Project description:Affymetrix 10K SNP mapping arrays were used to profile 14 basal cell carcinomas (BCCs) with matched blood DNA samples. Loss of heterozygosity (LOH) and copy number abnormality (CNA) profiles were derived from each tumour-blood pair. Keywords: Genomic DNA on Affymetrix 10K SNP array
Project description:BACKGROUND: Cervical carcinoma develops as a result of multiple genetic alterations. Different studies investigated genomic alterations in cervical cancer mainly by means of metaphase comparative genomic hybridization (mCGH) and microsatellite marker analysis for the detection of loss of heterozygosity (LOH). Currently, high throughput methods such as array comparative genomic hybridization (array CGH), single nucleotide polymorphism array (SNP array) and gene expression arrays are available to study genome-wide alterations. Integration of these 3 platforms allows detection of genomic alterations at high resolution and investigation of an association between copy number changes and expression. RESULTS: Genome-wide copy number and genotype analysis of 10 cervical cancer cell lines by array CGH and SNP array showed highly complex large-scale alterations. A comparison between array CGH and SNP array revealed that the overall concordance in detection of the same areas with copy number alterations (CNA) was above 90%. The use of SNP arrays demonstrated that about 75% of LOH events would not have been found by methods which screen for copy number changes, such as array CGH, since these were LOH events without CNA. Regions frequently targeted by CNA, as determined by array CGH, such as amplification of 5p and 20q, and loss of 8p were confirmed by fluorescent in situ hybridization (FISH). Genome-wide, we did not find a correlation between copy-number and gene expression. At chromosome arm 5p however, 22% of the genes were significantly upregulated in cell lines with amplifications as compared to cell lines without amplifications, as measured by gene expression arrays. For 3 genes, SKP2, ANKH and TRIO, expression differences were confirmed by quantitative real-time PCR (qRT-PCR). CONCLUSION: This study showed that copy number data retrieved from either array CGH or SNP array are comparable and that the integration of genome-wide LOH, copy number and gene expression is useful for the identification of gene specific targets that could be relevant for the development and progression in cervical cancer. Keywords: DNA copynumber RNA expression correlation
Project description:Genome-wide profiling of Copy Number Alterations (CNA) and Loss of Heterozygosity (LOH), gene expression and resequencing of pediatric AML. This study characterizes the CNA and LOH in a representative cross-section through subtypes of pediatric AML. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from cryopreserved diagnostic bone marrow or peripheral blood samples.
Project description:Genome-wide profiling of Copy Number Alterations (CNA) and Loss of Heterozygosity (LOH), gene expression and resequencing of pediatric AML. This study characterizes the CNA and LOH in a representative cross-section through subtypes of pediatric AML. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from cryopreserved diagnostic bone marrow or peripheral blood samples.
Project description:Genome-wide profiling of Copy Number Alterations (CNA) and Loss of Heterozygosity (LOH), gene expression and resequencing of pediatric AML. This study characterizes the CNA and LOH in a representative cross-section through subtypes of pediatric AML. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from cryopreserved diagnostic bone marrow or peripheral blood samples.
Project description:Genome-wide profiling of Copy Number Alterations (CNA) and Loss of Heterozygosity (LOH), gene expression and resequencing of pediatric AML. This study characterizes the CNA and LOH in a representative cross-section through subtypes of pediatric AML. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from cryopreserved diagnostic bone marrow or peripheral blood samples.
Project description:Intratumor mutational heterogeneity has been documented in primary non-small cell lung cancer. Here, we elucidate mechanisms of tumor evolution and heterogeneity in metastatic thoracic tumors (lung adenocarcinoma and thymic carcinoma) using whole-exome and transcriptome sequencing, SNP array for copy number alterations (CNA) and mass spectrometry-based quantitative proteomics of metastases obtained by rapid autopsy. APOBEC-mutagenesis, promoted by increased expression of APOBEC3 region transcripts and associated with a high-risk germline APOBEC3 variant, strongly correlated with mutational tumor heterogeneity. TP53 mutation status was associated with APOBEC hypermutator status. Interferon pathways were enriched in tumors with high APOBEC mutagenesis and IFN- induced expression of APOBEC3B in lung adenocarcinoma cells in culture suggesting a role for the immune microenvironment in the generation of mutational heterogeneity. CNA occurring late in tumor evolution correlated with downstream transcriptomic and proteomic heterogeneity, although global proteomic heterogeneity was significantly greater than transcriptomic and CNA heterogeneity. These results illustrate key mechanisms underlying multi-dimensional heterogeneity in metastatic thoracic tumors.
Project description:The integration of genomic and epigenomic data is becoming increasingly popular as we try to gain better understanding of the complex mechanisms driving the development and progression of cancer. However, this results in increased cost and sample depletion, the latter being particularly important when considering intra-tumour heterogeneity. We therefore sought to investigate the possible utility of high-density DNA methylation arrays to assess both aberrant methylation as well as changes in gene copy number. Comparing CN (Copy Number) data derived from the Infinium Human Methylation 450K arrays with that generated on SNP arrays, we demonstrate the utility of the Infinium arrays to detect single copy alterations as well as homozygous deletions and high level amplification with the reliability of current gold standard platforms. Furthermore, we show that the gene centric design of the Infinium methylation arrays allows identification of small single gene alterations, which would not be detected using standard SNP array analysis. These results show that Infinium 450K methylation arrays provide a robust and economic platform for detecting copy number and methylation changes in a single experiment. The ability to integrate such data from the same sample is critical for cancer research and will improve our understanding of how complex genomic and epigenomic interactions are driving the development and progression of a malignant phenotype.
Project description:Goal: To identify copy number variation in normal individuals using high density, non-polymorphic oligonucleotide probes Background DNA sequence diversity within the human genome may be more greatly affected by copy number variations (CNVs) than single nucleotide polymorphisms (SNPs). Although the importance of CNVs in genome wide association studies (GWAS) is becoming widely accepted, the optimal methods for identifying these variants are still under evaluation. We have previously reported a comprehensive view of CNVs in the HapMap DNA collection using high density 500K EA (Early Access) SNP genotyping arrays which revealed greater than 1,000 CNVs ranging in size from 1kb to over 3Mb. Although the arrays used most commonly for GWAS predominantly interrogate SNPs, CNV identification and detection does not necessarily require the use of DNA probes centered on polymorphic nucleotides and may even be hindered by the dependence on a successful SNP genotyping assay. Results In this study, we have designed and evaluated a high density array predicated on the use of non-polymorphic oligonucleotide probes for CNV detection. This approach effectively uncouples copy number detection from SNP genotyping and thus has the potential to significantly improve probe coverage for genome-wide CNV identification. This array, in conjunction with PCR-based, complexity-reduced DNA target, queries over 1.3M independent NspI restriction enzyme fragments in the 200bp to 1100bp size range, which is a several fold increase in marker density as compared to the 500K EA array. In addition, a novel algorithm was developed and validated to extract CNV regions and boundaries. Conclusions Using a well-characterized pair of DNA samples, close to 200 CNVs were identified, of which nearly 50% appear novel yet were independently validated using quantitative PCR. The results indicate that non-polymorphic probes provide a robust approach for CNV identification, and the increasing precision of CNV boundary delineation should allow a more complete analysis of their genomic organization. Keywords: Copy number variation (CNV) detection
Project description:Copy number profiling of 36 ovarian tumors on Affymetrix 100K SNP arrays Thirty-six ovarian tumors were profiled for copy-number alterations with the Affymetrix 100K Mapping Array. Copy number profiling of 36 ovarian tumors on Affymetrix 500K SNP arrays Sixteen ovary tumors were profiled for copy-number alterations with the high-resolution Affymetrix 500K Mapping Array.