Mus musculus
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA244443 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Cyclin C was cloned as a growth-promoting G1 cyclin1,2, and several studies postulated a role for cyclin C in driving cell proliferation3-8 . Moreover, cyclin C, together with its kinase partner, the cyclin-dependent kinase CDK8, is believed to represent an essential component of basal transcriptional machinery where it globally represses gene expression9-13. However, the function of cyclin C in vivo has never been addressed. Here we show that in the living organism cyclin C acts as a haploinsufficient tumor suppressor, through its function of controlling Notch1 oncogene levels. Cyclin C activates an “orphan” CDK19 kinase14, as well as CDK8 and CDK3. These cyclin C-CDK complexes phosphorylate Notch1 intracellular domain (ICN1), which allows binding of ICN1 to Fbw7 and triggers ICN1 polyubiquitination. Genetic ablation of cyclin C blocks ICN1 phosphorylation, disrupts Fbw7 binding, and decreases ICN1 ubiquitination in vivo, thereby strongly elevating ICN1 levels in several compartments of cyclin C knockout mice. Cyclin C was cloned as a growth-promoting G1 cyclin1,2, and several studies postulated a role for cyclin C in driving cell proliferation3-8 . Moreover, cyclin C, together with its kinase partner, the cyclin-dependent kinase CDK8, is believed to represent an essential component of basal transcriptional machinery where it globally represses gene expression9-13. However, the function of cyclin C in vivo has never been addressed. Here we show that in the living organism cyclin C acts as a haploinsufficient tumor suppressor, through its function of controlling Notch1 oncogene levels. Cyclin C activates an “orphan” CDK19 kinase14, as well as CDK8 and CDK3. These cyclin C-CDK complexes phosphorylate Notch1 intracellular domain (ICN1), which allows binding of ICN1 to Fbw7 and triggers ICN1 polyubiquitination. Genetic ablation of cyclin C blocks ICN1 phosphorylation, disrupts Fbw7 binding, and decreases ICN1 ubiquitination in vivo, thereby strongly elevating ICN1 levels in several compartments of cyclin C knockout mice.
2016-07-06 | PXD001237 | Pride
Project description:NOTCH1 is mutationally activated in ~15% of cases of chronic lymphocytic leukaemia (CLL), but its role in B-cell development and leukemogenesis is not known. Here, we report that the active intracellular portion of NOTCH1 (ICN1) is detectable in ~50% of peripheral blood CLL cases lacking gene mutations. We identify a ‘NOTCH1 CLL gene expression signature’ in CLL cells, and show that this signature is significantly enriched in primary CLL cases expressing ICN1, independent of NOTCH1 mutation. NOTCH1 target genes include key regulators of B-cell proliferation, survival and signal transduction physiology. In particular, we show that MYC is a direct target of NOTCH1 via B-cell specific distal regulatory elements, thus implicating this oncogene in the pathogenesis of the disease.
2017-03-24 | GSE92626 | GEO
Project description:NOTCH1 is mutationally activated in ~15% of cases of chronic lymphocytic leukaemia (CLL), but its role in B-cell development and leukemogenesis is not known. Here, we report that the active intracellular portion of NOTCH1 (ICN1) is detectable in ~50% of peripheral blood CLL cases lacking gene mutations. We identify a ‘NOTCH1 CLL gene expression signature’ in CLL cells, and show that this signature is significantly enriched in primary CLL cases expressing ICN1, independent of NOTCH1 mutation. NOTCH1 target genes include key regulators of B-cell proliferation, survival and signal transduction physiology. In particular, we show that MYC is a direct target of NOTCH1 via B-cell specific distal regulatory elements, thus implicating this oncogene in the pathogenesis of the disease.
2017-03-24 | GSE92701 | GEO
Project description:To examine Ikaros tumor suppressor mechanisms, we have utilized inducible RNAi to dynamically restore endogenous Ikaros expression in T-ALL driven by its knockdown. This causes rapid transcriptional repression of Notch1 and associated targets including Myc, even in leukemias harboring spontaneous activating Notch1 mutations (producing aberrant ICN1) similar to those found in 60% of human T-ALL. Ikaros restoration results in sustained regression of Notch1-wild type leukemias while endogenous or engineered ICN1 expression promotes rapid disease relapse, indicating that ICN1 functionally antagonizes Ikaros in T-ALL.
2015-02-02 | GSE54447 | GEO
Project description:To examine Ikaros tumor suppressor mechanisms, we have utilized inducible RNAi to dynamically restore endogenous Ikaros expression in T-ALL driven by its knockdown. This causes rapid transcriptional repression of Notch1 and associated targets including Myc, even in leukemias harboring spontaneous activating Notch1 mutations (producing aberrant ICN1) similar to those found in 60% of human T-ALL. Ikaros restoration results in sustained regression of Notch1-wild type leukemias while endogenous or engineered ICN1 expression promotes rapid disease relapse, indicating that ICN1 functionally antagonizes Ikaros in T-ALL.
2015-02-02 | GSE64899 | GEO
Project description:To examine Ikaros tumor suppressor mechanisms, we have utilized inducible RNAi to dynamically restore endogenous Ikaros expression in T-ALL driven by its knockdown. This causes rapid transcriptional repression of Notch1 and associated targets including Myc, even in leukemias harboring spontaneous activating Notch1 mutations (producing aberrant ICN1) similar to those found in 60% of human T-ALL. Ikaros restoration results in sustained regression of Notch1-wild type leukemias while endogenous or engineered ICN1 expression promotes rapid disease relapse, indicating that ICN1 functionally antagonizes Ikaros in T-ALL.
2015-02-02 | GSE64893 | GEO
Project description:We performed chromatin immunoprecipitation followed by high-throughput DNA sequencing (ChIP-seq) for ICN1 in thymic gd T cells from neonates of C57BL/6 mice. Sequence reads for ICN1 and Input were aligned with the mouse reference genome (mm10) by bowtie program (v1.0.0), and peak detection and identification of ICN1 binding sites were obtained with MACS program (v1.4.2). ChIP-seq data revealed that 12%, 6% and 47% of ICN1 binding sites were within -10kb upstream of transcription start site, +10kb downstream of 3'end and the bodies of genes, respectively. The other of ICN1 binding sites was intergenic. We also found that ICN1 directly bound -5.4kb upstream of transcript start site of IL-7 receptor alpha (IL-7Ra) locus, which were estimated as a new promoter region of IL-7Ra. Some of ICN1 binding sites (e.g. TCF1 promoter) were consistent with previous reports, but others (e.g. Nr4a1 promoter) were novel. These suggests that ICN1 was associated with a lot of transcriptional regulation in gd T cells. Examination of ICN1 binding sites in gd T cells
2014-11-14 | E-GEOD-56756 | biostudies-arrayexpress
Project description:Cyclin C was cloned as a growth-promoting G1 cyclin, and was also shown to regulate gene transcription. Here we report that in vivo cyclin C acts as a haploinsufficient tumour suppressor, by controlling Notch1 oncogene levels. Cyclin C activates an 'orphan' CDK19 kinase, as well as CDK8 and CDK3. These cyclin-C-CDK complexes phosphorylate the Notch1 intracellular domain (ICN1) and promote ICN1 degradation. Genetic ablation of cyclin C blocks ICN1 phosphorylation in vivo, thereby elevating ICN1 levels in cyclin-C-knockout mice. Cyclin C ablation or heterozygosity collaborates with other oncogenic lesions and accelerates development of T-cell acute lymphoblastic leukaemia (T-ALL). Furthermore, the cyclin C encoding gene CCNC is heterozygously deleted in a significant fraction of human T-ALLs, and these tumours express reduced cyclin C levels. We also describe point mutations in human T-ALL that render cyclin-C-CDK unable to phosphorylate ICN1. Hence, tumour cells may develop different strategies to evade inhibition by cyclin C.
2014-09-02 | GSE58712 | GEO
Project description:Cyclin C was cloned as a growth-promoting G1 cyclin1,2, and several studies postulated a role for cyclin C in driving cell proliferation3-8 . Moreover, cyclin C, together with its kinase partner, the cyclin-dependent kinase CDK8, is believed to represent an essential component of basal transcriptional machinery where it globally represses gene expression9-13. However, the function of cyclin C in vivo has never been addressed. Here we show that in the living organism cyclin C acts as a haploinsufficient tumor suppressor, through its function of controlling Notch1 oncogene levels. Cyclin C activates an “orphan” CDK19 kinase14, as well as CDK8 and CDK3. These cyclin C-CDK complexes phosphorylate Notch1 intracellular domain (ICN1), which allows binding of ICN1 to Fbw7 and triggers ICN1 polyubiquitination. Genetic ablation of cyclin C blocks ICN1 phosphorylation, disrupts Fbw7 binding, and decreases ICN1 ubiquitination in vivo, thereby strongly elevating ICN1 levels in several compartments of cyclin C knockout mice. Cyclin C was cloned as a growth-promoting G1 cyclin1,2, and several studies postulated a role for cyclin C in driving cell proliferation3-8 . Moreover, cyclin C, together with its kinase partner, the cyclin-dependent kinase CDK8, is believed to represent an essential component of basal transcriptional machinery where it globally represses gene expression9-13. However, the function of cyclin C in vivo has never been addressed. Here we show that in the living organism cyclin C acts as a haploinsufficient tumor suppressor, through its function of controlling Notch1 oncogene levels. Cyclin C activates an “orphan” CDK19 kinase14, as well as CDK8 and CDK3. These cyclin C-CDK complexes phosphorylate Notch1 intracellular domain (ICN1), which allows binding of ICN1 to Fbw7 and triggers ICN1 polyubiquitination. Genetic ablation of cyclin C blocks ICN1 phosphorylation, disrupts Fbw7 binding, and decreases ICN1 ubiquitination in vivo, thereby strongly elevating ICN1 levels in several compartments of cyclin C knockout mice.
2017-03-29 | MSV000080728 | MassIVE
Project description:To examine Ikaros tumor suppressor mechanisms, we have utilized inducible RNAi to dynamically restore endogenous Ikaros expression in T-ALL driven by its knockdown. This causes rapid transcriptional repression of Notch1 and associated targets including Myc, even in leukemias harboring spontaneous activating Notch1 mutations (producing aberrant ICN1) similar to those found in 60% of human T-ALL. Ikaros restoration results in sustained regression of Notch1-wild type leukemias while endogenous or engineered ICN1 expression promotes rapid disease relapse, indicating that ICN1 functionally antagonizes Ikaros in T-ALL. RNA-seq was performed on T-ALL (Vav-tTA;TRE-GFP-shIkaros primary leukemia ALL211) cells isolated from two untreated and two 3-day Dox-treated mice.
2015-02-02 | E-GEOD-64899 | biostudies-arrayexpress