Project description:This SuperSeries is composed of the following subset Series:; GSE13136: Identification of candidate neuroblastoma genes by combining genomic and expression microarrays: expression data; GSE13137: Identification of candidate neuroblastoma genes by combining genomic and expression microarrays: SNP data Experiment Overall Design: Refer to individual Series
Project description:Gene expression analysis was performed on 30 Neuroblastomas to identify genes whose transcription is significantly altered by recurrent chromosomal alterations. Genomic copy number losses and gains had been delineated in the tumours using FISH and SNP arrays. We have identified genes significantly altered by 7 recurrent alterations: 1p, 3p, 4p, 10q and 11q loss, 2p and 17q gain, and genes co-amplified and over-expressed as a result of MYCN amplification. Subsequently, correlation of microarray data with survival and expression within rodent neuroblastomas were used to identify genes likely to be involved in the disease progression, and identified a significant excess of differentially expressed genes which correlated with survival within the minimally altered regions on 17q and 4p; Identifying genes whose expression is consistently altered by chromosomal gains or losses is an important step in defining genes of biological relevance in a wide variety of tumour types. However, additional criteria are needed to discriminate further among the large number of candidate genes identified. This is particularly true for neuroblastoma, where multiple genomic copy number changes of proven prognostic value exist. We have used Affymetrix microarrays and a combination of fluorescent in-situ hybridisation and single nucleotide polymorphism (SNP) microarrays to establish expression profiles and delineate copy number alterations in 30 primary neuroblastomas. Correlation of microarray data with patient survival and analysis of expression within rodent neuroblastoma cell lines were then used to further define genes likely to be involved in the disease process. Using this approach we identify >1000 genes within 8 recurrent genomic alterations (loss of 1p, 3p, 4p, 10q and 11q, 2p gain, 17q gain, and the MYCN amplicon) whose expression is consistently altered by copy number change. Of these, 84 correlate with patient survival, with the minimal regions of 17q gain and 4p loss being significantly enriched for such genes. Orthologues of all but one of these genes on 17q are overexpressed in rodent neuroblastoma cell lines. A significant excess of SNPs whose copy number correlates with survival is also observed on proximal 4p in stage 4 tumours, and we find that deletion of 4p is associated with improved outcome in an extended cohort of tumours. These results define the major impact of genomic copy number alterations upon transcription within neuroblastoma, and highlight genes on distal 17q and proximal 4p for downstream analyses. They also suggest that integration of discriminators such as survival and comparative gene expression with microarray data may be useful in the identification of critical genes within regions of loss or gain in many human cancers. Experiment Overall Design: Chromosomal gains and losses were delineated in Stage 4 neuroblastomas to facilitate, in combination with expression array data, the identification of genes within regions of gain and loss whose expression is significantly altered by copy number change.
Project description:The specific genes that influence neuroblastoma biology and are targeted by genomic alterations remain largely unknown. We quantified mRNA expression in a highly annotated series of 101 prospectively collected diagnostic neuroblastoma primary tumors and the expression profiles were determined using Affymetrix U95Av2 arrays. Comparisons between the sample groups allow the identification of genes with localized expression patterns. This study demonstrates that the genomic data can be used to subcategorize the disease into molecular subsets and the regional copy number alterations are correlated with a broad number of transcriptional alterations genome wide. This data also suggests that multiple genes from several discrete regions of the human genome co-operate to supress neuroblastoma tumorigenesis and progression. Keywords: Disease state analysis, genetic modification
Project description:Gene expression analysis was performed on 30 Neuroblastomas to identify genes whose transcription is significantly altered by recurrent chromosomal alterations. Genomic copy number losses and gains had been delineated in the tumours using FISH and SNP arrays. We have identified genes significantly altered by 7 recurrent alterations: 1p, 3p, 4p, 10q and 11q loss, 2p and 17q gain, and genes co-amplified and over-expressed as a result of MYCN amplification. Subsequently, correlation of microarray data with survival and expression within rodent neuroblastomas were used to identify genes likely to be involved in the disease progression, and identified a significant excess of differentially expressed genes which correlated with survival within the minimally altered regions on 17q and 4p Identifying genes whose expression is consistently altered by chromosomal gains or losses is an important step in defining genes of biological relevance in a wide variety of tumour types. However, additional criteria are needed to discriminate further among the large number of candidate genes identified. This is particularly true for neuroblastoma, where multiple genomic copy number changes of proven prognostic value exist. We have used Affymetrix microarrays and a combination of fluorescent in-situ hybridisation and single nucleotide polymorphism (SNP) microarrays to establish expression profiles and delineate copy number alterations in 30 primary neuroblastomas. Correlation of microarray data with patient survival and analysis of expression within rodent neuroblastoma cell lines were then used to further define genes likely to be involved in the disease process. Using this approach we identify >1000 genes within 8 recurrent genomic alterations (loss of 1p, 3p, 4p, 10q and 11q, 2p gain, 17q gain, and the MYCN amplicon) whose expression is consistently altered by copy number change. Of these, 84 correlate with patient survival, with the minimal regions of 17q gain and 4p loss being significantly enriched for such genes. Orthologues of all but one of these genes on 17q are overexpressed in rodent neuroblastoma cell lines. A significant excess of SNPs whose copy number correlates with survival is also observed on proximal 4p in stage 4 tumours, and we find that deletion of 4p is associated with improved outcome in an extended cohort of tumours. These results define the major impact of genomic copy number alterations upon transcription within neuroblastoma, and highlight genes on distal 17q and proximal 4p for downstream analyses. They also suggest that integration of discriminators such as survival and comparative gene expression with microarray data may be useful in the identification of critical genes within regions of loss or gain in many human cancers. Keywords: Disease State Analysis
Project description:The specific genes that influence neuroblastoma biology and are targeted by genomic alterations remain largely unknown. We quantified mRNA expression in a highly annotated series of 101 prospectively collected diagnostic neuroblastoma primary tumors and the expression profiles were determined using Affymetrix U95Av2 arrays. Comparisons between the sample groups allow the identification of genes with localized expression patterns. This study demonstrates that the genomic data can be used to subcategorize the disease into molecular subsets and the regional copy number alterations are correlated with a broad number of transcriptional alterations genome wide. This data also suggests that multiple genes from several discrete regions of the human genome co-operate to supress neuroblastoma tumorigenesis and progression. Experiment Overall Design: A highly annotated series of 101 prospectively collected diagnostic neuroblastoma primary tumors were selected to quantify mRNA expression using an oligonucleotide based microarray. Genomic copy number status at the prognostically relevant loci 1p36,2p24(MYCN), 11q23 and 17q23 was determined by PCR and was aberrant in 26, 20, 40 and 38 cases, respectively. Fetal brain RNA was used as a control sample.