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Wang X, Zhao L, Wu X, Luo H, Wu D, Zhang M, Zhang J, Pakvasa M, Wagstaff W, He F, Mao Y, Zhang Y, Niu C, Wu M, Zhao X, Wang H, Huang L, Shi D, Liu Q, Ni N, Fu K, Hynes K, Strelzow J, El Dafrawy M, He TC, Qi H, Zeng Z. Development of a simplified and inexpensive RNA depletion method for plasmid DNA purification using size selection magnetic beads (SSMBs). Genes Dis 2021; 8:298-306. [PMID: 33997177 PMCID: PMC8093646 DOI: 10.1016/j.gendis.2020.04.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/03/2020] [Accepted: 04/22/2020] [Indexed: 02/07/2023] Open
Abstract
Plasmid DNA (pDNA) isolation from bacterial cells is one of the most common and critical steps in molecular cloning and biomedical research. Almost all pDNA purification involves disruption of bacteria, removal of membrane lipids, proteins and genomic DNA, purification of pDNA from bulk lysate, and concentration of pDNA for downstream applications. While many liquid-phase and solid-phase pDNA purification methods are used, the final pDNA preparations are usually contaminated with varied degrees of host RNA, which cannot be completely digested by RNase A. To develop a simple, cost-effective, and yet effective method for RNA depletion, we investigated whether commercially available size selection magnetic beads (SSMBs), such as Mag-Bind® TotalPure NGS Kit (or Mag-Bind), can completely deplete bacterial RNA in pDNA preparations. In this proof-of-principle study, we demonstrated that, compared with RNase A digestion and two commercial plasmid affinity purification kits, the SSMB method was highly efficient in depleting contaminating RNA from pDNA minipreps. Gene transfection and bacterial colony formation assays revealed that pDNA purified from SSMB method had superior quality and integrity to pDNA samples cleaned up by RNase A digestion and/or commercial plasmid purification kits. We further demonstrated that the SSMB method completely depleted contaminating RNA in large-scale pDNA samples. Furthermore, the Mag-bind-based SSMB method costs only 5-10% of most commercial plasmid purification kits on a per sample basis. Thus, the reported SSMB method can be a valuable and inexpensive tool for the removal of bacterial RNA for routine pDNA preparations.
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Affiliation(s)
- Xi Wang
- Ministry of Education Key Laboratory of Diagnostic Medicine, School of Laboratory and Diagnostic Medicine, Chongqing Medical University, Chongqing, 400016, PR China
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
| | - Ling Zhao
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
- Departments of Gastrointestinal Surgery, Obstetrics and Gynecology, and Nephrology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, PR China
| | - Xiaoxing Wu
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
- Departments of Gastrointestinal Surgery, Obstetrics and Gynecology, and Nephrology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, PR China
| | - Huaxiu Luo
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
- Department of Burn and Plastic Surgery, West China Hospital of Sichuan University, Chengdu, Sichuan Province, 610041, PR China
| | - Di Wu
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
| | - Meng Zhang
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
- Department of Orthopaedic Surgery, The First Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong Province, 510405, PR China
| | - Jing Zhang
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
- Departments of Gastrointestinal Surgery, Obstetrics and Gynecology, and Nephrology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, PR China
| | - Mikhail Pakvasa
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
| | - William Wagstaff
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
| | - Fang He
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
- Departments of Gastrointestinal Surgery, Obstetrics and Gynecology, and Nephrology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, PR China
| | - Yukun Mao
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
- Departments of Orthopaedic Surgery and Neurosurgery, The Affiliated Zhongnan Hospital of Wuhan University, Wuhan, Hubei Province, 430072, PR China
| | - Yongtao Zhang
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
- Department of Orthopaedic Surgery, The Affiliated Hospital of Qingdao University, Qingdao, Shandong Province, 266061, PR China
| | - Changchun Niu
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
- Department of Laboratory Diagnostic Medicine, Chongqing General Hospital, Chongqing, 400021, PR China
| | - Meng Wu
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
- Institute of Bone and Joint Research, The departments of Orthopaedic Surgery and Obstetrics and Gynecology, The First and Second Hospitals of Lanzhou University, Lanzhou, Gansu Province, 730030, PR China
| | - Xia Zhao
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
- Department of Orthopaedic Surgery, The Affiliated Hospital of Qingdao University, Qingdao, Shandong Province, 266061, PR China
| | - Hao Wang
- Ministry of Education Key Laboratory of Diagnostic Medicine, School of Laboratory and Diagnostic Medicine, Chongqing Medical University, Chongqing, 400016, PR China
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
| | - Linjuan Huang
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
- Departments of Gastrointestinal Surgery, Obstetrics and Gynecology, and Nephrology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, PR China
| | - Deyao Shi
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, 430022, PR China
| | - Qing Liu
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
- Department of Spine Surgery, Second Xiangya Hospital, Central South University, Changsha, Hunan Province, 410011, PR China
| | - Na Ni
- Ministry of Education Key Laboratory of Diagnostic Medicine, School of Laboratory and Diagnostic Medicine, Chongqing Medical University, Chongqing, 400016, PR China
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
| | - Kai Fu
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
- Departments of Orthopaedic Surgery and Neurosurgery, The Affiliated Zhongnan Hospital of Wuhan University, Wuhan, Hubei Province, 430072, PR China
| | - Kelly Hynes
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
| | - Jason Strelzow
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
| | - Mostafa El Dafrawy
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
| | - Tong-Chuan He
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
| | - Hongbo Qi
- Departments of Gastrointestinal Surgery, Obstetrics and Gynecology, and Nephrology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, PR China
| | - Zongyue Zeng
- Ministry of Education Key Laboratory of Diagnostic Medicine, School of Laboratory and Diagnostic Medicine, Chongqing Medical University, Chongqing, 400016, PR China
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL, 60637, USA
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Lee S, Sohn KC, Choi DK, Won M, Park KA, Ju SK, Kang K, Bae YK, Hur GM, Ro H. Ecdysone Receptor-based Singular Gene Switches for Regulated Transgene Expression in Cells and Adult Rodent Tissues. MOLECULAR THERAPY-NUCLEIC ACIDS 2016; 5:e367. [PMID: 27673563 PMCID: PMC5056996 DOI: 10.1038/mtna.2016.74] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Accepted: 07/25/2016] [Indexed: 11/09/2022]
Abstract
Controlled gene expression is an indispensable technique in biomedical research. Here, we report a convenient, straightforward, and reliable way to induce expression of a gene of interest with negligible background expression compared to the most widely used tetracycline (Tet)-regulated system. Exploiting a Drosophila ecdysone receptor (EcR)-based gene regulatory system, we generated nonviral and adenoviral singular vectors designated as pEUI(+) and pENTR-EUI, respectively, which contain all the required elements to guarantee regulated transgene expression (GAL4-miniVP16-EcR, termed GvEcR hereafter, and 10 tandem repeats of an upstream activation sequence promoter followed by a multiple cloning site). Through the transient and stable transfection of mammalian cell lines with reporter genes, we validated that tebufenozide, an ecdysone agonist, reversibly induced gene expression, in a dose- and time-dependent manner, with negligible background expression. In addition, we created an adenovirus derived from the pENTR-EUI vector that readily infected not only cultured cells but also rodent tissues and was sensitive to tebufenozide treatment for regulated transgene expression. These results suggest that EcR-based singular gene regulatory switches would be convenient tools for the induction of gene expression in cells and tissues in a tightly controlled fashion.
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Affiliation(s)
- Seoghyun Lee
- Department of Biological Sciences, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, Republic of Korea
| | - Kyung-Cheol Sohn
- Department of Dermatology, College of Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Dae-Kyoung Choi
- Department of Dermatology, College of Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Minho Won
- Department of Pharmacology, College of Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Kyeong Ah Park
- Department of Pharmacology, College of Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Sung-Kyu Ju
- Affiliated Research (and Development) Institute, Daejeon, Republic of Korea
| | - Kidong Kang
- Department of Pharmacology, College of Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Young-Ki Bae
- Comparative Biomedical Research Branch, Research Institute, National Cancer Center, Goyang, Republic of Korea
| | - Gang Min Hur
- Department of Pharmacology, College of Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Hyunju Ro
- Department of Biological Sciences, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, Republic of Korea
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The transcriptional repression activity of STAF65γ is facilitated by promoter tethering and nuclear import of class IIa histone deacetylases. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:579-91. [DOI: 10.1016/j.bbagrm.2014.05.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 04/28/2014] [Accepted: 05/13/2014] [Indexed: 12/31/2022]
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Kong Y, Zhang H, Chen X, Zhang W, Zhao C, Wang N, Wu N, He Y, Nan G, Zhang H, Wen S, Deng F, Liao Z, Wu D, Zhang J, Qin X, Haydon RC, Luu HH, He TC, Zhou L. Destabilization of heterologous proteins mediated by the GSK3β phosphorylation domain of the β-catenin protein. Cell Physiol Biochem 2013; 32:1187-99. [PMID: 24335169 PMCID: PMC4064945 DOI: 10.1159/000354518] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/23/2013] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND AND AIMS Wnt/β-catenin signaling plays important roles in development and cellular processes. The hallmark of canonical Wnt signaling activation is the stabilization of β-catenin protein in cytoplasm and/or nucleus. The stability of β-catenin is the key to its biological functions and is controlled by the phosphorylation of its amino-terminal degradation domain. Aberrant activation of β-catenin signaling has been implicated in the development of human cancers. It has been recently suggested that GSK3βmay play an essential role in regulating global protein turnover. Here, we investigate if the GSK3β phosphorylation site-containing degradation domain of β-catenin is sufficient to destabilize heterologous proteins. METHODS AND RESULTS We engineer chimeric proteins by fusing β-catenin degradation domain at the N- and/or C-termini of the enhanced green fluorescent protein (eGFP). In both transient and stable expression experiments, the chimeric GFP proteins exhibit a significantly decreased stability, which can be effectively antagonized by lithium and Wnt1. An activating mutation in the destruction domain significantly stabilizes the fusion protein. Furthermore, GSK3 inhibitor SB-216763 effectively increases the GFP signal of the fusion protein. Conversely, the inhibition of Wnt signaling with tankyrase inhibitor XAV939 results in a decrease in GFP signal of the fusion proteins, while these small molecules have no significant effects on the mutant destruction domain-GFP fusion protein. CONCLUSION Our findings strongly suggest that the β-catenin degradation domain may be sufficient to destabilize heterologous proteins in Wnt signaling-dependent manner. It is conceivable that the chimeric GFP proteins may be used as a functional reporter to measure the dynamic status of β-catenin signaling, and to identify potential anticancer drugs that target β-catenin signaling.
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Affiliation(s)
- Yuhan Kong
- The First Affiliated Hospital, Chongqing Medical University, Chongqing, China
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Schiffmacher AT, Keefer CL. CDX2 regulates multiple trophoblast genes in bovine trophectoderm CT-1 cells. Mol Reprod Dev 2013; 80:826-39. [PMID: 23836438 DOI: 10.1002/mrd.22212] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 06/27/2013] [Indexed: 11/06/2022]
Abstract
The bovine trophectoderm (TE) undergoes a dramatic morphogenetic transition prior to uterine endometrial attachment. Many studies have documented trophoblast-specific gene expression profiles at various pre-attachment stages, yet genetic interactions within the transitioning TE gene regulatory network are not well characterized. During bovine embryogenesis, transcription factors OCT4 and CDX2 are co-expressed during early trophoblast elongation. In this study, the bovine trophectoderm-derived CT-1 cell line was utilized as a genetic model to examine the roles of CDX2 and OCT4 within the bovine trophoblast gene regulatory network. An RT-PCR screen for TE-lineage transcription factors identified expression of CDX2, ERRB, ID2, SOX15, ELF5, HAND1, and ASCL2. CT-1 cells also express a nuclear-localized, 360 amino acid OCT4 ortholog of the pluripotency-specific human OCT4A. To delineate the roles of CDX2 and OCT4 within the CT-1 gene network, CDX2 and OCT4 levels were manipulated via overexpression and siRNA-mediated knockdown. An increase in CDX2 negatively regulated OCT4 expression, but increased expression of IFNT, HAND1, ASCL2, SOX15, and ELF5. A reduction of CDX2 levels exhibited a reciprocal effect, resulting in decreased expression of IFNT, HAND1, ASCL2, and SOX15. Both overexpression and knockdown of CDX2 increased ETS2 transcription. In contrast to CDX2, manipulation of OCT4 levels only revealed a positive autoregulatory mechanism and upregulation of ASCL2. Together, these results suggest that CDX2 is a core regulator of multiple trophoblast genes within CT-1 cells.
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Affiliation(s)
- Andrew T Schiffmacher
- Department of Animal and Avian Sciences, University of Maryland, College Park, Maryland
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Shui W, Yin L, Luo J, Li R, Zhang W, Zhang J, Huang W, Hu N, Liang X, Deng ZL, Hu Z, Shi LL, Luu HH, Haydon RC, He TC, Ho SH. Characterization of chondrocyte scaffold carriers for cell-based gene therapy in articular cartilage repair. J Biomed Mater Res A 2013; 101:3542-50. [PMID: 23629940 DOI: 10.1002/jbm.a.34661] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Revised: 01/27/2013] [Accepted: 02/07/2013] [Indexed: 11/10/2022]
Abstract
Articular cartilage lesions in the knee are common injuries. Chondrocyte transplant represents a promising therapeutic modality for articular cartilage injuries. Here, we characterize the viability and transgene expression of articular chondrocytes cultured in three-dimensional scaffolds provided by four types of carriers. Articular chondrocytes are isolated from rabbit knees and cultured in four types of scaffolds: type I collagen sponge, fibrin glue, hyaluronan, and open-cell polylactic acid (OPLA). The cultured cells are transduced with adenovirus expressing green fluorescence protein (AdGFP) and luciferase (AdGL3-Luc). The viability and gene expression in the chondrocytes are determined with fluorescence microscopy and luciferase assay. Cartilage matrix production is assessed by Alcian blue staining. Rabbit articular chondrocytes are effectively infected by AdGFP and exhibited sustained GFP expression. All tested scaffolds support the survival and gene expression of the infected chondrocytes. However, the highest transgene expression is observed in the OPLA carrier. At 4 weeks, Alcian blue-positive matrix materials are readily detected in OPLA cultures. Thus, our results indicate that, while all tested carriers can support the survival of chondrocytes, OPLA supports the highest transgene expression and is the most conductive scaffold for matrix production, suggesting that OPLA may be a suitable scaffold for cell-based gene therapy of articular cartilage repairs.
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Affiliation(s)
- Wei Shui
- Department of Orthopaedic Surgery of the Affiliated Hospitals, Chongqing Medical University, Chongqing 400016, China; Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637
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Design and Application of Synthetic Biology Devices for Therapy. Synth Biol (Oxf) 2013. [DOI: 10.1016/b978-0-12-394430-6.00009-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Interference with Sin3 function induces epigenetic reprogramming and differentiation in breast cancer cells. Proc Natl Acad Sci U S A 2010; 107:11811-6. [PMID: 20547842 DOI: 10.1073/pnas.1006737107] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Sin3A/B is a master transcriptional scaffold and corepressor that plays an essential role in the regulation of gene transcription and maintenance of chromatin structure, and its inappropriate recruitment has been associated with aberrant gene silencing in cancer. Sin3A/B are highly related, large, multidomian proteins that interact with a wide variety of transcription factors and corepressor components, and we examined whether disruption of the function of a specific domain could lead to epigenetic reprogramming and derepression of specific subsets of genes. To this end, we selected the Sin3A/B-paired amphipathic alpha-helices (PAH2) domain based on its established role in mediating the effects of a relatively small number of transcription factors containing a PAH2-binding motif known as the Sin3 interaction domain (SID). Here, we show that in both human and mouse breast cancer cells, the targeted disruption of Sin3 function by introduction of a SID decoy that interferes with PAH2 binding to SID-containing partner proteins reverted the silencing of genes involved in cell growth and differentiation. In particular, the SID decoy led to epigenetic reprogramming and reexpression of the important breast cancer-associated silenced genes encoding E-cadherin, estrogen receptor alpha, and retinoic acid receptor beta and impaired tumor growth in vivo. Interestingly, the SID decoy was effective in the triple-negative M.D. Anderson-Metastatic Breast-231 (MDA-MB-231) breast cancer cell line, restoring sensitivity to 17beta-estradiol, tamoxifen, and retinoids. Therefore, the development of small molecules that can block interactions between PAH2 and SID-containing proteins offers a targeted epigenetic approach for treating this type of breast cancer that may also have wider therapeutic implications.
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Escudero JM, Haller JL, Clay CM, Escudero KW. Microarray analysis of Foxl2 mediated gene regulation in the mouse ovary derived KK1 granulosa cell line: Over-expression of Foxl2 leads to activation of the gonadotropin releasing hormone receptor gene promoter. J Ovarian Res 2010; 3:4. [PMID: 20167115 PMCID: PMC2831895 DOI: 10.1186/1757-2215-3-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Accepted: 02/18/2010] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND The Foxl2 transcription factor is required for ovarian function during follicular development. The mechanism of Foxl2 regulation of this process has not been elucidated. Our approach to begin to understand Foxl2 function is through the identification of Foxl2 regulated genes in the ovary. METHODS Transiently transfected KK1 mouse granulosa cells were used to identify genes that are potentially regulated by Foxl2. KK1 cells were transfected in three groups (mock, activated, and repressed) and twenty-four hours later RNA was isolated and submitted for Affymetrix microarray analysis. Genesifter software was used to carry out analysis of microarray data. One identified target, the gonadotropin releasing hormone receptor (GnRHR) gene, was chosen for further study and validation of Foxl2 responsiveness. Transient transfection analyses were carried out to study the effect of Foxl2 over-expression on GnRHR gene promoter-luciferase fusion activity. Data generated was analyzed with GraphPad Prism software. RESULTS Microarray analysis identified 996 genes of known function that are potentially regulated by Foxl2 in mouse KK1 granulosa cells. The steroidogenic acute regulatory protein (StAR) gene that has been identified as Foxl2 responsive by others was identified in this study also, thereby supporting the effectiveness of our strategy. The GnRHR gene was chosen for further study because it is known to be expressed in the ovary and the results of previous work has indicated that Foxl2 may regulate GnRHR gene expression. Cellular levels of Foxl2 were increased via transient co-transfection of KK1 cells using a Foxl2 expression vector and a GnRHR promoter-luciferase fusion reporter vector. The results of these analyses indicate that over-expression of Foxl2 resulted in a significant increase in GnRHR promoter activity. Therefore, these transfection data validate the microarray data which suggest that Foxl2 regulates GnRHR and demonstrate that Foxl2 acts as an activator of the GnRHR gene. CONCLUSIONS Potential Foxl2 regulated ovarian genes have been identified through microarray analysis and comparison of these data to other microarray studies. The Foxl2 responsiveness of the GnRHR gene has been validated and provided evidence of Foxl2 transcriptional activation of the GnRHR gene promoter in the mouse ovary derived KK1 granulosa cell line.
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Affiliation(s)
- Jean M Escudero
- Department of Biological and Health Sciences, Texas A&M University- Kingsville, Kingsville, TX, USA
| | - Jodi L Haller
- Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Colin M Clay
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Kenneth W Escudero
- Department of Biological and Health Sciences, Texas A&M University- Kingsville, Kingsville, TX, USA
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Gallozzi M, Béringue V, Decaunes P, Le Dur A, Le Roux K, Tilly G, Le Guillou S, Herzog L, Peyre C, Ladroue A, Chapuis J, Vilotte M, Passet B, Costa J, Chenais N, Le Provost F, Laude H, Vilotte JL. Spatial and temporal down-regulation of transgene expression using the TRSID-silencer in mice: application to Prnp. FEBS Lett 2008; 582:2219-24. [PMID: 18501713 DOI: 10.1016/j.febslet.2008.05.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2008] [Revised: 05/05/2008] [Accepted: 05/08/2008] [Indexed: 10/22/2022]
Abstract
Spatial and temporal control of ovine prion protein (Prnp) gene expression was achieved in mice using two transgenes: a Prnp minigene with tet-operator sequences inserted 5' to exon 1 and a mouse neurofilament genomic clone carrying the chimeric-repressor TRSID cDNA. In bi-transgenic mice, ovine PrP(C) expression could be reversibly controlled in neuronal cells by doxycycline treatment whereas it remains constant in other cell types. Overall, this model opens opportunities to assess the involvement of cell types in prion diseases and PrP physiological function. It demonstrates the potentiality of the TRSID-silencer to precisely control temporal and spatial gene expression in vivo.
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Affiliation(s)
- Micaela Gallozzi
- Laboratoire de Génétique Biochimique et de Cytogénétique, Institut National de la Recherche Agronomique, 78350 Jouy-en-Josas, France
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Sotiropoulos V, Kaznessis YN. Synthetic tetracycline-inducible regulatory networks: computer-aided design of dynamic phenotypes. BMC SYSTEMS BIOLOGY 2007; 1:7. [PMID: 17408514 PMCID: PMC1885862 DOI: 10.1186/1752-0509-1-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Accepted: 01/09/2007] [Indexed: 02/07/2023]
Abstract
BACKGROUND Tightly regulated gene networks, precisely controlling the expression of protein molecules, have received considerable interest by the biomedical community due to their promising applications. Among the most well studied inducible transcription systems are the tetracycline regulatory expression systems based on the tetracycline resistance operon of Escherichia coli, Tet-Off (tTA) and Tet-On (rtTA). Despite their initial success and improved designs, limitations still persist, such as low inducer sensitivity. Instead of looking at these networks statically, and simply changing or mutating the promoter and operator regions with trial and error, a systematic investigation of the dynamic behavior of the network can result in rational design of regulatory gene expression systems. Sophisticated algorithms can accurately capture the dynamical behavior of gene networks. With computer aided design, we aim to improve the synthesis of regulatory networks and propose new designs that enable tighter control of expression. RESULTS In this paper we engineer novel networks by recombining existing genes or part of genes. We synthesize four novel regulatory networks based on the Tet-Off and Tet-On systems. We model all the known individual biomolecular interactions involved in transcription, translation, regulation and induction. With multiple time-scale stochastic-discrete and stochastic-continuous models we accurately capture the transient and steady state dynamics of these networks. Important biomolecular interactions are identified and the strength of the interactions engineered to satisfy design criteria. A set of clear design rules is developed and appropriate mutants of regulatory proteins and operator sites are proposed. CONCLUSION The complexity of biomolecular interactions is accurately captured through computer simulations. Computer simulations allow us to look into the molecular level, portray the dynamic behavior of gene regulatory networks and rationally engineer novel ones with useful applications. We are able to propose, test and accept or reject design principles for each network. Guided by simulations, we develop a set of design principles for novel tetracycline-inducible networks.
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Affiliation(s)
- Vassilios Sotiropoulos
- Department of Chemical Engineering and Materials Science, and Digital Technology Center, University of Minnesota, 421 Washington Ave SE, Minneapolis, MN 55455 USA
| | - Yiannis N Kaznessis
- Department of Chemical Engineering and Materials Science, and Digital Technology Center, University of Minnesota, 421 Washington Ave SE, Minneapolis, MN 55455 USA
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Bockamp E, Christel C, Hameyer D, Khobta A, Maringer M, Reis M, Heck R, Cabezas-Wallscheid N, Epe B, Oesch-Bartlomowicz B, Kaina B, Schmitt S, Eshkind L. Generation and characterization of tTS-H4: a novel transcriptional repressor that is compatible with the reverse tetracycline-controlled TET-ON system. J Gene Med 2007; 9:308-18. [PMID: 17330923 DOI: 10.1002/jgm.1012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Conditional gene regulatory systems ensuring tight and adjustable expression of therapeutic genes are central for developing future gene therapy strategies. Among various regulatory systems, tetracycline-controlled gene expression has emerged as a safe and reliable option. Moreover, the tightness of tetracycline-regulated gene switches can be substantially improved by complementing transcriptional activators with antagonizing repressors. METHODS To develop novel tetracycline-responsive transcriptional repressors, we fused various transcriptional silencing domains to the TetR (B/E) DNA-binding and dimerization domain of the Tn10-encoded tetracycline resistance operon (TetR (B/E)). The resulting fusion proteins were individually tested for their ability to repress transcription of the constitutively active hypoxanthine phosphoribosyltransferase (HPRT) promoter. In addition, compatibility with the commonly used reverse tetracycline-controlled transactivator system (rtTA-system) and responsiveness to the pharmacological effector doxycycline (DOX) were evaluated. Finally, inducibility, effector-dependent promoter activity and the modification of histone H3 and H4 of the active versus the repressed target promoter were determined. RESULTS Fusion of the human deacetylase 4 (HDAC4) carboxy-terminal silencing domain to TetR (B/E) resulted in a functional transcriptional repressor. This novel repressor, termed tTS-H4, efficiently reduced the activity of the murine HPRT promoter and a constitutively active human cytomegalovirus (hCMV) minimal promoter. Furthermore, combining tTS-H4 with the rtTA transcriptional activator allowed for grading, turning off and resuming target gene expression over several orders of magnitude without background. CONCLUSIONS The tTS-H4 repressor is compatible with the commonly used rtTA transcriptional activation system and is a versatile new tool for tightly and adjustably regulating conditional gene expression.
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Affiliation(s)
- Ernesto Bockamp
- Institute of Toxicology/Mouse Genetics, Johannes Gutenberg University, D-55131 Mainz, Germany.
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Ausserlechner MJ, Obexer P, Deutschmann A, Geiger K, Kofler R. A retroviral expression system based on tetracycline-regulated tricistronic transactivator/repressor vectors for functional analyses of antiproliferative and toxic genes. Mol Cancer Ther 2006; 5:1927-34. [PMID: 16928812 DOI: 10.1158/1535-7163.mct-05-0500] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Establishment of stably transfected mammalian cells with conditional expression of antiproliferative or proapoptotic proteins is often hampered by varying expression within bulk-selected cells and high background in the absence of the inducing drug. To overcome such limitations, we designed a gene expression system that transcribes the tetracycline-dependent rtTA2-M2-activator, TRSID-silencer, and selection marker as a tricistronic mRNA from a single retroviral vector. More than 92% of bulk-selected cells expressed enhanced green fluorescent protein or luciferase over more than three orders of magnitude in an almost linear, dose-dependent manner. To functionally test this system, we studied how dose-dependent expression of p27(Kip1) affects proliferation and viability of SH-EP neuroblastoma cells. Low to moderate p27(Kip1) expression caused transient G(0)-G(1) accumulation without reduced viability, whereas high p27(Kip1) levels induced significant apoptosis after 72 hours. This proves that this expression system allows concentration-dependent analysis of gene function and implicates p27(Kip1) as a critical regulator of both proliferation and apoptosis in SH-EP neuroblastoma cells.
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Affiliation(s)
- Michael J Ausserlechner
- Molecular Biology Research Laboratory, Pediatric Department, Medical University Innsbruck, Innrain 66, A-6020 Innsbruck, Austria.
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Uchida S, Sakai S, Furuichi T, Hosoda H, Toyota K, Ishii T, Kitamoto A, Sekine M, Koike K, Masushige S, Murphy G, Silva AJ, Kida S. Tight regulation of transgene expression by tetracycline-dependent activator and repressor in brain. GENES BRAIN AND BEHAVIOR 2006; 5:96-106. [PMID: 16436193 DOI: 10.1111/j.1601-183x.2005.00139.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Methods to temporally and spatially regulate gene mutations will provide a powerful strategy to investigate gene function in the brain. To develop these methods, we have established a tightly regulated system for transgene expression in the forebrain using both a tetracycline (Tc)-dependent transcription activator (rtTA) and a repressor (TetR-Kruppel-associated box). In this system, the repressor binds to the Tc-responsive element (TRE) in the absence of doxycycline (Dox), leading to the repression of leaky activation of TRE-mediated transcription caused by weak binding of rtTA to TRE. Upon Dox administration, only the activator binds to TRE and activates transcription. We tested this system in cultured cells by bicistronically expressing both the regulators using an internal ribosome entry site (IRES). In COS-1, HeLa and SHSY5Y cells, leaky transcription activation led by rtTA in the absence of Dox was repressed without decreasing the level of activated transcription in the presence of Dox. Using this system, transgenic mice were produced that express both the regulators using IRES in the forebrain under the control of the alphaCaMKII promoter and were bred with transgenic mice carrying the TRE-dependent reporter transgene. In reverse transcription-polymerase chain reaction and in situ hybridization analyses of the forebrain in adult double transgenic mice, the treatment of Dox induces reporter mRNA expression, which was not detected before the treatment and after the withdraw of Dox following the treatment. These results indicate that this system allows the tight regulation of transgene expression in a Dox-dependent fashion in the forebrain and will be useful in investigating gene function in the brain.
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Affiliation(s)
- S Uchida
- Department of Agricultural Chemistry, Faculty of Applied Bioscience, Tokyo University of Agriculture, Tokyo, Japan
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Agu CA, Klein R, Schwab S, König-Schuster M, Kodajova P, Ausserlechner M, Binishofer B, Bläsi U, Salmons B, Günzburg WH, Hohenadl C. The cytotoxic activity of the bacteriophage lambda-holin protein reduces tumour growth rates in mammary cancer cell xenograft models. J Gene Med 2006; 8:229-41. [PMID: 16170834 DOI: 10.1002/jgm.833] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The potential use of gene therapy for cancer treatment is being intensively studied. One approach utilises the expression of genes encoding cytotoxic proteins. Such proteins can affect cellular viability, for example by inhibiting the translation machinery or disturbing membrane integrity. The bacteriophage Lambda (lambda)-holin protein is known to form a lesion in the cytoplasmic membrane of E. coli, triggering bacterial cell lysis and thereby enabling the release of new bacteriophage particles. The aim of this study was to evaluate whether the lambda-holin protein has a cytotoxic impact on eukaryotic cells and whether it holds potential as a new therapeutic protein for cancer gene therapy. METHODS To explore this possibility, stably transfected human cell lines were established that harbour a tetracycline (Tet)-inducible system for controlled expression of the lambda-holin gene. The effect of the lambda-holin protein on eukaryotic cells was studied in vitro by applying several viability assays. We also investigated the effect of lambda-holin gene expression in vivo using a human breast cancer cell tumour xenograft as well as a syngeneic mammary adenocarcinoma mouse model. RESULTS The lambda-holin-encoding gene was inducibly expressed in eukaryotic cells in vitro. Expression led to a substantial reduction of cell viability of more than 98%. In mouse models, lambda-holin-expressing tumour cell xenografts revealed significantly reduced growth rates in comparison to xenografts not expressing the lambda-holin gene. CONCLUSIONS The lambda-holin protein is cytotoxic for eukaryotic cells in vitro and inhibits tumour growth in vivo suggesting potential therapeutic use in cancer gene therapy.
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Affiliation(s)
- Chukwuma A Agu
- Research Institute of Virology and Biomedicine, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Vienna, Austria
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Abstract
Contents Transgenic animals are more widely used for various purposes. Applications of animal transgenesis may be divided into three major categories: (i) to obtain information on gene function and regulation as well as on human diseases, (ii) to obtain high value products (recombinant pharmaceutical proteins and xeno-organs for humans) to be used for human therapy, and (iii) to improve animal products for human consumption. All these applications are directly or not related to human health. Animal transgenesis started in 1980. Important improvement of the methods has been made and are still being achieved to reduce cost as well as killing of animals and to improve the relevance of the models. This includes gene transfer and design of reliable vectors for transgene expression. This review describes the state of the art of animal transgenesis from a technical point of view. It also reports some of the applications in the medical field based on the use of transgenic animal models. The advance in the generation of pigs to be used as the source of organs for patients and in the preparation of pharmaceutical proteins from milk and other possible biological fluids from transgenic animals is described. The projects in course aiming at improving animal production by transgenesis are also depicted. Some the specific biosafety and bioethical problems raised by the different applications of transgenesis, including consumption of transgenic animal products are discussed.
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Affiliation(s)
- L-M Houdebine
- Biologie du Développement et Reproduction, Institut National de la Recherche Agronomique, Jouy-en-Josas Cedex, France.
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Zabala M, Wang L, Hernandez-Alcoceba R, Hillen W, Qian C, Prieto J, Kramer MG. Optimization of the Tet-on system to regulate interleukin 12 expression in the liver for the treatment of hepatic tumors. Cancer Res 2004; 64:2799-804. [PMID: 15087396 DOI: 10.1158/0008-5472.can-03-3061] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Interleukin 12 (IL-12) is a potent antitumoral cytokine, but it can be toxic at high doses. Therapy of liver tumors might benefit from the use of vectors enabling tight control of IL-12 expression in hepatic tissue for long periods of time. To this aim, we have improved the Tet-on system by modifying the minimal region of the inducible promoter and adjusting the level of the trans-activator using liver-specific promoters with graded activities. The resulting vectors allowed hepato-specific gene regulation with lower basal activity and higher inducibility compared with the original system in the absence of repressor molecules. The basal and final protein levels depend on the strength of the promoter that directs the transcripcional activator as well as the relative orientation of the two genes in the same plasmid. We have selected the construct combining minimal leakage with higher level of induced gene expression to regulate IL-12 after DNA transfer to mouse liver. Administration of doxycycline (Dox) enhanced IL-12 expression in a dose-dependent manner, whereas it was undetectable in serum in the noninduced state. Gene activation could be repeated several times, and sustained levels of IL-12 were achieved by daily administration of Dox. The antitumor effect of IL-12 was evaluated in a mouse model of metastatic colon cancer to the liver. Complete eradication of liver metastasis and prolonged survival was observed in all mice receiving Dox for 10 days. These data demonstrate the potential of a naked DNA gene therapy strategy to achieve tight control of IL-12 within the liver for the treatment of cancer.
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Affiliation(s)
- Maider Zabala
- Division of Hepatology and Gene Therapy, School of Medicine, Fundacion para la Investigacion Medica Aplicada (FIMA), University of Navarra, Pamplona, Spain
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Park JY, Luo Q, Jiang W, Kang Q, Peng Y, Strom C, Luu HH, Haydon RC, He TC. Dual regulation of gene expression mediated by tetracycline and Cre recombinase. Biotechniques 2004; 36:390-2, 394, 396. [PMID: 15038152 DOI: 10.2144/04363bm03] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Jae Yoon Park
- University of Chicago Medical Center, Chicago, IL, USA
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Lee EJ, Jameson JL. Cell-specific Cre-mediated activation of the diphtheria toxin gene in pituitary tumor cells: potential for cytotoxic gene therapy. Hum Gene Ther 2002; 13:533-42. [PMID: 11874631 DOI: 10.1089/10430340252809829] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Diphtheria toxin has been suggested for the treatment of malignant cancer. In this paper, we describe a strategy for targeting the expression of the diphtheria toxin gene to growth hormone (GH)-producing pituitary tumor cells using adenoviral vectors. We generated adenoviral vectors in which a stuffer DNA fragment, flanked by two loxP sequences, was placed between the GH or cytomegalovirus (CMV) promoters and the diphtheria toxin gene (GH-loxP-DT, and CMV-loxP-DT) or the beta-Gal gene (GH-loxP-Gal, and CMV-loxP-Gal). Co-infection of GH-loxP-DT with either CMV-Cre or GH-Cre induced cytotoxicity that was limited to GH4 cells. Little or no cytopathic effect was seen in GH4 cells infected with control viruses (CMV-loxP-Gal or GH-loxP-Gal with CMV-Cre or GH-Cre). To test the effectiveness of this strategy in vivo, GH4 cells were transplanted into nude mice. Intratumoral co-injection of adenoviruses carrying diphtheria toxin (GH-loxP-DT, and CMV-loxP-DT) and Cre recombinase (GH-Cre, and CMV-Cre) caused rapid regression of the transplanted GH4 tumors. These results indicate that Cre-mediated activation of a loxP-repressed form of the DT gene provides a useful strategy for targeted suicide gene therapy. This approach may be useful for GH-secreting adenomas and should be applicable to other neoplastic disorders.
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Affiliation(s)
- Eun Jig Lee
- Division of Endocrinology, Metabolism, and Molecular Medicine, Northwestern University Medical School, Chicago, IL 60611-2908, USA
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