During embryogenesis, enhancer-promoter interactions control gene transcriptional activation. These interactions can be tissue-specific or tissue-invariant and occur mostly within larger insulated regulatory domains called Topologically Associating Domains (TADs). Boundary elements, which delineate the extent of TADs, frequently interact with each other and have been associated with constitutive transcription and CTCF/Cohesin binding. In this work, we set out to investigate the regulatory role of a tissue-invariant, preformed interaction between two boundaries that involve the Shh gene and its unique limb enhancer, the ZRS, located one megabase away. Using CRISPR/Cas9 we specifically perturb CTCF binding sites or constitutive transcription at the ZRS-containing boundary, without altering the enhancer sequence. Using capture-HiC (cHiC) we show that both types of perturbation result in altered preformed chromatin interactions and lead to a reduction of Shh expression in developing limb buds. Finally, we demonstrate that the disruption of the chromatin structure in combination with a hypomorphic ZRS allele results in a dramatic Shh loss- of- function and digit agenesis. We thus propose that preformed chromatin structures can ensure stable enhancer promoter communication during development and robustness of gene transcriptional activation. Overall design: We performed transcriptome analysis to confirm the complete loss of the Lmbr1 transcript due to the deletion of its promoter and to detect other potential non-coding transcripts at the locus.
Preformed chromatin topology assists transcriptional robustness of <i>Shh</i> during limb development.
Cell line, Subject
View SamplesGene expression profiling of cultured skin fibroblasts obtained from patients affected with classical Ehlers Danlos syndrome (cEDS)
Molecular insights in the pathogenesis of classical Ehlers-Danlos syndrome from transcriptome-wide expression profiling of patients' skin fibroblasts.
Specimen part, Disease
View SamplesAnalysis of gene expression profiling of cultured skin fibroblasts obtained from patients affected with vascular Ehlers Danlos syndrome (vEDS)
Transcriptome analysis of skin fibroblasts with dominant negative COL3A1 mutations provides molecular insights into the etiopathology of vascular Ehlers-Danlos syndrome.
Disease
View SamplesTo screen for candidate genes that may contribute to the pathogenesis of ATS
GLUT10 deficiency leads to oxidative stress and non-canonical αvβ3 integrin-mediated TGFβ signalling associated with extracellular matrix disarray in arterial tortuosity syndrome skin fibroblasts.
Disease
View SamplesPediatric Acute Myeloid Leukemia (AML) is an aggressive and poor prognosis malignancy for which there are few effective targeted approaches, despite the numerous genetic alterations, including MLL gene rearrangements (MLL-r). The histone methyltransferase DOT1L is involved in supporting proliferation of MLL-r cells, for which a target inhibitor, Pinometostat, has been evaluated in a clinical trial recruiting pediatric MLL-r leukemic patients. However, modest clinical effects have been reported. Recent studies reported that additional leukemia subtypes lacking MLL-r are sensitive to DOT1L inhibition. Here we report that targeting DOT1L with Pinometostat sensitizes pediatric AML cells to further treatment with the multi-kinase inhibitor Sorafenib, irrespectively of MLL-r. DOT1L pharmacologic inhibition induces AML cell differentiation and modulated expression of genes with relevant roles in cancer development. Such modifications in transcriptional program impact on further treatments, inducing a strong sensitization to Sorafenib, with increased apoptosis and growth suppression of both AML cell lines and primary pediatric AML cells with diverse genotypes. We used microarrays to define differential regulation of gene expression in AML cell lines with or without MLL gene rearrangements following pharmacologic inhibition of DOT1L.
Inhibition of Methyltransferase DOT1L Sensitizes to Sorafenib Treatment AML Cells Irrespective of <i>MLL</i>-Rearrangements: A Novel Therapeutic Strategy for Pediatric AML.
Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Transcriptome-Wide Expression Profiling in Skin Fibroblasts of Patients with Joint Hypermobility Syndrome/Ehlers-Danlos Syndrome Hypermobility Type.
Disease, Disease stage
View SamplesTo unravel the molecular mechanisms potentially associated with the pathogenesis of the EDS-HT/JHS.
Transcriptome-Wide Expression Profiling in Skin Fibroblasts of Patients with Joint Hypermobility Syndrome/Ehlers-Danlos Syndrome Hypermobility Type.
Disease, Disease stage
View SamplesAcute lymphoblastic leukemia (ALL) is an heterogeneous disease comprising several subentities that differ for both immunophenotypic and molecular characteristics. Over the years, the biologic understanding of this neoplasm has largely increased. Gene expression profiling has recently allowed to identify specific signatures for the different ALL subsets and permitted identification of pathways deregulated by a given lesion. MicroRNAs (miRNAs) are small non-coding RNAs which play a pivotal role in several cellular functions. In this study, we investigated miRNA and gene expression profiles in a series of adult ALL cases by microarray analysis and combined them by bioinformatic analysis. Interestingly, those miRNAs which are differentially expressed between the ALL classes accounted for a large proportion of miRNA/mRNA expression pairs identified by the above analysis. Moreover, the analysis highlighted several putative miRNA targets involved in apoptosis and cell-cycle regulation.
Characterization of B- and T-lineage acute lymphoblastic leukemia by integrated analysis of MicroRNA and mRNA expression profiles.
Sex, Age, Specimen part
View SamplesDuring neurogenesis, expression of the basic Helix-Loop-Helix NeuroD6/Nex1/MATH-2 transcription factor parallels neuronal differentiation, while maintaining the differentiated state in the mature nervous system. To further dissect NeuroD6 differentiation properties, we previously generated a NeuroD6-overexpressing stable PC12 cell line, PC12-ND6, which displays a neuronal phenotype characterized by spontaneous neuritogenesis, accelerated NGF-induced differentiation, and increased regenerative capacity. Furthermore, we reported that NeuroD6 promotes long-term neuronal survival upon oxidative stress triggered by serum deprivation. In this study, we identified the NeuroD6-mediated transcriptional regulatory pathways linking neuronal differentiation to survival, by conducting a genome-wide microarray analysis using PC12-ND6 cells and serum deprivation as a stress paradigm. Through a series of filtering steps and a gene-ontology analysis, we found that NeuroD6 promotes distinct but overlapping gene networks, consistent with the differentiation, regeneration, and survival properties of PC12-ND6 cells. Using a gene set enrichment analysis, we provide the first evidence of a compelling link between NeuroD6 and a set of heat shock proteins in the absence of stress, which may be instrumental to confer stress tolerance to PC12-ND6 cells. Immunocytochemistry results showed that HSP27 and HSP70 interact with cytoskeletal elements, consistent with their roles in neuritogenesis and preserving cellular integrity. HSP70 also colocalizes with mitochondria located in the soma, growing neurites and growth cones of PC12-ND6 cells prior to and upon stress stimulus, consistent with its neuroprotective functions. Collectively, our findings support the notion that NeuroD6 links neuronal differentiation to survival via the network of molecular chaperones and endows the cells with increased stress tolerance.
NeuroD6 genomic signature bridging neuronal differentiation to survival via the molecular chaperone network.
Sex, Specimen part
View SamplesAberrant signal transduction contributes substantially to leukemogenesis. The Janus kinase 1 (JAK1) gene encodes a cytoplasmic tyrosine kinase that noncovalently associates with a variety of cytokine receptors and plays a nonredundant role in lymphoid cell precursor proliferation, survival, and differentiation. Somatic mutations in JAK1 occur in individuals with acute lymphoblastic leukemia (ALL). JAK1 mutations were more prevalent among adult subjects with the T cell precursor ALL, where they accounted for 18% of cases, and were associated with advanced age at diagnosis, poor response to therapy, and overall prognosis
ALL-associated JAK1 mutations confer hypersensitivity to the antiproliferative effect of type I interferon.
Specimen part
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