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Primary Sjögren syndrome (SS) is an autoimmune disease affecting exocrine glands, with predisposition to development of lymphoma (lymphomagenesis). We report a case of Sjogren's syndrome and discuss the role of FDG PET/CT in the primary diagnosis of lymphoma transformation in SS. Furthermore, we reviewed the literature regarding the utility of FDG PET/CT to assess systemic disease activity and also its role in the SS associated lymphoma with light into the new PET tracers that can be explored for these indications in the future. Published data suggest promising role of FDG PET/CT in SS associated lymphomas, and demands larger studies for its establishment. [ABSTRACT FROM AUTHOR]

Simple Summary: Kaposi sarcoma-associated herpesvirus (KSHV) is associated with lymphoproliferative disorders, including primary effusion lymphoma and multicentric Castleman disease. KSHV expresses viral proteins that aid in the evasion of antiviral immune responses and manipulate host factors and signaling to promote cell survival. By altering the cell environment, KSHV contributes to lymphomagenesis. Approximately 15–20% of cancers are caused by viruses. Kaposi sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8 (HHV8), is an oncogenic virus that is the etiologic agent of not only Kaposi sarcoma but also the lymphoproliferative disorders, primary effusion lymphoma (PEL) and multicentric Castleman disease (MCD). KSHV can infect a broad tropism of cells, including B lymphocytes, wherein KSHV encodes specific viral proteins that can transform the cell. KSHV infection precedes the progression of PEL and MCD. KSHV establishes lifelong infection and has two phases of its lifecycle: latent and lytic. During the latent phase, viral genomes are maintained episomally with limited gene expression. Upon sporadic reactivation, the virus enters its replicative lytic phase to produce infectious virions. KSHV relies on its viral products to modulate host factors to evade immune detection or to co-opt their function for KSHV persistence. These manipulations dysregulate normal cell pathways to ensure cell survival and inhibit antiviral immune responses, which in turn, contribute to KSHV-associated malignancies. Here, we highlight the known molecular mechanisms of KSHV that promote lymphomagenesis and how these findings identify potential therapeutic targets for KSHV-associated lymphomas. [ABSTRACT FROM AUTHOR]

The International Conference on Malignant Lymphoma (ICML) is a prominent global event where experts in lymphoma research gather to share new findings and advancements in the field. The 17th ICML meeting focused on various topics, including the role of superenhancers and enhancer RNAs in different types of lymphomas, epigenetic mechanisms in B- and T-cell lymphomas, and the impact of epigenetic alterations and the tumor microenvironment in follicular helper T-cell lymphoma. The conference also explored the effectiveness of epigenetic agents in modulating the tumor microenvironment and response to CAR T-cell therapy. Other areas of discussion included genetic subtypes of diffuse large B-cell lymphoma, the use of human brain organoids to study central nervous system lymphomas, and the cellular origin of Hodgkin Reed Sternberg cells in Hodgkin lymphoma. The conference highlighted the importance of understanding the biology of lymphomas to improve treatment strategies. [Extracted from the article]

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. [ABSTRACT FROM AUTHOR]

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease standing in the crossroads of autoimmunity and lymphomagenesis, characterized by chronic B-cell hyperactivity and ectopic lymphoid tissue neoformation, potentially driving lymphoid malignant transformation. Lymphoma development is considered the most serious complication of pSS. 'Old-classical' biomarkers (clinical, serological, hematological, and histological) validated in the past are analyzed under the perspective of recently published research. Biomarkers that have emerged during the last decade are subdivided to 'old-new' and 'newly proposed-novel' ones, including biomarkers pathophysiologically related to B-cell differentiation, lymphoid organization, and immune responses, identified in serum and tissue, both at genetic and protein level. Upcoming new imaging biomarkers, promising for further patient stratification, are also analyzed. Salivary gland enlargement and cryoglobulinemia still remain the best validated 'classical-old' biomarkers for lymphoma development. Though new biomarkers still need to be validated, some can be used for the identification of high-risk patients long before lymphoma diagnosis, and some might be more relevant in distinct age subgroups, while others have an added value in the assessment of lymphoma remission or relapse. Future development of composite indices, integrating old and recently proposed biomarkers, could contribute to a more precise lymphoma prediction model. [ABSTRACT FROM AUTHOR]

Most B cell lymphomas arise from the oncogenic transformation of B cells that have undergone the germinal center (GC) reaction of the T cell-dependent immune response, where high-affinity memory B cells and plasma cells are generated. The high proliferation of GC B cells coupled with occasional errors in the DNA-modifying processes of somatic hypermutation and class switch recombination put the cell at a risk to obtain transforming genetic aberrations, which may activate proto-oncogenes or inactivate tumour suppressor genes. Several subtypes of GC lymphomas harbor genetic mutations leading to constitutive, aberrant activation of the nuclear factor-κB (NF-κB) signaling pathway. In normal B cells, NF-κB has crucial biological roles in development and physiology. GC lymphomas highjack these activities to promote tumour-cell growth and survival. It has become increasingly clear that the separate canonical and non-canonical routes of the NF-κB pathway and the five downstream NF-κB transcription factors have distinct functions in the successive stages of GC B-cell development. These findings may have direct implications for understanding how aberrant NF-κB activation promotes the genesis of various GC lymphomas corresponding to the developmentally distinct GC B-cell subsets. The knowledge arising from these studies may be explored for the development of precision medicine approaches aimed at more effective treatments of the corresponding tumours with specific NF-κB inhibitors, thus reducing systemic toxicity. We here provide an overview on the patterns of genetic NF-κB mutations encountered in the various GC lymphomas and discuss the consequences of aberrant NF-κB activation in those malignancies as related to the biology of NF-κB in their putative normal cellular counterparts. [ABSTRACT FROM AUTHOR]

With inconsistent findings, evidence has been obtained in recent years that metabolic disorders are closely associated with the development of lymphomas. Studies and multiple analyses have been published also indicating that some solid tumor survivors develop a secondary lymphoma, whereas some lymphoma survivors subsequently develop a second malignant neoplasm (SMN), particularly solid tumors. An interaction between the multiple etiologic factors such as genetic factors and late effects of cancer therapy may play an important role contributing to the carcinogenesis in patients with metabolic diseases or with a primary cancer. In this review, we summarize the current knowledge of the multiple etiologic factors for lymphomagenesis, focusing on the SMN in lymphoma, secondary lymphomas in primary cancers, and the lymphomas associated to metabolic disorders/diseases, which have been received less attention previously. Further, we also review the data of coexistence of lymphomas and hepatocellular carcinoma (HCC) in patients with infection of hepatitis C virus and hepatitis B virus. [ABSTRACT FROM AUTHOR]

Non-Hodgkin's malignant lymphomas are a heterogeneous group of hematological malignancies, characterized by a variety of clinical, morphological, histopathological, immuno-histochemical, molecular and evolutionary features. They represent a form of cancer that develops from the lymphatic tissue, as a result of the malignant transformation of B (85%) or T (15%) lymphocytes. Lymphomagenesis is described as a multi-stage process involving the mutation and proliferation of cell clones. Oxidative stress is defined as an imbalance of cellular redox status caused by the production of reactive oxygen species (ROS) and/or by decreasing antioxidant systems that allows their accumulation in the cell. Small quantities of ROS are involved in physiological mechanisms such as cell growth and differentiation, cell signaling, antimicrobial defense, phagocytosis. Normally, cells are capable of defending themselves against ROS damage through various scavenger systems. On the other hand, excessive ROS contribute to various diseases such as carcinogenesis, ischemia, atherosclerosis, neurodegenerative diseases. Oxidative stress exerts noxious effects on the cell structures by inducing structural changes in membranes, lipids, proteins or DNA. The present review summarizes the latest findings in understanding the ROS-linked signaling pathways in the initiation of lymphomagenesis, disease progression, metastasis, as well as in the pharmacodynamics of specific treatments for this malignancy. [ABSTRACT FROM AUTHOR]

Epstein–Barr virus (EBV), which encodes >80 genes and nearly 50 non-coding RNAs, is a double-stranded DNA virus. EBV is associated with various types of lymphomas and lymphoproliferative disorders not only of B-cell but also T/NK-cell origin. However, the oncogenic mechanism remains poorly understood, including the EBV receptors expressed on T/NK cells, relationship of EBV with host genes, and epigenetic regulation of EBV and host genes. The roles of host and viral non-coding RNAs during tumorigenesis have been elucidated. EBV encodes at least 49 mature microRNAs (miRNAs), of which 44 are located in Bam HI-A rightward transcripts (BARTs) region, and the remaining five are located in Bam HI-H rightward fragment 1. BART miRNAs modulate cell differentiation, proliferation, apoptosis, and the cell cycle, and they are considered positive regulators of oncogenesis. We and others have recently reported that EBV-positive lymphomas frequently possess large deletions in BART miRNA clusters, suggesting that some viral miRNAs have suppressive effects on oncogenesis, and that deletion of these miRNAs may aid lymphoma formation. [ABSTRACT FROM AUTHOR]

Background: B-cell non-Hodgkin's lymphoma (B-NHL) is one of the major complications of primary Sjögren's syndrome (SS). Chronic inflammation and macrophages in SS minor salivary glands have been previously suggested as significant predictors for lymphoma development among SS patients. Lipoprotein-associated phospholipase A2 (Lp-PLA2)—a product mainly of tissue macrophages—is found in the circulation associated with lipoproteins and has been previously involved in cardiovascular, autoimmune, and malignant diseases, including lymphoma. Objective: The purpose of the current study was to investigate the contributory role of Lp-PLA2 in B-NHL development in the setting of primary SS. Methods: Lp-PLA2 activity in serum samples collected from 50 primary SS patients with no lymphoma (SS-nL), 9 primary SS patients with lymphoma (SS-L), and 42 healthy controls (HC) was determined by detection of [3H]PAF degradation products by liquid scintillation counter. Moreover, additional sera from 50 SS-nL, 28 SS-L, and 32 HC were tested for Lp-PLA2 activity using a commercially available ELISA kit. Lp-PLA2 mRNA, and protein expression in minor salivary gland (MSG) tissue samples derived from SS-nL, SS-L patients, and sicca controls (SC) were analyzed by real-time PCR, Western blot, and immunohistochemistry. Results: Serum Lp-PLA2 activity was significantly increased in SS-L compared to both SS-nL and HC by two independent methods implemented [mean ± SD (nmol/min/ml): 62.0 ± 13.4 vs 47.6 ± 14.4 vs 50.7 ± 16.6, p-values: 0.003 and 0.04, respectively, and 19.4 ± 4.5 vs 15.2 ± 3.3 vs 14.5 ± 3.0, p-values: <0.0001, in both comparisons]. ROC analysis revealed that the serum Lp-PLA2 activity measured either by radioimmunoassay or ELISA has the potential to distinguish between SS-L and SS-nL patients (area under the curve [AUC]: 0.8022, CI [95%]: 0.64–0.96, p-value: 0.004 for radioimmunoassay, and AUC: 0.7696, CI [95%]: 0.66–0.88, p-value: <0.0001, for ELISA). Lp-PLA2 expression in MSG tissues was also increased in SS-L compared to SS-nL and SC at both mRNA and protein level. ROC analysis revealed that both MSG mRNA and protein Lp-PLA2 have the potential to distinguish between SS-nL and SS-L patients (area under the curve [AUC] values of 0.8490, CI [95%]: 0.71–0.99, p-value: 0.0019 and 0.9444, CI [95%]: 0.79–1.00, p- value: 0.0389 respectively). No significant difference in either serum Lp-PLA2 activity or MSG tissue expression was observed between SS-nL and HC. Conclusions: Lp-PLA2 serum activity and MSG tissue mRNA/protein expression could be a new biomarker and possibly a novel therapeutic target for B-cell lymphoproliferation in the setting of SS. [ABSTRACT FROM AUTHOR]

Marek's disease virus (MDV) is a highly oncogenic alphaherpesvirus that causes immunosuppression, paralysis, and deadly lymphomas in chickens. In infected animals, B cells are efficiently infected and are thought to amplify the virus and transfer it to T cells. MDV subsequently establishes latency in T cells and transforms CD4+ T cells, resulting in fatal lymphomas. Despite many years of research, the exact role of the different B and T cell subsets in MDV pathogenesis remains poorly understood, mostly due to the lack of reverse genetics in chickens. Recently, Ig heavy chain J gene segment knockout (JH-KO) chickens lacking mature and peripheral B cells have been generated. To determine the role of these B cells in MDV pathogenesis, we infected JH-KO chickens with the very virulent MDV RB1B strain. Surprisingly, viral load in the blood of infected animals was not altered in the absence of B cells. More importantly, disease and tumor incidence in JH-KO chickens was comparable to wild-type animals, suggesting that both mature and peripheral B cells are dispensable for MDV pathogenesis. Intriguingly, MDV efficiently replicated in the bursa of Fabricius in JH-KO animals, while spread of the virus to the spleen and thymus was delayed. In the absence of B cells, MDV readily infected CD4+ and CD8+ T cells, allowing efficient virus replication in the lymphoid organs and transformation of T cells. Taken together, our data change the dogma of the central role of B cells, and thereby provide important insights into MDV pathogenesis. [ABSTRACT FROM AUTHOR]

Lymphoma is one of the most common malignancies in domestic cats. The lymphomagenic potential of Felis catus gammaherpesvirus 1 (FcaGHV1), a common infection in domestic cats, is unknown. In other species, including humans, cellular transformation by gammaherpesviruses is typically mediated by viral genes expressed during latency. We analysed tumour RNA, from diffuse large B-cell lymphomas (DLBCL) appearing in cats coinfected with FcaGHV1 and feline immunodeficiency virus (FIV) (n = 10), by high throughput transcriptome sequencing and reverse transcription PCR. A limited repertoire of FcaGHV transcripts was identified in five tumors, including homologs of oncogenic latency-associated transcripts, latency-associated nuclear antigen (LANA, ORF73) and vFLIP (F7), lytic genes (ORF50, ORF6, ORF59, F10), and an ORF unique to FcaGHV1, F20. In situ hybridization of FIV-associated DLBCLs (n = 9), post-transplant lymphomas (n = 6) and high-grade B and T-cell intestinal lymphomas (n = 8) identified a single case in which FcaGHV1 nucleic acid was detectable. These results demonstrate that FcaGHV1 transcripts can be detected in some FIV-associated lymphomas, but at low copy number, precluding assessment of a potential role for FcaGHV1 in lymphomagenesis. Future investigation of the FcaGHV1 transcriptome in clinical samples might employ viral enrichment and greater sequencing depth to enhance the retrieval of viral reads. Our results suggest prioritization of a subset of intestinal T-cell tumors, large granular lymphocyte lymphoma, for study. [ABSTRACT FROM AUTHOR]

In this review, we focus on the mechanisms underlying lymphomagenesis in chronic lymphocytic leukaemia, follicular lymphoma, mantle cell lymphoma and splenic marginal zone lymphoma. The cells of origin of these small B-cell lymphomas are distinct, as are the characteristic chromosomal lesions and clinical courses. One shared feature is retention of expression of surface immunoglobulin. Analysis of this critical receptor reveals the point of differentiation reached by the cell of origin. Additionally, the sequence patterns of the immunoglobulin-variable domains can indicate a role for stimulants of the B-cell receptor before, during and after malignant transformation. The pathways driven via the B-cell receptor are now being targeted by specific kinase inhibitors with exciting clinical effects. To consider routes to pathogenesis, potentially offering earlier intervention, or to identify causative factors, genetic tools are being used to track pretransformation events and the early phases in lymphomagenesis. These methods are revealing that chromosomal changes are only one of the many steps involved, and that the influence of surrounding cells, probably multiple and variable according to tissue location, is required, both to establish tumours and to maintain growth and survival. Similarly, the influence of the tumour microenvironment may protect malignant cells from eradication by treatment, and the resulting minimal residual disease will eventually give rise to relapse. The common and different features of the four lymphomas will be summarized to show how normal B lymphocytes can be subverted to generate tumours, how these tumours evolve and how their weaknesses can be attacked by targeted therapies. [ABSTRACT FROM AUTHOR]

Mantle cell lymphoma (MCL) is characterized by an aggressive clinical course and secondary resistance to currently available therapies in most cases. Therefore, despite recent advances in the treatment of this disease, it is still considered to be incurable in the majority of cases. MCL B cells retain their B cell antigen receptor (BCR) expression during and after neoplastic transformation. BCRs in MCL show distinct patterns of antigen selection and ongoing BCR signaling. However, little is known about the involved antigens and the mechanisms leading to lymphomagenesis and lymphoma progression in MCL. Recent preclinical and clinical studies have established a crucial role of the BCR and the potential of inhibiting its signaling in this disease. This has established the B cell antigen receptor signaling cascade as a very promising therapeutic target to improve outcome in MCL alone or in combination with chemo-immunotherapy in recent years. [ABSTRACT FROM AUTHOR]

Innate and adaptive immune cells within the microenvironment identify and eliminate cells displaying signs of malignant potential. Immunosurveillance effector Natural Killer (NK) cells and Cytotoxic T Lymphocytes (CTL) identify malignant cells through germline receptors such as NKG2D and in the case of CTLs, presentation of antigen through the T cell receptor. Manipulation of immunosurveillance through altered tumor-identifying ligand expression or secretion, resistance to cytotoxicity, or compromised cytotoxic cell activity through immune tolerance mechanisms all contribute to failure of these systems to prevent cancer development. This review examines the diverse mechanisms by which alterations in the immune microenvironment can promote lymphomagenesis. [ABSTRACT FROM AUTHOR]

When stringent criteria have been used, the Epstein Barr virus (EBV), the Kaposi's sarcoma herpesvirus (KSHV), human immunodeficiency virus type 1 (HIV-1) and human hepatitis C virus (HCV) have been identified with sufficient evidence to be causative agents of non-Hodgkin's Lymphomas. Initially, single viral infection was considered fully responsible for the oncogenic properties of each virus, while it is now established that in many cases, multiple viral agents collaborate as cofactors in inducing lymphomas, especially in the presence of HIV-dependent immunodeficiency. Viruses cooperate by using their specific pathogenetic mechanisms in different combinations. The aim of this review is to describe the cooperation between different viruses in the development of lymphomas including the evidences supporting their pathogenetic role. Viral cooperation, a mechanism by which different viruses coinfecting human tissues have synergistic or regulatory effects on carcinogenesis, targets neoplastic B cells as well as cells of the microenvironment, such as reactive T-cells, B cells and macrophages, as well as non-immune cells such as endothelial cells, that contribute to tumor microenvironment. The most important viral genes involved in cooperation include HIV-1 tat and vpu , EBV LMP-1 and EBNA-2 and KSHV KIE2, Rta and LANA. Lymphomagenesis related to viral cooperation represents an interesting topic where microenvironmental abnormalities may be particularly relevant, particularly because antiviral targeted therapies and therapies producing the reconstitution of the immune system may constitute areas of interest aiming at improving the outcome of virus associated lymphomas. While the immune component of the lymphoma microenvironment can be easily studied by immunological and molecular techniques, the definition of the non-immune component of the lymphoma microenvironment is largely incomplete and may be the issue of future investigations. Understanding the pathogenetic role of viral infection in specific malignancies and defining microenvironmental abnormalities and mechanisms of viral carcinogenesis are important steps toward precise diagnosis and accurate treatment strategies for HIV-associated cancers. [ABSTRACT FROM AUTHOR]

The article discusses primary cutaneous marginal zone lymphoma (PCMZL) which may present with a nodular pattern similar to cutaneous lymphoid hyperplasia (CLH) closely resembling a follicle center cell lymphoma which may in some cases result in a erroneous diagnostic interpretation. It suggests that PCMZL represents a clonal cutaneous expansion of memory post-germinal center B-cells with limited proliferative capability resulting from a T-cell-driven B-cell hyperplasia.

Studies have shown that hepatitis B virus (HBV) infection may play an important role in the lymphomagenesis of lymphoma, but no studies regarding the relationship between HBV infection and extranodal natural killer/T cell lymphoma (ENKTL) have been reported previously. One hundred and seven patients diagnosed with ENKTL were retrospectively reviewed. The hepatitis B surface antigen (HBsAg)-positive rate was 13.1%, and no significant correlation existed between HBV infection and clinical characteristics (p > 0.05). No significant difference existed in complete remission rate between HBsAg-positive and -negative groups (42.9% vs. 44.1%, p = 1.000). In a multivariate Cox regression model that included international prognostic index (IPI) score, induction chemotherapy regimen and HBsAg status, all these variables were independent prognostic factors for overall survival (OS) and progression-free survival (PFS) (p < 0.05). In conclusion, the HBsAg-positive rate in ENKTL was similar to that of the normal population in a high HBV endemic area, and HBsAg-positive status was an independent prognostic factor for OS and PFS. [ABSTRACT FROM AUTHOR]

Primary Sjögren Syndrome ( pSS) is an autoimmune disease associated with an increased risk of lymphoma. Lymphomas complicating pSS are mostly low-grade B cell non-Hodgkin lymphomas, predominantly of marginal zone histological type. Mucosal localization is predominant, notably mucosa-associated lymphoid tissue lymphomas. Lymphomas often develop in organs where pSS is active, such as salivary glands. Germinal centre (GC)-like structures, high TNFSF13B (BAFF) and Flt3-ligand (FLT3LG) levels and genetic impairment of TNFAIP3 are new predictors of lymphoma development. These new findings allow a better understanding of the pathogenic mechanisms leading to lymphoma. We propose the following scenario: auto-immune B cells with rheumatoid factor (RF) activity are continuously stimulated by immune complexes containing antibodies against more specific auto-antigens, such as SSA/Ro, SSB/La or others. Germline abnormality of TNFAIP3 leads to a decreased control of the NF- kB pathway and thus promotes survival of B cells and oncogenic mutations especially in GC structure. Moreover, B cells are stimulated by a positive loop of activation induced by BAFF secretion. Thus, lymphomagenesis associated with pSS exemplifies the development of antigen-driven B-cell lymphoma. The control of disease activity by a well-targeted immunosuppressor is the primary objective of the management of the patient in order to repress chronic B cell stimulation. [ABSTRACT FROM AUTHOR]

Activation-induced cytidine deaminase (AID) is essential for somatic hypermutation and class switch recombination of immunoglobulin (Ig) genes during B cell maturation and immune response. Expression of AID is tightly regulated due to its mutagenic and recombinogenic potential, which is known to target not only Ig genes, but also non-Ig genes, contributing to lymphomagenesis. In recent years, a new epigenetic function of AID and its link to DNA demethylation came to light in several developmental systems. In this review, we summarize existing evidence linking deamination of unmodified and modified cytidine by AID to base-excision repair and mismatch repair machinery resulting in passive or active removal ofDNAmethylation mark, with the focus on B cell biology. We also discuss potential contribution of AID-dependent DNA hypomethylation to lymphomagenesis. [ABSTRACT FROM AUTHOR]

Highlights: [•] BCL6 maintains a delicate balance between survival and apoptosis in germinal center (GC) B cells. [•] BCL6 maintains promoters and enhancers in a poised state in GC and lymphoma cells. [•] BCL6 mechanism of action varies among cell types in the immune system. [•] BCL6 mechanism-specific targeting kills lymphomas without harming other tissues. [Copyright &y& Elsevier]

The association between viruses and lymphomas has long been recognized; however, the pathophysiological phenomena behind this relationship are unclear, and have been the object of intense research. Although our understanding of such mechanisms is slowly improving, much is still left to learn. With the recent advances in cancer biology, a diversity of biological pathways and novel targets and agents have been described in patients with haematological malignancies and successfully put into clinical practice. Clear examples are rituximab and brentuximab vedotin in patients with B cell lymphomas and Hodgkin lymphoma respectively. The main purpose of this review is not only to succinctly summarize what we know regarding the pathogenesis and pathophysiology of virally induced lymphomas and to describe the current practices in terms of diagnosis of treatment of such lymphomas, but also to provide a scientific rationale for the use of novel therapies that are likely to improve the outcomes of patients with these conditions. [ABSTRACT FROM AUTHOR]

t(14;18)-positive cells can be detected not only in patients with follicular lymphoma (FL) but also in healthy individuals (HIs). We used epidemiological data and blood samples of the population-based Study of Health in Pomerania (SHIP) to analyze associations of FL risk factors and t(14;18)-positive cells in HIs. Buffy coat samples from 4152 study participants were tested by real-time polymerase chain reaction (PCR) for t(14;18)-positive cells. Of 3966 evaluable subjects, 1526 were t(14;18)-PCR positive [38.5%, median 3.9 t(14;18)-positive per million nucleated cells, range 0.6-9299]. In multivariable analyses, age and sex but not parameters of smoking exposure were significantly associated with t(14;18) prevalence (logistic regression, p < 0.001). Multivariable analyses of t(14;18)-frequency showed a positive association with age but not with sex or smoking. These age and sex associations in HIs require careful control in future studies of t(14;18) as a potential biomarker of lymphoma risk. [ABSTRACT FROM AUTHOR]

Abstract: A link with infectious agents, bacteria and viruses in particular, has been reported for many lymphoma entities. Marginal zone lymphomas (extranodal, nodal and splenic forms) are frequently associated with chronic infections, with important clinical, molecular, biological, and therapeutic implications. The well-known correlation between Helicobacter pylori and gastric MALT-lymphoma, the recently reported links between Chlamydophila psittaci and ocular adnexal MALT-lymphoma and Borrelia burgdorferi and cutaneous MALT lymphoma constitute the best studied examples of lymphomagenic activity of bacteria, while the hepatitis C virus represents the most extensively investigated virus associated with marginal zone lymphomas. Biological and clinical features, therapeutic implications and future perspectives of these lymphoma-microbial associations are discussed in this review. [Copyright &y& Elsevier]

The relatively recent discovery of micro RNAs (mi RNAs) has exposed an extra layer of gene expression regulation that affects many physiological and pathological processes of biology. Dysregulation of mi RNAs is a ubiquitous feature of cancer in general, including lymphomas. The identity of these aberrantly-expressed mi RNAs has been thoroughly investigated in all but a few types of lymphomas, however their functional role in lymphomagenesis much less so. This review focuses on those mi RNAs that have an experimentally confirmed functional role in the pathogenesis of the most frequent forms of lymphoma. In particular, the MIR15A/16-1 cluster, MIR21, MIR155, MIR17 HG ( MIR17-92 cluster) , MIR34A and MIR125B, which have in vivo animal model evidence for their involvement in lymphomagenesis, are highlighted. [ABSTRACT FROM AUTHOR]

Abstract: Four cats (24%) experimentally infected with FIV unexpectedly developed neoplastic changes within four months of inoculation. While FIV has previously been associated with neoplasia, the rapidity and high attack rate seen here is highly unusual. PCR for antigen receptor rearrangements (PARR) detected clonally rearranged T cells in two animals diagnosed with B cell follicular lymphoma by classical means. All cats were negative for feline leukemia virus; gamma-herpesvirus DNA was not amplified using degenerate primers. FIV proviral load in neoplastic tissue was two orders of magnitude lower than in the periphery, lower in neoplastic vs non-neoplastic lymph node, and clonal integration was not detected. We hypothesize that neoplasia was secondary to FIV immune dysregulation, and show that PARR can augment our capacity to phenotype these tumors and distinguish follicular hyperplasia from lymphoma. Age of exposure and relative virulence of the inoculum likely contributed to this unusual presentation of FIV infection. [Copyright &y& Elsevier]

Follicular lymphoma (FL) is characterized by an indolent and relapsing course. Recently, the clinical outcome of FL has been distinguished by immune microenvironment-associated gene signatures. In our study, gene expression profiling (GEP) was performed in 31 non-selected patients with follicular lymphoma (FL), 12 of whom were in relapse and the remaining 19 newly diagnosed. A custom oligonucleotide microarray (Agilent 8 × 15K) was used which contained probes for about 3500 genes, including those that had been previously published as demonstrating significant prognostic value. An unsupervised approach was not able to recognize clinically different FLs. As the previously published prognostically relevant gene signatures could not be properly verified, probably due to microarray platform differences, template matching was therefore used in order to define two gene sets with differential gene expression among our samples. These gene sets shared an overrepresentation of genes with similar biological functions and were termed 'T-CELL' and 'PROLIFERATION' profiles. The 'poor profile' was then defined by a high PROLIFERATION score (upper tertile) and/or low T-CELL score (lower tertile). The 'poor profile' cohort contained a significantly higher proportion of relapsed cases ( p < 0.05, Fisher's exact test). Additionally, a comparison of samples from initial diagnosis and from relapse showed significant differences mainly in the T-CELL profile ( p = 0.036; χ2). This supports the hypothesis that the number of T-cells and their expression pattern play a major role in FL development. [ABSTRACT FROM AUTHOR]

Abstract: Epidemiological data indicate a close relationship between chronic hepatitis C virus (HCV) infection and B-cell non-Hodgkin''s lymphoma (B-NHL), suggesting that chronic HCV infection is, at least in part, associated with B-lymphomagenesis. However, experimental data concerning these conditions remains elusive. In this study, we confirmed that peripheral blood B cells of chronic hepatitis C (CHC) patients were infected with HCV. Expression levels of activation-induced cytidine deaminase (AID) which are thought to be associated with occurrence of B-NHL were analyzed in these CHC B cells. It was demonstrated that AID mRNA/protein levels in CHC B cells were dramatically increased compared with those of healthy subjects. Furthermore, expression levels of several previously reported prognostic B-NHL marker genes in the B cell subset of CHC patients were increased. These results suggest a possible relationship between chronic HCV infection and B-lymphomagenesis. [Copyright &y& Elsevier]

Abstract: Mice that are deficient in p53 exhibit an early onset of multiple types of tumors, especially thymic lymphoma. However, it remains unclear to what extent each of the p53-regulated pathways exerts its tumor suppressor activity. p21Cip1/Waf1, acting down stream of p53, is a major G1/S checkpoint protein that restricts cell cycle progression into S phase in the presence of DNA damage. While at old ages p21−/− mice have a higher incidence of many types of tumors than p21+/+ mice, they are more resistant to thymic lymphomagenesis. In this study, we characterized mutagenesis in vivo in T cells of p21-deficient mice, using loss of heterozygosity (LOH) at Aprt locus as an indicator. We found that the spontaneous Aprt mutant frequency in T cells of p21−/− mice is lower than that in p21+/+ mice. The mutational spectra, however, are similar, with mitotic recombination being the predominant pathway. In contrast to the remarkable induction of LOH events in T cells of p53−/− mice exposed to X-rays, LOH in T cells of p21−/− mice is not significantly induced by X-rays. Correspondingly, lymphoid cells of p21−/− mice are more sensitive to IR-induced apoptosis than those of p21+/+ mice, in contrast to the radioresistance of p53-deficient lymphocytes. Reduction in mutation load in T cell lineages may contribute to the suppression of thymic lymphomagenesis in p21−/− mice. [Copyright &y& Elsevier]

This review is focused on the role of infectious agents in the development of some lymphoma entities. Associations involving bacterial infections mostly regard marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT)-type. Some paradigmatic examples of these associations include the Helicobacter pylori-related gastric MALT lymphoma and the more recently reported links between Chlamydophila psittaci and ocular adnexal MALT lymphomas and Borrelia burgdorferi and cutaneous MALT lymphomas. The well-documented association between Epstein–Barr virus infection and related lymphoproliferative disorders are analysed as an example of lymphotropic virus with tumourigenic activity. Molecular, biological and clinical features as well as therapeutic implications of these associations are analysed and future perspectives in this field are discussed. [ABSTRACT FROM AUTHOR]

Abstract: The MCT-1 oncogene, highly expressed in a subset of non-Hodgkin''s lymphomas interacts with the cap complex through its PUA domain. MCT-1 recruits DENR, a SUI1 motif containing protein that promotes translation initiation of cancer-related mRNAs. We reasoned that a PUA-domain mutant protein would repress MCT-1 function and attenuate the malignant phenotype. Human lymphoma cell lines expressing the PUA-domain mutant protein demonstrated reduced anchorage-independent growth and increased susceptibility to apoptosis. Significantly, we identified an altered translational profile in cells expressing the mutant protein. These data further buttress the role of the MCT-1 in lymphomagenesis and support the development of novel therapeutic strategies targeting MCT-1. [Copyright &y& Elsevier]

Reduced levels of the cyclin-dependent kinase inhibitor p27Kip1 connote poor prognosis in cancer. In human Burkitt lymphoma and in precancerous B cells and lymphomas arising in Eμ-Myc transgenic mice, p27Kip1 expression is markedly reduced. We show that the transcription of the Cks1 component of the SCFSkp2 complex that is necessary for p27Kip1 ubiquitylation and degradation is induced by Myc. Further, Cks1 expression is elevated in precancerous Eμ-Myc B cells, and high levels of Cks1 are also a hallmark of Eμ-Myc lymphoma and of human Burkitt lymphoma. Finally, loss of Cks1 in Eμ-Myc B cells elevates p27Kip1 levels, reduces proliferation and markedly delays lymphoma development and dissemination of disease. Therefore, Myc suppresses p27Kip1 expression, accelerates cell proliferation and promotes tumorigenesis at least in part through its ability to selectively induce Cks1. [ABSTRACT FROM AUTHOR]

p18Ink4c functions as a dedicated inhibitor of cyclin-D-dependent kinases. Loss of Ink4c predisposes mice to tumor development and, in a dose-dependent manner, complements the tumor-promoting effects of various oncogenes. We have now addressed whether Ink4c loss impacts B-cell tumor development in the Eμ-Myc transgenic mouse, a model of human Burkitt lymphoma. Loss of one or both alleles did not influence the onset of lymphoma in Eμ-Myc transgenics, and did not appreciably affect Myc's proliferative or apoptotic responses in precancerous B cells. Nevertheless, Ink4c loss modulated the effects of Myc-induced transformation by decreasing the frequency of Arf loss, an ordinarily common event in Eμ-Myc-induced lymphomas.Oncogene (2007) 26, 2833–2839. doi:10.1038/sj.onc.1210104; published online 13 November 2006 [ABSTRACT FROM AUTHOR]

Over the past 40 years, a substantial rise in the incidence of non-Hodgkin lymphoma (NHL) has been observed. Epidemiologic studies aimed at understanding this rise have revealed some association with occupational exposure. NHL is common among farmers, where pesticides have been described as the culprit. The association between pesticides and NHL has been demonstrated mainly in case-control studies, while retrospective cohorts have been less convincing. Pesticides including chlorphenol and phenoxyacetic acid herbicides, organochlorines, and organophosphate insecticides, carbamates, and fungicides have been associated with NHL. Although the causality has not been clearly proven, both genotoxic and nongenotoxic mechanisms for lymphomagenesis have been proposed. The leveling-off of NHL incidence in certain countries may be the result of a favorable change in pesticide usage patterns. Future studies, such as the Agricultural Health Study, may clarify the uncertainties regarding this issue. Copyright © 2006 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The cutaneous environment hosts a number of hematopoietic neoplasms that are dominated by primary cutaneous (PC) T-cell lymphomas. Recent progress in molecular biology and immunology has provided tools to investigate the pathogenesis and the biology of these neoplasms. This review highlights newest findings concerning the immune biology of CD4+CD56+ hematodermic neoplasms, and PC T-cell and B-cell lymphomas, speculating how these can be translated into more sophisticated, biology-based treatment approaches in the near future. [ABSTRACT FROM AUTHOR]

The parenteral iron administration effects on the acceleration of lymphomagenesis by radiofrequency exposure were investigated using an animal model that develops spontaneous lymphomas with ageing. Complementary studies of the in vivo uptake of 59 Fe-labeled ferric gluconate and ferric-ATP complex showed differences ob absorption and excretion between both iron compounds. In vitro assays of their effects on calcium cellular uptake using a cell model and tissues homogenates showed a molecular structure-dependence. The current results (mortality, clinical and histopathological examinations) demonstrated a synergism between radiofrequency and ferric gluconate, and the increased risk of radiofrequency exposure when it is simultaneous to parenteral iron administration. [ABSTRACT FROM AUTHOR]

Rel/NF-κB transcription factors are critical arbiters of immune responses, cell survival, and transformation, and are frequently deregulated in cancer. The p50 NF-κB1 component of Rel/NF-κB DNA-binding dimers regulates genes involved in both cell cycle traverse and apoptosis. Nfkb1 loss accelerates B cell growth and leads to increased B cell turnover in vivo, phenotypes akin to those manifested in B cells of Eμ-Myc transgenic mice, a model of human Burkitt lymphoma. Interestingly, Eμ-Myc B cells express reduced levels of cytoplasmic and nuclear NF-κB1 and have reduced Rel/NF-κB DNA-binding activity, suggesting that Myc-mediated repression of NF-κB1 might mediate its proliferative and apoptotic effects on B cells. Furthermore, Nfkb1 expression was reduced in the majority of Eμ-Myc lymphomas and was also suppressed in human Burkitt lymphoma. Nonetheless, loss of Nfkb1 did not appreciably affect Myc's proliferative or apoptotic responses in B cells and had no effect on lymphoma development in Eμ-Myc mice. Therefore, Nfkb1 is dispensable for Myc-induced lymphomagenesis.Oncogene (2005) 24, 6231–6240. doi:10.1038/sj.onc.1208779; published online 6 June 2005 [ABSTRACT FROM AUTHOR]

P100, which is encoded by NF-κB2, inhibits Rel dimers. It can also be processed into p52, one of the DNA binding sub-units of NF-κB/Rel factors. Several p100 C-terminal truncations that result from gene rearrangements are associated with lymphomagenesis. Here, we characterized a new p100 mutant that we termed p100HB. It originates from a point-mutation that generates a premature stop-codon, and thus the protein lacks the last 125 amino acids. We have detected p100HB in several human tumor cell lines. The truncated protein is mainly unprocessed, and although it still binds Rel dimers, it has reduced inhibitory potency compared to p100 and translocates into the nucleus. Thus, p100HB may be associated with deregulated NF-κB/Rel functions. [Copyright &y& Elsevier]

Simple Summary: The prevalence of Helicobacter pylori (HP)-negative gastric mucosa-associated lymphoid tissue (MALT) lymphoma has increased over the last two decades, whereas that of HP-positive gastric MALT lymphoma has decreased. Although the role of first-line antibiotics in the treatment of HP-negative gastric MALT lymphomas remains ambiguous, several case series have reported that a first-line HP eradication therapy (HPE)-like regimen could result in complete remission in a proportion of patients with localized HP-negative gastric MALT lymphoma. Previous sporadic reports have indicated that certain patients with extragastric MALT lymphoma can respond to first-line antibiotic treatment as well. These findings suggest that, in contrast to antibiotic-unresponsive tumors, antibiotic-responsive tumors may be recognized within the spectrum of HP-negative MALT lymphoma. In addition to conventional chemotherapy and immunochemotherapy, macrolide antibiotics and immunomodulatory drugs have been previously used and demonstrated to be efficacious. This article provides the spectrum and therapeutics for HP-negative MALT lymphoma. Helicobacter pylori (HP)-unrelated mucosa-associated lymphoid tissue (MALT) lymphoma includes the majority of extragastric MALT lymphomas and a small proportion of gastric MALT lymphomas. Although the role of first-line antibiotics in treating HP-negative gastric MALT lymphomas remains controversial, HP eradication therapy (HPE)-like regimens may result in approximately 20–30% complete remission (CR) for patients with localized HP-negative gastric MALT lymphoma. In these patients, H. heilmannii, H. bizzozeronii, and H. suis were detected in sporadic gastric biopsy specimens. Extragastric MALT lymphoma is conventionally treated with radiotherapy for localized disease and systemic chemotherapy for advanced and metastatic diseases. However, a proportion of extragastric MALT lymphomas, such as ocular adnexal lesions and small intestinal lesions, were reported to be controlled by antibiotics for Chlamydophila psittaci and Campylobacter jejuni, respectively. Some extragastric MALT lymphomas may even respond to first-line HPE. These findings suggest that some antibiotic-responsive tumors may exist in the family of HP-negative MALT lymphomas. Two mechanisms underlying the antibiotic responsiveness of HP-negative MALT lymphoma have been proposed. First, an HPE-like regimen may eradicate the antigens of unknown bacteria. Second, clarithromycin (the main component of HPE) may have direct or indirect antineoplastic effects, thus contributing to the CR of these tumors. For antibiotic-unresponsive HP-negative MALT lymphoma, high-dose macrolides and immunomodulatory drugs, such as thalidomide and lenalidomide, have reported sporadic success. Further investigation of new treatment regimens is warranted. [ABSTRACT FROM AUTHOR]

The risk of Burkitt lymphoma (BL) is increased in HIV-infected patients as compared to general population in Europe and in the US. This effect might be due to immune suppression and low CD4-cell counts associated with the development of AIDS. However, there is also evidence of a direct effect of HIV on B cell proliferation and differentiation, which may account for the development of B cell malignancies. We shall discuss possible mechanisms of implication of HIV in BL with a focus on the role of different viral components (Tat, Nef and gp120 proteins, viral envelope) in the c-myc/IgH translocation characteristic of BL. [ABSTRACT FROM AUTHOR]

Abstract: We have previously shown that AIDS-associated lymphomas and lymphoma cell lines contain mitochondrial genome concatemers not present in normal T-lymphocytes. Since cellular homeostasis and energy production rely heavily on mitochondrial DNA (mtDNA) stability, mutations in the mtDNA have long been linked to the development of various types of cancers. In most of the cases, however, neoplastically transformed cells harbor non-mutated mtDNA. Herein, we propose an alternative mechanism that shows how the formation of mitochondrial genome concatemers may promote oncogenic transformation of normal lymphoid progenitor cells when no mtDNA mutations or chromosomal aberrations are present. We detected high reactive oxygen species (ROS) levels in the lymphoma samples tested despite no identification of putative mutations in the coding mtDNA. We propose that the formation of atypical mtDNA configurations (i.e. dimers and concatemers) interferes with normal mitochondrial function. Unstable mitochondria lead to abnormal assembly and dysfunction of the oxidative phosphorylation (OXPHOS) complexes, eventually leading to oxidative stress from elevated production of intracellular ROS. ROS have been reported to activate transcription factors associated with cellular proliferation and apoptosis inhibition. Therefore, we hypothesize that formation of mitochondrial genome concatemers can augment endogenous ROS levels capable of promoting oncogenic transformation of normal lymphoid progenitor cells. [Copyright &y& Elsevier]

• NHL are a heterogenous neoplasms group characterized by a high percentage of refractory/ relapsed disease. • Tumor microenvironment interplay via exosomes plays a role in cancer development, progression and drug resistance acquisition. • Exosomes are a promising strategy to use as diagnostic and prognostic biomarkers holding the potential to be used as cancer liquid biopsy. • Understanding the role of exosomes in NHL may permit the discover of new therapeutic targets and the development of exosome-based cancer therapy. There has been a shift in the paradigm of Non-Hodgkin lymphomas, changing from the classical genetic aberration-based model to a more complex and dynamic model involving tumor microenvironment interactions. In this instance, exosomes have emerged as important mediators in intercellular communication by providing survival and proliferation signals, licensing immune evasion and acquisition of drug resistance. The capability to transfer molecular cargo made exosomes a focus of research to understand cancer pathogenesis and its progression pathways. Several studies identified exosomes transporting tumor-released components in peripheral blood and focused on understanding their clinical relevance in the diagnosis, prognostic and in monitoring cancer progression. Moreover, due to their biophysical properties and physiological function, exosomes have drawn attention as potential therapeutic target and drug delivery vehicles. This review will discuss the function of exosomes in Non-Hodgkin lymphomagenesis, highlight their potential as diagnosis and prognosis biomarkers, and as new therapeutic opportunities in lymphoma management. [ABSTRACT FROM AUTHOR]

Lymphoid malignancies frequently harbor genetic mutations leading to aberrant activation of nuclear factor-κB (NF-κB) signaling; in normal cells, this pathway has important roles in the control of cell growth, survival, stress responses, and inflammation. Malignancies with mutations in NF-κB pathway components can derive from all cell stages of mature B-cell development; however, aberrant NF-κB activity is particularly prevalent in aggressive subtypes of non-Hodgkin lymphoma and myeloma. NF-κB activation is mediated by two separate pathways, the canonical and alternative pathway, and five downstream transcription factor subunits. Recent findings implicate a predominant role for distinct NF-κB pathways and subunits in certain lymphoma subtypes and myeloma; findings which are complemented by the realization that individual NF-κB subunits can have unique, non-redundant biological roles in the putative tumor precursor cells, including activated B cells, germinal center B cells and plasma cells. The knowledge gained from these studies may be exploited for the development of therapeutic strategies to inhibit aberrant NF-κB activity at the level of the transcription-factor subunits and their target genes, as global inhibition of the pathway is toxic. Here, we provide an overview on the role of aberrant NF-κB activation in aggressive lymphoid malignancies and discuss the potential importance of individual NF-κB subunits in the pathogenesis of tumor subtypes. [ABSTRACT FROM AUTHOR]

One of the most important determinants of aging-related changes is a complex biological process emerged recently and called "immunosenescence". Immunosenescence refers to the inability of an aging immune system to produce an appropriate and effective response to challenge. This immune dysregulation may manifest as increased susceptibility to infection, cancer, autoimmune disease, and vaccine failure. At present, the relationship between immunosenescence and lymphoma in elderly patients is not defined in a satisfactory way. This review presents a brief overview of the interplay between aging, cancer and lymphoma, and the key topic of immunosenescence is addressed in the context of two main lymphoma groups, namely Non Hodgkin Lymphoma (NHL) and Hodgkin Lymphoma (HL). Epstein Barr Virus (EBV) plays a central role in the onset of neoplastic lymphoproliferation associated with immunological changes in aging, although the pathophysiology varies vastly among different disease entities. The interaction between immune dysfunction, immunosenescence and Epstein Barr Virus (EBV) infection appears to differ between NHL and HL, as well as between NHL subtypes. [ABSTRACT FROM AUTHOR]