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GSE18497
Homo sapiens
81 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Almost a quarter of pediatric patients with Acute Lymphoblastic Leukemia (ALL) suffer from relapses. The biological mechanisms underlying therapy response and development of relapses have remained unclear. In an attempt to better understand this phenomenon, we have analyzed 41 matched diagnosis relapse pairs of ALL patients using genomewide expression arrays (82 arrays) on purified leukemic cells. In roughly half of the patients very few differences between diagnosis and relapse samples were found (stable group), suggesting that mostly extra-leukemic factors (e.g., drug distribution, drug metabolism, compliance) contributed to the relapse. Therefore, we focused our further analysis on 20 samples with clear differences in gene expression (skewed group), reasoning that these would allow us to better study the biological mechanisms underlying relapsed ALL. After finding the differences between diagnosis and relapse pairs in this group, we identified four major gene clusters corresponding to several pathways associated with changes in cell cycle, DNA replication, recombination and repair, as well as B cell developmental genes. We also identified cancer genes commonly associated with colon carcinomas and ubiquitination to be upregulated in relapsed ALL. Thus, about half of relapses are due to selection or emergence of a clone with deregulated expression of a genes involved in pathways that regulate B cell signaling, development, cell cycle, cellular division and replication.
Publication Title
Genome-wide expression analysis of paired diagnosis-relapse samples in ALL indicates involvement of pathways related to DNA replication, cell cycle and DNA repair, independent of immune phenotype.
Sample Metadata Fields
Sex, Specimen part, Disease
View Samples- Homo sapiens
- 92 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
T-cell acute lymphoblastic leukemia (T-ALL) is mostly characterized by specific chromosomal abnormalities, some occurring in a mutually exclusive manner possibly delineating specific T-ALL subgroups. One subgroup, including MLL-rearranged, CALM-AF10 or inv(7)(p15q34) cases, is characterized by elevated expression of HOXA genes. Using a gene expression based clustering analysis of 67 T-ALL cases with recurrent molecular genetic abnormalities and 25 samples lacking apparent aberrations, we identified 5 new cases with elevated HOXA levels. Using array-CGH, a cryptic and recurrent deletion, del(9)(q34.11q34.13), was exclusively identified in 3 of these 5 cases. This deletion results in a conserved SET-NUP214 fusion product, that was also identified in the T-ALL cell line LOUCY. SET-NUP214 binds in the promoter regions of specific HOXA genes, where it may interact with CRM1 and DOT1L leading to the transcriptional activation of HOXA genes. Targeted inhibition of SET-NUP214 by siRNA abolished expression of HOXA genes, inhibited proliferation and induced differentiation in LOUCY but not in other T-ALL lines. We conclude that SET-NUP214 may contribute to the pathogenesis of T-ALL by enforcing T-cell differentiation arrest.
Publication Title
The recurrent SET-NUP214 fusion as a new HOXA activation mechanism in pediatric T-cell acute lymphoblastic leukemia.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 213 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Pediatric acute myeloid leukemia (AML) is a heterogeneous disease characterized by non-random genetic aberrations related to outcome. Detecting these aberrations however still lead to failures or false negative results. Therefore, we focused on the potential of gene expression profiles (GEP) to classify pediatric AML.
Publication Title
Evaluation of gene expression signatures predictive of cytogenetic and molecular subtypes of pediatric acute myeloid leukemia.
Sample Metadata Fields
Specimen part, Subject
View Samples- Homo sapiens
- 80 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
Individuals with Down syndrome (DS) are predisposed to develop acute megakaryoblastic leukemia (AMKL), characterized by expression of truncated GATA1 transcription factor protein (GATA1s) due to somatic mutation. The treatment outcome for DS-AMKL is more favorable than for AMKL in non-DS patients. To gain insight into gene expression differences in AMKL, we compared 24 DS and 39 non-DS AMKL samples. We found that non-DS-AMKL samples cluster in two groups, characterized by differences in expression of HOX/TALE family members. Both of these groups are distinct from DS-AMKL, independent of chromosome 21 gene expression. To explore alterations of the GATA1 transcriptome, we used cross-species comparison with genes regulated by GATA1 expression in murine erythroid precursors. Genes repressed after GATA1 induction in the murine system, most notably GATA-2, MYC, and KIT, show increased expression in DS-AMKL, suggesting that GATA1s fail to repress this class of genes. Only a subset of genes that are up-regulated upon GATA1 induction in the murine system show increased expression in DS-AMKL, including GATA1 and BACH1, a probable negative regulator of megakaryocytic differentiation located on chromosome 21. Surprisingly, expression of the chromosome 21 gene RUNX1, a known regulator of megakaryopoiesis, was not elevated in DS-AMKL. Our results identify relevant signatures for distinct AMKL entities and provide insight into gene expression changes associated with these related leukemias.
Publication Title
Identification of distinct molecular phenotypes in acute megakaryoblastic leukemia by gene expression profiling.
Sample Metadata Fields
Sex, Age
View Samples- Mus musculus
- 9 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
We compared the transcriptomes of EpiSCs maintained in the presence or absence of Wnt pathway inhibitor IWP2. We screened also our gene expression data for potential markers for genuine EpiSCs, maintained in the presence of Wnt inhibition and compared with ESC expression data. We compared the transcriptomes of EpiSCs maintained in the presence or absence of IWP2. The high level of Wnt-induced differentiation occurring in conventional EpiSC cultures may have interfered with the analysis of their characteristics. By applying Wnt inhibitors we are now able to establish the properties of genuine EpiSCs.
Publication Title
Endogenous WNT signals mediate BMP-induced and spontaneous differentiation of epiblast stem cells and human embryonic stem cells.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Mus musculus
- 7 Downloadable Samples
Illumina HiSeq 2000
Description
We have ablated TAF10 in the erythroid compartment only by crossing the TAF10lox mice with the EpoR-Cre mice and we have studied the development of the erythroid cells in vivo. TAF10 ablation led to embryonic death at E13.5 while at E12.5 there was a clear developmental defect which was reflected in the transcriptional profile of the fetal liver cells. Gata1-target genes were mostly affected and were responsible for the lethal phenotype. Overall design: mRNA from E12.5 fetal livers of TAF10lox/KO:EpoR-Cre+/- (TAF10KO) mice, TAF10HET and WT mice was profiled by NGS (Illumina).
Publication Title
TAF10 Interacts with the GATA1 Transcription Factor and Controls Mouse Erythropoiesis.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 6 Downloadable Samples
- Illumina HiSeq 2000
Description
Sp1 and Sp3 belong to the Specificity proteins (Sp)/Krüppel-like transcription factor family. They are closely related, ubiquitously expressed and recognize G-rich DNA motifs. They are thought to regulate generic processes such as cell cycle and growth control, metabolic pathways and apoptosis. Ablation of Sp1 or Sp3 in mice is lethal, and combined haploinsufficiency results in hematopoietic defects during the fetal stages. Here, we show that in adult mice conditional ablation of either Sp1 or Sp3 has minimal impact on hematopoiesis, while the simultaneous loss of Sp1 and Sp3 results in severe macrothrombocytopenia and platelet dysfunction. We employed flow cytometry, cell culture and electron microscopy and show that although megakaryocyte numbers are normal in bone marrow and spleen, they display a less compact demarcation membrane system and a striking inability to form proplatelets. Through megakaryocyte transcriptomics and platelet proteomics we identified several cytoskeleton-related proteins and downstream effector kinases, including Mylk, that were downregulated upon Sp1/Sp3 depletion, providing an explanation for the observed defects in megakaryopoiesis. We show that Mylk is required for proplatelet formation and stabilization and for ITAM-receptor mediated platelet aggregation. Our data highlights the specific vs generic role of these ubiquitous transcription factors in the highly specialized megakaryocytic lineage. Overall design: Megakaryocyte mRNA profiles of Sp1fl/fl::Sp3fl/fl (WTlox) and Pf4-Cre::Sp1fl/fl::Sp3fl/fl (dKO) mice were generated by deep sequencing, in triplicate.
Publication Title
Sp1/Sp3 transcription factors regulate hallmarks of megakaryocyte maturation and platelet formation and function.
Sample Metadata Fields
No sample metadata fields
View Samples GSE144829- Mus musculus
- 12 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Different osteoprogenitors (SSC, BCSP, Thy+) were sorted after 2 days of JUN induction, followed by RNA extraction and microarray analysis
Publication Title
Expansion of Bone Precursors through Jun as a Novel Treatment for Osteoporosis-Associated Fractures.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 6 Downloadable Samples
- Illumina HiSeq 2000
Description
We used RNA-Seq to analyse the interactions between Bmp4 and Wnt at a genome-wide level in EpiSCs treated for 48 hrs with Bmp4 and/or Wnt3a in the presence of Activin and bFGF. Overall design: Control EpiSC were cultured in the presence of IWP2 for 48h. Cells were cultured with BMP4 with or without IWP2; Wnt3a and Wnt3a with BMP4 for 48h.
Publication Title
Endogenous WNT signals mediate BMP-induced and spontaneous differentiation of epiblast stem cells and human embryonic stem cells.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 6 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Mammalian genomes contain numerous DNA elements with potential transcription regulatory function but unknown target genes. We used transgenic, gain-of-function mice with an ectopic copy of the beta-globin locus control region (LCR) to better understand how regulatory elements dynamically search the genome for target genes. We find that the LCR samples a restricted nuclear sub-volume in which it forms preferential contacts with genes controlled by shared transcription factors. One contacted gene, betah1, located on another chromosome, is upregulated, providing genetic demonstration that mammalian enhancers can function between chromosomes. Upregulation is not pan-cellular but confined to selected jackpot cells significantly enriched for inter-chromosomal LCR-betah1 interactions. This implies that long-range DNA contacts are relatively stable and cell-specific and, when functional, cause variegated expression. We refer to this as spatial effect variegation (SEV). The data provide a dynamic and mechanistic framework for enhancer action, important for assigning function to the one- and three-dimensional structure of DNA.
Publication Title
Variegated gene expression caused by cell-specific long-range DNA interactions.
Sample Metadata Fields
Specimen part, Disease
View Samples