We use mice containing a gene trap in the first intron of the Rest gene, which effectively eliminates transcription from all coding exons, to prematurely remove REST from neural progenitors. We find catastrophic DNA damage that occurs during S-phase of the cell cycle and concominant with activation of p53 pro-apoptotic sgnalling, with consequences including abnormal chromosome separation, apoptosis, and smaller brains.
The REST remodeling complex protects genomic integrity during embryonic neurogenesis.
Specimen part
View SamplesWe use mice containing a gene trap in the first intron of the Rest gene, which effectively eliminates transcription from all coding exons, to prematurely remove REST from neural progenitors. We find catastrophic DNA damage that occurs during S-phase of the cell cycle, with consequences including abnormal chromosome separation, apoptosis, and smaller brains. Further support for persistent effects is the latent appearance of proneural glioblastomas in adult mice also lacking the tumor suppressor, p53. A Rest deficient mouse line generated previously, using a conventional gene targeting approach, does not exhibit these phenotypes, likely due to a remaining C terminal peptide that still binds chromatin and recruits REST chromatin modifiers.Our results indicate that REST-mediated chromatin remodeling is required for proper S-phase dynamics, prior to its well-established role in relieving repression of neuronal genes at terminal differentiation.
The REST remodeling complex protects genomic integrity during embryonic neurogenesis.
Specimen part
View SamplesIn order to examine the consequences of human miR-34a induction on the transcriptome, HCT116 cells (a colon cancer cell line) were infected with a retrovirus that produces miR-34a. Gene expression profiles were then monitored using Affymetrix microarrays.
Transactivation of miR-34a by p53 broadly influences gene expression and promotes apoptosis.
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View SamplesXenograft models remain a cornerstone technology in the development of anti-cancer agents. The ability of immunocompromised rodents to support the growth of human tumors provides an invaluable transition between in vitro testing and clinical trials. Therefore, approaches to improve model selection are required. In this study, cDNA microarray data was generated for a collection of xenograft models at in vivo passages 1, 4 and 10 (P1, P4 and P10) along with originating cell lines (P0). These data can be mined to determine transcript expression 1) relative to other models 2) with successive in vivo passage and 3) during the in vitro (P0) to in vivo (P1) transition.
Gene expression profiling of 49 human tumor xenografts from in vitro culture through multiple in vivo passages--strategies for data mining in support of therapeutic studies.
No sample metadata fields
View SamplesTranscriptomic studies of human tumor xenografts are complicated by the presence of murine cellular mRNA. As such, it is useful to know the extent to which mouse mRNA cross-hybridizes to any given array platform. In this study, murine cDNA samples from diverse sources were hybridized to Affymetrix Human Genome U133 Plus 2.0 Arrays. In this regard it is possible to identify specific probes that are potential targets of cross-species interference.
Gene expression profiling of 49 human tumor xenografts from in vitro culture through multiple in vivo passages--strategies for data mining in support of therapeutic studies.
Specimen part, Cell line
View SamplesMissense FBXW7 mutations are prevalent in various tumors, including T-cell acute lymphoblastic leukemia (T-ALL). To study the effects of such lesions, we generated animals carrying regulatable Fbxw7 mutant alleles. We show here that these mutations specifically bolster cancer-initiating cell activity in collaboration with Notch1 oncogenes, but spare normal hematopoietic stem cell function. We were also able to show that FBXW7 mutations specifically affect the ubiquitylation and half-life of c-Myc protein, a key T-ALL oncogene. Using animals carrying c-Myc fusion alleles, we connected Fbxw7 function to c-Myc abundance and correlated c-Myc expression to leukemia-initiating activity.
The ubiquitin ligase FBXW7 modulates leukemia-initiating cell activity by regulating MYC stability.
Age, Specimen part
View SamplesNeuronal differentiation of PC12 cells in response to NGF is a prototypical model in which signal duration determines a biological response. Sustained ERK activity induced by NGF, as compared to transient activity induced by EGF, is critical to the differentiation of these cells. To characterize the transcriptional program activated preferentially by NGF, we compared global gene expression profiles between cells treated with NGF and EGF for 2-4 hrs, when sustained ERK signaling in response to NGF is most distinct from the transient signal elicited by EGF. This analysis identified 69 genes that were preferentially upregulated in response to NGF.
Global expression analysis identified a preferentially nerve growth factor-induced transcriptional program regulated by sustained mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) and AP-1 protein activation during PC12 cell differentiation.
Specimen part, Cell line, Time
View SamplesT-cell acute lymphoblastic leukemia (T-ALL) is an immature hematopoietic malignancy driven mainly by oncogenic activation of NOTCH1 signaling. In this study we abrogated the expression of JMJD3 (KDM6B) and UTX (KDM6A) H3K27me3 demethylases in human T-ALL lines and assayed for genome-wide expression changes using RNA sequencing. This piece of data was further integrated to ChIP-Sequencing analysis of H3K27me3 from the same treatment as well as H3K27me3 and JMJD3 genome-wide analysis from treatment of T-ALL lines with the GSKJ4 inhibitor. These results, coupled to genomic analysis of primary samples for the genomic status of the UTX gene in T-ALL, helped us to identify a hitherto unknown role of JMJD3as an oncogenice facilitator in leukemia whereas UTX seems to play a tumor suppressor role. Overall design: Whole RNA was extracted from 1-5 million T-ALL (lines) cells or primary cells using the RNAeasy kit (Qiagen) according to the manufacturer’s protocol. Poly-A+ (magnetic oligodT-containing beads (Invitrogen)) or Ribominus RNA was used for library preparation. cDNA preparation and strand-specific library construction was performed using the dUTP method. Libraries were sequenced on the Illumina HiSeq 2000 using 50bp single-read method. Differential gene expression analysis was performed for each matched knockdown vs control pairs, separately in each biological or technical replicate in each of two cell lines (CUTLL1, CEM). Three types of comparisons were tested: (a) JMJD3 knockdown vs Renilla, (b) JMJD3 knockdown vs UTX knockdown, and (c) UTX knockdown vs Renilla. Analysis was performed using both DEGseq and Cufflinks packages leading to very similar conclusions.
Contrasting roles of histone 3 lysine 27 demethylases in acute lymphoblastic leukaemia.
No sample metadata fields
View SamplesT-cell acute lymphoblastic leukemia (T-ALL) is an immature hematopoietic malignancy driven mainly by oncogenic activation of NOTCH1 signaling. In this study we chemically inhibited the H3K27me3 demethylase JMJD3 using the GSKJ4 inhibitor and assayed for genome-wide changes in H3K27me3 and JMJD3 enrichment. This piece of data was further integrated to expression changes using RNA sequencing as well as ChIP-Sequencing analysis of H3K27me3 upon genomic knock-down of JMJD3 and UTX. These results, coupled to genomic analysis of primary samples for the genomic status of the UTX gene in T-ALL, helped us to identify a hitherto unknown role of JMJD3 as an oncogenice facilitator in leukemia whereas UTX seems to play a tumor suppressor role. Overall design: Whole RNA was extracted from 1-5 million primary cells from CUTLL1 human T cell leukemia cells untreated or treated with 2micromolar GSKJ4 using the RNAeasy kit (Qiagen) according to the manufacturer’s protocol. Poly-A+ (magnetic oligodT-containing beads (Invitrogen)) or Ribominus RNA was used for library preparation. cDNA preparation and strand-specific library construction was performed using the dUTP method. Libraries were sequenced on the Illumina HiSeq 2000 using 50bp single-read method. Differential gene expression analysis was performed between knockout vs wild-type background samples. Analysis was performed using DEGseq package leading to very similar conclusions.
Contrasting roles of histone 3 lysine 27 demethylases in acute lymphoblastic leukaemia.
No sample metadata fields
View SamplesT-cell acute lymphoblastic leukemia (T-ALL) is an immature hematopoietic malignancy driven mainly by oncogenic activation of NOTCH1 signaling. In this study we conduct expression analysis in NOTCH1-IC-induced tumors in Utx wild-type (Utx+/+ or Utx+/Y) and knockout (Utx-/Y) background. These results, coupled to genomic analysis of primary samples for the genomic status of the UTX gene in T-ALL, helped us to characterize the hitherto understudied role of Utx as an oncogenic facilitator in leukemia and the contrasting expression signatures between JMJD3 and UTX in this disease. Overall design: Whole RNA was extracted from 1-5 million primary cells from Notch1-IC-expressing (sorted populations of) mouse T-ALL tumors using the RNAeasy kit (Qiagen) according to the manufacturer’s protocol. Poly-A+ (magnetic oligodT-containing beads (Invitrogen)) or Ribominus RNA was used for library preparation. cDNA preparation and strand-specific library construction was performed using the dUTP method. Libraries were sequenced on the Illumina HiSeq 2000 using 50bp single-read method. Differential gene expression analysis was performed between knockout vs wild-type background samples. Analysis was performed using DEGseq package leading to very similar conclusions.
Contrasting roles of histone 3 lysine 27 demethylases in acute lymphoblastic leukaemia.
No sample metadata fields
View Samples