The Role of c-MYC in B-Cell Lymphomas: Diagnostic and Molecular Aspects

The high-grade B-cell lymphomas: double hit and more

ABSTRACT

Both the 2022 World Health Organization Classification of Hematolymphoid Tumors, 5th Edition and the International Consensus Classification of lymphoma have refined the way we now approach high-grade B-cell lymphoma (HGBL) with MYC and BCL2 and/or BCL6 rearrangements moving the previous generation of classification a step forward. The unifying biology of MYC/BCL2 tumors has become clearer and their inferior prognosis confirmed compared with those with morphologic similar phenotypes but lacking the classifcation defining cytogenetic abnormalities. Fluorescent in situ hybridization testing has now become largely population based, and we have learned much from this. We can readily define molecular categories and apply these widely to clinical practice. Uncertainty has, however, been shed on the place of MYC/BCL6 translocations in defining a common disease group of double hit lymphoma due to biological heterogeneity. We have enhanced our knowledge of outcomes and the role of therapy intensification to overcome chemotherapy resistance in HGBL. For those patients failed by initial induction chemotherapy, immunotherapy approaches, including chimeric antigen receptor T-cell therapies, are improving outcomes. Novel inhibitors, targeting dysregulated oncogenic proteins, are being explored at pace. The rare, but difficult, diagnostic classification HGBL (not otherwise specified) remains a diagnosis of exclusion with limited data on an optimal clinical approach. The days of talking loosely of double- and triple-hit lymphoma are numbered as biology and outcomes may not be shared. This review synergizes the current data on biology, prognosis, and therapies in HGBL.

Prostate Cancer: A Review of Genetics, Current Biomarkers and Personalised Treatments

BACKGROUND

Prostate cancer is the second leading cause of cancer deaths in men, second only to lung cancer. Despite this, diagnosis and prognosis methods remain limited, with effective treatments being few and far between. Traditionally, prostate cancer is initially tested for through a prostate serum antigen (PSA) test and a digital rectum examination (DRE), followed by confirmation through an invasive prostate biopsy. The DRE and biopsy are uncomfortable for the patient, so less invasive, accurate diagnostic tools are needed. Current diagnostic tools, along with genes that hold possible biomarker uses in diagnosis, prognosis and indications for personalised treatment plans, were reviewed in this article.

RECENT FINDINGS

Several genes from multiple families have been identified as possible biomarkers for disease, including those from the MYC and ETS families, as well as several tumour suppressor genes, Androgen Receptor signalling genes and DNA repair genes. There have also been advances in diagnostic tools, including MRI-targeted and liquid biopsies. Several personalised treatments have been developed over the years, including those that target metabolism-driven prostate cancer or those that target inflammation-driven cancer.

CONCLUSION

Several advances have been made in prostate cancer diagnosis and treatment, but the disease still grows year by year, leading to more and more deaths annually. This calls for even more research into this disease, allowing for better diagnosis and treatment methods and a better chance of patient survival.

Circular RNA as a Biomarker for Diagnosis, Prognosis and Therapeutic Target in Acute and Chronic Lymphoid Leukemia

Circular RNAs (circRNAs) are single-stranded RNAs that have received much attention in recent years. CircRNAs lack a 5' head and a 3' poly-A tail. The structure of this type of RNAs make them resistant to digestion by exonucleases. CircRNAs are expressed in different cells and have various functions. The function of circRNAs is done by sponging miRNAs, changing gene expression, and protein production. The expression of circRNAs changes in different types of cancers, which causes changes in cell growth, proliferation, differentiation, and apoptosis. Changes in the expression of circRNAs can cause the invasion and progression of tumors. Studies have shown that changes in the expression of circRNAs can be seen in acute lymphoid leukemia (ALL) and chronic lymphoid leukemia (CLL). The conducted studies aim to identify circRNAs whose expression has changed in these leukemias and their more precise function so that these circRNAs can be identified as biomarkers, prediction of patient prognosis, and treatment targets for ALL and CLL patients. In this study, we review the studies conducted on the role and function of circRNAs in ALL and CLL patients. The results of the studies show that there is a possibility of using circRNAs as biomarkers in the identification and treatment of patients in the future.

Characterizing the Mutational Landscape of Diffuse Large B-Cell Lymphoma in a Prospective Cohort of Mexican Patients

Diffuse large B-cell lymphoma (DLBCL) is the most common B-cell malignancy worldwide. Molecular classifications have tried to improve cure rates. We prospectively examined and correlated the mutational landscape with the clinical features and outcomes of 185 Mexican patients (median age 59.3 years, 50% women) with newly diagnosed DLBCL. A customized panel of 79 genes was designed, based on previous international series. Most patients had ECOG performance status (PS) < 2 (69.2%), advanced-stage disease (72.4%), germinal-center phenotype (68.1%), and double-hit lymphomas (14.1%). One hundred and ten (59.5%) patients had at least one gene with driver mutations. The most common mutated genes were as follows: TP53, EZH2, CREBBP, NOTCH1, and KMT2D. The median follow-up was 42 months, and the 5-year relapse-free survival (RFS) and overall survival (OS) rates were 70% and 72%, respectively. In the multivariate analysis, both age > 50 years and ECOG PS > 2 were significantly associated with a worse OS. Our investigation did not reveal any discernible correlation between the presence of a specific mutation and survival. In conclusion, using a customized panel, we characterized the mutational landscape of a large cohort of Mexican DLBCL patients. These results need to be confirmed in further studies.

CRISPR-Cas9 Knockout Screens Identify DNA Damage Response Pathways and BTK as Essential for Cisplatin Response in Diffuse Large B-Cell Lymphoma

The recurrence of diffuse large B-cell lymphoma (DLBCL) has been observed in 40% of cases. The standard of care for refractory/relapsed DLBCL (RR-DLBCL) is platinum-based treatment prior to autologous stem cell transplantation; however, the prognosis for RR-DLBCL patients remains poor. Thus, to identify genes affecting the cisplatin response in DLBCL, cisplatin-based whole-genome CRISPR-Cas9 knockout screens were performed in this study. We discovered DNA damage response (DDR) pathways as enriched among identified sensitizing CRISPR-mediated gene knockouts. In line, the knockout of the nucleotide excision repair genes XPA and ERCC6 sensitized DLBCL cells to platinum drugs irrespective of proliferation rate, thus documenting DDR as essential for cisplatin sensitivity in DLBCL. Functional analysis revealed that the loss of XPA and ERCC6 increased DNA damage levels and altered cell cycle distribution. Interestingly, we also identified BTK, which is involved in B-cell receptor signaling, to affect cisplatin response. The knockout of BTK increased cisplatin sensitivity in DLBCL cells, and combinatory drug screens revealed a synergistic effect of the BTK inhibitor, ibrutinib, with platinum drugs at low concentrations. Applying local and external DLBCL cohorts, we addressed the clinical relevance of the genes identified in the CRISPR screens. BTK was among the most frequently mutated genes with a frequency of 3-5%, and XPA and ERCC6 were also mutated, albeit at lower frequencies. Furthermore, 27-54% of diagnostic DLBCL samples had mutations in pathways that can sensitize cells to cisplatin. In conclusion, this study shows that XPA and ERCC6, in addition to BTK, are essential for the response to platinum-based drugs in DLBCL.

Genetic profiles of oligometastatic non-small-cell lung cancer and corresponding brain metastases

OBJECTIVES

In patients with oligometastatic non-small-cell lung cancer (NSCLC), systemic therapy in combination with local ablative treatment of the primary tumour and all metastatic sites is associated with improved prognosis. For patient selection and treatment allocation, further knowledge about the molecular characteristics of the oligometastatic state is necessary. Here, we performed a genetic characterization of primary NSCLC and corresponding brain metastases (BM).

METHODS

We retrospectively identified patients with oligometastatic NSCLC and synchronous (<3 months) or metachronous (>3 months) BM who underwent surgical resection of both primary tumour and BM. Mutation profiling of formalin-fixed paraffin-embedded tumour cell blocks was performed by targeted next-generation sequencing using the Oncomine Focus Assay panel.

RESULTS

Sequencing was successful in 46 paired samples. An oncogenic alteration was present in 31 primary tumours (67.4%) and 40 BM (86.9%). The alteration of the primary tumours was preserved in the corresponding BM in 29 out of 31 cases (93.5%). The most prevalent oncogenic driver in both primary tumours and BM was a KRAS (Kirsten rat sarcoma viral oncogene) mutation (s = 21). In 16 patients (34.8%), the BM harboured additional oncogenic alterations. The presence of a private genetic alteration in the BM was an independent predictor of shorter overall survival.

CONCLUSIONS

In oligometastatic NSCLC, BM retain the main genetic alterations of the primary tumours. Patients may profit from targeted inhibition of mutated KRAS. Additional private genetic alterations in the BM are dismal.

Lessons learned from the Eµ-TCL1 mouse model of CLL

The Eµ-TCL1 mouse model has been used for over 20 years to study the pathobiology of chronic lymphocytic leukemia (CLL) and for preclinical testing of novel therapies. A CLL-like disease develops with increasing age in these mice due to a B cell specific overexpression of human TCL1. The reliability of this model to mirror human CLL is controversially discussed, as none of the known driver mutations identified in patients are found in Eµ-TCL1 mice. It has to be acknowledged that this mouse model was key to develop targeted therapies that aim at inhibiting the constitutive B cell receptor (BCR) signaling, a main driver of CLL. Inhibitors of BCR signaling became standard-of-care for a large proportion of patients with CLL as they are highly effective. The Eµ-TCL1 model further advanced our understanding of CLL biology owed to studies that crossed this mouse line with various transgenic mouse models and demonstrated the relevance of CLL-cell intrinsic and -extrinsic drivers of disease. These studies were instrumental in showing the relevance of the tumor microenvironment in the lymphoid tissues for disease progression and immune escape in CLL. It became clear that CLL cells shape and rely on stromal and immune cells, and that immune suppressive mechanisms and T cell exhaustion contribute to CLL progression. Based on this knowledge, new immunotherapy strategies were clinically tested for CLL, but so far with disappointing results. As some of these therapies were effective in the Eµ-TCL1 mouse model, the question arose concerning the translatability of preclinical studies in these mice. The aim of this review is to summarize lessons we have learnt over the last decades by studying CLL-like disease in the Eµ-TCL1 mouse model. The article focuses on pitfalls and limitations of the model, as well as the gained knowledge and potential of using this model for the development of novel treatment strategies to achieve the goal of curing patients with CLL.

Thinking Outside the Box: Indirect Myc Modulation in Canine B-Cell Lymphoma

B-cell lymphomas (BCL) is the most frequent hematological cancer in dogs. Treatment typically consists of chemotherapy, with CHOP-based protocols. However, outcome remains generally poor, urging the exploration of new therapeutic strategies with a targeted approach. Myc transcription factor plays a crucial role in regulating cellular processes, and its dysregulation is implicated in numerous human and canine malignancies, including canine BCL (cBCL). This study aims to evaluate the efficacy of indirectly inhibiting Myc in cBCL using BI2536 and MZ1 compounds in two in vitro models (CLBL-1 and KLR-1201). Both BI2536 and MZ1, alone and combined, affected cell viability in a significant concentration- and time-dependent manner. Western Blot revealed an upregulation of PLK1 expression in both cell lines upon treatment with BI2536, in association with a reduction in c-Myc protein levels. Conversely, MZ1 led to a decrease in its primary target, BRD4, along with a reduction in c-Myc. Furthermore, BI2536, both alone and in combination with MZ1, induced larger transcriptomic changes in cells compared to MZ1 alone, primarily affecting MYC target genes and genes involved in cell cycle regulation. These data underscore the potential role of Myc as therapeutic target in cBCL, providing a novel approach to indirectly modulate this molecule.

Ajania pacifica (Nakai) K. Bremer and Humphries Extract Limits MYC Expression to Induce Apoptosis in Diffuse Large B Cell Lymphoma

The proto-oncogene MYC is frequently dysregulated in patients with diffuse large B-cell lymphoma (DLBCL) and plays a critical role in disease progression. To improve the clinical outcomes of patients with DLBCL, the development of strategies to target MYC is crucial. The use of medicinal plants for developing anticancer drugs has garnered considerable attention owing to their diverse mechanisms of action. In this study, 100 plant extracts of flora from the Republic of Korea were screened to search for novel agents with anti-DLBCL effects. Among them, Ajania pacifica (Nakai) K. Bremer and Humphries extract (APKH) efficiently suppressed the survival of DLBCL cells, while showing minimal toxicity toward normal murine bone marrow cells. APKH suppressed the expression of anti-apoptotic BCL2 family members, causing an imbalance between the pro-apoptotic and anti-apoptotic BCL2 members. This disrupted mitochondrial membrane potential, cytochrome c release, and pro-caspase-3 activation and eventually led to DLBCL cell death. Importantly, MYC expression was markedly downregulated by APKH and ectopic expression of MYC in DLBCL cells abolished the pro-apoptotic effects of APKH. These results demonstrate that APKH exerts anti-DLBCL effects by inhibiting MYC expression. Moreover, when combined with doxorubicin, an essential component of the CHOP regimen (cyclophosphamide, doxorubicin, vincristine, and prednisone), APKH synergistically enhanced the therapeutic effect of doxorubicin. This indicates that APKH may overcome drug resistance, which is common in patients with refractory/relapsed DLBCL. To identify compounds with anti-DLBCL activities in APKH, the chemical profile analysis of APKH was performed using UPLC-QTOF/MSe analysis and assessed for its anticancer activity. Based on the UPLC-QTOF/MSe chemical profiling, it is conceivable that APKH may serve as a novel agent targeting MYC and sensitizing drug-resistant DLBCL cells to CHOP chemotherapy. Further studies to elucidate how the compounds in APKH exert tumor-suppressive role in DLBCL are warranted.

MYC protein is a high-risk factor in mantle cell lymphoma and identifies cases beyond morphology, proliferation and TP53/p53 - a Nordic Lymphoma Group study

The transcription factor MYC is a well-described oncogene with an important role in lymphomagenesis, but its significance for clinical outcome in mantle cell lymphoma (MCL) remains to be determined. We performed an investigation of the expression of MYC protein in a cohort of 251 MCL patients complemented by analyses of structural aberrations and mRNA, in a sub-cohort of patients. Fourteen percent (n=35) of patients showed high MYC protein expression with >20% positive cells (MYChigh), among whom only one translocation was identified, and 86% (n=216) of patients showed low MYC protein expression. Low copy number gains of MYC were detected in ten patients, but with no correlation to MYC protein levels. However, MYC mRNA levels correlated significantly to MYC protein levels with a R2 value of 0.76. Patients with a MYChigh tumor had both an independent inferior overall survival and an inferior progression-free survival (hazard ratio [HR]=2.03, 95% confidence interval [95% CI]: 1.2-3.4 and HR=2.2, 95% CI: 1.04-4.6, respectively) when adjusted for additional high-risk features. Patients with MYChigh tumors also tended to have additional high-risk features and to be older at diagnosis. A subgroup of 13 patients had concomitant MYChigh expression and TP53/p53 alterations and a substantially increased risk of progression (HR=16.9, 95% CI: 7.4-38.3) and death (HR=7.8, 95% CI: 4.4-14.1) with an average overall survival of only 0.9 years. In summary, we found that at diagnosis a subset of MCL patients (14%) overexpressed MYC protein, and had a poor prognosis but that MYC rearrangements were rare. Tumors with concurrent MYC overexpression and TP53/p53 alterations pinpointed MCL patients with a dismal prognosis with a median overall survival of less than 3 years. We propose that MYC needs to be assessed beyond the current high-risk factors in MCL in order to identify cases in need of alternative treatment.

Epigenetic Mechanisms in Latent Epstein-Barr Virus Infection and Associated Cancers

The Epstein-Barr Virus (EBV) is a double-stranded DNA-based human tumor virus that was first isolated in 1964 from lymphoma biopsies. Since its initial discovery, EBV has been identified as a major contributor to numerous cancers and chronic autoimmune disorders. The virus is particularly efficient at infecting B-cells but can also infect epithelial cells, utilizing an array of epigenetic strategies to establish long-term latent infection. The association with histone modifications, alteration of DNA methylation patterns in host and viral genomes, and microRNA targeting of host cell factors are core epigenetic strategies that drive interactions between host and virus, which are necessary for viral persistence and progression of EBV-associated diseases. Therefore, understanding epigenetic regulation and its role in post-entry viral dynamics is an elusive area of EBV research. Here, we present current outlooks of EBV epigenetic regulation as it pertains to viral interactions with its host during latent infection and its propensity to induce tumorigenesis. We review the important epigenetic regulators of EBV latency and explore how the strategies involved during latent infection drive differential epigenetic profiles and host-virus interactions in EBV-associated cancers.

Unraveling the Role of the NLRP3 Inflammasome in Lymphoma: Implications in Pathogenesis and Therapeutic Strategies

Inflammasomes are multimeric protein complexes, sensors of intracellular danger signals, and crucial components of the innate immune system, with the NLRP3 inflammasome being the best characterized among them. The increasing scientific interest in the mechanisms interconnecting inflammation and tumorigenesis has led to the study of the NLRP3 inflammasome in the setting of various neoplasms. Despite a plethora of data regarding solid tumors, NLRP3 inflammasome's implication in the pathogenesis of hematological malignancies only recently gained attention. In this review, we investigate its role in normal lymphopoiesis and lymphomagenesis. Considering that lymphomas comprise a heterogeneous group of hematologic neoplasms, both tumor-promoting and tumor-suppressing properties were attributed to the NLRP3 inflammasome, affecting neoplastic cells and immune cells in the tumor microenvironment. NLRP3 inflammasome-related proteins were associated with disease characteristics, response to treatment, and prognosis. Few studies assess the efficacy of NLRP3 inflammasome therapeutic targeting with encouraging results, though most are still at the preclinical level. Further understanding of the mechanisms regulating NLRP3 inflammasome activation during lymphoma development and progression can contribute to the investigation of novel treatment approaches to cover unmet needs in lymphoma therapeutics.

The USP35-CXCR3 Axis plays an oncogenic role in JeKo-1 mantle cell lymphoma cells

In B cells, the chemokine receptor CXCR3 is expressed only by a subset of B cells. However, CXCR3 is highly expressed in a rare type of B-cell lymphoma known as Mantle Cell Lymphoma (MCL) and CXCR3 inhibitor impairs proliferation and induces apoptosis in the MCL cell line JeKo-1. Despite this, the mechanism responsible for maintaining high levels of CXCR3 in MCL cells remains unclear. In this study, we assessed CXCR3 expression and amplification in MCL samples and confirmed that CXCR3 is overexpressed in MCL tissues. We also observed that CXCR3 amplification is present in a small portion of MCL patients and is associated with MCL classification. We then screened ubiquitin-specific proteases (USPs) that might control the degradation of CXCR3 protein. Our investigation revealed that USP35 acts as a potent stabilizer of CXCR3 protein. Knockdown of USP35 substantially reduced the CXCR3 protein levels in JeKo-1 cells, resulting in reduced cell viability, cell cycle arrest, increased apoptosis, and mitigated migration and invasion in these cells. At the molecular level, USP35 deubiquitinates and stabilizes CXCR3. USP35 deficiency attenuated the activation of the JAK1/STAT1 pathway and reduced the expression of β-catenin and c-Myc in JeKo-1 cells. Furthermore, we observed that overexpression of CXCR3 rescued the impaired tumorigenicity of USP35-deficient JeKo-1 cells, and the mechanism may be related to the fact that USP35 promotes CXCR3 deubiquitination to stabilize its expression. These findings collectively demonstrate the oncogenic role of the USP35-CXCR3 axis in JeKo-1 MCL cells.

MT1G Regulates c-MYC/P53 Signal to Inhibit Proliferation, Invasion and Migration and Promote Apoptosis in Colon Cancer Cells

INTRODUCTION

Colon cancer is a common and malignant cancer featuring high morbidity and poor prognosis.

AIMS

This study was performed to explore the regulatory role of MT1G in colon cancer as well as its unconcealed molecular mechanism.

METHODS

The expressions of MT1G, c-MYC, and p53 were assessed with the application of RT-qPCR and western blot. The impacts of MT1G overexpression on the proliferative ability of HCT116 and LoVo cells were measured by CCK-8 and BrdU incorporation assays. Additionally, transwell wound healing, and flow cytometry assays were employed to evaluate the invasive and migrative capacities as well as the apoptosis level of HCT116 and LoVo cells. Moreover, the activity of the P53 promoter region was assessed with the help of a luciferase reporter assay.

RESULTS

It was found that the expressions of MT1G at both mRNA and protein levels were greatly decreased in human colon cancer cell lines, particularly in HCT116 and LoVo cell lines. After transfection, it was discovered that the MT1G overexpression suppressed the proliferation, migration and invasion but promoted the apoptosis of HCT116 and LoVo cells, which were then partially reversed after overexpressing c-MYC. Additionally, MT1G overexpression reduced c-MYC expression but enhanced the p53 expression, revealing that the MT1G overexpression could regulate c-MYC/P53 signal. Elsewhere, it was also shown that c-MYC overexpression suppressed the regulatory effects of MT1G on P53.

CONCLUSION

To conclude, MT1G was verified to regulate c-MYC/P53 signal to repress the proliferation, migration and invasion but promote the apoptosis of colon cancer cells, which might offer a novel targeted-therapy for the improvement of colon cancer.

Oxadiazole Derivatives of Diclofenac as an Anti-proliferative Agent for B-cell Non-Hodgkin Lymphoma: An In vitro and In Silico Studies

BACKGROUND

Non-Hodgkin lymphoma of B cell origin is the common type of lymphoma- related malignancy with poor response rate with conventional front-line therapies.

AIM

The aim of the present study was to investigate the potential of new anti-inflammatory oxadiazole derivatives of Diclofenac as an anti-lymphoma agent through in vitro and in silico approaches.

METHODS

Anti-lymphoma potential was evaluated by alamar blue technique. MTT assay employed for cytotoxicity. Gene and protein expression studies was performed by qRT-PCR and ELISA respectively. Docking studies was performed by using MOE program.

RESULTS

Among five diclofenac derivatives, (II) showed promising anti-lymphoma effects, where it inhibited the expression of BCL-2, p-38 MAPK and TGF-β in both follicular and Burkitt's lymphoma cells and was non-toxic against normal human fibroblast cells. The in silico studies against BCL-2 revealed that the unsubstituted Sulphur group in (II) is involved in the crucial interactions with the binding site residue.

CONCLUSION

The compound (II) can be a potential therapeutic candidate for B-cell non-Hodgkin lymphoma and deserves further development as a novel anti-lymphoma agent.

Prognostic significance of copy number gains of MYC detected by fluorescence in situ hybridization in large B-cell lymphoma

The MYC protooncogene plays a critical role in many cellular processes. MYC translocations are recurrent in large B-cell lymphomas (LBCLs) where they exhibit a negative effect on survival. Gain of MYC copies is also frequently identified; however, there is no consensus on the frequency and prognostic significance of MYC copy gains. We collected FISH data for MYC with reflex testing for BCL2 and BCL6 and IHC results at diagnosis for a cohort of 396 de novo and transformed LBCL cases and compared progression-free (PFS) and overall survival (OS) to determine the prognostic impact of extra MYC copies. The prevalence of cases with MYC copy number gain was 20.9%. PFS was shorter for patients with ≥5 MYC copies compared to controls (p = 0.0005, HR = 2.25). .MYC gain trended towards worse OS; patients with ≥7MYC copies had worse OS (p = 0.013), similar to patients with MYC translocations. We propose that MYC gain represents a dose-dependent prognostic factor for LBCLs.

Plasmablastic Lymphoma. A State-of-the-Art Review: Part 1-Epidemiology, Pathogenesis, Clinicopathologic Characteristics, Differential Diagnosis, Prognostic Factors, and Special Populations

This two-part review aims to present a current and comprehensive understanding of the diagnosis and management of plasmablastic lymphoma. The first section, as presented in this paper, reviews epidemiology, etiology, clinicopathological characteristics, differential diagnosis, prognostic variables, and the impact of plasmablastic lymphoma on specific populations. Plasmablastic lymphoma (PBL) is a rare and aggressive form of lymphoma. Previous and modern studies have demonstrated a significant association between the human immunodeficiency virus (HIV) and the development of the disease. The limited occurrence of PBL contributes to a need for a more comprehensive understanding of the molecular mechanisms involved in its etiology. Consequently, the diagnostic procedure for PBL poses a significant difficulty. Among the group of CD20-negative large B-cell lymphomas, PBL can be correctly diagnosed by identifying its exact clinical characteristics, anatomical location, and morphological characteristics. PBL cells do not express CD20 or PAX5 but possess plasmacytic differentiation markers such as CD38, CD138, MUM1/IRF4, Blimp1, and XBP1. PBL must be distinguished from other B-cell malignancies that lack the CD20 marker, including primary effusion lymphoma, anaplastic lymphoma kinase-positive large B-cell lymphoma, and large B-cell lymphoma (LBCL). This condition is frequently associated with infections caused by the Epstein-Barr virus and genetic alterations involving the MYC gene. Despite advances in our comprehension of this disease, the prognosis remains dismal, resulting in a low overall survival rate, although recent reports suggest an apparent tendency towards substantial improvement.

Triple targeting of RSK, AKT, and S6K as pivotal downstream effectors of PDPK1 by TAS0612 in B-cell lymphomas

B-cell lymphomas (BCLs) are the most common disease entity among hematological malignancies and have various genetically and molecularly distinct subtypes. In this study, we revealed that the blockade of phosphoinositide-dependent kinase-1 (PDPK1), the master kinase of AGC kinases, induces a growth inhibition via cell cycle arrest and the induction of apoptosis in all eight BCL-derived cell lines examined, including those from activated B-cell-like diffuse large B-cell lymphoma (DLBCL), double expressor DLBCL, Burkitt lymphoma, and follicular lymphoma. We also demonstrated that, in these cell lines, RSK2, AKT, and S6K, but not PLK1, SGK, or PKC, are the major downstream therapeutic target molecules of PDPK1 and that RSK2 plays a central role and AKT and S6K play subsidiary functional roles as the downstream effectors of PDPK1 in cell survival and proliferation. Following these results, we confirmed the antilymphoma efficacy of TAS0612, a triple inhibitor for total RSK, including RSK2, AKT, and S6K, not only in these cell lines, regardless of disease subtypes, but also in all 25 patient-derived B lymphoma cells of various disease subtypes. At the molecular level, TAS0612 caused significant downregulation of MYC and mTOR target genes while inducing the tumor suppressor TP53INP1 protein in these cell lines. These results prove that the simultaneous blockade of RSK2, AKT, and S6K, which are the pivotal downstream substrates of PDPK1, is a novel therapeutic target for the various disease subtypes of BCLs and line up TAS0612 as an attractive candidate agent for BCLs for future clinical development.

The role of comorbidity indices and histochemical markers in surgically resected and non-resected primary central nervous system lymphoma

The role of surgical resection in primary central nervous system lymphoma (PCNSL) was not recognized until recently. However, prognostic factors for surgically treated PCNSL remain unclear. In the present study, we aimed to identify and compare the prognostic value of comorbidity indices and immunohistochemical markers in patients with surgically and non-surgically treated PCNSL. This retrospective single-center study analyzed patients who underwent either surgical resection or stereotactic biopsy for newly diagnosed PCNSL between January 2012 and December 2021. Clinical demographics, comorbidity indices, and immunohistochemical markers were analyzed. We included 23 and 18 patients who underwent stereotactic biopsy and surgical resection, respectively. The median overall survival (OS) was 11.05 months. Using multivariate Cox regression, we identified pretreatment prognostic nutritional index (PNI) (p = 0.009), positive BCL2 staining (p = 0.026), and infratentorial involvement (p = 0.004) as independent prognostic factors of OS. Predictors of progression-free survival (PFS) included PNI (p = 0.040), infratentorial involvement (p = 0.021), and surgical resection for PCNSL (p = 0.048). Subgroup analyses revealed that positive BCL2 (p = 0.048) and PD-L1 (p = 0.037) staining were associated with worse OS in the biopsy group. PNI and infratentorial involvement could significantly impact both OS and PFS in patients with PCNSL. Surgical resection could predict favorable PFS but not OS. Moreover, BCL2 and PD-L1 expression can be employed as prognostic markers in these patients.

Image-Based Deep Learning Detection of High-Grade B-Cell Lymphomas Directly from Hematoxylin and Eosin Images

Deep learning applications are emerging as promising new tools that can support the diagnosis and classification of different cancer types. While such solutions hold great potential for hematological malignancies, there have been limited studies describing the use of such applications in this field. The rapid diagnosis of double/triple-hit lymphomas (DHLs/THLs) involving MYC, BCL2 and/or BCL6 rearrangements is obligatory for optimal patient care. Here, we present a novel deep learning tool for diagnosing DHLs/THLs directly from scanned images of biopsy slides. A total of 57 biopsies, including 32 in a training set (including five DH lymphoma cases) and 25 in a validation set (including 10 DH/TH cases), were included. The DHL-classifier demonstrated a sensitivity of 100%, a specificity of 87% and an AUC of 0.95, with only two false positive cases, compared to FISH. The DHL-classifier showed a 92% predictive value as a screening tool for performing conventional FISH analysis, over-performing currently used criteria. The work presented here provides the proof of concept for the potential use of an AI tool for the identification of DH/TH events. However, more extensive follow-up studies are required to assess the robustness of this tool and achieve high performances in a diverse population.

Location, location, location: mapping the lymphoma tumor microenvironment using spatial transcriptomics

Lymphomas are a heterogenous group of lymphoid neoplasms with a wide variety of clinical presentations. Response to treatment and prognosis differs both between and within lymphoma subtypes. Improved molecular and genetic profiling has increased our understanding of the factors which drive these clinical dynamics. Immune and non-immune cells within the lymphoma tumor microenvironment (TME) can both play a key role in antitumor immune responses and conversely also support lymphoma growth and survival. A deeper understanding of the lymphoma TME would identify key lymphoma and immune cell interactions which could be disrupted for therapeutic benefit. Single cell RNA sequencing studies have provided a more comprehensive description of the TME, however these studies are limited in that they lack spatial context. Spatial transcriptomics provides a comprehensive analysis of gene expression within tissue and is an attractive technique in lymphoma to both disentangle the complex interactions between lymphoma and TME cells and improve understanding of how lymphoma cells evade the host immune response. This article summarizes current spatial transcriptomic technologies and their use in lymphoma research to date. The resulting data has already enriched our knowledge of the mechanisms and clinical impact of an immunosuppressive TME in lymphoma and the accrual of further studies will provide a fundamental step in the march towards personalized medicine.

Actionable loss of SLF2 drives B-cell lymphomagenesis and impairs the DNA damage response

The DNA damage response (DDR) acts as a barrier to malignant transformation and is often impaired during tumorigenesis. Exploiting the impaired DDR can be a promising therapeutic strategy; however, the mechanisms of inactivation and corresponding biomarkers are incompletely understood. Starting from an unbiased screening approach, we identified the SMC5-SMC6 Complex Localization Factor 2 (SLF2) as a regulator of the DDR and biomarker for a B-cell lymphoma (BCL) patient subgroup with an adverse prognosis. SLF2-deficiency leads to loss of DDR factors including Claspin (CLSPN) and consequently impairs CHK1 activation. In line with this mechanism, genetic deletion of Slf2 drives lymphomagenesis in vivo. Tumor cells lacking SLF2 are characterized by a high level of DNA damage, which leads to alterations of the post-translational SUMOylation pathway as a safeguard. The resulting co-dependency confers synthetic lethality to a clinically applicable SUMOylation inhibitor (SUMOi), and inhibitors of the DDR pathway act highly synergistic with SUMOi. Together, our results identify SLF2 as a DDR regulator and reveal co-targeting of the DDR and SUMOylation as a promising strategy for treating aggressive lymphoma.

MYC-targeted genes predict distant recurrence in patients with ocular adnexal extranodal marginal zone lymphoma

Ocular adnexal extranodal marginal zone lymphoma (OA-EMZL) is the most frequent subtype of ocular adnexal lymphoma, with a high propensity for recurrence. Distant recurrence (DR) as an essential prognostic event has unique clinical risk factors, but whether distinct molecular features exist remains poorly understood. Here, we identified potential biomarkers using proteomic analysis of 27 OA-EMZL samples. The MYC-targeted genes PCNA, MCM6, and MCM4 were identified as candidates. MYC-targeted genes were further identified as the most significantly activated gene set in patients with DR. The candidate genes were verified in samples from 11 patients with DR and 33 matched controls using immunohistochemistry. The 3-year and 5-year AUC values of MCM6 (0.699 and 0.757) were higher than those of Ki-67 (0.532 and 0.592). High expressions of MCM6 and MCM4 were significantly associated with shorter distant recurrence-free survival (Log-rank p = 0.017, Log-rank p = 0.0053). Multivariate Cox regression identified MCM6 expression as an independent risk factor for DR (HR, 6.86; 95% CI, 1.32-35.79; P = 0.02). Knockdown of c-Myc in B cells resulted in decreased MCM6 and MCM4 expression and reduced proliferative capacity. Our results suggest that activation of the MYC-targeted gene is a distinct molecular feature of DR in OA-EMZL. MYC-targeted gene, MCM6, is a promising pathological biomarker for DR.

Calcineurin-independent NFATc1 signaling is essential for survival of Burkitt lymphoma cells

In Burkitt lymphoma (BL), a tumor of germinal center B cells, the pro-apoptotic properties of MYC are controlled by tonic B cell receptor (BCR) signals. Since BL cells do not exhibit constitutive NF-κB activity, we hypothesized that anti-apoptotic NFATc1 proteins provide a major transcriptional survival signal in BL. Here we show that post-transcriptional mechanisms are responsible for the calcineurin (CN) independent constitutive nuclear over-expression of NFATc1 in BL and Eµ-MYC - induced B cell lymphomas (BCL). Conditional inactivation of the Nfatc1 gene in B cells of Eµ-MYC mice leads to apoptosis of BCL cells in vivo and ex vivo. Inhibition of BCR/SYK/BTK/PI3K signals in BL cells results in cytosolic re-location of NFATc1 and apoptosis. Therefore, NFATc1 activity is an integrated part of tonic BCR signaling and an alternative target for therapeutic intervention in BL.

PARP1 Inhibition Halts EBV+ Lymphoma Progression by Disrupting the EBNA2/MYC Axis

PARP1 has been shown to regulate EBV latency. However, the therapeutic effect of PARP1 inhibitors on EBV+ lymphomagenesis has not yet been explored. Here, we show that PARPi BMN-673 has a potent anti-tumor effect on EBV-driven LCL in a mouse xenograft model. We found that PARP1 inhibition induces a dramatic transcriptional reprogramming of LCLs driven largely by the reduction of the MYC oncogene expression and dysregulation of MYC targets, both in vivo and in vitro. PARP1 inhibition also reduced the expression of viral oncoprotein EBNA2, which we previously demonstrated depends on PARP1 for activation of MYC. Further, we show that PARP1 inhibition blocks the chromatin association of MYC, EBNA2, and tumor suppressor p53. Overall, our study strengthens the central role of PARP1 in EBV malignant transformation and identifies the EBNA2/MYC pathway as a target of PARP1 inhibitors and its utility for the treatment of EBNA2-driven EBV-associated cancers.

Diagnostic and prognostic value of c-MYC gene expression in hematological malignancies

Introduction

c-MYC plays vital role in regulation of cell proliferation and has been associated with tumorigenesis. This study is aimed at assessing diagnostic and prognostic value of plasma c-MYC expression to aid in early diagnosis and prognosis of hematological malignancies.

Methods

Plasma c-MYC expression was determined by quantitative real time PCR using EVA Green chemistry and cluster of differentiation markers performed via immunocytochemistry.

Result

Plasma c-MYC was higher in subject with hematological malignancies (8.8 ± 1.1) when compared with apparently healthy controls (4.5 ± 0.5). A screening cut-off c-MYC ratio value of 9.42 with sensitivity and specificity of 65.5% and 100% respectively were obtained using receiver operator characteristic curve analysis. Plasma c-MYC was found to have no prognostic value using Kaplan-Meier analysis.

Conclusion

Plasma c-MYC ratio showed promising screening/diagnostic value for hematological malignancies.

Comprehensive FISH testing using FFPE tissue microarray of primary lymph node tissue identifies secondary cytogenetic abnormalities in Mantle Cell Lymphoma

INTRODUCTION

Mantle Cell Lymphoma (MCL), is characterised by the reciprocal translocation t(11;14) resulting in CCND1-IGH gene fusion and subsequent upregulation of the CCND1 gene. Rearrangements of MYC and losses of CDKN2A and TP53 have been identified as biomarkers informing prognostic and potentially therapeutic information however these are not routinely assessed in MCL investigation. We aimed to identify additional cytogenetic changes using fluorescence in situ hybridisation (FISH) on formalin fixed paraffin embedded (FFPE) primary lymph node tissue microarrays in a cohort of 28 patients diagnosed with MCL between 2004 and 2019. FISH results were compared with corresponding immunohistochemistry (IHC) biomarkers to determine if IHC was a reliable screening tool to direct FISH testing.

METHOD

FFPE lymph node tissue samples were constructed into tissue microarrays (TMA) which were stained with 7 immunohistochemical biomarkers: Cyclin D1, c-Myc, p16, ATM, p53, Bcl-6 and Bcl-2. The same TMAs were hybridised with FISH probes for the corresponding genes; CCND1-IGH, MYC, CDKN2A, ATM, TP53, BCL6 and BCL2. FISH and the corresponding IHC biomarkers were analysed to determine if secondary cytogenetic changes could be identified and if IHC could be used as a reliable, inexpensive predictor of FISH abnormalities to potentially direct FISH testing.

RESULTS

CCND1-IGH fusion was detected in 27/28 (96%) of samples. Additional cytogenetic changes were identified by FISH in 15/28 (54%) of samples. Two additional abnormalities were detected in 2/28 (7%) samples. Cyclin D1 IHC overexpression was an excellent predictor of CCND1-IGH fusion. MYC and ATM IHC were useful screening tests to direct FISH testing and identified cases with poor prognostic features including blastoid change. IHC did not show clear concordance with FISH for other biomarkers.

CONCLUSION

FISH using FFPE primary lymph node tissue can detect secondary cytogenetic abnormalities in patients with MCL which are associated with an inferior prognosis. An expanded FISH panel including MYC, CDKN2A, TP53 and ATM should be considered in cases where anomalous IHC expression or is seen for these markers or if the patient appears to have the blastoid variant of the disease.

Co-Detection of EBV and Human Polyomavirus JCPyV in a Case of AIDS-Related Multifocal Primary Central Nervous System Diffuse Large B-Cell Lymphoma

The human neurotropic Polyomavirus JCPyV is the widespread opportunistic causative pathogen of the fatal demyelinating disease progressive multifocal leukoencephalopathy; however, it has also been implicated in the oncogenesis of several types of cancers. It causes brain tumors when intracerebrally inoculated into rodents, and genomic sequences of different strains and expression of the viral protein large T-Antigen have been detected in a wide variety of glial brain tumors and CNS lymphomas. Here, we present a case of an AIDS-related multifocal primary CNS lymphoma in which JCPyV genomic sequences of the three regions of JCPyV and expression of T-Antigen were detected by PCR and immunohistochemistry, respectively. No capsid proteins were detected, ruling out active JCPyV replication. Sequencing of the control region revealed that Mad-4 was the strain of JCPyV present in tumor cells. In addition, expression of viral proteins LMP and EBNA-1 from another ubiquitous oncogenic virus, Epstein-Barr, was also detected in the same lymphocytic neoplastic cells, co-localizing with JCPyV T-Antigen, suggesting a potential collaboration between these two viruses in the process of malignant transformation of B-lymphocytes, which are the site of latency and reactivation for both viruses.

MYC-driven synthesis of Siglec ligands is a glycoimmune checkpoint

The Siglecs (sialic acid-binding immunoglobulin-like lectins) are glycoimmune checkpoint receptors that suppress immune cell activation upon engagement of cognate sialoglycan ligands. The cellular drivers underlying Siglec ligand production on cancer cells are poorly understood. We find the MYC oncogene causally regulates Siglec ligand production to enable tumor immune evasion. A combination of glycomics and RNA-sequencing of mouse tumors revealed the MYC oncogene controls expression of the sialyltransferase St6galnac4 and induces a glycan known as disialyl-T. Using in vivo models and primary human leukemias, we find that disialyl-T functions as a "don't eat me" signal by engaging macrophage Siglec-E in mice or the human ortholog Siglec-7, thereby preventing cancer cell clearance. Combined high expression of MYC and ST6GALNAC4 identifies patients with high-risk cancers and reduced tumor myeloid infiltration. MYC therefore regulates glycosylation to enable tumor immune evasion. We conclude that disialyl-T is a glycoimmune checkpoint ligand. Thus, disialyl-T is a candidate for antibody-based checkpoint blockade, and the disialyl-T synthase ST6GALNAC4 is a potential enzyme target for small molecule-mediated immune therapy.

Investigating In Situ Expression of c-MYC and Candidate Ubiquitin-Specific Proteases in DLBCL and Assessment for Peptidyl Disruptor Molecule against c-MYC-USP37 Complex

Diffuse Large B-Cell Lymphoma (DLBCL) is the most common form of non-Hodgkin's lymphoma (NHL). Elevated expression of c-MYC in DLBCL is associated with poor prognosis of the disease. In different cancers, c-MYC has been found regulated by different ubiquitin-specific proteases (USPs), but to date, the role of USPs in c-MYC regulation has not been investigated in DLBCL. In this study, in situ co expression of c-MYC and three candidates USPs, USP28, USP36 and USP37, have been investigated in both the ABC and GCB subtypes of DLBCL. This shows that USP37 expression is positively correlated with the c-MYC expression in the ABC subtype of DLBCL. Structurally, both c-MYC and USP37 has shown large proportion of intrinsically disordered regions, minimizing their chances for full structure crystallization. Peptide array and docking simulations has shown that N-terminal region of c-MYC interacts directly with residues within and in proximity of catalytically active C19 domain of the USP37. Given the structural properties of the interaction sites in the c-MYC-USP37 complex, a peptidyl inhibitor has been designed. Molecular docking has shown that the peptide fits well in the targeted site of c-MYC, masking most of its residues involved in the binding with USP37. The findings could further be exploited to develop therapeutic interventions against the ABC subtype of DLBCL.

Development of a Prognostic Scoring System using MYC Expression and Soluble Interleukin Receptor -2 level for Diffuse Large B-cell Lymphoma

Background

Diffuse large B-cell lymphoma, not otherwise specified (DLBCL-NOS), is the most frequent type of lymphoid neoplasm.

Methods

We investigated the relationships between clinical factors of DLBCL-NOS and MYC immunohistochemistry (IHC) staining.

Results

A total of 110 patients diagnosed with DLBCL-NOS from 2012 to 2020 at Tottori University Hospital and treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) chemotherapy were included. IHC staining of MYC in formalin-fixed, paraffin-embedded tumor specimens was performed, and ROC-curve analysis revealed the cut-off value of the MYC positive rate as 55%. The 2-year overall survival (OS) rates of the MYC-negative and -positive groups were 84.7% vs 57.7% (P = 0.0091), and the progression-free survival rates were 77.8% vs 54.7% (P = 0.016), respectively. Multivariate analysis for OS showed prognostic significance of MYC positivity [hazards ratio (HR): 2.496; P = 0.032], and serum levels of soluble interleukin-2 receptor (sIL-2R) > 2000 U/mL (HR: 3.950; P = 0.0019), as well as age > 75 (HR: 2.356; P = 0.068). The original scoring system was developed based on these findings. By assigning one point to each item, age (> 75), MYC positivity, and sIL-2R level (> 2000), all patients were classified into three risk categories: group 1 (0 points), group 2 (1 point), and group 3 (2-3 points). The 2-year survival rates were 100%, 83.0%, and 47.1% for the groups 1, 2, and 3, respectively (P < 0.0001).

Conclusion

We suggest that a prognostic scoring system using MYC expression and soluble interleukin receptor -2 level is useful for the prediction of prognosis, contributing to further stratification in DLBCL-NOS.

Tissue-Specific microRNA Expression Profiling to Derive Novel Biomarkers for the Diagnosis and Subtyping of Small B-Cell Lymphomas

Accurate diagnosis of the most common histological subtypes of small B-cell lymphomas is challenging due to overlapping morphological features and limitations of ancillary testing, which involves a large number of immunostains and molecular investigations. In addition, a common diagnostic challenge is to distinguish reactive lymphoid hyperplasia that do not require additional stains from such lymphomas that need ancillary investigations. We investigated if tissue-specific microRNA (miRNA) expression may provide potential biomarkers to improve the pathology diagnostic workflow. This study seeks to distinguish reactive lymphoid proliferation (RL) from small B-cell lymphomas, and to further distinguish the four main subtypes of small B-cell lymphomas. Two datasets were included: a discovery cohort (n = 100) to screen for differentially expressed miRNAs and a validation cohort (n = 282) to develop classification models. The models were evaluated for accuracy in subtype prediction. MiRNA gene set enrichment was also performed to identify differentially regulated pathways. 306 miRNAs were detected and quantified, resulting in 90-miRNA classification models from which smaller panels of miRNAs biomarkers with good accuracy were derived. Bioinformatic analysis revealed the upregulation of known and other potentially relevant signaling pathways in such lymphomas. In conclusion, this study suggests that miRNA expression profiling may serve as a promising tool to aid the diagnosis of common lymphoid lesions.

Primary diffuse large B-cell lymphoma of the breast: A retrospective study of outcomes and insulin resistance

OBJECTIVES

To investigate the clinicopathological features, insulin resistance (IR) status, and the outcomes of populations with diffuse large B-cell lymphoma (DLBCL) of the breast.

METHODS

This study was carried out at Department of Haematology, the Fourth Hospital of Hebei Medical University, Shijiazhuang, China, that included 32 patients treated form January 2009 to June 2020. The primary endpoints of the study were their survival time.

RESULTS

There were 32 patients in the study. A total of 18 (56.2%) patients had IR. In terms of treatment, 31.2% were treated with surgery, most (93.8%) received chemotherapy, and 25% received radiotherapy and intrathecal therapy. Univariate analysis indicated the patients with stages III-IV, B symptoms, tumour recurrence, PAX5 positivity, and c-MYC positivity showed a shorter survival time (p<0.05). The overall survival and progression-free survival (PFS) rates in IR group were shorter than those without IR, but there was no statistical difference (p>0.05). Multivariate analysis indicated that tumour recurrence shortened the 5-year PFS of the patients (p=0.037).

CONCLUSION

Primary DLBCL of the breast was very rare; more than half of the cases had IR, but IR did not affect their survival.

B-cell lymphoblastic lymphoma following intravenous BNT162b2 mRNA booster in a BALB/c mouse: A case report

Unprecedented immunization campaigns have been rolled out worldwide in an attempt to contain the ongoing COVID-19 pandemic. Multiple vaccines were brought to the market, among two utilizing novel messenger ribonucleic acid technology. Despite their undisputed success in decreasing COVID-19-associated hospitalizations and mortality, various adverse events have been reported. The emergence of malignant lymphoma is one of such rare adverse events that has raised concern, although an understanding of the mechanisms potentially involved remains lacking. Herein, we present the first case of B-cell lymphoblastic lymphoma following intravenous high-dose mRNA COVID-19 vaccination (BNT162b2) in a BALB/c mouse. Two days following booster vaccination (i.e., 16 days after prime), at only 14 weeks of age, our animal suffered spontaneous death with marked organomegaly and diffuse malignant infiltration of multiple extranodal organs (heart, lung, liver, kidney, spleen) by lymphoid neoplasm. Immunohistochemical examination revealed organ sections positive for CD19, terminal deoxynucleotidyl transferase, and c-MYC, compatible with a B-cell lymphoblastic lymphoma immunophenotype. Our murine case adds to previous clinical reports on malignant lymphoma development following novel mRNA COVID-19 vaccination, although a demonstration of direct causality remains difficult. Extra vigilance is required, with conscientious reporting of similar cases and a further investigation of the mechanisms of action explaining the aforementioned association.

Plasmablastic lymphoma: from genetics to treatment

Plasmablastic lymphoma (PBL) represents a rare distinct lymphoma entity with plasmablastic morphology and plasmacytic immunophenotype that is characterized by an aggressive clinical course. Standard chemotherapeutic regimens often remain insufficient to cure affected patients. Recently, comprehensive molecular analyses of large cohorts of primary PBL samples have revealed the mutational landscape as well as the pattern of copy number alterations of this rare lymphoma subtype. Identification of recurrent aberrations affecting the JAK-STAT, RAS-RAF, NOTCH, IRF4, and MYC signaling pathways drive the molecular pathogenesis of PBL and hold great potential for novel targeted therapeutic approaches.

The lncRNA KTN1-AS1 co-regulates a variety of Myc-target genes and enhances proliferation of Burkitt lymphoma cells

Long non-coding RNAs (lncRNAs) are involved in many normal and oncogenic pathways through a diverse repertoire of transcriptional and posttranscriptional regulatory mechanisms. LncRNAs that are under tight regulation of well-known oncogenic transcription factors such as c-Myc (Myc) are likely to be functionally involved in their disease-promoting mechanisms. Myc is a major driver of many subsets of B cell lymphoma and to date remains an undruggable target. We identified three Myc-induced and four Myc-repressed lncRNAs by use of multiple in vitro models of Myc-driven Burkitt lymphoma and detailed analysis of Myc binding profiles. We show that the top Myc-induced lncRNA KTN1-AS1 is strongly upregulated in different types of B cell lymphoma compared with their normal counterparts. We used CRISPR-mediated genome editing to confirm that the direct induction of KTN1-AS1 by Myc is dependent on the presence of a Myc E-box-binding motif. Knockdown of KTN1-AS1 revealed a strong negative effect on the growth of three BL cell lines. Global gene expression analysis upon KTN1-AS1 depletion shows a strong enrichment of key genes in the cholesterol biosynthesis pathway as well as co-regulation of many Myc-target genes, including a moderate negative effect on the levels of Myc itself. Our study suggests a critical role for KTN1-AS1 in supporting BL cell growth by mediating co-regulation of a variety of Myc-target genes and co-activating key genes involved in cholesterol biosynthesis. Therefore, KTN1-AS1 may represent a putative novel therapeutic target in lymphoma.

Genomic landscape of mature B-cell non-Hodgkin lymphomas - an appraisal from lymphomagenesis to drug resistance

BACKGROUND

Mature B-cell non-Hodgkin lymphomas are one of the most common hematological malignancies with a divergent clinical presentation, phenotype, and course of disease regulated by underlying genetic mechanism.

MAIN BODY

Genetic and molecular alterations are not only critical for lymphomagenesis but also largely responsible for differing therapeutic response in these neoplasms. In recent years, advanced molecular tools have provided a deeper understanding regarding these oncogenic drives for predicting progression as well as refractory behavior in these diseases. The prognostic models based on gene expression profiling have also been proved effective in various clinical scenarios. However, considerable overlap does exist between the genotypes of individual lymphomas and at the same time where additional molecular lesions may be associated with each entity apart from the key genetic event. Therefore, genomics is one of the cornerstones in the multimodality approach essential for classification and risk stratification of B-cell non-Hodgkin lymphomas.

CONCLUSION

We hereby in this review discuss the wide range of genetic aberrancies associated with tumorigenesis, immune escape, and chemoresistance in major B-cell non-Hodgkin lymphomas.

B-cell Lymphoma 6 (BCL6): From Master Regulator of Humoral Immunity to Oncogenic Driver in Pediatric Cancers

B-cell lymphoma 6 (BCL6) is a protooncogene in adult and pediatric cancers, first identified in diffuse large B-cell lymphoma (DLBCL) where it acts as a repressor of the tumor suppressor TP53, conferring survival, protection, and maintenance of lymphoma cells. BCL6 expression in normal B cells is fundamental in the regulation of humoral immunity, via initiation and maintenance of the germinal centers (GC). Its role in B cells during the production of high affinity immunoglobins (that recognize and bind specific antigens) is believed to underpin its function as an oncogene. BCL6 is known to drive the self-renewal capacity of leukemia-initiating cells (LIC), with high BCL6 expression in acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), and glioblastoma (GBM) associated with disease progression and treatment resistance. The mechanisms underpinning BCL6-driven therapy resistance are yet to be uncovered; however, high activity is considered to confer poor prognosis in the clinical setting. BCL6's key binding partner, BCL6 corepressor (BCOR), is frequently mutated in pediatric cancers and appears to act in concert with BCL6. Using publicly available data, here we show that BCL6 is ubiquitously overexpressed in pediatric brain tumors, inversely to BCOR, highlighting the potential for targeting BCL6 in these often lethal and untreatable cancers. In this review, we summarize what is known of BCL6 (role, effect, mechanisms) in pediatric cancers, highlighting the two sides of BCL6 function, humoral immunity, and tumorigenesis, as well as to review BCL6 inhibitors and highlight areas of opportunity to improve the outcomes of patients with pediatric cancer.

Proteasome Inhibitors Silence Oncogenes in Multiple Myeloma through Localized Histone Deacetylase 3 (HDAC3) Stabilization and Chromatin Condensation

Proteasome inhibitors have become the standard of care for multiple myeloma (MM). Blocking protein degradation particularly perturbs the homeostasis of short-lived polypeptides such as transcription factors and epigenetic regulators. To determine how proteasome inhibitors directly impact gene regulation, we performed an integrative genomics study in MM cells. We discovered that proteasome inhibitors reduce the turnover of DNA-associated proteins and repress genes necessary for proliferation through epigenetic silencing. Specifically, proteasome inhibition results in the localized accumulation of histone deacetylase 3 (HDAC3) at defined genomic sites, which reduces H3K27 acetylation and increases chromatin condensation. The loss of active chromatin at super-enhancers critical for MM, including the super-enhancer controlling the proto-oncogene c-MYC, reduces metabolic activity and cancer cell growth. Epigenetic silencing is attenuated by HDAC3 depletion, suggesting a tumor-suppressive element of this deacetylase in the context of proteasome inhibition. In the absence of treatment, HDAC3 is continuously removed from DNA by the ubiquitin ligase SIAH2. Overexpression of SIAH2 increases H3K27 acetylation at c-MYC-controlled genes, increases metabolic output, and accelerates cancer cell proliferation. Our studies indicate a novel therapeutic function of proteasome inhibitors in MM by reshaping the epigenetic landscape in an HDAC3-dependent manner. As a result, blocking the proteasome effectively antagonizes c-MYC and the genes controlled by this proto-oncogene.

Human complete NFAT1 deficiency causes a triad of joint contractures, osteochondromas, and B-cell malignancy

The discovery of humans with monogenic disorders has a rich history of generating new insights into biology. Here we report the first human identified with complete deficiency of nuclear factor of activated T cells 1 (NFAT1). NFAT1, encoded by NFATC2, mediates calcium-calcineurin signals that drive cell activation, proliferation, and survival. The patient is homozygous for a damaging germline NFATC2 variant (c.2023_2026delTACC; p.Tyr675Thrfs∗18) and presented with joint contractures, osteochondromas, and recurrent B-cell lymphoma. Absence of NFAT1 protein in chondrocytes caused enrichment in prosurvival and inflammatory genes. Systematic single-cell-omic analyses in PBMCs revealed an environment that promotes lymphomagenesis with accumulation of naïve B cells (enriched for oncogenic signatures MYC and JAK1), exhausted CD4+ T cells, impaired T follicular helper cells, and aberrant CD8+ T cells. This work highlights the pleiotropic role of human NFAT1, will empower the diagnosis of additional patients with NFAT1 deficiency, and further defines the detrimental effects associated with long-term use of calcineurin inhibitors.

TCR-Independent Metabolic Reprogramming Precedes Lymphoma-Driven Changes in T-cell Fate

Chronic T-cell receptor (TCR) signaling in the tumor microenvironment is known to promote T-cell dysfunction. However, we reasoned that poorly immunogenic tumors may also compromise T cells by impairing their metabolism. To address this, we assessed temporal changes in T-cell metabolism, fate, and function in models of B-cell lymphoma driven by Myc, a promoter of energetics and repressor of immunogenicity. Increases in lymphoma burden most significantly impaired CD4+ T-cell function and promoted regulatory T cell (Treg) and Th1-cell differentiation. Metabolomic analyses revealed early reprogramming of CD4+ T-cell metabolism, reduced glucose uptake, and impaired mitochondrial function, which preceded changes in T-cell fate. In contrast, B-cell lymphoma metabolism remained robust during tumor progression. Finally, mitochondrial functions were impaired in CD4+ and CD8+ T cells in lymphoma-transplanted OT-II and OT-I transgenic mice, respectively. These findings support a model, whereby early, TCR-independent, metabolic interactions with developing lymphomas limits T cell-mediated immune surveillance.

TP53 mutations and RNA-binding protein MUSASHI-2 drive resistance to PRMT5-targeted therapy in B-cell lymphoma

To identify drivers of sensitivity and resistance to Protein Arginine Methyltransferase 5 (PRMT5) inhibition, we perform a genome-wide CRISPR/Cas9 screen. We identify TP53 and RNA-binding protein MUSASHI2 (MSI2) as the top-ranked sensitizer and driver of resistance to specific PRMT5i, GSK-591, respectively. TP53 deletion and TP53R248W mutation are biomarkers of resistance to GSK-591. PRMT5 expression correlates with MSI2 expression in lymphoma patients. MSI2 depletion and pharmacological inhibition using Ro 08-2750 (Ro) both synergize with GSK-591 to reduce cell growth. Ro reduces MSI2 binding to its global targets and dual treatment of Ro and PRMT5 inhibitors result in synergistic gene expression changes including cell cycle, P53 and MYC signatures. Dual MSI2 and PRMT5 inhibition further blocks c-MYC and BCL-2 translation. BCL-2 depletion or inhibition with venetoclax synergizes with a PRMT5 inhibitor by inducing reduced cell growth and apoptosis. Thus, we propose a therapeutic strategy in lymphoma that combines PRMT5 with MSI2 or BCL-2 inhibition.

ctDNA Is Useful to Detect Mutations at Codon 641 of Exon 16 of EZH2, a Biomarker for Relapse in Patients with Diffuse Large B-Cell Lymphoma

Simple Summary

It is well known that epigenetic modifications and proteins involved in this process are important in the biogenesis of diffuse large B-cell lymphoma. In this sense, we decided to analyze the EZH2 mutations, which are frequent in this neoplasm, using ctDNA to demonstrate the utility of this tool for searching these mutations. The importance of the study of this gene is due to its role in the biogenesis of lymphomas and also because there are selective inhibitors targeting EZH2. This targeted therapy could be particularly effective in patients with activating mutations in EZH2, remarking the importance of its detection.

Abstract

(1) Background: The epigenetic regulator EZH2 is a subunit of the polycomb repressive complex 2 (PRC2), and methylates H3K27, resulting in transcriptional silencing. It has a critical role in lymphocyte differentiation within the lymph node. Therefore, mutations at this level are implicated in lymphomagenesis. In fact, the mutation at the Y641 amino acid in the EZH2 gene is mutated in up to 40% of B-cell lymphomas. (2) Methods: We compared the presence of exon 16 EZH2 mutations in tumor samples and ctDNA in a prospective trial. These mutations were determined by Sanger sequencing and ddPCR. (3) Results: One hundred and thirty-eight cases were included. Ninety-eight were germinal center, and twenty had EZH2 mutations. Mean follow-up (IQR 25–75) was 23 (7–42) months. The tumor samples were considered the standard of reference. Considering the results of the mutation in ctDNA by Sanger sequencing, the sensibility (Se) and specificity (Sp) were 52% and 99%, respectively. After adding the droplet digital PCR (ddPCR) analysis, the Se and Sp increased to 95% and 100%, respectively. After bivariate analysis, only the presence of double-hit lymphoma (p = 0.04) or EZH2 mutations were associated with relapse. The median Progression free survival (PFS) (95% interval confidence) was 27.7 (95% IC: 14–40) vs. 44.1 (95% IC: 40–47.6) months for the mutated vs. wild-type (wt) patients. (4) Conclusions: The ctDNA is useful for analyzing EZH2 mutations, which have an impact on PFS.

Non-canonical DNA structures: Diversity and disease association

A complete understanding of DNA double-helical structure discovered by James Watson and Francis Crick in 1953, unveil the importance and significance of DNA. For the last seven decades, this has been a leading light in the course of the development of modern biology and biomedical science. Apart from the predominant B-form, experimental shreds of evidence have revealed the existence of a sequence-dependent structural diversity, unusual non-canonical structures like hairpin, cruciform, Z-DNA, multistranded structures such as DNA triplex, G-quadruplex, i-motif forms, etc. The diversity in the DNA structure depends on various factors such as base sequence, ions, superhelical stress, and ligands. In response to these various factors, the polymorphism of DNA regulates various genes via different processes like replication, transcription, translation, and recombination. However, altered levels of gene expression are associated with many human genetic diseases including neurological disorders and cancer. These non-B-DNA structures are expected to play a key role in determining genetic stability, DNA damage and repair etc. The present review is a modest attempt to summarize the available literature, illustrating the occurrence of non-canonical structures at the molecular level in response to the environment and interaction with ligands and proteins. This would provide an insight to understand the biological functions of these unusual DNA structures and their recognition as potential therapeutic targets for diverse genetic diseases.

Leukemic High Grade B Cell Lymphoma is Associated With MYC Translocation, Double Hit/Triple Hit Status, Transformation, and CNS Disease Risk: The Mayo Clinic Experience

INTRODUCTION

Leukemic involvement in high grade B cell lymphoma (L-HGBL) is rare and has been sparsely described in the literature. We report our experience in a large single institution multicenter academic setting.

MATERIALS AND METHODS

Medical records of patients with HGBL who received care at Mayo Clinic between 2003 and 2020 were reviewed. L-HGBL was confirmed by peripheral blood smear and flow cytometry with corroboration from tissue and bone marrow biopsy findings.

RESULTS

Twenty patients met inclusion criteria. All patients had significant bone marrow involvement by HGBL. Leukemic involvement presented in 11 of 20 (55%) in the de novo and 9 of 20 (45%) in the relapsed setting. Seven of 20 patients had DLBCL, NOS, 6 of 20 had transformation (t-DLBCL), 3 of 20 had transformed double/triple hit lymphoma (t-DHL/THL), 2 of 20 had double hit lymphoma (DHL), and 2 of 20 had HGBL with intermediate features between DLBCL and Burkitt lymphoma. Nine of 15 patients had MYC translocation. Based on Hans criteria, 11 of 20 had germinal center B-cell (GCB) cell of origin (COO) and 9/20 had non-GCB COO. Five of 11 de novo patients experienced CNS relapse/progression. All de novo patients received anthracycline-based chemoimmunotherapy. Eighteen of 20 patients died of progressive disease. Median overall survival was significantly better in the de novo compared to relapsed group (8.9 months vs. 2.8 months, P = .01). COO, MYC status, DHL/THL status, HGBL subtype, or treatment group did not demonstrate a significant effect on overall survival.

CONCLUSION

L-HGBL carries a poor prognosis and is associated with MYC translocation, DHL/THL status, transformation, and high CNS risk. Novel therapeutic approaches are needed for L-HGBL.

The Pt(S-pr-thiosal)2 and BCL1 Leukemia Lymphoma: Antitumor Activity In Vitro and In Vivo

B cell malignancies are, despite the development of targeted therapy in a certain percentage of the patients still a chronic disease with relapses, requiring multiple lines of therapy. Regimens that include platinum-based drugs provide high response rates in different B cell lymphomas, high-risk chronic lymphocytic leukemia (CLL), and devastating complication of CLL, Richter’s syndrome. The aim of this study was to explore the potential antitumor activity of previously synthetized platinum(IV) complex with alkyl derivatives of thyosalicilc acid, PtCl2(S-pr-thiosal)2, toward murine BCL1 cells and to delineate possible mechanisms of action. The PtCl2(S-pr-thiosal)2 reduced the viability of BCL1 cells in vitro but also reduced the growth of metastases in the leukemia lymphoma model in BALB/c mice. PtCl2(S-pr-thiosal)2 induced apoptosis, inhibited proliferation of BCL1 cells, and induced cell cycle disturbance. Treatment of BCL1 cells with PtCl2(S-pr-thiosal)2 inhibited expression of cyclin D3 and cyclin E and enhanced expression of cyclin-dependent kinase inhibitors p16, p21, and p27 resulting in cell cycle arrest in the G1 phase, reduced the percentage of BCL1 cells in the S phase, and decreased expression of Ki-67. PtCl2(S-pr-thiosal)2 treatment reduced expression of phosphorylated STAT3 and downstream-regulated molecules associated with cancer stemness and proliferation, NANOG, cyclin D3, and c-Myc, and expression of phosphorylated NFκB in vitro and in vivo. In conclusion, PtCl2(S-pr-thiosal)2 reduces STAT3 and NFκB phosphorylation resulting in inhibition of BCL1 cell proliferation and the triggering of apoptotic cell death.

Isolation and characterization of anti-inflammatory and anti-proliferative compound, for B-cell Non-Hodgkin lymphoma, from Nyctanthes arbor-tristis Linn

ETHNOPHARMACOLOGICAL RELEVANCE

Nyctanthes arbor-tristis Linn. is native to Indo-Pak sub-continent and has high medicinal values in Ayureda. This plant has been used traditionally for the treatment of sciatica, rheumatism, chronic fever, diabetes, snakebite, dysentery, cachexia and cancer. Studies have shown many pharmacological properties such as anti-cancer efficacy against Dalton's ascetic lymphoma, cytotoxicity against T-cell leukemia, anti-inflammatory, anti-diabetic and anti-oxidant effects.

AIM OF THE STUDY

Aim of the study was to explore the anti-inflammatory and anti-proliferative potential of N. arbor-tristis.

MATERIAL AND METHODS

Ethanol extract of fresh and uncrushed aerial parts of N. arbor-tristis was used in the present study. A new compound nyctanthesin A was isolated following a bioactivity-guided fractionation and chromatographic separations. Its chemical structure was elucidated through spectral studies including 1D, 2D-NMR experiments and HREIMS. The intracellular reactive oxygen species (ROS) and nitric oxide (NO) generation from phagocytes were detected by chemiluminescence technique and Griess method, respectively. TNF-α and TGF-β production was quantified by ELISA. Anti-lymphoma and cytotoxic activities were assessed by alamar blue and MTT assays, respectively. The transcription and protein expression level of Bcl-2, COX-2, p38 MAPK, PDL-1, NF-κB, c-Myc and PNF-κB was performed by qRT-PCR and protein blot assays, respectively.

RESULTS

Petroleum ether insoluble fraction of the ethanol extract of fresh and uncrushed aerial parts of N. arbor-tristis revealed anti-inflammatory potential by inhibiting ROS. A previously undescribed compound nyctanthesin A was isolated from this fraction and characterized by UV, IR, NMR and HREIMS. It showed significant anti-inflammatory property by inhibiting ROS, NO and TNF-α production. The strong anti-proliferative effects on B- cell lymphoma cells, DOHH2 and Raji, revealed its anti-lymphoma potential along with non-toxic profile against BJ and NIH-3T3 fibroblast cells of normal origin. The qRT-PCR results showed marked inhibition of Bcl-2, COX-2, p38 MAPK, PDL-1, c-Myc, NF-κB, and PNF-κB at transcription level in DOHH2 cells with comparatively lesser but significant effects in Raji cells, where the expression of Bcl-2 gene was not affected. The protein expression of PNF-κB in DOHH2 cells was inhibited by 66% (P < 0.05) and COX-2 in both cell lines was inhibited by 50% (P < 0.05) at 60 μg/mL. A moderate non-significant inhibition of TGF-β (∼20%) was observed in both cell lines at 100 μg/mL CONCLUSIONS: Scientific evidences reported here validate the anti-inflammatory and anti-cancer potential of the plant.

Classifying Germinal Center Derived Lymphomas-Navigate a Complex Transcriptional Landscape

Classification of lymphoid neoplasms is based mainly on histologic, immunologic, and (rarer) genetic features. It has been supplemented by gene expression profiling (GEP) in the last decade. Despite the considerable success, particularly in associating lymphoma subtypes with specific transcriptional programs and classifier signatures of up- or downregulated genes, competing molecular classifiers were often proposed in the literature by different groups for the same classification tasks to distinguish, e.g., BL versus DLBCL or different DLBCL subtypes. Moreover, rarer sub-entities such as MYC and BCL2 "double hit lymphomas" (DHL), IRF4-rearranged large cell lymphoma (IRF4-LCL), and Burkitt-like lymphomas with 11q aberration pattern (mnBLL-11q) attracted interest while their relatedness regarding the major classes is still unclear in many respects. We explored the transcriptional landscape of 873 lymphomas referring to a wide spectrum of subtypes by applying self-organizing maps (SOM) machine learning. The landscape reveals a continuum of transcriptional states activated in the different subtypes without clear-cut borderlines between them and preventing their unambiguous classification. These states show striking parallels with single cell gene expression of the active germinal center (GC), which is characterized by the cyclic progression of B-cells. The expression patterns along the GC trajectory are discriminative for distinguishing different lymphoma subtypes. We show that the rare subtypes take intermediate positions between BL, DLBCL, and FL as considered by the 5th edition of the WHO classification of haemato-lymphoid tumors in 2022. Classifier gene signatures extracted from these states as modules of coregulated genes are competitive with literature classifiers. They provide functional-defined classifiers with the option of consenting redundant classifiers from the literature. We discuss alternative classification schemes of different granularity and functional impact as possible avenues toward personalization and improved diagnostics of GC-derived lymphomas.

T-cell Dysfunction upon Expression of MYC with Altered Phosphorylation at Threonine 58 and Serine 62

As a transcription factor that promotes cell growth, proliferation, and apoptosis, c-MYC (MYC) expression in the cell is tightly controlled. Disruption of oncogenic signaling pathways in human cancers can increase MYC protein stability, due to altered phosphorylation ratios at two highly conserved sites, Threonine 58 (T58) and Serine 62 (S62). The T58 to Alanine mutant (T58A) of MYC mimics the stabilized, S62 phosphorylated, and highly oncogenic form of MYC. The S62A mutant is also stabilized, lacks phosphorylation at both Serine 62 and Threonine 58, and has been shown to be nontransforming in vitro. However, several regulatory proteins are reported to associate with MYC lacking phosphorylation at S62 and T58, and the role this form of MYC plays in MYC transcriptional output and in vivo oncogenic function is understudied. We generated conditional c-Myc knock-in mice in which the expression of wild-type MYC (MYCWT), the T58A mutant (MYCT58A), or the S62A mutant (MYCS62A) with or without expression of endogenous Myc is controlled by the T-cell-specific Lck-Cre recombinase. MYCT58A expressing mice developed clonal T-cell lymphomas with 100% penetrance and conditional knock-out of endogenous Myc accelerated this lymphomagenesis. In contrast, MYCS62A mice developed clonal T-cell lymphomas at a much lower penetrance, and the loss of endogenous MYC reduced the penetrance while increasing the appearance of a non-transgene driven B-cell lymphoma with splenomegaly. Together, our study highlights the importance of regulated phosphorylation of MYC at T58 and S62 for T-cell transformation.

IMPLICATIONS

Dysregulation of phosphorylation at conserved T58 and S62 residues of MYC differentially affects T-cell development and lymphomagenesis.