Perivascular adipose tissue (PVAT) is thought to play a role in vascular homeostasis and in the pathogenesis of diseases of large vessels, including abdominal aortic aneurysm (AAA). We tested the hypothesis that locally restricted transcriptional profiles characterize PVAT surrounding AAA. Using a genome-wide approach, we investigated the PVAT transcriptome of AAA in 30 patients with either large (55 mm) or small (<55 mm) aneurysm diameter. We performed a data adjustment step using the DaMiRseq R/Bioconductor package, to remove the effect of confounders as produced by high-throughput gene expression techniques. We compared PVAT of AAA with PVAT of not-dilated abdominal aorta of each patient to limit the effect of inter-individual variability, using the limma R/Bioconductor package. We found highly consistent differences in PVAT gene expression clearly distinguishing PVAT of AAA from PVAT of not-dilated aorta, which increased in number and magnitude with increasing AAA diameter. These changes did not systemically affect other abdominal adipose depots (omental or subcutaneous fat). We dissected putative mechanisms associated with PVAT involvement in AAA through a functional enrichment network analysis: both innate and adaptive immune-response genes along with genes related to cell-death pathways, metabolic processes of collagen, sphingolipids, aminoglycans and extracellular matrix degradation were strongly overrepresented in PVAT of AAA compared with PVAT of not-dilated aorta. Our results provide support to a possible role of PVAT in AAA pathogenesis and suggest that AAA is an immunologic disease with an underlying autoimmune component. These disease-specific expression signatures could help identifying pharmacological targets for preventing AAA progression.
Genome-Wide Expression Profiling Unveils Autoimmune Response Signatures in the Perivascular Adipose Tissue of Abdominal Aortic Aneurysm.
Sex, Age, Specimen part, Subject
View SamplesInterleukin-6 (IL-6) is an important growth factor for estrogen receptor-alpha (ER) positive breast cancer, and elevated serum IL-6 is associated with poor prognosis. We firstly demonstrated that pSTAT3 is the primary downstream IL-6 signaling pathway in ER-positive breast cancer, using ten different breast cancer cell lines. Three-dimensional cultures of these cell lines were also used to develop a 17-gene IL-6 specific gene signature that could be used to identify IL-6 driven disease. This signature included a variety of genes involved in immune cell function and migration, cell growth and apoptosis, and the tumor microenvironment. To further validate this IL-6 signature, we obtained 36 human ER-positive breast cancer tumor samples with matched serum for gene expression profiling and determination of an IL-6 pathway activation score (PAS). Patients with high IL-6 PAS were also enriched for elevated serum IL-6 (>=10 pg/ml). We then utilized a murine MCF-7 xenograft model to determine the role of IL-6 in ER-positive breast cancer and potential anti-IL-6 therapy in vivo. When IL-6 was administered in vivo, MCF-7 cells engrafted without the need for estrogen supplementation. Subsequently, we prophylactically treated mice at MCF-7 engraftment with an anti-IL-6 antibody (siltuximab), fulvestrant or combination therapy. Siltuximab alone was able to blunt MCF-7 engraftment. Similarly, when tumors were allowed to grow to 125 mm3 before treatment, siltuximab alone demonstrated tumor regressions in 90% (9/10) of tumors. Given the established role for IL-6 in ER+ breast cancer, this data demonstrates the potential for anti-IL-6 therapeutics.
Interleukin-6 is a potential therapeutic target in interleukin-6 dependent, estrogen receptor-α-positive breast cancer.
Specimen part
View SamplesMedulloblastoma (MB) is the most common malignant primary pediatric brain tumor and is currently divided into 4 subtypes based on different genomic alterations, gene expression profiles and response to treatment: WNT, Sonic Hedgehog (SHH), Group 3 and Group 4. The extensive heterogeneity has made it difficult to assess the relevance of genes to malignant progression. For example, expression of the transcription factor, OTX2, is frequently dysregulated in multiple MB variants; however, it's role may be subtype specific. Here, we utilized human embryonic stem cell-derived neural precursors to determine the role of OTX2 in MB tumor progression using gain and loss of function studies.
OTX2 exhibits cell-context-dependent effects on cellular and molecular properties of human embryonic neural precursors and medulloblastoma cells.
Specimen part
View SamplesNotch signaling regulates several cellular processes including cell fate decisions and proliferation in both invertebrates and mice. However, comparatively less is known about the role of Notch during early human development. Here, we examined the function of Notch signaling during hematopoietic lineage specification from human pluripotent stem cells (hPSCs) of both embryonic and adult fibroblast origin. Using immobilized Notch ligands and siRNA to Notch receptors we have demonstrated that Notch1, but not Notch2 activation, induced HES1 expression and generation of committed hematopoietic progenitors. Using gain and loss of function approaches, this was shown to be attributed to Notch signaling regulation through HES1, that dictated cell fate decisions from bipotent precursors either to the endothelial or hematopoietic lineages at the clonal level. Our study reveals a previously unappreciated role for the Notch pathway during early human hematopoiesis, whereby Notch signaling via HES1 represents a toggle switch of hematopoietic vs. endothelial fate specification.
Notch-HES1 signaling axis controls hemato-endothelial fate decisions of human embryonic and induced pluripotent stem cells.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Characterization of a novel OTX2-driven stem cell program in Group 3 and Group 4 medulloblastoma.
Cell line
View SamplesMedulloblastoma (MB) is the most common malignant primary pediatric brain cancer. Among the most aggressive subtypes, Group 3 and Group 4 originate from stem/progenitor cells, frequently metastasize, and often display the worst prognosis, yet, as the names imply, we know the least about the molecular mechanisms driving their progression. Here, we show that the transcription factor orthodenticle homeobox 2 (OTX2) promotes self-renewal while inhibiting differentiation in vitro and increases tumor-initiating capacity from MB stem cell populations in vivo. Characterization of the OTX2 regulatory network revealed a novel relationship between OTX2 and genes associated with multiple axon guidance signaling pathways in Group 3 and Group 4 MB stem/progenitor cells. In particular, OTX2 levels were negatively correlated with semaphorin (SEMA) signaling, as expression of 9 SEMA pathway genes is upregulated following OTX2 knockdown with some being potential direct OTX2 targets. Importantly, this negative correlation between OTX2 and SEMA pathway genes was also observed in patient samples, with lower expression of SEMA4D associated with poor outcome in Group 3 and 4 tumors. Functional studies using established and newly derived MB cell lines demonstrated that increased levels of SEMA pathway genes are associated with decreased self-renewal and growth, and that RHO signaling, known to mediate the effects of SEMA genes, is contributing to the OTX2 KD phenotype. Our study provides critical mechanistic insight into the networks controlled by OTX2 in self-renewing MB cells and reveals novel roles for axon guidance genes and their downstream effectors as putative tumor suppressors and therapeutic targets in Group 3 and Group 4 MB.
Characterization of a novel OTX2-driven stem cell program in Group 3 and Group 4 medulloblastoma.
Cell line
View SamplesWe used microarrays to investigate differential gene expression in different thyroid hormone receptor beta mouse models. Hypothyroid wild type, TRbeta KO and TRbeta GS mutant mice were treated with T3 or vehicle alone. Microarray analysis revealed that the gene expression pattern in TRbeta GS mutant mice was similar to that in TRbeta KO mice.
Noncanonical thyroid hormone signaling mediates cardiometabolic effects in vivo.
No sample metadata fields
View SamplesHodgkin's lymphoma (HL) is one of the most frequent hematological malignancies. Due to its extraordinary composition, few tumor cells surrounded by a reactive infiltrate, HL can be seen as an ideal model system for research focusing on tumor immunology. In fact, the tumor cells of HL, so called Hodgkin/Reed-Sternberg (HRS) cells attract CD4+ T cells, which then build rosettes with the HRS cells. HRS cells further modulate the tumor microenvironment with the help of CD4+ T cells to avoid tumor rejection. Here, we mimicked this scenario using compatible CD4+ T cells receiveing data of profound interactions for the first time, as former studies were performed with allogeneic donors. Finally, we genetically retargeted compatible CD4+ T cells to kill HRS cells.
Tumor-infiltrating HLA-matched CD4(+) T cells retargeted against Hodgkin and Reed-Sternberg cells.
Cell line
View SamplesBiochemical fractionation of HEK293 nuclei and RNA-seq of chromatin-associated and soluble-nuclear RNA. Overall design: Nuclei from three biological replicates were isolated by detergent lysis, fractionated, then three chromatin and three soluble RNA samples were converted to cDNA using Illumina TruSeq stranded protocol, and sequenced on Illumina HiSeq2000
Nuclear Fractionation Reveals Thousands of Chromatin-Tethered Noncoding RNAs Adjacent to Active Genes.
No sample metadata fields
View SamplesThe Rac nucleotide Exchange Factor (Rac-GEF) P-Rex1 is highly expressed in breast cancer, specifically in the luminal subtype, and is an essential mediator of actin cytoskeleton reorganization and cell migratory responses induced by ErbB and other tyrosine-kinase receptors. Heregulin, a growth factor highly expressed in mammary tumors, causes the activation of P-Rex1 and Rac1 in breast cancer cells via ErbB3, leading to a motile response. Since there is limited information about P-Rex1 downstream effectors, we carried out a microarray analysis to identify genes regulated by P-Rex1 in the context of HRG stimulation. In T-47D breast cancer cells, HRG treatment caused major changes in gene expression, including genes associated with motility, adhesion, invasiveness and metastasis. Silencing P-Rex1 expression from T-47D cells using RNAi altered the induction and repression of a subset of HRG-regulated genes, among them genes associated with extracellular matrix organization, migration, and chemotaxis. HRG induction of MMP10, a gene encoding for metalloproteinase-10, was found to be highly sensitive both to P-Rex1 depletion as well as inhibition of Rac1 function by the GTPase Activating Protein (GAP) 2-chimaerin, suggesting the dependence of the P-Rex1/Rac1 pathway for the induction of genes critical for breast cancer invasiveness. Notably, there is a significant association in the expression of P-Rex1 and MMP10 in human luminal breast cancer, and their co-expression is indicative of poor prognosis.
Characterization of a P-Rex1 gene signature in breast cancer cells.
No sample metadata fields
View Samples