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Safe S. Specificity Proteins (Sp) and Cancer. Int J Mol Sci 2023; 24:5164. [PMID: 36982239 PMCID: PMC10048989 DOI: 10.3390/ijms24065164] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 03/01/2023] [Accepted: 03/03/2023] [Indexed: 03/10/2023] Open
Abstract
The specificity protein (Sp) transcription factors (TFs) Sp1, Sp2, Sp3 and Sp4 exhibit structural and functional similarities in cancer cells and extensive studies of Sp1 show that it is a negative prognostic factor for patients with multiple tumor types. In this review, the role of Sp1, Sp3 and Sp4 in the development of cancer and their regulation of pro-oncogenic factors and pathways is reviewed. In addition, interactions with non-coding RNAs and the development of agents that target Sp transcription factors are also discussed. Studies on normal cell transformation into cancer cell lines show that this transformation process is accompanied by increased levels of Sp1 in most cell models, and in the transformation of muscle cells into rhabdomyosarcoma, both Sp1 and Sp3, but not Sp4, are increased. The pro-oncogenic functions of Sp1, Sp3 and Sp4 in cancer cell lines were studied in knockdown studies where silencing of each individual Sp TF decreased cancer growth, invasion and induced apoptosis. Silencing of an individual Sp TF was not compensated for by the other two and it was concluded that Sp1, Sp3 and Sp4 are examples of non-oncogene addicted genes. This conclusion was strengthened by the results of Sp TF interactions with non-coding microRNAs and long non-coding RNAs where Sp1 contributed to pro-oncogenic functions of Sp/non-coding RNAs. There are now many examples of anticancer agents and pharmaceuticals that induce downregulation/degradation of Sp1, Sp3 and Sp4, yet clinical applications of drugs specifically targeting Sp TFs are not being used. The application of agents targeting Sp TFs in combination therapies should be considered for their potential to enhance treatment efficacy and decrease toxic side effects.
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Affiliation(s)
- Stephen Safe
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843, USA
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Da CM, Liao HY, Deng YS, Zhao GH, Ma L, Zhang HH. Transcription Factor SP2 Regulates Ski-mediated Astrocyte Proliferation In Vitro. Neuroscience 2021; 479:22-34. [PMID: 34687796 DOI: 10.1016/j.neuroscience.2021.10.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 09/24/2021] [Accepted: 10/11/2021] [Indexed: 10/20/2022]
Abstract
Transcription factors bind specific sequences upstream of the 5' end of their target genes to ensure proper spatiotemporal expression of the target gene. This study aims to demonstrate that the transcription factor SP2 regulates expression of the Ski gene, which has specific binding sites for SP2, and thus enables Ski to regulate astrocyte proliferation. The upstream regulation mechanism of astrocyte proliferation was explored to further regulate the formation of glial scar in specific time and space after spinal cord injury. JASPAR and UCSC databases were used to predict transcription factor binding and the threshold was gradually reduced to screen transcription factors upstream of Ski, leading to the identification of SP2. Next, we analyzed the correlation between the expression of SP2 and Ski in normal astrocytes and reactive astrocytes, as well as the changes in astrocyte proliferation. To confirm that SP2 regulates Ski during astrocyte proliferation, astrocytes were transfected siRNA targeting SP2 and then astrocyte proliferation were analyzed. Finally, a dual luciferase reporter assay and Chromatin immunoprecipitation (ChIP) assay confirmed that the promoter region of Ski contained a specific SP2 binding site. This is the first that SP2 has been identified and confirmed to play an important role in astrocyte proliferation by regulating Ski expression. These results may help identify novel targets for the treatment of spinal cord injury.
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Affiliation(s)
- Chao-Ming Da
- The Second Clinical Medical College of Lanzhou University, 82 Cuiying Men, Lanzhou 730030, PR China; Gansu Provincial Maternal and Child Health Hospital, 143Qilihe North Street, Lanzhou 730050, PR China
| | - Hai-Yang Liao
- The Second Clinical Medical College of Lanzhou University, 82 Cuiying Men, Lanzhou 730030, PR China
| | - Yin-Shuan Deng
- Gansu Provincial Maternal and Child Health Hospital, 143Qilihe North Street, Lanzhou 730050, PR China
| | - Guang-Hai Zhao
- The Second Clinical Medical College of Lanzhou University, 82 Cuiying Men, Lanzhou 730030, PR China; Gansu Provincial Maternal and Child Health Hospital, 143Qilihe North Street, Lanzhou 730050, PR China
| | - Lin Ma
- The Second Clinical Medical College of Lanzhou University, 82 Cuiying Men, Lanzhou 730030, PR China; Gansu Provincial Maternal and Child Health Hospital, 143Qilihe North Street, Lanzhou 730050, PR China
| | - Hai-Hong Zhang
- The Second Clinical Medical College of Lanzhou University, 82 Cuiying Men, Lanzhou 730030, PR China.
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Yu S, Ruan X, Liu X, Zhang F, Wang D, Liu Y, Yang C, Shao L, Liu Q, Zhu L, Lin Y, Xue Y. HNRNPD interacts with ZHX2 regulating the vasculogenic mimicry formation of glioma cells via linc00707/miR-651-3p/SP2 axis. Cell Death Dis 2021; 12:153. [PMID: 33542193 PMCID: PMC7862279 DOI: 10.1038/s41419-021-03432-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 12/15/2020] [Accepted: 12/29/2020] [Indexed: 12/16/2022]
Abstract
Studies have found that RNA-binding proteins (RBPs) are dysfunctional and play a significant regulatory role in the development of glioma. Based on The Cancer Genome Atlas database and the previous studies, we selected heterogeneous nuclear ribonucleoprotein (HNRNPD) as the research candidate and sought its downstream targeted genes. In the present study, HNRNPD, linc00707, and specific protein 2 (SP2) were highly expressed, while zinc fingers and homeboxes 2 (ZHX2) and miR-651-3p were remarkedly downregulated in glioma tissues and cells. HNRNPD, linc00707, and SP2 knockdown or ZHX2 and miR-651-3p overexpression suppressed glioma cells proliferation, migration, and invasion and vasculogenic mimicry (VM) formation. Knockdown of HNRNPD increased the stability of ZHX2 mRNA. ZHX2 bound to the promoter region of linc00707 and negatively regulate its expression. Linc00707 could bind with miR-651-3p, while miR-651-3p bound to the 3' untranslated region (3'UTR) of SP2 mRNA to negatively regulate its expression. The transcription factor SP2 directly bound to the promoter regions of the VM formation-related proteins MMP2, MMP9, and VE-cadherin, playing a role in promoting transcription in order to regulate the VM formation ability of glioma cells.
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Affiliation(s)
- Sifei Yu
- Department of Neurobiology, School of Life Sciences, China Medical University, Shenyang, 110122, People's Republic of China
- Key Laboratory of Cell Biology, Ministry of Public Health of China, China Medical University, Shenyang, 110122, People's Republic of China
- Key Laboratory of Medical Cell Biology, Ministry of Education of China, China Medical University, Shenyang, 110122, People's Republic of China
| | - Xuelei Ruan
- Department of Neurobiology, School of Life Sciences, China Medical University, Shenyang, 110122, People's Republic of China
- Key Laboratory of Cell Biology, Ministry of Public Health of China, China Medical University, Shenyang, 110122, People's Republic of China
- Key Laboratory of Medical Cell Biology, Ministry of Education of China, China Medical University, Shenyang, 110122, People's Republic of China
| | - Xiaobai Liu
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, 110004, People's Republic of China
- Liaoning Research Center for Translational Medicine in Nervous System Disease, Shenyang, 110004, People's Republic of China
- Key Laboratory of Neuro-oncology in Liaoning Province, Shenyang, 110004, People's Republic of China
| | - Fangfang Zhang
- Department of Neurobiology, School of Life Sciences, China Medical University, Shenyang, 110122, People's Republic of China
- Key Laboratory of Cell Biology, Ministry of Public Health of China, China Medical University, Shenyang, 110122, People's Republic of China
- Key Laboratory of Medical Cell Biology, Ministry of Education of China, China Medical University, Shenyang, 110122, People's Republic of China
| | - Di Wang
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, 110004, People's Republic of China
- Liaoning Research Center for Translational Medicine in Nervous System Disease, Shenyang, 110004, People's Republic of China
- Key Laboratory of Neuro-oncology in Liaoning Province, Shenyang, 110004, People's Republic of China
| | - Yunhui Liu
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, 110004, People's Republic of China
- Liaoning Research Center for Translational Medicine in Nervous System Disease, Shenyang, 110004, People's Republic of China
- Key Laboratory of Neuro-oncology in Liaoning Province, Shenyang, 110004, People's Republic of China
| | - Chunqing Yang
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, 110004, People's Republic of China
- Liaoning Research Center for Translational Medicine in Nervous System Disease, Shenyang, 110004, People's Republic of China
- Key Laboratory of Neuro-oncology in Liaoning Province, Shenyang, 110004, People's Republic of China
| | - Lianqi Shao
- Department of Neurobiology, School of Life Sciences, China Medical University, Shenyang, 110122, People's Republic of China
- Key Laboratory of Cell Biology, Ministry of Public Health of China, China Medical University, Shenyang, 110122, People's Republic of China
- Key Laboratory of Medical Cell Biology, Ministry of Education of China, China Medical University, Shenyang, 110122, People's Republic of China
| | - Qianshuo Liu
- Department of Neurobiology, School of Life Sciences, China Medical University, Shenyang, 110122, People's Republic of China
- Key Laboratory of Cell Biology, Ministry of Public Health of China, China Medical University, Shenyang, 110122, People's Republic of China
- Key Laboratory of Medical Cell Biology, Ministry of Education of China, China Medical University, Shenyang, 110122, People's Republic of China
| | - Lu Zhu
- Department of Neurobiology, School of Life Sciences, China Medical University, Shenyang, 110122, People's Republic of China
- Key Laboratory of Cell Biology, Ministry of Public Health of China, China Medical University, Shenyang, 110122, People's Republic of China
- Key Laboratory of Medical Cell Biology, Ministry of Education of China, China Medical University, Shenyang, 110122, People's Republic of China
| | - Yang Lin
- Department of Neurobiology, School of Life Sciences, China Medical University, Shenyang, 110122, People's Republic of China
- Key Laboratory of Cell Biology, Ministry of Public Health of China, China Medical University, Shenyang, 110122, People's Republic of China
- Key Laboratory of Medical Cell Biology, Ministry of Education of China, China Medical University, Shenyang, 110122, People's Republic of China
| | - Yixue Xue
- Department of Neurobiology, School of Life Sciences, China Medical University, Shenyang, 110122, People's Republic of China.
- Key Laboratory of Cell Biology, Ministry of Public Health of China, China Medical University, Shenyang, 110122, People's Republic of China.
- Key Laboratory of Medical Cell Biology, Ministry of Education of China, China Medical University, Shenyang, 110122, People's Republic of China.
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Zhu Y, Cui J, Liu J, Hua W, Wei W, Sun G. Sp2 promotes invasion and metastasis of hepatocellular carcinoma by targeting TRIB3 protein. Cancer Med 2020; 9:3592-3603. [PMID: 32160655 PMCID: PMC7221442 DOI: 10.1002/cam4.2977] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 01/20/2020] [Accepted: 02/14/2020] [Indexed: 12/27/2022] Open
Abstract
Objective To explore the biological function and molecular mechanism of Sp2 in hepatocellular carcinoma (HCC). Methods Tissue microarray immunohistochemistry and western blot were used to study the expression of Sp2 in hepatocellular tissue and adjacent non‐neoplastic tissues (ANT). In HCC cell lines, the role of Sp2 was determined by in vitro experiments such as CCK8, clone formation test, Transwell assay, wound‐healing assay, and flow cytometry apoptotic analysis, and its possible mechanism was analyzed. Results Compared with ANT, Sp2 expression in HCC tissues was significantly up‐regulated, which was strongly associated with stage of tumor and poor prognosis of patients. TCGA database were further confirmed these results. Besides, functional studies had shown that Sp2 knockdown not only leads to a decrease in cell proliferation and an increase in cell apoptosis but also inhibits the cells' abilities of migration and invasion. Sp2 silencing could inhibit the expression of TRIB3 protein and down‐regulate the endoplasmic reticulum stress (ERS) level of HCC. Conclusion Sp2 may play a part in promoting cancer by regulating TRIB3 protein, which may be a factor of prognostic and a potential new therapeutic target for HCC.
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Affiliation(s)
- Yue Zhu
- Department of Oncology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Jie Cui
- Department of Oncology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Jiatao Liu
- Department of Pharmacy, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Wei Hua
- Department of Pharmacy, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Wei Wei
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei, China
| | - Guoping Sun
- Department of Oncology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
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Salmon M, Spinosa M, Zehner ZE, Upchurch GR, Ailawadi G. Klf4, Klf2, and Zfp148 activate autophagy-related genes in smooth muscle cells during aortic aneurysm formation. Physiol Rep 2019; 7:e14058. [PMID: 31025534 PMCID: PMC6483937 DOI: 10.14814/phy2.14058] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 02/21/2019] [Accepted: 02/22/2019] [Indexed: 01/08/2023] Open
Abstract
Abdominal aortic aneurysms (AAAs) are a progressive dilation of the aorta that is characterized by an initial influx of inflammatory cells followed by a pro-inflammatory, migratory, proliferative, and eventually apoptotic smooth muscle cell phenotype. In recent years, the mechanisms related to the initial influx of inflammatory cells have become well-studied; the mechanisms related to chronic aneurysm formation, smooth muscle cell apoptosis and death are less well-characterized. Autophagy is a generally believed to be a protective cellular mechanism that functions to recycle defective proteins and cellular organelles to maintain cellular homeostasis. Our goal with the present study was to investigate the role of autophagy in smooth muscle cells during AAA formation. Levels of the autophagy factors, Beclin, and LC3 were elevated in human and mouse AAA tissue via both qPCR and immunohistochemical analysis. Confocal staining in human and mouse AAA tissue demonstrated Beclin and LC3 were present in smooth muscle cells during AAA formation. Treatment of smooth muscle cells with porcine pancreatic elastase or interleukin (IL)-1β activated autophagy-related genes in vitro while treatment with a siRNA to Kruppel-like transcription factor 4 (Klf4), Kruppel-like transcription factor 2 (Klf2) or Zinc-finger protein 148 (Zfp148) separately inhibited activation of autophagy genes. Chromatin immunoprecipitation assays demonstrated that Klf4, Klf2, and Zfp148 separately bind autophagy genes in smooth muscle cells following elastase treatment. These results demonstrate that autophagy is an important mechanism related to Klfs in smooth muscle cells during AAA formation.
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Affiliation(s)
- Morgan Salmon
- Department of SurgeryUniversity of Virginia School of MedicineCharlottesvilleVirginiaUSA
| | - Michael Spinosa
- Department of SurgeryUniversity of Virginia School of MedicineCharlottesvilleVirginiaUSA
| | - Zendra E. Zehner
- Department of BiochemistryVirginia Commonwealth University Medical CenterRichmondVirginiaUSA
| | | | - Gorav Ailawadi
- Department of SurgeryUniversity of Virginia School of MedicineCharlottesvilleVirginiaUSA
- The Robert M. Berne Cardiovascular Research CenterUniversity of Virginia School of MedicineCharlottesvilleVirginiaUSA
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Liu Y, Guan J, Chen X. Identification of Differentially Expressed Genes under the Regulation of Transcription Factors in Osteosarcoma. Pathol Oncol Res 2018; 25:1091-1102. [PMID: 30411296 DOI: 10.1007/s12253-018-0519-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 10/25/2018] [Indexed: 12/11/2022]
Abstract
The present study was to investigate and identify the differentially expressed genes (DEGs) in the transcriptional regulatory network of osteosarcoma (OS). The gene expression dataset from Gene Expression Omnibus (GEO) datasets was downloaded. DEGs were identified and their functional annotation was also conducted. In addition, differentially expressed transcription factors (TFs) and the regulatory genes were identified. The electronic validation was used to verify the expression of selected genes. The integrated analysis led to 932 DEGs. The results of functional annotation indicated that these DEGs significantly enriched in the p53 signaling pathway, Jak-STAT signaling pathway and Wnt signaling pathway. ZNF354C, NFIC, NFATC2, SP2, FOXO3, EGR1, ZEB1, RREB1, EGR2 and SRF were covered by most TFs. The expression levels of NFIC and EGR2 in electronic validation were compatible with our bio-informatics result. In conclusion, the deregulation of these genes may provide valuable information in understanding the underlying molecular mechanism in the OS.
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Affiliation(s)
- Yang Liu
- Department of Orthopaedics, The First Affiliated Hospital of Bengbu Medical College, No. 287, ChangHuai Road, Bengbu, 233004, Anhui Province, China
| | - Jianzhong Guan
- Department of Orthopaedics, The First Affiliated Hospital of Bengbu Medical College, No. 287, ChangHuai Road, Bengbu, 233004, Anhui Province, China.
| | - Xiaotian Chen
- Department of Orthopaedics, The First Affiliated Hospital of Bengbu Medical College, No. 287, ChangHuai Road, Bengbu, 233004, Anhui Province, China
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Zhou X, Chen Z, Cai X. Identification of epigenetic modulators in human breast cancer by integrated analysis of DNA methylation and RNA-Seq data. Epigenetics 2018; 13:473-489. [PMID: 29940789 DOI: 10.1080/15592294.2018.1469894] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Human tumors undergo massive changes in DNA methylation. Recent studies showed that site-specific methylation of CpG sites is determined by the DNA sequence context surrounding the CpG site, which alludes to a possible mechanism for site-specific aberrant DNA methylation in cancer through DNA-binding proteins. In this paper, DNA methylation data and RNA-Seq data of breast tumors and normal tissues in the database of The Cancer Genome Atlas (TCGA) were integrated with information of DNA motifs in seven databases to find DNA-binding proteins and their binding motifs that were involved in aberrant DNA methylation in breast cancer. A total of 42,850 differentially methylated regions (DMRs) that include 77,298 CpG sites were detected in breast cancer. One hundred eight DNA motifs were found to be enriched in DMRs, and 109 genes encoding proteins binding to these motifs were determined. Based on these motifs and genes, 63 methylation modulator genes were identified to regulate differentially methylated CpG sites in breast cancer. A network of these 63 modulator genes and 645 transcription factors was constructed, and 20 network modules were determined. A number of pathways and gene sets related to breast cancer were found to be enriched in these network modules. The 63 methylation modulator genes identified may play an important role in aberrant methylation of CpG sites in breast cancer. They may help to understand site-specific dysregulation of DNA methylation and provide epigenetic markers for breast cancer.
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Affiliation(s)
- Xin Zhou
- a Department of Electrical and Computer Engineering , University of Miami , Coral Gables , FL , USA
| | - Zhibin Chen
- b Department of Microbiology and Immunology, Miller School of Medicine , University of Miami , Miami , FL , USA.,c Sylvester Comprehensive Cancer Center , University of Miami , Miami , FL , USA
| | - Xiaodong Cai
- a Department of Electrical and Computer Engineering , University of Miami , Coral Gables , FL , USA.,c Sylvester Comprehensive Cancer Center , University of Miami , Miami , FL , USA
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Genetic polymorphisms and their association with brain and behavioural measures in heterogeneous stock mice. Sci Rep 2017; 7:41204. [PMID: 28145470 PMCID: PMC5286500 DOI: 10.1038/srep41204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 12/16/2016] [Indexed: 12/30/2022] Open
Abstract
Although the search for quantitative trait loci for behaviour remains a considerable challenge, the complicated genetic architecture of quantitative traits is beginning to be understood. The current project utilised heterogeneous stock (HS) male mice (n = 580) to investigate the genetic basis for brain weights, activity, anxiety and cognitive phenotypes. We identified 126 single nucleotide polymorphisms (SNPs) in genes involved in regulation of neurotransmitter systems, nerve growth/death and gene expression, and subsequently investigated their associations with changes in behaviour and/or brain weights in our sample. We found significant associations between four SNP-phenotype pairs, after controlling for multiple testing. Specificity protein 2 (Sp2, rs3708840), tryptophan hydroxylase 1 (Tph1, rs262731280) and serotonin receptor 3A (Htr3a, rs50670893) were associated with activity/anxiety behaviours, and microtubule-associated protein 2 (Map2, rs13475902) was associated with cognitive performance. All these genes except for Tph1 were expressed in the brain above the array median, and remained significantly associated with relevant behaviours after controlling for the family structure. Additionally, we found evidence for a correlation between Htr3a expression and activity. We discuss our findings in the light of the advantages and limitations of currently available mouse genetic tools, suggesting further directions for association studies in rodents.
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Zinc finger independent genome-wide binding of Sp2 potentiates recruitment of histone-fold protein Nf-y distinguishing it from Sp1 and Sp3. PLoS Genet 2015; 11:e1005102. [PMID: 25793500 PMCID: PMC4368557 DOI: 10.1371/journal.pgen.1005102] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 02/25/2015] [Indexed: 11/19/2022] Open
Abstract
Transcription factors are grouped into families based on sequence similarity within functional domains, particularly DNA-binding domains. The Specificity proteins Sp1, Sp2 and Sp3 are paradigmatic of closely related transcription factors. They share amino-terminal glutamine-rich regions and a conserved carboxy-terminal zinc finger domain that can bind to GC rich motifs in vitro. All three Sp proteins are ubiquitously expressed; yet they carry out unique functions in vivo raising the question of how specificity is achieved. Crucially, it is unknown whether they bind to distinct genomic sites and, if so, how binding site selection is accomplished. In this study, we have examined the genomic binding patterns of Sp1, Sp2 and Sp3 in mouse embryonic fibroblasts by ChIP-seq. Sp1 and Sp3 essentially occupy the same promoters and localize to GC boxes. The genomic binding pattern of Sp2 is different; Sp2 primarily localizes at CCAAT motifs. Consistently, re-expression of Sp2 and Sp3 mutants in corresponding knockout MEFs revealed strikingly different modes of genomic binding site selection. Most significantly, while the zinc fingers dictate genomic binding of Sp3, they are completely dispensable for binding of Sp2. Instead, the glutamine-rich amino-terminal region is sufficient for recruitment of Sp2 to its target promoters in vivo. We have identified the trimeric histone-fold CCAAT box binding transcription factor Nf-y as the major partner for Sp2-chromatin interaction. Nf-y is critical for recruitment of Sp2 to co-occupied regulatory elements. Equally, Sp2 potentiates binding of Nf-y to shared sites indicating the existence of an extensive Sp2-Nf-y interaction network. Our results unveil strikingly different recruitment mechanisms of Sp1/Sp2/Sp3 transcription factor members uncovering an unexpected layer of complexity in their binding to chromatin in vivo. A major question in eukaryotic gene regulation is how transcription factors with similar structural features elicit specific biological responses. We used the three transcription factors Sp1, Sp2 and Sp3 as a paradigm for investigating this question. All three proteins are ubiquitously expressed, and they share glutamine-rich domains as well as a conserved bona fide zinc finger DNA binding domain. Yet, each of the three proteins carries out unique functions in vivo, and each is absolutely essential for mouse development. By genome-wide binding analysis, we found that Sp1 and Sp3 on the one hand, and Sp2 on the other hand engage completely different protein domains for their genomic binding site selection. Most strikingly, the zinc finger domain of Sp2 is dispensable for recruitment to its target sites in vivo. Moreover, we provide strong evidence that the histone-fold protein Nf-y is necessary for recruitment of Sp2. Conversely, Sp2 potentiates Nf-y binding showing that binding of Sp2 and Nf-y to shared sites is mutually dependent. Our findings uncover an unexpected mechanistic diversity in promoter recognition by seemingly similar transcription factors. This work has broader implications for our understanding of how members of other multi-protein transcription factor families could achieve specificity.
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Zhao LY, Yao Y, Han J, Yang J, Wang XF, Tong DD, Song TS, Huang C, Shao Y. miR-638 suppresses cell proliferation in gastric cancer by targeting Sp2. Dig Dis Sci 2014; 59:1743-53. [PMID: 24623314 DOI: 10.1007/s10620-014-3087-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 02/19/2014] [Indexed: 01/07/2023]
Abstract
BACKGROUND MicroRNAs play important roles in the development and progression of various cancers. Recent studies have shown that miR-638 was downregulated in several tumors; however, its role in gastric cancer (GC) has not been investigated in detail. AIMS The purpose of this study was to determine the role of miR-638 and to elucidate its regulatory mechanism in GC. METHODS The expression levels of miR-638 and specificity protein 2 (Sp2) were detected by real-time PCR and Western blotting in GC. After pcDNA6.2-GW/EmGFP-miR-638 vector, miR-638 inhibitor and Sp2-siRNA transfection, the AGS cell proliferation was investigated by MTT assay and cell cycle, and apoptosis was detected using the Annexin V/PI. In addition, the regulation of Sp2 by miR-638 was evaluated by real-time RT-PCR, Western blot and luciferase reporter assays; cyclin D1 expression was measured by Western blotting. RESULTS The expression of miR-638 is dramatically down-regulated and Sp2 expression is remarkably up-regulated in GC tissues. Luciferase assays revealed that miR-638 inhibited Sp2 expression by targeting the 3'-UTR of Sp2 mRNA. Overexpression of miR-638 and Sp2-siRNA reduced Sp2 expression at both the mRNA and protein levels in vitro, and inhibition of miR-638 increased Sp2 expression. Moreover, we found that miR-638 overexpression and Sp2-siRNA markedly suppressed cell proliferation with decreasing expression of cyclin D1 and inducing G1-phase cell-cycle arrest in vitro; inhibition of miR-638 significantly promoted cell proliferation by increasing expression of cyclin D1 and leading more cells into the S and G2/M phase. CONCLUSIONS Our results demonstrated that miR-638 suppressed GC cell proliferation by targeting Sp2 with influence on the expression of cyclin D1. We suggest that miR-638 might be a candidate predictor or an anticancer therapeutic target for GC patients.
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Affiliation(s)
- Ling Yu Zhao
- Department of Genetics and Cell Biology, Environment and Genes Related to Diseases Key Laboratory of Education Ministry, College of Medicine, Xi'an Jiaotong University, Xi'an, 710061, People's Republic of China,
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Safe S, Imanirad P, Sreevalsan S, Nair V, Jutooru I. Transcription factor Sp1, also known as specificity protein 1 as a therapeutic target. Expert Opin Ther Targets 2014; 18:759-69. [PMID: 24793594 DOI: 10.1517/14728222.2014.914173] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Specificity protein (Sp) transcription factors (TFs) are members of the Sp/Kruppel-like factor family, and Sp proteins play an important role in embryonic and early postnatal development. Sp1 has been the most extensively investigated member of this family, and expression of this protein decreases with age, whereas Sp1 and other family members (Sp3 and Sp4) are highly expressed in tumors and cancer cell lines. AREA COVERED The prognostic significance of Sp1 in cancer patients and the functional pro-oncogenic activities of Sp1, Sp3 and Sp4 in cancer cell lines are summarized. Several different approaches have been used to target downregulation of Sp TFs and Sp-regulated genes, and this includes identification of different structural classes of antineoplastic agents including NSAIDs, natural products and their synthetic analogs and several well-characterized drugs including arsenic trioxide, aspirin and metformin. The multiple pathways involved in drug-induced Sp downregulation are also discussed. EXPERT OPINION The recognition by the scientific and clinical community that experimental and clinically used antineoplastic agents downregulate Sp1, Sp3 and Sp4, and pro-oncogenic Sp-regulated genes will facilitate future clinical applications for individual drug and drug combination therapies that take advantage of their unusual effects.
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Affiliation(s)
- Stephen Safe
- Texas A&M University, Veterinary Physiology and Pharmacology , 4466 TAMU, College Station, TX 77843-4466 , USA
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Frantzi M, Zoidakis J, Papadopoulos T, Zürbig P, Katafigiotis I, Stravodimos K, Lazaris A, Giannopoulou I, Ploumidis A, Mischak H, Mullen W, Vlahou A. IMAC fractionation in combination with LC-MS reveals H2B and NIF-1 peptides as potential bladder cancer biomarkers. J Proteome Res 2013; 12:3969-79. [PMID: 23924207 DOI: 10.1021/pr400255h] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Improvement in bladder cancer (BC) management requires more effective diagnosis and prognosis of disease recurrence and progression. Urinary biomarkers attract special interest because of the noninvasive means of urine collection. Proteomic analysis of urine entails the adoption of a fractionation methodology to reduce sample complexity. In this study, we applied immobilized metal affinity chromatography in combination with high-resolution LC-MS/MS for the discovery of native urinary peptides potentially associated with BC aggressiveness. This approach was employed toward urine samples from patients with invasive BC, noninvasive BC, and benign urogenital diseases. A total of 1845 peptides were identified, corresponding to a total of 638 precursor proteins. Specific enrichment for proteins involved in nucleosome assembly and for zinc-finger transcription factors was observed. The differential expression of two candidate biomarkers, histone H2B and NIF-1 (zinc finger 335) in BC, was verified in independent sets of urine samples by ELISA and by immunohistochemical analysis of BC tissue. The results collectively support changes in the expression of both of these proteins with tumor progression, suggesting their potential role as markers for discriminating BC stages. In addition, the data indicate a possible involvement of NIF-1 in BC progression, likely as a suppressor and through interactions with Sox9 and HoxA1.
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Affiliation(s)
- Maria Frantzi
- Biomedical Research Foundation Academy of Athens, Athens, Greece
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Liang H, Xiao G, Yin H, Hippenmeyer S, Horowitz JM, Ghashghaei HT. Neural development is dependent on the function of specificity protein 2 in cell cycle progression. Development 2013; 140:552-61. [PMID: 23293287 DOI: 10.1242/dev.085621] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Faithful progression through the cell cycle is crucial to the maintenance and developmental potential of stem cells. Here, we demonstrate that neural stem cells (NSCs) and intermediate neural progenitor cells (NPCs) employ a zinc-finger transcription factor specificity protein 2 (Sp2) as a cell cycle regulator in two temporally and spatially distinct progenitor domains. Differential conditional deletion of Sp2 in early embryonic cerebral cortical progenitors, and perinatal olfactory bulb progenitors disrupted transitions through G1, G2 and M phases, whereas DNA synthesis appeared intact. Cell-autonomous function of Sp2 was identified by deletion of Sp2 using mosaic analysis with double markers, which clearly established that conditional Sp2-null NSCs and NPCs are M phase arrested in vivo. Importantly, conditional deletion of Sp2 led to a decline in the generation of NPCs and neurons in the developing and postnatal brains. Our findings implicate Sp2-dependent mechanisms as novel regulators of cell cycle progression, the absence of which disrupts neurogenesis in the embryonic and postnatal brain.
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Affiliation(s)
- Huixuan Liang
- Department of Molecular Biomedical Sciences and Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA
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14
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Yeo S, Choi YG, Hong YM, Lim S. Neuroprotective changes of thalamic degeneration-related gene expression by acupuncture in an MPTP mouse model of parkinsonism: microarray analysis. Gene 2012; 515:329-38. [PMID: 23235115 DOI: 10.1016/j.gene.2012.12.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 10/12/2012] [Accepted: 12/02/2012] [Indexed: 01/18/2023]
Abstract
Acupuncture stimulations at GB34 and LR3 inhibit the reduction of tyrosine hydroxylase in the nigrostriatal dopaminergic neurons in the parkinsonism animal models. Especially, behavioral tests showed that acupuncture stimulations improved the motor dysfunction in a previous study by almost 87.7%. The thalamus is a crucial area for the motor circuit and has been identified as one of the most markedly damaged areas in Parkinson's disease (PD), so acupuncture stimulations might also have an effect on the thalamic damage. In this study, gene expression changes following acupuncture at the acupoints were investigated in the thalamus of a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism model using a whole transcript array. It was confirmed that acupuncture at these acupoints could inhibit the decrease of tyrosine hydroxylase in the thalamic regions of the MPTP model, while acupuncture at the non-acupoints could not suppress this decrease by its level shown in the acupoints. GeneChip gene array analysis showed that 18 (5 annotated genes: Dnase1l2, Dusp4, Mafg, Ndph and Pgm5) of the probes down-regulated in MPTP, as compared to the control, were exclusively up-regulated by acupuncture at the acupoints, but not at the non-acupoints. In addition, 14 (3 annotated genes; Serinc2, Sp2 and Ucp2) of the probes up-regulated in MPTP, as compared to the control, were exclusively down-regulated by acupuncture at the acupoints, but not at the non-acupoints. The expression levels of the representative genes in the microarray were validated by real-time RT-PCR. These results suggest that the 32 probes (8 annotated genes) which are affected by MPTP and acupuncture may be responsible for exerting the inhibitory effect of acupuncture in the thalamus which can be damaged by MPTP intoxication.
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Affiliation(s)
- Sujung Yeo
- Research Group of Pain and Neuroscience, WHO Collaborating Center for Traditional Medicine, East-West Medical Research Institute, Kyung Hee University, Seoul, Republic of Korea
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15
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Terrados G, Finkernagel F, Stielow B, Sadic D, Neubert J, Herdt O, Krause M, Scharfe M, Jarek M, Suske G. Genome-wide localization and expression profiling establish Sp2 as a sequence-specific transcription factor regulating vitally important genes. Nucleic Acids Res 2012; 40:7844-57. [PMID: 22684502 PMCID: PMC3439921 DOI: 10.1093/nar/gks544] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The transcription factor Sp2 is essential for early mouse development and for proliferation of mouse embryonic fibroblasts in culture. Yet its mechanisms of action and its target genes are largely unknown. In this study, we have combined RNA interference, in vitro DNA binding, chromatin immunoprecipitation sequencing and global gene-expression profiling to investigate the role of Sp2 for cellular functions, to define target sites and to identify genes regulated by Sp2. We show that Sp2 is important for cellular proliferation that it binds to GC-boxes and occupies proximal promoters of genes essential for vital cellular processes including gene expression, replication, metabolism and signalling. Moreover, we identified important key target genes and cellular pathways that are directly regulated by Sp2. Most significantly, Sp2 binds and activates numerous sequence-specific transcription factor and co-activator genes, and represses the whole battery of cholesterol synthesis genes. Our results establish Sp2 as a sequence-specific regulator of vitally important genes.
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Affiliation(s)
- Gloria Terrados
- Institute of Molecular Biology and Tumor Research, Philipps-University, Emil-Mannkopff-Str. 2, D-35032 Marburg, Germany
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