Background: Central nervous system (CNS) metastases represent a major problem in the treatment of HER2-positive breast cancer due to the disappointing efficacy of HER2-targeted therapies in the brain microenvironment. The antibody-drug conjugate ado-trastuzumab emtansine (T-DM1) has shown efficacy in trastuzumab-resistant systemic breast cancer. Here, we tested the hypothesis that T-DM1 could overcome trastuzumab resistance in preclinical models of brain metastases.
Preclinical Efficacy of Ado-trastuzumab Emtansine in the Brain Microenvironment.
Specimen part, Disease, Time
View SamplesThe ubiquitin proteasome system (UPS) is known to possess important regulatory functions in the immune response. To gain a better and first comprehensive insight into the mechanisms underlying the conversion of immature to mature DC in terms of the expression of UPS related genes, we undertook a comparative gene expression profiling during DC maturation in response to four different prototypic maturation stimuli.
Maturation of human dendritic cells is accompanied by functional remodelling of the ubiquitin-proteasome system.
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View SamplesEfficient processing of target antigens by the ubiquitin-proteasome-system (UPS) is essential for treatment of cancers by T cell therapies. However, immune escape due to impaired expression of IFN--inducible components of the antigen presentation machinery and consequent inefficient processing of HLA-dependent tumor epitopes can be one important reason for failure of such therapies. Here, we show that repeated short-term co-cultures of Melan-A/MART-1 tumor antigen-expressing melanoma cells with Melan-A/MART-1 (26-35)-specific CTL led to the generation of clones resistant to CTL-mediated cell death. To determine which of the UPS components and its associated pathways was responsible for CTL escape; three UKRV-Mel-15a clones were subjected to microarray gene expression analysis.
Exposure to Melan-A/MART-126-35 tumor epitope specific CD8(+)T cells reveals immune escape by affecting the ubiquitin-proteasome system (UPS).
Specimen part
View SamplesIncreased antigen cross-presentation but impaired cross-priming after activation of PPAR is mediated by up-regulation of B7H1
Increased antigen cross-presentation but impaired cross-priming after activation of peroxisome proliferator-activated receptor gamma is mediated by up-regulation of B7H1.
Specimen part
View SamplesThe Nucleosome Remodeling and Deacetylase (NuRD) complex plays an important role in gene expression regulation, stem cell self-renewal, and lineage commitment. Yet little is known about the dynamics of NuRD during cellular differentiation. Here, we study these dynamics using genome-wide profiling and quantitative interaction proteomics in mouse embryonic stem cells (ESCs) and neural progenitor cells (NPCs). The genomic targets of NuRD are highly dynamic during differentiation, with most binding occurring at cell-type specific promoters and enhancers. We identify ZFP296 as a novel, ESC-specific NuRD interactor that also interacts with the SIN3A complex. ChIP-sequencing in Zfp296 knockout (KO) ESCs reveals decreased NuRD binding both genome-wide and at ZFP296 binding sites, although this has little effect on the transcriptome. Nevertheless, Zfp296 KO ESCs exhibit delayed induction of lineage-specific markers upon differentiation to embryoid bodies. In summary, we identify an ESC-specific NuRD interacting protein which regulates genome-wide NuRD binding and cellular differentiation. Overall design: RNA-seq samples of wildtype R1 ESCs and Zfp296 CRISPR KO clone 2 R1 ESCs
NuRD-interacting protein ZFP296 regulates genome-wide NuRD localization and differentiation of mouse embryonic stem cells.
Specimen part, Subject
View SamplesBackground: Cerebral ischemia/reperfusion injury is a common secondary effect of cardiac arrest which is largely responsible for postresuscitative mortality. Therefore development of therapies which restore and protect the brain function after cardiac arrest is essential. Methylene blue (MB) has been experimentally proven neuroprotective in a porcine model of global ischemia-reperfusion in experimental cardiac arrest. However, no comprehensive analyses have been conducted at gene expression level.
Immunoproteasomes preserve protein homeostasis upon interferon-induced oxidative stress.
Specimen part
View SamplesThe translocation t(7;12)(q36;p13) occurs in infants and very young children with AML and usually has a fatal prognosis. Whereas the transcription factor ETV6, located at chromosome 12p13, has largely been studied in different leukemia types, the influence of the translocation partner HB9 (chr. 7q36), is still unknown. This is particularly surprising as ectopic expression of HB9 is the only recurrent molecular hallmark of translocation t(7;12) AML. We investigated the influence of HB9 as a potential oncogene on cell proliferation and cell cycle in vitro, as well as on hematopoietic stem cell differentiation in vivo using murine and human model systems. We show, that HB9 induces premature senescence in human HT1080 and murine NIH3T3 cells, providing for the first time evidence for an oncogenic potential of HB9. Furthermore, HB9-transduced primary murine hematopoietic stem and progenitor cells underwent a profound differentiation arrest and accumulated at the megakaryocyte/erythrocyte progenitor stage, resulting in a premalignant myeloid cell population in vivo. Concomitantly, HB9 expression upregulates erythropoiesis-related genes in primary human hematopoietic stem and progenitor cells, and enriches gene expression profiles for cell cycle and mitosis-related biological processes. In summary, the novel findings of HB9 dependent premature senescence and perturbed hematopoietic differentiation shed light on the oncogenic properties of HB9 in translocation t(7;12) AML and offer novel targets for therapeutic intervention. Overall design: CD34+ cells were transduced with either GFP or HB9
The homeobox transcription factor HB9 induces senescence and blocks differentiation in hematopoietic stem and progenitor cells.
Specimen part, Subject
View SamplesThe ubiquitin proteasome system (UPS) is known to possess important regulatory functions in the immune response. To gain a better and first comprehensive insight into the mechanisms of remodelling of UPS related gene expression inresponse to interferon-gamma, we undertook a comparative gene expression profiling during interferon-gamma stimulation at very early time points.
Immunoproteasomes preserve protein homeostasis upon interferon-induced oxidative stress.
Specimen part, Time
View SamplesTo study the molecular mediators of naturally rewarding effects of palatable food we used a model of palatable snacking (Ulrich-Lai et al., 2007) in which rats are given chronic, brief access to a limited amount of sucrose solution (30%). Single housed, male Long-Evans rats (250g) (n=12 per group) from Harlan Labs (Indianapolis, IN) received normal rat chow (Harlan Teklad) and water ad libitum for the duration of the experiment. After a one-week period of acclimation, rats were randomly assigned to drink treatment groups of either 30% sucrose solution or water. Rats received a 14-day regimen of twice daily (9:30 and 15:30) brief (maximum of 30 minutes) limited (up to 4 mL) access of their assigned drink solution. Drink solutions were delivered via a graduated sipper placed onto the cage top in addition to the existing water bottle and sippers were immediately removed when the animal had consumed 4mL or after the 30-minute access period, whichever occurred first. Drink intake, food intake, and body weight were monitored throughout the experiment to verify that the rats learned to drink sucrose, that they adjusted chow intake for calories consumed from sucrose (~10%), and that there was no effect on body weight gain as is normally seen with this model (Ulrich-Lai et al., 2007). Drink treatment terminated on day 14 and at 8:00 on the morning of day 15, the rats were sacrificed by rapid decapitation. BLA tissue was dissected, RNA extracted, and gene expression changes between water and sucrose groups were accessed by microarray.
Pleasurable behaviors reduce stress via brain reward pathways.
Sex, Specimen part, Treatment
View SamplesPioneer transcription factors are able to recognise and bind their motif sequences in inaccessible or closed chromatin, and their ability to achieve this is required to establish new regulatory elements and transcriptional networks during development and cellular reprogramming. An essential feature of this pioneering activity is the transition from inaccessible chromatin to a nucleosome-depleted and accessible chromatin state typical of normal regulatory elements, and this is believed to facilitate further transcription factor binding events. However, the mechanisms by which many pioneer transcription factors achieve this remarkable feat remain elusive. Here we reveal that the pluripotency-associated pioneer factor OCT4 binds inaccessible chromatin to shape the chromatin accessibility, transcription factor co-binding and regulatory potential of thousands of distal regulatory elements in mouse embryonic stem cells, demonstrating that its pioneering activity is a feature of normal pluripotency, and not just reprogramming. The accessible chromatin formed at OCT4 binding sites relies on the chromatin remodelling factor BRG1, which is recruited to these sites by OCT4. The occupancy of BRG1 is then required to support OCT4/SOX2 co-binding and normal expression of the pluripotency-associated transcriptome, and this reliance on BRG1 reflects OCT4 binding dynamics during cellular reprograming and early mouse development. Together these observations reveal a distinct requirement for the chromatin remodelling factor BRG1 in shaping the pioneering activity of OCT4 and regulating the pluripotency network in embryonic stem cells. Overall design: ZHBTC4 and Brg1fl/fl mouse embryonic stem cells were used to ablate OCT4 and BRG1 expression respectively, followed by ATAC-seq, ChIP-seq or RNA-seq to examine their contribution towards chromatin accessibility, transcription factor occupancy, and gene expression.
The pioneer factor OCT4 requires the chromatin remodeller BRG1 to support gene regulatory element function in mouse embryonic stem cells.
Cell line, Treatment, Subject
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