Ewing Tumors (ET) are highly malignant tumors, localized in bone or soft tissue and are molecularly defined by ews/ets translocations. We identified histone methyl-transferase Enhancer of Zeste, Drosophila, Homolog 2 (EZH2) to be increased in ET. EZH2s suppressive activity maintains stemness in normal and malignant cells. Here we found EZH2 to be upregulated by the pathognomonic fusion oncogene EWS-FLI1 in ET and mesenchymal stem cells. Downregulation of EZH2 by RNA interference in ET suppressed oncogenic transformation by inhibiting clonogenicity in vitro. Similarly, tumor development and metastasis in immunodeficient Rag2-/-C-/- mice was suppressed. EZH2-mediated gene silencing was shown to be dependent on histone deacetylase (HDAC) activity. Subsequent microarray analysis of EZH2 knock down, HDAC-inhibitor treatment and confirmation in independent assays revealed an undifferentiated phenotype maintained by EZH2 in ET. Downregulation of EZH2 decreased histone H3 lysine 27 trimethylation (H3K27me3) at target loci. EZH2 regulated stemness genes such as nerve growth factor receptor (NGFR) as well as genes involved in neuroectodermal differentiation (EMP1, EPHB2, GFAP, GAP43). These data suggest that EZH2 might play a central role in Ewing Tumor pathology shaping the oncogenicity and stem cell phenotype of this tumor presumably by epigenetic regulation.
EZH2 is a mediator of EWS/FLI1 driven tumor growth and metastasis blocking endothelial and neuro-ectodermal differentiation.
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View SamplesAim was to identify cellular factors that regulate HPV-16 late gene expression at the level of RNA processing
Heterogeneous Nuclear Ribonucleoprotein C Proteins Interact with the Human Papillomavirus Type 16 (HPV16) Early 3'-Untranslated Region and Alleviate Suppression of HPV16 Late L1 mRNA Splicing.
Specimen part, Cell line
View SamplesThe goal of this study is to simultaneously interrogate host and parasite gene expression programs in human macrophages infected with the intracellular parasites from the genus Leishmania. We conducted high-resolution sequencing of the transcriptomes of human macrophages infected with Leishmania spp. using an RNA-seq approach. An array of computational tools was applied to map reads to the Leishmania and human genomes and reconstruct full-length transcripts. mRNA abundance was determined for Leishmania and human genes at various time points post-infection, enabling us to identify co-expression patterns that correlate with the biology of the parasite and to obtain a preliminary analysis of the dynamic nature of parasite and host cell gene expression programs in the context of infection. This study provides a solid framework for future functional and genomic studies of leishmaniasis as well as intracellular pathogenesis in general.
Dual Transcriptome Profiling of Leishmania-Infected Human Macrophages Reveals Distinct Reprogramming Signatures.
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View SamplesPolycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder that affects 5-10% of reproductive aged women. The hallmark characteristic of PCOS is increased ovarian androgen synthesis. Previous studies by our laboratory demonstrated that increased androgen synthesis is a stable biochemical phenotype of PCOS theca cells which are the primary source of ovarian androgen production. The increase in theca cell steroidogenesis was due to an increase in expression of several steroidogenic enzymes including CYP17 and CYP11A but not StAR. Interestingly, the anti-epileptic drug valproic acid induces increased theca cell androgen synthesis and increased CYP17 and CYP11A mRNA levels. In this study we have characterized the gene expression profiles of theca cells obtained from normal or polycystic ovaries which were maintained in the absence (UNT) or presence (VPA) of valproic acid. The data identifed new candidate genes and novel signaling pathways which may contribute to the manifestation of PCOS phenotypes including increased androgen production. The experiments in this study were carried using the Affymetrix U133A and U133B oligonucleotide chips.
Valproate-induced alterations in human theca cell gene expression: clues to the association between valproate use and metabolic side effects.
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View SamplesHfe disruption in the mouse leads to experimental hemochromatosis by a mechanism which remains elusive. Evidence for at least five modifier genes has been obtained. These account for the higher iron load of Hfe-deficient D2 mice compared to B6 mice. Gene expression profling was used to clarify the mechanism of Hfe action and to identify potential modifier genes.
Gene expression profiling of Hfe-/- liver and duodenum in mouse strains with differing susceptibilities to iron loading: identification of transcriptional regulatory targets of Hfe and potential hemochromatosis modifiers.
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View SamplesMacrophages readily change their phenotype in response to exogenous stimuli. In this work, macrophages were stimulated under a variety of experimental conditions, and alterations in mRNA levels were analyzed. We identified three transcriptionally related populations of macrophages with immunoregulatory activity. They were generated by stimulating cells with TLR ligands, in the presence of three different “reprogramming” signals; high density immune complexes (IC), prostaglandin E2 (PGE2), or adenosine (Ado). All three of these cell populations produced higher levels of transcripts for IL-10, and growth and angiogenic factors. They also secreted reduced levels of inflammatory cytokines IL-1Beta, IL-6, and IL-12. All three macrophage phenotypes could partially rescue mice from lethal endotoxemia, and therefore we consider each to have immunoregulatory activity. This immunoregulatory activity occurred equally well in macrophages from stat6-deficient mice. The lack of STAT6 did not affect macrophages’ ability to reciprocally change cytokine production or to rescue mice from lethal endotoxemia. Furthermore, treatment of macrophages with IL-4 failed to induce similar phenotypic or transcriptional alterations. This work demonstrates that there are multiple ways to generate macrophages with immunoregulatory activity. These immunoregulatory macrophages are transcriptionally and functionally related, and quite distinct from macrophages treated with IL-4.
The generation of macrophages with anti-inflammatory activity in the absence of STAT6 signaling.
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View SamplesThe goal of this study is to simultaneously examine host and parasite gene expression programs in skin lesions of human patients infected with the intracellular parasite Leishmania. We conducted high-resolution sequencing of the transcriptomes from early and late stage cutaneous leishmaniasis biopsies using an RNA-seq approach. An array of computational tools was applied to map reads to the Leishmania and human genomes and reconstruct full-length transcripts. mRNA abundance was determined for Leishmania and human genes, helping to explain tuning of the immune response to parasite transcriptomic profiles present in the lesion microenvironment. This data provided a deeper look at the transcriptomic profile of the host response in conjunction with a novel look at the parasite transcriptome in human cutaneous lesions. These data also offer the first glimpse of Leishmania gene expression profiles specific to the cutaneous manifestation of disease in human patients. This metatranscriptomic study provides a solid framework for future functional, genomic, and clinical studies of leishmaniasis as well as intracellular pathogenesis in general.
Meta-transcriptome Profiling of the Human-Leishmania braziliensis Cutaneous Lesion.
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View SamplesChildren with acute measles were admitted to the University Teaching Hospital in Lusaka, Zambia. Peripheral blood was collected at hospital entry, discharge and 1-month follow-up. Control samples were also collected from uninfected children. All children were HIV negative.
Gene expression changes in peripheral blood mononuclear cells during measles virus infection.
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View SamplesIntegrins have long been known to have a role in adhesion of neural stem cells within the neuroepithelium, but little is known about their role in regulating stem cell behaviour through signalling. We aimed to investigate the effect of integrin-beta 1 signalling (itgb1) on these cells by transfection of a constitutively active itgb1. This creates a heterogenous pattern of expression allowing the study of cell-autonomous and non-cell autonomous effects.
Integrin signalling regulates the expansion of neuroepithelial progenitors and neurogenesis via Wnt7a and Decorin.
Specimen part
View SamplesLIN28 is an RNA-binding protein expressed in many developing tissues. It can block let-7 microRNA processing and help promote pluripotency. We observe LIN28 expression in the developing neural tube, colocalizing with SOX2, suggesting a role in neural development. To better understand its normal developmental function, we investigated LIN28 activity during neurogliogenesis in vitro where the succession of neuronal to glial cell fates occurs as it does in vivo. LIN28 expression was high in undifferentiated cells, and was down-regulated rapidly upon differentiation. Constitutive LIN28 expression caused a complete block of gliogenesis and an increase in neurogenesis. LIN28 expression was compatible with neuronal differentiation and did not increase proliferation. LIN28 caused significant changes in gene expression prior to any effect on let-7, notably on Igf2. Furthermore, a mutant LIN28 that permitted let-7 accumulation was still able to completely block gliogenesis. Thus, at least two biological activities of LIN28 are genetically separable and may involve distinct mechanisms. LIN28 can differentially promote and inhibit specific fates and does not function exclusively by blocking let-7 family miRNAs. Importantly, LIN28s role in cell fate succession in vertebrate cells is analogous to its activity as a developmental timing regulator in C. elegans.
LIN28 alters cell fate succession and acts independently of the let-7 microRNA during neurogliogenesis in vitro.
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