No description.
MicroRNA sequence and expression analysis in breast tumors by deep sequencing.
No sample metadata fields
View SamplesTo more concretely elucidate the long-term effects of chronic SSRI exposure during adulthood, the long-term consequences of chronic fluoxetine (12 mg/kg) versus vehicle treatment during adulthood (postnatal day (PND) 67-88) on gene expression in the hippocampus were investigated. The study showed that adult chronic fluoxetine exposure causes on the long-term changes in the expression of genes related to, amongst others, myelination Overall design: Comparison of gene expression in hippocampus tissue of fluoxetine and methylcellulose-exposed rats (postnatal day 128). 2 rats pooled per sample, 2 samples per treatment group
Long-term consequences of chronic fluoxetine exposure on the expression of myelination-related genes in the rat hippocampus.
No sample metadata fields
View SamplesFetal asphyctic (FA) preconditioning is effective in attenuating brain damage incurred by a subsequent perinatal asphyctic insult. Unraveling mechanisms of this endogenous neuroprotection, activated by FA preconditioning, is an important step towards new clinical strategies for asphyctic neonates. Genomic reprogramming is thought to be, at least in part, responsible for the protective effect of preconditioning. Therefore, we investigated whole genome differential expression in the preconditioned rat brain.
Fetal asphyctic preconditioning alters the transcriptional response to perinatal asphyxia.
Sex, Specimen part
View SamplesWhile the roles of parenchymal microglia in brain homeostasis and disease are fairly clear, other brain-resident myeloid cells remain less understood. By dissecting border regions and combining single-cell RNA sequencing with high-dimensional cytometry, bulk RNA-sequencing, fate-mapping and microscopy, we reveal the diversity of non-parenchymal brain macrophages. Border-associated macrophages (BAMs) residing in the dura mater, subdural meninges and choroid plexus consisted of distinct subsets with tissue-specific transcriptional signatures, and their cellular composition changed during postnatal development. BAMs exhibited a mixed ontogeny and subsets displayed distinct self-renewal capacities upon depletion and repopulation. Single-cell and fate-mapping analysis both suggested there is a unique microglial subset residing on the apical surface of the choroid plexus epithelium. Finally, gene network analysis and conditional deletion revealed IRF8 as a master regulator that drives the maturation and diversity of brain macrophages. Our results provide a framework for understanding host-macrophage interactions in the healthy and diseased brain. Overall design: sample of WT choroid plexus, sample of WT dura mater, sample of WT enriched SDM, sample of WT whole brain, sample of 9 months old APP/PS1 mice, sample of 16 months old APP/PS1 mice, sample of 16 months old WT mice, sample of Irf8 KO whole brain, sample of Irf8 KO choroid plexus, sample of Irf8 WT whole brain, sample of Irf8 WT choroid plexus, sample of dura mater with standard protocol and with ActD protocol, sample of choroid plexus with standard protocol and ActD protocol.
A single-cell atlas of mouse brain macrophages reveals unique transcriptional identities shaped by ontogeny and tissue environment.
Specimen part, Cell line, 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 SamplesTumor-associated macrophages (TAMs) have immunosuppressive capacity in mouse models of cancer. Here we show that the genetic deletion of the microRNA (miRNA)-processing enzyme DICER in TAMs broadly programs them to a CD11c+MRC1-/low M1-like immunostimulatory phenotype characterized by activated interferon-? (IFN-?)/STAT1/IRF signaling. M1-like TAM programming fostered the recruitment of cytotoxic T-cells (CTLs), including tumor-antigen-specific CTLs, inhibited tumor growth, and enhanced the efficacy of PD1 checkpoint blockade. Bioinformatics analysis of TAM transcriptomes identified a limited set of miRNAs putatively involved in TAM programming. Re-expression of Let-7 in Dicer-deficient TAMs was sufficient to partly rescue the M2-like (protumoral) TAM phenotype and abate tumor CTL infiltration. Targeted suppression of DICER activity in TAMs may, therefore, stimulate antitumor immunity and enhance the efficacy of cancer immunotherapy. Overall design: To explore the role of DICER in the development, activation and immunological functions of TAMs, we crossed homozygous LysM-Cre (Clausen et al., 1999) with Dicerlox/lox (Harfe et al., 2005) mice to obtain mice with myeloid-cell-specific Dicer1 gene deletion (LysM-Cre;Dicer–/–, referred to as D–/–). These mice were then backcrossed to LysM-Cre to obtain the control LysM-Cre; Dicer+/+ mice (referred to as D+/+). Both LysM-Cre and Dicerlox/lox mutations were always homozygous in our experiment. We then inoculated Lewis lung carcinoma (LLC) cells subcutaneously (s.c.) in D–/– and control D+/+ mice. Once the tumors were established, we isolated by fluorescence-activated cell sorting (FACS) tumor-associated macrophages (F4/80+ cells).
Suppression of microRNA activity amplifies IFN-γ-induced macrophage activation and promotes anti-tumour immunity.
Specimen part, Subject
View SamplesAtypical teratoid/rhabdoid tumor (ATRT) is one of the most common brain tumors in infants. Although the prognosis of ATRT patients is poor, some patients respond favorably to current treatments, suggesting molecular inter-tumor heterogeneity. To investigate this further, we genetically and epigenetically analyzed a large series of human ATRTs. Three distinct molecular subgroups of ATRTs, associated with differences in demographics, tumor location, and type of SMARCB1 alterations, were identified. Whole-genome DNA and RNA sequencing found no recurrent mutations in addition to SMARCB1 that would explain the differences between subgroups. Whole-genome bisulfite sequencing and H3K27Ac chromatin-immunoprecipitation sequencing of primary tumors, however, revealed clear differences, leading to the identification of subgroup-specific regulatory networks and potential therapeutic targets.
Atypical Teratoid/Rhabdoid Tumors Are Comprised of Three Epigenetic Subgroups with Distinct Enhancer Landscapes.
Sex, Age
View SamplesGlioblastoma (GBM) is an incurable brain tumor carrying a dismal prognosis, which displays considerable heterogeneity. We have recently identified recurrent H3F3A mutations affecting two critical positions of histone H3.3 (K27, G34) in one-third of pediatric GBM. Here we show that each of these H3F3A mutations defines an epigenetic subgroup of GBM with a distinct global methylation pattern, and are mutually exclusive with IDH1 mutation (characterizing a CpG-Island Methylator Phenotype (CIMP) subgroup). Three further epigenetic subgroups were enriched for hallmark genetic events of adult GBM (EGFR amplification, CDKN2A/B deletion) and/or known transcriptomic signatures. We also demonstrate that the two H3F3A mutations give rise to GBMs in separate anatomic compartments, with differential regulation of OLIG1/2 and FOXG1, possibly reflecting different cellular origins.
Hotspot mutations in H3F3A and IDH1 define distinct epigenetic and biological subgroups of glioblastoma.
Sex
View SamplesPilocytic astrocytomas (PA) are the most common brain tumor in pediatric patients and can cause significant morbidity, including chronic neurological deficiencies. They are characterized by activating alterations in the mitogen-activated protein kinase (MAPK) pathway, but little else is known about their development. To further define their molecular development, we analysed the global DNA methylation profiles of 61 PAs and 6 normal cerebellum samples and integrated this data with transcriptome profiling. These data revealed two subgroups of PA that separate according to tumor location (infratentorial versus supratentorial), and identified key neural developmental genes that are differentially methylated between the two groups. Significant expression differences were identified for the majority of differentially methylated genes, and these were unexpectedly associated with a strong positive correlation between methylation and expression. We also identified a large number of differentially methylated/expressed genes between cerebellar PAs and normal cerebellum, which included additional developmental genes.
Differential expression and methylation of brain developmental genes define location-specific subsets of pilocytic astrocytoma.
Sex, Specimen part
View SamplesThe LEF/TCF family of transcription factors are downstream effectors of the WNT signaling pathway, which drives colon tumorigenesis. LEF/TCFs have a DNA sequence-specific HMG box that binds Wnt Response Elements (WREs). The E tail isoforms of TCFs are alternatively spliced to include a second DNA binding domain called the C-clamp. We show that induction of a dominant negative C-clamp version of TCF1 (dnTCF1E) induces a p21-dependent stall in the growth of DLD1 colon cancer cells. Induction of a C-clamp mutant did not induce p21 or stall cell growth. Microarray analysis revealed that induction of p21 by dnTCF1EWT correlated with a decrease in expression of p21 suppressors that act at multiple levels from transcription (SP5, YAP1, RUNX1), to RNA stability (MSI2), and protein stability (CUL4A). We show that the C-clamp is a sequence specific DNA binding domain that can make contacts with 5-RCCG-3 elements upstream or downstream of WREs. The C-clamp-RCCG interaction was critical for TCF1E mediated transcriptional control of p21-connected target gene promoters. Our results indicate that a WNT/p21 circuit is driven by C-clamp target gene selection.
A WNT/p21 circuit directed by the C-clamp, a sequence-specific DNA binding domain in TCFs.
Specimen part
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