The SWI/SNF-family chromatin remodeling protein ATRX is a tumor suppressor in sarcomas, gliomas and other malignancies. Its loss of function facilitates the alternative lengthening of telomeres (ALT) pathway in tumor cells, while it also affects Polycomb repressive complex 2 (PRC2) silencing of its target genes. To further define the role of inactivating ATRX mutations in carcinogenesis, we knocked out atrx in our previously published p53/nf1-deficient zebrafish line that develops malignant peripheral nerve sheath tumors and gliomas. Complete inactivation of atrx using CRISPR-cas9 was lethal in developing fish and resulted in an alpha-thalassemia-like phenotype including reduced alpha-globin expression. In p53/nf1-deficient zebrafish neither peripheral nerve sheath tumors nor gliomas showed accelerated onset in atrx+/- fish, but these fish developed various tumors that were not observed in their atrx+/+ siblings, including epithelioid sarcoma, angiosarcoma, undifferentiated pleomorphic sarcoma and rare types of carcinoma. Most of these cancer types are included in the AACR Genie database of human tumors associated with mutant ATRX, indicating that our zebrafish model reliably reflects a role for ATRX-loss in the early pathogenesis of these types of human cancers. RNA-seq of p53/nf1- and p53/nf1/atrx-deficient tumors revealed that down-regulation of telomerase accompanied ALT-mediated lengthening of the telomeres in atrx-mutant samples. Moreover, inactivating mutations in atrx disturbed PRC2-target gene silencing, indicating a connection between ATRX loss and PRC2 dysfunction in cancer development. Overall design: Gene expression values were derived from paired end RNA-Seq data that compared zebrafish samples from p53/nf1/atrx-deficient tumors to samples from atrx-wildtype controls (3 vs. 3 samples).
Loss of atrx cooperates with p53-deficiency to promote the development of sarcomas and other malignancies.
Subject
View SamplesPurpose: Next-generation sequencing (NGS) has revolutionized systems-based analysis of cellular pathways. The goals of this study are to compare NGS transcriptome profiling (RNA-seq) from whole eye, after removal of the lens and cornea from 1-2 month old miR-211-/- mice and compare it with wt mice Methods: Whole eye (after removal of the lens and cornea) mRNA profiles of 1-2 month old wild-type (WT) and neural miR-211-/-mice were generated by deep sequencing, in multiple biological replicates, five for WT and six for miR-211-/- animals, using Illumina GAIIx. The sequence reads that passed quality filters were analyzed at the transcript isoform level with two methods: Burrows–Wheeler Aligner (BWA) followed by ANOVA (ANOVA) and TopHat followed by Cufflinks. qRT–PCR validation was performed using TaqMan and SYBR Green assays RNA-Seq libraries were prepared from whole eye, after removal of the lens and cornea from miR-211-/- mice. Results: Each library was sequenced using 100 bp paired-end sequencing on the Illumina HiSeq 1000 system. Gene abundances from RNA-Seq data were quantified using RSEM45. Using an optimized data analysis workflow, we mapped about 30 million sequence reads per sample to the mouse genome. This approach yielded read count values for a total of 38253 mouse genes annotated in GenCode. We only considered genes that had at least 1 count per million in at least five out of 11 samples as expressed, yielding a total of 15590 genes. Next we performed differential gene expression analysis to determine the transcriptional effects of miR-211 deletion. This analysis yielded a total of 63 genes that were differentially expressed with a False Discovery Rate (FDR) <0.1 (Fig. 4). Of these, the expression levels of 61 genes were significantly decreased upon miR-211 deletion, while only 2 genes were upregulated. Conclusions: Our study represents the first detailed analysis of whole eye transcriptomes, with biologic replicates, generated by RNA-seq technology on miR-211-/-. Overall design: Whole eye (after removal of the lens and cornea) mRNA profiles of 1-2 month old wild-type (WT) and neural miR-211-/-mice were generated by deep sequencing, in multiple biological replicates, five for WT and six for miR-211-/- animals, using Illumina GAIIx.
MiR-211 is essential for adult cone photoreceptor maintenance and visual function.
Specimen part, Subject
View SamplesNOTCH proteins regulate signaling pathways involved in cellular differentiation, proliferation and death. Overactive Notch signaling as been observed in numerous cancers and has been extensively studied in the context of T-cell acute lymphoblastic leukemia (T-ALL) where more than 50% of pateints harbour mutant NOTCH1. Small molecule modulators of these proteins would be important for understanding the role of NOTCH proteins in malignant and normal biological processes.
Direct inhibition of the NOTCH transcription factor complex.
Specimen part, Cell line
View SamplesExpression of a constitutively active Notch-1 intracellular domain (NICD) in MCF-10A cells was found to induce two distinct types of 3D structures: large, hyperproliferative structures and small, growth-arrested structures with reduced cell-to-matrix adhesion. These heterogeneous phenotypes reflect differences in Notch pathway activation levels. High Notch activity caused loss of cell adhesion and inhibition of proliferation, whereas low Notch activity maintained matrix adhesion and provoked a strong hyperproliferative response. In order to gain insight into the dosage-dependent transcriptional events triggered by Notch1 activation, gene expression profiles induced 48 hours after infection of MCF-10A cells with retroviral vectors expressing full-length Notch-1, L1601P+P, or NICD were compared. Full-length Notch-1 induced the weakest effect, L1601P+P induced an intermediate effect and NICD induced the strongest effect. Results provide insight into the dichotomous activites of Notch during development and tumorigenesis.
Dose-dependent induction of distinct phenotypic responses to Notch pathway activation in mammary epithelial cells.
Cell line
View SamplesPlatelets are a rich source of many cytokines and chemokines including transforming growth factor -1 (TGF1). TGF1 is required to convert conventional CD4+ T (Tconv) cells into induced regulatory T (iTreg) cells that express the transcription factor Foxp3. To explore whether other platelet contents will affect the properties of TGF induced Treg cell, we used platelet lysate that contain many other cytokines and chemokines besides TGF1 (pltTGF) to induce Foxp3 expression (pltTGFb-iTreg) from conventional CD4+ T (Tconv) cells. We used purified TGF1 to induce Treg (purTGF-iTreg) cells as a control. Gene expression profiles in iTreg cells were analyzed by microarray asay.
TGF-β1 along with other platelet contents augments Treg cells to suppress anti-FVIII immune responses in hemophilia A mice.
No sample metadata fields
View SamplesAlthough transcriptional programs associated with T-cell specification and commitment have been described, the functional hierarchy and the roles of key regulators in structuring/ orchestrating these programs remain unclear. Activation of Notch signaling in uncommitted precursors by the thymic stroma initiates the T-cell differentiation program. One regulator first induced in these precursors is the DNA binding protein Tcf-1, a T-cell specific mediator of Wnt signaling. Yet the specific contribution of Tcf-1 to early T-cell development and the signals inducing it in these cells remain unclear. Here we assign functional significance to Tcf-1 as a gatekeeper of T-cell fate. We show that Tcf-1 is directly activated by Notch signals. Tcf-1 is required at the earliest phase of Tcell determination for progression beyond the early thymic progenitor (ETP) stage. The global expression profile of Tcf-1 deficient progenitors indicates that basic processes of DNA metabolism are downregulated in its absence and the blocked T-cell progenitors become abortive and die by apoptosis. Our data thus add an important functional relationship to the roadmap of T-cell development.
T-cell factor 1 is a gatekeeper for T-cell specification in response to Notch signaling.
Specimen part
View SamplesDietary polyunsaturated fatty acids (PUFA) are suggested to modulate immune function, but the effects of dietary fatty acids composition on gene expression patterns in immune organs have not been fully characterized. In the current study we investigated how dietary fatty acids composition affects the total transcriptome profile, and especially, immune related genes, in bone marrow cells (BMC) and spleen (SPL). Four tissues with metabolic function, skeletal muscle (SKM), white adipose tissue (WAT), brown adipose tissue (BAT), and liver (LIV), were investigated as a comparison. Following 8 weeks on low fat diet (LFD), high fat diet (HFD) rich in saturated fatty acids (HFD-S), or HFD rich in PUFA (HFD-P), tissue transcriptomics were analyzed by microarray and metabolic health assessed by fasting blood glucose level, HOMA-IR index, oral glucose tolerance test as well as quantification of crown-like structures in WAT. Interestingly, SKM and BMC were relatively inert to the diets, whereas the two adipose tissues (WAT and BAT) were mainly affected by HFD per se (both HFD-S and HFD-P). In particular, WAT gene expression was driven closer to that of the immune organs SPL and BMC by HFDs. Remarkably, the spleen, showed a major response to HFD-P, but not to HFD-S, whereas the LIV exhibited different responses to both of the HFDs. Further, HFD-P corrected the metabolic phenotype induced by HFD-S. Hence, the quantity and composition of dietary fatty acids affected the transcriptome in a distinct manner. Especially, PUFA prompted a specific regulation of immune related genes in the spleen. Thus, PUFA can regulate immune function by influencing gene expression.
Six Tissue Transcriptomics Reveals Specific Immune Suppression in Spleen by Dietary Polyunsaturated Fatty Acids.
Sex, Specimen part
View SamplesNotch is normally activated by cleavage and nuclear translocation of its intracellular domain (ICN1), which turns on downstream target genes. Human T cell acute lymphoblastic leukemia (T-ALL), an aggressive immature T cell malignancy, is associated with Notch 1 gain-of-function mutations in more than 50% of the cases. Efforts to date to identify direct Notch1 targets have been confounded by the lack of a method to turn Notch1 on in a controlled fashion in T-ALL cells that are poised to respond to Notch signals. Of note, because Notch signaling activates transcriptional repressors that feedback to dampen the expression of many target genes (a process referred to as incoherent logic), it is likely that many direct targets are missed in Notch off analyses, which are further complicated by an inability to identify direct targets in a clear-cut fashion. We have overcome this limitation by developing a GSI washout method that results in the rapid translocation of activated Notch1 to the nucleus. We intend to use this method to study the assembly and loading of transcriptional complexes onto downstream targets, the kinetics of target activation. To date, our efforts have been devoted to comparing the gene expression signature of Notch-on and Notch-off in the human T-ALL cell line CUTLL. In addition to previously identified Notch1 target genes, we have also identified a series of novel genes upregulated by GSI washout in the presence of cycloheximide, suggesting that they are likely to be direct targets.
Genome-wide analysis reveals conserved and divergent features of Notch1/RBPJ binding in human and murine T-lymphoblastic leukemia cells.
Cell line
View SamplesGenomewide gene expression analysis of lymphoid cell lines of Hodgkin, non-Hodgkin and acute leukemia origin
High-level expression of Mastermind-like 2 contributes to aberrant activation of the NOTCH signaling pathway in human lymphomas.
No sample metadata fields
View SamplesAnalysis of five Notch signaling-dependent human T-ALL cell lines (ALLSIL, DND41, HPBALL, KOPTK1, TALL-1) treated with gamma-secretase inhibitor (GSI) to block Notch signaling. Samples include parental cells, cells rescued by retroviral transduction with ICN (a GSI-independent form of activated Notch1), and cells retrovirally transduced with c-Myc (an important downstream target of Notch1). Results allow segregation of bona fide Notch targets from other genes affected by gamma-secretase inhibition as well as from targets downstream of c-Myc.
High-level IGF1R expression is required for leukemia-initiating cell activity in T-ALL and is supported by Notch signaling.
Cell line
View Samples