Necroptosis serves as a backup for Caspase-8-mediated apoptosis in B cells and blocks lymphomagenesis
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE309171 | GEO | 2026/09/24
REPOSITORIES: GEO
Similar Datasets
Project description:Diffuse large B cell lymphoma (DLBCL) is a highly heterogenous malignant disease that remains a major clinical challenge as relapsed and refractory disease is difficult to treat. Apoptosis evasion is a major feature of DLBCL. However, while the suppression of intrinsic apoptosis has long been recognized as a lymphoma-promoting event, the role of extrinsic apoptosis has remained poorly defined. Here, we demonstrated at the genetic level that expression of cFLIP, the most crucial, non-redundant inhibitor of extrinsic apoptosis, in B cells is necessary for the development of diffuse large B cell lymphoma (DLBCL) in an autochthonous murine model. Indeed, B cell-specific deletion of Cflar, the gene encoding for cFLIP, prevented lymphomagenesis mediated by oncogenic Myd88 and overexpression of BCL2. In human lymphoma cells, we showed that the absence of cFLIP sensitizes ABC- but not GCB DLBCL subtype cells to TRAIL- or LPS-induced, Caspase-8-mediated apoptosis. Furthermore, we unveiled a cell death-independent role of cFLIP in the suppression of pro-inflammatory cytokines at the transcriptional level, selectively in the ABC subtype. These results indicate that the suppression of intrinsic apoptosis can support lymphomagenesis only if extrinsic apoptosis is properly controlled. Moreover, licensing extrinsic apoptosis via cFLIP deletion can efficiently promote the death of DLBCL cells despite the suppression of the intrinsic pathway. Overall, these data provide the rationale for the development of cFLIP inhibitors for the treatment of ABC DLBCL and possibly other haematological cancers.
2026-03-15 | GSE322653 | GEO
Project description:The project aims to evaluate the contribution of ADAR1 RNA editing to B cell lymphomagenesis, specifically in diffuse large B cell lymphoma (DLBCL). Within our DLBCL cohort, RNA editing targets transcripts within known lymphoma-driving pathways such as apoptosis, p53 and NF-kB signaling, as well as the previously unrecognized RIG-I-like pathway. In the latter context, we show that ADAR1-mediated editing in the MAVS transcript correlates with increased MAVS protein expression levels, associating with increased interferon/NF-kB signaling and increased T cell exhaustion. To confirm this mechanism, we have performed LC-MSMS analysis on a DLBCL cell line (RCK8) in the presence or absence of ADAR1 (Figure S11D ). Additionally, using targeted RNA base editing tools to restore editing within MAVS 3'UTR in ADAR1-deficient cells, we demonstrate that editing is likely to be causal to an increase in downstream signaling in the absence of activation by canonical nucleic acid receptor sensing. To confirm that this signaling increase depends on an increase of MAVS protein upon specific editing, we have performed LC-MSMS analysis on the same samples (Figure 4G).
2023-07-20 | PXD041549 | Pride
Project description:BTG1 is recurrently mutated in the MCD/C5 subgroup of diffuse large B cell lymphoma (DLBCL), but the functions of this gene in lymphomagenesis have never been investigated so far. Here we provide evidence that Btg1 knock out accelerates the development of a lethal lymphoproliferative disease driven by Bcl2 overexpression. Exploring the clinical association between BTG1 mutation and extranodal dissemination, we discovered BCAR1 as a new BTG1 partner. Following BTG1 inactivation, overactivation of the BCAR1-RAC1 pathway induced major remodeling of the actin cytoskeleton and increased migration capacities of lymphoma cells in vitro and in vivo. These modifications were targetable with the SRC inhibitor dasatinib, which opens interesting clinical perspectives in BTG1 mutated DLBCL
2022-03-10 | MSV000089045 | MassIVE
Project description:Despite the dual roles of GALNT3 in various cellular processes related to tumorigenesis and solid tumors, the clinical and biological significance of GALNT3 in lymphomagenesis remains largely unknown. Herein, our bioinformatics analysis uncovers that GALNT3 dependent glucose metabolism was significantly elevated in DLBCL. Our DLBCL cohort study revealed that GALNT3 positivity is significantly associated with worse prognosis and clinical outcomes in DLBCL pathogenesis. Biologically, GALNT3 overexpression were found to promote DLBCL cell proliferation and cell cycle progression, while silencing GALNT3 inhibited lymphomagenesis. RNA-seq uncovers that GALNT3 upregulated FGFR2-MAPK signaling pathway in DLBCL. Moreover, protein mass spectrometry identified two potential O-glycosylation sites of FGFR2 (Thr319 and Ser299). Further point mutation of glycosylation sites, confirmed that GALNT3 O-glycosylates FGFR2 through Thr319. Besides, in vitro and in vivo rescue experiments demonstrated that Thr319 is dispensable for GALNT3-FGFR2-MAPK induced lymphomagenesis. In vitro pharmacological inhibition of FGFR2 with a selective inhibitor Futibatinib further demonstrated that Futibatinib inhibits DLBCL cell growth, cell proliferation, induced cell cycle arrest, promoted cell apoptosis. Further in vivo study also indicated that combination of Futibatinib with chemotherapy demonstrated better anti-tumor activity relative to single drug therapy in DLBCL treatment. Collectively, our data highlight the importance of considering the GALNT3-FGFR2-MAPK signaling axis as an attractive therapeutic target for lymphomagenesis.
2026-01-28 | GSE285695 | GEO
Project description:EZH2 mediates the humoral immune response and drives lymphomagenesis through de novo formation of bivalent chromatin domains and critical germinal center (GC) B cell promoters. We show that such formation is dependent on the presense of BCL6 and the presence of non-canonical PRC1-BCOR complex. We observe that BCL6 and EZH2 cooperate to accelerate diffuse large B cell lymphoma (DLBCL) development and combinatorial targeting of these repressors results in enhanced anti-lymphoma activity in vitro, in vivo, and in primary human DLBCLs. DLBCL cell lines treated with BCL6 inhibitor 79-6.1085
2016-07-20 | E-GEOD-73109 | biostudies-arrayexpress
Project description:Caspase-8 and FADD play key roles in the regulation of cell death by necroptosis. The absence of either protein results in early embryonic lethality due to the activation of the kinase RIPK3 and its phosphorylation of the necroptosis executioner, MLKL. We genetically engineered and characterized a mouse model to monitor MLKL phosphorylation in the absence of necroptosis in vivo. Ablation of caspase-8 or FADD resulted in the transcriptional upregulation in several tissues of ZBP1, a cytosolic nucleic acid sensor capable of activating RIPK3, and ZBP1 was required for spontaneous phosphorylation of MLKL. Our findings provide a novel mechanism by which the FADD-Caspase-8 complex prevents necroptosis.
2022-09-19 | GSE208744 | GEO
Project description:Breast cancer (BC) is the most common type of cancer among women worldwide and underlies relapse, disease progression and metastasis. Resistance to chemotherapy and programmed cell death (PCD), including apoptosis, strongly affects BC therapy success and remains a major challenge. Although necroptosis, a lytic, and via damage-associated molecular patterns (DAMP) release, highly immunogenic mode of PCD, might overcome apoptosis resistance, there is an urgent need for physiological and translational human models to model necroptosis and PCD resistance in BC. Here, we apply 3D patient-derived, metastatic human mammary organoids (hMOs) to model apoptosis resistance, necroptosis and inflammatory signaling using single-cell CITE-sequencing, time-lapse live cell brightfield and immunofluorescent confocal microscopy as well as biochemical approaches. Smac mimetic-triggered apoptosis triggered could be confirmed in a panel of BC hMOs. Upon inducing apoptosis resistance with caspase inhibition, BC hMOs rapidly undergo necroptosis with profound MLKL phosphorylation. Necroptotic cell death was preceded by prominent transcriptional upregulation of inflammatory cyto- and chemokines, including interferons, that activate natural killer cells. Finally, necroptosis and the expression and release of inflammatory messengers in metastatic BC hMOs could be attenuated upon the inhibition of linear ubiquitination. We describe a novel experimental platform to model PCD, inflammation and necroptosis that allows therapeutic screening to overcome chemotherapy resistance in patient-derived metastatic BC hMOs. With this platform, we identified necroptosis-induced interferon signaling, suggesting Smac mimetics and necroptosis as potential immunotherapy strategy against metastatic BC.
2026-04-07 | GSE320583 | GEO
Project description:Abstract. Deregulated c-MYC is found in a variety of cancers where it promotes proliferation as well as apoptosis. In many hematological malignancies enhanced NF-kB exerts prosurvival functions. Here we investigated the role of NF-kB in mouse and human c-MYC-transformed lymphomas. The NF-kB-pathway is extinguished in murine lymphoma cells and extrinsic stimuli typically inducing NF-kB activity fail to activate this pathway. Genetic activation of the NF-kB pathway induces apoptosis in these cells, while inhibition of NF-kB by an IkBa superrepressor provides a selective advantage in vivo. Furthermore, in human Burkitt´s lymphoma cells we find that NF-kB activation induces apoptosis. NF-kB upregulates Fas and predisposes to Fas-induced cell death, which is caspase 8 mediated and can be prevented by CFLAR overexpression. We conclude that c-MYC overexpression sensitizes cells to NF-kB-induced apoptosis and persistent inacvtivity of NF-kB signaling is a prerequisite for MYC-mediated tumorigenesis. We could also show that low immunogenicity and Fas insensitivity of MYC driven lymphoma cells is reversed by activation of NF-kB. Our observations provide a molecular explanation for the described absence of the NF-kB signaling in Burkitt´s lymphoma and question the applicability of NF-kB inhibitors as candidates for treatment of this cancer.
2009-07-22 | GSE17129 | GEO
Project description:Diffuse large B cell lymphoma (DLBCL) is one of the most common and aggressive types of B cell lymphoma. Subtype heterogeneity cannot be completely explained by genomic alterations and/or gene expression differences, suggesting that additional mechanisms are involved. Here, we explore the contribution of an epitranscriptomic modification to B cell lymphomagenesis. Our data demonstrate that ADAR1-mediated RNA editing (deamination of adenosine to inosine) targets novel candidate driver genes within well-known disease-associated pathways in DLBCL. Within these pathways, DNA mutations and RNA editing events are often mutually exclusive at the gene level, suggesting that tumours can modulate pathway outcomes by altering sequence at either the genomic or the transcriptomic level. In contrast to what has been found in solid tumours, in DLBCL low ADAR1 expression correlates with low interferon-stimulated gene (ISG) scores and with a microenvironment that is not inflamed. To investigate the molecular mechanism behind the inability of DLBCL to mount an ISG response upon loss of ADAR1, we focused on one candidate MAVS, a central regulator of ISG (as well as NFkB) signaling. MAVS is never mutated but robustly edited by ADAR1 at its 3’UTR, and editing correlates with increased MAVS protein levels and increased downstream activation of the ISG as well as NFkB pathways. Using targeted base editing tools to specifically restore MAVS editing in ADAR1-deficient cells, we demonstrate that MAVS editing is directly causal to an increase in expression of genes downstream this signaling pathway. Our data imply that DLBCL tumours edit MAVS to strengthen NFkB signaling, to which they are dependent on survival; thus, targeted loss of MAVS editing might sensitize tumours to cell death. Overall, ADAR1-mediated RNA editing represents a new tumour evasion mechanism underlying DLBCL lymphomagenesis, with features distinct from those derived from solid tumours to date.
2022-09-01 | GSE145011 | GEO
Project description:Dynamic control of ubiquitination by deubiquitinating enzymes is essential for almost all biological processes. Ubiquitin-specific peptidase 22 (USP22) is part of the SAGA complex and catalyzes the removal of monoubiquitination from histone H2B, thereby regulating gene transcription. However, novel roles for USP22 have recently emerged, such as tumor development and cell death. Apart from apoptosis, the relevance of USP22 in other programmed cell death pathways still remains unclear. Here, we describe a novel role for USP22 in controlling necroptotic cell death in a variety of tumor cell lines. Loss of USP22 expression significantly delays TNF/Smac mimetic/zVAD.fmk (TBZ)-induced necroptosis, without affecting TNF-mediated NF-B activation or extrinsic apoptosis. Mass-spectrometric ubiquitin remnant profiling identified lysine 518 of Receptor-interacting protein kinase 3 (RIPK3) as USP22-dependent ubiquitination target during necroptosis induction. Mutation of K518 in RIPK3 reduced necroptosisassociated RIPK3 ubiquitination and amplified necrosome formation and necroptotic cell death. In conclusion, we identify a novel role of USP22 in necroptosis and further elucidate the relevance of ubiquitination as crucial regulator of necroptotic cell death.
2021-05-03 | PXD020909 | Pride