Crosstalk and complexity within signaling pathways has limited our ability to devise rational strategies for using network biology to treat human disease. This is particularly problematic in cancer where oncogenes that drive or maintain the tumorigenic state alter the normal flow of molecular information within signaling networks that control growth, survival and death. Understanding the architecture of oncogenic signaling pathways, and how these networks are re-wired by ligands or drugs, could provide opportunities for the specific targeting of oncogene-driven tumors. Here we use a systems biology-based approach to explore synergistic therapeutic strategies to optimize the killing of triple negative breast cancer cells, an incompletely understood tumor type with a poor treatment outcome. Using targeted inhibition of oncogenic signaling pathways combined with DNA damaging chemotherapy, we report the surprising finding that time-staggered EGFR inhibition, but not simultaneous co-administration, can dramatically sensitize the apoptotic response of a subset of triple-negative cells to conventional DNA damaging agents. A systematic analysis of the order and timing of inhibitor/genotoxin presentationusing a combination of high-density time-dependent activity measurements of signaling networks, gene expression profiles, cell phenotypic responses, and mathematical modelingrevealed an approach for altering the intrinsic oncogenic state of the cell through dynamic re-wiring of oncogenic signaling pathways. This process converts these cells to a less tumorigenic state that is more susceptible to DNA damage-induced cell death, through re-activation of an extrinsic apoptotic pathway whose function is suppressed in the oncogene-addicted state.
Sequential application of anticancer drugs enhances cell death by rewiring apoptotic signaling networks.
Cell line, Treatment
View SamplesIntroduction: In the recently completed Dutch GLUCOLD study, treatment of COPD patients with fluticasone salmeterol reduced the rate of decline in FEV1. These results indicate that ICS can have therapeutic efficacy in COPD. Aim: To explore the molecular mechanisms by which ICS exert their effects, we performed genome-wide gene expression profiling on bronchial biopsies from COPD patients who participated in the GLUCOLD study. Methods: An Affymetrix Human Gene Array ST version 1.0 was performed in a total of 221 bronchial biopsies that were available from 90 COPD patients at baseline and after 6 and 30 months of therapy. Linear mixed effects modeling was used to analyze treatment-specific changes in gene expression. A validation set was included and pathway analysis was performed with Gene Set Enrichment Analysis (GSEA). Results: The expression of 138 genes significantly decreased after both 6 and 30 months of treatment with fluticasone salmeterol versus placebo, whereas the expression of 140 genes increased. A more pronounced treatment-induced change in expression of 51 of these 278 genes was associated with a slower rate of decline in FEV1. Genes that decreased with treatment were involved in pathways related to cell cycle, oxidative phosphorylation, epithelial cell signaling, p53 signaling and T cell signaling. Genes that increased with treatment were involved in pathways related to focal adhesion, gap junction and extracellular matrix deposition. Conclusion: The present study suggests that gene expression in biological pathways of COPD is dynamic with treatment and reflects disease activity. This study opens the gate to targeted and phenotype-driven therapy of COPD.
Airway gene expression in COPD is dynamic with inhaled corticosteroid treatment and reflects biological pathways associated with disease activity.
Age
View SamplesBACKGROUND: We have previously reported gene expression changes in the bronchial airway epithelium of active chronic smokers. In this study, we investigate the effects of Acute Smoke Exposure (ASE) from cigarettes on airway epithelial gene expression. METHODS: Bronchial airway epithelial cell brushings were collected via fiberoptic bronchoscopy from 63 individuals without recent exposure to cigarette smoke (> 2 days), at baseline and at 24 hours after smoking three cigarettes. RNA from these samples was profiled on Affymetrix Human Gene 1.0 ST microarrays. Differential gene expression was assessed using linear modeling and compared to previous smoking-related gene-expression signatures using Gene Set Enrichment Analysis (GSEA). RESULTS: We identified 91 genes differentially expressed 24-hours after exposure to three cigarettes (FDR < 0.25). ASE induces genes involved in xenobiotic metabolism, oxidative stress, and inflammation; and represses genes involved in cilium morphogenesis, and cell cycle. Genes induced by in vivo ASE are concordantly altered by ASE in vitro. While many genes altered by ASE are altered similarly in the airway of chronic smokers, metallothionein genes were induced by ASE and suppressed among chronic smokers. Metallothioneins were also suppressed in the bronchial airway of current and former chronic smokers with lung cancer relative to those with benign disease. CONCLUSIONS: Acute exposure to as little as three cigarettes alters gene-expression in bronchial airway epithelium in a manner that largely resembles the changes seen in chronic active smokers. The difference in the short-term and long-term effects of smoking on metallothionein expression and its relationship to lung cancer requires further study given these enzymes role in responding to oxidative stress.
Impact of acute exposure to cigarette smoke on airway gene expression.
Sex
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Mechanisms of epigenetic and cell-type specific regulation of Hey target genes in ES cells and cardiomyocytes.
Specimen part
View SamplesIn gastrulation, distinct progenitor cell populations are induced and sorted into the three germ layers ectoderm, mesoderm and endoderm. In order to identify genes involved in germ layer specification and morphogenesis, we identified genes differentially expressed between ectodermal and mesendodermal progenitor cells. To do so, we first generated highly enriched pools of ectodermal and mesendodermal progenitor cells. Mesendodermal cells were generated by over-expressing the Nodal signal Cyclops in wild type embryos and ectodermal cells were taken from mz-one-eyed-pinhead (oep) mutant embryos. We then compared the transcriptome of ectodermal versus mesendodermal cells taken from embryos at 7 hours post fertilization (hpf). In wild type embryos at this stage (70% epiboly), the first ectodermal and mesendodermal progenitor cells have already been sorted into their respective germ layers and ingression of mesendodermal progenitors is still ongoing.
Identification of regulators of germ layer morphogenesis using proteomics in zebrafish.
Age, Specimen part, Subject, Time
View SamplesWe used an in vitro cardiomyocyte differentiation system with inducible Hey1 or Hey2 expression to study target gene regulation in cardiomyocytes (CM) generated from murine embryonic stem cells (ESC). The effects of Hey1 and Hey2 are largely redundant, but cell type specific. The number of regulated genes is comparable between ESC and CM, but the total number of binding sites is much higher, especially in ESC, targeting mainly genes involved in transcriptional regulation and developmental processes. Repression by Hey generally correlates with the extent of Hey-binding to target promoters, subsequent Hdac recruitment and lower histone acetylation. Functionally, treatment with the Hdac inhibitor TSA abolished Hey target gene regulation. However, in CM the repressive effect of Hey-binding is lost for a subset of genes. These lack Hey-dependent histone deacetylation in CM and are enriched for binding sites of cardiac specific activators like Srf, Nkx2-5, and Gata4.
Mechanisms of epigenetic and cell-type specific regulation of Hey target genes in ES cells and cardiomyocytes.
No sample metadata fields
View SamplesWe used an in vitro cardiomyocyte differentiation system with inducible Hey1 or Hey2 expression to study target gene regulation in cardiomyocytes (CM) generated from murine embryonic stem cells (ESC). The effects of Hey1 and Hey2 are largely redundant, but cell type specific. The number of regulated genes is comparable between ESC and CM, but the total number of binding sites is much higher, especially in ESC, targeting mainly genes involved in transcriptional regulation and developmental processes. Repression by Hey generally correlates with the extent of Hey-binding to target promoters, subsequent Hdac recruitment and lower histone acetylation. Functionally, treatment with the Hdac inhibitor TSA abolished Hey target gene regulation. However, in CM the repressive effect of Hey-binding is lost for a subset of genes. These lack Hey-dependent histone deacetylation in CM and are enriched for binding sites of cardiac specific activators like Srf, Nkx2-5, and Gata4. Overall design: ES cells and cardiomyocytes with Hey1 or Hey2 overexpression were compared to control cells
Mechanisms of epigenetic and cell-type specific regulation of Hey target genes in ES cells and cardiomyocytes.
No sample metadata fields
View SamplesRNA-seq analysis of murine eGFP+ relbfl/flnfkb2fl/flCg1-Cre and Cg1-Cre splenic germinal center B cells identifies genes regulated by the transcription factors RELB and p52 (NF-kB2) in germinal center B cells. Overall design: Germinal center B cells from 12-week old relbfl/flnfkb2fl/flCg1-Cre and Cg1-Cre littermate mice immunized with sheep red blood cells (SRBC) were isolated at day 7 after immunization by flow cytometric sorting from splenic mononuclear cells. RNA was isolated, amplified and submitted for RNA-sequencing on an Illumina HiSeq2500 instrument for 35-40 million 2x50 paired-ended reads.
Transcription factors of the alternative NF-κB pathway are required for germinal center B-cell development.
Age, Specimen part, Subject
View SamplesInterleukin-1 receptor associated kinase 1 (IRAK1) is an important component of the IL-1R and TLR signaling pathways, which influence Th cell differentiation. Here, we show that IRAK1 promotes Th17 development by mediating IL-1 induced upregulation of IL-23R and subsequent STAT3 phosphorylation, thus enabling sustained IL-17 production. Moreover, we show that IRAK1 signaling fosters Th1 differentiation by mediating T-bet induction and counteracts Treg generation. Cotransfer experiments revealed that Irak1-deficient CD4+ T cells have a cell-intrinsic defect in generating Th1 and Th17 cells under inflammatory conditions in spleen, mesenteric lymph nodes and colon tissue. Furthermore, IRAK1 expression in T cells was shown to be essential for T cell accumulation in the inflamed intestine and mLNs. Transcriptome analysis ex vivo revealed that IRAK1 promotes T cell activation and induction of gut-homing molecules in a cell-intrinsic manner. Accordingly, Irak1-deficient T cells failed to upregulate surface expression of 47 integrin after transfer into Rag1-/- mice and their ability to induce colitis was greatly impaired. Lack of IRAK1 in recipient mice provided additional protection from colitis. Therefore, IRAK1 plays an important role in intestinal inflammation by mediating T cell activation, differentiation and their accumulation in the gut. Thus, IRAK1 is a promising novel target for therapy of inflammatory bowel diseases.
IRAK1 Drives Intestinal Inflammation by Promoting the Generation of Effector Th Cells with Optimal Gut-Homing Capacity.
No sample metadata fields
View SamplesRNAseq analysis of CD40 + IgM in vitro-stimulated (6 hours) murine relafl/flCD19-Cre (furtheron designated as RELA) and CD19-Cre (furtheron designated as WT) splenic B cells identifies genes regulated by the transcription factor RELA in activated B cells. Overall design: Splenic B cells from 12-week old relafl/flCD19-Cre and CD19-Cre littermate mice were isolated by magnetic cell separation from splenic mononuclear cells and stimulated in vitro for 6 hours with anti-CD40 and anti-IgM. RNA was isolated and submitted for RNA-sequencing on an Illumina HiSeq2000 instrument for 30 million single-ended reads.
Germinal center B cell maintenance and differentiation are controlled by distinct NF-κB transcription factor subunits.
No sample metadata fields
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