Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA110813 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Astrocytomas are heterogeneous intracranial glial neoplasms ranging from the highly aggressive malignant glioblastoma multiforme (GBM) to the indolent, low-grade pilocytic astrocytoma. We have investigated whether DNA microarrays can identify gene expression differences between high-grade and low-grade glial tumors. We compared the transcriptional profile of 45 astrocytic tumors including 21 GBMs and 19 pilocytic astrocytomas using oligonucleotide-based microarrays. Of the approximately 6800 genes that were analyzed, a set of 360 genes provided a molecular signature that distinguished between GBMs and pilocytic astrocytomas. Many transcripts that were increased in GBM were not previously associated with gliomas and were found to encode proteins with properties that suggest their involvement in cell proliferation or cell migration. Microarray-based data for a subset of genes was validated using real-time quantitative reverse transcription-PCR. Immunohistochemical analysis also localized the protein products of specific genes of interest to the neoplastic cells of high-grade astrocytomas. Our study has identified a large number of novel genes with distinct expression patterns in high-grade and low-grade gliomas.
2015-06-25 | GSE70231 | GEO
Project description:Paediatric low-grade gliomas (LGGs) account for about a third of all brain tumours in children. We conducted a detailed study of DNA methylation to improve our understanding of the biology of pilocytic and diffuse astrocytomas. Comparisons were performed between tumours and normal brain controls from matching location, and between pilocytic and diffuse astrocytomas. Pilocytic astrocytomas were found to have a distinctive signature involving 315 CpG sites, with the majority of the sites (312 CpG sites) hypomethylated in pilocytic astrocytomas. Additionally many of the sites were located within annotated enhancers. The distinct signature in pilocytic astrocytomas was not present in diffuse astrocytomas or in published profiles of other brain tumours and normal brain tissue. On further analysis of the 315 CpG sites, the AP-1 transcription factor complex was predicted to bind within 200bp of a subset of teh 315 differentially methylated CpG sites. We also observed up-regulation of the AP-1 factors, FOS and FOSL1 in pilocytic astrocytomas. Our findings highlight novel epigenetic differences between pilocytic and diffuse astrocytomas, in addition to well-described alterations involving BRAF, MYB and FGFR1.
2016-05-10 | GSE77241 | GEO
Project description:Proteogenomics reveals two distinct biological pilocytic astrocytoma subgroups
| PRJNA865354 | ENA
Project description:Pilocytic astrocytoma (PA) is the most common pediatric brain tumor and driven by aberrant MAPK signaling, typically mediated by BRAF alterations. While five-year overall survival rates exceed 95%, tumor recurrence constitutes a major clinical challenge in incompletely resected tumors despite chemotherapeutic or radiation based therapies. Therefore, we used proteogenomics to discern the biological heterogeneity of PA to improve classification of this tumor entity and identify novel therapeutic targets. Our proteogenomics approach integrates RNA sequencing and LC/MS-based proteomic profiling data from a cohort of 58 confirmed, primary PA samples. An integrative genomics approach was conducted to discern the biological heterogeneity of PA and to identify aberrant pathway activation in these biological subgroups. In summary, Pilocytic astrocytomas segregate into two groups where younger patients are significantly associated with Group 1. Importantly, we validate the two distinct biological subgroups in two non-overlapping cohorts. The biological heterogeneity seen here may improve biological classification and reveal novel therapeutic targets specifically useful for non-resectable tumors with high risk of recurrent or progressive disease.
2023-10-24 | PXD035773 | Pride
Project description:Copy number analysis of 21 paediatric low-grade astrocytomas identified a discrete copy number gain of 1.9Mb in chromosome band 7q34. The gain was present in 12/14 cerebellar pilocytic astrocytomas. Subsequent analysis of tumour cDNA indentified a novel gene fusion between KIAA1549 and BRAF in these tumours. Copy number analysis of 21 paediatric low-grade astrocytomas using the Affymetrix GeneChip Human Mapping 250K Nsp Array. This study comprised 14 pilocytic astrocytomas, 4 diffuse astrocytomas, one pilomyxoid astrocytoma, one pilomyxoid glioma and one pleomorphic xanthoastrocytoma. Tumours were compared to the mean of two normal male DNA controls.
2010-04-09 | E-GEOD-14960 | biostudies-arrayexpress
Project description:Astrocytomas are heterogeneous intracranial glial neoplasms ranging from the highly aggressive malignant glioblastoma multiforme (GBM) to the indolent, low-grade pilocytic astrocytoma. We have investigated whether DNA microarrays can identify gene expression differences between high-grade and low-grade glial tumors. We compared the transcriptional profile of 45 astrocytic tumors including 21 GBMs and 19 pilocytic astrocytomas using oligonucleotide-based microarrays. Of the approximately 6800 genes that were analyzed, a set of 360 genes provided a molecular signature that distinguished between GBMs and pilocytic astrocytomas. Many transcripts that were increased in GBM were not previously associated with gliomas and were found to encode proteins with properties that suggest their involvement in cell proliferation or cell migration. Microarray-based data for a subset of genes was validated using real-time quantitative reverse transcription-PCR. Immunohistochemical analysis also localized the protein products of specific genes of interest to the neoplastic cells of high-grade astrocytomas. Our study has identified a large number of novel genes with distinct expression patterns in high-grade and low-grade gliomas. hanas-00078 Assay Type: Gene Expression Provider: Affymetrix Array Designs: Hu6800 Organism: Homo sapiens (ncbitax) Tissue Sites: Brain Material Types: synthetic_DNA, synthetic_RNA, organism_part Disease States: Primary Glioma, Normal
2015-06-25 | E-GEOD-70231 | biostudies-arrayexpress
Project description:Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Characterization of DNA copy number changes in 54 glial brain tumors using a cDNA microarray-based comparative genomic hybridization method. Tumors: 54 fresh-frozen glioma specimens subjected to standard WHO classification. Specimens included astrocytic [3 juvenile pilocytic astrocytomas, 1 low-grade astrocytic glioma, 3 anaplastic astrocytomas, 31 glioblastomas (of these 3 secondary glioblastomas and 2 gliosarcomas)], oligodendroglial [5 oligodendrogliomas, 3 anaplastic oligodendrogliomas], and 7 anaplastic oligoastrocytomas tumors. One tumor had been classified as glioneuronal neoplasm. Human male and female genomic reference DNA was purchased from Promega (Promega, Madison, WI). The results provide insights into molecular genetic changes associated with gliomagenesis. Keywords: other
2005-05-27 | GSE1991 | GEO
Project description:Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Characterization of DNA copy number changes in 54 glial brain tumors using a cDNA microarray-based comparative genomic hybridization method. Tumors: 54 fresh-frozen glioma specimens subjected to standard WHO classification. Specimens included astrocytic [3 juvenile pilocytic astrocytomas, 1 low-grade astrocytic glioma, 3 anaplastic astrocytomas, 31 glioblastomas (of these 3 secondary glioblastomas and 2 gliosarcomas)], oligodendroglial [5 oligodendrogliomas, 3 anaplastic oligodendrogliomas], and 7 anaplastic oligoastrocytomas tumors. One tumor had been classified as glioneuronal neoplasm. Human male and female genomic reference DNA was purchased from Promega (Promega, Madison, WI). The results provide insights into molecular genetic changes associated with gliomagenesis.
2010-06-10 | E-GEOD-1991 | biostudies-arrayexpress
Project description:Pilocytic astrocytoma (PA) is the most common pediatric brain tumor and driven by aberrant MAPK signaling, typically mediated by BRAF alterations. While five-year overall survival rates exceed 95%, tumor recurrence constitutes a major clinical challenge in incompletely resected tumors despite chemotherapeutic or radiation based therapies. Therefore, we used proteogenomics to discern the biological heterogeneity of PA to improve classification of this tumor entity and identify novel therapeutic targets. Our proteogenomics approach integrates RNA sequencing and LC/MS-based proteomic profiling data from a cohort of 58 confirmed, primary PA samples. An integrative genomics approach was conducted to discern the biological heterogeneity of PA and to identify aberrant pathway activation in these biological subgroups. In summary, pilocytic astrocytomas segregate into two groups where younger patients are significantly associated with Group 1. Importantly, we validate the two distinct biological subgroups in two non-overlapping cohorts. The biological heterogeneity seen here may improve biological classification and reveal novel therapeutic targets specifically useful for non-resectable tumors with high risk of recurrent or progressive disease.
2023-09-20 | GSE210353 | GEO
Project description:Gene expression profiling in 50 glial brain tumors and 4 normal brains using 42,000-feature cDNA microarrays (from total RNA). Tumors: 50 fresh-frozen glioma specimens subjected to standard WHO classification. Specimens included astrocytic [2 juvenile pilocytic astrocytomas, 1 low-grade astrocytic glioma, 1 anaplastic astrocytomas, 31 glioblastomas (of these 2 secondary glioblastomas and 2 gliosarcomas)], oligodendroglial [5 oligodendrogliomas, 3 anaplastic oligodendrogliomas], and 6 anaplastic oligoastrocytomas tumors. One tumor had been classified as glioneuronal neoplasm. Normal brain was purchased from Stratagene. Stratagene Universal Common Reference was used as reference RNA. The results provide insights into molecular mechanisms and pathways associated with gliomagenesis.
2005-10-06 | E-SMDB-3152 | biostudies-arrayexpress