Project description:The gene expression profiles of two groups of triplicate human glioblastoma (GBM) xenografts grown in immunodeficient rats were compared. The first group of xenografts was derived from a patient biopsy with Epidermal Growth Factor Receptor (EGFR) amplification which grows highly invasive and is independent of angiogenesis. The second group was obtained by introducing a dominant-negative EGFR mutant into the tumor cells, leading to a progression of the tumors to an angiogenic phenotype associated with a transition from a proneural to a mesenchymal GBM molecular subtype.
Project description:The invasive nature of glioblastoma (GBM) represents a major clinical challenge contributing to poor outcomes. Invasion of GBM into healthy tissue restricts therapeutic access and surgical resection. Therefore, effective anti-invasive strategies of GBM cells can be key to increase the efficacy of chemotherapy against this devastating disease. As cancer stem or initiating cells are considered to retain the tumorigenic potential in a number of tumors including glioblastoma, we studied the invasion capabilities of glioblastoma initiating cells (GICs) that were isolated from the peritumoral (PT) tissue, which surrounds the tumor mass (TM) and remains in the brain after tumor removal. We found that PT-GICs are less proliferative but more invasive compared to TM-GICs. Gene expression arrays of cells derived from the tumor mass and the peritumoral tissue of three glioblastoma cases
Project description:The infiltrative nature of Glioblastoma (GBM), the most aggressive primary brain tumor, critically prevents complete surgical resection and masks tumor cells behind the blood brain barrier reducing the efficacy of systemic treatment. New insight in molecular pathways underlying invasion to identify novel invasion-specific molecular targets are likely to improve treatment success and patient outcome. In the present study, we used a genome-wide interference screen to determine invasion-essential genes and identified the AN1/A20 zing finger domain containing protein 3 (ZFAND3) as a crucial driver of invasion in GBM. Using patient-derived cellular GBM models, we validated that loss of ZFAND3 dampens the invasive capacity of GBM, whereas ZFAND3 overexpression increases motility in GBM cells that were initially not invasive. At the mechanistic level, we demonstrate that ZFAND3 activity requires nuclear localization and integral zinc-finger domains. Using integrated transcriptomic and proteomic approaches coupled with reporter assays, we identify ZFAND3 as a novel functional member of a protein complex encompassing PUF60 to activate transcription and GBM cell invasion. Our findings indicate that ZFAND3 regulates the promoter of invasion-related genes such as COL6, FN1 and NRCAM through direct binding to GC rich regions. To harness the therapeutic potential of this transcriptional complex, further investigation in ZFAND3 function in GBM and related invasive cancer types is warranted.
Project description:Glioblastoma multiforme (GBM) is the most prevalent and deadliest adult brain tumor. To systematically characterize the pathways governing brain invasion, we developed a three-dimensional (3D) ex vivo organotypic invasion model with clinical relevance to GBM. We used this model to enrich for highly invasive GBM cell population. Using next-generation sequencing to transcriptomically profile highly invasive and poorly invasive GBM cell populations, we have identified a network of extracellular matrix (ECM) components, including multiple collagens and collagen-interacting proteins, which are upregulated by invading GBM cells and strongly correlate in expression with clinical glioma progression outcomes. We identify the interferon regulatory factor 3 (IRF3) as a direct transcriptional repressor of ECM factors in GBM and show that IRF3 acts as an endogenous suppressor of GBM invasion. Therapeutic activation of IRF3 by inhibiting casein kinase 2 (CK2) -- a negative regulator of IRF3 phosphorylation -- downregulated the expression of ECM factors and suppressed GBM invasion in ex vivo and in vivo models across a panel of patient-derived GBM cell lines representative of the main molecular GBM subtypes in the clinic. Our findings illustrate an integrated and systematic approach for the discovery of novel pathways regulating brain tumor invasion and provide a strong mechanistic insight into the notorious, yet poorly understood, invasion capacity of GBM tumors.
Project description:One of the most detrimental hallmarks of glioblastoma multiforme (GBM) is cellular invasiveness, considered a potential cause of tumor recurrence. Infiltrated GBM cells are difficult to completely eradicate surgically and with local therapeutic modalities. Although much effort has focused on understanding the various mechanisms controlling GBM invasiveness, the nature of the invasiveness remains poorly characterized. Here, we established a highly invasive glioma cell line (U87R4 cells) and a non-invasive cell line (U87L4 cells) from U87MG glioma cells following four rounds of serial in vivo intracranial transplantation. Compared to U87L4 cells, U87R4 cells were highly invasive and had glioma stem cell-like properties. Microarray analysis showed that apoptosis-inducing genes (caspase3 and PDCD4) were downregulated, whereas several cancer stem cell-relevant genes (Wnt10A, Frizzled 4, and CD44) were upregulated in U87R4 cells compared to U87L4 cells. U87R4 cells were resistant to anticancer drug-induced cell death, which was partially due to downregulation of caspase3 and PDCD4. U87R4 cells retained activated Wnt/β-catenin signaling through Frizzled 4, which was sufficient to control neurosphere formation. In addition, Frizzled 4 promoted expression of the epithelial to mesenchymal transition regulator, SNAI1, and acquisition of a mesenchymal phenotype. Taken together, our results indicate that Frizzled 4 may be a member of the Wnt signaling family that governs both stemness and invasiveness of glioma stem cells, and may be a major cause of GBM recurrence and poor prognosis. We established a highly invasive glioma cell line (U87R4 cells) and a non-invasive cell line (U87L4 cells) from U87MG glioma cells following four rounds of serial in vivo intracranial transplantation to characterize the mRNA expression profile of highly invasive glioma cells compared to non-invasive/parental glioma cell lines.
Project description:Glioblastoma (GBM) is a highly heterogeneous malignant brain tumour. We took multi-region spatially separated samples from tumours and isolated invasive GBM cells using FACS based on 5ALA of near normal brain parenchyma. RNAseq was then performed to compare expression profiles for tumour cells from different microenvironment.
Project description:Most patients affected by Glioblastoma multiforme (GBM) experience a recurrence of the disease because of the spreading of tumor-initiating cells (TICs) beyond surgical boundary. Unveiling and targeting molecular mechanisms causing this process is a logic goal to impair GBM killing ability. In an orthotopic xenograph model, we have noticed that GBM TICs isolated from several patients may fall into two classes of invasive behavior: nodular or diffuse. In order to identify genes responsible for the diffusive type of invasion, we have compared by genome expression analysis, cultured GBM TICs belonging to the two classes. This analysis allowed us to identify a small group of regulated genes in the diffusive type of GBM TICs. The gene ontology process of cell adhesion and the localization of the gene product functions to the plasmamembrane resulted significantly associated to this gene set. Real time RT-PCR and immunofluorescence analyses performed for a selected subgroup of regulated genes/gene products confirmed the results obtained by the expression analysis. Some of the genes that we found upregulated in our screening were already proven to be involved in Glioma cell invasion supporting our study. However, we have also identified genes that were not previously implicated in this process. To assess whether these are required to sustain TICs GBM invasion, we silenced a subset of them and evaluated in Boyden chamber the invasive ability of the cells. Our study provides novel target genes to be evaluated for the inhibition of GBM diffusion within the SNC. As we observed that GBM TICs may fall into two classes of M-bM-^@M-^\in vivoM-bM-^@M-^] invasive behavior in mouse orthotopic transplantation: expansive or highly diffusive, resulting in the hostM-bM-^@M-^Ys white and gray matters substitution, we decided to identify genes associated with the latter phenotype by microarray analysis. Three replicates of each class were analyzed.
Project description:The invasive nature of glioblastoma (GBM) represents a major clinical challenge contributing to poor outcomes. Invasion of GBM into healthy tissue restricts therapeutic access and surgical resection. Therefore, effective anti-invasive strategies of GBM cells can be key to increase the efficacy of chemotherapy against this devastating disease. As cancer stem or initiating cells are considered to retain the tumorigenic potential in a number of tumors including glioblastoma, we studied the invasion capabilities of glioblastoma initiating cells (GICs) that were isolated from the peritumoral (PT) tissue, which surrounds the tumor mass (TM) and remains in the brain after tumor removal. We found that PT-GICs are less proliferative but more invasive compared to TM-GICs.
Project description:This experiment aims at assessing the molecular difference at the transcriptome level of invasive and angiogenic phenotype samples from a rat brain tumor model.
Project description:Glioblastoma multiforme (GBM) is characterized by the close relationship of glioma stem cells (GSC) with aberrant vascularization. It has been established that GSC-derived extracellular vesicles (GSC-EVs) and their cargoes are proangiogenic in vitro. To elucidate gene regulatory mechanisms of neovascularization both in vitro and in vivo, we performed RNA-seq and DNA methylation profiling of the response of human brain endothelial cells to GSC-EVs as well as histoepigenetic analysis of GBM molecular profiles in the TCGA collection. The gene regulatory responses showed a footprint of post-transcriptional gene silencing by EV-derived miRNAs. Remarkably, EVs and normal vascular growth factors stimulated highly distinct gene regulatory responses, both converging on angiogenesis, providing exciting new insight into targetable angiogenic signaling in GBM.