In cytotoxic T cells (CTL), Protein Kinase B /Akt is activated by the T cell antigen receptor (TCR) and the cytokine Interleukin 2 (IL2), in part by phosophorylation of Akt by Phospholipid dependent kinase 1 (PDK1).
Protein kinase B controls transcriptional programs that direct cytotoxic T cell fate but is dispensable for T cell metabolism.
Specimen part
View SamplesBlastic plasmacytoid dendritic cell neoplasm (BPDCN) is an aggressive hematological. We used transcriptomic analysis to investigate LXR pathway, and cholesterol metabolism in leukemic cells. Malignancy with a poor prognosis that derives from plasmacytoid dendritic cells (PDC). No consensus for optimal treatment modalities is available today and the full characterization of this leukemia is still emerging. We identified here a BPDCN-specific transcriptomic profile when compared to those of acute myeloid leukemia (AML) and T-acute lymphoblastic leukemia (T-ALL), as well as the transcriptomic signature of primary PDC. This BPDCN gene signature identified a dysregulation of genes involved in cholesterol homeostasis, some of them being liver X receptor (LXR) target genes. LXR agonist treatment of primary BPDCN cells and BPDCN cell lines restored LXR target gene expression and increased cholesterol efflux via the upregulation of ATP Binding Cassette (ABC) transporters, ABCA1 and ABCG1. LXR agonist treatment was responsible for limiting BPDCN cell proliferation and inducing intrinsic apoptotic cell death. LXR activation in BPDCN cells was shown to interfere with three signaling pathways associated with leukemic cell survival, namely: NF-B activation, as well as Akt and STAT5 phosphorylation in response to the BPDCN growth/survival factor IL-3. These effects were increased by the stimulation of cholesterol efflux through a lipid acceptor, the apolipoprotein A1. In vivo experiments using a mouse model of BPDCN cell xenograft revealed a decrease of leukemic cell infiltration and BPDCN-induced cytopenia associated with an increased survival after LXR agonist treatment. This demonstrates that cholesterol homeostasis is modified in BPDCN and can be normalized by treatment with LXR agonists which can be proposed as a new therapeutic approach.
LXR agonist treatment of blastic plasmacytoid dendritic cell neoplasm restores cholesterol efflux and triggers apoptosis.
Specimen part, Disease, Disease stage
View SamplesWe run microarrays from three per group Sv129 female mice, ten weeks old, which were maintained at 28C (warm conditions) or 6 C (cold stimulated) for ten days, while standard animal house temperature is 22 C.
Brown and white adipose tissues: intrinsic differences in gene expression and response to cold exposure in mice.
Sex, Age, Specimen part
View SamplesMyocardial infarction (MI) often results in left ventricular (LV) remodeling followed by heart failure (HF). It is of great clinical importance to understand the molecular mechanisms that trigger transition from compensated LV injury to HF and to identify relevant diagnostic biomarkers. In this study, we performed transcriptional profiling of LVs in rats with a wide range of experimentally induced infarct sizes and of peripheral blood mononuclear cells (PBMCs) in animals that developed HF.
Transcriptional profiling of left ventricle and peripheral blood mononuclear cells in a rat model of postinfarction heart failure.
Specimen part
View SamplesSoybean aphids are phloem-feeding pests that can cause significant yield losses in soybean plants. Soybean aphids thrive on susceptible soybean lines but not on resistant lines.
Multiple phytohormone signals control the transcriptional response to soybean aphid infestation in susceptible and resistant soybean plants.
Specimen part
View SamplesDevelopmental checkpoints in stem/progenitor cells are critical to the determination, commitment and differentiation into distinct lineages. Cancer cells often retain expression of lineage-specific checkpoint proteins, but their potential impact in cancer remains elusive. T lymphocytes mature in the thymus following a highly orchestrated developmental process that entails the successive rearrangements and expression of T-cell receptor (TCR) genes. Low affinity recognition of self-peptide/MHC complexes (self-pMHC) presented by thymic epithelial cells by the TCR of CD4+CD8+ (DP) cortical thymocytes transduces positive selection signals that ultimately shape the developing T cell repertoire. DP thymocytes not receiving these signals die by lack of stimulation whereas those that recognize self-pMHC with high affinity undergo TCR-mediated apoptosis and negative selection. In T-cell acute lymphoblastic leukaemia (T-ALL), leukaemic transformation of maturating thymocytes results from the acquisition of multiple genetic and epigenetic alterations in oncogenes and tumour suppressor genes, that disrupt the normal regulatory circuits and drive clonal expansion of differentiation-arrested lymphoblasts. We show here that TCR triggering by negatively-selecting self-pMHC prevented T-ALL development and leukaemia maintenance in mice. Induction of TCR signalling by high affinity self-pMHC or treatment with monoclonal antibodies to the CD3 signalling chain (anti-CD3) caused massive leukaemic cell death and a gene expression program resembling that of thymocyte negative selection. Importantly, anti-CD3 treatment hampered leukaemogenesis in mice transplanted with either mouse or patient-derived T-ALLs. These data provide a rationale for targeted therapy based on anti-CD3 treatment of T-ALL patients and demonstrate that endogenous developmental checkpoint proteins are amenable to therapeutic intervention in cancer cells.
Triggering the TCR Developmental Checkpoint Activates a Therapeutically Targetable Tumor Suppressive Pathway in T-cell Leukemia.
Cell line
View SamplesWe identify sites of combinatorial control by performing high throughput ChIP experiments on p300, CREB-binding protein (CBP), the deacetylase SIRT1 and on multiple DNA-binding transcription factors in three different tissues. We present a quantitative model of transcriptional regulation that reveals the contribution of each binding site to tissue-specific gene expression in several mouse cell types. Binding to both evolutionarily conserved and non-conserved sequences is found to contribute significantly to transcriptional regulation. We demonstrate that binding location strongly predicts the expression level of nearby genes.
A quantitative model of transcriptional regulation reveals the influence of binding location on expression.
Specimen part
View SamplesThe goal of this experiment was to compare the genes expressed in malignant peripheral nerve sheath tumors (MPNSTs) that arise in zebrafish as a result of homozygous mutation of the p53 gene or heterozygous mutation of several different ribosomal protein (rp) mutations. Since MPNSTs arise very rarely in wild type zebrafish, it seemed a possibility that p53 and rps may in fact be functioning in similar pathways. The tumors arising from the different mutations had been previously classified as similar by histology, thus the goal of the array experiments was to establish if any molecular signatures could be found that could delineate the p53 from the rp MPNSTs.
Loss of p53 synthesis in zebrafish tumors with ribosomal protein gene mutations.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Novel subtype-specific genes identify distinct subpopulations of callosal projection neurons.
Specimen part
View Samples3 subtypes of cortical projection neurons were purified by fluorescence-activated cell sorting (FACS) at 4 different stages of development from mouse cortex. A detailed description of the data set is described in Arlotta, P et al (2005) and Molyneaux, BJ et al (2009). The hybridization cocktails used here were originally applied to the Affymetrix mouse 430A arrays and submitted as GEO accession number GSE2039. The same hybridization cocktails were then applied to the Affymetrix mouse 430 2.0 arrays, and those data are contained in this series.
Novel subtype-specific genes identify distinct subpopulations of callosal projection neurons.
Specimen part
View Samples