Project description:Next generation sequencing platforms were used to identify STAT3 targets in the background of EGFRvIII expresssion mRNA of 3 EGFRvIII positive brain tumor stem cell lines (BTSC #68, 73, and 90) were compared to an EGFRvIII negative line (#41) to identify EGFRvIII-regulated targets in human BTSC. EGFRvIII-dependent targets in mouse astrocytes were identified by mRNA-seq analyses of EGFRvIII- or MSCV-expressing astrocytes. STAT3-differentially regulated genes in EGFRvIII expressing mouse astrocytes were obtained by subjecting EGFRvIII,STAT3f/f and EGFRvIII, STAT3-/- astrocytes to mRNA-Seq analyses. Sites of STAT3 occupancy in EGFRvIII expressing astrocytes were identified by ChIP-Seq using a STAT3 antibody or IgG control. We identified OSMR as a direct target of STAT3 in both EGFRvIII-expressing human BTSC and mouse astrocytes. Therefore to identify OSMR-regulated genes, we used a lentiviral mediated RNAi system to knockdown OSMR in EGFRvIII-expressing astrocytes. OSMR-dependent differentially expressed genes were obtained by comparison of OSMR knockdown (KD1 and KD2) astrocytes to control groups (ShRNA control and Vector control)
Project description:Co-amplification of EGFR and EGFRvIII, a tumor-specific truncation mutant of EGFR, represent hallmark genetic lesions in glioblastoma. We report that EGFR and EGFRvIII stimulate the innate immune defense receptor Toll-like Receptor 2 (TLR2); and that knockdown of TLR2 led to a dramatic survival advantage in glioblastoma xenografts. EGFR and EGFRvIII activated TLR2 in a ligand-independent manner, promoting tumor growth and immune evasion. We show that EGFR and EGFRvIII cooperate to activate the Rho-associated protein kinase ROCK2, modulating malignant progression both by activating TLR2 and WNT signaling, and through remodeling the tumor microenvironment.
Project description:EGFRvIII is the most common deletion mutant of EGFR in human cancer and its levels are highly correlated with poor prognosis in GBM. The deletion of exons 2-7 removes most of the extracellular ligand binding domain, so it is unable to bind EGF or other EGFR-binding ligands. Nevertheless, the mutant receptor is constitutively phosphorylated, and is capable of activating downstream signaling pathways at a low level. To comprehensively identify the downstream signaling consequences of the EGFRvIII, we incorporated phosphoproteomic, transcription profiling and DNase-Seq data from U87MG glioblastoma cells expressing titrated levels of this mutant receptor. Total RNA were extracted from U87MG cells engineered to expressed different levels of EGFRvIII: medium (U87M; 1.5 million copies of EGFRvIII receptor per cell), high (U87H; 2 million copies per cell), super-high (U87SH; 2.5 million copies per cell), and kinase-dead EGFRvIII (U87DK; 2 million copies of kinase dead EGFRvIII per cell). RNA was hybridized to Affymetrix microarrays.
Project description:Glioblastoma multiforme (GBM) is a highly aggressive and heterogeneous form of primary brain tumors, driven by a complex repertoire of oncogenic alterations, including the constitutively active epidermal growth factor receptor (EGFRvIII). EGFRvIII impacts both cell-intrinsic and non-cell autonomous aspects of GBM progression, including cell invasion, angiogenesis and modulation of the tumor microenvoiront, this is, at least in part, attributable to the release and intercellular trafficking of extracellular vesicles (EVs), heterogeneous membrane structures containing multiple bioactive macromolecules. Here we analyzed the impact of EGFRvIII on the profile of glioma EVs using a series of isogenic tumor cell lines, in which this oncogene exhibits a strong transforming activity. Thus, we observed that EGFRvIII expression alters several properties of glioma EVs, including their output and global protein composition. Using mass spectrometry, quantitative proteomic analysis and Gene Ontology terms filters, we observed that EVs released by EGFRVIII-transformed cells were enriched for extracellular exosome and focal adhesion related proteins. Among them, we validated the association of pro-invasive proteins (CD44, BSG, CD151) with EVs of EGFRvIII expressing cells, and down-regulation of exosomal markers (CD81 and CD82) in EVs of their indolent counterparts. Nano-flow cytometry revealed that the EV output from individual glioma cell lines was highly heterogeneous, such that only a fraction of EVs contained specific proteins such as EGFR, CD9, or others. Notably, cells expressing EGFRvIII released ample EVs double positive for CD44/BSG, and these proteins also co-localized in cellular filopodia. We also detected the expression of homophilic adhesion molecules and increased homologous EV uptake by EGFRvIII-positive glioma cells. These results suggest that oncogenic EGFRvIII reprograms the proteome of GBM-related EVs, a notion with considerable implications for their biological activity and properties relevant for development of EV-based cancer biomarkers.
Project description:The trascription profiles of PDGF-B and EGFRvIII induced glioma models were compared. We show that both models converge towards a phenotype that resembles proneural glioblastoma subset.
Project description:Glioblastoma cell lines were xenografted onto mice and resulting tumors were profiled by microarray. Xenograft recipient mice were NOD/SCID/gamma (NSG) male mice 3 months old. In this set, 6 total samples were analyzed. There were three biological replicates for each of two conditions: EGFRvIII containing tumors and control. Arrays were analyzed for gene expression using GeneBase and for alternative splicing using MADS+ software.
Project description:STAT3, an essential transcription factor with pleiotropic functions, plays critical roles in the pathogenesis of autoimmunity. Despite recent data linking STAT3 with inflammatory bowel disease, exactly how it contributes to chronic intestinal inflammation is not known. Using a T cell transfer model of colitis we found that STAT3 expression in T cells was essential for the induction of both colitis and systemic inflammation. STAT3 was critical in modulating the balance of T helper 17 (Th17) and regulatory T (Treg) cells, as well as in promoting CD4+ T cell proliferation. We used chromatin immunoprecipitation and massive parallel sequencing (ChIP-Seq) to define the genome-wide targets of STAT3 in CD4+ T cells. We found that STAT3 bound to multiple genes involved in Th17 cell differentiation, cell activation, proliferation and survival, regulating both expression and epigenetic modifications. Thus, STAT3 orchestrates multiple critical aspects of T cell function in inflammation and homeostasis. This SuperSeries is composed of the following subset Series: GSE21669: Diverse Targets of the Transcription Factor STAT3 Contribute to T Cell Pathogenicity and Homeostasis [ChIP-seq] GSE21670: Diverse Targets of the Transcription Factor STAT3 Contribute to T Cell Pathogenicity and Homeostasis [Affymetrix Expression] Refer to individual Series
Project description:EGFRvIII is the most common deletion mutant of EGFR in human cancer and its levels are highly correlated with poor prognosis in GBM. The deletion of exons 2-7 removes most of the extracellular ligand binding domain, so it is unable to bind EGF or other EGFR-binding ligands. Nevertheless, the mutant receptor is constitutively phosphorylated, and is capable of activating downstream signaling pathways at a low level. To comprehensively identify the downstream signaling consequences of the EGFRvIII, we incorporated phosphoproteomic, transcription profiling and DNase-Seq data from U87MG glioblastoma cells expressing titrated levels of this mutant receptor.