Project description:We find that, in contrast to most cancer types, beta-catenin activation in preB-ALL cells supresses proliferation and leads to cell death. Proteomic analyses indicate that unlike in solid tumors beta-catenin interacts with Ikaros factors (IKZF1 and IKZF3) in pre-B cells. We performed RNA-seq in order to examine changes in expression upon beta-catenin activation in the presence and absence of Ikaros factors.
Project description:We find that, in contrast to most cancer types, beta-catenin activation in preB-ALL cells supresses proliferation and leads to cell death. Proteomic analyses indicate that unlike in solid tumors beta-catenin interacts with Ikaros factors (IKZF1 and IKZF3) in pre-B cells. In order to examine the interaction between IKZF1/IKZF3 and beta-catenin we performed ChIPseq to assay chromatin state and TF binding in CTNNB1-GOF and IKZF1/3-LOF conditions.
Project description:The Wnt signaling pathway is deregulated in over 90% of human colorectal cancers. β Catenin, the central signal transducer of the Wnt pathway, can directly modulate gene expression by interacting with transcription factors of the TCF/LEF-family. In the present study we investigate the role of Wnt signaling in the homeostasis of intestinal epithelium using tissue-specific, inducible beta-catenin gene ablation in adult mice. Block of Wnt/beta-catenin signaling resulted in rapid loss of transient-amplifying cells and crypt structures. Importantly, intestinal stem cells were induced to terminally differentiate upon deletion of beta-catenin resulting in a complete block of intestinal homeostasis and fatal loss of intestinal function. Transcriptional profiling of mutant crypt mRNA isolated by laser capture micro dissection confirmed those observations and allowed to identify genes potentially responsible for the functional preservation of intestinal stem cells. Keywords: genetic modification
Project description:e used interaction and expression proteomic techniques in conjunction with RNA-Seq transcriptomic analysis to analyse how a β-catenin stabilizing mutation alters molecular networks in colorectal cancer cells. Integrated computational analyses of allowed us to identify significantly altered sub-networks linked to β-catenin oncogenesis.
Project description:We used interaction and expression proteomic techniques in conjunction with RNA-Seq transcriptomic analysis to analyse how a β-catenin stabilizing mutation alters molecular networks in colorectal cancer cells. Integrated computational analyses of allowed us to identify significantly altered sub-networks linked to β-catenin oncogenesis.
Project description:The Wnt signaling pathway is deregulated in over 90% of human colorectal cancers. β Catenin, the central signal transducer of the Wnt pathway, can directly modulate gene expression by interacting with transcription factors of the TCF/LEF-family. In the present study we investigate the role of Wnt signaling in the homeostasis of intestinal epithelium using tissue-specific, inducible beta-catenin gene ablation in adult mice. Block of Wnt/beta-catenin signaling resulted in rapid loss of transient-amplifying cells and crypt structures. Importantly, intestinal stem cells were induced to terminally differentiate upon deletion of beta-catenin resulting in a complete block of intestinal homeostasis and fatal loss of intestinal function. Transcriptional profiling of mutant crypt mRNA isolated by laser capture micro dissection confirmed those observations and allowed to identify genes potentially responsible for the functional preservation of intestinal stem cells. Experiment Overall Design: laser capture microdissection of intestinal crypts, control vs. beta-catenin mutant (2days after induction of deletion by tamoxifen), two rounds of amplification of mRNA
Project description:Constitutive activation of the anti-apoptotic NF-κB signaling pathway is a hallmark of the activated B-cell-like (ABC) subtype of diffuse large B-cell lymphomas (DLBCL) that is characterized by adverse survival. Recurrent oncogenic mutations are found in the scaffold protein CARMA1 (CARD11) that connects B-cell receptor (BCR) signaling to the canonical NF-κB pathway. We asked how far additional downstream processes are activated and contribute to the oncogenic potential of DLBCL-derived CARMA1 mutants. To this end, we expressed oncogenic CARMA1 mutants in the NF-κB negative DLBCL lymphoma cell line BJAB. By a proteomic approach we identified recruitment of β-Catenin and its destruction complex consisting of APC, AXIN1, CK1α and GSK3β to oncogenic CARMA1. Recruitment of the β-Catenin destruction complex was independent of CARMA1-BCL10-MALT1 (CBM) complex formation or constitutive NF-κB activation and promoted the stabilization of β-Catenin. Elevated β-Catenin expression was detected in cell lines and biopsies from ABC DLBCL that rely on chronic BCR signaling. Increased β-Catenin amounts alone were not sufficient to induce classical WNT target gene signatures, but could augment TCF/LEF dependent transcriptional activation in response to WNT signaling. In conjunction with NF-κB, β-Catenin enhanced expression of immune suppressive IL-10 and repressed anti-tumoral CCL3, indicating that β-Catenin may induce a favorable tumor microenvironment. Thus, parallel activation of NF-κB and β-Catenin signaling by gain-of-function mutations in CARMA1 can augment WNT stimulation and is required for maintaining high expression of distinct NF-κB target genes and can thereby trigger cell intrinsic and extrinsic processes that promote DLBCL lymphomagenesis.
Project description:Aberrant activation of the Wnt/β-catenin signaling pathway is a hallmark of colorectal cancer (CRC). Here, we identify the deubiquitinating enzyme USP17 as a critical regulator of β-catenin stability in CRC. We demonstrate that USP17 directly interacts with and deubiquitinates β-catenin, preventing its degradation and enhancing its stability. CRISPR/Cas9-mediated knockout of USP17 in CRC-derived cell lines significantly reduced β-catenin levels and suppressed epithelial-mesenchymal transition (EMT), as evidenced by distinct morphological changes and altered expression of classical EMT markers. USP17 depletion reduced the proliferation of CRC cell lines and impaired CRC tumor growth in vivo. Conversely, USP17 overexpression in immortalized rat enterocytes elevated β-catenin levels and enhanced KRAS-induced cell proliferation. RNA sequencing and quantitative proteomic analysis of USP17-depleted CRC cells revealed significant suppression of the transcriptional coactivator function of β-catenin, impacting key oncogenic-related pathways. Our findings establish USP17 as a key regulator of β-catenin signaling and highlight its potential as a candidate therapeutic target in CRC.