Knockdown of the transcription factor PU.1 (Spi1) leads to acute myeloid leukemia (AML) in mice. We examined the transcriptome of PU.1 knockdown hematopoietic stem cells (HSC) in the preleukemic phase by linear amplification and genome-wide array analysis to identify transcriptional changes preceding malignant transformation. Hierarchical cluster analysis and principal component analysis clearly distinguished PU.1 knockdown from wildtype HSC. Jun family transcription factors c-Jun and JunB were among the top downregulated targets. Retroviral restoration of c-Jun expression in bone marrow cells of preleukemic mice partially rescued the PU.1-initiated myelomonocytic differentiation block. Lentiviral restoration of JunB at the leukemic stage led to reduced clonogenic growth, loss of leukemic self-renewal capacity, and prevented leukemia in transplanted NOD-SCID mice. Examination of 305 AML patients confirmed the correlation between PU.1 and JunB downregulation and suggests its relevance in human disease. These results delineate a transcriptional pattern that precedes the leukemic transformation in PU.1 knockdown HSC and demonstrate that decreased levels of c-Jun and JunB contribute to the development of PU.1-induced AML by blocking differentiation (c-Jun) and increasing self-renewal (JunB). Therefore, examination of disturbed gene expression in HSC can identify genes whose dysregulation is essential for leukemic stem cell function and are targets for therapeutic interventions.
Essential role of Jun family transcription factors in PU.1 knockdown-induced leukemic stem cells.
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Sox9 Controls Self-Renewal of Oncogene Targeted Cells and Links Tumor Initiation and Invasion.
Specimen part
View SamplesSox9 is a transcription factor expressed in most solid tumors. However, the molecular mechanisms underlying Sox9 function during tumorigenesis remain unclear. Here, using a genetic mouse model of basal cell carcinoma (BCC), the most frequent cancer in human, we show that Sox9 is expressed from the earliest step of tumor formation in a Wnt/-catenin dependent manner. Deletion of Sox9 together with the constitutive activation of Hedgehog (HH) signaling completely prevents BCC formation and leads to a progressive loss of oncogene expressing cells. Transcriptional profiling of oncogene expressing cells with Sox9 deletion, combined with in vivo ChIP-sequencing uncovers a cancer-specific gene network regulated by Sox9 that promotes stemness, extracellular matrix (ECM) deposition and cytoskeleton remodeling while repressing epidermal differentiation. Our study identifies the molecular mechanisms regulated by Sox9 that links tumor initiation and invasion.
Sox9 Controls Self-Renewal of Oncogene Targeted Cells and Links Tumor Initiation and Invasion.
Specimen part
View SamplesThe C57BL/6.NOD-Aec1Aec2 mouse is a model for primary Sjgrens syndrome and was constructed by introducing two genetic intervals derived from the NOD mouse that confers Sjgrens syndrome (SjS)-like disease in SjS-non-susceptible C57BL/6 mice.
Transcriptional landscapes of emerging autoimmunity: transient aberrations in the targeted tissue's extracellular milieu precede immune responses in Sjögren's syndrome.
Sex, Age, Specimen part
View SamplesThe transcriptomic changes induced in primary mouse hepatocytes (C57BL/6 ) by 7M of cisplatin after treatment for 24 and 48h
Characterisation of cisplatin-induced transcriptomics responses in primary mouse hepatocytes, HepG2 cells and mouse embryonic stem cells shows conservation of regulating transcription factor networks.
Cell line, Treatment, Time
View SamplesDREAM/KChIP-3 is a calcium-dependent transcriptional repressor highly expressed in immune cells. Transgenic mice expressing a dominant active DREAM mutant show reduced serum immunoglobulin levels. In vitro assays show that reduced immunoglobulin secretion is an intrinsic defect of transgenic B cells that occurs without impairment in plasma cell differentiation but with an accelerated entry in cell division and an increase in class switch recombination. B cells from DREAM knockout mice did not show any phenotype, due to compensation by endogenous KChIP-2. Expression arrays revealed modified expression of Edem1 and Derlin3, two proteins related to the ER-associated degradation pathway and of Klf9, a cell-cycle regulator. Our results disclose a function of DREAM and KChIP-2 in Ig subclass production in B lymphocytes.
Increased B cell proliferation and reduced Ig production in DREAM transgenic mice.
Specimen part
View SamplesBetter understanding alveolarization mechanisms could help improving prevention and treatment of diseases characterized by reduced alveolar number, especially bronchopulmonary dysplasia (BPD). Although signaling through fibroblast growth factor (FGF) receptors is essential for alveolarization, involved ligands are unidentified. FGF18 whose expression peaks during alveolar septation is likely to be involved. Herein, a mouse model of inducible, lung-targeted FGF18-transgene was used to advance the onset of FGF18 expression, and genome-wide expression changes were determined.
Profiling target genes of FGF18 in the postnatal mouse lung: possible relevance for alveolar development.
Specimen part, Disease
View SamplesHomologue of Enhancer-of-split 1 (Hes1) is a transcription factor that regulates neuronal plasticity, promoting the growth of dendrites and increasing the GABAergic input. A higher expression of Hes1 also results in neuronal resistance against the noxious activity of amyloid beta, the main agent in the advent and progression of the Alzheimer's disease. As a transcription factor, Hes1 controls de expression of many genes. Using the microarray technology we have detected that the expression of one secreted synaptic protein, cerebellin 4 (Cbln4) was particularly increased upon overexpression of Hes1. We also present evidence that Cbln4 plays an essential role in the formation and maintenance of inhibitory GABAergic connections and that either overexpression of Cbln4 in cultured hippocampal neurons or the application of recombinant Cbln4 to the cultures increased the number of GABAergic varicosities and rescued neurons from amyloid beta induced cell death.
Cerebellin 4, a synaptic protein, enhances inhibitory activity and resistance of neurons to amyloid-β toxicity.
Specimen part
View SamplesMurine GVH-SSc dorsal scapular skin samples were analyzed to determine the effect of IFNAR-1 inhibition on gene expression at day 14 and day 28. Gene expression in GVH-SSc skin from mice treated with a neutralizing IFNAR-1 antibody was compared to that in GVH-SSc skin from mice treated with isotype IgG, with skin from syngeneic graft controls as reference.
Type I IFNs Regulate Inflammation, Vasculopathy, and Fibrosis in Chronic Cutaneous Graft-versus-Host Disease.
Sex
View SamplesQuantitative assays for human DNA and mRNA were used to examine the paradox that intravenously (IV) infused human multipotent stromal cells (hMSCs) can enhance tissue repair without significant engraftment. After 2 X 106 hMSCs were IV infused into mice, most of the cells were trapped as emboli in lung. The cells in lung disappeared with a half-life of about 24 hr but < 1,000 cells appeared in 6 other tissues. The hMSCs in lung up-regulated expression of multiple genes with a large increase in the anti-inflammatory protein TSG-6. After myocardial infarction, IV hMSCs but not hMSCs transduced with TSG-6 siRNA decreased inflammatory responses, reduced infarct size, and improved cardiac function. IV administration of recombinant TSG-6 also reduced inflammatory responses and reduced infarct size. The results suggest improvements in animal models and patients after IV infusions of MSCs are at least in part explained by activation of MSCs to secrete TSG-6.
Intravenous hMSCs improve myocardial infarction in mice because cells embolized in lung are activated to secrete the anti-inflammatory protein TSG-6.
Specimen part, Disease
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