Affymetrix SNP array data of melanoma cell lines
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE60218 | GEO | 2015/01/01
SECONDARY ACCESSION(S): PRJNA257778
REPOSITORIES: GEO
Similar Datasets
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.
2016-07-27 | GSE80736 | 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:Here we report on a bulk culture termed MCM1, which was derived from a 61 year old male diagnosed with a nodular melanoma stage T2a, N0. At passage three of culturing, DNA was isolated and Affymetrix SNP6.0 array hybridizations were performed. Cultured MCM1 cells revealed overall identical copy number gains and losses as compared with the primary patient-derived lesion and were therefore used in this study.
2012-06-18 | GSE35991 | GEO
Project description:Marginal zone B-cell lymphomas (MZL) have been divided into three distinct subtypes (extranodal MZL of MALT type, nodal MZL; splenic MZL). Nevertheless, the relationship between them is still unclear. We performed a comprehensive analysis of genomic DNA copy number changes in a very large series of MZL cases with the aim of addressing this question. Samples from 218 MZL patients (25 nodal, 57 MALT, 134 splenic and two not better specified MZL) were analyzed with the Affymetrix Human Mapping 250K SNP arrays, and the data combined with matched gene expression in 33/218 cases. MALT lymphoma presented significantly more frequently gains at 3p, 6p, 18p and del(6q23) (TNFAIP3/A20), whilst splenic MZL was associated with del(7q31), del(8p). Nodal MZL did not show statistically significant differences when compared with MALT lymphoma while lacked the splenic MZL-related 7q losses. Gains of 3q and 18q gains were common to all three subtypes. Del(8p) was often present together with del(17p) (TP53). While del(17p) did not determine a worse outcome and del(8p) was only of borderline significance, the presence of both deletions had a highly significant negative impact on the outcome of splenic MZL.
2011-02-01 | GSE24881 | GEO
Project description: Not available
| S-DIXA-D-1096 | biostudies-other
Project description:Here we report on a bulk culture termed MCM1, which was derived from a 61 year old male diagnosed with a nodular melanoma stage T2a, N0. At passage three of culturing, DNA was isolated and Affymetrix SNP6.0 array hybridizations were performed. Cultured MCM1 cells revealed overall identical copy number gains and losses as compared with the primary patient-derived lesion and were therefore used in this study. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA, which was extracted from a patient derived melanoma sample and from a cellline generated from the same melanoma sample at passage three.
2012-06-17 | E-GEOD-35991 | biostudies-arrayexpress
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.
2013-09-19 | GSE44019 | GEO
Project description:A consanguineous family segregating anhidrosis (recessive, familial) Shared homozygous regions were identified by comparing SNP genotyping results from four affected family members
2014-09-05 | GSE61122 | GEO
Project description:Genetic alterations lead to resistance to immunotherapy
2017-05-24 | GSE96884 | GEO
Project description:BackgroundCopy number data are routinely being extracted from genome-wide association study chips using a variety of software. We empirically evaluated and compared four freely-available software packages designed for Affymetrix SNP chips to estimate copy number: Affymetrix Power Tools (APT), Aroma.Affymetrix, PennCNV and CRLMM. Our evaluation used 1,418 GENOA samples that were genotyped on the Affymetrix Genome-Wide Human SNP Array 6.0. We compared bias and variance in the locus-level copy number data, the concordance amongst regions of copy number gains/deletions and the false-positive rate amongst deleted segments.ResultsAPT had median locus-level copy numbers closest to a value of two, whereas PennCNV and Aroma.Affymetrix had the smallest variability associated with the median copy number. Of those evaluated, only PennCNV provides copy number specific quality-control metrics and identified 136 poor CNV samples. Regions of copy number variation (CNV) were detected using the hidden Markov models provided within PennCNV and CRLMM/VanillaIce. PennCNV detected more CNVs than CRLMM/VanillaIce; the median number of CNVs detected per sample was 39 and 30, respectively. PennCNV detected most of the regions that CRLMM/VanillaIce did as well as additional CNV regions. The median concordance between PennCNV and CRLMM/VanillaIce was 47.9% for duplications and 51.5% for deletions. The estimated false-positive rate associated with deletions was similar for PennCNV and CRLMM/VanillaIce.ConclusionsIf the objective is to perform statistical tests on the locus-level copy number data, our empirical results suggest that PennCNV or Aroma.Affymetrix is optimal. If the objective is to perform statistical tests on the summarized segmented data then PennCNV would be preferred over CRLMM/VanillaIce. Specifically, PennCNV allows the analyst to estimate locus-level copy number, perform segmentation and evaluate CNV-specific quality-control metrics within a single software package. PennCNV has relatively small bias, small variability and detects more regions while maintaining a similar estimated false-positive rate as CRLMM/VanillaIce. More generally, we advocate that software developers need to provide guidance with respect to evaluating and choosing optimal settings in order to obtain optimal results for an individual dataset. Until such guidance exists, we recommend trying multiple algorithms, evaluating concordance/discordance and subsequently consider the union of regions for downstream association tests.
| S-EPMC3146450 | biostudies-literature