Overexpression of ecotropic viral integration site 1 (EVI1) is associated with aggressive disease in acute myeloid leukemia (AML). Despite of its clinical importance, little is known about the mechanism through which EVI1 confers resistance to antileukemic drugs. Here, we show that a human myeloid cell line constitutively overexpressing EVI1 after infection with a retroviral vector (U937_EVI1) was partially resistant to etoposide and daunorubicin as compared to empty vector infected control cells (U937_vec). Similarly, inducible expression of EVI1 in HL-60 cells decreased their sensitivity to daunorubicin. Gene expression microarray analyses of U937_EVI1 and U937_vec cells cultured in the absence or presence of etoposide showed that 77 and 419 genes were regulated by EVI1 and etoposide, respectively. Notably, mRNA levels of 26 of these genes were altered by both stimuli, indicating that EVI1 regulated genes were strongly enriched among etoposide regulated genes and vice versa. One of the genes that were induced by both EVI1 and etoposide was CDKN1A/p21/WAF, which in addition to its function as a cell cycle regulator plays an important role in conferring chemotherapy resistance in various tumor types. Indeed, overexpression of CDKN1A in U937 cells mimicked the phenotype of EVI1 overexpression, similarly conferring partial resistance to antileukemic drugs.
EVI1 inhibits apoptosis induced by antileukemic drugs via upregulation of CDKN1A/p21/WAF in human myeloid cells.
Cell line, Treatment
View SamplesL-3,4-dihydroxyphenylalanine (levodopa) treatment is the major pharmacotherapy for Parkinson's disease. However, almost all patients receiving levodopa eventually develop debilitating involuntary movements (dyskinesia). While it is known that striatal spiny projection neurons (SPNs) are involved in the genesis of this movement disorder, the molecular basis of dyskinesia is not understood. In this study, we identify distinct cell-type-specific gene expression changes that occur in sub-classes of SPNs upon induction of a parkinsonian lesion followed by chronic levodopa treatment. We identify several hundred genes whose expression is correlated with levodopa dose, many of which are under the control of AP-1 and ERK signaling. In spite of homeostatic adaptations involving several signaling modulators, AP-1-dependent gene expression remains highly dysregulated in direct pathway SPNs (dSPNs) upon chronic levodopa treatment. We also discuss which molecular pathways are most likely to dampen abnormal dopaminoceptive signaling in spiny projection neurons, hence providing potential targets for antidyskinetic treatments in Parkinson's disease.
Molecular adaptations of striatal spiny projection neurons during levodopa-induced dyskinesia.
Specimen part, Treatment
View SamplesAlterations to corticostriatal glutamatergic function are early pathophysiological changes associated with Huntington?s disease (HD). The factors that regulate the maintenance of corticostriatal glutamatergic synapses post-developmentally are not well understood. Recently, the striatum-enriched transcription factor Foxp2 was implicated in the development of these synapses. Here we show that, in mice, overexpression of Foxp2 in the adult striatum of two models of HD leads to rescue of HD-associated behaviors, while knockdown of Foxp2 in wild-type mice leads to development of HD-associated behaviors. We note that Foxp2 encodes the longest polyglutamine repeat protein in the human reference genome, and we show that it can be sequestered into aggregates with polyglutamine-expanded mutant Huntingtin protein (mHTT). Foxp2 overexpression in HD model mice leads to altered expression of several genes associated with synaptic function, genes which present new targets for normalization of corticostriatal dysfunction in HD. Overall design: 4 mice per group of each: Con+Con, Con+Foxp2, BACHD+Con, BACHD+Foxp2 Foxp2 or Control virus was injected into BACHD and Control mice, mRNA was isolated and sequenced
Control of Huntington's Disease-Associated Phenotypes by the Striatum-Enriched Transcription Factor Foxp2.
Specimen part, Subject
View SamplesHypothesis: Overexpression of the GLUT1 facilitative glucose transporter, in A7r5 vascular smooth muscle cells, is sufficient and/or necessary to induce alterations in gene expression which influence apoptosis, growth, and proliferation.
GLUT1-induced cFLIP expression promotes proliferation and prevents apoptosis in vascular smooth muscle cells.
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
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 SamplesThe tryptophan degrading enzyme TDO2 is downregulated upon HIF1alpha stabilization by exposure to both hypoxia as well as chemical hypoxia mimetics such as DMOG in glioblastoma cell line A172.
Hypoxia Inducible Factor 1α Inhibits the Expression of Immunosuppressive Tryptophan-2,3-Dioxygenase in Glioblastoma.
Cell line
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 Samples