Affymetrix SNP array data for metastatic melanoma specimens
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE44019 | GEO | 2013/09/19
SECONDARY ACCESSION(S): PRJNA188324
REPOSITORIES: GEO
Similar Datasets
Project description:Comparison between the copy number of differentially methylated sites between lymph node metastasis from melanoma patients with good prognosis and melanoma brain metastasis. All samples are taken from different patients, and were established as cell lines in the John Wayne Cancer Institute. Sixteen metastatic melanomas were run on Affymetrix Genome-Wide Human SNP Array 6.0. Lymph node metastases and brain metastases genetic copy number variations were compared.
2013-09-19 | E-GEOD-44019 | biostudies-arrayexpress
Project description:Melanoma is one of the most aggressive and treatment-resistant cancers. It represents the most life-threatening neoplasm of the skin, and its incidence has been increasing for the last three decades. Melanoma evolves from the local transformation of melanocytes to primary tumors, which can metastasize to multiple organs. Brain metastases represent one of the most significant causes of death in cutaneous melanoma patients. Despite aggressive multi-modality threapy, patients with melanoma brain metastasis have a median survival of less than a year, with a majority of these patients dying as a result of their intracranial disease. To identify alterations in gene expression related to brain metastasis, we used Affymetrix expression arrays to assess differentially expressed genes in melanocytes, lymph node metastases, and brain metastases. Total RNA from twenty-two specimens representing normal melanocytes (n=3), melanoma lymph node metastasis (n=12), and melanoma brain metastasis (n=7) was extracted and analyzed by Affymetrix expression arrays. Melanocytes specimens were used as control samples. Melanocytes were acquired from Invitrogen (LifeTechnologies). Metastatic melanoma specimens were taken from different patients, established as cell lines in the John Wayne Cancer Institute. Early passages (less than 6) were used to perform expression analysis.
2013-09-19 | E-GEOD-44660 | biostudies-arrayexpress
Project description:Melanoma is one of the most aggressive and treatment-resistant cancers. It represents the most life-threatening neoplasm of the skin, and its incidence has been increasing for the last three decades. Melanoma evolves from the local transformation of melanocytes to primary tumors, which can metastasize to multiple organs. Brain metastases represent one of the most significant causes of death in cutaneous melanoma patients. Despite aggressive multi-modality threapy, patients with melanoma brain metastasis have a median survival of less than a year, with a majority of these patients dying as a result of their intracranial disease. To identify alterations in gene expression related to brain metastasis, we used Affymetrix expression arrays to assess differentially expressed genes in melanocytes, lymph node metastases, and brain metastases.
2013-09-19 | GSE44660 | GEO
Project description:A proportion of superficial esophageal squamous cell carcinoma, a type of less invasive esophageal squamous cell carcinoma (ESCC), would have metastasis after esophagectomy or endoscopic resection with poor prognosis. The purpose of this study was to discover the whole-genome copy number alteration (CNA) profiles of superficial ESCC and compare the CNAs of superficial ESCC patients with and without metastasis after surgery. Thirty eight superficial ESCC cases, including 19 cases with metastasis and 19 cases without metastasis within 5 years after surgery, were analyzed CNAs by Affymetrix OncoScan™ FFPE Assay. A 39-gene signature was initially constructed to identify high risk of metastasis in superficial ESCC patients. In addition, amplification of 11q13.3 (FGF4) and deletion of 9p21.3 (CDKN2A) were identified as recurrent CNAs across all 38 superficial ESCC cases. And amplifications of 3p26.33 (SOX2-OT), 8q24.21 (MYC), 14q21.1 (FOXA1) and deletion of 3p12.1 (GBE1) were identified as recurrent CNAs among metastasis cases only. Our study provided a 39-gene signature tool to identified high risk metastasis in superficial ESCC and suggested that amplifications of SOX2-OT, MYC, FOXA1 genes and deletion of GBE1 gene might play a vital role in metastasis among superficial ESCC.
2017-06-10 | GSE78926 | GEO
Project description:Melanoma recurrence frequently occurs after a latency period of several years. In vivo studies demonstrated that tumor cells overcoming latency show a T cell-edited phenotype, suggesting a relevant role for CD8+ T cells in maintaining metastatic latency. Here, in a patient model of multiple recurrent lesions, we illustrate the genetic evolution of poorly immunogenic melanoma phenotypes, evolving in the presence of autologous tumor antigen-specific CD8+ T cells. Melanoma cells from two of three late recurrent metastases, developing within a 6-year latency period, lacked HLA class I expression. HLA class I-negative tumor cells became clinically apparent 1.5 and 6 years into stage IV disease. Genome profiling by SNP arrays revealed total T-cell resistance in both metastases originating from a shared chromosome 15q alteration and independently acquired focal B2M gene deletions. A third HLA class I-positive lesion developed in year 3 of stage IV disease. By HLA haplotype loss lesion-derived melanoma cells acquired resistance towards dominant T-cell clonotypes targeting early stage III tumor cells. Early disease melanoma cells showed a dedifferentiated MITFnegative phenotype, recently described to be associated with immunosuppression, in contrast to the MITFhigh phenotype of T cell-edited tumor cells from late metastases. In summary, our study demonstrates that tumor recurrences after long-term latency develop towards T-cell resistance by independent genetic events, suggesting a mechanism of T cell-driven genetic evolution of melanoma as a means to evade immune recognition and tumor immunotherapy. Genetic alterations lead to loss of tumor antigen presentation. Cell lines were generated from tumor material, differences in T cell recognition were observed and Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from the cell lines. SNP analysis of different melanoma cell lines obtained from one melanoma patient (4 cell lines from different metastasis of one patient with matching germline DNA).
2016-07-27 | E-GEOD-80736 | biostudies-arrayexpress
Project description:Genetic variations play an important role in tumor development and metastasis. Hepatocellular carcinoma (HCC) is one of leading cause of cancer-related death. Despite improvements in surveillance and clinical treatment strategies, the prognosis of HCC remains dismal. Affymetrix SNP 6.0 array were used to evaluate the genetic characteristics of tumor DNA in 30 HBV-related HCC patients who were underwent liver transplantation. Recurrence related SNPs were selected and validated.
2012-10-26 | GSE29667 | GEO
Project description:Allele call files from on 250K StyI SNP array using DNA from 60 human cell lines from metastasized melanoma and from 44 corresponding peripheral blood mononuclear cells (CEL and CHP files provided). Analysis of the 250K StyI arrays was performed for 60 malignant melanoma cell lines derived from metastatic tumors of melanoma patients with GCOS and GTYPE (Affymetrix). In addition, DNA from peripheral blood mononuclear cells (PBMC) was available for 44 of the 60 samples.
2010-04-13 | E-GEOD-17534 | biostudies-arrayexpress
Project description:Gene expression microarrays measure the levels of messenger ribonucleic acid (mRNA) in a sample using probe sequences that hybridize with transcribed regions. These probe sequences are designed using a reference genome for the relevant species. However, most model organisms and all humans have genomes that deviate from their reference. These variations, which include single nucleotide polymorphisms, insertions of additional nucleotides, and nucleotide deletions, can affect the microarray's performance. Genetic experiments comparing individuals bearing different population-associated single nucleotide polymorphisms that intersect microarray probes are therefore subject to systemic bias, as the reduction in binding efficiency due to a technical artifact is confounded with genetic differences between parental strains. This problem has been recognized for some time, and earlier methods of compensation have attempted to identify probes affected by genome variants using statistical models. These methods may require replicate microarray measurement of gene expression in the relevant tissue in inbred parental samples, which are not always available in model organisms and are never available in humans.By using sequence information for the genomes of organisms under investigation, potentially problematic probes can now be identified a priori. However, there is no published software tool that makes it easy to eliminate these probes from an annotation. I present equalizer, a software package that uses genome variant data to modify annotation files for the commonly used Affymetrix IVT and Gene/Exon platforms. These files can be used by any microarray normalization method for subsequent analysis. I demonstrate how use of equalizer on experiments mapping germline influence on gene expression in a genetic cross between two divergent mouse species and in human samples significantly reduces probe hybridization-induced bias, reducing false positive and false negative findings.The equalizer package reduces probe hybridization bias from experiments performed on the Affymetrix microarray platform, allowing accurate assessment of germline influence on gene expression.
| S-EPMC4518889 | biostudies-literature
Project description:We searched for putative phenotypic and genotypic differences between primary lesions and melanoma metastasis. Therefore, we investigated melanoma cells derived either from the primary tumor or from lymph node metastasis of the same individual patient. In vitro studies revealed high migratory and anchorage-independent growth of metastasis-derived cells. Unexpectedly, whole genome DNA analysis displayed a total of 10 homozygous losses in the primum-derived cell line, whereas the metastasis–derived cell line only shared 5 of those losses. We further tested these cells in a mouse model for intradermal melanoma growth and detected fast growth of the metastasis-derived cell line and delayed growth of primum-derived cells. However, after re-grafting of primum-derived cells, tumor growth kinetic was accelerated and therefore comparable to metastasis-derived cells. Moreover, re-grafted primum-derived cells now also harboured the same reduced DNA deletion pattern, identical to human metastasis-derived cells. We conclude that our xenotransplantation model mimics clonal selection from a heterogeneous starting population, and we suggest that tumor cell progression at the metastatic niche can occur parallel and independently from the primary tumor. Therefore, we propose that for mutation-targeted therapy approaches, the genotyping procedure should include primary as well as metastatic melanoma biopsies.
2011-04-07 | GSE22461 | GEO
Project description:We searched for putative phenotypic and genotypic differences between primary lesions and melanoma metastasis. Therefore, we investigated melanoma cells derived either from the primary tumor or from lymph node metastasis of the same individual patient. In vitro studies revealed high migratory and anchorage-independent growth of metastasis-derived cells. Unexpectedly, whole genome DNA analysis displayed a total of 10 homozygous losses in the primum-derived cell line, whereas the metastasis–derived cell line only shared 5 of those losses. We further tested these cells in a mouse model for intradermal melanoma growth and detected fast growth of the metastasis-derived cell line and delayed growth of primum-derived cells. However, after re-grafting of primum-derived cells, tumor growth kinetic was accelerated and therefore comparable to metastasis-derived cells. Moreover, re-grafted primum-derived cells now also harboured the same reduced DNA deletion pattern, identical to human metastasis-derived cells. We conclude that our xenotransplantation model mimics clonal selection from a heterogeneous starting population, and we suggest that tumor cell progression at the metastatic niche can occur parallel and independently from the primary tumor. Therefore, we propose that for mutation-targeted therapy approaches, the genotyping procedure should include primary as well as metastatic melanoma biopsies. DNA was extracted from in vitro grown cell lines, and Affymetrix SNP6.0 arrays were performed according to the manufacturer's instructions. Intensity Log2 ratios were used to manually search for homozygous deletions via the genotyping console.
2011-04-07 | E-GEOD-22461 | biostudies-arrayexpress