Pediatric 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 SamplesCD24, or heat stable antigen, is a cell surface sialoglycoprotein expressed on immature cells that disappears after the cells have reached their final differentiation stage. CD24 may be important in human embryonic kidney epithelial cell differentiation. In mice, CD24 expression is up-regulated in the early metanephros and localized to developing epithelial structures but the role and expression of CD24 in the developing human kidney has not been well described. In normal human fetal kidneys from 8 to 38 weeks gestation, CD24 expression was up-regulated and restricted to the early epithelial aggregates of the metanephric blastema and to the committed proliferating tubular epithelia of the S-shape nephron; however individual CD24+ cells were identified in the interstitium of later gestation and postnatal kidneys. In freshly isolated cells, FACS analysis demonstrated distinct CD24+ and CD24+133+ cell populations, constituting up to 16% and 14% respectively of the total cells analyzed. Isolated and expanded CD24+ clones displayed features of an epithelial progenitor cell line. Early fetal urinary tract obstruction resulted in an upregulation of CD24 expression, both in developing epithelial structures of early gestation kidneys and in the cells of the injured tubular epithelium of the later gestation kidneys. These results highlight the cell specific expression of CD24 in the developing human kidney and dysregulation in fetal urinary tract obstruction.
Ontogeny of CD24 in the human kidney.
Age, Specimen part
View SamplesCatechol-O-methyltransferase (COMT) is an ubiquitously expressed enzyme that maintains basic biologic functions by inactivating catechol substrates. In humans, polymorphic variance at the COMT locus has been associated with modulation of pain sensitivity (Andersen & Skorpen, 2009) and risk for developing psychiatric disorders (Harrison & Tunbridge, 2008). A functional haplotype associated with increased pain sensitivity was shown to result in decreased COMT activity by altering mRNA secondary structure-dependent protein translation (Nackley et al., 2006). However, the exact mechanisms whereby COMT modulates pain sensitivity and behavior remain unclear and can be further studied in animal models. We have pursued a genome-wide approach to examining gene expression in multiple brain regions in inbred strains of mice and have discovered that Comt1 is differentially expressed. This expression difference was validated with qPCR. A B2-B4 Short Interspersed Element (SINE) was inserted in the 3'UTR of Comt1 in 14 strains that also shared a common haplotype. Experiments using mammalian expression vectors of full-length cDNA clones with and without the SINE element demonstrate that strains with the SINE haplotype (+SINE) have greater Comt1 enzymatic activity. +SINE mice also exhibit behavioral differences in anxiety assays and decreased pain sensitivity. These results suggest that a haplotype, defined by a 3'UTR B2-B4 SINE element, regulates Comt1 expression and mouse behavior.
Comt1 genotype and expression predicts anxiety and nociceptive sensitivity in inbred strains of mice.
Sex, Specimen part
View SamplesThe objective of this study was to elucidate age-related differences in gene expression profiles of rhesus monkey bone marrow-derived mesenchymal stem cells (rhMSC) obtained from fetal, infant, and adult donors relevant to their growth and other properties. Although a high degree of similarity was observed in the rhMSC gene expression profiles when comparing the three age groups, significant differences were found that strongly parallel gene expression profiles of human MSC. The potential functional relevance of differential gene expression was most apparent when comparing fetal and adult rhMSC transcript profiles. Overall, the observed gene expression profiles are consistent with a loss of rhMSC pluripotency and proliferative capacity with advancing donor age. In addition, these data highlight the importance of use of non-human primates as a model system for studying the properties of human stem cells.
Age-related gene expression profiles of rhesus monkey bone marrow-derived mesenchymal stem cells.
No sample metadata fields
View Samplesassess the efficacy of Pimasertib to characterize its mechanism of action
Combination of the MEK inhibitor pimasertib with BTK or PI3K-delta inhibitors is active in preclinical models of aggressive lymphomas.
Cell line, Treatment, Time
View SamplesFbw7, the substrate recognition subunit of SCF(Fbw7) ubiquitin ligase, mediates turnover of multiple proto-oncoproteins and promotes its own degradation. Fbw7-mediated substrate degradation is antagonized by the Usp28 deubiquitinase. We now show, using knockout mice, that Usp28 preferentially deubiquitinates and stabilizes Fbw7. Monoallelic deletion of Usp28 maintains stable Fbw7 but destabilizes Fbw7 substrates. In contrast, complete knockout of Usp28 promotes Pin1-dependent autocatalytic turnover of Fbw7, accumulation of Fbw7 substrates and oncogenic transformation. Overexpression of Usp28 stabilizes both Fbw7 and its substrates and similarly enhances transformation. We propose that dual regulation of Fbw7 activity by Usp28 maintains physiological levels of Fbw7 substrates, and that both loss and overexpression of Usp28 in human cancer promote Fbw7 substrate accumulation. Overall design: RNAseq experiments of E13.5 murine embryonic fibroblasts (MEFs) derived from animals in which Usp28 was either deleted (-/-), wildtype (+/+) or heterozygous (+/-). In a first set of experiments immortalized MEFs of all three genotypes were analysed in biological triplicates. In a second set of experiments immortalized and Ras transformed MEFs of all three genotypes and MEFs which overexpress USP28 (+/+/+) where sequenced in duplicates.
Dual regulation of Fbw7 function and oncogenic transformation by Usp28.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Kdm2b maintains murine embryonic stem cell status by recruiting PRC1 complex to CpG islands of developmental genes.
Specimen part, Cell line
View SamplesPolycomb group (PcG) proteins play important roles in repressing lineage-specific genes and maintaining the undifferentiated state of mouse embryonic stem cells (mESCs). However, the mechanisms by which PcG proteins are recruited to their targets are largely unknown. Here, we show that the histone demethylase Kdm2b is highly expressed in mESCs and regulated by the pluripotent factors Oct4/Sox2 directly. Depletion of Kdm2b in mESCs causes de-repression of lineage-specific genes and induces early differentiation. The function of Kdm2b depends on its CXXC-ZF domain, which mediates Kdm2bs genome-wide binding to CpG islands (CGIs). Kdm2b interacts with the core components of the Polycomb repressive complex 1 (PRC1) and recruits the complex to the CGIs of early lineage-specific genes. Thus, our study not only reveals a novel Oct4/Sox2-Kdm2b-PRC1-CGI regulatory axis and its function in maintaining undifferentiated state of mESCs, but also demonstrates a critical function of Kdm2b in recruiting PRC1 to the CGIs of lineage-specific genes to repress their expression.
Kdm2b maintains murine embryonic stem cell status by recruiting PRC1 complex to CpG islands of developmental genes.
Specimen part, Cell line
View SamplesClinical symptoms of dengue virus (DENV) infection, the most prevalent arthropod-borne viral disease, range from classical mild dengue fever to severe, life-threatening dengue shock syndrome. However, most DENV infections cause few or no symptoms. Asymptomatic DENV-infected patients provide a unique opportunity to decipher the host immune responses leading to virus elimination without negative impact on an individuals health. We used an integrated approach of transcriptional profiling and immunological analysis to compare a Cambodian population of strictly asymptomatic viremic individuals with clinical dengue patients. Whereas inflammatory pathways and innate immune response pathways were similar between asymptomatic individuals and clinical dengue patients, expression of proteins related to antigen presentation and subsequent T and B cell activation pathways were differentially regulated, independent of viral load and previous DENV infection history. Feedback mechanisms controlled the immune response in asymptomatic viremic individuals, as demonstrated by increased activation of T cell apoptosis-related pathways and FcRIIB signaling associated with decreased anti-DENV specific antibody concentrations. Taken together, our data illustrate that symptom-free DENV infection in children is associated with determined by increased activation of the adaptive immune compartment and proper control mechanisms, leading to elimination of viral infection without excessive immune activation, with implications for novel vaccine development strategies
Increased adaptive immune responses and proper feedback regulation protect against clinical dengue.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesCytochrome oxydases and quinol monooxygenase were removed from the E. coli genome resulting in oxygen-independent physiology
Deletion of genes encoding cytochrome oxidases and quinol monooxygenase blocks the aerobic-anaerobic shift in Escherichia coli K-12 MG1655.
No sample metadata fields
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