i: Experimental Cell Research. - : Elsevier BV. - 0014-4827. ; 344:1, s. 120-131
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Tidskriftsartikel (refereegranskat)abstract
- Radiotherapy of thyroid cancer with I-131 is abrogated by inherent loss of radioiodine uptake due to loss of sodium iodide symporter (NIS) expression in poorly differentiated tumor cells. It is also known that ionizing radiation per se down-regulates NIS (the stunning effect), but the mechanism is unknown. Here we investigated whether loss of NIS-mediated iodide transport may be elicited by DNA damage. Calicheamicin, a fungal toxin that specifically cleaves double-stranded DNA, induced a full scale DNA damage response mediated by the ataxia-telangiectasia mutated (ATM) kinase in quiescent normal thyrocytes. At sublethal concentrations (< 1 nM) calicheamicin blocked NIS mRNA expression and transepithelial iodide transport as stimulated by thyrotropin; loss of function occurred at a much faster rate than after I-131 irradiation. KU-55933, a selective ATM kinase inhibitor, partly rescued NIS expression and iodide transport in DNA-damaged cells. Prolonged ATM inhibition in healthy cells also repressed NIS-mediated iodide transport. ATM-dependent loss of iodide transport was counteracted by IGF-1. Together, these findings indicate that NIS, the major iodide transporter of the thyroid gland, is susceptible to DNA damage involving ATM-mediated mechanisms. This uncovers novel means of poor radioiodine uptake in thyroid cells subjected to extrinsic or intrinsic genotoxic stress. (C) 2016 Elsevier Inc. All rights reserved.
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| 3. |
- Ingeson-Carlsson, Camilla, et al.
(författare)
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Differential effects of MAPK pathway inhibitors on migration and invasiveness of BRAF(V600E) mutant thyroid cancer cells in 2D and 3D culture
- 2015
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Ingår i: Experimental Cell Research. - : Elsevier BV. - 0014-4827. ; 338:2, s. 127-135
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Tidskriftsartikel (refereegranskat)abstract
- Tumor microenvironment influences targeted drug therapy. In this study we compared drug responses to RAF and MEK inhibitors on tumor cell migration in 2D and 3D culture of BRAF(V600E) mutant cell lines derived from human papillary (BCPAP) and anaplastic (SW1736) thyroid carcinomas. Scratch wounding was compared to a double-layered collagen gel model developed for analysis of directed tumor cell invasion during prolonged culture. In BCPAP both PLX4720 and U0126 inhibited growth and migration in 2D and decreased tumor cell survival in 3D. In SW1736 drugs had no effect on migration in 2D but decreased invasion in 3D, however this related to reduced growth. Dual inhibition of BRAF(V600E) and mEK reduced but did not prevent SW1736 invasion although rebound phosphorylation of ERK in response to PLX4720 was blocked by U0126. These findings indicate that anti-tumor drug effects in vitro differ depending on culture conditions (2D vs. 3D) and that the invasive features of anaplastic thyroid cancer depend on non-MEK mechanism(s). (C) 2015 Elsevier Inc. All rights reserved.
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| 4. |
- Ingeson-Carlsson, Camilla, et al.
(författare)
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Dual contribution of MAPK and PI3K in epidermal growth factor-induced destabilization of thyroid follicular integrity and invasion of cells into extracellular matrix
- 2014
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Ingår i: Experimental Cell Research. - : Elsevier BV. - 0014-4827. ; 326:2, s. 210-218
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Tidskriftsartikel (refereegranskat)abstract
- Normal thyrocytes grown as reconstituted follicles in collagen gel were evaluated for drug effects of small molecule kinase inhibitors on growth factor-induced cell migration in a 3D context. MEK inhibition by U0126 only partially antagonized EGF/serum-induced cell migration from the basal follicular surface into the matrix. Combined treatment with U0126 and LY294002, a PI3K blocker, was necessary to abolish migration. However, exposure to only LY294002 facilitated the response to EGF by breakdown of the original follicular structure. In the same time EGF promoted thyroid cell survival that was compromised by LY294002 in absence of EGF. Cells treated with EGF and LY294002 retained the ability to form follicles. The findings indicate that dual inhibition of MAPK and PI3K/AKT pathways is required to fully block matrix invasion of EGF-stimulated thyroid cells. Conversely, single drug treatment with PI3K inhibitor adversely promotes invasiveness probably by destabilizing the follicular epithelium. (C) 2014 Elsevier Inc. All rights reserved.
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| 5. |
- Ingeson-Carlsson, Camilla
(författare)
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Reversal of thyroid dedifferentiation and an invasive phenotype by small molecule kinase inhibitors: an experimental study on normal and malignant cells
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Refractoriness to I-131 in dedifferentiated thyroid cancer is a great concern that restricts radioiodine therapy. There is also a lack of knowledge in understanding the mechanisms leading to repressed sodium iodide symporter (NIS) expression and impaired iodide uptake in tumor cells. With this background, paper I investigated how NIS and iodide transport in normal thyrocytes were affected during dedifferentiation induced by epidermal growth factor (EGF). This was done on highly differentiated thyroid epithelial cells cultured in low (0.5%) or high (5%) content of fetal bovine serum either on filter in bicameral inserts or embedded in 3D collagen gel. EGF abolished TSH-stimulated transcription of NIS in both type of cultures. U0126, a MEK inhibitor, reversed this effect but only in serum-starved 2D cultures. Inhibition of MAPK signaling failed to recover NIS-mediated iodide uptake in the presence of serum and in 3D-cultured follicles irrespective of serum. In contrast, EGF-induced down-regulation of thyroglobulin, the thyroid prohormone, was blocked by MEK inhibition. These findings suggest an additional mechanism besides the classical MAPK signaling that negatively regulates NIS and confer resistance to small molecule kinase inhibitors targeting the MAPK pathway in dedifferentiated thyroid cells. In tumor progression cancer cells lose the ancestral epithelial phenotype and become invasive. Many mechanisms cooperate in this process including joint signaling of the MAPK and PI3K/AKT pathways, suggesting combined targeted treatment with kinase inhibitors would more effectively counteract invasiveness. This possibility was addressed in paper II in which cell migration into extracellular matrix from EGF-stimulated follicles was monitored during treatment with inhibitors of MEK (U0126) and PI3K (LY294002). Indeed, dual inhibition was required to prevent both cell proliferation and migration in response to EGF. Notably, single inhibition of PI3K adversely increased EGF-induced migration and invasion, probably by promoting disintegration of the follicular epithelium. As LY294002 did not compromise cell survival in the presence of EGF these findings call for caution in use of PI3K inhibitors as monotherapy of tumors with a constitutively activated MAPK pathway. Activating BRAFV600E mutation is a common driver in thyroid cancer. Acquired drug resistance involving rebound activation of MAPK signaling restricts the promising possibility to treat BRAF mutant tumors with kinase-selective inhibitors as PLX4720. Combined drug treatment to overcome this is suggested. In paper III inhibitor efficacy on tumor cell migration was investigated in BRAFV600E mutant cell lines derived from papillary (BCPAP) and anaplastic (SW1736) thyroid cancer. Besides conventional scratch wounding a double-layered collagen gel model was developed for analysis of directed tumor cell invasion during prolonged culture. Both PLX4720 and U0126 inhibited BCPAP cell migration and reduced tumor cell viability in 3D culture. 2D migration of SW1736 cells resisted even combined drug treatment, whereas embedded in collagen gel both drugs reduced the invading cell numbers. However, dual inhibition of BRAFV600E and MEK did not prevent invasion although rebound activation of MAPK was blocked. This suggests presence of highly invasive tumor cell subclones in anaplastic cancer that escape targeted drug therapy due to MAPK independence.
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| 6. |
- Ingeson-Carlsson, Camilla, et al.
(författare)
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Switching from MAPK-dependent to MAPK-independent repression of the sodium-iodide symporter in 2D and 3D cultured normal thyroid cells.
- 2013
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Ingår i: Molecular and cellular endocrinology. - : Elsevier BV. - 1872-8057 .- 0303-7207. ; 381:1-2, s. 241-54
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Tidskriftsartikel (refereegranskat)abstract
- Loss of sodium-iodide symporter (NIS) expression in thyroid tumour cells primarily caused by constitutive MAPK pathway activation is often refractory to small molecule MAPK inhibitors. Suggested mechanisms are rebound MAPK signalling and activation of alternative signalling pathways. Here we provide evidence that failure to recover down-regulated NIS by MEK inhibition is not specific to tumour cells. NIS mRNA levels remained repressed in TSH-stimulated primary thyroid cells co-treated with epidermal growth factor (EGF) and pan-MEK inhibitor U0126 in the presence of 5% fetal bovine serum or, independently of serum, in 3D cultured thyroid follicles. This led to inhibited iodide transport and iodination. In contrast, U0126 restituted thyroglobulin synthesis in EGF-treated follicular cells. Serum potentiated TSH-stimulated NIS expression in 2D culture. U0126 blocked down-regulation of NIS only in serum-starved cells with a diminished TSH response. Together, this suggests that morphogenetic signals modify the expression of NIS and recovery response to MEK inhibition.
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