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Ryan J, Curran CE, Hennessy E, Newell J, Morris JC, Kerin MJ, Dwyer RM. The sodium iodide symporter (NIS) and potential regulators in normal, benign and malignant human breast tissue. PLoS One 2011; 6:e16023. [PMID: 21283523 PMCID: PMC3023714 DOI: 10.1371/journal.pone.0016023] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Accepted: 12/03/2010] [Indexed: 02/02/2023] Open
Abstract
Introduction The presence, relevance and regulation of the Sodium Iodide Symporter (NIS) in human mammary tissue remains poorly understood. This study aimed to quantify relative expression of NIS and putative regulators in human breast tissue, with relationships observed further investigated in vitro. Methods Human breast tissue specimens (malignant n = 75, normal n = 15, fibroadenoma n = 10) were analysed by RQ-PCR targeting NIS, receptors for retinoic acid (RARα, RARβ), oestrogen (ERα), thyroid hormones (THRα, THRβ), and also phosphoinositide-3-kinase (PI3K). Breast cancer cells were treated with Retinoic acid (ATRA), Estradiol and Thyroxine individually and in combination followed by analysis of changes in NIS expression. Results The lowest levels of NIS were detected in normal tissue (Mean(SEM) 0.70(0.12) Log10 Relative Quantity (RQ)) with significantly higher levels observed in fibroadenoma (1.69(0.21) Log10RQ, p<0.005) and malignant breast tissue (1.18(0.07) Log10RQ, p<0.05). Significant positive correlations were observed between human NIS and ERα (r = 0.22, p<0.05) and RARα (r = 0.29, p<0.005), with the strongest relationship observed between NIS and RARβ (r = 0.38, p<0.0001). An inverse relationship between NIS and PI3K expression was also observed (r = −0.21, p<0.05). In vitro, ATRA, Estradiol and Thyroxine individually stimulated significant increases in NIS expression (range 6–16 fold), while ATRA and Thyroxine combined caused the greatest increase (range 16–26 fold). Conclusion Although NIS expression is significantly higher in malignant compared to normal breast tissue, the highest level was detected in fibroadenoma. The data presented supports a role for retinoic acid and estradiol in mammary NIS regulation in vivo, and also highlights potential thyroidal regulation of mammary NIS mediated by thyroid hormones.
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Affiliation(s)
- James Ryan
- Division of Surgery, School of Medicine, National University of Ireland Galway (NUIG), Galway, Ireland
| | - Catherine E. Curran
- Division of Surgery, School of Medicine, National University of Ireland Galway (NUIG), Galway, Ireland
| | - Emer Hennessy
- Division of Surgery, School of Medicine, National University of Ireland Galway (NUIG), Galway, Ireland
| | - John Newell
- School of Mathematics, Statistics and Applied Mathematics and Clinical Research Facility, National University of Ireland Galway (NUIG), Galway, Ireland
| | - John C. Morris
- Division of Endocrinology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Michael J. Kerin
- Division of Surgery, School of Medicine, National University of Ireland Galway (NUIG), Galway, Ireland
| | - Roisin M. Dwyer
- Division of Surgery, School of Medicine, National University of Ireland Galway (NUIG), Galway, Ireland
- * E-mail:
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102
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Thyroid hormone receptor β1 domains responsible for the antagonism with the ras oncogene: role of corepressors. Oncogene 2010; 30:854-64. [DOI: 10.1038/onc.2010.464] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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103
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Kapoor R, Ghosh H, Nordstrom K, Vennstrom B, Vaidya VA. Loss of thyroid hormone receptor β is associated with increased progenitor proliferation and NeuroD positive cell number in the adult hippocampus. Neurosci Lett 2010; 487:199-203. [PMID: 20959135 DOI: 10.1016/j.neulet.2010.10.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Revised: 09/15/2010] [Accepted: 10/07/2010] [Indexed: 02/08/2023]
Abstract
Adult hippocampal neurogenesis is modulated by perturbations in thyroid hormone status; however the role of specific thyroid hormone receptors (TRs) in this process is not completely understood. We show here that loss of the TRβ gene results in a significant increase in the proliferation of adult hippocampal progenitors, without any change in immature neuron number or in the neuronal and glial differentiation of progenitors. Using the mitotic marker 5'-bromo-2-deoxyuridine (BrdU) or the endogenous cell cycle marker, proliferating cell nuclear antigen (PCNA), we find a significant increase in the number of BrdU- and PCNA-immunopositive cells within the subgranular zone (SGZ) of the dentate gyrus subfield in TRβ-/- mice. Further, we find that TRβ-/- mice exhibit a significant increase in the numbers of NeuroD-positive cells within the SGZ, suggesting that the increased numbers of proliferating progenitors translate into enhanced numbers of neuroblasts. Interestingly, the number of BrdU-positive cells that persist 4 weeks post-BrdU injection is unaltered in TRβ-/- mice, indicating that the enhanced proliferation does not result in increased hippocampal neurogenesis. This is also supported by the evidence of no change in the numbers of cells expressing markers of immature neurons such as doublecortin or polysialylated neural cell adhesion molecule. Furthermore, no change is observed in the neuronal or glial differentiation of BrdU-positive cells in the TRβ-/- mice. Taken together, our results provide novel evidence for a role of TRβ in modulating hippocampal progenitor cell division, and implicate this receptor in the effects of thyroid hormone on adult hippocampal neurogenesis.
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Affiliation(s)
- Richa Kapoor
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| | - Himanish Ghosh
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| | - Kristina Nordstrom
- Department of Cell and Molecular Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Björn Vennstrom
- Department of Cell and Molecular Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Vidita A Vaidya
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
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104
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Untranslated regions of thyroid hormone receptor beta 1 mRNA are impaired in human clear cell renal cell carcinoma. Biochim Biophys Acta Mol Basis Dis 2010; 1802:995-1005. [PMID: 20691260 DOI: 10.1016/j.bbadis.2010.07.025] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 07/26/2010] [Accepted: 07/29/2010] [Indexed: 12/12/2022]
Abstract
Thyroid hormone receptor β1 (TRβ1) is a hormone-dependent transcription factor activated by 3,5,3'-l-triiodothyronine (T3). TRβ1 functions as a tumor suppressor and disturbances of the THRB gene are frequent findings in cancer. Translational control mediated by untranslated regions (UTRs) regulates cell proliferation, metabolism and responses to cellular stress, processes that are involved in carcinogenesis. We hypothesized that reduced TRβ1 expression in clear cell renal cell cancer (ccRCC) results from regulatory effects of TRβ1 5' and 3'UTRs on protein translation. We determined TRβ1 expression and alternative splicing of TRβ1 5' and 3'UTRs in ccRCC and control tissue together with expression of the type 1 deiodinase enzyme (coded by DIO1, a TRβ1 target gene). Tissue concentrations of T3 (which are generated in part by D1) and expression of miRNA-204 (an mRNA inhibitor for which a putative interaction site was identified in the TRβ1 3'UTR) were also determined. TRβ1 mRNA and protein levels were reduced by 70% and 91% in ccRCC and accompanied by absent D1 protein, a 58% reduction in tissue T3 concentration and 2-fold increase in miRNA-204. Structural analysis of TRβ1 UTR variants indicated that reduced TRβ1 expression may be maintained in ccRCC by posttranscriptional mechanisms involving 5'UTRs and miRNA-204. The tumor suppressor activity of TRβ1 indicates that reduced TRβ1 expression and tissue hypothyroidism in ccRCC tumors is likely to be involved in the process of carcinogenesis or in maintaining a proliferative advantage to malignant cells.
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105
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VRK2 inhibits mitogen-activated protein kinase signaling and inversely correlates with ErbB2 in human breast cancer. Mol Cell Biol 2010; 30:4687-97. [PMID: 20679487 DOI: 10.1128/mcb.01581-09] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The epidermal growth factor (EGF)-ErbB-mitogen-activated protein kinase (MAPK) transcription signaling pathway is altered in many types of carcinomas, and this pathway can be regulated by new protein-protein interactions. Vaccinia-related kinase (VRK) proteins are Ser-Thr kinases that regulate several signal transduction pathways. In this work, we study the effect of VRK2 on MAPK signaling using breast cancer as a model. High levels of VRK2 inhibit EGF and ErbB2 activation of transcription by the serum response element (SRE). This effect is also detected in response to H-Ras(G12V) or B-Raf(V600E) oncogenes and is accompanied by a reduction in phosphorylated extracellular signal-regulated kinase (ERK) levels, p90RSK levels, and SRE-dependent transcription. Furthermore, VRK2 knockdown has the opposite effect, increasing the transcriptional response to stimulation with EGF and leading to increased levels of ERK phosphorylation. The molecular mechanism lies between MAPK/ERK kinase (MEK) and ERK, since MEK remains phosphorylated while ERK phosphorylation is blocked by VRK2A. This inhibition of the ERK signaling pathway is a consequence of a direct protein-protein interaction between VRK2A, MEK, and kinase suppressor of Ras 1 (KSR1). Identification of new correlations in human cancer can lead to a better understanding of the biology of individual tumors. ErbB2 and VRK2 protein levels were inversely correlated in 136 cases of human breast carcinoma. In ErbB2(+) tumors, there is a significant reduction in the VRK2 level, suggesting a role for VRK2A in ErbB2-MAPK signaling. Thus, VRK2 downregulation in carcinomas permits signal transmission through the MEK-ERK pathway without affecting AKT signaling, causing a signal imbalance among pathways that contributes to the phenotype of breast cancer.
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Tuckermann J, Bourguet W, Mandrup S. Meeting report: nuclear receptors: transcription factors and drug targets connecting basic research with translational medicine. Mol Endocrinol 2010; 24:1311-21. [PMID: 20519330 DOI: 10.1210/me.2010-0083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The biannual European Molecular Biology Organization (EMBO) conference on nuclear receptors was organized by Beatrice Desvergne and Laszlo Nagy and took place in Cavtat near Dubrovnik on the Adriatic coast of Croatia September 25-29, 2009. The meeting brought together researchers from all over the world covering a wide spectrum from fundamental mechanistic studies to metabolism, clinical studies, and drug development. In this report, we summarize the recent and exciting findings presented by the speakers at the meeting.
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Affiliation(s)
- Jan Tuckermann
- Leibniz Institute for Age Research-Fritz Lipmann Institute, D-07745 Jena, Germany
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107
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Lu C, Zhao L, Ying H, Willingham MC, Cheng SY. Growth activation alone is not sufficient to cause metastatic thyroid cancer in a mouse model of follicular thyroid carcinoma. Endocrinology 2010; 151:1929-39. [PMID: 20133453 PMCID: PMC2851190 DOI: 10.1210/en.2009-1017] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
TSH is the major stimulator of thyrocyte proliferation, but its role in thyroid carcinogenesis remains unclear. To address this question, we used a mouse model of follicular thyroid carcinoma (FTC) (TRbeta(PV/PV) mice). These mice, harboring a dominantly negative mutation (PV) of the thyroid hormone-beta receptor (TRbeta), exhibit increased serum thyroid hormone and elevated TSH. To eliminate TSH growth-stimulating effect, TRbeta(PV/PV) mice were crossed with TSH receptor gene knockout (TSHR(-/-)) mice. Wild-type siblings of TRbeta(PV/PV) mice were treated with an antithyroid agent, propylthiouracil, to elevate serum TSH for evaluating long-term TSH effect (WT-PTU mice). Thyroids from TRbeta(PV/PV)TSHR(-/-) showed impaired growth with no occurrence of FTC. Both WT-PTU and TRbeta(PV/PV) mice displayed enlarged thyroids, but only TRbeta(PV/PV) mice developed metastatic FTC. Molecular analyses indicate that PV acted, via multiple mechanisms, to activate the integrins-Src-focal adhesion kinase-p38 MAPK pathway and affect cytoskeletal restructuring to increase tumor cell migration and invasion. Thus, growth stimulated by TSH is a prerequisite but not sufficient for metastatic cancer to occur. Additional genetic alterations (such as PV), destined to alter focal adhesion and migration capacities, are required to empower hyperplastic follicular cells to invade and metastasize. These in vivo findings provide new insights in understanding carcinogenesis of the human thyroid.
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Affiliation(s)
- Changxue Lu
- Laboratory of Molecular Biology, National Cancer Institute, 37 Convent Drive, Room 5128, Bethesda, Maryland 20892-4264, USA
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108
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Zhu XG, Zhao L, Willingham MC, Cheng SY. Thyroid hormone receptors are tumor suppressors in a mouse model of metastatic follicular thyroid carcinoma. Oncogene 2010; 29:1909-19. [PMID: 20062085 PMCID: PMC3443884 DOI: 10.1038/onc.2009.476] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Revised: 11/16/2009] [Accepted: 11/19/2009] [Indexed: 11/09/2022]
Abstract
Aberrant expression and mutations of thyroid hormone receptor genes (TRs) are closely associated with several types of human cancers. To test the hypothesis that TRs could function as tumor suppressors, we took advantage of mice with deletion of all functional TRs (TRalpha1(-/-)TRbeta(-/-) mice). As these mice aged, they spontaneously developed follicular thyroid carcinoma with pathological progression from hyperplasia to capsular invasion, vascular invasion, anaplasia and metastasis to the lung, similar to human thyroid cancer. Detailed molecular analysis revealed that known tumor promoters such as pituitary tumor-transforming gene were activated and tumor suppressors such as peroxisome proliferator-activated receptor gamma and p53 were suppressed during carcinogenesis. In addition, consistent with the human cancer, AKT-mTOR-p70(S6K) signaling and vascular growth factor and its receptor were activated to facilitate tumor progression. This report presents in vivo evidence that functional loss of both TRalpha1 and TRbeta genes promotes tumor development and metastasis. Thus, TRs could function as tumor suppressors in a mouse model of metastatic follicular thyroid cancer.
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Affiliation(s)
- X-G Zhu
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| | - L Zhao
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| | - MC Willingham
- Department of Pathology, Wake Forest University, Winston-Salem, NC, USA
| | - S-Y Cheng
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
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109
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Lu C, Cheng SY. Thyroid hormone receptors regulate adipogenesis and carcinogenesis via crosstalk signaling with peroxisome proliferator-activated receptors. J Mol Endocrinol 2010; 44:143-54. [PMID: 19741045 PMCID: PMC3464095 DOI: 10.1677/jme-09-0107] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Peroxisome proliferator-activated receptors (PPARs) and thyroid hormone receptors (TRs) are members of the nuclear receptor superfamily. They are ligand-dependent transcription factors that interact with their cognate hormone response elements in the promoters to regulate respective target gene expression to modulate cellular functions. While the transcription activity of each is regulated by their respective ligands, recent studies indicate that via multiple mechanisms PPARs and TRs crosstalk to affect diverse biological functions. Here, we review recent advances in the understanding of the molecular mechanisms and biological impact of crosstalk between these two important nuclear receptors, focusing on their roles in adipogenesis and carcinogenesis.
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Affiliation(s)
- Changxue Lu
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 37 Convent Drive, Room 5128, Bethesda, Maryland 20892-4264, USA
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Iwasaki Y, Sunaga N, Tomizawa Y, Imai H, Iijima H, Yanagitani N, Horiguchi K, Yamada M, Mori M. Epigenetic Inactivation of the Thyroid Hormone Receptor β1 Gene at 3p24.2 in Lung Cancer. Ann Surg Oncol 2010; 17:2222-8. [DOI: 10.1245/s10434-010-0956-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Indexed: 11/18/2022]
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Abstract
BACKGROUND Thyroid cancer is the most common endocrine tumor and is increasing in incidence. The aim of this study was to review mouse models of differentiated thyroid cancer and how they elucidate human thyroid cancer biology. SUMMARY Differentiated thyroid cancer, primarily papillary and follicular, comprises the majority of thyroid cancers. There has been tremendous growth in the cross-talk between basic science and clinical practice for thyroid cancer management. Insight into the framework of genes responsible for differentiated thyroid cancer has been gained through the use of mouse models. Common genetic alterations found in human papillary thyroid cancer such as RET/PTC rearrangements or the BRAF(V600E) mutation have genetically modified mouse counterparts. These and other preclinical mouse models have validated the importance of the cyclic adenosine monophosphate (cAMP)/protein kinase A and mitogen-activated protein kinase (MAPK) signaling pathways in papillary thyroid cancer (PTC). RAS mutations have a role in both papillary and follicular thyroid cancer development. Mice with overactivation of the phosphatidylinol-3-kinase (PI3K)-AKT and/or thyrotropin-regulated signaling pathways have been found to develop follicular thyroid cancer. Additional mouse models of thyroid cancer that utilize inducible expression systems are in development or are being characterized and will better reflect the majority of human thyroid cancers which are non-hereditary. Advances in in vivo imaging of mice allow for earlier detection of metastasis and the ability to follow tumor growth or regression which may be used in evaluation of pharmaceutical agents. CONCLUSIONS Mouse models have expanded our understanding of the altered signaling pathways that contribute to thyroid cancer tumorigenesis and provide a powerful tool to develop novel diagnostic approaches and therapies.
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Affiliation(s)
- Caroline S. Kim
- Molecular Oncology Research Institute and Division of Endocrinology, Diabetes, and Metabolism, Tufts Medical Center, Boston, Massachusetts
| | - Xuguang Zhu
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
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Chan IH, Privalsky ML. Thyroid hormone receptor mutants implicated in human hepatocellular carcinoma display an altered target gene repertoire. Oncogene 2009; 28:4162-74. [PMID: 19749797 PMCID: PMC2787677 DOI: 10.1038/onc.2009.265] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Thyroid hormone receptors (TRs) are hormone-regulated transcription factors that control multiple aspects of normal physiology and development. Mutations in TRs have been identified at high frequency in certain cancers, including human hepatocellular carcinomas (HCCs). The majority of HCC-TR mutants bear lesions within their DNA recognition domains, and we have hypothesized that these lesions change the mutant receptors' target gene repertoire in a way crucial to their function as oncoproteins. Using stable cell transformants and expression array analysis, we determined that mutant TRs isolated from two different HCCs do, as hypothesized, display a target gene repertoire distinct from that of their normal TR progenitors. Only a subset of genes regulated by wild-type TRs was regulated by the corresponding HCC-TR mutants. More surprisingly, the HCC-TR mutants also gained the ability to regulate additional target genes not recognized by the wild-type receptors, and were not simply restricted to repression, but could also activate a subset of their target genes. We conclude that the TR mutants isolated from HCC have sustained multiple alterations from their normal progenitors that include not only changes in their transcriptional outputs, but also changes in the genes they target; both are likely to contribute to neoplasia.
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Affiliation(s)
- I H Chan
- Department of Microbiology, College of Biological Sciences, University of California at Davis, Davis, CA 95616, USA
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113
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Aranda A, Martínez-Iglesias O, Ruiz-Llorente L, García-Carpizo V, Zambrano A. Thyroid receptor: roles in cancer. Trends Endocrinol Metab 2009; 20:318-24. [PMID: 19716314 DOI: 10.1016/j.tem.2009.03.011] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Revised: 03/18/2009] [Accepted: 03/24/2009] [Indexed: 11/16/2022]
Abstract
The thyroid hormone receptors, encoded by the TRalpha and TRbeta genes, are ligand-dependent transcription factors that belong to the nuclear receptor superfamily. In addition to the role of these receptors in growth, development and metabolism, there is increasing evidence that they also inhibit transformation and act as tumor suppressors. Aberrant TR action, as well as receptor silencing, are common events in human cancer, and TRs also have an important role in tumor progression in experimental animal models, suggesting that these receptors constitute a novel therapeutic target in cancer. This review highlights recent studies on mechanisms by which loss of expression and/or function of these receptors results in a selective advantage for cellular transformation, tumor development and metastatic growth.
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Affiliation(s)
- Ana Aranda
- Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Arturo Duperier 4, 28029 Madrid, Spain.
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Martínez-Iglesias O, García-Silva S, Regadera J, Aranda A. Hypothyroidism enhances tumor invasiveness and metastasis development. PLoS One 2009; 4:e6428. [PMID: 19641612 PMCID: PMC2712768 DOI: 10.1371/journal.pone.0006428] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Accepted: 06/29/2009] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Whereas there is increasing evidence that loss of expression and/or function of the thyroid hormone receptors (TRs) could result in a selective advantage for tumor development, the relationship between thyroid hormone levels and human cancer is a controversial issue. It has been reported that hypothyroidism might be a possible risk factor for liver and breast cancer in humans, but a lower incidence of breast carcinoma has been also reported in hypothyroid patients METHODOLOGY/PRINCIPAL FINDINGS In this work we have analyzed the influence of hypothyroidism on tumor progression and metastasis development using xenografts of parental and TRbeta1-expressing human hepatocarcinoma (SK-hep1) and breast cancer cells (MDA-MB-468). In agreement with our previous observations tumor invasiveness and metastasis formation was strongly repressed when TRbeta-expressing cells were injected into euthyroid nude mice. Whereas tumor growth was retarded when cells were inoculated into hypothyroid hosts, tumors had a more mesenchymal phenotype, were more invasive and metastatic growth was enhanced. Increased aggressiveness and tumor growth retardation was also observed with parental cells that do not express TRs. CONCLUSIONS/SIGNIFICANCE These results show that changes in the stromal cells secondary to host hypothyroidism can modulate tumor progression and metastatic growth independently of the presence of TRs on the tumor cells. On the other hand, the finding that hypothyroidism can affect differentially tumor growth and invasiveness can contribute to the explanation of the confounding reports on the influence of thyroidal status in human cancer.
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Affiliation(s)
- Olaia Martínez-Iglesias
- Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas y Universidad Autónoma de Madrid, Madrid, Spain
| | - Susana García-Silva
- Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas y Universidad Autónoma de Madrid, Madrid, Spain
| | - Javier Regadera
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Ana Aranda
- Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas y Universidad Autónoma de Madrid, Madrid, Spain
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115
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Molecular mechanisms involved in farnesol-induced apoptosis. Cancer Lett 2009; 287:123-35. [PMID: 19520495 DOI: 10.1016/j.canlet.2009.05.015] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 05/14/2009] [Accepted: 05/15/2009] [Indexed: 12/11/2022]
Abstract
The isoprenoid alcohol farnesol is an effective inducer of cell cycle arrest and apoptosis in a variety of carcinoma cell types. In addition, farnesol has been reported to inhibit tumorigenesis in several animal models suggesting that it functions as a chemopreventative and anti-tumor agent in vivo. A number of different biochemical and cellular processes have been implicated in the growth-inhibitory and apoptosis-inducing effects of farnesol. These include regulation of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase and CTP:phosphocholine cytidylyltransferase alpha (CCTalpha), rate-limiting enzymes in the mevalonate pathway and phosphatidylcholine biosynthesis, respectively, and the generation of reactive oxygen species. In some cell types the action of farnesol is mediated through nuclear receptors, including activation of farnesoid X receptor (FXR) and peroxisome proliferator-activated receptors (PPARs). Recent studies have revealed that induction of endoplasmic reticulum (ER) stress and the subsequent activation of the unfolded protein response (UPR) play a critical role in the induction of apoptosis by farnesol in lung carcinoma cells. This induction was found to be dependent on the activation of the MEK1/2-ERK1/2 pathway. In addition, farnesol induces activation of the NF-kappaB signaling pathway and a number of NF-kappaB target genes. Optimal activation of NF-kappaB was reported to depend on the phosphorylation of p65/RelA by the MEK1/2-MSK1 signaling pathway. In a number of cells farnesol-induced apoptosis was found to be linked to activation of the apoptosome. This review provides an overview of the biochemical and cellular processes regulated by farnesol in relationship to its growth-inhibitory, apoptosis-promoting, and anti-tumor effects.
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