Endocrine therapy is the main therapeutic option for patients with estrogen receptor alpha positive (ER+) breast cancer. Nevertheless, most of them become estrogen-independent and relapse after the treatment. Ret is a tyrosine kinase receptor that shows elevated expression levels in ER+ human breast tumors. In this study, we demonstrate that activation of the Ret receptor promotes proliferation as well as cell migration irrespective of endocrine therapy. Microarray data show that Ret activation involves changes in the expression of inflammatory- and motility-related genes. In vivo treatment with a Ret pathway inhibitor in a ER+/Ret+ mouse mammary cancer model, reduces tumor growth and lung metastasis even after endocrine therapy. Additionally, we show a connection between Ret and inflammatory pathways. The pro-inflamatory cytokine IL6 lies at the core of this regulation, which involves a positive feedback loop with IL6 and the Ret pathway reciprocally stimulating each other to further leading metastasis risk. Our findings provide insight into endocrine resistance mechanism and point at the Ret pathway as a potential target for future therapies.
Ret inhibition decreases growth and metastatic potential of estrogen receptor positive breast cancer cells.
Cell line, Treatment, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
RNA-Seq provides new insights in the transcriptome responses induced by the carcinogen benzo[a]pyrene.
Cell line, Compound, Time
View SamplesWhole-genome transcriptome measurements are pivotal for characterizing carcinogenic mechanisms of chemicals and predicting toxic classes, such as genotoxicity, from in vitro and in vivo assays. DNA microarrays have evolved as the gold standard for this purpose. In recent years deep sequencing technologies have been developed that hold the promise of measuring the transcriptome with RNA-seq in a more accurate and unbiased manner than microarrays. So far, however, few applications have been published that assess the performance of RNA-seq within a toxicogenomics context. Here, we applied RNA-seq for the characterization of the in vitro transcriptomic responses in HepG2 cells upon exposure to benzo[a]pyrene (BaP), a well-known DNA damaging carcinogen. We demonstrate the performance of RNA-seq with respect to the identification of differentially expressed genes and associated pathways, in comparison with microarray technology. RNA-seq data generates more complete and thus accurate data on differentially expressed genes and affected pathways than microarrays. Additionally, we highlight the potential of RNA-seq for characterizing mechanisms related to alternative splicing and thereby gathering new information. Exposure to BaP alters the isoform distribution for many genes, including regulators of cell death and DNA repair such as TP53, BCL2 and XPA, which are relevant for genotoxic responses. Finally, we demonstrate that RNA-seq enables to investigate allele-specific gene expression, although no changes for that could be observed. Our results provide evidence that RNA-seq is a powerful tool for toxicology which, compared to microarrays, is capable of adding valuable information at the transcriptome level for characterizing toxic effects caused by chemicals.
RNA-Seq provides new insights in the transcriptome responses induced by the carcinogen benzo[a]pyrene.
Cell line, Compound, Time
View SamplesType I Interferons encompasses a large family of closely related cytokines comprising of at least 13 IFN- isotypes and single IFN-. Both IFN- and IFN- exert their activity through a common receptor IFNAR. Type I Interferons have broad regulatory effects and various subtypes of dendritic cells are influenced by this cytokines. In our study we asked question whether the low, constitutive levels of type I Interferons produced under steady state conditions are important for proper function of splenic conventional dendritic cells.
Absence of IFN-beta impairs antigen presentation capacity of splenic dendritic cells via down-regulation of heat shock protein 70.
Sex, Age, Specimen part
View SamplesTo gain insights into the interplay between DNA methylation and gene regulation we generated a basepair resolution reference map of the mouse methylome in stem cells and neurons. High genome coverage allowed for a novel quantitative analysis of local methylation states, which identified Low Methylated Regions (LMR) with an average methylation of 30%. These regions are evolutionary conserved, reside outside of CpG islands and distal to promoters. They represent regulatory regions evidenced by their DNaseI hypersensitivity and chromatin marks of enhancer elements. LMRs are occupied by transcription factors (TF) and their reduced methylation requires TF binding while introduction of TF binding sites creates LMRs de novo. This dependency on TF activity is further evident when comparing the methylomes of embryonic stem cells and derived neuronal cells. LMRs present in both cell types are occupied by broadly expressed factors, while LMRs present at only one state are occupied by cell-type specific TFs. Methylome data can thus enhance the prediction of occupied TF binding sites and identification of active regulatory regions genome-wide. Our study provides reference methylomes for the mouse at two cell states, identifies a novel and highly dynamic feature of the epigenome that defines distal regulatory elements and shows that transcription factor binding dynamically shapes mammalian methylomes. Overall design: Strand specific expression profiling by high throughput sequencing.
DNA-binding factors shape the mouse methylome at distal regulatory regions.
Specimen part, Cell line, Subject
View SamplesIn this study gene expression profiles for 307 cases of advanced bladder cancers were compared to molecular phenotype at the tumor cell level. TUR-B tissue for RNA extraction was macrodissected from the close vicinity of the tissue sampled for immunohistochemistry to ensure high-quality sampling and to minimize the effects of intra-tumor heterogeneity. Despite excellent agreement between gene expression values and IHC-score at the single marker level, broad differences emerge when samples are clustered at the global mRNA versus tumor cell (IHC) levels. Classification at the different levels give different results in a systematic fashion, which implicates that analysis at both levels is required for optimal subtype-classification of bladder cancer.
Molecular classification of urothelial carcinoma: global mRNA classification versus tumour-cell phenotype classification.
Specimen part
View SamplesWe compared the transcriptome in E16.5 embryonic mouse cortex isolated by microdissection, in control (+/+) mice and in mice with mutation in frizzled3 (Fzd3) and Celsr3. Overall design: Triplicate RNA samples prepared for each genotype
Feedback regulation of apical progenitor fate by immature neurons through Wnt7-Celsr3-Fzd3 signalling.
Specimen part, Subject
View SamplesPolycomb protein group (PcG)-dependent trimethylation on H3-K27(H3K27me3) regulates identity of embryonic stem cells (SCs). How H3K27me3 governs adult SCs and tissue development is unclear. Here, we conditionally target H3-K27-methyltransferases Ezh2 and Ezh1 to address their roles in mouse skin homeostasis. Postnatal phenotypes appear only in doubly-targeted skin, where H3K27me3 is abolished, revealing functional redundancy in EZH1/2 proteins. Surprisingly, while Ezh1/2-null hair follicles (HFs) arrest morphogenesis and degenerate due to defective proliferation and increased apoptosis, epidermis hyperproliferates and survives engraftment. mRNA-microarray studies reveal that despite these striking phenotypic differences, similar genes are upregulated in HF and epidermal Ezh1/2-null progenitors. Featured prominently are a) PcG-controlled non-skin lineage genes, whose expression is still significantly lower than in native tissues, and b) the PcG-regulated Ink4a/Inkb/Arf locus. Interestingly, even though Ink4a/Arf/Ink4b genes are fully activated in HF cells, they only partially so in epidermal-progenitors. Importantly, transduction of Ink4b/Ink4a/Arf shRNAs restores proliferation/survival of Ezh1/2-null HF progenitors in vitro, pointing towards the relevance of this locus to the observed HF phenotypes. Our findings reveal new insights into Polycomb-dependent tissue control and provide a new twist to how different progenitors within one tissue respond to loss of H3K27me3.
EZH1 and EZH2 cogovern histone H3K27 trimethylation and are essential for hair follicle homeostasis and wound repair.
Sex, Age, Specimen part
View SamplesDynamical response to oxygen downshift under fermentation conditions was tested by taking sample before (S1) and after (S2, S3 and S4) the oxygen downshift. The dynamical changes relevant for ongoing research on physiology were applied.
Norvaline is accumulated after a down-shift of oxygen in Escherichia coli W3110.
No sample metadata fields
View SamplesMouse hair follicles undergo synchronized cycles. Cyclical regeneration and hair growth is fueled by hair follicle stem cells (HFSCs). HFSCs regenerate hair in response to canonical Wnt signalling. We used RNA-seq to unfold genome-wide chromatin landscapes of ß-catenin within the native HFSC-niche. Overall design: ß-catenin control and cKO hair follicle stem cells (HFSCs) at the onset of anagen skins were FACS-purified for RNA-sequcencing. Telogen quiescent hair follicle stem cells (HFSCs) were FACS-purified for ChIP-sequcencing. Telogen>anagen activated bulge hair follicle stem cells (HFSCs) were FACS-purified for RNA-sequcencing.
In vivo transcriptional governance of hair follicle stem cells by canonical Wnt regulators.
No sample metadata fields
View Samples