Project description:Neural-tumor interactions drive glioma growth as evidenced in preclinical models, but clinical validation is limited. We present an epigenetically defined neural signature of glioblastoma that independently predicts patients’ survival. We use reference signatures of neural cells to deconvolve tumor DNA and classify samples into low- or high-neural tumors. High-neural glioblastomas exhibit hypomethylated CpG sites and upregulation of genes associated with synaptic integration. Single-cell transcriptomic analysis reveals a high abundance of stem cell-like malignant cells in high-neural glioblastoma, primarily of the neural lineage. These cells are further classified as neural precursor cell-like, astrocyte cell-like, and oligodendrocyte precursor-like, alongside oligodendrocytes and neurons. In line with these findings, high-neural glioblastoma cells engender neuron-to-glioma synapse formation in vitro and in vivo and show an unfavorable survival after xenografting. In patients, a high-neural signature associated with decreased survival. High-neural tumors also exhibit increased functional connectivity in magnetencephalography and resting-state magnet resonance imaging and can be detected via DNA analytes and brain-derived neurotrophic factor in patients’ plasma. The prognostic importance of the neural signature was further validated in patients diagnosed with diffuse midline glioma. Our study presents an epigenetically defined malignant neural signature in high-grade gliomas that is prognostically relevant. High-neural gliomas likely require a maximized surgical resection approach for improved outcomes.
Project description:Glioma represents a serious health burden in terms of morbidity and mortality. The prognostic significance of the lymphoid and myeloid infiltrates in glioma is not clearly determined. Moreover, the characterization of different leukocyte subsets in the tumor microenvironment relies mainly on immunohistochemistry observations, and data about their association with prognosis are contradictory. Here, we performed acomprehensive study of both the tumor-infiltrating and circulating immune compartments of patients with high-grade glioma. We identified prognostic tumor and peripheral immune signatures, which associate increased inflammation, immune infiltration and activation with shorter overall survival in high-grade glioma patients. Importantly, we confirmed our observations by flow cytometry analysis and validated the tumor-signature using the TCGA dataset. In addition, both tumor genotype and grade associated with the degree of glioma immune infiltration. Unlike in the majority of cancers, lymphocyte infiltration at the tumor site is anegative prognostic factor in glioma, suggesting the ambivalent pro-tumorigenic role of immune responses in glioma.
Project description:The concept that solid tumors are maintained by a productive interplay between neoplastic and non-neoplastic elements has gained traction with the demonstration that stromal fibroblasts and immune system cells dictate cancer development and progression. While less studied, brain tumor (glioma) biology is likewise influenced by non-neoplastic immune system cells (macrophages and microglia) which interact with neoplastic glioma cells to create a unique physiological state (glioma ecosystem) distinct from that found in the normal tissue. To explore this neoplastic ground state, we leveraged several preclinical mouse models of neurofibromatosis type 1 (NF1) optic glioma, a low-grade astrocytoma whose formation and maintenance requires productive interactions between non-neoplastic and neoplastic cells, and employed whole tumor RNA-sequencing and mathematical deconvolution strategies to characterize this low-grade glioma ecosystem as an aggregate of cellular and acellular elements. Using this approach, we demonstrate that optic gliomas generated by altering the germline Nf1 gene mutation, the glioma cell of origin, or the presence of co-existing genetic alterations represent molecularly-distinct tumors. However, these optic glioma tumors share a 25-gene core signature, not found in normal optic nerve, that is normalized by microglia inhibition (minocycline), but not conventional (carboplatin) or molecularly-targeted (rapamycin) chemotherapy. Lastly, we identify a genetic signature conferred by Pten reduction and corrected by PI3K inhibition. This signature predicts progression-free survival in patients with either low-grade or high-grade glioma. Collectively, these findings support the concept that gliomas are composite ecological systems whose biology and response to therapy may be best defined by examining the tumor as a whole.
Project description:Novel prognostic subclasses of high-grade astrocytoma are identified and discovered to resemble stages in neurogenesis. One tumor class displaying neuronal lineage markers shows longer survival, while two tumor classes enriched for neural stem cell markers display equally short survival. Poor prognosis subclasses exhibit either markers of proliferation or of angiogenesis and mesenchyme. Analysis of gene expression data is described in Phillips et al., Cancer Cell, 2006. Experiment Overall Design: 77 primary high-grade astrocytomas and 23 matched recurrences were profiled to identify changes in gene expression that relate to both survival and disease progression. Samples include WHO grade III and IV astrocytomas with a wide range of survival times.
Project description:High-grade glioma is highly aggressive and malignant, resistant to combined therapies and easy to relapse. A better understanding of circRNA biological function in high-grade glioma might contribute to the therapeutic efficacy. Here, a circRNA merely up-regulated in high-grade glioma, circGLIS3 (hsa_circ_0002874, originating from exon 2 of GLIS3), was validated by microarray and qRT-PCR. Functional experiments uncovered that up-regulation of circGLIS3 promoted glioma cell migration and invasion, and showed aggressive characteristics in tumor-bearing mice. Fluorescence in situ hybridization, RNA pull-down, RNA immunoprecipitation and immunohistochemical staining showed that circGLIS3 could promoted Ezrin T567 phosphorylation. Further investigation showed that circGLIS3 could be excreted by glioma through exosomes and induced endothelial cells angiogenesis. This study indicates that circGLIS3 is up-regulated in high-grade glioma and contributes to the invasion and angiogenesis of glioma via promoting Ezrin T567 phosphorylation.
Project description:High-grade glioma is highly aggressive and malignant, resistant to combined therapies and easy to relapse. A better understanding of circRNA biological function in high-grade glioma might contribute to the therapeutic efficacy. Here, a circRNA merely up-regulated in high-grade glioma, circGLIS3 (hsa_circ_0002874, originating from exon 2 of GLIS3), was validated by microarray and qRT-PCR. Functional experiments uncovered that up-regulation of circGLIS3 promoted glioma cell migration and invasion, and showed aggressive characteristics in tumor-bearing mice. Fluorescence in situ hybridization, RNA pull-down, RNA immunoprecipitation and immunohistochemical staining showed that circGLIS3 could promoted Ezrin T567 phosphorylation. Further investigation showed that circGLIS3 could be excreted by glioma through exosomes and induced endothelial cells angiogenesis. This study indicates that circGLIS3 is up-regulated in high-grade glioma and contributes to the invasion and angiogenesis of glioma via promoting Ezrin T567 phosphorylation.
Project description:Gliomas are the most frequent type of primary tumor of the central nervous system in adults with significant morbidity and mortality. Despite the development of novel, complex, multidisciplinary, and targeted therapies, glioma therapy has not progressed much over the last decades. Therefore, there is an urgent need to develop novel patient-adjusted immunotherapies that actively stimulate antitumor T cells generating long-term memory and thus resulting in significant clinical benefits. This work aimed to investigate the efficacy and molecular mechanism of dendritic cell (DC) vaccines loaded with glioma cells undergoing immunogenic cell death (ICD) induced by photosens based photodynamic therapy (PS-PDT) and to identify reliable prognostic genes’ signatures for predicting patients’ overall survival (OS). The analysis of the transcriptional program of the ICD-based DC vaccine led to the identification of robust induction of Th17 signature when used as a vaccine, these DCs demonstrate retinoic acid receptor-related orphan receptor-γt dependent efficacy in orthotopic mouse model. Moreover, by comparative analysis of transcriptome program of the ICD-based DC vaccine with transcriptome data from the TCGA-low grade glioma (LGG) dataset the four-gene signature (CFH, GALNT3, SMC4, VAV3) associated with OS of glioma patients have been identified. This model has been validated on OS of CGGA-LGG, TCGA-glioblastoma multiforme (GBM) and CGGA-GBM datasets to determine whether it has a similar prognostic value. For this the sensitivity and specificity of the prognostic model for predicting the OS were evaluated by calculating the area under curve (AUC) of the time-dependent receiver operating characteristic (ROC) curve. The values of AUC for TCGA-LGG, CGGA-LGG, TCGA-GBM and CGGA-GBM were, respectively, 0.75, 0.73, 0.9 and 0.69 for predicting 5-year survival rates. These data open attractive prospects for improving glioma therapy by employing ICD and PS-PDT-based DC vaccines to induce Th17 immunity and to use this prognostic model to predict the OS of glioma patients.
Project description:There is little overlap on publicily avaiable gene signatures and it is unclear how relevant these are to glioma biology. MYC is a very dynamically regulated gene, and it's gene signature will vary with respect to cell context. To determine what genes fall within the MYC signature of glioma, we performed ChIP-SEQ upon 4 different glioma PDX with two different MYC antibodies. The overlapping enriched genes will provide context of a MYC signature within the context of glioma.