High Myc activity is an independent negative prognostic factor for diffuse large B cell lymphomas
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE31311 | GEO | 2011/11/01
SECONDARY ACCESSION(S): PRJNA146019
REPOSITORIES: GEO
Similar Datasets
Project description:In this study we investigated to which extend aberrant c Myc activity plays a functional role in other aNHL and whether it is independent from MYC translocations. Based on a combined microarray analysis of human germinal centre (GC) B cells transfected with c Myc and 220 aNHLs cases, we developed a ‘c Myc index’. This data set contains expresssion profiles from Germinal center B-cells transfected with control or Myc expression vectors. The corresponding lymphoma gene expression profiles are included in the series with GEO accession GSE4475. Expression profiling of germinal center B-cells extracted from human tonsils with and without ectopic expression of Myc.
2011-11-01 | E-GEOD-31311 | biostudies-arrayexpress
Project description:Diffuse large B-cell lymphoma (DLBCL), the most common subtype of non-Hodgkin's lymphoma, is clinically heterogeneous: 40% of patients respond well to current therapy and have prolonged survival, whereas the remainder succumb to the disease. We proposed that this variability in natural history reflects unrecognized molecular heterogeneity in the tumours. Using DNA microarrays, we have conducted a systematic characterization of gene expression in B-cell malignancies. Here we show that there is diversity in gene expression among the tumours of DLBCL patients, apparently reflecting the variation in tumour proliferation rate, host response and differentiation state of the tumour. We identified two molecularly distinct forms of DLBCL which had gene expression patterns indicative of different stages of B-cell differentiation. One type expressed genes characteristic of germinal centre B cells ('germinal centre B-like DLBCL'); the second type expressed genes normally induced during in vitro activation of peripheral blood B cells ('activated B-like DLBCL'). Patients with germinal centre B-like DLBCL had a significantly better overall survival than those with activated B-like DLBCL. The molecular classification of tumours on the basis of gene expression can thus identify previously undetected and clinically significant subtypes of cancer.
2005-06-28 | E-SMDB-183 | biostudies-arrayexpress
Project description:The distinction between the Burkitt lymphoma and diffuse large B-cell lymphoma is imprecise using current diagnostic criteria. We applied transcriptional and genomic profiling to molecularly define Burkitt lymphoma. Gene expression profiling employing Affymetrix GeneChips (U133A) was performed in 220 mature aggressive B-cell lymphomas, including a core group of eight Burkitt lymphomas, which fulfilled all diagnostic criteria of the WHO classification. A molecular signature of Burkitt lymphoma was generated. Chromosomal abnormalities were detected by interphase fluorescence in-situ hybridization and array comparative genomic hybridization. The molecular Burkitt lymphoma signature identified 44 cases. Fifteen of these cases lacked a morphology typical for Burkitt/Burkitt-like lymphoma. The vast majority (88%) of the 176 lymphomas without the molecular Burkitt lymphoma signature represented diffuse large B-cell lymphomas. In 20% of these cases a MYC break was detectable which was associated with complex chromosomal changes. Our molecular definition of Burkitt lymphoma sharpens and extends the spectrum of Burkitt lymphoma. In mature aggressive B-cell lymphomas without a Burkitt lymphoma signature, a chromosomal break in the MYC locus proved to be associated with adverse clinical outcome. Experiment Overall Design: 220 diffuse large B-cell lymphoma and Burkitt lymphoma samples hybridized to 221 HGU133A Affymetrix GeneChips
2008-06-13 | E-GEOD-4475 | biostudies-arrayexpress
Project description:Diffuse large B-cell lymphoma (DLBCL) is the commonest form of lymphoid malignancy, with a prevalence of about 40% worldwide. Its classification encompasses a common form, also termed as "not otherwise specified" (NOS), and a series of variants, which are rare and at least in part related to viral agents. Over the last two decades, DLBCL-NOS, which accounts for more than 80% of the neoplasms included in the DLBCL chapter, has been the object of an increasing number of molecular studies which have led to the identification of prognostic/predictive factors that are increasingly entering daily practice. In this review, the main achievements obtained by gene expression profiling (with respect to both neoplastic cells and the microenvironment) and next-generation sequencing will be discussed and compared. Only the amalgamation of molecular attributes will lead to the achievement of the long-term goal of using tailored therapies and possibly chemotherapy-free protocols capable of curing most (if not all) patients with minimal or no toxic effects.
| S-EPMC8003012 | biostudies-literature
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:EIF4A1 and cofactors EIF4B and EIF4H have been well characterised in cancers, including B cell malignancies, for their ability to promote the translation of oncogenes with structured 5’ untranslated regions. However, very little is known of their roles in non-malignant cells. Using mouse models to delete Eif4a1, Eif4b or Eif4h in B cells we show that EIF4A1, but not EIF4B or EIF4H, is essential for B cell development and the germinal centre response. Following B cell activation in vitro, EIF4A1 facilitates an increased rate of protein synthesis, MYC expression and expression of cell cycle regulators. However, EIF4A1-deficient cells remain viable whereas inhibition of EIF4A1 and EIF4A2 by Hippuristanol treatment induces cell death.
2023-11-09 | PXD046710 | Pride
Project description:Follicular lymphoma (FL) is the second most common forms of B cell lymphoma that result from the expansion of germinal center (GC) B cells. Here, we aimed to find differential expression of genes between noemal spleen, indoent FL (VavPBcl2/vector) and transformed and aggressive FL (VavPBcl2/MYC) in our mouse model.
2019-12-20 | GSE142335 | GEO
Project description:Loss of function mutations within KMT2D are a striking feature of the germinal centre lymphomas, with lesions present in 80% of Follicular Lymphoma (FL) and 30% of Diffuse Large B-cell Lymphoma (DLBCL), resulting in decreased H3K4 methylation and altered gene expression. The KDM5 family normally maintains homeostasis through demethylating H3K4me3/2, thus negatively regulating gene expression. We hypothesised that inhibition of KDM5 may re-establish H3K4 methylation and restore the expression of genes repressed upon loss of KMT2D. Using a selective inhibitor of the KDM5 family we were able to increase H3K4me3 levels in DLBCL cell lines, predominantly at gene promoters, ultimately leading to decreased proliferation and cell death in KMT2D mutant cell lines. This appeared to be driven by an increase in the expression of negative regulators of B cell survival pathways, many of which have previously been described as targets of KMT2D and CREBBP, resulting in diminished BCR signalling. We also observed decreased BCL2 expression in all examined t(14;18) positive cell lines, alongside changes in other BCL2 family members in sensitive cell lines. KDM5 sensitivity was confirmed to be dependent on the presence of KMT2D mutations by generating de novo KMT2D mutant cell lines and correcting naturally mutant cell lines, which displayed greater and lesser sensitivity to KDM5 inhibition respectively. KDM5 inhibition may therefore be an effective therapeutic strategy for ameliorating KMT2D loss of function mutations in malignancies such as germinal centre lymphomas.
2021-06-01 | GSE114492 | GEO
Project description:Loss of function mutations within KMT2D are a striking feature of the germinal centre lymphomas, with lesions present in 80% of Follicular Lymphoma (FL) and 30% of Diffuse Large B-cell Lymphoma (DLBCL), resulting in decreased H3K4 methylation and altered gene expression. The KDM5 family normally maintains homeostasis through demethylating H3K4me3/2, thus negatively regulating gene expression. We hypothesised that inhibition of KDM5 may re-establish H3K4 methylation and restore the expression of genes repressed upon loss of KMT2D. Using a selective inhibitor of the KDM5 family we were able to increase H3K4me3 levels in DLBCL cell lines, predominantly at gene promoters, ultimately leading to decreased proliferation and cell death in KMT2D mutant cell lines. This appeared to be driven by an increase in the expression of negative regulators of B cell survival pathways, many of which have previously been described as targets of KMT2D and CREBBP, resulting in diminished BCR signalling. We also observed decreased BCL2 expression in all examined t(14;18) positive cell lines, alongside changes in other BCL2 family members in sensitive cell lines. KDM5 sensitivity was confirmed to be dependent on the presence of KMT2D mutations by generating de novo KMT2D mutant cell lines and correcting naturally mutant cell lines, which displayed greater and lesser sensitivity to KDM5 inhibition respectively. KDM5 inhibition may therefore be an effective therapeutic strategy for ameliorating KMT2D loss of function mutations in malignancies such as germinal centre lymphomas.
2021-06-01 | GSE152642 | GEO
Project description:Study of the effects of Tfam deletion on germinal centre B cells
2022-07-19 | GSE208021 | GEO