The microenvironment in classical Hodgkin lymphoma: an actively shaped and essential tumor component

Melanoma and cannabinoids: A possible chance for cancer treatment

The endocannabinoid system is composed by a complex and ubiquitous network of endogenous lipid ligands, enzymes for their synthesis and degradation, and receptors, which can also be stimulated by exogenous compounds, such as those derived from the Cannabis sativa. Cannabis and its bioactive compounds, including cannabinoids and non-cannabinoids, have been extensively studied in different conditions. Recent data have shown that the endocannabinoid system is responsible for maintaining the homeostasis of various skin functions such as proliferation, differentiation and release of inflammatory mediators. Because of their role in regulating these key processes, cannabinoids have been studied for the treatment of skin cancers and melanoma; their anti-tumour effects regulate skin cancer progression and are mainly related to the inhibition of tumour growth, proliferation, invasion and angiogenesis, through apoptosis and autophagy induction. This review aims at summarising the current field of research on the potential uses of cannabinoids in the melanoma field.

The causal effect of adipose tissue on Hodgkin's lymphoma: two-sample Mendelian randomization study and validation

Background

Extensive research has been conducted on the correlation between adipose tissue and the risk of malignant lymphoma. Despite numerous observational studies exploring this connection, uncertainty remains regarding a causal relationship between adipose tissue and malignant lymphoma.

Methods

The increase or decrease in adipose tissue was represented by the height of BMI. The BMI and malignant lymphoma genome-wide association studies (GWAS) used a summary dataset from the OPEN GWAS website. Single-nucleotide polymorphisms (SNPs) that met the criteria of P <5e-8 and LD of r2 = 0.001 in the BMI GWAS were chosen as genetic instrumental variants (IVs). Proxy SNPs with LD of r2 > 0.8 were identified, while palindromic and outlier SNPs were excluded. Mendelian randomization (MR) analysis used five methods, including inverse-variance weighted (IVW) model, weighted median (WM), MR-Egger, simple mode, and weighted mode. Sensitivity assessments included Cochran's Q test, MR-Egger intercept test, and leave-one-out analysis. Participants randomly selected by the National Center for Health Statistics (NHANSE) and newly diagnosed HL patients at Fujian Medical University Union Hospital were used for external validation.

Results

The results of the MR analysis strongly supported the causal link between BMI and Hodgkin's lymphoma (HL). The research demonstrated that individuals with lower BMI face a significantly increased risk of developing HL, with a 91.65% higher risk (ORIVW = 0.0835, 95% CI 0.0147 - 0.4733, P = 0.005). No signs of horizontal or directional pleiotropy were observed in the MR studies. The validation results aligned with the results from the MR analysis (OR = 0.871, 95% CI 0.826 - 0.918, P< 0.001). And there was no causal relationship between BMI and non-Hodgkin's lymphoma (NHL).

Conclusions

The MR analysis study demonstrated a direct correlation between lower BMI and HL. This suggested that a decrease in adipose tissue increases the risk of developing HL. Nevertheless, further research is essential to grasp the underlying mechanism of this causal association comprehensively.

Redirecting NK cells to the lymph nodes to augment their lymphoma-targeting capacity

CAR-NK cells can induce remission in lymphoma patients. We speculate that the full potential of adoptive NK cell immunotherapy against lymphoma is restricted by their poor lymph node (LN) homing capacity. Here, we have utilized a clinically approved transfection method with the aim of redirecting NK cells to LNs. Electroporation of ex vivo expanded NK cells with mRNAs coding for CCR7, CXCR5, and CD62L resulted in increased in vitro migration towards chemokines and mouse LN-derived supernatant. Following infusion into SCID/Beige mice, modified NK cells showed enhanced LN homing. Importantly, lymphoma patient-derived NK cells were equally well expanded and engineered as healthy donor NK cells, highlighting their translational potential. Additionally, the introduction of high-affinity CD16, together with the homing molecules, also augmented their ADCC capacity against autologous lymphoma cells. Hence, genetic engineering can be utilized to enhance NK cell LN homing. The homing concept may synergize with CAR- or monoclonal/bi-/tri-specific antibody-based approaches.

Immunomodulatory Precision: A Narrative Review Exploring the Critical Role of Immune Checkpoint Inhibitors in Cancer Treatment

An immune checkpoint is a signaling pathway that regulates the recognition of antigens by T-cell receptors (TCRs) during an immune response. These checkpoints play a pivotal role in suppressing excessive immune responses and maintaining immune homeostasis against viral or microbial infections. There are several FDA-approved immune checkpoint inhibitors (ICIs), including ipilimumab, pembrolizumab, and avelumab. These ICIs target cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death protein 1 (PD-1), and programmed death ligand 1 (PD-L1). Furthermore, ongoing efforts are focused on developing new ICIs with emerging potential. In comparison to conventional treatments, ICIs offer the advantages of reduced side effects and durable responses. There is growing interest in the potential of combining different ICIs with chemotherapy, radiation therapy, or targeted therapies. This article comprehensively reviews the classification, mechanism of action, application, and combination strategies of ICIs in various cancers and discusses their current limitations. Our objective is to contribute to the future development of more effective anticancer drugs targeting immune checkpoints.

Potential Associations between Vascular Biology and Hodgkin's Lymphoma: An Overview

Hodgkin's lymphoma (HL) is a lymphatic neoplasm typically found in the cervical lymph nodes. The disease is multifactorial, and in recent years, the relationships between various vascular molecules have been explored in the field of vascular biology. The connection between vascular biology and HL is intricate and the roles of several pathways remain unclear. This review summarizes the cellular and molecular relationships between vascular biology and HL. Proteins associated with various functions in vascular biology, including cytokines (TNF-α, IL-1, IL-13, and IL-21), chemokines (CXCL10, CXCL12, and CCL21), adhesion molecules (ELAM-1/VCAM-1), and growth factors (BDNF/NT-3, platelet-derived growth factor receptor-α), have been linked to tumor activity. Notable tumor activities include the induction of paracrine activation of NF-kB-dependent pathways, upregulation of adhesion molecule regulation, genome amplification, and effective loss of antigen presentation mediated by MHC-II. Preclinical study models, primarily those using cell culture, have been optimized for HL. Animal models, particularly mice, are also used as alternatives to complex biological systems, with studies primarily focusing on the physiopathogenic evaluation of the disease. These biomolecules warrant further study because they may shed light on obscure pathways and serve as targets for prevention and/or treatment interventions.

Classic Hodgkin lymphoma in young people

Classic Hodgkin lymphoma (CHL) is a unique form of lymphoid cancer featuring a heterogeneous tumor microenvironment and a relative paucity of malignant Hodgkin and Reed-Sternberg (HRS) cells with characteristic phenotype. Younger individuals (children, adolescents and young adults) are affected as often as the elderly, producing a peculiar bimodal age-incidence profile that has generated immense interest in this disease and its origins. Decades of epidemiological investigations have documented the populations most susceptible and identified multiple risk factors that can be broadly categorized as either biological or environmental in nature. Most risk factors result in overt immunodeficiency or confer more subtle alterations to baseline health, physiology or immune function. Epstein Barr virus, however, is both a risk factor and well-established driver of lymphomagenesis in a significant subset of cases. Epigenetic changes, along with the accumulation of somatic driver mutations and cytogenetic abnormalities are required for the malignant transformation of germinal center-experienced HRS cell precursors. Chromosomal instability and the influence of endogenous mutational processes are critical in this regard, by impacting genes involved in key signaling pathways that promote the survival and proliferation of HRS cells and their escape from immune destruction. Here we review the principal features, known risk factors and lymphomagenic mechanisms relevant to newly diagnosed CHL, with an emphasis on those most applicable to young people.

Updates in pathobiological aspects of anaplastic large cell lymphoma

Anaplastic large cell lymphomas (ALCL) encompass several distinct subtypes of mature T-cell neoplasms that are unified by the expression of CD30 and anaplastic cytomorphology. Identification of the cytogenetic abnormality t(2;5)(p23;q35) led to the subclassification of ALCLs into ALK+ ALCL and ALK- ALCL. According to the most recent World Health Organization (WHO) Classification of Haematolymphoid Tumours as well as the International Consensus Classification (ICC) of Mature Lymphoid Neoplasms, ALCLs encompass ALK+ ALCL, ALK- ALCL, and breast implant-associated ALCL (BI-ALCL). Approximately 80% of systemic ALCLs harbor rearrangement of ALK, with NPM1 being the most common partner gene, although many other fusion partner genes have been identified to date. ALK- ALCLs represent a heterogeneous group of lymphomas with distinct clinical, immunophenotypic, and genetic features. A subset harbor recurrent rearrangement of genes, including TYK2, DUSP22, and TP63, with a proportion for which genetic aberrations have yet to be characterized. Although primary cutaneous ALCL (pc-ALCL) is currently classified as a subtype of primary cutaneous T-cell lymphoma, due to the large anaplastic and pleomorphic morphology together with CD30 expression in the malignant cells, this review also discusses the pathobiological features of this disease entity. Genomic and proteomic studies have contributed significant knowledge elucidating novel signaling pathways that are implicated in ALCL pathogenesis and represent candidate targets of therapeutic interventions. This review aims to offer perspectives on recent insights regarding the pathobiological and genetic features of ALCL.

The Tumor Microenvironment in Classic Hodgkin's Lymphoma in Responder and No-Responder Patients to First Line ABVD Therapy

Although classical Hodgkin lymphoma (CHL) is typically curable, 15-25% of individuals eventually experience a relapse and pass away from their disease. In CHL, the cellular microenvironment is constituted by few percent of H/RS (Hodgkin/Reed-Sternberg) tumor cells surrounded from a heterogeneous infiltration of inflammatory cells. The interplay of H/RS cells with other immune cells in the microenvironment may provide novel strategies for targeted immunotherapies. In this paper we analyzed the microenvironment content in CHL patients with responsive disease (RESP) and patients with relapsed/refractory disease to treatment (REL). Our results indicate the increase of CD68+ and CD163+ macrophages, the increase of PDL-1+ cells and of CD34+ microvessels in REL patients respective to RESP patients. In contrast we also found the decrease of CD3+ and of CD8+ lymphocytes in REL patients respective to RESP patients. Finally, in REL patients our results show the positive correlation between CD68+ macrophages and PDL-1+ cells as well as a negative correlation between CD163+ and CD3+.

Prognostic value of lesion dissemination in doxorubicin, bleomycin, vinblastine, and dacarbazine-treated, interimPET-negative classical Hodgkin Lymphoma patients: A radio-genomic study

We evaluated the prognostic role of the largest distance between two lesions (Dmax), defined by positron emission tomography (PET) in a retrospective cohort of newly diagnosed classical Hodgkin Lymphoma (cHL) patients. We also explored the molecular bases underlying Dmax through a gene expression analysis of diagnostic biopsies. We included patients diagnosed with cHL from 2007 to 2020, initially treated with ABVD, with available baseline PET for review, and with at least two FDG avid lesions. Patients with available RNA from diagnostic biopsy were eligible for gene expression analysis. Dmax was deduced from the three-dimensional coordinates of the baseline metabolic tumor volume (MTV) and its effect on progression free survival (PFS) was evaluated. Gene expression profiles were correlated with Dmax and analyzed using CIBERSORTx algorithm to perform deconvolution. The study was conducted on 155 eligible cHL patients. Using its median value of 20 cm, Dmax was the only variable independently associated with PFS (HR = 2.70, 95% CI 1.1-6.63, pValue = 0.03) in multivariate analysis of PFS for all patients and for those with early complete metabolic response (iPET-). Among patients with iPET-low Dmax was associated with a 4-year PFS of 90% (95% CI 82.0-98.9) significantly better compared to high Dmax (4-year PFS 72.4%, 95% CI 61.9-84.6). From the analysis of gene expression profiles differences in Dmax were mostly associated with variations in the expression of microenvironmental components. In conclusion our results support tumor dissemination measured through Dmax as novel prognostic factor for cHL patients treated with ABVD.

Novel Approaches in Molecular Characterization of Classical Hodgkin Lymphoma

Simple Summary

The unique tumor composition of classical Hodgkin lymphoma (cHL), with only a small fraction of malignant Hodgkin and Reed–Sternberg cells within the tumor tissue, has created many challenges to characterize the genetic alterations that drive this lymphoid malignancy. Major advances in sequencing technologies and detailed analysis of circulating tumor DNA in blood samples of patients have provided important contributions to enhance our understanding of the pathogenesis of cHL. In this review, we provide an overview of the recent advances in genotyping the clonal and mutational landscape of cHL. In addition, we discuss different next-generation sequencing applications to characterize tumor tissue and cell-free DNA, which are now available to improve the diagnosis of cHL, and to monitor therapeutic response or disease progression during treatment and follow up of cHL patients.

Abstract

Classical Hodgkin lymphoma (cHL) represents a B-cell lymphoproliferative disease characterized by clonal immunoglobulin gene rearrangements and recurrent genomic aberrations in the Hodgkin Reed–Sternberg cells in a reactive inflammatory background. Several methods are available for the molecular analysis of cHL on both tissue and cell-free DNA isolated from blood, which can provide detailed information regarding the clonal composition and genetic alterations that drive lymphoma pathogenesis. Clonality testing involving the detection of immunoglobulin and T cell receptor gene rearrangements, together with mutation analysis, represent valuable tools for cHL diagnostics, especially for patients with an atypical histological or clinical presentation reminiscent of a reactive lesion or another lymphoma subtype. In addition, clonality assessment may establish the clonal relationship of composite or subsequent lymphoma presentations within one patient. During the last few decades, more insight has been obtained on the molecular mechanisms that drive cHL development, including recurrently affected signaling pathways (e.g., NF-κB and JAK/STAT) and immune evasion. We provide an overview of the different approaches to characterize the molecular composition of cHL, and the implementation of these next-generation sequencing-based techniques in research and diagnostic settings.

Plasma protein biomarker profiling reveals major differences between acute leukaemia, lymphoma patients and controls

Aiming to accommodate the unmet need for easily accessible biomarkers with a focus on biological differences between haematological diseases, the diagnostic value of plasma proteins in acute leukaemias and lymphomas was investigated. A multiplex proximity extension assay (PEA) was used to analyze 183 proteins in diagnostic plasma samples from 251 acute leukaemia and lymphoma patients and compared with samples from 60 healthy controls. Multivariate modelling using partial least square discriminant analysis revealed highly significant differences between distinct disease subgroups and controls. The model allowed explicit distinction between leukaemia and lymphoma, with few patients misclassified. Acute leukaemia samples had higher levels of proteins associated with haemostasis, inflammation, cell differentiation and cell-matrix integration, whereas lymphoma samples demonstrated higher levels of proteins known to be associated with tumour microenvironment and lymphoma dissemination. PEA technology can be used to screen for large number of plasma protein biomarkers in low µL sample volumes, enabling the distinction between controls, acute leukaemias and lymphomas. Plasma protein profiling could help gain insights into the pathophysiology of acute leukaemia and lymphoma and the technique may be a valuable tool in the diagnosis of these diseases.

The Hodgkin Lymphoma Immune Microenvironment: Turning Bad News into Good

The classic Hodgkin lymphoma (cHL) tumor microenvironment (TME) is by far the most abundant component of tumors and is responsible for most of their biological and clinical characteristics. Recent advances in our knowledge of these networks in cellular interactions allow us to understand that the neoplastic Hodgkin and Reed Sternberg (HRS) cells, although they are in the minority, are the main architects of this dysregulated immune milieu. Here, we review the major changes that have happened in recent years: from TME as a helpless bystander, reflecting an ineffective immune response, to a dynamic tumor-promoting and immunosuppressive element. The HRS cells promote survival through interconnected intrinsic and extrinsic alterations, boosting pro-tumoral signaling pathways through genetic aberrations and autocrine growth signals, in parallel with abnormal cytokine secretion for the recruitment and selection of the best cell partners for this immunosuppressive TME. In turn, cHL is already proving to be the perfect model with which to address an immune checkpoint blockade. Preliminary data demonstrate the utility of druggable key signaling pathways in this ensemble, such as JAK-STAT, NF-κB, and others. In addition, myriad biomarkers predicting a response await validation by new in situ multiplex analytical methods, single-cell gene expression, and other techniques. Together, these components will define the functional phenotypes with which we will elucidate the molecular pathogenesis of the disease and improve the survival of patients who are refractory to conventional therapies.

The Effect of the Tumor Microenvironment on Lymphoid Neoplasms Derived from B Cells

Lymphomas are characteristic tumors surrounded by an inflammatory microenvironment. The cells of the microenvironment are essential for the growth and survival of neoplastic cells and are recruited through the effect of cytokines/chemokines. Lymphomas include heterogeneous groups of neoplasms infiltrating various lymphoid structures which may arise from B lymphocytes, T lymphocytes, and natural killer (NK) cells at various stages of their differentiation state. In this review article, we analyze the literature data concerning the involvement of the tumor microenvironment (TME) in the progression of lymphomas and the recent advances in the analysis of microenvironment components in the most common forms: some mature B cell lymphoma neoplasms and classic Hodgkin lymphomas. The complex crosstalk between the TME and tumor cells led to the discovery of many mechanisms usable as molecular-targeted therapy through the control of diverse elements of the TME, varying from inhibitors of angiogenic cytokines and their receptors to the regulation of cells' activities and the novel immune checkpoint inhibitors.

CD4+ T cells in classical Hodgkin lymphoma express exhaustion associated transcription factors TOX and TOX2

In classical Hodgkin lymphoma (cHL), the highly abundant CD4+ T cells in the vicinity of tumor cells are considered essential for tumor cell survival, but are ill-defined. Although they are activated, they consistently lack expression of activation marker CD26. In this study, we compared sorted CD4+CD26- and CD4+CD26+ T cells from cHL lymph node cell suspensions by RNA sequencing and T cell receptor variable gene segment usage analysis. This revealed that although CD4+CD26- T cells are antigen experienced, they have not clonally expanded. This may well be explained by the expression of exhaustion associated transcription factors TOX and TOX2, immune checkpoints PDCD1 and CD200, and chemokine CXCL13, which were amongst the 100 significantly enriched genes in comparison with the CD4+CD26+ T cells. Findings were validated in single-cell RNA sequencing data from an independent cohort. Interestingly, immunohistochemistry revealed predominant and high frequency of staining for TOX and TOX2 in the T cells attached to the tumor cells. In conclusion, the dominant CD4+CD26- T cell population in cHL is antigen experienced, polyclonal, and exhausted. This population is likely a main contributor to the very high response rates to immune checkpoint inhibitors in cHL.

Lysyl-Oxidase Dependent Extracellular Matrix Stiffness in Hodgkin Lymphomas: Mechanical and Topographical Evidence

Simple Summary

Alterations of the composition and architecture of the extracellular matrix (ECM), leading to increased stiffness, is known to condition development, invasiveness and severity of neoplasms. In this study, we report increased lymph node (LN) stiffness in human lymphomas, measured by LN elastometry or by computerized imaging of bioptic specimens. Stiffness matched to lymphoma histotype and grading. The enzyme lysyl oxidase (LOX) is involved in the rise of collagen cross-linking in Hodgkin lymphomas, while altered architecture, shown by scanning electron microscopy and polarized light microscopy is involved in advanced follicular lymphomas. Based on these data, digital pathology may help in the staging of lymphomas, and lysyl oxidase may represent a target for therapy in Hodgkin lymphomas.

Abstract

Purpose: The biochemical composition and architecture of the extracellular matrix (ECM) is known to condition development and invasiveness of neoplasms. To clarify this point, we analyzed ECM stiffness, collagen cross-linking and anisotropy in lymph nodes (LN) of Hodgkin lymphomas (HL), follicular lymphomas (FL) and diffuse large B-cell lymphomas (DLBCL), compared with non-neoplastic LN (LDN). Methods and Results: We found increased elastic (Young’s) modulus in HL and advanced FL (grade 3A) over LDN, FL grade 1–2 and DLBCL. Digital imaging evidenced larger stromal areas in HL, where increased collagen cross-linking was found; in turn, architectural modifications were documented in FL3A by scanning electron microscopy and enhanced anisotropy by polarized light microscopy. Interestingly, HL expressed high levels of lysyl oxidase (LOX), an enzyme responsible for collagen cross-linking. Using gelatin scaffolds fabricated with a low elastic modulus, comparable to that of non-neoplastic tissues, we demonstrated that HL LN-derived mesenchymal stromal cells and HL cells increased the Young’s modulus of the extracellular microenvironment through the expression of LOX. Indeed, LOX inhibition by β-aminopropionitrile prevented the gelatin stiffness increase. Conclusions: These data indicate that different mechanical, topographical and/or architectural modifications of ECM are detectable in human lymphomas and are related to their histotype and grading.

CCR7 in Blood Cancers - Review of Its Pathophysiological Roles and the Potential as a Therapeutic Target

According to the classical paradigm, CCR7 is a homing chemokine receptor that grants normal lymphocytes access to secondary lymphoid tissues such as lymph nodes or spleen. As such, in most lymphoproliferative disorders, CCR7 expression correlates with nodal or spleen involvement. Nonetheless, recent evidence suggests that CCR7 is more than a facilitator of lymphatic spread of tumor cells. Here, we review published data to catalogue CCR7 expression across blood cancers and appraise which classical and novel roles are attributed to this receptor in the pathogenesis of specific hematologic neoplasms. We outline why novel therapeutic strategies targeting CCR7 might provide clinical benefits to patients with CCR7-positive hematopoietic tumors.

Hodgkin Lymphoma: A Special Microenvironment

Classical Hodgkin's lymphoma (cHL) is one of the most particular lymphomas for the few tumor cells surrounded by an inflammatory microenvironment. Reed-Sternberg (RS) and Hodgkin (H) cells reprogram and evade antitumor mechanisms of the normal cells present in the microenvironment. The cells of microenvironment are essential for growth and survival of the RS/H cells and are recruited through the effect of cytokines/chemokines. We summarize recent advances in gene expression profiling (GEP) analysis applied to study microenvironment component in cHL. We also describe the main therapies that target not only the neoplastic cells but also the cellular components of the background.

Immunodeficiency-associated Hodgkin lymphoma

Introduction: Hodgkin lymphoma (HL) can occur in different host conditions, i.e. in the general population and immunocompromised individuals, either during HIV infection or solid organ/hematopoietic transplantation and immunosuppressive drug treatment.Areas covered: Areas covered include multidimensional characteristics of tumor cells and cellular composition of tumor microenvironment of HL. Current conventional treatments and new treatment strategies for HL in immunosuppressed patients, especially in persons living with HIV (PLWH), are also discussed.PubMed and MEDLINE were used for database searches to identify articles in English published from 1989 to 2020.Expert opinion: For people with post-transplant HL or for those with HIV/AIDS-associated HL, standard treatments mirror those in the general population. In the last decade, the combination of cART with anti-neoplastic treatments, alongside with current anti-rejection therapies, has increased long-term survival of people with HL and acquired immune deficiencies. High-dose chemotherapy and autologous stem cell transplantation have been favorably proven as salvage therapy in PLWH with relapsed and refractory HL. Immune checkpoint inhibitors emerged as an area of clinical investigation for relapsed and refractory HL in the general population. Pembrolizumab, an anti-programmed cell death protein 1 (PD-1) drug, resulted safe in PLWH indicating that PD-1 ligand assessment should be advisable in HIV-associated HL.

Epstein-Barr virus recruits PDL1-positive cells at the microenvironment in pediatric Hodgkin lymphoma

BACKGROUND

Classic Hodgkin lymphoma (cHL) is a lymphoid malignancy in which the microenvironment, where the neoplastic cells are immersed, contributes to the lymphomagenesis process. Epstein-Barr virus (EBV) presence also influences cHL microenvironment composition and contributes to pathogenesis. An increase in PDL1 expression in tumor cells and at the microenvironment was demonstrated in adult cHL. Therefore, our aim was to assess PD1/PDL1 pathway and EBV influence on this pathway in pediatric cHL, given that in Argentina, our group proved a higher incidence of EBV-associated pediatric lymphoma in children.

METHODS

For that purpose, EBV presence was assessed by in situ hybridization, whereas PD1 and PDL1 expressions were studied by immunohistochemistry. PDL1 genetic alterations were analyzed by FISH, and survival was evaluated for PD1 and PDL1 expressions.

RESULTS

EBV presence demonstrated no influence neither on PD1 expression at the microenvironment nor on PDL1 expression at HRS tumor cells. Unexpectedly, only 38% pediatric cHL displayed PDL1 genetic alterations by FISH, and no difference was observed regarding EBV presence. However, in EBV-related cHL cases, a higher number of PDL1 + cells were detected at the microenvironment.

CONCLUSION

Even though a high cytotoxic environment was previously described in EBV-related pediatric cHL, it might be counterbalanced by an immunoregulatory micro-environmental PDL1 + niche. This regulation may render a cytotoxic milieu that unsuccessfully try to eliminate EBV + Hodgkin Reed Sternberg tumor cells in pediatric patients.

Dissecting Clonal Hematopoiesis in Tissues of Classical Hodgkin Lymphoma Patients

Clonal hematopoiesis predisposes to hematological malignancies. However, clonal hematopoiesis is understudied in classical Hodgkin lymphoma (cHL), a mature B-cell neoplasm exhibiting the most abundant microenvironment. We analyzed clonal hematopoiesis in 40 cHL cases by sequencing microdissected tumor cells and matched normal cells from blood and/or lymph nodes. Five patients had blood and/or tissue clonal hematopoiesis. In three of five patients (all failing first-line therapy), clonal hematopoiesis spread through the tissue microenvironment extensively, and featured mutant DNMT3A^R882H , KRAS^G60D and DNMT3A^R882H +TET2^Q1274 * in 33%, 92% and 60% of non-neoplastic cells, respectively. In the latter case, DNMT3A/TET2-mutant clonal hematopoiesis seeded the neoplastic clone, which was infected by the Epstein-Barr virus and showed almost no other somatic mutations exome-wide. In the former case, DNMT3A-mutant clonal hematopoiesis did not originate the neoplastic clone despite dominating the blood and B-cell lineage (~94% leukocytes; ~96% mature blood B cells), yet led to NPM1-mutated acute myeloid leukemia 6 years after therapy for cHL. Our results expand to cHL the spectrum of hematologic malignancies associated with clonal hematopoiesis.

Rosetting T cells in Hodgkin lymphoma are activated by immunological synapse components HLA class II and CD58

A unique feature of Hodgkin lymphoma (HL) is the presence of CD4+ T cells that surround, protect, and promote survival of tumor cells. The adhesion molecules involved in this so-called T-cell rosetting are important components of the immunological synapse (IS). However, it is unknown whether this synapse is fully assembled and leads to T-cell activation by enabling interaction between the T-cell receptor (TCR) and human leukocyte antigen class II (HLA-II). We established a novel rosetting model by coculturing HLA-II-matched peripheral blood mononuclear cells with HL cell lines and showed IS formation with activation of rosetting T cells. HLA-II downregulation by class II transactivator knockout did not affect the extent of rosetting, but almost completely abrogated T-cell activation. Intriguingly, the level of CD58 expression correlated with the extent of rosette formation, and CD58 knockout or CD2 blockade reduced both rosette formation and T-cell activation. The extension of our findings to primary HL tissue by immunohistochemistry and proximity ligation assays showed interaction of CD2 with CD58 and of TCR-associated CD4 with HLA-II. In conclusion, T-cell rosetting in HL is established by formation of the IS, and activation of rosetting T cells critically depends on the interaction of both TCR-HLA-II and CD2-CD58.

AP-1 family transcription factors: a diverse family of proteins that regulate varied cellular activities in classical hodgkin lymphoma and ALK+ ALCL

Classical Hodgkin lymphoma (cHL) and anaplastic lymphoma kinase-positive, anaplastic large cell lymphoma (ALK+ ALCL) are B and T cell lymphomas respectively, which express the tumour necrosis factor receptor superfamily member, CD30. Another feature shared by cHL and ALK+ ALCL is the aberrant expression of multiple members of the activator protein-1 (AP-1) family of transcription factors which includes proteins of the Jun, Fos, ATF, and Maf subfamilies. In this review, we highlight the varied roles these proteins play in the pathobiology of these lymphomas including promoting proliferation, suppressing apoptosis, and evading the host immune response. In addition, we discuss factors contributing to the elevated expression of these transcription factors in cHL and ALK+ ALCL. Finally, we examine therapeutic strategies for these lymphomas that exploit AP-1 transcriptional targets or the signalling pathways they regulate.

The Evolving Knowledge on T and NK Cells in Classic Hodgkin Lymphoma: Insights into Novel Subsets Populating the Immune Microenvironment

Simple Summary

In classic Hodgkin lymphoma, T and NK cells constitute a significant fraction of the reactive microenvironment established by malignant Hodgkin Reed–Sternberg cells. Despite their abundance, T and NK cells remain largely ineffective because of two coordinated levels of immune evasion. The first is based on the acquisition of regulatory properties or exhausted phenotypes that cripple their antitumor activity. The second is represented by their peculiar spatial distribution, with the most immunosuppressive subpopulations lying in close proximity of neoplastic cells. Recent discoveries about the functional role and the spatial orientation of T and NK cells in classic Hodgkin lymphoma are the focus of this review.

Abstract

Classic Hodgkin lymphoma (cHL) is a unique lymphoid neoplasm characterized by extensive immune infiltrates surrounding rare malignant Hodgkin Reed–Sternberg (HRS) cells. Different subsets of T and NK cells have long been recognized in the cHL microenvironment, yet their distinct contribution to disease pathogenesis has remained enigmatic. Very recently, novel platforms for high dimensional analysis of immune cells, such as single-cell RNA sequencing and mass cytometry, have revealed unanticipated insights into the composition of T- and NK-cell compartments in cHL. Advances in imaging techniques have better defined specific T-helper subpopulations physically interacting with neoplastic cells. In addition, the identification of novel cytotoxic subsets with an exhausted phenotype, typically enriched in cHL milieu, is shedding light on previously unrecognized immune evasion mechanisms. This review examines the immunological features and the functional properties of T and NK subsets recently identified in the cHL microenvironment, highlighting their pathological interplay with HRS cells. We also discuss how this knowledge can be exploited to predict response to immunotherapy and to design novel strategies to improve PD-1 blockade efficacy.

Clinical relevance of NKT cells and soluble MIC-A in Hodgkin lymphoma

Previous studies demonstrated that the majority of Hodgkin lymphoma (HL) patients achieve response after treatment, while 5% become refractory. Studies analyzing the role of lymphocyte subsets in peripheral blood are limited. This investigation sought to evaluate peripheral blood lymphocyte subsets and soluble MHC class I chain-related proteins A and B (sMIC-A/B) and their correlation with survival in patients with newly diagnosed HL. The study recruited 36 patients and 72 healthy donors. HL patients showed a decrease in CD4, B, monocytes, NK, and NKT cells; and an increase in γ-δ T cells and soluble MIC-A serum levels. Higher values of s-MIC-A  >100 ng/mL and NKT cells >40 µL correlated with poor overall survival (OS). In conclusion, in HL peripheral blood CD4 T and B cells, monocytes, NK, and NKT cells were decreased, while s-MIC-A and γ-δ T cells increased. Higher values of s-MIC-A and NKT cells correlated with poor survival.

B Cells versus T Cells in the Tumor Microenvironment of Malignant Lymphomas. Are the Lymphocytes Playing the Roles of Muhammad Ali versus George Foreman in Zaire 1974?

Malignant lymphomas are a heterogeneous group of malignancies that develop both in nodal and extranodal sites. The different tissues involved and the highly variable clinicopathological characteristics are linked to the association between the lymphoid neoplastic cells and the tissues they infiltrate. The immune system has developed mechanisms to protect the normal tissue from malignant growth. In this review, we aim to explain how T lymphocyte-driven control is linked to tumor development and describe the tumor-suppressive components of the resistant framework. This manuscript brings forward a new insight with regard to intercellular and intracellular signaling, the immune microenvironment, the impact of therapy, and its predictive implications. A better understanding of the key components of the lymphoma environment is important to properly assess the role of both B and T lymphocytes, as well as their interplay, just as two legendary boxers face each other in a heavyweight title final, as was the case of Ali versus Foreman.

[Microenvironment in classical Hodgkin lymphoma]

Classical Hodgkin lymphoma (cHL) is histologically characterized by a quantitatively dominating immune cell infiltrate. Its composition differs depending on the histological subtype and EBV (Epstein-Barr-Virus) status. Current pathogenic concepts postulate that the malignant cells, the so-called Hodgkin and Reed-Sternberg (HRS) cells, act as master recruiters, thereby actively shaping the microenvironment to support their proliferation and outgrowth. This view on the pathogenesis of cHL is further solidified by genetic studies, which have identified important mechanisms by which the HRS cells are enabled to escape immune surveillance. Besides an insufficient antigen presentation mediated by mutations and structural chromosomal changes in key components or regulators of major histocompatibility class I and II molecules, copy number gains of the 9p24.1 genomic locus encompassing JAK2 and the ligands of the programmed cell death protein 1 (PD-1), PD-L1 and PD-L2, play an important role in the pathogenesis of this disease as the engagement of those ligands with their cognate receptor leads to suppression of the immune response. Of importance, the reversibility of this inhibitory receptor-ligand interaction is key to the clinical success that checkpoint inhibitors had and continue to have in cHL patients, especially in the relapse setting. In addition, comprehensive assessment of microenvironment composition, integration with results from genetic studies, and correlation with clinical outcomes have led to the development of prognostic models, which may assist in an improved risk stratification, informed selection of treatment regimens, and therefore better outcomes.

Hodgkin lymphoma

Hodgkin lymphoma (HL) is a B cell lymphoma characterized by few malignant cells and numerous immune effector cells in the tumour microenvironment. The incidence of HL is highest in adolescents and young adults, although HL can affect elderly individuals. Diagnosis is based on histological and immunohistochemical analyses of tissue from a lymph node biopsy; the tissue morphology and antigen expression profile enable classification into one of the four types of classic HL (nodular sclerosis, mixed cellularity, lymphocyte-depleted or lymphocyte-rich HL), which account for the majority of cases, or nodular lymphocyte-predominant HL. Although uncommon, HL remains a crucial test case for progress in cancer treatment. HL was among the first systemic neoplasms shown to be curable with radiation therapy and multiagent chemotherapy. The goal of multimodality therapy is to minimize lifelong residual treatment-associated toxicity while maintaining high levels of effectiveness. Recurrent or refractory disease can be effectively treated or cured with high-dose chemotherapy followed by autologous haematopoietic stem cell transplantation, and prospective trials have demonstrated the potency of immunotherapeutic approaches with antibody-drug conjugates and immune checkpoint inhibitors. This Primer explores the wealth of information that has been assembled to understand HL; these updated observations verify that HL investigation and treatment remain at the leading edge of oncological research.

EBNA2-deleted Epstein-Barr virus (EBV) isolate, P3HR1, causes Hodgkin-like lymphomas and diffuse large B cell lymphomas with type II and Wp-restricted latency types in humanized mice

EBV transforms B cells in vitro and causes human B-cell lymphomas including classical Hodgkin lymphoma (CHL), Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL). The EBV latency protein, EBNA2, transcriptionally activates the promoters of all latent viral protein-coding genes expressed in type III EBV latency and is essential for EBV's ability to transform B cells in vitro. However, EBNA2 is not expressed in EBV-infected CHLs and BLs in humans. EBV-positive CHLs have type II latency and are largely driven by the EBV LMP1/LMP2A proteins, while EBV-positive BLs, which usually have type I latency are largely driven by c-Myc translocations, and only express the EBNA1 protein and viral non-coding RNAs. Approximately 15% of human BLs contain naturally occurring EBNA2-deleted viruses that support a form of viral latency known as Wp-restricted (expressing the EBNA-LP, EBNA3A/3B/3C, EBNA1 and BHRF1 proteins), but whether Wp-restricted latency and/or EBNA2-deleted EBV can induce lymphomas in humanized mice, or in the absence of c-Myc translocations, is unknown. Here we show that a naturally occurring EBNA2-deleted EBV strain (P3HR1) isolated from a human BL induces EBV-positive B-cell lymphomas in a subset of infected cord blood-humanized (CBH) mice. Furthermore, we find that P3HR1-infected lymphoma cells support two different viral latency types and phenotypes that are mutually exclusive: 1) Large (often multinucleated), CD30-positive, CD45-negative cells reminiscent of the Reed-Sternberg (RS) cells in CHL that express high levels of LMP1 but not EBNA-LP (consistent with type II viral latency); and 2) smaller monomorphic CD30-negative DLBCL-like cells that express EBNA-LP and EBNA3A but not LMP1 (consistent with Wp-restricted latency). These results reveal that EBNA2 is not absolutely required for EBV to form tumors in CBH mice and suggest that P3HR1 virus can be used to model EBV positive lymphomas with both Wp-restricted and type II latency in vivo.

Role of ADAM10 as a CD30 Sheddase in Classical Hodgkin Lymphoma

Cancer cells generally recruit and influence non-malignant immune cells to support the tumor growth. Classical Hodgkin lymphoma (cHL) is a good example because the affected lymphoid tissue contains only a few malignant Hodgkin and Reed-Sternberg (H-RS) cells, which are supported by a massive infiltrate of lymphocytes, fibroblasts, and innate immune cells. The transmembrane receptor CD30, which is selectively expressed on the H-RS cells, plays an important role, not only in cell stimulation and intercellular communication but also in tumor diagnosis and targeted tumor therapy. Different protein processing pathways influence its functionality. Depending on the conditions, the receptor is internalized or released. The release of CD30 occurs either as an intact molecule, embedded in the membrane of extracellular vesicles (EVs), or as a cleaved soluble ectodomain (sCD30). CD30 cleavage is predominantly catalyzed by ADAM10. The enzyme is catalytically active in cells as well as in EVs and gradually releases sCD30. Because the circulation contains no CD30⁺ donor cells, this mechanism explains that the cleaved ectodomain represents the predominant form of CD30 in the plasma of cHL patients. CD30 processing might influence the impact of CD30 antibody-drug conjugates, such as Brentuximab Vedotin (BV). Whereas, ADAM10-degraded CD30 impedes the BV efficacy, tumor-derived EVs load bystander cells with CD30 and generate new targets among supporter cells. This crossfire effect might contribute to the enormous clinical impact of BV, whereas the ADAM10-dependent cleavage to the mild systemic off-target effects of the treatment with BV.

The scope of viral causation of human cancers: interpreting virus density from an evolutionary perspective

Most known oncogenic viruses of humans use DNA as their genomic material. Research over the past quarter century has revealed that their oncogenicity results largely from direct interference with barriers to oncogenesis. In contrast to viruses that have been accepted causes of particular cancers, candidate viral causes tend to have fewer viral than cellular genomes in the tumours. These low viral loads have caused researchers to conclude that the associated viruses are not primary causes of the associated cancers. Consideration of differential survival, reproduction and infiltration of cells in a tumour suggest, however, that viral loads could be low even when viruses are primary causes of cancer. Resolution of this issue has important implications for human health because medical research tends to be effective at preventing and controlling infectious diseases. Mathematical models may clarify the problem and help guide future research by assessing whether low viral loads are likely outcomes of the differential survival, reproduction, and infiltration of cells in a tumour and, more generally, the extent to which viruses contribute to cancer. This article is part of the theme issue 'Silent cancer agents: multi-disciplinary modelling of human DNA oncoviruses'.

A Gene Expression-based Model to Predict Metabolic Response After Two Courses of ABVD in Hodgkin Lymphoma Patients

PURPOSE

Early response to ABVD, assessed with interim FDG-PET (iPET), is prognostic for classical Hodgkin lymphoma (cHL) and supports the use of response adapted therapy. The aim of this study was to identify a gene-expression profile on diagnostic biopsy to predict iPET positivity (iPET⁺).

EXPERIMENTAL DESIGN

Consecutive untreated patients with stage I-IV cHL who underwent iPET after two cycles of ABVD were identified. Expression of 770 immune-related genes was analyzed by digital expression profiling (NanoString Technology). iPET was centrally reviewed according to the five-point Deauville scale (DS 1-5). An iPET⁺ predictive model was derived by multivariate regression analysis and assessed in a validation set identified using the same inclusion criteria.

RESULTS

A training set of 121 and a validation set of 117 patients were identified, with 23 iPET⁺ cases in each group. Sixty-three (52.1%), 19 (15.7%), and 39 (32.2%) patients had stage I-II, III, and IV, respectively. Diagnostic biopsy of iPET⁺ cHLs showed transcriptional profile distinct from iPET^-. Thirteen genes were stringently associated with iPET⁺. This signature comprises two functionally stromal-related nodes. Lymphocytes/monocytes ratio (LMR) was also associated to iPET⁺. In the training cohort a 5-gene/LMR integrated score predicted iPET⁺ [AUC, 0.88; 95% confidence interval (CI), 0.80-0.96]. The score achieved a 100% sensitivity to identify DS5 cases. Model performance was confirmed in the validation set (AUC, 0.68; 95% CI, 0.52-0.84). Finally, iPET score was higher in patients with event versus those without.

CONCLUSIONS

In cHL, iPET is associated with a genetic signature and can be predicted by applying an integrated gene-based model on the diagnostic biopsy.

Systemic immune-inflammation index predicting survival outcome in patients with classical Hodgkin lymphoma

Aim: To evaluate the prognostic significance of neutrophil lymphocyte ratio, prognostic nutritional index, systemic immune-inflammation index (SII) and B2M in Hodgkin Lymphoma (HL). Materials & methods: Neutrophil-lymphocyte ratio, prognostic nutritional index, SII and B2M were analyzed to assess their prognostic value via the Kaplan-Meier method and Cox regression analysis in 122 HL patients, retrospectively. Results: SII was found to have the highest area under curve and the most sensitive and specific among all markers. In univariate analyses, all four parameters were prognostic for overall survival and progression-free survival, in multivariate analyzes only SII was found to be independent factors for both of them. Conclusion: SII can be suggested as a novel independent and better prognostic factor for predicting overall survival and progression-free survival in HL.

M1-like macrophage polarization prevails in young children with classic Hodgkin Lymphoma from Argentina

The microenvironment in classical Hodgkin lymphoma (cHL) comprises a mixture of different types of cells, which are responsible for lymphoma pathogenesis and progression. Even though microenvironment composition in adult cHL has been largely studied, only few groups studied pediatric cHL, in which both Epstein Barr virus (EBV) infection and age may display a role in their pathogenesis. Furthermore, our group described that EBV is significantly associated with cHL in Argentina in patients under the age of 10 years old. For that reason, our aim was to describe the microenvironment composition in 46 pediatric cHL patients. M1-like polarization status prevailed in the whole series independently of EBV association. On the other hand, in children older than 10 years, a tolerogenic environment illustrated by higher FOXP3 expression was proved, accompanied by a macrophage polarization status towards M2. In contrast, in children younger than 10 years, M1-like was prevalent, along with an increase in cytotoxic GrB+ cells. This study supports the notion that pediatric cHL exhibits a particular tumor microenvironment composition.

Classical Hodgkin lymphoma cells may promote an IL-17-enriched microenvironment

In classical Hodgkin lymphoma (cHL), the significance of the interplay between Hodgkin and Reed-Sternberg cells (HRS) and reactive T cells remains poorly defined. By immunohistochemistry on bioptic cHL specimens, we found that HRS and surrounding T lymphocytes stained positive for IL-17 in 40% of cases. IL-17 was detectable in a similar proportion of patients' sera and correlated with disease burden. Supernatants of KM-H2 and HDLM-2 cHL cell lines guided preferential chemotaxis of CCR6⁺ T lymphocytes. Coculture of cHL cell lines with PBMC promoted the enrichment of Th17 lymphocytes and Foxp3⁺/IL-17⁺ cells, whereas T regulatory cells slightly decreased. Soluble CD30 downmodulated membrane CD30 expression on T cells and contributed to their polarization shift by stimulating IL-17 production and reducing IFN-γ synthesis. Thus, HRS and a number of reactive CD4⁺ T cells, attracted by tumor-secreted chemokines, produce an IL-17 tumor-shaped inflammatory milieu in a cHL subset.

Formation of the Immunosuppressive Microenvironment of Classic Hodgkin Lymphoma and Therapeutic Approaches to Counter It

Classic Hodgkin lymphoma (cHL) is characterized by a few tumor cells surrounded by a protective, immunosuppressive tumor microenvironment composed of normal cells that are an active part of the disease. Hodgkin and Reed-Sternberg (HRS) cells evade the immune system through a variety of different mechanisms. They evade antitumor effector T cells and natural killer cells and promote T cell exhaustion. Using cytokines and extracellular vesicles, they recruit normal cells, induce their proliferation and "educate" (i.e. reprogram) them to become immunosuppressive and protumorigenic. Therefore, alternative treatment strategies are being developed to target not only tumor cells but also the tumor microenvironment. Here we summarize current knowledge on the ability of HRS cells to build their microenvironment and to educate normal cells to become immunosuppressive. We also describe therapeutic strategies to counteract formation of the tumor microenvironment and related processes leading to T cell exhaustion and repolarization of immunosuppressive tumor-associated macrophages.

Immune targeting of the microenvironment in classical Hodgkin's lymphoma: insights for the hematologist

While up to 80% of patients with Hodgkin's lymphoma (HL) are cured with first-line therapy, relapsed/refractory (R/R) disease remains a clinical challenge and is fatal for many young patients. HL is unique in that the tumor cells (Hodgkin Reed-Sternberg; HRS cells) are a small fraction (<1%) of the tumor bulk, with the remaining tumor composed of the cells of the tumor microenvironment (TME). The support and integrity of the TME is necessary for HRS cell growth and survival. Targeting the programmed death 1 pathway has shown exciting activity in relapsed HL and led to United States Food and Drug Administration approval of the checkpoint inhibitors, nivolumab and pembrolizumab, for R/R HL. Novel combinations with checkpoint blockade therapy (CBT), targeted approaches such as combinations of CBT with brentuximab vedotin or chemotherapy, chimeric antigen receptor T-cells, and the use of CBT to potentially sensitize to subsequent therapy are being investigated as treatment approaches. As understanding of the HL TME grows, hopefully this will increase the number of rational therapeutic targets.

Pregnancy rate and outcome of pregnancies in long-term survivors of Hodgkin's lymphoma

Thanks to the increased number of young survivors of Hodgkin's lymphoma (HL), management of the pregnancies of women who have a history of exposure to chemotherapies and radiation therapy is becoming increasingly common. Many patients and clinicians are worried that pregnancy after the diagnosis of HL may increase the risk of relapse, despite a lack of empirical evidence to support such concerns. In the present study, we included 89 women diagnosed with HL between 2006 and 2015 under the age of 50 years, who were in complete remission and alive without relapse > 1 year after treatment. We determined the pregnancy rate, time to pregnancy, and the disease-free survival. We found no evidence of significant impairment of the fertility of female HL long-term survivors and no evidence that a pregnancy increases the relapse rate among women in remission from HL. Survivors of HL need to consider a range of factors when deciding on future reproduction.

Challenges of driving CD30-directed CAR-T cells to the clinic

Chimeric antigen receptor T (CAR-T) cells are a promising new treatment for patients with relapsed or refractory hematologic malignancies, including lymphoma. Given the success of CAR-T cells directed against CD19, new targets are being developed and tested, since not all lymphomas express CD19. CD30 is promising target as it is universally expressed in virtually all classical Hodgkin lymphomas, anaplastic large cell lymphomas, and in a proportion of other lymphoma types, including cutaneous T cell lymphomas and diffuse large B cell lymphomas. Preclinical studies with CD30-directed CAR-T cells support the feasibility of this approach. Recently, two clinical trials of CD30-directed CAR-T cells in relapsed/refractory CD30+ lymphomas, including Hodgkin lymphoma, have been reported with minimal toxicities noted and preliminary efficacy seen in a proportion of patients. However, improving the persistence and expansion of CAR-T cells is key to further enhancing the efficacy of this treatment approach. Future directions include optimizing the lymphodepletion regimen, enhancing migration to the tumor site, and combination with other immune regulators. Several ongoing and upcoming clinical trials of CD30-directed CAR-T cells are expected to further enhance this approach to treat patients with relapsed and refractory CD30+ lymphomas.

[Expressions and prognostic significance of PTEN and PD-1 protein in patients with classical Hodgkin's lymphoma]

目的

分析肿瘤免疫耐受信号通路的重要因子PD-1和PTEN在经典型霍奇金淋巴瘤（CHL）患者中的表达及其与患者临床特征和预后的相关性。

方法

回顾性分析2003年2月至2013年8月诊治的56例CHL患者的临床资料。采用免疫组织化学染色法检测CHL患者PD-1和PTEN蛋白的表达，采用原位杂交法检测EBV及EBV编码的小mRNA（EBER），并结合患者的临床特征与生存状态进行相关性分析。

结果

①56例患者中，男34例，女22例，中位年龄25（7~71）岁，PTEN阳性者11例（19.64%），PD-1阳性者14例（25.00%）。②PTEN和PD-1表达呈正相关（rs=0.320，P=0.016）；PTEN表达与Ann Arbor分期、IPS评分和有无大包块（≥5 cm）明显相关，PD-1仅与有无大包块相关（P值均<0.05）。③中位随访43（5~86）个月，多因素分析结果显示：年龄≥45岁（P<0.001）、IPS评分>2分（P=0.026）、EBER阳性（P=0.004）、PTEN蛋白高表达（P=0.035）是影响患者5年总生存的不良预后因素，也是影响5年无进展生存的不良预后因素（P值分别为0.007、0.014、0.002、0.024）。

结论

肿瘤免疫逃逸信号通路因子PTEN与CHL患者的预后相关，对CHL患者的预后判断有一定作用，同时也为CHL的免疫治疗提供了新思路和理论依据。

The c-Jun and JunB transcription factors facilitate the transit of classical Hodgkin lymphoma tumour cells through G1

Classical Hodgkin Lymphoma (cHL) is primarily a B cell lymphoid neoplasm and a member of the CD30–positive lymphomas. cHL and the other CD30–positive lymphomas are characterized by the elevated expression and/or constitutive activation of the activator protein-1 (AP-1) family transcription factors, c-Jun and JunB; however, the specific roles they play in the pathobiology of cHL are unclear. In this report we show that reducing either c-Jun or JunB expression with short-hairpin RNAs (shRNAs) reduced the growth of cHL cell lines in vitro and in vivo, primarily through impairing cell cycle transition through G₁. We further investigated the effect of c-Jun and JunB knock-down on proliferation in another CD30–positive lymphoma, anaplastic lymphoma kinase-positive, anaplastic large cell lymphoma (ALK+ ALCL). We found that JunB knock-down in most ALK+ ALCL cell lines examined also resulted in reduced proliferation that was associated with a G₀/G₁ cell cycle defect. In contrast, c-Jun knock-down in multiple ALK+ ALCL cell lines had no effect on proliferation. In summary, this study directly establishes that both c-Jun and JunB play roles in promoting HRS cell proliferation. Furthermore, we demonstrate there are similarities and differences in c-Jun and JunB function between cHL and ALK+ ALCL.

Microenvironment Cell Contribution to Lymphoma Immunity

Lymphoma microenvironment is a complex system composed of stromal cells, blood vessels, immune cells as well as extracellular matrix, cytokines, exosomes, and chemokines. In this review, we describe the function, localization, and interactions between various cellular components. We also summarize their contribution to lymphoma immunity in the era of immunotherapy. Publications were identified from searching Pubmed. Primary literature was carefully evaluated for replicability before incorporating into the review. We describe the roles of mesenchymal stem/stromal cells (MSCs), lymphoma-associated macrophages (LAMs), dendritic cells, cytotoxic T cells, PD-1 expressing CD4+ tumor infiltrating lymphocytes (TILs), T-cells expressing markers of exhaustion such as TIM-3 and LAG-3, regulatory T cells, and natural killer cells. While it is not in itself a cell, we also include a brief overview of the lymphoma exosome and how it contributes to anti-tumor effect as well as immune dysfunction. Understanding the cellular players that comprise the lymphoma microenvironment is critical to developing novel therapeutics that can help block the signals for immune escape and promote tumor surveillance. It may also be the key to understanding mechanisms of resistance to immune checkpoint blockade and immune-related adverse events due to certain types of immunotherapy.

Independent Mechanisms Lead to Genomic Instability in Hodgkin Lymphoma: Microsatellite or Chromosomal Instability †

Background: Microsatellite and chromosomal instability have been investigated in Hodgkin lymphoma (HL). Materials and Methods: We studied seven HL cell lines (five Nodular Sclerosis (NS) and two Mixed Cellularity (MC)) and patient peripheral blood lymphocytes (100 NS-HL and 23 MC-HL). Microsatellite instability (MSI) was assessed by PCR. Chromosomal instability and telomere dysfunction were investigated by FISH. DNA repair mechanisms were studied by transcriptomic and molecular approaches. Results: In the cell lines, we observed high MSI in L428 (4/5), KMH2, and HDLM2 (3/5), low MSI in L540, L591, and SUP-HD1, and none in L1236. NS-HL cell lines showed telomere shortening, associated with alterations of nuclear shape. Small cells were characterized by telomere loss and deletion, leading to chromosomal fusion, large nucleoplasmic bridges, and breakage/fusion/bridge (B/F/B) cycles, leading to chromosomal instability. The MC-HL cell lines showed substantial heterogeneity of telomere length. Intrachromosmal double strand breaks induced dicentric chromosome formation, high levels of micronucleus formation, and small nucleoplasmic bridges. B/F/B cycles induced complex chromosomal rearrangements. We observed a similar pattern in circulating lymphocytes of NS-HL and MC-HL patients. Transcriptome analysis confirmed the differences in the DNA repair pathways between the NS and MC cell lines. In addition, the NS-HL cell lines were radiosensitive and the MC-cell lines resistant to apoptosis after radiation exposure. Conclusions: In mononuclear NS-HL cells, loss of telomere integrity may present the first step in the ongoing process of chromosomal instability. Here, we identified, MSI as an additional mechanism for genomic instability in HL.

Are EBV-related and EBV-unrelated Hodgkin lymphomas different with regard to susceptibility to checkpoint blockade?

Epstein-Barr virus (EBV)–related and EBV-unrelated classical Hodgkin lymphomas (cHLs) are morphologically and phenotypically indistinguishable. However, the tumor microenvironment of EBV-related cHLs contains higher numbers of macrophages and higher expression levels of PD-L1 than that of EBV-unrelated cHLs. Moreover, viral oncoprotein LMP1 may sustain an immunosuppressive microenvironment by inducing/enhancing production of immunosuppressive cytokines and the expression of PD-1. The presence of enhanced immunosuppressive features in EBV-related cHL should make EBV-related cHL patients more susceptible to checkpoint blockade.

Targeting Immune System Alterations in Hodgkin Lymphoma

PURPOSE OF REVIEW

This review discusses novel immunotherapeutic approaches to treat Hodgkin lymphoma (HL), specifically PD-1 inhibitors and cellular immunotherapy.

RECENT FINDINGS

PD-1 inhibitors have shown promising results in the treatment of relapsed or refractory HL, leading to FDA approval of nivolumab and pembrolizumab, although complete remissions are rare. Chimeric antigen receptor T cells directed against CD30 have been investigated with preliminary clinical trials showing minimal toxicities and some responses in heavily pre-treated patients with HL. HL is unique as it consists of a small percentage of malignant cells (Hodgkin Reed Sternberg cells) surrounded by an inflammatory microenvironment which promotes tumor growth and suppresses immune responses, making it an ideal target for immunotherapeutic approaches, such as PD-1 inhibitors and cellular immunotherapy. Current research is focused on overcoming barriers to efficacy via rational combinations that overcome resistance to therapy.

Contribution of Epstein⁻Barr Virus Latent Proteins to the Pathogenesis of Classical Hodgkin Lymphoma

Pathogenic viruses have evolved to manipulate the host cell utilising a variety of strategies including expression of viral proteins to hijack or mimic the activity of cellular functions. DNA tumour viruses often establish latent infection in which no new virions are produced, characterized by the expression of a restricted repertoire of so-called latent viral genes. These latent genes serve to remodel cellular functions to ensure survival of the virus within host cells, often for the lifetime of the infected individual. However, under certain circumstances, virus infection may contribute to transformation of the host cell; this event is not a usual outcome of infection. Here, we review how the Epstein–Barr virus (EBV), the prototypic oncogenic human virus, modulates host cell functions, with a focus on the role of the EBV latent genes in classical Hodgkin lymphoma.

Priming of the Cells: Hypoxic Preconditioning for Stem Cell Therapy

Objective:

Stem cell-based therapies are promising in regenerative medicine for protecting and repairing damaged brain tissues after injury or in the context of chronic diseases. Hypoxia can induce physiological and pathological responses. A hypoxic insult might act as a double-edged sword, it induces cell death and brain damage, but on the other hand, sublethal hypoxia can trigger an adaptation response called hypoxic preconditioning or hypoxic tolerance that is of immense importance for the survival of cells and tissues.

Data Sources:

This review was based on articles published in PubMed databases up to August 16, 2017, with the following keywords: “stem cells,” “hypoxic preconditioning,” “ischemic preconditioning,” and “cell transplantation.”

Study Selection:

Original articles and critical reviews on the topics were selected.

Results:

Hypoxic preconditioning has been investigated as a primary endogenous protective mechanism and possible treatment against ischemic injuries. Many cellular and molecular mechanisms underlying the protective effects of hypoxic preconditioning have been identified.

Conclusions:

In cell transplantation therapy, hypoxic pretreatment of stem cells and neural progenitors markedly increases the survival and regenerative capabilities of these cells in the host environment, leading to enhanced therapeutic effects in various disease models. Regenerative treatments can mobilize endogenous stem cells for neurogenesis and angiogenesis in the adult brain. Furthermore, transplantation of stem cells/neural progenitors achieves therapeutic benefits via cell replacement and/or increased trophic support. Combinatorial approaches of cell-based therapy with additional strategies such as neuroprotective protocols, anti-inflammatory treatment, and rehabilitation therapy can significantly improve therapeutic benefits. In this review, we will discuss the recent progress regarding cell types and applications in regenerative medicine as well as future applications.