Array Comparative Genomic Hybridization of Merkel Cell Carcinoma Tumors
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE13239 | GEO | 2009/01/01
SECONDARY ACCESSION(S): PRJNA109513
REPOSITORIES: GEO
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Project description:Array-CGH profiles of Merkel cell carcinoma tumors Experiment Overall Design: We perfromed array-CGH on 25 Merkel cell carcinoma tumor samples (2 primary/metastasis pairs) looking for recurrent gains/losses among the cohort of tumors. Experiment Overall Design: Results from the Analysis of Copy Errors (ACE) may be found in GSE13239_MccACEAnalyzedData.txt. Experiment Overall Design: The overall profiles of the primary/metastasis pairs are similar. These metastases samples, 1m and 3m, were excluded from the ACE analysis.
2009-01-14 | E-GEOD-13239 | biostudies-arrayexpress
Project description:Purpose: Due to the rarity of Merkel Cell Carcinoma (MCC), prospective clinical trials have not been practical. This study seeks to identify biomarkers to differentiate between patients with a good and poor prognosis. Methods: Patients were stratified into good, moderate or poor prognosis. Merkel cell carcinoma (MCC) patients were stratified into one of three groups based upon status 24 months following treatment. Poor prognosis patients either presented with or progressed to distant metastasis. Patients with favorable prognosis had local disease presentation with no subsequent recurrence or nodal disease at presentation with no progression during follow-up of longer than 24 months. Moderate prognosis had recurrent local disease, development of nodal metastasis, or nodal disease at presentation with no progression during follow-up of fewer than 24 months. Using ArcturusXT Laser Capture Microdissection (Molecular Devices), tumor cells were isolated from the specific areas of interest. The captured tumor tissue was subjected to RNA extraction using the Invitrogen PureLinkM-bM-^DM-" FFPE RNA Isolation Kit. The extracted RNA was analyzed for integrity with the Agilent Bioanalyzer then amplified and hybridized to Affymetrix GeneChip Human Exon 1.0 ST arrays using the NuGEN WT- OvationM-bM-^DM-" FFPE System. Results: A total of 191 genes showed significant differential expression (pM-bM-^IM-$0.05 and 1.5-fold cutoff) between the different between the good and poor prognosis groups. Keratin 20 (KRT20) and Neurofilament protein (NEFM) have been identified in previous studies as proteins of interest in MCC. Our study showed these genes to be significantly upregulated in patients with a poor prognosis. Of interest, phospholipase A2, group X was upregulated in poor responders. Phospholipases liberate arachidonic acid from cellular membranes which can be metabolized to eicosanoids through three major pathways: the cyclooxygenase (COX), the lipoxygenase (LOX) and the cytochrome P450 monooxygenase pathways. This pathway has been implicated in several cancers. Conclusions: The study identified genes with a previous association with MCC as well as some novel genes. These genes provide the basis for further research into possible biomarkers that will enable the differentiation between patients with a good and poor prognosis. Using laser capture microdissection, tumor cells of patients with a good (n=5), moderate (n=3), and poor prognosis (n=7) were isolated from paraffin embedded archival tissue of 15 patients with Merkel cell carcinoma. Affymetrix Human Exon 1.0ST microarrays were utilized to compare gene expression signatures from good and poor prognosis patients.
2014-02-20 | E-GEOD-36150 | biostudies-arrayexpress
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
2005-02-09 | GSE1755 | GEO
Project description:Dermatofibrosarcoma protuberans (DFSP) is an aggressive spindle cell neoplasm. It is associated with the chromosomal translocation, t(17:22), which fuses the COL1A1 and PDGFbeta genes. We determined the characteristic gene expression profile of DFSP and characterized DNA copy number changes in DFSP by array-based comparative genomic hybridization (array CGH). Fresh frozen and formalin-fixed, paraffin-embedded samples of DFSP were analyzed by array CGH (four cases) and DNA microarray analysis of global gene expression (nine cases). The nine DFSPs were readily distinguished from 27 other diverse soft tissue tumors based on their gene expression patterns. Genes characteristically expressed in the DFSPs included PDGFbeta and its receptor, PDGFRB, APOD, MEOX1, PLA2R, and PRKCA. Array CGH of DNA extracted either from frozen tumor samples or from paraffin blocks yielded equivalent results. Large areas of chromosomes 17q and 22q, bounded by COL1A1 and PDGFbeta, respectively, were amplified in DFSP. Expression of genes in the amplified regions was significantly elevated. Our data shows that: 1) DFSP has a distinctive gene expression profile; 2) array CGH can be applied successfully to frozen or formalin-fixed, paraffin-embedded tumor samples; 3) a characteristic amplification of sequences from chromosomes 17q and 22q, demarcated by the COL1A1 and PDGFbeta genes, respectively, was associated with elevated expression of the amplified genes.
2005-11-03 | E-SMDB-2439 | biostudies-arrayexpress
Project description:Merkel cell carcinoma is supposed to be derived from Merkel cells after infection by Merkel cell polyomavirus (MCV) and other poorly known events. A transcriptional profiling with cDNA microarrays was performed on cells from MCV+ Merkel cell carcinomas and isolated normal Merkel cells. This microarray revealed numerous significantly upregulated genes and down-regulated genes. The extensive list of genes identified in these experiments provides a large body of potentially valuable information of Merkel cell carcinoma carcinogenesis and could represent a source of potential targets for cancer therapy. Two-conditions experiment, MCV vs Normal Merkel Cell. Biological replicates : 4 MCV (Cy5), 1 control = pool of Normal Merkel cells from 3 liftings
2014-01-01 | E-GEOD-50434 | biostudies-arrayexpress
Project description:miRNAs are excellent tumor biomarkers because of their cell-type specificity and abundance. However, many miRNA detection methods, such as real-time (RT)-PCR, obliterate valuable visuospatial information in tissue samples. To enable miRNA visualization in formalin-fixed paraffin-embedded (FFPE) tissues, we developed multicolor miRNA fluorescence in situ hybridization (FISH). For proof-of-concept, we differentiated two skin tumors, namely Basal cell carcinoma (BCC) and Merkel cell carcinoma (MCC), with overlapping histologic features but distinct cellular origins. Using sequencing-based miRNA profiling and discriminant analysis, we identified tumor-specific miRNAs (miR-205 and miR-375) in BCC and MCC respectively. We addressed three major shortcomings in miRNA FISH, identifying optimal conditions for miRNA fixation and rRNA retention using model compounds and HPLC analyses, enhancing signal amplification and detection by increasing probe-hapten linker lengths, and improving probe specificity using shortened probes with minimal rRNA sequence complementarity. We validated our method on 4 BCC and 12 MCC tumors. Amplified miR-205 and miR-375 signals were normalized against directly detectable reference rRNA signals. Tumors were classified using pre-defined cut-off values; all were correctly identified in blinded analysis. We established a reliable miRNA FISH technique for parallel visualization of differentially expressed miRNAs in FFPE tumor tissues
2013-03-14 | GSE45146 | GEO
Project description:miRNAs are excellent tumor biomarkers because of their cell-type specificity and abundance. However, many miRNA detection methods, such as real-time (RT)-PCR, obliterate valuable visuospatial information in tissue samples. To enable miRNA visualization in formalin-fixed paraffin-embedded (FFPE) tissues, we developed multicolor miRNA fluorescence in situ hybridization (FISH). For proof-of-concept, we differentiated two skin tumors, namely Basal cell carcinoma (BCC) and Merkel cell carcinoma (MCC), with overlapping histologic features but distinct cellular origins. Using sequencing-based miRNA profiling and discriminant analysis, we identified tumor-specific miRNAs (miR-205 and miR-375) in BCC and MCC respectively. We addressed three major shortcomings in miRNA FISH, identifying optimal conditions for miRNA fixation and rRNA retention using model compounds and HPLC analyses, enhancing signal amplification and detection by increasing probe-hapten linker lengths, and improving probe specificity using shortened probes with minimal rRNA sequence complementarity. We validated our method on 4 BCC and 12 MCC tumors. Amplified miR-205 and miR-375 signals were normalized against directly detectable reference rRNA signals. Tumors were classified using pre-defined cut-off values; all were correctly identified in blinded analysis. We established a reliable miRNA FISH technique for parallel visualization of differentially expressed miRNAs in FFPE tumor tissues 6 MCC samples 2 normal skin samples were profiled with Agilent miRNA array platform
2013-03-14 | E-GEOD-45146 | biostudies-arrayexpress
Project description:Automated array-CGH optimized for archival formalin-fixed, paraffin-embedded tumor material
| PRJNA98399 | ENA
Project description:Gene-expression profiles of formalin-fixed, paraffin-embedded human hepatocellular carcinoma tissues obtained at the time of surgical resection. Gene-expression profiling was performed using formalin-fixed, paraffin-embedded hepatocellular carcinoma tissues obtained at the time of surgical resection.
2011-02-17 | E-GEOD-19977 | biostudies-arrayexpress
Project description:Aim of this study is to test if a reference channel of a different array can be used to make array CGH more sensitive, cost effective and less labor intensive. The BT474 breast cancer cell line was compared to a mix of normal reference DNAs hybridized on different arrays and days and DNA copy number profiles were evaluated. Quality was assessed, using regular dual channel array CGH as a standard, using four quality measures; i.e. the MAD (median absolute deviation) value of chromosome 2, an amplitude of the ErbB2 gene amplification, a deletion on chromosome 9 and a deflection on chromosome 8. In addition, the use of a reference channel of a different array was tested for genomic DNA derived from formalin-fixed paraffin-embedded tumor tissue samples. This so called across array CGH (aaCGH) analysis yielded slightly higher quality chromosomal copy number profiles when using the same dye compared to analysis using two different dyes, both when exchanging fluorescent signals of hybridizations performed on different arrays and on different days. This approach avoids redundant hybridizations of the same reference material in every experiment and allows hybridization of two test samples on one array. AaCGH analysis substantially reduces cost of consumables and labor while yielding at least equivalent quality as the dual channel procedure. Keywords: array CGH data, across array CGH analysis
2007-12-31 | GSE8628 | GEO