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.
Project description:Lysophosphatidic acid receptor 1 (LPA1) is a phospholipid which has been linked to adult hippocampal neurogenesis and learning deficits. Here we investigated whether LPA acts directly on the hippocampal stem cells and whether LPA1 could be a functional marker for their prospective isolation. Our results reveal that exogenous LPA increases precursor potential in vitro and net neurogenesis in vivo, an effect that is mediated by Akt activation. Using a mouse reporter line, immunohistochemistry and flow cytometry followed by in vitro cell culture, we show that, in contrast to the subventricular zone, neural precursor cells in the adult mouse dentate gyrus express LPA1-GFP. Fluorescence-activated cell sorting for LPA1-GFP in combination with Prominin-1 and epidermal growth factor receptor expression allowed the efficient isolation of a very pure population of hippocampal stem cells. Transcriptional analysis revealed a profile suggesting immune response and cytokine signaling as molecular regulators of adult hippocampal neural stem cells. RNA from cells sorted (FACS) from the dentate gyrus of adult LPA1-GFP (lysophosphatidic acid receptor) reporter mice. Sorting was based on the markers EGFR (Egfr), LPA1 (Lpar1) and Prominin1 (Prom1). From each of 4 replicates, 3 populations (stem cells, progenitor cells, niche cells) were sequenced.
Project description:The intrinsic drivers of migration in glioblastoma (GBM) are poorly understood. To better capture the native molecular imprint of GBM and its developmental context, we isolate human stem cell populations from GBM (GSC) and germinal matrix tissues and map their chromatin accessibility via ATAC-seq. We uncover two distinct regulatory GSC signatures, a developmentally-shared/proliferative and a tumor-specific/migratory one in which TEAD1/4 motifs are uniquely overrepresented. Using ChIP-PCR we validate TEAD1 trans occupancy at accessibility sites within EGFR, AQP4, and CDH4. To further characterize TEAD’s functional role in GBM, we knockout TEAD1 or TEAD4 in patient-derived GBM lines using CRISPR-Cas9. TEAD1 ablation robustly diminishes migration, both in vitro and in vivo, and alters migratory and EMT transcriptome signatures with consistent downregulation of its target AQP4. TEAD1 overexpression restores AQP4 expression, and both TEAD1 and AQP4 overexpression rescue migratory deficits in TEAD1-knockout cells, implicating a direct regulatory role for TEAD1-AQP4 in GBM migration.
Project description:Recent studies demonstrated that tumor cells with stem cell-like properties can be cultured from human glioblastomas by using conditions that select for the expansion of neural stem cells. We established glioblastoma stem-like (GS-) cell cultures from 9 different glioblastomas, 8 of which generated stably expandable cell lines. Analyzing GS-cell cultures, we discovered two clearly discernable phenotypes. Microarray analysis showed that the 4 GSf cell lines shared expression profiles dominated by genes involved in nervous system development and neuropeptide signaling, while the 5 GSr lines shared expression signatures enriched for extracellular matrix-proteins. Keywords: Cell line comparison
Project description:Glioblastoma ranks among the most aggressive and lethal of all human cancers. Functionally defined glioma stem cells (GSCs) contribute to this poor prognosis by driving therapeutic resistance and maintenance of cellular heterogeneity. To understand the molecular processes essential for GSC maintenance and tumorigenicity, we interrogated the super-enhancer landscapes of primary glioblastoma specimens and in vitro GSCs. GSCs epigenetically upregulated ELOVL2, a key polyunsaturated fatty acid synthesis enzyme. Targeting ELOVL2 inhibited glioblastoma cell growth and tumor initiation. ELOVL2 depletion altered cellular membrane phospholipid composition, disrupted membrane structural properties, and diminished EGFR signaling through control of fatty acid elongation. In support of the translational potential of these findings, dual targeting of polyunsaturated fatty acid synthesis and EGFR signaling had a combinatorial cytotoxic effect on GSCs.
Project description:Cancer stem cells are believed to be responsible for tumor initiation and development. Much current research on human brain tumors is focused on the stem-like properties of glioblastoma stem cells. Anaplastic lymphoma kinase (ALK) and its ligand pleiotrophin are required for maintaining the stem-like properties and tumorigenicity of glioblastoma stem cells. Human glioblastoma stem cells (GB2) were infected with a lentivirus expressing an shRNA targeting ALK or pleiotrophin.
Project description:Identification of genes enriched in putative stem/progenitor cells (CD133highPDGFRb- cell population) from the mouse embryonic pancreas that are purified by fluorescence activated cell sorting (FACS). Success in islet transplantation-based therapies for type 1 diabetes mellitus and an extreme shortage of pancreatic islets has motivated efforts to develop renewable sources of islet-replacement tissue. Only a few attempts have been made at prospective isolation of pancreatic stem/progenitor cells, due to the lack of specific markers and the development of cell culture method. This study demonstrates the isolation of pancreatic stem/progenitor cells from the embryonic pancreas by cell sorting. RT-PCR and microarray analysis demonstrated that pancreatic stem/progenitor cells are enriched in CD133highPDGFRb- cell population. During in vivo differentiation, these cell populations have the ability for self-renewal and multipotency, including the formation of insulin-producing cells. Since the strategy is based on the cell sorting using cell surface markers common to human and rodents, it may promote strategies to derive transplantable islet-replacement tissues from human pancreatic stem/progenitor cells. Keywords: Cell type comparison
Project description:Prospective isolation is critical to understand the cellular and molecular aspects of stem cell heterogeneity. Here we identify the cell surface antigen CD9 as a novel positive marker that provides a simple alternative for hematopoietic stem cell-isolation at high purity