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GSE33427
Saccharomyces cerevisiae
14 Downloadable Samples
Affymetrix Yeast Genome 2.0 Array (yeast2)
Description
Arsenic metalloid is a double-edge sword. On the one hand it is a very toxic and powerful carcinogen, and on the other it has been successfully used in the treatment of acute promyelocytic leukemia. In order to prevent the deleterious effects caused by arsenic compounds, almost all living organisms have developed mechanisms to eliminate it. In this study genome-wide response of S. cerevisiae to arsenic shows that this metal interferes with genes involved in the iron homeostasis including those encoding proteins that function in iron uptake, incorporation into FeS clusters, and more. In addition our data indicate that Yap1 transcriptionally controls the iron homeostasis regulator AFT2 as well as its direct target, MRS4. Most importantly in response to arsenate exposure Yap1 strongly regulates the expression of several genes involved in the Fe-S proteins biosynthesis, namely NBP35 and YFH1. Interestingly mRNA levels encoding Fet3, Ferro-O2-oxidoreductase required for high-affinity iron uptake, are drastically destabilized upon arsenic exposure. Such destabilization is due to the 5 to 3 exonuclease Xrn1 localized in the P Bodies. Moreover FET3 mRNA decay is not mediated by Cth2 and is independent on the formation of ROS responsible for the toxic effects of arsenic compounds. Strikingly, in presence of arsenate fet3 mutant shows resistance over the wild-type which leads us to suggest that Fet3 has a role in arsenic toxicity. Unexpectedly arsenic treatment seems to activate the non-reductive iron uptake in order to maintain the cellular iron homeostasis. Furthermore our genetic, biochemical, and physiological analysis demonstrate that aft1 mutant is sensitive to arsenic compounds and such phenotype is reversible upon addition of iron. We also show that arsenic exposure induces iron deficiency in aft1 mutant. In conclusion this work shows for the first time that arsenic, a chemotherapy drug used to treat a specific type of acute promyelocytic leukemia (APL), disrupts iron homeostasis and our results suggest that this disruption is independent on ROS generation. Finally we provide preliminary data confirming that such disruption also takes place in mammalian cells, an observation that can be very relevant in term of clinical applications.
Publication Title
Arsenic stress elicits cytosolic Ca(2+) bursts and Crz1 activation in Saccharomyces cerevisiae.
Sample Metadata Fields
Time
View Samples- Homo sapiens
- 15 Downloadable Samples
IlluminaHiSeq2000
Description
Human erythroblasts purified from cord blood were cultured in vitro and FACS-sorted into five highly purified populations representing distinct differentiation stages: proerythroblasts, early basophilic erythroblasts, late basophilic erythroblasts, polychromatophilic erythroblasts, and orthochromatophilic erythroblasts. The methods for culture and sorting experiments are given in Hu et al. 2013. For each RNA-seq library, RNA was isolated from 1x 106 sorted human erythroblasts using RNeasy Plus Mini kits (Qiagen). Libraries were then prepared using Illumina TruSeqTM RNA kits to obtain 50 nt reads. Collaborators at the New Your Blood Center were responsible for erythroblast culture, FACS purification of erythroblast populations, and acquisition of RNA-seq data. Collaborators at U.C. Berkeley and Lawrence Berkeley National Laboratory performed data analysis and experimental validation of alternative splicing in erythroblasts. Results: Differentiating erythroblasts execute a dynamic alternative splicing program that is enriched in genes affecting cell cycle, organelle organization, chromatin function, and RNA processing. Alternative splicing plays a major role in regulating gene expression to ensure synthesis of appropriate proteome at each stage as the cells remodel in preparation for production of mature red cells. Overall design: Erythroid differentiation stage-specific transcriptome analysis was performed by RNA-seq analysis of highly purified erythroblast populations
Publication Title
A dynamic alternative splicing program regulates gene expression during terminal erythropoiesis.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 25 Downloadable Samples
- Affymetrix Human Genome U133A 2.0 Array (hgu133a2)
Description
Plasmablastic lymphoma is a high grade B cell lymphoma with plasmablastic morphology and a terminally differentiated B cell immunophenotype, usually arising in the setting of immunodeficiency and often demonstrating Epstein Barr Virus positivity. The molecular and genetic mechanisms underlying the pathogenesis of PBL are largely unknown. To better understand its pathogenesis, herein we have analyzed global gene expression of PBL and compared that to gene expression profiles of diffuse large B cell lymphoma. While overlaps in transcriptomes between these malignancies were identified, we have shown that the gene expression profile of plasmablastic lymphoma is distinct, demonstrating striking downregulation of B cell receptor signaling genes, BCL6, BCL11A SPI-B, targets of NFKB1, and upregulation of mitochondrial genes, PRMT5, MYC and MYC targets and IL21, implicating these alterations in the pathogenesis of this lymphoma. In addition we show the usefulness of SWAP-70 immunohistochemistry in the differentiation of immunoblastic diffuse large B cell lymphoma and plasmablastic lymphoma. Our findings provide justification for considering plasmablastic lymphoma as a specific lymphoma entity and provide insight into the unique transcriptional aberrations occurring in this high-grade lymphoma.
Publication Title
Gene expression analysis of plasmablastic lymphoma identifies downregulation of B-cell receptor signaling and additional unique transcriptional programs.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 8 Downloadable Samples
- Illumina HiSeq 2500
Description
Growing evidence implicates the importance of glia, particularly astrocytes, in neurological and psychiatric diseases. Here, we describe a rapid and robust method for the differentiation of highly pure populations of astrocytes from human induced pluripotent stem cells (hiPSCs), via a neural progenitor cell (NPC) intermediate. Using this method, we generated hiPSC-derived astrocyte populations (hiPSC-astrocytes) from 42 NPC lines (derived from 30 individuals) with an average of ~90% S100ß-positive cells. Transcriptomic analysis demonstrated that the hiPSC-astrocytes are highly similar to primary human fetal astrocytes and characteristic of a non-reactive state. hiPSC-astrocytes respond to inflammatory stimulants, display phagocytic capacity and enhance microglial phagocytosis. hiPSC-astrocytes also possess spontaneous calcium transient activity. Our novel protocol is a reproducible, straightforward (single media) and rapid (<30 days) method to generate homogenous populations of hiPSC-astrocytes that can be used for neuron-astrocyte and microglia-astrocyte co-cultures for the study of neuropsychiatric disorders. Overall design: 6 hiPSC-derived astrocyte lines were generated. Total RNA were extracted from these hiPSC-astrocytes as well as 2 primary astrocyte lines and analyzed by RNA sequencing.
Publication Title
An Efficient Platform for Astrocyte Differentiation from Human Induced Pluripotent Stem Cells.
Sample Metadata Fields
Sex, Specimen part, Subject
View Samples- Homo sapiens
- 763 Downloadable Samples
- Affymetrix Human Gene 1.1 ST Array (hugene11st)
Description
Affimetrix Human Gene 1.1 ST Array profiling of 763 primary medullobalstoma samples used for identification of Medullobastoma subtypes
Publication Title
Intertumoral Heterogeneity within Medulloblastoma Subgroups.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 12 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Combinatorial actions of relatively few transcription factors control hematopoietic differentiation. To investigate this process in erythro-megakaryopoiesis, we correlated the genome-wide chromatin occupancy signatures of four master hematopoietic transcription factors (GATA1, GATA2, TAL1, and FLI1) and three diagnostic histone modification marks with the gene expression changes that occur during development of primary cultured megakaryocytes (MEG) and primary erythroblasts (ERY) from murine fetal liver hematopoietic stem/progenitor cells. We identified a robust, genome-wide mechanism of MEG-specific lineage priming by a previously described stem/progenitor cell-expressed transcription factor heptad (GATA2, LYL1, TAL1, FLI1, ERG, RUNX1, LMO2) binding to MEG-associated cis-regulatory modules (CRMs) in multipotential progenitors. This is followed by genome-wide GATA factor switching that mediates further induction of MEG-specific genes following lineage commitment. Interaction between GATA and ETS factors appears to be a key determinant of these processes. In contrast, ERY-specific lineage priming is biased toward GATA2-independent mechanisms. In addition to its role in MEG lineage priming, GATA2 plays an extensive role in late megakaryopoiesis as a transcriptional repressor at loci defined by a specific DNA signature. Our findings reveal important new insights into how ERY and MEG lineages arise from a common bipotential progenitor via overlapping and divergent functions of shared hematopoietic transcription factors.
Publication Title
Divergent functions of hematopoietic transcription factors in lineage priming and differentiation during erythro-megakaryopoiesis.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 12 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Combinatorial actions of relatively few transcription factors control hematopoietic differentiation. To investigate this process in erythro-megakaryopoiesis, we correlated the genome-wide chromatin occupancy signatures of four master hematopoietic transcription factors (GATA1, GATA2, SCL/TAL1 and FLI1) and three diagnostic histone modification marks with the gene expression changes that occur during development of primary megakaryocytes (MEG) and erythroblasts (ERY) from murine fetal liver hematopoietic stem/progenitor cells. We identified a robust, genome-wide mechanism of MEG-specific lineage priming by a previously described stem/progenitor cell-expressed transcription factor heptad (GATA2, LYL1, SCL/TAL1, FLI1, ERG, RUNX1, LMO2) binding to MEG-specific cis-regulatory modules in multipotential hematopoietic progenitors. This is followed by genome-wide GATA factor switching that mediates further induction of MEG-specific genes following lineage commitment. Interaction between GATA and ETS factors appears to be a key determinant of these processes. In contrast, ERY-specific lineage priming occurs is biased toward GATA2-independent mechanisms. In addition to its role in MEG lineage priming, GATA2 plays an extensive role in late megakaryopoiesis as a transcriptional repressor at loci defined by a specific DNA signature. Our findings reveal important new insights into how ERY and MEG lineages arise from a common bipotential precursor via overlapping and divergent functions of shared hematopoietic transcription factors.
Publication Title
Divergent functions of hematopoietic transcription factors in lineage priming and differentiation during erythro-megakaryopoiesis.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 2 Downloadable Samples
- NextSeq 500
Description
Mutations in the RNA splicing complex member SRSF2 are found frequently in myelodysplastic syndrome and related malignancies such as chronic myelomonocytic leukemia. These mutations cluster on proline 95, with P95H the most frequent. How SRSF2P95H mutations modify hematopoiesis and promote MDS/MPN development is not clear. We have established a conditionally activatable Srsf2P95H/+ knock-in allele which, when expressed within the hematopoietic stem cell populations caused profound myeloid bias, at the expense of erythroid and lymphoid cells, and a reduced frequency and competitive repopulation of HSCs. Long-term aging of Srsf2P95H/+ resulted in the development of MDS/MPN characterised by myeloid dysplasia and monocytosis. Reproducible key phenotypic features make this a mouse model suitable for mechanistic and preclinical MDS sudies. Overall design: RNAseq of whole bone marrow in vivo tamoxifen treated R26CreERT2 Srsf2 P95H generated by deep sequencing, using Illumina NextSeq500
Publication Title
<i>Srsf2</i><i><sup>P95H</sup></i> initiates myeloid bias and myelodysplastic/myeloproliferative syndrome from hemopoietic stem cells.
Sample Metadata Fields
Sex, Age, Specimen part, Subject
View Samples- Homo sapiens
- 14 Downloadable Samples
- IlluminaHiSeq2000
Description
High expression of the ETS family transcription factor ERG is associated with poor clinical outcome in acute myeloid leukemia (AML) and acute T-cell lymphoblastic leukemia (T-ALL). In murine models, high ERG expression induces both T-ALL and AML. However, no study to date has defined the effect of high ERG expression on primary human hematopoietic cells. In the present study, human CD34+ cells were transduced with retroviral vectors to elevate ERG gene expression to levels detected in high ERG AML. RNA sequencing was performed on purified populations of transduced cells to define the effects of high ERG on gene expression in human CD34+ cells. Integration of the genome-wide expression data with other data sets revealed that high ERG drives an expression signature that shares features of normal hematopoietic stem cells, high ERG AMLs, early T-cell precursor-ALLs and leukemic stem cell signatures associated with poor clinical outcome. Functional assays linked this gene expression profile to enhanced progenitor cell expansion. These results support a model whereby a stem cell gene expression network driven by high ERG in human cells enhances the expansion of the progenitor pool, providing opportunity for the acquisition and propagation of mutations and the development of leukemia. Overall design: RNA sequencing in ERG overexpressing human CD34+ cells
Publication Title
Overexpression of ERG in cord blood progenitors promotes expansion and recapitulates molecular signatures of high ERG leukemias.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 9 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
The Ets transcription factor, ERG, plays a central role in definitive hematopoiesis and its overexpression in acute myeloid leukemia is associated with a stem cell signature and bad prognosis. However, little is known about the underlying mechanism by which ERG causes leukemia. Therefore we sought to identify ERG targets that participate in development of leukemia by integration of expression arrays and Chromatin immunoprecipitation.
Publication Title
Genome-scale expression and transcription factor binding profiles reveal therapeutic targets in transgenic ERG myeloid leukemia.
Sample Metadata Fields
No sample metadata fields
View Samples