Lifelong murine gene expression profiles in relation to chronological and biological aging in multiple organs
Life spanning murine gene expression profiles in relation to chronological and pathological aging in multiple organs.
Age, Specimen part
View SamplesBy gating cell cycle progression to specific times of the day, the intracellular circadian clock is thought to reduce the exposure of replicating cells to potentially hazardous environmental and endogenous genotoxic compounds. Although core clock gene defects that eradicate circadian rhythmicity can cause an altered in vivo genotoxic stress response and aberrant proliferation rate, it remains to be determined to what extent these cell-cycle-related phenotypes are due to a cell-autonomous lack of circadian oscillations. We investigated the DNA damage sensitivity and proliferative capacity of cultured primary Cry1-/-|Cry2-/- fibroblasts. Contrasting previous in vivo studies, we show that the absence of CRY proteins does not affect the cell-autonomous DNA damage response upon exposure of primary cells in vitro to genotoxic agents, but causes cells to proliferate faster. By comparing primary wild type, Cry1-/-|Cry2-/-, Cry1+/-|Cry2-/- and Cry1-/-|Cry2+/- fibroblasts, we provide evidence that CRY proteins influence cell cycle progression in a cell-autonomous, but circadian clock-independent manner and that the accelerated cell cycle progression of Cry-deficient cells is caused by global dysregulation of Bmal1-dependent gene expression. These results suggest that the inconsistency between in vivo and in vitro observations might be attributed to systemic circadian control rather than a direct cell-autonomous control.
Mammalian cryptochromes impinge on cell cycle progression in a circadian clock-independent manner.
Specimen part
View SamplesWe analysed the translatome and transcriptome of Arabidopsis thaliana Col-0 WT at five distinct physiological states during seed germination.
Extensive translational regulation during seed germination revealed by polysomal profiling.
Specimen part, Time
View SamplesT-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.
The recurrent SET-NUP214 fusion as a new HOXA activation mechanism in pediatric T-cell acute lymphoblastic leukemia.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Histone methyltransferase MLL3 contributes to genome-scale circadian transcription.
Specimen part, Time
View SamplesTotal RNA was isolated from liver samples of C57/BL6 mice over a circadian time course, 3 biological replicate samples per time point were collected and processed individually. RNA from each individual biological replicate sample was extracted using RNeasy mini kit (Qiagen Cat# 74106) and hybridized on an Affymetrix mouse Gene ST1.0 microarray.
Histone methyltransferase MLL3 contributes to genome-scale circadian transcription.
Specimen part, Time
View SamplesAberrant splice variants are involved in the initiation and/or progression of glial brain tumors. We therefore set out to identify splice variants that are differentially expressed between histological subgroups of gliomas. Splice variants were identified using a novel platform that profiles the expression of virtually all known and predicted exons present in the human genome. Exon-level expression profiling was performed on 26 glioblastomas, 22 oligodendrogliomas and 6 control brain samples. Our results demonstrate that Human Exon arrays can identify subgroups of gliomas based on their histological appearance and genetic aberrations. We next used our expression data to identify differentially expressed splice variants. In two independent approaches, we identified 49 and up to 459 exons that are differentially spliced between glioblastomas and oligodendrogliomas a subset of which (47% and 33%) were confirmed by RT-PCR. In addition, exon-level expression profiling also identified >700 novel exons. Expression of ~67% of these candidate novel exons was confirmed by RT-PCR. Our results indicate that exon-level expression profiling can be used to molecularly classify brain tumor subgroups, can identify differentially regulated splice variants and can identify novel exons. The splice variants identified by exon-level expression profiling may help to detect the genetic changes that cause or maintain gliomas and may serve as novel treatment targets.
Identification of differentially regulated splice variants and novel exons in glial brain tumors using exon expression arrays.
No sample metadata fields
View SamplesChildhood acute lymphoblastic leukemia (ALL) comprises a large group of genetic subtypes with a favorable prognosis characterized by a TEL-AML1-fusion, hyperdiploidy (>50 chromosomes) or E2A-PBX1 fusion and a smaller group with unfavorable outcome characterized by either a BCR-ABL-fusion, MLL-rearrangement or T-ALL.
A subtype of childhood acute lymphoblastic leukaemia with poor treatment outcome: a genome-wide classification study.
No sample metadata fields
View SamplesChildhood acute lymphoblastic leukemia (ALL) comprises a large group of genetic subtypes with a favorable prognosis characterized by a TEL-AML1-fusion, hyperdiploidy (>50 chromosomes) or E2A-PBX1 fusion and a smaller group with unfavorable outcome characterized by either a BCR-ABL-fusion, MLL-rearrangement or T-ALL.
A subtype of childhood acute lymphoblastic leukaemia with poor treatment outcome: a genome-wide classification study.
No sample metadata fields
View SamplesDrosophila neuroblasts have emerged as a model for stem cell biology that is ideal for genetic analysis but is limited by the lack of cell-type specific gene expression data. Here, we describe a methodology to isolate large numbers of pure neuroblasts and differentiating neurons that retain both cell cycle and lineage characteristics. We determine transcriptional profiles by mRNA sequencing and identify 28 predicted neuroblast specific transcription factors, which can be arranged in a network containing hubs for Notch signaling, growth control and chromatin regulation. Overexpression and RNAi for these factors identify Klumpfuss as a regulator of self-renewal. We show that loss of Klu function causes premature differentiation while overexpression results in the formation of transplantable brain tumors. Our data represent a valuable resource for Drosophila developmental neurobiology and we describes methodology that can be applied to other invertebrate stem cell lineages as well. Overall design: comparison of transcriptomes of Drosophila melanogaster larval neuroblasts and their differentiated daughter cells (neurons)
FACS purification and transcriptome analysis of drosophila neural stem cells reveals a role for Klumpfuss in self-renewal.
Specimen part, Subject
View Samples