Background and Purpose—Analyzing genes involved in development and rupture of intracranial aneurysms can enhance knowledge about the pathogenesis of aneurysms, and identify new treatment strategies. We compared gene expression between ruptured and unruptured aneurysms and control intracranial arteries. Methods—We determined expression levels with RNA sequencing. Applying a multivariate negative binomial model, we identified genes that were differentially expressed between 44 aneurysms and 16 control arteries, and between 22 ruptured and 21 unruptured aneurysms. The differential expression of 8 relevant and highly significant genes was validated using digital polymerase chain reaction. Pathway analysis was used to identify enriched pathways. We also analyzed genes with an extreme pattern of differential expression: only expressed in 1 condition without any expression in the other. Results—We found 229 differentially expressed genes in aneurysms versus controls and 1489 in ruptured versus unruptured aneurysms. The differential expression of all 8 genes selected for digital polymerase chain reaction validation was confirmed. Extracellular matrix pathways were enriched in aneurysms versus controls, whereas pathways involved in immune response and the lysosome pathway were enriched in ruptured versus unruptured aneurysms. Immunoglobulin genes were expressed in aneurysms, but showed no expression in controls. Conclusions—For rupture of intracranial aneurysms, we identified the lysosome pathway as a new pathway and found further evidence for the role of the immune response. Our results also point toward a role for immunoglobulins in the pathogenesis of aneurysms. Immune-modifying drugs are, therefore, interesting candidate treatment strategies in the prevention of aneurysm development and rupture. Overall design: RNA sequencing of 44 intracranial aneurysm samples (including 21 unruptured, 22 ruptured and 1 undetermined) and 16 control samples of the intracranial cortical artery
RNA Sequencing Analysis of Intracranial Aneurysm Walls Reveals Involvement of Lysosomes and Immunoglobulins in Rupture.
Sex, Age, Subject
View SamplesThe study aims to determine the set of transcriptional cell types that make up the mouse brain
Molecular Architecture of the Mouse Nervous System.
Sex, Specimen part, Cell line
View SamplesCancer-associated inflammatory processes in the tumour microenvironment, as well as systemically, are strongly linked with poor disease outcome in cancer patients. For most human solid tumour types, high systemic neutrophil-to-lymphocyte ratios (NLR) are associated with increased metastasis and poor overall survival and recent experimental studies have demonstrated a causal relationship between neutrophils and metastasis formation. However, to date, the cancer cell-intrinsic mechanisms dictating the substantial heterogeneity in systemic neutrophilic inflammation between tumour-bearing hosts are largely unresolved. Using a panel of 16 distinct genetically engineered mouse models (GEMMs) for breast cancer, we demonstrate that tumour cell-intrinsic loss of p53 changes the phenotype and function of macrophages in the microenvironment, leading to activation of a systemic inflammatory cascade that drives neutrophil expansion. Mechanistically, p53 loss in cancer cells induces secretion of Wnt ligands that act in a paracrine fashion to stimulate IL-1b production from tumour-associated macrophages. Intratumoural IL-1ß production stimulates an inflammatory cascade leading to the systemic accumulation of neutrophils. Pharmacological and genetic blockade of cancer cell-derived Wnt secretion reverses IL-1ß expression by macrophages and subsequent systemic neutrophilic inflammation. Collectively, using pre-clinical mouse models for breast cancer, we demonstrate a novel mechanistic link between loss of p53 in cancer cells, Wnt ligand secretion and systemic immune activation. This illustrates the importance of cancer cell-intrinsic genetic aberrations in dictating cancer-associated inflammation. These insights set the stage for personalized immune intervention strategies for cancer patients. Overall design: In this study, gene expression profiles of tumours from genetically engineered mouse models (GEMMs) were analysed using RNA sequencing. Analysis was performed on bulk tumours of 10 GEMMs with different tissue-specific mutations driving tumorigenesis, totalling to 125 different tumours (n=5 or more per group). Subsequently, samples were grouped according to p53 status of the tumour (models containing Trp53 floxed alleles, or not) and comparisons were made between p53-KO and p53-WT tumours.
Loss of p53 triggers WNT-dependent systemic inflammation to drive breast cancer metastasis.
Cell line, Subject
View SamplesFour different molecular classifications of muscle-invasive bladder cancer (MIBC) based on gene expression have been proposed. With the ultimate goal of utilizing these molecular subtypes for personalized treatment, we investigated their significance in the context of neoadjuvant cisplatin-based chemotherapy (NAC).
Impact of Molecular Subtypes in Muscle-invasive Bladder Cancer on Predicting Response and Survival after Neoadjuvant Chemotherapy.
Age, Disease, Disease stage, Treatment
View SamplesThe current test strategy for carcinogenicity is generally based on in vitro and in vivo genotoxicity assays. Non-genotoxic carcinogens (NGTXC) are negative for genotoxicity and go undetected. Therefore, alternative tests to detect these chemicals are urgently needed. NGTXC act through different modes of action, which complicates the development of such assays. We have demonstrated recently in primary mouse hepatocytes that some, but certainly not all, NGTXC can be categorized according to their mode of action based on feature detection at a gene expression level (Schaap et al. 2012, PMID22710402). Identification of a wider range of chemicals probably requires multiple in vitro systems. In the current study we describe the added value of using mouse embryonic stem cells. In this study the focus is on NGTXC, but we also included genotoxic carcinogens and non-carcinogens. This approach enables us to assess the robustness of this method and to evaluate the system for recognizing features of chemicals in general, which is important for application in future risk assessment.
A novel toxicogenomics-based approach to categorize (non-)genotoxic carcinogens.
Specimen part
View SamplesLeukemias that harbor translocations involving the mixed lineage leukemia gene (MLL) possess unique biological characteristics and often have an unfavorable prognosis. Gene expression analyses demonstrate a distinct profile for MLL-rearranged leukemias with consistent high-level expression of select Homeobox genes including HOXA9. Here, we investigated the effects of HOXA9 suppression in MLL-rearranged and MLL-germline leukemias utilizing RNAi. Gene expression profiling after HOXA9 suppression demonstrated co-downregulation of a program highly expressed in human MLL-AML (this study) and murine MLL-leukemia (Krivtsov et al. 2006) stem cells including HOXA10, MEIS1, PBX3 and MEF2C. Our data indicates an important role for HOXA9 in human MLL-rearranged leukemias, and suggests targeting HOXA9 or downstream programs may be a novel therapeutic option.
HOXA9 is required for survival in human MLL-rearranged acute leukemias.
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View SamplesActivation of macrophages by inflammatory stimuli leads to reprogramming of mitochondrial metabolism to support the production of pro-inflammatory cytokines. Hallmarks of this metabolic rewiring are downregulation of a-ketoglutarate formation via isocitrate dehydrogenase (IDH) and accumulation of glutamine-derived succinate, which enhances the inflammatory response via the activity of succinate dehydrogenase (SDH). Here, we identify the nuclear receptor Nur77 (Nr4a1) as a key regulator of the pro-inflammatory metabolic switch in macrophages. Nur77-deficient macrophages fail to downregulate IDH expression and accumulate higher levels of succinate and other downstream TCA cycle metabolites in response to an inflammatory stimulus. Consequently, these macrophages produce more nitric oxide and pro-inflammatory cytokines in an SDH-dependent manner. In vivo, bone marrow Nur77 deficiency exacerbates atherosclerosis development and leads to increased systemic succinate levels. In conclusion, Nur77 supports an anti-inflammatory metabolic state in macrophages that protects against chronic inflammatory diseases such as atherosclerosis. Overall design: Gene expression profiling by RNA-seq was performed in triplicate in RAW264.7 mouse macrophage stable cell lines with doxycycline-inducible overexpression of HA-tagged NUR77 or GFP as control.
Nuclear Receptor Nur77 Limits the Macrophage Inflammatory Response through Transcriptional Reprogramming of Mitochondrial Metabolism.
Cell line, Treatment, Subject
View SamplesOxidative and Cytokinin treatment of Arabidopsis wildtype, crf6 mutant, and CRF6 overexpressing seedlings
Cytokinin Response Factor 6 Represses Cytokinin-Associated Genes during Oxidative Stress.
Age
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Drug-induced histone eviction from open chromatin contributes to the chemotherapeutic effects of doxorubicin.
Age, Specimen part, Cell line, Treatment, Time
View SamplesOne major class of anti-cancer drugs targets topoisomerase II to induce DNA double-strand breaks and cell death of fast growing cells. In vitro experiments showed that doxorubicin can induce histone eviction as well as DNA damage, while etoposide can only induce DNA damage. Here, we compare the transcription responses of different tissues to doxorubicin or etoposide treatment in vivo.
Drug-induced histone eviction from open chromatin contributes to the chemotherapeutic effects of doxorubicin.
Age, Specimen part, Treatment, Time
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