Effect of a gamma secretase inhibitor on the T29 cell line
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
SUBMITTER: Susan Chan
PROVIDER: E-GEOD-46095 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:The mouse Ikaros-deficient thymic lymphoma cell line T29 was treated with a gamma-secretase inhibitor or vehicle (DMSO) for 36h and subjected to transcriptome analysis.
2013-04-17 | GSE46095 | GEO
Project description:Lineage-negative thymocytes were cultured on OP9-DL1 stromal cells for 16h in the presence of DMSO or the gamma secretase inhibitor MRK-003. DN3 cells cells were then sorted and their transcriptome analyzed. 8 samples
2013-04-17 | E-GEOD-46091 | biostudies-arrayexpress
Project description:The mouse Ikaros-deficient thymic lymphoma cell line T29 was transduced with an empty retrovirus (MigR1) or a retrovirus expressing an fusion proein between Ikaros1 and the ligand binding domain of the estrogen receptor. Cells trreated with ethanol or 4-hydroxy-tamoxyfen (4OHT) for 24h were profiled. We used expression of an inducible ersion of the Ikaros protein in an Ikaros-deficient cell line to identify Ikaros-regulated genes
2013-04-17 | E-GEOD-46088 | biostudies-arrayexpress
Project description:The mouse Ikaros-deficient thymic lymphoma cell line T29 was transduced with a retrovirus expressing an fusion protein between a dominant-negative form of Mastermind and the ligand binding domain of the estrogen receptor. Cells trreated with Ethanol or 4-hydroxy-tamoxyfen for 24h were profiled. We used expression of an inducible ersion of the dominant negative Mastermind protein in an Ikaros-deficient cell line to identify Notch-regulated genes
2013-04-17 | E-GEOD-46089 | biostudies-arrayexpress
Project description:γ-secretase is an intra-membrane-cleaving aspartyl protease implicated in the processing of a wide range of type I membrane proteins including the Notch receptor and the amyloid-β precursor protein (APP). It thus regulates a diverse array of cellular and biological processes including the differentiation of neuronal embryonic stem cells, or intestinal stem cells, with the latter controlling the self-renewing of the intestinal epithelium. Indeed, proteolysis of these proteins by γ-secretase triggers signaling cascades by releasing intracellular domains (ICDs) which, following association with adaptor proteins and nuclear translocation, modulate the transcription of different genes by binding directly to their promoters. The pronounced proliferative and regenerative effects of Notch signaling and its implication in the generation of the Aβ-peptides, makes γ-secretase a therapeutic target for several types of cancer and for Alzheimerâs disease. To investigate the broad effects of γ-secretase activity onto the cellular transcriptome, Chinese hamster ovary (CHO) cells with enhanced γ-secretase were compared to cells with abolished γ-secretase activity via a microarray designed for a genetically close species, mouse. Our findings will potentially help to decipher the biology of γ-secretase, including a better understanding of the roles of this enzyme in gene transcription. We compared the transcriptomes of two CHO cell lines displaying extreme differences in γ-secretase activity. The S-1 cell line overexpressed the four components of γ-secretase (NCT, APH1aL, PS1, and PEN2) and was characterized by a marked increase in the level of PS1 heterodimers associated with 8-fold increased γ-secretase activity compared to untransfected controls. The other cell line consisted of wild type CHO cells incubated with DAPT, a well-known γ-secretase inhibitor. The two cell lines were used in combination with a mouse microarray to analyze gene transcription under enhanced γ-secretase. Two samples, S1 and DAPT treated CHO- were used in biological triplicates each.
2010-05-15 | E-GEOD-16379 | biostudies-arrayexpress
Project description:The aim of the experiment was to visualize genes under the control of Ikaros during early T cell development. We used mice carrying floxed Ikaros alleles that were crossed with the Rosa26-CreERT2 mice, and which were injected with tamoxifen for 4 days. DN4 thymocytes were sorted from 4 mice (5-6 week-old) which are positive or not for the Rosa26-CreERT2 transgene. DN4 cells were sorted from 2 Ikf/f Rosa26-CreERT2+ mice and 2 Ikf/f mice, which were all treated with tamoxifen for 4 days. Loss of Ikaros was confirmed in sorted cells from the Ikf/f Rosa26-CreERT2+ mice by western blot. Gene expression profiles were determined on total RNA from sorted cells with Affymetrix Mouse Gene arrays.
2013-04-17 | E-GEOD-46093 | biostudies-arrayexpress
Project description:Glucocorticoids are an essential component of the treatment of lymphoid malignancies and resistance to glucocorticoid therapy constitutes a prominent clinical problem in relapsed and refractory lymphoblastic leukemias. Constitutively active NOTCH signaling is involved in the pathogenesis of over 50% of T-cell lymphoblastic leukemia (T-ALL) which harbor activating mutations in the NOTCH1 gene. Aberrant NOTCH1 signaling has been shown to protect normal thymocytes from glucocorticoid induced cell death. Here we analyzed the interaction of glucocorticoid therapy with inhibition of NOTCH signaling in the treatment of T-ALL. Gamma-secretase inhibitors (GSI), which block the activation of NOTCH receptors, amplified the transcriptional changes induced by glucocorticoid treatment, including glucocorticoid receptor autoinduction and restored sensitivity to dexamethasone in glucocorticoid-resistant T-ALL cells. Apoptosis induction upon inhibition of NOTCH signaling and activation of the glucocorticoid receptor was dependent on transcriptional upregulation of BIM and subsequent activation of the mitochondrial/intrinsic cell death pathway. Finally, we used a mouse xenograft model of T-ALL to demonstrate that combined treatment with dexamethasone and a GSI results in improved antileukemic effects in vivo. These studies provide insight in the mechanisms of glucocorticoid resistance and serve as rationale for the use of glucocorticoid and GSIs in combination in the treatment of T-ALL. Experiment Overall Design: Duplicate samples (biologic replicas) from CUTLL1 cells were treated for 24 hours with vehicle only (DMSO), dexamethasone (1microM), a gamma-secretase inhibitor (CompE 100nM) and a combination of dexamethasome plus gamma secretase inhibitor at the same concentrations indicated before. Gene expression profiling was analyzed to identify gene expression signatures assocuated with glucocorticoid treatment (dexamethasone), inhibition of NOTCH1 by gamma secretase inhibitor (CompE) or the combination of both treatments.
2009-01-13 | E-GEOD-7067 | biostudies-arrayexpress
Project description:The Ikaros zink finger transcription factor is a critical regulator of the hematopietic system, and plays an important role in the regulation of the development and function of several blood cell lineages. We used microarrays to characterize how Ikaros deficieny affects global transcription in the hematopoietic stem and progenitor cells from wild-type and Ikaros mutant mice. lin- Sca1+ c-Kit+ (LSK) cells, that contains the hematopoietic stem cells and the multipotent progenitor cells, were sorted by FACS from the bone marrow of 6-7 weeks old WT and IkL/L mutant mice. Total RNA extracted from these cells was subjected to transcriptome analysis.
2015-11-03 | E-GEOD-61147 | 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:We have investigated the role of the Notch pathway in the generation and maintenance of KrasG12V-driven non-small cell lung carcinomas (NSCLCs). We demonstrate by genetic means that γ-secretase and Rbpj activities are both essential in the formation of NSCLCs. Interestingly, pharmacologic treatment of mice carrying endogenous NSCLCs with a γ-secretase inhibitor (GSI) blocks cancer growth and induces partial regression. Treated cancers show a reduction in Hes1 levels, reduced phosphorylated Erk, decreased proliferation and higher apoptosis. We demonstrate that HES1 directly binds and represses the promoter of DUSP1, a dual phosphatase with activity against phospho-ERK, and this repression is relieved by GSI treatment both in mouse and human NSCLCs. Our data provide proof for the in vivo therapeutic potential of γ-secretase inhibitors in primary NSCLCs and provide a mechanistic explanation for its therapeutical effect. We have included 6 samples. 3 with vehicle and 3 with the gamma-secretase inhibitor DAPT and we compare both groups.
2012-12-01 | E-GEOD-38054 | biostudies-arrayexpress