Identification of gene expression changes in DLBCL cells by DNMT1 knockdown
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE70637 | GEO | 2017/10/10
SECONDARY ACCESSION(S): PRJNA289251
REPOSITORIES: GEO
Similar Datasets
Project description:Primary bone diffuse large B-cell lymphoma (PB-DLBCL) is a rare extranodal lymphoma subtype. This retrospective study elucidates the currently unknown genetic background of a large clinically well-annotated cohort of DLBCL with osseous localizations (O-DLBCL), including PB-DLBCL. 103 O-DLBCL patients were included and compared with 63 (extra)nodal non-osseous (NO)-DLBCLs with germinal center B-cell phenotype (NO-DLBCL-GCB). Cell-of-origin (COO) was determined by immunohistochemistry and gene-expression-profiling (GEP) using (extended)-NanoString/Lymph2Cx. Mutational profiles were identified with targeted next-generation deep-sequencing, including 52 B-cell lymphoma-relevant genes. O-DLBCLs, including 34 PB-DLBCL, were predominantly classified as GCB-phenotype based on immunohistochemistry (74%) and NanoString analysis (88%). Unsupervised hierarchical clustering of an extended-NanoString/Lymph2Cx demonstrated significantly different GEP-clusters for PB-DLBCL as opposed to NO-DLBCL-GCB (P<0.001). Expression levels of 23 genes of two different targeted GEP-panels, indicated a centrocyte–like phenotype for PB-DLBCL, whereas NO-DLBCL-GCB showed a centroblast-like constitution. PB-DLBCL had significantly more frequent mutations in four GCB-associated genes, i.e. B2M, EZH2, IRF8, and TNFRSF14, compared to NO-DLBCL-GCB (P=0.031, P=0.010, P=0.047, and P=0.003). PB-DLBCL with its corresponding specific mutational profile were significantly associated with a superior overall survival compared to equivalent Ann Arbor limited-stage I/II NO-DLBCL-GCB (P=0.011). This study is the first to demonstrate that PB-DLBCL is characterized by a GCB-phenotype, with a centrocyte-like GEP-pattern and a GCB-associated mutational profile (both involved in immune surveillance) and a favorable prognosis. These novel biology-associated features provide evidence that PB-DLBCL represents a distinct extranodal DLBCL entity and its specific mutational landscape holds potential for targeted therapies (e.g. EZH2-inhibitors). The NanoString analsyis consisted out of 219 probes for Lymph2Cx classifier (COO), MYC-activity GEP score, CNV-associated GEP signature, consensus clustering, and immune-ratio signature. This custome probeset was used to differentiate GEPs between osseous and non-osseos DLBCL of the GCB-phenotype.
2021-06-04 | GSE176126 | GEO
Project description:We studied transcriptional changes by Affymetrix human microarrays in 2 DLBCL cell lines as a result of shRNA mediated knockdown of EZH2. In eukaryotes, epigenetic post-translational modification of histones is critical for regulation of chromatin structure and gene expression. EZH2 is the catalytic subunit of the Polycomb Repressive Complex 2 (PRC2) and is responsible for repressing target gene expression through methylation of histone H3 on lysine 27 (H3K27). Over-expression of EZH2 is implicated in tumorigenesis and correlates with poor prognosis in multiple tumor types. Recent reports have identified somatic heterozygous mutations of Y641 and A677 residues within the catalytic SET domain of EZH2 in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). The Y641 residue is the most frequently mutated residue, with 22% of GCB (Germinal Cell B-cell) DLBCL and FL harboring mutations at this site. These lymphomas exhibit increased H3K27 tri-methylation (H3K27me3) due to altered substrate preferences of the mutant enzymes. However, it is unknown whether direct inhibition of EZH2 methyltransferase activity alone will be effective in treating lymphomas carrying activating EZH2 mutations. Herein, we demonstrate that GSK126, a potent, highly-selective, SAM-competitive, small molecule inhibitor of EZH2 methyltransferase activity, decreases global H3K27me3 levels and reactivates silenced PRC2 target genes. GSK126 effectively inhibits the proliferation of EZH2 mutant DLBCL cell lines and dramatically inhibits the growth of EZH2 mutant DLBCL xenografts in mice. Together, these data demonstrate that pharmacological inhibition of EZH2 activity may provide a promising treatment for EZH2 mutant lymphoma. Pfeiffer and KARPAS-422 cells were treated with either shRNA targeting EZH2 (shEZH2) or a non targeting control (shNTC) for 10 days.
2012-10-12 | E-GEOD-41239 | biostudies-arrayexpress
Project description:GCB subtype DLBCL with BCL2 translocation
| PRJNA744546 | ENA
Project description:RNA-seq data for 6 de novo GCB subtype DLBCL patients with BCL2 translocation
2022-07-01 | GSE179689 | GEO
Project description:High expression of the FOXP1 transcription factor distinguishes the highly aggressive Activated B Cell (ABC) type of Diffuse Large B Cell Lymphoma (DLBCL) from the more indolent Germinal Center (GCB) DLBCL subtype and is correlated with poor prognosis. A genetic or functional role for FOXP1 in lymphomagenesis and/or tumor maintenance, however, remains unknown. Here, we report that sustained expression of FOXP1 is necessary for ABC DLBCL cell line survival. Genome-wide transcript profiling reveals that FOXP1 acts directly and indirectly by enforcing expression of known ABC DLBCL hallmarks, including the classical NF-kappaB survival pathway. Our data further suggest that FOXP1 maintains the ABC subtype distinction by repressing gene expression programs dominant in GCB DLBCL and supports a model in which the target of ABC DLBCL transformation is a transitory cell type en route from the germinal center B cell to the terminally differentiated plasma cell.
2015-12-01 | GSE64586 | GEO
Project description:Germinal center B-cell-like diffuse large B-cell lymphoma (GCB-DLBCL) is one of the most common subtypes of B-cell non-Hodgkin lymphoma. The tumor microenvironment (TME) is responsible for therapy resistance and relapse in GCB-DLBCL, while most studies have focused on targeting tumor cells instead of the TME. Stromal cells are the main component of the TME in GCB-DLBCL. How stromal cells interact with GCB-DLBCL tumor cells and protect GCB-DLBCL from cell death remain elusive. Here we reported that a CD40/RANK pathway-mediated positive feedback loop mediated the interaction of stromal cells and GCB-DLBCL to enhance the survival of GCB-DLBCL tumor cells. The viability of primary GCB-DLBCL patient-derived xenograft tumor cells was increased when they were cocultured with different tissue-derived stromal cells. We demonstrated that stromal cells promoted tumor cell survival not only through excreted cytokines but also depending more on direct contact. Furthermore, CD40 ligand (CD40L) expressed on stromal cells activated CD40 signaling in tumor cells, protecting tumor cells from apoptosis and upregulating RANK ligand (RANKL). RANK activation by RANKL in tumor cells enhanced the expression of CD40L and BAFF in stromal cells, both of which in turn promoted tumor cell survival through activating canonical and noncanonical NF-B signaling. In addition, CD40 activation upregulated the expression of KDM6B, and KDM6B further mediated the activation of canonical and noncanonical NF-B signaling, the downstream signaling pathways of the CD40 activation, all leading to tumor cell survival. These results further suggest that CD40-KDM6B-NF-B axis serve as a potential target for GCB-DLBCL therapy.
2022-05-09 | GSE202370 | GEO
Project description:Multi-agent chemotherapy still represents the first-line standard-of-care treatment for diffuse large B-cell lymphoma (DLBCL), the most common form of lymphoma in adults. However, the clinicopathological and molecular heterogeneity of DLBCLs poses a major challenge in their successful therapy. At least two major subtypes, i.e. germinal center B-cell-like (GCB) and the aggressive activated B-cell-like (ABC) DLBCL, which differ both in their gene expression profile and in their mutation patterns, have been identified. Here we demonstrate a broad inhibitory effect of dimethyl fumarate (DMF) on the outgrowth of both DLBCL subtypes, even though the molecular basis for its efficacy differs between GCB and ABC DLBCL. Due to high expression of arachidonate 5-lipoxygenase in concert with low glutathione and glutathione peroxidase 4 levels, DMF induced lipid peroxidation and thus ferroptotic cell death in GCB DLBCL. In contrast, in ABC DLBCL inhibition of NF-κB and STAT3 activity essentially contributed to DMF-dependent cytotoxicity. Interestingly, the BCL-2 specific BH3 mimetic ABT-199 or an inhibitor of the ferroptosis suppressor protein 1 synergized with DMF treatment in inducing cell death in DLBCL cell lines. Collectively, our findings identify the established and approved drug DMF as a promising novel therapeutic option in the treatment of both GCB and ABC DLBCL.
2021-07-01 | GSE164267 | GEO
Project description:To identify differentially expressed genes regulated by FOXP1 in DLBCL cells via gene expression profiling of GCB-DLBCL (DB, K422) and ABC-DLBCL (OCI-Ly3, HBL-1) cell lines treated with siRNA targeting FOXP1 or non-silencing siRNA control. Two GCB-DLBCL (DB, K422) and two ABC-DLBCL (OCI-Ly3, HBL-1) cell lines were each treated separately with two independent siRNA oligonucleotides targeting FOXP1 (siFOXP1_308, siFOXP1_309) or non-silencing siRNA (siCtrl). Biological replicates derived from three independent experiments were obtained, RNA-extracted and subsequently hybridized into a human microarray platform for gene expression profiling.
2015-10-27 | E-GEOD-71526 | biostudies-arrayexpress
Project description:Constitutive activation of the nuclear factor-kappa B (NF-kB) pathway is a hallmark of the activated B-cell-like (ABC) subtype of diffuse large B-cell lymphoma (DLBCL). Recurrent mutations of NF-kB regulators that cause constitutive activity of this oncogenic pathway have been identified. However, it remains unclear how specific target genes are regulated. We identified the IkB-like protein NFKBIZ that binds NF-kB subunits and enhances transactivation of some NF-kB target genes while repressing others, to be upregulated in ACB compared to GCB DLBCL primary patient samples (p=5.1 x 10^-37). Knockdown of NFKBIZ by RNA interference was toxic to ABC but not GCB DLBCL cell lines. Gene expression profiling following NFKBIZ knockdown significantly downregulated a large number of NF-kB target genes, suggesting a central role in regulating NF-kB signaling. To further investigate the molecular mechanisms of how NFKBIZ mediates NF-kB signaling in ABC DLBCL, we performed immunoprecipitations and detected an interaction of NFKBIZ with both p50 and p52 NF-kB subunits, indicating that both the canonical and non-canonical NF-kB pathways are regulated by NFKBIZ. Collectively, our data imply that NFKBIZ is required for NF-kB signaling in ABC DLBCL and thus might represent a promising molecular target for future therapies. The complete dataset is comprised of three experiments with the male HBL-1 ABC DLBCL cell line: a) 8 paired GEP measurements after NFKBIZ inhibition by shRNA, b) 6 paired GEP measurements after applying the MLN inhibitor and c) 4 two-color measurements after applying a MALT inhibitor. This dataset includes 8 paired GEP measurements after NFKBIZ inhibition by shRNA.
2013-07-22 | E-GEOD-46971 | biostudies-arrayexpress
Project description:Gene expression profiling was performed for 28 DLBCL primary clinical samples and assignment of activated B-cell-like(ABC)/germinal center B-cell-like (GCB) DLBCL classes, B-cell-associated gene signature (BAGS), and a probability of response to doxorubicin was performed for each sample.
2016-10-05 | GSE74266 | GEO