Affymetrix SNP array data for Pediatric malignant glioma samples
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Aleksandr Lisovich
PROVIDER: E-GEOD-25589 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Clinical laboratories are adopting array comparative genomic hybridization (AGH) as a standard clinical test. A number of whole genome AGH systems are available, but little is known about the comparative performance in a clinical context. We prospectively studied 30 children with idiopathic MR and both unaffected parents of each child using Affymetrix 500K GeneChip SNP arrays, Agilent Human Genome 244K oligonucleotide arrays and NimbleGen 385K Whole-Genome oligonucleotide arrays. We determined whether CNVs called on these platforms were detected by Illumina Hap550 beadchips or SMRT 32K BAC whole genome tiling arrays and tested 15 of the 30 trios on Affymetrix 6.0 SNP array. The Affymetrix 500K, Agilent and NimbleGen platforms identified 3061 autosomal and 117 X chromosome CNVs in 30 trios. 147 of these CNVs were de novo, but only 33 (22%) of the de novo CNVs were found on more than one platform. Performing genotype-phenotype correlations, we identified 7 pathogenic and 4 possibly pathogenic CNVs for MR. All 11 of these CNVs were detected by both the Agilent and NimbleGen arrays, 9 by the Affymetrix 500K and Illumina beadchips, and 5 by the SMRT BAC array. Two of the 4 pathogenic or possibly pathogenic CNVs present in the trios tested with the Affymetrix 6.0 array were identified. Our findings demonstrate that different results are obtained with different AGH platforms and illustrate the trade-off that exists between sensitivity and specificity. The large number of apparently false positive CNV calls supports the need for validating clinically important findings with a different methodology. 45 trios were analysed consisting of child (proband) and both normal parents.
2011-02-17 | E-GEOD-27216 | biostudies-arrayexpress
Project description:Clinical laboratories are adopting array comparative genomic hybridization (AGH) as a standard clinical test. A number of whole genome AGH systems are available, but little is known about the comparative performance in a clinical context. We prospectively studied 30 children with idiopathic MR and both unaffected parents of each child using Affymetrix 500K GeneChip SNP arrays, Agilent Human Genome 244K oligonucleotide arrays and NimbleGen 385K Whole-Genome oligonucleotide arrays. We determined whether CNVs called on these platforms were detected by Illumina Hap550 beadchips or SMRT 32K BAC whole genome tiling arrays and tested 15 of the 30 trios on Affymetrix 6.0 SNP array. The Affymetrix 500K, Agilent and NimbleGen platforms identified 3061 autosomal and 117 X chromosome CNVs in 30 trios. 147 of these CNVs were de novo, but only 33 (22%) of the de novo CNVs were found on more than one platform. Performing genotype-phenotype correlations, we identified 7 pathogenic and 4 possibly pathogenic CNVs for MR. All 11 of these CNVs were detected by both the Agilent and NimbleGen arrays, 9 by the Affymetrix 500K and Illumina beadchips, and 5 by the SMRT BAC array. Two of the 4 pathogenic or possibly pathogenic CNVs present in the trios tested with the Affymetrix 6.0 array were identified. Our findings demonstrate that different results are obtained with different AGH platforms and illustrate the trade-off that exists between sensitivity and specificity. The large number of apparently false positive CNV calls supports the need for validating clinically important findings with a different methodology. 15 trios were analysed consisting of child (proband) and both normal parents. We performed separate hybridizations for the mother, father, and child and then performed pair-wise comparisons of the normalized hybridization intensities for the child to the mother and of the child to the father in silico.
2011-02-17 | E-GEOD-27145 | biostudies-arrayexpress
Project description:We studied twenty-eight growth restricted patients (twenty-two with Silver-Russell syndrome, OMIM#180860) and their parents with the Affymetrix 250K Sty SNP microarray. All patients were molecularly undefined, and thus the aim was to look for copy number alterations that might contribute to the growth restriction. Aberrations found in parents were used to reduce the list of interesting variations to de novo variants.
2009-09-06 | E-MTAB-56 | biostudies-arrayexpress
Project description:We used high-resolution SNP genotyping to identify regions of genomic gain and loss in the genome of 212 medulloblastomas, a malignant pediatric brain tumor. Focal amplifications of fifteen known oncogenes and focal deletions of twenty known tumor suppressor genes (TSG) were revealed, most not previously implicated in medulloblastoma. Importantly, we identified novel amplifications and homozygous deletions, including recurrent, mutually exclusive, highly focal genetic events in genes targeting histone lysine methylation, particularly histone 3, lysine 9 (H3K9). Post-translational modification of histone proteins is critical for regulation of gene expression, can participate in determining stem cell fates, and has been implicated in carcinogenesis. Consistent with our genetic data, restoration of expression of genes controlling H3K9 methylation greatly diminishes proliferation of medulloblastoma in vitro. Copy number aberrations of genes with critical roles in writing, reading, removing, and blocking the state of histone lysine methylation, particularly H3K9, suggest that defective control of the histone code contributes to the pathogenesis of medulloblastoma. Keywords: Affymetrix SNP array Genomic DNA isolated from fresh frozen primary human medulloblastomas and medulloblastoma cell lines were subjected to SNP genotyping using either Affymetrix 100K or 500K GeneChip Mapping array sets for the purpose of obtaining genome-wide copy number and LOH profiles.
2010-04-06 | E-GEOD-14437 | biostudies-arrayexpress
Project description:Renal epithelial neoplasms have characteristic chromosomal imbalances that can be used for classification. We have previously shown that virtual karyotypes (v-karyotype) derived from SNP microarrays can be performed on formalin-fixed paraffin embedded (FFPE) tissue samples but a direct comparison with karyotypes obtained by conventional cytogenetics has not been done. 20 archival FFPE tumor samples were analyzed with Affymetrix 10K 2.0 or 250K Nsp SNP microarrays. 19 archival FFPE tumor samples were analyzed with Affymetrix 10K 2.0 or 250K Nsp SNP microarrays and virtual-karyotype results compared to those obtained by Cytogenetics.
2009-02-19 | E-GEOD-12808 | biostudies-arrayexpress
Project description:The contribution of copy number (CN)-altered genes in cervical carcinogenesis is unknown owing to a lack of correlation with gene expression. We mapped CN-altered genes in 31 cervical cancers (CCs), and investigated the expression of 21,000 genes in 55 CCs using microarrays. Biological processes associated with genes deregulated by gene dosage and the relationship between gene dosage and patient survival were investigated. CN-altered genome (CN-AG) percentages varied widely among tumors from 0% to 32.2% (mean = 8.1 ± 8.9). Tumors were classified as low (mean = 0.5 ± 0.6, n = 11), medium (mean = 5.4 ± 2.4, n = 10), or high (mean = 19.2 ± 6.6, n = 10) CN. The highest %CN-AG was found in 3q, which contributed an average of 55% of all CN alterations. Genome-wide, only 5.3% of CN-altered genes were deregulated by gene dosage; by contrast, the rate in fully duplicated 3q was twice as high. Amplification of 3q explained 23.6% of deregulated genes in whole tumors (r2 = 0.236, p = 0.006; analysis of variance), including those in 3q and other chromosomes. A total of 862 genes were deregulated exclusively in high-CN tumors, but only 22.9% were CN altered. This result suggests that the remaining genes are not deregulated directly by gene dosage but by mechanisms induced in trans by CN-altered genes. Anaphase-promoting complex/cyclosome (APC/C)-dependent proteasome proteolysis, glycolysis, and apoptosis were upregulated, whereas cell adhesion and angiogenesis were downregulated exclusively in high-CN tumors. The high %CN-AG and upregulated gene expression profiles of APC/C-proteasome-dependent proteolysis and glycolysis were associated with poor patient survival, although only the first 2 correlations were statistically significant (p < 0.05, log-rank test). The data suggest that inhibitors of APC/C-dependent proteasome proteolysis and glycolysis may be useful treatments in these patients. In this study 31 tumors and 25 reference controls were used for analysis of copy number alterations using the 500K microarray. The results obtained from 500K array analysis were validated in 15 of the 31 tumors with a higher density microarray (Cytoscan HD). For the analysis of gene expression 55 cervical tumors (27 of them belong to the group of 31 tumors analyzed for copy number) and 17 controls were used. Please note that the sample R397 in the CytoScanHD_Array set corresponds to the R392 sample in the other data sets (due to an error in file name). Please note that there is no processed data for the control samples and only one cnchp file for each pair of .CEL files (STY and NSP). Therefore, the 'CN4.cnchp' processed data files are linked to the Series records and the processed data file is indicated in the description field of the corresponding sample records.
2015-06-04 | E-GEOD-52901 | biostudies-arrayexpress
Project description:We investigated chromosomal imbalances in samples from patients with androgen insensitive prostate cancer. 4 archival FFPE tumor samples were analyzed with Affymetrix 250K Nsp SNP microarrays and virtual-karyotype results for PTEN region were compared to PTEN deletion analysis by FISH.
2010-04-03 | E-GEOD-13439 | biostudies-arrayexpress
Project description:Genetic lesions characteristic for RCC subtypes can be identified by virtual karyotyping with SNP microarrays. In this study, we examined whether virtual karyotypes could be used to better classify a cohort of morphologically challenging/unclassified RCC. Tumor resection specimens from 17 patients were profiled by virtual karyotyping with Affymetrix 10K 2.0 or 250K Nsp SNP Mapping arrays and were also evaluated independently by a panel of seven genito-urinary pathologists. Tumors were classified by the established pattern of genomic imbalances based on a reference cohort of 98 cases with classic morphology and compared to the morphologic diagnosis of the pathologist panel. In 3 cases, samples from areas with different morphologic appearance were also tested (n=5).
2009-03-13 | E-GEOD-14670 | biostudies-arrayexpress
Project description:In the majority of colorectal cancers (CRC) under clinical suspicion for a hereditary cause, the disease-causing genetic factors are still to be discovered. In order to identify such genetic factors we stringently selected a discovery cohort of 41 CRC index patients with microsatellite-stable tumors. All patients were below 40 years of age at diagnosis and/or exhibited an overt family history. We employed genome-wide copy number profiling using high-resolution SNP-based array CGH on germline DNA, which resulted in the identification of novel copy number variants (CNVs) in 6 patients (15%) encompassing, among others, the cadherin gene CDH18, the bone morphogenetic protein antagonist family gene GREM1, and the breakpoint cluster region gene BCR. In addition, two genomic deletions were encountered encompassing two microRNA genes, hsa-mir-491/KIAA1797 and hsa-mir-646/AK309218. None of these CNVs has previously been reported in relation to CRC predisposition in humans, nor were they encountered in large control cohorts (>1,600 unaffected individuals). Since several of these newly identified candidate genes may be functionally linked to CRC development, our results illustrate the potential of this approach for the identification of novel candidate genes involved in CRC predisposition. Copy number detection was performed using CNAG2.0 software for 250k SNP arrays and using the Affymetrix Genotyping Console v2.1 software for SNP 6.0 arrays, Reference genomes are included in this data set. Germline genomic DNA from 41 patients with early-onset microsatellite stable colorectal cancer was hybridized on Affymetrix Nsp/6.0 SNP-based arrays according to manufacturer's procedures.
2010-11-01 | E-GEOD-13429 | biostudies-arrayexpress
Project description:Hypothesis: Non-small cell lung cancer (NSCLC) is characterized by a multitude of genetic aberrations with unknown clinical impact. In this study, we aimed to identify gene copy number changes that correlate with clinical outcome in NSCLC. To maximize the chance to identify clinically relevant events, we applied a strategy involving two prognostically extreme patient groups. Results: Genetic aberrations were strongly associated with tumor histology. In adenocarcinoma (n=50), gene copy number gains on chromosome 8q21-q24.3 (177 genes) were more frequent in long-term survivors. In squamous cell carcinoma (n=28), gains on chromosome 14q23.1-24.3 (133 genes) were associated with shorter survival, whereas losses in a neighboring region, 14q31.1-32.33 (110 genes), correlated with favorable outcome. In accordance with copy number gains and losses, mRNA expression levels of corresponding genes were increased or decreased, respectively. Conclusion: Comprehensive tumor profiling permits the integration of genomic, histologic and clinical data. We identified gene copy number gains and losses, with corresponding changes in mRNA levels, that were associated with prognosis in adenocarcinoma and squamous cell carcinoma of the lung. Short-term (<20 months; n=53) and long-term survivors (>58 months;n=47) were selected from a clinically well-characterized NSCLC patient cohort with available fresh-frozen tumor specimens. The samples were analyzed using high-resolution SNP-array technology. The molecular data was combined with information on clinical parameters.
2011-11-01 | E-GEOD-28572 | biostudies-arrayexpress