CREM (cAMP responsive element modulator) together with CREB and ATF-1 belong to the CREB family of transcriptional factors, that respond to cyclic AMP signaling and bind to cAMP responsive element (CRE) sites in promoters of selected genes. CREM can produce isoforms that have either activating or repressing functions, depending on the transcription of specific exons. In testis, it is involved in the regulation of spermatogenesis.
Novel insights into the downstream pathways and targets controlled by transcription factors CREM in the testis.
Specimen part, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Transcription factor TLX1 controls retinoic acid signaling to ensure spleen development.
Specimen part
View SamplesThe molecular mechanisms underlying asplenia, a condition often associated with overwhelming infections remain largely unknown. During spleen development, the transcription factor TLX1 controls morphogenesis and organ expansion, and loss of it causes spleen agenesis. However, the downstream signaling pathways that are deregulated in the absence of TLX1 are mostly unknown. Herein, we demonstrate that loss of Tlx1 in the splenic mesenchyme causes increased retinoic acid (RA) signaling. Increased RA activity causes premature differentiation of the splenic mesenchyme and reduced vasculogenesis of the splenic anlage. Moreover, excess or deficiency in RA signaling, as observed in Cyp26b1 or Rdh10 mutants respectively, also results in spleen growth arrest. Genome-wide analysis revealed that TLX1 binds RA-associated genes through the AP-1 site and cooperates with the AP-1 family transcription factors to regulate transcription. Pharmacological inhibition of RA signaling partially rescues the spleen defect. These findings establish the critical role of TLX1 in controlling RA metabolism, and provide novel mechanistic insights into the molecular determinants underlying congenital asplenia.
Transcription factor TLX1 controls retinoic acid signaling to ensure spleen development.
Specimen part
View SamplesHere we tested a hypothesis that epileptogenesis influences expression pattern of genes in the basolateral amygdala that are critical for fear conditioning. Whole genome molecular profiling of basolateral rat amygdala was performed to compare the transcriptome changes underlying fear learning in epileptogenic and control animals. Our analysis revealed that after acquisition of fear conditioning 26 genes were regulated differently in the basolateral amygdala of both groups. Thus, our study provides the first evidence that not only the damage to the neuronal pathways but also altered composition or activity level of molecular machinery responsible for formation of emotional memories within surviving pathways can contribute to impairment in emotional learning in epileptogenic animals. Understanding the function of those genes in emotional learning provides an attractive avenue for identification of novel drug targets for treatment of emotional disorders after epileptogenesis-inducing insult.
Epileptogenesis alters gene expression pattern in rats subjected to amygdala-dependent emotional learning.
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View SamplesContext: In many cancers, specific subpopulations of cells appear to be uniquely capable of initiating and maintaining tumors. The strongest support for this cancer stem cell model comes from transplantation assays in immune-deficient mice indicating that human acute myeloid leukemia (AML) is organized as a cellular hierarchy driven by self-renewing leukemia stem cells (LSC). This model has significant implications for the development of novel therapies, but its clinical significance remains unclear.
Association of a leukemic stem cell gene expression signature with clinical outcomes in acute myeloid leukemia.
Disease, Disease stage, Subject
View SamplesAcute Myeloid Leukemia AML is a cancer in which the process of normal cell hematopoietic differentiation is disrupted. Evidence exists that AML comprises a hierarchy with leukemic stem cells giving rise to more differentiated, but immature and functionally incompetent populations. The similarity of these AML subpopulations to normal stages of hematopoietic differentiation has not been dissected comprehensively at the transcriptional level. Here we introduce Normal Memory Analysis (NorMA), a data analysis method that extracts from omic data the remnants of the healthy normal-like phenotype. Applying NorMA to gene expression data from AML uncovered a wealth of information in the normal-like component of data: the normal hematopoietic memory of AML tumor cells. We found significant variation within the patient population, and we found strong association of this normal hematopoietic memory with survival. We found that undifferentiated NorMA phenotype has significantly worse survival than differentiated NorMA phenotype, showing that the NorMA classification of tumors captures a biologically meaningful stratification of patients, with highly significant survival association. Patients with NorMA phenotype in the undifferentiated Hematopoietic Stem Cell HSC stage had the worst survival, with median survival time under 6 months. We further found significant survival differences between tumor groups with differentiated NorMA phenotype, depending on their hematopoietic path: AML patients with NorMA phenotype in megakaryocyte-erythroid progenitor MEP stage had significantly better survival than those with NorMA phenotype in granulocyte-macrophage progenitor GMP stage. Thus NorMA produced a stratification of AML cohorts by differentiation stage, with significant outcome differences. It also provided clean molecular signatures for these stages. NorMA can be used in many other contexts, to explore for example the tumor cell of origin, or disease predisposition.
An LSC epigenetic signature is largely mutation independent and implicates the HOXA cluster in AML pathogenesis.
Specimen part
View SamplesUsing primary cultures of normal human prostate epithelial cells, we developed a novel prostasphere-based, label-retention assay that permits identification and isolation of stem cells at a single cell level. Their bona fide stem cell nature was confirmed using in vitro and in vivo regenerative assays and documentation of symmetric/asymmetric division. Robust WNT10B and KRT13 expression without E-cadherin or KRT14 staining distinguished individual stem cells from daughter progenitors in spheroids. Following FACS to separate stem and progenitor cells, RNA-seq identified unique gene signatures for the separate populations which may serve as biomarkers. Pathways enrichment in stem cells identified ribosome biogenesis and membrane estrogen-receptor signaling with NF?B signaling enriched in progenitors and these were biologically confirmed. Further, bioassays identified heightened autophagy flux and reduced metabolism in stem cells relative to progenitors. These approaches similarly identified cancer stem-like cells from prostate cancer specimens and prostate, breast and colon cancer cell lines suggesting wide applicability. Together, the present studies isolate and identify unique characteristics of normal human prostate stem cells and uncover processes that maintain stem cell homeostasis in the prostate gland. Overall design: Comparing RNA-seq gene profiles in label-retaining prostate stem cells and non-retaining progenitor cells
Isolation and functional interrogation of adult human prostate epithelial stem cells at single cell resolution.
Specimen part, Subject
View SamplesViral infections of the CNS are of increasing concern, especially among immunocompromised populations. Rodent models are often inappropriate for studies of CNS infection, as many viruses, including JC Virus (JCV) and HIV, cannot replicate in rodent cells. Consequently, human fetal brain-derived multipotential CNS progenitor cells (NPCs) that can be differentiated into neurons, oligodendrocytes, or astrocytes, have served as a model for CNS studies. NPCs can be non-productively infected by JCV, while infection of progenitor-derived astrocytes (PDAs) is robust. We profiled cellular gene expression at multiple times during differentiation of NPCs to PDAs. Several activated transcription factors show commonality between cells of the brain in which JCV replicates and lymphocytes in which JCV is likely latent. Bioinformatic analysis determined transcription factors that may influence the favorable transcriptional environment for JCV in PDAs. This study attempts to provide a framework for understanding the functional transcriptional profile necessary for productive JCV infection.
Differentiation of human fetal multipotential neural progenitor cells to astrocytes reveals susceptibility factors for JC virus.
Specimen part, Time
View SamplesHuman diffuse intrinsic pontine gliomas (DIPG) are an aggressive form of pediatric brain tumors that arise in the pons in young children thus resulting in significant morbidity and very poor survival. Recent data suggest that mutations in the histone H3.3 variant are often found in these tumors, though the mechanism of their contribution to oncogenesis remains to be elucidated. Here we report that the combination of constitutive PDGFRA activation and p53 suppression as well as expression of the K27M mutant form of the histone H3.3 variant leads to neoplastic transformation of hPSC-derived neural precursors. Our study demonstrates that human ES cells represent an excellent platform for the modeling of human tumors in vitro and in vivo, which could potentially lead to the elucidation of the molecular mechanisms underlying neoplastic transformation and the identification of novel therapeutic targets.
Use of human embryonic stem cells to model pediatric gliomas with H3.3K27M histone mutation.
Specimen part
View SamplesBCRABL1+ precursor B-cell acute lymphoblastic leukemia (BCR ABL1+ B-ALL) is an aggressive hematopoietic neoplasm characterized by a block in differentiation due in part to the somatic loss of transcription factors required for B-cell development. We hypothesized that overcoming this differentiation block by forcing cells to reprogram to the myeloid lineage would reduce the leukemogenicity of these cells. We found that primary human BCRABL1+ B-ALL cells could be induced to reprogram into macrophage-like cells by exposure to myeloid differentiation-promoting cytokines in vitro or by transient expression of the myeloid transcription factor C/EBP or PU.1. The resultant cells were clonally related to the primary leukemic blasts but resembled normal macrophages in appearance, immunophenotype, gene expression, and function. Most importantly, these macrophage-like cells were unable to establish disease in xenograft hosts, indicating that lineage reprogramming eliminates the leukemogenicity of BCRABL1+ B-ALL cells, and suggesting a previously unidentified therapeutic strategy for this disease. Finally, we determined that myeloid reprogramming may occur to some degree in human patients by identifying primary CD14+ monocytes/ macrophages in BCRABL1+ B-ALL patient samples that possess the BCRABL1+ translocation and clonally recombined VDJ regions.
Reprogramming of primary human Philadelphia chromosome-positive B cell acute lymphoblastic leukemia cells into nonleukemic macrophages.
No sample metadata fields
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