Project description:22 pairs of normal colon\colon adenocarcinoma samples were genotyped using Illumina HumanOmni1-Quad BeadChip to estimate copy number alterations
Project description:22 pairs of normal colon\colon adenocarcinoma samples were genotyped using Illumina HumanOmni1-Quad BeadChip to estimate copy number alterations Genomic DNA of 22 colon adenocarcinoma samples and 22 corresponding normal colon samples were genotyped using Illumina HumanOmni1-Quad BeadChip to estimate copy number alterations.
Project description:High-resolution microarray-based whole genome genotyping (WGG) techniques based on SNP analysis have successfully been applied in cancer genomics to study gene copy number alterations and allele-specific aberrations such as loss-of-heterozygosity (LOH). Problems in data interpretation arise when WGG is applied on tumor tissue specimens, in which normal cell components and tumor subpopulations frequently exist. Such heterogeneity may lead to reduced detection of cancer cell specific genomic alterations. To circumvent problems with sample heterogeneity, we propose using a segmentation strategy derived from DNA copy number analysis for detection of LOH and allelic imbalance. We generated an experimental dilution series of a tumor cell line mixed with its paired normal cell line and simulated data for such dilutions to test the strategy. We also used data sets generated on both Affymetrix and Illumina WGG platforms, including paired tumor-normal samples and tumors previously characterized by FISH. We tested the segmentation strategy against several reported algorithms. We demonstrate high sensitivity and specificity of the segmentation strategy for detecting both minute and gross allelic imbalances originating from DNA copy number gain, loss, and neutral events in tumor specimens. For example, hemizygous copy number loss can be detected in samples containing only 20-25% tumor cells. Furthermore, the strategy can identify cell subpopulation specific events and accurately estimate the fraction of cells affected by an allelic imbalance. Thus, the segmentation strategy extends the usefulness of WGG platforms for investigation of allelic imbalances in heterogeneous tumor genomes.
Project description:Somatic copy number alterations of 17 paired tumor and metastasis tissue samples were measured by Agilent array-based comparative genomic hybridization (CGH). Seven colon adenocarcinomas with paired liver metastasis and 10 liver carcinoma with metastasis to the lymph node, adrenal gland or lung were analyzed.
Project description:GeneSeek HD Bovine 77k Genotyping array is used to estimate population structure and ancestry of bovine and evaluate loci responsible for complex traits. Further, copy number variation of bovine can be estimated by GeneSeek HD Bovine 77k Genotyping array. Here, we estimate population structure and ancestry of Qinchuan cattle.
Project description:Genome-wide DNA copy number was studied to determine whether the Wilms' tumor samples generally show normal copy number variation comparing to the colon tumor samples We used custom Nimblegen microarrays to determine the genome-wide DNA copy number in human Wilms' Tumor samples
Project description:In order to benchmark the reproducibility of Affymetrix Genome-Wide Human SNP Array 6.0 for detecting copy-number alterations, we performed replicate hybridizations of 3 tumor cell lines and 2 paired normal cell lines obtained from the American Type Culture Collection (ATCC). We calculated copy numbers at each SNP probeset by a custom copy-number pipeline (PMID: 18772890). For each cell line, copy number data from replicate arrays are supplied in the accompanying matrix files. For each SNP probeset, we calculated the median copy number across replicate arrays. We compared the copy-number alterations detected by Circular Binary Segmentation segmentation of these arrays with statistical analyses of short sequence reads obtained from the Illumina/Solexa 1G GenomeAnalyzer. Shotgun sequencing results can be found in the NCBI Short Read Archive, accession number SRP000246 Keywords: disease state analysis 21 replicates of HCC1143 (breast ductal carcinoma), 21 replicates of HCC1143BL (matched normal), 13 replicates of HCC1954 (breast ductal carcinoma), 11 replicates of HCC1954BL (matched normal), 1 replicate of NCI-H2347 (lung adenocarcinoma), 1 replicate of NCI-H2347BL (matched normal)
Project description:In order to benchmark the reproducibility of Affymetrix 238K Sty arrays for detecting copy-number alterations. We performed replicate hybridizations of 3 tumor cell lines and 2 paired normal cell lines obtained from the American Type Culture Collection (ATCC). We calculated copy numbers at each SNP probeset by array pre-processing with the GISTIC algorithm (PMID: 18077431). For each SNP probeset, we calculated the median copy number across replicate arrays. The median copy number profile for each tumor cell line was segmented with the GLAD algorithm (PMID: 15381628) to partition the genome into regions of constant copy number. We compared the copy-number alterations detected by GLAD segmentation of these arrays with statistical analyses of short sequence reads obtained from the Illumina/Solexa 1G GenomeAnalyzer. Shotgun sequencing results can be found in the NCBI Short Read Archive, accession number SRP000246. Keywords: disease state analysis 77 replicates of HCC1143 (breast ductal carcinoma), 69 replicates of HCC1143BL (matched normal), 42 replicates of HCC1954 (breast ductal carcinoma), 36 replicates of HCC1954BL (matched normal), 1 replicate of NCI-H2347 (lung adenocarcinoma)
Project description:In order to examine if acquired copy number alterations in DNA repair genes is commonly observed in therapy-related AML, we used this custom built NimbleGen array with dense tiling of probes in 170 DNA repair genes to interrogate paired normal (skin) and tumor (bone marrow) samples.
Project description:Ovarian cancer is characterized by multiple structural aberrations; most are passenger alterations which do not confer tumor growth. Like many cancers, it is a heterogeneous disease and till date, the histotype-specific copy number landscape has been difficult to elucidate. To dissect the heterogeneity of ovarian cancer and understand the pathogenesis of its various histotypes, we developed an in silico hypothesis-driven workflow to identify histotype-specific copy number aberrations across multiple datasets of epithelial ovarian cancer. In concordance with previous studies on global copy number changes, our study showed similar alterations. However, when the landscape was de-convoluted into histotypes, distinct alterations were observed. We report here a comprehensive histotype-specific copy number landscape of ovarian cancer and showed that there is genomic diversity between the histotypes; some involving well known cancer genes and some novel potential driver genes. Besides preferential occurrence of alterations in some histotypes, opposite trends of alteration were observed; such as ERBB2 amplification in mucinous but deletion in serous tumors. The landscape highlights the need for identifying histotype-specific aberrations in ovarian cancer and present potential to tailor management of ovarian cancer based on molecular signature of histotypes. 56 samples containing the 4 histotypes were used for this study. It contained 12 clear cell carcinoma, 6 endometrioid adenocarcinoma, 2 mucinous adenocarcinoma, 5 mucinous-borderline tumors, 26 serous adenocarcinoma, and 5 serous-borderline tumors. Data was pre-processed and normalized with Hapmap JPT using the Affymetric Genotyping Console.