BET inhibition targets ABC-DLBCL constitutive B-cell receptor signaling through PAX5
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ABSTRACT:
PROVIDER: PRJNA870880 | ENA |
REPOSITORIES: ENA
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Project description:B-cell receptor (BCR) signaling is essential for the diffuse large B-cell lymphoma (DLBCL) subtype that originates from activated B-cells (ABC). ABC-DLBCL cells are sensitive to Bruton tyrosine kinase intervention. However, ABC-DLBCL patients had overall response rates of 33-37% for Bruton tyrosine kinase inhibitors, suggesting the evaluation of combination-based treatment for improved efficacy. We investigated the efficacy and mechanism of AZD5153 combined with the Bruton tyrosine kinase inhibitor acalabrutinib in ABC-DLBCL preclinical models. AZD5153 is a bivalent BET inhibitor that simultaneously engages the two bromodomains of BRD4. Adding AZD5153 to acalabrutinib demonstrated a combination benefit in ABC-DLBCL cell lines and PDX models. Differential expression analyses in treated tumors identified significant alterations of BCR, PAX5, RELB/alternative NFκB, and toll-like receptor/interferon signaling. PAX5 is a transcription factor for BCR signaling genes and may be critical to the perpetually active BCR signaling in ABC-DLBCL. We demonstrate that AZD5153 decreases PAX5 expression, while acalabrutinib disruption to BCR signaling inhibits PAX5 activation. Furthermore, several interferons were decreased by AZD5153 and acalabrutinib in tumors. Adding IFNß1 to cells in vitro restored PAX5 activation. Our results demonstrate AZD5153 enhances the efficacy of acalabrutinib through PAX5 and BCR mechanisms that are critical for ABC-DLBCL.
2022-08-24 | GSE211549 | GEO
Project description:In the activated B cell-like (ABC) subtype of diffuse large B cell lymphoma (DLBCL), NF-kappaB activity is essential for viability of the malignant cells and is sustained by constitutive activity of IkappaB kinase (IKK) in the cytoplasm. Here, we report an unexpected role for the bromodomain and extraterminal domain (BET) proteins BRD2 and BRD4 in maintaining oncogenic IKK activity in ABC DLBCL. IKK activity was reduced by small molecules targeting BET proteins as well as by genetic knockdown of BRD2 and BRD4 expression, thereby inhibiting downstream NF-kappaB-driven transcriptional programs and killing ABC DLBCL cells. Using a high-throughput platform to screen for drug-drug synergy, we observed that the BET inhibitor JQ1 combined favorably with multiple drugs targeting B cell receptor signaling, one pathway that activates IKK in ABC DLBCL. The BTK kinase inhibitor ibrutinib, which is in clinical development for the treatment of ABC DLBCL, synergized strongly with BET inhibitors in killing ABC DLBCL cells in vitro and in a xenograft mouse model. These findings provide a mechanistic basis for the clinical development of BET protein inhibitors in ABC DLBCL, particularly in combination with other modulators of oncogenic IKK signaling.
2014-08-01 | GSE58791 | GEO
Project description:In the activated B cell-like (ABC) subtype of diffuse large B cell lymphoma (DLBCL), NF-kappaB activity is essential for viability of the malignant cells and is sustained by constitutive activity of IkappaB kinase (IKK) in the cytoplasm. Here, we report an unexpected role for the bromodomain and extraterminal domain (BET) proteins BRD2 and BRD4 in maintaining oncogenic IKK activity in ABC DLBCL. IKK activity was reduced by small molecules targeting BET proteins as well as by genetic knockdown of BRD2 and BRD4 expression, thereby inhibiting downstream NF-kappaB-driven transcriptional programs and killing ABC DLBCL cells. Using a high-throughput platform to screen for drug-drug synergy, we observed that the BET inhibitor JQ1 combined favorably with multiple drugs targeting B cell receptor signaling, one pathway that activates IKK in ABC DLBCL. The BTK kinase inhibitor ibrutinib, which is in clinical development for the treatment of ABC DLBCL, synergized strongly with BET inhibitors in killing ABC DLBCL cells in vitro and in a xenograft mouse model. These findings provide a mechanistic basis for the clinical development of BET protein inhibitors in ABC DLBCL, particularly in combination with other modulators of oncogenic IKK signaling. For JQ1 time course gene expression profiling, HBL1 and LP1 cells were treated with either DMSO or 100nM JQ1 for 1h, 3h, 8h, and 24h. For shRNA gene expression profiling, HBL1 cells were infected with either a Ctrl shRNA or with shRNA targeting BRD2 or BRD4. Following puromycin selection, shRNA expression was induced for 1 day and 2 days.
2014-08-01 | E-GEOD-58791 | biostudies-arrayexpress
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:We have developed a novel immunocompetent multi-lesion mouse model of activated B cell diffuse large B-cell lymphoma (ABC-DLBCL; the pBIC mice) that recapitulates relatively fast the molecular, cellular and tumor microenvironment of aggressive human ABC-DLBCL. We demonstrate that perturbed p53 signaling cooperates with constitutive NF-kB activation in GC-experienced plasmablasts with blocked terminal differentiation to promote lymphomagenesis and tumor progression through triggering downstream intracellular molecular addictions (e.g. deregulating Foxp1 and AID pathways) and intercellular immunosuppressive signals for evading anti-tumoral responses (e.g. MHC-II antigen presentation and deregulating PD-L1/PD-1 immune checkpoint). Our immunocompetent ABC-DLBCL murine model provides in vivo evidence that PD-1 blockade cooperates with anti-CD20-based current standard-of-care therapy to reshape the immunosuppressive TME and facilitate long-term anti-tumoral responses. Therefore, our results support that immune checkpoints may hold promising therapeutic potential in ABC-DLBCL.
2019-04-19 | GSE116288 | GEO
Project description:We have developed a novel immunocompetent multi-lesion mouse model of activated B cell diffuse large B-cell lymphoma (ABC-DLBCL; the pBIC mice) that recapitulates relatively fast the molecular, cellular and tumor microenvironment of aggressive human ABC-DLBCL. We demonstrate that perturbed p53 signaling cooperates with constitutive NF-kB activation in GC-experienced plasmablasts with blocked terminal differentiation to promote lymphomagenesis and tumor progression through triggering downstream intracellular molecular addictions (e.g. deregulating Foxp1 and AID pathways) and intercellular immunosuppressive signals for evading anti-tumoral responses (e.g. MHC-II antigen presentation and deregulating PD-L1/PD-1 immune checkpoint). Our immunocompetent ABC-DLBCL murine model provides in vivo evidence that PD-1 blockade cooperates with anti-CD20-based current standard-of-care therapy to reshape the immunosuppressive TME and facilitate long-term anti-tumoral responses. Therefore, our results support that immune checkpoints may hold promising therapeutic potential in ABC-DLBCL.
2019-04-19 | GSE117119 | GEO
Project description:RNA interference screens identified the transcription factor IRF4 as essential for the survival of the activated B-cell-like subtype of diffuse large B-cell lymphoma (ABC-DLBCL). Analysis of IRF4 genomic targets in ABC-DLBCL and Multiple Myeloma (MM) revealed that IRF4 regulates distinct networks in these cancers. IRF4 peaks in ABC-DLBCL, but not MM, were enriched for a composite ETS-IRF DNA motif that can be bound by heterodimers of IRF4 and the ETS-family transcription factor SPIB, whose expression is also essential for ABC-DLBCL survival. Gene expression and ChIP-Seq analysis identified essential genes co-regulated by IRF4 and SPIB. Together, these factors regulate a critical oncogenic loop by activating CARD11, which controls ABC-DLBCL survival via the NF-kB pathway. The interaction between IRF4 and SPIB presents an attractive therapeutic target in this aggressive lymphoma.
2012-08-16 | GSE32456 | GEO
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 4 two-color measurements of the male HBL-1 ABC DLBCL cell line after applying a MALT inhibitor.
2013-07-22 | E-GEOD-46973 | 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: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 6 paired GEP measurements after applying the MLN inhibitor.
2013-07-22 | E-GEOD-46972 | biostudies-arrayexpress