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Kim BM, Song HS, Kim JY, Kwon EY, Ha SY, Kim M, Choi JH. Functional characterization of ABCA4 genetic variants related to Stargardt disease. Sci Rep 2022; 12:22282. [PMID: 36566289 PMCID: PMC9790013 DOI: 10.1038/s41598-022-26912-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 12/21/2022] [Indexed: 12/25/2022] Open
Abstract
The ATP-binding cassette subfamily 4 (ABCA4), a transporter, is localized within the photoreceptors of the retina, and its genetic variants cause retinal dystrophy. Despite the clinical importance of the ABCA4 transporter, a few studies have investigated the function of each variant. In this study, we functionally characterized ABCA4 variants found in Korean patients with Stargardt disease or variants of the ABCA4 promoter region. We observed that four missense variants-p.Arg290Gln, p.Thr1117Ala, p.Cys1140Trp, and p.Asn1588Tyr-significantly decreased ABCA4 expression on the plasma membrane, which could be due to intracellular degradation. There are four major haplotypes in the ABCA4 proximal promoter. We observed that the H1 haplotype (c.-761C>A) indicated significantly increased luciferase activity compared to that of the wild-type, whereas the H3 haplotype (c.-1086A>C) indicated significantly decreased luciferase activity (P < 0.01 and 0.001, respectively). In addition, c.-900A>T in the H2 haplotype exhibited significantly increased luciferase activity compared with that of the wild-type. Two transcription factors, GATA-2 and HLF, were found to function as enhancers of ABCA4 transcription. Our findings suggest that ABCA4 variants in patients with Stargardt disease affect ABCA4 expression. Furthermore, common variants of the ABCA4 proximal promoter alter the ABCA4 transcriptional activity, which is regulated by GATA-2 and HLF transcription factors.
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Affiliation(s)
- Bo Min Kim
- grid.255649.90000 0001 2171 7754Department of Pharmacology, Inflammation-Cancer Microenvironment Research Center, College of Medicine, Ewha Womans University, 25 Magokdong-Ro 2-Gil, Gangseo-Gu, Seoul, 07804 Korea
| | - Hyo Sook Song
- grid.255649.90000 0001 2171 7754Department of Pharmacology, Inflammation-Cancer Microenvironment Research Center, College of Medicine, Ewha Womans University, 25 Magokdong-Ro 2-Gil, Gangseo-Gu, Seoul, 07804 Korea
| | - Jin-Young Kim
- grid.255649.90000 0001 2171 7754Department of Pharmacology, Inflammation-Cancer Microenvironment Research Center, College of Medicine, Ewha Womans University, 25 Magokdong-Ro 2-Gil, Gangseo-Gu, Seoul, 07804 Korea
| | - Eun Young Kwon
- grid.255649.90000 0001 2171 7754Department of Pharmacology, Inflammation-Cancer Microenvironment Research Center, College of Medicine, Ewha Womans University, 25 Magokdong-Ro 2-Gil, Gangseo-Gu, Seoul, 07804 Korea
| | - Seung Yeon Ha
- grid.255649.90000 0001 2171 7754Department of Pharmacology, Inflammation-Cancer Microenvironment Research Center, College of Medicine, Ewha Womans University, 25 Magokdong-Ro 2-Gil, Gangseo-Gu, Seoul, 07804 Korea
| | - Minsuk Kim
- grid.255649.90000 0001 2171 7754Department of Pharmacology, Inflammation-Cancer Microenvironment Research Center, College of Medicine, Ewha Womans University, 25 Magokdong-Ro 2-Gil, Gangseo-Gu, Seoul, 07804 Korea
| | - Ji Ha Choi
- grid.255649.90000 0001 2171 7754Department of Pharmacology, Inflammation-Cancer Microenvironment Research Center, College of Medicine, Ewha Womans University, 25 Magokdong-Ro 2-Gil, Gangseo-Gu, Seoul, 07804 Korea
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Hough C, Notley C, Mo A, Videl B, Lillicrap D. Heterogeneity and reciprocity of FVIII and VWF expression, and the response to shear stress in cultured human endothelial cells. J Thromb Haemost 2022; 20:2507-2518. [PMID: 35950488 PMCID: PMC9850489 DOI: 10.1111/jth.15841] [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: 03/24/2022] [Revised: 07/06/2022] [Accepted: 07/18/2022] [Indexed: 01/25/2023]
Abstract
BACKGROUND Substantial phenotypic heterogeneity exists in endothelial cells and while much of this heterogeneity results from local microenvironments, epigenetic modifications also contribute. METHODS Cultured human umbilical vein endothelial cells, human pulmonary microvascular endothelial cells, human hepatic sinusoidal endothelial cells, human lymphatic endothelial cells (hLECs), and two different isolations of endothelial colony forming cells (ECFCs) were assessed for levels of factor VIII (FVIII) and von Willebrand factor (VWF) RNA and protein. The intracellular location and co-localization of both proteins was evaluated with immunofluorescence microscopy and stimulated release toof FVIII and VWF from Weibel-Palade bodies (WPBs) was evaluated. Changes in expression of FVIII and VWF RNA after hLECs and ECFCs were exposed to 2 or 15 dynes/cm2 of laminar shear stress were also assessed. RESULTS We observed considerable heterogeneity in FVIII and VWF expression among the endothelial cells. With the exception of hLECs, FVIII RNA and protein were barely detectable in any of the endothelial cells and a reciprocal relationship between levels of FVIII and VWF appears to exist. When FVIII and VWF are co-expressed, they do not consistently co-localize in the cytoplasm. However, in hLECs where significantly higher levels of FVIII are expressed, FVIII and VWF co-localize in WPBs and are released together when stimulated. Expression of both FVIII and VWF is markedly reduced when hLECs are exposed to higher or lower levels of laminar shear stress, while in ECFCs there is a minimal response for both proteins. CONCLUSIONS Variable levels of FVIII and VWF RNA and protein exist in a subset of cultured human endothelial cells. Higher levels of FVIII present in hLECs co-localize with VWF and are released together when exposed to a secretagogue.
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Affiliation(s)
- Christine Hough
- Department of Pathology and Molecular Medicine, Richardson Laboratory, Queen's University, Kingston, Ontario, Canada
| | - Colleen Notley
- Department of Pathology and Molecular Medicine, Richardson Laboratory, Queen's University, Kingston, Ontario, Canada
| | - Aomei Mo
- Department of Pathology and Molecular Medicine, Richardson Laboratory, Queen's University, Kingston, Ontario, Canada
| | - Barbara Videl
- Department of Pathology and Molecular Medicine, Richardson Laboratory, Queen's University, Kingston, Ontario, Canada
| | - David Lillicrap
- Department of Pathology and Molecular Medicine, Richardson Laboratory, Queen's University, Kingston, Ontario, Canada
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Xiang DM, Sun W, Ning BF, Zhou TF, Li XF, Zhong W, Cheng Z, Xia MY, Wang X, Deng X, Wang W, Li HY, Cui XL, Li SC, Wu B, Xie WF, Wang HY, Ding J. The HLF/IL-6/STAT3 feedforward circuit drives hepatic stellate cell activation to promote liver fibrosis. Gut 2018; 67:1704-1715. [PMID: 28754776 DOI: 10.1136/gutjnl-2016-313392] [Citation(s) in RCA: 155] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 06/07/2017] [Accepted: 06/11/2017] [Indexed: 12/27/2022]
Abstract
BACKGROUND AND AIMS Liver fibrosis is a wound-healing response that disrupts the liver architecture and function by replacing functional parenchyma with scar tissue. Recent progress has advanced our knowledge of this scarring process, but the detailed mechanism of liver fibrosis is far from clear. METHODS The fibrotic specimens of patients and HLF (hepatic leukemia factor)PB/PB mice were used to assess the expression and role of HLF in liver fibrosis. Primary murine hepatic stellate cells (HSCs) and human HSC line Lx2 were used to investigate the impact of HLF on HSC activation and the underlying mechanism. RESULTS Expression of HLF was detected in fibrotic livers of patients, but it was absent in the livers of healthy individuals. Intriguingly, HLF expression was confined to activated HSCs rather than other cell types in the liver. The loss of HLF impaired primary HSC activation and attenuated liver fibrosis in HLFPB/PB mice. Consistently, ectopic HLF expression significantly facilitated the activation of human HSCs. Mechanistic studies revealed that upregulated HLF transcriptionally enhanced interleukin 6 (IL-6) expression and intensified signal transducer and activator of transcription 3 (STAT3) phosphorylation, thus promoting HSC activation. Coincidentally, IL-6/STAT3 signalling in turn activated HLF expression in HSCs, thus completing a feedforward regulatory circuit in HSC activation. Moreover, correlation between HLF expression and alpha-smooth muscle actin, IL-6 and p-STAT3 levels was observed in patient fibrotic livers, supporting the role of HLF/IL-6/STAT3 cascade in liver fibrosis. CONCLUSIONS In aggregate, we delineate a paradigm of HLF/IL-6/STAT3 regulatory circuit in liver fibrosis and propose that HLF is a novel biomarker for activated HSCs and a potential target for antifibrotic therapy.
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Affiliation(s)
- Dai-Min Xiang
- The International Cooperation Laboratory on Signal Transduction, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China.,Nelson Institute of Environmental Medicine, New York University School of Medicine, New York, USA.,National Center for Liver Cancer, Shanghai, China
| | - Wen Sun
- The International Cooperation Laboratory on Signal Transduction, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Bei-Fang Ning
- Department of Gastroenterology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Teng-Fei Zhou
- The International Cooperation Laboratory on Signal Transduction, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Xiao-Feng Li
- The International Cooperation Laboratory on Signal Transduction, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Wei Zhong
- Department of Gastroenterology, Renji Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Zhuo Cheng
- The International Cooperation Laboratory on Signal Transduction, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Ming-Yang Xia
- The International Cooperation Laboratory on Signal Transduction, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Xue Wang
- The International Cooperation Laboratory on Signal Transduction, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Xing Deng
- Department of Gastroenterology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Wei Wang
- Department of Gastroenterology, Changzheng Hospital, Second Military Medical University, Shanghai, China.,Department of Gastroenterology, Lanzhou General Hospital of Lanzhou Military Command, Lanzhou, China
| | - Heng-Yu Li
- The International Cooperation Laboratory on Signal Transduction, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Xiu-Liang Cui
- The International Cooperation Laboratory on Signal Transduction, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Shi-Chao Li
- The International Cooperation Laboratory on Signal Transduction, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Bin Wu
- Department of Gastroenterology and Endoscopy, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou 510630, China
| | - Wei-Fen Xie
- Department of Gastroenterology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Hong-Yang Wang
- The International Cooperation Laboratory on Signal Transduction, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China.,National Center for Liver Cancer, Shanghai, China
| | - Jin Ding
- The International Cooperation Laboratory on Signal Transduction, Shanghai Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China.,National Center for Liver Cancer, Shanghai, China
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Gong X, Liu Y, Zhang X, Wei Z, Huo R, Shen L, He L, Qin S. Systematic functional study of cytochrome P450 2D6 promoter polymorphisms in the Chinese Han population. PLoS One 2013; 8:e57764. [PMID: 23469064 PMCID: PMC3585152 DOI: 10.1371/journal.pone.0057764] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 01/25/2013] [Indexed: 01/15/2023] Open
Abstract
The promoter polymorphisms of drug-metabolizing genes can lead to interindividual differences in gene expression, which may result in adverse drug effects and therapeutic failure. Based on the database of CYP2D6 gene polymorphisms in the Chinese Han population established by our group, we functionally characterized the single nucleotide polymorphisms (SNPs) of the promoter region and corresponding haplotypes in this population. Using site-directed mutagenesis, all the five SNPs identified and ten haplotypes with a frequency equal to or greater than 0.01 in the population were constructed on a luciferase reporter system. Dual luciferase reporter systems were used to analyze regulatory activity. The activity produced by Haplo3(−2183G>A, −1775A>G, −1589G>C, −1431C>T, −1000G>A, −678A>G), Haplo8(−2065G>A, −2058T>G, −1775A>G, −1589G>C, −1235G>A, −678A>G) and MU3(−498C>A) was 0.7−, 0.7−, 1.2− times respectively compared with the wild type in human hepatoma cell lines(p<0.05). These findings might be useful for optimizing pharmacotherapy and the design of personalized medicine.
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Affiliation(s)
- Xueli Gong
- Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders(Ministry of Education), Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Genome Pilot Institutes for Genomics and Human Health, Shanghai, China
| | - Yichen Liu
- Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders(Ministry of Education), Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Genome Pilot Institutes for Genomics and Human Health, Shanghai, China
| | | | - Zhiyun Wei
- Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders(Ministry of Education), Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Genome Pilot Institutes for Genomics and Human Health, Shanghai, China
| | - Ran Huo
- Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders(Ministry of Education), Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Genome Pilot Institutes for Genomics and Human Health, Shanghai, China
| | - Lu Shen
- Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders(Ministry of Education), Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Genome Pilot Institutes for Genomics and Human Health, Shanghai, China
| | - Lin He
- Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders(Ministry of Education), Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Genome Pilot Institutes for Genomics and Human Health, Shanghai, China
- Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Shengying Qin
- Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders(Ministry of Education), Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Genome Pilot Institutes for Genomics and Human Health, Shanghai, China
- * E-mail:
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Dorn DC, Kou CA, Png KJ, Moore MA. The effect of cantharidins on leukemic stem cells. Int J Cancer 2009; 124:2186-99. [DOI: 10.1002/ijc.24157] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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6
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Williams FMK, Carter AM, Kato B, Falchi M, Bathum L, Surdulescu G, Kyvik KO, Palotie A, Spector TD, Grant PJ. Identification of quantitative trait loci for fibrin clot phenotypes: the EuroCLOT study. Arterioscler Thromb Vasc Biol 2009; 29:600-5. [PMID: 19150881 PMCID: PMC3508477 DOI: 10.1161/atvbaha.108.178103] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVE Fibrin makes up the structural basis of an occlusive arterial thrombus, and variability in fibrin phenotype relates to cardiovascular risk. The aims of the current study from the EU consortium EuroCLOT were to (1) determine the heritability of fibrin phenotypes and (2) identify QTLs associated with fibrin phenotypes. METHODS AND RESULTS 447 dizygotic (DZ) and 460 monozygotic (MZ) pairs of healthy UK white female twins and 199 DZ twin pairs from Denmark were studied. D-dimer, an indicator of fibrin turnover, was measured by ELISA and measures of clot formation, morphology, and lysis were determined by turbidimetric assays. Heritability estimates and genome-wide linkage analysis were performed. Estimates of heritability for d-dimer and turbidometric variables were in the range 17% to 46%, with highest levels for maximal absorbance which provides an estimate of clot density. Genome-wide linkage analysis revealed 6 significant regions with LOD >3 on 5 chromosomes (5, 6, 9, 16, and 17). CONCLUSIONS The results indicate a significant genetic contribution to variability in fibrin phenotypes and highlight regions in the human genome which warrant further investigation in relation to ischemic cardiovascular disorders and their therapy.
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Affiliation(s)
- Frances M K Williams
- Department of Twin Research and Genetic Epidemiology, King's College London, St Thomas' Hospital, London, UK.
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7
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Wang G, Wang Y, Feng W, Wang X, Yang JY, Zhao Y, Wang Y, Liu Y. Transcription factor and microRNA regulation in androgen-dependent and -independent prostate cancer cells. BMC Genomics 2008; 9 Suppl 2:S22. [PMID: 18831788 PMCID: PMC2559887 DOI: 10.1186/1471-2164-9-s2-s22] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Background Prostate cancer is one of the leading causes of cancer death in men. Androgen ablation, the most commonly-used therapy for progressive prostate cancer, is ineffective once the cancer cells become androgen-independent. The regulatory mechanisms that cause this transition (from androgen-dependent to androgen-independent) remain unknown. In this study, based on the microarray data comparing global gene expression patterns in the prostate tissue between androgen-dependent and -independent prostate cancer patients, we indentify a set of transcription factors and microRNAs that potentially cause such difference, using a model-based computational approach. Results From 335 position weight matrices in the TRANSFAC database and 564 microRNAs in the microRNA registry, our model identify 5 transcription factors and 7 microRNAs to be potentially responsible for the level of androgen dependency. Of these transcription factors and microRNAs, the estimated function of all the 5 transcription factors are predicted to be inhibiting transcription in androgen-independent samples comparing with the dependent ones. Six out of 7 microRNAs, however, demonstrated stimulatory effects. We also find that the expression levels of three predicted transcription factors, including AP-1, STAT3 (signal transducers and activators of transcription 3), and DBP (albumin D-box) are significantly different between androgen-dependent and -independent patients. In addition, microRNA microarray data from other studies confirm that several predicted microRNAs, including miR-21, miR-135a, and miR-135b, demonstrate differential expression in prostate cancer cells, comparing with normal tissues. Conclusion We present a model-based computational approach to identify transcription factors and microRNAs influencing the progression of androgen-dependent prostate cancer to androgen-independent prostate cancer. This result suggests that the capability of transcription factors to initiate transcription and microRNAs to facilitate mRNA degradation are both decreased in androgen-independent prostate cancer. The proposed model-based approach indicates that considering combinatorial effects of transcription factors and microRNAs in a unified model provides additional transcriptional and post-transcriptional regulatory mechanisms on global gene expression in the prostate cancer with different hormone-dependency.
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Affiliation(s)
- Guohua Wang
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang 150001, PR China.
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Dai L, Cutler JA, Savidge GF, Mitchell MJ. Characterization of a causative mutation of hemophilia A identified in the promoter region of the factor VIII gene (F8). J Thromb Haemost 2008; 6:193-5. [PMID: 17944985 DOI: 10.1111/j.1538-7836.2007.02806.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Schrem H, Klempnauer J, Borlak J. Liver-enriched transcription factors in liver function and development. Part II: the C/EBPs and D site-binding protein in cell cycle control, carcinogenesis, circadian gene regulation, liver regeneration, apoptosis, and liver-specific gene regulation. Pharmacol Rev 2004; 56:291-330. [PMID: 15169930 DOI: 10.1124/pr.56.2.5] [Citation(s) in RCA: 169] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In the first part of our review (see Pharmacol Rev 2002;54:129-158), we discussed the basic principles of gene transcription and the complex interactions within the network of hepatocyte nuclear factors, coactivators, ligands, and corepressors in targeted liver-specific gene expression. Now we summarize the role of basic region/leucine zipper protein family members and particularly the albumin D site-binding protein (DBP) and the CAAT/enhancer-binding proteins (C/EBPs) for their importance in liver-specific gene expression and their role in liver function and development. Specifically, regulatory networks and molecular interactions were examined in detail, and the experimental findings summarized in this review point to pivotal roles of DBP and C/EBPs in cell cycle control, carcinogenesis, circadian gene regulation, liver regeneration, apoptosis, and liver-specific gene regulation. These regulatory proteins are therefore of great importance in liver physiology, liver disease, and liver development. Furthermore, interpretation of the vast data generated by novel genomic platform technologies requires a thorough understanding of regulatory networks and particularly the hierarchies that govern transcription and translation of proteins as well as intracellular protein modifications. Thus, this review aims to stimulate discussions on directions of future research and particularly the identification of molecular targets for pharmacological intervention of liver disease.
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Affiliation(s)
- Harald Schrem
- Center for Drug Research and Medical Biotechnology, Fraunhofer Institut für Toxikologie und Experimentelle Medizin, Nicolai Fuchs Str. 1, 30625 Hannover, Germany
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Crable SC, Anderson KP. A PAR domain transcription factor is involved in the expression from a hematopoietic-specific promoter for the human LMO2 gene. Blood 2003; 101:4757-64. [PMID: 12609830 DOI: 10.1182/blood-2002-09-2702] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The transcription factor LMO2 is believed to exert its effect through the formation of protein-protein interactions with other DNA-binding factors such as GATA-1 and TAL1. Although LMO2 has been shown to be critical for the formation of the erythroid cell lineage, the gene is also expressed in a number of nonerythroid tissues. In this report, we demonstrate that the more distal of the 2 promoters for the LMO2 gene is highly restricted in its pattern of expression, directing the hematopoietic-specific expression of this gene. Deletion and mutation analyses have identified a critical cis element in the first untranslated exon of the gene. This element is a consensus-binding site for a small family of basic leucine zipper proteins containing a proline and acidic amino acid-rich (PAR) domain. Although all 3 members of this family are produced in erythroid cells, only 2 of these proteins, thyrotroph embryonic factor and hepatic leukemia factor, can activate transcription from this LMO2 promoter element. These findings represent a novel mechanism in erythroid gene regulation because PAR proteins have not previously been implicated in this process.
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Affiliation(s)
- Scott C Crable
- Division of Hematology/Oncology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, OH, USA
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Abstract
E2A-HLF, the chimeric fusion protein resulting from the leukemogenic translocation t(17;19), appears to employ evolutionarily conserved signaling cascades for its transforming and antiapoptotic functions. These arise from both impairment of normal E2A function and activation of a survival pathway triggered through the HLF bZip DNA binding and dimerization domain. Recent reports identify wild-type E2A as a tumor suppressor in T lymphocytes. Moreover, E2A-HLF has been shown to activate SLUG, a mammalian homologue of the cell death specification protein CES-1 in Caenorhabditis elegans, which appears to regulate an evolutionarily conserved cell survival program. Recently, several key mouse models have been generated, enabling further elucidation of these pathways on a molecular genetic level in vivo. In this review, we discuss the characteristics of both components of the fusion protein with regard to their contribution to the regulation of cell fate and the oncogenic potential of E2A-HLF.
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Affiliation(s)
- M G Seidel
- Pediatric Oncology Department, Dana-Farber Cancer Institute, 44 Binney Street, M-630, Boston, Massachusetts, MA 02115, USA
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Korte W. Changes of the coagulation and fibrinolysis system in malignancy: their possible impact on future diagnostic and therapeutic procedures. Clin Chem Lab Med 2000; 38:679-92. [PMID: 11071061 DOI: 10.1515/cclm.2000.099] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The interaction between malignant cell growth and the coagulation and fibrinolysis system has been a well known phenomenon for decades. During recent years, this area of research has received new attention. Experimental data suggest a role for the coagulation and fibrinolysis system in tumor development, progression and metastasis. Also, clinical research suggests that targeting the coagulation system or fibrinolysis system might influence the course of malignant disease beneficially. This paper reviews data on various hemostatic and fibrinolytic parameters in malignancy; the possible use of such parameters as risk markers in oncology patients; and possible targets of anti-neoplastic therapies using anticoagulant and/or antifibrinolytic strategies. Current evidence suggests that the tissue factor/factor VIIa pathway mediates the most abundant procoagulant stimulus in malignancy via the increase in thrombin generation. Tissue factor has been suggested to mediate pro-metastatic properties via coagulation-dependent and coagulation-independent pathways; tissue factor has also been implicated in tumor neo-angiogenesis. However, so far no model has been validated that would allow the use of tissue factor in its soluble or insoluble form as a marker for risk stratification in tumor patients. On the other hand, there is now good evidence that parts of the fibrinolytic system, such as urokinase-type plasminogen activator and its receptor ("uPAR"), can be used as strong predictors of outcome in several types of cancer, specifically breast cancer. Observation of various treatment options in patients with thromboembolic disease and cancer as well as attempts to use anticoagulants and/or therapies modulating the fibrinolytic system as anti-neoplastic treatment strategies have yielded exciting results. These data indicate that anticoagulant therapy, and specifically low molecular weight heparin therapy, is likely to have anti-neoplastic effects; and that their use in addition to chemotherapy will probably improve outcome of tumor treatment in certain types of cancer. However, the body of clinical data is still relatively small and the question whether or not we should routinely consider the coagulation and/or fibrinolysis system as therapeutic targets in cancer patients is yet to be answered.
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Affiliation(s)
- W Korte
- Institute for Clinical Chemistry and Haematology, Kantonsspital, St. Gallen, Switzerland.
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