Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA308140 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:We performed an RNA pulldown against a methyl group on the mRNA cap using a fusion protein, GST-eIF4E, highly specific for a m7G-mRNA cap. We performed RNA-seq on both the pulldowns and inputs and normalized our pulldown to input in order to determine which genes MYC targets for mRNA cap methylation above and beyond any affect at the transcriptional level. We found that MYC targets approximately 30% of transcripts for enhanced mRNA cap methylation above 1.2 fold on a global scale following 24 h of MYC induction, specifically transcripts involved in the canonical Wnt/β-catenin signaling pathway. We used this dataset to validate transcripts targeted by MYC for mRNA cap methylation and to help us determine the mechanism responsible for this phenomenon.
2017-01-06 | GSE76614 | GEO
Project description:Canonical Wnt/B-catenin signaling is frequently dysregulated in myeloid leukemias and is implicated in leukemogenesis. Nuclear-localized β-catenin is indicative of active Wnt signaling and is frequently observed in acute myeloid leukemia (AML) patients; however, some patients exhibit little or no β-catenin nuclear-localization even where cytosolic B-catenin is abundant. Differential propensity for nuclear-localized β-catenin is also observed in cell lines. To investigate the factors mediating the nuclear-localization of B-catenin we carried out a nuclear/cytoplasmic proteomic analysis of the B-catenin interactome in myeloid leukemia cells. From this we identified hundreds of putative novel B-catenin-interactors. Comparison of interacting factors between Wnt-responsive cells (high nuclear B-catenin, K562/HEL) versus Wnt-unresponsive cells (low nuclear B-catenin, ML1) suggested the established interactor, LEF1, is a key factor mediating the nuclear-localization of B-catenin in myeloid leukemia. The relative levels of nuclear LEF1 and B-catenin were tightly correlated in both cell lines and in primary AML blasts. Furthermore, LEF1 knockdown inhibited B-catenin nuclear-localization and transcriptional activation in Wnt-responsive cells. Conversely, LEF1 overexpression was able to promote both nuclear-localization and B-catenin-dependent transcriptional responses in previously Wnt-unresponsive cells. This study is the first to present a B-catenin interactome in hematopoietic cells and reveals LEF1 as a critical regulator of canonical Wnt signaling in myeloid leukemia.
2019-01-11 | PXD009305 | Pride
Project description:The Wnt-signalling pathway is one of the core de-regulated pathways in chronic lymphocytic leukemia (CLL), activated in a subset of patients by somatic coding mutations. Here we describe an alternative mechanism of Wnt-activation in malignant B cells, mediated by Notch2 activity in mesenchymal stromal cells (MSC) in the tumor microenvironment. We identified that tumor cells specifically induce and activate Notch2 in MSCs. Notch2 orchestrates the expression of target genes essential for the activation of canonical Wnt-signaling in CLL cells. Mechanistically, stromal Notch2 mediates the stabilization of â-catenin by inhibiting the activation of Gsk3-â in malignant B cells. Pharmacological inhibition of the Wnt-pathway mitigates microenvironment-mediated survival of malignant B cells in vitro. Similarly, inhibition of Notch-signaling impaired survival of CLL cells and disease engraftment in a PDX mouse model. Notch2 activation in the tumour microenvironment is a pre-requisite for the GSK3-â dependent activation of the canonical Wnt-signaling in tumor cells.
2018-09-19 | PXD010401 | Pride
Project description:<p>Hepatoblastoma (HB) is the most common pediatric liver tumor, affecting mostly children under 3 years of age. This rare tumor represents 1% of all pediatric cancers. Genetic studies have shown that HB is characterized by high frequency mutations of the CTNNB1 gene encoding beta-catenin (around 75%) and relative genomic stability. Here we have analyzed the transcriptional profile of 21 HBs compared to matched non-tumor livers by Cap Analysis of Gene Expression (CAGE), which provides accurate and quantitative profiling of all transcripts. CAGE analysis revealed strong upregulation of known Wnt target coding genes in most tumors analyzed, consistent with previous transcriptomic studies. To better define the Wnt-dependent transcriptional landscape of HB, we integrated CAGE data with TCF4 ChIP-seq data from a CTNNB1-mutated cancer cell line and with the FANTOM5 genomic coordinates of TCF/LEF binding motifs. Both TCF/LEF binding motifs and ChIP-seq peaks were strongly enriched in the immediate upstream region, not only for protein-coding genes, but also for non-coding transcripts. Among the selected 112 top Wnt target genes at FDR<1.0E-6 and fold change>8, we found clear over-representation (66%) of distant transcription start sites (TSSs) representing lncRNAs and enhancer RNAs, which raises the question of their role in HB pathogenesis. Analysis of the 112 promoters using CAGEd-oPOSSUM confirmed the predominant involvement of Tcf/Lef transcription factors, together with HNF4G, GATA2, Sox3 and Ets-related genes. Finally, the 112 Wnt target signature defined 3 tumor subclasses, T1, T2 and T3, characterized by progressive alteration of the non-coding part of the transcriptome and significant differences in clinical behavior.</p>
| phs001433 | dbGaP
Project description:The transactivation of TCF target genes induced by Wnt pathway mutations constitutes the primary transforming event in colorectal cancer (CRC). We show that disruption of beta-catenin/TCF-4 activity in CRC cells induces a rapid G1 arrest and blocks a genetic program that is physiologically active in the proliferative compartment of colon crypts. Coincidently, an intestinal differentiation program is induced. The TCF-4 target gene c-MYC plays a central role in this switch by direct repression of the p21(CIP1/WAF1) promoter. Following disruption of beta-catenin/TCF-4 activity, the decreased expression of c-MYC releases p21(CIP1/WAF1) transcription, which in turn mediates G1 arrest and differentiation. Thus, the beta-catenin/TCF-4 complex constitutes the master switch that controls proliferation versus differentiation in healthy and malignant intestinal epithelial cells.
2005-09-02 | E-SMDB-1723 | biostudies-arrayexpress
Project description:Tumor: tumor microenvironment (TME) interactions are critical for tumor progression and the composition and structure of the local extracellular matrix (ECM) are key determinants of tumor metastasis. We recently reported that activation of Wnt/beta- catenin signaling in Ewing sarcoma cells induces widespread transcriptional changes that are associated with acquisition of a metastatic tumor phenotype. Significantly, ECM protein-encoding genes were found to be enriched among Wnt/beta-catenin induced transcripts, leading us to hypothesize that activation of canonical Wnt signaling might induce changes in the Ewing sarcoma secretome. To address this hypothesis, conditioned media from Ewing sarcoma cell lines cultured in the presence or absence of Wnt3a was collected for proteomic analysis. Label-free mass spectrometry was used to identify and quantify differentially secreted proteins. We then used in silico databases to identify only proteins annotated as secreted. Comparison of the secretomes of two Ewing sarcoma cell lines revealed numerous shared proteins, as well as a degree of heterogeneity, in both basal and Wnt-stimulated conditions. Gene set enrichment analysis of secreted proteins revealed that Wnt stimulation reproducibly resulted in increased secretion of proteins involved in ECM organization, ECM receptor interactions, and collagen formation. In particular, Wnt-stimulated Ewing sarcoma cells upregulated secretion of structural collagens, as well as matricellular proteins, such as the metastasis-associated protein, tenascin C (TNC). Interrogation of published databases confirmed reproducible correlations between Wnt/beta-catenin activation and TNC and COL1A1 expression in patient tumors. In summary, this first study of the Ewing sarcoma secretome reveals that Wnt/beta-catenin activated tumor cells upregulate secretion of ECM proteins. Such Wnt/beta-catenin mediated changes are likely to impact on tumor: TME interactions that contribute to metastatic progression.
2018-02-07 | PXD007909 | Pride
Project description:During mammalian kidney development, mesenchymal nephron progenitors (cap mesenchyme) differentiate into the epithelial cells that go on to form the nephron. Although differentiation of nephron progenitors is triggered by activation of Wnt/b-catenin signaling, constitutive activation of Wnt/b-catenin signaling blocks epithelialization of nephron progenitors. Full epithelialization of nephron progenitors requires transient activation of Wnt/b-catenin signaling. We performed transcriptional profiling of nephron progenitors responding to constitutive or transient activation of Wnt/b-catenin signaling.
2012-09-11 | GSE39583 | GEO
Project description:The transactivation of TCF target genes induced by Wnt pathway mutations constitutes the primary transforming event in colorectal cancer (CRC). We show that disruption of beta-catenin/TCF-4 activity in CRC cells induces a rapid G1 arrest and blocks a genetic program that is physiologically active in the proliferative compartment of colon crypts. Coincidently, an intestinal differentiation program is induced. The TCF-4 target gene c-MYC plays a central role in this switch by direct repression of the p21(CIP1/WAF1) promoter. Following disruption of beta-catenin/TCF-4 activity, the decreased expression of c-MYC releases p21(CIP1/WAF1) transcription, which in turn mediates G1 arrest and differentiation. Thus, the beta-catenin/TCF-4 complex constitutes the master switch that controls proliferation versus differentiation in healthy and malignant intestinal epithelial cells. Groups of assays that are related as part of a time series. Computed
2005-09-10 | E-GEOD-3282 | biostudies-arrayexpress
Project description:The objective of this study was to identify genes regulated by canonical Wnt signaling in mouse embryonic stem cells (ESCs).Canonical Wnt signaling supports the pluripotency of mouse ESCs but also promotes differentiation of early mammalian cell lineages. To explain these paradoxical observations, we explored the gene regulatory networks at play. Canonical Wnt signaling is intertwined with the pluripotency network comprising Nanog, Oct4, and Sox2 in mouse ESCs. In defined media supporting the derivation and propagation of mouse ESCs, Tcf3 and ?-catenin interact with Oct4; Tcf3 binds to Sox motif within Oct-Sox composite motifs that are also bound by Oct4-Sox2 complexes. Further, canonical Wnt signaling up-regulates the activity of the Pou5f1 distal enhancer via the Sox motif in mouse ESCs. When viewed in the context of published studies on Tcf3 and ?-catenin mutants, our findings suggest that Tcf3 counters pluripotency by competition with Sox2 at these sites, and Tcf3 inhibition is blocked by ?-catenin entry into this complex. Wnt pathway stimulation also triggers ?-catenin association at regulatory elements with classic Lef/Tcf motifs associated with differentiation programs. The failure to activate these targets in the presence of a MEK/ERK inhibitor essential for mouse ESC culture suggests that MEK/ERK signaling and canonical Wnt signaling combine to promote mouse ESC differentiation. Triplicates of mouse embryonic stem cells cultured with GSK3 inhibitor CHIR99021 or with Wnt pathway inhibitor XAV939.
2013-03-01 | E-GEOD-43420 | biostudies-arrayexpress
Project description:Canonical Wnt/β-catenin signalling is an essential regulator of various cellular functions throughout development and adulthood. Aberrant Wnt/β-catenin signalling also contributes to various pathologies including cancer, necessitating an understanding of cell context dependent mechanisms regulating this pathway. Since protein-protein interactions underpin β-catenin function and localization, we sought to identify novel β-catenin interacting partners by affinity purification coupled with tandem mass spectrometry in vascular smooth muscle cells (VSMCs), where β-catenin is involved in both physiological and pathological control of cell proliferation. Here, we report novel components of the VSMC β-catenin interactome.
2018-10-25 | PXD010421 | Pride