Ascl2 acts as an R-spondin/Wnt responsive switch to control stemness in intestinal crypts [array]
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE57053 | GEO | 2014/12/31
SECONDARY ACCESSION(S): PRJNA245327
REPOSITORIES: GEO
Similar Datasets
Project description:Wnt signals control three functions of intestinal crypts: maintenance of Lgr5 stem cells, proliferation of transit-amplifying daughters and formation of Paneth cells. Here, we study how the Wnt effector β-catenin/Tcf4 cooperates with the Wnt-activated transcription factor Ascl2 to control a stem cell transcription program. DNA elements that are co-occupied and synergistically regulated by Ascl2 and Tcf4 specifically map to stem cell genes. In vitro, Tcf4-/- mini-guts are rescued by Ascl2 expression, while Ascl2-/- organoids are rescued by Wnt signaling. A direct auto-activatory loop leads to an on/off expression pattern of Ascl2 with a threshold that depends on the previous state. Wnt/R-spondin1 activates this loop. This mechanism interprets Wnt levels in crypts and translates this continuous signal into a discrete Ascl2 âonâ or âoffâ decision. In turn Ascl2, together with β-catenin/Tcf, activates stem cell genes. Thus, Ascl2 forms a transcriptional 'stemness switch' that is both Wnt-responsive and Wnt-dependent Examination of Tcf4, B-catenin and Ascl2 DNA occupancy in murine intestinal organoids and human colorectal cancer cell lines *** Original raw files unavailable due to loss during backup ***
2016-07-15 | E-GEOD-84456 | biostudies-arrayexpress
Project description:Wnt signals control three functions of intestinal crypts: maintenance of Lgr5 stem cells, proliferation of transit-amplifying daughters and formation of Paneth cells. Here, we study how the Wnt effector β-catenin/Tcf4 cooperates with the Wnt-activated transcription factor Ascl2 to control a stem cell transcription program. DNA elements that are co-occupied and synergistically regulated by Ascl2 and Tcf4 specifically map to stem cell genes. In vitro, Tcf4-/- mini-guts are rescued by Ascl2 expression, while Ascl2-/- organoids are rescued by Wnt signaling. A direct auto-activatory loop leads to an on/off expression pattern of Ascl2 with a threshold that depends on the previous state. Wnt/R-spondin1 activates this loop. This mechanism interprets Wnt levels in crypts and translates this continuous signal into a discrete Ascl2 “on” or “off” decision. In turn Ascl2, together with β-catenin/Tcf, activates stem cell genes. Thus, Ascl2 forms a transcriptional 'stemness switch' that is both Wnt-responsive and Wnt-dependent
2016-07-15 | GSE84456 | GEO
Project description:The canonical Wnt pathway plays a central role in stem cell maintenance, differentiation and proliferation in the intestinal epithelium. Constitutive, aberrant activity of the TCF4/β-catenin transcriptional complex is the primary transforming factor in colorectal cancer. Despite significant recent inroads, the full complement of Wnt target genes and the mechanisms of regulation remain incompletely understood. Here we identify a nuclear long non-coding RNA, termed WiNTRLINC1, as a direct target of TCF4/β-catenin in colorectal cancer cells. WiNTRLINC1 positively regulates the expression of its close neighbor ASCL2, a transcription factor that controls intestinal stem cell fate. WiNTRLINC1 interacts with TCF4/β-catenin to mediate the juxtaposition/physical contact of its own promoter with the regulatory regions of ASCL2. ASCL2, in turn, regulates WiNTRLINC1 expression. This feedforward regulatory loop controls stem cell-related gene expression and is highly amplified in colorectal cancer.
2016-06-09 | GSE69036 | GEO
Project description:Background: Wnt signaling maintains the undifferentiated state of intestinal crypt progenitor cells by inducing the formation of nuclear TCF4/beta-catenin complexes. In colorectal cancer, activating mutations in Wnt pathway components cause inappropriate activation of TCF4/beta-catenin -driven transcription. Despite the passage of a decade after the discovery of TCF4 and beta-catenin as the molecular effectors of the Wnt signal, few transcriptional activators essential and unique to the regulation of this transcription program have been found. Methodology/Principal Findings: Using proteomics, we identified the leukemia-associated Mllt10/Af10 and the methyltransferase Dot1l, as Tcf4/beta-catenin interactors in mouse small intestinal crypts. Mllt10/Af10-Dot1l, essential for transcription elongation, are recruited to Wnt target genes in a beta-catenin -dependent manner, resulting in H3K79 methylation over their coding regions in vivo in proliferative crypts of mouse small intestine, in colorectal cancer and Wnt-inducible HEK293T cells. Depletion of MLLT10/AF10 in colorectal cancer and Wnt-inducible HEK293T cells followed by expression array analysis identifies MLLT10/AF10 and DOT1L as essential activators dedicated to Wnt target gene regulation. In contrast, previously published b-catenin coactivators p300 and beta-catenin displayed a more pleiotropic target gene expression profile controlling Wnt and other pathways. tcf4, mllt10/af10 and dot1l are co-expressed in Wnt-driven tissues in zebrafish and essential for Wnt-reporter activity. Intestinal differentiation defects in apc-mutant zebrafish can be rescued by depletion of Mllt10 and Dot1l, establishing these genes as activators downstream of Apc in Wnt target gene activation in vivo. Morpholino-depletion of mllt10/af10-dot1l in zebrafish results in defects in intestinal homeostasis and a significant reduction in the in vivo expression of direct Wnt target genes and in the number of proliferative intestinal epithelial cells. Conclusions/Significance: We conclude that Mllt10/Af10-Dot1l are essential, dedicated activators of Wnt-dependent transcription, critical for maintenance of intestinal proliferation and homeostasis. The methyltransferase Dot1l may present an attractive candidate for drug targeting in colorectal cancer. 6 samples for Ls174T cells: si-b-catenin against si-control and dyeswap of it, si-control, si-MLLT10, si-BRG1 and si-P300 are hybridized against common reference RNA; 6 samples of HEK293T cells: Wnt3A or control medium (CM) induction for 9 hours, si-MLLT10, si-DOT1L, si-BRG1 and si-P300 upon 9 hour Wnt3A induction are all hybridized against common reference RNA
2010-04-20 | E-GEOD-21367 | biostudies-arrayexpress
Project description:Wnt signalling maintains the undifferentiated state of intestinal crypt/progenitor cells through the TCF4/Ã-catenin activating transcriptional complex. In colorectal cancer, activating mutations in Wnt pathway components lead to inappropriate activation of the TCF4/Ã-catenin transcriptional program and tumourigenesis in the gut epithelium. The mechanisms by which TCF4/Ã-catenin activate key target genes are not well understood. Using a proteomics approach, we identified Tnik, a member of the Germinal centre kinase family, as a Tcf4 interactor in the proliferative crypts of mouse small intestine. Tnik is recruited to promoters of Wnt target genes in mouse crypts and in Ls174T colorectal cancer cells in a Ã-catenin dependent manner. Depletion of TNIK and expression of TNIK kinase mutants abrogated TCF-LEF transcription, highlighting the essential role of the kinase activity in Wnt target gene activation. siRNA depletion of TNIK followed by expression array analysis demonstrated that TNIK is an essential and exclusive activator of Wnt induced transcriptional program. As an essential component in the TCF4/Ã-catenin activator complex, the kinase TNIK may present an attractive candidate for drug targeting in colorectal cancer. HEK293T cells: Wnt3A vs control medium (CM) induction for 4, 7 and 9 hours; si-TNIK vs si-control after Wnt3A induction at 4 and 7 hours (2 biological replicates for 7 hour time point); dyeswap for each experiment (i.e. 12 arrays in total).
2010-08-18 | E-GEOD-17623 | biostudies-arrayexpress
Project description:Background: Wnt signaling maintains the undifferentiated state of intestinal crypt progenitor cells by inducing the formation of nuclear TCF4/beta-catenin complexes. In colorectal cancer, activating mutations in Wnt pathway components cause inappropriate activation of TCF4/beta-catenin-driven transcription. Despite the passage of a decade after the discovery of TCF4 and beta-catenin as the molecular effectors of the Wnt signal, few transcriptional activators essential and unique to the regulation of this transcription program have been found. Methodology/Principal Findings: Using proteomics, we identified the leukemia-associated Mllt10/Af10 and the methyltransferase Dot1l, as Tcf4/beta-catenin interactors in mouse small intestinal crypts. Mllt10/Af10-Dot1l, essential for transcription elongation, are recruited to Wnt target genes in a beta-catenin -dependent manner, resulting in H3K79 methylation over their coding regions in vivo in proliferative crypts of mouse small intestine, in colorectal cancer and Wnt-inducible HEK293T cells. Depletion of MLLT10/AF10 in colorectal cancer and Wnt-inducible HEK293T cells followed by expression array analysis identifies MLLT10/AF10 and DOT1L as essential activators dedicated to Wnt target gene regulation. In contrast, previously published b-catenin coactivators p300 and beta-catenin displayed a more pleiotropic target gene expression profile controlling Wnt and other pathways. tcf4, mllt10/af10 and dot1l are co-expressed in Wnt-driven tissues in zebrafish and essential for Wnt-reporter activity. Intestinal differentiation defects in apc-mutant zebrafish can be rescued by depletion of Mllt10 and Dot1l, establishing these genes as activators downstream of Apc in Wnt target gene activation in vivo. Morpholino-depletion of mllt10/af10-dot1l in zebrafish results in defects in intestinal homeostasis and a significant reduction in the in vivo expression of direct Wnt target genes and in the number of proliferative intestinal epithelial cells. Conclusions/Significance: We conclude that Mllt10/Af10-Dot1l are essential, dedicated activators of Wnt-dependent transcription, critical for maintenance of intestinal proliferation and homeostasis. The methyltransferase Dot1l may present an attractive candidate for drug targeting in colorectal cancer.
2010-04-20 | GSE21367 | GEO
Project description:Wnt signalling maintains the undifferentiated state of intestinal crypt/progenitor cells through the TCF4/ß-catenin activating transcriptional complex. In colorectal cancer, activating mutations in Wnt pathway components lead to inappropriate activation of the TCF4/ß-catenin transcriptional program and tumourigenesis in the gut epithelium. The mechanisms by which TCF4/ß-catenin activate key target genes are not well understood. Using a proteomics approach, we identified Tnik, a member of the Germinal centre kinase family, as a Tcf4 interactor in the proliferative crypts of mouse small intestine. Tnik is recruited to promoters of Wnt target genes in mouse crypts and in Ls174T colorectal cancer cells in a ß-catenin dependent manner. Depletion of TNIK and expression of TNIK kinase mutants abrogated TCF-LEF transcription, highlighting the essential role of the kinase activity in Wnt target gene activation. siRNA depletion of TNIK followed by expression array analysis demonstrated that TNIK is an essential and exclusive activator of Wnt induced transcriptional program. As an essential component in the TCF4/ß-catenin activator complex, the kinase TNIK may present an attractive candidate for drug targeting in colorectal cancer.
2009-08-13 | GSE17623 | GEO
Project description:Previous studies have shown that the main function of VASP is to regulate the cytoskeleton and play an important role in promoting tumor cell metastasis. In this study, we first reveal that VASP is located in the nucleus of breast cancer cells and elucidate a Wnt/β-catenin/VASP positive feedback loop. We identify that VASP is a target gene of Wnt/β-catenin signaling pathway, and activation of Wnt/β-catenin signaling pathway can significantly upregulate VASP protein expression, while upregulated VASP protein can in turn promote translocation of β-catenin and DVL3 proteins into the nucleus. In the nucleus, VASP, DVL3, β-catenin and TCF4 can form VASP/DVL3/β-catenin/TCF4 protein complex, activating Wnt/β-catenin signaling pathway, and promoting the expression of target genes VASP, c-myc and cyclin D1. Thus, our study reveals that there is a Wnt/β-catenin/VASP malignant positive feedback loop in breast cancer, which promotes the proliferation and migration of breast cancer cells, and breaking this positive feedback loop may provide new strategy for breast cancer treatment.
2022-12-25 | GSE136406 | GEO
Project description:Previous studies have shown that the main function of VASP is to regulate the cytoskeleton and play an important role in promoting tumor cell metastasis. In this study, we first reveal that VASP is located in the nucleus of breast cancer cells and elucidate a Wnt/β-catenin/VASP positive feedback loop. We identify that VASP is a target gene of Wnt/β-catenin signaling pathway, and activation of Wnt/β-catenin signaling pathway can significantly upregulate VASP protein expression, while upregulated VASP protein can in turn promote translocation of β-catenin and DVL3 proteins into the nucleus. In the nucleus, VASP, DVL3, β-catenin and TCF4 can form VASP/DVL3/β-catenin/TCF4 protein complex, activating Wnt/β-catenin signaling pathway, and promoting the expression of target genes VASP, c-myc and cyclin D1. Thus, our study reveals that there is a Wnt/β-catenin/VASP malignant positive feedback loop in breast cancer, which promotes the proliferation and migration of breast cancer cells, and breaking this positive feedback loop may provide new strategy for breast cancer treatment.
2022-12-25 | GSE142702 | GEO
Project description:Wnt signaling plays a major role in early neural development. An aberrant activation in Wnt/β-catenin pathway leads to defective anteroposterior patterning, resulting in neural tube closure defects (NTDs). Changes in folate metabolism may participate in early embryo fate determination. We report here that in C57BL/6C mouse embryonic stem cells (mESC), folate deficiency activates Wnt/β-catenin pathway by upregulating a chorion-specific transcription factor Gcm1. Specifically, folate deficiency promotes the formation of the Gcm1/β-catenin/T-cell factor (TCF4) complex to regulate the Wnt target gene transactivation through the Wnt-responsive elements. Moreover, the enhanced transcriptional activity of Gcm1 is found to be dependent on CREB binding protein. Lastly, in NTDs mouse models and low folate NTDs human brain samples, Gcm1 and Wnt/β-catenin target genes related to neural tube closure are specifically overexpressed. These results indicate that low folate promotes Wnt/β-catenin signaling via activating Gcm1, leading to aberrant vertebrate neural development
2018-12-27 | GSE124339 | GEO