Project description:Diffuse large B-cell lymphoma (DLBCL) represents the most common subtype of malignant lymphoma and is heterogeneous with respect to morphology, biology, and clinical presentation.However, a robust prognostic factor based on cell biology of DLBCL has not yet been determined.To find the biomarker which may associate with clinical outcome in patients with DLBCL, microarray analysis was performed to screen a novel biomarker.
Project description:CC-122 is a next-generation cereblon E3 ligase modulating agent that has demonstrated promising clinical efficacy in relapsed or refractory diffuse large B‐cell lymphoma (R/R DLBCL) patients. Mechanistically, CC-122 induces the degradation of IKZF1/3, leading to T cell activation and robust cell-autonomous killing in DLBCL. Here, we report a genome-wide CRISPR/Cas9 positive selection screen for CC-122 in a DLBCL cell line SU-DHL-4 with follow-up mechanistic characterization in 6 DLBCL cell lines to identify genes regulating the response to CC-122. Top-ranked CC-122 resistance genes encode not only well-defined members or regulators of the CUL4-DDB1-RBX1-CRBN E3 ubiquitin ligase complex, but also key components of several signaling and transcriptional networks that have not previously been shown to modulate the response to other cereblon modulators. Ablation of CYLD, NFKBIA, TRAF2, or TRAF3 induces hyper-activation of the canonical and/or non-canonical NF-κB pathways and subsequently diminishes CC-122-induced apoptosis in 5 out of 6 DLBCL cell lines. Depletion of KCTD5, the substrate receptor of the CUL3-RBX1-KCTD5 ubiquitin ligase complex, promotes the stabilization of its cognate substrate, GNG5, resulting in CC-122 resistance in HT, SU-DHL-4, and WSU-DLCL2. Furthermore, knockout of AMBRA1 renders resistance to CC-122 in SU-DHL-4 and U-2932, whereas knockout of RFX7 leads to resistance specifically in SU-DHL-4. The ubiquitous and cell line-specific mechanisms of CC-122 resistance in DLBCL cell lines revealed in this work pinpoint genetic alternations that are potentially associated with clinical resistance in patients, and facilitate the development of biomarker strategies for patient stratification, which may improve clinical outcome of CC-122 for R/R DLBCL.
Project description:To identify TGF-β regulated lncRNAs in glioblastoma, we performed a genome-wide microarray screen in T98G glioma cells. T98G cells were treated with 10 ng/ml TGF-β (24h) and differentially expressed lncRNAs were identified using microarray in comparison with control cells.
Project description:Genomic profiles of DLBCL (Diffuse Large B-cell Lymphoma) patients 20 DLBCL patients were selected for detection of genomic aberrations
Project description:Interferon regulatory factor 4 (IRF4) is a transcriptional regulator with critical roles in the normal development and malignant transformation of lymphocytes. Recently we have shown that plasma cell cancers (multiple myeloma, MM) are addicted to an aberrant gene expression program ochestrated by wild-type IRF4 for their survival. Here we show that an aggressive malignancy of mature B cells, the activated B cell for of Diffuse Large B Cell lymphoma (ABC-DLBC), also depends on IRF4 for survival. With genome-wide expression profiling and localization (ChIP-Seq) assays, we identified IRF4 target genes in ABC-DLBCL as members of diverse pathways related to B cell biology and malignant behavior, distinct from IRF4 targets in MM. For example, we find the gene encoding the NFkB signal transduction adapter protein CARD11 is a target of IRF4 activation, driving the critical NFkB pathway in ABC-DLBCL. Further, we find enrichment of DNA binding motifs for ETS-IRF factors in regions of IRF4 binding in ABC-DLBCL suggesting cooperative activity between IRF4 and an ETS family transcription factor. Through complementation assays we show that IRF4 and the critical ABC-DLBCL ETS factor SPIB interact with one another and are key to ABC-DLBCL survival. Together our data show that ABC-DLBCL is addicted to the interaction between IRF4 and SPIB, in part through a positive feedback loop invovling CARD11 and the activation of the NFkB pathway. These data suggest theraepeutic potential in targeting the IRF4:SPIB interface in ABC-DLBCL.