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Fleming A, Zhou J, Wallace SS, Burrows CJ. A Role for the Fifth G-Track in G-Quadruplex Forming Oncogene Promoter Sequences during Oxidative Stress: Do These "Spare Tires" Have an Evolved Function? ACS CENTRAL SCIENCE 2015; 1:226-233. [PMID: 26405692 PMCID: PMC4571166 DOI: 10.1021/acscentsci.5b00202] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Indexed: 05/24/2023]
Abstract
Uncontrolled inflammation or oxidative stress generates electron-deficient species that oxidize the genome increasing its instability in cancer. The G-quadruplex (G4) sequences regulating the c-MYC, KRAS, VEGF, BCL-2, HIF-1α, and RET oncogenes, as examples, are targets for oxidation at loop and 5'-core guanines (G) as showcased in this study by CO3•- oxidation of the VEGF G4. Products observed include 8-oxo-7,8-dihydroguanine (OG), spiroiminodihydantoin (Sp), and 5-guanidinohydantoin (Gh). Our previous studies found that OG and Gh, when present in the four G-tracks of the solved structure for VEGF and c-MYC, were not substrates for the base excision repair (BER) DNA glycosylases in biologically relevant KCl solutions. We now hypothesize that a fifth G-track found a few nucleotides distant from the G4 tracks involved in folding can act as a "spare tire," facilitating extrusion of a damaged G-run into a large loop that then becomes a substrate for BER. Thermodynamic, spectroscopic, and DMS footprinting studies verified the fifth domain replacing a damaged G-track with OG or Gh at a loop or core position in the VEGF G4. These new "spare tire"-containing strands with Gh in loops are now found to be substrates for initiation of BER with the NEIL1, NEIL2, and NEIL3 DNA glycosylases. The results support a hypothesis in which regulatory G4s carry a "spare-tire" fifth G-track for aiding in the repair process when these sequences are damaged by radical oxygen species, a feature observed in a large number of these sequences. Furthermore, formation and repair of oxidized bases in promoter regions may constitute an additional example of epigenetic modification, in this case of guanine bases, to regulate gene expression in which the G4 sequences act as sensors of oxidative stress.
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Affiliation(s)
- Aaron
M. Fleming
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Jia Zhou
- Department
of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont 05045, United States
| | - Susan S. Wallace
- Department
of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont 05045, United States
| | - Cynthia J. Burrows
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
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Mizuno S, Bogaard HJ, Ishizaki T, Toga H. Role of p53 in lung tissue remodeling. World J Respirol 2015; 5:40-46. [DOI: 10.5320/wjr.v5.i1.40] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 11/25/2014] [Accepted: 12/19/2014] [Indexed: 02/06/2023] Open
Abstract
The tumor suppressor gene p53 regulates a wide range of cellular processes including cell cycle progression, proliferation, apoptosis and tissue development and remodeling. Lung cell apoptosis and tissue remodeling have critical roles in many lung diseases. Abnormal proliferation or resistance to apoptosis of lung cells will lead to structural changes of many lung tissues, including the pulmonary vascular wall, small airways and lung parenchyma. Among the many lung diseases caused by vascular cell apoptosis and tissue remodeling are chronic obstructive pulmonary disease, bronchial asthma and pulmonary arterial hypertension. Recent advances in biology and medicine have provided new insights and have resulted in new therapeutic strategies for tissue remodeling in human and animal models. This review is focused on lung disease susceptibility associated with the p53 pathway and describes molecular mechanisms upstream and downstream of p53 in lung tissue remodeling. Improved understanding of structural changes associated with pulmonary vascular remodeling and lung cell apoptosis induced by the p53 pathway may new provide therapeutic targets.
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Data integration reveals key homeostatic mechanisms following low dose radiation exposure. Toxicol Appl Pharmacol 2015; 285:1-11. [PMID: 25655199 DOI: 10.1016/j.taap.2015.01.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 01/21/2015] [Accepted: 01/25/2015] [Indexed: 12/25/2022]
Abstract
The goal of this study was to define pathways regulated by low dose radiation to understand how biological systems respond to subtle perturbations in their environment and prioritize pathways for human health assessment. Using an in vitro 3-D human full thickness skin model, we have examined the temporal response of dermal and epidermal layers to 10 cGy X-ray using transcriptomic, proteomic, phosphoproteomic and metabolomic platforms. Bioinformatics analysis of each dataset independently revealed potential signaling mechanisms affected by low dose radiation, and integrating data shed additional insight into the mechanisms regulating low dose responses in human tissue. We examined direct interactions among datasets (top down approach) and defined several hubs as significant regulators, including transcription factors (YY1, MYC and CREB1), kinases (CDK2, PLK1) and a protease (MMP2). These data indicate a shift in response across time - with an increase in DNA repair, tissue remodeling and repression of cell proliferation acutely (24-72h). Pathway-based integration (bottom up approach) identified common molecular and pathway responses to low dose radiation, including oxidative stress, nitric oxide signaling and transcriptional regulation through the SP1 factor that would not have been identified by the individual data sets. Significant regulation of key downstream metabolites of nitrative stress was measured within these pathways. Among the features identified in our study, the regulation of MMP2 and SP1 was experimentally validated. Our results demonstrate the advantage of data integration to broadly define the pathways and networks that represent the mechanisms by which complex biological systems respond to perturbation.
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Angiogenesis in the placenta: the role of reactive oxygen species signaling. BIOMED RESEARCH INTERNATIONAL 2015; 2015:814543. [PMID: 25705690 PMCID: PMC4325211 DOI: 10.1155/2015/814543] [Citation(s) in RCA: 128] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2014] [Accepted: 08/28/2014] [Indexed: 02/07/2023]
Abstract
Proper placental development and function are central to the health of both the mother and the fetus during pregnancy. A critical component of healthy placental function is the proper development of its vascular network. Poor vascularization of the placenta can lead to fetal growth restriction, preeclampsia, and in some cases fetal death. Therefore, understanding the mechanisms by which uterine stressors influence the development of the placental vasculature and contribute to placental dysfunction is of central importance to ensuring a healthy pregnancy. In this review we discuss how oxidative stress observed in maternal smoking, maternal obesity, and preeclampsia has been associated with aberrant angiogenesis and placental dysfunction resulting in adverse pregnancy outcomes. We also highlight that oxidative stress can influence the expression of a number of transcription factors important in mediating angiogenesis. Therefore, understanding how oxidative stress affects redox-sensitive transcription factors within the placenta may elucidate potential therapeutic targets for correcting abnormal placental angiogenesis and function.
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Beishline K, Azizkhan-Clifford J. Sp1 and the 'hallmarks of cancer'. FEBS J 2015; 282:224-58. [PMID: 25393971 DOI: 10.1111/febs.13148] [Citation(s) in RCA: 369] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 09/26/2014] [Accepted: 11/10/2014] [Indexed: 12/19/2022]
Abstract
For many years, transcription factor Sp1 was viewed as a basal transcription factor and relegated to a role in the regulation of so-called housekeeping genes. Identification of Sp1's role in recruiting the general transcription machinery in the absence of a TATA box increased its importance in gene regulation, particularly in light of recent estimates that the majority of mammalian genes lack a TATA box. In this review, we briefly consider the history of Sp1, the founding member of the Sp family of transcription factors. We review the evidence suggesting that Sp1 is highly regulated by post-translational modifications that positively and negatively affect the activity of Sp1 on a wide array of genes. Sp1 is over-expressed in many cancers and is associated with poor prognosis. Targeting Sp1 in cancer treatment has been suggested; however, our review of the literature on the role of Sp1 in the regulation of genes that contribute to the 'hallmarks of cancer' illustrates the extreme complexity of Sp1 functions. Sp1 both activates and suppresses the expression of a number of essential oncogenes and tumor suppressors, as well as genes involved in essential cellular functions, including proliferation, differentiation, the DNA damage response, apoptosis, senescence and angiogenesis. Sp1 is also implicated in inflammation and genomic instability, as well as epigenetic silencing. Given the apparently opposing effects of Sp1, a more complete understanding of the function of Sp1 in cancer is required to validate its potential as a therapeutic target.
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Affiliation(s)
- Kate Beishline
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
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Fosen KM, Thom SR. Hyperbaric oxygen, vasculogenic stem cells, and wound healing. Antioxid Redox Signal 2014; 21:1634-47. [PMID: 24730726 PMCID: PMC4175035 DOI: 10.1089/ars.2014.5940] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 04/14/2014] [Indexed: 12/15/2022]
Abstract
SIGNIFICANCE Oxidative stress is recognized as playing a role in stem cell mobilization from peripheral sites and also cell function. RECENT ADVANCES This review focuses on the impact of hyperoxia on vasculogenic stem cells and elements of wound healing. CRITICAL ISSUES Components of the wound-healing process in which oxidative stress has a positive impact on the various cells involved in wound healing are highlighted. A slightly different view of wound-healing physiology is adopted by departing from the often used notion of sequential stages: hemostatic, inflammatory, proliferative, and remodeling and instead organizes the cascade of wound healing as overlapping events or waves pertaining to reactive oxygen species, lactate, and nitric oxide. This was done because hyperoxia has effects of a number of cell signaling events that converge to influence cell recruitment/chemotaxis and gene regulation/protein synthesis responses which mediate wound healing. FUTURE DIRECTIONS Our alternative perspective of the stages of wound healing eases recognition of the multiple sites where oxidative stress has an impact on wound healing. This aids the focus on mechanistic events and the interplay among various cell types and biochemical processes. It also highlights the areas where additional research is needed.
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Affiliation(s)
- Katina M. Fosen
- Department of Emergency Medicine, Institute for Environmental Medicine, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania
| | - Stephen R. Thom
- Department of Emergency Medicine, University of Maryland, Baltimore, Maryland
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Anguria P, Kitinya J, Ntuli S, Carmichael T. The role of heredity in pterygium development. Int J Ophthalmol 2014; 7:563-73. [PMID: 24967209 DOI: 10.3980/j.issn.2222-3959.2014.03.31] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 03/01/2014] [Indexed: 11/02/2022] Open
Abstract
Several risk factors, which include heredity, ultra-violet (UV) light and chronic inflammation, contribute to pterygium development. However, there is no report integrating these factors in the pathogenesis of pterygium. The aim of this review is to describe the connection between heredity, UV, and inflammation in pterygium development. Existing reports indicate that sunlight exposure is the main factor in pterygium occurrence by inducing growth factor production or chronic inflammation or DNA damage. Heredity may be a factor. Our studies on factors in pterygium occurrence and recurrence identify that heredity is crucial for pterygium to develop, and that sunlight is only a trigger, and that chronic inflammation promotes pterygium enlargement. We propose that genetic factors may interfere with the control of fibrovascular proliferation while UV light or (sunlight) most likely only triggers pterygium development by inducing growth factors which promote vibrant fibrovascular proliferation in predisposed individuals. It also just triggers inflammation and collagenolysis, which may be promoters of the enlargement of the fibrovascular mass. Pterygium probably occurs in the presence of exuberant collagen production and profuse neovascularisation.
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Affiliation(s)
- Peter Anguria
- Department of Neurosciences, Division of Ophthalmology, University of the Witwatersrand Johannesburg, 7 York Road, Park Town 2193, South Africa
| | - James Kitinya
- Department of Anatomic Pathology, University of Limpopo Polokwane Campus, Private Bag X9316 Polokwane 0700, South Africa
| | - Sam Ntuli
- Department of Public Health Medicine, University of Limpopo Polokwane Campus, Private Bag X9316 Polokwane 0700, South Africa
| | - Trevor Carmichael
- Department of Neurosciences, Division of Ophthalmology, University of the Witwatersrand Johannesburg, 7 York Road, Park Town 2193, South Africa
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Gupta S, Ghulmiyyah J, Sharma R, Halabi J, Agarwal A. Power of proteomics in linking oxidative stress and female infertility. BIOMED RESEARCH INTERNATIONAL 2014; 2014:916212. [PMID: 24900998 PMCID: PMC4036646 DOI: 10.1155/2014/916212] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 03/30/2014] [Accepted: 04/07/2014] [Indexed: 01/11/2023]
Abstract
Endometriosis, PCOS, and unexplained infertility are currently the most common diseases rendering large numbers of women infertile worldwide. Oxidative stress, due to its deleterious effects on proteins and nucleic acids, is postulated to be the one of the important mechanistic pathways in differential expression of proteins and in these diseases. The emerging field of proteomics has allowed identification of proteins involved in cell cycle, as antioxidants, extracellular matrix (ECM), cytoskeleton, and their linkage to oxidative stress in female infertility related diseases. The aim of this paper is to assess the association of oxidative stress and protein expression in the reproductive microenvironments such as endometrial fluid, peritoneal fluid, and follicular fluid, as well as reproductive tissues and serum. The review also highlights the literature that proposes the use of the fertility related proteins as potential biomarkers for noninvasive and early diagnosis of the aforementioned diseases rather than utilizing the more invasive methods used currently. The review will highlight the power of proteomic profiles identified in infertility related disease conditions and their linkage with underlying oxidative stress. The power of proteomics will be reviewed with regard to eliciting molecular mechanisms for early detection and management of these infertility related conditions.
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Affiliation(s)
- Sajal Gupta
- Center for Reproductive Medicine, Cleveland Clinic Foundation, 10681 Carnegie Avenue, Desk X11, Cleveland, OH 44195, USA
| | - Jana Ghulmiyyah
- Center for Reproductive Medicine, Cleveland Clinic Foundation, 10681 Carnegie Avenue, Desk X11, Cleveland, OH 44195, USA
| | - Rakesh Sharma
- Center for Reproductive Medicine, Cleveland Clinic Foundation, 10681 Carnegie Avenue, Desk X11, Cleveland, OH 44195, USA
| | - Jacques Halabi
- Center for Reproductive Medicine, Cleveland Clinic Foundation, 10681 Carnegie Avenue, Desk X11, Cleveland, OH 44195, USA
| | - Ashok Agarwal
- Center for Reproductive Medicine, Cleveland Clinic Foundation, 10681 Carnegie Avenue, Desk X11, Cleveland, OH 44195, USA
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Hertel J, Hirche C, Wissmann C, Ebert MP, Höcker M. Transcription of the vascular endothelial growth factor receptor-3 (VEGFR3) gene is regulated by the zinc finger proteins Sp1 and Sp3 and is under epigenetic control: transcription of vascular endothelial growth factor receptor 3. Cell Oncol (Dordr) 2014; 37:131-45. [PMID: 24710631 DOI: 10.1007/s13402-014-0169-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/06/2014] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND In the past, the vascular endothelial growth factor receptor-3 (VEGFR-3) has been linked to the regulation of lymphangiogenesis and the lymphatic spread of solid malignancies. The molecular mechanisms controlling VEGFR3 gene expression have, however, remained poorly understood. Here, we aimed at assessing these mechanisms through VEGFR3 gene promoter analysis and the identification of transcription factors binding to it. In addition, we focussed on epigenetic modifications underlying VEGFR3 transcription regulation. METHODS 5' Deletion analyses for the identification of functional promoter elements, electrophoretic mobility shift assays, chromatin immunoprecipitations, methylation-specific PCRs, and Trichostatin A (TSA) and 5-Aza desoxycytidine (5-Aza dC) treatments were performed in this study. RESULTS Following the isolation of a 2 kb stretch of 5'-flanking DNA of VEGFR3, we identified a novel GC-rich element (GRE) spanning -101/-66 sufficient for VEGFR3 transcription and activated by Sp1 and Sp3, respectively. Histone de-acetylase inhibition by TSA led to the accumulation of acetylated histones H3/H4 at the VEGFR3 gene promoter, up-regulation of its mRNA levels, and transactivation of promoter reporter constructs in endothelial cell lines. Similarly, methylation inhibition by 5-Aza dC triggered up-regulation of VEGFR3 mRNA levels and increased promoter activity. TSA and 5-Aza-dC did not influence Sp1/Sp3 binding, but increased the transactivating capacity of both transcription factors, suggesting epigenetic modification as an underlying mechanism. CONCLUSIONS Here we describe the identification of regulatory elements controlling human VEGFR3 gene expression and show that histone acetylation and CpG methylation are important determinants of VEGFR3 transcription regulation. These findings may facilitate the development of intervention strategies aimed at targeting VEGFR3-based tumor lymphangiogenesis and/or lymphatic tumor spread.
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Affiliation(s)
- Johannes Hertel
- Laboratory for Angiogenesis and Tumor Metastasis, Campus Mitte, Charité University Hospital Berlin, Charitéplatz 1, 10117, Berlin, Germany
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Lin IC, Sheen JM, Tain YL, Chou MH, Huang LT, Yang KD. Vascular Endothelial Growth Factor-A in <i>Lactobacillus Casei </i>Cell Wall Extract-Induced Coronary Arteritis of a Murine Model. Circ J 2014; 78:752-762. [DOI: 10.1253/circj.cj-13-0612] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Affiliation(s)
- I-Chun Lin
- Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine
| | - Jiunn-Ming Sheen
- Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine
| | - You-Lin Tain
- Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine
| | - Ming-Huei Chou
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University
| | - Li-Tung Huang
- Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine
| | - Kuender D. Yang
- Department of Medical Research, Show Chwan Memorial Hospital in Chang Bing
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Agrawal P, Hatzakis E, Guo K, Carver M, Yang D. Solution structure of the major G-quadruplex formed in the human VEGF promoter in K+: insights into loop interactions of the parallel G-quadruplexes. Nucleic Acids Res 2013; 41:10584-92. [PMID: 24005038 PMCID: PMC3905851 DOI: 10.1093/nar/gkt784] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
UNLABELLED Vascular endothelial growth factor (VEGF) proximal promoter region contains a poly G/C-rich element that is essential for basal and inducible VEGF expression. The guanine-rich strand on this tract has been shown to form the DNA G-quadruplex structure, whose stabilization by small molecules can suppress VEGF expression. We report here the nuclear magnetic resonance structure of the major intramolecular G-quadruplex formed in this region in K(+) solution using the 22mer VEGF promoter sequence with G-to-T mutations of two loop residues. Our results have unambiguously demonstrated that the major G-quadruplex formed in the VEGF promoter in K(+) solution is a parallel-stranded structure with a 1:4:1 loop-size arrangement. A unique capping structure was shown to form in this 1:4:1 G-quadruplex. Parallel-stranded G-quadruplexes are commonly found in the human promoter sequences. The nuclear magnetic resonance structure of the major VEGF G-quadruplex shows that the 4-nt middle loop plays a central role for the specific capping structures and in stabilizing the most favored folding pattern. It is thus suggested that each parallel G-quadruplex likely adopts unique capping and loop structures by the specific middle loops and flanking segments, which together determine the overall structure and specific recognition sites of small molecules or proteins. LAY SUMMARY The human VEGF is a key regulator of angiogenesis and plays an important role in tumor survival, growth and metastasis. VEGF overexpression is frequently found in a wide range of human tumors; the VEGF pathway has become an attractive target for cancer therapeutics. DNA G-quadruplexes have been shown to form in the proximal promoter region of VEGF and are amenable to small molecule drug targeting for VEGF suppression. The detailed molecular structure of the major VEGF promoter G-quadruplex reported here will provide an important basis for structure-based rational development of small molecule drugs targeting the VEGF G-quadruplex for gene suppression.
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Affiliation(s)
- Prashansa Agrawal
- Department of Pharmacology and Toxiocology, College of Pharmacy, University of Arizona, 1703 E. Mabel St, Tucson, AZ 85721, USA, Department of Chemistry, University of Arizona, Tucson, AZ 85721, USA, BIO5 Institute, University of Arizona, Tucson, AZ 85721, USA and The Arizona Cancer Center, Tucson, AZ 85724, USA
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Takahashi K, Miyokawa-Gorin K, Handa K, Kitahara A, Moriya R, Onuma H, Sumitani Y, Tanaka T, Katsuta H, Nishida S, Yoshimoto K, Ohno H, Ishida H. Endogenous oxidative stress, but not ER stress, induces hypoxia-independent VEGF120 release through PI3K-dependent pathways in 3T3-L1 adipocytes. Obesity (Silver Spring) 2013; 21:1625-34. [PMID: 23670941 DOI: 10.1002/oby.20206] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 11/14/2012] [Indexed: 01/31/2023]
Abstract
OBJECTIVE Expressions of vascular endothelial growth factor (VEGF) are increased in obese adipocytes and is secreted from obese adipose tissue through hypoxia-independent pathways. Therefore, we investigated the hypoxia-independent mechanism underlying increased expression and release of VEGF in obese adipocytes. DESIGN AND METHODS We compared signal transduction pathways regulating VEGF with those regulating monocyte chemoattractant protein-1 (MCP-1), which is increased in obese adipocytes, in an in vitro model of artificially hypertrophied 3T3-L1 adipocytes preloaded with palmitate, without the influence of hypoxia. RESULTS Palmitate-preloaded cells exhibited significantly enhanced oxidative stress (P < 0.01) and showed increased VEGF120 and MCP-1 release (P < 0.01, respectively), while endoplasmic reticulum (ER) stress was not induced. Increased VEGF120 release was significantly decreased with PI3K inhibitor LY294002 (P < 0.01). In addition, antioxidant N-acetyl-cysteine (NAC) markedly diminished not only VEGF120 secretion (P < 0.01) but also augmented Akt phosphorylation on Ser473 (P < 0.01). In contrast, increased MCP-1 release was suppressed with JNK inhibitor SP600125 and p38 MAPK inhibitor SB203580 (P < 0.01). CONCLUSIONS VEGF120 release from hypertrophied adipocytes can be enhanced through PI3K pathways activated by oxidative stress but not by ER stress, suggesting that VEGF120 secretion is regulated through oxidative stress-dependent pathways distinct from those involved in MCP-1 release through either JNK or p38 MAPK activation.
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Affiliation(s)
- Kazuto Takahashi
- Third Department of Internal Medicine, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
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63
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Pang L, Zhang Y, Yu Y, Zhang S. Resistin promotes the expression of vascular endothelial growth factor in ovary carcinoma cells. Int J Mol Sci 2013; 14:9751-66. [PMID: 23652833 PMCID: PMC3676810 DOI: 10.3390/ijms14059751] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 04/18/2013] [Accepted: 04/24/2013] [Indexed: 12/16/2022] Open
Abstract
Resistin is a novel hormone that is secreted by human adipocytes and mononuclear cells and is associated with obesity, insulin resistance and inflammation. Recently, resistin has been postulated to play a role in angiogenesis. Here, we investigated the hypothesis that resistin regulates ovary carcinoma production of vascular endothelial growth factor (VEGF) and the angiogenic processes. We found that in human ovarian epithelial carcinoma cells (HO-8910), resistin (10–150 ng/mL) enhanced both VEGF protein and mRNA expression in a time- and concentration-dependent manner, as well as promoter activity. Furthermore, resistin enhanced DNA-binding activity of Sp1 with VEGF promoter in a PI3K/Akt-dependent manner. PI3K/Akt activated by resistin led to increasing interaction with Sp1, triggering a progressive phosphorylation of Sp1 on Thr453 and Thr739, resulting in the upregulation of VEGF expression. In an in vitro angiogenesis system for endothelial cells (EA.hy926) co-cultured with HO-8910 cells, we observed that the addition of resistin stimulated endothelial cell tube formation, which could be abolished by VEGF neutralizing antibody. Our findings suggest that the PI3K/Akt-Sp1 pathway is involved in resistin-induced VEGF expression in HO-8910 cells and indicates that antiangiogenesis therapy may be beneficial treatment against ovarian epithelial carcinoma, especially in obese patients.
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Affiliation(s)
- Li Pang
- Department of Obstetrics and Gynecology, Shengjing Hospital Affiliated to China Medical University, Shenyang 110004, Liaoning, China; E-Mails: (L.P.); (Y.Y.)
| | - Yi Zhang
- Department of Gynecology, the First Affiliated Hospital of China Medical University, Shenyang 110001, Liaoning, China; E-Mail:
| | - Yu Yu
- Department of Obstetrics and Gynecology, Shengjing Hospital Affiliated to China Medical University, Shenyang 110004, Liaoning, China; E-Mails: (L.P.); (Y.Y.)
| | - Shulan Zhang
- Department of Obstetrics and Gynecology, Shengjing Hospital Affiliated to China Medical University, Shenyang 110004, Liaoning, China; E-Mails: (L.P.); (Y.Y.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel./Fax: +86-24-966-151-41211
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Chiu CL, Morgan CT, Lupton SJ, Lind JM. Parent of origin influences the cardiac expression of vascular endothelial growth factor (Vegfa). BMC MEDICAL GENETICS 2013; 14:43. [PMID: 23560444 PMCID: PMC3626619 DOI: 10.1186/1471-2350-14-43] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 03/25/2013] [Indexed: 11/10/2022]
Abstract
Background Vascular endothelial growth factor A (VEGFA) is a major regulator of both physiological and pathological angiogenesis. Associations between polymorphisms in VEGFA and complex disease have been inconsistent. The parent from whom the allele was inherited may account for these inconsistencies. This study examined the parent of origin effect on the expression of murine Vegfa. Methods Two homozygous, inbred mouse strains A/J (AJ) and 129x1/SvJ (129) were crossed to produce reciprocal AJ129 and 129AJ offspring, respectively. RNA was extracted from cardiac tissue of 6 week old male (n = 8) and female (n = 8) parental, and male and female F1 offspring mice (AJ129 n = 8 and 129AJ n = 8). Vegfa and Hif1a expression levels were measured by qPCR and compared between the F1 offspring from the reciprocal crosses. Results We found significant differences in the expression of Vegfa in F1 offspring (AJ129 and 129AJ mice) of the reciprocal crosses between AJ and 129 mice. Offspring of male AJ mice had significantly higher expression of Vegfa than offspring of male 129 mice (p = 0.006). This difference in expression was not the result of preferential allele expression (allelic imbalance). Expression of Hif1a, a transcriptional regulator of Vegfa expression, was also higher in F1 offspring of an AJ father (p = 0.004). Conclusion Differences in Vegfa and Hif1a gene expression are likely the result of an upstream angiogenic regulator gene that is influenced by the parent of origin. These results highlight the importance of including inheritance information, such as parent of origin, when undertaking allelic association studies.
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Affiliation(s)
- Christine L Chiu
- University of Western Sydney, School of Medicine, Penrith, NSW 2751, Locked Bag 1797, Australia.
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Sinha S, Pal K, Elkhanany A, Dutta S, Cao Y, Mondal G, Iyer S, Somasundaram V, Couch FJ, Shridhar V, Bhattacharya R, Mukhopadhyay D, Srinivas P. Plumbagin inhibits tumorigenesis and angiogenesis of ovarian cancer cells in vivo. Int J Cancer 2013; 132:1201-12. [PMID: 22806981 PMCID: PMC3496826 DOI: 10.1002/ijc.27724] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 06/25/2012] [Indexed: 11/11/2022]
Abstract
Angiogenesis is a hallmark of tumor development and metastatic progression, and anti-angiogenic drugs targeting the VEGF pathway have shown to decrease the disease progression in cancer patients. In this study, we have analyzed the anti-proliferative and anti-angiogenic property of plumbagin in cisplatin sensitive, BRCA2 deficient, PEO-1 and cisplatin resistant, BRCA2 proficient PEO-4 ovarian cancer cells. Both PEO-1 and PEO-4 ovarian cancer cells are sensitive to plumbagin irrespective of BRCA2 status in both normoxia and hypoxia. Importantly, plumbagin treatment effectively inhibits VEGF-A and Glut-1 in PEO-1 and PEO-4 ovarian cancer cells. We have also analyzed the p53 mutant, cisplatin resistant, and BRCA2 proficient OVCAR-5 cells. Plumbagin challenge also restricts the VEGF induced pro-angiogenic signaling in HUVECs and subsequently endothelial cell proliferation. In addition, we observe a significant effect on tumor regression among OVCAR-5 tumor-bearing mice treated with plumbagin, which is associated with significant inhibition of Ki67 and vWF expressions. Plumbagin also significantly reduces CD31 expression in an ear angiogenesis assay. Collectively, our studies indicate that plumbagin, as an anti-cancer agent disrupts growth of ovarian cancer cells through the inhibition of proliferation as well as angiogenesis.
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Affiliation(s)
- Sutapa Sinha
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN-55905
| | - Krishnendu Pal
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN-55905
| | | | - Shamit Dutta
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN-55905
| | - Ying Cao
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN-55905
| | - Gourish Mondal
- Department of Laboratory medicine and Pathology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN-55905
| | - Seethalakshmi Iyer
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN-55905
| | - Veena Somasundaram
- Rajiv Gandhi Centre for Biotechnology, Thycaud PO, Thiruvananthapuram 695014, Kerala, India
| | - Fergus J. Couch
- Department of Laboratory medicine and Pathology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN-55905
| | - Viji Shridhar
- Department of Laboratory medicine and Pathology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN-55905
| | - Resham Bhattacharya
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN-55905
| | - Debabrata Mukhopadhyay
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN-55905
| | - Priya Srinivas
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN-55905
- Rajiv Gandhi Centre for Biotechnology, Thycaud PO, Thiruvananthapuram 695014, Kerala, India
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66
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Distribution of selenium and oxidative stress in breast tumor-bearing mice. Nutrients 2013; 5:594-607. [PMID: 23429470 PMCID: PMC3635215 DOI: 10.3390/nu5020594] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 01/29/2013] [Accepted: 02/05/2013] [Indexed: 01/08/2023] Open
Abstract
The present study investigated the effects of breast tumors on the blood and tissue distribution of essential trace mineral selenium (Se), and oxidative stress status of mice. Female 10-week-old BALB/cByJNarl mice were randomly assigned into control (CNL) and breast tumor-bearing (TB) groups. TB mice were injected subcutaneously into the right hind thigh with 5 × 10(6) EMT6 mouse mammary tumor cells. After 22 days, we measured Se concentrations, Se-dependent glutathione peroxidase (GPx) activities, and malondialdehyde (MDA) products (indicator of oxidative stress) in plasma, various tissues, and plasma vascular endothelial growth factor (VEGF) concentrations. There were no significant differences in body weights and daily intake between both groups. Compared with the CNL group, TB mice have decreases in plasma Se concentrations and GPx activities, as well as higher plasma VEGF and MDA concentrations. Plasma Se concentrations were also negatively correlated with plasma MDA and VEGF concentrations. Furthermore, tissue Se concentrations and GPx activities in TB animals were lower; whereas the MDA concentrations higher in various tissues including liver, kidney, brain, lung, spleen, and thymic tissues. In conclusion, disruption of Se homeostasis critically reflects oxidative stress in target tissues, thus may increase the risk for progression of breast cancer and metastasis.
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67
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Eisermann K, Broderick CJ, Bazarov A, Moazam MM, Fraizer GC. Androgen up-regulates vascular endothelial growth factor expression in prostate cancer cells via an Sp1 binding site. Mol Cancer 2013; 12:7. [PMID: 23369005 PMCID: PMC3616929 DOI: 10.1186/1476-4598-12-7] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 01/21/2013] [Indexed: 11/26/2022] Open
Abstract
Background Vascular Endothelial Growth Factor (VEGF) is regulated by a number of different factors, but the mechanism(s) behind androgen-mediated regulation of VEGF in prostate cancer are poorly understood. Results Three novel androgen receptor (AR) binding sites were discovered in the VEGF promoter and in vivo binding of AR to these sites was demonstrated by chromatin immunoprecipitation. Mutation of these sites attenuated activation of the VEGF promoter by the androgen analog, R1881 in prostate cancer cells. The transcription factors AR and Sp1 were shown to form a nuclear complex and both bound the VEGF core promoter in chromatin of hormone treated CWR22Rv1 prostate cancer cells. The importance of the Sp1 binding site in hormone mediated activation of VEGF expression was demonstrated by site directed mutagenesis. Mutation of a critical Sp1 binding site (Sp1.4) in the VEGF core promoter region prevented activation by androgen. Similarly, suppression of Sp1 binding by Mithramycin A treatment significantly reduced VEGF expression. Conclusions Our mechanistic study of androgen mediated induction of VEGF expression in prostate cancer cells revealed for the first time that this induction is mediated through the core promoter region and is dependent upon a critical Sp1 binding site. The importance of Sp1 binding suggests that therapy targeting the AR-Sp1 complex may dampen VEGF induced angiogenesis and, thereby, block prostate cancer progression, helping to maintain the indolent form of prostate cancer.
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Affiliation(s)
- Kurtis Eisermann
- School of Biomedical Sciences, Kent State University, Kent, OH, USA
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68
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Saito M, Kohara M, Tsukiyama-Kohara K. Hepatitis C virus promotes expression of the 3β-hydroxysterol δ24-reductase through Sp1. J Med Virol 2012; 84:733-46. [PMID: 22431021 DOI: 10.1002/jmv.23250] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Hepatitis C virus (HCV) establishes chronic infection, which often causes hepatocellular carcinoma. Overexpression of 3β-hydroxysterol Δ24-reductase (DHCR24) by HCV has been shown to impair the p53-mediated cellular response, resulting in tumorigenesis. In the present study, the molecular mechanism by which HCV promotes the expression of DHCR24 was investigated. A significant increase in DHCR24 mRNA transcription was observed in a cell line expressing complete HCV genome, whereas no significant difference in the expression of DHCR24 was seen in cell lines expressing individual viral proteins. The 5'-flanking genomic region of DHCR24 was characterized to explore the genomic region and host factor(s) involved in the transcriptional regulation of DHCR24. As a result, the HCV response element (-167/-140) was identified, which contains AP-2α, MZF-1, and Sp1 binding motifs. The binding affinity of the host factor to this response element was increased in nuclear extracts from cells infected with HCV and corresponded with augmented affinity of Sp1. Both mithramycin A (Sp1 inhibitor) and small interfering RNA targeting Sp1 prevented the binding of host factors to the response element. Silencing of Sp1 also downregulated the increased expression of DHCR24. The binding affinity of Sp1 to the response element was augmented by oxidative stress, whereas upregulation of DHCR24 in cells expressing HCV was blocked significantly by a reactive oxygen species scavenger. Elevated phosphorylation of Sp1 in response to oxidative stress was mediated by the ATM kinase. Thus, activation of Sp1 by oxidative stress is involved in the promotion of expression of DHCR24 by HCV.
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Affiliation(s)
- Makoto Saito
- Department of Experimental Phylaxiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
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69
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Vandhana S, Lakshmi TSR, Indra D, Deepa PR, Krishnakumar S. Microarray Analysis and Biochemical Correlations of Oxidative Stress Responsive Genes in Retinoblastoma. Curr Eye Res 2012; 37:830-41. [DOI: 10.3109/02713683.2012.678544] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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70
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Feng J, Zhang Y, Xing D. Low-power laser irradiation (LPLI) promotes VEGF expression and vascular endothelial cell proliferation through the activation of ERK/Sp1 pathway. Cell Signal 2012; 24:1116-25. [PMID: 22326662 DOI: 10.1016/j.cellsig.2012.01.013] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 01/10/2012] [Accepted: 01/26/2012] [Indexed: 12/11/2022]
Abstract
Angiogenesis, the growth of new blood vessels from pre-existing vessels, represents an excellent therapeutic target for the treatment of wound healing and cardiovascular disease. Herein, we report that LPLI (low-power laser irradiation) activates ERK/Sp1 (extracellular signal-regulated kinase/specificity protein 1) pathway to promote VEGF expression and vascular endothelial cell proliferation. We demonstrate for the first time that LPLI enhances DNA-binding and transactivation activity of Sp1 on VEGF promoter in vascular endothelial cells. Moreover, Sp1-regulated transcription is in an ERK-dependent manner. Activated ERK by LPLI translocates from cytoplasm to nuclear and leads to increasing interaction with Sp1, triggering a progressive phosphorylation of Sp1 on Thr453 and Thr739, resulting in the upregulation of VEGF expression. Furthermore, selective inhibition of Sp1 by mithramycin-A or shRNA suppresses the promotion effect of LPLI on cell cycle progression and proliferation, which is also significantly abolished by inhibition of ERK activity. These findings highlight the important roles of ERK/Sp1 pathway in angiogenesis, supplying potential strategy for angiogenesis-related diseases with LPLI treatment.
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Affiliation(s)
- Jie Feng
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China
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71
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Azar WJ, Azar SHX, Higgins S, Hu JF, Hoffman AR, Newgreen DF, Werther GA, Russo VC. IGFBP-2 enhances VEGF gene promoter activity and consequent promotion of angiogenesis by neuroblastoma cells. Endocrinology 2011; 152:3332-42. [PMID: 21750048 DOI: 10.1210/en.2011-1121] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
IGF binding protein (IGFBP)-2 is one of the most significant genes in the signature of major aggressive cancers. Previously, we have shown that IGFBP-2 enhances proliferation and invasion of neuroblastoma cells, suggesting that IGFBP-2 activates a protumorigenic gene expression program in these cells. Gene expression profiling in human neuroblastoma SK-N-SHEP (SHEP)-BP-2 cells indicated that IGFBP-2 overexpression activated a gene expression program consistent with enhancement of tumorigenesis. Regulation was significant for genes involved in proliferation/survival, migration/adhesion, and angiogenesis, including the up-regulation of vascular endothelial growth factor (VEGF) mRNA (>2-fold). Specific transcriptional activation of the VEGF gene by IGFBP-2 overexpression was demonstrated via cotransfection of a VEGF promoter Luciferase construct in SHEP-BP-2. Cotransfection of VEGF promoter Luciferase construct with IGFBP-2 protein in wild-type SHEP cells indicated that transactivation of VEGF promoter only occurs in the presence of intracellular IGFBP-2. Cell fractionation and immunofluorescence in SHEP-BP-2 cells demonstrated nuclear localization of IGFBP-2. These findings suggest that transcriptional activation of VEGF promoter is likely to be mediated by nuclear IGFBP-2. The levels of secreted VEGF (up to 400 pg/10(6) cells) suggested that VEGF might elicit angiogenic activity. Hence, SHEP-BP-2 cells and control clones cultured in collagen sponge were xenografted onto chick embryo chorioallantoic membrane. Neomicrovascularization was observed by 72 h, solely in the SHEP-BP-2 cell xenografts. In conclusion, our data indicate that IGFBP-2 is an activator of aggressive behavior in cancer cells, involving nuclear entry and activation of a protumorigenic gene expression program, including transcriptional regulation of the VEGF gene and consequent proangiogenic activity of NB cell xenografts in vivo.
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Affiliation(s)
- Walid J Azar
- Centre for Hormone Research, Cell Biology, Murdoch Childrens Research Institute, Royal Children's Hospital, Flemington Road, Parkville 3052, Victoria, Australia
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72
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Weigent DA. High molecular weight isoforms of growth hormone in cells of the immune system. Cell Immunol 2011; 271:44-52. [PMID: 21741628 DOI: 10.1016/j.cellimm.2011.06.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 05/06/2011] [Accepted: 06/01/2011] [Indexed: 01/05/2023]
Abstract
A substantial body of research exists to support the idea that cells of the immune system produce growth hormone (GH). However, the structure and mechanism of action of lymphocyte-derived GH continues to remain largely unknown. Here we present the results of Western analysis of whole cell extracts showing that different molecular weight isoforms of GH of approximately 100, 65, and 48 kDa can be detected in primary mouse cells of the immune system and in the mouse EL4 cell line. The identity of the 65 and 48 kDa isoforms of GH were confirmed by mass spectrometry. The various isoforms were detected in both enriched T and B spleen cell populations. The large molecular weight isoform appears to reside primarily in the cytoplasm, whereas the lower molecular weight 65 and 48 kDa isoforms were detected primarily in the nucleus. These results also suggest that GH isoforms are induced by oxidative stress. In EL4 cells overexpressing GH, the expression of luciferase controlled by a promoter containing the antioxidant response element is increased almost threefold above control. The data suggest that the induction of isoforms of the GH molecule in cells of the immune system may be an important mechanism of adaptation and/or protection of lymphoid cells under conditions of oxidative stress.
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Affiliation(s)
- Douglas A Weigent
- University of Alabama at Birmingham, Department of Physiology and Biophysics, Birmingham, AL 35294-0005, United States.
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73
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Ray A, Dhar S, Ray BK. Control of VEGF expression in triple-negative breast carcinoma cells by suppression of SAF-1 transcription factor activity. Mol Cancer Res 2011; 9:1030-41. [PMID: 21665940 DOI: 10.1158/1541-7786.mcr-10-0598] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Angiogenesis plays a significant role in cancer by providing increased blood supply to the affected tissues and thus bringing in growth factors, cytokines, and various nutrients for tumor growth. VEGF is the most prominent angiogenic agent that is markedly induced in cancer. Induction of VEGF has been widely studied but as cancer cells are quite adept at acquiring new alternative processes to circumvent surrounding environmental pressures, our understanding of the molecular mechanisms regulating VEGF expression in cancer, especially in triple-negative breast cancer cells, remains incomplete. Here, we present evidence of a novel mode of VEGF induction in triple-negative MDA-MB-231 breast cancer cells that is regulated by serum amyloid A activating factor 1 (SAF-1) transcription factor. Inhibition of SAF-1 by antisense short hairpin RNA profoundly reduces VEGF expression along with reduction in endothelial cell proliferation and migration. By both in vitro and in vivo molecular studies, we show that the effect of SAF-1 is mediated through its direct interaction with the VEGF promoter. In correlation, DNA-binding activity of SAF-1 is found to be significantly higher in MDA-MB-231 breast cancer cells. Examination of several breast cancer samples further revealed that SAF-1 is overexpressed in clinical breast cancer tissues. Taken together, these findings reveal that SAF-1 is a hitherto unrecognized participant in inducing VEGF expression in triple-negative breast cancer cells, an aggressive form of breast cancer that currently lacks effective treatment options. Suppression of SAF-1 activity in these cells can inhibit VEGF expression, providing a possible new method to control angiogenesis.
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Affiliation(s)
- Alpana Ray
- Department of Veterinary Pathobiology, University of Missouri, 124 Connaway Hall, Columbia, MO 65211, USA.
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74
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SUMO2 and SUMO3 transcription is differentially regulated by oxidative stress in an Sp1-dependent manner. Biochem J 2011; 435:489-98. [DOI: 10.1042/bj20101474] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Protein SUMOylation (SUMO is small ubiquitin-related modifier) is a dynamic process that is strictly regulated under physiological and pathological conditions. However, little is known about how various intra- or extra-cellular stimuli regulate expression levels of components in the SUMO system. SUMO isoforms SUMO2 and SUMO3 can rapidly convert to be conjugated in response to a variety of cellular stresses. Owing to the limitations of sequence homology, SUMO2 and SUMO3 cannot be differentiated between and are thus referred to as SUMO2/3. Whether these two isoforms are regulated in distinct manners has never been addressed. In the present paper we report that the expression of SUMO3, but not SUMO2, can be down-regulated at the transcription level by cellular oxidative stress. In the present study, we checked SUMO2 and SUMO3 mRNA levels in cells exposed to various doses of H2O2 and in cells bearing different levels of ROS (reactive oxygen species). We found an inverse relationship between SUMO3 transcription and ROS levels. We characterized a promoter region specific for the mouse Sumo3 gene that is bound by the redox-sensitive transcription factor Sp1 (specificity protein 1) and demonstrated oxidation of Sp1, as well as suppression of Sp1–DNA binding upon oxidative stress. This revealed for the first time that the expression of SUMO2 and SUMO3 is regulated differently by ROS. These findings may enhance our understanding about the regulation of SUMOylation and also shed light on the functions of Sp1.
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75
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Tammali R, Reddy ABM, Srivastava SK, Ramana KV. Inhibition of aldose reductase prevents angiogenesis in vitro and in vivo. Angiogenesis 2011; 14:209-21. [PMID: 21409599 DOI: 10.1007/s10456-011-9206-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Accepted: 03/05/2011] [Indexed: 02/06/2023]
Abstract
We have recently shown that aldose reductase (AR, EC 1.1.1.21) a nicotinamide adenine dinucleotide phosphate-dependent aldo-keto reductase, known to be involved in oxidative stress-signaling, prevents human colon cancer cell growth in culture as well as in nude mice xenografts. Inhibition of AR also prevents azoxymethane-induced aberrant crypt foci formation in mice. In order to understand the chemopreventive mechanism(s) of AR inhibition in colon cancer, we have investigated the role of AR in the mediation of angiogenic signals in vitro and in vivo models. Our results show that inhibition of AR significantly prevented the VEGF- and FGF -induced proliferation and expression of proliferative marker Ki67 in the human umbilical vein endothelial cells (HUVEC). Further, AR inhibition or ablation with siRNA prevented the VEGF- and FGF -induced invasion and migration in HUVEC. AR inhibition also prevented the VEGF- and FGF- induced secretion/expression of IL-6, MMP2, MMP9, ICAM, and VCAM. The anti-angiogenic feature of AR inhibition in HUVEC was associated with inactivation of PI3 K/AKT and NF-κB (p65) and suppression of VEGF receptor 2 protein levels. Most importantly, matrigel plug model of angiogenesis in rats showed that inhibition of AR prevented infiltration of blood cells, invasion, migration and formation of capillary like structures, and expression of blood vessels markers CD31 and vWF. Thus, our results demonstrate that AR inhibitors could be novel agents to prevent angiogenesis.
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Affiliation(s)
- Ravinder Tammali
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
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76
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Sun D, Guo K, Shin YJ. Evidence of the formation of G-quadruplex structures in the promoter region of the human vascular endothelial growth factor gene. Nucleic Acids Res 2011; 39:1256-65. [PMID: 20959293 PMCID: PMC3045601 DOI: 10.1093/nar/gkq926] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 09/24/2010] [Accepted: 09/27/2010] [Indexed: 11/29/2022] Open
Abstract
The polypurine/polypyrimidine (pPu/pPy) tract of the human vascular endothelial growth factor (VEGF) gene is proposed to be structurally dynamic and to have potential to adopt non-B DNA structures. In the present study, we further provide evidence for the existence of the G-quadruplex structure within this tract both in vitro and in vivo using the dimethyl sulfate (DMS) footprinting technique and nucleolin as a structural probe specifically recognizing G-quadruplex structures. We observed that the overall reactivity of the guanine residues within this tract toward DMS was significantly reduced compared with other guanine residues of the flanking regions in both in vitro and in vivo footprinting experiments. We also demonstrated that nucleolin, which is known to bind to G-quadruplex structures, is able to bind specifically to the G-rich sequence of this region in negatively supercoiled DNA. Our chromatin immunoprecipitation analysis further revealed binding of nucleolin to the promoter region of the VEGF gene in vivo. Taken together, our results are in agreement with our hypothesis that secondary DNA structures, such as G-quadruplexes, can be formed in supercoiled duplex DNA and DNA in chromatin in vivo under physiological conditions similar to those formed in single-stranded DNA templates.
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Affiliation(s)
- Daekyu Sun
- College of Pharmacy, University of Arizona, Tucson, AZ 85721, USA.
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77
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Heo J. Redox control of GTPases: from molecular mechanisms to functional significance in health and disease. Antioxid Redox Signal 2011; 14:689-724. [PMID: 20649471 DOI: 10.1089/ars.2009.2984] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Small GTPases, including the proto-oncoprotein Ras and Rho GTPases, are involved in various cellular signaling events. Some of these small GTPases are redox sensitive, including Ras, Rho, Ran, Dexras1, and Rhes GTPases. Thus, the redox-mediated regulation of these GTPases often determines the course of their cellular signaling cascades. This article takes into consideration the application of Marcus theory to potential redox-based molecular mechanisms in the regulation of these redox-sensitive GTPases and the relevance of such mechanisms to a specific redox-sensitive motif. The discussion also takes into account various diseases, including cancers, heart, and neuronal disorders, that are often linked with the dysregulation of the redox signaling cascades associated with these redox-sensitive GTPases.
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Affiliation(s)
- Jongyun Heo
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019, USA.
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Hota SK, Hota KB, Prasad D, Ilavazhagan G, Singh SB. Oxidative-stress-induced alterations in Sp factors mediate transcriptional regulation of the NR1 subunit in hippocampus during hypoxia. Free Radic Biol Med 2010; 49:178-91. [PMID: 20381604 DOI: 10.1016/j.freeradbiomed.2010.03.027] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Revised: 03/16/2010] [Accepted: 03/30/2010] [Indexed: 11/23/2022]
Abstract
Ascent to high altitude is associated with tissue hypoxia resulting from the decrease in partial pressure of atmospheric oxygen. The hippocampus, in particular, is highly vulnerable to hypoxic insult, which at least in part can be attributed to the occurrence of glutamate excitotoxicity. Although this excitotoxic damage is often related to increased NMDA receptor activation and subsequent calcium-mediated free radical generation, the mechanisms involving the transcriptional regulation of NMDA receptor subunit expression by hypoxic stress remains to be explored. Our study reveals a novel mechanism for the regulation of expression of the NR1 subunit of NMDA receptors by the Sp family of transcription factors through an oxidative-stress-mediated mechanism that also involves the molecular chaperone Hsp90. The findings not only show the occurrence of lipid peroxidation and DNA damage in hippocampal cells exposed to hypoxia but also reveal a calcium-independent mechanism of selective oxidation and degradation of Sp3 by the 20S proteasome. This along with increased DNA binding activity of Sp1 leads to NR1 upregulation in the hippocampus during hypoxic stress. The study therefore provides evidence for free radical-mediated regulation of gene expression in hypoxia and the scope of the use of antioxidants in preventing excitotoxic neuronal damage during hypoxia.
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Affiliation(s)
- Sunil Kumar Hota
- Defence Institute of High Altitude Research, Leh, Ladakh, Jammu and Kashmir, India
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Ellrichmann M, Ritter PR, Schrader H, Schmidt WE, Meier JJ, Schmitz F. Gastrin stimulates the VEGF-A promotor in a human colon cancer cell line. ACTA ACUST UNITED AC 2010; 165:146-50. [PMID: 20600355 DOI: 10.1016/j.regpep.2010.06.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 05/26/2010] [Accepted: 06/22/2010] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Hypergastrinemia has been observed in patients suffering from colorectal cancer. Vascular endothelial growth factor (VEGF) is known to play a pivotal role in tumour growth. Therefore, we addressed whether gastrin-17-gly and gastrin-17-amide regulate VEGF-A-gene and protein expression. MATERIALS AND METHODS Colo-320-cells were stably transfected with a VEGF-Luciferase-reporter gene. Luciferase activity was assessed after stimulation with various gastrin concentrations. Relevant promotor elements were identified by deletion analyses. VEGF protein levels in culture supernatants were quantified by ELISA. RESULTS VEGF-A stimulation with gastrin induced a dose- and time-dependent stimulation of luciferase activity. The greatest activities were found 6h after stimulation at concentrations of 10(-)(6)mmol/l. VEGF-promotor expression resulted in significantly (p<0.05) increased VEGF-A protein secretion. These effects were restricted to gastrin-17-amide. CONCLUSION Gastrin-17-amide enhances VEGF-A gene and protein expression in Colo320 cells stably transfected with a wild-type CCK-B/gastrin receptor. The induction of VEGF-A transcription and translation may contribute to the carcinogenic effects of gastrin observed in clinical studies. Therefore, CCK-B receptor antagonists may represent a treatment strategy in patients with colorectal cancer.
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Affiliation(s)
- Mark Ellrichmann
- Department of Medicine I, St. Josef Hospital, Ruhr-University Bochum, Gudrunstrasse 56, Bochum, Germany.
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Leptin upregulates VEGF in breast cancer via canonic and non-canonical signalling pathways and NFkappaB/HIF-1alpha activation. Cell Signal 2010; 22:1350-62. [PMID: 20466060 DOI: 10.1016/j.cellsig.2010.05.003] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Accepted: 05/05/2010] [Indexed: 01/26/2023]
Abstract
High levels of VEGF and leptin are strongly linked to worse prognosis of breast cancer. Leptin signalling upregulates VEGF in human and mouse mammary tumor cells (MT), but the specific molecular mechanisms are largely unknown. Pharmacologic and genetic approaches were used to dissect the mechanism of leptin regulation of VEGF protein and mRNA in MT (4T1, EMT6 and MMT). A series of VEGF-promoter Luc-reporters (full-length and transcription factor-binding deletions) were transfected into MT to analyze leptin regulation of VEGF transcription. Deletion analysis of VEGF promoter and RNA knockdown shows that HIF-1alpha and NFkappaB are essentials for leptin regulation of VEGF. Leptin activation of HIF-1alpha was mainly linked to canonic (MAPK, PI-3K) and non-canonic (PKC, JNK and p38 MAP) signalling pathways. Leptin non-canonic signalling pathways (JNK, p38 MAP and to less extent PKC) were linked to NFkappaB activation. SP1 was involved in leptin regulation of VEGF in 4T1 cells. AP1 was not involved and AP2 repressed leptin-induced increase of VEGF. Overall, these data suggest that leptin signalling regulates VEGF mainly through HIF-1alpha and NFkappaB. These results delineate a comprehensive mechanism for leptin regulation of VEGF in MT. Disruption of leptin signalling could be used as a novel way to treat breast cancer.
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Abstract
Polypurine/polypyrimidine (pPu/pPy) tracts, which exist in the promoter regions of many growth-related genes, have been proposed to be very dynamic in their conformation. In this chapter, we describe a detailed protocol for DNase I and S1 nuclease footprinting experiments with supercoiled plasmid DNA containing the promoter regions to probe whether there are conformational transitions to B-type DNA, melted DNA, and G-quadruplex structures within this tract. This is demonstrated with the proximal promoter region of the human vascular endothelial growth factor (VEGF) gene, which also contains multiple binding sites for Sp1 and Egr-1 transcription factors.
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82
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Zhuge Y, Liu ZJ, Habib B, Velazquez OC. Diabetic foot ulcers: effects of hyperoxia and SDF-1α on endothelial progenitor cells. Expert Rev Endocrinol Metab 2010; 5:113-125. [PMID: 30934386 DOI: 10.1586/eem.09.61] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Diabetes mellitus is a common disease afflicting many people. In addition to coronary artery disease, diabetic retinopathy and renal failure, diabetic patients face abnormal wound healing and have increased lower extremity ulcers and amputations. In diabetes, wound healing is altered due to both macrovascular and microvascular processes. While the former can be addressed with surgical intervention, the latter is more difficult to correct. Neovascularization within the granulation tissue via angiogenesis and vasculogenesis is critical for wound healing. Endothelial progenitor cells (EPCs) have been implicated in vasculogenesis. Mobilization of EPCs from the bone marrow is impaired in diabetes and homing of EPCs to the wound is also abnormal. Recent studies show that hyperoxia and administration of exogenous stromal-derived factor-1α increases circulatory and wound levels of EPCs and improves wound healing in diabetic mice. These findings have great potential for translation into human counterparts as the treatment for this prevalent disease matures.
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Affiliation(s)
- Ying Zhuge
- a University of Miami, Sylvester Comprehensive Cancer Center, Miami, FL, USA
| | - Zhao-Jun Liu
- b University of Miami Sylvester Comprehensive Cancer Center, Miami, FL, USA and Division of Vascular and Endovascular Surgery, DeWitt Daughtry Family Department of Surgery, University of Miami Miller School of Medicine, Room 3016, Holtz Center - JMH East Tower, 1611 NW 12th Avenue, Miami, FL 33136, USA
| | - Bianca Habib
- a University of Miami, Sylvester Comprehensive Cancer Center, Miami, FL, USA
| | - Omaida C Velazquez
- c University of Miami, Sylvester Comprehensive Cancer Center, Miami, FL, USA and Chief, Division of Vascular and Endovascular Surgery, DeWitt Daughtry Family Department of Surgery, University of Miami, Miller School of Medicine, Room 3016, Holtz Center - JMH East Tower, 1611 NW 12th Avenue, Miami, FL 33136, USA.
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83
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Cho SG, Yi Z, Pang X, Yi T, Wang Y, Luo J, Wu Z, Li D, Liu M. Kisspeptin-10, a KISS1-derived decapeptide, inhibits tumor angiogenesis by suppressing Sp1-mediated VEGF expression and FAK/Rho GTPase activation. Cancer Res 2009; 69:7062-70. [PMID: 19671799 PMCID: PMC3242001 DOI: 10.1158/0008-5472.can-09-0476] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Kisspeptin-10 (Kp-10), a decapeptide derived from the primary translation product of KISS1 gene, has been reported previously to be a key hormone for puberty and an inhibitor for tumor metastasis via the activation of G protein-coupled receptor 54. However, whether Kp-10 inhibits angiogenesis, which is critical for tumor growth and metastasis and other human diseases, is still unknown. Here we show that Kp-10 significantly inhibits human umbilical vein endothelial cell (HUVEC) migration, invasion, and tube formation, key processes in angiogenesis. Using chicken chorioallantoic membrane assay and vascular endothelial growth factor (VEGF)-induced mouse corneal micropocket assay, we show that Kp-10 inhibits angiogenesis in vivo. Furthermore, Kp-10 inhibits tumor growth in severe combined immunodeficient mice xenografted with human prostate cancer cells (PC-3) through inhibiting tumor angiogenesis, whereas Kp-10 has little effect on the proliferation of HUVECs and human prostate cancer cells. In deciphering the underlying molecular mechanisms, we show that Kp-10 suppresses VEGF expression by inhibiting the binding of specificity protein 1 to VEGF promoter and by blocking the activation of c-Src/focal adhesion kinase and Rac/Cdc42 signaling pathways in HUVECs, leading to the inhibition of tumor angiogenesis.
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Affiliation(s)
- Sung-Gook Cho
- Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology and Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, Houston, Texas 77030, USA
- Interdisciplinary Genetics Program, Texas A&M University, College Station, TX77843
| | - Zhengfang Yi
- Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology and Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, Houston, Texas 77030, USA
- Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China
| | - Xiufeng Pang
- Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology and Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, Houston, Texas 77030, USA
- Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China
| | - Tingfang Yi
- Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China
| | - Ying Wang
- Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology and Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, Houston, Texas 77030, USA
| | - Jian Luo
- Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China
| | - Zirong Wu
- Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China
| | - Dali Li
- Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China
| | - Mingyao Liu
- Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology and Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, Houston, Texas 77030, USA
- Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China
- Interdisciplinary Genetics Program, Texas A&M University, College Station, TX77843
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84
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Regulation of RASSF1A in nasopharyngeal cells and its response to UV irradiation. Gene 2009; 443:55-63. [DOI: 10.1016/j.gene.2009.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 05/04/2009] [Accepted: 05/12/2009] [Indexed: 11/15/2022]
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85
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McFee RM, Artac RA, McFee RM, Clopton DT, Smith RAL, Rozell TG, Cupp AS. Inhibition of vascular endothelial growth factor receptor signal transduction blocks follicle progression but does not necessarily disrupt vascular development in perinatal rat ovaries. Biol Reprod 2009; 81:966-77. [PMID: 19605787 DOI: 10.1095/biolreprod.109.078071] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We hypothesized that vascular endothelial growth factor A (VEGFA) angiogenic isoforms and their receptors, FLT1 and KDR, regulate follicular progression in the perinatal rat ovary. Each VEGFA angiogenic isoform has unique functions (based on its exons) that affect diffusibility, cell migration, branching, and development of large vessels. The Vegfa angiogenic isoforms (Vegfa_120, Vegfa_164, and Vegfa_188) were detected in developing rat ovaries, and quantitative RT-PCR determined that Vegfa_120 and Vegfa_164 mRNA was more abundant after birth, while Vegfa_188 mRNA was highest at Embryonic Day 16. VEGFA and its receptors were localized to pregranulosa and granulosa cells of all follicle stages and to theca cells of advanced-stage follicles. To determine the role of VEGFA in developing ovaries, Postnatal Day 3/4 rat ovaries were cultured with 8 muM VEGFR-TKI, a tyrosine kinase inhibitor that blocks FLT1 and KDR. Ovaries treated with VEGFR-TKI had vascular development reduced by 94% (P < 0.0001), with more primordial follicles (stage 0), fewer early primary, transitional, and secondary follicles (stages 1, 3, and 4, respectively), and greater total follicle numbers compared with control ovaries (P < 0.005). V1, an inhibitor specific for KDR, was utilized to determine the effects of only KDR inhibition. Treatment with 30 muM V1 had no effect on vascular density; however, treated ovaries had fewer early primary, transitional, and secondary follicles and more primary follicles (stage 2) compared with control ovaries (P < 0.05). We conclude that VEGFA may be involved in primordial follicle activation and in follicle maturation and survival, which are regulated through vascular-dependent and vascular-independent mechanisms.
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Affiliation(s)
- Renee M McFee
- Department of Animal Science, Kansas State University, Manhattan, Kansas, USA
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86
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Eyries M, Collins T, Khachigian LM. Modulation of Growth Factor Gene Expression in Vascular Cells by Oxidative Stress. ACTA ACUST UNITED AC 2009; 11:133-9. [PMID: 15370072 DOI: 10.1080/10623320490482691] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Reactive oxygen species (ROS) generated in and around vascular endothelium may play a role in normal cellular signaling mechanisms but may also be an important causative factor in endothelial dysfunction underlying the development of atherosclerosis, diabetes complications, and ischemia-reperfusion injury. ROS influence a variety of molecular and cellular activities, including changes in the cellular localization of regulatory factors, protein modification, and altered gene expression, which in turn influence cellular phenotype. One mechanism by which ROS exert their cellular effects involves their ability to modulate the expression and function of vascular genes, such as vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), and platelet-derived growth factor (PDGF), which play key atherogenic roles by their regulation of cell growth, differentiation, and fibroproliferative responsiveness. In this review the authors describe the changes induced by oxidative stress on the profile of growth factor gene expression in endothelial cells, and the impact these modifications have on endothelial phenotype as well as on the behavior of neighboring vascular smooth muscle cells and fibroblasts. The authors also discuss the involvement of redox-sensitive transcription factors in these regulatory processes.
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Affiliation(s)
- Melanie Eyries
- The Centre for Vascular Research, Department of Pathology, The University of New South Wales, Sydney, Australia
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87
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Kim S, Choi JH, Lim HI, Lee SK, Kim WW, Kim JS, Kim JH, Choe JH, Yang JH, Nam SJ, Lee JE. Silibinin prevents TPA-induced MMP-9 expression and VEGF secretion by inactivation of the Raf/MEK/ERK pathway in MCF-7 human breast cancer cells. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2009; 16:573-580. [PMID: 19181503 DOI: 10.1016/j.phymed.2008.11.006] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Accepted: 11/19/2008] [Indexed: 05/27/2023]
Abstract
Matrix metalloproteinase-9 (MMP-9) and vascular endothelial growth factor (VEGF) expression are pivotal steps in cancer metastasis. Herein, we investigated the effect of silibinin, a major constituent (flavanolignan) of the fruits of Silybum marianum, on 12-O-tetradecanoyl phorbol-13-acetate (TPA)-induced MMP-9 and VEGF expression in MCF-7 human breast cancer cells. The expression of MMP-9 and VEGF in response to TPA was increased, whereas TPA-induced MMP-9 and VEGF expression was decreased by silibinin. To investigate the regulatory mechanism of silibinin on TPA-induced MMP-9 and VEGF expression, we pretreated cells with various inhibitors, such as UO126 (MEK1/2 inhibitor), SP600125 (JNK inhibitor), and SB203580 (p38 inhibitor). Interestingly, TPA-induced MMP-9 expression was significantly inhibited by UO126, but not by SP600125 and SB203580. In addition, we pretreated cells with 100 microM silibinin prior to TPA treatment. TPA-induced MEK and ERK phosphorylation was significantly decreased by silibinin in MCF7 cells. TPA-induced VEGF expression was also suppressed by UO126. On the other hand, we found that adenoviral constitutive active-MEK (Ad-CA-MEK) significantly increased MMP-9 and VEGF expression. Taken together, we suggest that the inhibition of TPA-induced MMP-9 and VEGF expression by silibinin is mediated by the suppression of the Raf/MEK/ERK pathway in MCF-7 breast cancer cells.
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Affiliation(s)
- Sangmin Kim
- Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Kangnam-gu, Seoul 135-710, South Korea
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88
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Policastro LL, Ibañez IL, Durán HA, Soria G, Gottifredi V, Podhajcer OL. Suppression of cancer growth by nonviral gene therapy based on a novel reactive oxygen species-responsive promoter. Mol Ther 2009; 17:1355-64. [PMID: 19436270 DOI: 10.1038/mt.2009.103] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Increased reactive oxygen species (ROS) production has been reported as a distinctive feature of different pathologies including cancer. Therefore, we assessed whether increased ROS production in the cancer microenvironment could be selectively exploited to develop a selective anticancer therapy. For this purpose, we constructed a novel chimeric promoter, based on a ROS-response motif located in the VEGF gene promoter placed, in turn, downstream of a second ROS-response motif obtained from the early growth response 1 (Egr-1) gene promoter. The activity of the chimeric promoter was largely dependent on variations in intracellular ROS levels and showed a high inducible response to exogenous H(2)O(2). Transient expression of the thymidine kinase (TK) gene driven by the chimeric promoter, followed by gancyclovir (GCV) administration, inhibited human colorectal cancer and melanoma cell growth in vitro and in vivo. Moreover, electrotransfer of the TK gene followed by GCV administration exerted a potent therapeutic effect on established tumors. This response was improved when combined with chemotherapeutic drugs. Thus, we show for the first time that a distinctive pro-oxidant state can be used to develop new selective gene therapeutics for cancer.
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Affiliation(s)
- Lucía L Policastro
- Department of Radiobiology, National Atomic Energy Commission-CONICET, Buenos Aires, Argentina
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89
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90
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Muller M. Cellular senescence: molecular mechanisms, in vivo significance, and redox considerations. Antioxid Redox Signal 2009; 11:59-98. [PMID: 18976161 DOI: 10.1089/ars.2008.2104] [Citation(s) in RCA: 183] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Cellular senescence is recognized as a critical cellular response to prolonged rounds of replication and environmental stresses. Its defining characteristics are arrested cell-cycle progression and the development of aberrant gene expression with proinflammatory behavior. Whereas the mechanistic events associated with senescence are generally well understood at the molecular level, the impact of senescence in vivo remains to be fully determined. In addition to the role of senescence as an antitumor mechanism, this review examines cellular senescence as a factor in organismal aging and age-related diseases, with particular emphasis on aberrant gene expression and abnormal paracrine signaling. Senescence as an emerging factor in tissue remodeling, wound repair, and infection is considered. In addition, the role of oxidative stress as a major mediator of senescence and the role of NAD(P)H oxidases and changes to intracellular GSH/GSSG status are reviewed. Recent findings indicate that senescence and the behavior of senescent cells are amenable to therapeutic intervention. As the in vivo significance of senescence becomes clearer, the challenge will be to modulate the adverse effects of senescence without increasing the risks of other diseases, such as cancer. The uncoupled relation between cell-cycle arrest and the senescent phenotype suggests that this is an achievable outcome.
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Affiliation(s)
- Michael Muller
- Centre for Education and Research on Ageing, ANZAC Research Institute, University of Sydney, Concord RG Hospital, Concord, Sydney, Australia.
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91
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Liu ZJ, Velazquez OC. Hyperoxia, endothelial progenitor cell mobilization, and diabetic wound healing. Antioxid Redox Signal 2008; 10:1869-82. [PMID: 18627349 PMCID: PMC2638213 DOI: 10.1089/ars.2008.2121] [Citation(s) in RCA: 186] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Diabetic foot disease is a major health problem, which affects 15% of the 200 million patients with diabetes worldwide. Diminished peripheral blood flow and decreased local neovascularization are critical factors that contribute to the delayed or nonhealing wounds in these patients. The correction of impaired local angiogenesis may be a key component in developing therapeutic protocols for treating chronic wounds of the lower extremity and diabetic foot ulcers. Endothelial progenitor cells (EPCs) are the key cellular effectors of postnatal neovascularization and play a central role in wound healing, but their circulating and wound-level numbers are decreased in diabetes, implicating an abnormality in EPC mobilization and homing mechanisms. The deficiency in EPC mobilization is presumably due to impairment of eNOS-NO cascade in bone marrow (BM). Hyperoxia, induced by a clinically relevant hyperbaric oxygen therapy (HBO) protocol, can significantly enhance the mobilization of EPCs from the BM into peripheral blood. However, increased circulating EPCs failed to reach to wound tissues. This is partly a result of downregulated production of SDF-1alpha in local wound lesions with diabetes. Administration of exogenous SDF-1alpha into wounds reversed the EPC homing impairment and, with hyperoxia, synergistically enhanced EPC mobilization, homing, neovascularization, and wound healing.
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Affiliation(s)
- Zhao-Jun Liu
- The DeWitt Daughtry Family Department of Surgery, Leonard M. Miller School of Medicine, University of Miami, Miami, Florida 33136, USA
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92
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Birk DM, Barbato J, Mureebe L, Chaer RA. Current insights on the biology and clinical aspects of VEGF regulation. Vasc Endovascular Surg 2008; 42:517-30. [PMID: 18799497 DOI: 10.1177/1538574408322755] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Vascular endothelial growth factor (VEGF) is a key molecule that orchestrates the formation and function of vascular networks. Impaired regulation of angiogenesis is implicated in a number of pathologic states. For instance, neoplasias exhibit uncontrolled angiogenesis, whereas ischemia and states of vascular insufficiency involve reduced VEGF activity. As the role of VEGF has been elucidated in these disease processes, its therapeutic role has been developed. The Food and Drug Administration has approved several anti-VEGF agents for treating colorectal, lung, and kidney cancer. VEGF-inducing agents have also been used experimentally to induce angiogenesis in patients with critical limb ischemia. As more knowledge is gathered about the biology of VEGF and its receptors, there is greater promise for therapeutic modulation of VEGF expression. The purpose of this review is to describe the various therapeutic and biologic factors that regulate the expression of VEGF.
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Affiliation(s)
- Daniel M Birk
- College of Physicians and Surgeons, Columbia University, New York, USA
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93
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Mora-López F, Pedreño-Horrillo N, Delgado-Pérez L, Brieva JA, Campos-Caro A. Transcription of PRDM1, the master regulator for plasma cell differentiation, depends on an SP1/SP3/EGR-1 GC-box. Eur J Immunol 2008; 38:2316-24. [PMID: 18604866 DOI: 10.1002/eji.200737861] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The positive regulatory domain containing 1, encoded by the PRDM1 gene, is a transcriptional repressor considered as a master regulator that is required and sufficient for plasma cell differentiation. In the present study we have performed sequence analysis of the upstream region of the human PRDM1 gene to detect the minimal promoter region necessary for PRDM1 gene transcription. This region comprises the region upstream of the initiation site, as well as the first exon. Collectively, deletion and mutation analysis in conjunction with luciferase reporter assays, EMSA and supershift assays identified a phylogenetically conserved GC-box as an essential element for PRDM1 expression. This GC-box element matches to a binding site for multiple transcription factors such as SP1 and SP3 isoforms as well as early growth response 1. Chromatin immunoprecipitation assays confirmed the in vivo binding capability of these factors to the human PRDM1 promoter. These studies together characterize for the first time the basal activity of the human PRDM1 promoter, through which several factors, including SP1, SP3 and early growth response 1, modulate its expression through a conserved GC-box.
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94
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Sun D, Liu WJ, Guo K, Rusche JJ, Ebbinghaus S, Gokhale V, Hurley LH. The proximal promoter region of the human vascular endothelial growth factor gene has a G-quadruplex structure that can be targeted by G-quadruplex-interactive agents. Mol Cancer Ther 2008; 7:880-9. [PMID: 18413801 DOI: 10.1158/1535-7163.mct-07-2119] [Citation(s) in RCA: 146] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Previous studies on the functional analysis of the human vascular endothelial growth factor (VEGF) promoter using the full-length VEGF promoter reporter revealed that the proximal 36-bp region (-85 to -50 relative to transcription initiation site) is essential for basal or inducible VEGF promoter activity in several human cancer cells. This region consists of a polypurine (guanine) tract that contains four runs of at least three contiguous guanines separated by one or more bases, thus conforming to a general motif capable of forming an intramolecular G-quadruplex. Here, we show that the G-rich strand in this region is able to form an intramolecular propeller-type parallel-stranded G-quadruplex structure in vitro by using the electrophoretic mobility shift assay, dimethyl sulfate footprinting technique, the DNA polymerase stop assay, circular dichroism spectroscopy, and computer-aided molecular modeling. Two well-known G-quadruplex-interactive agents, TMPyP4 and Se2SAP, stabilize G-quadruplex structures formed by this sequence in the presence of a potassium ion, although Se2SAP is at least 10-fold more effective in binding to the G-quadruplex than TMPyP4. Between these two agents, Se2SAP better suppresses VEGF transcription in different cancer cell lines, including HEC1A and MDA-MB-231. Collectively, our results provide evidence that specific G-quadruplex structures can be formed in the VEGF promoter region, and that the transcription of this gene can be controlled by ligand-mediated G-quadruplex stabilization. Our results also provide further support for the idea that G-quadruplex structures may play structural roles in vivo and therefore might provide insight into novel methodologies for rational drug design.
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Affiliation(s)
- Daekyu Sun
- BIO5 Institute, Room 102, 1657 East Helen Street, Tucson, AZ 85721, USA.
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95
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Rui X, Tsao J, Scheys JO, Hammer GD, Schimmer BP. Contributions of specificity protein-1 and steroidogenic factor 1 to Adcy4 expression in Y1 mouse adrenal cells. Endocrinology 2008; 149:3668-78. [PMID: 18388192 PMCID: PMC2453098 DOI: 10.1210/en.2008-0203] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The type 4 adenylyl cyclase, Adcy4, is the least abundant of five different adenylyl cyclase isoforms expressed in the Y1 mouse adrenocortical cell line and is deficient in a Y1 mutant with impaired steroidogenic factor 1 (SF1) activity. This study examines the contributions of SF1 and other DNA promoter/regulatory elements to Adcy4 expression in the Y1 cell line and its derivative Adcy4-deficient mutant. Primer extension and in silico analyses indicate that Adcy4 transcription initiates from multiple sites just downstream of a GC-rich sequence. Luciferase reporter gene assays identify a 124-bp sequence, situated 19 bp upstream of the major transcription start site and highly conserved among several mammalian species, as the major determinant of Adcy4 expression in Y1 cells and as a site of compromised activity in the Adcy4-deficient mutant. EMSAs using competitor nucleotides and specific antibodies indicate that this conserved region contains three specificity protein (Sp)-1/Sp3-binding sites and one SF1-binding site. As determined by site-specific mutagenesis, the 5'-most Sp1/Sp3-site enhances promoter activity, whereas the middle Sp1/Sp3 and SF1 sites each repress Adcy4 promoter activity. In the Adcy4-deficient mutant, mutating the SF1 site restores Adcy4 promoter activity and knocking down SF1 with small interfering RNAs increases Adcy4 expression, confirming the contribution of SF1 to the mutant phenotype. These studies demonstrate roles for Sp1/Sp3 and SF1 in Adcy4 expression in Y1 cells and establish a repressor function for SF1 in certain promoter contexts.
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Affiliation(s)
- Xianliang Rui
- Banting and Best Department of Medical Research, University of Toronto, 112 College Street, Toronto, Ontario, Canada
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96
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Aiba I, Hossain A, Kuo MT. Elevated GSH level increases cadmium resistance through down-regulation of Sp1-dependent expression of the cadmium transporter ZIP8. Mol Pharmacol 2008; 74:823-33. [PMID: 18556457 DOI: 10.1124/mol.108.046862] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Cadmium is a nonessential toxic metal in mammals. Its toxicity is mainly caused by interactions with cellular proteins that result in protein dysfunction and then disturb normal cellular functions. Glutathione (GSH) has been reported to play a role in cadmium resistance by serving as a cofactor for multidrug resistance protein 1/GS-X pump-mediated cadmium elimination. To further investigate the role of GSH in cadmium toxicity, we carried out a comparative study using small-cell lung cancer-derived cell lines, SR3A, and those that were stably transfected with glutamate cysteine ligase catalytic subunit (GCLC), a rate-limiting enzyme in GSH biosynthesis. These GCLC stably transfected cell lines produced higher levels of GSH and were more resistant to cadmium toxicity than the parental cell line was. The rates of cadmium uptake were reduced in these GCLC-transfected cell lines, which were associated with down-regulation of the cadmium transporter ZIP8/SLC39A8. Further analyses demonstrated that Sp1 binding site at the proximal promoter region of ZIP8 was sensitive to the GSH level and that the expression level of transcription factor Sp1 was reduced by increased GSH levels. We also demonstrated that low concentrations of cadmium exposure down-regulated ZIP8 expression with concomitant reduction of Sp1 expression. Taken together, these results demonstrate the importance of Sp1 in the regulation of ZIP8 expression. More important, our results reveal a new mechanism by which elevated GSH levels confer cadmium resistance by down-regulation of ZIP8 expression through the suppression of Sp1.
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Affiliation(s)
- Isamu Aiba
- Department of Molecular Pathology, M.D. Anderson Cancer Center, Houston, TX 77054, USA
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97
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Breen E, Tang K, Olfert M, Knapp A, Wagner P. Skeletal Muscle Capillarity during Hypoxia: VEGF and Its Activation. High Alt Med Biol 2008; 9:158-66. [DOI: 10.1089/ham.2008.1010] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Affiliation(s)
- Ellen Breen
- Departments of Medicine and Physiology, University of California at San Diego
| | - Kechun Tang
- Departments of Medicine and Physiology, University of California at San Diego
| | - Mark Olfert
- Departments of Medicine and Physiology, University of California at San Diego
| | - Amy Knapp
- Departments of Medicine and Physiology, University of California at San Diego
| | - Peter Wagner
- Departments of Medicine and Physiology, University of California at San Diego
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98
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Wagner M, Schmelz K, Dörken B, Tamm I. Transcriptional regulation of human survivin by early growth response (Egr)-1 transcription factor. Int J Cancer 2008; 122:1278-87. [PMID: 18027854 DOI: 10.1002/ijc.23183] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Survivin, a member of the inhibitor of apoptosis protein family, is involved in both, inhibition of apoptosis and regulation of cell division. Because of the tumor-specific expression of survivin, the reduction of its expression is an important therapeutic option in the treatment of malignant diseases. Thus, we analyzed the transcriptional regulation of survivin in order to establish survivin as a target gene for new therapeutic approaches. Here, we describe a novel regulatory region within the survivin promoter. After treatment with phorbol 12-myristate-13-acetate, the early growth response (Egr)-1 transcription factor binds to the sequence 5'GAGGGGGCG 3' within the human survivin promoter in vitro and in entire cells. In reporter-gene assays and overexpression experiments, survivin is downregulated following exogenous expression of wildtype Egr-1. Using p53 wildtype and mutated cell lines, we show that Egr-1 negatively regulates survivin expression and sensitizes cell lines to TRAIL-induced apoptosis.
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Affiliation(s)
- Mandy Wagner
- Department of Hematology and Oncology, Universitätsmedizin Berlin, Charité, Campus Virchow, Augustenburger Platz 1, 13353 Berlin, Germany
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Sen CK, Roy S. Redox signals in wound healing. Biochim Biophys Acta Gen Subj 2008; 1780:1348-61. [PMID: 18249195 DOI: 10.1016/j.bbagen.2008.01.006] [Citation(s) in RCA: 201] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Revised: 12/31/2007] [Accepted: 01/14/2008] [Indexed: 12/19/2022]
Abstract
Physical trauma represents one of the most primitive challenges that threatened survival. Healing a problem wound requires a multi-faceted comprehensive approach. First and foremost, the wound environment will have to be made receptive to therapies. Second, the appropriate therapeutic regimen needs to be identified and provided while managing systemic limitations that could secondarily limit the healing response. Unfortunately, most current solutions seem to aim at designing therapeutic regimen with little or no consideration of the specific details of the wound environment and systemic limitations. One factor that is centrally important in making the wound environment receptive is correction of wound hypoxia. Recent work have identified that oxygen is not only required to disinfect wounds and fuel healing but that oxygen-dependent redox-sensitive signaling processes represent an integral component of the healing cascade. Over a decade ago, it was proposed that in biological systems oxidants are not necessarily always the triggers for oxidative damage and that oxidants such as H2O2 could actually serve as signaling messengers and drive several aspects of cellular signaling. Today, that concept is much more developed and mature. Evidence supporting the role of oxidants such as H2O2 as signaling messenger is compelling. A complete understanding of the continuum between the classical and emergent roles of oxygen requires a thorough consideration of current concepts in redox biology. The objective of this review is to describe our current understanding of how redox-sensitive processes may drive dermal tissue repair.
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Affiliation(s)
- Chandan K Sen
- Comprehensive Wound Center, Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University Medical Center, Columbus, Ohio 43210, USA.
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Roy S, Khanna S, Sen CK. Redox regulation of the VEGF signaling path and tissue vascularization: Hydrogen peroxide, the common link between physical exercise and cutaneous wound healing. Free Radic Biol Med 2008; 44:180-92. [PMID: 18191754 DOI: 10.1016/j.freeradbiomed.2007.01.025] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2006] [Revised: 12/14/2006] [Accepted: 01/05/2007] [Indexed: 12/17/2022]
Abstract
Vascularization, under physiological or pathophysiological conditions, typically takes place by one or more of the following processes: angiogenesis, vasculogenesis, arteriogenesis, and lymphangiogenesis. Although all of these mechanisms of vascularization have sufficient contrasting features to warrant consideration under separate cover, one common feature shared by all is their sensitivity to the VEGF signaling pathway. Conditions such as wound healing and physical exercise result in increased production of reactive oxygen species such as H(2)O(2), and both are associated with increased tissue vascularization. Understanding these two scenarios of adult tissue vascularization in tandem offers the potential to unlock the significance of redox regulation of the VEGF signaling pathway. Does H(2)O(2) support tissue vascularization? H(2)O(2) induces the expression of the most angiogenic form of VEGF, VEGF-A, by a HIF-independent and Sp1-dependent mechanism. Ligation of VEGF-A to VEGFR2 results in signal transduction leading to tissue vascularization. Such ligation generates H(2)O(2) via an NADPH oxidase-dependent mechanism. Disruption of VEGF-VEGFR2 ligation-dependent H(2)O(2) production or decomposition of such H(2)O(2) stalls VEGFR2 signaling. Numerous antioxidants exhibit antiangiogenic properties. Current evidence lends firm credence to the hypothesis that low-level endogenous H(2)O(2) supports vascular growth.
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Affiliation(s)
- Sashwati Roy
- Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University Medical Center, Columbus, OH 43210, USA.
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