This SuperSeries is composed of the SubSeries listed below.
Molecular classification of mature aggressive B-cell lymphoma using digital multiplexed gene expression on formalin-fixed paraffin-embedded biopsy specimens.
Sex, Age, Specimen part, Disease
View SamplesThe most frequent mature aggressive B-cell lymphomas are diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma (BL). Patients suffering from molecularly defined BL (mBL) but treated with a regimen developed for DLBCL show an unfavorable outcome compared to mBL treated with chemotherapy regimens for BL. Distinguishing BL from DLBCL by conventional histopathology is challenging in lymphomas that have features common to both diseases (aggressive B-cell lymphoma unclassifiable with features of DLBCL and BL [intermediates]). Moreover, DLBCL are a heterogeneous group of lymphomas comprising distinct molecular subtypes: the activated B-cell (ABC)-like, the germinal center B-cell-like (GCB) and the unclassifyable subtype as defined by gene expression profiling (GEP). Attempts to replace GEP with techniques applicable to formalin-fixed paraffin-embedded (FFPE) tissue led to algorithms for immunohistochemical stainings (IHS). Disappointingly, the algorithms yielded conflicting results with respect to their prognostic potential, raising concerns about their validity. Furthermore, IHS algorithms did not provide a fully resolved classification: They did not identify mBL; nor did they separate ABC from unclassified DLBCL.
Molecular classification of mature aggressive B-cell lymphoma using digital multiplexed gene expression on formalin-fixed paraffin-embedded biopsy specimens.
Sex, Age, Specimen part
View SamplesIn lymphomas derived from mature B cells the expression of the transcription factor PAX5 is maintained whereas classical Hodgkin lymphoma displays significantly reduced PAX5 expression despite its derivation from mature B cells. To elucidate the functional role of PAX5 in classical Hodgkin lymphoma, we re-established the PAX5 expression in the Hodgkin cell line L428 with and without epigenetic modulation. To this end, we stably transfected the Hodgkin cell line L428 with an inducible PAX5 expression construct. Although the overexpressed PAX5 was transcriptionally active as demonstrated by synthetic reporter constructs, no induction of the B-cell phenotype was achieved. PAX5 chromatin immunoprecipitation with subsequent next generation sequencing in B-cell lines and the PAX5 overexpressing L428 cell line showed different binding patterns. Since epigenetic restrictions might affect PAX5 binding, combined DNA demethylation and histone acetylation was performed. However, no re-expression of B-cell genes was observed also under these conditions. Thus, PAX5 is not sufficient for the re-activation of the B-cell program in Hodgkin cells despite epigenetic opening of the chromatin. This clearly indicates that the repression of the B-cell identity of the Hodgkin cells is caused and secured by complex molecular mechanisms.
PAX5 overexpression is not enough to reestablish the mature B-cell phenotype in classical Hodgkin lymphoma.
Cell line, Treatment
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 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 goal of this study was to provide a global assessment of the host''s response to M. gallisepticum over a 7-day time course Overall design: Differential gene expression was assessed between Rlow infected and Hayflick''s only ''control chickens'' on days 1, 3, 5, and 7 (5 infected per day, 4 controls on day 1, 5 controls per days 3, 5, and 7), 39 total chickens assessed.
Transcriptional Profiling of the Chicken Tracheal Response to Virulent Mycoplasma gallisepticum Strain R<sub>low</sub>.
Subject, Time
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