Project description:Data underlying Sander et al., Oncogene 2005, June 20, Comparative genomic hybridization on mouse cDNA microarrays and its application to a murine lymphoma model. Includes both array CGH and expression data. Abstract: Microarray-based formats offer a high-resolution alternative to conventional, chromosome-based comparative genomic hybridization (CGH) methods for assessing DNA copy number alteration (CNA) genome-wide in human cancer. For murine tumors, array CGH should provide even greater advantage, since murine chromosomes are more difficult to individually discern. We report here the adaptation and evaluation of a cDNA microarray-based CGH method for the routine characterization of CNAs in murine tumors, using mouse cDNA microarrays representing approximately 14,000 different genes, thereby providing an average mapping resolution of 109 kb. As a first application, we have characterized CNAs in a set of 10 primary and recurrent lymphomas derived from a Myc-induced murine lymphoma model. In primary lymphomas and more commonly in Myc-independent relapses, we identified a recurrent genomic DNA loss at chromosome 3G3-3H4, and recurrent amplifications at chromosome 3F2.1-3G3 and chromosome 15E1/E2-15F3, the boundaries of which we defined with high resolution. Further, by profiling gene expression using the same microarray platform, we identified within CNAs the relevant subset of candidate cancer genes displaying comparably altered expression, including Mcl1 (myeloid cell leukemia sequence 1), a highly expressed antiapoptotic gene residing within the chr 3 amplicon peak. CGH on mouse cDNA microarrays therefore represents a reliable method for the high-resolution characterization of CNAs in murine tumors, and a powerful approach for elucidating the molecular events in tumor development and progression in murine models. A disease state experiment design type is where the state of some disease such as infection, pathology, syndrome, etc is studied. Keywords: disease_state_design, arrayCGH, expression profiling
Project description:Data underlying Sander et al., Oncogene 2005, June 20, Comparative genomic hybridization on mouse cDNA microarrays and its application to a murine lymphoma model. Includes both array CGH and expression data. Abstract: Microarray-based formats offer a high-resolution alternative to conventional, chromosome-based comparative genomic hybridization (CGH) methods for assessing DNA copy number alteration (CNA) genome-wide in human cancer. For murine tumors, array CGH should provide even greater advantage, since murine chromosomes are more difficult to individually discern. We report here the adaptation and evaluation of a cDNA microarray-based CGH method for the routine characterization of CNAs in murine tumors, using mouse cDNA microarrays representing approximately 14,000 different genes, thereby providing an average mapping resolution of 109 kb. As a first application, we have characterized CNAs in a set of 10 primary and recurrent lymphomas derived from a Myc-induced murine lymphoma model. In primary lymphomas and more commonly in Myc-independent relapses, we identified a recurrent genomic DNA loss at chromosome 3G3-3H4, and recurrent amplifications at chromosome 3F2.1-3G3 and chromosome 15E1/E2-15F3, the boundaries of which we defined with high resolution. Further, by profiling gene expression using the same microarray platform, we identified within CNAs the relevant subset of candidate cancer genes displaying comparably altered expression, including Mcl1 (myeloid cell leukemia sequence 1), a highly expressed antiapoptotic gene residing within the chr 3 amplicon peak. CGH on mouse cDNA microarrays therefore represents a reliable method for the high-resolution characterization of CNAs in murine tumors, and a powerful approach for elucidating the molecular events in tumor development and progression in murine models. A disease state experiment design type is where the state of some disease such as infection, pathology, syndrome, etc is studied. Using regression correlation
Project description:For the purpose of characterization of the 9p24 amplicon, we carried out high-resolution array CGH (Agilent 244K chip) analysis of four cancer cell lines, including three breast cancer cell lines, Colo824, HCC1954 and HCC70, and one esophageal cancer cell line, KYSE150.
Project description:Array-based comparative genomic hybridisation is a high-resolution method for measuring chromosomal copy number changes. Here we present a validated protocol using in-house spotted oligonucleotide libraries for array CGH. This oligo array CGH platform yields reproducible results and is capable of detecting single copy gains, multi-copy amplifications as well as homozygous and heterozygous deletions as small as 100 kb with high resolution. A human oligonucleotide library was printed on amine binding slides. Arrays were hybridised using a hybstation and analysed using BleuFuse feature extraction software, with over 95% of spots passing quality control. The protocol allows as little as 300 ng of input DNA without the need for amplification or target reduction and a 90% reduction of Cot1-DNA without compromising quality. High quality results have also been obtained with DNA from archival tissue. Finally, in addition to human oligo arrays, we have applied the protocol successfully to mouse oligo arrays. We believe that this oligo-based platform using “off-the-shelf” oligo-libraries provides an easy accessible alternative to BAC arrays for CGH, which is cost-effective, available at high resolution and easily implemented for any sequenced organism without compromising the quality of the results. Keywords: comparative genomic hybridization, oligonucleotide,
Project description:Malignant melanoma is an aggressive heterogeneous disease for which new biomarkers for diagnosis and clinical outcome are needed. We investigated by array-CGH the presence of DNA gains and losses to provide better genomic profile of primary malignant melanoma and to explore the possibility to distinguish metastatic from non metastatic melanomas using this technology. High resolution array-CGH (Agilent Technologies, Palo Alto, CA), with more than 40.000 probes, has been used to analyze 20 frozen tissues of vertical growth phase primary melanoma with a minimum follow-up time of 36 months. Eight patients developed nodal metastatic disease and twelve did not. For results validation, 83 additional melanoma samples with similar clinical characteristics were analysed by FISH. DNA copy number aberrations (CNA) were observed in 19 out of 20 cases. The most frequent changes were complete or partial losses in chromosomes 9 (12 cases, 60%) and 10 (9 cases, 45%), partial gains or trisomies of chromosome 7 (10 cases, 50%); and monosomy of chromosome 19 (7 cases, 35%). Sixty-four recurrent aberrant regions (SORIs) were precisely delimited and used as variables for clustering. Unsupervised Cluster analysis allowed the segregation of samples into two genomic groups that naturally fitted with the metastatic condition of the cases. Four of these aberrant regions were chosen for their biological interest and were confirmed as aberrant using FISH technique on fixed paraffin embedded tissues. Conclusion: Supervised classification allowed obtaining aberrations useful to separate samples with different clinical outcome. Obtained results are useful to improve the knowledge about melanoma tumorigenesis but unfortunately cannot be used as a marker for metastatic progression. Keywords: Comparative Genomic Hybridization - array; Genomic Instability
Project description:Distinguishing between Spitz nevus and melanoma presents a challenging task for clinicians and pathologists. Most of these lesions are submitted entirely in formalin for histologic analysis by conventional hematoxylin and eosin-stained sections, and fresh-frozen material for ancillary studies is rarely collected. Molecular techniques, such as comparative genomic hybridization (CGH), can detect chromosomal alterations in tumor DNA that differ between these 2 lesions. This study investigated the ability of high-resolution array-based CGH to serve as a diagnostic test in distinguishing Spitz nevus and melanoma using DNA isolated from formalin-fixed and paraffin-embedded samples. Two of 3 Spitz nevi exhibited no significant chromosomal alterations, while the third showed gain of the short arm of chromosome 11p. The latter finding has previously been described as characteristic of a subset of Spitz nevi. The 2 melanomas showed multiple copy number alterations characteristic of melanoma such as 1q amplification and chromosome 9 deletion. This study has shown the utility of array-based CGH as a potential molecular test in distinguishing Spitz nevus from melanoma. The assay is capable of using archival paraffin-embedded, formalin-fixed material; is technically easier to perform as compared with conventional CGH; is more sensitive than conventional CGH in being able to detect focal alterations; and can detect copy number alterations even with relatively small amounts of lesional tissue as is typical of many skin tumors. Series_type = clinical_history_design A clinical history design type is where the organisms clinical history of diagnosis, treatments, e.g. vaccinations, surgery etc. Keywords: other