Targeted sequencing of follicular lymphoma tumour samples from the UK's Haematological Malignancy Research Network
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ABSTRACT:
PROVIDER: EGAS00001005238 | EGA |
REPOSITORIES: EGA
Similar Datasets
Project description:Follicular lymphoma (FL) is genetically characterized by the presence of the t(14;18)(q32;q21) chromosomal translocation in approximately 90% of cases. In contrast to FL carrying the t(14;18), their t(14;18)-negative counterparts are less well studied regarding their immunohistochemical, genetic, molecular and clinical features. Within a previously published series of 184 FL grade 1-3A with available gene expression data, we identified 17 FL lacking the t(14;18). Comparative genomic hybridization and high resolution SNP array profiling demonstrated that gains/amplifications of the BCL2 gene locus in 18q were restricted to the t(14;18)-positive FL subgroup. A comparison of gene expression profiles revealed an enrichment of germinal center B-cell associated signatures in t(14;18)-positive FL, whereas activated B-cell like, NFƒÛB, proliferation and bystander cell signatures were enriched in t(14;18)-negative FL. These findings were confirmed by immunohistochemistry in an independent validation series of 84 FL, in which 32% of t(14;18)-negative FL showed weak or absent CD10 expression and 91% an increased Ki67 proliferation rate. Although overall survival did not differ between FL with and without t(14;18), our findings suggest distinct molecular features of t(14;18)-negative FL.
2009-06-03 | GSE16131 | GEO
Project description:Follicular lymphoma (FL) is genetically characterized by the presence of the t(14;18)(q32;q21) chromosomal translocation in approximately 90% of cases. In contrast to FL carrying the t(14;18), their t(14;18)-negative counterparts are less well studied regarding their immunohistochemical, genetic, molecular and clinical features. Within a previously published series of 184 FL grade 1-3A with available gene expression data, we identified 17 FL lacking the t(14;18). Comparative genomic hybridization and high resolution SNP array profiling demonstrated that gains/amplifications of the BCL2 gene locus in 18q were restricted to the t(14;18)-positive FL subgroup. A comparison of gene expression profiles revealed an enrichment of germinal center B-cell associated signatures in t(14;18)-positive FL, whereas activated B-cell like, NFƒÛB, proliferation and bystander cell signatures were enriched in t(14;18)-negative FL. These findings were confirmed by immunohistochemistry in an independent validation series of 84 FL, in which 32% of t(14;18)-negative FL showed weak or absent CD10 expression and 91% an increased Ki67 proliferation rate. Although overall survival did not differ between FL with and without t(14;18), our findings suggest distinct molecular features of t(14;18)-negative FL. Fresh-frozen tumor-biopsy specimens were obtained from 184 untreated patients who had received a diagnosis of follicular lymphoma. RNA was extracted from the biopsy specimens and was examined for gene expression with the use of Affymetrix U133A and U133B microarrays.
2009-06-02 | E-GEOD-16131 | biostudies-arrayexpress
Project description:A subset of FL in adults are negative for t(14;18) translocation and BCL2 expression The tumor shows low grade cytology and lack both BCL2 expression and t(14;18) translocation. The genetic alterations involved in the pathogenesis of FL without t(14;18)-negative translocation and BCL2 expression are not well known.
2020-11-23 | GSE80103 | GEO
Project description:Follicular lymphoma (FL) is an indolent, but incurable subtype of non-Hodgkin lymphoma. These tumor harbor t (14;18) translocation in at least 90% of patients. Recently, activating EZH2 mutations have been Follicular lymphoma (FL) is an indolent, but incurable subtype of non-Hodgkin lymphoma. These tumor harbor t (14;18) translocation in at least 90% of patients. Recently, activating EZH2 mutations have been found in a significant number of patients with FL. Gene expression profiling (GEP) was performed to determine differential gene-expression between the EZH2 mutated vs unmutated subgroups in FL.
2014-07-01 | GSE55267 | GEO
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. Four subgroups of follicular lymphoma were analyzed: NMZL (n=14), t-FL (n=12), LOC t+FL (n=16), DIS t+FL (n=14).
2013-07-16 | E-GEOD-40641 | biostudies-arrayexpress
Project description:Background: 15% of high and 50% of low stage FL lack the t(14;18). Nevertheless, most of these cases express BCL2 by so far unknown mechanisms. Principals/Methodology: To find molecular mechanisms, triggering FL-pathogenesis in t(14;18)-negative FL, the exonic SNV-profiles of 33 FL with and 16 FL without t(14;18) were assessed by whole exome-sequencing and external SNV-data integration. The SNV-profile of the whole exome-sequenced FL was correlated with copy number, LOH and gene-expression data. Finally, the N-glycosylation status was assessed (LympTrack assay) in a separate validation cohort. Results: SNVs in FL with and without t(14;18) affected different genes, but accumulated in similar pathways, e.g. apoptosis, epigenetic processes and cell cycle/proliferation. Mutations in genes associated with immune-response were more prominently and those associated with NFkB and N-glycosylation selectively enriched in t(14;18)-negative FL. ~50% of mutated genes showed BCL2-asociation at high confidence in FL with and without t(14;18). Moreover, among the genes mutated in t(14;18)-negative FL 555 (~1/3) were affected by copy number alterations and/or copy-neutral LOH, 125 were differently expressed between FL with and without t(14;18) (p<0.01) and 62 were differentially expressed and affected by copy number alterations and/or copy-neutral LOH. N-glycosylation was strongly reduced in t(14;18)-negative FL as compared to results reported for historical FL cohorts. Conclusion: These results suggest a stronger crosstalk with the microenvironment that may compensate for the lack of N-glycosylation and a diverse portfolio of SNVs that may contribute to the upregulation of BCL2 and FL pathogenesis in t(14;18)-negative FL.
| EGAS00001002164 | EGA
Project description:Follicular lymphoma (FL) is an indolent, but incurable subtype of non-Hodgkin lymphoma. These tumor harbor t (14;18) translocation in at least 90% of patients. Recently, activating EZH2 mutations have been Follicular lymphoma (FL) is an indolent, but incurable subtype of non-Hodgkin lymphoma. These tumor harbor t (14;18) translocation in at least 90% of patients. Recently, activating EZH2 mutations have been found in a significant number of patients with FL. Gene expression profiling (GEP) was performed to determine differential gene-expression between the EZH2 mutated vs unmutated subgroups in FL. Total RNA extracted from fresh frozen specimens with FL diagnosis were processed for hybridization to Affymetrix HG-U133 plus 2 arrays. To enhance the identification of differential gene expression in FL tumor cells only, FL cases with a high B-cell content (enriched B-cell signature of >2-fold above the mean of the B-cell signature (pan B-cell markers) in the entire FL data set) were chosen for analysis.
2014-07-01 | E-GEOD-55267 | biostudies-arrayexpress
Project description:Targeted sequencing was applied to an unselected population-based follicular lymphoma (FL) cohort (n=548) diagnosed in the UK's Haematological Malignancy Research Network catchment population of ~4 million (14 centres).
DNA extracted from FL samples was sequenced with a 293-gene panel using the Illumina HiSeq 2500. All data are provided in the CRAM format.
| EGAD00001007657 | EGA
Project description:Follicular lymphoma (FL) shows heterogenous expression of the cell surface B-cell marker, CD20. In order to investigate whether this heterogeneity also marks underlying transcriptional heterogeneity, we sorted tumor B-cells from 8 FL specimens based upon their intermediate or high expression of CD20 and transcriptionally profiled them. CD20 intermediate and CD20 high tumor B-cells were sorted by FACS, RNA extracted, and profiled using Affymetrix U133 plus 2.0 microarrays.
2013-01-01 | E-GEOD-38816 | biostudies-arrayexpress
Project description:Follicular lymphoma (FL) shows heterogenous expression of the cell surface B-cell marker, CD20. In order to investigate whether this heterogeneity also marks underlying transcriptional heterogeneity, we sorted tumor B-cells from 8 FL specimens based upon their intermediate or high expression of CD20 and transcriptionally profiled them.
2013-01-01 | GSE38816 | GEO