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Zou H, Yu D, Yao S, Ding F, Li J, Li L, Li X, Zhao S, Pang Y, Hao H, Du W, Zhao X, Dai Y, Zhu H. Efficient Editing of the ZBED6-Binding Site in Intron 3 of IGF2 in a Bovine Model Using the CRISPR/Cas9 System. Genes (Basel) 2022; 13:genes13071132. [PMID: 35885915 PMCID: PMC9325003 DOI: 10.3390/genes13071132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 05/16/2022] [Accepted: 05/16/2022] [Indexed: 12/04/2022] Open
Abstract
Background: Insulin-like growth factor 2 is a growth-promoting factor that plays an important role in the growth and development of mammals. A nucleotide substitution in intron 3 of IGF2—which disrupts the ZBED6-binding site—affects muscle mass, organ size, and fat deposition in pigs. The ZBED6-binding site is also conserved in cattle. Methods: In the present study, we introduced mutations in the ZBED6-binding site in intron3 of IGF2 in bovine fetal fibroblasts using the CRISPR/Cas9 system, and investigated the effect of disruption of ZBED6 binding on IGF2 expression. Results: Eleven biallelic-mutant single-cell clones were established, three of which contained no foreign DNA residues. Single-cell clones 93 and 135 were used to produce cloned embryos. Dual-luciferase reporter assay in C2C12 cells demonstrated that the mutation in the ZBED6-binding site increases the promoter 3 activity of bovine IGF2. A total of 49 mutant cloned embryos were transplanted into surrogate cows. Unfortunately, all cloned embryos died before birth. IGF2 was found to be hypomethylated in the only fetus born (stillborn), which may have been due to the incomplete reprogramming. Conclusions: We efficiently constructed IGF2-edited cell lines and cloned embryos, which provided a theoretical basis and experimental materials for beef cattle breeding.
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Affiliation(s)
- Huiying Zou
- Embryo Biotechnology and Reproduction Laboratory, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (H.Z.); (D.Y.); (S.Y.); (J.L.); (S.Z.); (Y.P.); (H.H.); (W.D.); (X.Z.)
| | - Dawei Yu
- Embryo Biotechnology and Reproduction Laboratory, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (H.Z.); (D.Y.); (S.Y.); (J.L.); (S.Z.); (Y.P.); (H.H.); (W.D.); (X.Z.)
| | - Shun Yao
- Embryo Biotechnology and Reproduction Laboratory, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (H.Z.); (D.Y.); (S.Y.); (J.L.); (S.Z.); (Y.P.); (H.H.); (W.D.); (X.Z.)
| | - Fangrong Ding
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China; (F.D.); (L.L.); (X.L.)
| | - Junliang Li
- Embryo Biotechnology and Reproduction Laboratory, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (H.Z.); (D.Y.); (S.Y.); (J.L.); (S.Z.); (Y.P.); (H.H.); (W.D.); (X.Z.)
| | - Ling Li
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China; (F.D.); (L.L.); (X.L.)
| | - Xue Li
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China; (F.D.); (L.L.); (X.L.)
| | - Shanjiang Zhao
- Embryo Biotechnology and Reproduction Laboratory, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (H.Z.); (D.Y.); (S.Y.); (J.L.); (S.Z.); (Y.P.); (H.H.); (W.D.); (X.Z.)
| | - Yunwei Pang
- Embryo Biotechnology and Reproduction Laboratory, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (H.Z.); (D.Y.); (S.Y.); (J.L.); (S.Z.); (Y.P.); (H.H.); (W.D.); (X.Z.)
| | - Haisheng Hao
- Embryo Biotechnology and Reproduction Laboratory, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (H.Z.); (D.Y.); (S.Y.); (J.L.); (S.Z.); (Y.P.); (H.H.); (W.D.); (X.Z.)
| | - Weihua Du
- Embryo Biotechnology and Reproduction Laboratory, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (H.Z.); (D.Y.); (S.Y.); (J.L.); (S.Z.); (Y.P.); (H.H.); (W.D.); (X.Z.)
| | - Xueming Zhao
- Embryo Biotechnology and Reproduction Laboratory, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (H.Z.); (D.Y.); (S.Y.); (J.L.); (S.Z.); (Y.P.); (H.H.); (W.D.); (X.Z.)
| | - Yunping Dai
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China; (F.D.); (L.L.); (X.L.)
- Correspondence: (Y.D.); (H.Z.)
| | - Huabin Zhu
- Embryo Biotechnology and Reproduction Laboratory, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (H.Z.); (D.Y.); (S.Y.); (J.L.); (S.Z.); (Y.P.); (H.H.); (W.D.); (X.Z.)
- Correspondence: (Y.D.); (H.Z.)
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Ghanipoor-Samami M, Javadmanesh A, Burns BM, Thomsen DA, Nattrass GS, Estrella CAS, Kind KL, Hiendleder S. Atlas of tissue- and developmental stage specific gene expression for the bovine insulin-like growth factor (IGF) system. PLoS One 2018; 13:e0200466. [PMID: 30001361 PMCID: PMC6042742 DOI: 10.1371/journal.pone.0200466] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 06/27/2018] [Indexed: 01/04/2023] Open
Abstract
The insulin-like growth factor (IGF) axis is fundamental for mammalian growth and development. However, no comprehensive reference data on gene expression across tissues and pre- and postnatal developmental stages are available for any given species. Here we provide systematic promoter- and splice variant specific information on expression of IGF system components in embryonic (Day 48), fetal (Day 153), term (Day 277, placenta) and juvenile (Day 365–396) tissues of domestic cow, a major agricultural species and biomedical model. Analysis of spatiotemporal changes in expression of IGF1, IGF2, IGF1R, IGF2R, IGFBP1-8 and IR genes, as well as lncRNAs H19 and AIRN, by qPCR, indicated an overall increase in expression from embryo to fetal stage, and decrease in expression from fetal to juvenile stage. The stronger decrease in expression of lncRNAs (average ―16-fold) and ligands (average ―12.1-fold) compared to receptors (average ―5.7-fold) and binding proteins (average ―4.3-fold) is consistent with known functions of IGF peptides and supports important roles of lncRNAs in prenatal development. Pronounced overall reduction in postnatal expression of IGF system components in lung (―12.9-fold) and kidney (―13.2-fold) are signatures of major changes in organ function while more similar hepatic expression levels (―2.2-fold) are evidence of the endocrine rather than autocrine/paracrine role of IGFs in postnatal growth regulation. Despite its rapid growth, placenta displayed a more stable expression pattern than other organs during prenatal development. Quantitative analyses of contributions of promoters P0-P4 to global IGF2 transcript in fetal tissues revealed that P4 accounted for the bulk of transcript in all tissues but skeletal muscle. Demonstration of IGF2 expression in fetal muscle and postnatal liver from a promoter orthologous to mouse and human promoter P0 provides further evidence for an evolutionary and developmental shift from placenta-specific P0-expression in rodents and suggests that some aspects of bovine IGF expression may be closer to human than mouse.
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Affiliation(s)
- Mani Ghanipoor-Samami
- Robinson Research Institute, The University of Adelaide, Adelaide, South Australia, Australia
- JS Davies Epigenetics and Genetics Group, Davies Research Centre, School of Animal and Veterinary Sciences, Roseworthy Campus, The University of Adelaide, Roseworthy, South Australia, Australia
| | - Ali Javadmanesh
- Robinson Research Institute, The University of Adelaide, Adelaide, South Australia, Australia
- JS Davies Epigenetics and Genetics Group, Davies Research Centre, School of Animal and Veterinary Sciences, Roseworthy Campus, The University of Adelaide, Roseworthy, South Australia, Australia
| | - Brian M. Burns
- Centre for Animal Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Rockhampton, Queensland, Australia
| | - Dana A. Thomsen
- Robinson Research Institute, The University of Adelaide, Adelaide, South Australia, Australia
- JS Davies Epigenetics and Genetics Group, Davies Research Centre, School of Animal and Veterinary Sciences, Roseworthy Campus, The University of Adelaide, Roseworthy, South Australia, Australia
| | - Greg S. Nattrass
- Livestock Systems, South Australian Research and Development Institute (SARDI), Roseworthy, South Australia, Australia
| | - Consuelo Amor S. Estrella
- Robinson Research Institute, The University of Adelaide, Adelaide, South Australia, Australia
- JS Davies Epigenetics and Genetics Group, Davies Research Centre, School of Animal and Veterinary Sciences, Roseworthy Campus, The University of Adelaide, Roseworthy, South Australia, Australia
| | - Karen L. Kind
- JS Davies Epigenetics and Genetics Group, Davies Research Centre, School of Animal and Veterinary Sciences, Roseworthy Campus, The University of Adelaide, Roseworthy, South Australia, Australia
| | - Stefan Hiendleder
- Robinson Research Institute, The University of Adelaide, Adelaide, South Australia, Australia
- JS Davies Epigenetics and Genetics Group, Davies Research Centre, School of Animal and Veterinary Sciences, Roseworthy Campus, The University of Adelaide, Roseworthy, South Australia, Australia
- * E-mail:
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Rotwein P. Similarity and variation in the insulin-like growth factor 2 - H19 locus in primates. Physiol Genomics 2018; 50:425-439. [PMID: 29602297 PMCID: PMC6032289 DOI: 10.1152/physiolgenomics.00030.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 03/22/2018] [Accepted: 03/23/2018] [Indexed: 02/07/2023] Open
Abstract
Insulin-like growth factor 2 (IGF2), a small, secreted protein, is critical for fetal and prenatal growth in humans and other mammals. The IGF2 gene and its mouse homolog comprise part of a conserved linkage group that is regulated by parental imprinting, with IGF2/ Igf2 being expressed from the paternal chromosome, and the adjacent H19 gene from the maternal chromosome. By using information extracted from public genomic and gene expression databases, I have now analyzed this locus in nine nonhuman primate species representing over 60 million years of evolutionary divergence from a common progenitor. Both IGF2 and H19 genes and the entire locus have been conserved among these primates. Each primate IGF2 gene except for gibbon and marmoset is composed of 10 exons and contains five potential promoters, each with distinctive 5'-untranslated exons. Similarly, except for marmoset and mouse lemur, H19 consists of six exons and has two promoters. DNA sequence conservation is high, not only in orthologous exons and promoters, but also in a putative imprinting control region located 5' to H19 and in multiple potential distal enhancer elements found 3' to H19. Collectively, these results support the hypothesis that common regulatory processes shaped the IGF2 - H19 locus before the onset of primate speciation more than 85 million years ago. This study also leads to the conclusion that inaccuracies in data presentation in genetic repositories could limit our ability to develop novel insights about roles of individual genes and multigene loci in mammalian physiology and disease.
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Affiliation(s)
- Peter Rotwein
- Department of Biomedical Sciences, Paul L. Foster School of Medicine, Texas Tech Health University Health Sciences Center , El Paso, Texas
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Abstract
Healthy tissue growth depends on a well-controlled and context-appropriate balance of cellular proliferation, cell cycle arrest, and programmed cell death (apoptosis). Disturbance of this balance by activation of oncogenes, inactivation/mutation of tumor suppressor genes, or inhibition of apoptosis can promote tumorigenesis. This mini-review will focus on evidence for the contribution of insulin-like growth factor (IGF) signaling and its regulation by the transcription factor, p53, to tumor development and progression.
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Affiliation(s)
- Cheryl A Conover
- Division of Endocrinology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
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Rotwein P. The complex genetics of human insulin-like growth factor 2 are not reflected in public databases. J Biol Chem 2018; 293:4324-4333. [PMID: 29414792 DOI: 10.1074/jbc.ra117.001573] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 01/15/2018] [Indexed: 01/02/2023] Open
Abstract
Recent advances in genetics present unique opportunities for enhancing knowledge about human physiology and disease susceptibility. Understanding this information at the individual gene level is challenging and requires extracting, collating, and interpreting data from a variety of public gene repositories. Here, I illustrate this challenge by analyzing the gene for human insulin-like growth factor 2 (IGF2) through the lens of several databases. IGF2, a 67-amino acid secreted peptide, is essential for normal prenatal growth and is involved in other physiological and pathophysiological processes in humans. Surprisingly, none of the genetic databases accurately described or completely delineated human IGF2 gene structure or transcript expression, even though all relevant information could be found in the published literature. Although IGF2 shares multiple features with the mouse Igf2 gene, it has several unique properties, including transcription from five promoters. Both genes undergo parental imprinting, with IGF2/Igf2 being expressed primarily from the paternal chromosome and the adjacent H19 gene from the maternal chromosome. Unlike mouse Igf2, whose expression declines after birth, human IGF2 remains active throughout life. This characteristic has been attributed to a unique human gene promoter that escapes imprinting, but as shown here, it involves several different promoters with distinct tissue-specific expression patterns. Because new testable hypotheses could lead to critical insights into IGF2 actions in human physiology and disease, it is incumbent that our fundamental understanding is accurate. Similar challenges affecting knowledge of other human genes should promote attempts to critically evaluate, interpret, and correct human genetic data in publicly available databases.
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Affiliation(s)
- Peter Rotwein
- From the Department of Biomedical Sciences, Paul L. Foster School of Medicine, Texas Tech Health University Health Sciences Center, El Paso, Texas 79905
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Lee SC, Min HY, Jung HJ, Park KH, Hyun SY, Cho J, Woo JK, Kwon SJ, Lee HJ, Johnson FM, Lee HY. Essential role of insulin-like growth factor 2 in resistance to histone deacetylase inhibitors. Oncogene 2016; 35:5515-26. [PMID: 27086926 DOI: 10.1038/onc.2016.92] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 01/16/2016] [Accepted: 02/15/2016] [Indexed: 02/07/2023]
Abstract
Histone deacetylase (HDAC) inhibitors (HDIs) are promising anticancer therapies and have been clinically used for the treatment of hematological malignancy. However, their efficacy in solid tumors is marginal and drug resistance hampers their further clinical utility. To develop novel strategies for the HDI-based anticancer therapeutics in non-small cell lung cancer (NSCLC), in the present study, we investigated the mechanisms underlying resistance to HDI treatment in NSCLC cells. We show the STAT3-mediated IGF2/IGF-1R signaling cascade as a key modulator for both acquired and primary HDI resistance. The treatment with HDI upregulated IGF2 transcription in NSCLC cells carrying intrinsic or acquired drug resistance via direct binding of STAT3 in IGF2 P3 and P4 promoters. Acetylated STAT3 emerged upon HDAC inhibition was protected from the proteasome-mediated degradation of STAT3 and functioned as a direct transcription factor for IGF2 expression. Genomic or pharmacological strategies targeting STAT3 diminished the HDI-induced IGF2 mRNA expression and overcame the resistance to HDI treatment in HDI-resistant NSCLC- or patient-derived tumor xenograft models. These findings provide new insights into the role of acetylated STAT3-mediated activation of IGF2 transcription in HDI resistance, suggesting IGF2 or STAT3 as novel targets to overcome HDI resistance in NSCLC.
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Marášek P, Dzijak R, Studenyak I, Fišerová J, Uličná L, Novák P, Hozák P. Paxillin-dependent regulation of IGF2 and H19 gene cluster expression. J Cell Sci 2015; 128:3106-16. [PMID: 26116569 PMCID: PMC4541046 DOI: 10.1242/jcs.170985] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 05/31/2015] [Indexed: 12/15/2022] Open
Abstract
Paxillin (PXN) is a focal adhesion protein that has been implicated in signal transduction from the extracellular matrix. Recently, it has been shown to shuttle between the cytoplasm and the nucleus. When inside the nucleus, paxillin promotes cell proliferation. Here, we introduce paxillin as a transcriptional regulator of IGF2 and H19 genes. It does not affect the allelic expression of the two genes; rather, it regulates long-range chromosomal interactions between the IGF2 or H19 promoter and a shared distal enhancer on an active allele. Specifically, paxillin stimulates the interaction between the enhancer and the IGF2 promoter, thus activating IGF2 gene transcription, whereas it restrains the interaction between the enhancer and the H19 promoter, downregulating the H19 gene. We found that paxillin interacts with cohesin and the mediator complex, which have been shown to mediate long-range chromosomal looping. We propose that these interactions occur at the IGF2 and H19 gene cluster and are involved in the formation of loops between the IGF2 and H19 promoters and the enhancer, and thus the expression of the corresponding genes. These observations contribute to a mechanistic explanation of the role of paxillin in proliferation and fetal development.
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Affiliation(s)
- Pavel Marášek
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics AS CR, Prague 142 20, Czech Republic Faculty of Science, Charles University in Prague, Prague 128 43, Czech Republic
| | - Rastislav Dzijak
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics AS CR, Prague 142 20, Czech Republic Department of Genome Integrity, Institute of Molecular Genetics AS CR, Prague 142 20, Czech Republic
| | - Irina Studenyak
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics AS CR, Prague 142 20, Czech Republic
| | - Jindřiška Fišerová
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics AS CR, Prague 142 20, Czech Republic
| | - Lívia Uličná
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics AS CR, Prague 142 20, Czech Republic
| | - Petr Novák
- Laboratory of Structural Biology and Cell Signaling, Institute of Microbiology AS CR, Prague 142 00, Czech Republic
| | - Pavel Hozák
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics AS CR, Prague 142 20, Czech Republic
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Abstract
Central neurocytoma (CN) is a well-differentiated tumor of neural cells occurring within the ventricles. It is composed of monomorphic cells with round, regular nuclei within clear cytoplasm and must be distinguished from other clear cell tumors. Immunohistochemical markers of CN that aid in diagnosis include synaptophysin and neuronal nuclear antigen. The molecular biology of these tumors is becoming increasingly elucidated, particularly with the use of microarray analyses. Several oncogenic pathways have been suggested by these studies. Although progress continues to be made, knowledge of CN has yet to dictate targeted therapies in treating patients with these tumors.
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Affiliation(s)
- Phillip A Bonney
- Department of Neurosurgery, University of Oklahoma Health Sciences Center, 1000 North Lincoln Boulevard, Suite 4000, Oklahoma City, OK 73104, USA
| | - Lillian B Boettcher
- Department of Neurosurgery, University of Oklahoma Health Sciences Center, 1000 North Lincoln Boulevard, Suite 4000, Oklahoma City, OK 73104, USA
| | - Richard S Krysiak
- Department of Neurosurgery, University of Oklahoma Health Sciences Center, 1000 North Lincoln Boulevard, Suite 4000, Oklahoma City, OK 73104, USA
| | - Kar-Ming Fung
- Department of Pathology, University of Oklahoma Health Sciences Center, 940 Stanton L. Young Boulevard, BMSB 451, Oklahoma City, OK 73104, USA
| | - Michael E Sughrue
- Department of Neurosurgery, University of Oklahoma Health Sciences Center, 1000 North Lincoln Boulevard, Suite 4000, Oklahoma City, OK 73104, USA; Oklahoma Comprehensive Brain Tumor Clinic, Oklahoma City, OK 73104, USA.
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Gan L, Xie L, Zuo F, Xiang Z, He N. Transcriptomic analysis of Rongchang pig brains and livers. Gene 2015; 560:96-106. [PMID: 25637719 DOI: 10.1016/j.gene.2015.01.051] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 12/31/2014] [Accepted: 01/26/2015] [Indexed: 01/01/2023]
Abstract
Recent developments in high-throughput RNA sequencing (RNA-seq) technology have led to a dramatic impact on our understanding of the structure and expression profiles of the mammalian transcriptome. To gain insights into the usefulness of swine production and biomedical model, the transcriptome profiling of Rongchang pig brains and livers was characterized using RNA-seq technology to uncover functional candidate molecules. In the study, total RNAs from brains and livers of Rongchang pig were sequenced and 8.6Gb sequencing data was obtained. This analysis revealed tissue specificity through the identification of 5575 and 4600 differentially expressed genes (DEGs) in brains and livers, respectively and the functional analysis of DEGs. Furthermore, 83 neuropeptide gene transcripts, 69 neuropeptide receptor gene transcripts, 10 pro-neuropeptide convertase gene transcripts and many other neuropeptide related protein gene transcripts were identified. Totally, the major characteristics of the transcriptional profiles of Rongchang pig brains and livers were present.
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Affiliation(s)
- Ling Gan
- The Department of Veterinary Medicine, Rongchang Campus, Southwest University, Rongchang, Chongqing 402460, China.
| | - Liwei Xie
- Center of Molecular Medicine, University of Georgia, Athens, GA 30602, USA.
| | - Fuyuan Zuo
- The Department of Animal Husbandry, Rongchang Campus, Southwest University, Rongchang, Chongqing 402460, China.
| | - Zhonghuai Xiang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing 400715, China.
| | - Ningjia He
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing 400715, China.
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Jiao S, Ren H, Li Y, Zhou J, Duan C, Lu L. Differential regulation of IGF-I and IGF-II gene expression in skeletal muscle cells. Mol Cell Biochem 2013; 373:107-13. [PMID: 23054195 DOI: 10.1007/s11010-012-1479-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 09/26/2012] [Indexed: 12/22/2022]
Abstract
Insulin-like growth factor (IGF)-I and IGF-II play major roles in the regulation of skeletal muscle growth and differentiation, and both are locally expressed in muscle cells. Recent studies have demonstrated that IGF-II up-regulates its own gene expression during myogenesis and this auto-regulatory loop is critical for muscle differentiation. How local IGF-I is regulated in this process is unclear. Here, we report that while IGF-II up-regulated its own gene expression, it suppressed IGF-I gene expression during myogenesis. These opposite effects of IGF-II on IGF-I and IGF-II genes expression were time dependent and dose dependent. It has been shown that IGFs activate the PI3K-Akt-mTOR, p38 MAPK, and Erk1/2 MAPK pathways. In myoblasts, we examined their role(s) in mediating the opposite effects of IGF-II. Our results showed that both the PI3K-Akt-mTOR and p38 MAPK pathways played critical roles in increasing IGF-II mRNA expression. In contrast, mTOR was required for down-regulating the IGF-I gene expression by IGF-II. In addition, Akt, Erk1/2 MAPK, and p38 MAPK pathways were also involved in the regulation of basal levels of IGF-I and IGF-II genes during myogenesis. These findings reveal a previously unrecognized negative feedback mechanism and extend our knowledge of IGF-I and IGF-II gene expression and regulation during myogenesis.
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Chen M, Macpherson A, Owens J, Wittert G, Heilbronn LK. Obesity alone or with type 2 diabetes is associated with tissue specific alterations in DNA methylation and gene expression of PPARGC1A and IGF2. ACTA ACUST UNITED AC 2012. [DOI: 10.7243/2050-0866-1-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Arai M, Kawachi T, Setiawan A, Kobayashi M. Hypoxia-selective growth inhibition of cancer cells by furospinosulin-1, a furanosesterterpene isolated from an Indonesian marine sponge. ChemMedChem 2011; 5:1919-26. [PMID: 20839272 DOI: 10.1002/cmdc.201000302] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
It is generally accepted that cancer cells, which have adapted to the hypoxic environments in tumor tissues, aggravate cancer pathology by promoting tumor growth, angiogenesis, metastasis, and drug resistance. Therefore, compounds that selectively inhibit the growth of tumor cells in hypoxic environments are expected to provide new leads for promising anticancer drugs. Furospinosulin-1, a marine-sponge-derived furanosesterterpene, exhibited selective antiproliferative activity against DU145 human prostate cancer cells under hypoxic conditions in concentrations ranging from 1 to 100 μM. Furospinosulin-1 also demonstrated antitumor activity at 10-50 mg kg(-1) oral administration in a mouse model inoculated with sarcoma S180 cells. Mechanistic analysis revealed that furospinosulin-1 suppresses transcription of the insulin-like growth factor-2 gene (IGF-2), which is selectively induced under hypoxic conditions through prevention of the binding of nuclear proteins to the Sp1 consensus sequence in the IGF-2 promoter region.
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Affiliation(s)
- Masayoshi Arai
- Graduate School of Pharmaceutical Sciences, Osaka University, Yamada-oka 1-6, Suita, Osaka 565-0871, Japan.
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Ba Y, Yu H, Liu F, Geng X, Zhu C, Zhu Q, Zheng T, Ma S, Wang G, Li Z, Zhang Y. Relationship of folate, vitamin B12 and methylation of insulin-like growth factor-II in maternal and cord blood. Eur J Clin Nutr 2011; 65:480-5. [PMID: 21245875 DOI: 10.1038/ejcn.2010.294] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND/OBJECTIVE One of the speculated mechanisms underlying fetal origin hypothesis of breast cancer is the possible influence of maternal environment on epigenetic regulation, such as changes in DNA methylation of the insulin-like growth factor-2 (IGF2) gene. The aim of the study is to investigate the relationship between folate, vitamin B(12) and methylation of the IGF2 gene in maternal and cord blood. SUBJECTS/METHODS We conducted a cross-sectional study to measure methylation patterns of IGF2 in promoters 2 (P2) and promoters 3 (P3). RESULTS The percentage of methylation in IGF2 P3 was higher in maternal blood than in cord blood (P<0.0001), whereas the methylation in P2 was higher in cord blood than in maternal blood (P=0.016). P3 methylation was correlated between maternal and cord blood (P<0.0001), but not P2 (P=0.06). The multivariate linear regression model showed that methylation patterns of both promoters in cord blood were not associated with serum folate levels in either cord or maternal blood, whereas the P3 methylation patterns were associated with serum levels of vitamin B(12) in mother's blood (mean change (MC)=-0.22, P=0.0014). Methylation patterns in P2 of maternal blood were associated with serum levels of vitamin B(12) in mother's blood (MC=-0.23, P=0.012), exposure to passive smoking (MC=0.46, P=0.034) and mother's weight gain during pregnancy (MC=0.23, P=0.019). CONCLUSIONS The study suggests that environment influences methylation patterns in maternal blood, and then the maternal patterns influence the methylation status and levels of folate and vitamin B(12) in cord blood.
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Bebbere D, Bogliolo L, Ariu F, Fois S, Leoni GG, Succu S, Berlinguer F, Ledda S. Different temporal gene expression patterns for ovine pre-implantation embryos produced by parthenogenesis or in vitro fertilization. Theriogenology 2010; 74:712-23. [DOI: 10.1016/j.theriogenology.2010.03.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Revised: 03/23/2010] [Accepted: 03/25/2010] [Indexed: 10/19/2022]
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16
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Lo JH, Chen TT. CCAAT/enhancer binding protein beta2 is involved in growth hormone-regulated insulin-like growth factor-II gene expression in the liver of rainbow trout (Oncorhynchus mykiss). Endocrinology 2010; 151:2128-39. [PMID: 20228168 DOI: 10.1210/en.2009-0960] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Previously, we showed that levels of different CCAAT/enhancer binding protein (C/EBP) mRNAs in the liver of rainbow trout were modulated by GH and suggested that C/EBPs might be involved in GH-induced IGF-II gene expression. As a step toward further investigation, we have developed monospecific polyclonal antibodies to detect rainbow trout C/EBPalpha, -beta1, -beta2, and -delta2 isoform proteins. Injection of GH into adult rainbow trout resulted in a significant increase of C/EBPbeta1, C/EBPbeta2, and C/EBPdelta2 proteins in the liver. Chromatin immunoprecipitation analysis revealed that C/EBPbeta2 binds to multiple sites at the 5' promoter/regulatory region, introns, and the 3' untranslated region of the IGF-II gene. GH treatment reduced C/EBPbeta2 binding to several of these regions at 6 h after injection. The decreased occupancy of C/EBPbeta2 coincided well with an increase of histone H4 acetylation at the proximal promoter and elevation of the IGF-II mRNA level. Immunoblotting analysis showed that C/EBPbeta2 existed predominately as a truncated form in the liver, and cotransfection analysis further showed that the truncated C/EBPbeta2 acted as a negative regulator on IGF-II proximal promoter. GH treatment caused deacetylation of C/EBPbeta2 in the liver. In addition, we observed a GH-dependent interaction of C/EBPbeta2 with a complex involving histone H1. All together, these results suggest that C/EBPbeta2 was regulated at multiple levels by GH, and C/EBPbeta2 may play a suppressive role in mediating GH-induced IGF-II expression in the liver of rainbow trout.
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Affiliation(s)
- Jay H Lo
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269, USA
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17
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PELLEGRINI M, ARGIBAY P, GOMEZ D. Dietary factors, genetic and epigenetic influences in colorectal cancer. Exp Ther Med 2010; 1:241-250. [PMID: 22993535 PMCID: PMC3445943 DOI: 10.3892/etm_00000038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Accepted: 11/10/2009] [Indexed: 01/05/2023] Open
Abstract
Genetic influences, together with epigenetic components and dietary factors, play a fundamental role in the initiation and progression of cancer by causing a number of deregulations. Colorectal cancer (CRC) is a disease influenced by dietary factors, for which established genetic and epigenetic alterations have been identified. Within CRC, there are hereditary syndromes that present mutations in the germ-line hMLH1, and also alterations in the methylation of the promoters. Epigenetics has also been established as a pathway of carcinogenesis. In the present review, we analyzed studies conducted to discern the different pathways leading to established CRC, stressing the importance of identifying factors that may predict CRC at an early stage, since it is mostly a silent disease observed at the clinical level in advanced stages.
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Affiliation(s)
- M.L. PELLEGRINI
- Instituto de Ciencias Básicas y Medicina Experimental, Hospital Italiano de Buenos Aires
| | - P. ARGIBAY
- Instituto de Ciencias Básicas y Medicina Experimental, Hospital Italiano de Buenos Aires
| | - D.E. GOMEZ
- Laboratorio de Oncología Molecular, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Buenos Aires,
Argentina
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18
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Souren NY, Paulussen AD, Steyls A, Loos RJ, Brandao RD, Gielen M, Smeets HJ, Beunen G, Fagard R, Derom C, Vlietinck R, Geraedts JP, Zeegers MP. Parent-of-origin specific linkage and association of the IGF2 gene region with birth weight and adult metabolic risk factors. Int J Obes (Lond) 2009; 33:962-70. [PMID: 19546867 DOI: 10.1038/ijo.2009.126] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
OBJECTIVE The maternally imprinted insulin-like growth factor 2 (IGF2) gene is an important fetal growth factor and is also suggested to have postnatal metabolic effects. In this study, we examined whether common polymorphisms in IGF2 (6815_6819delAGGGC, 1156T>C and 820G>A (ApaI)) and a microsatellite marker in the close vicinity of IGF2 were linked to or associated with birth weight and adult metabolic risk factors. DESIGN AND PARTICIPANTS Polymorphisms were genotyped in 199 monozygotic complete twin pairs, 109 dizygotic complete twin pairs, 15 single twins, 231 mothers and 228 fathers recruited from the East Flanders Prospective Twin Survey. Conventional and parent-of-origin specific linkage and association analyses were carried out with birth weight, adult body height and parameters quantifying obesity, insulin sensitivity and dyslipidaemia measured at adult age (mean age 25 years). RESULTS In the parent-of-origin specific association analysis, in which only the paternally inherited allele was incorporated, the 1156T>C SNP (single nucleotide polymorphism) showed significant association with IGF-binding protein 1 (IGFBP1) levels (T and C (mean (95% CI)): 13.2 (12.1-14.3) and 16.2 (14.6-18.0) ng ml(-1), P=0.002). No linkage was observed in either the conventional or in the parent-of-origin specific linkage analysis. CONCLUSION This study suggests that paternally inherited alleles of a common polymorphism in the IGF2 gene affect IGFBP1 levels.
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Li C, Bin Y, Curchoe C, Yang L, Feng D, Jiang Q, O'Neill M, Tian XC, Zhang S. Genetic imprinting of H19 and IGF2 in domestic pigs (Sus scrofa). Anim Biotechnol 2008; 19:22-7. [PMID: 18228173 DOI: 10.1080/10495390701758563] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The genes insulin-like growth factor 2 (IGF2) and H19 express paternally and maternally, respectively, in humans, mice, sheep, and cattle. Additionally, IGF2 has been shown to be regulated by at least four promoters in a tissue- or development-specific manner. In the domestic pigs, the promoter- and tissue-specific imprinting pattern of IGF2 has not been well characterized, nor is the imprinting pattern of H19. In the present study, we identified two polymorphisms in each of IGF2 (exons 2 and 9) and H19 (exons 1 and 5) and determined the imprinting status of these two genes in 13 organs / tissues of week-old pigs. IGF2 P1 transcript is bi-allelically expressed (not imprinted) in all major organs studied, while the majority of IGF2 transcripts are expressed from promoters 2-4 and are imprinted. H19 is exclusively expressed from the maternal allele in all major organs, concurrent with observations in other species.
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Affiliation(s)
- Chao Li
- College of Animal Science, South China Agricultural University, Guangzhou, People's Republic of China
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20
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Abstract
Loss of imprinting (LOI) is a common epigenetic event in cancer and may serve as an early biomarker in some cancers. To obtain a better understanding of LOI, we studied 41 bladder tumors and their adjacent normal bladder mucosa. We found 2/9 (22.2%) cases that displayed LOI of IGF2 and 2/16 (12.5%) that had LOI of H19, as determined by the evaluation of mRNA for biallelic expression. In addition, we examined allele-specific methylation of the differentially methylated regions (DMR) of IGF2 and H19 using a new allele-specific pyrosequencing assay. We found that DNA methylation changes were a common finding (21/30, 70%) in the DMR regions, but could not clearly link DNA methylation changes with LOI as measured by biallelic expression. LOI and allele-specific DNA methylation changes are present in bladder cancer; however, a better understanding of the biology of LOI and its relationship to DNA methylation changes is needed before its use as an epigenetic biomarker.
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Affiliation(s)
- Hyang-Min Byun
- Division of Hematology, University of Southern California/Norris Comprehensive Cancer Center, Los Angeles, California 90033, USA
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21
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Engström W, Shokrai A, Otte K, Granérus M, Gessbo A, Bierke P, Madej A, Sjölund M, Ward A. Transcriptional regulation and biological significance of the insulin like growth factor II gene. Cell Prolif 2007; 31:173-89. [PMID: 9925986 PMCID: PMC6647699 DOI: 10.1111/j.1365-2184.1998.tb01196.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The insulin like growth factors I and II are the most ubiquitous in the mammalian embryo. Moreover they play a pivotal role in the development and growth of tumours. The bioavailability of these growth factors is regulated on a transcriptional as well as on a posttranslational level. The expression of non-signalling receptors as well as binding proteins does further tune the local concentration of IGFs. This paper aims at reviewing how the transcription of the IGF genes is regulated. The biological significance of these control mechanisms will be discussed.
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Affiliation(s)
- W Engström
- Department of Pathology, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala, Sweden
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22
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Flisikowski K, Adamowicz T, Strabel T, Jankowski T, Switonski M, Zwierzchowski L. An InDel polymorphism in exon 6 of IGF2 associated with the breeding value of Polish Holstein-Friesian bulls. Biochem Genet 2007; 45:139-43. [PMID: 17242995 DOI: 10.1007/s10528-006-9071-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- K Flisikowski
- Institute of Genetics and Animal Breeding, Jastrzebiec, 05-552 Wólka Kosowska, Poland.
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23
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Beeghly AC, Katsaros D, Wiley AL, Rigault de la Longrais IA, Prescott AT, Chen H, Puopolo M, Rutherford TJ, Yu H. IGF-II promoter methylation and ovarian cancer prognosis. J Cancer Res Clin Oncol 2007; 133:713-23. [PMID: 17569086 DOI: 10.1007/s00432-007-0211-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2006] [Accepted: 03/23/2007] [Indexed: 12/22/2022]
Abstract
PURPOSE The insulin-like growth factor-II (IGF-II) gene has four promoters that produce distinct transcripts which vary by tissue type and developmental stage. Dysregulation of normal promoter usage has been shown to occur in cancer; DNA methylation regulates promoter use. Thus, we sought to examine if DNA methylation varies among IGF-II promoters in ovarian cancer and if methylation patterns are related to clinical features of the disease. STUDY DESIGN Tumor tissue, clinical data, and follow-up information were collected from 215 patients diagnosed with primary epithelial ovarian cancer. DNA extracted from tumor tissues was analyzed for IGF-II promoter methylation with seven methylation specific PCR (MSP) assays: three for promoter 2 (P2) and two assays each for promoters 3 and 4 (P3 and P4). RESULTS Methylation was found to vary among the seven assays: 19.3% in P2A, 45.6% in P2B, 50.9% in P2C, 48.4% in P3A, 13.1% in P3B, 5.1% in P4A, and 6.1% in P4B. Methylation in any of the three P2 assays was associated with high tumor grade (P = 0.043), suboptimal debulking (P = 0.036), and disease progression [hazards ratio (HR) = 1.73, 95% confidence interval (CI) 1.09-2.74]. When comparing promoter methylation patterns, differential methylation of P2 and P3 was found to be associated with disease prognosis; patients with P3 but not P2 methylation were less likely to have disease progression (HR = 0.39, 95% CI 0.17-0.91) compared to patients with P2 but not P3 methylation. CONCLUSIONS This study shows that methylation varies among three IGF-II promoters in ovarian cancer and that this variation seems to have biologic implications as it relates to clinical features and prognosis of the disease.
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Affiliation(s)
- A C Beeghly
- Department of Epidemiology and Public Health, Yale University School of Medicine, 60 College Street, New Haven, CT, 06520-8034, USA
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24
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Kraaij R, van der Weel L, de Ridder CMA, van der Korput HAGM, Zweistra JLM, van Rijswijk ALCT, Bangma CH, Trapman J. A small chimeric promoter for high prostate-specific transgene expression from adenoviral vectors. Prostate 2007; 67:829-39. [PMID: 17394196 DOI: 10.1002/pros.20560] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Specificity of transgene expression is important for safety during gene therapeutical applications. For prostate cancer, transcriptional targeting has been applied but was hampered by loss of specificity and low activity. We constructed a small chimeric promoter for high and prostate-specific transgene expression from adenoviral vectors. METHODS A chimeric promoter, composed of the prostate-specific antigen (PSA) enhancer and the rat probasin promoter, was cloned into an adenoviral vector and its activity was compared to vectors containing conventional prostate-specific promoters and the constitutive Cytomegalovirus (CMV) promoter in in vitro and in vivo prostate cancer models. RESULTS The chimeric PSA-probasin promoter was the most active prostate-specific promoter reaching up to 20% of CMV promoter activity while maintaining prostate-specificity. CONCLUSIONS The chimeric PSA-probasin promoter is a small promoter that can be utilized in viral vectors for high prostate-specific transgene expression.
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Affiliation(s)
- Robert Kraaij
- Department of Urology, Erasmus MC, Rotterdam, The Netherlands.
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25
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Monk D, Sanches R, Arnaud P, Apostolidou S, Hills FA, Abu-Amero S, Murrell A, Friess H, Reik W, Stanier P, Constância M, Moore GE. Imprinting of IGF2 P0 transcript and novel alternatively spliced INS-IGF2 isoforms show differences between mouse and human. Hum Mol Genet 2006; 15:1259-69. [PMID: 16531418 DOI: 10.1093/hmg/ddl041] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Genomic imprinting is limited to a subset of genes that play critical roles in fetal growth, development and behaviour. One of the most studied imprinted genes encodes insulin-like growth factor 2, and aberrant imprinting and DNA methylation of this gene is associated with the growth disorders Beckwith-Wiedemann and Silver-Russell syndromes and many human cancers. Specific isoforms of this gene have been shown to be essential for normal placental function, as mice carrying paternal null alleles for the Igf2-P0 transcript are growth restricted at birth. We report here the identification of three novel human transcripts from the IGF2 locus. One is equivalent to the mouse Igf2-P0 transcript, whereas the two others (INSIGF long and short) originate from the upstream INS gene that alternatively splices to downstream IGF2 exons. In order to elucidate the molecular mechanisms involved in the complex imprinting of these novel IGF2 transcripts, both the allele-specific expression and methylation for all the IGF2 promoters including P0 and the INSIGF transcripts were analysed in human tissues. Similar to the mouse, the human IGF2-P0 transcript is paternally expressed; however, its expression is not limited to placenta. This expression correlates with tissue-specific promoter methylation on the maternal allele. The two novel INSIGF transcripts reported here use the INS promoter and show highly restricted tissue expression profiles including the pancreas. As previously reported for INS in the yolk sac, we demonstrate complex, tissue-specific imprinting of these transcripts. The finding of additional transcripts within this locus will have important implications for IGF2 regulation in both cancer and metabolism.
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Affiliation(s)
- D Monk
- Institute of Reproductive and Developmental Biology, Imperial College London, London W12 0NN, UK.
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26
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Curchoe C, Zhang S, Bin Y, Zhang X, Yang L, Feng D, O'Neill M, Tian XC. Promoter-specific expression of the imprinted IGF2 gene in cattle (Bos taurus). Biol Reprod 2005; 73:1275-81. [PMID: 16120826 DOI: 10.1095/biolreprod.105.044727] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The domestic cattle (Bos taurus) has been a good animal model for embryo biotechnologies, such as in vitro fertilization and nuclear transfer. However, animals produced from these technologies often suffer from large-calf syndrome, suggesting fetal growth disregulation. The product of the insulin-like growth factor 2 (IGF2) gene is one of the most important fetal mitogens known to date. A detailed analysis of age-, tissue-, and allele-specific expression of IGF2 has not been performed in the bovine mainly because the majority of the bovine sequence has been unavailable. In the present study, we obtained virtually the entire sequence of the bovine IGF2 cDNA, identified expressed single-nucleotide polymorphisms (SNPs) in both exons 3 and 10, and determined the age-, tissue-, and promoter-specific expression of bovine IGF2 in fetal, calf, and adult tissues. We found that, similar to the human and mouse, bovine IGF2 is subjected to extensive transcriptional regulation through multiple promoters, alternative splicing and polyadenylation, as well as genetic imprinting. However, major differences were found in the regulation of the bovine IGF2 in nearly all aspects of age-, tissue-, promoter-, and allele-specific expression of IGF2, and the promoter-specific loss of imprinting from every other species studied, including cattle's close relatives, the sheep and the pig. The data presented here are of important reference value to cattle produced from embryo biotechnologies.
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Affiliation(s)
- Carol Curchoe
- Department of Animal Science/Center for Regenerative Biology, University of Connecticut, Storrs 06269, USA
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27
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Hartmann W, Koch A, Brune H, Waha A, Schüller U, Dani I, Denkhaus D, Langmann W, Bode U, Wiestler OD, Schilling K, Pietsch T. Insulin-like growth factor II is involved in the proliferation control of medulloblastoma and its cerebellar precursor cells. Am J Pathol 2005; 166:1153-62. [PMID: 15793295 PMCID: PMC1602379 DOI: 10.1016/s0002-9440(10)62335-8] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Medulloblastomas (MBs), the most frequent malignant brain tumors of childhood, presumably originate from cerebellar neural precursor cells. An essential fetal mitogen involved in the pathogenesis of different embryonal tumors is insulin-like growth factor II (IGF-II). We screened human MB biopsies of the classic (CMB) and desmoplastic (DMB) variants for IGF2 transcripts of the four IGF2 promoters. We found IGF2 transcription from the imprinted promoter P3 to be significantly increased in the desmoplastic variant compared to the classic subgroup. This was not a result of loss of imprinting of IGF2 in desmoplastic tumors. We next examined the interaction of IGF-II and Sonic hedgehog (Shh), which serves as a critical mitogen for cerebellar granule cell precursors (GCPs) in the external granule cell layer from which DMBs are believed to originate. Mutations of genes encoding components of the Shh-Patched signaling pathway occur in approximately 50% of DMBs. To analyze the effects of IGF-II on Hedgehog signaling, we cultured murine GCP and human MB cells in the presence of Shh and Igf-II. In GCPs, a synergistic effect of Shh and Igf-II on proliferation and gli1 and cyclin D1 mRNA expression was found. Igf-II, but not Shh, induced phosphorylation of Akt and its downstream target Gsk-3beta. In six of nine human MB cell lines IGF-II displayed a growth-promoting effect that was mediated mainly through the IGF-I receptor. Together, our data point to an important role of IGF-II for the proliferation control of both cerebellar neural precursors and MB cells.
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Affiliation(s)
- Wolfgang Hartmann
- Department of Neuropathology, University of Bonn Medical Center, Sigmund-Freud-St. 25, D-53105 Bonn, Germany
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28
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Zatkova A, Rouillard JM, Hartmann W, Lamb BJ, Kuick R, Eckart M, von Schweinitz D, Koch A, Fonatsch C, Pietsch T, Hanash SM, Wimmer K. Amplification and overexpression of the IGF2 regulator PLAG1 in hepatoblastoma. Genes Chromosomes Cancer 2004; 39:126-37. [PMID: 14695992 DOI: 10.1002/gcc.10307] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
There is evidence that 8q amplification is associated with poor prognosis in hepatoblastoma. A previous comparative genomic hybridization analysis identified a critical region in chromosomal bands 8q11.2-q13. Using restriction landmark genomic scanning in combination with a virtual genome scan, we showed that this region is delineated by sequences within contig NT_008183 of chromosomal subbands 8q11.22-q11.23. A real-time PCR-based genomic copy number assay of 20 hepatoblastomas revealed gain or amplification in this critical chromosomal region in eight tumors. The expression of four genes and expressed sequence tags (ESTs) within this newly defined region was assayed by real-time reverse transcriptase polymerase chain reaction (RT-PCR) in four tumors with and six tumors without gain or amplification. The PLAG1 oncogene was found to be highly expressed in all but one tumor compared to normal liver tissue. Furthermore, quantitative RT-PCR revealed that the expression level of the developmentally regulated transcription factor PLAG1 was 3-12 times greater in hepatoblastoma tumors and cell lines compared to age-matched normal liver and comparable to the expression in fetal liver tissue. PLAG1 has been shown be a transcriptional activator of IGF2 in other tumor types. Using luciferase reporter assays, we demonstrated that PLAG1 transactivates transcription from the embryonic IGF2 promoter P3, also in hepatoblastoma cell lines. Thus, our results provide evidence that PLAG1 overexpression may be responsible for the frequently observed up-regulation of IGF2 in hepatoblastoma and therefore may be implicated in the molecular pathogenesis of this childhood neoplasia.
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Affiliation(s)
- Andrea Zatkova
- Institut für Medizinische Biologie, Universität Wien, Vienna, Austria
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29
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Abstract
Carboxylesterases are a broad class of enzymes important in the detoxification of many ester- or amide-bond containing xenobiotics. They also activate analgesics, anticancer prodrugs, and other biologically active compounds, such as cocaine and heroin. The objective of this work was to identify the CES2 gene structure, complex 5' untranslated regions and three potential promoters for the initiation of transcription in different human tissues. Using bioinformatics and progressive reverse transcriptase-polymerase chain reaction, we found that the 5' untranslated region is more than 1100 bases longer than previously reported. Rapid amplification of cDNA ends showed three distinctive transcription start sites at -74, -629 and -1187. DNA fragments upstream of each of the three transcription start sites were found to be transcriptionally active in HepG2 cells. The distal promoter is active in both orientations, suggesting its potential role in the transcription of another gene, CGI-128, located immediately upstream to the distal promoter in the opposite direction with respect to CES2. Hybridization analyses showed that CES2 is highly expressed in the heart, skeletal muscle, colon, spleen, kidney and liver, but considerably less expressed in fetal tissues (e.g. fetal heart, kidney, spleen, and liver) and cancer cells. It is also evident that the distal promoter is responsible for low level expression of the gene in many tissues, whereas the other two promoters are tissue specific. These findings shed some light on CES2 gene regulation, a gene important in the metabolism of many drugs.
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Affiliation(s)
- Michael H Wu
- Section of Haematology/Oncology, Department of Medicine, University of Chicago, Chicago, Illinois 60637-1470, USA
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30
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Jouvenot Y, Ginjala V, Zhang L, Liu PQ, Oshimura M, Feinberg AP, Wolffe AP, Ohlsson R, Gregory PD. Targeted regulation of imprinted genes by synthetic zinc-finger transcription factors. Gene Ther 2003; 10:513-22. [PMID: 12621455 DOI: 10.1038/sj.gt.3301930] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Epigenetic control of transcription is essential for mammalian development and its deregulation causes human disease. For example, loss of proper imprinting control at the IGF2-H19 domain is a hallmark of cancer and Beckwith-Wiedemann syndrome, with no targeted therapeutic approaches available. To address this deficiency, we engineered zinc-finger transcription proteins (ZFPs) that specifically activate or repress the IGF2 and H19 genes in a domain-dependent manner. Importantly, we used these ZFPs successfully to reactivate the transcriptionally silent IGF2 and H19 alleles, thus overriding the natural mechanism of imprinting and validating an entirely novel avenue for 'transcription therapy' of human disease.
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Affiliation(s)
- Y Jouvenot
- Sangamo BioSciences, Inc., Point Richmond Tech Center, Richmond, CA 94804, USA
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31
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Abstract
Elafin (also known as skin-derived anti-leukoproteinase/trappin-2) is an epithelial host-defense protein that is absent in normal skin but highly induced in keratinocytes of inflamed skin (e.g., psoriasis), in epidermal skin tumors, and after wounding. Previously, it was shown that in cultured keratinocytes, elafin expression is induced by serum or tumor necrosis factor-alpha, and that expression is suppressed by retinoids, dithranol, and p38 mitogen-activated protein kinase inhibitors. Here we have studied the regulation of elafin gene expression in epidermal keratinocytes at the molecular level. First we determined the transcription start site of the elafin gene and found that the elafin mRNA possesses an unusually short 5'-untranslated region. Using transient transfection of luciferase reporter constructs of the elafin promoter, we mapped a 440 bp region upstream of the translation start site that conferred high-level expression in keratinocytes, but not in A431 cells or cells of mesenchymal origin. We observed that the promoter constructs were not subjected to the same regulation as the endogenous elafin gene as these constructs were highly active independent of keratinocyte stimulation. When elafin promoter constructs were stably transfected in the HaCaT keratinocyte cell line, tumor necrosis factor-alpha inducible expression of both the endogenous elafin gene and the transgene was observed, suggesting that regulation of the elafin gene is also dependent on chromatin structure. We found, however, that a stably transfected 4 kb elafin promoter fragment did not confer retinoid sensitivity indicating that additional sequences are required for proper regulation. This study reveals the complex regulation of a gene that can be used as a paradigm for the specific differentiation program of activated epidermal keratinocytes.
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Affiliation(s)
- Arno Pol
- Department of Dermatology, University Medical Center St Radboud, Nijmegen, The Netherlands.
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Eriksson T, Frisk T, Gray SG, von Schweinitz D, Pietsch T, Larsson C, Sandstedt B, Ekström TJ. Methylation changes in the human IGF2 p3 promoter parallel IGF2 expression in the primary tumor, established cell line, and xenograft of a human hepatoblastoma. Exp Cell Res 2001; 270:88-95. [PMID: 11597130 DOI: 10.1006/excr.2001.5336] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Hepatoblastoma (HB) is a rare malignant embryonal liver tumor. Its pathogenesis has been associated with altered regulation of the IGF2 and H19 genes, and previous studies have suggested a correlation between abnormal methylation and altered expression of these genes in hepatoblastoma. Upregulation of the activity of the IGF2 promoter P3 has previously been shown to be tightly correlated with demethylation in hepatoblastoma. Here, we have used bisulfite genomic sequencing to characterize the methylation pattern of the IGF2 promoter P3 in the hepatoblastoma-derived cell line Hep T1, in the original tumor from which Hep T1 is derived, and in nude mouse xenografts of the Hep T1 cell line. The results show a clear difference in methylation pattern of the most proximal region of the IGF2 P3 promoter between the primary tumor, the cell line, and the xenografts. RNase protection and mRNA in situ hybridization revealed that variations in methylation patterns was paralleled by the levels of IGF2 P3 mRNA, which was detectable in the primary tumor and xenografts, but not in the cell line. Furthermore, it was demonstrated that H19 was reactivated and demethylated in the HepT1 cell line by 5-azaCytidine, in contrast to IGF2 P3, which was not demethylated or reactivated. We suggest that methylation of the proximal IGF2 P3 is important for its regulation.
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Affiliation(s)
- T Eriksson
- Laboratory for Molecular Development and Tumor Biology, Experimental Alcohol and Drug Addicition Research Section, Department of Clinical Neuroscience, Karolinska Institutet, CMM, L8:01, Stockholm, S-171 76, Sweden
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Dai B, Wu H, Holthuizen E, Singh P. Identification of a novel cis element required for cell density-dependent down-regulation of insulin-like growth factor-2 P3 promoter activity in Caco2 cells. J Biol Chem 2001; 276:6937-44. [PMID: 11112775 DOI: 10.1074/jbc.m007789200] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The activity of the exogenous, full-length insulin-like growth factor-2 (IGF-2) P3 promoter is significantly up-regulated during the logarithmic growth phase but rapidly declines in confluent CaCo2 cells undergoing differentiation. Nuclear run-on assays confirmed cell density-dependent regulation of endogenous P3 promoter. To identify regulatory elements in the P3 promoter that may be required for regulating cell density-dependent transcriptional activity, we used the methods of promoter truncation, electrophoretic mobility shift assay, DNase footprinting, and mutation analysis. The relative activity of the full-length (-1229/+140) and truncated (-1090/+140) promoter was identical, being approximately 19, 27, 7, and 3% of pSV-luc activity on days 3, 5, 7, and 9 of cell culture, respectively. However, truncation to -1048 resulted in complete loss of cell density-dependent down-regulation of P3 promoter activity on days 7 and 9, suggesting the presence of regulatory elements between -1091 and -1048 sequence. Further stepwise truncation to -515 did not change promoter activity. Truncation to -138/+140 resulted in complete loss of promoter activity, suggesting that the core promoter was within the -515/-138 segment. A 14-base pair footprint (-1084/-1070) was identified by DNase footprinting within the distal -1091/-1048 segment. Electrophoretic mobility shift assay with wild type and mutant probes confirmed the presence of a novel 7-base pair (CGAGGGC) (-1084/-1078) cis element (P3-D); its mutation abolished binding. Functionality of P3-D cis element was confirmed by measuring the activity of core P3 promoter ligated to distal P3 segment containing either the mutant or wild type P3-D element. We have, therefore, identified a novel cis element, P3-D, that appears to play a critical role in regulating IGF-2 P3 promoter activity in a cell density/differentiation-dependent manner.
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Affiliation(s)
- B Dai
- Department of Anatomy and Neurosciences, The University of Texas Medical Branch, Galveston, Texas 77555-1043, USA
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Abstract
The chum salmon insulin-like growth factor II (IGF-II) gene is highly expressed in liver tissue. In this study we demonstrate that two transcription factors, Sp1 and C/EBPbeta, are involved in the enhanced expression of the salmon IGF-II gene. The presence of the fish homolog for C/EBPbeta in salmon liver RNA was confirmed by Northern blotting. The sIGF-II promoter was activated up to 20-fold by co-transfection with C/EBPbeta. The functional importance of four out of the five putative C/EBPbeta binding sites was demonstrated with mutational analysis in transient transfection assays. The transcription factor Sp1 binds to two sites within the salmon IGF-II promoter. Interestingly, mutation of the Sp1 binding sites decreases not only the basal IGF-II promoter activity but also the C/EBPbeta-induced transactivation. These results demonstrate that liver-enriched C/EBPbeta and ubiquitously expressed Sp1 each activate the sIGF-II promoter and that Sp1 is required for full transactivation of the sIGF-II gene by C/EBPbeta. This suggests that C/EBPbeta and Sp1 act in synergy.
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Affiliation(s)
- A Y Palamarchuk
- Laboratory for Physiological Chemistry, University Medical Center, Universiteitsweg 100, 3584 CG, Utrecht, The Netherlands
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Svaren J, Ehrig T, Abdulkadir SA, Ehrengruber MU, Watson MA, Milbrandt J. EGR1 target genes in prostate carcinoma cells identified by microarray analysis. J Biol Chem 2000; 275:38524-31. [PMID: 10984481 DOI: 10.1074/jbc.m005220200] [Citation(s) in RCA: 142] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The EGR1 transactivator is overexpressed in prostate cancer, and its expression pattern suggests that EGR1 could potentially regulate a number of steps involved in initiation and progression of prostate cancer, such as mitogenesis, invasiveness, angiogenesis, and metastasis. To identify potential EGR1 target genes in an unbiased manner, we have utilized adenovirus-mediated expression of EGR1 in a prostate cancer cell line to identify specific genes that are induced by EGR1. Using oligonucleotide arrays, a number of EGR1-regulated genes were identified and their regulation was confirmed by quantitative reverse transcription-polymerase chain reaction analysis. One of the largest gene classes identified in this screen includes several neuroendocrine-associated genes (neuron-specific enolase, neurogranin), suggesting that EGR1 overexpression may contribute to the neuroendocrine differentiation that often accompanies prostate cancer progression. This screen also identified several growth factors such as insulin-like growth factor-II, platelet-derived growth factor-A, and transforming growth factor-beta1, which have previously been implicated in enhancing tumor progression. The insulin-like growth factor-II gene lies within the 11p15.5 chromosomal locus, which contains a number of other imprinted genes, and EGR1 expression was found to induce at least two other genes in this locus (IPL, p57(KIP2)). Based on our results, coupling adenoviral overexpression with microarray and quantitative reverse transcription-polymerase chain reaction analyses could be a versatile strategy for identifying target genes of transactivators.
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Affiliation(s)
- J Svaren
- Departments of Pathology and Internal Medicine, Division of Laboratory Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Abstract
The genomic imprinting of the maternal allele defines the monoallelic expression of the IGF-II gene in most human tissues. The loss of imprinting (LOI) leading to biallelic overexpression of IGF-II has been reported in several human malignancies, including uterine leiomyosarcoma. To ascertain if LOI occurs in endometrial malignancies, the allelic expression of the IGF-II gene was examined in samples of normal human endometrium (n=22) and endometrial tumors (n=12) by assessing the ApaI polymorphism in cDNA segments amplified by RT-PCR. The biallelic overexpression of IGF-II mRNA, involving activation of all four (P1-P4) promoters, was detected in one normal endometrium and in one endometrial carcinosarcoma. Low level biallelic expression of IGF-II was also detected in two samples of hormone-unresponsive/Type II endometrial carcinomas. The level of IGF-I mRNA in these four samples was low. The IGF-IR mRNA was overexpressed in all endometrial cancers including the carcinosarcoma sample, but not in normal endometrium. These data suggest that LOI associated with overexpression of IGF-II and concomitant overexpression of IGF-IR may play a role in the rare carcinosarcoma of the endometrium.
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Affiliation(s)
- R N Roy
- Department of Obstetrics and Gynecology, St. Michael's Hospital, 30 Bond Street, Toronto, Ontario, Canada
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Abstract
The two contiguous IGF2 (human insulin-like growth factor II) and H19 genes are reciprocally imprinted in both human and mouse. In most tissues, IGF2 is transcribed only from the paternal chromosome while H19 is transcribed only from the maternal allele. The presence of a differential methylation region (DMR) on the two parental alleles at the 5' flanking region of H19 has been proposed to constitute the gametic imprint, which controls the reciprocal allelic expression of the two genes. Using bisulfite genomic sequencing, we have assessed the methylation status of cytosine (including 154 CpG sites) in six CpG-rich regions of the human IGF2-H19 genes. In a CpG island near promoter P3 of the IGF2 gene, more than 99.8% of all cytosines were converted to thymidine by sodium bisulfite mutagenesis, indicating that none of the CpGs was methylated. In the IGF2 exon 8-9 region, mosaic methylation of 56 CpG sites was observed in fetal tissues and in adult blood DNA. In contrast to the mosaic methylation of IGF2, the allelic methylation of the human H19 DMR was uniform. In the CpG region located 2 kb upstream (-2362 to -1911) of the H19 transcription site, all 25 CpG sites were completely methylated on only one parental allele. Uniform allele-specific methylation was also observed in the CpG island proximal to the H19 promoter (-711 to -290) with complete methylation of all 25 CpG sites in one parental allele. In contrast, the CpG region in the H19 promoter (-292 to +15) was mosaically methylated in all tissues. In addition, cytosine was methylated at three CpNpG and GpNpC sites on the top DNA strand and one CpNpG site on the bottom DNA strand from the fetal brain. The cytosines at CpG sites were methylated on both DNA strands (symmetric methylation) while cytosines at the CpNpG and GpNpC sites were methylated on only one DNA strand (asymmetric methylation). The asymmetric methylation was associated with tissue-specific disruption of H19 genomic imprinting in fetal brain.
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Affiliation(s)
- T H Vu
- Medical Service and GRECC, Stanford University School of Medicine, Palo Alto, California 94304, USA.
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Mineo R, Fichera E, Liang SJ, Fujita-Yamaguchi Y. Promoter usage for insulin-like growth factor-II in cancerous and benign human breast, prostate, and bladder tissues, and confirmation of a 10th exon. Biochem Biophys Res Commun 2000; 268:886-92. [PMID: 10679300 DOI: 10.1006/bbrc.2000.2225] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Upregulation of insulin-like growth factor (IGF)-II expression has been reported for a variety of childhood and adulthood tumors. We determined IGF-II gene promoter usage in human cancerous and benign tissues by semiquantitative RT-PCR using P1-P4-specific primers. Although the human IGF-II gene structure is commonly thought to consist of nine exons and four promoters, we detected substantial utilization of a previously reported exon 4b, which is downstream of exon 4. Thus, exon 4b was intensively studied using 4b-specific primers. IGF-II gene promoter usage is highly variable in malignant and benign breast, prostate, and bladder tissues. While a majority of samples utilized P2-P4 promoters in a variety of combinations, when quantitated, P3 and P4 promoters were much more active than P2 promoter. This study not only demonstrated that IGF-II gene promoter usage is highly variable in malignant and benign tissues, but suggested that alternatively spliced exon 4b should be recognized as a 10th exon.
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Affiliation(s)
- R Mineo
- Department of Molecular Biology, Beckman Research Institute of the City of Hope, Duarte, California 91010, USA
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Abstract
Rhabdomyosarcomas are characterized by loss of heterozygosity (LOH) at chromosome region 11p15.5, a region known to contain several imprinted genes including insulin-like growth factor 2 (IGF2), H19, and p57(KIP2). We analyzed 48 primary tumour samples and found distinct genetic changes at 11p15.5 in alveolar and embryonal histological subtypes. LOH was a feature of embryonal tumours, but at a lower frequency than previous studies. Loss of imprinting (LOI) of the IGF2 gene was detected in 6 of 13 informative cases, all harbouring PAX3-FKHR or PAX7-FKHR fusion genes characteristic of alveolar histology. In contrast, H19 imprinting was maintained in 14 of 15 informative cases and the case with H19 LOI had maintenance of the IGF2 imprint indicating separate mechanisms controlling imprinting of IGF2 and H19. The adult promoter of IGF2, P1, was used in 5 of 14 tumours and its expression was unrelated to IGF2 imprinting status implying a further mechanism of altered IGF2 regulation. The putative tumour suppressor gene p57(KIP2) was expressed in 15 of 29 tumours and expression was unrelated to allele status. Moreover, in tumours with p57(KIP2) expression, there was no evidence for inactivating mutations, suggesting that p57(KIP2) is not a tumour suppressor in rhabdomyosarcoma.
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Affiliation(s)
- J Anderson
- Section of Paediatric Oncology, Institute of Cancer Research, Sutton, Surrey, UK.
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Abstract
BACKGROUND/AIM Genomic imprinting is a chromosomal modification causing differential expression of maternal and paternal alleles. Loss of imprinting (LOI) of IGF-II and H19 has been suggested to be an early oncogenic event in cancerogenesis. Aim of the present study was to describe the status of IGF-II and H19 imprinting in adult human pancreatic tissues. METHODS Allele-specific gene expression was studied using RNA and DNA from human pancreatic cancer, chronic pancreatitis, and normal pancreas tissues heterozygous for ApaI (IGF-II) or RsaI (H19) restriction fragment length polymorphism. Reverse-transcriptase polymerase chain reaction products were digested with either ApaI or RsaI and analyzed on agarose gels to study the status of allelic expression. The expression level of H19 and IGF-II was studied on Northern blots or by polymerase chain reaction. RESULTS H19 was imprinted in normal pancreas and in chronic pancreatitis. H19 LOI was observed in 1 of 4 informative cancer tissues and was not associated with increased H19 transcript levels. Biallelic expression of IGF-II was found in 6 of 10 informative cancer tissues and in 6 of 9 informative normal tissues. In chronic pancreatitis, the IGF-II gene was imprinted in all informative samples. IGF-II mRNA was not overexpressed in the tissues showing LOI. CONCLUSION Low frequencies of H19 LOI and the lack of correlation between biallelic expression and overexpression observed for both H19 and IGF-II suggest that LOI of H19 and IGF-II is not a relevant oncogenic factor during human exocrine pancreatic cancerogenesis.
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Affiliation(s)
- A E Micha
- Department of Internal Medicine I, University of Ulm, Germany
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Scharnhorst V, Dekker P, van der Eb AJ, Jochemsen AG. Internal translation initiation generates novel WT1 protein isoforms with distinct biological properties. J Biol Chem 1999; 274:23456-62. [PMID: 10438524 DOI: 10.1074/jbc.274.33.23456] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The Wilms' tumor 1 gene, WT1, is homozygously mutated in a subset of Wilms' tumors. Heterozygous mutations in WT1 give rise to congenital anomalies. During embryogenesis, WT1 is expressed mainly in the kidneys, uterus, and testes. Alternative splicing of the WT1 mRNA results in synthesis of four main WT1 protein isoforms with molecular masses of 52-54 kDa. In addition, translation initiation at a CUG upstream of the initiator AUG generates four larger WT1 proteins of 60-62 kDa. We describe here the existence of novel WT1 isoforms and demonstrate that they are derived from translation initiation at the second in-frame AUG of the WT1 mRNA. These N-terminally truncated WT1 proteins of 36-38 kDa can be detected in several cell lines, mouse testes, and Wilms' tumor specimens. They can bind to DNA and direct transcription from reporter constructs. The shorter WT1 protein lacking the two splice inserts has a greater transcription activation potential than the corresponding main WT1 protein isoform but shows no transcription repression potential. Overexpression of full-length or N-terminally truncated WT1 efficiently induces apoptosis. These data show that additional WT1 isoforms with distinct transcription-regulatory properties exist, which further increases the complexity of WT1 expression and activity.
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Affiliation(s)
- V Scharnhorst
- Laboratory of Molecular Carcinogenesis and Centre for Biomedical Genetics, Leiden University Medical Center, P.O. Box 9503, 2300 RA Leiden, The Netherlands
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Abstract
The use of alternative promoters represents an important mechanism for the regulation of growth hormone receptor (GHR) gene expression. Two promoters have been isolated previously for the GHR gene: the P1 promoter that drives liver-specific expression, and the P2 promoter that drives ubiquitous expression. In the present study, we isolated a third GHR promoter termed P3. The P3 promoter was GC-rich and TATA-less. The P3 promoter was able to drive the expression of a luciferase reporter gene in cell lines Hep G2, PLC/PRF/5, and BHK-21. In vivo, the P3 promoter initiated transcription from two major sites in exon 1C of the GHR gene in many tissues. In the adult bovine liver, the P3-transcribed GHR mRNA represented only 10% of the total GHR mRNA pool. In non-hepatic tissues such as kidney, skeletal muscle, mammary gland, and uterus, P3-transcribed GHR mRNA represented 30-40% of the total GHR mRNA pool. Within the bovine GHR gene, the P3 promoter was located immediately downstream from the P2 promoter. In transfected cells, the P2 promoter served as an enhancer for the P3 promoter. Existence and co-regulation of two ubiquitous promoters may be a mechanism for achieving a high level of expression of the GHR gene in multiple tissues.
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Affiliation(s)
- H Jiang
- Department of Animal Sciences, University of Missouri, Columbia, Missouri 65211, USA
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Abstract
IGF-II plays an important role in growth and development of vertebrates and is highly expressed in adult salmon liver. In the present study, we demonstrate that a liver-enriched transcription factor, hepatocyte nuclear factor 3beta (HNF-3beta), is an activator of the chum salmon IGF-II gene. Multiple binding sites for HNF-3beta were identified within the 5'-UTR using electrophoretic mobility shift assays and mutation of these sites prevents binding of HNF-3beta. In transient transfection assays it was shown that mutation of the HNF-3beta binding sites results in a substantial decrease of HNF-3beta-activated salmon IGF-II gene expression. This is the first identified transcription factor that is functionally involved in the regulation of fish IGF-II expression.
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Affiliation(s)
- A Y Palamarchuk
- Laboratory for Physiological Chemistry, Utrecht University, The Netherlands
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Baltus B, van Dijk TB, Caldenhoven E, Zanders E, Raaijmakers JA, Lammers JW, Koenderman L, de Groot RP. An AP-1 site in the promoter of the human IL-5R alpha gene is necessary for promoter activity in eosinophilic HL60 cells. FEBS Lett 1998; 434:251-4. [PMID: 9742933 DOI: 10.1016/s0014-5793(98)00991-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Interleukin-5 (IL-5) plays a crucial role in the proliferation, differentiation and activation of eosinophils. The IL-5 receptor is composed of an IL-5-specific alpha subunit, which is expressed by eosinophils and basophils, and a beta c-subunit shared with the receptors for IL-3 and GM-CSF. We identified an AP-1 element which is important for IL-5R alpha promoter activity in eosinophilic HL60 cells. The AP-1 site and the previously identified EOS1 site cooperate, since single mutation of either of the sites decreased promoter activity. We show that the AP-1 site of the IL-5R alpha promoter binds multiple proteins, including cJun, CREB, and CREM.
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Affiliation(s)
- B Baltus
- Department of Pulmonary Diseases, University Hospital Utrecht, The Netherlands
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Abstract
BACKGROUND & AIMS Insulin-like growth factor (IGF)-II gene is overexpressed in colon cancers. Transcriptional up-regulation may be the major mechanism contributing to its overexpression. IGF-II messenger RNA (mRNA) levels are up-regulated during proliferation followed by a significant decline during differentiation of Caco-2 cells. Mechanisms underlying transcriptional regulation of the IGF-II gene promoters (P1-P4) have yet to be examined in colon cancers, which was the basis for this study. METHODS Ribonuclease protection assay was used to measure IGF-II mRNA derived from P1-P4. To determine if changes in the IGF-II transcripts reflected differences in promoter activity, transient transfection assays with the full-length P1-P4-luciferase expression vectors were performed. RESULTS Both P3- and P4-derived transcripts were significantly up-regulated during the proliferative phase of the cells (days 3-6 in culture) and declined rapidly in cells undergoing differentiation (days 7-10); conversely, P1- and P2-derived transcripts were not detected. Similarly, transcriptional activity of P3 and P4 promoters reached peak levels by days 4-6 and declined rapidly thereafter. P1 and P2 were relatively inactive on all days. CONCLUSIONS The activity of the P3 and P4 promoters may play a selective role in regulating IGF-II mRNA levels during growth and differentiation of colon cancer cells.
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Affiliation(s)
- P Singh
- Department of Anatomy and Neurosciences, University of Texas Medical Branch, Galveston, USA.
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Zhan S, Zhang L, Van M, Young C, Helman LJ. Biallelic expression of all four IGF-II promoters and its association with increased methylation of H19 gene in human brain. Brain Res 1998; 792:283-90. [PMID: 9593943 DOI: 10.1016/s0006-8993(98)00157-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The human IGF-II gene is maternally imprinted in all tissues except adult liver and the choroid plexus/leptomeninges of the central nervous system where IGF-II is biallelically expressed. In human liver, it has recently been reported that this biallelic expression only involves the promoter P1 while the promoters P2-P4 direct IGF-II transcription monoallelically. To explore whether or not biallelic expression of the IGF-II promoters in human CNS displays the same pattern as in liver, we examined the allelic expression status of the four IGF-II promoters in human brain. We found that all four IGF-II promoters in human fetal and adult brain were expressed from both parental alleles. Furthermore, the levels of methylation of the 3' region of H19 gene in fetal brain were higher than those in other tissues with monoallelic expression of IGF-II. Since similar findings have been reported in Wilms' tumor, these data suggest a similar mechanism may be responsible for loss of imprinting of IGF-II in normal brain and Wilms' tumor.
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Affiliation(s)
- S Zhan
- Pediatric Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Li J, Saunders JC, Fowden AL, Dauncey MJ, Gilmour RS. Transcriptional regulation of insulin-like growth factor-II gene expression by cortisol in fetal sheep during late gestation. J Biol Chem 1998; 273:10586-93. [PMID: 9553119 DOI: 10.1074/jbc.273.17.10586] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The objective of this study was to determine the mechanisms by which cortisol down-regulates hepatic insulin-like growth factor-II (IGF-II) gene expression in late gestation. Leader exons 6 and 7 of the ovine IGF-II gene, with their 5'-flanking regions, were first isolated. Characterization of transcription start sites revealed a unique site for exon 6 and three dispersed sites for exon 7. Nuclear run-on assays showed a 5-fold higher transcription rate of the IGF-II gene in liver of adrenalectomized fetuses compared with control animals, suggesting that regulation of IGF-II gene expression by cortisol is at the transcriptional level. RNase protection assays demonstrated hepatic leader exon 7 expression in adrenalectomized fetuses to be more than 2-fold higher than in controls, whereas it was reduced by 50% in cortisol-infused fetuses compared with controls. There was no effect on the expression of other leader exons. Functions of the upstream regulatory region of leader exon 7 (i.e. promoter P4) were investigated by luciferase transient expression. A region of -172 bases downstream relative to the first transcription site of leader exon 7 was shown to retain basal promoter activity and respond to cortisol. These results suggest that cortisol may induce the prenatal decline in ovine hepatic IGF-II expression by suppressing promoter P4 of the IGF-II gene.
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Affiliation(s)
- J Li
- Department of Cellular Physiology, Babraham Institute, Babraham, Cambridge CB2 4AT, United Kingdom
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Otte K, Choudhury D, Charalambous M, Engström W, Rozell B. A conserved structural element in horse and mouse IGF2 genes binds a methylation sensitive factor. Nucleic Acids Res 1998; 26:1605-12. [PMID: 9512529 PMCID: PMC147450 DOI: 10.1093/nar/26.7.1605] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The equine IGF2 gene has been cloned and characterised. It spans a 9 kb region, which is substantially less than the corresponding human gene. Three coding exons and three untranslated leader exons, all highly homologous to those in other species, were identified. Downstream of the polyadenylation site in exon 6, a dinucleotide repeat sequence was identified. Three putative promoters (P1-P3) were localised in the 5' region of the gene. RNase protection analysis revealed two active promoters in fetal tissues, P2 and P3, whereas P3 was the only promoter active in adult tissues. This represents a transcriptional pattern different from that in humans or rodents. A novel structural element, an inverted repeat, is predicted in the 3' region of the IGF2 gene. This repeat is conserved between species and located in a region which is differentially methylated in the human and mouse genes and might therefore be involved in the imprinting mechanism. The inverted repeat acquires a stem-loop structure in vitro with a hybrid A/B-DNA conformation in the stem area. Both in horse and mouse, a methylation-sensitive protein binds this structure with a strong requirement for the loop area. Furthermore, the protein might be developmentally regulated.
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Affiliation(s)
- K Otte
- Department of Pathology, Swedish University of Agricultural Sciences, PO Box 7028, 75007 Uppsala, Sweden.
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49
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Affiliation(s)
- J S Malter
- Department of Pathology and Laboratory Medicine, University of Wisconsin Hospital and Clinic, Madison 53792, USA
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50
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Zhang L, Zhan Q, Zhan S, Kashanchi F, Fornace AJ, Seth P, Helman LJ. p53 regulates human insulin-like growth factor II gene expression through active P4 promoter in rhabdomyosarcoma cells. DNA Cell Biol 1998; 17:125-31. [PMID: 9502429 DOI: 10.1089/dna.1998.17.125] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The developmentally regulated human insulin-like growth factor II (IGFII) gene is expressed at high levels in many types of tumors and promotes the proliferation of tumor cells with a high incidence of p53 gene defects. We have previously shown that p53 inhibits IGFII P3 promoter activity and decreases endogenous IGFII gene expression derived from the P3 promoter in rhabdomyosarcomas by interfering with TBP binding to the TATA element of the IGFII P3 promoter. In this report, we demonstrate that wild-type p53 expression in rhabdomyosarcoma cell lines containing mutant p53 leads to a decrease in the activity of another active IGFII promoter, P4, and a 5-fold reduction of IGFII mRNA derived from the P4 promoter. This inhibition of P4 activity is associated with direct binding of p53 to the P4 proximal promoter element despite the lack of a p53 consensus binding site. Our results suggest that p53 inhibits IGFII P4 promoter activity by a mechanism different than its effect on the P3 promoter. These data also supply further evidence of cross-talk between the IGF and p53 signaling pathways.
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Affiliation(s)
- L Zhang
- Molecular Oncology Section, Pediatric Oncology Branch, National Cancer Institute, Bethesda, MD 20892-1928, USA
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