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Gunjača I, Benzon B, Pleić N, Babić Leko M, Pešutić Pisac V, Barić A, Kaličanin D, Punda A, Polašek O, Vukojević K, Zemunik T. Role of ST6GAL1 in Thyroid Cancers: Insights from Tissue Analysis and Genomic Datasets. Int J Mol Sci 2023; 24:16334. [PMID: 38003522 PMCID: PMC10671354 DOI: 10.3390/ijms242216334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 11/10/2023] [Accepted: 11/13/2023] [Indexed: 11/26/2023] Open
Abstract
Thyroid cancer is the predominant endocrine-related malignancy. ST6 β-galactoside α2,6-sialyltransferase 1 (ST6GAL1) has been studied in various types of cancers; however, the expression and function of ST6GAL1 in thyroid cancer has not been investigated so far. Previously, we conducted two genome-wide association studies and have identified the association of the ST6GAL1 gene with plasma thyroglobulin (Tg) levels. Since Tg levels are altered in thyroid pathologies, in the current study, we wanted to evaluate the expression of ST6GAL1 in thyroid cancer tissues. We performed an immunohistochemical analysis using human thyroid tissue from 89 patients and analyzed ST6GAL1 protein expression in papillary thyroid cancer (including follicular variant and microcarcinoma) and follicular thyroid cancer in comparison to normal thyroid tissue. Additionally, ST6GAL1 mRNA levels from The Cancer Genome Atlas (TCGA, n = 572) and the Genotype-Tissue Expression (GTEx) project (n = 279) were examined. The immunohistochemical analysis revealed higher ST6GAL1 protein expression in all thyroid tumors compared to normal thyroid tissue. TCGA data revealed increased ST6GAL1 mRNA levels in both primary and metastatic tumors versus controls. Notably, the follicular variant of papillary thyroid cancer exhibited significantly higher ST6GAL1 mRNA levels than classic papillary thyroid cancer. High ST6GAL1 mRNA levels significantly correlated with lymph node metastasis status, clinical stage, and reduced survival rate. ST6GAL1 emerges as a potential cancer-associated glycosyltransferase in thyroid malignancies, offering valuable insights into its diagnostic and prognostic significance.
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Affiliation(s)
- Ivana Gunjača
- Department of Medical Biology, School of Medicine, University of Split, 21000 Split, Croatia; (N.P.); (M.B.L.); (D.K.)
| | - Benjamin Benzon
- Department of Anatomy, Histology and Embryology, School of Medicine, University of Split, 21000 Split, Croatia; (B.B.); (K.V.)
| | - Nikolina Pleić
- Department of Medical Biology, School of Medicine, University of Split, 21000 Split, Croatia; (N.P.); (M.B.L.); (D.K.)
| | - Mirjana Babić Leko
- Department of Medical Biology, School of Medicine, University of Split, 21000 Split, Croatia; (N.P.); (M.B.L.); (D.K.)
| | - Valdi Pešutić Pisac
- Clinical Department of Pathology, Forensic Medicine and Cytology, University Hospital of Split, 21000 Split, Croatia;
| | - Ana Barić
- Department of Nuclear Medicine, University Hospital of Split, 21000 Split, Croatia; (A.B.); (A.P.)
| | - Dean Kaličanin
- Department of Medical Biology, School of Medicine, University of Split, 21000 Split, Croatia; (N.P.); (M.B.L.); (D.K.)
| | - Ante Punda
- Department of Nuclear Medicine, University Hospital of Split, 21000 Split, Croatia; (A.B.); (A.P.)
| | - Ozren Polašek
- Department of Public Health, School of Medicine, University of Split, 21000 Split, Croatia;
| | - Katarina Vukojević
- Department of Anatomy, Histology and Embryology, School of Medicine, University of Split, 21000 Split, Croatia; (B.B.); (K.V.)
| | - Tatijana Zemunik
- Department of Medical Biology, School of Medicine, University of Split, 21000 Split, Croatia; (N.P.); (M.B.L.); (D.K.)
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Kiriya M, Kawashima A, Fujiwara Y, Tanimura Y, Yoshihara A, Nakamura Y, Tanigawa K, Kondo T, Suzuki K. Thyroglobulin regulates the expression and localization of the novel iodide transporter solute carrier family 26 member 7 (SLC26A7) in thyrocytes. Endocr J 2022; 69:1217-1225. [PMID: 35644541 DOI: 10.1507/endocrj.ej22-0082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Solute carrier family 26 member 7 (SLC26A7), identified as a causative gene for congenital hypothyroidism, was found to be a novel iodide transporter expressed on the apical side of the follicular epithelium of the thyroid. We recently showed that TSH suppressed the expression of SLC26A7 and induces its localization to the plasma membrane, where it functions. We also showed that the ability of TSH to induce thyroid hormone synthesis is completely reversed by an autocrine negative-feedback action of thyroglobulin (Tg) stored in the follicular lumen. In the present study, we investigated the potential effect of follicular Tg on SLC26A7 expression and found that follicular Tg significantly suppressed the promoter activity, mRNA level, and protein level of SLC26A7 in rat thyroid FRTL-5 cells. In addition, follicular Tg inhibited the ability of TSH to induce the membrane localization of SLC26A7. In rat thyroid sections, the expression of SLC26A7 was weaker in follicles with a higher concentration of Tg, as evidenced by immunofluorescence staining. These results indicate that Tg stored in the follicular lumen is a feedback suppressor of the expression and membrane localization of SLC26A7, thereby downregulating the transport of iodide into the follicular lumen.
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Affiliation(s)
- Mitsuo Kiriya
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Tokyo 173-8605, Japan
- Department of Pathology, Faculty of Medicine, University of Yamanashi, Yamanashi 409-3898, Japan
| | - Akira Kawashima
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Tokyo 173-8605, Japan
| | - Yoko Fujiwara
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Tokyo 173-8605, Japan
| | - Yuta Tanimura
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Tokyo 173-8605, Japan
| | - Aya Yoshihara
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Tokyo 173-8605, Japan
- Center for Medical Education, Faculty of Medicine, Toho University, Tokyo 143-8540, Japan
| | - Yasuhiro Nakamura
- Center for Promotion of Pharmaceutical Education & Research, Faculty of Pharma-Science, Teikyo University, Tokyo 173-8605, Japan
| | - Kazunari Tanigawa
- Department of Molecular Pharmaceutics, Faculty of Pharma-Science, Teikyo University, Tokyo 173-8605, Japan
| | - Tetsuo Kondo
- Department of Pathology, Faculty of Medicine, University of Yamanashi, Yamanashi 409-3898, Japan
| | - Koichi Suzuki
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Tokyo 173-8605, Japan
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Pleić N, Babić Leko M, Gunjača I, Boutin T, Torlak V, Matana A, Punda A, Polašek O, Hayward C, Zemunik T. Genome-Wide Association Analysis and Genomic Prediction of Thyroglobulin Plasma Levels. Int J Mol Sci 2022; 23:ijms23042173. [PMID: 35216288 PMCID: PMC8876738 DOI: 10.3390/ijms23042173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 02/08/2022] [Accepted: 02/12/2022] [Indexed: 02/05/2023] Open
Abstract
Thyroglobulin (Tg) is an iodoglycoprotein produced by thyroid follicular cells which acts as an essential substrate for thyroid hormone synthesis. To date, only one genome-wide association study (GWAS) of plasma Tg levels has been performed by our research group. Utilizing recent advancements in computation and modeling, we apply a Bayesian approach to the probabilistic inference of the genetic architecture of Tg. We fitted a Bayesian sparse linear mixed model (BSLMM) and a frequentist linear mixed model (LMM) of 7,289,083 variants in 1096 healthy European-ancestry participants of the Croatian Biobank. Meta-analysis with two independent cohorts (total n = 2109) identified 83 genome-wide significant single nucleotide polymorphisms (SNPs) within the ST6GAL1 gene (p<5×10-8). BSLMM revealed additional association signals on chromosomes 1, 8, 10, and 14. For ST6GAL1 and the newly uncovered genes, we provide physiological and pathophysiological explanations of how their expression could be associated with variations in plasma Tg levels. We found that the SNP-heritability of Tg is 17% and that 52% of this variation is due to a small number of 16 variants that have a major effect on Tg levels. Our results suggest that the genetic architecture of plasma Tg is not polygenic, but influenced by a few genes with major effects.
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Affiliation(s)
- Nikolina Pleić
- Department of Medical Biology, School of Medicine, University of Split, Šoltanska 2, 21000 Split, Croatia; (N.P.); (M.B.L.); (I.G.); (A.M.)
| | - Mirjana Babić Leko
- Department of Medical Biology, School of Medicine, University of Split, Šoltanska 2, 21000 Split, Croatia; (N.P.); (M.B.L.); (I.G.); (A.M.)
| | - Ivana Gunjača
- Department of Medical Biology, School of Medicine, University of Split, Šoltanska 2, 21000 Split, Croatia; (N.P.); (M.B.L.); (I.G.); (A.M.)
| | - Thibaud Boutin
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK; (T.B.); (C.H.)
| | - Vesela Torlak
- Department of Nuclear Medicine, University Hospital Split, Spinčićeva 1, 21000 Split, Croatia; (V.T.); (A.P.)
| | - Antonela Matana
- Department of Medical Biology, School of Medicine, University of Split, Šoltanska 2, 21000 Split, Croatia; (N.P.); (M.B.L.); (I.G.); (A.M.)
| | - Ante Punda
- Department of Nuclear Medicine, University Hospital Split, Spinčićeva 1, 21000 Split, Croatia; (V.T.); (A.P.)
| | - Ozren Polašek
- Department of Public Health, School of Medicine, University of Split, Šoltanska 2, 21000 Split, Croatia;
| | - Caroline Hayward
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK; (T.B.); (C.H.)
| | - Tatijana Zemunik
- Department of Medical Biology, School of Medicine, University of Split, Šoltanska 2, 21000 Split, Croatia; (N.P.); (M.B.L.); (I.G.); (A.M.)
- Correspondence: ; Tel.: +385-2155-7888
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Coscia F, Taler-Verčič A. Cryo-EM: A new dawn in thyroid biology. Mol Cell Endocrinol 2021; 531:111309. [PMID: 33964321 PMCID: PMC8316605 DOI: 10.1016/j.mce.2021.111309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/25/2021] [Accepted: 04/27/2021] [Indexed: 11/09/2022]
Abstract
The thyroid gland accumulates the rare dietary element iodine and incorporates it into iodinated thyroid hormones, utilising several tightly regulated reactions and molecular mechanisms. Thyroid hormones are essential in vertebrates and play a central role in many biological processes, such as development, thermogenesis and growth. The control of these functions is exerted through the binding of hormones to nuclear thyroid hormone receptors that rule the transcription of numerous metabolic genes. Over the last 50 years, thyroid biology has been studied extensively at the cellular and organismal levels, revealing its multiple clinical implications, yet, a complete molecular understanding is still lacking. This includes the atomic structures of crucial pathway components that would be needed to elucidate molecular mechanisms. Here we review the currently known protein structures involved in thyroid hormone synthesis, regulation, transport, and actions. We also highlight targets for future investigations that will significantly benefit from recent advances in macromolecular structure determination by electron cryo-microscopy (cryo-EM). As an example, we demonstrate how cryo-EM was crucial to obtain the structure of the large thyroid hormone precursor protein, thyroglobulin. We discuss modern cryo-EM compared to other structure determination methods and how an integrated structural and cell biological approach will help filling the molecular knowledge gap in our understanding of thyroid hormone metabolism. Together with clinical, cellular and high-throughput 'omics' studies, atomic structures of thyroid components will provide an important framework to map disease mutations and to interpret and predict thyroid phenotypes.
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Affiliation(s)
- Francesca Coscia
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK; Human Technopole, Via Cristina Belgioioso 171, 20157, Milano, Italy.
| | - Ajda Taler-Verčič
- University of Ljubljana, Faculty of Medicine, Institute of Biochemistry and Molecular Genetics, Vrazov Trg 2, 1000, Ljubljana, Slovenia
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Single-cell RNA sequencing reveals the regenerative potential of thyroid follicular epithelial cells in metastatic thyroid carcinoma. Biochem Biophys Res Commun 2020; 531:552-558. [PMID: 32811644 DOI: 10.1016/j.bbrc.2020.06.050] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 06/10/2020] [Indexed: 02/07/2023]
Abstract
Thyroid stimulating hormone deficiency is the cornerstone of treatment for metastatic thyroid cancer. Due to the loss of follicular epithelial cells in thyroid cancer, the thyroid gland degenerates to 85% of its original size. When thyroid stimulating hormone is restored, follicular epithelial cells in thyroid cancer regenerate, which is postulated to be related to stem-like cells. By single cell RNA seq, we found a group of rare thyroid follicular epithelial cells in mouse metastatic thyroid cancer, which expressed stem-like genes (CD44V6+ and CD133+) and a large number of differentiated cells (CD44V6+ and CD24+). In mouse and in organoids, the two subsets contribute equally to metastatic thyroid cancer regeneration. The analysis of human metastatic thyroid cancer revealed that the differentiated thyroid follicular epithelial cell subpopulation was similar to that of the stem like epithelial cell subpopulation, and the regeneration potential was also enhanced after thyroid stimulating hormone ablation. Accordingly, we propose that the regeneration of metastatic thyroid cancer is driven by almost all persistent thyroid follicular epithelial cells, not only by few stem-like cells.
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Chen F, Wang H, Li Q, Li Z, Luo Y. [Progress in the research of negative feedback effect of thyroglobulin]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2019; 39:125-126. [PMID: 30692078 DOI: 10.12122/j.issn.1673-4254.2019.01.20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Thyroglobulin is the most important and abundant protein in thyroid follicles and has been widely studied as a tumor marker of thyroid cancer recurrence and persistence. Tg is considered the material basis of thyroid hormone synthesis and does not participate in the regulation of thyroid hormone synthesis and secretion. This review summarizes the recent progress in the research of thyroid hormone synthesis and secretion regulation via a negative feedback regulation mechanism by the thyroid-hypothalamus-pituitary axis. Thyroglobulin can negatively regulate the synthesis of thyroid hormone by thyroid follicular cells and antagonize the positive regulation of thyrotropin TSH. The function of thyroid follicular cells is presumably a result of Tg and TSH interaction, and a follicular cycle model is proposed to explain the causes of follicular heterogeneity in glands. We also discuss the prospects and clinical significance of studies into the negative feedback regulation mechanism of the thyroid-hypothalamus-pituitary axis and compare two theories for this mechanism.
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Affiliation(s)
- Fei Chen
- Department of Thyroid Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - Hongjuan Wang
- Department of Thyroid Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - Qiang Li
- Department of Thyroid Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - Zhichao Li
- Department of Thyroid Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - Yuqian Luo
- Department of Laboratory Medicine, Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing 210008, China
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Shi XZ, Xue L, Jin X, Xu P, Jia S, Shen HM. Different expression of sodium-iodide importer (NIS) between lactating breast and thyroid tissues may be due to structural difference of thyroid-stimulating hormone receptor (TSHR). J Endocrinol Invest 2017; 40:41-48. [PMID: 27531173 DOI: 10.1007/s40618-016-0524-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 07/21/2016] [Indexed: 10/21/2022]
Abstract
OBJECTIVE Thyroid-stimulating hormone (TSH) binds TSH receptor (TSHR) on thyroid cell membranes, which will lead activation of cyclic adenosine 3',5'-monophosphate/protein kinase A signaling pathway. Through this pathway, TSHR regulates the expression of sodium-iodide symporter (NIS) to complete iodine intake. In recent studies, it is found that TSHR is widely expressed in a variety of extra-thyroidal tissues. TSHR expressions as well as distribution in normal mammary gland tissues have not been reported. The physiological mechanism of the TSHR in the extra-thyroidal tissues has also been controversial. METHODS In this study, immunohistochemistry and immunofluorescence were used to characterize the expression distribution of TSHR protein in lactating breast. DNA sequence of TSHR cDNA from mice lactating breast was determined and then compared with TSHR cDNA from mice thyroidal tissue. RESULTS A 173 amino acid (AA) fragment deletion was found in the extra-cellular domain of lactating breast TSHR. The expression levels of NIS mRNA were compared between two tissues, and the level of NIS mRNA in lactating breasts was lower than the one in thyroidal tissues. CONCLUSION The lower expression of NIS in lactating breast may be due to the 173 AA deletion in the TSHR resulting the lower binding of TSH to the TSHR. For the first time, this finding may explain the reason of the lower NIS expression in lactating breast.
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Affiliation(s)
- X-Z Shi
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University; Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health (23618504), Harbin, 150081, China
- Department of Epidemiology, Public Health School, Shenyang Medical College, Shenyang, China
| | - L Xue
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University; Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health (23618504), Harbin, 150081, China
| | - X Jin
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University; Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health (23618504), Harbin, 150081, China
| | - P Xu
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University; Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health (23618504), Harbin, 150081, China
| | - S Jia
- R.D. Center, PacificBio Inc., Irvine, CA, 92602, USA
| | - H-M Shen
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University; Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health (23618504), Harbin, 150081, China.
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Luo Y, Akama T, Okayama A, Yoshihara A, Sue M, Oda K, Hayashi M, Ishido Y, Hirano H, Hiroi N, Katoh R, Suzuki K. A Novel Role for Flotillin-Containing Lipid Rafts in Negative-Feedback Regulation of Thyroid-Specific Gene Expression by Thyroglobulin. Thyroid 2016; 26:1630-1639. [PMID: 27676653 DOI: 10.1089/thy.2016.0187] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Thyroglobulin (Tg) stored in thyroid follicles regulates follicular function in thyroid hormone (TH) synthesis by suppressing thyroid-specific gene expression in a concentration-dependent manner. Thus, Tg is an intrinsic negative-feedback regulator that can restrain the effect of thyrotropin (TSH) in the follicle. However, the underlying mechanisms by which Tg exerts its prominent autoregulatory effect following recognition by thyrocytes remains unclear. METHODS In order to identify potential proteins that recognize and interact with Tg, mass spectrometry was used to analyze immunoprecipitated Tg-bound proteins derived from Tg-treated rat thyroid FRTL-5 cells. RESULTS Flotillin 1 and flotillin 2, two homologs that are integral membrane proteins in lipid rafts, were identified as novel Tg-binding proteins with high confidence. Further studies revealed that flotillins physically interact with endocytosed Tg, and together these proteins redistribute from the cell membrane to cytoplasmic vesicles. Treatment with the lipid raft disrupter methyl-β-cyclodextrin abolished both the endocytosis and the negative-feedback effect of Tg on thyroid-specific gene expression. Meanwhile, siRNA-mediated knockdown of flotillin 1 or flotillin 2 also significantly inhibited Tg effects on gene expression. CONCLUSION Together these results indicate that flotillin-containing lipid rafts are essential for follicular Tg to be recognized by thyrocytes and exert its negative-feedback effects in the thyroid.
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Affiliation(s)
- Yuqian Luo
- 1 Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University , Tokyo, Japan
- 2 Laboratory of Molecular Diagnostics, Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases , Tokyo, Japan
- 3 Department of Pathology, Faculty of Medicine, University of Yamanashi , Yamanashi, Japan
| | - Takeshi Akama
- 2 Laboratory of Molecular Diagnostics, Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases , Tokyo, Japan
| | - Akiko Okayama
- 4 Advanced Medical Research Center, Yokohama City University , Yokohama, Japan
| | - Aya Yoshihara
- 1 Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University , Tokyo, Japan
- 2 Laboratory of Molecular Diagnostics, Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases , Tokyo, Japan
- 5 Department of Education Planning and Development, Faculty of Medicine, Toho University , Tokyo, Japan
| | - Mariko Sue
- 2 Laboratory of Molecular Diagnostics, Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases , Tokyo, Japan
- 6 Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Toho University , Tokyo, Japan
| | - Kenzaburo Oda
- 1 Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University , Tokyo, Japan
- 2 Laboratory of Molecular Diagnostics, Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases , Tokyo, Japan
- 6 Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Toho University , Tokyo, Japan
| | - Moyuru Hayashi
- 1 Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University , Tokyo, Japan
- 2 Laboratory of Molecular Diagnostics, Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases , Tokyo, Japan
| | - Yuko Ishido
- 1 Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University , Tokyo, Japan
- 2 Laboratory of Molecular Diagnostics, Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases , Tokyo, Japan
| | - Hisashi Hirano
- 3 Department of Pathology, Faculty of Medicine, University of Yamanashi , Yamanashi, Japan
| | - Naoki Hiroi
- 5 Department of Education Planning and Development, Faculty of Medicine, Toho University , Tokyo, Japan
| | - Ryohei Katoh
- 3 Department of Pathology, Faculty of Medicine, University of Yamanashi , Yamanashi, Japan
| | - Koichi Suzuki
- 1 Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University , Tokyo, Japan
- 2 Laboratory of Molecular Diagnostics, Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases , Tokyo, Japan
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Abstract
Thyroglobulin (Tg), the most important and abundant protein in thyroid follicles, is well known for its essential role in thyroid hormone synthesis. In addition to its conventional role as the precursor of thyroid hormones, we have uncovered a novel function of Tg as an endogenous regulator of follicular function over the past decade. The newly discovered negative feedback effect of Tg on follicular function observed in the rat and human thyroid provides an alternative explanation for the observation of follicle heterogeneity. Given the essential role of the regulatory effects of Tg, we consider that dysregulation of normal Tg function is associated with multiple human thyroid diseases including autoimmune thyroid disease and thyroid cancer. Additionally, extrathyroid Tg may serve a regulatory function in other organs. Further exploration of Tg action, especially at the molecular level, is needed to obtain a better understanding of both the physiological and pathological roles of Tg.
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Ishido Y, Yamazaki K, Kammori M, Sugishita Y, Luo Y, Yamada E, Yamada T, Sellitti DF, Suzuki K. Thyroglobulin suppresses thyroid-specific gene expression in cultures of normal but not neoplastic human thyroid follicular cells. J Clin Endocrinol Metab 2014; 99:E694-702. [PMID: 24433000 DOI: 10.1210/jc.2013-3682] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT It was shown in the rat thyroid that thyroglobulin (Tg) stored in the follicular lumen is a potent regulator of thyroid-specific gene expression to maintain the function of individual follicles. However, the actions of Tg as a regulatory molecule in human thyroid have not been studied. OBJECTIVE Our objective was to determine the effect of Tg on gene expression in normal and diseased human thyroid and to examine whether the proposed model of negative-feedback autocrine regulation of thyroid function by Tg is applicable in the human as well as the rat. DESIGN Primary cultures of human thyrocytes were established from normal thyroid, Graves' disease thyroid, adenomatous goiter, follicular adenoma, and papillary carcinoma tissues obtained during surgery. Cells were stimulated with physiologic (ie, follicular) concentrations of Tg, and mRNA and protein expression of genes involved in thyroid hormonogenesis were evaluated. The effects of Tg on thyroid-specific gene expression were also assessed in 2 human papillary carcinoma cell lines. RESULTS Transcript levels of genes participating in thyroid hormone biosynthesis were significantly reduced by Tg in thyrocyte cultures derived from normal and Graves' thyroid, but not in cultures derived from thyroid neoplasms and adenomatous goiter. CONCLUSION It was confirmed that Tg acts as a negative-feedback regulator of gene expression in human thyrocytes, suggesting that Tg signaling may constitute a common mechanism for maintaining thyroid homeostasis in species with follicular thyroid morphology. However, certain diseases of intrinsic thyroid overgrowth appear to be associated with an escape from the regulatory mechanism of Tg.
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Affiliation(s)
- Yuko Ishido
- Laboratory of Molecular Diagnostics (Y.I., Y.L., K.S.), Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases, Tokyo 189-0002, Japan; Thyroid Disease Institute (K.Y., M.K., Y.S., E.Y, T.Y.), Kanaji Thyroid Hospital, Tokyo 114-0015, Japan; and Department of Medicine (D.F.S.), Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814
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11
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Abstract
BACKGROUND The established paradigm for thyroglobulin (Tg) function is that of a high molecular weight precursor of the much smaller thyroid hormones, triiodothyronine (T3) and thyroxine (T4). However, speculation regarding the cause of the functional and morphologic heterogeneity of the follicles that make up the thyroid gland has given rise to the proposition that Tg is not only a precursor of thyroid hormones, but that it also functions as an important signal molecule in regulating thyroid hormone biosynthesis. SUMMARY Evidence supporting this alternative paradigm of Tg function, including the up- or downregulation by colloidal Tg of the transcription of Tg, iodide transporters, and enzymes employed in Tg iodination, and also the effects of Tg on the proliferation of thyroid and nonthyroid cells, is examined in the present review. Also discussed in detail are potential mechanisms of Tg signaling in follicular cells. CONCLUSIONS Finally, we propose a mechanism, based on experimental observations of Tg effects on thyroid cell behavior, that could account for the phenomenon of follicular heterogeneity as a highly regulated cycle of increasing and decreasing colloidal Tg concentration that functions to optimize thyroid hormone production through the transcriptional activation or suppression of specific genes.
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Affiliation(s)
- Donald F. Sellitti
- Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Koichi Suzuki
- Laboratory of Molecular Diagnostics, Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases, Tokyo, Japan
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12
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Akama T, Luo Y, Sellitti DF, Kawashima A, Tanigawa K, Yoshihara A, Ishido Y, Nakamura K, Tanoue A, Suzuki K. Thyroglobulin increases thyroid cell proliferation via the suppression of specific microRNAs. Mol Endocrinol 2014; 28:368-79. [PMID: 24479877 DOI: 10.1210/me.2013-1266] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Thyroglobulin (Tg), stored in the follicular lumen, has also been shown recently to perform two unexpected roles: as an autocrine negative-feedback suppressor of thyroid function in the presence of TSH and as a potent inducer of thyroid cell growth in the absence of TSH. However, the underlying molecular mechanism(s) remain unclear. To elucidate a molecular pathway linking Tg to increased cell proliferation, we examined the regulation of microRNAs (miRNAs) by Tg using an miRNA microarray. We identified 21 miRNAs whose expression was significantly suppressed by Tg in rat thyroid FRTL-5 cells. Using specific miRNA analogs, we determined that miR-16, miR-24, and miR-195 mediate the induction of thyroid cell growth by Tg. The expression of miR-16 and miR-195 target genes, Mapk8, Ccne1, and Cdc6, which were previously shown to be essential for TSH-stimulated thyroid cell growth, were also induced by Tg. Moreover, the Tg-induced expression of these genes was reduced by overexpression of miR-16 and miR-195. Similarly, the induction of c-Myc by Tg was reduced by miR-24 overexpression. These results suggest that Tg could alter thyroid cell proliferation by increasing the expression of cell division-related genes such as Mapk8, Ccne1, Cdc6, and c-Myc through its suppression of specific microRNAs (miR-16, miR-24, and miR-195). In addition, we identified phosphatidylinositol 3-kinase as a key signaling pathway, linking Tg with cell proliferation. The present data support an important role for miRNAs as effectors for the effect of Tg on cell proliferation and perhaps other functions of Tg in the thyroid cell.
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Affiliation(s)
- Takeshi Akama
- Laboratory of Molecular Diagnostics (T.A., Y.L., A.K., K.T., A.Y, Y.I., K.N., K.S.), Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases, Higashimurayama-shi, Tokyo 189-0002, Japan; Department of Medicine, Uniformed Services University of the Health Sciences (D.F.S.), Bethesda, Maryland 20814-4799; and Department of Pharmacology, National Research Institute for Child Health and Development (K.N., A.T.), Setagaya-ku, Tokyo 157-8538, Japan
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