Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Copy number alterations in pleural mesothelioma

ABSTRACT: Integrated profiling of somatic molecular alterations present in tumors is necessary to further our understanding of the tumorigenic process. We investigated the potential relationships between gene copy number alterations and DNA methylation profiles in a case series of pleural mesotheliomas (n=23). Gene copy number (CN) alterations profiled with 500K SNP arrays and DNA methylation measured at over 750 cancer-related genes with methylation bead-arrays were examined concomitantly. Considering each probed locus, there were no instances of significantly correlated CN alteration and methylation (no loci with Q < 0.05) and averaging loci over their associated genes revealed only two genes with significantly correlated CN and methylation alterations (Q < 0.04). In contrast to the lack of discrete correlations, the overall extent of tumor CN alteration was significantly associated with DNA methylation profile when comparing CN alteration extent among methylation profile classes (P < 0.02), and there was evidence that this association was partially attributable to prevalent allele loss observed at the maintenance DNA methyltransferase DNMT1. Taken together, this work indicates a strong association between global genetic and global epigenetic dysregulation in mesothelioma rather than a discrete, local coordination of gene inactivation, and further highlights the utility and necessity of integrative genomics approaches in cancer biology. From the total study population, 23 tumors from the incident case series were chosen for copy number alteration profiling by hybridizing 5ml containing â¥ 50ng/ml of tumor or matched peripheral blood DNA to each of the two GeneChipsÂ® that comprise the Human Mapping 500K single-nucleotide polymorphism array set (Affymetrix, Santa Clara, CA), following manufacturer protocols and standard operating procedures at the Harvard Partners Microarray Core servicing facility. Probe intensities at each locus were determined in the GCOS software and genotypes calls were generated using the Genotyping Analysis Software (Affymetrix). Probe signals were normalized to their matched referent peripheral blood sample data using the Copy Number Analysis Tool v4.0.1 software (CNAT) (Affymetrix) with median scaling and default tuning parameters, and copy number states were inferred by Hidden Markov Model analysis. The supplementary file 'GSE21057_tumor_copy_number.txt' contains the (blood-normalized) copy number calls for each tumor sample.

ORGANISM(S): Homo sapiens

SUBMITTER: Brock Christensen

PROVIDER: E-GEOD-21057 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Publications

Integrated profiling reveals a global correlation between epigenetic and genetic alterations in mesothelioma.

Christensen Brock C BC Houseman E Andres EA Poage Graham M GM Godleski John J JJ Bueno Raphael R Sugarbaker David J DJ Wiencke John K JK Nelson Heather H HH Marsit Carmen J CJ Kelsey Karl T KT

Cancer research 20100629 14

Development of mesothelioma is linked mainly to asbestos exposure, but the combined contributions of genetic and epigenetic alterations are unclear. We investigated the potential relationships between gene copy number (CN) alterations and DNA methylation profiles in a case series of pleural mesotheliomas (n = 23). There were no instances of significantly correlated CN alteration and methylation at probed loci, whereas averaging loci over their associated genes revealed only two genes with signif ...[more]

PMID: 20587528

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Project description:Chromosomal DNA copy number alterations are a hallmark of human malignancies, including hepatocellular carcinoma (HCC). However, which oncogenes or tumor suppressors located on regions with DNA copy number aberration may contribute to HCC initiation and progression still remain obscure. Here we performed a genome-wide DNA copy number analysis on human HCC samples to identify novel potential oncogenes or tumor suppressors with DNA copy number aberrations. Genome-wide DNA copy numbers analysis was performed with single nucleotide polymorphism micoarray. RT-PCR and immunohistochemical staining were employed to evaluate the NOXIN expression in HCC samples. Colony formation, cell cycle analysis and tumor xenograft assays were performed to assess the role of NOXIN in HCC cells. Reciprocal co-immunoprecipitation experiments were used to detect the interaction between NOXIN and DNA polymerase a primase. Genome-wide DNA copy number analysis on 43 paired HCC samples indentified the smallest DNA amplification region containing NOXIN, along with the elevated transcript. NOXIN overexpression was significantly associated with HCC tumor stage. Enforced NOXIN promoted cellular proliferation, colony formation, cell migration and in vivo tumorigenicity, whereas RNA interference against NOXIN can attenuate these effects. Interestingly, NOXIN overexpression can accelerate the G1-S transition of cell cycle progression through enhancing DNA synthesis in HCC cells, as indicated by bromodeoxyuridine incorporation. Furthermore, NOXIN can interact with DNA polymerase a, implying that NOXIN may promote de novo DNA synthesis via affiliating formation of DNA polymerase-primase complex. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from hepatocellular carcinoma and adjacent liver tissue samples. Copy number analysis of Affymetrix 500K SNP arrays was performed for 43 hepatocellular carcinoma tissue samples, which their adjacent liver tissues were used as references for copy number inference.

Project description:Integrated profiling of somatic molecular alterations present in tumors is necessary to further our understanding of the tumorigenic process. We investigated the potential relationships between gene copy number alterations and DNA methylation profiles in a case series of pleural mesotheliomas (n=23). Gene copy number (CN) alterations profiled with 500K SNP arrays and DNA methylation measured at over 750 cancer-related genes with methylation bead-arrays were examined concomitantly. Considering each probed locus, there were no instances of significantly correlated CN alteration and methylation (no loci with Q < 0.05) and averaging loci over their associated genes revealed only two genes with significantly correlated CN and methylation alterations (Q < 0.04). In contrast to the lack of discrete correlations, the overall extent of tumor CN alteration was significantly associated with DNA methylation profile when comparing CN alteration extent among methylation profile classes (P < 0.02), and there was evidence that this association was partially attributable to prevalent allele loss observed at the maintenance DNA methyltransferase DNMT1. Taken together, this work indicates a strong association between global genetic and global epigenetic dysregulation in mesothelioma rather than a discrete, local coordination of gene inactivation, and further highlights the utility and necessity of integrative genomics approaches in cancer biology. Mesotheliomas were obtained following surgical resection at Brigham and Women’s Hospital through the International Mesothelioma Program from a pilot study conducted in 2002 and an incident case series beginning in 2005 as previously described (PMIDs: 19118007 and 19638575). All patients provided informed consent under the approval of the appropriate Institutional Review Boards. Clinical information, including histologic diagnosis was obtained from pathology reports. The study pathologist confirmed the histologic diagnoses and further assessed the percent tumor from resected specimens (mean >60%). DNA extraction and methylation analysis: DNA from fresh frozen tissue and matched whole blood was isolated with QIAamp DNA mini kit (Qiagen, Valencia, CA) following the manufacturer’s protocol. Tumor DNA was modified with sodium bisulfite using the EZ DNA Methylation Kit (Zymo Research, Orange, CA). Illumina GoldenGate® methylation bead arrays interrogated 1505 CpG loci associated with 803 cancer-related genes processed at the UCSF Institute for Human Genetics, Genomics Core Facility using methods described in (28). The GoldenGate methylation data used in the analysis has been previously described (PMIDs: 19118007 and 19638575).

Dataset Information

Copy number alterations in pleural mesothelioma

Publications

Integrated profiling reveals a global correlation between epigenetic and genetic alterations in mesothelioma.

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