B cell acute lymphoblastic leukaemia (B-ALL) cells express high levels of CXCR4 chemokine receptors for homing and retention within the marrow microenvironment. Bone marrow stromal cells (BMSC) secrete CXCL12, the ligand for CXCR4, and protect B-ALL cells from cytotoxic drugs. Therefore, the therapeutic use of CXCR4 antagonists has been proposed to disrupt cross talk between B-ALL cells and the protective stroma. Because CXCR4 antagonists can have activating agonistic function, we compared the genetic and pharmacological deletion of CXCR4 in B-ALL cells, using CRISPR-Cas9 gene editing and CXCR4 antagonists that are in clinical use (plerixafor, BKT140). Both genetic and pharmacological CXCR4 inhibition significantly reduced B-ALL cell migration to CXCL12 gradients and beneath BMSC, and restored drug sensitivity to dexamethasone, vincristine and cyclophosphamide. NOD/SCID/IL-2rγnull mice injected with CXCR4 gene-deleted B-ALL cells had significant delay in disease progression and superior survival when compared to control mice injected with CXCR4 wild-type B-ALL cells. These findings indicate that anti-leukaemia activity of CXCR4 antagonists is primarily due to CXCR4 inhibition, rather than agonistic activity, and corroborate that CXCR4 is an important target to overcome stroma-mediated drug resistance in B-ALL.
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http://dx.doi.org/10.1111/bjh.14075 | DOI Listing |
Hemasphere
January 2025
Children's Cancer Institute, Lowy Cancer Research Centre, School of Clinical Medicine, UNSW Medicine & Health, UNSW Centre for Childhood Cancer Research UNSW Sydney Sydney New South Wales Australia.
Antibody-drug conjugates (ADCs) combining monoclonal antibodies with cytotoxic payloads are a rapidly emerging class of immune-based therapeutics with the potential to improve the treatment of cancer, including children with relapse/refractory acute lymphoblastic leukemia (ALL). CD123, the α subunit of the interleukin-3 receptor, is overexpressed in ALL and is a potential therapeutic target. Here, we show that pivekimab sunirine (PVEK), a recently developed ADC comprising the CD123-targeting antibody, G4723A, and the cytotoxic payload, DGN549, was highly effective in vivo against a large panel of pediatric ALL patient-derived xenograft (PDX) models ( = 39).
View Article and Find Full Text PDFJ Hematol Oncol
January 2025
Bavarian Cancer Research Center (BZKF), R/R ALL Study Group, Bavaria, Germany.
Anti-CD19 chimeric antigen receptor T cells (CAR) are a well-established treatment option for children and young adults suffering from relapsed/refractory B-lineage acute lymphoblastic leukemia. Bridging therapy is used to control disease prior to start of lymphodepletion before CAR infusion and thereby improve efficacy of CAR therapy. However, the effect of different bridging strategies on outcome, side effects and response to CAR therapy is still poorly understood.
View Article and Find Full Text PDFJ Med Virol
January 2025
The Wistar Institute, Philadelphia, Pennsylvania, USA.
Epstein-Barr virus (EBV) is a ubiquitous human ɣ-herpesvirus implicated in various malignancies, including Burkitt's lymphoma and gastric carcinomas. In most EBV-associated cancers, the viral genome is maintained as an extrachromosomal episome by the EBV nuclear antigen-1 (EBNA1). EBNA1 is considered to be a highly stable protein that interacts with the ubiquitin-specific protease 7 (USP7).
View Article and Find Full Text PDFCD19-directed chimeric antigen receptor-engineered (CD19 CAR) T-cell therapy elicits high response rates but fails to induce durable responses in most adults with relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). In a previous clinical trial (NCT01865617), we observed anti-CAR immune responses associated with impaired in vivo CAR T-cell expansion after second infusions. Because these CD8+ T-cell responses were predominantly directed at peptides derived from the murine single chain variable fragment (scFv) in the CAR, we conducted a clinical trial investigating the safety and efficacy of CD19 CAR T-cells engineered with a CAR incorporating a fully human scFv (JCAR021) in adults with R/R B-ALL (NCT03103971).
View Article and Find Full Text PDFJ Nat Med
January 2025
Chongqing Academy of Chinese Materia Medica, Chongqing University of Chinese Medicine, Chongqing, 402760, China.
Non-Hodgkin lymphomas (NHL), including diffuse large B-cell lymphoma (DLBCL), Burkitt lymphoma (BL), and follicular lymphoma (FL), predominantly arise from B cells undergoing germinal center (GC) reactions. The transcriptional repressor B-cell lymphoma 6 (BCL6) is indispensable for GC formation and contributes to lymphomagenesis via its BTB domain-mediated suppression of target genes. Dysregulation of BCL6 underpins the pathogenesis of GC-derived NHL.
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