scholarly journals Study of the antilymphoma activity of pracinostat reveals different sensitivities of DLBCL cells to HDAC inhibitors

2021 ◽  
Vol 5 (10) ◽  
pp. 2467-2480
Author(s):  
Afua Adjeiwaa Mensah ◽  
Filippo Spriano ◽  
Giulio Sartori ◽  
Valdemar Priebe ◽  
Luciano Cascione ◽  
...  
Keyword(s):  
Oxidative Phosphorylation ◽  
B Cell ◽  
Histone Deacetylase Inhibitors ◽  
Single Agent ◽  
B Cell Lymphoma ◽  
Cell Receptor ◽  
B Cell Receptor ◽  
Clinical Activity ◽  
Nonhistone Proteins ◽  
Hdaci Treatment

Abstract Histone deacetylase inhibitors (HDACis) are antitumor agents with distinct efficacy in hematologic tumors. Pracinostat is a pan-HDACi with promising early clinical activity. However, similar to other HDACis, its activity as a single agent is limited. Diffuse large B-cell lymphoma (DLBCL) includes distinct molecular subsets or metabolically defined subtypes that rely in different ways on the B-cell receptor signaling pathway, oxidative phosphorylation, and glycolysis for their survival. The antitumor activity of pracinostat has not been determined in lymphomas. We performed preclinical in vitro activity screening of 60 lymphoma cell lines that included 25 DLBCLs. DLBCL cells belonging to distinct metabolic subtypes were treated with HDACis for 6 hours or 14 days followed by transcriptional profiling. DLBCL xenograft models enabled assessment of the in vivo antilymphoma activity of pracinostat. Combination treatments with pracinostat plus 10 other antilymphoma agents were performed. Western blot was used to assess acetylation levels of histone and nonhistone proteins after HDACi treatment. Robust antiproliferative activity was observed across all lymphoma histotypes represented. Focusing on DLBCL, we identified a low-sensitivity subset that almost exclusively consists of the oxidative phosphorylation (OxPhos)-DLBCL metabolic subtype. OxPhos-DLBCL cells also showed poorer sensitivity to other HDACis, including vorinostat. Transcriptomic analysis revealed fewer modulated transcripts but an enrichment of antioxidant pathway genes after HDACi treatment of OxPhos-DLBCLs compared with high-sensitivity B-cell receptor (BCR)–DLBCLs. Pharmacologic inhibition of antioxidant production rescued sensitivity of OxPhos-DLBCLs to pracinostat whereas BCR-DLBCLs were unaffected. Our study provides novel insights into the antilymphoma activity of pracinostat and identifies a differential response of DLBCL metabolic subtypes to HDACis.

Targeting B-cell receptor and PI3K signaling in diffuse large B-cell lymphoma

Blood ◽  
2021 ◽  
Author(s):  
Wendan Xu ◽  
Philipp Berning ◽  
Georg Lenz
Keyword(s):  
B Cell ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Cell Receptor ◽  
Genetic Alterations ◽  
B Cell Receptor ◽  
Special Focus ◽  
Large B Cell Lymphoma ◽  
Bcr Signaling ◽  
Large B Cell

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous diagnostic category comprising distinct molecular subtypes characterized by diverse genetic aberrations that dictate patient outcome. As roughly one-third of DLBCL patients are not cured by current standard chemo-immunotherapy a better understanding of the molecular pathogenesis is warranted to improve outcome. B-cell receptor (BCR) signaling is crucial for the development, growth and survival of both normal and a substantial fraction of malignant B-cells. Various analyses revealed genetic alterations of central components of the BCR or its downstream signaling effectors in some subtypes of DLBCL. Thus, BCR signaling and the downstream NF-κB and PI3K cascades have been proposed as potential targets for the treatment of DLBCL patients. As one of the main effectors of BCR activation, PI3K mediated signals play a crucial role in the pathogenesis and survival of DLBCL. In this review, we summarize our current understanding of BCR signaling with a special focus on the PI3K pathway in DLBCL and how to utilize this knowledge therapeutically.

scholarly journals Targeted inhibition of PI3Kα/δ is synergistic with BCL-2 blockade in genetically defined subtypes of DLBCL

Blood ◽  
2019 ◽  
Vol 133 (1) ◽  
pp. 70-80 ◽  
Author(s):  
Kamil Bojarczuk ◽  
Kirsty Wienand ◽  
Jeremy A. Ryan ◽  
Linfeng Chen ◽  
Mariana Villalobos-Ortiz ◽  
...  
Keyword(s):  
B Cell ◽  
Cell Lymphoma ◽  
Single Agent ◽  
Xenograft Model ◽  
Myeloid Cell ◽  
B Cell Lymphoma ◽  
Cell Receptor ◽  
Synergistic Activity ◽  
Genetic Bases

Abstract Inhibition of the B-cell receptor (BCR) signaling pathway is a promising treatment strategy in multiple B-cell malignancies. However, the role of BCR blockade in diffuse large B-cell lymphoma (DLBCL) remains undefined. We recently characterized primary DLBCL subsets with distinct genetic bases for perturbed BCR/phosphoinositide 3-kinase (PI3K) signaling and dysregulated B-cell lymphoma 2 (BCL-2) expression. Herein, we explore the activity of PI3K inhibitors and BCL-2 blockade in a panel of functionally and genetically characterized DLBCL cell line models. A PI3K inhibitor with predominant α/δ activity, copanlisib, exhibited the highest cytotoxicity in all BCR-dependent DLBCLs. The proapoptotic effect of copanlisib was associated with DLBCL subtype-specific dysregulated expression of BCL-2 family members including harakiri (HRK) and its antiapoptotic partner BCL extra large (BCL-xL), BCL2 related protein A1, myeloid cell leukemia 1 (MCL-1), and BCL2 interacting mediator of cell death. Using functional BH3 profiling, we found that the cytotoxic activity of copanlisib was primarily mediated through BCL-xL and MCL-1–dependent mechanisms that might complement BCL-2 blockade. For these reasons, we evaluated single-agent activity of venetoclax in the DLBCLs and identified a subset with limited sensitivity to BCL-2 blockade despite having genetic bases of BCL-2 dysregulation. As these were largely BCR-dependent DLBCLs, we hypothesized that combined inhibition of PI3Kα/δ and BCL-2 would perturb BCR-dependent and BCL-2–mediated survival pathways. Indeed, we observed synergistic activity of copanlisib/venetoclax in BCR-dependent DLBCLs with genetic bases for BCL-2 dysregulation in vitro and confirmed these findings in a xenograft model. These results provide preclinical evidence for the rational combination of PI3Kα/δ and BCL-2 blockade in genetically defined DLBCLs.

Diffuse large B-cell lymphoma in Southeast Asian cohort: expression patterns of B-cell receptor (BCR) repertoire and its linkage with molecular subtypes and response to R-CHOP therapy

2019 ◽  
Vol 72 (9) ◽  
pp. 630-635 ◽  
Author(s):  
Noraidah Masir ◽  
Ariz Akhter ◽  
Tariq M Roshan ◽  
Chandramaya Sabrina Florence ◽  
Faridah Abdul-Rahman ◽  
...  
Keyword(s):  
Southeast Asia ◽  
B Cell ◽  
Targeted Therapies ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Cell Receptor ◽  
B Cell Receptor ◽  
Large B Cell Lymphoma ◽  
Large B Cell ◽  
Chop Therapy

AimsHeightened B-cell receptor (BCR) activity in diffuse large B-cell lymphoma (DLBCL) is well established, and a subset of patients with relapsed DLBCL can benefit from BCR-targeted therapies. Universal outreach of such emerging therapies mandates forming a global landscape of BCR molecular signalling in DLBCL, including Southeast Asia.Methods79 patients with DLBCL (nodal, 59% and extranodal, 41%) treated with rituximab combined with cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) therapy were selected. Expression levels of BCR and linked signalling pathway molecules were inter-related with Lymph2Cx-based cell of origin (COO) types and overall survival (OS).ResultsActivated B-cell (ABC) type DLBCL constituted 49% (39/79) compared with germinal centre B-cell (GCB) type DLBCL (29/79; 37%) and revealed poor prognosis (p=0.013). In ABC-DLBCL, high BTK expression exerted poor response to R-CHOP, while OS in ABC-DLBCL with low BTK expression was similar to GCB-DLBCL subtype (p=0.004). High LYN expression coupled with a poor OS for ABC-DLBCL as well as GCB-DLBCL subtypes (p=0.001). Furthermore, high coexpression of BTK/LYN (BTKhigh/LYNhigh) showed poor OS (p=0.019), which linked with upregulation of several genes associated with BCR repertoire and nuclear factor-kappa B pathway (p<0.01). In multivariate analysis, high BTK and LYN expression retained prognostic significance against established clinical predictive factors such as age, International Prognostic Index and COO (p<0.05).ConclusionsOur data provide a clear association between high BCR activity in DLBCL and response to therapy in a distinct population. Molecular data provided here will pave the pathway for the provision of promising novel-targeted therapies to patients with DLBCL in Southeast Asia.

scholarly journals B-cell receptor-guided delivery of peptide-siRNA complex for B-cell lymphoma therapy

2015 ◽  
Vol 15 (1) ◽  
Author(s):  
Nunzia Migliaccio ◽  
Camillo Palmieri ◽  
Immacolata Ruggiero ◽  
Giuseppe Fiume ◽  
Nicola M Martucci ◽  
...  
Keyword(s):  
B Cell ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Cell Receptor ◽  
B Cell Receptor ◽  
Lymphoma Therapy

scholarly journals Dramatic Response with Single-Agent Ibrutinib in Multiply Relapsed Marginal Zone Lymphoma with MYD88L265P Mutation

2017 ◽  
Vol 10 (3) ◽  
pp. 813-818 ◽  
Author(s):  
Ryan C. Lynch ◽  
Ranjana H. Advani
Keyword(s):  
B Cell ◽  
Signaling Pathway ◽  
Marginal Zone ◽  
Single Agent ◽  
Cell Receptor ◽  
Marginal Zone Lymphoma ◽  
B Cell Receptor ◽  
Receptor Signaling Pathway ◽  
B Cell Receptor Signaling ◽  
Cell Receptor Signaling

The B-cell receptor signaling pathway is important in the lymphomagenesis of many lymphomas, including marginal zone lymphoma (MZL). Herein we describe a case of extranodal MZL refractory to multiple lines of therapy. The presence of an IgM paraprotein prompted further evaluation, and the patient was found to have an MYD88L265P mutation. Treatment with ibrutinib led to a dramatic response with prompt resolution of symptoms and significant improvement in measurable sites of disease. The excellent response to ibrutinib in our patient with MYD88L265P-mutated refractory MZL supports a biological rationale for its use.

scholarly journals Survival of human lymphoma cells requires B-cell receptor engagement by self-antigens

2015 ◽  
Vol 112 (44) ◽  
pp. 13447-13454 ◽  
Author(s):  
Ryan M. Young ◽  
Tianyi Wu ◽  
Roland Schmitz ◽  
Moez Dawood ◽  
Wenming Xiao ◽  
...  
Keyword(s):  
B Cell ◽  
B Cell Lymphoma ◽  
Cell Receptor ◽  
B Cell Receptor ◽  
Large B Cell Lymphoma ◽  
Bcr Signaling ◽  
Human Lymphoma ◽  
V Region ◽  
Pathway Inhibition ◽  
Self Antigens

The activated B-cell–like (ABC) subtype of diffuse large B-cell lymphoma (DLBCL) relies on chronic active B-cell receptor (BCR) signaling. BCR pathway inhibitors induce remissions in a subset of ABC DLBCL patients. BCR microclusters on the surface of ABC cells resemble those generated following antigen engagement of normal B cells. We speculated that binding of lymphoma BCRs to self-antigens initiates and maintains chronic active BCR signaling in ABC DLBCL. To assess whether antigenic engagement of the BCR is required for the ongoing survival of ABC cells, we developed isogenic ABC cells that differed solely with respect to the IgH V region of their BCRs. In competitive assays with wild-type cells, substitution of a heterologous V region impaired the survival of three ABC lines. The viability of one VH4-34+ ABC line and the ability of its BCR to bind to its own cell surface depended on V region residues that mediate the intrinsic autoreactivity of VH4-34 to self-glycoproteins. The BCR of another ABC line reacted with self-antigens in apoptotic debris, and the survival of a third ABC line was sustained by reactivity of its BCR to an idiotypic epitope in its own V region. Hence, a diverse set of self-antigens is responsible for maintaining the malignant survival of ABC DLBCL cells. IgH V regions used by the BCRs of ABC DLBCL biopsy samples varied in their ability to sustain survival of these ABC lines, suggesting a screening procedure to identify patients who might benefit from BCR pathway inhibition.

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