Unknown,Transcriptomics,Genomics,Proteomics

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Comparison of primary neuroblastoma tumors and derivative early-passage cell lines using genome-wide SNP array analysis

ABSTRACT: Stromal contamination is one of the major confounding factors in the analysis of primary solid tumor samples by single nucleotide polymorphism (SNP) arrays. As we propose to employ genome-wide SNP microarray analysis as a diagnostic platform for neuroblastoma, the sensitivity, specificity, and accuracy of these studies must be optimized. In order to investigate the effects of stroma, we derived early passage cell lines from nine primary tumors and compared their genomic signature with that of the primary tumors by 100K SNP array analysis. The average concordance between tumor and cell line for raw LOH (loss of heterozygosity) calls was 96% (range 91%-99%) and for raw copy number alterations (CNA), 71% (range 43%-87%). In general, there were a larger number of LOH events identified in the cell lines compared to the matched tumor samples (mean increase 3.2% ± 1.9%). We have developed an algorithm that shows that the presence of stroma contributes to under-reporting of LOH and copy number loss (CNL). Notable findings in this sample set were uniparental disomy (UPD) of chromosome arms 11p, 1q, 14q, and 15q and a novel area of amplification on chromosome band 11p15. Our analysis demonstrates that LOH was identified significantly more often in derived cell lines compared to the original tumor samples. While these may in part be due to clonal selection during adaptation to tissue culture, our study indicates contamination by normal stromal elements may be a major contributing factor in underestimation of LOH and CNL events. Keywords: genome wide SNP analysis Nine human neuroblastoma tumor samples with paired blood samples and derivative cell lines

ORGANISM(S): Homo sapiens

SUBMITTER: Samuel Volchenboum

PROVIDER: E-GEOD-14656 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Comparison of primary neuroblastoma tumors and derivative early-passage cell lines using genome-wide single nucleotide polymorphism array analysis.

Volchenboum Samuel L SL Li Cheng C Li Shuli S Attiyeh Edward F EF Reynolds C Patrick CP Maris John M JM Look A Thomas AT George Rani E RE

Cancer research 20090512 10

Stromal contamination is one of the major confounding factors in the analysis of solid tumor samples by single nucleotide polymorphism (SNP) arrays. As we propose to use genome-wide SNP microarray analysis as a diagnostic platform for neuroblastoma, the sensitivity, specificity, and accuracy of these studies must be optimized. To investigate the effects of stromal contamination, we derived early-passage cell lines from nine primary tumors and compared their genomic signature with that of the pri ...[more]

PMID: 19435921

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Project description:The frequent occurrence of persistent or relapsed disease following induction chemotherapy in AML necessitates a better understanding of the clonal relationship of AML in various disease phases. In this study, we employed SNP 6.0 array-based genomic profiling of acquired copy number aberrations (aCNA) and copy neutral LOH (cnLOH) together with sequence analysis of recurrently mutated genes to characterize paired AML genomes. We analyzed 28 AML sample pairs from patients that achieved complete remission with chemotherapy and subsequently relapsed and 11 sample pairs from patients with persistent disease following induction chemotherapy. Through review of aCNA/cnLOH and gene mutation profiles in informative cases we demonstrate that relapsed AML invariably represents reemergence or evolution of a founder clone. Furthermore, all individual aCNA or cnLOH detected at presentation persisted at relapse indicating that this lesion type is proximally involved in AML evolution. Analysis of informative paired persistent AML disease samples uncovered cases with two coexisting dominant clones of which at least one was chemotherapy sensitive and one resistant, respectively. These data support the conclusion that incomplete eradication of AML founder clones rather than stochastic emergence of fully unrelated novel clones underlies AML relapse and persistence with direct implications for clinical AML research This study is based on 39 patients with AML for which either paired enrollment or relapse samples or persistent disease samples were available. The patients were enrolled into this study at the University of Michigan Comprehensive Cancer Center. The study was approved by the University of Michigan Institutional Review Board (IRBMED #2004-1022) and written informed consent was obtained from all patients prior to enrollment. Genomic DNA was extracted from purified AML blasts and paired buccal cells. DNA thus obtained was hybridized to Affymetrix SNP 6.0 arrays. Note: There is no normal sample available for MIAML015.

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Dataset Information

Comparison of primary neuroblastoma tumors and derivative early-passage cell lines using genome-wide SNP array analysis

Publications

Comparison of primary neuroblastoma tumors and derivative early-passage cell lines using genome-wide single nucleotide polymorphism array analysis.

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