The Role of Immune Checkpoint Inhibitors in Classical Hodgkin Lymphoma

Genetic and pharmaceutical targeting of HIF1α allows combo-immunotherapy to boost graft vs. leukemia without exacerbation graft vs. host disease

Despite potential impact on the graft vs. leukemia (GVL) effect, immunotherapy targeting CTLA-4 and/or PD-1 has not been successfully combined with bone marrow transplant (BMT) because it exacerbates graft vs. host disease (GVHD). Here, using models of GVHD and leukemia, we demonstrate that targeting hypoxia-inducible factor 1α (HIF1α) via pharmacological or genetic approaches reduces GVHD by inducing PDL1 expression on host tissue while selectively inhibiting PDL1 in leukemia cells to enhance the GVL effect. More importantly, combination of HIF1α inhibition with anti-CTLA-4 antibodies allows simultaneous inhibition of both PDL1 and CTLA-4 checkpoints to achieve better outcomes in models of mouse and human BMT-leukemia settings. These findings provide an approach to enhance the curative effect of BMT for leukemia and broaden the impact of cancer immunotherapy.

Prevention and management of hepatitis B virus reactivation in patients with hematological malignancies in the targeted therapy era

Hepatitis due to hepatitis B virus (HBV) reactivation can be serious and potentially fatal, but is preventable. HBV reactivation is most commonly reported in patients receiving chemotherapy, especially rituximab-containing therapy for hematological malignancies and those receiving stem cell transplantation. Patients with inactive and even resolved HBV infection still have persistence of HBV genomes in the liver. The expression of these silent genomes is controlled by the immune system. Suppression or ablation of immune cells, most importantly B cells, may lead to reactivation of seemingly resolved HBV infection. Thus, all patients with hematological malignancies receiving anticancer therapy should be screened for active or resolved HBV infection by blood tests for hepatitis B surface antigen (HBsAg) and antibody to hepatitis B core antigen. Patients found to be positive for HBsAg should be given prophylactic antiviral therapy. For patients with resolved HBV infection, there are two approaches. The first is pre-emptive therapy guided by serial HBV DNA monitoring, and treatment with antiviral therapy as soon as HBV DNA becomes detectable. The second approach is prophylactic antiviral therapy, particularly for patients receiving high-risk therapy, especially anti-CD20 monoclonal antibody or hematopoietic stem cell transplantation. Entecavir and tenofovir are the preferred antiviral choices. Many new effective therapies for hematological malignancies have been introduced in the past decade, for example, chimeric antigen receptor (CAR)-T cell therapy, novel monoclonal antibodies, bispecific antibody drug conjugates, and small molecule inhibitors, which may be associated with HBV reactivation. Although there is limited evidence to guide the optimal preventive measures, we recommend antiviral prophylaxis in HBsAg-positive patients receiving novel treatments, including Bruton's tyrosine kinase inhibitors, B-cell lymphoma 2 inhibitors, and CAR-T cell therapy. Further studies are needed to determine the risk of HBV reactivation with these agents and the best prophylactic strategy.

CC Chemokine Ligand-2: A Promising Target for Overcoming Anticancer Drug Resistance

Simple Summary

Drug resistance is an obstacle to cancer therapy, and the underlying mechanisms are still being explored. CC chemokine ligand-2 (CCL2) is one of the key proinflammatory chemokines that regulate the migration and infiltration of multiple inflammatory cells, such as monocytes and macrophages. CCL2 can be secreted by tumor cells and multiple cell types, mediating the formation of the tumor-promoting and immunosuppressive microenvironment to promote cancer development, progression, and anticancer drug resistance. Notably, CCL2 is also frequently overexpressed in drug-resistant cancer cells. Here, we review recent findings regarding the role of CCL2 in the development of resistance to multiple anticancer reagents. In addition, the possible mechanisms by which CCL2 participates in anticancer drug resistance are discussed, which may provide new therapeutic targets for reversing cancer resistance.

Abstract

CC chemokine ligand-2 (CCL2), a proinflammatory chemokine that mediates chemotaxis of multiple immune cells, plays a crucial role in the tumor microenvironment (TME) and promotes tumorigenesis and development. Recently, accumulating evidence has indicated that CCL2 contributes to the development of drug resistance to a broad spectrum of anticancer agents, including chemotherapy, hormone therapy, targeted therapy, and immunotherapy. It has been reported that CCL2 can reduce tumor sensitivity to drugs by inhibiting drug-induced apoptosis, antiangiogenesis, and antitumor immunity. In this review, we mainly focus on elucidating the relationship between CCL2 and resistance as well as the underlying mechanisms. A comprehensive understanding of the role and mechanism of CCL2 in anticancer drug resistance may provide new therapeutic targets for reversing cancer resistance.

Immune Subtype Profiling and Establishment of Prognostic Immune-Related lncRNA Pairs in Human Ovarian Cancer

This study collected immune-related genes (IRGs) and used gene expression data from TCGA database to construct a molecular subtype of ovarian cancer (OV) based on immune-related lncRNA gene pairs (IRLnc_GPs). The relationships between molecular subtypes and prognosis and clinical characteristics were further explored. IRGs were acquired from the ImmPort database, and round-robin pairing of immune-related lncRNAs was performed. The NMF algorithm was used to identify molecular subtypes, and the immune score of a single sample was calculated through ESTIMATE, TIMER, ssGSEA, MCPcounter, and CIBERSORT. The relationship between molecular subtypes and immune microenvironments was identified. A hypergeometric test was used to test the lncRNA pairs among the OV molecular subtypes (C1 and C2 subtypes). The BH method was used to screen the different lncRNA pairs, and a predictive risk model was constructed and verified. Finally, correlation analysis between the risk model, immune checkpoint genes, and chemotherapy drugs was carried out. Based on IRLnc_GP to classify 373 OV samples of TCGA, the samples were divided into two subtypes, and the prognosis between the subtypes showed significant differences. The C1 subtype with a poor prognosis was more related to the pathways of tumor occurrence and development. We identified 180 differential lncRNA pairs between subtypes and constructed a prognostic risk model based on 8 IRLnc_GPs. In the independent dataset, the distribution of subtypes in functional modules was different and highly repeatable. There were significant differences in the molecular and clinical characteristics of the subtypes and the drug sensitivity of immunotherapy/chemotherapy. In conclusion, the risk model established based on IRLnc_GP can better evaluate the prognosis of OV samples and can also assess the effects of different drug treatments in the high- and low-risk groups, providing new insights and ideas for the treatment of OV.

CD30+ Lymphoproliferative Disorders as Potential Candidates for CD30-Targeted Therapies

CONTEXT.—

In the early 1980s, a monoclonal antibody termed Ki-1 was developed against a cell line derived from a patient with Hodgkin lymphoma. This antibody detected a limited number of benign activated lymphocytes in lymphoid tissue, whereas in Hodgkin lymphoma it appeared to be nearly specific for Reed-Sternberg cells and their mononuclear variants. Subsequent studies showed that Ki-1 expression defined a new type of lymphoma that was later designated anaplastic large cell lymphoma with or without anaplastic large cell kinase expression/translocation. In the past 30 years, numerous new lymphoma entities have been defined, many of which are variably positive for CD30. Many virally transformed lymphoproliferative disorders are also frequently positive for CD30.

OBJECTIVE.—

To illustrate the broad spectrum of CD30+ hematologic malignancies and to provide an update of CD30-targeted therapies.

DATA SOURCES.—

Personal experiences and published works in PubMed.

CONCLUSIONS.—

Because of its low expression in normal tissue, CD30 was studied as a therapeutic target for many years. However, the first functional humanized antibody against CD30 was developed only about 10 years ago. Brentuximab vedotin is a humanized anti-CD30 antibody linked to a cytotoxin, and was approved by the US Food and Drug Administration in 2012 for treating refractory Hodgkin lymphoma and anaplastic large cell lymphoma. Since then, the list of Food and Drug Administration-approved CD30-targeted hematologic malignancies has grown. Recently, the therapies using tumor antigen-specific chimeric antigen receptor T cells targeting CD30 have incited a great deal of enthusiasm and are studied in clinical trials.

Ophthalmic Manifestations of Hodgkin Lymphoma: A Review

Background

Hodgkin lymphoma (HL) is a hematopoietic neoplasm characterized by cancerous Reed-Sternberg cells. In contrast to ophthalmic manifestations by non-HL that are well recognized, there is paucity of the literature as it relates to ophthalmic manifestation by HL. We performed a comprehensive review of published studies (case reports and small case series) to characterize the ophthalmic manifestations of HL.

Summary

Thirty patients were identified with ophthalmic manifestation of HL. Thirteen (43%) were male, and 14 (46%) were female (in 3 cases, sex was not specified). The median age at ophthalmic presentation was 27 years. Diagnosis of HL was made after ophthalmic manifestation in 10 (33%) cases, whereas 11 (36%) cases had a prior diagnosis of HL. Ophthalmic manifestations can be classified into 3 main groups; direct infiltration, inflammatory reaction, and paraneoplastic process. Seven cases had infiltration of the optic nerve. Uveal inflammatory reaction was reported in 21 cases. The presence of intraocular Reed-Sternberg cells had been confirmed in 1 case with granulomatous uveitis. Conjunctival and corneal reaction was seen in 3 cases. HL was in stage 2 or higher, with only 1 case with stage 1A (12 cases HL stage not specified). Seven cases (22%) died of HD, all were diagnosed with advanced lymphoma, and none was treated with chemotherapy.

Key Message

Ocular involvement in HL is extremely rare. A few cases of histopathologically confirmed optic nerve/tract infiltration are within the spectrum of CNS involvement by HL. Inflammatory uveitis is the most common ophthalmic association of HL. In the presence of prior known diagnosis of HL, restaging should be considered to exclude recurrence. Toxicity or adverse reaction to drugs used to treat HL may also contribute to ophthalmic involvement.

Reappraising the Role of Allogeneic Hematopoietic Stem Cell Transplantation in Relapsed and Refractory Hodgkin’s Lymphoma: Recent Advances and Outcomes

Hodgkin’s lymphoma is a rare yet highly curable disease in the majority of patients treated with modern chemotherapy regimens. For patients who fail to respond to or relapse after initial systemic therapies, treatment with high-dose chemotherapy and autologous hematopoietic stem cell transplantation can provide a cure for many with chemotherapy-responsive lymphoma. Patients who relapse after autologous transplant or those with chemorefractory disease have poor prognosis and represent a high unmet need. Allogeneic hematopoietic stem cell transplantation provides a proven curative therapy for these patients and should be considered, especially in young and medically fit patients. The use of newer agents in this disease such as brentuximab vedotin and immune checkpoint inhibitors can help bring more patients to transplantation and should be considered as well.

A Pan-Cancer Landscape of HOX-Related lncRNAs and Their Association With Prognosis and Tumor Microenvironment

The highly conserved homology cassette family (HOX) as well as 18 referenced long non-coding antisense transcripts (HOXATs) play vital roles in the development of some cancers. Nevertheless, their expression patterns as well as their association with cancer prognosis and the tumor microenvironment (TME) in pan-cancers are still unclear. Here, based on public databases, the expression levels of HOXATs, their prognostic potentials, and correlation with tumor mutation burden (TMB), immune cell infiltration, immune subtype, immune response-related genes, and stemness scores corresponding to 33 tumor types were analyzed systematically using R language. The results of the analysis indicated that different cancer tissues show different HOXAT expression profiles. Further, HOXAT expression showed association with cancer prognosis and immune and stemness regulation. Gene set enrichment analysis also demonstrated that HOXATs participate in cancer- and immune-related pathways, and based on their expression levels, HOTAIRM1 and HOXB-AS1 showed potential involvement in oncogenesis as well as possible involvement in immune regulation across a variety of cancer types. Further investigation also confirmed a significantly higher expression of HOXB-AS1 in GBM than in lower grade glioma tissues. Importantly, in vitro cell function experiments indicated that HOXB-AS1 supports cancer stem cell and plays a fundamental role in glioma metastasis. In conclusion, our results provide valuable resources that can guide the investigation of the mechanisms related to the role of HOXATs in cancers as well as therapeutic analysis in this regard.

New Insights into the Biology and Diagnosis of Splenic Marginal Zone Lymphomas

Splenic marginal zone lymphoma (SMZL) is a small B-cell lymphoma, which has been recognized as a distinct pathological entity since the WHO 2008 classification. It classically presents an indolent evolution, but a third of patients progress rapidly and require aggressive treatments, such as immuno-chemotherapy or splenectomy, with all associated side effects. In recent years, advances in the comprehension of SMZL physiopathology have multiplied, thanks to the arrival of new devices in the panel of available molecular biology techniques, allowing the discovery of new molecular findings. In the era of targeted therapies, an update of current knowledge is needed to guide future researches, such as those on epigenetic modifications or the microenvironment of these lymphomas.

PD-1 and LAG-3 Checkpoint Blockade: Potential Avenues for Therapy in B-Cell Lymphoma

The dependence of cancer on an immunotolerant tumor microenvironment (TME) is well established. Immunotherapies that overcome tumor-induced immune suppression have been central to recent advancements in oncology. This is highlighted by the success of agents that interrupt PD-1 mediated immune suppression in a range of cancers. However, while PD-1 blockade has been paradigm-shifting in many malignancies, the majority of cancers show high rates of primary resistance to this approach. This has led to a rapid expansion in therapeutic targeting of other immune checkpoint molecules to provide combination immune checkpoint blockade (ICB), with one such promising approach is blockade of Lymphocyte Activation Gene 3 (LAG-3). Clinically, lymphoproliferative disorders show a wide spectrum of responses to ICB. Specific subtypes including classical Hodgkin lymphoma have demonstrated striking efficacy with anti-PD-1 therapy. Conversely, early trials of ICB have been relatively disappointing in common subtypes of Non-Hodgkin lymphoma. In this review, we describe the TME of common lymphoma subtypes with an emphasis on the role of prominent immune checkpoint molecules PD-1 and LAG3. We will also discuss current clinical evidence for ICB in lymphoma and highlight key areas for further investigation where synergistic dual checkpoint blockade of LAG-3 and PD-1 could be used to overcome ICB resistance.

Cancer Therapy-Related Cardiovascular Complications in Clinical Practice: Current Perspectives

Cardiovascular (CV) diseases and cancer are the leading causes of death in Europe and the United States. Both diseases have extensive overlap and share common risk factors, symptoms, and outcomes. As the number of patients with both cancer and CV diseases continues to rise, the field of cardio-oncology is gaining increased attention. A frequent problem during anti-cancer treatment is cardiotoxicity caused by the side-effects of chemo-, immuno-, targeted, and radiation therapies. This problem may manifest as acute coronary syndrome, myocarditis, arrhythmias, or heart failure. Modern cardio-oncology spans many different research areas. While some researchers focus on treating patients that have already developed cardiotoxicity, others aim to identify new methods for preventing cardiotoxicity before, during, and after anti-cancer therapy. Both groups share the common understanding that regular monitoring of cancer patients is the basis for optimal medical treatment. Optimal treatment can only be achieved through close cooperation between cardiologists and oncologists. This review summarizes the current views on cardio-oncology and discusses the cardiotoxicities associated with commonly used chemotherapeutics.

A novel scoring system for TIGIT expression in classic Hodgkin lymphoma

Clinical use of immune-checkpoints inhibitors (anti PD-1/PD-L1) resulted very effective for the treatment of relapsed/refractory classic Hodgkin Lymphoma (CHL). Recently, T cell Ig and ITIM domains (TIGIT) has been recognized as an immune checkpoint receptor able to negatively regulate T cell functions. Herein, we investigated the expression of TIGIT in CHL microenvironment in order to find a potential new target for inhibitor therapy. TIGIT, PD-1 and PD-L1 expression was evaluated in 34 consecutive patients with CHL. TIGIT expression in T lymphocytes surrounding Hodgkin Reed-Sternberg (HRS) cells was observed in 19/34 patients (56%), of which 11 (58%) had advanced stages. In 16/19 (84%) cases, TIGIT+ peritumoral T lymphocytes showed also PD-1 expression. All 15 TIGIT− patients had PD-L1 expression in HRS cells (100%) while among 19 TIGIT+ patients, 11 (58%) were PD-L1+ and 8 (42%) were PD-L1−. Using a new scoring system for TIGIT immunoreactivity, all TIGIT+ cases with higher score (4/19) were PD-L1−. Our results confirm co-expression of TIGIT and PD-1 in peritumoral T lymphocytes. Of relevance, we demonstrated a mutually exclusive expression of TIGIT and PD-L1 using new TIGIT scoring system able to identify this immunocheckpoints’ modulation. These results pave the way to new therapeutic strategies for relapsed/refractory CHL.

Overcoming the Hurdles of Autologous T-Cell-Based Therapies in B-Cell Non-Hodgkin Lymphoma

Simple Summary

The activity of novel therapies that utilize patient’s own T-cells to induce remission of B-cell non-Hodgkin lymphoma (B-NHL), including chronic lymphocytic leukemia (CLL), is still suboptimal. In this review, we summarize the clinical efficacy of T-cell-based therapies in B-NHL and provide a biologic rationale for the observed (lack of) responses. We describe and compare the acquired T-cell dysfunctions that occur in the different subtypes of B-NHL. Furthermore, we discuss new insights that could enhance the efficacy of T-cell-based therapies for B-NHL and CLL.

Abstract

The next frontier towards a cure for B-cell non-Hodgkin lymphomas (B-NHL) is autologous cellular immunotherapy such as immune checkpoint blockade (ICB), bispecific antibodies (BsAbs) and chimeric antigen receptor (CAR) T-cells. While highly successful in various solid malignancies and in aggressive B-cell leukemia, this clinical success is often not matched in B-NHL. T-cell subset skewing, exhaustion, expansion of regulatory T-cell subsets, or other yet to be defined mechanisms may underlie the lack of efficacy of these treatment modalities. In this review, a systematic overview of results from clinical trials is given and is accompanied by reported data on T-cell dysfunction. From these results, we distill the underlying pathways that might be responsible for the observed differences in clinical responses towards autologous T-cell-based cellular immunotherapy modalities between diffuse large B-cell lymphoma (DLBCL), chronic lymphocytic leukemia (CLL), follicular lymphoma (FL), mantle cell lymphoma (MCL), and marginal zone lymphoma (MZL). By integration of the clinical and biological findings, we postulate strategies that might enhance the efficacy of autologous-based cellular immunotherapy for the treatment of B-NHL.

Molecular Pathogenesis of Hodgkin Lymphoma: Past, Present, Future

Our understanding of the tumorigenesis of classical Hodgkin lymphoma (cHL) and the formation of Reed–Sternberg cells (RS-cells) has evolved drastically in the last decades. More recently, a better characterization of the signaling pathways and the cellular interactions at play have paved the way for new targeted therapy in the hopes of improving outcomes. However, important gaps in knowledge remain that may hold the key for significant changes of paradigm in this lymphoma. Here, we discuss the past, present, and future of cHL, and review in detail the more recent discoveries pertaining to genetic instability, anti-apoptotic signaling pathways, the tumoral microenvironment, and host-immune system evasion in cHL.

Blockade of CCL2 expression overcomes intrinsic PD-1/PD-L1 inhibitor-resistance in transglutaminase 2-induced PD-L1 positive triple negative breast cancer

Anti-PD-1/PD-L1 immunotherapy, as a treatment for many tumors, has shown good efficacy. However, responses to immunotherapy did not always occur or last long., i.e. primary or acquired resistance, even tumors were PD-L1 positive. Several oncogenic pathways, including PI3K/AKT activation by PTEN loss and NF-κB activation, induce PD-L1 expression and PD-L1 inhibitor-resistance. They also induce expression of CCL2, an inhibitory chemokine that blocks T cell tracking into the tumor by binding to CCR2 on the T cell surface. In this study, we showed that transglutaminase 2 (TG2), a post-translational modification enzyme, induced ubiquitin-proteasome dependent degradation of tumor suppressors including PTEN and IκBα by peptide cross-linking, inducing CCL2 as well as PD-L1 expression via PI3K/AKT and NF-κB activation. It also induced PD-L1 inhibitor-resistance because CCL2 was expressed despite increased PD-L1, which was blocked by PD-L1 inhibitor. We also revealed that inhibition of TG2, instead of PD-L1, restored T cell-dependent killing effect by blocking expression of both PD-L1 and CCL2 in PD-L1(+) triple negative breast cancer (TNBC) cells. In addition, the TG2-expressing TNBC patient group showed higher PD-L1 expression incidence than did the TG2-negative TNBC patient group. In conclusion, TG2 induces primary PD-1/PD-L1 inhibitor-resistance by inducing CCL2 expression. TG2 blockade can be utilized as an excellent therapeutic strategy to overcome PD-L1 inhibitor-resistance in PD-L1(+) TNBC patients. Our study suggested that PD-L1 expression alone might not always be a predictive biomarker for PD-L1(+) TNBC, but TG2 could be a useful predictive marker to select PD-L1 inhibitor-resistant TNBC patients.

Identification of Immune-Related Genes Contributing to the Development of Glioblastoma Using Weighted Gene Co-expression Network Analysis

Background: The tumor microenvironment (TME) of human glioblastoma (GBM) exhibits considerable immune cell infiltration, and such cell types have been shown to be widely involved in the development of GBM. Here, weighted correlation network analysis (WGCNA) was performed on publicly available datasets to identify immune-related molecules that may contribute to the progression of GBM and thus be exploited as potential therapeutic targets. Methods: WGCNA was used to identify highly correlated gene clusters in Chinese Glioma Genome Atlas glioma dataset. Immune-related genes in significant modules were subsequently validated in the Cancer Genome Atlas (TCGA) and Rembrandt databases, and impact on GBM development was examined in migration and vascular mimicry assays in vitro and in an orthotopic xenograft model (GL261 luciferase-GFP cells) in mice. Results: WGCNA yielded 14 significant modules, one of which (black) contained genes involved in immune response and extracellular matrix formation. The intersection of these genes with a GO immune-related gene set yielded 47 immune-related genes, five of which exhibited increased expression and association with worse prognosis in GBM. One of these genes, TREM1, was highly expressed in areas of pseudopalisading cells around necrosis and associated with other proteins induced in angiogenesis/hypoxia. In macrophages induced from THP1 cells, TREM1 expression levels were increased under hypoxic conditions and associated with markers of macrophage M2 polarization. TREM1 siRNA knockdown in induced macrophages reduced their ability to promote migration and vascular mimicry in GBM cells in vitro, and treatment of mice with LP-17 peptide, which blocks TREM1, inhibited growth of GL261 orthotopic xenografts. Finally, blocking the cytokine receptor for CSF1 in induced macrophages also impeded their potential to promote tumor migration and vascular mimicry in GBM cells. Conclusions: Our results demonstrated that TREM1 could be used as a novel immunotherapy target for glioma patients.

Autoantibody profiling identifies predictive biomarkers of response to anti-PD1 therapy in cancer patients

Background: Programmed cell death protein 1 (PD1) inhibitors have revolutionized cancer therapy, yet many patients fail to respond. Thus, the identification of accurate predictive biomarkers of therapy response will improve the clinical benefit of anti-PD1 therapy.

Method: We assessed the baseline serological autoantibody (AAb) profile against ~2300 proteins in 10 samples and ~4600 proteins in 35 samples with alveolar soft part sarcoma (ASPS), non-small-cell lung cancer (NSCLC) and lymphoma using Nucleic Acid Programmable Protein Arrays (NAPPA). 23 selected potential AAb biomarkers were verified using simple, affordable and rapid enzyme linked immune sorbent assay (ELISA) technology with baseline plasma samples from 12 ASPS, 16 NSCLC and 46 lymphoma patients. SIX2 and EIF4E2 AAbs were further validated in independent cohorts of 17 NSCLC and 43 lymphoma patients, respectively, using ELISA. The IgG subtypes in response to therapy were also investigated.

Results: Distinct AAb profiles between ASPS, NSCLC and lymphoma were observed. In ASPS, the production of P53 and PD1 AAbs were significantly increased in non-responders (p=0.037). In NSCLC, the SIX2 AAb was predictive of response with area under the curve (AUC) of 0.87, 0.85 and 0.90 at 3 months, 4.5 months, 6 months evaluation time points, respectively. In the validation cohort, the SIX2 AAb was consistently up-regulated in non-responders (p=0.024). For lymphoma, the EIF4E2 AAb correlated with a favorable response with AUCs of 0.68, 0.70, and 0.70 at 3 months, 4.5 months, and 6 months, respectively. In the validation cohort, the AUCs were 0.74, 0.75 and 0.66 at 3 months, 4.5 months, and 6 months, respectively. The PD1 and PD-L1 IgG2 AAbs were highly produced in ~20% of lymphoma responders. Furthermore, bioinformatics analysis revealed antigen functions of these AAb biomarkers.

Conclusion: This study provides the first evidence that AAb biomarkers selected using high-throughput protein microarrays can predict anti-PD1 therapeutic response and guide anti-PD1 therapy.

Prognostic Impact of Tumor-Associated Macrophages on Survival Is Checkpoint Dependent in Classical Hodgkin Lymphoma

Tumor microenvironment and immune escape affect pathogenesis and survival in classical Hodgkin lymphoma (cHL). While tumor-associated macrophage (TAM) content has been associated with poor outcomes, macrophage-derived determinants with clinical impact have remained undefined. Here, we have used multiplex immunohistochemistry and digital image analysis to characterize TAM immunophenotypes with regard to expression of checkpoint molecules programmed cell death ligand 1 (PD-L1) and indoleamine 2,3-dioxygenase 1 (IDO-1) from the diagnostic tumor tissue samples of 130 cHL patients, and correlated the findings with clinical characteristics and survival. We show that a large proportion of TAMs express PD-L1 (CD68⁺, median 32%; M2 type CD163⁺, median 22%), whereas the proportion of TAMs expressing IDO-1 is lower (CD68⁺, median 5.5%; CD163⁺, median 1.4%). A high proportion of PD-L1 and IDO-1 expressing TAMs from all TAMs (CD68⁺), or from CD163⁺ TAMs, is associated with inferior outcome. In multivariate analysis with age and stage, high proportions of PD-L1⁺ and IDO-1⁺ TAMs remain independent prognostic factors for freedom from treatment failure (PD-L1⁺CD68⁺/CD68⁺, HR = 2.63, 95% CI 1.17–5.88, p = 0.019; IDO-1⁺CD68⁺/CD68⁺, HR = 2.48, 95% CI 1.03–5.95, p = 0.042). In contrast, proportions of PD-L1⁺ tumor cells, all TAMs or PD-L1⁻ and IDO-1⁻ TAMs are not associated with outcome. The findings implicate that adverse prognostic impact of TAMs is checkpoint-dependent in cHL.

Classical Hodgkin's Lymphoma in the Era of Immune Checkpoint Inhibition

The ligation of programmed cell death 1 (PD-1) with programmed cell death ligand PD-L activates the immune checkpoint leading to T-cell dysfunction, exhaustion, and tolerance, especially in Hodgkin lymphoma (HL) where the PD-L/ Janus kinase (Jak) signaling was frequently found altered. Anti-PD-1 or anti-PD-L1 monoclonal antibodies can reverse this immune checkpoint, releasing the brake on T-cell responses. The characterization of the mechanisms regulating both the expression of PD-1 and PD-L and their function(s) in HL is ongoing. We provide in this review the recent findings focused on this aim with special attention on the major research topics, such as adverse events and resistance to PD-1–PD-L1 inhibitor treatment, together with a part about angiogenesis, extracellular vesicles, and microbiome in HL pathogenesis.

An etiological role for the Epstein-Barr virus in the pathogenesis of classical Hodgkin lymphoma

Although a pathogenic role for the Epstein-Barr virus (EBV) is largely undisputed for tumors that are consistently EBV genome positive (eg, nasopharyngeal carcinoma, endemic Burkitt lymphoma), this is not the case for classical Hodgkin lymphoma (cHL), a tumor with only a variable EBV association. In light of recent developments in immunotherapeutics and small molecules targeting EBV, we believe it is now timely to reevaluate the role of EBV in cHL pathogenesis.

Recent Findings in the Regulation of Programmed Death Ligand 1 Expression

With the recent approvals for the application of monoclonal antibodies that target the well-characterized immune checkpoints, immune therapy shows great potential against both solid and hematologic tumors. The use of these therapeutic monoclonal antibodies elicits inspiring clinical results with durable objective responses and improvements in overall survival. Agents targeting programmed cell death protein 1 (PD-1; also known as PDCD1) and its ligand (PD-L1) achieve a great success in immune checkpoints therapy. However, the majority of patients fail to respond to PD-1/PD-L1 axis inhibitors. Expression of PD-L1 on the membrane of tumor and immune cells has been shown to be associated with enhanced objective response rates to PD-1/PD-L1 inhibition. Thus, an improved understanding of how PD-L1 expression is regulated will enable us to better define its role as a predictive marker. In this review, we summarize recent findings in the regulation of PD-L1 expression.

Lymph node fine-needle cytology in the era of personalised medicine. Is there a role?

The 2016 World Health Organisation revised classification of lymphoma has sub-classified well-defined entities and added a number of provisional entities on the basis of new knowledge on genetic, epigenetics and phenotypical data; prognostic and predictive features are also part of this classification. New knowledge on well-defined entities further enlightens the mechanisms of lymphomagenesis, which are more complex and multifactorial than once believed. Therapies are also more complex because traditional clinical trials have been integrated with new drugs and compounds with unique mechanisms of actions against distinct molecular targets. As lymphoma acquires additional genetic and phenotypic features over the time, pathological assessment is also necessary. Histological evaluation and tissue collection by surgical biopsies are necessary for phenotypical and molecular purposes; however, these are demanding procedures for both the patient and the health care system. At the same time, the choice of the best treatment for a specific entity, in different phases and different patients requires information that may not be available when the biopsy is performed. Fine needle aspiration cytology (FNAC) is successfully used in lymph nodes (LNs) in combination with different ancillary techniques and might be used to assess the phenotypic and genetic profile of specific targets and to get key information for therapy, in different phases and stages of the disease, with the option to re-check the same target over time, without surgical excision. This brief review describes LN-FNAC diagnostic criteria, current therapies for lymphomas and the potential role of LN-FNAC in selecting non-Hodgkin lymphomas patients for specific targeted treatments.

Viral-Targeted Strategies Against EBV-Associated Lymphoproliferative Diseases

Epstein-Barr virus (EBV) is strongly associated with a spectrum of EBV-associated lymphoproliferative diseases (EBV-LPDs) ranging from post-transplant lymphoproliferative disorder, B cell lymphomas (e.g., endemic Burkitt lymphoma, Hodgkin lymphoma, and diffuse large B cell lymphoma) to NK or T cell lymphoma (e.g., nasal NK/T-cell lymphoma). The virus expresses a number of latent viral proteins which are able to manipulate cell cycle and cell death processes to promote survival of the tumor cells. Several FDA-approved drugs or novel compounds have been shown to induce killing of some of the EBV-LPDs by inhibiting the function of latent viral proteins or activating the viral lytic cycle from latency. Here, we aim to provide an overview on the mechanisms by which EBV employs to drive the pathogenesis of various EBV-LPDs and to maintain the survival of the tumor cells followed by a discussion on the development of viral-targeted strategies based on the understanding of the patho-mechanisms.

MiRNA Dysregulation in Childhood Hematological Cancer

For decades, cancer biology focused largely on the protein-encoding genes that have clear roles in tumor development or progression: cell-cycle control, apoptotic evasion, genome instability, drug resistance, or signaling pathways that stimulate growth, angiogenesis, or metastasis. MicroRNAs (miRNAs), however, represent one of the more abundant classes of cell modulators in multicellular organisms and largely contribute to regulating gene expression. Many of the ~2500 miRNAs discovered to date in humans regulate vital biological processes, and their aberrant expression results in pathological and malignant outcomes. In this review, we highlight what has been learned about the roles of miRNAs in some of the most common human pediatric leukemias and lymphomas, along with their value as diagnostic/prognostic factors.