Dll1 acts as a tumor suppressor in neural stem cells to induce an astroglial lineage-restricted glioblastoma
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE32293 | GEO | 2011/09/24
SECONDARY ACCESSION(S): PRJNA146365
REPOSITORIES: GEO
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Project description:There is increasing evidence for tissue stem cells as potential source for cancers. However, the cellular and molecular mechanisms at the origin of this transformation remain elusive. Here we show that Delta-like1 (Dll1) mutation induces the oncogenic transformation of neural stem cell–derived neurospheres into oncogenic spheres capable of generating histological and molecular human glioblastoma (GBM)-like tumors upon subcutaneous and intracranial transplantations into nude mice. Serial transplantation assays suggest that Dll1 spheres tumorigenicity results from the oncogenic transformation of normal neural stem cell into GBM-producing stem cell. Compared differentiation of Dll1 vs. WT spheres shows the presence in Dll1 spheres of a subpopulation of cells which although fated to a glial lineage fail to differentiate terminally, in keeping with the astrocytic promoting function of Delta-Notch. This population of astrocyte progenitors proliferates actively and fails to down-regulate EGFR phosphorylation. These studies suggest that Dll1-induced tumorigenesis is restricted to the astrocytic lineage thereby providing a model for human GBM as well as an explanation for the duality of Notch signaling acting either as an oncogene or a tumor suppressor in stem/progenitor cells derived tumors, depending on the lineage commitment. Comparison between control (WT) and mutants (Dll1-3 and Dll1-5) cells was performed. Two biological replicates (n=3 each replicate) were used, and each replicate (n=3, total RNA pooled) was dye-swaped.
2011-09-23 | E-GEOD-32293 | biostudies-arrayexpress
Project description:BACKGROUND: The Notch signaling pathway is an evolutionary conserved signal transduction pathway involved in embryonic patterning and regulation of cell fates during development and self-renewal. Recent studies have demonstrated that this pathway is integral to a complex system of interactions, involving as well other signal transduction pathways, and implicated in distinct human diseases. Delta-like 1 (Dll1) is one of the known ligands of the Notch receptors. The role of the Notch ligands is less well understood. Loss-of-function of Dll1 leads to embryonic lethality, but reduction of Delta-like 1 protein levels has not been studied in adult stage. METHODOLOGY/PRINCIPAL FINDINGS: Here we present the haploinsufficient phenotype of Dll1 and a missense mutant Dll1 allele (Dll1(C413Y)). Haploinsufficiency leads to a complex phenotype with several biological processes altered. These alterations reveal the importance of Dll1 mainly in metabolism, energy balance and in immunology. The animals are smaller, lighter, with altered fat to lean ratio and have increased blood pressure and a slight bradycardia. The animals have reduced cholesterol and triglyceride levels in blood. At the immunological level a subtle phenotype is observed due to the effect and fine-tuning of the signaling network at the different levels of differentiation, proliferation and function of lymphocytes. Moreover, the importance of the proteolytic regulation of the Notch signaling network emphasized. CONCLUSIONS/SIGNIFICANCE: In conclusion, slight alterations in one player of Notch signaling alter the entire organism, emphasizing the fine-tuning character of this pathway in a high number of processes. Four organs (liver, spleen, thymus, brain) of the Dll1 mutant mouse line analysed by cDNA microarray technology. Experiments include four biological replicates for reference (wildtype) and mutant animals. Two technical replicates for each mutant mouse were performed. As reference pooled RNA of the same organ was used. 50% of the chip hybridisations are dye sway experiments.
2009-03-01 | E-GEOD-12954 | biostudies-arrayexpress
Project description:BACKGROUND: The Notch signaling pathway is an evolutionary conserved signal transduction pathway involved in embryonic patterning and regulation of cell fates during development and self-renewal. Recent studies have demonstrated that this pathway is integral to a complex system of interactions, involving as well other signal transduction pathways, and implicated in distinct human diseases. Delta-like 1 (Dll1) is one of the known ligands of the Notch receptors. The role of the Notch ligands is less well understood. Loss-of-function of Dll1 leads to embryonic lethality, but reduction of Delta-like 1 protein levels has not been studied in adult stage. METHODOLOGY/PRINCIPAL FINDINGS: Here we present the haploinsufficient phenotype of Dll1 and a missense mutant Dll1 allele (Dll1(C413Y)). Haploinsufficiency leads to a complex phenotype with several biological processes altered. These alterations reveal the importance of Dll1 mainly in metabolism, energy balance and in immunology. The animals are smaller, lighter, with altered fat to lean ratio and have increased blood pressure and a slight bradycardia. The animals have reduced cholesterol and triglyceride levels in blood. At the immunological level a subtle phenotype is observed due to the effect and fine-tuning of the signaling network at the different levels of differentiation, proliferation and function of lymphocytes. Moreover, the importance of the proteolytic regulation of the Notch signaling network emphasized. CONCLUSIONS/SIGNIFICANCE: In conclusion, slight alterations in one player of Notch signaling alter the entire organism, emphasizing the fine-tuning character of this pathway in a high number of processes.
2009-03-01 | GSE12954 | GEO
Project description:It has been previously described that in glioblastoma (GBM), BMPs deplete the tumorigenic potential of glioblastoma stem cells (GSCs), promoting their differentiation towards the astrocytic lineage. To gain more insight on how BMPs regulate differentiation in GSCs, we are interested in identifying new BMP target genes in GBM cells. To this end, the patient derived glioblastoma cell lines U3031MG and U3034MG were stimulated or not with 30ng/ml BMP7 for 2 and 24 h, total RNA was isolated from three biological replicates per condition, and a microarray screen with the Affymetrix U133plus2 platform was performed.
2021-05-01 | E-MTAB-9811 | biostudies-arrayexpress
Project description:Notch expressed on CD4+ T cells transduces signals that mediate their effector functions and survival by interacting with Notch ligands on adjacent cells. Although Notch signaling is known to be cis-inhibited by Notch ligands expressed on the same cells, the role of Notch ligands on T cells remain unclear. In this report we demonstrate that the Notch ligand Dll1 on CD4+ T cells transduces signals required for the maintenance of activated CD4+ T cells without affecting Notch signaling in the same cells. T cell-specific Dll1-deficient (Dll1-/-) mice did not show any defect in T cell development in thymus or spleen. Co-transfer of CD4+ T cells from Dll1-/- and control mice into recipient mice followed by immunization revealed a rapid decline of CD4+ T cells from Dll1-/- mice compared with control cells. Dll1-/- mice exhibited lower clinical scores of experimental autoimmune encephalitis than control mice. The expression of Notch target genes in CD4+ T cells from Dll1-/- mice was not affected, suggesting that Dll1 deficiency in T cells does not affect cis Notch signaling. Overexpression of the intracellular domain of Dll1 in Dll1-deficient CD4+ T cells partially rescued impaired survival. Our data highlight Dll1 as an independent regulator of Notch-signaling for the survival of activated CD4+ T cells, and provide new insight into the physiological roles of Notch ligands as well as a regulatory mechanism important for maintaining adaptive immune responses The mRNA expression in activated CD4+ T cells from mouse was obtained by DNA microarray analysis. These mRNA expression was compared.
2016-01-09 | E-GEOD-76693 | biostudies-arrayexpress
Project description:Glioblastomas (GBM) are poorly differentiated astrocytic tumors arising in the Central Nervous System (CNS), which despite aggressive treatments are still characterized by a fatal outcome. Several studies have shown the existence of a subpopulation of cells within glioma tumors displaying cancer stem cells properties. As the term âtumor initiating cellsâ (TICs) is frequentely used to describe cells as these with cancer stem cells capacity. Because TICs promotes the tumor chemo- and radio-resistance and angiogenesis it is conceivable that finding a mean to kill these cells would lead to a better therapy for GBM. The NOTCH gene has an important role during the CNS development, in the maintenance of dividing cells in promoting neural lineage entry of Embryonic Stem Cells and the differentiation of astroglia from the rat adult hippocampus-derived multipotent progenitors. The activation of the NOTCH signaling requires the proteolytic processing of this type I integral membrane protein by a two step process catalyzed first by a metalloprotease and then by the gamma-secretase. An increased activation of the NOTCH signaling has been implicated in several tumors types. Recently some studies showed that this pathway induces the survival/proliferation in GBM and glioma cells, and the expression of stem cell properties in glioma cells. Accordingly to these findings, the inhibition of this pathway leads to depletion of stem-like cells and blocks the engraftment in embryonal brain tumors. Furthermore, enhanced NOTCH signaling may lead to one of the tumor resistance mechanisms deployed by GBM. Targeting the NOTCH pathway specifically in GBM TICs appears therefore as a rational approach for exploring novel and hopefully more effective therapeutic strategies for the management of this malignancy. Several molecular tools are available for targeting the Notch pathway such as specific siRNAs, shRNAs or drugs such as gamma-secretase inhibitors. Among these tools, the latter are small peptides/molecules able to inhibit the gamma-secretase by distinct mechanisms. In this study we used two drugs known as gamma-secretase inhibitors, to investigate by gene expression profiling, their ability to interfere specifically with the proliferative properties of GBM TICs previously obtained in our laboratory. Our data show that one of these two drugs, LLNle, is effective in killing these cells in vitro by activating protein catabolic process mediated by the proteasome, suggesting that preclinical studies should definitely be carried on to evaluate whether LLNle is able to significantly improve the survival in hybrid human GBM-animal models. Gamma-secretase inhibitors have been proposed as drugs able to kill cancer cells by targeting the NOTCH pathway. In this study we employed two of such inhibitors, namely the z-Leu-leu-Nle-CHO (LLNle) and N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT), to verify whether they were effective in vitro in the killing of human GBM tumor initiating cells (TICs). We first established that of the two drugs only LLNle reduces the viability of GBM TICs obtained from three different patients in the low micromolar range. Cells were treated with 7.5 μM LLNle or DAPT or vehicle alone (DMSO 0.1%) and kept in a humidified 5% CO2 atmosphere at 37°C for the indicated time period (24 or 48 hours). To establish which cellular processes are activated in GBM TICs by LLNle we generated and analyzed the gene expression profile after treatment with this compound and with DAPT and DMSO (vehicle). Our data show that LLNle induces upregulation of genes coding for proteasome subunits and subsequently mitotic arrest in these cells by repressing genes required for DNA synthesis and mitotic progression and by activation of genes acting as mitotic inhibitors. Our data are consistent with proteasome inhibition by LLNle, subsequent upregulation of proteasome activity and subsequent unleash of the apoptotic process in GBM TICs.
2010-04-09 | E-GEOD-14581 | biostudies-arrayexpress
Project description:Notch expressed on CD4+ T cells transduces signals that mediate their effector functions and survival by interacting with Notch ligands on adjacent cells. Although Notch signaling is known to be cis-inhibited by Notch ligands expressed on the same cells, the role of Notch ligands on T cells remain unclear. In this report we demonstrate that the Notch ligand Dll1 on CD4+ T cells transduces signals required for the maintenance of activated CD4+ T cells without affecting Notch signaling in the same cells. T cell-specific Dll1-deficient (Dll1-/-) mice did not show any defect in T cell development in thymus or spleen. Co-transfer of CD4+ T cells from Dll1-/- and control mice into recipient mice followed by immunization revealed a rapid decline of CD4+ T cells from Dll1-/- mice compared with control cells. Dll1-/- mice exhibited lower clinical scores of experimental autoimmune encephalitis than control mice. The expression of Notch target genes in CD4+ T cells from Dll1-/- mice was not affected, suggesting that Dll1 deficiency in T cells does not affect cis Notch signaling. Overexpression of the intracellular domain of Dll1 in Dll1-deficient CD4+ T cells partially rescued impaired survival. Our data highlight Dll1 as an independent regulator of Notch-signaling for the survival of activated CD4+ T cells, and provide new insight into the physiological roles of Notch ligands as well as a regulatory mechanism important for maintaining adaptive immune responses
2016-01-09 | GSE76693 | GEO
Project description:Glioblastomas (GBM) are poorly differentiated astrocytic tumors arising in the Central Nervous System (CNS), which despite aggressive treatments are still characterized by a fatal outcome. Several studies have shown the existence of a subpopulation of cells within glioma tumors displaying cancer stem cells properties. As the term “tumor initiating cells” (TICs) is frequentely used to describe cells as these with cancer stem cells capacity. Because TICs promotes the tumor chemo- and radio-resistance and angiogenesis it is conceivable that finding a mean to kill these cells would lead to a better therapy for GBM. The NOTCH gene has an important role during the CNS development, in the maintenance of dividing cells in promoting neural lineage entry of Embryonic Stem Cells and the differentiation of astroglia from the rat adult hippocampus-derived multipotent progenitors. The activation of the NOTCH signaling requires the proteolytic processing of this type I integral membrane protein by a two step process catalyzed first by a metalloprotease and then by the gamma-secretase. An increased activation of the NOTCH signaling has been implicated in several tumors types. Recently some studies showed that this pathway induces the survival/proliferation in GBM and glioma cells, and the expression of stem cell properties in glioma cells. Accordingly to these findings, the inhibition of this pathway leads to depletion of stem-like cells and blocks the engraftment in embryonal brain tumors. Furthermore, enhanced NOTCH signaling may lead to one of the tumor resistance mechanisms deployed by GBM. Targeting the NOTCH pathway specifically in GBM TICs appears therefore as a rational approach for exploring novel and hopefully more effective therapeutic strategies for the management of this malignancy. Several molecular tools are available for targeting the Notch pathway such as specific siRNAs, shRNAs or drugs such as gamma-secretase inhibitors. Among these tools, the latter are small peptides/molecules able to inhibit the gamma-secretase by distinct mechanisms. In this study we used two drugs known as gamma-secretase inhibitors, to investigate by gene expression profiling, their ability to interfere specifically with the proliferative properties of GBM TICs previously obtained in our laboratory. Our data show that one of these two drugs, LLNle, is effective in killing these cells in vitro by activating protein catabolic process mediated by the proteasome, suggesting that preclinical studies should definitely be carried on to evaluate whether LLNle is able to significantly improve the survival in hybrid human GBM-animal models.
2009-12-21 | GSE14581 | GEO
Project description:The most critical stage in initiation of melanoma metastasis is the radial to vertical growth transition, yet the triggers of this transition remain elusive. We introduce a novel perspective, suggesting that the microenvironment drives melanoma metastasis independently of mutation acquisition. Here we examined the changes in microenvironment that occur during melanoma radial growth. We show that direct contact of melanoma cells with the remote epidermal layer triggers vertical invasion via Notch signaling activation, the latter serving to inhibit MITF function. Briefly, within the native Notch ligand-free microenvironment, MITF, the melanocyte lineage master regulator, binds and represses miR-222/221 promoter in an RBPJK-dependent manner. However, when radial growth brings melanoma cells into contact with distal differentiated keratinocytes that express Notch ligands, the activated Notch intracellular domain impairs MITF binding to miR-222/221 promoter. This de-repression of miR-222/221 expression triggers initiation of invasion. Our findings may direct novel prevention opportunities via targeting specific microenvironment. Two replicates of Notch-activated cells that were seeded on Delta-like-1 (DLL1) (2 ng/µl ) coated plates were compared to two replicates of cells without Notch activation. The goal of this experiment is to evaluate the changes of miRs expression in melanoma cells upon Notch signaling activation.
2015-07-30 | E-GEOD-69403 | biostudies-arrayexpress
Project description:Objective DLL1 is a mammalian Notch ligand with essential functions during embryonic development. We tagged endogenous DLL1 in one homologous recombination step such that AcGFP-HA tagged DLL1 could be converted by Cre-mediated site-specific recombination into StrepFlag tagged DLL1. We anticipated that this should allow us to visualise DLL1 in living cells as well as allow for sorting and enrichment of DLL1-expressing cells and efficient purification of DLL1 protein complex. Results We generated constructs to express a DLL1 variant that carried C-terminal in frame an AcGFPHA tag flanked by loxP sites followed by a StrepFlag tag out of frame. Cre-mediated recombination removed AcGFP-HA and added StrepFlag in frame to DLL1. The AcGFPHAstopStrepFlag tag was added to the Dll1 cDNA to allow for tests in cultured cells in vitro and was introduced into endogenous DLL1 in mice using ES cells modified by homologous recombination. Tagged DLL1 protein was detected by antibodies against GFP and HA or Flag, respectively, both in CHO cell and embryo lysates. In CHO cells the AcGFP protein fused to DLL1 was functional. In vivo AcGFP expression was below the level of detection by direct fluorescence. However, the StrepFlag tag allowed us to specifically purify DLL1 complexes from embryo lysates. Homozygous mice expressing AcGFPHA or StrepFlag-tagged DLL1 revealed a vertebral column phenotype reminiscent of disturbances in AP polarity during somitogenesis, a process most sensitive to reduced DLL1 function. Thus, even small C-terminal tags can impinge on sensitive developmental processes requiring DLL1 activity.
2021-11-03 | PXD024680 | Pride