Project description:<p>We used massively parallel, paired-end sequencing of expressed transcripts (RNA-seq) to detect novel gene fusions in short-term cultures of glioma stem-like cells freshly isolated from nine patients carrying primary glioblastoma multiforme (GBM). The culture of primary GBM tumors under serum-free conditions selects cells that retain phenotypes and genotypes closely mirroring primary tumor profiles as compared to serum-cultured glioma cell lines that have largely lost their developmental identities.</p>
Project description:The purpose of this study is to determine whether the combination of two agents, INC280 and bevacizumab, is safe and effective when administered to patients with Glioblastoma Multiforme (GBM) who have progressed after receiving prior therapy or who have unresectable GBM.
Project description:Overexpression of the Polycomb group protein Enhancer of Zeste Homolog 2 (EZH2) occurs in diverse malignancies, including prostate cancer, breast cancer, and glioblastoma multiforme (GBM) (1). Based on its ability to modulate transcription of key genes implicated in cell cycle control, DNA repair and cell differentiation, EZH2 is believed to play a crucial role in tissue-specific stem cell maintenance and tumor development. Here we show that targeted pharmacologic disruption of EZH2 by the S-adenosylhomocysteine hydrolase inhibitor 3-Deazaneplanocin A (DZNep), or its specific down-regulation by shRNA, strongly impairs GBM cancer stem cell self-renewal in vitro and tumor-initiating capacity in vivo. Using genome-wide expression analysis of DZNep-treated GBM cancer stem cells, we found the expression of c-myc, recently reported to be essential for GBM cancer stem cells, to be strongly repressed upon EZH2 depletion. Specific shRNA-mediated down-regulation of EZH2 in combination with chromatin immunoprecipitation (ChIP) experiments revealed that c-myc is a direct target of EZH2 in GBM cancer stem cells. Taken together, our observations provide evidence that direct transcriptional regulation of c-myc by EZH2 may constitute a novel mechanism underlying GBM cancer stem cell maintenance and suggest that EZH2 may be a valuable new therapeutic target for GBM management. Experiment Overall Design: Three samples of cancer stem-cell enriched gliospheres from primary glioblastoma multiforme cell cultures were treated with DZNep. Untreated gliospheres from the same cultures were used as controls.
Project description:Glioblastoma multiforme (GBM) is a lethal malignancy whose clinical intransigence has been linked to extensive intra-clonal genetic and phenotypic diversity and therapeutic resistance of cancer stem cells (CSCs). This interpretation embodies an implicit assumption that CSCs are themselves genetically diverse. To test this, we screened neurosphere cultures by SNP arrays to identify copy number alterations (CNA) (minimum of three) that could be visualised in single cells by multi-colour FISH. Interrogation of neurosphere-derived cells (from four patients) and cells derived from secondary transplants of these same cells in Nod/Scid mice allowed us to infer clonal phylogenic architecture and the likely derivation of functional CSCs. This proof-of-principle experiment revealed that more than one sub-clone (but not all) in each GBM had functionally defined, genetically distinct stem cells.
Project description:glioblastoma multiforme genomic profiling by single nucleotide polymorphism microarray<br><br>Human GBM (glioblastoma multiforme)cell lines (U87, U118, U138, U343, U373, T98G) were maintained in Dulbecco's modified Eagle's medium with 10 % fetal calf serum, 10 U/ml penicillin-G, and 10 mg/ml streptomycin. All cells were incubated at 37 oC in 5% CO2.<br><br>Four primary GBM explants were established from patients with glioblastoma multiforme undergoing surgery as following described: Tumor specimens were immediately transported to the laboratory, finely minced to single cell suspension and cultured in complete medium [Ham's F-12/DME High Glucose medium containing 10% fetal calf serum, 10 U/ml penicillin-G, and 10 mg/ml streptomycin and 2 mM glutamax-1 into 100 cm2 tissue culture plastic dishes the second passage. All cells were incubated at 37 oC in 5% CO2.<br><br>GBM (glioblastoma multiforme) tissue samples were quick frozen. <br><br>Standard proteinase K-phenol-chloroform extraction method was used to extract DNA from GBM samples, cell lines and explants.<br><br>The matched peripheral blood data can be used as normalized data for their matched tumor tissue data. <br><br>The cell lines samples and two explants without normalized data, but they can be normalized by one of the peripheral blood DNA data.
Project description:Developmental fate decisions are dictated by master transcription factors (TFs) that interact with cis-regulatory elements to direct transcriptional programs. Certain malignant tumors may also depend on a cellular hierarchy reminiscent of normal development but superimposed on underlying genetic aberrations. In glioblastoma (GBM), a subset of stem-like tumor- propagating cells (TPCs) appears to drive tumor progression and underlie therapeutic resistance, yet remain poorly understood. Here, we identify a core set of neurodevelopmental TFs (POU3F2, SOX2, SALL2, OLIG2) essential for GBM propagation. These TFs coordinately bind and activate TPC-specific regulatory elements, and are sufficient to fully reprogram differentiated GBM cells to ‘induced’ TPCs that recapitulate the epigenetic landscape and phenotype of native TPCs. We reconstruct a TF network model that highlights critical interactions and identifies novel therapeutic targets for eliminating TPCs. Our study establishes the epigenetic basis of a developmental hierarchy in a devastating malignancy, provides detailed insight into the underlying gene regulatory programs, and suggests attendant therapeutic strategies. Histone modification profiling for H3K27ac and transcription factors in glioblastoma cell line reprogramming
Project description:Glioblastoma multiforme (GBM) is a highly heterogeneous disease that shows an wide range of genetic abnormalities in comparison to other astrocytic tumors. We have extracted between 4 and 8 tumor subsamples from different areas of the malignant tissue that were at least 1cm apart. Our aim to asses the intra-tumoral heterogeneity by comparing copy number aberrations in different tumor areas to uncover important dynamics underlying GBM progression.