Copy number analysis of high-grade osteosarcoma
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Marieke Kuijjer
PROVIDER: E-GEOD-33153 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:High-grade osteosarcoma is a tumor with a complex genomic profile, occurring primarily in adolescents with a second peak at middle age. The extensive genomic alterations obscure the identification of genes driving tumorigenesis during osteosarcoma development. In order to identify such driver genes, we integrated DNA copy number profiles (Affymetrix SNP 6.0) of 32 diagnostic biopsies with 84 expression profiles (Illumina Human-6 v2.0) of high-grade osteosarcoma as compared with its putative progenitor cells, i.e. mesenchymal stem cells (n=12) or osteoblasts (n=3). In addition, we performed paired analyses between copy number and expression profiles of a subset of 29 patients for which both DNA and mRNA profiles were available. Integrative analyses were performed in Nexus Copy Number software and statistical language R. Paired analyses were performed on all probes detecting significantly differentially expressed genes in corresponding LIMMA analyses. For both non-paired and paired analyses, copy number aberration frequency was set to >35%. Non-paired and paired integrative analyses resulted in 45 and 101 genes, respectively, which were present in both analyses using different control sets. Paired analyses detected >90% of all genes found with the corresponding non-paired analyses. Remarkably, approximately twice as many genes as found in the corresponding non-paired analyses were detected. Affected genes were intersected with differentially expressed genes in osteosarcoma cell lines, resulting in 31 new osteosarcoma driver genes. Cell division related genes, such as MCM4 and LATS2, were overrepresented and genomic-instability was predictive for metastasis-free survival, suggesting that deregulation of the cell cycle is a driver of osteosarcomagenesis. This SuperSeries is composed of the following subset Series: GSE28974: Genome-wide gene expression profiling of mesenchymal stem cells GSE33153: Copy number analysis of high-grade osteosarcoma GSE33382: Genome-wide gene expression analysis of high-grade osteosarcoma For data processing, we refer to the individual series. We performed both non-paired and paired integrative analyses on SNP and gene expression data. Non-paired integrative analysis was performed by importing lists of differentially expressed genes into the Copy Number module of Nexus software version 5 (BioDiscovery, CA). Based on the length of the gene list, Nexus software performs a Fisher's exact test in order to determine whether the number of differentially expressed genes in a specific region with a significant copy number alteration is larger than expected by chance. Genes present in such regions of copy number alteration with FDR-adjusted P-values (Q-bounds in Nexus software) < 0.05 were returned from this integrative analysis. Nexus software only reports genes which are both gained and overexpressed, or both deleted and downregulated. For the paired integrative analysis, copy number data of all autosomal overlapping genes between the copy number and gene expression arrays were exported from Nexus software, and converted into a binary file containing all genes with a gain (1) and no gain (0), and a similar binary file for losses. As in the non-paired integrative analysis, we did not apply any restrictions on the size of copy number alterations. Gene expression data of each probe for each sample were normalized against average gene expression of the corresponding probes over all control samples (either expression data from 12 MSCs, or from 3 osteoblasts). This was performed by subtracting the average expression of the control samples from the expression levels of the sample of interest, since these are log-transformed expression values. For both analyses, only genes that were significantly differentially expressed between the 84 osteosarcoma samples and the specific control set were analyzed, in order to make sure that no genes returned from the integrative analysis were not significantly differentially expressed. Subse quently, genes that overlapped between the copy number binary files and that matched the fold change of expression (upregulation for genes with gains, and downregulation for genes with losses) were returned.
2012-03-27 | E-GEOD-33383 | biostudies-arrayexpress
Project description:Renal cell carcinoma (RCC) exhibits some unusual features and genes commonly mutated in cancer are rarely mutated in clear-cell RCC (ccRCC), the most common type. The most prevalent genetic alteration in ccRCC is the inactivation of the tumor suppressor gene VHL. Using whole-genome and exome sequencing we discovered BAP1 as a novel tumor suppressor in ccRCC that shows little overlap with mutations in PBRM1, another recent tumor suppressor. Whereas VHL was mutated in 81% of the patients (142/176), PBRM1 was lost in 58% and BAP1 in 15% of the patients analyzed. All these tumor suppressor genes are located in chromosome 3p, which is partially or completely lost in most ccRCC patients. However, BAP1 but not PBRM1 loss was associated with higher Fuhrman grade and, therefore, poorer outcome. Xenograft tumors (tumorgrafts) implanted orthotopically in mice retained >92% of mutations and exhibited similar DNA copy number alterations to corresponding primary tumors. Thus, after inactivation of VHL, the acquisition of a mutation in BAP1 or PBRM1 defines a different program that might alter the fate of the patient. Our results establish the foundation for an integrated pathological and molecular genetic classification of about 70% of ccRCC patients, paving the way for subtype-specific treatments exploiting genetic vulnerabilities. The genomic DNA of clear-cell renal cell carcinoma (ccRCC) primary tumors, tumors growing in immunodeficient mice (tumorgrafts), and normal samples were labeled and hybridized to Affymetrix SNP arrays 6.0.
2012-06-09 | E-GEOD-25540 | biostudies-arrayexpress
Project description:Osteosarcoma in dogs is a spontaneously occurring disease with a global tumor gene expression signature indistinguishable from human pediatric tumors and clinical progression is remarkably similar. Unlike human OS, canine OS is a highly heritable disease with some large and giant dog breeds at >10x increased risk. We did a genome wide association study of osteosarcoma using the Illumina CanineHD genotyping array in three breeds: greyhound (mortality from OS = 26%), rottweiler (17%) and Irish wolfhound (IWH, 21%) and identified 33 inherited risk loci explaining 55 to 85% of phenotype variance in each breed. Data created for a genome-wide association studio of heritable osteosarcoma risk factors in dogs, including 267 racing greyhounds (153 affected (A) + 114 unaffected (U)), 135 rottweilers (80 A + 55 U), 141 IWH (76 A + 65 U) and 19 AKC greyhounds using the Illumina CanineHD array (~170,000 SNPs genomewide)
2013-11-12 | E-GEOD-51734 | biostudies-arrayexpress
Project description:Osteosarcoma in dogs is a spontaneously occurring disease with a global tumor gene expression signature indistinguishable from human pediatric tumors and clinical progression is remarkably similar. Unlike human OS, canine OS is a highly heritable disease with some large and giant dog breeds at >10x increased risk. We did a genome wide association study of osteosarcoma using the Illumina CanineHD genotyping array in three breeds: greyhound (mortality from OS = 26%), rottweiler (17%) and Irish wolfhound (IWH, 21%) and identified 33 inherited risk loci explaining 55 to 85% of phenotype variance in each breed. Data created for a genome-wide association studio of heritable osteosarcoma risk factors in dogs, including 267 racing greyhounds (153 affected (A) + 114 unaffected (U)), 135 rottweilers (80 A + 55 U), 141 IWH (76 A + 65 U) and 19 AKC greyhounds using the Illumina CanineHD array (~170,000 SNPs genomewide)
2013-11-12 | E-GEOD-51973 | biostudies-arrayexpress
Project description:Osteosarcoma in dogs is a spontaneously occurring disease with a global tumor gene expression signature indistinguishable from human pediatric tumors and clinical progression is remarkably similar. Unlike human OS, canine OS is a highly heritable disease with some large and giant dog breeds at >10x increased risk. We did a genome wide association study of osteosarcoma using the Illumina CanineHD genotyping array in three breeds: greyhound (mortality from OS = 26%), rottweiler (17%) and Irish wolfhound (IWH, 21%) and identified 33 inherited risk loci explaining 55 to 85% of phenotype variance in each breed. Data created for a genome-wide association studio of heritable osteosarcoma risk factors in dogs, including 267 racing greyhounds (153 affected (A) + 114 unaffected (U)), 135 rottweilers (80 A + 55 U), 141 IWH (76 A + 65 U) and 19 AKC greyhounds using the Illumina CanineHD array (~170,000 SNPs genomewide)
2013-11-12 | E-GEOD-51976 | biostudies-arrayexpress
Project description:We sequenced two tumor/normal pairs obtained from two paediatric medulloblastoma patients (MB14 and MB24) with at least 30x coverage on all commonly used next-generation sequencing platforms for whole genome sequencing (SOLiD 4, 5500xl SOLiD, Illumina's HiSeq2000, and Complete Genomic' technology). The normal tissue samples came from venous blood. We compared their ability to call single nucleotide variations (SNVs) in whole-genome sequencing data with high confidence. As gold standard for SNV calling, we used genotypes determined by Affymetrix SNP 6.0 Array Technology (total of 907,551 SNPs after quality filtering).
2013-06-01 | E-MTAB-1159 | biostudies-arrayexpress
Project description:Chordomas are rare, low to intermediate grade malignant bone tumors of the axial skeleton, believed to originate from the notochord. Treatment options are limited and mainly restricted to surgical excision, as chordomas have been proven to be largely resistant to conventional ionizing radiation and chemotherapy. Therefore a new cell line was established. The cell line has been characterized by immunohistochemistry,western blot and karyotyping using cobra fish technology. Copy number variations (CNV) and loss-of heterozygosity (LOH) from fibroblasts, tumor tissue, low and high cell line passage was evaluted by using Affymetrix 6.0SNP Arrays. DNA isolated from the patients MNCs was used as control. The cell line MUG-Chor1 is highly similar to genetic profiles of chordomas and provides therefore a powerful tool for further investigations. Affymetrix SNP 6.0 arrays were performed according to the manufacturer's directions on DNA extracted from cryo material or cell lines. Copy number analysis of Affymetrix SNP 6.0 arrays was performed for 4 samples. 60 samples from HapMap database were used as references for copy number inference.
2012-07-11 | E-GEOD-25720 | biostudies-arrayexpress
Project description:Purpose: More than 90% of children with diffuse intrinsic pontine glioma (DIPG) die within 2 years of diagnosis. There is a dire need to identify therapeutic targets, however lack of patient material for research has limited progress. We evaluated a large cohort of diffuse intrinsic pontine gliomas (DIPGs) to identify recurrent genomic abnormalities and gene expression signatures underlying DIPG. Patients and Methods: We used single nucleotide polymorphism arrays to evaluate genomic copy number imbalances in 43 DIPGs from 40 patients and in 8 low-grade exophytic brainstem gliomas. Gene expression arrays were used to evaluate expression signatures from 27 DIPGs, 6 low-grade exophytic brainstem gliomas and 66 low-grade gliomas arising outside the brainstem. Results: Frequencies of specific large-scale and focal imbalances varied significantly between DIPGs and pediatric glioblastomas outside the brainstem. Focal amplifications of genes within the receptor tyrosine kinase-Ras-PI3-kinase signaling pathway were found in 47% of DIPG, with PDGFRA and MET showing the highest frequency. 30% of DIPG contained focal amplifications of cell-cycle regulatory genes controlling RB phosphorylation, and 21% had concurrent amplification of genes from both pathways. Some tumors showed heterogeneity in amplification patterns. DIPGs showed distinct gene expression signatures relating to developmental processes compared to pediatric glioblastomas arising outside the brainstem, while expression signatures of low-grade exophytic brainstem gliomas were similar to low-grade gliomas outside the brainstem. Copy number analaysis: 43 DIPG samples, 8 Low Grade Gliomas using SNP6.0. Available matched normals are also profiled with SNP6.0. Expression analysis: 29 DIPG samples, 6 Low grade samples Please contact Suzanne Baker at Suzanne.Baker@stjude.org for CEL files and genotype calls.
2011-09-20 | E-GEOD-26576 | biostudies-arrayexpress
Project description:One aspect of intra-tumoral heterogeneity in glioblastoma involves subpopulations of cells capable of self-renewal and indefinite propagation. Conceptually, this capacity is frequently treated as a static property. Here we provide data suggesting that tumorigenicity in glioblastomais a dynamic property that can be acquired or lost. Integrated expression analyses suggest that tumorigenicity is determined by the level of MYC expression relative to a threshold. Transitions between tumorigenic and non-tumorigenic cell states are associated with changes in histone modifications at the MYC locus, suggesting tumorigenicity is epigenetically regulated. To verify genomic stability at the nucleotide level, we tested whether subclones derived from single cells shared common Single-Nucleotide Polymorphisms (SNPs). Ten single cell-derived subclones of U87MG underwent SNP profiling by Affymetrix Human Mapping 250K Nsp arrays.
2014-03-28 | E-GEOD-56316 | biostudies-arrayexpress
Project description:Osteosarcomas are the most common primary malignant tumours of bone, and almost all conventional osteosarcomas are high-grade tumours showing complex genomic aberrations. We have integrated genome-wide genetic and epigenetic profiles from the EuroBoNeT panel of 19 human osteosarcoma cell lines based on microarray technologies. The cell lines showed complex patterns of DNA copy number changes, where copy number gains were significantly associated with gene-rich regions of the genome and losses with gene-poor areas. Integration of the datasets showed that the mRNA levels were regulated by either alterations in DNA copy number or DNA methylation. Using a recurrence threshold of 6/19 (> 30 %) cell lines, 348 genes were identified as having alterations of two data types (gain or hypo-methylation/over-expression, loss or hyper-methylation/under-expression). These genes are involved in embryonic skeletal system development and morphogenesis, as well as remodelling of extracellular matrix. Several genes were hyper-methylated and under-expressed compared to normal osteoblasts, and expression could be reactivated by demethylation using 5-Aza-2M-bM-^@M-^Y-deoxycytidine treatment for all four genes tested. Globally, there was as expected a significant positive association between gain and over-expression, loss and under-expression as well as hyper-methylation and under-expression, but gain was also associated with hyper-methylation and under-expression, suggesting that hyper-methylation may oppose the effects of increased copy number for some genes. Integrative analysis of genome-wide genetic and epigenetic alterations identified mechanistic dependencies and relationships between DNA copy number and DNA methylation in terms of regulating mRNA expression levels in osteosarcomas, contributing to better understanding of osteosarcoma biology. Comparison of DNA copy number changes in 19 osteosarcoma cell lines
2012-12-06 | E-GEOD-36003 | biostudies-arrayexpress