This SuperSeries is composed of the SubSeries listed below.
Linking proteomic and transcriptional data through the interactome and epigenome reveals a map of oncogene-induced signaling.
Specimen part, Cell line
View SamplesEGFRvIII is the most common deletion mutant of EGFR in human cancer and its levels are highly correlated with poor prognosis in GBM. The deletion of exons 2-7 removes most of the extracellular ligand binding domain, so it is unable to bind EGF or other EGFR-binding ligands. Nevertheless, the mutant receptor is constitutively phosphorylated, and is capable of activating downstream signaling pathways at a low level.
Linking proteomic and transcriptional data through the interactome and epigenome reveals a map of oncogene-induced signaling.
Specimen part, Cell line
View SamplesRNA-Seq performed on Dicer KO and WT murine mesenchymal stem cells from total RNA MicroRNAs (miRNAs) are small non-coding RNAs that regulates development and disease but induce only moderate repression of directs mRNA targets, suggesting that they coordinate with other modes ofs cellular regulation to effect large changes in gene expression. Ins this work we decouple direct effects of global miRNA loss froms transcriptional changes downstream in a pair of isogenic murines fibroblast cell lines with and without Dicer expression. Wes demonstrate how effects on direct miRNA targets are amplified bys transcription machinery through the construction of a network models that identifies specific transcription factors that cause changes ins mRNA expression upon Dicer loss. Through transcription factors over-expression, we delineate miRNA-mediated transcriptional programss and identify miRNA-mediated coherent and incoherent feed-forwards loops, suggesting a functional role of the interaction between miRNAss and transcription factors. In total, our results indicate thats miRNAs tightly control transcription factors within a denses interconnected network to modulate gene expression. Overall design: Total RNA was analyzed from adult mesenchymal stem cells (immortalized monoclonal lines of murine MSCs) with and without Dicer (WT: Dicer f/f, KO: Dicer -/-), as well as from WT cells transfected with an empty vector or a vector containing Tead4, Sox9 or Pbx3 transcripts.
Elucidating MicroRNA Regulatory Networks Using Transcriptional, Post-transcriptional, and Histone Modification Measurements.
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View SamplesWe investigate the contribution of IRE1 signaling to the modulation of U87 glioma cells transcriptome upon various stresses. To this end, IRE1 control and IRE1 dominant negative expressing U87 glioma cells were subjected to environmental or chemical challenges and their transcriptome monitored using Affymetrix microarrays.
Posttranscriptional regulation of PER1 underlies the oncogenic function of IREα.
Cell line, Treatment
View SamplesThere is a critical need in cancer therapeutics to identify targeted therapies that will improve outcomes and decrease toxicities compared to conventional, cytotoxic chemotherapy. Ewing sarcoma is a highly aggressive bone and soft tissue cancer that is caused by the EWS-FLI1 fusion protein. Although EWS-FLI1 is specific for cancer cells, and required for tumorigenesis, directly targeting this transcription factor has proven challenging. Consequently, targeting unique dependencies or key downstream mediators of EWS-FLI1 represent important alternative strategies. We used gene expression data derived from a genetically defined model of Ewing sarcoma to interrogate the Connectivity Map and identify a class of drugs, iron chelators, that downregulate a significant number of EWS-FLI1 target genes. We then identified ribonucleotide reductase M2 (RRM2), the iron-dependent subunit of ribonucleotide reductase (RNR), as one mediator of iron chelator toxicity in Ewing sarcoma cells. Inhibition of RNR in Ewing sarcoma cells led to apoptosis and cell death in vitro and attenuated tumor growth in vivo in a xenograft model. Additionally, we discovered that the sensitivity of Ewing sarcoma cells to inhibition or suppression of RNR is mediated, in part, by high levels of SLFN11, a protein that sensitizes cells to DNA damage. This work demonstrates a unique dependency of Ewing sarcoma cells on RNR and supports further exploration of clinically used inhibitors of RNR as a therapeutic approach in treating this cancer.
Gene expression signature based screening identifies ribonucleotide reductase as a candidate therapeutic target in Ewing sarcoma.
Specimen part, Cell line, Treatment
View SamplesExperiments performed over the past three decades have shown that nucleosomes are transcriptional repressors. In Saccharomyces cerevisiae, depletion of histone H4 results in the genome-wide transcriptional de-repression of hundreds genes. The mechanism of de-repression is hypothesized to be rooted directly in chromatin changes. To test this, we reproduced classical H4 depletion experiments by conditional repression of all histone H3 transcription, which depletes the supply of nucleosomes in vivo. RNA-seq results were consistent with the earlier studies, but much more sensitive, revealing nearly 2500 de-repressed genes. Changes in chromatin organization were determined by MNase-seq. Nucleosomes that were preferentially retained occurred in regions of high DNA-encoded nucleosome affinity, and were marked with H3K36me2, which is linked to transcription elongation. Nucleosomes harboring acetyl marks or that contained the variant histone H2A.z were preferentially lost. Genes that were de-repressed lost or rearranged nucleosomes at their promoter, but not in the gene body. Therefore, a combination of DNA-encoded nucleosome stability and nucleosome composition dictates which nucleosomes will be lost under conditions of limiting histone protein. This, in turn, governs which genes will experience a loss of regulatory fidelity. Overall design: MNase-seq experiments consist of three wildtype (1 single-end and 2 paired-end) and four mutant (DCB200.1/H3 shutoff; 2 single-end, 2 paired-end) replicates. Each replicate contains two timepoints reflecting chromatin immediately after ("O hours") and 3 hours after transition to media containing dextrose. RNA-seq data includes three replicates from wildtype or H3 depleted cells after 3 hours in media containing dextrose.
In vivo effects of histone H3 depletion on nucleosome occupancy and position in Saccharomyces cerevisiae.
Cell line, Subject, Time
View SamplesHuntington disease (HD) is associated with increased nuclear accumulation of the repressor element-1 silencing transcription factor (REST) which govens a huge gene network. An alternative REST splicing event (E3) eliminates a motif essential for nuclear targeting of REST.
Modulation of nuclear REST by alternative splicing: a potential therapeutic target for Huntington's disease.
Cell line, Treatment
View SamplesMechanical overload in the heart induces pathological remodeling that typcially leads to heart failure. We sought to build an in vitro model of heart failure by applying cyclic stretch to engineered isotropic (iso) and anisotropic (aniso) NRVM tissues.
Recapitulating maladaptive, multiscale remodeling of failing myocardium on a chip.
Specimen part
View SamplesInteraction of hematopoietic progenitors with the thymic stromal microenvironment induces them to proliferate, adopt the T cell fate, and asymmetrically diverge into multiple T lineages. Progenitors at various developmental stages are stratified among different regions of the thymus, implying that the corresponding microenvironments differ from one another, and provide unique sets of signals to progenitors migrating between them. The nature of these differences remains undefined. Here we use novel physical and computational approaches to characterize these stromal subregions, distinguishing gene expression in microdissected tissues from that of their lymphoid constituents. Using this approach, we comprehensively map gene expression in functionally distinct stromal microenvironments, and identify clusters of genes that define each region. Quite unexpectedly, we find that the central cortex lacks distinctive features of its own, and instead appears to function by sequestering unique microenvironments found at the cortical extremities, and modulating the relative proximity of progenitors moving between them.
Spatial mapping of thymic stromal microenvironments reveals unique features influencing T lymphoid differentiation.
Specimen part
View SamplesAlthough mutations in Kras are present in 21% of lung tumors, there is a high level of heterogeneity in phenotype and outcomes amongst lung cancer patients suggesting the importance of other pathways. Wnt/-catenin signaling is a known oncogenic pathway that plays a well defined role in colon and skin cancer but its role in lung cancer remains unclear. We show that activation of Wnt/-catenin in the bronchiolar epithelium of the adult lung does not promote tumor development by itself. However, activation of Wnt/- catenin signaling leads to a dramatic increase in tumor formation both in overall tumor number and size compared to KrasG12D alone. We show that activation of Wnt/- catenin signaling significantly alters the KrasG12D tumor phenotype resulting in a phenotypic switch from bronchiolar epithelium to the highly proliferative distal progenitors found in the embryonic lung. This is associated with a decrease in E- cadherin expression at the cell surface which may increase metastasis in Wnt/-catenin signaling positive tumors. Together, these data suggest that activation of Wnt/-catenin signaling in combination with other oncogenic pathways in lung epithelium may lead to a more aggressive phenotype due to the imposition of an embryonic distal progenitor phenotype accompanied by decreased E-cadherin expression.
Wnt/β-catenin signaling accelerates mouse lung tumorigenesis by imposing an embryonic distal progenitor phenotype on lung epithelium.
Sex, Age, Specimen part
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