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Chen G, Luo D, Zhong N, Li D, Zheng J, Liao H, Li Z, Lin X, Chen Q, Zhang C, Lu Y, Chan YT, Ren Q, Wang N, Feng Y. GPC2 Is a Potential Diagnostic, Immunological, and Prognostic Biomarker in Pan-Cancer. Front Immunol 2022; 13:857308. [PMID: 35345673 PMCID: PMC8957202 DOI: 10.3389/fimmu.2022.857308] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 02/01/2022] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Glypican 2 (GPC2), a member of glypican (GPC) family genes, produces proteoglycan with a glycosylphosphatidylinositol anchor. It has shown its ascending significance in multiple cancers such as neuroblastoma, malignant brain tumor, and small-cell lung cancer. However, no systematic pan-cancer analysis has been conducted to explore its function in diagnosis, prognosis, and immunological prediction. METHODS By comprehensive use of datasets from The Cancer Genome Atlas (TCGA), Cancer Cell Line Encyclopedia (CCLE), Genotype-Tissue Expression Project (GTEx), cBioPortal, Human Protein Atlas (HPA), UALCAN, StarBase, and Comparative Toxicogenomics Database (CTD), we adopted bioinformatics methods to excavate the potential carcinogenesis of GPC2, including dissecting the correlation between GPC2 and prognosis, gene mutation, immune cell infiltration, and DNA methylation of different tumors, and constructed the competing endogenous RNA (ceRNA) networks of GPC2 as well as explored the interaction of GPC2 with chemicals and genes. RESULTS The results indicated that GPC2 was highly expressed in most cancers, except in pancreatic adenocarcinoma, which presented at a quite low level. Furthermore, GPC2 showed the early diagnostic value in 16 kinds of tumors and was positively or negatively associated with the prognosis of different tumors. It also verified that GPC2 was a gene associated with most immune-infiltrating cells in pan-cancer, especially in thymoma. Moreover, the correlation with GPC2 expression varied depending on the type of immune-related genes. Additionally, GPC2 gene expression has a correlation with DNA methylation in 20 types of cancers. CONCLUSION Through pan-cancer analysis, we discovered and verified that GPC2 might be useful in cancer detection for the first time. The expression level of GPC2 in a variety of tumors is significantly different from that of normal tissues. In addition, the performance of GPC2 in tumorigenesis and tumor immunity also confirms our conjecture. At the same time, it has high specificity and sensitivity in the detection of cancers. Therefore, GPC2 can be used as an auxiliary indicator for early tumor diagnosis and a prognostic marker for many types of tumors.
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Affiliation(s)
- Guoming Chen
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Dongqiang Luo
- Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Nan Zhong
- Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Danyun Li
- Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Jiyuan Zheng
- Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Hui Liao
- Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zhuoyao Li
- Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xiaoxiao Lin
- Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Qiqi Chen
- Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Cheng Zhang
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Yuanjun Lu
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Yau-Tuen Chan
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Qing Ren
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Ning Wang
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Yibin Feng
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
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Calvo E, Soria JC, Ma WW, Wang T, Bahleda R, Tolcher AW, Gernhardt D, O'Connell J, Millham R, Giri N, Wick MJ, Adjei AA, Hidalgo M. A Phase I Clinical Trial and Independent Patient-Derived Xenograft Study of Combined Targeted Treatment with Dacomitinib and Figitumumab in Advanced Solid Tumors. Clin Cancer Res 2016; 23:1177-1185. [PMID: 27733479 DOI: 10.1158/1078-0432.ccr-15-2301] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 08/24/2016] [Accepted: 09/15/2016] [Indexed: 11/16/2022]
Abstract
Purpose: This phase I, open-label, single-arm trial assessed the safety and tolerability of dacomitinib-figitumumab combination therapy in patients with advanced solid tumors.Experimental Design: A standard 3 + 3 dose escalation/de-escalation design was utilized. Starting doses were figitumumab 20 mg/kg administered intravenously once every 3 weeks and dacomitinib 30 mg administered orally once daily. We also performed an independent study of the combination in patient-derived xenograft (avatar mouse) models of adenoid cystic carcinoma.Results: Of the 74 patients enrolled, the most common malignancies were non-small cell lung cancer (24.3%) and colorectal cancer (14.9%). The most common treatment-related adverse events in the 71 patients who received treatment across five dose levels were diarrhea (59.2%), mucosal inflammation (47.9%), and fatigue and acneiform dermatitis (45.1% each). The most common dose-limiting toxicity was mucosal inflammation. Dosing schedules of dacomitinib 10 or 15 mg daily plus figitumumab 20 mg/kg every 3 weeks after a figitumumab loading dose were tolerated by patients over multiple cycles and considered recommended doses for further evaluation. Objective responses were seen in patients with adenoid cystic carcinoma, ovarian carcinoma, and salivary gland cancer. Pharmacokinetic analysis did not show any significant drug-drug interaction. In the adenoid cystic carcinoma xenograft model, figitumumab exerted significant antitumor activity, whereas dacomitinib did not. Figitumumab-sensitive tumors showed downregulation of genes in the insulin-like growth factor receptor 1 pathway.Conclusions: Dacomitinib-figitumumab combination therapy was tolerable with significant dose reductions of both agents to less than the recommended single-agent phase II dose of each drug. Preliminary clinical activity was demonstrated in the potential target tumor adenoid cystic carcinoma. Clin Cancer Res; 23(5); 1177-85. ©2016 AACRSee related commentary by Sundar et al., p. 1123.
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Affiliation(s)
- Emiliano Calvo
- START Madrid, Centro Integral Oncológico Clara Campal, Madrid, Spain.
| | | | - Wen Wee Ma
- Roswell Park Cancer Institute, Buffalo, New York
| | - Tao Wang
- Pfizer Inc., Groton, Connecticut
| | | | | | | | | | | | | | | | - Alex A Adjei
- Roswell Park Cancer Institute, Buffalo, New York
| | - Manuel Hidalgo
- START Madrid, Centro Integral Oncológico Clara Campal, Madrid, Spain
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Dempster EL, Pidsley R, Schalkwyk LC, Owens S, Georgiades A, Kane F, Kalidindi S, Picchioni M, Kravariti E, Toulopoulou T, Murray RM, Mill J. Disease-associated epigenetic changes in monozygotic twins discordant for schizophrenia and bipolar disorder. Hum Mol Genet 2011; 20:4786-96. [PMID: 21908516 PMCID: PMC3221539 DOI: 10.1093/hmg/ddr416] [Citation(s) in RCA: 319] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 09/07/2011] [Indexed: 01/11/2023] Open
Abstract
Studies of the major psychoses, schizophrenia (SZ) and bipolar disorder (BD), have traditionally focused on genetic and environmental risk factors, although more recent work has highlighted an additional role for epigenetic processes in mediating susceptibility. Since monozygotic (MZ) twins share a common DNA sequence, their study represents an ideal design for investigating the contribution of epigenetic factors to disease etiology. We performed a genome-wide analysis of DNA methylation on peripheral blood DNA samples obtained from a unique sample of MZ twin pairs discordant for major psychosis. Numerous loci demonstrated disease-associated DNA methylation differences between twins discordant for SZ and BD individually, and together as a combined major psychosis group. Pathway analysis of our top loci highlighted a significant enrichment of epigenetic changes in biological networks and pathways directly relevant to psychiatric disorder and neurodevelopment. The top psychosis-associated, differentially methylated region, significantly hypomethylated in affected twins, was located in the promoter of ST6GALNAC1 overlapping a previously reported rare genomic duplication observed in SZ. The mean DNA methylation difference at this locus was 6%, but there was considerable heterogeneity between families, with some twin pairs showing a 20% difference in methylation. We subsequently assessed this region in an independent sample of postmortem brain tissue from affected individuals and controls, finding marked hypomethylation (>25%) in a subset of psychosis patients. Overall, our data provide further evidence to support a role for DNA methylation differences in mediating phenotypic differences between MZ twins and in the etiology of both SZ and BD.
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Affiliation(s)
| | - Ruth Pidsley
- MRC Social, Genetic and Developmental Psychiatry Centre and
| | | | - Sheena Owens
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, De Crespigny Park, Denmark Hill, London SE5 8AF, UK and
| | - Anna Georgiades
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, De Crespigny Park, Denmark Hill, London SE5 8AF, UK and
| | - Fergus Kane
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, De Crespigny Park, Denmark Hill, London SE5 8AF, UK and
| | - Sridevi Kalidindi
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, De Crespigny Park, Denmark Hill, London SE5 8AF, UK and
| | - Marco Picchioni
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, De Crespigny Park, Denmark Hill, London SE5 8AF, UK and
- St Andrew's Academic Centre, Northampton NN1 5BG, UK
| | - Eugenia Kravariti
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, De Crespigny Park, Denmark Hill, London SE5 8AF, UK and
| | - Timothea Toulopoulou
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, De Crespigny Park, Denmark Hill, London SE5 8AF, UK and
| | - Robin M. Murray
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, De Crespigny Park, Denmark Hill, London SE5 8AF, UK and
| | - Jonathan Mill
- MRC Social, Genetic and Developmental Psychiatry Centre and
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Araujo APB, Ribeiro MEOB, Ricci R, Torquato RJ, Toma L, Porcionatto MA. Glial cells modulate heparan sulfate proteoglycan (HSPG) expression by neuronal precursors during early postnatal cerebellar development. Int J Dev Neurosci 2010; 28:611-20. [PMID: 20638466 DOI: 10.1016/j.ijdevneu.2010.07.228] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Revised: 06/24/2010] [Accepted: 07/09/2010] [Indexed: 01/17/2023] Open
Abstract
Cerebellum controls motor coordination, balance, eye movement, and has been implicated in memory and addiction. As in other parts of the CNS, correct embryonic and postnatal development of the cerebellum is crucial for adequate performance in the adult. Cellular and molecular defects during cerebellar development can lead to severe phenotypes, such as ataxias and tumors. Knowing how the correct development occurs can shed light into the mechanisms of disease. Heparan sulfate proteoglycans are complex molecules present in every higher eukaryotic cells and changes in their level of expression as well as in their structure lead to drastic functional alterations. This work aimed to investigate changes in heparan sulfate proteoglycans expression during cerebellar development that could unveil control mechanisms. Using real time RT-PCR we evaluated the expression of syndecans, glypicans and modifying enzymes by isolated cerebellar granule cell precursors, and studied the influence of soluble glial factors on the expression of those genes. We evaluated the possible involvement of Runx transcription factors in the response of granule cell precursors to glial factors. Our data show for the first time that cerebellar granule cell precursors express members of the Runx family and that the expression of those genes can also be controlled by glial factors. Our results also show that the expression of all genes studied vary during postnatal development and treatment of precursors with glial factors indicate that the expression of heparan sulfate proteoglycan genes as well as genes encoding heparan sulfate modifying enzymes can be modulated by the microenvironment, reflecting the intricate relations between neuron and glia.
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Affiliation(s)
- Ana Paula B Araujo
- Departamento de Bioquímica, Universidade Federal de São Paulo, Rua Três de Maio, 100, 04044-020 São Paulo, SP, Brazil.
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Abstract
Quantitative real-time polymerase chain reaction (qRT-PCR) is a flexible and scalable method for analyzing transcript abundance that can be used at a single gene or high-throughput (>100 genes) level. Information obtained from this technique can be used as an indicator of potential regulation of glycosylation at the transcript level when combined with glycan structural or protein abundance data. This chapter describes detailed methods to design and perform qRT-PCR analyses and provides examples of information that can be obtained from the technique.
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Affiliation(s)
- Alison V Nairn
- The Complex Carbohydrate Research Center and the Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
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Saravanan C, Cao Z, Head SR, Panjwani N. Detection of differentially expressed wound-healing-related glycogenes in galectin-3-deficient mice. Invest Ophthalmol Vis Sci 2009; 50:5690-6. [PMID: 19643959 PMCID: PMC3005591 DOI: 10.1167/iovs.08-3359] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
PURPOSE A prior study showed that exogenous galectin-3 (Gal-3) stimulates re-epithelialization of corneal wounds in wild-type (Gal-3(+/+)) mice but, surprisingly, not in galectin-3-deficient (Gal-3(-/-)) mice. In an effort to understand why the injured corneas of Gal-3(-/-) mice are unresponsive to exogenous Gal-3, the present study was designed to determine whether genes encoding the enzymes that regulate the synthesis of glycan ligands of Gal-3 are differentially expressed in Gal-3(-/-) corneas compared with the Gal-3(+/+) corneas. METHODS Glycogene microarray technology was used to identify differentially expressed glycosyltransferases in healing Gal-3(+/+) and Gal-3(-/-) corneas. RESULTS Of approximately 2000 glycogenes on the array, the expression of 8 was upregulated and that of 14 was downregulated more than 1.3-fold in healing Gal-3(-/-) corneas. A galactosyltransferase, beta3GalT5, which has the ability to synthesize Gal-3 ligands was markedly downregulated in healing Gal-3(-/-) corneas. The genes for polypeptide galactosaminyltransferases (ppGalNAcT-3 and -7) that are known to initiate O-linked glycosylation and N-aspartyl-beta-glucosaminidase, which participates in the removal of N-glycans, were found to be upregulated in healing Gal-3(-/-) corneas. Microarray data were validated by qRT-PCR. CONCLUSIONS Based on the known functions of the differentially expressed glycogenes, it appears that the glycan structures on glycoproteins and glycolipids, synthesized as a result of the differential glycogene expression pattern in healing Gal-3(-/-) corneas may lead to the downregulation of specific counterreceptors for Gal-3. This may explain, at least in part, why, unlike healing Gal-3(+/+) corneas, the healing Gal-3(-/-) corneas are unresponsive to the stimulatory effect of exogenous Gal-3 on re-epithelialization of corneal wounds.
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Affiliation(s)
- Chandrassegar Saravanan
- Department of Ophthalmology and The New England Eye Center, Tufts University School of Medicine, Boston, Massachusetts
- Program in Cell, Molecular and Developmental Biology, Tufts University School of Medicine, Boston, Massachusetts
| | - Zhiyi Cao
- Department of Ophthalmology and The New England Eye Center, Tufts University School of Medicine, Boston, Massachusetts
| | - Steven R. Head
- DNA Array Core Facility, The Scripps Research Institute, La Jolla, California
| | - Noorjahan Panjwani
- Department of Ophthalmology and The New England Eye Center, Tufts University School of Medicine, Boston, Massachusetts
- Program in Cell, Molecular and Developmental Biology, Tufts University School of Medicine, Boston, Massachusetts
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Salehi Z. In vivo injection of fibroblast growth factor-2 into the cisterna magna induces glypican-6 expression in mouse brain tissue. J Clin Neurosci 2009; 16:689-92. [PMID: 19254844 DOI: 10.1016/j.jocn.2008.06.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Revised: 06/03/2008] [Accepted: 06/05/2008] [Indexed: 11/28/2022]
Abstract
The proteoglycans (PGs) are multifunctional macromolecules composed of a core polypeptide and a variable number of glycosaminoglycan chains. In the nervous system, PGs regulate the structural organization of the extracellular matrix (ECM) and modulate growth factor activities and cell proliferation and migration. Most cortical neurons are generated from neural precursor cells that reside in the ventricular zone of the embryonic brain. The proliferation and differentiation of neural precursor cells are regulated by various growth and neurotrophic factors. Fibroblast growth factor-2 (FGF-2) is an important mitogen for cortical neural precursor cells, and glypicans regulate the action of FGF-2 on neural precursor cells. Glypican-6 is one of the most abundant ECM molecules in the brain. In this study the effects of FGF-2 on glypican-6 expression in brain tissue have been investigated. FGF-2 was injected into the cerebrospinal fluid (CSF) through the cisterna magna of mouse pups. Using Western blotting, it was shown that the expression of glypican-6 is increased in response to infusion of FGF-2 into the CSF. The injection of anti-FGF-2 antibody into the cisterna magna decreased glypican-6 expression in brain tissue. The results from this study suggest that glypican-6 is important in regulating FGF-2 activity during cerebral cortical development.
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Affiliation(s)
- Zivar Salehi
- Department of Biology, Faculty of Sciences, University of Guilan, Rasht, Iran.
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Ermonval M, Petit D, Le Duc A, Kellermann O, Gallet PF. Glycosylation-related genes are variably expressed depending on the differentiation state of a bioaminergic neuronal cell line: implication for the cellular prion protein. Glycoconj J 2008; 26:477-93. [PMID: 18937066 DOI: 10.1007/s10719-008-9198-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Revised: 09/17/2008] [Accepted: 10/01/2008] [Indexed: 12/26/2022]
Abstract
A striking feature of the cellular prion protein (PrP(C)) is the heterogeneity of its glycoforms, whose contribution to PrP(C) function has yet to be defined. Using the 1C11 neuronal bioaminergic differentiation model and a glycomics approach, we show here a correlation between differential PrP(C) N-glycosylations in 1C11(5-HT) serotonergic and 1C11(NE) noradrenergic cells compared to their 1C11 precursor cells and a variation of the glycogenome expression status in these cells. In particular, expression of genes involved in N-glycan synthesis or in the modeling of chondroitin and heparan sulfate proteoglycans appeared to be modulated. Our results highlight that, the expression of glycosylation-related genes is regulated during bioaminergic neuronal differentiation, consistent with a participation of glycoconjugates in neuronal development and plasticity. A neuronal regulation of glycosylation processes may have direct implications on some neurospecific functions of PrP(C) and may participate in specific brain targeting of prion strains.
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Affiliation(s)
- Myriam Ermonval
- Différenciation Cellulaire et Prions, Département de Biologie Cellulaire et Infections, Institut Pasteur, 75015, Paris, France.
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Nairn AV, York WS, Harris K, Hall EM, Pierce JM, Moremen KW. Regulation of glycan structures in animal tissues: transcript profiling of glycan-related genes. J Biol Chem 2008; 283:17298-313. [PMID: 18411279 DOI: 10.1074/jbc.m801964200] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Glycan structures covalently attached to proteins and lipids play numerous roles in mammalian cells, including protein folding, targeting, recognition, and adhesion at the molecular or cellular level. Regulating the abundance of glycan structures on cellular glycoproteins and glycolipids is a complex process that depends on numerous factors. Most models for glycan regulation hypothesize that transcriptional control of the enzymes involved in glycan synthesis, modification, and catabolism determines glycan abundance and diversity. However, few broad-based studies have examined correlations between glycan structures and transcripts encoding the relevant biosynthetic and catabolic enzymes. Low transcript abundance for many glycan-related genes has hampered broad-based transcript profiling for comparison with glycan structural data. In an effort to facilitate comparison with glycan structural data and to identify the molecular basis of alterations in glycan structures, we have developed a medium-throughput quantitative real time reverse transcriptase-PCR platform for the analysis of transcripts encoding glycan-related enzymes and proteins in mouse tissues and cells. The method employs a comprehensive list of >700 genes, including enzymes involved in sugar-nucleotide biosynthesis, transporters, glycan extension, modification, recognition, catabolism, and numerous glycosylated core proteins. Comparison with parallel microarray analyses indicates a significantly greater sensitivity and dynamic range for our quantitative real time reverse transcriptase-PCR approach, particularly for the numerous low abundance glycan-related enzymes. Mapping of the genes and transcript levels to their respective biosynthetic pathway steps allowed a comparison with glycan structural data and provides support for a model where many, but not all, changes in glycan abundance result from alterations in transcript expression of corresponding biosynthetic enzymes.
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Affiliation(s)
- Alison V Nairn
- Complex Carbohydrate Research Center and the Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
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André S, Sanchez-Ruderisch H, Nakagawa H, Buchholz M, Kopitz J, Forberich P, Kemmner W, Böck C, Deguchi K, Detjen KM, Wiedenmann B, von Knebel Doeberitz M, Gress TM, Nishimura SI, Rosewicz S, Gabius HJ. Tumor suppressor p16INK4a--modulator of glycomic profile and galectin-1 expression to increase susceptibility to carbohydrate-dependent induction of anoikis in pancreatic carcinoma cells. FEBS J 2007; 274:3233-56. [PMID: 17535296 DOI: 10.1111/j.1742-4658.2007.05851.x] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Expression of the tumor suppressor p16(INK4a) after stable transfection can restore the susceptibility of epithelial tumor cells to anoikis. This property is linked to increases in the expression and cell-surface presence of the fibronectin receptor. Considering its glycan chains as pivotal signals, we assumed an effect of p16(INK4a) on glycosylation. To test this hypothesis for human Capan-1 pancreatic carcinoma cells, we combined microarray for selected glycosyltransferase genes with 2D chromatographic glycan profiling and plant lectin binding. Major differences between p16-positive and control cells were detected. They concerned expression of beta1,4-galactosyltransferases (down-regulation of beta1,4-galactosyltransferases-I/V and up-regulation of beta1,4-galactosyltransferase-IV) as well as decreased alpha2,3-sialylation of O-glycans and alpha2,6-sialylation of N-glycans. The changes are compatible with increased beta(1)-integrin maturation, subunit assembly and binding activity of the alpha(5)beta(1)-integrin. Of further functional relevance in line with our hypothesis, we revealed differential reactivity towards endogenous lectins, especially galectin-1. As a result of reduced sialylation, the cells' capacity to bind galectin-1 was enhanced. In parallel, the level of transcription of the galectin-1 gene increased conspicuously in p16(INK4a)-positive cells, and even figured prominently in a microarray on 1996 tumor-associated genes and in proteomic analysis. The cells therefore gain optimal responsiveness. The correlation between genetically modulated galectin-1 levels and anoikis rates in engineered transfectants inferred functional significance. To connect these findings to the fibronectin receptor, galectin-1 was shown to be co-immunoprecipitated. We conclude that p16(INK4a) orchestrates distinct aspects of glycosylation that are relevant for integrin maturation and reactivity to an endogenous effector as well as the effector's expression. This mechanism establishes a new aspect of p16(INK4a) functionality.
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Affiliation(s)
- Sabine André
- Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians-University Munich, Germany.
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Qu Q, Crandall JE, Luo T, McCaffery PJ, Smith FI. Defects in tangential neuronal migration of pontine nuclei neurons in the Largemyd mouse are associated with stalled migration in the ventrolateral hindbrain. Eur J Neurosci 2006; 23:2877-86. [PMID: 16819976 DOI: 10.1111/j.1460-9568.2006.04836.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The LARGE gene encodes a putative glycosyltransferase that is required for normal glycosylation of dystroglycan, and defects in LARGE can cause abnormal neuronal migration in congenital muscular dystrophy (CMD). Previous studies have focused on radial migration, which is disrupted at least in part due to breaks in the basal lamina. Through analysis of precerebellar nuclei development in the Large(myd) mouse hindbrain, we show that tangential migration of a subgroup of hindbrain neurons may also be disrupted. Within the precerebellar nuclei, the pontine nuclei (PN) are severely disrupted, whereas the inferior olive (IO), external cuneate nuclei (ECN) and lateral reticular nuclei (LRN) appear unaffected. Large and dystroglycan are widely expressed in the hindbrain, including in the pontine neurons migrating in the anterior extramural migratory stream (AES). BrdU labeling and immunohistochemical studies suggest normal numbers of neurons begin their journey towards the ventral midline in the AES in the Large(myd) mouse. However, migration stalls and PN neurons fail to reach the midline, surviving as ectopic clusters of cells located under the pial surface dorsally and laterally to where they normally would finish their migration near the ventral midline. Stalling of PN neurons at this location is also observed in other migration disorders in mice. These observations suggest that glycan-dependent dystroglycan interactions are required for PN neurons to correctly respond to signals at this important migrational checkpoint.
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Affiliation(s)
- Qiang Qu
- University of Massachusetts Medical School, Shriver Center, 200 Trapelo Road, Waltham, MA 02452, USA
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Manzini MC, Ward MS, Zhang Q, Lieberman MD, Mason CA. The stop signal revised: immature cerebellar granule neurons in the external germinal layer arrest pontine mossy fiber growth. J Neurosci 2006; 26:6040-51. [PMID: 16738247 PMCID: PMC6675227 DOI: 10.1523/jneurosci.4815-05.2006] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
During the formation of neuronal circuits, afferent axons often enter target regions before their target cells are mature and then make temporary contacts with nonspecific targets before forming synapses on specific target cells. The regulation of these different steps of afferent-target interactions is poorly understood. The cerebellum is a good model for addressing these aspects, because cerebellar development is well defined and identified neurons in the circuitry can be purified and combined in vitro. Previous reports from our laboratory showed that cultured granule neurons specifically arrest the extension of their pontine mossy fiber afferents, leading us to propose that granule cells arrested growth of their afferents as a prelude to synaptogenesis. However, we knew little about the differentiation state of the cultured granule cells that mediate afferent arrest. In this study, we better define the purified granule cell fraction by marker expression and morphology, and demonstrate that only freshly plated granule cells in the precursor and premigratory state arrest mossy fiber outgrowth. Mature granule cells, in contrast, support extension, defasciculation, and synapse formation, as in vivo. In addition, axonal tracing in vivo during the first postnatal week indicates that immature mossy fibers extend into the Purkinje cell layer but never into the external germinal layer (EGL), where precursors of granule cell targets reside. We found that the stop-growing signals are dependent on heparin-binding factors, and we propose that such signals in the EGL restrict the extension of mossy fiber afferents and prevent invasion of proliferative regions.
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Raman R, Venkataraman M, Ramakrishnan S, Lang W, Raguram S, Sasisekharan R. Advancing glycomics: implementation strategies at the consortium for functional glycomics. Glycobiology 2006; 16:82R-90R. [PMID: 16478800 DOI: 10.1093/glycob/cwj080] [Citation(s) in RCA: 180] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Glycomics-an integrated approach to study structure-function relationships of complex carbohydrates (or glycans)-is an emerging field in this age of post-genomics. Realizing the importance of glycomics, many large scale research initiatives have been established to generate novel resources and technologies to advance glycomics. These initiatives are generating and cataloging diverse data sets necessitating the development of bioinformatic platforms to acquire, integrate, and disseminate these data sets in a meaningful fashion. With the consortium for functional glycomics (CFG) as the model system, this review discusses databases and the bioinformatics platform developed by this consortium to advance glycomics.
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Affiliation(s)
- Rahul Raman
- Center for Biomedical Engineering, Massachusetts Institute of Technology; Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
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Comelli EM, Head SR, Gilmartin T, Whisenant T, Haslam SM, North SJ, Wong NK, Kudo T, Narimatsu H, Esko JD, Drickamer K, Dell A, Paulson JC. A focused microarray approach to functional glycomics: transcriptional regulation of the glycome. Glycobiology 2005; 16:117-31. [PMID: 16237199 DOI: 10.1093/glycob/cwj048] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Glycosylation is the most common posttranslational modification of proteins, yet genes relevant to the synthesis of glycan structures and function are incompletely represented and poorly annotated on the commercially available arrays. To fill the need for expression analysis of such genes, we employed the Affymetrix technology to develop a focused and highly annotated glycogene-chip representing human and murine glycogenes, including glycosyltransferases, nucleotide sugar transporters, glycosidases, proteoglycans, and glycan-binding proteins. In this report, the array has been used to generate glycogene-expression profiles of nine murine tissues. Global analysis with a hierarchical clustering algorithm reveals that expression profiles in immune tissues (thymus [THY], spleen [SPL], lymph node, and bone marrow [BM]) are more closely related, relative to those of nonimmune tissues (kidney [KID], liver [LIV], brain [BRN], and testes [TES]). Of the biosynthetic enzymes, those responsible for synthesis of the core regions of N- and O-linked oligosaccharides are ubiquitously expressed, whereas glycosyltransferases that elaborate terminal structures are expressed in a highly tissue-specific manner, accounting for tissue and ultimately cell-type-specific glycosylation. Comparison of gene expression profiles with matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) profiling of N-linked oligosaccharides suggested that the alpha1-3 fucosyltransferase 9, Fut9, is the enzyme responsible for terminal fucosylation in KID and BRN, a finding validated by analysis of Fut9 knockout mice. Two families of glycan-binding proteins, C-type lectins and Siglecs, are predominately expressed in the immune tissues, consistent with their emerging functions in both innate and acquired immunity. The glycogene chip reported in this study is available to the scientific community through the Consortium for Functional Glycomics (CFG) (http://www.functionalglycomics.org).
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Affiliation(s)
- Elena M Comelli
- Department of Molecular Biology and Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
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