Elucidating the role of the polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3) and its closest homolog-GALNT6 in mediating aberrant O-glycosylation associated with ovarian cancer dissemination
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PROVIDER: PRJNA414047 | ENA |
REPOSITORIES: ENA
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Project description:Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy, thus understanding molecular changes associated with EOC progression could lead to the identification of essential therapeutic targets. Glycosylation is a post-translational modification (PTM) that participates in major pathophysiology events, including tumorigenesis. Aberrant mucin-type or O-glycosylation in cancer is frequently attributed to altered expression of different N-acetylgalactosaminyltransferases (GalNAc-Ts). We have previously identified the N-acetylgalactosaminyltransferase 3 (GALNT3) gene as a potential EOC oncogene, possibly implicated in aberrant O-glycosylation in EOC cells. Literature reports are suggestive for genetic and functional redundancy between different GalNAc-Ts, and our previous data were indicative for an induction of the GALNT6 expression upon GALNT3 suppression in EOC cells. Here we show that GALNT3 gene knockout (KO) in the A2780s EOC cells leads to strong GALNT6 upregulation. Moreover, A2780s cell migration, invasion, proliferation and cell cycle analysis were significantly reduced in double GALNT3/T6 gene KO cells compared to single GALNT3 gene KO. Furthermore, MUC1 expression was downregulated in both GALNT3 KO and GALNT3/6 KO, with a more prominent decrease observed in the double KO clone. In vivo studies supported the observed functional redundancy imposed by GALNT6, as animals injected with double GALNT3/T6 KO EOC cell clones displayed a significant increase in survival rates compared to those injected with the control and the GALNT3 KO clones. Collectively our data strongly suggest for possible functional redundancy of the two GalNAc-Ts (GALNT3 and T6) in EOC, with the perspective to use both of these genes as EOC markers and/or therapeutic targets.
2019-05-07 | GSE104861 | GEO
Project description:GalNAc-transferase (GalNAc-T) isoforms modify distinct subsets of the O-glycoproteome and GalNAc-type O-glycosylation is found on most proteins trafficking through the secretory pathway in metazoan cells. The O-glycoproteome is regulated by up to 20 polypeptide GalNAc-Ts and the contributions and biological functions of individual GalNAc-Ts are poorly understood. Here, we used a zinc-finger nuclease (ZFN)-directed knockout strategy to probe the contributions of the major GalNAc-Ts (GalNAc-T1 and T2) in liver cells, and explore how the GalNAc-T repertoire quantitatively affects the O-glycoproteome. We demonstrate that the majority of the O-glycoproteome is covered by redundancy, whereas distinct subsets of substrates are modified by non-redundant functions of GalNAc-T1 and T2. Differential transcriptomic analysis indicates that loss of function of a GalNAc-T induces specific transcriptional response. The non-redundant O-glycoproteome subsets for and the transcriptional responses for each isoform appeared to be related to different cellular processes, and for the GalNAc-T2 isoform supporting a role in lipid metabolism. The results demonstrate that GalNAc-Ts have non-redundant glycosylation functions, and that these may affect distinct cellular processes. The data provides a comprehensive resource for unique substrates for individual GalNAc-Ts. Our study provides a new view on the regulation of the O-glycoproteome, suggesting that the plurality of GalNAc-Ts arose to regulate distinct protein functions and cellular processes.
2015-09-30 | E-MTAB-3844 | biostudies-arrayexpress
Project description:Deconstruction of O-glycosylation – Polypeptide GalNAc-T Isoforms Direct Distinct Subsets of the O-Glycoproteome
| PRJEB10772 | ENA
Project description:Previously, we have identified the polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3) gene as notably hypomethylated in low-malignant potential (LMP) and high-grade (HG) serous epithelial ovarian tumors, compared to normal ovarian tissues. Here we show that GALNT3 is strongly overexpressed in both LMP and HG serous EOC tumors, thus suggesting that epigenetic mechanisms might be implicated in GALNT3 overexpression in serous epithelial ovarian cancer (EOC). Moreover, GALNT3 expression significantly correlated with shorter progression-free survival (PFS) periods in serous EOC patients with advanced disease. Knockdown of the GALNT3 expression in EOC cells led to sharp decrease of cell proliferation and induced S-phase cell cycle arrest. Additionally, GALNT3 suppression significantly inhibited EOC cell migration and invasion. Gene expression profiling and consecutive network and pathway analyses confirmed these findings, as numerous genes and pathways known previously to be implicated in ovarian tumorigenesis, including EOC tumor invasion and metastasis, were found to be downregulated upon GALNT3 suppression, while some tumor suppressor genes were induced. Moreover, GALNT3 downregulation was associated with reduced MUC1 protein expression in EOC cells, probably related to destabilization of the MUC1 protein due to lack of GALNT3 glycosylation activity.Taken together, our data are indicative for a strong oncogenic potential of the GALNT3 gene in advanced EOC and identify this transferase as a novel EOC biomarker and putative EOC therapeutic target. Our findings also suggest that GALNT3 overexpression might contribute to ovarian etiology through aberrant mucin O-glycosylation.
2014-05-22 | GSE52602 | GEO
Project description:Previously, we have identified the polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3) gene as notably hypomethylated in low-malignant potential (LMP) and high-grade (HG) serous epithelial ovarian tumors, compared to normal ovarian tissues. Here we show that GALNT3 is strongly overexpressed in both LMP and HG serous EOC tumors, thus suggesting that epigenetic mechanisms might be implicated in GALNT3 overexpression in serous epithelial ovarian cancer (EOC). Moreover, GALNT3 expression significantly correlated with shorter progression-free survival (PFS) periods in serous EOC patients with advanced disease. Knockdown of the GALNT3 expression in EOC cells led to sharp decrease of cell proliferation and induced S-phase cell cycle arrest. Additionally, GALNT3 suppression significantly inhibited EOC cell migration and invasion. Gene expression profiling and consecutive network and pathway analyses confirmed these findings, as numerous genes and pathways known previously to be implicated in ovarian tumorigenesis, including EOC tumor invasion and metastasis, were found to be downregulated upon GALNT3 suppression, while some tumor suppressor genes were induced. Moreover, GALNT3 downregulation was associated with reduced MUC1 protein expression in EOC cells, probably related to destabilization of the MUC1 protein due to lack of GALNT3 glycosylation activity.Taken together, our data are indicative for a strong oncogenic potential of the GALNT3 gene in advanced EOC and identify this transferase as a novel EOC biomarker and putative EOC therapeutic target. Our findings also suggest that GALNT3 overexpression might contribute to ovarian etiology through aberrant mucin O-glycosylation. To better understand the molecular mechanisms of GALNT3 gene action in ovarian cancer cells, we employed the Agilent Whole Human Genome microarrays, containing ~ 44,000 genes to identify global gene expression changes upon GALNT3 suppression in A2780s cells. We compared the gene expression of the previously selected clone shRNA- GALNT3-knockdown clones 1 & 2 (sh-cl1 & sh-cl2) against the corresponding control (ctrl) clone. The microarray experiments were performed in duplicates, as four hybridizations were carried out for the GALNT3-suppressing cell clones against the corresponding control, using a fluorescent dye reversal (dye-swap) technique.
2014-05-22 | E-GEOD-52602 | biostudies-arrayexpress
Project description:This laboratory focuses on the molecular mechanisms of neuropsychiatric and neurodegenerative disorders Our goal is to elucidate mechanisms by which regulated expression of proteoglycans and glycosylation-related genes contribute to neurodegenerative diseases involving the striatum. A number of studies have demonstrated that neural proteoglycans are involved structural organization of the striatum and formation of dopaminergic connections to and from the striatum. Several proteoglycans are also associated with neuronal regeneration and some have been shown to be components of filamentous inclusions found in neurodegenerative disorders. In addition, the localization and proper function of dopamine receptors, which are predominantly expressed in the striatum, are governed by N-linked glycosylation events. Huntingtonís Disease (HD), a progressive neurodegenerative disorder, results in selective degeneration of the striatum. This is caused by a mutation in the protein, huntingtin, however, the mechanisms responsible for neuronal degeneration remain unknown. Similar to the brains of HD patients, HD transgenic mice exhibit huntingtin protein aggregation and nuclear inclusions, selective degeneration of dopamine neurons in the striatum and dopamine receptor dysfunction. In this study, the gene expression patterns of HD transgenic mice were analyzed. Four groups, pre-symptomatic HD mice (6 weeks old), WT control (6 weeks), post symptomatic HD (16 weeks), and WT control (16 weeks), were hybridized and analyzed using the GLYCOv2 array. Each group was hybridized in triplicate.
2011-03-02 | E-GEOD-27588 | biostudies-arrayexpress
Project description:This laboratory focuses on the molecular mechanisms of neuropsychiatric and neurodegenerative disorders Our goal is to elucidate mechanisms by which regulated expression of proteoglycans and glycosylation-related genes contribute to neurodegenerative diseases involving the striatum. A number of studies have demonstrated that neural proteoglycans are involved structural organization of the striatum and formation of dopaminergic connections to and from the striatum. Several proteoglycans are also associated with neuronal regeneration and some have been shown to be components of filamentous inclusions found in neurodegenerative disorders. In addition, the localization and proper function of dopamine receptors, which are predominantly expressed in the striatum, are governed by N-linked glycosylation events. Huntingtonís Disease (HD), a progressive neurodegenerative disorder, results in selective degeneration of the striatum. This is caused by a mutation in the protein, huntingtin, however, the mechanisms responsible for neuronal degeneration remain unknown. Similar to the brains of HD patients, HD transgenic mice exhibit huntingtin protein aggregation and nuclear inclusions, selective degeneration of dopamine neurons in the striatum and dopamine receptor dysfunction.
2011-03-02 | GSE27588 | GEO
Project description:Elucidating the BT4338 regulon
| PRJNA553806 | ENA
Project description:These research areas concentrate on stress induced proteases in recombinant Escherichia coli, glycosylation heterogeneity due to bioprocess conditions produced in mammalian cells, and metabolic engineering of E. coli. The hypothesis of this project is that recombinant protein glycosylation is inefficient under normal bioreactor conditions since the additional glycosylation reactions necessary for the recombinant protein exceed the metabolic capacity of the cells. Normal bioreactor conditions have been optimized for cell growth, and sometimes for protein productivity. Only recently has it been accepted that optimal glycosylation may not occur under optimal growth or protein productivity conditions. Specific Aim: Determine the relationship between bioreactor conditions and glycosylation gene expression in NS0 cells.
2011-04-29 | GSE28920 | GEO
Project description:These research areas concentrate on stress induced proteases in recombinant Escherichia coli, glycosylation heterogeneity due to bioprocess conditions produced in mammalian cells, and metabolic engineering of E. coli. The hypothesis of this project is that recombinant protein glycosylation is inefficient under normal bioreactor conditions since the additional glycosylation reactions necessary for the recombinant protein exceed the metabolic capacity of the cells. Normal bioreactor conditions have been optimized for cell growth, and sometimes for protein productivity. Only recently has it been accepted that optimal glycosylation may not occur under optimal growth or protein productivity conditions. Specific Aim: Determine the relationship between bioreactor conditions and glycosylation gene expression in NS0 cells. EXPERIMENT: Mouse NS0 myeloma cells were grown in culture, stressed with 5 mM NaCl, 10 mM proline plus 5 mM ammonia, or 5 mM ammonia, along with an unstressed control group. The growth of the cultures were followed until the late exponential phase (90 hours), at which time two 50 mLs of cells were harvested and RNA extracted. Samples were prepared in triplicate, for a total of 12 samples. The RNA was amplified and labeled by Microarray Core (E) and hybridized to the GLYCOv3 microarrays.
2011-04-29 | E-GEOD-28920 | biostudies-arrayexpress