The role of CD40/CD40L and interferon regulatory factor 4 in Hodgkin lymphoma microenvironment

The Relationship of CCL5 and CCR1 Variants with Response Rate and Survival Taking into Account Thalidomide/Bortezomib Treatment in Patients with Multiple Myeloma

(1) Background: Chemokines and chemokine receptors play an important role in tumor development. The aim of this study was to check the significance of CCL5 and CCR1 variants with response rate, survival, and the level of regulated on activation, normal T cells expressed and secreted (RANTES/CCL5) in multiple myeloma (MM) patients; (2) Methods: Genomic DNA from 101 newly diagnosed MM patients and 100 healthy blood donors were analyzed by Real-time PCR method (for CCL5 and CCR1 genotyping). In a subgroup of 70 MM patients, serum samples were collected to determine the level of RANTES; (3) Results: multivariate Cox regression showed increased risk of disease relapse or progression (HR = 4.77; p = 0.01) in MM patients with CG + CC genotypes of CCL5 rs2280788. In contrast, CT + TT genotypes of CCL5 rs2107538 were associated withdecreased risk of death (HR = 0.18; p = 0.028) and disease relapse or progression (HR = 0.26; p = 0.01). In MM patients with major genotypes of rs2280789, rs2280788, and rs2107538, higher survival rates were observed in response to treatment with thalidomide and bortezomib. Statistically significant lower RANTES levels were seen in minor genotypes and heterozygotes of CCL5 and CCR1 variants; (4) Conclusions: Major genotypes of CCL5 variants may be independent positive prognostic factors in MM.

The Medium Obtained from the Culture of Hodgkin Lymphoma Cells Affects the Biophysical Characteristics of a Fibroblast Cell Model

The neoplastic Hodgkin-Reed-Sternberg (HRS) cells in Hodgkin lymphoma (HL) represent only 1-10% of cells and are surrounded by an inflammatory microenvironment. The HL cytokine network is a key point for the proliferation of HRS cells and for the maintenance of an advantageous microenvironment for HRS survival. In the tumor microenvironment (TME), the fibroblasts are involved in crosstalk with HRS cells. The aim of this work was to study the effect of lymphoma cell conditioned medium on a fibroblast cell population and evaluate modifications of cell morphology and proliferation. Hodgkin lymphoma-derived medium was used to obtain a population of "conditioned" fibroblasts (WS-1 COND). Differences in biophysical parameters were detected by the innovative device Celector^®. Fibroblast-HL cells interactions were reproduced in 3D co-culture spheroids. WS-1 COND showed a different cellular morphology with an enlarged cytoplasm and enhanced metabolism. Area and diameter cell values obtained by Celector^® measurement were increased. Co-culture spheroids created with WS-1 COND showed a tighter aggregation than those with non-conditioned WS-1. The presence of soluble factors derived from HRS cells in the conditioned medium was adequate for the proliferation of fibroblasts and conditioned fibroblasts in a 3D HL model allowed to develop a representative model of the in vivo TME.

A new approach to the study of Hodgkin lymphoma by flow cytometry

Hodgkin lymphoma (HL) appears to originate from germinal centre B cells but lacks expression of most B cell markers. In contrast to non-Hodgkin B lymphomas, HL is not routinely diagnosed using flow cytometry techniques, and diagnosis is mainly based on immunohistochemical and cytomorphological pathology studies. Hodgkin and Reed-Sternberg cells are large and fragile, making them difficult to study by flow cytometry. The aim of this study was to characterise the CD71 expression pattern on CD4+ T cells from HL patients and to design a simple flow cytometry algorithm to complement the histopathological diagnosis of HL. The present study suggests the utility of a conventional staining protocol with a simple panel of seven markers (CD15, CD30, CD4, CD8, CD71, CD3, and CD45) and a well-defined analysis strategy. The proposed algorithm uses the CD71 ratio (calculated as the percentage of CD71+ CD4+ T cells divided by the percentage of CD71+ CD45+ CD3- lymphocytes), with a cut-off of 0.5 to establish diagnosis groups as suggestive (≥0.5) or not suggestive (<0.5) of HL. In HL, CD71 expression is higher on CD4+ T lymphocytes than on non-T lymphocytes. In addition, the CD4+ T cell population is increased in HL patients, with no change in amounts of CD8+ T cells. Application of the CD71 ratio algorithm yielded a sensitivity of 82% and specificity of 87%, with 84.61% of patients correctly diagnosed. Although histopathology remains the gold standard for definitive HL diagnosis, the proposed flow cytometry method provides a rapid method to guide the study that would allow a more robust and integrated diagnosis. Moreover, the procedure is easily applicable in most clinical laboratories as it does not require state-of-the-art cytometers and uses standard reagents.

Cytokines in Thyroid-Associated Ophthalmopathy

Thyroid-associated ophthalmopathy (TAO), also known as thyroid eye disease (TED) or Graves' orbitopathy (GO), is a complex autoimmune condition causing visual impairment, disfigurement, and harm to patients' physical and mental health. The pathogenesis of TAO has not been fully elucidated, and the mainstream view is that coantigens shared by the thyroid and orbit trigger remodeling of extraocular muscles and orbital connective tissues through an inflammatory response. In recent years, cytokines and the immune responses they mediate have been crucial in disease progression, and currently, common evidence has shown that drugs targeting cytokines, such as tocilizumab, infliximab, and adalimumab, may be novel targets for therapy. In this review, we summarize the research development of different cytokines in TAO pathogenesis in the hope of discovering new therapeutic targets.

Tumor Immune Microenvironment in Lymphoma: Focus on Epigenetics

Lymphoma is a neoplasm arising from B or T lymphocytes or natural killer cells characterized by clonal lymphoproliferation. This tumor comprises a diverse and heterogeneous group of malignancies with distinct clinical, histopathological, and molecular characteristics. Despite advances in lymphoma treatment, clinical outcomes of patients with relapsed or refractory disease remain poor. Thus, a deeper understanding of molecular pathogenesis and tumor progression of lymphoma is required. Epigenetic alterations contribute to cancer initiation, progression, and drug resistance. In fact, over the past decade, dysregulation of epigenetic mechanisms has been identified in lymphomas, and the knowledge of the epigenetic aberrations has led to the emergence of the promising epigenetic therapy field in lymphoma tumors. However, epigenetic aberrations in lymphoma not only have been found in tumor cells, but also in cells from the tumor microenvironment, such as immune cells. Whereas the epigenetic dysregulation in lymphoma cells is being intensively investigated, there are limited studies regarding the epigenetic mechanisms that affect the functions of immune cells from the tumor microenvironment in lymphoma. Therefore, this review tries to provide a general overview of epigenetic alterations that affect both lymphoma cells and infiltrating immune cells within the tumor, as well as the epigenetic cross-talk between them.

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.

An Immune-Related Gene Prognostic Index for Triple-Negative Breast Cancer Integrates Multiple Aspects of Tumor-Immune Microenvironment

Simple Summary

Triple-negative breast cancer (TNBC) is the most refractory subtype of breast cancer. Immune checkpoint inhibitor (ICI) therapy has made progress in TNBC treatment. PD-L1 expression is a useful biomarker of ICI therapy efficacy. However, tumor-immune microenvironment (TIME) factors, such as immune cell compositions and tumor-infiltrating lymphocyte (TIL) status, also influence tumor immunity. Therefore, it is necessary to seek biomarkers that are associated with multiple aspects of TIME in TNBC. In this study, we developed an immune-related gene prognostic index (IRGPI) with a substantial prognostic value for TNBC. Moreover, the results from multiple cohorts reproducibly demonstrate that IRGPI is significantly associated with immune cell compositions, the exclusion and dysfunction of TILs, as well as PD-1 and PD-L1 expression in TIME. Therefore, IRGPI is a promising biomarker closely related to patient survival and TIME of TNBC and may have a potential effect on the immunotherapy strategy of TNBC.

Abstract

Tumor-immune cell compositions and immune checkpoints comprehensively affect TNBC outcomes. With the significantly improved survival rate of TNBC patients treated with ICI therapies, a biomarker integrating multiple aspects of TIME may have prognostic value for improving the efficacy of ICI therapy. Immune-related hub genes were identified with weighted gene co-expression network analysis and differential gene expression assay using The Cancer Genome Atlas TNBC data set (n = 115). IRGPI was constructed with Cox regression analysis. Immune cell compositions and TIL status were analyzed with CIBERSORT and TIDE. The discovery was validated with the Molecular Taxonomy of Breast Cancer International Consortium data set (n = 196) and a patient cohort from our hospital. Tumor expression or serum concentrations of CCL5, CCL25, or PD-L1 were determined with immunohistochemistry or ELISA. The constructed IRGPI was composed of CCL5 and CCL25 genes and was negatively associated with the patient’s survival. IRGPI also predicts the compositions of M0 and M2 macrophages, memory B cells, CD8⁺ T cells, activated memory CD4 T cells, and the exclusion and dysfunction of TILs, as well as PD-1 and PD-L1 expression of TNBC. IRGPI is a promising biomarker for predicting the prognosis and multiple immune characteristics of TNBC.

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.

Hodgkin Lymphoma in People Living with HIV

Simple Summary

Hodgkin lymphoma (HL) is a non-AIDS defining neoplasm, but people living with HIV (PLWH) have between a 5- and 26-fold higher risk of developing it than the general population. Epstein-Barr virus is present in almost all HIV-related HL cases, and plays an important role in its etiopathogenesis. Despite the aggressive characteristics, the prognosis of HL affecting PLWH is similar to that of the general population if patients are treated following the same recommendations. Administration of cART concomitantly with chemotherapy is highly recommended. However, this combination may be challenging due to drug–drug interactions and overlapping toxicity. Thus, interdisciplinary collaboration between hemato-oncologists and HIV specialists is crucial for the optimal treatment of both lymphoma and HIV infection.

Abstract

Despite widespread use of combined antiretroviral therapy (cART) and increased life expectancy in people living with HIV (PLWH), HIV-related lymphomas (HRL) remain a leading cause of cancer morbidity and mortality for PLWH, even in patients optimally treated with cART. While the incidence of aggressive forms of non-Hodgkin lymphoma decreased after the advent of cART, incidence of Hodgkin lymphoma (HL) has increased among PLWH in recent decades. The coinfection of Epstein–Barr virus plays a crucial role in the pathogenesis of HL in the HIV setting. Currently, PLWH with HRL, including HL, are treated similarly to HIV-negative patients and, importantly, the prognosis of HL in PLWH is approaching that of the general population. In this regard, effective cART during chemotherapy is strongly recommended since it has been shown to improve survival rates in all lymphoma subtypes, including HL. As a consequence, interdisciplinary collaboration between HIV specialists and hemato-oncologists for the management of potential drug–drug interactions and overlapping toxicities between antiretroviral and antineoplastic drugs is crucial for the optimal treatment of PLWH with HL. In this article the authors review and update the epidemiological, clinical and biological aspects of HL presenting in PLWH with special emphasis on advances in prognosis and the factors that have contributed to it.

Engaging the Innate and Adaptive Antitumor Immune Response in Lymphoma

Immunotherapy has emerged as a powerful therapeutic strategy for many malignancies, including lymphoma. As in solid tumors, early clinical trials have revealed that immunotherapy is not equally efficacious across all lymphoma subtypes. For example, immune checkpoint inhibition has a higher overall response rate and leads to more durable outcomes in Hodgkin lymphomas compared to non-Hodgkin lymphomas. These observations, combined with a growing understanding of tumor biology, have implicated the tumor microenvironment as a major determinant of treatment response and prognosis. Interactions between lymphoma cells and their microenvironment facilitate several mechanisms that impair the antitumor immune response, including loss of major histocompatibility complexes, expression of immunosuppressive ligands, secretion of immunosuppressive cytokines, and the recruitment, expansion, and skewing of suppressive cell populations. Accordingly, treatments to overcome these barriers are being rapidly developed and translated into clinical trials. This review will discuss the mechanisms of immune evasion, current avenues for optimizing the antitumor immune response, clinical successes and failures of lymphoma immunotherapy, and outstanding hurdles that remain to be addressed.

The CCL5/CCR5 Axis in Cancer Progression

Tumor cells can “hijack” chemokine networks to support tumor progression. In this context, the C-C chemokine ligand 5/C-C chemokine receptor type 5 (CCL5/CCR5) axis is gaining increasing attention, since abnormal expression and activity of CCL5 and its receptor CCR5 have been found in hematological malignancies and solid tumors. Numerous preclinical in vitro and in vivo studies have shown a key role of the CCL5/CCR5 axis in cancer, and thus provided the rationale for clinical trials using the repurposed drug maraviroc, a CCR5 antagonist used to treat HIV/AIDS. This review summarizes current knowledge on the role of the CCL5/CCR5 axis in cancer. First, it describes the involvement of the CCL5/CCR5 axis in cancer progression, including autocrine and paracrine tumor growth, ECM (extracellular matrix) remodeling and migration, cancer stem cell expansion, DNA damage repair, metabolic reprogramming, and angiogenesis. Then, it focuses on individual hematological and solid tumors in which CCL5 and CCR5 have been studied preclinically. Finally, it discusses clinical trials of strategies to counteract the CCL5/CCR5 axis in different cancers using maraviroc or therapeutic monoclonal antibodies.

Fibroblasts in Nodular Sclerosing Classical Hodgkin Lymphoma Are Defined by a Specific Phenotype and Protect Tumor Cells from Brentuximab-Vedotin Induced Injury

Classical Hodgkin lymphoma (cHL) is one of the most common malignant lymphomas in Western Europe. The nodular sclerosing subtype of cHL (NS cHL) is characterized by a proliferation of fibroblasts in the tumor microenvironment, leading to fibrotic bands surrounding the lymphoma infiltrate. Several studies have described a crosstalk between the tumour cells of cHL, the Hodgkin- and Reed-Sternberg (HRS) cells, and cancer-associated fibroblasts. However, to date a deep molecular characterization of these fibroblasts is lacking. Thus, the aim of the present study is a comprehensive characterization of these fibroblasts. Gene expression profiling and methylation profiles of fibroblasts isolated from primary lymph node suspensions revealed persistent differences between fibroblasts obtained from NS cHL and lymphadenitis. NS cHL derived fibroblasts exhibit a myofibroblastic phenotype characterized by myocardin (MYOCD) expression. Moreover, TIMP3, an inhibitor of matrix metalloproteinases, was strongly upregulated in NS cHL fibroblasts, likely contributing to the accumulation of collagen in sclerotic bands of NS cHL. As previously shown for other types of cancer-associated fibroblasts, treatment by luteolin could reverse this fibroblast phenotype and decrease TIMP3 secretion. NS cHL fibroblasts showed enhanced proliferation when they were exposed to soluble factors released from HRS cells. For HRS cells, soluble factors from fibroblasts were not sufficient to protect them from Brentuximab-Vedotin induced cell death. However, HRS cells adherent to fibroblasts were protected from Brentuximab-Vedotin induced injury. In summary, we confirm the importance of fibroblasts for HRS cell survival and identify TIMP3 which probably contributes as a major factor to the typical fibrosis observed in NS cHL.

Elevated plasma RANTES in fibrodysplasia ossificans progressiva - A novel therapeutic target?

Fibrodysplasia ossificans progressiva (FOP) is a rare hereditary disease caused by a mutation in the intracellular domain of the activin A receptor type I and is characterized by episodes (flare-ups) of progressive heterotopic endochondral ossification (HO) in the soft tissues. The mutation alone is not sufficient for the occurrence of HO since flare-ups are triggered by inflammation and activation of the innate immune system. A number of cellular and humoral mediators have been implicated in animal and in vitro models. Observations in humans support the inflammatory nature of the condition, but data on the involved mediators are variable. We hypothesize that for induction of flare-ups in patients with FOP increase in at least one of the pro-inflammatory cytokines is both essential and sufficient to trigger the entire process of the inflammatory cells influx resulting in the novel ectopic bone formation and we suggest that C-C motif ligand 5 (CCL5), a pro-inflammatory chemokine also known as Regulated on activation, normal T-cell expressed and secreted (RANTES), might be the key candidate. CCL5 is a chemoattractant for all cellular types implicated in HO and is produced by the cells of the tissue microenvironment at the sites of HO as well as by the pro-inflammatory cellular mediators. CCL5 induces ossification in cultured human pluripotent mesenchymal cells (hMSCs) and in the primary culture of monocytes from FOP patients (but not from their healthy relatives), stimulation with lipopolysaccharide induces CCL5 expression. Finally, in a pilot study we used a panel of 23 cytokines and chemokines to screen the plasma samples of three subjects: a female patient with FOP during a flare-up; a female patient with hyperostosis corticalis generalisata (van Buchem disease), another rare disease characterized by excessive bone formation at the sites where it regularly occurs that does not include inflammatory events; and a healthy woman without bone disorders. There appeared a rather clear-cut signal of a 2-fold higher level of CCL5 in the FOP patient vs. the healthy subject and the van Buchem patient. Evaluation of the hypothesis would require an international prospective study, with main motivation being the lack of a conclusive treatment as the major unmet need in FOP. A treatment targeting CCL5 receptor already exists and is used in HIV-infected patients.

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 Checkpoint Inhibition in Classical Hodgkin Lymphoma: From Early Achievements towards New Perspectives

Immune checkpoint inhibition (ICI) became one of the major breakthroughs in cancer treatment over the past decade and entered into therapy within standard oncohematology practice. ICI has demonstrated impressive response rates as salvage therapy in relapsed/refractory (R/R) classical Hodgkin lymphoma (cHL) and is now being tested as an adjunction to chemotherapy in the frontline settings. CHL exquisite sensitivity to PD-1/PD-L1 axis inhibition relies on a particular biological background. By contrast, non-Hodgkin lymphomas (NHL) have demonstrated heterogeneous response rates using ICI. These observations highlight discrepancies between various types of lymphomas in terms of genetic alterations, immune microenvironment interactions, and disease phenotype. This review aims to focus on cHL immune escape mechanisms, focusing on cHL biological sensitivity to PD-1 blockade. We will summarize the available data issued from clinical trials on ICI in cHL and its safety profile. Going beyond the current use of monoclonal antibodies (mAb) targeting immune checkpoints in clinical practice, we will offer an overview of new combinatory therapeutic perspectives where cHL immunotherapy may be considered.

The Role of Immune Checkpoint Inhibitors in Classical Hodgkin Lymphoma

Hodgkin Lymphoma (HL) is a unique disease entity both in its pathology and the young patient population that it primarily affects. Although cure rates are high, survivorship can be linked with significant recent long-term morbidity associated with both chemotherapy and radiotherapy. The most significant advances have been with the use of the anti-CD30-drug conjugated antibody brentuximab vedotin (BV) and inhibitors of program death 1 (PD-1). HL is genetically wired to up-regulate program death ligand 1 (PD-L1) in >95% of cases, creating a state of so-called &ldquo;T cell exhaustion&rdquo;, which can be reversed with immune checkpoint-inhibitor blockade. The overall and complete response rates to PD-1 inhibitors in patients with relapsed or refractory HL are 70% and 20%, respectively, with a long median duration of response of ~16 months. In fact, PD-1 inhibitors can benefit a wide spectrum of relapsed HL patients, including some who have &ldquo;progressive disease&rdquo; by strict response criteria. We review the biology of HL, with a focus on the immune micro-environment and mechanisms of immune evasion. We also provide the rationale supporting the use of PD-1 inhibitors in HL and highlight some of the challenges of monitoring disease response in patients treated with this immunotherapy.

Inhibition of the CCL5/CCR5 Axis against the Progression of Gastric Cancer

Despite the progress made in molecular and clinical research, patients with advanced-stage gastric cancer (GC) have a bad prognosis and very low survival rates. Furthermore, it is challenging to find the complex molecular mechanisms that are involved in the development of GC, its progression, and its resistance to therapy. The interactions of chemokines, also known as chemotactic cytokines, with their receptors regulate immune and inflammatory responses. However, updated research demonstrates that cancer cells subvert the normal chemokine role, transforming them into fundamental constituents of the tumor microenvironment (TME) with tumor-promoting effects. C-C chemokine ligand 5 (CCL5) is a chemotactic cytokine, and its expression and secretion are regulated in T cells. C-C chemokine receptor type 5 (CCR5) is expressed in T cells, macrophages, other leukocytes, and certain types of cancer cells. The interaction between CCL5 and CCR5 plays an active role in recruiting leukocytes into target sites. This review summarizes recent information on the role of the CCL5 chemokine and its receptor CCR5 in GC cell proliferation, metastasis formation, and in the building of an immunosuppressive TME. Moreover, it highlights the development of new therapeutic strategies to inhibit the CCL5/CCR5 axis in different ways and their possible clinical relevance in the treatment of GC.

Novel Molecular Mechanism of Regulation of CD40 Ligand by the Transcription Factor GLI2

The interaction between tumor cells and their surrounding microenvironment is essential for the growth and persistence of cancer cells. This interaction is mediated, in part, by cytokines. Although the role of cytokines in normal and malignant cell biology is well established, many of the molecular mechanisms regulating their expression remain elusive. In this article, we provide evidence of a novel pathway controlling the transcriptional activation of CD40L in bone marrow-derived stromal cells. Using a PCR-based screening of cytokines known to play a role in the biology of bone marrow malignancies, we identified CD40L as a novel GLI2 target gene in stromal cells. CD40L plays an important role in malignant B cell biology, and we found increased Erk phosphorylation and cell growth in malignant B cells cocultured with CD40L-expressing stromal cells. Further analysis indicated that GLI2 overexpression induced increased CD40L expression, and, conversely, GLI2 knockdown reduced CD40L expression. Using luciferase and chromatin immunoprecipitation assays, we demonstrate that GLI2 directly binds and regulates the activity of the CD40L promoter. We found that the CCR3-PI3K-AKT signaling modulates the GLI2-CD40L axis, and GLI2 is required for CCR3-PI3K-AKT-mediated regulation of the CD40L promoter. Finally, coculture of malignant B cells with cells stably expressing human CD40L results in increased Erk phosphorylation and increased malignant B cell growth, indicating that CD40L in the tumor microenvironment promotes malignant B cell activation. Therefore, our studies identify a novel molecular mechanism of regulation of CD40L by the transcription factor GLI2 in the tumor microenvironment downstream of CCR3 signaling.

Advances in the pathophysiology and treatment of relapsed/refractory Hodgkin's lymphoma with an emphasis on targeted therapies and transplantation strategies

Hodgkin’s lymphoma (HL) is highly curable with first-line therapy. However, a minority of patients present with refractory disease or experience relapse after completion of frontline treatment. These patients are treated with salvage chemotherapy followed by autologous stem cell transplantation (ASCT), which remains the standard of care with curative potential for refractory or relapsed HL. Nevertheless, a significant percentage of such patients will progress after ASCT, and allogeneic hematopoietic stem cell transplantation remains the only curative approach in that setting. Recent advances in the pathophysiology of refractory or relapsed HL have provided the rationale for the development of novel targeted therapies with potent anti-HL activity and favorable toxicity profile, in contrast to cytotoxic chemotherapy. Brentuximab vedotin and programmed cell death-1-based immunotherapy have proven efficacy in the management of refractory or relapsed HL, whereas several other agents have shown promise in early clinical trials. Several of these agents are being incorporated with transplantation strategies in order to improve the outcomes of refractory or relapsed HL. In this review we summarize the current knowledge regarding the mechanisms responsible for the development of refractory/relapsed HL and the outcomes with current treatment strategies, with an emphasis on targeted therapies and hematopoietic stem cell transplantation.

The role of T cells in the microenvironment of Hodgkin lymphoma

The cellular microenvironment in HL is dominated by a mixed infiltrate of inflammatory cells with typically only 1 or a few percent of HRS tumor cells. HRS cells orchestrate this infiltrate by the secretion of a multitude of chemokines. T cells are usually the largest population of cells in the HL tissue, encompassing Th cells, T(regs), and CTLs. Th cells and T(regs) presumably provide essential survival signals for the HRS cells, and the T(regs) also play an important role in rescuing HRS cells from an attack by CTLs and NK cells. The interference with this complex interplay of HRS cells with other immune cells in the microenvironment may provide novel strategies for targeted immunotherapies.

Serum levels of chemokines CCL4 and CCL5 in cirrhotic patients indicate the presence of hepatocellular carcinoma

BACKGROUND

Most hepatocellular carcinomas (HCCs) are diagnosed at an advanced stage. The prognostic value of serum tumour markers alpha-fetoprotein (AFP) and des-gamma-carboxy prothrombin (DCP) is limited. The aim of our study is to evaluate the diagnostic value of serum growth factors, apoptotic and inflammatory mediators of cirrhotic patients with and without HCC.

METHODS

Serum samples were collected from cirrhotic potential liver transplant patients (LTx) with (n=61) and without HCC (n=78) as well as from healthy controls (HCs; n=39). Serum concentrations of CRP, neopterin and IL-6 as markers of inflammation and thrombopoietin (TPO), GCSF, FGF basic and VEGF, HMGB1, CK-18 (M65) and CK18 fragment (M30) and a panel of proinflammatory chemokines (CCL2, CCL3, CCL4, CCL5, CXCL5 and IL-8) were measured. Chi square, Fisher exact, Mann-Whitney U-tests, ROC curve analysis and forward stepwise logistic regression analyses were applied.

RESULTS

Patients with HCC had higher serum TPO and chemokines (P<0.001 for TPO, CCL4, CCL5 and CXCL5) and lower CCL2 (P=0.008) levels than cirrhotic patients without HCC. Multivariate forward stepwise regression analysis for significant parameters showed that among the studied parameters CCL4 and CCL5 (P=0.001) are diagnostic markers of HCC. Serum levels of TPO and chemokines were lower, whereas M30 was significantly higher in cirrhotic patients than in HCs.

CONCLUSIONS

High serum levels of inflammatory chemokines such as CCL4 and CCL5 in the serum of cirrhotic patients indicate the presence of HCC.

Microenvironment abnormalities and lymphomagenesis: Immunological aspects

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

Lymphomagenesis in Hodgkin lymphoma

Hodgkin lymphoma (HL) accounts for approximately 0.6% of all new cancer cases, 10% of all lymphomas in the USA, leading to an approximate 9000 new cases per year. It is very unique in that the neoplastic Hodgkin and Reed-Sternberg (HRS) cells of classical HL account for only 1% of the tumor tissue in most cases, with various inflammatory cells including B-cells, T-cells, mast cells, macrophages, eosinophils, neutrophils, and plasma cells comprising the tumor microenvironment. Recent research has identified germinal center B-cells to be the cellular origin of HRS cells. Various transcription factor dysregulation in these neoplastic cells that explains for the loss of B-cell phenotype as well as acquisition of survival and anti-apoptotic features of HRS cells has been identified. Aberrant activation of nuclear factor-kappa B (NF-κB), Janus kinase (JAK)/signal transducer and activator of transcription (STAT), and phosphoinositide 3-kinase (PI3K) pathways play a central role in HL pathogenesis. Both intrinsic genetic mechanisms as well as extrinsic signals have been identified to account for the constitutive activation of these pathways. The extrinsic factors that regulate the activation of transcription pathways in HRS cells have also been studied in detail. Cytokines and chemokines produced both by the HRS cells as well as cells of the microenvironment of HL work in an autocrine and/or paracrine manner to promote survival of HRS cells as well as providing mechanisms for immune escape from the body's antitumor immunity. The understanding of various mechanisms involved in the lymphomagenesis of HL including the importance of its microenvironment has gained much interest in the use of these microenvironmental features as prognostic markers as well as potential treatment targets. In this article, we will review the pathogenesis of HL starting with the cellular origin of neoplastic cells and the mechanisms supporting its pathogenesis, especially focusing on the microenvironment of HL and its associated cytokines.

New antibody approaches to lymphoma therapy

The CD20-directed monoclonal antibody rituximab established a new era in lymphoma therapy. Since then other epitopes on the lymphoma surface have been identified as potential targets for monoclonal antibodies (mAb). While most mAbs eliminate lymphoma cells mainly by antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity or direct cell death, others counter mechanisms utilized by malignant cells to evade immune surveillance. Expression of PD-L1 on malignant or stromal cells in the tumor environment for example leads to T-cell anergy. Targeting either PD-1 or PD-L1 via mAbs can indirectly eliminate cancer cells by unblocking the host intrinsic immune response. Yet another mechanism of targeted therapy with mAbs are bi-specific T-cell engagers (BiTE) such as blinatumomab, which directly engages the host immune cells. These examples highlight the broad spectrum of available therapies targeting the lymphoma surface with mAbs utilizing both passive and active immune pathways. Many of these agents have already demonstrated significant activity in clinical trials. In this review we will focus on novel CD20-directed antibodies as well as mAbs directed against newer targets like CD19, CD22, CD40, CD52 and CCR4. In addition we will review mAbs unblocking immune checkpoints and the BiTE blinatumomab. Given the success of mAbs and the expansion in active and passive immunotherapies, these agents will play an increasing role in the treatment of lymphomas.

Customized targeted therapy in Hodgkin lymphoma: hype or hope?

Although most patients with Hodgkin lymphoma (HL) are cured with primary therapy, patients with primary refractory disease or relapse after initial treatment have poor outcomes and represent an unmet medical need. Recent advances in unraveling the biology of HL have yielded a plethora of novel targeted therapies. This review provides an overview of the data behind the hype generated by these advances and addresses the question of whether or not clinically these targeted therapies offer hope for patients with HL.

The inflammatory chemokine CCL5 and cancer progression

Until recently, inflammatory chemokines were viewed mainly as indispensable “gate keepers” of immunity and inflammation. However, updated research indicates that cancer cells subvert the normal chemokine system and these molecules and their receptors become important constituents of the tumor microenvironment with very different ways to exert tumor-promoting roles. The CCR5 and the CCL5 ligand have been detected in some hematological malignancies, lymphomas, and a great number of solid tumors, but extensive studies on the role of the CCL5/CCR axis were performed only in a limited number of cancers. This review summarizes updated information on the role of CCL5 and its receptor CCR5 in cancer cell proliferation, metastasis, and the formation of an immunosuppressive microenvironment and highlights the development of newer therapeutic strategies aimed to inhibit the binding of CCL5 to CCR5, to inhibit CCL5 secretion, or to inhibit the interactions among tumor cells and the microenvironment leading to CCL5 secretion.

The EBV oncogene LMP1 protects lymphoma cells from cell death through the collagen-mediated activation of DDR1

Expression of the EBV oncogene LMP1 in primary human germinal center B cells, upregulates DDR1, a receptor tyrosine kinase activated by collagen Primary HRS cells overexpress DDR1, and its activation significantly increases lymphoma cell survival in vitro

Phase IA/II, multicentre, open-label study of the CD40 antagonistic monoclonal antibody lucatumumab in adult patients with advanced non-Hodgkin or Hodgkin lymphoma

Despite advancements in the treatment of non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL), patients continue to relapse and thus a need for new targeted therapies remains. The CD40 receptor is highly expressed on neoplastic B cells and activation leads to enhanced proliferation and survival. Lucatumumab (HCD122) is a fully human antagonistic CD40 monoclonal antibody. A phase IA/II study was designed to determine the maximum tolerated dose (MTD) and activity of lucatumumab in patients with relapsed/refractory lymphoma. Determination of the MTD was the primary objective of the phase IA dose escalation portion and clinical response was the primary objective of the phase II dose expansion portion. Patients received escalating doses of lucatumumab administered intravenously once weekly for 4 weeks of an 8-week cycle. MTD was determined at 4 mg/kg of lucatumumab. A total of 111 patients with NHL (n = 74) and HL (n = 37) were enrolled. Responses were observed across various lymphoma subtypes. The overall response rate by computed tomography among patients with follicular lymphoma (FL) and marginal zone lymphoma of mucosa-associated lymphatic tissue (MZL/MALT) was 33·3% and 42·9%, respectively. Lucatumumab demonstrates modest activity in relapsed/refractory patients with advanced lymphoma, suggesting that targeting of CD40 warrants further investigation.

Effects of CD40 ligation combined with chemotherapy drugs on human breast cancer cell lines

OBJECTIVE

To investigate the influence of recombinant human CD40 ligand (rhCD40L) on the biological behaviour of breast cancer cells.

METHODS

MDA-MB-23l and MDA-MB-435 treated with rhCD40L were observed for changes in the cell cycle, in membrane proteins, and in mRNA levels of B cell lymphoma-extra-large (Bcl-xl), Bcl-2 associated X protein (Bax) and regulated upon activation, normal T cell expressed and secreted (RANTES). Effects of rhCD40L on cell proliferation in the presence or absence of interferon (IFN)-γ (500 IU/ml) and/or doxorubicin (20 ng/ml) were also determined.

RESULTS

rhCD40L dose-dependently inhibited cell proliferation. Combination of rhCD40L with IFN-γ or doxorubicin potentiated the inhibitory activity. After treatment, an increase in cells entering the G₁ phase of the cell cycle was observed, with a significant decrease in the number entering the S phase. Levels of several membrane proteins including CD95L and CD120a were also increased. Reverse transcription-polymerase chain reaction revealed an increase in the Bax/Bcl-xl mRNA ratio and an increase in RANTES.

CONCLUSION

rhCD40L treatment of breast cancer cells mediates a variety of anti-tumour effects, not only by direct cytotoxic activity but also by upregulation of adhesion molecules, co-stimulators and cytokines to rectify T cell immunity.

Role of immune escape mechanisms in Hodgkin's lymphoma development and progression: a whole new world with therapeutic implications

Hodgkin's lymphoma represents one of the most frequent lymphoproliferative syndromes, especially in young population. Although HL is considered one of the most curable tumors, a sizeable fraction of patients recur after successful upfront treatment or, less commonly, are primarily resistant. This work tries to summarize the data on clinical, histological, pathological, and biological factors in HL, with special emphasis on the improvement of prognosis and their impact on therapeutical strategies. The recent advances in our understanding of HL biology and immunology show that infiltrated immune cells and cytokines in the tumoral microenvironment may play different functions that seem tightly related with clinical outcomes. Strategies aimed at interfering with the crosstalk between tumoral Reed-Sternberg cells and their cellular partners have been taken into account in the development of new immunotherapies that target different cell components of HL microenvironment. This new knowledge will probably translate into a change in the antineoplastic treatments in HL in the next future and hopefully will increase the curability rates of this disease.