The chromatin of individual chromosomes is organized into chromosome territories (CTs) in the interphase nucleus. The spatial arrangement of CTs is non-random and evolutionarily conserved. The gene-dense and gene-poor CTs are positioned in the nuclear center and periphery, respectively. As candidates for key molecules involved in nuclear organization, we have investigated the nuclear actin-related proteins (Arps), which include the evolutionarily conserved actin-family together with conventional actin. We used a conditional knockout system with chicken DT40 cells to analyze the functions of the actin-related protein Arp6. Consistent with a previous identification of Arp6 in the SRCAP chromatin remodeling complex, the histone variant H2AZ was significantly decreased in the chromatin of Arp6-deficient cells. Most importantly, Arp6-deficient cells had impaired radial positioning of both gene-poor macrochromosome and gene-rich microchromosome CTs. A transcription microarray analysis of the cells suggests that the radial positioning of CTs impacts only a limited number of genes and plays an active role in repression, rather than in induction. As far as we know, this report is the first observation that an inner nuclear protein is required for the radial distribution of CTs, and will provide new insight into the mechanisms and physical significance of the positioning of CTs in the nucleus.
The actin family member Arp6 and the histone variant H2A.Z are required for spatial positioning of chromatin in chicken cell nuclei.
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View SamplesThe histone variant H2A.Z is evolutionarily conserved from yeast to vertebrates. H2A.Z regulates gene expression when localized to promoter region. Recently, we identified two genes encoding H2A.Z, H2A.Z-1 and H2A.Z-2 in vertebrate genome. However, it is not clear that both H2A.Z-1 and H2A.Z-2 were required for the function of H2A.Z in gene regulation. To address this issue, we generated the H2A.Z-1 and H2A.Z-2 double knock out (KO) cells in chicken DT40 cells. The expression pattern of H2A.Z-1 and H2A.Z-2 double KO cells was compared with WT cells to characterize the genes regulated by H2A.Z-1 and H2A.Z-2.
The actin family member Arp6 and the histone variant H2A.Z are required for spatial positioning of chromatin in chicken cell nuclei.
Specimen part, Cell line
View SamplesThe aim of this study was to identify differentially expressed signatures of non-invasive (EGFR+) and invasive (HLA-G+) human trophoblast subtypes. These populations were isolated from single first trimester placentas from 10-12 weeks of gestation. Overall design: We performed RNAseq to analyze the global expression profile of two different trophoblastic subtypes.
Metabolism of cholesterol and progesterone is differentially regulated in primary trophoblastic subtypes and might be disturbed in recurrent miscarriages.
Specimen part, Subject
View SamplesEpendymal tumors across age groups have been classified and graded solely by histopathology. It is, however, commonly accepted that this classification scheme has limited clinical utility based on its lack of reproducibility in predicting patient outcome. We aimed at establishing a reliable molecular classification using DNA methylation fingerprints and gene expression data of the tumors on a large cohort of 500 tumors. Nine robust molecular subgroups, three in each anatomic compartment of the central nervous system (CNS), were identified.
Molecular Classification of Ependymal Tumors across All CNS Compartments, Histopathological Grades, and Age Groups.
Sex, Specimen part
View SamplesAryl hydrocarbon receptor (AHR) activation by tryptophan (Trp) catabolites enhances tumor malignancy and suppresses anti-tumor immunity. Hitherto, indoleamine-2,3-dioxygenase 1 (IDO1) or tryptophan- 2, 3-dioxygenase (TDO2) are recognized as the main Trp-catabolizing enzymes (TCEs) responsible for the generation of AHR agonists. Here, the ability of the aromatic L-amino acid oxidase, interleukin 4 induced 1 (IL4I1), to activate the AHR was investigated using IL4I1 knockout CAS-1 glioblastoma cells.
IL4I1 Is a Metabolic Immune Checkpoint that Activates the AHR and Promotes Tumor Progression.
Cell line
View SamplesAnalysis of the effect of IL4I1 on gene expression of CD8 T-cells in CLL
IL4I1 Is a Metabolic Immune Checkpoint that Activates the AHR and Promotes Tumor Progression.
Sex
View SamplesIndole-3-pyruvate (I3P), an endogenous metabolite derived from tryptophan by gut microbiota and IL4I1 enzyme in humans can potentially activate the transcriptional activity of the Aryl Hydrocarbon receptor. Here we test this by stimulating AHR proficient U-87MG cells with I3P alone or in combination with the AHR antagonist SR1.
IL4I1 Is a Metabolic Immune Checkpoint that Activates the AHR and Promotes Tumor Progression.
Cell line
View SamplesPrimitive neuroectodermal tumors of the central nervous system (CNS PNETs) are highly aggressive, poorly differentiated embryonal tumors occurring predominantly in young children. Using DNA methylation and gene expression profiling we have demonstrated that a significant proportion of institutionally diagnosed CNS PNETs display molecular profiles indistinguishable from those of various other well defined CNS tumor entities, facilitating diagnosis and appropiate therapy for children with these tumors. From the remaining fraction of CNS PNETs, we have identified four distinct new CNS tumor entities extending to other neuroepithelial tumors, each associated with a recurrent genetic alteration and particular histopathological and clinical features. These molecular entities, designated CNS Neuroblastoma with FOXR2 activation (CNS NB FOXR2), CNS Ewing sarcoma family tumor with CIC alteration (CNS EFT CIC), CNS high grade neuroepithelial tumor with MN1 alteration (CNS HGNET MN1), and CNS high grade neuroepithelial tumor with BCOR alteration (CNS HGNET BCOR), will enable meaningful clinical trials and the development of therapeutic strategies for patients affected by these poorly differentiated CNS tumors.
New Brain Tumor Entities Emerge from Molecular Classification of CNS-PNETs.
Sex, Age
View SamplesEwing sarcoma family of tumors (ESFT) are aggressive bone and soft tissue tumors of unknown cellular origin. Most ESFT express EWS-FLI1, a chimeric protein which functions as a growth-promoting oncogene in ESFT but is toxic to most normal cells. A major difficulty in understanding EWS-FLI1 function has been the lack of an adequate model in which to study EWS-FLI1-induced transformation. Although the cell of origin of ESFT remains elusive, both mesenchymal (MSC) and neural crest (NCSC) have been implicated. We recently developed the tools to generate NCSC from human embryonic stem cells (hNCSC). In the current study we used this model to test the hypothesis that neural crest-derived stem cells are the cells of origin of ESFT and to evaluate the consequences of EWS-FLI1 expression on human neural crest biology.
Modeling initiation of Ewing sarcoma in human neural crest cells.
Specimen part
View SamplesIn tumor tissues, hypoxia is a commonly observed feature resulting from rapidly proliferating cancer cells outgrowing the surrounding vasculature network. The four-step isogenic BJ cell model enables studies of defined steps of tumorigenesis: the normal, immortalized, transformed, and metastasizing stages. By transcriptome profiling under atmospheric and moderate hypoxic (3% O2) conditions, we observed that despite being highly similar, the four cell lines responded strikingly different to hypoxia. We demonstrate that the transcriptome adaptation to moderate hypoxia resembles the process of malignant transformation. The transformed cells displayed a distinct capability of metabolic switching, reflected in reversed gene expression patterns for several genes involved in oxidative phosphorylation and glycolytic pathways. By profiling the stage-specific responses to hypoxia, we identified ASS1 as a potential prognostic marker in hypoxic tumors. This study demonstrates the usefulness of the BJ cell model for highlighting the interconnection of pathways involved in malignant transformation and hypoxic response. Overall design: 16 paired-end samples in total: 4 different cell lines sequenced in duplicate across 2 conditions each.
Transcriptome profiling of the interconnection of pathways involved in malignant transformation and response to hypoxia.
Specimen part, Treatment, Subject
View Samples