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Boughanem H, Yubero-Serrano EM, López-Miranda J, Tinahones FJ, Macias-Gonzalez M. Potential Role of Insulin Growth-Factor-Binding Protein 2 as Therapeutic Target for Obesity-Related Insulin Resistance. Int J Mol Sci 2021; 22:ijms22031133. [PMID: 33498859 PMCID: PMC7865532 DOI: 10.3390/ijms22031133] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/13/2021] [Accepted: 01/21/2021] [Indexed: 12/26/2022] Open
Abstract
Evidence from observational and in vitro studies suggests that insulin growth-factor-binding protein type 2 (IGFBP2) is a promising protein in non-communicable diseases, such as obesity, insulin resistance, metabolic syndrome, or type 2 diabetes. Accordingly, great efforts have been carried out to explore the role of IGFBP2 in obesity state and insulin-related diseases, which it is typically found decreased. However, the physiological pathways have not been explored yet, and the relevance of IGFBP2 as an important pathway integrator of metabolic disorders is still unknown. Here, we review and discuss the molecular structure of IGFBP2 as the first element of regulating the expression of IGFBP2. We highlight an update of the association between low serum IGFBP2 and an increased risk of obesity, type 2 diabetes, metabolic syndrome, and low insulin sensitivity. We hypothesize mechanisms of IGFBP2 on the development of obesity and insulin resistance in an insulin-independent manner, which meant that could be evaluated as a therapeutic target. Finally, we cover the most interesting lifestyle modifications that regulate IGFBP2, since lifestyle factors (diet and/or physical activity) are associated with important variations in serum IGFBP2.
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Affiliation(s)
- Hatim Boughanem
- Department of Endocrinology and Nutrition, Institute of Biomedical Research Institute in Malaga (IBIMA), Virgen de la Victoria University Hospital, 29010 Málaga, Spain;
| | - Elena M. Yubero-Serrano
- Lipids and Atherosclerosis Unit, Maimonides Institute for Biomedical Research in Cordoba (IMIBIC), Reina Sofia University Hospital, University of Córdoba, 14004 Córdoba, Spain; (E.M.Y.-S.); (J.L.-M.)
- CIBEROBN (CIBER in Physiopathology of Obesity and Nutrition), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - José López-Miranda
- Lipids and Atherosclerosis Unit, Maimonides Institute for Biomedical Research in Cordoba (IMIBIC), Reina Sofia University Hospital, University of Córdoba, 14004 Córdoba, Spain; (E.M.Y.-S.); (J.L.-M.)
- CIBEROBN (CIBER in Physiopathology of Obesity and Nutrition), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Francisco J. Tinahones
- Department of Endocrinology and Nutrition, Institute of Biomedical Research Institute in Malaga (IBIMA), Virgen de la Victoria University Hospital, 29010 Málaga, Spain;
- CIBEROBN (CIBER in Physiopathology of Obesity and Nutrition), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Correspondence: (F.J.T.); (M.M.-G.); Tel.: +34-951-036-2647 (F.J.T. & M.M.-G.); Fax: +34-951-924-651 (F.J.T. & M.M.-G.)
| | - Manuel Macias-Gonzalez
- Department of Endocrinology and Nutrition, Institute of Biomedical Research Institute in Malaga (IBIMA), Virgen de la Victoria University Hospital, 29010 Málaga, Spain;
- CIBEROBN (CIBER in Physiopathology of Obesity and Nutrition), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Correspondence: (F.J.T.); (M.M.-G.); Tel.: +34-951-036-2647 (F.J.T. & M.M.-G.); Fax: +34-951-924-651 (F.J.T. & M.M.-G.)
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Rabiee N, Ahmadi S, Arab Z, Bagherzadeh M, Safarkhani M, Nasseri B, Rabiee M, Tahriri M, Webster TJ, Tayebi L. Aptamer Hybrid Nanocomplexes as Targeting Components for Antibiotic/Gene Delivery Systems and Diagnostics: A Review. Int J Nanomedicine 2020; 15:4237-4256. [PMID: 32606675 PMCID: PMC7314593 DOI: 10.2147/ijn.s248736] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 04/01/2020] [Indexed: 12/11/2022] Open
Abstract
With the passage of time and more advanced societies, there is a greater emergence and incidence of disease and necessity for improved treatments. In this respect, nowadays, aptamers, with their better efficiency at diagnosing and treating diseases than antibodies, are at the center of attention. Here, in this review, we first investigate aptamer function in various fields (such as the detection and remedy of pathogens, modification of nanoparticles, antibiotic delivery and gene delivery). Then, we present aptamer-conjugated nanocomplexes as the main and efficient factor in gene delivery. Finally, we focus on the targeted co-delivery of genes and drugs by nanocomplexes, as a new exciting approach for cancer treatment in the decades ahead to meet our growing societal needs.
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Affiliation(s)
- Navid Rabiee
- Department of Chemistry, Sharif University of Technology, Tehran, Iran
| | - Sepideh Ahmadi
- Student Research Committee, Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Zeynab Arab
- Department of Chemistry, Sharif University of Technology, Tehran, Iran
| | | | - Moein Safarkhani
- Department of Chemistry, Sharif University of Technology, Tehran, Iran
| | - Behzad Nasseri
- Chemical Engineering Department and Bioengineering Division, Hacettepe University, Beytepe, Ankara06800, Turkey
- Chemical Engineering and Applied Chemistry Department, Atilim University, Ankara, Turkey
| | - Mohammad Rabiee
- Biomaterial Group, Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
| | | | - Thomas J Webster
- Department of Chemical Engineering, Northeastern University, Boston, MA02115, USA
| | - Lobat Tayebi
- Marquette University School of Dentistry, Milwaukee, WI53233, USA
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Wang YF, Wu LQ, Liu YN, Bi YY, Wang H. Gestational age and childhood leukemia: A meta-analysis of epidemiologic studies. ACTA ACUST UNITED AC 2017; 23:253-262. [PMID: 29099685 DOI: 10.1080/10245332.2017.1396056] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVE An increasing amount of evidence shows that childhood leukemia is initiated in utero. Birth characteristics initiated in utero, such as gestational age, may play a role in leukemogenesis. The purpose of our meta-analysis is to explore the association between gestational age and childhood leukemia. METHODS Relevant studies up to 21 April 2017 were collected by searching PubMed and EMBASE databases. Subgroup analysis, sensitivity analysis and publication bias assessment were conducted. RESULTS A total of 13 studies were included. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) for preterm birth and postterm birth were 1.06 (0.98, 1.13) and 1.01 (0.90, 1.13) for childhood leukemia, 1.04 (0.97, 1.11) and 1.03 (0.95, 1.12) for acute lymphocytic leukemia (ALL), 1.20 (1.00, 1.44) and 1.20 (1.00, 1.43) for acute myeloid leukemia (AML), compared with full-term birth. Study type and study region were the reasons behind the heterogeneity. In subgroup analyses, the summary ORs with 95% CI for childhood leukemia and ALL were 1.23 (1.07, 1.41) and 1.21 (1.06, 1.39) for postterm birth in cohort studies. No significant changes in sensitivity analyses and no publication bias were observed in our analysis. CONCLUSION Our results suggest that both preterm and postterm infants have an elevated risk of developing AML. In addition, postterm birth increased the risk of childhood leukemia and ALL in cohort studies. However, more studies are warranted to validate these results and explore the biologic mechanisms underlying these relationships.
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Affiliation(s)
- Yang-Feng Wang
- a Department of Occupational and Environmental Health, School of Health Sciences , Wuhan University , Wuhan , People's Republic of China
| | - Li-Qun Wu
- a Department of Occupational and Environmental Health, School of Health Sciences , Wuhan University , Wuhan , People's Republic of China
| | - Yi-Ni Liu
- a Department of Occupational and Environmental Health, School of Health Sciences , Wuhan University , Wuhan , People's Republic of China
| | - Yong-Yi Bi
- a Department of Occupational and Environmental Health, School of Health Sciences , Wuhan University , Wuhan , People's Republic of China
| | - Hong Wang
- a Department of Occupational and Environmental Health, School of Health Sciences , Wuhan University , Wuhan , People's Republic of China
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Shahidi-Hamedani N, Shier WT, Moghadam Ariaee F, Abnous K, Ramezani M. Targeted gene delivery with noncovalent electrostatic conjugates of sgc-8c aptamer and polyethylenimine. J Gene Med 2014; 15:261-9. [PMID: 23794147 DOI: 10.1002/jgm.2718] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 06/18/2013] [Accepted: 06/19/2013] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND Several strategies have been shown to improve the transfection efficiency of polyethylenimine (PEI) as a nonviral gene delivery vector. In the present study, a nucleic acid aptamer specific for protein tyrosine kinase 7 (PTK7) surface marker, sgc-8c, was conjugated electrostatically to pre-formed 10-kDa PEI/plasmid DNA polyplexes, and the ability of the conjugate to transfer genetic material was evaluated in MOLT-4 human acute lymphoblastic leukemia T-cells, which express PTK7 on their surface. METHODS Polyplexes (plasmid DNA-vector conjugates), prepared using PEI-sgc-8c conjugate and pCMVLuc as a reporter gene, were characterized in terms of particle size, surface charge and the extent of DNA condensation. Polyplexes were also evaluated for cytotoxicity using the MTS colorimetric assay, as well as for transfection efficiency in MOLT-4 cells, and compared with the results obtained in U266 cells, which lack cell surface PTK7. RESULTS Relative to pDNA/PEI, the size of pDNA/PEI/sgc-8c aptamer polyplexes increased with decreasing zeta potential. In MOLT-4 cells, pDNA/PEI/sgc-8c aptamer polyplexes exhibited an almost six- to eight-fold increase in transfection efficiency compared to that of pDNA/PEI polyplex, indicating that conjugation of sgc-8c aptamer to pre-formed 10-kDa PEI/plasmid DNA polyplexes achieved effective targeting without covalent attachment, whereas receptor-mediated conducted transfection was confirmed by performing a competitive transfection experiment and a cellular uptake study. CONCLUSIONS The results of the present study provide an example of the usefulness of a nucleic acid aptamer in the form of noncovalent, electrostatic conjugates as an approach for enhancing the transfection efficiency of a polycation vector such as PEI without significant induced cytotoxicity.
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Affiliation(s)
- Nasim Shahidi-Hamedani
- Pharmaceutical Research Centre, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
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Li Z, Miard S, Laplante M, Sonenberg N, Picard F. Insulin stimulates IGFBP-2 expression in 3T3-L1 adipocytes through the PI3K/mTOR pathway. Mol Cell Endocrinol 2012; 358:63-8. [PMID: 22410287 DOI: 10.1016/j.mce.2012.02.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2011] [Revised: 02/15/2012] [Accepted: 02/23/2012] [Indexed: 11/30/2022]
Abstract
Insulin-like growth factor binding protein 2 (IGFBP-2) has been implicated in the etiology of several diseases, including the metabolic syndrome. Although IGFBP-2 derives mostly from the liver, recent evidence in mice and humans indicate that aging and obesity are associated with altered IGFBP-2 levels in white adipocytes. The present study was aimed at determining the mechanisms that control IGFBP-2 expression in mature adipocytes. IGFBP-2 mRNA and protein expression in serum-deprived 3T3-L1 adipocytes were twofold increased by acute insulin treatment. Co-treatments with the phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin or the mammalian target of rapamycin (mTOR) inhibitor rapamycin blunted the effects of insulin. Coherently, IGFBP-2 mRNA levels were robustly increased in adipocytes lacking either TSC2 or 4E-BP1. Insulin triggered the recruitment of CAAT/enhancer binding protein α (C/EBPα) to the IGFBP-2 proximal promoter. These findings suggest that insulin upregulates IGFBP-2 expression through a PI3K/mTOR/C/EBPα pathway in white adipocytes.
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Affiliation(s)
- Zhuo Li
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Laval University, QC, Canada G1V 4G5
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Dokmanovic M, Shen Y, Bonacci TM, Hirsch DS, Wu WJ. Trastuzumab regulates IGFBP-2 and IGFBP-3 to mediate growth inhibition: implications for the development of predictive biomarkers for trastuzumab resistance. Mol Cancer Ther 2011; 10:917-28. [PMID: 21487052 DOI: 10.1158/1535-7163.mct-10-0980] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Activation of insulin-like growth factor-I receptor (IGF-IR) signaling is an important mechanism for trastuzumab resistance. IGF-binding proteins (IGFBP) modulate IGF-IR signaling and play important roles in the control of breast cancer progression. In this article, we report that trastuzumab treatment enhances the expression and secretion of IGFBP-3 in SKBR3 cells, a trastuzumab-sensitive breast cancer cell line, and that this upregulation of IGFBP-3 induced by trastuzumab correlates with trastuzumab-mediated growth inhibition. We describe a new role for IGFBP-3 in the regulation of IGF-I-mediated cross-talk between IGF-IR and ErbB2 signaling pathways. In particular, treatment of SKBR3 cells with recombinant IGFBP-3 blocks IGF-I-induced activation of IGF-IR and ErbB2, and stable expression of IGFBP-3 inhibits SKBR3 cell growth. We find an inverse relationship in the levels of secreted IGFBP-3 such that high levels of IGFBP-3 are associated with trastuzumab-sensitive breast cancer cells (SKBR3 and BT-474), whereas low levels of IGFBP-3 are found in trastuzumab-resistant cells (clone 3 and JIMT-1). In contrast to IGFBP-3, the secretion and expression of IGFBP-2 are upregulated in trastuzumab-resistant SKBR3 cells. Furthermore, we show that IGFBP-2 stimulates activation of ErbB2 and that trastuzumab reduces IGFBP-2-stimulated ErbB2 activation. Based on our data, we propose a novel mechanism of action whereby trastuzumab enhances the expression and secretion of IGFBP-3, which interferes with IGF-I-mediated mitogenic signaling via autocrine and paracrine mechanisms and reduces IGFBP-2-induced ErbB2 activation to mediate growth inhibition. Changes in secretion profiles of IGFBP-2 and IGFBP-3 in trastuzumab-sensitive and trastuzumab-resistant cells may promote the development of IGFBP-2 and IGFBP-3 as predictive biomarkers for trastuzumab resistance.
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Affiliation(s)
- Milos Dokmanovic
- Division of Monoclonal Antibodies, Office of Biotechnology Products, Office of Pharmaceutical Science, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, HFD-123, 29 Lincoln Dr., NIH Bldg 29B, Room 3 NN-15, Bethesda, MD 20892, USA
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Mireuta M, Darnel A, Pollak M. IGFBP-2 expression in MCF-7 cells is regulated by the PI3K/AKT/mTOR pathway through Sp1-induced increase in transcription. Growth Factors 2010; 28:243-55. [PMID: 20370577 DOI: 10.3109/08977191003745472] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Insulin-like growth factor binding protein 2 (IGFBP-2) has been implicated in the pathophysiology of neoplasia. The PI3K/AKT/mTOR pathway has recently been shown to be a predominant regulator of IGFBP-2 at the protein level in MCF-7 breast cancer cells. However, there are gaps in knowledge with respect to the molecular mechanisms that underlie this regulation. Here, we show that the PI3K/AKT/mTOR pathway regulates IGFBP-2 protein levels by modulating IGFBP-2 mRNA abundance in MCF-7 cells. This change is achieved by regulating transcription through a critical region present in the first 200 bp upstream of the transcription initiation site where Sp1 transcription factor binds and drives transcription. IGF-1 treatment leads to increased nuclear abundance of Sp1 and increased IGFBP-2 mRNA and protein levels. Rapamycin and LY294002 induce a decline in Sp1 nuclear abundance and IGFBP-2 mRNA and protein levels. This work provides a mechanistic explanation for the observed effects of the PI3K/AKT/mTOR pathway on IGFBP-2 levels in MCF-7 cells.
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Affiliation(s)
- Matei Mireuta
- Departments of Medicine and Oncology, Lady Davis Institute for Medical Research, Montreal SMBD Jewish General Hospital, and McGill University, Montreal, Quebec, CanadaH3T 1E2
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Martin JL, Baxter RC. Expression of insulin-like growth factor binding protein-2 by MCF-7 breast cancer cells is regulated through the phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin pathway. Endocrinology 2007; 148:2532-41. [PMID: 17289850 DOI: 10.1210/en.2006-1335] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
IGF binding protein-2 (IGFBP-2) has been implicated in the development and spread of a number of tumor types, and its abrogation in experimental models of cancer is associated with decreased tumor growth. This suggests that targeted inhibition of IGFBP-2 expression in some cancers may have therapeutic benefit. In this study, we investigated signaling pathways involved in extracellular IGFBP-2 expression in an IGF- and estrogen-responsive breast cancer cell line, MCF-7. IGFBP-2 was present at approximately 150 ng per 10(6) cells in serum-free MCF-7-conditioned medium and constituted the predominant IGFBP. Inhibition of the phosphatidylinositol 3-kinase signaling pathway using LY294002, or the downstream signaling intermediate mammalian target of rapamycin using rapamycin, markedly reduced IGFBP-2 in conditioned medium to approximately 25% of untreated levels (P < 0.001); there was no effect of inhibition of p38 MAPK, and an inhibitor of p44/42 MAPK activation, PD98059, caused only a slight reduction in extracellular IGFBP-2. IGFBP-2 levels were increased 25-30% by estradiol, whereas IGF-I (100 ng/ml) increased IGFBP-2 levels 2-fold (P < 0.001) by a type 1 IGF receptor (IGFR1)-dependent mechanism. Estradiol enhanced the effect of IGF-I on IGFBP-2 levels, and this was associated with increased phosphorylation of IGFR1. Basal, IGF-, or estradiol-stimulated IGFBP-2 was abrogated by LY294002 and rapamycin and an inhibitor of IGFR1 tyrosine kinase activity, AG1024. Modulation of intracellular hypoxia-inducible factor-1alpha had no effect on IGFBP-2 expression. These findings indicate that IGFBP-2 is regulated predominantly through the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin pathway, the target of a number of anticancer agents currently in clinical trial and use.
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Affiliation(s)
- Janet L Martin
- Kolling Institute of Medical Research, University of Sydney, Royal North Shore Hospital, St. Leonards, New South Wales 2065, Australia.
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Kwak I, Song S, Blum JL, Simmen RCM, Simmen FA. Enhancer- and silencer-like sequences that mediate insulin-like growth factor-binding protein-2 gene expression in uterine cells of pregnancy. DNA Cell Biol 2006; 25:6-18. [PMID: 16405396 DOI: 10.1089/dna.2006.25.6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The regulation of insulin-like growth factor-binding protein-2 (IGFBP-2) gene transcription in specific cell and developmental contexts is not well understood. Here, we identified DNA regions that mediate IGFBP-2 gene transcription in two of the three major cell types of the uterine endometrium of the early pregnant pig. Two clusters of transcriptional start sites at nucleotides -109/-105 and -96/-87 (+1, translational initiation site) in the porcine IGFBP-2 gene were localized in uterine endometrium and in primary cultures of endometrial glandular epithelial (GE) and stromal (ST) fibroblastic cells. Upstream regions of this gene (spanning -1,397/+73) were fused to a luciferase reporter gene, and the constructs were transiently transfected into endometrial GE and ST cells representative of pregnancy days 12 and 18 (day 115 = parturition). A short (110 bp) upstream region (-874/-765) stimulated the IGFBP-2 and heterologous SV40 promoters in the two cell types at both pregnancy days. Two noncontiguous copies of the novel sequence motif TCAGGG within the 110-bp fragment were implicated in transcriptional activity, since block mutation of these sequences led to a repression of SV40 basal promoter activity in endometrial cells. Southwestern blotting identified an endometrial nuclear protein of 34-kDa molecular weight that bound an oligonucleotide containing this motif, and EMSA suggested robust expression of this protein in early pregnancy endometrium and in ovary but at much reduced levels in endometrium at later pregnancy. A pair of E-box elements (CANNTG) within the 110 bp region was stimulatory to IGFBP-2 promoter activity; block mutation of these converted the 110-bp region into a potent transcriptional silencer in all but day 18 ST cells. Results identify novel DNA motifs that regulate the IGFBP-2 gene promoter in uterine endometrium in pregnancy-associated fashion.
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Affiliation(s)
- Inseok Kwak
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA
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Chen JY, Chou MJ, Gong HY, Huang TC, Wu JL, Kuo CM. Cloning and biological analysis of the zebrafish (Danio rerio) insulin-like growth factor binding protein-2 proximal promoter region. DNA Cell Biol 2005; 24:199-208. [PMID: 15767786 DOI: 10.1089/dna.2005.24.199] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Insulin-like growth factor binding protein 2 (IGFBP-2) plays an important role in the regulation of IGF's action and endocrinology in fish. To understand the molecular mechanism which controls transcription of the IGFBP-2 gene, we cloned and sequenced the IGFBP-2 proximal promoter region of the zebrafish IGFBP-2 gene and characterized its activity by firefly luciferase transient transfection expression assays. Different fragments of the zebrafish IGFBP-2 5'-flanking region were transfected into Hela and ZFL cells. In these cell lines, maximum promoter activity was located in the 900 base pairs (bp) of the zebrafish IGFBP-2 5' flanking region in the ZFL cell line and 318 bp of the zebrafish IGFBP-2 5' flanking region in the Hela cell line. The in vivo actions of the IGFBP-2 promoter on developmental stage expression were further investigated in transgenic zebrafish in which an IGFBP-2 (900-bp) promoter-driven green fluorescent protein encoding the GFP cDNA transgene was microinjected into zebrafish embryos. Morphological and RT-PCR studies of transgenic zebrafish indicated that the IGFBP-2 promoter-driven GFP transcripts appeared for the first time in the 32-cell stage. These results indicate that the IGFBP-2 promoter is active in a development-specific manner. These results suggest that the IGFBP-2 promoter plays an important role in teleost embryo growth.
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Affiliation(s)
- Jyh-Yih Chen
- Marine Research Station, Institute of Zoology, Academia Sinica, Ilan, Taiwan, Republic of China
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Vorwerk P, Wex H, Bessert C, Hohmann B, Schmidt U, Mittler U. Loss of imprinting of IGF-II gene in children with acute lymphoblastic leukemia. Leuk Res 2003; 27:807-12. [PMID: 12804639 DOI: 10.1016/s0145-2126(03)00014-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Insulin-like growth factor-II (IGF-II) is known to be involved in the regulation of growth, differentiation and cell death in normal human tissues. In a variety of human tumors, the IGF-II gene is overexpressed and considered to be a stimulator for tumor growth through autocrine and paracrine mechanisms. The IGF-II gene is normally parental imprinted, only the paternal allele being expressed in most tissues. Several reports about biallelic expression (loss of imprinting (LOI)) of the IGF-II gene in different tumors suggest a role of dysregulation of IGF-II imprinting in tumorigenesis. However, biallelic expression of IGF-II gene has also been reported in different tissues of a significant number of normal controls, indicating either a normal phenomenon or an elevated cancer risk in this group of persons. Although LOI of IGF-II presumably promotes tumorigenesis by increasing IGF-II expression, elevated IGF-II levels in those patients have not been reported. We studied IGF-II gene expression in malignant lymphoblasts of 124 children suffering from acute lymphoblastic leukemia, 196 cord blood samples from healthy newborns and mononuclear cells (MNC) from 50 healthy age matched children. The ApaI polymorphism in exon 9 of the IGF-II gene and allele-specific exon-connection RT-PCR was used for determination of the imprinting status. From 44 informative ALL-patients, 24 (54%) showed LOI of the IGF-II gene. Twenty percent of the informative cord blood samples (N=56) and 14% of the informative MNC samples from healthy controls (N=22) showed biallelic expression of IGF-II. In the ALL-patients, no statistical significant correlation between LOI patients and relapse rate, surviving rate and risk groups could be detected. We conclude that LOI of IGF-II occurs in malignant lymphoblasts of children suffering from acute lymphoblastic leukemia in more than 50% of the patients. In MNC from cord blood and peripheral MNC from healthy controls, biallelic expression could be detected in up to 20% of all cases. The importance of LOI in ALL-patients needs to be further evaluated to determine its impact in leukemogenesis.
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Affiliation(s)
- Peter Vorwerk
- Department of Pediatric Oncology, Otto von Guericke University, Emanuel-Larisch-Weg 17-19, D-39112 Magdeburg, Germany.
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Seurin D, Lassarre C, Bienvenu G, Babajko S. Insulin-like growth factor binding protein-6 inhibits neuroblastoma cell proliferation and tumour development. Eur J Cancer 2002; 38:2058-65. [PMID: 12376212 DOI: 10.1016/s0959-8049(02)00240-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In neuroblastoma cells, survival and proliferation are dependent upon the insulin-like growth factor (IGF) system. IGFs actively participate in cell growth, whereas IGFBP-6, is associated with the arrest of growth. With a view to blocking IGF-II action, we produced recombinant human IGFBP-6 capable of binding IGFs with affinities between 1.23 and 6.36 x 10(9) M(-1). Ex vivo mitogenic activities were tested on two human neuroblastoma cell lines, in which 100 ng/ml IGFBP-6 completely abolished the effects of both endogenous and exogenous IGF-II. In vivo, nude mice previously injected with neuroblastoma cells were submitted to either 15 daily injections of 4-20 microg IGFBP-6 or implantation of mini-pumps diffusing 20-100 microg IGFBP-6 over 2 weeks. The result was an average 18% reduction in the incidence and development of tumours. Delivery of the IGFBP-6 via mini-pumps also delayed tumour appearance by 6-15 days. Our results therefore show the involvement of IGFBP-6 in neuroblastoma cell growth, both ex vivo in terms of proliferation and in vivo in terms of tumour development.
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Affiliation(s)
- D Seurin
- Unit de Recherches sur la Regulation de la Croissance, U. 515, Institut National de la Santé et de la Recherche Médicale, Hôpital Saint Antoine, 184, rue du Faubourg Saint Antoine, 75571 Paris Cedex 12, France
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