Ontology highlight
ABSTRACT:
PROVIDER: PRJNA579562 | ENA |
REPOSITORIES: ENA
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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:We studied 277 lymphoma samples (198 FL and 79 transformed FL [tFL]) using a single-nucleotide polymorphism array to identify the secondary chromosomal abnormalities that drive the development of FL and its transformation to diffuse large B-cell lymphoma. Affymetrix 250K NspI SNP arrays were performed according to the manufacturer's directions on DNA extracted from frozen follicular lymphoma or transformed follicular lymphoma tumor specimens
2015-03-30 | E-GEOD-67385 | biostudies-arrayexpress
Project description:Purpose: Follicular lymphoma is a common lymphoma of adults. Although its course is often indolent, a substantial proportion of patients have a poor prognosis, often due to rapid progression or transformation to a more aggressive lymphoma. Currently available clinical prognostic scores, such as the follicular lymphoma international prognostic index, are not able to optimally predict transformation or poor outcome. Experimental Design: Gene expression profiling was done on primary lymphoma biopsy samples. Results: Using a statistically conservative approach, predictive interaction analysis, we have identified pairs of interacting genes that predict poor outcome, measured as death within 5 years of diagnosis. The best gene pair performs >1,000-fold better than any single gene or the follicular lymphoma international prognostic index in our data set. Many gene pairs achieve outcome prediction accuracies exceeding 85% in extensive cross-validation and noise sensitivity computational analyses.Many genes repeatedly appear in top-ranking pairs, suggesting that they reproducibly provide predictive capability. Conclusions:The evidence reported here may provide the basis for an expression-based, multigene test for predicting poor follicular lymphoma outcomes. Keywords: Comparative genomics
2008-10-15 | GSE13029 | GEO
Project description:Transformation of Follicular Lymphoma to Diffuse Large Cell Lymphoma: Alternative Patterns with Increased or Decreased Expression of c-myc and its Regulated genes The natural history of follicular lymphoma (FL) is frequently characterized by transformation to a more aggressive diffuse large B cell lymphoma (DLBCL). We compared the gene expression profiles between transformed DLBCL and their antecedent FL. No genes were observed to increase or decrease their expression in all the cases of histological transformation. However, two different gene expression profiles associated with the transformation process were defined, one in which c-myc and genes regulated by c-myc showed increased expression and one in which these same genes showed decreased expression. Further, there was a striking difference in gene expression profiles between transformed DLBCL and de novo DLBCL, since the gene expression profile of transformed DLBCL was more similar to their antecedent FL than to de novo DLBCL. The study demonstrates that transformation from FL to DLBCL can occur by alternative pathways and that transformed DLBCL and de novo DLBCL have very different gene expression profiles that may underlie the different clinical behaviors of these two types of morphologically similar lymphomas.
2005-09-23 | E-SMDB-963 | biostudies-arrayexpress
Project description:Nodal marginal zone lymphoma is a poorly defined entity in the WHO classification, largely based on criteria by exclusion and the diagnosis often remains subjective. Follicular Lymphoma lacking t(14;18), have similar characteristics which results in a major potential diagnostic overlap which this study aims to dissect. Four subgroups of lymphoma samples (n=56) were analyzed with high-resolution arrayCGH; Nodal marginal zone lymphoma, t(14;18)-negative Follicular Lymphoma, localized t(14:18)-positive Follicular Lymphoma and disseminated t(14;18)-positive Follicular Lymphoma. Gains on chromosomes 7, 8 and 12 were observed in all subgroups. The mean number of aberrations was higher in disseminated t(14;18)-positive Follicular Lymphoma compared to localized t(14:18)-positive Follicular Lymphoma (p<0.01) and the majority of alterations in localized t(14:18)-positive Follicular Lymphoma were also found in disseminated t(14;18)-positive Follicular Lymphoma. Nodal marginal zone lymphoma was marked by 3q gains with amplifications of four genes. A different overall pattern of aberrations was seen in t(14;18)-negative Follicular Lymphoma compared to t(14;18)-positive Follicular Lymphoma. t(14;18)-negative Follicular Lymphoma is marked by specific (focal) gains on chromosome 3 as observed in Nodal marginal zone lymphoma. Our results support the notion that localized t(14:18)-positive Follicular Lymphoma represents an early phase of disseminated t(14;18)-positive Follicular Lymphoma. t(14;18)-negative Follicular Lymphoma bears aberrations that are more alike Nodal marginal zone lymphoma, suggesting a relation between these groups.
2013-07-16 | GSE40641 | GEO
Project description:Transformation of Follicular Lymphoma to Diffuse Large Cell Lymphoma: Alternative Patterns with Increased or Decreased Expression of c-myc and its Regulated genes The natural history of follicular lymphoma (FL) is frequently characterized by transformation to a more aggressive diffuse large B cell lymphoma (DLBCL). We compared the gene expression profiles between transformed DLBCL and their antecedent FL. No genes were observed to increase or decrease their expression in all the cases of histological transformation. However, two different gene expression profiles associated with the transformation process were defined, one in which c-myc and genes regulated by c-myc showed increased expression and one in which these same genes showed decreased expression. Further, there was a striking difference in gene expression profiles between transformed DLBCL and de novo DLBCL, since the gene expression profile of transformed DLBCL was more similar to their antecedent FL than to de novo DLBCL. The study demonstrates that transformation from FL to DLBCL can occur by alternative pathways and that transformed DLBCL and de novo DLBCL have very different gene expression profiles that may underlie the different clinical behaviors of these two types of morphologically similar lymphomas. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set Using regression correlation
2005-10-18 | E-GEOD-3458 | biostudies-arrayexpress
Project description:Follicular lymphoma (FL) is the second most common B-cell malignancy representing one quarter of Non-Hodgkin's Lymphomas. Although the disease has a relatively long median survival, the illness follows a fluctuating course of progression punctuated by remissions of variable duration. For as many as half of patients, transformation to a more aggressive lymphoma (t-FL) may occur; this event is often associated with a particularly poor response to treatment. SNP analysis has revealed the presence of large regions of homozygosity in the absence of copy number change. These events can result in the selection of of daughter cells made homozygous for a pre-existing mutation. We have used SNPs array technology to investigate regions of loss of hetrozygosity in the absence of copy number change in order to establish the contribution of these abnormalities to the evolution of FL and t-FL. Experiment Overall Design: DNA from 26 pairs of follicular and transformed follicular lymphoma samples and 3 cell lines were analysed using Affymetrix 10K SNP arrays. The genotype data of transformed follicular lymphoma samples were compared with the data from the corresponding follicular lymphoma sample.
2008-06-17 | E-GEOD-7425 | biostudies-arrayexpress
Project description:Transformation of follicular lymphoma (FL) to a more aggressive disease is associated with rapid progression and death. Existing molecular markers for transformation are few and their clinical impact is limited. Here, we report on a whole-genome study of DNA copy numbers and gene expression profiles in serial FL biopsies. We identified 698 genes with high correlation between gene expression and copy number and the molecular network most enriched for these cis-associated genes. This network includes 14 cis-associated genes directly related to the NFκB pathway. For each of these 14 genes, the correlated NFκB target genes were identified and corresponding expression scores defined. The scores for six of the cis-associated NFκB pathway genes (BTK, IGBP1, IRAK1, ROCK1, TMED7-TICAM2 and TRIM37) were significantly associated with transformation. The results suggest that genes regulating B-cell survival and activation are involved in transformation of FL Expression profiles were obtained from 81 biopsies origniating from 41 patients diagnosed with follicular lymphoma using Affymetrix HG U133 Plus 2.0 Gene Chip. Of these, 49 biopsies were from 24 patients with subsequent transformation to higher-grade lymphoma (DLBCL) (43 with histological diagnosis FL and 6 with DLBCL) and 32 biopsies were from 17 patients without any signs transformation
2014-01-07 | E-GEOD-53820 | biostudies-arrayexpress
Project description:Most B cell lymphomas arise in the germinal center (GC), where humoral immune responses evolve from potentially oncogenic cycles of mutation, proliferation, and clonal selection. Although lymphoma gene expression diverges significantly from GC-B cells, underlying mechanisms that alter the activities of corresponding regulatory elements (REs) remain elusive. Here we define the complete pathogenic circuitry of human follicular lymphoma (FL), which activates or decommissions transcriptional circuits from normal GC-B cells and commandeers enhancers from other lineages. Moreover, independent sets of transcription factors, whose expression is deregulated in FL, target commandeered versus decommissioned REs. Our approach reveals two distinct subtypes of low-grade FL, whose pathogenic circuitries resemble GC-B or activated B cells. Remarkably, FL-altered enhancers also are enriched for sequence variants, including somatic mutations, which disrupt transcription factor binding and expression of circuit-linked genes. Thus, the pathogenic regulatory circuitry of FL reveals distinct genetic and epigenetic etiologies for GC-B transformation. Molecular profiling of follicular lymphoma, resting peripheral blood and tonsillar B cells using Formaldehyde-Assisted Isolation of Regulatory Elements (FAIRE) and chromatin immunoprecipitation (H3ac and H3K27ac).
2015-01-15 | E-GEOD-62245 | biostudies-arrayexpress