The growth factor interleukin-3 (IL-3) promotes the survival and growth of multipotent hematopoietic progenitors and stimulates myelopoiesis. It has also been reported to oppose terminal granulopoiesis and to support leukemic cell growth through autocrine or paracrine mechanisms. We used kinetic microarray, Northern Blotting and bioinformatics analysis of IL-3 dependent myeloblasts to determine whether IL-3 acts in part by regulating the rate of turnover of mRNA transcripts in specific functional pathways. Our results indicate that exposure of myeloblasts to IL-3 causes immediate early stabilization of hundreds of transcripts in pathways relevant to myeloblast function. Examples include transcripts associated with proliferation and leukemic transformation (pik3cd, myb, pim-1), hematopoietic development (cited2), differentiation control (cdkn1a) and RNA processing (BRF1, BRF2). A domain in the 3-utr of IL-6 that mediates IL-3 responsiveness contains AU-rich elements that bind proteins known to modulate mRNA stability, however a known destabilizing protein (AUF1) is shown not to mediate degradation in the absence of IL-3. These findings support a model of IL-3 action through mRNA stability control and suggest that aberrant stabilization of this network of transcripts could contribute to growth patterns observed in leukemia.
IL-3 and oncogenic Abl regulate the myeloblast transcriptome by altering mRNA stability.
No sample metadata fields
View SamplesThis study was performed to identify gene expression differences in not otherwise specified soft tissue sarcomas (NOS, malignant fibrous histiocytomas) and correlate them to histological findings and the clinical course. RNA was isolated and differential gene expression was analysed by the microarray technique.
Malignant fibrous histiocytoma--pleomorphic sarcoma, NOS gene expression, histology, and clinical course. A pilot study.
Sex
View SamplesGSE2240 contains two different experimental subsets:
Functional profiling of human atrial and ventricular gene expression.
No sample metadata fields
View SamplesThe production of Tobacco Acid Pyrophosphatase (TAP), an enzyme commonly used for the removal of the 5’cap of eukaryotic mRNAs, has been recently discontinued. Here we performed a comparison of current alternatives for the mapping of 5’cap mRNAs and the associated transcription start sites in Sacharomyces cerevisiae. Specifically we compared TAP with Cap-clip and a Decapping Pyrophosphohydrolase. Our results suggest that Cap-clip is a good alternative for TAP. Overall design: We used two biological replicates of S. cerevisiae that was grown to exponential phase (OD600 ~1) in rich media (YPAD). Samples where processed until the dephosphorylation step (CIP treatment). After that each sample was split in 4 aliquots: TAP treatment, Cap-Clip treatment, Decapping Pyrophosphohydrolase treatment or no treatment (negative control). From that step all samples are processed in parallel.
Widespread Co-translational RNA Decay Reveals Ribosome Dynamics.
Treatment, Subject
View SamplesWe used microarrays to detail the global program of gene expression during early hESC differentiation to mesendoderm using FBS, with and without RUNX1 depletion.
Transient RUNX1 Expression during Early Mesendodermal Differentiation of hESCs Promotes Epithelial to Mesenchymal Transition through TGFB2 Signaling.
Specimen part, Cell line
View SamplesThe TRIM-NHL protein Brain tumor (Brat) acts as a tumor suppressor in the Drosophila brain, but how it suppresses tumor formation is not completely understood. Here, we combine temperature controlled brat RNAi with transcriptome analysis to identify the immediate brat targets in Drosophila neuroblasts. Besides the known target Deadpan (Dpn), our experiments identify the transcription factor Zelda (Zld) as a critical target of brat. Our data show that Zld is expressed in neuroblasts and required to allow re-expression of Dpn in transit amplifying intermediate neural progenitors. Upon neuroblast division, Brat is enriched in one daughter cell where its NHL domain directly binds to specific motifs in the 3'UTR of dpn and zld mRNA to mediate their degradation. In brat mutants, both Dpn and Zld continue to be expressed, but inhibition of either transcription factor prevents tumorigenesis. Our genetic and biochemical data indicate that Dpn inhibition requires higher Brat levels than Zld inhibition and suggest a model where stepwise post-transcriptional inhibition of distinct factors ensures sequential generation of fates in a stem cell lineage. Overall design: Comparison of transcriptomes of Drosophila melanogaster control and brat RNAi larval brain type II neural stem cell lineages.
The tumor suppressor Brat controls neuronal stem cell lineages by inhibiting Deadpan and Zelda.
Specimen part, Subject
View SamplesAnti-sense non-coding transcripts, genes-within-genes, and convergent gene pairs are prevalent among eukaryotes. The existence of such transcription units raises the question of what happens when RNA polymerase II (RNAPII) molecules collide head-to-head. Here we use a combination of biochemical and genetic approaches in yeast to show that polymerases transcribing opposite DNA strands cannot bypass each other. RNAPII stops, but does not dissociate upon head-to-head collision in vitro, suggesting that opposing polymerases represent insurmountable obstacles for each other. Head-to-head collision in vivo results in RNAPII stopping as well, and removal of collided RNAPII from the DNA template can be achieved via ubiquitylation-directed proteolysis. Indeed, in cells lacking efficient RNAPII poly-ubiquitylation, the half-life of collided polymerases increases, so that these can be detected between convergent genes by ChIP-Seq. These results provide new insight into fundamental mechanisms of gene traffic control, and point to an unexplored effect of anti-sense transcription on gene regulation via polymerase collision. Overall design: Total RNA was extracted from WT or Elongin C deletion mutant (elc1?) cells and strand-specific RNA-Seq was performed. Three biological replicates were performed for WT and elc1?.
RNA polymerase II collision interrupts convergent transcription.
Cell line, Subject
View SamplesThe onset and progression of breast cancer are linked to genetic and epigenetic changes that alter the normal programming of cells. Epigenetic modifications of DNA and histones contribute to chromatin structure that results in the activation or repression of gene expression. Several epigenetic pathways have been shown to be highly deregulated in cancer cells. Targeting specific histone modifications represents a viable strategy to prevent oncogenic transformation, tumor growth or metastasis. Methylation of histone H3 lysine 4 has been extensively studied and shown to mark genes for expression; however this residue can also be acetylated and the specific function of this alteration is less well known. To define the relative roles of histone H3 methylation (H3K4me3) and acetylation (H3K4ac) in breast cancer, we determined genomic regions enriched for both marks in normal-like (MCF10A), transformed (MCF7) and metastatic (MDA-MB-231) cells using a genome-wide ChIP-Seq approach. Our data revealed a genome-wide gain of H3K4ac associated with both early and late breast cancer cell phenotypes, while gain of H3K4me3 was predominantly associated with late stage cancer cells. Enrichment of H3K4ac was overrepresented at promoters of genes associated with cancer-related phenotypic traits, such as estrogen response and epithelial-to-mesenchymal transition pathways. Our findings highlight an important role for H3K4ac in predicting epigenetic changes associated with early stages of transformation. In addition, our data provide a valuable resource for understanding epigenetic signatures that correlate with known breast cancer-associated oncogenic pathways. Overall design: RNA-Seq of cell lines MCF10A, MCF7 and MDA-MB-231.
Histone H3 lysine 4 acetylation and methylation dynamics define breast cancer subtypes.
No sample metadata fields
View SamplesAnalysis of gene expressions in mouse splenic dendritic cells (DCs). DCs were purified into two subsets, CD8-positive and -negative ones. DCs were expanded in vivo by injecting Flt3L-producing tumors into the backs of C57BL/6 mice.
A new triggering receptor expressed on myeloid cells (Trem) family member, Trem-like 4, binds to dead cells and is a DNAX activation protein 12-linked marker for subsets of mouse macrophages and dendritic cells.
No sample metadata fields
View SamplesBackground: The transcription factor EVI1 regulates cellular proliferation, differentiation, and apoptosis, and contributes to an aggressive course of disease in myeloid leukemias and other malignancies. Notwithstanding, knowledge about the target genes mediating its biological and pathological functions remains limited. We therefore aimed to identify and characterize novel EVI1 target genes in human myeloid cells. Methods: U937T_EVI1, a previously established human myeloid cell line expressing EVI1 in a tetracycline regulable manner, was subjected to genome wide gene expression microarray analysis. qRT-PCR was used to confirm the regulation of MS4A3 by EVI1. Reporter constructs containing various parts of the MS4A3 upstream region were employed in luciferase assays, and direct binding of EVI1 to the MS4A3 promoter was investigated by chromatin immunoprecipitation. U937 derivative cell lines experimentally expressing EVI1 and/or MS4A3 were generated by retroviral transduction, and tested for their tumorigenicity by subcutaneous injection into severe combined immunodeficient mice. Experimental results were tested for statistical significance using ANOVA and Student's t-test (two-tailed). Results: Gene expression microarray analysis identified 27 unique genes that were up-regulated and 29 that were down-regulated in response to EVI1 induction in the human myeloid cell line, U937. The most strongly repressed gene was membrane-spanning-4-domains subfamily-A member-3 (MS4A3), and its down-regulation by EVI1 was confirmed by qRT-PCR in additional, independent experimental model systems. Reporter gene assays and chromatin immunoprecipitation showed that EVI1 regulated MS4A3 via direct binding to a promoter proximal region. Experimental re-expression of MS4A3 in an EVI1 overexpressing cell line counteracted the tumor promoting effect of EVI1 in a murine xenograft model. Conclusions: Our data reveal MS4A3 as a novel direct target of EVI1 in human myeloid cells, and show that its repression plays a role in EVI1 mediated tumor aggressiveness.
EVI1 promotes tumor growth via transcriptional repression of MS4A3.
Cell line, Time
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