Project description:Glioblastoma, the most common and malignant brain tumor, harbors stem-like cells that self-renew and propagate upon serial transplantation. Although they share functional, morphological and developmental similarities to adult brain neural stem cells, stem cell characteristic pathways contributing to glioblastoma stem-like cells have not been consistently determined. Towards this goal we have provided an internally coherent molecular reference that compares adult neural and glioblastoma stem cells cultivated under identical conditions. Genes dysregulated between these populations are correlated with clinical outcome in glioblastoma, and are highly expressed in embryonic and induced pluripotent stem cells. The resource yields a key role for Wnt and a core group of dysregulated pathways. We have verified the contribution to proliferation and sphere formation of Wnt- differentially activated genes through the Wnt inhibitor SFRP1. The glioblastoma and neural stem cell gene-expression and pathway comparative resource provides a powerful new tool for the identification of potential therapeutic targets. 14 samples was analyzed; 5 individual samples of adult neural stem cells and 9 individual samples of glioma stem cells
Project description:Glioblastoma, the most common and malignant brain tumor, harbors stem-like cells that self-renew and propagate upon serial transplantation. Although they share functional, morphological and developmental similarities to adult brain neural stem cells, stem cell characteristic pathways contributing to glioblastoma stem-like cells have not been consistently determined. Towards this goal we have provided an internally coherent molecular reference that compares adult neural and glioblastoma stem cells cultivated under identical conditions. Genes dysregulated between these populations are correlated with clinical outcome in glioblastoma, and are highly expressed in embryonic and induced pluripotent stem cells. The resource yields a key role for Wnt and a core group of dysregulated pathways. We have verified the contribution to proliferation and sphere formation of Wnt- differentially activated genes through the Wnt inhibitor SFRP1. The glioblastoma and neural stem cell gene-expression and pathway comparative resource provides a powerful new tool for the identification of potential therapeutic targets.
Project description:Malignant glioblastoma (GBM) is a highly aggressive brain tumor with a dismal prognosis and limited therapeutic options. Genomic profiling of GBM samples in the TCGA database has identified four molecular subtypes (Proneural, Neural, Classical and Mesenchymal), which may arise from different glioblastoma stem-like cell (GSC) populations. In the present study, we identify two GSC populations that produce GBM tumors by subcutaneous and intracranial injection with identical histological features. Gene expression analysis revealed that xenografts of GSCs grown as spheroid cultures had a Classical molecular subtype similar to that of bulk tumor cells. In contrast xenografts of GSCs grown as adherent cultures on laminin-coated plates expressed a Mesenchymal gene signature. Adherent GSC-derived xenografts had high STAT3 and ANGPTL4 expression as well as enrichment for stem cell markers, transcriptional networks and pro-angiogenic markers characteristic of the Mesenchymal subtype. Examination of clinical samples from GBM patients showed that STAT3 expression was directly correlated with ANGPTL4 expression, and that increased expression of these genes correlated with poor patient survival and performance. A pharmacological STAT3 inhibitor abrogated STAT3 binding to the ANGPTL4 promoter and exhibited anticancer activity in vivo. Taken together, we identified two distinct GSC populations that produce histologically identical tumors but with very different gene expression patterns, and a STAT3/ ANGPTL4 pathway in glioblastoma that may serve as a target for therapeutic intervention. 2 samples of each variable were analyzed. Cells were cultured under normal adherent conditon (Bulk tumor cells), non-adherent plates with stem cell medium (Sp-GSC) or laminin-coated plates with stem cell medium (Ad-GSC). Xenografts were generated in NSG mice by subcutaneous inoculation.
Project description:Chromatin accessibility discriminates stem from mature cell populations, enabling the identification of primitive stem-like cells in primary tumors, such as Glioblastoma (GBM) where self-renewing cells driving cancer progression and recurrence are prime targets for therapeutic intervention. We show, using single-cell chromatin accessibility, that primary GBMs harbor a heterogeneous self-renewing population whose diversity is captured in patient-derived glioblastoma stem cells (GSCs). In depth characterization of chromatin accessibility in GSCs identifies three GSC states: Reactive, Constructive, and Invasive, each governed by uniquely essential transcription factors and present within GBMs in varying proportions. Orthotopic xenografts reveal that GSC states associate with survival, and identify an invasive GSC signature predictive of low patient survival. Our chromatin-driven characterization of GSC states improves prognostic precision and identifies dependencies to guide combination therapies.
Project description:Characterization of non-neoplastic and malignant human stem cell populations in their native state can provide new insights into gliomagenesis. Here we developed a purification strategy to directly isolate EGFR+/– populations from human germinal matrix (GM) and adult subventricular zone autopsy tissues, and from de-novo glioblastoma (GBM) resections, enriching for cells capable of binding EGF ligand (LBEGFR+), and uniquely compared their functional and molecular properties. LBEGFR+ populations in both GM and GBM encompassed all sphere-forming cells and displayed proliferative stem cell properties in vitro. In xenografts, LBEGFR+ GBM cells showed robust tumor initiation and progression to high-grade, infiltrative gliomas. Whole transcriptome sequencing analysis confirmed enrichment of proliferative pathways in both developing and neoplastic freshly isolated EGFR+ populations, and identified both unique and shared sets of genes. The ability to prospectively isolate stem cell populations using native ligand-binding ability opens new doors into understanding both normal human progenitors and tumor cell biology.