Homo sapiens
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ABSTRACT:
PROVIDER: PRJNA113747 | ENA |
REPOSITORIES: ENA
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Project description:Our studies provide direct evidence that O-glycosylation pathways play a role in the regulation of cell growth through apoptosis and proliferation pathways. Eight small molecular weight analogues of the GalNAc-alpha-1-O-serine/threonine structure based on 1-benzyl-2-acetamido-2- deoxy-alpha-O-D-galactopyranoside have been synthesised and tested in 5 human colorectal cancer cell lines. Three inhibitors, 1-benzyl-2-acetamido-2-deoxy-alpha-O-D-galactopyranoside and the corresponding 2-azido- and C-glycoside analogues, were screened in two colorectal cancer cell lines at 0.5mM and showed induction of apoptosis. Proliferation was down regulated in the same two cell lines with all three inhibitors, as detected by Ki67 staining and gene array. Treatment both cell lines with inhibitors led to changes in glycosylation detected with peanut lectin. The competitive action of the inhibitors resulted in the intracellular formation of 28 aryl-glycan products which were identified by MALDI and electrospray mass spectroscopy. The structures found map onto known O-glycosylation biosynthetic pathways and showed a differential pattern for each of the inhibitors in both cell lines. Gene array analysis of the glycogenes illustrated a pattern of glycosytransferases that matched the glycan structures found in glycoproteins and aryl-glycans formed in the PC/AA/C1/SB10C cells, however there was no action of the three inhibitors on glycogene transcript levels. The inhibitors act at both intermediary metabolic and genomic levels, resulting in altered protein glycosylation and arylglycan formation. These events may play a part in growth arrest. Keywords: Response to inhibitors, Apoptosis, Aryl-glycans, Benzyl-O-GalNAc, Growth Inhibition, O-Glycans
2008-08-18 | GSE12422 | GEO
Project description:Our studies provide direct evidence that O-glycosylation pathways play a role in the regulation of cell growth through apoptosis and proliferation pathways. Eight small molecular weight analogues of the GalNAc-alpha-1-O-serine/threonine structure based on 1-benzyl-2-acetamido-2- deoxy-alpha-O-D-galactopyranoside have been synthesised and tested in 5 human colorectal cancer cell lines. Three inhibitors, 1-benzyl-2-acetamido-2-deoxy-alpha-O-D-galactopyranoside and the corresponding 2-azido- and C-glycoside analogues, were screened in two colorectal cancer cell lines at 0.5mM and showed induction of apoptosis. Proliferation was down regulated in the same two cell lines with all three inhibitors, as detected by Ki67 staining and gene array. Treatment both cell lines with inhibitors led to changes in glycosylation detected with peanut lectin. The competitive action of the inhibitors resulted in the intracellular formation of 28 aryl-glycan products which were identified by MALDI and electrospray mass spectroscopy. The structures found map onto known O-glycosylation biosynthetic pathways and showed a differential pattern for each of the inhibitors in both cell lines. Gene array analysis of the glycogenes illustrated a pattern of glycosytransferases that matched the glycan structures found in glycoproteins and aryl-glycans formed in the PC/AA/C1/SB10C cells, however there was no action of the three inhibitors on glycogene transcript levels. The inhibitors act at both intermediary metabolic and genomic levels, resulting in altered protein glycosylation and arylglycan formation. These events may play a part in growth arrest. Experiment Overall Design: The effects of the O-glycan inhibitors Benzyl 2-azido-2-deoxy-alpha-D-galactopyranoside (alpha-OBn GalN3), Benzyl 2-acetamido-2-deoxy-alpha-D-galactopyranoside (alpha-OBn GalNAc), and 2-(2-acetamido-2-deoxy-alpha-D-galactopyranosyl)-1-phenylethane (alpha-CBn GalNAc) on the colorectal cancer cell line PC/AA/C1/SB10C were examined. Experiment Overall Design: The PC/AA/C1/SB10C cells were treated with with 0.5 mM of the inhibitors for four days. In control experiments cells were cultivated without inhibitor. All experiments were performed twice. Total RNA was extracted with RNAzol reagent in accordance to the manufacturer instructions (PeQLab, Biotechnology Fareham, UK), treated with RNase-free DNase (DNA-free, Ambion,Warrington, UK) and integrity verified using the Agilent Bioanalyzer (Agilent Technologies, West Lothian, UK), by the presence of the 28S and 18S rRNA on agarose gels and an A260/280 ratio in the range of 1.9â2.1. A sample (5 μg) of total RNA was used for production of biotinylated cRNA as described in the Affymetrix GeneChip analysis instruction manual (Affymetrix UK, High Wycombe, UK). The human genome 133A 2.0 array was then hybridized with the biotin-labeled cRNA fragments for 16 h at 45°C. Washing steps for the chip, staining with streptavidin-phycoerythrin, signal amplification and scanning were performed according to the manufacturerâs instructions (Affymetrix UK, High Wycombe, UK). Signal values were exported with the GeneChip operating software (GCOS, Affymetrix). Further analyses were performed with the software âCorrXpressionâ, which is described in detail elsewhere (Klein et al. 2005, J Mol Med. 83:362-376; Wessel et al. 2006, In Silico Biol.6:61-70).
2008-10-25 | E-GEOD-12422 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE11944: Mucosal Glycan Foraging Enhances the Fitness and Transmission of a Saccharolytic Human Distal Gut Symbiont GSE11953: Mucosal Glycan Foraging Enhances the Fitness and Transmission of a Saccharolytic Human Distal Gut Symbiont: ECF mutant GSE11962: Growth of B. thetaiotaomicron on purified host mucosal glycans and glycan fragments Refer to individual Series
2008-11-20 | E-GEOD-11980 | biostudies-arrayexpress
Project description:Various cancers such as colorectal cancer (CRC) are associated with alterations in protein glycosylation. CRC cell lines are frequently used to study these (glyco)biological changes and their mechanisms. However, differences between CRC cell lines with regard to their glycosylation have hitherto been largely neglected. Here, we comprehensively characterized the N-glycan profiles of 25 different CRC cell lines, derived from primary tumors and metastatic sites, in order to investigate their potential as glycobiological tumor model systems and to reveal glycans associated with cell line phenotypes. We applied an optimized, high-throughput membrane-based enzymatic glycan release for small sample amounts. Released glycans were derivatized to stabilize and differentiate between a2,3- and a2,6-linked N-acetylneuraminic acids, followed by N-glycosylation analysis by MALDI-TOF(/TOF)-MS. Our results showed pronounced differences between the N-glycosylation patterns of CRC cell lines. CRC cell line profiles differed from tissue-derived N-glycan profiles with regard to their high-mannose N-glycan content but showed a large overlap for complex type N-glycans, supporting their use as a glycobiological cancer model system. Importantly, we could show that the high-mannose N-glycans did not only occur as intracellular precursors but were also present at the cell surface. The obtained CRC cell line N-glycan features were not clearly correlated with mRNA expression levels of glycosyltransferases, demonstrating the usefulness of performing the structural analysis of glycans. Finally, correlation of CRC cell line glycosylation features with cancer cell markers and phenotypes revealed an association between highly fucosylated glycans and CDX1 and/or villin mRNA expression that both correlate with cell differentiation. Together, our findings provide new insights into CRC-associated glycan changes and setting the basis for more in-depth experiments on glycan function and regulation.
2017-02-03 | MTBLS227 | MetaboLights
Project description:Despite advances, treatment of unresectable colorectal cancer remains a clinical challenge and the incidence of this malignancy is increasing in individuals below the age of fifty. Integrated genomic, transcriptomic, proteomic, and mechanistic studies identified the tyrosine kinase receptors EphB2 and EphB4 as colorectal cancer drivers, and EphA2 activity as a cancer resistance mechanism to epidermal growth factor receptor and BRAF inhibitors. Reduction of EphB2 and EphB4 activity suppresses colorectal cancer cell growth and survival and is a potential target for colorectal cancer therapy. Here, we report the design and synthesis of two novel inhibitors, 1 and 3, that selectively bind with high affinity to A and B-type Eph receptor tyrosine kinases, inhibit A and B-type Eph tyrosine kinase activity, induce cell cycle arrest and confer a protracted state of growth reduction to colorectal cancer cells. 1 and 3 bind to EphA2 arresting the activation loop containing the conserved Asp-Phe-Gly (“DFG”)-motif in an inactive conformation and show a conserved hydrogen bond interaction with the so-called gatekeeper residue, the activation loop, alphaC helix, and hinge region of the kinase, typical of kinase inhibitors. These results demonstrate that pharmacological inhibition of Eph tyrosine kinase receptors is a valid therapeutic approach for the treatment of colorectal cancer.
2024-05-23 | PXD031880 | Pride
Project description:Symbiotic bacteria inhabiting the distal human gut have evolved under intense pressure to utilize complex carbohydrates, predominantly plant cell wall glycans abundant in our diets. These substrates are recalcitrant to depolymerization by digestive enzymes encoded in the human genome, but are efficiently targeted by some of the ~103-104 bacterial species that inhabit this niche. These species augment our comparatively narrow carbohydrate digestive capacity by unlocking otherwise unusable sugars and fermenting them into host-absorbable forms, such as short-chain fatty acids. We used phenotype profiling, whole-genome transcriptional analysis and molecular genetic approaches to investigate complex glycan utilization by two fully sequenced and closely related human gut symbionts: Bacteroides thetaiotaomicron and Bacteroides ovatus. Together these species target all of the common glycosidic linkages found in the plant cell wall, as well as host polysaccharides, but each species exhibits a unique ‘glycan niche’: in vitro B. thetaiotaomicron targets plant cell wall pectins in addition to linkages contained in host N- and O-glycans; B. ovatus uniquely targets hemicellulosic polysaccharides along with several pectins, but is deficient in host glycan utilization. Growth of Bacteroides thetaiotaomicron in vitro in minimal medium plus different purified complex glycans. Observation of increased gene expression was used to determine genes that are involved in metabolism of each glycan. Two biological replicates each.
2011-05-01 | E-GEOD-25572 | biostudies-arrayexpress
Project description:Activation of murine CD4+ and CD8+ T lymphocytes leads to dramatic remodeling of N-linked glycans. Naïve and activated CD4 T cells, CD8 T cells and B cells were compared for their N-linked glycan structures by MALDI-TOF MS profiling and for expression of glycan transferase genes to assess the biosynthetic basis for any change observed. The major change observed in activated CD4 and CD8 T cells was dramatic reduction of sialylated bi-antennary N-glycans carrying the terminal NeuGc?2-6Gal sequence, and corresponding increase in glycans carrying the Gal?1-3Gal sequence. This change was accounted for by a decrease in the expression of the sialyltransferase ST6Gal, and increase in the expression of the galactosyltransferase ?1-3GalT. Conversely, in B cells no change in terminal sialylation of N-linked glycans was evident, and the expression of the same two glycosyltransferases were increased and decreased, respectively. Keywords = N-linked glycosylation, T cell, B cell, activation, glycosyltransferase, carbohydrate, glycomics, glycan, galactosyltransferase, sialyltransferase Keywords: other
2005-05-03 | GSE2554 | GEO
Project description:It has been demonstrated that Ring finger protein 43 (RNF43) is overexpressed in colorectal cancer and mediates cancer cell proliferation. We found that RNF43 was frequently overexpressed in HCC, and knockdown of RNF43 could induce apoptosis and inhibit proliferation, invasion, colony formation and xenograft growth of HCC cells. Suggesting that RNF43 is involved in tumorigenesis and progression of HCC. We used microarrays to profile gene expression patterns before and after RNF43 knockdown, and identified differentially expressed genes during this process.
2012-10-04 | GSE41326 | GEO
Project description:It has been demonstrated that Ring finger protein 43 (RNF43) is overexpressed in colorectal cancer and mediates cancer cell proliferation. We found that RNF43 was frequently overexpressed in HCC, and knockdown of RNF43 could induce apoptosis and inhibit proliferation, invasion, colony formation and xenograft growth of HCC cells. Suggesting that RNF43 is involved in tumorigenesis and progression of HCC. We used microarrays to profile gene expression patterns before and after RNF43 knockdown, and identified differentially expressed genes during this process. HepG2 cells were transfected with RNF43 siRNA or negative control siRNA in triplicate. Forty-eight hours after transfection, total RNA was extracted,labeled and hybridized to HG-U133 Plus 2.0 arrays.
2012-10-04 | E-GEOD-41326 | biostudies-arrayexpress
Project description:Small molecule inhibitors of glycosylation enzymes are valuable tools for dissecting glycan functions and potential drug candidates. Screening for inhibitors of glycosyltransferases are mainly performed by in vitro enzyme assays with difficulties moving candidates to cells and animals. Here, we circumvent this by employing a cell-based screening assay using glycoengineered cells expressing tailored reporter glycoproteins. We focused on GalNAc-type O-glycosylation, and selected the GalNAc-T11 isoenzyme that selectively glycosylates the endocytic low density lipoprotein receptor (LDLR)-related proteins as target. Our screen of a limited small molecule compound library did not identify selective inhibitors of GalNAc-T11, however we identified two compounds that broadly inhibited Golgi-localized glycosylation processes. These compounds mediated reversible fragmentation of the Golgi system without affecting secretion. We demonstrate how these inhibitors can be used to manipulate glycosylation in cells to induce expression of truncated O-glycans and augment binding of cancer-specific Tn-glycoprotein antibodies and to inhibit expression of heparan sulfate and binding and infection of SARS-CoV-2.
2023-05-05 | PXD039334 | Pride