Immunotherapy: Beyond Anti-PD-1 and Anti-PD-L1 Therapies

Computational analysis of whole slide images predicts PD-L1 expression and progression-free survival in immunotherapy-treated non-small cell lung cancer patients

BACKGROUND

Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment by significantly improving the efficacy of treatments and tolerability for patients with non-small cell lung cancer (NSCLC). However, even after meticulous selection based on molecular criteria, only 20-30% of the patients respond to ICIs. This highlights the urgent clinical need to develop more precise biomarkers to better identify individuals who will benefit from these expensive therapies.

METHODS

Data from NSCLC patients treated with immunotherapy were collected from two institutions. From the histological images of tumors, pathomics features were extracted. We employed six machine learning models and seven feature selection methods to predict expression of the programmed death-ligand 1 (PD-L1), a current biomarker used to select patients for immunotherapy, and progression-free survival (PFS). The association between pathomics features and biological pathways was explored to validate pathomics-based signatures. We performed gene set enrichment analysis to identify the pathways enriched with the predictive signatures.

RESULTS

Handcrafted histological features were extracted from the whole slide images (WSI). The Support Vector Machines model with the SurfStar feature selection method, offered the best results, with an area under the curve (AUC) of around 0.66 for both the training and validation sets to predict PD-L1. For the prediction of PFS, the most effective model was linear discriminant analysis using the Multi Surf feature selection method with an AUC of 0.71 for the training set and 0.62 for the validation set. We found immune pathways to be upregulated in the high PD-L1 and high PFS groups, confirming the utility of image analysis for predicting clinical endpoints in patients treated with immunotherapy.

CONCLUSION

Our models, based on the analysis of histological images, can serve as predictive biomarkers for PD-L1 and PFS. This approach, focused on histological images, enables the distinction of patients based on treatment response, thus providing clinicians with a valuable tool for patient management. With further validation on external cohorts, these models could enhance clinical decision-making through analysis of routine medical images.

Transmission of peripheral blood α-synuclein fibrils exacerbates synucleinopathy and neurodegeneration in Parkinson's disease by endothelial Lag3 endocytosis

Parkinson's disease (PD) is an age-related neurodegenerative disorder. The pathological feature of PD is abnormal α-synuclein (α-syn) formation and transmission. Recent evidence demonstrates that α-syn preformed fibrils (α-syn PFFs) can be detected in the serum of patients with PD. The peripheral blood α-syn PFF can cross the blood-brain barrier (BBB) and aggravate neuronal damage, but the mechanism remains to be elucidated. We constructed the PD mouse models of different severity: the mild pathology (A53T ONLY) and the severe pathology (A53T + Brain FIB); this was followed by α-syn PFFs intravenous injection. Then, we used endothelium-specific Lag3 knockout mice (Lag3-ECs-CKO) to decrease the blood α-syn PFFs spreading. We observed that intravenous transmission of α-syn PFFs significantly aggravated motor deficits, dopaminergic neuron loss, neuroinflammation, and pathologic α-syn deposition in A53T ONLY, but not in A53T + Brain FIB. Blocking endothelial Lag3 endocytosis by Lag3-ECs-CKO decreased the blood α-syn PFFs spreading and improved the symptoms and pathogenesis of PD mice. Our findings reveal the role of peripheral blood α-syn PFFs transmission in the mild pathology or early-stage PD and the mechanism of endothelial Lag3 endocytosis in the pathology of α-syn transmission. Targeting endothelial Lag3 to prevent α-syn from spreading from the blood to the brain may be a disease-modifying therapy in early-stage PD.NEW & NOTEWORTHY This study highlights the transmission mechanism of peripheral blood α-synuclein preformed fibrils (α-syn PFFs) through endothelial Lag3 endocytosis in the mild pathology or early-stage Parkinson's disease (PD). Targeting endothelial Lag3 as a perspective of decreasing peripheral blood α-syn PFFs transmission may be a disease-modifying therapy in early-stage PD.

Durvalumab and tremelimumab in patients with advanced rare cancer: a multi-centre, non-blinded, open-label phase II basket trial

Background

Dual inhibition of cytotoxic T-lymphocyte associated protein 4 (CTLA-4) and programmed death ligand 1 (PD-L1) has been shown to be an effective treatment strategy in many cancers. We sought to determine the objective response rate of combination durvalumab (D) plus tremelimumab (TM) in parallel cohorts of patients with carefully selected rare cancer types in which these agents had not previously been evaluated in phase II trials and for which there was clinical or biological rationale for dual immune checkpoint inhibitor therapy to be active.

Methods

We designed a multi-centre, non-blinded, open-label phase II basket trial with each of the following 8 rare cancers considered a separate phase II trial: salivary carcinoma, carcinoma of unknown primary (CUP) with tumour infiltrating lymphocytes and/or expressing PD-L1, mucosal melanoma, acral melanoma, osteosarcoma, undifferentiated pleomorphic sarcoma, clear cell carcinoma of the ovary (CCCO) or squamous cell carcinoma of the anal canal (SCCA). The primary objective was to evaluate the response rate of the combination of D and TM, and the secondary objectives were to evaluate the tolerability and safety of D and TM combination. Eligible patients had advanced, metastatic or recurrent, or unresectable cancer with no known life-prolonging treatment option, age ≥16 years, ECOG performance status 0 or 1. Patients received D (1500 mg IV) + TM (75 mg IV) on Day 1 q4 weeks for 4 cycles followed by D q4 weeks until disease progression. This trial is registered with ClinicalTrials.gov, NCT02879162.

Findings

From December 14th, 2016, to August 14, 2019, 140 patients enrolled into seven cohorts. The rare melanoma cohorts were closed due to lack of accrual. Of the 140 patients enrolled, 138 were eligible, 138 were evaluable for toxicity and 128 (91%) were evaluable for response. Durable responses were noted in all cohorts except for osteosarcoma. The overall response rate for eligible patients was 16% (95% CI: 10-23%). The response rates in each cancer cohort were undifferentiated pleomorphic sarcoma 15% (n = 3/20; 95% CI 3-38%), salivary carcinoma 20% (n = 4/20; 95% CI: 6-44%), CUP 17% (n = 3/18; 95% CI 4-41%), SCCA 10% (n = 2/20; 95% CI 12-32%) and CCCO 21% (n = 8/39; 95% CI 9-37%). Grade 3/4 adverse events were rare, where 4 patients experienced grade 4 related events and39 patients experienced grade 3 events.

Interpretation

Durvalumab + tremelimumab treatment resulted in meaningful responses in salivary carcinoma and CCCO and deserves further exploration in front-line studies.

Funding

AstraZeneca and Canadian Cancer Society.

The intricate dance of tumor evolution: Exploring immune escape, tumor migration, drug resistance, and treatment strategies

Recent research has unveiled fascinating insights into the intricate mechanisms governing tumor evolution. These studies have illuminated how tumors adapt and proliferate by exploiting various factors, including immune evasion, resistance to therapeutic drugs, genetic mutations, and their ability to adapt to different environments. Furthermore, investigations into tumor heterogeneity and chromosomal aberrations have revealed the profound complexity that underlies the evolution of cancer. Emerging findings have also underscored the role of viral influences in the development and progression of cancer, introducing an additional layer of complexity to the field of oncology. Tumor evolution is a dynamic and complex process influenced by various factors, including immune evasion, drug resistance, tumor heterogeneity, and viral influences. Understanding these elements is indispensable for developing more effective treatments and advancing cancer therapies. A holistic approach to studying and addressing tumor evolution is crucial in the ongoing battle against cancer. The main goal of this comprehensive review is to explore the intricate relationship between tumor evolution and critical aspects of cancer biology. By delving into this complex interplay, we aim to provide a profound understanding of how tumors evolve, adapt, and respond to treatment strategies. This review underscores the pivotal importance of comprehending tumor evolution in shaping effective approaches to cancer treatment.

Fish Uses CTLA-4 Immune Checkpoint to Suppress mTORC1-Controlled T-Cell Glycolysis and Immunity

As an immune checkpoint, cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) suppresses the activation, proliferation, and effector function of T cells, thus preventing an overexuberant response and maintaining immune homeostasis. However, whether and how this immune checkpoint functions in early vertebrates remains unknown. In the current study, using a Nile tilapia (Oreochromis niloticus) model, we investigated the suppression of T cell response by CTLA-4 in bony fish. Tilapia CTLA-4 is constitutively expressed in lymphoid tissues, and its mRNA and protein expression in lymphocytes are upregulated following PHA stimulation or Edwardsiella piscicida infection. Blockade of CTLA-4 signaling enhanced T cell activation and proliferation but inhibited activation-induced T cell apoptosis, indicating that CTLA-4 negatively regulated T cell activation. In addition, blocking CTLA-4 signaling in vivo increased the differentiation potential and cytotoxicity of T cells, resulting in an enhanced T cell response during E. piscicida infection. Tilapia CTLA-4 competitively bound the B7.2/CD86 molecule with CD28, thus antagonizing the CD28-mediated costimulatory signal of T cell activation. Furthermore, inhibition of mammalian/mechanistic target of rapamycin complex 1 (mTORC1) signaling, c-Myc, or glycolysis markedly impaired the CTLA-4 blockade-enhanced T cell response, suggesting that CTLA-4 suppressed the T cell response of tilapia by inhibiting mTORC1/c-Myc axis-controlled glycolysis. Overall, the findings indicate a detailed mechanism by which CTLA-4 suppresses T cell immunity in tilapia; therefore, we propose that early vertebrates have evolved sophisticated mechanisms coupling immune checkpoints and metabolic reprogramming to avoid an overexuberant T cell response.

Cancer Cell-Intrinsic Alterations Associated with an Immunosuppressive Tumor Microenvironment and Resistance to Immunotherapy in Lung Cancer

Despite the great clinical success of immunotherapy in lung cancer patients, only a small percentage of them (<40%) will benefit from this therapy alone or combined with other strategies. Cancer cell-intrinsic and cell-extrinsic mechanisms have been associated with a lack of response to immunotherapy. The present study is focused on cancer cell-intrinsic genetic, epigenetic, transcriptomic and metabolic alterations that reshape the tumor microenvironment (TME) and determine response or refractoriness to immune checkpoint inhibitors (ICIs). Mutations in KRAS, SKT11(LKB1), KEAP1 and TP53 and co-mutations of these genes are the main determinants of ICI response in non-small-cell lung cancer (NSCLC) patients. Recent insights into metabolic changes in cancer cells that impose restrictions on cytotoxic T cells and the efficacy of ICIs indicate that targeting such metabolic restrictions may favor therapeutic responses. Other emerging pathways for therapeutic interventions include epigenetic modulators and DNA damage repair (DDR) pathways, especially in small-cell lung cancer (SCLC). Therefore, the many potential pathways for enhancing the effect of ICIs suggest that, in a few years, we will have much more personalized medicine for lung cancer patients treated with immunotherapy. Such strategies could include vaccines and chimeric antigen receptor (CAR) cells.

CD39/CD73/A2AR pathway and cancer immunotherapy

Cancer development is closely associated with immunosuppressive tumor microenvironment (TME) that attenuates antitumor immune responses and promotes tumor cell immunologic escape. The sequential conversion of extracellular ATP into adenosine by two important cell-surface ectonucleosidases CD39 and CD73 play critical roles in reshaping an immunosuppressive TME. The accumulated extracellular adenosine mediates its regulatory functions by binding to one of four adenosine receptors (A1R, A2AR, A2BR and A3R). The A2AR elicits its profound immunosuppressive function via regulating cAMP signaling. The increasing evidence suggests that CD39, CD73 and A2AR could be used as novel therapeutic targets for manipulating the antitumor immunity. In recent years, monoclonal antibodies or small molecule inhibitors targeting the CD39/CD73/A2AR pathway have been investigated in clinical trials as single agents or in combination with anti-PD-1/PD-L1 therapies. In this review, we provide an updated summary about the pathophysiological function of the adenosinergic pathway in cancer development, metastasis and drug resistance. The targeting of one or more components of the adenosinergic pathway for cancer therapy and circumvention of immunotherapy resistance are also discussed. Emerging biomarkers that may be used to guide the selection of CD39/CD73/A2AR-targeting treatment strategies for individual cancer patients is also deliberated.

Cancer-associated fibroblasts: The chief architect in the tumor microenvironment

Stromal heterogeneity of tumor microenvironment (TME) plays a crucial role in malignancy and therapeutic resistance. Cancer-associated fibroblasts (CAFs) are one of the major players in tumor stroma. The heterogeneous sources of origin and subsequent impacts of crosstalk with breast cancer cells flaunt serious challenges before current therapies to cure triple-negative breast cancer (TNBC) and other cancers. The positive and reciprocal feedback of CAFs to induce cancer cells dictates their mutual synergy in establishing malignancy. Their substantial role in creating a tumor-promoting niche has reduced the efficacy of several anti-cancer treatments, including radiation, chemotherapy, immunotherapy, and endocrine therapy. Over the years, there has been an emphasis on understanding CAF-induced therapeutic resistance in order to enhance cancer therapy results. CAFs, in the majority of cases, employ crosstalk, stromal management, and other strategies to generate resilience in surrounding tumor cells. This emphasizes the significance of developing novel strategies that target particular tumor-promoting CAF subpopulations, which will improve treatment sensitivity and impede tumor growth. In this review, we discuss the current understanding of the origin and heterogeneity of CAFs, their role in tumor progression, and altering the tumor response to therapeutic agents in breast cancer. In addition, we also discuss the potential and possible approaches for CAF-mediated therapies.

Adenosinergic axis and immune checkpoint combination therapy in tumor: A new perspective for immunotherapy strategy

There are two figures and one table in this review, the review consists of 5823 words, without the description of figures and table, but including references.

Tumor cells escape anti-tumor immune responses in various ways, including functionally shaping the microenvironment through the secretion of various chemokines and, cytokines. Adenosine is a powerful immunosuppressive metabolite, that is frequently elevated in the extracellular tumor microenvironment (TME). Thus, it has recently been proposed as a novel antitumor immunoassay for targeting adenosine- generating enzymes, such as CD39, CD73, and adenosine receptors. In recent years, the discovery of the immune checkpoints, such as programmed cell death 1(PD-1) and cytotoxic T lymphocyte antigen 4 (CTLA-4), has also greatly changed treatment methods and ideas for malignant tumors. Malignant tumor immunotherapy has been developed from point-to-point therapy targeting immune checkpoints, combining different points of different pathways to create a therapy based on the macroscopic immune regulatory system network. This article reviews the theoretical basis of the adenosine energy axis and immune checkpoint combined therapy for malignant tumors and the latest advances in malignant tumors.

Acquired resistance for immune checkpoint inhibitors in cancer immunotherapy: challenges and prospects

Drug resistance has become an obstacle to the further development of immunotherapy in clinical applications and experimental studies. In the current review, the acquired resistance to immunotherapy was examined. The mechanisms of acquired resistance were based on three aspects as follows: The change of the tumor functions, the upregulated expression of inhibitory immune checkpoint proteins, and the effects of the tumor microenvironment. The combined use of immunotherapy and other therapies is performed to delay acquired resistance. A comprehensive understanding of acquired drug resistance may provide ideas for solving this dilemma.

Anti-PD-1 therapy activates tumoricidic properties of NKT cells and contributes to the overall deceleration of tumor progression in a model of murine mammary carcinoma

Background/Aim. Immune checkpoint therapy is a well-established therapeutic approach in the treatment of malignant diseases and is thought to be mostly based on facilitating the adaptive immune response. However, the cells of the innate immune response, such as natural killer T (NKT) cells, might also be important for a successful anti-programmed cell death protein-1 (anti-PD-1) therapy, as they initiate the antitumor immune response. The aim of this study was to investigate the influence of anti-PD-1 therapy on the immune response against tumors. Methods. For tumor induction, 4T1 cells synergic to BALB/c back-ground were used, after which mice underwent anti-PD-1 treatment. After the mice were sacrificed, NKT cells, dendritic cells (DCs), and macrophages derived from spleen and primary tumor tissue were analyzed using flow cytometry. Results. Anti-PD-1 therapy enhanced the expression of activating molecules CD69, NKp46, and NKG2D in NKT cells of the tumor and spleen. This therapy activated NKT cells directly and indirectly via DCs. Activated NKT cells acquired tumoricidic properties directly, by secreting perforin, and indirectly by stimulating M1 macrophages polarization. Conclusion. Anti-PD-1 therapy activates changes in DCs and macrophages of primary tumor tissue towards protumoricidic activity. Since anti-PD-1 therapy induces significant changes in NKT cells, DCs, and macrophages, the efficacy of the overall antitumor response is increased and has significantly decelerated tumor growth.

Nobel Prize for immune checkpoint inhibitors, understanding the immunological switching between immunosuppression and autoimmunity

INTRODUCTION

Immune checkpoint inhibitors (ICIs) are a revolutionary form of immunotherapy in cancer. However, the percentage of patients responding to therapy is relatively low, while adverse effects occur in a large number of patients. In addition, the therapeutic mechanisms of ICIs are not yet completely described.

AREAS COVERED

The initial view (articles published in PubMed, Scopus, Web of Science, etc.) was that ICIs increase tumor-specific immunity. Recent data (collected from the same databases) suggest that the ICIs pharmacotherapy actually extends beyond the topic of immune reactivity, including additional immune pathways, such as disrupting immunosuppression and increasing tumor-specific autoimmunity. Unfortunately, there is no clear delimitation between these specific autoimmune reactions that are therapeutically beneficial, and nonspecific autoimmune reactions/toxicity that can be extremely severe side effects.

EXPERT OPINION

Immune checkpoint mechanisms perform a non-selective immune regulation, maintaining a dynamic balance between immunosuppression and autoimmunity. By blocking these mechanisms, ICIs actually perform an immunological reset, decreasing immunosuppression and increasing tumor-specific immunity and predisposition to autoimmunity. The predisposition to autoimmunity induces both side effects and beneficial autoimmunity. Consequently, further studies are necessary to maximize the beneficial tumor-specific autoimmunity, while reducing the counterproductive effect of associated autoimmune toxicity.

Precision medicine in clinical oncology: the journey from IgG antibody to IgE

PURPOSE OF REVIEW

Cancer is one of the leading causes of death and the incidence rates are constantly rising. The heterogeneity of tumors poses a big challenge for the treatment of the disease and natural antibodies additionally affect disease progression. The introduction of engineered mAbs for anticancer immunotherapies has substantially improved progression-free and overall survival of cancer patients, but little efforts have been made to exploit other antibody isotypes than IgG.

RECENT FINDINGS

In order to improve these therapies, 'next-generation antibodies' were engineered to enhance a specific feature of classical antibodies and form a group of highly effective and precise therapy compounds. Advanced antibody approaches include among others antibody-drug conjugates, glyco-engineered and Fc-engineered antibodies, antibody fragments, radioimmunotherapy compounds, bispecific antibodies and alternative (non-IgG) immunoglobulin classes, especially IgE.

SUMMARY

The current review describes solutions for the needs of next-generation antibody therapies through different approaches. Careful selection of the best-suited engineering methodology is a key factor in developing personalized, more specific and more efficient mAbs against cancer to improve the outcomes of cancer patients. We highlight here the large evidence of IgE exploiting a highly cytotoxic effector arm as potential next-generation anticancer immunotherapy.

Biomarkers and Gene Signatures to Predict Durable Response to Pembrolizumab in Non-Small Cell Lung Cancer

Simple Summary

Not all patients with advanced or metastatic non-small cell lung cancer (NSCLC) respond to pembrolizumab, even if their tumor expresses PD-L1. This is a monocentric study aimed at identifying potential predictive biomarkers for pembrolizumab first-line treatment. Tumor microenvironment was characterized by gene expression analysis in 46 tumor samples from 25 NSCLC patients with and 21 without durable clinical benefit. As expected, patients achieving clinical benefit had a greater infiltration of immune cells. In particular, CD8 T-cell and NK cell scores were strongly associated with durable benefit. Single immune cell markers such as XCL1/2 showed a high performance in predicting durable response to pembrolizumab with an AUC of 0.85. In the same series PD-L1 expression levels had an AUC equal to 0.61. Identified predictive biomarkers can improve patients’ selection, thus optimizing treatment definition.

Abstract

Pembrolizumab has been approved as first-line treatment for advanced Non-small cell lung cancer (NSCLC) patients with tumors expressing PD-L1 and in the absence of other targetable alterations. However, not all patients that meet these criteria have a durable benefit. In this monocentric study, we aimed at refining the selection of patients based on the expression of immune genes. Forty-six consecutive advanced NSCLC patients treated with pembrolizumab in first-line setting were enrolled. The expression levels of 770 genes involved in the regulation of the immune system was analysed by the nanoString system. PD-L1 expression was evaluated by immunohistochemistry. Patients with durable clinical benefit had a greater infiltration of cytotoxic cells, exhausted CD8, B-cells, CD45, T-cells, CD8 T-cells and NK cells. Immune cell scores such as CD8 T-cell and NK cell were good predictors of durable response with an AUC of 0.82. Among the immune cell markers, XCL1/2 showed the better performance in predicting durable benefit to pembrolizumab, with an AUC of 0.85. Additionally, CD8A, CD8B and EOMES showed a high specificity (>0.86) in identifying patients with a good response to treatment. In the same series, PD-L1 expression levels had an AUC of 0.61. The characterization of tumor microenvironment, even with the use of single markers, can improve patients’ selection for pembrolizumab treatment.

Upregulation of HOXC9 generates interferon-gamma resistance in gastric cancer by inhibiting the DAPK1/RIG1/STAT1 axis

Clinical reports indicate that gastric cancer (GC) has a high mortality rate, but its pathological mechanism remains poorly understood. This work integrated bioinformatics analysis with experimental verification to explore novel biomarkers of gastric cancer. First, weighted gene coexpression network analysis was applied to screen significant genes correlated with GC development. Gene set enrichment analysis was also used to unearth the most relevant biological functions of significant genes. As a result, we discovered homeobox C9 (HOXC9) as a novel oncogene in GC, primarily through negatively regulating immune response. High expression of HOXC9 predicted a poor prognosis in GC patients, and knocking down HOXC9 efficiently enhanced the interferon‐gamma (IFNγ)‐dependent apoptosis in two GC cell lines as well as organoids from patients. Furthermore, cleaved caspase‐3/7 and phosphorylated signal transducer and activator of transcription 1 (p‐STAT1) were also significantly enhanced in HOXC9 knockdown cells and organoids treated with IFNγ. Mechanistically, we found that HOXC9 inhibited the death‐associated protein kinase 1 (DAPK1) and its downstream retinoic acid‐inducible gene‐I (RIG1) to generate GC IFNγ resistance. In summary, we identified and confirmed that HOXC9 generates IFNγ resistance in GC by inhibiting the DAPK1/RIG1/p‐STAT1 axis.

Modulating the wayward T cell: New horizons with immune checkpoint inhibitor treatments in autoimmunity, transplant, and cancer

The T-cell response is regulated by the balance between costimulatory and coinhibitory signals. Immune checkpoints are essential for efficient T-cell activation, but also for maintaining self-tolerance and protecting tissues from damage caused by the immune system, and for providing protective immunity. Modulating immune checkpoints can serve diametric goals, such that blocking a coinhibitory molecule can unleash anti-cancer immunity whereas stimulating the same molecule can reduce an over-reaction in autoimmune disease. The purpose of this review is to examine the regulation of T-cell costimulation and coinhibition, which is central to the processes underpinning autoimmunity, transplant rejection and immune evasion in cancer. We will focus on the immunomodulation agents that regulate these unwanted over- and under-reactions. The use of such agents has led to control of symptoms and slowing of progression in patients with rheumatoid arthritis, reduced rejection rates in transplant patients, and prolonged survival in patients with cancer. The management of immune checkpoint inhibitor treatment in certain challenging patient populations, including patients with pre-existing autoimmune conditions or transplant patients who develop cancer, as well as the management of immune-related adverse events in patients receiving antitumor therapy, is examined. Finally, the future of immune checkpoint inhibitors, including examples of emerging targets that are currently in development, as well as recent insights gained using new molecular techniques, is discussed. T-cell costimulation and coinhibition play vital roles in these diverse therapeutic areas. Targeting immune checkpoints continues to be a powerful avenue for the development of agents suitable for treating autoimmune diseases and cancers and for improving transplant outcomes. Enhanced collaboration between therapy area specialists to share learnings across disciplines will improve our understanding of the opposing effects of treatments for autoimmune disease/transplant rejection versus cancer on immune checkpoints, which has the potential to lead to improved patient outcomes.

Hyperprogression: A novel response pattern under immunotherapy

Checkpoint blockade therapy has shown significant therapeutic benefits and resulted in durable responses in patients with various tumors. However, accumulating evidence has demonstrated that 4-29% of all patients with cancers with various histologies may suffer from tumor flare following such therapy. This novel tumor response pattern, termed hyperprogression, is a potentially deleterious side effect of checkpoint blockade therapy that accelerates disease progression in a subset of patients. In this review, we describe possible immune checkpoint blockade biomarkers and the epidemiology, different definitions, and predictors of hyperprogression based on the research findings and further present the available evidence supporting pathophysiological hypotheses that might explain hyperprogression during checkpoint blockade therapy. We also compare hyperprogression and pseudoprogression. Finally, we discuss areas requiring further study.

B4GALT1 Is a New Candidate to Maintain the Stemness of Lung Cancer Stem Cells

BACKGROUND

According to the cancer stem cells (CSCs) hypothesis, a population of cancer cells with stem cell properties is responsible for tumor propagation, drug resistance, and disease recurrence. Study of the mechanisms responsible for lung CSCs propagation is expected to provide better understanding of cancer biology and new opportunities for therapy.

METHODS

The Lung Adenocarcinoma (LUAD) NCI-H460 cell line was grown either as 2D or as 3D cultures. Transcriptomic and genome-wide chromatin accessibility studies of 2D vs. 3D cultures were carried out using RNA-sequencing and Assay for Transposase Accessible Chromatin with high-throughput sequencing (ATAC-seq), respectively. Reverse transcription polymerase chain reaction (RT-PCR) was also carried out on RNA extracted from primary cultures derived from malignant pleural effusions to validate RNA-seq results.

RESULTS

RNA-seq and ATAC-seq data disentangled transcriptional and genome accessibility variability of 3D vs. 2D cultures in NCI-H460 cells. The examination of genomic landscape of genes upregulated in 3D vs. 2D cultures led to the identification of 2D cultures led to the identification of Beta-1,4-galactosyltranferase 1 (B4GALT1) as the top candidate. B4GALT1 as the top candidate. B4GALT1 was validated as a stemness factor, since its silencing caused strong inhibition of 3D spheroid formation.

CONCLUSION

Combined transcriptomic and chromatin accessibility study of 3D vs. 2D LUAD cultures led to the identification of B4GALT1 as a new factor involved in the propagation and maintenance of LUAD CSCs.

Sustained partial remission of a metastatic NEN using off-label immunotherapy with pembrolizumab

Neuroendocrine neoplasms (NEN) are a heterogeneous group of tumors, which can be histologically separated by primary location, proliferation rate and differentiation of tumor cells. The therapeutic options and outcome depend on grading, staging and resectability of the tumor. Established treatment options of neuroendocrine tumors (NET) and carcinomas (NEC) are based especially on surgery, tumor specific medical treatments, peptide guided radioreceptor therapy (PRRT) and locoregional therapies. We report about a patient diagnosed with a pancreatic, non-functional NET/NEC G2/3 with a proliferation rate of 20% at initial immunohistochemical diagnosis. During the course of the disease, the proliferation rate increased up to more than 50% over a period of 5 years. Due to loss of response to established therapies (i.e. systemic chemotherapy, targeted therapy and brachytherapy), an off-label immunotherapy with the PD-1 antibody pembrolizumab was initiated based on a 30% PD-L1 expression in tumor cells. This report is the first demonstrating a partial remission of a pancreatic NEN using pembrolizumab monotherapy with a hepatic tumor volume reduction of at least 66%, combined with an improvement of the Karnofsky score rising from 60% to 100%. This case offers insight into the potential role of immunotherapy in a subgroup of neuroendocrine neoplasms.

The features of circulating and tumor-infiltrating γδ T cells in melanoma patients display critical perturbations with prognostic impact on clinical outcome

γδT cells hold a pivotal role in tumor immunosurveillance through their prompt activation and cytokine secretion, their ability to kill tumor cells in an Human Leukocyte Antigen (HLA)-unrestricted manner, and their combination of features of both innate and adaptive immunity. These unique properties and functional plasticity render them very attractive both as targets and vectors for cancer immunotherapy. Yet, these potent and fascinating antitumor effectors have not been extensively explored in melanoma. We provided here a detailed investigation of the phenotypic and functional properties of circulating and tumor-infiltrating γδT cells in melanoma patients, and their impact on clinical evolution. High proportions of circulating- and tumor-infiltrating γδT and δ2+ subset were associated with better clinical outcome. We reported however that circulating and tumor-infiltrating γδT cells from melanoma patients displayed an altered expression of NCR, KIR, and immune checkpoints, and identified NKp44, PD1, 41BB/41BBL, TIM3, and LAG3 as crucial checkpoints allowing immune escape and tumor progression. Notably, melanoma drastically impaired the ability of γδT cells to exhibit activation molecules, secrete cytokines, and display cytotoxicity toward melanoma in response to stimulation with phosphoantigens. It drove them toward regulatory and Th17 profiles associated with poor clinical outcomes. Our study highlights that melanoma hijacked γδT cells to escape from immune control, and revealed that circulating and tumor-infiltrating γδT cell features are promising potential biomarkers of clinical evolution. Such understanding of the physiopathology of γδT cells may help designing new therapeutic approaches exploiting the antitumor potential of γδT cells while counteracting their skewing by tumors to improve patient outcomes.

Immune profiling reveals the diverse nature of the immune response in NSCLC and reveals signaling pathways that may influence the anti-tumor immune response

Recent FDA approvals of immunotherapy for NSCLC provide patients new treatment options, and these approvals also highlight the importance of the immune response in cancer treatment. While immunotherapy provides patients a new treatment option, the therapy is effective in less than half of the treated patients. To attain greater insight into the tumor-immune microenvironment, NSCLC tumors were analyzed by IHC and RNA-seq. IHC was used to identify NSCLC tumors that contain low, moderate, or high levels of CD8+ positive cells as a manifestation of an active anti-tumor immune response. Gene expression analysis identified an emergent gene signature that is associated with high and moderate levels of CD8 in NSCLC. In addition, the NSCLC tumors also express a unique combination of genes that may indicate complex anti-tumor immune responses (INFG-related genes, STATs, CXCL9, OX40, PD-L1, PD-L2, IDO1, and CD47). Several NSCLC tumors also express the immune checkpoint PD-L1 and at least one additional immune inhibitory molecule (IDO1, PD-L2, or others), which may explain the lack of a therapeutic response to treatments that disrupt only one immune checkpoint pathway.

Harnessing the innate immune system and local immunological microenvironment to treat colorectal cancer

Significant progress in the development of new immunotherapies has led to successful clinical trials for malignant melanoma and non-small cell lung cancer; however, for the majority of solid tumours of the gastrointestinal tract, little or no progress has been seen. The efficacy of immunotherapies is limited by the complexities of a diverse set of immune cells, and interactions between the tumour cells and all other cells in the local microenvironment of solid tumours. A large fraction of immune cells present in and around solid tumours derive from the innate arm of the immune system and using these cells against tumours offers an alternative immunotherapeutic option, especially as current strategies largely harness the adaptive arm of the immune system. This option is currently being investigated and attempts at using the innate immune system for gastrointestinal cancers are showing initial results. Several important factors, including cytokines, chemotherapeutics and the microbiome, influence the plasticity and functionality of innate (myeloid) cells in the microenvironment, and this complexity of regulation has limited translation into successful trials so far. In this review, current concepts of the immunobiology of the innate arm in the tumour microenvironment are presented in the context of clinical translation.

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.

Diacylglycerol kinase ζ (DGKζ) and Casitas b-lineage proto-oncogene b-deficient mice have similar functional outcomes in T cells but DGKζ-deficient mice have increased T cell activation and tumor clearance

Targeting negative regulators downstream of the T cell receptor (TCR) represents a novel strategy to improve cancer immunotherapy. Two proteins that serve as critical inhibitory regulators downstream of the TCR are diacylglycerol kinase ζ (DGKζ), a regulator of Ras and PKC-θ signaling, and Casitas b-lineage proto-oncogene b (Cbl-b), an E3 ubiquitin ligase that predominantly regulates PI(3)K signaling. We sought to compare the signaling and functional effects that result from deletion of DGKζ, Cbl-b, or both (double knockout, DKO) in T cells, and to evaluate tumor responses generated in a clinically relevant orthotopic pancreatic tumor model. We found that whereas deletion of Cbl-b primarily served to enhance NF-κB signaling, deletion of DGKζ enhanced TCR-mediated signal transduction downstream of Ras/Erk and NF-κB. Deletion of DGKζ or Cbl-b comparably enhanced CD8⁺ T cell functional responses, such as proliferation, production of IFNγ, and generation of granzyme B when compared with WT T cells. DKO T cells demonstrated enhanced function above that observed with single knockout T cells after weak, but not strong, stimulation. Deletion of DGKζ, but not Cbl-b, however, resulted in significant increases in numbers of activated (CD44^hi) CD8⁺ T cells in both non-treated and tumor-bearing mice. DGKζ-deficient mice also had enhanced control of pancreatic tumor cell growth compared to Cbl-b-deficient mice. This represents the first direct comparison between mice of these genotypes and suggests that T cell immunotherapies may be better improved by targeting TCR signaling molecules that are regulated by DGKζ as opposed to molecules regulated by Cbl-b.

Optimizing the Targeting of Mouse Parvovirus 1 to Murine Melanoma Selects for Recombinant Genomes and Novel Mutations in the Viral Capsid Gene

Combining virus-enhanced immunogenicity with direct delivery of immunomodulatory molecules would represent a novel treatment modality for melanoma, and would require development of new viral vectors capable of targeting melanoma cells preferentially. Here we explore the use of rodent protoparvoviruses targeting cells of the murine melanoma model B16F10. An uncloned stock of mouse parvovirus 1 (MPV1) showed some efficacy, which was substantially enhanced following serial passage in the target cell. Molecular cloning of the genes of both starter and selected virus pools revealed considerable sequence diversity. Chimera analysis mapped the majority of the improved infectivity to the product of the major coat protein gene, VP2, in which linked blocks of amino acid changes and one or other of two apparently spontaneous mutations were selected. Intragenic chimeras showed that these represented separable components, both contributing to enhanced infection. Comparison of biochemical parameters of infection by clonal viruses indicated that the enhancement due to changes in VP2 operates after the virus has bound to the cell surface and penetrated into the cell. Construction of an in silico homology model for MPV1 allowed placement of these changes within the capsid shell, and revealed aspects of the capsid involved in infection initiation that had not been previously recognized.

Current progress in innovative engineered antibodies

As of May 1, 2017, 74 antibody-based molecules have been approved by a regulatory authority in a major market. Additionally, there are 70 and 575 antibody-based molecules in phase III and phase I/II clinical trials, respectively. These total 719 antibody-based clinical stage molecules include 493 naked IgGs, 87 antibody-drug conjugates, 61 bispecific antibodies, 37 total Fc fusion proteins, 17 radioimmunoglobulins, 13 antibody fragments, and 11 immunocytokines. New uses for these antibodies are being discovered each year. For oncology, many of the exciting new approaches involve antibody modulation of T-cells. There are over 80 antibodies in clinical trials targeting T cell checkpoints, 26 T-cell-redirected bispecific antibodies, and 145 chimeric antigen receptor (CAR) cell-based candidates (all currently in phase I or II clinical trials), totaling more than 250 T cell interacting clinical stage antibody-based candidates. Finally, significant progress has been made recently on routes of delivery, including delivery of proteins across the blood-brain barrier, oral delivery to the gut, delivery to the cellular cytosol, and gene- and viral-based delivery of antibodies. Thus, there are currently at least 864 antibody-based clinical stage molecules or cells, with incredible diversity in how they are constructed and what activities they impart. These are followed by a next wave of novel molecules, approaches, and new methods and routes of delivery, demonstrating that the field of antibody-based biologics is very innovative and diverse in its approaches to fulfill their promise to treat unmet medical needs.

Evaluating the significance of density, localization, and PD-1/PD-L1 immunopositivity of mononuclear cells in the clinical course of lung adenocarcinoma patients with brain metastasis

BACKGROUND

Management of lung cancer patients who suffer from brain metastases represents a major challenge. Considering the promising results with immune checkpoint inhibitor treatment, evaluating the status of immune cell (IC) infiltrates in the prognosis of brain metastasis may lead to better therapeutic strategies with these agents. The aim of this study was to characterize the distribution of ICs and determine the expression of the checkpoint molecules programmed death protein 1 (PD-1) and its ligand, PD-L1, in brain metastasis of lung adenocarcinoma (LUAD) patients and to analyze their clinicopathological correlations.

METHODS

We determined the presence of peritumoral mononuclear cells (mononuclear ring) and the density of intratumoral stromal mononuclear cells on brain metastasis tissue sections of 208 LUAD patients. PD-L1/PD-1 expressions were analyzed by immunohistochemistry.

RESULTS

Mononuclear rings were significantly associated with better survival after brain metastasis surgery. Cases with massive stromal IC infiltration also showed a tendency for better overall survival. Lower expression of PD-1 and PD-L1 was associated with better survival in patients who underwent surgery for the primary tumor and had multiple brain metastases. Steroid administration and chemotherapy appear not to influence the density of IC in brain metastasis.

CONCLUSION

This is the first study demonstrating the independent prognostic value of mononuclear rings in LUAD cases with brain metastasis. Our results also suggest that the density of tumor-associated ICs in addition to PD-L1 expression of tumor cells and ICs as well as PD-1 expression of ICs may hold relevant information for the appropriate selection of patients who might benefit from anti-PD-L1 or anti-PD-1 therapy.

Immune checkpoint inhibitors for advanced non-small cell lung cancer: emerging sequencing for new treatment targets

Lung cancer is the leading cause of cancer-related deaths in the world. Immune checkpoint inhibitors (ICI) stimulate cytotoxic lymphocyte activity against tumour cells. These agents are available for the treatment of non-small cell lung cancer (NSCLC) after failure of platinum-based therapy. One recent study has demonstrated that ICI monotherapy was superior to platinum-based chemotherapy for first-line treatment. Nevertheless, this benefit was only for a minority of the population (30%) whose tumour programmed death receptor ligand-1 (PD-L1) expression was above 50%. Therefore, several strategies are under investigation. One option for patients with PD-L1 expression lower than 50% may be the combination of ICI with platinum-based chemotherapy or with ICIs against different targets. However, all of these combinations are at an early stage of investigation and may be very expensive or toxic, producing several harmful adverse events.

Novel insights into mesothelioma biology and implications for therapy

Malignant mesothelioma is a universally lethal cancer that is increasing in incidence worldwide. There is a dearth of effective therapies, with only one treatment (pemetrexed and cisplatin combination chemotherapy) approved in the past 13 years. However, the past 5 years have witnessed an exponential growth in our understanding of mesothelioma pathobiology, which is set to revolutionize therapeutic strategies. From a genomic standpoint, mesothelioma is characterized by a preponderance of tumour suppressor alterations, for which novel therapies are currently in development. Other promising antitumour agents include inhibitors against angiogenesis, mesothelin and immune checkpoints, which are at various phases of clinical trial testing.

[Progress in Immunotherapy for Squamous Non-small Cell Lung Cancer]

近几年来，肺鳞癌在化疗及靶向治疗上的进展不够显著，但免疫治疗却在肺鳞癌的治疗上取得了突破性的进展。免疫治疗通过免疫系统来清除肿瘤细胞，主要分为免疫检查点抑制剂及治疗性疫苗。免疫检查点抑制剂，包括抗细胞毒性T淋巴细胞抗原4（cytotoxic T-lymphocyte associated antigen 4, CTLA-4）抗体与抗程序性死亡受体-1（programmed death receptor 1, PD-1）抗体等多种药物已进行了肺鳞癌的Ⅱ期、Ⅲ期临床试验，并取得了一定成果。免疫治疗将成为肺鳞癌治疗的一种重要手段。