Genomic alterations and gene expression in primary diffuse large B cell lymphomas of immune privileged sites
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE10524 | GEO | 2008/06/19
SECONDARY ACCESSION(S): PRJNA107873
REPOSITORIES: GEO
Similar Datasets
Project description:Primary diffuse large B cell lymphomas of different immune-privileged sites (IP-DLBCL) share many clinical and biological features, such as a relatively poor prognosis, preferential dissemination to other immune-privileged sites and deletion of the HLA region, which suggests that IP-DLBCL represents a separate entity. To further investigate the nature of IP-DLBCL, we investigated site-specific genomic aberrations in 16 testicular, 9 central nervous system (CNS) and 15 nodal DLBCL using array-CGH. We also determined minimal common regions of gain and loss. Using robust algorithms, the array-CGH data were combined with gene expression data to explore pathways deregulated by chromosomal aberrations. Keywords: comparative genomic hybridisation, gene expression, tumor type comparison Whole tissue sections of 16 testicular, 9 central nervous system (CNS) and 15 nodal DLBCL were used for isolation of genomic DNA and total RNA. Genomic aberrations were determined using an in house printed CGH array containing ~3700 large genomic insert clones. Gene expression was analyzed on Affymetrix HU133 plus 2.0 oligo arrays. Gene expression data and arrayCGH data were combined using the R program ACE-it.
2008-06-18 | E-GEOD-10524 | biostudies-arrayexpress
Project description:Recurrent genomic aberrations have been obtained using a genome-wide DNA profiling. DNA copy number profiling by SNP array. 12 DLBCL samples. No technical replications.
2010-04-08 | E-GEOD-15127 | biostudies-arrayexpress
Project description:Loss of human leukocyte antigen (HLA) expression on tumor cells is frequent in diffuse large B cell lymphoma (DLBCL) arising in immune-privileged sites such as the testis and central nervous system and is associated with small homozygous deletions of HLA-DQ/DR and larger hemizygous deletions of the major histocompatibility complex (MHC) region. To better understand the significance of downregulation of HLA class II expression in relation to the homozygous and hemizygous deletions, we analyzed global gene expression patterns in a series of 26 testicular diffuse large B-cell lymphomas (DLBCL) after characterization of these deletions. Low levels of HLA-DR mRNA in whole testicular DLBCL samples were associated with a strong downregulation of numerous immune-related genes specific for T-cells, macrophages, antigen presentation and processing, lymphocyte activation, chemokines and chemokine receptors and the complement system. Interestingly, hemizygous and homozygous deletions in the MHC region did not have any additional impact on global gene expression. Keywords: Gene expression
2006-04-01 | GSE4157 | GEO
Project description:We superimposed array comparative genomic hybridization (aCGH) data onto existing expression array profiles (GSE3892) to sift out the pivotal genes underlying the pathogenesis of a well defined series of diffuse large B-cell lymphomas (DLBCL). 280 gained and over-expressed genes were identified, located on chromosomes 1q, 3q, 7, 12p12, 18q and 21q. At the most frequently gained region the oncogene MDMX/MDM4 was concurrently over-expressed, which is a critical regulator of p53 function. In regions of frequent chromosomal loss, 36 genes were concurrently down-regulated, restricted to 6q and 15p. These putative tumor suppressor genes included PERP, MAP3K5, CCNDBP1 and β2M, and loss of 6q was associated with poor clinical outcome. Genes identified and chromosomal regions validated in an independent series of DLBCL patients. Overall design fields: Copy number profiles (array CGH) of a series of 42 Diffuse large B-cell lymphoma patient samples were analyzed a) for frequency of aberrations and b) for impact on gene expression. No duplicate samples or dye-swaps were analyzed. a) Statistical analysis of Array CGH data Calling: Areas of gains and losses and their frequencies throughout the dataset were determined from the Bluefuse ratios within the statistical package â??CGHcallâ?? (van de Wiel et al., 2007). Briefly, after smoothing outliers and median normalization, â??DNAcopyâ?? segmentation (Olshen et al., 2004) was applied within CGHcall, after which a call was assigned to each position on the genome. Within CGHcall the probabilities of the calls were determined per chromosomal arm, and a cellularity correction of 0.75 was applied to each sample because tumor cellularity in all DLBCL is estimated to be maximal 75%, taking into account all stromal, endothelial en infiltrating lymphocytes. After calling, we applied â??CGHregionsâ?? (van de Wiel and van Wieringen 2007) to determine regions of consecutive clones with highly similar calls for all samples. This dimension reduction further increases robustness and statistical power for downstream statistical analyses. Called data were used for all downstream analyses. b) Integration with expression data To integrate called array CGH data with expression array data, the array CGH and expression integration tool, ACE-it (van Wieringen et al., 2006), was used. For ACE-it analysis chromosomal amplifications were included in the gains. ACE-it uses the one-sided Wilcoxon rank sum to test which chromosomal aberrations recurrently affect RNA expression and adjust p-values for multiple testing. Only those clones were taken into account which had at least 20% (9) of the samples in one of the other calling states (gain or loss). Only genes were considered relevant with a false discovery rate of <0.1. References - Olshen AB, Venkatraman ES, Lucito R, Wigler M (2004) Circular binary segmentation for the analysis of array-based DNA copy number data. Biostatistics 5: 557-72. - van de Wiel MA, Kim KI, Vosse SJ, van Wieringen WN, Wilting SM, Ylstra B (2007) CGHcall: calling aberrations for array CGH tumor profiles. Bioinformatics 23: 892-4. - van de Wiel MA, van Wieringen WN. CGHregions: dimension reduction for array CGH data with minimal information loss. Cancer Informatics. In press 2007. - van Wieringen WN, Belien JA, Vosse SJ, Achame EM, Ylstra B (2006) ACE-it: a tool for genome-wide integration of gene dosage and RNA expression data. Bioinformatics 22: 1919-20.
2010-06-25 | E-GEOD-5138 | biostudies-arrayexpress
Project description:Despite recent therapeutic improvements, the clinical course of diffuse large B-cell lymphoma (DLBCL) still differs considerably among patients. We conducted this retrospective multi-centre study to evaluate the impact of genomic aberrations detected using a high-density genome wide-single nucleotide polymorphism-based array on clinical outcome in a population of DLBCL patients treated with R-CHOP-21 (rituximab, cyclophosphamide, doxorubicine, vincristine and prednisone repeated every 21 d). 167 DNA samples were analysed using the GeneChip Human Mapping 250K NspI. Genomic anomalies were analysed regarding their impact on the clinical course of 124 patients treated with R-CHOP-21. Unsupervised clustering was performed to identify genetically related subgroups of patients with different clinical outcomes. Twenty recurrent genetic lesions showed an impact on the clinical course. Loss of genomic material at 8p23.1 showed the strongest statistical significance and was associated with additional aberrations, such as 17p- and 15q-. Unsupervised clustering identified five DLBCL clusters with distinct genetic profiles, clinical characteristics and outcomes. Genetic features and clusters, associated with a different outcome in patients treated with R-CHOP, have been identified by arrayCGH. DNA copy number profiling by SNP array.
2009-04-01 | GSE15127 | GEO
Project description:Myelodysplastic syndromes (MDS) are a group of clonal disorders of hematopoietic stem cells. Mesenchymal stem cells (MSC) are the progenitors of the Bone Marrow (BM) stroma and have been involved in the physiopathology of MDS. The presence of cytogenetic aberrations on MSC from MDS patients is controversial. The aim of the study is to characterize BM derived MSC from patients with MDS using: kinetic studies, immunophenotyping, fluorescent in situ hybridisation (FISH) analysis and genetic changes by array based comparative genomic hybridization (array-CGH). 32 cases of untreated MDS were included in the study. MSC from MDS achieved confluence at a slower rate than donor-MSC, and the antigenic expression of CD105 and CD104 was also lower. Array-CGH studies showed DNA genomic changes that were proved not to be somatic, and gains were more frequent than looses. The results of array-CGH were confirmed by FISH. When an unsupervised hierarchical cluster analysis was performed two clusters were identified: one of them included the 5q- syndrome patients, while the other incorporated the rest of the MDS patients. Our results shows, for the first time, that MSC from MDS display genomic aberrations, assessed by array-CGH and FISH, some of them specially linked to particular MDS subtypes. Keywords: Genomic comparison between mesenchymal cells
2008-08-01 | GSE10822 | GEO
Project description:Our model removes T cells as targets for lymphomagenesis as well as eliminating T cell-dependent immune surveillance. These mice exclusively develop early onset IgM+ B cell lymphomas that histologically and genetically resemble the activated B cell-like (ABC) subset of human diffuse large B cell lymphomas (DLBCL). This dataset includes the array CGH of B-cell lymphomas (tumors) from ATMKO.CD3eKO mice.
2015-07-18 | GSE59577 | GEO
Project description:Molecular pathogenesis of posttransplant (PT) lymphoproliferative disorder, including the most prevalent diffuse large B cell lymphoma (DLBCL), is largely unknown. We have recently showed that Epstein-Barr Virus (EBV)+ and EBV- PT-DLBCL are biologically different, but gene expression profile of the latter lymphoma is similar to that of immunocompetent (IC) DLBCL. To validate these findings on a genomic level, we performed array CGH analysis of 21 EBV+ and 6 EBV- PT-DLBCL, and 11 control IC-DLBCL. Genomic and transcriptomic data were subsequently integrated. Notably, EBV+ and EBV- PT-DLBCL revealed only one shared recurrent imbalance, while EBV- PT-DLBCL displayed at least 10 aberrations recurrent in IC-DLBCL, among others gain of 3/3q and 18q, and loss of 6q23/TNFAIP3 and 9p21/CDKN2A. EBV+ PT-DLBCL showed distinct aberrations, including the most prevalent gain/amplification of 9p24.1 targeting PDCD1LG2/PDL2. Significant differential representation/expression of 3p13/FOXP1 and 9p21/CDKNA2 in EBV+ PT-DLBCL when compared with EBV- PT-/IC-DLBCL, suggests that the oncogene FOXP1 and the tumor suppressor gene CDKNA2 are not implicated in pathogenesis of EBV+ PT-DLBCL. In summary, genomic profiling of PT-/IC-DLBCL confirmed biological distinctness of EBV+ and EBV- PT-DLBCL, and relationship between EBV- PT-DLBCL and IC-DLBCL. These findings support the hypothesis that EBV- PT-DLBCL are coincidental lymphomas in transplant recipients
2015-06-02 | GSE69440 | GEO
Project description:Follicular lymphoma (FL) is one of the most common types of indolent B-cell lymphoma in Western countries. FL commonly transforms to more aggressive diffuse large B-cell lymphoma (DLBCL) at reported frequencies between 15 - 60%. We have used microarray comparative genomic hybridisation (aCGH) at 1 Mb resolution to study copy number changes in paired tumor samples (primary FL and a subsequent tDLBCL) as well as de novo DLBCL cases to outline genetic mechanisms of transformation from follicular lymphoma to diffuse large B-cell lymphoma.
2014-04-18 | GSE56884 | GEO
Project description:Background: Amyotrophic lateral sclerosis (ALS) is a devastating disorder of the central nervous system that leads to progressive loss of upper and lower motor neurons. Most cases are sporadic and of unknown aetiology. In this study, we screened 71 patients with sporadic ALS for the presence of DNA copy number variations, in order to identify novel candidate disease genes. Methods: We have used sub-megabase resolution BAC array comparative genomic hybridisation to detect genomic imbalances in our ALS patient cohort. In order to distinguish phenotypically neutral copy number variations occurring frequently in the normal population from disease-associated aberrations, we screened our results against both the Database of Genomic Variants and a reference data set of approximately 700 normal individuals and probands with other disorders analysed in our laboratory. Aberrations with potential relevance for disease aetiology were verified by oligo array CGH. Findings: In 71 patients with sporadic ALS, we identified a total of six duplications and seven deletions that scored above our threshold. Twelve of these thirteen variations were smaller than 1Mb. Seven were observed exclusively in ALS patients and thus likely play causal roles in the disorder. Analysis of these regions highlighted, for example, the SLC1A7 (EAAT5) glutamate transporter and the kinesin family member KIF9 as good positional and functional candidate genes for ALS. Interpretation: Non-polymorphic sub-microscopic duplications and deletions observable by array CGH are frequent in patients with sporadic ALS. Analysis of such aberrations serves as an excellent starting point in deciphering the aetiology of this complex disease. Keywords: array CGH
2008-12-25 | GSE7950 | GEO