Mammary tumors in transgenic mice expressing constitutively active and C-terminally truncated variants of STAT5
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE15119 | GEO | 2009/03/06
SECONDARY ACCESSION(S): PRJNA114871
REPOSITORIES: GEO
Similar Datasets
Project description:Stat5 is a latent transcription factor that regulates essential growth and survival functions in normal cells. Constitutive activity of Stat5 and the involvement of its C-terminally truncated variant have been implicated in blood cell malignancies and mammary or breast cancer. To distinguish the individual contributions of the Stat5 variants to mammary tumorigenesis, global gene-expression profiling was performed on transgenic STAT5-induced tumors. Experiment Overall Design: Mammary tumors derived from transgenic mice carrying one of two Stat5 variants were collected for RNA extraction and hybridization on Affymetrix GeneChip® Mouse Genome 430A 2.0 array.
2009-03-14 | E-GEOD-15119 | biostudies-arrayexpress
Project description:BackgroundStat5 is a latent transcription factor that regulates essential growth and survival functions in normal cells. Constitutive activity of Stat5 and the involvement of its C-terminally truncated variant have been implicated in blood cell malignancies and mammary or breast cancer. To distinguish the individual contributions of the Stat5 variants to mammary tumorigenesis, global gene-expression profiling was performed on transgenic STAT5-induced tumors.ResultsWe identified 364 genes exhibiting differential expression in mammary tumors developed in transgenic mice expressing constitutively active STAT5 (STAT5ca) vs. its C-terminally truncated variant (STAT5Delta750). These genes mediate established Stat5 effects on cellular processes such as proliferation and cell death, as well as yet-unrelated homeostatic features, e.g. carbohydrate metabolism. A set of 14 genes linked STAT5Delta750 expression to the poorly differentiated carcinoma phenotype and STAT5ca to the highly differentiated papillary adenocarcinoma.Specifically affected genes exhibited differential expression in an individual tumor set vs. its counterpart and the intact mammary gland: 50 genes were specifically affected by STAT5ca, and 94% of these were downregulated, the latter involved in suppression of tumor suppressors and proliferation antagonistics. This substantial downregulation distinguishes the STAT5ca-induced tumorigenic consequences from the relatively equal effect of the STAT5Delta750 on gene expression, which included significant elevation in the expression of oncogenes and growth mediators.STAT5Delta750 mRNA expression was below detection levels in the tumors and the amount of STAT5ca transcript was not correlated with the expression of its specifically affected genes. Interestingly, we identified several groups of three to eight genes affected by a particular STAT5 variant with significant correlated expression at distinct locations in the clustergram.ConclusionThe different gene-expression profiles in mammary tumors caused by the STAT5Delta750 and STAT5ca variants, corroborated by the absence of a direct link to transgenic STAT5 expression, imply distinct metabolic consequences for their oncogenic role which probably initiate early in tumor development. Tumorigenesis may involve induction of growth factor and oncogenes by STAT5Delta750 or suppression of tumor suppressors and growth antagonists by STAT5ca. The list of genes specifically affected by the STAT5 variants may provide a basis for the development of a marker set for their distinct oncogenic role.
| S-EPMC2689279 | biostudies-literature
Project description:Cytokines utilize the transcription factor STAT5 to control cell-specific and universal genes. In general, the magnitude of cell-restricted gene activation greatly exceeds that of universal genes, with a mechanistic explanation yet to be supplied. Genome-wide studies have identified putative STAT5-based mammary-specific enhancers and universal STAT5-controlled regulatory elements, an opportunity to investigate mechanisms underlying their differential response to cytokines. We have now interrogated the integrity and function of both categories of regulatory elements using biological and genetic approaches. During lactation, STAT5 occupies mammary-specific and universal cytokine-responsive elements. Following lactation, prolactin levels decline and STAT5-dependent enhancers at mammary-specific genes are decommissioned with 24 hours while universal regulatory complexes remain intact. These differential sensitivities are linked to STAT5 concentrations and the mammary-specific Stat5 autoregulatory enhancer. In its absence, mammary-specific enhancers, but not universal elements, fail to be fully established. Upon termination of lactation, STAT5 binding to a subset of mammary enhancers is substituted by STAT3. No STAT3 binding was observed at the most sensitive STAT5 enhancers, suggesting that upon hormone withdrawal their chromatin becomes inaccessible. This study, for the first time, provides molecular insight into the differential sensitivities of mammary-specific and universal cytokine-sensing enhancers.
2016-09-12 | GSE84115 | GEO
Project description:Signal Transducers and Activators of Transcription (STATs) are principal transcription factors downstream of cytokine receptors. Although STAT5A is expressed in most tissues it remains to be understood why its premier, non-redundant functions are restricted to prolactin-induced mammary gland development. We report that the ubiquitously expressed Stat5a/b locus is subject to lineage-specific transcriptional control in mammary epithelium. Genome-wide surveys of epigenetic status and transcription factor occupancy uncovered a putative mammary-specific enhancer within the intergenic sequences separating the two Stat5 genes. This region exhibited several hallmarks of genomic enhancers, including DNaseI hypersensitive sites, H3K27 acetylation and binding by GR and MED1. Mammary-specific STAT5 binding was obtained at two canonical STAT5 binding motifs. CRISPR/Cas9-mediated genome editing was used to delete these STAT5 binding sites in mice and determine their biological function. Mutant animals exhibited an 80% reduction of Stat5 levels in mammary epithelium and a concomitant reduction of STAT5-dependent gene expression. Transcriptome analysis identified a class of mammary-restricted genes that was particularly dependent on high STAT5 levels as a result of the intergenic enhancer. Taken together, the mammary-specific enhancer enables a positive feedback circuit that underlies the remarkable abundance of STAT5 and, in turn, controls the efficacy of STAT5-dependent mammary physiology. ChIP-seq for H3K27ac, RNA Pol II, and MED1 in mammary tissues at L1, and ChIP-seq for H3K27ac and GR in mammary tissues at p13. mRNA-seq in WT at L1, line B (GAS2 mutation only) and line C (both GAS1 and GAS2 mutations) at L1 in mammary tissues, and DNase-seq in WT mammary tissues at L1.
2015-09-05 | E-GEOD-72724 | biostudies-arrayexpress
Project description:Signal Transducers and Activators of Transcription (STATs) are principal transcription factors downstream of cytokine receptors. Although STAT5A is expressed in most tissues it remains to be understood why its premier, non-redundant functions are restricted to prolactin-induced mammary gland development. We report that the ubiquitously expressed Stat5a/b locus is subject to lineage-specific transcriptional control in mammary epithelium. Genome-wide surveys of epigenetic status and transcription factor occupancy uncovered a putative mammary-specific enhancer within the intergenic sequences separating the two Stat5 genes. This region exhibited several hallmarks of genomic enhancers, including DNaseI hypersensitive sites, H3K27 acetylation and binding by GR and MED1. Mammary-specific STAT5 binding was obtained at two canonical STAT5 binding motifs. CRISPR/Cas9-mediated genome editing was used to delete these STAT5 binding sites in mice and determine their biological function. Mutant animals exhibited an 80% reduction of Stat5 levels in mammary epithelium and a concomitant reduction of STAT5-dependent gene expression. Transcriptome analysis identified a class of mammary-restricted genes that was particularly dependent on high STAT5 levels as a result of the intergenic enhancer. Taken together, the mammary-specific enhancer enables a positive feedback circuit that underlies the remarkable abundance of STAT5 and, in turn, controls the efficacy of STAT5-dependent mammary physiology.
2015-09-05 | GSE72724 | GEO
Project description:Mammary tumors in transgenic mice expressing constitutively active and C-terminally truncated variants of STAT5
| PRJNA114871 | ENA
Project description:In several cancer types, STAT (Signal transducer and activator of transcription) transcription factors are constitutively activated. We previously identified a target gene, LPP/miR-28 (LIM domain containing preferred translocation partner in lipoma), induced by constitutive activation of STAT5, but not by transient cytokine-activated STAT5. Here, we demonstrate in transformed hematopoietic cells that binding of both STAT5B and p53 to chromatin is required for transcriptional activity of an alternative LPP/miR-28 promoter. Using a genome-wide approach, we identified 463 genomic positions at promoter regions where STAT5B and p53 are co-localized on the chromatin. At these positions, p53 chromatin binding is dependent on persistent STAT5B activation. The transcriptional activity of selected promoters bound by STAT5B and p53 was significantly changed upon STAT5 or p53 inhibition, and the transcription of these target genes is frequently altered in platelets of myeloproliferative neoplasm patients harboring mutations constitutively activating STAT5. These data suggest that the constitutive STAT5 activation recruits p53 in cancer cells and thereby activates oncogenic transcriptional programs. STAT5B and p53 ChIP-chip with or without JAK2 inhibition (ruxolitinib) to inhibit STAT5 phosphorylation and DNA binding.
2014-02-01 | E-GEOD-38143 | biostudies-arrayexpress
Project description:Tau is a microtubule-associated protein that ensures neuronal shape and function. Besides, Tau is a central player in Alzheimer’s disease (AD) and related Tauopathies where it is found aggregated in degenerating neurons. Mechanisms leading to Tau pathology and its progression are far from being elucidated. Among Tau species found in AD brains, several yet unidentified truncated Tau fragments are showed. A major step forward in the understanding of the role of Tau truncation would be to identify the precise cleavage sites of Tau species. This key step is mandatory to generate appropriate experimental tools in order to investigate the impact of each identified truncated-species on Tau function/dysfunction. Here, we achieved an optimized proteomics approach and succeed in identifying a number of new N-terminally truncated-Tau species from human brain. As N-terminal residues of these fragments are located broadly across Tau sequence, one could expect to have different effects on Tau. We initiated cell-based functional studies by analyzing biochemical characteristics of two N-terminally truncated Tau species starting at residues Met11 and Gln124 (accordingly to the longest Tau isoform) regarding Tau microtubule function. Our results surprisingly showed that the ability of Tau to bind and stabilize microtubules was greater when the first 123 residues are truncated, suggesting that Tau N-terminus would have a role in regulation of microtubule stabilization. Overall, future studies based on our new N-terminally truncated-Tau species will provide new knowledge on the role of truncation in Tau biology as well as in AD pathological process.
2017-04-27 | MSV000081020 | MassIVE
Project description:Establishment and differentiation of mammary alveoli during pregnancy are controlled by prolactin through the transcription factor STAT5. As pregnancy progresses mammary signature genes are activated in a defined temporal order, which coincides with the recruitment of STAT5 to respective regulatory sequences. This study addressed the question whether the methyltransferase and transcriptional co-activator EZH2 controls the differentiation clock of mammary epithelium. Ablation of Ezh2 from mammary stem cells resulted in precocious differentiation of alveolar epithelium during pregnancy and the activation of mammary-specific STAT5 target genes. This coincided with enhanced occupancy by STAT5, EZH1 and Pol II to these loci. Limited activation of differentiation-specific genes was also observed in mammary epithelium lacking both EZH2 and STAT5, suggesting a modulating but not mandatory role for STAT5. Notably, loss of EZH2 did not result in overt changes in genome-wide and gene-specific H3K27me3 patterns, suggesting that enhanced EZH1 recruitment can compensate for the loss of EZH2. Differentiated mammary epithelia failed to form in the combined absence of EZH1 and EZH2. Transplantation experiments failed to demonstrate a role for EZH2 in the biology of mammary stem and progenitor cells. In summary, while EZH1 and EZH2 serve redundant functions in the establishment of H3K27me3 and formation of mammary alveoli, the presence of EZH2 is required to obtain controlled temporal differentiation of mammary epithelium. mRNA-seq in WT;MMTV-Cre (Control) at p13 and p18, E1-/- (E1KO), Ezh2f/f;MMTV-Cre(E2KO), Stat5f/f;MMTV-Cre(S5KO), and Ezh2f/f;Stat5f/f;MMTV-Cre (E2S5DKO) at p13 mammary tissues. ChIP-seq for H3K27me3, STAT5, EZH1, EZH2 and PolII in mammary tissues at p13
2015-08-31 | E-GEOD-70440 | biostudies-arrayexpress
Project description:Tau is a microtubule-associated protein that ensures neuronal shape and function. Besides, Tau is a central player in Alzheimer’s disease (AD) and related Tauopathies where it is found aggregated in degenerating neurons. Mechanisms leading to Tau pathology and its progression are far from being elucidated. Among Tau species found in AD brains, several yet unidentified truncated Tau fragments are showed. A major step forward in the understanding of the role of Tau truncation would be to identify the precise cleavage sites of Tau species. This key step is mandatory to generate appropriate experimental tools in order to investigate the impact of each identified truncated-species on Tau function/dysfunction. Here, we achieved an optimized proteomics approach and succeed in identifying a number of new N-terminally truncated-Tau species from human brain. As N-terminal residues of these fragments are located broadly across Tau sequence, one could expect to have different effects on Tau. We initiated cell-based functional studies by analyzing biochemical characteristics of two N-terminally truncated Tau species starting at residues Met11 and Gln124 (accordingly to the longest Tau isoform) regarding Tau microtubule function. Our results surprisingly showed that the ability of Tau to bind and stabilize microtubules was greater when the first 123 residues are truncated, suggesting that Tau N-terminus would have a role in regulation of microtubule stabilization. Overall, future studies based on our new N-terminally truncated-Tau species will provide new knowledge on the role of truncation in Tau biology as well as in AD pathological process.
2015-05-15 | PXD001353 | Pride