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Ma Q, Li Y, An L, Guo L, Liu X. Assessment of causal association between differentiated thyroid cancer and disordered serum lipid profile: a Mendelian randomization study. Front Endocrinol (Lausanne) 2023; 14:1291445. [PMID: 38189054 PMCID: PMC10771623 DOI: 10.3389/fendo.2023.1291445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Accepted: 11/20/2023] [Indexed: 01/09/2024] Open
Abstract
Background Research has shown that the disordered serum lipid profile may be associated with the risk of differentiated thyroid cancer (DTC). Whether this association reflect causal effect is still unclear. The aim of this study was to evaluate the causality of circulating lipoprotein lipids on DTC. Methods Mendelian randomization (MR) analysis was conducted to evaluate the relationship between the circulating lipoprotein lipids and DTC risk using single-nucleotide polymorphisms (SNPs) from a genome-wide association (GWA) study containing a high-incidence Italian population of 690 cases samples with DTC and 497 controls. Results Univariate and multivariate mendelian randomization analysis demonstrated that 'total cholesterol', 'HDL cholesterol', 'apolipoprotein B' and 'ratio of apolipoprotein B to apolipoprotein A1' were correlated with DTC. According to sensitivity analysis, our results were reliable. Furthermore, multivariate analysis revealed that there is no causative association between DTC and any of the many cause factors when they interact with one another, suggesting that there was a deep interaction between the four factors, which could affect each other. Finally, the mechanism of the related effects each other as well as the target genes with significant SNP regulatory effects in DTC was explored by conducting functional enrichment analysis and constructing the regulatory networks. Conclusions We obtained four exposure factors (total cholesterol, HDL cholesterol, apolipoprotein B and ratio of apolipoprotein B to apolipoprotein A1) closely related to DTC, which laid a theoretical foundation for the treatment of DTC.
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Lee J, Chan ST, Kim JY, Ou JHJ. Hepatitis C Virus Induces the Ubiquitin-Editing Enzyme A20 via Depletion of the Transcription Factor Upstream Stimulatory Factor 1 To Support Its Replication. mBio 2019; 10:e01660-19. [PMID: 31337730 PMCID: PMC6650561 DOI: 10.1128/mbio.01660-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 06/28/2019] [Indexed: 12/27/2022] Open
Abstract
Tumor necrosis factor alpha-induced protein 3 (TNFAIP3), also known as A20, is a ubiquitin-editing enzyme capable of ubiquitination or deubiquitination of its target proteins. In this study, we show that hepatitis C virus (HCV) infection could induce the expression of A20 via the activation of the A20 promoter. The induction of A20 by HCV coincided with the loss of upstream stimulatory factor 1 (USF-1), a transcription factor known to suppress the A20 promoter. The role of USF-1 in the regulation of the A20 promoter in HCV-infected cells was confirmed by the chromatin immunoprecipitation (ChIP) assay, and its depletion was apparently mediated by proteasomes, as USF-1 could be stabilized by the proteasome inhibitor MG132 to suppress the A20 expression. As the overexpression of A20 enhanced the replication of HCV and the silencing of A20 had the opposite effect, A20 is a positive regulator of HCV replication. Our further studies indicated that A20 enhanced the activity of the HCV internal ribosome entry site (IRES). In conclusion, our results demonstrated that HCV could induce the expression of A20 via the depletion of USF-1 to enhance its replication. Our study provided important information for further understanding the interaction between HCV and its host cells.IMPORTANCE Hepatitis C virus establishes chronic infection in approximately 85% of the patients whom it infects. However, the mechanism of how HCV evades host immunity to establish persistence is unclear. In this report, we demonstrate that HCV could induce the expression of the ubiquitin-editing enzyme A20, an important negative regulator of the tumor necrosis factor alpha (TNF-α) and NF-κB signaling pathways. This induction of A20 enhanced HCV replication as it could stimulate the HCV IRES activity to enhance the translation of HCV proteins. The induction of A20 was mediated by the depletion of USF-1, a suppressor of the A20 promoter. Our study thus provides important information for further understanding the interaction between HCV and its host cells.
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Affiliation(s)
- Jiyoung Lee
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Stephanie T Chan
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Ja Yeon Kim
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Jing-Hsiung James Ou
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
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Yuan Q, Bu Q, Li G, Zhang J, Cui T, Zhu R, Mu D. Association between single nucleotide polymorphisms of upstream transcription factor 1 (USF1) and susceptibility to papillary thyroid cancer. Clin Endocrinol (Oxf) 2016; 84:564-70. [PMID: 26052935 DOI: 10.1111/cen.12832] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 01/02/2015] [Accepted: 06/01/2015] [Indexed: 11/27/2022]
Abstract
BACKGROUND Thyroid cancer, predominantly by papillary thyroid cancer (PTC), is a malignant tumour of endocrine system with increasing incidence rate worldwide. Upstream transcription factor 1 (USF1) regulates a variety of biological processes by transactivation of functional genes. In this study, we investigated the association between USF1 polymorphisms and PTC risk. MATERIAL & METHODS A total of 334 patients with PTC, 186 patients with benign nodules (BN) and 668 healthy controls were enrolled in our study. Tag-SNPs were identified in Chinese Han in Beijing (CHB) from International HapMap Project Databases. Genomic DNAs were extracted by TaqMan Blood DNA kits. SNPs of USF1 were genotyped by TaqMan SNPs genotyping assay. Odds ratios (OR) and corresponding 95% confidence interval (CI) were used to assess the association between USF1 genetic variants and PTC risk. The statistical analyses were carried out with spss 13.0 software. RESULTS Five tag-SNPs were retrieved to capture all the genetic variants of USF1. Among the five tag-SNPs, genetic variants in rs2516838, rs3737787 and rs2516839 have significant association with PTC risk. The rs2516838 polymorphisms dominant model (CG+GG vs CC: OR = 0·71; 95% CI: 0·52-0·97; P = 0·033) and allelic model (C vs G: OR = 0·031; 95% CI: 0·56-0·97; P = 0·031) indicated it may act as a protective factor against PTC. On the contrary, the results of rs3737787 polymorphisms: dominant model (CT+TT vs CC: OR = 1·55; 95%CI: 1·09-2·02; P = 0·001) and allelic model (C vs T: OR = 1·35; 95%CI: 1·10-1·64; P = 0·003), as well as the results of rs2516839 polymorphisms: dominant model (GA+AA vs GG: OR = 1·77; 95%CI: 1·31-2·38; P < 0·001) and allelic model (G vs A: OR = 1·36; 95%CI: 1·13-1·63; P = 0·014), revealed that they may act as risk factors for PTC. CONCLUSION In this study, we found the SNPs of rs2516838 (mutant G alleles vs wild C alleles), rs3737787 (mutant T alleles vs wild C alleles) and rs2516839 (mutant A alleles vs wild G alleles) were significantly associated with PTC risk. Further large-scale studies with different ethnicities are still needed to validate our findings and explore the underlying mechanism of USF1 in PTC development.
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Affiliation(s)
- Qingzhong Yuan
- Department of Hepatobiliary Breast Thyroid Surgery, Shengli Oilfield Central Hospital, Dongying, China
| | - Qingao Bu
- Department of Hepatobiliary Breast Thyroid Surgery, Shengli Oilfield Central Hospital, Dongying, China
| | - Guoqiang Li
- Department of Hepatobiliary Breast Thyroid Surgery, Shengli Oilfield Central Hospital, Dongying, China
| | - Jun Zhang
- Department of Hepatobiliary Breast Thyroid Surgery, Shengli Oilfield Central Hospital, Dongying, China
| | - Tao Cui
- Department of Hepatobiliary Breast Thyroid Surgery, Shengli Oilfield Central Hospital, Dongying, China
| | - Rui Zhu
- Department of Hepatobiliary Breast Thyroid Surgery, Shengli Oilfield Central Hospital, Dongying, China
| | - Dongpo Mu
- Department of Hepatobiliary Breast Thyroid Surgery, Shengli Oilfield Central Hospital, Dongying, China
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Qi L, Higgins CE, Higgins SP, Law BK, Simone TM, Higgins PJ. The basic helix-loop-helix/leucine zipper transcription factor USF2 integrates serum-induced PAI-1 expression and keratinocyte growth. J Cell Biochem 2015; 115:1840-7. [PMID: 24905330 DOI: 10.1002/jcb.24861] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 05/30/2014] [Indexed: 01/30/2023]
Abstract
Plasminogen activator inhibitor type-1 (PAI-1), a major regulator of the plasmin-dependent pericellular proteolytic cascade, is prominently expressed during the tissue response to injury although the factors that impact PAI-1 induction and their role in the repair process are unclear. Kinetic modeling using established biomarkers of cell cycle transit (c-MYC; cyclin D1; cyclin A) in synchronized human (HaCaT) keratinocytes, and previous cytometric assessments, indicated that PAI-1 transcription occurred early after serum-stimulation of quiescent (G0) cells and prior to G1 entry. It was established previously that differential residence of USF family members (USF1→USF2 switch) at the PE2 region E box (CACGTG) characterized the G0 → G1 transition period and the transcriptional status of the PAI-1 gene. A consensus PE2 E box motif (5'-CACGTG-3') at nucleotides -566 to -561 was required for USF/E box interactions and serum-dependent PAI-1 transcription. Site-directed CG → AT substitution at the two central nucleotides inhibited formation of USF/probe complexes and PAI-1 promoter-driven reporter expression. A dominant-negative USF (A-USF) construct or double-stranded PE2 "decoy" attenuated serum- and TGF-β1-stimulated PAI-1 synthesis. Tet-Off induction of an A-USF insert reduced both PAI-1 and PAI-2 transcripts while increasing the fraction of Ki-67(+) cells. Conversely, overexpression of USF2 or adenoviral-delivery of a PAI-1 vector inhibited HaCaT colony expansion indicating that the USF1 → USF2 transition and subsequent PAI-1 transcription are critical events in the epithelial go-or-grow response. Collectively, these data suggest that USF2, and its target gene PAI-1, regulate serum-stimulated keratinocyte growth, and likely the cadence of cell cycle progression in replicatively competent cells as part of the injury repair program.
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Affiliation(s)
- Li Qi
- Center for Cell Biology & Cancer Research, Albany Medical College, Albany, New York, 12208
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Significant association between upstream transcription factor 1 rs2516839 polymorphism and hepatocellular carcinoma risk: a case–control study. Tumour Biol 2014; 36:2551-8. [DOI: 10.1007/s13277-014-2871-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 11/18/2014] [Indexed: 12/13/2022] Open
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Chen B, Chen XP, Wu MS, Cui W, Zhong M. Expressions of heparanase and upstream stimulatory factor in hepatocellular carcinoma. Eur J Med Res 2014; 19:45. [PMID: 25149140 PMCID: PMC4237794 DOI: 10.1186/s40001-014-0045-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 08/06/2014] [Indexed: 01/18/2023] Open
Abstract
Background The expression of heparanase (HPSE) was associated with postoperative metastatic recurrence in patients with hepatocellular carcinoma (HCC). The six E-box binding sites in the core promoter of the HPSE gene suggested that transcription factors of E-box such as upstream stimulatory factor (USF) might regulate the transcription of the HPSE gene. The aim of our study is to measure the levels of HPSE and USF expression and investigate the relationship between USF expression and clinicopathological parameters in patients with HCC. Methods HPSE, USF1 and USF2 expressions in human HCC cell lines (BEL-7402, HepG2 and HCCLM3) and 15 fresh human HCC tissue samples were measured by real-time reverse transcriptase-PCR and Western blot analysis. The normal liver cell line QSG7701 or fresh normal liver tissue samples obtained from 15 additional surgical patients with hepatic rupture was used as a control. The protein expressions were determined by immunohistochemistry in paraffin-embedded human HCC tissues and corresponding non-neoplastic tumor surrounding tissues (NTST) of 57 patients. Results HPSE, USF1 and USF2 mRNA expressions were increased in HCC cell lines and HCC tissues compared with normal liver cell line and normal liver tissue. The protein expressions of HPSE, USF1 and USF2 in HCC cell lines and HCC tissues were also increased. Both USF1 and USF2 expressions were positively correlated with HPSE. USF1 and USF2 expressions were increased in patients with liver cirrhosis, worse tissue differentiation, advanced HCC stages and metastatic recurrence. Conclusions Increased USF in HCC is associated with HPSE expression. USF might be an important factor in regulating HPSE expression and act as a novel marker of metastatic recurrence of HCC patients.
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Affiliation(s)
| | - Xiao-Peng Chen
- Department of General Surgery, Affiliated Yijishan Hospital of Wannan Medical College, Wuhu 241001, Anhui Province, China.
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p53 requires the stress sensor USF1 to direct appropriate cell fate decision. PLoS Genet 2014; 10:e1004309. [PMID: 24831529 PMCID: PMC4022457 DOI: 10.1371/journal.pgen.1004309] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 03/02/2014] [Indexed: 11/19/2022] Open
Abstract
Genomic instability is a major hallmark of cancer. To maintain genomic integrity, cells are equipped with dedicated sensors to monitor DNA repair or to force damaged cells into death programs. The tumor suppressor p53 is central in this process. Here, we report that the ubiquitous transcription factor Upstream Stimulatory factor 1 (USF1) coordinates p53 function in making proper cell fate decisions. USF1 stabilizes the p53 protein and promotes a transient cell cycle arrest, in the presence of DNA damage. Thus, cell proliferation is maintained inappropriately in Usf1 KO mice and in USF1-deficient melanoma cells challenged by genotoxic stress. We further demonstrate that the loss of USF1 compromises p53 stability by enhancing p53-MDM2 complex formation and MDM2-mediated degradation of p53. In USF1-deficient cells, the level of p53 can be restored by the re-expression of full-length USF1 protein similarly to what is observed using Nutlin-3, a specific inhibitor that prevents p53-MDM2 interaction. Consistent with a new function for USF1, a USF1 truncated protein lacking its DNA-binding and transactivation domains can also restore the induction and activity of p53. These findings establish that p53 function requires the ubiquitous stress sensor USF1 for appropriate cell fate decisions in response to DNA-damage. They underscore the new role of USF1 and give new clues of how p53 loss of function can occur in any cell type. Finally, these findings are of clinical relevance because they provide new therapeutic prospects in stabilizing and reactivating the p53 pathway. Cancer is a complex disease that is characterized by the sequential accumulation of genetic mutations. Exposure to environmental agents, such as solar ultraviolet, induces such alterations and thus contributes to the development of genomic instability. The tumor suppressor p53 has a central role in orchestrating cellular responses to genotoxic stress. In response to DNA-damage, p53 is stabilized and activated to direct cell fate decisions. Cells in which p53 stabilization is compromised become more vulnerable to mutagenic agents and hence the mutation rate increases, which promotes tumor development. Stabilization of p53 is thus a critical step towards cancer prevention. Using a genetic approach, we demonstrate that the ubiquitous transcription factor Upstream Stimulatory factor 1 (USF1) is required for immediate p53 stabilization and appropriate cell fate decisions following genotoxic stress. Furthermore, we show that this involves a novel function of USF1 that underscores its critical role as a stress sensor. The loss of USF1 expression should thus be considered as a potential initiator of tumorigenesis in the context of environmental insults.
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Bychkov A, Saenko V, Nakashima M, Mitsutake N, Rogounovitch T, Nikitski A, Orim F, Yamashita S. Patterns of FOXE1 expression in papillary thyroid carcinoma by immunohistochemistry. Thyroid 2013; 23:817-28. [PMID: 23327367 PMCID: PMC3704107 DOI: 10.1089/thy.2012.0466] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND FOXE1, a thyroid-specific transcription factor also known as TTF-2, was recently identified as a major genetic risk factor for papillary thyroid carcinoma (PTC). Its role in thyroid carcinogenesis, however, remains unknown. The purpose of the present study was to assess the relationship between the FOXE1 immunohistochemical features and the clinical and genetic characteristics of PTC. METHODS Immunohistochemical staining of FOXE1 was performed in 48 PTC cases. Two single nucleotide polymorphisms immediately inside (rs1867277) or in the vicinity (rs965513) of the FOXE1 gene were genotyped by direct sequencing. Histopathological, clinical, and genetic data were included in statistical analyses. RESULTS FOXE1 exhibited cytoplasmic overexpression in tumor tissue compared to the normal counterpart (p<0.001). Both cancer and normal thyroid cells demonstrated the highest FOXE1 scores in the areas closest to the tumor border (<300 μm) compared with more distant areas (p<0.001). No differences in FOXE1 staining distributions were found between microcarcinomas and PTC of larger size, between different histopathological variants of PTC, and encapsulated and nonencapsulated tumors. Multivariate regression analysis revealed that nuclear FOXE1 expression in neoplastic cells in the vicinity of the tumor border independently associated with the genotype at rs1867277 (the dominant model of inheritance, p=0.037) and tumor multifocality (p=0.032), and with marginal significance with capsular invasion (p=0.051). CONCLUSIONS FOXE1 overexpression and translocation to the cytoplasm are phenotypic hallmarks of tumor cells suggesting that FOXE1 is involved in the pathogenesis of PTC. Nuclear FOXE1 expression in tumor cells in the vicinity of the PTC border is associated with the presence of a risk allele of rs1867277 (c.-238G>A) in the 5' untranslated region of the FOXE1 gene, as well as with pathological characteristics of PTC, suggesting possible FOXE1 involvement in the facilitation of tumor development beginning at an early stage.
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Affiliation(s)
- Andrey Bychkov
- Department of Radiation Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Vladimir Saenko
- Department of Health Risk Control, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Masahiro Nakashima
- Department of Tumor and Diagnostic Pathology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Norisato Mitsutake
- Department of Radiation Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
- Nagasaki University Research Center for Genomic Instability and Carcinogenesis, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Tatiana Rogounovitch
- Department of Radiation Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Alyaksandr Nikitski
- Department of Radiation Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Florence Orim
- Department of Radiation Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Shunichi Yamashita
- Department of Radiation Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
- Department of Health Risk Control, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
- Fukushima Medical University, Fukushima, Japan
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Olave NC, Grenett MH, Cadeiras M, Grenett HE, Higgins PJ. Upstream stimulatory factor-2 mediates quercetin-induced suppression of PAI-1 gene expression in human endothelial cells. J Cell Biochem 2011; 111:720-6. [PMID: 20626032 DOI: 10.1002/jcb.22760] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The polyphenol quercetin (Quer) represses expression of the cardiovascular disease risk factor plasminogen activator inhibitor-1 (PAI-1) in cultured endothelial cells (ECs). Transfection of PAI-1 promoter-luciferase reporter deletion constructs identified a 251-bp fragment (nucleotides -800 to -549) responsive to Quer. Two E-box motifs (CACGTG), at map positions -691 (E-box1) and -575 (E-box2), are platforms for occupancy by several members of the c-MYC family of basic helix-loop-helix leucine zipper (bHLH-LZ) proteins. Promoter truncation and electrophoretic mobility shift/supershift analyses identified upstream stimulatory factor (USF)-1 and USF-2 as E-box1/E-box2 binding factors. ECs co-transfected with a 251 bp PAI-1 promoter fragment containing the two E-box motifs (p251/luc) and a USF-2 expression vector (pUSF-2/pcDNA) exhibited reduced luciferase activity versus p251/luc alone. Overexpression of USF-2 decreased, while transfection of a dominant-negative USF construct increased, EC growth consistent with the known anti-proliferative properties of USF proteins. Quer-induced decreases in PAI-1 expression and reduced cell proliferation may contribute, at least in part, to the cardioprotective benefit associated with daily intake of polyphenols.
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Affiliation(s)
- Nélida C Olave
- Department of Medicine, University of Alabama at Birmingham, Alabama, USA
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[Progress of studies on family members and functions of animal bHLH transcription factors]. YI CHUAN = HEREDITAS 2010; 32:307-30. [PMID: 20423885 DOI: 10.3724/sp.j.1005.2010.00307] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
bHLH transcription factors play essential roles in the regulation of eukaryotic growth and development. Animal bHLH transcription factors comprise of 45 families. They are involved in regulating biological processes such as neurogenesis, myogenesis, gut development and response to environmental toxins. In the past two decades, extensive studies had been conducted on identification of bHLH family members and their biological functions in animals. Based on introduction of origin of the 45 animal bHLH family names, this article reviewed the progresses of studies on bHLH family members and functions of three model animals namely mouse, fruit fly and nematode. There are 114, 59 and 42 bHLH proteins in mouse, fruit fly and nematode, respectively. Among them, the functions of 108 mouse, 47 fruit fly and 20 nematode bHLH proteins have been well characterized. Among the 22 nematode bHLH proteins of unknown functions, 15 have not yet been assigned into certain families. This article also explained misused names of several bHLH family members, thus providing clear and overall background information for relevant researchers to conduct in-depth studies on structures and functions of bHLH transcription factors.
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Galibert MD, Corre S. In vivo and in vitro tools to identify and study transcriptional regulation of USF-1 target genes. Methods Mol Biol 2010; 647:339-55. [PMID: 20694678 DOI: 10.1007/978-1-60761-738-9_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In response to environmental stress, cells trigger a number of molecular mechanisms to control their survival and growth. These include changes in gene expression with corresponding Post-translational modifications to critical transcriptional-control proteins. Transcription is a highly-regulated process that is impacted by a large number of ubiquitous and specific factors. In order to determine how gene expression is regulated in response to environmental cues, it is necessary to correlate modifications to specific transcription proteins with an accurate assessment of the transcriptional response. This chapter details quantitative Real Time PCR (qPCR) and Luciferase assay protocols to illustrate, both in vivo and in vitro, the role of the USF-1 transcription factor in the UV-dependant regulation of pigmentation genes (POMC and MC1R). The procedures have been optimized for the USF-1 transcription factor and the regulation of specific target genes in response to physiological UV doses.
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Affiliation(s)
- Marie-Dominique Galibert
- Genetic and Development Institute of Rennes, Transcriptional Regulation and Oncogenesis Team, Rennes University, Rennes, France.
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Kim KS, Jung HS, Chung YJ, Jung TS, Jang HW, Lee MS, Kim KW, Chung JH. Overexpression of USF increases TGF-beta1 protein levels, but G1 phase arrest was not induced in FRTL-5 cells. J Korean Med Sci 2008; 23:870-6. [PMID: 18955796 PMCID: PMC2580023 DOI: 10.3346/jkms.2008.23.5.870] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transforming growth factor-beta1 (TGF-beta1) is a potent inhibitor of cellular growth and proliferation by G1 phase arrest or apoptosis. We investigated the association of TGF-beta1 with the anti-proliferative effect of upstream stimulatory factor (USF) in Fischer rat thyroid cell line (FRTL-5) cells. [methyl-(3)H] thymidine uptake was measured after treatment of FRTL-5 cells with TGF-beta1 to identify its anti-proliferative effect. USF-1 and USF-2 proteins were in vitro translated, and an electrophoretic mobility shift assay was performed to identify the interaction between USF and the TGF-beta1 promoter. FRTL-5 cells were transfected with USF cDNA, and then the expression of TGF-beta1 was examined with Northern and Western blotting. The cell cycle-regulating proteins associated with TGF-beta1 were also measured. TGF-beta1 significantly inhibited [methyl-(3)H] thymidine uptake in FRTL-5 cells. Two specific binding sites for USF were found in the TGF-beta1 promoter: -1,846 approximately -1,841 (CACATG) and -621 approximately -616 (CATGTG). Overexpression of USF increased both the mRNA levels and protein levels of TGF-beta1. However, the expression of cyclin D1, CDK4, cyclin E, and CDK2, and the phosphorylation of retinoblastoma protein remained unchanged. Overexpression of USF in FRTL-5 cells increased the expression of TGF-beta10 through specific binding to TGF-beta1 promoter. However, the USF-induced expression of TGF-beta1 did not cause G1 arrest.
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Affiliation(s)
| | - Hye Seung Jung
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | | | - Tae Sik Jung
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Hye Won Jang
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Myung-Shik Lee
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Kwang-Won Kim
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jae Hoon Chung
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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García-Jiménez C, Santisteban P. Thyroid-stimulating hormone/cAMP-mediated proliferation in thyrocytes. Expert Rev Endocrinol Metab 2008; 3:473-491. [PMID: 30290436 DOI: 10.1586/17446651.3.4.473] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Current research on thyrotropin-activated proliferation in the thyrocyte needs to be aimed at a better understanding of crosstalk and negative-feedback mechanisms with other proliferative pathways, especially the insulin/IGF-1-induced phosphoinositol-3 kinase pathway and the serum-induced MAPK or Wnt pathways. Convergence of proliferative pathways in mTOR is a hotspot of current research, and combined treatment using double class inhibitors for thyroid cancer may bring some success. New thyroid-stimulating hormone receptor (TSHR)-interacting proteins, a better picture of cAMP targets, a deeper knowledge of the action of the protein kinase A regulatory subunits, especially their interactions with the replication machinery, and a further understanding of mechanisms that lead to cell cycle progression through G1/S and G2/M checkpoints are areas that need further elucidation. Finally, massive information coming from microarray data analysis will prompt our understanding of thyroid-stimulating hormone-promoted thyrocyte proliferation in health and disease.
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Affiliation(s)
- Custodia García-Jiménez
- a Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Avda Atenas s/n, 28922 Alcorcón, Madrid, Spain.
| | - Pilar Santisteban
- b Instituto de Investigaciones Biomédicas 'Alberto Sols', CSIC, C/Arturo Duperier, 4, 28932 Madrid, Spain.
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