Citations

Abstract Background: Antigen receptor stimulation induces assembly of the CARMA1-BCL10-MALT1 (CBM) signaling complex, which leads to activation of downstream transcriptional regulators including NF-κB and subsequent lymphocyte activation. Gain-of-function mutations in B-cell receptor subunits, CARMA1, or BCL10 which lead to constitutive activation of MALT1 underly the pathogenesis of multiple lymphoid malignancies, including activated B-cell–type diffuse large B-cell lymphoma (ABC-DLBCL). During previous efforts to identify regulators of MALT1 activity in lymphocytes, we discovered that G-protein-coupled receptor kinase 2 (GRK2) binds to MALT1, inhibits MALT1 scaffolding and proteolytic activities, and functions as a tumor suppressor in MALT1-dependent lymphomas. Notably, GRK2 mRNA expression is markedly lower in a subset of DLBCL tumors in comparison to normal B cells and lower GRK2 is associated with decreased patient survival in ABC-DLBCL. In light of these findings, we investigated the molecular mechanisms regulating GRK2 expression and then characterized the roles of specific GRK2-targeting miRNAs in ABC-DLBCL. Methods and Results: After finding that global impairment of miRNA processing through DICER1 depletion leads to increased GRK2 protein, we conducted bioinformatic analyses of patient tumor samples and microRNA Data Integration Portal screening to identify candidate microRNAs that target GRK2 in ABC-DLBCL. Direct targeting of GRK2 by candidate miRNAs was then confirmed by GRK2 3’UTR reporter assay. We tested for expression of three candidate microRNAs in ABC-DLBCL cells and observed elevated expression in both OCI-LY3 and TMD8 cells, which exhibited reduced GRK2 mRNA expression compared with primary B cells. Inhibition of candidate miRNAs in ABC-DLBCL cells, using anti-miRNA Locked Nucleic Acids (LNA) inhibitors, led to enhanced GRK2 expression, reduced MALT1 activity and decreased cell proliferation. Conversely, stable overexpression of candidate microRNAs led to reduced GRK2 expression, enhanced MALT1 activity and increased cell proliferation. In vivo, treatment of mice with inhibitors of candidate microRNAs abrogates the growth of ABC-DLBCL xenograft tumors. Conclusion: We have identified three miRNAs that negatively regulate GRK2 expression in ABC-DLBCL. By targeting GRK2 for downregulation, these miRNAs promote MALT1 oncoprotein scaffold and protease activities. Furthermore, inhibitors of these miRNAs enhance GRK2 expression and thereby suppress MALT1 activity and MALT1-dependent tumor cell proliferation in vitro and inhibit MALT1-dependent tumor growth in vivo. MicroRNA inhibitors that enhance GRK2 expression could represent a new approach for restraining MALT1-dependent lymphoma. Citation Format: Jing Cheng, Mei Smyers, Matt Trotta, Neil M. Carleton, Lisa M. Maurer, Uma R. Chandran, Min Xia, Ari M. Melnick, Peter C. Lucas, Linda M. McAllister-Lucas. Inhibitors of GRK2-targeting-microRNAs: New therapeutic strategies for MALT1-dependent lymphomas [abstract]. In: Proceedings of the Fifth AACR International Meeting on Advances in Malignant Lymphoma: From Discovery to Clinical Impact; 2026 Jun 24-27; Philadelphia, PA. Philadelphia (PA): AACR; Blood Cancer Discov 2026;7(3_Suppl):Abstract nr A033.

Abstract Introduction: Large B-cell lymphoma (LBCL) harboring chromosomal rearrangements (double-hit, DH) or coexpression of MYC and BCL2 (double-expressor, DE) represents biologically aggressive subgroups with inferior clinical outcomes. Oncogene-driven DNA replication stress (ODRS) is a hallmark of MYC and BCL2 dysregulation; however, the DNA damage response (DDR) pathways that sustain replication and cell survival under ODRS remain incompletely defined in DLBCL. Identifying DDR dependencies induced by ODRS may reveal therapeutically actionable vulnerabilities in DH/DE-LBCL. Methods: We studied DH/DE-LBCL cell lines (OCILY1, SUDHL2, DOHH2), non-DH/DE-LBCL cell lines (HT, KARPAS422, HBL1), and benign retinal pigment epithelial (RPE) cells engineered to overexpress MYC and/or BCL2. ODRS and DNA damage were assessed by phosphorylation of RPA (S4/S8, S33) and H2AX histone (γH2AX), respectively, using immunofluorescence, immunohistochemistry, and western blot (WB). Activity of homologous recombination (HR), nonhomologous end-joining (NHEJ), and microhomology-mediated end joining (MMEJ) pathways were quantified with established reporter assays. POLΘ (gene: POLQ) expression, an MMEJ marker, was evaluated by qPCR and WB. DDR activity was assessed using genomic signatures from whole-exome sequencing data of 404 LBCL patients. In vitro sensitivity of LBCL cells to POLΘ and PARP inhibitors was assessed with publicly available small-molecule inhibitors using CellTiterGlo and clonogenic assays, and therapeutic efficacy was validated in a DH-LBCL xenograft model in NRG mice. Results: DH/DE-LBCL cells and primary tumors exhibited increased ODRS and persistent DNA damage compared with non-DH/DE-LBCL models, including accumulation of γH2AX in mitosis. Functional profiling revealed selective upregulation of MMEJ in MYC/BCL2-overexpressing cells, with minimal changes in HR or NHEJ activity. POLQ expression was significantly increased in DH/DE-LBCL cell lines and primary samples, and the ID6 signature (associated with MMEJ activity) was significantly enriched in DH-LBCL tumors compared to non-DH/DE-LBCL tumors. POLΘ inhibition demonstrated greater toxicity in DH/DE-LBCL and in MYC-overexpressing RPE cells compared to non-DH/DE-LBCL and wild-type RPEs. Combined inhibition of POLΘ and PARP resulted in marked synergy in vitro. The therapeutic efficacy of POLΘ inhibition, with the synthetic lethality of concurrent PARP inhibition, was validated in the DH-LBCL xenograft model. Concurrent POLΘ and PARP inhibition with small-molecule inhibitors induced an antitumor effect in vivo, with increased overall survival in mice compared with vehicle- or olaparib-single-agent-treated groups. Conclusions: ODRS in DH/DE-LBCL creates a selective dependence on MMEJ mediated by POLΘ. Therapeutic targeting of POLΘ, alone or in combination with PARP inhibition, exploits this vulnerability and represents a promising strategy for this high-risk LBCL subset. These findings provide a biological rationale for clinical translation of POLΘ-directed therapies in DH/DE-LBCL. Citation Format: Cecilia Ayala-Zambrano, Dongni Yi, Michelle Manske, Kimberly Gwin, Richar Kandasamy, Surendra Dasari, Anne Novak, Shuhei Asada, Xiaosheng Wu, Zhenkun Lou, Thomas Witzig, Jithma Abeykoon. c-MYC/BCL2 induced replication stress drives dependence on POLQ-mediated microhomology-mediated end joining in aggressive large B-cell lymphoma [abstract]. In: Proceedings of the Fifth AACR International Meeting on Advances in Malignant Lymphoma: From Discovery to Clinical Impact; 2026 Jun 24-27; Philadelphia, PA. Philadelphia (PA): AACR; Blood Cancer Discov 2026;7(3_Suppl):Abstract nr A029.

Abstract The purpose of this study was to explore epigenetic dysregulation resulting from deleterious SPEN mutations in diffuse large B cell lymphoma (DLBCL). Truncating (tr) SPEN mutations are among defining variants in LymphGen:BN2 and DLBclass:C1. We previously found SPEN mutations enriched in DLBCL that failed to reach EFS24, and inferior survival was observed in SPEN-tr vs all other BN2 and C1. Differential gene expression (DEG) in these groups identified >1000 DEGs including upregulation of IKZF3 and BCL2 and downregulation of MHC-II, overall suggesting an alternative, aggressive biology for a subset of BN2/C1 cases generally thought to have favorable outcomes. In healthy cells, SPEN is a dynamic epigenetic regulator with roles in chromatin formation and as a NOTCH co-repressor. We hypothesized that loss of SPEN reprograms the epigenetic landscape to drive the aggressive phenotype in affected DLBCL. Methods: OCI-LY3 cell line with CRISPR/Cas9-induced SPEN-tr mutations was analyzed by ATAC and RNA-seq. Diagnostic DLBCL FFPE tumor biopsies from the Molecular Epidemiology Resource (MER) were analyzed by 850k/EPIC methylation array (n=164). SPEN-depleted OCI-LY3 cells displayed significant (|Log2FC|>2) peaks of open (n=3083) and closed (n=1729) chromatin indicative of systemic epigenetic reprogramming, with enriched peaks (FDR<0.01, |Log2FC|>2) converging on pro-survival and immune evasion (ATP11C, BCL11B, RAG1/2 genes) and negatively enriched for cell cycle and apoptotic pathways (CDK6, TP63, CD80 genes). Chromatin accessibility featured enrichment for TCF3/4 and ZEB1 binding motifs and depletion of EBF1, REL, and NFKB1/2 motifs (FDR<0.0001, |Z-score|>5), suggesting a shift to an activated, post-germinal center program (via open TCF3/4 motifs) with reduced reliance on NF-kB signaling. Footprinting analysis further revealed decreased occupancy at NFKB2 and REL/B motifs, and reduced occupancy at HES1 with elevated occupancy at Rbpjl motifs (p<0.05, |Score|>0.2) indicating downregulation of NF-kB is in favor of non-canonical Notch transcription programming. Merging gene expression and accessibility, gene-peak concordance was observed for elevated CXCR4 and IL6 expression and decreased SOCS1, CD274 (PD-L1), and CCND1 expression (FDR<0.01, |Log2FC|>1), suggesting expression programs feature uncontrolled JAK/STAT signaling (via high IL6, low SOCS1) with immune evasion mechanisms independent of PD-L1. By methylation array, strong epigenetic reprogramming was observed in SPEN-tr DLBCL (n=8), where differential methylation analysis vs WT (n=146), vs BN2 (n=4), and vs C1 (n=15) samples revealed hypermethylation signatures (p<0.05, |FC|>1) indicative of reduced cell-cell signaling and antigen presentation pathways (including HLA-A/G/H). In conclusion, SPEN-depletion triggers systemic epigenetic reprogramming to enhance immune evasion and non-canonical Notch target genes. SPEN-tr DLBCL should be considered with heightened risk estimation and as prime candidates for personalized treatments beyond standard therapy. Citation Format: Janek S. Walker, Joseph P. Novak, Abigail R. Dropik, Zilin Xianyu, Michelle K. Manske, Matthew J. Maurer, Eric Mou, Rebecca L. King, Stephen M. Ansell, Thomas M. Habermann, Thomas E. Witzig, James R. Cerhan, Anne J. Novak. Deleterious SPEN mutations induce epigenetic reprogramming to promote survival and enhance immune evasion pathways in an aggressive subset of BN2/C1 DLBCL tumors [abstract]. In: Proceedings of the Fifth AACR International Meeting on Advances in Malignant Lymphoma: From Discovery to Clinical Impact; 2026 Jun 24-27; Philadelphia, PA. Philadelphia (PA): AACR; Blood Cancer Discov 2026;7(3_Suppl):Abstract nr A006.

Objectives Rheumatoid factor (RF) and anticitrullinated protein antibodies (ACPA) are linked to disease activity, severity and cardiovascular risk in rheumatoid arthritis (RA). Since RA-related inflammation associates with cardiovascular disease, we investigated whether RF and ACPA status influence the relationship between RA activity and event risk. Methods We assessed 3952 cardiovascular disease-free patients with prevalent RA registered in an international observational consortium between 1985 and 2012. Main outcome was a first major adverse cardiovascular event (MACE) including myocardial infarction, stroke and cardiovascular death. Follow-up accrued from enrolment until first MACE or censoring. Multivariable Cox models stratified by centre risk evaluated disease activity, RF, ACPA and their interactions. Results We recorded 184 first MACE events over 22 981 patient-years. Disease activity associated with MACE (HR 1.18 (95% CI 1.03 to 1.35)), whereas RF (HR 1.26 (0.82 to 1.94)) and ACPA (HR 1.25 (0.85 to 1.83)) did not reach statistical significance, though CIs were wide and a clinically meaningful association cannot be excluded. A three-way interaction between disease activity, RF and ACPA on MACE (p for interaction=0.044) was observed. RA activity associated with MACE in seronegative and double seropositive (p≤0.047), but not single RF-positive or ACPA-positive patients. Among RF-negative participants, RA activity was linked to MACE in ACPA-negative but not positive ones (p for interaction=0.003). Among ACPA-positive patients, disease activity was linked to MACE in RF-positive but not RF-negative ones (p for interaction=0.040). Conclusions Disease activity may better discriminate inflammation-driven cardiovascular risk in seronegative and double seropositive than single RF-positive or ACPA-positive patients. Risk protection through lowering disease activity may be serostatus dependent.

Importance Clinical trials in cardiovascular medicine aim to deliver high-quality evidence with greater efficiency, including smaller sample sizes and shorter timelines. The selection of sensitive and reliable end points is central to this goal. Right ventricular (RV) structure and function play a critical role in many cardiovascular conditions; however, RV-specific parameters remain underused and inconsistently applied in interventional clinical trials. In this article, the current and emerging role of RV-focused imaging and hemodynamic parameters as end points in clinical trials are explored and a comprehensive framework for their development, validation, and broader implementation is proposed. Observations Across multiple disease domains, RV-focused parameters derived from echocardiography, cardiac magnetic resonance imaging, computed tomography, and right-sided heart catheterization demonstrate potential value in assessing the therapeutic effects of new medicines or devices across a wide range of conditions including heart failure, cardiomyopathies, valve diseases, pulmonary hypertension, and congenital heart conditions. However, their use is inconsistent, and feasibility challenges are common, particularly in multicenter clinical trial settings. Key limitations include variability in imaging acquisition, incomplete data capture, lack of standardized protocols, and insufficient validation linking short-term RV changes to long-term clinical outcomes. Emerging tools such as artificial intelligence may improve reproducibility and efficiency, while collaborative, multidisciplinary efforts are essential for advancing end-point development. Conclusions and Relevance RV-specific end points hold substantial promise for enhancing the sensitivity and mechanistic insight of clinical trials but remain inadequately integrated into current practice. Optimal end-point selection requires balancing clinical relevance, analytical validity, and operational feasibility, with consideration of disease-specific pathophysiology and trial design. Standardization of acquisition, validation of clinically meaningful changes, and centralized data analysis are important next steps. Broader adoption of robust RV metrics supported by technological innovation and cross-sector collaboration has the potential to improve trial efficiency, accelerate therapeutic development, and ultimately enhance patient outcomes.

This Viewpoint describes writing letters of recommendation in the era of artificial intelligence.

This cohort study examines patterns of bone-modifying agent use from 2013 to 2024 among men with metastatic castration-resistant prostate cancer.

This economic evaluation assesses the costs, reimbursements, and estimated net operating margin of single- and 2-stage strategies for managing bile duct stone clearance to compare the financial outcomes of both strategies.

Abstract Background: Although some vaccines seem to be associated with a lower risk of lymphoma, their impact on outcomes is largely unknown. Methods: Data from a large prospective lymphoma cohort study were utilized to estimate associations of self-reported history of vaccination against hepatitis A, hepatitis B, influenza, and yellow fever with event-free survival (EFS) and overall survival (OS) using Cox proportional hazard models. Results: None of the vaccines were associated with EFS [hazard ratio (HR) 0.77–1] or OS (HRs 0.96–1.04). Similarly, there were no significant associations between the vaccines and outcomes for each lymphoma subtype. Conclusions: Prior vaccination against selected viruses was not associated with EFS or OS among patients with lymphoma. Impact: We did not find evidence for an impact of prior vaccination on lymphoma prognosis.