Molecular Subgroups of Diffuse Large B Cell Lymphoma: Biology and Implications for Clinical Practice

Should we use nomograms for risk predictions in diffuse large B cell lymphoma patients? A systematic review

Models based on risk stratification are increasingly reported for Diffuse large B cell lymphoma (DLBCL). Due to a rising interest in nomograms for cancer patients, we aimed to review and critically appraise prognostic models based on nomograms in DLBCL patients. A literature search in PubMed/Embase identified 59 articles that proposed prognostic models for DLBCL by combining parameters of interest (e.g., clinical, laboratory, immunohistochemical, and genetic) between January 2000 and 2024. Of them, 40 studies proposed different gene expression signatures and incorporated them into nomogram-based prognostic models. Although most studies assessed discrimination and calibration when developing the model, many lacked external validation. Current nomogram-based models for DLBCL are mainly developed from publicly available databases, lack external validation, and have no applicability in clinical practice. However, they may be helpful in individual patient counseling, although careful considerations should be made regarding model development due to possible limitations when choosing nomograms for prognostication.

Real-World Outcomes of Adolescents and Young Adults with Diffuse Large B-Cell Lymphoma: A Multicenter Retrospective Cohort Study

Purpose: Patients with diffuse large B-cell lymphoma (DLBCL) are typically treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). However, a standard of care for managing adolescents and young adults (AYAs) with DLBCL is lacking. We examine treatment approaches and outcomes of this population. Methods: We included 90 AYAs (15-39 years) diagnosed with DLBCL between 2008 and 2018 in three tertiary centers in Peru. Overall response rates (ORR) were available for all patients. Overall survival (OS) and progression-free survival (PFS) rates were estimated using the Kaplan-Meier method. Results: The median age at diagnosis was 33 years, 57% were males, 57% had good performance status (Lansky/Karnofsky ≥90), and 61% were diagnosed with early-stage disease (Ann Arbor stages I-II). R-CHOP (n = 69, 77%) was the most frequently used first-line regimen, with an ORR of 91%. With a median follow-up of 83 months, the 5-year OS and PFS among all patients were 79% and 67%, respectively. Among the patients who received R-CHOP, the 5-year OS and PFS were 77% and 66%, respectively. Of the 29 (32%) patients with relapsed/refractory (R/R) disease, 83% received second-line treatment and only 14% underwent consolidation therapy with autologous transplantation. The 3-year OS for R/R DLBCL was 36%. Conclusion: Our data show that AYAs with DLBCL who received conventional therapy had comparable outcomes to those observed in studies conducted among the adult population. However, the prognosis for AYAs with R/R disease was dismal, indicating the unmet need for developing and increasing access to novel treatment modalities in AYAs.

Automatic subtyping of Diffuse Large B-cell Lymphomas (DLBCL): Raman-based genetic and metabolic classification

Diffuse large B-cell lymphoma (DLBCL), the most common non-Hodgkin's lymphoma in adults, is a genetically and metabolically heterogeneous group of aggressive malignancies. The complexity of their molecular composition and the variability in clinical presentation make clinical diagnosis and treatment selection a serious challenge. The challenge is therefore to quickly and correctly classify DLBCL cells. In this work, we show that Raman imaging is a tool with high diagnostic potential, providing unique information about the biochemical components of tumor cells and their metabolism. We present models of classification of lymphoma cells based on their Raman spectra. The models automatically and efficiently identify DLBCL cells and assign them to a given cell-of-origin (COO) subtype (activated B cell-like (ABC) or germinal center B cell-like (GCB)) or, respectively, to a comprehensive cluster classification (CCC) subtype (OxPhos/non-OxPhos). In addition, we describe each lymphoma subtype by its unique spectral profile, linking it to biochemical, genetic, or metabolic features.

B-Cell Receptor Signaling and Beyond: The Role of Igα (CD79a)/Igβ (CD79b) in Normal and Malignant B Cells

B-cell receptor (BCR) is a B cell hallmark surface complex regulating multiple cellular processes in normal as well as malignant B cells. Igα (CD79a)/Igβ (CD79b) are essential components of BCR that are indispensable for its functionality, signal initiation, and signal transduction. CD79a/CD79b-mediated BCR signaling is required for the survival of normal as well as malignant B cells via a wide signaling network. Recent studies identified the great complexity of this signaling network and revealed the emerging role of CD79a/CD79b in signal integration. In this review, we have focused on functional features of CD79a/CD79b, summarized signaling consequences of CD79a/CD79b post-translational modifications, and highlighted specifics of CD79a/CD79b interactions within BCR and related signaling cascades. We have reviewed the complex role of CD79a/CD79b in multiple aspects of normal B cell biology and how is the normal BCR signaling affected by lymphoid neoplasms associated CD79A/CD79B mutations. We have also summarized important unresolved questions and highlighted issues that remain to be explored for better understanding of CD79a/CD79b-mediated signal transduction and the eventual identification of additional therapeutically targetable BCR signaling vulnerabilities.

Chemical Probes for Profiling of MALT1 Protease Activity

The paracaspase MALT1 is a key regulator of the human immune response. It is implicated in a variety of human diseases. For example, deregulated protease activity drives the survival of malignant lymphomas and is involved in the pathophysiology of autoimmune/inflammatory diseases. Thus, MALT1 has attracted attention as promising drug target. Although many MALT1 inhibitors have been identified, molecular tools to study MALT1 activity, target engagement and inhibition in complex biological samples, such as living cells and patient material, are still scarce. Such tools are valuable to validate MALT1 as a drug target in vivo and to assess yet unknown biological roles of MALT1. In this review, we discuss the recent literature on the development and biological application of molecular tools to study MALT1 activity and inhibition.

Co-Targeting of BTK and TrxR as a Therapeutic Approach to the Treatment of Lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a haematological malignancy representing the most diagnosed non-Hodgkin's lymphoma (NHL) subtype. Despite the approved chemotherapies available in clinics, some patients still suffer from side effects and relapsed disease. Recently, studies have reported the role of the Trx system and the BCR signalling pathway in cancer development and drug resistance. In this regard, we assessed a potential link between the two systems and evaluated the effects of [Au(d2pype)₂]Cl (TrxR inhibitor) and ibrutinib (BTK inhibitor) alone and in combination on the cell growth of two DLBCL lymphoma cell lines, SUDHL2 and SUDHL4. In this study, we show higher expression levels of the Trx system and BCR signalling pathway in the DLBCL patient samples compared to the healthy samples. The knockdown of TrxR using siRNA reduced BTK mRNA and protein expression. A combination treatment with [Au(d2pype)₂]Cl and ibrutinib had a synergistic effect on the inhibition of lymphoma cell proliferation, the activation of apoptosis, and, depending on lymphoma cell subtype, ferroptosis. Decreased BTK expression and the cytoplasmic accumulation of p65 were observed after the combination treatment in the DLBCL cells, indicating the inhibition of the NF-κB pathway. Thus, the co-targeting of BTK and TrxR may be an effective therapeutic strategy to consider for DLBCL treatment.

Fc receptor-like 1 (FCRL1) is a novel biomarker for prognosis and a possible therapeutic target in diffuse large B-cell lymphoma

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin's lymphoma, which can involve various types of mature B-cells. Considering that the incidence of DLBCL has increased, additional research is required to identify novel and effective prognostic and therapeutic molecules. Fc receptor-like 1 (FCRL1) acts as an activation co-receptor of human B-cells. Aberrant expression of this molecule has been reported in a number of B-cell-related disorders. Moreover, the clinical significance and prognosis value of FCRL1 in DLBCL are not completely identified.

METHODS

In this study, the expression levels of FCRL1 were determined in thirty patients with DLBCL and 15 healthy controls (HCs). In addition, the correlation between FCRL1 expressions with clinicopathological variables of DLBCL patients were examined. Then, the potential roles of FCRL1 in proliferation, apoptosis, and cell cycle distribution of B-cells from DLBCL patients were determined using flow cytometry analysis, after knockdown of this marker using retroviral short hairpin RNA interference. Quantitative real time-PCR, western blotting, and enzyme-linked immunosorbent assay were also used to identify the possible effects of FCRL1 knockdown on the expression levels of BCL-2, BID, BAX, intracellular signaling pathway PI3K/p-Akt, and p65 nuclear factor-kappa B (NF-κB) in the B-cells of DLBCL.

RESULTS

Statistical analysis revealed higher levels of FCRL1 expression in the B-cells of DLBCL patients compared to HCs at both protein and mRNA levels. A positive correlation was observed between the FCRL1 expression and some clinicopathological parameters of DLBCL patients. In addition, FCRL1 knockdown significantly decreased cell proliferation and stimulated apoptosis as well as G1 cell cycle arrest in the B-cells of DLBCL patients. The levels of p65 NF-κB and PI3K/p-Akt expressions were markedly reduced after knockdown of FCRL1 expression.

CONCLUSIONS

These results suggested that FCRL1 could be a potential novel biomarker for prognosis and/or a possible effective therapeutic target for treatment of patients with DLBCL.

Successful CNS-Centric Therapeutic Management and Genomic Profiling of Primary Cranial Vault Diffuse Large B-Cell Lymphoma

Primary cranial vault lymphoma (PCVL) is a rare lymphoma involving the skull with or without extra- and intracranial extension. Most cases of PCVL are diffuse large B-cell lymphoma (DLBCL). We report a case of primary cranial vault diffuse large B-cell lymphoma (PCV-DLBCL) that was successfully treated with anthracycline-based chemoimmunotherapy (CIT) alternating with central nervous system (CNS)-directed CIT with high-dose methotrexate and high-dose cytarabine. CNS-centric therapy was given for suspected cerebral cortical involvement and presumed elevated risk of CNS recurrence. The patient has remained in complete remission for 4.25 years following treatment. We suggest that PCV-DLBCL is potentially curable with CNS-directed therapy. Additionally, we provide genomic profiling results indicating an indeterminate cell of origin and multiple genetic mutations which are not frequently seen in DLBCL.

Copy Number Alteration and Mutational Profile of High-Grade B-Cell Lymphoma with MYC and BCL2 and/or BCL6 Rearrangements, Diffuse Large B-Cell Lymphoma with MYC-Rearrangement, and Diffuse Large B-Cell Lymphoma with MYC-Cluster Amplification

Diffuse large B-cell lymphoma (DLBCL) with MYC alteration is classified as high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements (double/triple-hit lymphoma; DHL/THL), DLBCL with MYC rearrangement (single-hit lymphoma; SHL) and DLBCL with MYC-cluster amplification (MCAD). To elucidate the genetic features of DHL/THL, SHL, and MCAD, 23 lymphoma cases from Tokai University Hospital were analyzed. The series included 10 cases of DHL/THL, 10 cases of SHL and 3 cases of MCAD. The analysis used whole-genome copy number microarray analysis (OncoScan) and a custom-made next-generation sequencing (NGS) panel of 115 genes associated with aggressive B-cell lymphomas. The copy number alteration (CNA) profiles were similar between DHL/THL and SHL. MCAD had fewer CNAs than those of DHL/THL and SHL, except for +8q24. The NGS profile characterized DHL/THL with a higher "mutation burden" than SHL (17 vs. 10, p = 0.010), and the most relevant genes for DHL/THL were BCL2 and SOCS1, and for SHL was DTX1. MCAD was characterized by mutations of DDX3X, TCF3, HLA-A, and TP53, whereas MYC was unmutated. In conclusion, DHL/THL, SHL, and MCAD have different profiles.

The path towards consensus genome classification of diffuse large B-cell lymphoma for use in clinical practice

Diffuse large B-cell lymphoma (DLBCL) is a widely heterogeneous disease in presentation, treatment response and outcome that results from a broad biological heterogeneity. Various stratification approaches have been proposed over time but failed to sufficiently capture the heterogeneous biology and behavior of the disease in a clinically relevant manner. The most recent DNA-based genomic subtyping studies are a major step forward by offering a level of refinement that could serve as a basis for exploration of personalized and targeted treatment for the years to come. To enable consistent trial designs and allow meaningful comparisons between studies, harmonization of the currently available knowledge into a single genomic classification widely applicable in daily practice is pivotal. In this review, we investigate potential avenues for harmonization of the presently available genomic subtypes of DLBCL inspired by consensus molecular classifications achieved for other malignancies. Finally, suggestions for laboratory techniques and infrastructure required for successful clinical implementation are described.

Developing high-affinity decoy receptors to treat multiple myeloma and diffuse large B cell lymphoma

Disease relapse and treatment-induced immunotoxicity pose significant clinical challenges for patients with hematological cancers. Here, we reveal distinctive requirements for neutralizing TNF receptor ligands APRIL and BAFF and their receptor activity in MM and DLBCL, impacting protein translation and production in MM cells and modulating the translation efficiency of the ATM interactor (ATMIN/ACSIZ). Therapeutically, we investigated the use of BCMA decoy receptor (sBCMA-Fc) as an inhibitor of APRIL and BAFF. While wild-type sBCMA-Fc effectively blocked APRIL signaling in MM, it lacked activity in DLBCL due to its weak BAFF binding. To expand the therapeutic utility of sBCMA-Fc, we engineered an affinity-enhanced mutant sBCMA-Fc fusion molecule (sBCMA-Fc V3) 4- and 500-fold stronger in binding to APRIL and BAFF, respectively. The mutant sBCMA-Fc V3 clone significantly enhanced antitumor activity against both MM and DLBCL. Importantly, we also demonstrated an adequate toxicity profile and on-target mechanism of action in nonhuman primate studies.

Biological and Clinical Implications of Gene-Expression Profiling in Diffuse Large B-Cell Lymphoma: A Proposal for a Targeted BLYM-777 Consortium Panel as Part of a Multilayered Analytical Approach

Gene-expression profiling (GEP) is used to study the molecular biology of lymphomas. Here, advancing insights from GEP studies in diffuse large B-cell lymphoma (DLBCL) lymphomagenesis are discussed. GEP studies elucidated subtypes based on cell-of-origin principles and profoundly changed the biological understanding of DLBCL with clinical relevance. Studies integrating GEP and next-generation DNA sequencing defined different molecular subtypes of DLBCL entities originating at specific anatomical localizations. With the emergence of high-throughput technologies, the tumor microenvironment (TME) has been recognized as a critical component in DLBCL pathogenesis. TME studies have characterized so-called "lymphoma microenvironments" and "ecotypes". Despite gained insights, unexplained chemo-refractoriness in DLBCL remains. To further elucidate the complex biology of DLBCL, we propose a novel targeted GEP consortium panel, called BLYM-777. This knowledge-based biology-driven panel includes probes for 777 genes, covering many aspects regarding B-cell lymphomagenesis (f.e., MYC signature, TME, immune surveillance and resistance to CAR T-cell therapy). Regarding lymphomagenesis, upcoming DLBCL studies need to incorporate genomic and transcriptomic approaches with proteomic methods and correlate these multi-omics data with patient characteristics of well-defined and homogeneous cohorts. This multilayered methodology potentially enhances diagnostic classification of DLBCL subtypes, prognostication, and the development of novel targeted therapeutic strategies.