Dose and time course response of lapatinib in breast cancer cell lines.
Delineation of molecular mechanisms of sensitivity to lapatinib in breast cancer cell lines using global gene expression profiles.
Disease, Disease stage, Cell line, Compound, Time
View SamplesCTLA-4 is thought to inhibit effector T cells both intrinsically, by competing with CD28 for B7 ligands, and extrinsically, through the action of regulatory T cells. We studied in vivo responses of normal and CTLA-4-deficient antigen-specific murine effector CD4+ T cells. In order to do these studies in a physiological model of immunity to foreign antigen, we transferred small numbers of congenically marked RAG2-deficient 5C.C7 T cells with either a normal or knockout allele of CTLA-4 into normal syngeneic B10.A recipient mice. The T cells were then activated by immunization with MCC peptide and LPS. To look for transcriptional signatures of negative regulation of T cell responses by CTLA-4, we used microarray analysis to compare transcripts in wild type and CTLA-4 KO 5C.C7 T cells four days after immunization. This is the first instance in which differences are observed in extent of accumulation of wild type and CTLA-4 KO 5C.C7 T cells.
Cutting edge: CTLA-4 on effector T cells inhibits in trans.
Specimen part
View SamplesHuman diffuse intrinsic pontine gliomas (DIPG) are an aggressive form of pediatric brain tumors that arise in the pons in young children thus resulting in significant morbidity and very poor survival. Recent data suggest that mutations in the histone H3.3 variant are often found in these tumors, though the mechanism of their contribution to oncogenesis remains to be elucidated. Here we report that the combination of constitutive PDGFRA activation and p53 suppression as well as expression of the K27M mutant form of the histone H3.3 variant leads to neoplastic transformation of hPSC-derived neural precursors. Our study demonstrates that human ES cells represent an excellent platform for the modeling of human tumors in vitro and in vivo, which could potentially lead to the elucidation of the molecular mechanisms underlying neoplastic transformation and the identification of novel therapeutic targets.
Use of human embryonic stem cells to model pediatric gliomas with H3.3K27M histone mutation.
Specimen part
View SamplesInhibition of Brd4 with Jq1 in neurons with or without BDNF stimulation Overall design: Examination of the effects of Jq1 treatment on primary mouse cortical neurons
BET protein Brd4 activates transcription in neurons and BET inhibitor Jq1 blocks memory in mice.
No sample metadata fields
View SamplesEndogenous retroviruses (ERVs) have provided an evolutionary advantage in the diversification of transcript regulation and are thought to be involved in the establishment of extraembryonic tissues during development. However, silencing of these elements remains critical for the maintenance of genome stability. Here, we define a new chromatin state that is uniquely characterized by the combination of the histone variant H3.3 and H3K9me3, two chromatin ‘marks’ that have previously been considered to belong to fundamentally opposing chromatin states. H3.3/H3K9me3 heterochromatin is fundamentally distinct from ‘canonical’ H3K9me3 heterochromatin that has been under study for decades and this unique functional interplay of a histone variant and a repressive histone mark is crucial for silencing ERVs in ESCs. Our study solidifies the emerging notion that H3.3 is not a histone variant associated exclusively with “active” chromatin and further suggests that its incorporation at unique heterochromatic regions may be central to its function during development and the maintenance of genome stability. Overall design: RNA-seq analysis of three embryonic stem cell lines WT, H3.3 KO1, and H3.3 KO2)
Histone H3.3 is required for endogenous retroviral element silencing in embryonic stem cells.
No sample metadata fields
View SamplesWidespread epigenetic disruptions in FXS mice leads to transcriptional changes that likely contribute to the neuronal phenotpyes underlying FXS. Overall design: 7DIV cultured cortical neurons from WT or Fmr1 KO mice were treated for 24 hours with vehicle, Jq1, or THZ, performed in triplicate.
Excess Translation of Epigenetic Regulators Contributes to Fragile X Syndrome and Is Alleviated by Brd4 Inhibition.
Treatment, Subject
View SamplesSnt2 is a yeast chromatin-interacting protein whose function has not been well characterized, that was recently shown to associate with Ecm5 and the Rpd3 deacetylase. Using chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq), we show that in response to H2O2, Snt2 and Ecm5 colocalize to promoters of genes involved in various aspects of the environmental stress response. By integrating these ChIP-seq results with expression analysis, we identify a key set of target genes that require Snt2 for proper expression after H2O2 stress. Finally, by mapping Snt2 and Ecm5 localization before and after rapamycin treatment, we identify a subset of H2O2-specific Snt2 and Ecm5 target promoters that are also targeted in response to rapamycin. Our results establish a function for Snt2 in regulating transcriptional changes in response to oxidative stress, and suggest Snt2 may have a role in additional stress pathways. Overall design: RNA-seq analysis to look at gene expression levels in wild-type, snt2 deletion, or ecm5 deletion strains before or 0.5 hours after treatment with H2O2 (final concentration 0.4 mM). This sequencing was done on biological triplicate samples.
The yeast Snt2 protein coordinates the transcriptional response to hydrogen peroxide-mediated oxidative stress.
Subject
View SamplesWe used microarrays to determine how the quality and quantity of peptide-MHC impact TCR-induced gene expression in vivo.
Distinct influences of peptide-MHC quality and quantity on in vivo T-cell responses.
No sample metadata fields
View SamplesVertebrate ancestors had only cone-like photoreceptors. The duplex retina evolved in jawless vertebrates with the advent of highly photosensitive rod-like photoreceptors. Despite cones being the arbiters of high-resolution color vision, rods emerged as the dominant photoreceptor in mammals during a nocturnal phase early in their evolution. We investigated the evolutionary and developmental origins of rods in two divergent vertebrate retinae. In mice, we discovered genetic and epigenetic vestiges of short wavelength cones in developing rods and cell lineage tracing validated the genesis of rods from S-cones. Curiously, rods did not derive from S-cones in zebrafish. Our study illuminates several questions regarding the evolution of duplex retina and supports the hypothesis that, in mammals, the S-cone lineage was recruited via the Maf-family transcription factor NRL to augment rod photoreceptors. We propose that this developmental mechanism allowed the adaptive exploitation of scotopic niches during the nocturnal bottleneck early in mammalian evolution. Overall design: GFP positive cells from Nrlp-GFP or Nrlp-GFP;Nrl-KO mouse retinas at post-natal ages P2, P4, P6, P10, P14, and P28 were isolated by flow sorting by FACSAria II (Becton Dickinson). Total RNA was extracted by Trizol LS (Life Technologies) and analyzed by 2100 Bioanalyzer (Agilent Technologies Genomics). High quality of total RNA (RIN: >7.0) was subjected to sequencing library construction using 20 ng of total RNA as input. Libraries were constructed using a stranded modification of the Illumina TruSeq mRNA (Brooks, et al. Meth Mol Biol 2012). Each library was single-end sequenced in an independent lane of a GAIIx at a length of 76 bases. Fastq files were generated from reads passing chastity filter.
Recruitment of Rod Photoreceptors from Short-Wavelength-Sensitive Cones during the Evolution of Nocturnal Vision in Mammals.
Specimen part, Cell line, Subject
View SamplesMammalian spermatogonial stem cells (SSCs) spontaneously convert to multipotent adult spermatogonial-derived stem cells (MASCs) during in vitro expansion. Here, we examine the epigenetic signature of SSCs and MASCs, identifying bivalent histone H3-lysine4 and -lysine27 trimethylation at somatic gene promoters in SSCs and an ESC-like promoter chromatin state in MASCs. Overall design: Examination of gene expression in different cell types.
Epigenetic profiles signify cell fate plasticity in unipotent spermatogonial stem and progenitor cells.
Specimen part, Cell line, Subject
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