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Peng X, Zhang Y, Sun Y, Wang L, Song W, Li Q, Zhao R. Overexpressing modified human TRβ1 suppresses the proliferation of breast cancer MDA-MB-468 cells. Oncol Lett 2018; 16:785-792. [PMID: 29963146 PMCID: PMC6019938 DOI: 10.3892/ol.2018.8764] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 04/04/2018] [Indexed: 12/31/2022] Open
Abstract
A number of studies have indicated that thyroid hormone receptor β1 (TRβ1) functions as a tumor suppressor. TRs mediate transcriptional responses through a highly conserved DNA-binding domain (DBD). A novel rat TRβ isoform (rTRβΔ) was previously identified, in which a novel exon, N (108 bp), is located between exons 3 and 4 within the DBD; this exon represents the only difference between rTRβΔ and rTRβ1. In vitro, rTRβΔ exhibits a stronger tumor-suppressive capacity than rTRβ1, and further analysis revealed a high level of conservation between the rat and human DBD sequences. In the present study, an artificially modified human TRβ1 (m-hTRβ1) was constructed via the introduction of the 108-bp sequence into the corresponding position of the wild-type human TRβ1 (wt-hTRβ1) DBD. An electrophoretic mobility shift assay and transfection experiments confirmed that m-hTRβ1 is functional. Overexpression of m-hTRβ1 inhibits the proliferation of MDA-MB-468 cells in the presence of triiodothyronine by promoting apoptosis, which may be associated with the upregulation of Caspase-3 and Bak gene expression and the activation of the Caspase-3 protein. In addition, the pro-apoptotic effect of m-hTRβ1 was stronger, compared with wt-hTRβ1. These results indicated that m-hTRβ1 may act as a tumor suppressor in MDA-MB-468 cells. These data provided a novel insight into gene therapy for breast cancer.
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Affiliation(s)
- Xiaoxiang Peng
- Department of Laboratory Medicine, Weifang Medical University, Weifang, Shandong 261053, P.R. China.,Department of Clinical Laboratory, Key Discipline of Clinical Laboratory Medicine of Shandong, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261053, P.R. China
| | - Yangyang Zhang
- Department of Laboratory Medicine, Weifang Medical University, Weifang, Shandong 261053, P.R. China.,Department of Clinical Laboratory, Key Discipline of Clinical Laboratory Medicine of Shandong, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261053, P.R. China
| | - Yanli Sun
- Department of Laboratory Medicine, Weifang Medical University, Weifang, Shandong 261053, P.R. China.,Department of Clinical Laboratory, Key Discipline of Clinical Laboratory Medicine of Shandong, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261053, P.R. China
| | - Lujuan Wang
- Department of Laboratory Medicine, Weifang Medical University, Weifang, Shandong 261053, P.R. China.,Department of Clinical Laboratory, Key Discipline of Clinical Laboratory Medicine of Shandong, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261053, P.R. China
| | - Wei Song
- Department of Laboratory Medicine, Weifang Medical University, Weifang, Shandong 261053, P.R. China.,Department of Clinical Laboratory, Key Discipline of Clinical Laboratory Medicine of Shandong, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261053, P.R. China
| | - Qian Li
- Department of Laboratory Medicine, Weifang Medical University, Weifang, Shandong 261053, P.R. China.,Department of Clinical Laboratory, Key Discipline of Clinical Laboratory Medicine of Shandong, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261053, P.R. China
| | - Ronglan Zhao
- Department of Laboratory Medicine, Weifang Medical University, Weifang, Shandong 261053, P.R. China.,Department of Clinical Laboratory, Key Discipline of Clinical Laboratory Medicine of Shandong, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261053, P.R. China
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Peng X, Zhou Y, Sun Y, Song W, Meng X, Zhao C, Zhao R. Overexpression of modified human TRβ1 suppresses the growth of hepatocarcinoma SK-hep1 cells in vitro and in xenograft models. Mol Cell Biochem 2018; 449:207-218. [PMID: 29679278 PMCID: PMC6223806 DOI: 10.1007/s11010-018-3357-1] [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: 12/29/2017] [Accepted: 04/16/2018] [Indexed: 11/25/2022]
Abstract
Association studies suggest that TRβ1 functions as a tumor suppressor. Thyroid hormone receptors (TRs) mediate transcriptional responses through a highly conserved DNA-binding domain (DBD). We previously constructed an artificially modified human TRβ1 (m-TRβ1) via the introduction of a 108-bp exon sequence into the corresponding position of the wild-type human TRβ1 (TRβ1) DBD. Studies confirmed that m-TRβ1 was functional and could inhibit the proliferation of breast cancer MDA-MB-468 cells in vitro. To understand the role of m-TRβ1 in liver tumor development, we adopted a gain-of-function approach by stably expressing TRβ (m-TRβ1 and TRβ1) genes in a human hepatocarcinoma cell line, SK-hep1 (without endogenous TRβ), and then evaluated the effects of the expressed TRβ on cancer cell proliferation, migration, and tumor growth in cell-based studies and xenograft models. In the presence of 3,5,3-l-triiodothyronine (T3), the expression of TRβ in SK-hep1 cells inhibited cancer cell proliferation and impeded tumor cell migration through the up-regulation of 4-1BB, Caspase-3, and Bak gene expression; down-regulation of Bcl-2 gene expression; and activation of the Caspase-3 protein. TRβ expression in SK-hep1 led to less tumor growth in xenograft models. Additionally, the anti-tumor effect of m-TRβ1 was stronger than that of TRβ1. These data indicate that m-TRβ1 can act as a tumor suppressor in hepatocarcinoma and its role was significantly better than that of TRβ1.
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Affiliation(s)
- Xiaoxiang Peng
- Department of Laboratory Medicine, Weifang Medical University, Weifang, 261053, Shandong, China
- Key Discipline of Clinical Laboratory Medicine of Shandong Province, Affiliated Hospital of Weifang Medical University, Weifang, 261053, Shandong, China
| | - Yuntao Zhou
- Central Hospital of Zibo, Zibo, 255020, Shandong, China
| | - Yanli Sun
- Department of Laboratory Medicine, Weifang Medical University, Weifang, 261053, Shandong, China
- Key Discipline of Clinical Laboratory Medicine of Shandong Province, Affiliated Hospital of Weifang Medical University, Weifang, 261053, Shandong, China
| | - Wei Song
- Department of Laboratory Medicine, Weifang Medical University, Weifang, 261053, Shandong, China
- Key Discipline of Clinical Laboratory Medicine of Shandong Province, Affiliated Hospital of Weifang Medical University, Weifang, 261053, Shandong, China
| | - Xiangying Meng
- Department of Laboratory Medicine, Weifang Medical University, Weifang, 261053, Shandong, China
- Key Discipline of Clinical Laboratory Medicine of Shandong Province, Affiliated Hospital of Weifang Medical University, Weifang, 261053, Shandong, China
| | - Chunling Zhao
- Key Laboratory of Biological Medicine in Universities of Shandong Province, Weifang Medical University, Weifang, 261053, Shandong, China
| | - Ronglan Zhao
- Department of Laboratory Medicine, Weifang Medical University, Weifang, 261053, Shandong, China.
- Key Discipline of Clinical Laboratory Medicine of Shandong Province, Affiliated Hospital of Weifang Medical University, Weifang, 261053, Shandong, China.
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Anyetei-Anum CS, Roggero VR, Allison LA. Thyroid hormone receptor localization in target tissues. J Endocrinol 2018; 237:R19-R34. [PMID: 29440347 PMCID: PMC5843491 DOI: 10.1530/joe-17-0708] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 02/12/2018] [Indexed: 12/28/2022]
Abstract
The thyroid hormone receptors, TRα1, TRβ1 and other subtypes, are members of the nuclear receptor superfamily that mediate the action of thyroid hormone signaling in numerous tissues to regulate important physiological and developmental processes. Their most well-characterized role is as ligand-dependent transcription factors; TRs bind thyroid hormone response elements in the presence or absence of thyroid hormone to facilitate the expression of target genes. Although primarily residing in the nucleus, TRα1 and TRβ1 shuttle rapidly between the nucleus and cytoplasm. We have identified multiple nuclear localization signals and nuclear export signals within TRα1 and TRβ1 that interact with importins and exportins, respectively, to mediate translocation across the nuclear envelope. More recently, enigmatic cytoplasmic functions have been ascribed to other TR subtypes, expanding the diversity of the cellular response to thyroid hormone. By integrating data on localization signal motifs, this review provides an overview of the complex interplay between TR's dynamic transport pathways and thyroid hormone signaling activities. We examine the variation in TR subtype response to thyroid hormone signaling, and what is currently known about regulation of the variety of tissue-specific localization patterns, including targeting to the nucleus, the mitochondria and the inner surface of the plasma membrane.
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Affiliation(s)
| | - Vincent R Roggero
- Department of BiologyCollege of William and Mary, Williamsburg, Virginia, USA
| | - Lizabeth A Allison
- Department of BiologyCollege of William and Mary, Williamsburg, Virginia, USA
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