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.
High Myc activity is an independent negative prognostic factor for diffuse large B cell lymphomas.
Specimen part, Treatment
View SamplesRecently global gene expression profiling of patients samples lead to a molecular definition of Burkitt Lymphoma (BL) with lymphocyte enhancer-binding factor 1 (LEF1) as a signature gene. Here we report the discovery of nucleic LEF1 in a very high proportion of BL cases (15/18) and LEF1 target genes. Germinal center B cells were devoid of detectable nuclear LEF1 expression as mantle cell lymphoma (0/5), marginal zone lymphoma (0/6), follicular lymphoma (0/12) or diffuse large B cell lymphoma (DLBCL) (1/31). Using whole genome gene expression profiling after transient knockdown of LEF1 in BL cell lines, new LEF1 target genes were identified. The joint expression of these genes in primary BL samples shows that LEF1 is not only expressed aberrantly in BL but also transcriptionally active. Our study identified aberrantly expressed LEF1 and its target genes suggesting an important functional role in BLs.
Aberrant lymphocyte enhancer-binding factor 1 expression is characteristic for sporadic Burkitt's lymphoma.
Cell line
View SamplesExpression data of BL2 Burkitt Lymphoma cell line (controls and samples treated with different B cell specific stimuli)
Global gene expression changes of in vitro stimulated human transformed germinal centre B cells as surrogate for oncogenic pathway activation in individual aggressive B cell lymphomas.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Characterization of genomic imbalances in diffuse large B-cell lymphoma by detailed SNP-chip analysis.
Sex, Age
View SamplesThe pathogenesis of diffuse large B cell lymphomas (DLBCL) is only partly understood. We analyzed 148 DLBCL by high resolution single nucleotide polymorphism (SNP)-chips to characterize genomic imbalances. Seventy-nine cases were of the germinal center B-cell like (GCB) type of DLBCL, 49 of the activated B-cell like (ABC) subtype and 20 were type 3 DLBCL. Twenty-four regions of recurrent genomic gains and 38 regions of recurrent genomic losses were identified over the whole cohort, with a median of 25 imbalances per case for ABC-DLBCL and 19 per case for GCB-DLBCL. Several recurrent copy number changes showed differential frequencies in the GCB- and ABC-DLBCL subgroups, including gains of HDAC7A predominantly in GCB-DLBCL (38% of cases) and losses of BACH2 and CASP8AP2 predominantly in ABC-DLBCL (35%), hinting at disparate pathogenetic mechanisms in these entities. Correlating gene expression and copy number revealed a strong gene dosage effect in all tumors, with 34% of probesets showing a concordant expression change in affected regions. Two new potential tumor suppressor genes emerging from the analysis, CASP3 and IL5RA, were sequenced in 10 and 16 candidate cases, respectively. However, no mutations were found, pointing to a potential haploinsufficiency effect of these genes, considering their reduced expression in cases with deletions. This work thus describes differences and similarities in the landscape of genomic aberrations in the DLBCL subgroups in a large collection of cases, confirming already known targets, but also discovering novel copy number changes with possible pathogenetic relevance.
Characterization of genomic imbalances in diffuse large B-cell lymphoma by detailed SNP-chip analysis.
Sex, Age
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Identification of a new gene regulatory circuit involving B cell receptor activated signaling using a combined analysis of experimental, clinical and global gene expression data.
Specimen part, Cell line, Treatment, Time
View SamplesSince follicular lymphoma (FL) grade 3A often coexist with a FL1/2 component a linear progression model of FL1, FL2 and FL3A has been developed. FL3B, on the other hand, is supposed to be more closely related to diffuse large B-cell lymphoma (DLBCL) and both FL3B and DLBCL are often simultaneously present in one tumor (DLBCL/FL3B).
Gene expression profiling reveals a close relationship between follicular lymphoma grade 3A and 3B, but distinct profiles of follicular lymphoma grade 1 and 2.
Sex, Age, Specimen part
View SamplesTo discover new essential regulatory pathways in B lymphoma cells a combined analysis of experimental and clinical high throughput data was performed. Among others, a specific cluster of coherently expressed genes named BCR.1 was identified in primary lymphoma samples. These coherently expressed genes are suppressed by -IgM treatment of lymphoma cells in vitro. This B cell receptor activation leads to a G2 phase prolongation, delayed entry into the M phase, an overall diminished capacity of the cells to enter into mitosis and defects in metaphases. Cytogenetic changes are detected under long term -IgM treatment. Furthermore, an inverse correlation of BCR.1 genes with c-Myc coregulated genes in distinct groups of lymphoma patients is observed. In addition to the impact of c-Myc in the regulation of cell cycle regulators, BCR.1 genes are regulated by a combined action of IKK2, MAPK14 and JNK. Finally, the BCR.1 index discriminates activated B cell like and germinal centre B cell like diffuse large B cell lymphoma. Therefore, a new regulatory circuit is described affecting cell cycle and chromosome instability in B cells.
Identification of a new gene regulatory circuit involving B cell receptor activated signaling using a combined analysis of experimental, clinical and global gene expression data.
Specimen part, Time
View SamplesTo discover new essential regulatory pathways in B lymphoma cells a combined analysis of experimental and clinical high throughput data was performed. Among others, a specific cluster of coherently expressed genes named BCR.1 was identified in primary lymphoma samples. These coherently expressed genes are suppressed by -IgM treatement of lymphoma cells in vitro. This B cell receptor activation leads to a G2 phase prolongation, delayed entry into the M phase, an overall diminished capacity of the cells to enter into mitosis and defects in metaphases. Cytogenetic changes are detected under long term -IgM treatment. Furthermore, an inverse correlation of BCR.1 genes with c-Myc coregulated genes in distinct groups of lymphoma patients is observed. In addition to the impact of c-Myc in the regulation of cell cycle regulators, BCR.1 genes are regulated by a combined action of IKK2, MAPK14 and JNK. Finally, the BCR.1 index discriminates activated B cell like and germinal centre B cell like diffuse large B cell lymphoma. Therefore, a new regulatory circuit is described affecting cell cycle and chromosome instability in B cells.
Identification of a new gene regulatory circuit involving B cell receptor activated signaling using a combined analysis of experimental, clinical and global gene expression data.
Specimen part
View SamplesThe spectrum of entities, the therapeutic strategy and the outcome of mature aggressive B-cell lymphomas (maB-NHL) differs between children and adolescents on the one hand and adult patients on the other. Whereas adult maB-NHL have been studied in detail, data on molecular profiling of pediatric maB-NHL are hitherto lacking. Our aim was to characterize pediatric maB-NHL on the molecular level and to evaluate whether a molecular diagnosis of pediatric maB-NHL reveals clinically relevant groups.
Molecular profiling of pediatric mature B-cell lymphoma treated in population-based prospective clinical trials.
Age
View Samples