Project description:Primary Mediastinal large B-cell lymphoma (PMBL) is a rare form of non-Hodgkin lymphoma (NHL) representing 2% of mature B-cell NHL in patients less than 18 years of age.We compared the gene expression profiling between fully humanized anti-CD20 targeted monoclonal antibody recognizing a unique CD20 type II epitope, obinutuzumab and IgG or PBS treated Karpas Primary Mediastinal B-cell lymphoma (PMBL) cell line. -
Project description:Genetic TNFAIP3 (A20) inactivation is a classical somatic lymphoma lesion and the genomic trait in haploinsufficiency of A20 (HA20). Single-cell sequencing reveals “pre-lymphoma” transcription signatures in lymphocytes of HA20 patients.
Project description:Genetic TNFAIP3 (A20) inactivation is a classical somatic lymphoma lesion and the genomic trait in haploinsufficiency of A20 (HA20). In a cohort of 33 HA20 patients, we show that heterozygous TNFAIP3 loss skews immune repertoires towards lymphocytes with classical self-reactive antigen receptors typically found in B and T cell lymphomas.
Project description:The pathogenesis of classical Hodgkin lymphoma (cHL), the most common lymphoma in the young, is still enigmatic, largely because its Hodgkin and Reed-Sternberg (HRS) tumor cells are rare in the involved lymph node and therefore difficult to analyze. Here, by overcoming this technical challenge and performing for the first time a genome-wide transcriptional analysis of microdissected HRS cells in comparison to other B-cell lymphomas, cHL lines and normal B-cell subsets, we show that they differ extensively from the usually studied cHL cell lines, that the lost B-cell identity of cHLs is not linked to the acquisition of a plasma cell-like gene expression program, and that Epstein-Barr virus infection of HRS cells has a minor transcriptional influence on the established cHL clone. Moreover, although cHL appears a distinct lymphoma entity overall, HRS cells of its histological subtypes diverged in their similarity to other related lymphomas. Unexpectedly, we identified two molecular subgroups of cHL associated to differential strengths of the transcription factor activity of the NOTCH1, MYC and IRF4 proto-oncogenes. Finally, HRS cells display deregulated expression of several genes potentially highly relevant to lymphoma pathogenesis, including silencing of the apoptosis-inducer BIK and of INPP5D, an inhibitor of the PI3K-driven oncogenic pathway. The present study complements the GSE12453 and GSE14879 records by adding the following 10 samples: 5 primary tumor samples and 5 cell line samples. The 5 primary tumor samples represent 1000-2000 neoplastic cells microdissected from frozen biopsies of 5 cases of primary mediastinal B-cell lymphoma (PMBL). The 5 cell line samples represent 500-1000 living neoplastic cells isolated by fluorescence-activated cell sorting from growing cultures of the classical Hodgkin lymphoma (cHL) cell lines L1236, L428, KMH2 and HDLM2 and the lymphocyte-predominant Hodgkin lymphoma (lpHL) cell line DEV.
Project description:Analysis of differential gene expression in human non-Hodgkin`s lymphoma cell lines and a primary leukaemic tumor sample of large cell anaplastic type in comparison with Hodgkin`s lymphoma cell lines and other non-Hodgkin`s lymphoma samples and non-neoplastic lymphocytes Keywords: cell type comparison
Project description:Analysis of differential gene expression in human non-Hodgkin`s lymphoma cell lines and a primary leukaemic tumor sample of large cell anaplastic type in comparison with Hodgkin`s lymphoma cell lines and other non-Hodgkin`s lymphoma samples and non-neoplastic lymphocytes Experiment Overall Design: Samples were analyzed to be compared to publically available data sets
Project description:Unique and shared cytogenetic abnormalities have been documented for marginal zone lymphomas (MZLs) arising at different sites. Recently, homozygous deletions of the chromosomal band 6q23, involving the tumor necrosis factor alpha-induced protein 3 (TNFAIP3, A20) gene, a negative regulator of NF-kappa B, were described in ocular adnexal MZL, suggesting a role for A20 as a tumor suppressor in this disease entity. Here, we investigated inactivation of A20 by DNA mutations or deletions in a panel of extranodal (EMZL), nodal (NMZL) and splenic (SMZL) MZLs. Inactivating mutations encoding truncated A20 proteins were identified in 6/32 (18.8%) MZLs, including 3/11 (27.3%) EMZLs, 2/9 (22.2%) NMZLs, and 1/12 (8.3%) SMZLs. Two additional unmutated non-splenic MZLs also showed mono- or biallelic A20 deletions by FISH and/or array-CGH. Thus, A20 loss by both somatic mutations and/or deletions represents a common genetic aberration across all MZL subtypes, which may contribute to lymphomagenesis by inducing constitutive NF-kappa B activation. Keywords: Genome variation profiling by SNP array 27 MZL samples. No technical replications.
Project description:Diffuse large B-cell lymphoma (DLBCL), the most common form of lymphoma in adulthood, comprises multiple biologically and clinically distinct subtypes including germinal center B cell-like (GCB) and activated B cell like (ABC) DLBCL. Gene expression profile studies have shown that its most aggressive subtype, ABC-DLBCL, is associated with constitutive activation of the NF-kB transcription complex. However, except for a small fraction of cases, it remains unclear whether NF-kB activation in these tumors represents an intrinsic program of the tumor cell of origin or a pathogenetic event. Here we show that >50% of ABC-DLBCL and a smaller fraction of GCB-DLBCL carry somatic mutations at multiple genes, including negative (TNFAIP3/A20) and positive (CARD11, TRAF2, TRAF5, MAP3K7/TAK1 and TNFRSF11A/RANK) regulators of NF-kB. Of these, the A20 gene, which encodes for a ubiquitin-modifying enzyme involved in termination of NF-kB responses, is the most commonly affected one, with ~30% of the patients displaying biallelic inactivation by mutations and/or deletions, suggesting a tumor suppressor role. Less frequently, missense mutations of TRAF2 and CARD11 produce molecules with significantly enhanced ability to activate NF-kB. Thus, our results demonstrate that NF-kB activation in DLBCL is caused by genetic lesions affecting multiple genes, whose loss or activation may promote lymphomagenesis by leading to abnormally prolonged NF-kB responses. We show that most ABC-DLBCL and a smaller fraction of GCB-DLBCL display genetic lesions affecting multiple NFkB pathway genes, with A20 representing the most frequently mutated gene Experiment Overall Design: DLBCL biopsies from 73 patients were collected from the archives of the Departments of Pathology at Columbia University and Weill Cornell Medical College. Total RNA was extracted from frozen tumor biopsies and processed according to Affymetrix standard protocols. Purified tonsillar geminal center cells (centroblasts and centrocytes, 5 samples each from different individuals) were purified by magnetic cell separation as described in Klein et al, PNAS 2003.
Project description:This series represents the data set of Array CGH from the paper (submit for publication): “Homozygous deletions localize novel tumor suppressor genes in B-cell lymphomas. Mestre et all. ” and it's web supplement. The molecular nature of many secondary events in the pathogenesis of B-cell non Hodgkin lymphoma (B-NHL) remains unknown. We used high-resolution CGH to BAC microarrays to characterize the genomes of 48 B-cell non-Hodgkin lymphoma (B-NHL) cell lines of different origins. Array CGH identified, on average, 20 genomic alterations per cell line, including regional gains and losses as well as previously uncharacterized aberrations. Different genomic patterns were observed among the B-NHL subtypes. To search for possible oncogenic target genes, gene expression profiling was performed in the cell lines models. Integrative genomic and gene expression analyses have identified amplified oncogenes in B-cell non-Hodgkin lymphoma (B-NHL), but the capability of such technologies to localize tumor suppressor genes within homozygous deletions remains unexplored. Array-based comparative genomic hybridization (CGH) and gene expression microarray analysis of 48 cell lines derived from patients with different B-NHLs delineated twenty homozygous deletions at seven chromosome areas, all of which contained tumor suppressor gene targets. Further investigation revealed that only a fraction of primary biopsies presented inactivation of these genes by point mutation or intragenic deletion, but instead some of them were frequently silenced by epigenetic mechanisms. Our microarray strategy has identified novel candidate suppressors inactivated by genetic and epigenetic mechanisms that substantially vary among the B-NHL subtypes. Keywords: Array CGH, B-cell non-Hodgkin lymphoma, genomic amplification, homozygous deletion