Project description:Whole genome tiling path array CGH was used to measure the copy number profiles of 271 NSCLC tumors 271 microdissected NSCLC tumors
Project description:A custom microarray was used to measure the gene expression of NSCLC tumors. This represents a subset of samples which also have matched DNA copy number profiles from array CGH experiments 49 microdissected NSCLC tumor samples
Project description:A custom microarray was used to measure the gene expression of NSCLC tumors. This represents a subset of samples which also have matched DNA copy number profiles from array CGH experiments
Project description:We used microarray CGH analysis with a tiling path BAC DNA microarray to profile DNA copy number alterations in 164 serous ovarian adenocarcinomas. Survival probabilities modelled by proportional hazards were used to stratify cases into good, intermediate or poor survival groups. Comparison of aCGH data from these groups was used to identify genomic alterations associated with patient survival.
Project description:Gene amplifications and deletions frequently contribute to tumorigenesis. Characterization of these DNA copy-number changes is important for both the basic understanding of cancer and its diagnosis. Comparative genomic hybridization (CGH) was developed to survey DNA copy-number variations across a whole genome. With CGH, differentially labelled test and reference genomic DNAs are co-hybridized to normal metaphase chromosomes, and fluorescence ratios along the length of chromosomes provide a cytogenetic representation of DNA copy-number variation. CGH, however, has a limited ( approximately 20 Mb) mapping resolution, and higher-resolution techniques, such as fluorescence in situ hybridization (FISH), are prohibitively labour-intensive on a genomic scale. Array-based CGH, in which fluorescence ratios at arrayed DNA elements provide a locus-by-locus measure of DNA copy-number variation, represents another means of achieving increased mapping resolution. Published array CGH methods have relied on large genomic clone (for example BAC) array targets and have covered only a small fraction of the human genome. cDNAs representing over 30,000 radiation-hybrid (RH)-mapped human genes provide an alternative and readily available genomic resource for mapping DNA copy-number changes. Although cDNA microarrays have been used extensively to characterize variation in human gene expression, human genomic DNA is a far more complex mixture than the mRNA representation of human cells. Therefore, analysis of DNA copy-number variation using cDNA microarrays would require a sensitivity of detection an order of magnitude greater than has been routinely reported. We describe here a cDNA microarray-based CGH method, and its application to DNA copy-number variation analysis in breast cancer cell lines and tumours. This study is described more fully in Pollack JR et al.(1999) Nat Genet 23:41-6 Keywords: other
Project description:Cervical cancer is the second most common malignancy in women worldwide, with high risk subtypes of human papillomavirus (HPV) constituting the major etiological agent. However, only a small percentage of women infected by the virus develop disease suggesting that additional host genetic alterations are necessary for disease progression. In this study we examined the genomes of a panel of commonly used model cervical cancer cell lines using a recently developed whole genome tiling path array for CGH analysis. Detailed analysis of genomic profiles enabled the detection of many novel aberrations which may have been missed by conventional cytogenetic methods. In total, 27 minimal regions of recurrent copy number alteration were identified that are potentially involved in tumorigenesis. Interestingly, fine mapping of the 3q gain, which is associated with the progression of precursor lesions to invasive cervical cancer, identified a minimal region of alteration harboring genes distinct from previous candidates. Novel regions of gene amplification, including the co-amplification of both the Birc and MMP gene clusters on 11q22, were also evident. Lastly, characterization of genomic structure at sites of HPV integration identified the copy number gain of host cellular sequences between the viral-host genomic boundaries in both SiHa and SW756, suggesting a direct role for HPV integration in the development of genetic abnormalities that initiate cervical cancer. This work represents the highest resolution look at a cervical cancer genome to date and offers definitive characterization of the alteration status of these cancer genomes. Whole genome tiling path array CGH profiles of 8 Cervical Cancer Cell Lines
Project description:Deletions and amplifications of the human genomic sequence (Copy Number Polymorphisms, or 'CNPs') are the cause for numerous diseases and a potential cause of phenotypic variation in the normal population. Comparative Genomic Hybridization (CGH) has been developed as a useful tool for detecting alterations in DNA copy number that involve blocks of DNA several kilobases or greater in size. We have developed High-Resolution CGH (HR-CGH) to detect accurately and with relatively little bias the presence and extent of chromosomal aberrations in human DNA. Maskless array synthesis was used to construct arrays containing 393,000 oligonucleotides with isothermal probes of 45-85 bp in length; arrays tiling the β-globin locus and chromosome 22q were prepared. Arrays with 9 bp tiling path were used to map a 622 bp heterozygous deletion in the β-globin locus. Arrays with an 85 bp tiling path were used to analyze DNA from patients with copy number changes in the pericentromeric region of chromosome 22. Heterozygous deletions and duplications as well as partial triploidies and partial tetraploidies of portions of chromosome 22q were mapped with high resolution in each patient, and the precise breakpoint of two deletions was confirmed by DNA sequencing. Additional peaks potentially corresponding to known and novel additional CNPs were also observed. Our results demonstrate that HR-CGH allows the detection of copy-number changes in any given region of the human genome comprehensively and at an unprecedented level of resolution. Keywords: high resolution comparative genome hybridization (HR-CGH)
Project description:Recents studies in mammalian genomes have uncovered the extent of copy number variation (CNV) that contributes to phenotypic diversity, including health and disease status. Here we report the first glimpse of CNVs in the pig genome covering part of the chromosomes 4, 7, 14 and 17 already sequenced and assembled. We used a custom tiling oligonucleotide array with a median probe spacing of 409 bp to screen 12 unrelated Duroc boar founders of a vast-family material. After a strict CNV calling pipeline it was identified 40 copy number variable regions covering all the four chromosomes, with some overlapping segmental duplications and pig unigenes. This CNV snapshot analysis lays the groundwork for a better understanding of porcine phenotypes and genotypes for the identification of important economic traits. Keywords: comparative genome hybridization, CNV, Sus Scrofa, Nimblegen tiling array A custom 385k tiling-path array CGH was designed (Nimblegen Systems) to cover the preliminary Sus Scrofa assembly for chromosomes 4, 7, 14 and 17, from the August 2007 release (http://www.sanger.ac.uk/Projects/S_scrofa/), which was the newest version at the time of the experiment. From a pig family-material comprising 14 boar founders, 700 sows and about 12.000 offspring, 12 Duroc boar founders (A, B, C, D, E, G, H, J, K, L, M and N) were selected to function as test animals. An unrelated boar of the Hampshire breed was selected as the common reference. Each of the 12 boars were hybridized twice (technical replicates, 24 arrays) against the common reference.
Project description:Gene amplifications and deletions frequently contribute to tumorigenesis. Characterization of these DNA copy-number changes is important for both the basic understanding of cancer and its diagnosis. Comparative genomic hybridization (CGH) was developed to survey DNA copy-number variations across a whole genome. With CGH, differentially labelled test and reference genomic DNAs are co-hybridized to normal metaphase chromosomes, and fluorescence ratios along the length of chromosomes provide a cytogenetic representation of DNA copy-number variation. CGH, however, has a limited ( approximately 20 Mb) mapping resolution, and higher-resolution techniques, such as fluorescence in situ hybridization (FISH), are prohibitively labour-intensive on a genomic scale. Array-based CGH, in which fluorescence ratios at arrayed DNA elements provide a locus-by-locus measure of DNA copy-number variation, represents another means of achieving increased mapping resolution. Published array CGH methods have relied on large genomic clone (for example BAC) array targets and have covered only a small fraction of the human genome. cDNAs representing over 30,000 radiation-hybrid (RH)-mapped human genes provide an alternative and readily available genomic resource for mapping DNA copy-number changes. Although cDNA microarrays have been used extensively to characterize variation in human gene expression, human genomic DNA is a far more complex mixture than the mRNA representation of human cells. Therefore, analysis of DNA copy-number variation using cDNA microarrays would require a sensitivity of detection an order of magnitude greater than has been routinely reported. We describe here a cDNA microarray-based CGH method, and its application to DNA copy-number variation analysis in breast cancer cell lines and tumours. This study is described more fully in Pollack JR et al.(1999) Nat Genet 23:41-6