SR proteins are well-characterized RNA binding proteins that promote exon inclusion by binding to exonic splicing enhancers (ESEs). However, it has been unclear whether regulatory rules deduced on model genes apply generally to activities of SR proteins in the cell. Here, we report global analyses of two prototypical SR proteins SRSF1 (SF2/ASF) and SRSF2 (SC35) using splicing-sensitive arrays and CLIP-seq on mouse embryo fibroblasts (MEFs). Unexpectedly, we find that these SR proteins promote both inclusion and skipping of exons in vivo, but their binding patterns do not explain such opposite responses. Further analyses reveal that loss of one SR protein is accompanied by coordinated loss or compensatory gain in the interaction of other SR proteins at the affected exons. Therefore, specific effects on regulated splicing by one SR protein actually depend on a complex set of relationships with multiple other SR proteins in mammalian genomes. Overall design: SRSF1 and SRSF2 CLIP-seq
Genome-wide analysis reveals SR protein cooperation and competition in regulated splicing.
Specimen part, Subject
View SamplesMetastasis is the leading cause of death for cancer patients. Consequently it is imperative that we improve our understanding of the molecular mechanisms that underlie progression of tumour growth towards malignancy. Advances in genome characterisation technologies have been very successful in identifying commonly mutated or misregulated genes in a variety of human cancers. However the difficulty in evaluating whether these candidate genes drive tumour progression remains a major challenge. Using the genetic amenability of Drosophila melanogaster we generated tumours with specific genotypes in the living animal and carried out a detailed systematic loss-of-function analysis to identify conserved genes that enhance or suppress epithelial tumour progression. This enabled the discovery of functional cooperative regulators of invasion and the establishment of a network of conserved invasion suppressors. This includes constituents of the cohesin complex, which can either promote individual or collective invasion, depending on the severity of effect on cohesin function.
A Genetic Analysis of Tumor Progression in Drosophila Identifies the Cohesin Complex as a Suppressor of Individual and Collective Cell Invasion.
Cell line
View SamplesOnly a minority of medulloblastoma cells can self-renew and sustain tumor growth. In the Patched1+/- mouse model, these cells are quiescent and express the stem cell marker Sox2. We sought to define the gene expression profiling of these cells to gain insight into the molecular pathways that govern this population.
Quiescent sox2(+) cells drive hierarchical growth and relapse in sonic hedgehog subgroup medulloblastoma.
Specimen part
View SamplesPrimary glioblastoma (GBM) cultures vary with respect to differentiation competency. We sought to identify putative transcription factors necessary for the differentiation of GBM cultures. In this dataset, we include expression data obtained from 2 human-fetal neural stem cell (HF-NS) cultures and 2 GBM stem cell (GSC) cultures. We assessed changes in gene expression from 3 timepoints during an in vitro differentiation protocol.
ASCL1 Reorganizes Chromatin to Direct Neuronal Fate and Suppress Tumorigenicity of Glioblastoma Stem Cells.
Specimen part, Time
View SamplesMutations in the histone 3 variant H3.3 have been identified in one-third of pediatric glioblastomas (GBMs), but not in adult tumors. Here we show that H3.3 is a dynamic determinant of functional properties in adult GBM. H3.3 is repressed by mixed lineage leukemia 5 (MLL5) in self-renewing GBM cells. MLL5 is a global epigenetic repressor that orchestrates reorganization of chromatin structure by punctuating chromosomes with foci of compacted chromatin, favoring tumorigenic and self-renewing properties. Conversely, H3.3 antagonizes self-renewal and promotes differentiation. We exploited these epigenetic states to rationally identify two small molecules that effectively curb cancer stem cell properties in a preclinical model. Our work uncovers a role for MLL5 and H3.3 in maintaining self-renewal hierarchies in adult GBM.
MLL5 Orchestrates a Cancer Self-Renewal State by Repressing the Histone Variant H3.3 and Globally Reorganizing Chromatin.
Specimen part, Time
View SamplesThe aim of this study was to assess the impact of oocyte competence on subsequent fertility. Based on knowledge already accessible in mammals and on bioinformatics tools including the chicken genome sequence, we focused on the expression of genes involved in the processes of fertilization and of early embryo development. The study was performed using two complementary approaches: a descriptive study of standard laying hens and then a differential study performed with hens from experimental lines expressing broad variations of achieved fertility (approximately 20 per cent). A differential kinetic study is performed on INRA lines selected on the basis of their fertility potential in purpose of hopefully access gene markers of fertility performance.
Identification of germinal disk region derived genes potentially involved in hen fertility.
No sample metadata fields
View SamplesThe aim of this study was to assess the impact of oocyte competence on subsequent fertility. Based on knowledge already accessible in mammals and on bioinformatics tools including the chicken genome sequence, we focused on the expression of genes involved in the processes of fertilization and of early embryo development.
Search for the genes involved in oocyte maturation and early embryo development in the hen.
No sample metadata fields
View SamplesIn the clinical setting, mutations in the CFTR gene enhance the inflammatory response to P. aeruginosa (PA01) infection, but measurements of the inflammatory response to pathogen stimulation by isolated airway epithelia can yield variable results. In this series, we exposed CFBE41o- cells over-expressing F508/F508 CFTR and CFBE41o- cells rescued with wt-CFTR to P. aeruginosa biofilms. P. aeruginosa elicited a more robust increase in cytokine and chemokine expression (e.g., IL-8, CXCL2, CXCL3, CXCR4 and TNF-) in CFBE-wt-CFTR cells compared to CFBE-F508-CFTR cells. These results demonstrate that CFBE41o- cells complemented with wt-CFTR mount a more robust inflammatory response to P. aeruginosa than CFBE41o- F508/F508-CFTR cells.
Does the F508-CFTR mutation induce a proinflammatory response in human airway epithelial cells?
Specimen part
View SamplesWhile the hypothalamo-pituitary-adrenal axis (HPA) activates a general stress response by increasing glucocorticoid (Gc) synthesis, biological stress resulting from infections triggers the inflammatory response through production of cytokines. The pituitary gland integrates some of these signals by responding to the pro-inflammatory cytokines IL6 and LIF and to a negative Gc feedback loop. The present work used whole-genome approaches to define the LIF/STAT3 regulatory network and to delineate cross-talk between this pathway and Gc action. Genome-wide ChIP-chip identified 3 449 STAT3 binding sites, whereas 2 396 genes regulated by LIF and/or Gc were found by expression profiling. Surprisingly, LIF on its own changed expression of only 85 genes but the joint action of LIF and Gc potentiated the expression of more than a thousand genes. Accordingly, activation of both LIF and Gc pathways also potentiated STAT3 and GR recruitment to many STAT3 targets. Our analyses revealed an unexpected gene cluster that requires both stimuli for delayed activation: 83% of the genes in this cluster are involved in different cell defense mechanisms. Thus, stressors that trigger both general stress and inflammatory responses lead to activation of a stereotypic innate cellular defense response.
Regulatory network analyses reveal genome-wide potentiation of LIF signaling by glucocorticoids and define an innate cell defense response.
Specimen part, Time
View SamplesFetal mice (16 days gestation) were administered feline immunodeficiency virus (FIV)-based lentiviral viral particles containing the gene encoding GFP. Six liver tumors developed in three mice between the ages of 273 and 484 days, each mouse developed 2 tumors. These tumors and non-tumorous liver tissue from the same animals and animals that did not develop tumors and untransduced controls were harvested and microarrays were performed on total RNA extracted from these samples. We were interested in investigating the link between lentiviral integration and gene expression.
Transduction of fetal mice with a feline lentiviral vector induces liver tumors which exhibit an E2F activation signature.
Sex, Age, Specimen part
View Samples