The immune checkpoint adenosine 2A receptor is associated with aggressive clinical outcomes and reflects an immunosuppressive tumor microenvironment in human breast cancer

Background

The crosstalk between the immune system and cancer cells has aroused considerable interest over the past decades. To escape immune surveillance cancer cells evolve various strategies orchestrating tumor microenvironment. The discovery of the inhibitory immune checkpoints was a major breakthrough due to their crucial contribution to immune evasion. The A2AR receptor represents one of the most essential pathways within the TME. It is involved in several processes such as hypoxia, tumor progression, and chemoresistance. However, its clinical and immunological significance in human breast cancer remains elusive.

Methods

The mRNA expression and protein analysis were performed by RT-qPCR and immunohistochemistry. The log-rank (Mantel-Cox) test was used to estimate Kaplan-Meier analysis for overall survival. Using large-scale microarray data (METABRIC), digital cytometry was conducted to estimate cell abundance. Analysis was performed using RStudio software (7.8 + 2023.03.0) with EPIC, CIBERSORT, and ImmuneCellAI algorithms. Tumor purity, stromal and immune scores were calculated using the ESTIMATE computational method. Finally, analysis of gene set enrichment (GSEA) and the TISCH2 scRNA-seq database were carried out.

Results

Gene and protein analysis showed that A2AR was overexpressed in breast tumors and was significantly associated with high grade, elevated Ki-67, aggressive molecular and histological subtypes, as well as poor survival. On tumor infiltrating immune cells, A2AR was found to correlate positively with PD-1 and negatively with CTLA-4. On the other hand, our findings disclosed more profuse infiltration of protumoral cells such as M0 and M2 macrophages, Tregs, endothelial and exhausted CD8+ T cells within A2ARhigh tumors. According to the Single-Cell database, A2AR is expressed in malignant, stromal and immune cells. Moreover, it is related to tumor purity, stromal and immune scores. Our results also revealed that CD8+T cells from A2ARhigh patients exhibited an exhausted functional profile. Finally, GSEA analysis highlighted the association of A2AR with biological mechanisms involved in tumor escape and progression.

Conclusion

The present study is the first to elucidate the clinical and immunological relevance of A2AR in breast cancer patients. In light of these findings, A2AR could be deemed a promising therapeutic target to overcome immune evasion prevailing within the TME of breast cancer patients.

Monocytic MDSCs exhibit superior immune suppression via adenosine and depletion of adenosine improves efficacy of immunotherapy

Immune checkpoint inhibitor (ICI) therapy is effective against many cancers for a subset of patients; a large percentage of patients remain unresponsive to this therapy. One contributing factor to ICI resistance is accumulation of monocytic myeloid-derived suppressor cells (M-MDSCs), a subset of innate immune cells with potent immunosuppressive activity against T lymphocytes. Here, using lung, melanoma, and breast cancer mouse models, we show that CD73-expressing M-MDSCs in the tumor microenvironment (TME) exhibit superior T cell suppressor function. Tumor-derived PGE2, a prostaglandin, directly induces CD73 expression in M-MDSCs via both Stat3 and CREB. The resulting CD73 overexpression induces elevated levels of adenosine, a nucleoside with T cell-suppressive activity, culminating in suppression of antitumor CD8+ T cell activity. Depletion of adenosine in the TME by the repurposed drug PEGylated adenosine deaminase (PEG-ADA) increases CD8+ T cell activity and enhances response to ICI therapy. Use of PEG-ADA can therefore be a therapeutic option to overcome resistance to ICIs in cancer patients.

Emerging therapeutic strategies for enhancing sensitivity and countering resistance to programmed cell death protein 1 or programmed death-ligand 1 inhibitors in non-small cell lung cancer

The availability of agents targeting the programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) immune checkpoint has transformed treatment of advanced and/or metastatic non-small cell lung cancer (NSCLC). However, a substantial proportion of patients treated with these agents do not respond or experience only a brief period of clinical benefit. Even among those whose disease responds, many subsequently experience disease progression. Consequently, novel approaches are needed that enhance antitumor immunity and counter resistance to PD-(L)1 inhibitors, thereby improving and/or prolonging responses and patient outcomes, in both PD-(L)1 inhibitor-sensitive and inhibitor-resistant NSCLC. Mechanisms contributing to sensitivity and/or resistance to PD-(L)1 inhibitors in NSCLC include upregulation of other immune checkpoints and/or the presence of an immunosuppressive tumor microenvironment, which represent potential targets for new therapies. This review explores novel therapeutic regimens under investigation for enhancing responses to PD-(L)1 inhibitors and countering resistance, and summarizes the latest clinical evidence in NSCLC.

Bintrafusp Alfa, a Bifunctional Fusion Protein Targeting TGF-β and PD-L1, in Patients With Non-Small Cell Lung Cancer Resistant or Refractory to Immune Checkpoint Inhibitors

BACKGROUND

Bintrafusp alfa is a first-in-class bifunctional fusion protein composed of the extracellular domain of transforming growth factor beta receptor II (a TGF-β "trap") fused to a human immunoglobulin G1 monoclonal antibody blocking programmed cell death 1 ligand 1 (PD-L1). We report the efficacy and safety in patients with non-small cell lung cancer (NSCLC) that progressed following anti-PD-(L)1 therapy.

MATERIALS AND METHODS

In this expansion cohort of NCT02517398-a global, open-label, phase I trial-adults with advanced NSCLC that progressed following chemotherapy and was primary refractory or had acquired resistance to anti-PD-(L)1 treatment received intravenous bintrafusp alfa 1200 mg every 2 weeks until confirmed progression, unacceptable toxicity, or trial withdrawal. The primary endpoint was best overall response (by Response Evaluation Criteria in Solid Tumors version 1.1 adjudicated by independent review committee); secondary endpoints included safety.

RESULTS

Eighty-three eligible patients (62 [74.7%] treated with ≥3 prior therapies) received bintrafusp alfa. Four patients (3 primary refractory, 1 acquired resistant) had confirmed partial responses (objective response rate, 4.8%; 95% CI, 1.3%-11.9%), and 9 had stable disease. Tumor cell PD-L1 expression was not associated with response. Nineteen patients (22.9%) experienced grade ≥3 treatment-related adverse events, most commonly asthenia (3 [3.6%]) and fatigue, eczema, and pruritus (2 each [2.4%]). One patient had grade 4 amylase increased. One patient died during treatment for pneumonia before initiation of bintrafusp alfa.

CONCLUSION

Although the primary endpoint was not met, bintrafusp alfa showed some clinical activity and a manageable safety profile in patients with heavily pretreated NSCLC, including prior anti-PD-(L)1 therapy. Tumor responses occurred irrespective of whether disease was primary refractory or had acquired resistance to prior anti-PD-(L)1 therapy.

At the crossroads of immunotherapy for oncogene-addicted subsets of NSCLC

Non-small-cell lung cancer (NSCLC) has become a paradigm of precision medicine, with the discovery of numerous disease subtypes defined by specific oncogenic driver mutations leading to the development of a range of molecularly targeted therapies. Over the past decade, rapid progress has also been made in the development of immune-checkpoint inhibitors (ICIs), especially antagonistic antibodies targeting the PD-L1-PD-1 axis, for the treatment of NSCLC. Although many of the major oncogenic drivers of NSCLC are associated with intrinsic resistance to ICIs, patients with certain oncogene-driven subtypes of the disease that are highly responsive to specific targeted therapies might also derive benefit from immunotherapy. However, the development of effective immunotherapy approaches for oncogene-addicted NSCLC has been challenged by a lack of predictive biomarkers for patient selection and limited knowledge of how ICIs and oncogene-directed targeted therapies should be combined. Therefore, whether ICIs alone or with chemotherapy or even in combination with molecularly targeted agents would offer comparable benefit in the context of selected oncogenic driver alterations to that observed in the general unselected NSCLC population remains an open question. In this Review, we discuss the effects of oncogenic driver mutations on the efficacy of ICIs and the immune tumour microenvironment as well as the potential vulnerabilities that could be exploited to overcome the challenges of immunotherapy for oncogene-addicted NSCLC.

Metabolic modulation of immune checkpoints and novel therapeutic strategies in cancer

Cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) or programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1)-based immune checkpoint inhibitors (ICIs) have led to significant improvements in the overall survival of patients with certain cancers and are expected to benefit patients by achieving complete, long-lasting remissions and cure. However, some patients who receive ICIs either fail treatment or eventually develop immunotherapy resistance. The existence of such patients necessitates a deeper understanding of cancer progression, specifically nutrient regulation in the tumor microenvironment (TME), which includes both metabolic cross-talk between metabolites and tumor cells, and intracellular metabolism in immune and cancer cells. Here we review the features and behaviors of the TME and discuss the recently identified major immune checkpoints. We comprehensively and systematically summarize the metabolic modulation of tumor immunity and immune checkpoints in the TME, including glycolysis, amino acid metabolism, lipid metabolism, and other metabolic pathways, and further discuss the potential metabolism-based therapeutic strategies tested in preclinical and clinical settings. These findings will help to determine the existence of a link or crosstalk between tumor metabolism and immunotherapy, which will provide an important insight into cancer treatment and cancer research.

Immunoregulatory signal networks and tumor immune evasion mechanisms: insights into therapeutic targets and agents in clinical development

Through activation of immune cells, the immune system is responsible for identifying and destroying infected or otherwise damaged cells including tumorigenic cells that can be recognized as foreign, thus maintaining homeostasis. However, tumor cells have evolved several mechanisms to avoid immune cell detection and killing, resulting in tumor growth and progression. In the tumor microenvironment, tumor infiltrating immune cells are inactivated by soluble factors or tumor promoting conditions and lose their effects on tumor cells. Analysis of signaling and crosstalk between immune cells and tumor cells have helped us to understand in more detail the mechanisms of tumor immune evasion and this forms basis for drug development strategies in the area of cancer immunotherapy. In this review, we will summarize the dominant signaling networks involved in immune escape and describe the status of development of therapeutic strategies to target tumor immune evasion mechanisms with focus on how the tumor microenvironment interacts with T cells.

Emerging strategies in targeting tumor-resident myeloid cells for cancer immunotherapy

Immune checkpoint inhibitors targeting programmed cell death protein 1, programmed death-ligand 1, and cytotoxic T-lymphocyte-associated protein 4 provide deep and durable treatment responses which have revolutionized oncology. However, despite over 40% of cancer patients being eligible to receive immunotherapy, only 12% of patients gain benefit. A key to understanding what differentiates treatment response from non-response is better defining the role of the innate immune system in anti-tumor immunity and immune tolerance. Teleologically, myeloid cells, including macrophages, dendritic cells, monocytes, and neutrophils, initiate a response to invading pathogens and tissue repair after pathogen clearance is successfully accomplished. However, in the tumor microenvironment (TME), these innate cells are hijacked by the tumor cells and are imprinted to furthering tumor propagation and dissemination. Major advancements have been made in the field, especially related to the heterogeneity of myeloid cells and their function in the TME at the single cell level, a topic that has been highlighted by several recent international meetings including the 2021 China Cancer Immunotherapy workshop in Beijing. Here, we provide an up-to-date summary of the mechanisms by which major myeloid cells in the TME facilitate immunosuppression, enable tumor growth, foster tumor plasticity, and confer therapeutic resistance. We discuss ongoing strategies targeting the myeloid compartment in the preclinical and clinical settings which include: (1) altering myeloid cell composition within the TME; (2) functional blockade of immune-suppressive myeloid cells; (3) reprogramming myeloid cells to acquire pro-inflammatory properties; (4) modulating myeloid cells via cytokines; (5) myeloid cell therapies; and (6) emerging targets such as Siglec-15, TREM2, MARCO, LILRB2, and CLEVER-1. There is a significant promise that myeloid cell-based immunotherapy will help advance immuno-oncology in years to come.

The Purinergic Landscape of Non-Small Cell Lung Cancer

Lung cancer is the most common cancer worldwide. Despite recent therapeutic advances, including targeted therapies and immune checkpoint inhibitors, the disease progresses in almost all advanced lung cancers and in up to 50% of early-stage cancers. The purpose of this review is to discuss whether purinergic checkpoints (CD39, CD73, P2RX7, and ADORs), which shape the immune response in the tumor microenvironment, may represent novel therapeutic targets to combat progression of non-small cell lung cancer by enhancing the antitumor immune response.

Clinical definition of acquired resistance to immunotherapy in patients with metastatic non-small-cell lung cancer

Acquired resistance (AR) to programmed cell death protein 1/programmed death-ligand 1 [PD-(L)1] blockade is frequent in non-small-cell lung cancer (NSCLC), occurring in a majority of initial responders. Patients with AR may have unique properties of persistent antitumor immunity that could be re-harnessed by investigational immunotherapies. The absence of a consistent clinical definition of AR to PD-(L)1 blockade and lack of uniform criteria for ensuing enrollment in clinical trials remains a major barrier to progress; such clinical definitions have advanced biologic and therapeutic discovery. We examine the considerations and potential controversies in developing a patient-level definition of AR in NSCLC treated with PD-(L)1 blockade. Taking into account the specifics of NSCLC biology and corresponding treatment strategies, we propose a practical, clinical definition of AR to PD-(L)1 blockade for use in clinical reports and prospective clinical trials. Patients should meet the following criteria: received treatment that includes PD-(L)1 blockade; experienced objective response on PD-(L)1 blockade (inclusion of a subset of stable disease will require future investigation); have progressive disease occurring within 6 months of last anti-PD-(L)1 antibody treatment or rechallenge with anti-PD-(L)1 antibody in patients not exposed to anti-PD-(L)1 in 6 months.

From Bench to Bedside: How the Tumor Microenvironment Is Impacting the Future of Immunotherapy for Renal Cell Carcinoma

Immunotherapy has revolutionized the treatment landscape for many cancer types. The treatment for renal cell carcinoma (RCC) has especially evolved in recent years, from cytokine-based immunotherapies to immune checkpoint inhibitors. Although clinical benefit from immunotherapy is limited to a subset of patients, many combination-based approaches have led to improved outcomes. The success of such approaches is a direct result of the tumor immunology knowledge accrued regarding the RCC microenvironment, which, while highly immunogenic, demonstrates many unique characteristics. Ongoing translational work has elucidated some of the mechanisms of response, as well as primary and secondary resistance, to immunotherapy. Here, we provide a comprehensive review of the RCC immunophenotype with a specific focus on how preclinical and clinical data are shaping the future of immunotherapy.

Novel classes of immunotherapy for breast cancer

Immune-checkpoint inhibitors have profoundly changed the treatment landscape for many tumor types. Despite marked improvements in disease control for highly immunogenic cancers, the clinical impact of checkpoint inhibitors in breast cancers to date is limited. Breast cancer is a heterogeneous disease with different levels of PD-L1 expression and variable tumor microenvironment (TME) composition according to molecular subtype. With emerging evidence of the role of different factors involved in immune evasion, there are promising new immunotherapy targets that will reshape early drug development for metastatic breast cancer. This review examines the available evidence for existing and emerging immuno-oncology (IO) approaches including small molecules targeting different regulators of the cancer-immunity cycle.

Clinical Perspectives to Overcome Acquired Resistance to Anti-Programmed Death-1 and Anti-Programmed Death Ligand-1 Therapy in Non-Small Cell Lung Cancer

Immune checkpoint inhibitors have changed the paradigm of treatment options for non-small cell lung cancer (NSCLC). Monoclonal antibodies targeting programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) have gained wide attention for their application, which has been shown to result in prolonged survival. Nevertheless, only a limited subset of patients show partial or complete response to PD-1 therapy, and patients who show a response eventually develop resistance to immunotherapy. This article aims to provide an overview of the mechanisms of acquired resistance to anti-PD-1/PD-L1 therapy from the perspective of tumor cells and the surrounding microenvironment. In addition, we address the potential therapeutic targets and ongoing clinical trials, focusing mainly on NSCLC.

Novel combinatorial strategies for boosting the efficacy of immune checkpoint inhibitors in advanced breast cancers

The year 2019 witnessed the first approval of an immune checkpoint inhibitor (ICI) for the management of triple negative breast cancers (TNBC) that are metastatic and programmed death ligand (PD)-L1 positive. Extensive research has focused on testing ICI-based combinatorial strategies, with the ultimate goal of enhancing the response of breast tumors to immunotherapy to increase the number of breast cancer patients benefiting from this transformative treatment. The promising investigational strategies included immunotherapy combinations with monoclonal antibodies (mAbs) against human epidermal growth factor receptor (HER)-2 for the HER2 + tumors versus cyclin-dependent kinase (CDK)4/6 inhibitors in the estrogen receptor (ER) + disease. Multiple approaches are showing signals of success in advanced TNBC include employing Poly (ADP-ribose) polymerase (PARP) inhibitors, tyrosine kinase inhibitors, MEK inhibitors, phosphatidylinositol 3‑kinase (PI3K)/protein kinase B (AKT) signaling inhibitors or inhibitors of adenosine receptor, in combination with the classical PD-1/PD-L1 immune checkpoint inhibitors. Co-treatment with chemotherapy, high intensity focused ultrasound (HIFU) or interleukin-2-βɣ agonist have also produced promising outcomes. This review highlights the latest combinatorial strategies under development for overcoming cancer immune evasion and enhancing the percentage of immunotherapy responders in the different subsets of advanced breast cancers.

Roles of the Dynamic Tumor Immune Microenvironment in the Individualized Treatment of Advanced Clear Cell Renal Cell Carcinoma

Immune checkpoint inhibitors (ICIs) are currently a first-line treatment option for clear cell renal cell carcinoma (ccRCC). However, recent clinical studies have shown that a large number of patients do not respond to ICIs. Moreover, only a few patients achieve a stable and durable response even with combination therapy based on ICIs. Available studies have concluded that the response to immunotherapy and targeted therapy in patients with ccRCC is affected by the tumor immune microenvironment (TIME), which can be manipulated by targeted therapy and tumor genomic characteristics. Therefore, an in-depth understanding of the dynamic nature of the TIME is important for improving the efficacy of immunotherapy or combination therapy in patients with advanced ccRCC. Here, we explore the possible mechanisms by which the TIME affects the efficacy of immunotherapy and targeted therapy, as well as the factors that drive dynamic changes in the TIME in ccRCC, including the immunomodulatory effect of targeted therapy and genomic changes. We also describe the progress on novel therapeutic modalities for advanced ccRCC based on the TIME. Overall, this review provides valuable information on the optimization of combination therapy and development of individualized therapy for advanced ccRCC.

Immune and metabolic checkpoints blockade: Dual wielding against tumors

Recent advances in cancer immunotherapy have raised hopes for treating cancers that are resistant to conventional therapies. Among the various immunotherapy methods, the immune checkpoint (IC) blockers were more promising and have paved their way to the clinic. Tumor cells induce the expression of ICs on the immune cells and derive them to a hyporesponsive exhausted phenotype. IC blockers could hinder immune exhaustion in the tumor microenvironment and reinvigorate immune cells for an efficient antitumor response. Despite the primary success of IC blockers in the clinic, the growing numbers of refractory cases require an in-depth study of the cellular and molecular mechanisms underlying IC expression and function. Immunometabolism is recently found to be a key factor in the regulation of immune responses. Activated or exhausted immune cells exploit different metabolic pathways. Tumor cells can suppress antitumor responses via immunometabolism alteration. Therefore, it is expected that concurrent targeting of ICs and immunometabolism pathways can cause immune cells to restore their antitumor activity. In this review, we dissected the reciprocal interactions of immune cell metabolism with expression and signaling of ICs in the tumor microenvironment. Recent findings on dual targeting of ICs and metabolic checkpoints have also been discussed.

Update of early phase clinical trials in cancer immunotherapy

Immunotherapy has revolutionized the landscape of cancer treatment and become a standard pillar of the treatment. The two main drivers, immune checkpoint inhibitors and chimeric antigen receptor T cells, contributed to this unprecedented success. However, despite the striking clinical improvements, most patients still suffer from disease progression because of the evolution of primary or acquired resistance. This mini-review summa-rizes new treatment options including novel targets and interesting combinational approaches to increase our understanding of the mechanisms of the action of and resistance to immunotherapy, to expand our knowledge of advances in biomarker and therapeutics development, and to help to find the most appropriate option or a way of overcoming the resistance for cancer patients.

Update of early phase clinical trials in cancer immunotherapy

Immunotherapy has revolutionized the landscape of cancer treatment and become a standard pillar of the treatment. The two main drivers, immune checkpoint inhibitors and chimeric antigen receptor T cells, contributed to this unprecedented success. However, despite the striking clinical improvements, most patients still suffer from disease progression because of the evolution of primary or acquired resistance. This mini-review summarizes new treatment options including novel targets and interesting combinational approaches to increase our understanding of the mechanisms of the action of and resistance to immunotherapy, to expand our knowledge of advances in biomarker and therapeutics development, and to help to find the most appropriate option or a way of overcoming the resistance for cancer patients. [BMB Reports 2021; 54(1): 70-88].

Myeloid Cells as Clinical Biomarkers for Immune Checkpoint Blockade

Immune checkpoint inhibitors are becoming standard treatments in several cancer types, profoundly changing the prognosis of a fraction of patients. Currently, many efforts are being made to predict responders and to understand how to overcome resistance in non-responders. Given the crucial role of myeloid cells as modulators of T effector cell function in tumors, it is essential to understand their impact on the clinical outcome of immune checkpoint blockade and on the mechanisms of immune evasion. In this review we focus on the existing clinical evidence of the relation between the presence of myeloid cell subsets and the response to anti-PD(L)1 and anti-CTLA-4 treatment. We highlight how circulating and tumor-infiltrating myeloid populations can be used as predictive biomarkers for immune checkpoint inhibitors in different human cancers, both at baseline and on treatment. Moreover, we propose to follow the dynamics of myeloid cells during immunotherapy as pharmacodynamic biomarkers. Finally, we provide an overview of the current strategies tested in the clinic that use myeloid cell targeting together with immune checkpoint blockade with the aim of uncovering the most promising approaches for effective combinations.

Targeting Immunometabolism Mediated by CD73 Pathway in EGFR-Mutated Non-small Cell Lung Cancer: A New Hope for Overcoming Immune Resistance

Despite the relevant antitumor efficacy of immunotherapy in advanced non-small cell lung cancer (NSCLC), the results in patients whose cancer harbors activating epidermal growth factor receptor (EGFR) mutations are disappointing. The biological mechanisms underlying immune escape and both unresponsiveness and resistance to immunotherapy in EGFR-mutant NSCLC patients have been partially investigated. To this regard, lung cancer immune escape largely involves high amounts of adenosine within the tumor milieu with broad immunosuppressive effects. Indeed, besides immune checkpoint receptors and their ligands, other mechanisms inducing immunosuppression and including adenosine produced by ecto-nucleotidases CD39 and CD73 contribute to lung tumorigenesis and progression. Here, we review the clinical results of immune checkpoint inhibitors in EGFR-mutant NSCLC, focusing on the dynamic immune composition of EGFR-mutant tumor microenvironment. The adenosine pathway-mediated dysregulation of energy metabolism in tumor microenvironment is suggested as a potential mechanism involved in the immune escape process. Finally, we report the strong rationale for planning strategies of combination therapy with immune checkpoints blockade and adenosine signaling inhibition to overcome immune escape and immunotherapy resistance in EGFR-mutated NSCLC.

Manipulation of Metabolic Pathways and Its Consequences for Anti-Tumor Immunity: A Clinical Perspective

In the relatively short history of anti-tumor treatment, numerous medications have been developed against a variety of targets. Intriguingly, although many anti-tumor strategies have failed in their clinical trials, metformin, an anti-diabetic medication, demonstrated anti-tumor effects in observational studies and even showed its synergistic potential with immune checkpoint inhibitors (ICIs) in subsequent clinical studies. Looking back from bedside-to-bench, it may not be surprising that the anti-tumor effect of metformin derives largely from its ability to rewire aberrant metabolic pathways within the tumor microenvironment. As one of the most promising breakthroughs in oncology, ICIs were also found to exert their immune-stimulatory effects at least partly via rewiring metabolic pathways. These findings underscore the importance of correcting metabolic pathways to achieve sufficient anti-tumor immunity. Herein, we start by introducing the tumor microenvironment, and then we review the implications of metabolic syndrome and treatments for targeting metabolic pathways in anti-tumor therapies. We further summarize the close associations of certain aberrant metabolic pathways with impaired anti-tumor immunity and introduce the therapeutic effects of targeting these routes. Lastly, we go through the metabolic effects of ICIs and conclude an overall direction to manipulate metabolic pathways in favor of anti-tumor responses.

CD200 and CD200R1 are differentially expressed and have differential prognostic roles in non-small cell lung cancer

CD200, a member of the immunoglobulin superfamily, interacts with its receptor CD200R1 to modulate cancer immune microenvironments. Here, we explored the clinicopathological and prognostic implications of the CD200/CD200R1 axis in non-small-cell lung cancer (NSCLC) patients. We evaluated CD200/CD200R1 expression in the tumors and stroma of 632 NSCLC patients using immunohistochemistry. Associations between CD200/CD200R1 expression levels and clinicopathological data were analyzed. We also examined their expression in lung cancer cell lines. Changes in endogenous immune-related factors and cell proliferation were evaluated by CD200 and CD200R1 knockdown and CD200Fc fusion protein administration. CD200 expression was observed mainly in the tumor, and also in the stroma among a few cases, whereas CD200R1 expression was observed in both the tumor and stroma. High tumoral CD200 expression was significantly associated with female sex, never-smoking status, adenocarcinoma histology, EGFR mutation, and a low density of tumor-infiltrating lymphocytes. Meanwhile, high CD200R1 expression in the tumor and stroma was associated with ever smoking, non-adenocarcinoma histology, and increased tumor-infiltrating lymphocytes. High CD200R1 expression was associated with worse survival (log-rank, P <.001 for both tumor and stroma), whereas high CD200 expression was associated with better survival outcomes (log-rank, P <.001). The transient knockdown of CD200R1 in lung cancer cell lines impaired cell proliferation, and the in vitro modulation of CD200 and CD200R1 altered endogenous oncogenic and inflammation-related gene expression. CD200R1 expression was associated with poor prognosis, whereas CD200 expression was an independent favorable prognostic factor. Our results suggest the importance of CD200 and CD200R1 in lung cancer biology.

Immune checkpoint inhibitors: The linchpins of modern immunotherapy

Immune checkpoint inhibitors (ICIs) have revolutionized our approach to cancer treatment in the past decade. While monoclonal antibodies to CTLA-4 and PD-1/PD-L1 have produced remarkable and durable responses in a subset of patients, the majority of patients will still develop primary or adaptive resistance. With complex mechanisms of resistance limiting the efficacy of checkpoint inhibitor monotherapy, it is critical to develop combination approaches to allow more patients to benefit from immunotherapy. In this review, I approach the current landscape of ICI research from the perspective of sarcomas, a rare group of bone and soft tissue cancers that have had limited benefit from checkpoint inhibitor monotherapy, and little investigation of biomarkers to predict responses. By surveying the various mechanisms of resistance and treatment modalities being explored in other solid tumors, I outline how ICIs will undoubtedly serve as the critical foundation for future directions in modern immunotherapy.

Towards individualized therapy for metastatic renal cell carcinoma

Over the past decade, the treatment landscape for patients with metastatic renal cell carcinoma (RCC) has evolved dramatically. The therapeutic options available have expanded and now include immune-checkpoint inhibitors, novel targeted agents and combination strategies, and thus optimal patient selection and treatment sequencing are increasingly pertinent for optimizing clinical outcomes. A better understanding of the underlying biology of the tumour and its microenvironment continues to drive the inception of new diagnostic and therapeutic approaches. Furthermore, many biomarkers robustly associated with treatment and disease-specific outcomes have been identified, and their integration into clinical decision-making for patients with advanced-stage disease will soon become a reality. Herein, we review relevant aspects of the molecular biology of metastatic RCC, with an emphasis on predictive and prognostic biomarkers, and suggest tailored algorithms to individualize and guide treatment approaches for specific subgroups of patients.

Immunity, Hypoxia, and Metabolism-the Ménage à Trois of Cancer: Implications for Immunotherapy

It is generally accepted that metabolism is able to shape the immune response. Only recently we are gaining awareness that the metabolic crosstalk between different tumor compartments strongly contributes to the harsh tumor microenvironment (TME) and ultimately impairs immune cell fitness and effector functions. The major aims of this review are to provide an overview on the immune system in cancer; to position oxygen shortage and metabolic competition as the ground of a restrictive TME and as important players in the anti-tumor immune response; to define how immunotherapies affect hypoxia/oxygen delivery and the metabolic landscape of the tumor; and vice versa, how oxygen and metabolites within the TME impinge on the success of immunotherapies. By analyzing preclinical and clinical endeavors, we will discuss how a metabolic characterization of the TME can identify novel targets and signatures that could be exploited in combination with standard immunotherapies and can help to predict the benefit of new and traditional immunotherapeutic drugs.

Detailed analysis of adenosine A2a receptor (ADORA2A) and CD73 (5'-nucleotidase, ecto, NT5E) methylation and gene expression in head and neck squamous cell carcinoma patients

Background: The adenosine A2a receptor (A2aR) and the adenosine synthesizing enzyme CD73 have recently evolved as a novel immunotherapeutic target. However, little is known about epigenetic modification of the encoding genes ADORA2A and NT5E. Methods: In the present study, we evaluated methylation at 23 loci of ADORA2A and 17 loci of NT5E with regard to transcriptional activity, human papilloma virus (HPV) status, immune cell infiltration, and outcome in a cohort of 279 head and neck squamous carcinoma (HNSCC) patients obtained from The Cancer Genome Atlas (TCGA). Methylation and mRNA expression were generated by the Infinium HumanMethylation450 BeadChip and Illumina HiSeq 2000 RNA Sequencing Version 2 analysis (Illumina, Inc., San Diego, CA, USA). HPV status was assessed by RNA-Seq data analysis of the viral genes E6 and E7. Results: Thirteen out of 23 ADORA2A loci and 15/17 NT5E loci were significantly correlated with mRNA levels (p < 0.05). Inverse correlations were predominately found in promoter regions, while positive correlations were more profound at intragenic loci. ADORA2A hypermethylation was significantly associated with poor overall survival (OS, p ≤ 0.030), whereas NT5E hypomethylation was associated with decreased OS in HPV-positive tumors (p ≤ 0.024) and increased OS in HPV-negative HNSCC (p ≤ 0.029). Further, we found significant correlations between methylation and immune cell infiltrates. Conclusion: Our data might point towards a significant role of the A2aR/CD73 axis during cancer progression in HNSCC.

Clinical and molecular features of innate and acquired resistance to anti-PD-1/PD-L1 therapy in lung cancer

Hypothesis

The majority of non-small cell lung cancer (NSCLC) patients treated with anti-PD-1/PD-L1 therapy develop either innate or acquired resistance. Across tumor types, the “T cell-inflamed” tumor microenvironment correlates with clinical response to immunotherapy. We hypothesize that clinical characteristics may be predictive of resistance and that “T cell-inflamed” NSCLC tumors can be identified by gene expression profiling.

Results

Of 93 patients, 36 (38.7%) had innate resistance and 57 (61.3%) had initial benefit to immunotherapy. Innate resistance was associated with non-smokers (p = 0.013), more involved disease sites (p = 0.011), more prior therapy (p = 0.001), and a lower albumin level (p = 0.014). Among patients with initial benefit, factors associated with subsequent progression-free survival included higher Karnofsky Performance Status (KPS) (p = 0.004) and lower depth of response to anti-PD-1 therapy (p = 0.003). A “T cell-inflamed” microenvironment was identified in 42% of TCGA adenocarcinoma samples versus 21.0% of squamous cell.

Discussion

Specific clinical characteristics appear to be predictive of either innate or acquired resistance to anti-PD-1/PD-L1 therapy. A “T cell-inflamed” tumor was more common in adenocarcinoma than squamous histology.

Methods

A retrospective review of NSCLC patients treated with anti-PD-1/PD-L1 monotherapy. Patients with innate resistance to anti-PD-1/PD-L1 therapy (defined as progression at first CT evaluation) were compared to patients with initial clinical benefit. Among those with initial clinical benefit, we identified prognostic factors for time to progression (acquired resistance) or death. To further corroborate our findings on limited numbers, immune gene expression profiling of all NSCLC samples from the TCGA database was also pursued.

Emerging immunotherapy in advanced renal cell carcinoma

Immunotherapy has recently catapulted to the forefront of treatments for patients with solid tumors. Given its inherent immunogenic properties, renal cell carcinoma (RCC) has historically responded to immunotherapy and remains primed for further development. Although immunotherapy with high-dose interleukin 2 was a primary treatment for advanced RCC (aRCC), recent discoveries of key molecular and immunological alterations have led to the FDA-approval of nivolumab, an antiprogrammed cell death inhibitor, which has demonstrated an overall survival in patients with previously treated aRCC. However, despite recent therapeutic advances, aRCC remains an incurable disease for most patients. In this review, we assess the current landscape and future developments of immunotherapy in aRCC.