Purpose: Recurrent ASXL1 mutations are frequently observed in all spectrums of myeloid malignancies and published data suggests that ASXL1 mutations may be involved in leukemic transformation as a tumor suppressor. Yet the molecular mechanisms of cell desitiny regulated by ASXL1 are to be further delineated. Methods: mRNA profiles of wild-type (WT) and CRISPR/Cas9 induced ASXL1 mutated U937 cell lines were generated by next generation sequencing, using Illumina HiSeq2500. Sequence reads were trimmed to remove possible adapter sequences and nucleotides with poor quality at the ends. Remaining sequence reads were then aligned to the human reference genome (hg19) using Tophat2. Gene read counts were measured using FeatureCounts and FPKM values were calculated with cufflinks. edgeR was used to identify differentially expressed genes between conditions, and topGO was used for annotation (Alexa, Rahnenfuhrer, and Lengauer, 2006). Sample comparison for differential gene expression was as follows: WTblk and WT1 versus MT2, MT3, MT4, and MT5. Gene enrichment set analysis (GSEA) was conducted with KEGG, Biocarta, and Reactome pathway datasets (Subramanian et al., 2005). Results: ASXL1-mutated cells displayed impaired differentiation capacity. RNA-seq was used to compare transcriptomes of ASXL1-mutated and WT U937 cells. Transcriptom analysis revealed that ASXL1 mutations decreased the expression of genes essential to myeloid differentiation, including CYBB and CLEC5A genes, which manifested in ASXL1-MT U937 cells as perturbed potential of differentiation compared with WT cells. Also, gene set enrichment analysis revealed that ASXL1 mutations masively affected gene sets relating to cell death and survival. Conclusion: By introduction of mutations into genome using the CRISPR/Cas9 system, we established ASXL1-mutated U937 cell lines. Our results indicated that ASXL1 mutations perturbed monocytic/phagocyte differentiation, which is a hallmark of myeloid malignancies, by down regulating genes essential to myeloid differentiation, including CYBB and CLEC5A, also massively affected multiple gene sets involving in cell survival. Overall design: mRNA profiles of wild type (WT) and ASXL1 mutated U937 cell lines were generated by deep sequencing using Illumina HiSeq2500
CRISPR/Cas9-mediated ASXL1 mutations in U937 cells disrupt myeloid differentiation.
Specimen part, Cell line, Subject
View SamplesC/EBP (CCAAT enhancer binding protein) is a transcription factor that plays a crucial role in survival and transformation of ALK+ anaplastic large cell lymphoma (ALCL). The aim of this study was to identify the downstream targets of C/EBP responsible for ALK-mediated oncogenesis. C/EBP was knocked down in ALK+ ALCL cell lines with a C/EBP-shRNA, followed by gene expression profiling (GEP). GEP analysis revealed a reproducible signature of genes that were significantly regulated by C/EBP. Classification into biological categories revealed overrepresentation of genes involved in the immune response, apoptosis and cell proliferation. Transcriptional regulation by C/EBP was found in 6 of 11 (BCL2A1, G0S2, TRIB1, S100A9, DDX21 and DDIT4) genes investigated by chromatin immunoprecipitation. We demonstrated that BCL2A1, G0S2 and DDX21 play a crucial role in survival and proliferation of ALK+ ALCL cells. DDX21, a gene involved in rRNA biogenesis, was found differentially overexpressed in primary ALK+ ALCL cases. All three candidate genes were validated in primary ALCL cases by either immunohistochemistry or RT-qPCR. In conclusion, we identified and validated several key C/EBP-regulated genes with major impact on survival and cell growth in ALK+ ALCL, supporting the central role of C/EBP in ALK-mediated oncogenesis.
Identification of C/EBPβ target genes in ALK+ anaplastic large cell lymphoma (ALCL) by gene expression profiling and chromatin immunoprecipitation.
Sex, Cell line
View SamplesNeuroprotective therapies for retinal degeneration may be used to rescue retinal cells and preserve vision. Hypoxic preconditioning stabilizes the transcription factor HIF-1 in the retina and strongly protects photoreceptors in an animal model of light-induced retinal degeneration.
Analysis of the retinal gene expression profile after hypoxic preconditioning identifies candidate genes for neuroprotection.
No sample metadata fields
View SamplesAlveolar soft-part sarcoma (ASPS) is an extremely rare, highly vascular soft tissue sarcoma affecting predominantly adolescents and young adults. In an attempt to gain insight into the pathobiology of this enigmatic tumor, we performed the first genome-wide gene expression profiling study.
Gene expression profiling of alveolar soft-part sarcoma (ASPS).
No sample metadata fields
View SamplesThe infant leukemia-associated gene, Ott1(Rbm15), has broad regulatory effects within the murine hematopoiesis. However, germline Ott1 deletion results in fetal demise prior to E10.5, indicating additional developmental requirements for Ott1. The spen gene family, to which Ott1 belongs, has a transcriptional activation/repression domain and RNA recognition motifs, and in Drosophila has a significant role in the development of the head and thorax. Early Ott1-deficient embryos show growth retardation and incomplete closure of the notochord. Further analysis demonstrated placental defects in the spongiotrophoblast and syncytiotrophoblast layers, resulting in an arrest of vascular branching morphogenesis. Rescue of the placental defect using a conditional allele with a trophoblast-sparing cre transgene allowed embryos to form a normal placenta and survive gestation. This result shows that the process of vascular branching morphogenesis in Ott1-deficient animals is regulated by the trophoblast compartment rather than the fetal vasculature. Mice surviving to term manifested hyposplenia and abnormal cardiac development. Analysis of global gene expression of Ott1-deficient embryonic hearts shows enrichment of hypoxia-related genes and significant alteration of several candidate genes critical for cardiac development. Thus, Ott1-dependent pathways in addition to being implicated in leukemogenesis, may also be important in the pathogenesis of placental insufficiency and cardiac malformations.
Ott1 (Rbm15) is essential for placental vascular branching morphogenesis and embryonic development of the heart and spleen.
No sample metadata fields
View SamplesThe infant leukemia-associated gene, Ott1 (Rbm15), has broad regulatory effects on embryonic development and hematopoiesis. Embryonic deletion of Ott1 results in defects to the placenta, spleen and heart. Conditional deletion within the adult hematopoietic compartment demonstrates a requirement in pre-B development and inhibitory roles in myeloid progenitor and megakaryocyte populations. Ott1-deleted bone marrow has an expansion of the Lin- Sca-1+ c-Kit+ (LSK) population which includes the hematopoietic stem cell (HSC) population. Functional HSC testing through competitive repopulation of irradiated recipients demonstrated however, a severe defect in Ott1-deficient HSCs, despite adequate numbers of immunophenotypically identified long term HSCs. Although mice deleted in situ for Ott1 are able to maintain hematopoiesis in steady state over a normal lifetime, but when subjected to proliferative stress, the HSC population loses the self-renewing, G0 fraction and undergoes bone marrow failure.
Hematopoietic stem cells lacking Ott1 display aspects associated with aging and are unable to maintain quiescence during proliferative stress.
Specimen part
View SamplesIt is currently unclear whether tissue changes surrounding multifocal epithelial tumors are a cause or consequence of cancer. Here, we provide evidence that loss of mesenchymal Notch/CSL signaling causes tissue alterations, including stromal atrophy and inflammation, which precede and are potent triggers for epithelial tumors. Mice carrying a mesenchymal-specific deletion of CSL/RBP-JK, a key Notch effector, exhibit spontaneous multifocal keratinocyte tumors that develop after dermal atrophy and inflammation. CSL-deficient dermal fibroblasts promote increased tumor cell proliferation through up-regulation of c-Jun and c-Fos expression and consequently higher levels of diffusible growth factors, inflammatory cytokines, and matrix remodeling enzymes. In human skin samples, stromal fields adjacent to cutaneous squamous cell carcinomas and multifocal premalignant actinic keratosis lesions exhibit decreased Notch/CSL signaling and associated molecular changes. Importantly, these changes in gene expression are also induced by UVA, a known environmental cause of cutaneous field cancerization and skin cancer.
Multifocal epithelial tumors and field cancerization from loss of mesenchymal CSL signaling.
Specimen part
View SamplesAssessing the impact of HIV-1 infection on trancriptional program of quiescent CD4 T lymphocytes. Such cells were made susceptible to HIV-1 by dowmodulating SAMHD1 restriction factor using VLP-Vpx without any activation signal.
CD32a is a marker of a CD4 T-cell HIV reservoir harbouring replication-competent proviruses.
Sex, Specimen part
View SamplesRod-derived Cone Viability Factor (RdCVF, alias nxnl1) is a retina-specific protein identified for its therapeutic potential in supporting cone survival during retinal degeneration.
The disruption of the rod-derived cone viability gene leads to photoreceptor dysfunction and susceptibility to oxidative stress.
Disease, Disease stage
View SamplesCentrosome defects are a common feature of many cancers. Surprisingly, flies can proceed through the majority of development without centrosomes or with amplified centrosomes in most of their cells. It is unclear whether this is because centrosome defects do not cause many problems in Drosophila cells, or because they can adapt to cope with any problems that arise. Indeed, centrosome loss and centrosome amplification predispose fly brain cells to form tumours. Here we assess how centrosome loss or centrosome amplification perturbs cell physiology by profiling the global transcriptome of Drosophila larval brains and imaginal discs that either lack centrosomes or have too many centrosomes.
Centrosome loss or amplification does not dramatically perturb global gene expression in Drosophila.
Specimen part
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