Project description:The study investigates the role of NF1 mutation and neuronal activity on the initiation of optic pathway glioma, a type of low-grade glioma. the RNAseq dataset investigates mRNA expression profile of human pilocytic astrocytomas (WHO grade I)
Project description:We performed whole genome SNP profiling on DNA samples from 236 patients with NF1, 123 with glimoa tumors and 113 without; 117 females and 119 males, together with 29 control samples. To identify polymorphisms in human adenylate cyclase 8 (AC8) which correlate with glioma risk in NF1 in a sex-specific manner, Ac8 SNP were extracted and further analyzed for their sex-specific NF1-associated glioma risk. Three SNPs on ADCY8 were found signficant while other SNPs on CXCR7 and ADCYAP1 were promising. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from blood samples or saliva samples in three separate sets with one processed in Washington University and two in University of Utah. The data included 29 control samples and 236 NF1 patient samples (123 with and 113 without GBM) with 153 blood specimen and 97 saliva specimen.
Project description:We performed whole genome SNP profiling on DNA samples from 236 patients with NF1, 123 with glimoa tumors and 113 without; 117 females and 119 males, together with 29 control samples. To identify polymorphisms in human adenylate cyclase 8 (AC8) which correlate with glioma risk in NF1 in a sex-specific manner, Ac8 SNP were extracted and further analyzed for their sex-specific NF1-associated glioma risk. Three SNPs on ADCY8 were found signficant while other SNPs on CXCR7 and ADCYAP1 were promising.
Project description:Gioma stem cells from Nf1-associated optic gliomas and NSCs from third ventricle zone show differencies in gene expression patterns and physiological functions. We used microarrays to identify differential gene expression between glioma stem cells and the control counterparts including the wild type and Nf1-/- neural stem cells from the third ventricle.
Project description:Solid cancers develop within a supportive microenvironment that promotes tumor formation and continued growth through the elaboration of mitogens and chemokines. Within these tumors, monocytes (macrophages and microglia) represent rich sources of these stromal factors. Leveraging a genetically-engineered mouse model of neurofibromatosis type 1 (NF1) low-grade brain tumor (optic glioma), previous studies have demonstrated that microglia are important for glioma formation and maintenance. To identify the tumor-associated microglial factors that support glioma growth (gliomagens), we employed a comprehensive large scale discovery effort using optimized advanced RNA-sequencing methods. Candidate gliomagens were prioritized to identify potential secreted or membrane-bound proteins, which were next validated by quantitative RT-PCR and RNA FISH following minocycline-mediated microglial inactivation in vivo. Using these selection criteria, Ccl5 was identified as a highly expressed chemokine in both genetically engineered Nf1 mouse and human optic gliomas. As a candidate gliomagen, recombinant Ccl5 increased Nf1-deficient optic nerve astrocyte growth in vitro. Importantly, consistent with its critical role in maintaining tumor growth, Ccl5 inhibition with neutralizing antibodies reduced Nf1 mouse optic glioma growth in vivo. Collectively, these findings establish Ccl5 as critical stromal growth factor in low-grade glioma maintenance relevant to future microglia-targeted therapies for brain tumors.
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:As the list of putative driver mutations in glioma grows, we are just beginning toAs the list of putative driver mutations in glioma grows, we are just beginning to elucidate the effects of dysregulated developmental signaling pathways on the transformation of neural cells. We have employed a postnatal, mosaic, autochthonous, glioma model that captures the first hours and days of gliomagenesis in more resolution than conventional genetically engineered mouse models of cancer. We provide evidence that disruption of the Nf1-Ras pathway in the ventricular zone at multiple signaling nodes uniformly results in rapid neural stem cell depletion, progenitor hyperproliferation, and gliogenic lineage restriction. Abolishing Ets subfamily activity, which is upregulated downstream of Ras, rescues these phenotypes and blocks glioma initiation. Thus, the Nf1-Ras-Ets axis might be one of the select molecular pathways that are perturbed for initiation and maintenance in glioma. Mouse Gene 1.0 ST Microarrays from Affimetryx were used for microarray analysis. For each experiment, total RNA was fluorescently labeled and hybridized. 3 cell lines derived from in vivo electroporated neural stem and progenitors were compared.
Project description:To examine the effect of Nf1 inactivation in astrocytes on normal microglia in the optic nerve, microglia from Nf1 flox/flox (FF) and Nf1 flox/flox; GFAP-Cre (FFC) were flow sorted. High throughput RNA-seq was employed to compare the expression profiles, and upregulated genes in microglia supportive to Nf1 deficient astrocytes were verified.