Tumor CTLA-4 overexpression predicts poor survival in patients with nasopharyngeal carcinoma

Identification of Two Distinct Immune Subtypes in Hepatitis B Virus (HBV)-Associated Hepatocellular Carcinoma (HCC)

HBV is the most common risk factor for HCC development, accounting for almost 50% of cases worldwide. Despite significant advances in immunotherapy, there is limited information on the HBV-HCC tumor microenvironment (TME), which may influence the response to checkpoint inhibitors. Here, we characterize the TME in a unique series of liver specimens from HBV-HCC patients to identify who might benefit from immunotherapy. By combining an extensive immunohistochemistry analysis with the transcriptomic profile of paired liver samples (tumor vs. nontumorous tissue) from 12 well-characterized Caucasian patients with HBV-HCC, we identified two distinct tumor subtypes that we defined immune-high and immune-low. The immune-high subtype, seen in half of the patients, is characterized by a high number of infiltrating B and T cells in association with stromal activation and a transcriptomic profile featuring inhibition of antigen presentation and CTL activation. All the immune-high tumors expressed high levels of CTLA-4 and low levels of PD-1, while PD-L1 was present only in four of six cases. In contrast, the immune-low subtype shows significantly lower lymphocyte infiltration and stromal activation. By whole exome sequencing, we documented that four out of six individuals with the immune-low subtype had missense mutations in the CTNNB1 gene, while only one patient had mutations in this gene in the immune-high subtype. Outside the tumor, there were no differences between the two subtypes. This study identifies two distinctive immune subtypes in HBV-associated HCC, regardless of the microenvironment observed in the surrounding nontumorous tissue, providing new insights into pathogenesis. These findings may be instrumental in the identification of patients who might benefit from immunotherapy.

Advances in tumor immune microenvironment of head and neck squamous cell carcinoma: A review of literature

Squamous cell carcinoma is seen as principal malignancy of head and neck. Tumor immune microenvironment plays a vital role in the occurrence, development and treatment of head and neck squamous cell carcinoma (HNSCC). The effect of immunotherapy, in particular, is closely related to tumor immune microenvironment. This review searched for high-quality literature included within PubMed, Web of Science, and Scopus using the keywords "head and neck cancers," "tumor microenvironment" and "immunotherapy," with the view to summarizing the characteristics of HNSCC immune microenvironment and how various subsets of immune cells promote tumorigenesis. At the same time, based on the favorable prospects of immunotherapy having been shown currently, the study is committed to pinpointing the latest progress of HNSCC immunotherapy, which is of great significance in not only further guiding the diagnosis and treatment of HNSCC, but also conducting its prognostic judgement.

The dynamic role of immune checkpoint molecules in diagnosis, prognosis, and treatment of head and neck cancers

Head and neck cancer (HNC) is the sixth most common cancer type, accounting for approximately 277,597 deaths worldwide. Recently, the Food and Drug Administration (FDA) has approved immune checkpoint blockade (ICB) agents targeting programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) as a treatment regimen for head and neck squamous cell carcinomas (HNSCC). Studies have reported the role of immune checkpoint inhibitors as targeted therapeutic regimens that unleash the immune response against HNSCC tumors. However, the overall response rates to immunotherapy vary between 14-32% in recurrent or metastatic HNSCC, with clinical response and treatment success being unpredictable. Keeping this perspective in mind, it is imperative to understand the role of T cells, natural killer cells, and antigen-presenting cells in modulating the immune response to immunotherapy. In lieu of this, these immune molecules could serve as prognostic and predictive biomarkers to facilitate longitudinal monitoring and understanding of treatment dynamics. These immune biomarkers could pave the path for personalized monitoring and management of HNSCC. In this review, we aim to provide updated immunological insight on the mechanism of action, expression, and the clinical application of immune cells' stimulatory and inhibitory molecules as prognostic and predictive biomarkers in HNC. The review is focused mainly on CD27 and CD137 (members of the TNF-receptor superfamily), natural killer group 2 member D (NKG2D), tumor necrosis factor receptor superfamily member 4 (TNFRSF4 or OX40), S100 proteins, PD-1, PD-L1, PD-L2, T cell immunoglobulin and mucin domain 3 (TIM-3), cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), lymphocyte-activation gene 3 (LAG-3), indoleamine-pyrrole 2,3-dioxygenase (IDO), B and T lymphocyte attenuator (BTLA). It also highlights the importance of T, natural killer, and antigen-presenting cells as robust biomarker tools for understanding immune checkpoint inhibitor-based treatment dynamics. Though a comprehensive review, all aspects of the immune molecules could not be covered as they were beyond the scope of the review; Further review articles can cover other aspects to bridge the knowledge gap.

High CTLA-4 transcriptomic expression correlates with high expression of other checkpoints and with immunotherapy outcome

Background

CTLA-4 impedes the immune system's antitumor response. There are two Food and Drug Administration-approved anti-CTLA-4 agents - ipilimumab and tremelimumab - both used together with anti-PD-1/PD-L1 agents.

Objective

To assess the prognostic implications and immunologic correlates of high CTLA-4 in tumors of patients on immunotherapy and those on non-immunotherapy treatments.

Design/methods

We evaluated RNA expression levels in a clinical-grade laboratory and clinical correlates of CTLA-4 and other immune checkpoints in 514 tumors, including 489 patients with advanced/metastatic cancers and full outcome annotation. A reference population (735 tumors; 35 histologies) was used to normalize and rank transcript abundance (0-100 percentile) to internal housekeeping gene profiles.

Results

The most common tumor types were colorectal (140/514, 27%), pancreatic (55/514, 11%), breast (49/514, 10%), and ovarian cancers (43/514, 8%). Overall, 87 of 514 tumors (16.9%) had high CTLA-4 transcript expression (⩾75th percentile rank). Cancers with the largest proportion of high CTLA-4 transcripts were cervical cancer (80% of patients), small intestine cancer (33.3%), and melanoma (33.3%). High CTLA-4 RNA independently/significantly correlated with high PD-1, PD- L2, and LAG3 RNA levels (and with high PD-L1 in univariate analysis). High CTLA-4 RNA expression was not correlated with survival from the time of metastatic disease [N = 272 patients who never received immune checkpoint inhibitors (ICIs)]. However, in 217 patients treated with ICIs (mostly anti-PD-1/anti-PD- L1), progression-free survival (PFS) and overall survival (OS) were significantly longer among patients with high versus non-high CTLA-4 expression [hazard ratio, 95% confidence interval: 0.6 (0.4-0.9) p = 0.008; and 0.5 (0.3-0.8) p = 0.002, respectively]; results were unchanged when 18 patients who received anti-CTLA-4 were omitted. Patients whose tumors had high CTLA-4 and high PD-L1 did best; those with high PD-L1 but non-high CTLA-4 and/or other expression patterns had poorer outcomes for PFS (p = 0.004) and OS (p = 0.009) after immunotherapy.

Conclusion

High CTLA-4, especially when combined with high PD-L1 transcript expression, was a significant positive predictive biomarker for better outcomes (PFS and OS) in patients on immunotherapy.

Combinations of radiotherapy with immunotherapy in nasopharyngeal carcinoma

BACKGROUND

The treatment of nasopharyngeal carcinoma (NPC) is currently based on concurrent chemoradiotherapy. The prognosis of early NPC is better, while the prognosis of advanced NPC is poor. Immunotherapy is becoming increasingly commonly employed in clinical practice as a new strategy for treating malignant tumors. It has shown promising results in the treatment of certain malignant tumors, making it a current clinical research hotspot.

METHODS

This review summarizes the current immunotherapy on NPC, highlighting the application of immunotherapy and radiotherapy in the treatment of NPC.

RESULTS

X-rays can either increase or suppress anti-tumor immune responses through various pathways and mechanisms. Immune checkpoint inhibitors can usually enhance X-ray-induced anti-tumor immune responses. Detecting the immune checkpoint markers and tumor mutation markers, and the functional status of effector cells in patients can aid in the development of individualized treatment that improves the treatment efficacy with reducing drug resistance and adverse reactions. The development of a multivalent vaccine for NPC will help improve the efficacy of the vaccine. Combining techniques that increase the tumor antigens release, such as radiotherapy and oncolytic virus vaccines, may enhance the ability of the immune response.

CONCLUSIONS

To shed further light on the application of immunotherapy in NPC, large pooled studies must accumulate sufficient cases with detailed exposure data.

Charting new frontiers: Co-inhibitory immune checkpoint proteins in therapeutics, biomarkers, and drug delivery systems in cancer care

Cancer remains a major health concern globally. Immune checkpoint inhibitors (ICIs) target co-inhibitory immune checkpoint molecules and have received approval for treating malignancies like melanoma and non-small cell lung cancer. While CTLA-4 and PD-1/PD-L1 are extensively researched, additional targets such as LAG-3, TIGIT, TIM-3, and VISTA have also demonstrated effective in cancer therapy. Combination treatments, which pair ICIs with interventions such as radiation or chemotherapy, amplify therapeutic outcomes. However, ICIs can lead to diverse side effects, and their varies across patients and cancers. Hence, identifying predictive biomarkers to guide therapy is essential. Notably, expression levels of molecules like PD-1, CTLA-4, and LAG-3 have been linked to tumor progression and ICI therapy responsiveness. Recent advancements in drug delivery systems (DDSs) further enhance ICI therapy efficacy. This review explores predominant DDSs for ICI delivery, such as hydrogel, microparticle, and nanoparticle, which offer improved therapeutic effects and reduced toxicity. In summary, we discuss the future of immune therapy focusing on co-inhibitory checkpoint molecules, pinpoint challenges, and suggest avenues for developing efficient, safer DDSs for ICI transport.

FAM72 family proteins as poor prognostic markers in clear cell renal carcinoma

Purpose

This study aimed to investigate the prognostic significance of the Family with Sequence Similarity 72 member (FAM72) gene family in clear cell renal carcinoma (ccRCC) using a bioinformatic approach.

Patients and methods

To investigate the association between FAM72 and ccRCC, we utilized various databases and analysis tools, including TCGA, GEPIA, Metscape, cBioPortal, and MethSurv. We conducted an analysis of FAM72 expression levels in ccRCC tissues compared to normal kidney tissues and performed univariate and multivariate Cox analysis to determine the relationship between FAM72 expression and patient prognosis. Furthermore, we carried out Gene Ontology (GO) and Gene Set Enrichment Analysis (GSEA) to identify enriched biological processes associated with FAM72 expression. Additionally, we analyzed immune cell infiltration and the level of methylation in ccRCC patients. Our bioinformatic analysis revealed that FAM72 expression levels were significantly higher in ccRCC tissues than in normal kidney tissues. High expression of FAM72 was associated with poor prognosis in ccRCC patients and was found to be an independent prognostic factor for ccRCC. GO and GSEA analyses indicated that FAM72 was enriched in biological processes related to mitosis, cell cycle, and DNA metabolism. Moreover, we found a significant correlation between FAM72 and immune cell infiltration and the level of methylation in ccRCC patients.

Conclusion

Our findings suggest that FAM72 could serve as an unfavorable prognostic molecular marker for ccRCC. A comprehensive understanding of FAM72 could provide crucial insights into tumor progression and prognosis.

Functional analysis of CTLA4 promoter variant and its possible implication in colorectal cancer immunotherapy

Background

Colorectal cancer (CRC) is a prevalent cancer, ranking as the third most common. Recent advances in our understanding of the molecular causes of this disease have highlighted the crucial role of tumor immune evasion in its initiation and progression. CTLA4, a receptor that acts as a negative regulator of T cell responses, plays a pivotal role in this process, and genetic variations in CTLA4 have been linked to CRC susceptibility, prognosis, and response to therapy.

Methods

We conducted a case-control study involving 98 CRC patients and 424 controls. We genotyped the CTLA4 c.-319C > T variant (rs5742909) and performed an association analysis by comparing allele frequencies between the patients and controls. To assess the potential functional impact of this variant, we first performed an In Silico analysis of transcription factor binding sites using Genomatix. Finally, to validate our findings, we conducted a luciferase reporter gene assay using different cell lines and an electrophoretic mobility shift assay (EMSA).

Results

The case-control association analysis revealed a significant association between CTLA4 c.-319C > T and CRC susceptibility (p = 0.023; OR 1.89; 95% CI = 1.11-3.23). Genomatix analysis identified LEF1 and TCF7 transcription factors as specific binders to CTLA4 c.-319C. The reporter gene assay demonstrated notable differences in luciferase activity between the c.-319 C and T alleles in COS-7, HCT116, and Jurkat cell lines. EMSA analysis showed differences in TCF7 interaction with the CTLA4 C and T alleles.

Conclusion

CTLA4 c.-319C > T is associated with CRC susceptibility. Based on our functional validation results, we proposed that CTLA4 c.-319C > T alters gene expression at the transcriptional level, triggering a stronger negative regulation of T-cells and immune tumoral evasion.

CTLA-4 and its inhibitors in esophageal cancer: efficacy of therapy and potential mechanisms of adverse events

Esophageal cancer is one of the most prevalent diseases in the world, and its prognosis remains poor. Surgery, chemotherapy, and radiotherapy are the most common treatment strategies for esophageal cancer. Although these conventional treatment methods are sometimes beneficial, patients with esophageal cancer still have a high risk of local relapse and metastasis. Thus, novel and effective therapies are needed. Immune checkpoint inhibitors are a type of immunotherapy being studied as a treatment for patients with advanced cancers, and strategies using such inhibitors have rapidly progressed to be recognized as transformative treatments for various cancers in recent years. Immune checkpoint inhibitors combined with chemotherapy or radiotherapy have become the first-line and second-line treatment strategies for advanced esophageal cancer. In addition, immune checkpoint inhibitors have also been recognized as another option for patients with terminal esophageal cancer who cannot benefit from chemotherapy, and they even have potential benefits as a novel neoadjuvant treatment option for locally advanced esophageal cancer. Currently, there are two types of immune checkpoint inhibitors commonly applied in clinical practice: immune checkpoint inhibitors targeting programmed death 1/programmed cell death ligand 1 and immune checkpoint inhibitors targeting cytotoxic T-lymphocyte-associated protein 4. However, cytotoxic T-lymphocyte-associated protein 4 immune checkpoint inhibitors are rarely used compared with programmed death 1/programmed cell death ligand 1 inhibitors in esophageal cancer and other cancers, and the clinical benefit is unclear. We analyzed and summarized the efficacy and safety of cytotoxic T-lymphocyte-associated protein 4 immune checkpoint inhibitors in the treatment of esophageal cancer. Due to the lack of clinical applications, it is expected that cytotoxic T-lymphocyte-associated protein 4 immune checkpoint inhibitors in combination with other treatments may provide superior benefits and improve the prognosis of patients with esophageal cancer.

The Current State of Neoadjuvant Therapy in Resectable Advanced Stage Melanoma

The advent of effective immunotherapy and targeted therapy has significantly improved outcomes in advanced-stage resectable melanoma. Currently, the mainstay of treatment of malignant melanoma is surgery followed by adjuvant systemic therapies. However, recent studies have shown a potential role for neoadjuvant therapy in the treatment of advanced-stage resectable melanoma. Mechanistically, neoadjuvant immunotherapy may yield a more robust response than adjuvant immunotherapy, as the primary tumor serves as an antigen in this setting rather than only micrometastatic disease after the index procedure. Additionally, targeted therapy has been shown to yield effective neoadjuvant cytoreduction, and oncolytic viruses may also increase the immunogenicity of primary tumors. Effective neoadjuvant therapy may serve to decrease tumor size and thus reduce the extent of required surgery and thus morbidity. It also allows for assessment of pathologic response, facilitating prognostication as well as tailoring future therapy. The current literature consistently supports that neoadjuvant therapy, even as little as one dose, is associated with improved outcomes and is well-tolerated. Some patients with a complete pathological response may even avoid surgery completely. These results challenge the current paradigm of a surgery-first approach and provide further evidence supporting neoadjuvant therapy in advanced-stage resectable melanoma. Further research into the optimal treatment schedule and dose timing is warranted, as is the continued investigation of novel therapies and combinations of therapies.

Immunotherapy and targeted therapy for lung cancer: Current status and future perspectives

Lung cancer has the highest incidence of morbidity and mortality throughout the globe. A large number of patients are diagnosed with lung cancer at the later stages of the disease. This eliminates surgery as an option and places complete dependence on radiotherapy or chemotherapy, and/or a combination of both, to halt disease progression by targeting the tumor cells. Unfortunately, these therapies have rarely proved to be effective, and this necessitates the search for alternative preventive approaches to reduce the mortality rate of lung cancer. One of the effective therapies against lung cancer comprises targeting the tumor microenvironment. Like any other cancer cells, lung cancer cells tend to use multiple pathways to maintain their survival and suppress different immune responses from the host's body. This review comprehensively covers the role and the mechanisms that involve the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in lung adenocarcinoma and methods of treating it by altering the tumor microenvironment. It focuses on the insight and understanding of the lung cancer tumor microenvironment and chemokines, cytokines, and activating molecules that take part in angiogenesis and metastasis. The review paper accounts for the novel and current immunotherapy and targeted therapy available for lung cancer in clinical trials and in the research phases in depth. Special attention is being paid to mark out single or multiple genes that are required for malignancy and survival while developing targeted therapies for lung cancer treatment.

Disrupting cancer angiogenesis and immune checkpoint networks for improved tumor immunity

Immune checkpoint inhibitors (ICIs) have advanced the field of cancer immunotherapy in patients by sustaining effector immune cell activity within the tumor microenvironment. However, the approach in general is still faced with issues related to ICI response duration/resistance, treatment eligibility, and safety, which indicates a need for further refinements. As immune checkpoint upregulation is inextricably linked to cancer-induced angiogenesis, newer clinical efforts have demonstrated the feasibility of disrupting both tumor-promoting networks to mediate enhanced immune-driven protection. This review focuses on such key evidence stipulating the necessity of co-applying ICI and anti-angiogenic strategies in cancer patients, with particular interest in highlighting newer engineered antibody approaches that may provide theoretically superior multi-pronged and safe therapeutic combinations.

Prognostic significance of AKR1C4 and the advantage of combining EBV DNA to stratify patients at high risk of locoregional recurrence of nasopharyngeal carcinoma

Background

Distinguishing patients at a greater risk of recurrence is essential for treating locoregional advanced nasopharyngeal carcinoma (NPC). This study aimed to explore the potential of aldo–keto reductase 1C4 (AKR1C4) in stratifying patients at high risk of locoregional relapse.

Methods

A total of 179 patients with locoregionally advanced NPC were grouped by different strategies; they were: (a) divided into two groups according to AKR1C4 expression level, and (b) classified into three clusters by integrating AKR1C4 and Epstein-Barr virus (EBV) DNA. The Kaplan–Meier method was used to calculate locoregional relapse-free survival (LRFS), overall survival (OS), progression-free survival (PFS), and distant metastasis-free survival (DMFS). The Cox proportional hazards model was used to determine potential prognostic factors, and a nomogram was generated to predict 3-year and 5-year LRFS.

Results

A significant difference in the 5-year LRFS was observed between the high and low AKR1C4 expression groups (83.3% vs. 92.7%, respectively; p = 0.009). After integrating AKR1C4 expression and EBV DNA, the LRFS (84.7%, 84.5%, 96.9%, p = 0.014) of high-, intermediate-, and low- AKR1C4 and EBV DNA was also significant. Multivariate analysis indicated that AKR1C4 expression (p = 0.006) was an independent prognostic factor for LRFS. The prognostic factors incorporated into the nomogram were AKR1C4 expression, T stage, and EBV DNA, and the concordance index of the nomogram for locoregional relapse was 0.718.

Conclusions

In conclusion, high AKR1C4 expression was associated with a high possibility of relapse in NPC patients, and integrating EBV DNA and AKR1C4 can stratify high-risk patients with locoregional recurrence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09924-3.

Differential regulation of CTLA4 expression through BTK-dependent and independent mechanisms in CLL

Ibrutinib suppresses CLL cell CTLA4 expression in vitro and in vivo.

CTLA4 expression on CLL is regulated by non-BTKs that differ from T-cell CTLA4 regulation.

Cytotoxic T lymphocyte antigen 4 (CTLA4) is a major immune checkpoint and target for cancer immunotherapy. Although originally discovered and primarily studied on T cells, its role on other cell types has also been recognized in recent years. Here we describe an unexpected interaction between ibrutinib (a targeted inhibitor of Bruton tyrosine kinase [BTK]) and CTLA4 expression on malignant chronic lymphocytic leukemia (CLL) cells. Although BTK itself does play a role in CTLA4 expression in CLL, we demonstrate that ibrutinib’s main suppressive effect on CTLA4 protein expression and trafficking occurs through non-BTK targets influenced by this drug. This suppression is not seen in T cells, indicating a different mechanism of CTLA4 regulation in CLL vs T cells. Appreciating this distinct mechanism and the beneficial non-BTK effects of ibrutinib may contribute to understanding the immune benefits of ibrutinib treatment and lead to therapeutic approaches to improve immune function in patients with CLL by suppressing CTLA4 expression.

Immunomodulatory Properties of Immune Checkpoint Inhibitors-More than Boosting T-Cell Responses?

The approval of immune checkpoint inhibitors (ICI) that serve to enhance effector T-cell anti-tumor responses has strongly improved success rates in the treatment of metastatic melanoma and other tumor types. The currently approved ICI constitute monoclonal antibodies blocking cytotoxic T-lymphocyte-associated protein (CTLA)-4 and anti-programmed cell death (PD)-1. By this, the T-cell-inhibitory CTLA-4/CD80/86 and PD-1/PD-1L/2L signaling axes are inhibited. This leads to sustained effector T-cell activity and circumvents the immune evasion of tumor cells, which frequently upregulate PD-L1 expression and modulate immune checkpoint molecule expression on leukocytes. As a result, profound clinical responses are observed in 40-60% of metastatic melanoma patients. Despite the pivotal role of T effector cells for triggering anti-tumor immunity, mounting evidence indicates that ICI efficacy may also be attributable to other cell types than T effector cells. In particular, emerging research has shown that ICI also impacts innate immune cells, such as myeloid cells, natural killer cells and innate lymphoid cells, which may amplify tumoricidal functions beyond triggering T effector cells, and thus improves clinical efficacy. Effects of ICI on non-T cells may additionally explain, in part, the character and extent of adverse effects associated with treatment. Deeper knowledge of these effects is required to further develop ICI treatment in terms of responsiveness of patients to treatment, to overcome resistance to ICI and to alleviate adverse effects. In this review we give an overview into the currently known immunomodulatory effects of ICI treatment in immune cell types other than the T cell compartment.

The effects of immune checkpoint modulators on the clinical course of patients with resectable hepatocellular carcinoma

Background/Aim

Immune checkpoint proteins regulating T-cell mediated anti-tumor immunity have been reported to affect clinical outcomes in multiple malignancies. This study aimed to investigate the prognostic effect of histological expression of immune checkpoint proteins in patients with resected hepatocellular carcinoma (HCC).

Methods

A total of 221 patients with HCC who underwent curative resection were included. Expression of programmed-cell death ligand-1 (PD-L1) in tumor cells (tPD-L1) and tumor infiltrating mononuclear cells (TIMCs) (iPD-L1), programmed-cell death-1 in TIMCs (iPD-1), and cytotoxic T lymphocyte antigen-4 in TIMCs (iCTLA-4) were measured immunohistochemically.

Results

Histo-positivity for iCTLA-4, iPD-1, iPD-L1, and tPD-L1 was 32.1%, 42.5%, 35.3%, and 14.9%, respectively. Multivariate logistic analyses revealed that male sex and tumor >5 cm were variables related to iCTLA-4 positivity (odds ratio [OR], 0.46 and 1.94, respectively; P<0.05). Poor differentiation was related to PD-L1 expression in both tumor cells and TIMCs (OR, 2.88 and 3.46, respectively; P<0.05). Microvascular invasion was significantly associated only with iPD-L1 (OR, 2.24; P<0.05). In time-dependent outcome analyses, expression of immune checkpoint proteins in TIMCs (i.e., iCTLA-4, iPD-1, and iPD-L1) was significantly related to longer overall survival and non-cancer-related survival (all P<0.05), but not to time-to-recurrence or cancer-specific deaths. Concurrent activation of the PD-1:PD-L1 and CTLA-4 pathways predicted improved outcomes in terms of overall survival and non-cancer related survival (P=0.06 and P=0.03, respectively).

Conclusions

Immune checkpoint proteins upregulated in TIMCs in HCC tissues have individual and additive effects in prolonging the survival of patients, specifically in terms of survival not related to cancer recurrence.

Combination of genetically engineered T cells and immune checkpoint blockade for the treatment of cancer

Immune checkpoint (IC) blockade using monoclonal antibodies is currently one of the most successful immunotherapeutic interventions to treat cancer. By reinvigorating antitumor exhausted T cells, this approach can lead to durable clinical responses. However, the majority of patients either does not respond or present a short-lived response to IC blockade, in part due to a scarcity of tumor-specific T cells within the tumor microenvironment. Adoptive transfer of T cells genetically engineered to express chimeric antigen receptors (CARs) or engineered T cell receptors (TCRs) provide the necessary tumor-specific immune cell population to target cancer cells. However, this therapy has been considerably ineffective against solid tumors in part due to IC-mediated immunosuppressive effects within tumor microenvironment. These limitations could be overcome by associating adoptive cell transfer of genetically engineered T cells and IC blockade. In this comprehensive review, we highlight the strategies and outcomes of preclinical and clinical attempts to disrupt IC signaling in adoptive T cell transfer against cancer. These strategies include combined administration of genetically engineered T cells and IC inhibitors, engineered T cells with intrinsic modifications to disrupt IC signaling and the design of CARs against IC molecules. The current landscape indicates that the synergy of the fast-paced refinements of gene-editing technologies and synthetic biology and the increased comprehension of IC signaling will certainly translate into novel and more effective immunotherapeutic approaches to treat patients with cancer.

Squamous cell carcinoma of the lung: Improving the detection and management of immune-related adverse events

INTRODUCTION

Immune checkpoint inhibitors (ICIs) have revolutionized treatment for patients with non-small lung cancer (NSCLC). Currently approved ICIs are monoclonal antibodies that target programmed death receptor 1 (PD-1), its ligand PD-L1, or CTLA-4. With ICIs comes a novel collection of toxicities: immune-related adverse events (IRAEs). Management of IRAEs requires multidisciplinary expertise. We review the biology of IRAEs and their management in patients with squamous NSCLC.

AREAS COVERED

We review the pathophysiology of ICIs and IRAEs. For IRAEs related to squamous NSCLC, Cochrane Central, EMBASE, and PubMed were queried for trials with patients with squamous cell carcinoma or adenocarcinoma histology, who were assessed for incidence rates of IRAEs. Thirteen trials met inclusion criteria. National guidelines are reviewed to outline management strategies for IRAEs.

EXPERT OPINION

IRAEs are unique compared to standard chemotherapy. As the role of ICIs expand across all stages of squamous cell NSCLC and with different combinations of antineoplastics, management of IRAEs will become crucial. Optimal management of IRAEs requires multidisciplinary teamwork. Further investigation into the pathophysiology of IRAEs can enhance current management strategies.

Combination therapy with immune checkpoint inhibitors (ICIs); a new frontier

Recently, immune checkpoint inhibitors (ICIs) therapy has become a promising therapeutic strategy with encouraging therapeutic outcomes due to their durable anti-tumor effects. Though, tumor inherent or acquired resistance to ICIs accompanied with treatment-related toxicities hamper their clinical utility. Overall, about 60-70% of patients (e.g., melanoma and lung cancer) who received ICIs show no objective response to intervention. The resistance to ICIs mainly caused by alterations in the tumor microenvironment (TME), which in turn, supports angiogenesis and also blocks immune cell antitumor activities, facilitating tumor cells' evasion from host immunosurveillance. Thereby, it has been supposed and also validated that combination therapy with ICIs and other therapeutic means, ranging from chemoradiotherapy to targeted therapies as well as cancer vaccines, can capably compromise tumor resistance to immune checkpoint blocked therapy. Herein, we have focused on the therapeutic benefits of ICIs as a groundbreaking approach in the context of tumor immunotherapy and also deliver an overview concerning the therapeutic influences of the addition of ICIs to other modalities to circumvent tumor resistance to ICIs.

Recent advances in immunotherapy for hepatocellular carcinoma

BACKGROUND

Treatment of hepatocellular carcinoma (HCC) is challenging as most patients are diagnosed at advanced stage with underlying chronic liver conditions. Conventional systemic chemotherapy has failed in HCC, and the clinical efficacy of FDA-approved molecular targeted agents such as sorafenib and lenvatinib remains unsatisfactory.

DATA SOURCES

Literature search was conducted in PubMed for relevant articles published before January 2021. The search aimed to identify recent developments in immune-based treatment approaches for HCC. Information of clinical trials was obtained from https://clinicaltrials.gov/.

RESULTS

Two immune checkpoint inhibitors (ICIs), nivolumab and pembrolizumab were approved as monotherapies, which has revolutionized HCC treatment. Besides, combination ICIs have also got accelerated FDA approval recently. Immune-based therapies have challenged targeted drugs owing to their safety, tolerability, and survival benefits. In addition to the significant success in ICIs, other immunotherapeutic strategies such as cancer vaccine, chimeric antigen receptor T-cells, natural killer cells, cytokines, and combination therapy, have also shown promising outcomes in clinical trials. Various diagnostic and prognostic biomarkers have been identified which can help in clinical decision making when starting treatment with ICIs.

CONCLUSIONS

Immunotherapy has emerged as one of the mainstream treatment modalities for advanced HCC in recent years. However, challenges such as low response rate and acquired resistance in previously respondent patients still exist. Further research is needed to understand the unique resistance mechanism to immunotherapy and to discover more predictive biomarkers to guide clinical decision making.

Enhancement of interleukin-2 production by bovine peripheral blood mononuclear cells treated with the combination of anti-programmed death-ligand 1 and cytotoxic T lymphocyte antigen 4 chimeric monoclonal antibodies

Our previous studies demonstrate the therapeutic efficacy against bovine diseases of an anti-bovine programmed death-ligand 1 (PD-L1) chimeric antibody. In humans, PD-1 and PD-L1 antibodies are more effective when combined with an antibody targeting cytotoxic T lymphocyte antigen 4 (CTLA-4) and these combination therapies are therefore clinically used. Here we generated an anti-bovine CTLA-4 chimeric antibody (chAb) to enhance the therapeutic efficacy of the PD-L1 antibody. We further analyzed the effects of dual blockade of CTLA-4 and PD-1 pathways on T-cell responses. The established anti-bovine CTLA-4 chAb showed comparable blocking activity on the binding of bovine CTLA-4 to CD80 and CD86 as the anti-bovine CTLA-4 mouse monoclonal antibody. Anti-bovine CTLA-4 chAb also significantly increased IL-2 production from bovine peripheral blood mononuclear cells (PBMCs). Further, the combination of anti-CTLA-4 chAb with anti-PD-L1 chAb significantly upregulated IL-2 production by PBMCs. These results suggest that the combination of antibodies have higher potential to enhance immune responses against pathogens compared with single administration.

Expression of immune checkpoint regulators, cytotoxic T lymphocyte antigen 4 (CTLA-4), and CD137 in cervical carcinoma

Immune checkpoint inhibitors have a significant role in oncology. One of these immune checkpoints is cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). Inhibition of the CTLA-4 pathway has already led to the FDA approval of Ipilimumab (anti-CTLA-4), a targeted therapy for melanoma and other malignancies. CD137 is an inducible, costimulatory receptor of the tissue-necrosis-factor-receptor superfamily expressed on the activated immune cells. Clinical trials have also been set for anti-CD137 in several malignancies. We assessed CTLA-4 and CD137 expression on a tissue microarray (TMA) comprising of 99 core tissues which included normal, non-neoplastic, and neoplastic cervical lesions. When detected as strong granular cytoplasmic reaction in the epithelial cells, CTLA-4 expression was scored as positive. For CD137, the results were recorded based on the presence or absence of staining reaction on the cell membranes of the lymphoplasmacytic infiltrates. Overall, CTLA-4 was positive in 30% (30/100) of the cervical malignancies. Sub-categorically, 20% of invasive endocervical adenocarcinomas, 63% of adenosquamous carcinomas, and 31% of squamous cell carcinomas were positive for CTLA-4 with a tendency toward lower grade squamous cell carcinomas (SCCs). CD137 was positive in 100% lymphoplasmacytic infiltrates of endocervical adenocarcinomas, 90.5% of SCCs, and 87.5% of adenosquamous carcinomas. This study has found a significant expression of CTLA-4 in cervical cancer cells and CD137 positivity of lymphoplasmacytic infiltrates with potential for future targeted immunotherapy.

MicroRNA and Other Non-Coding RNAs in Epstein-Barr Virus-Associated Cancers

EBV is a direct causative agent in around 1.5% of all cancers. The oncogenic properties of EBV are related to its ability to activate processes needed for cellular proliferation, survival, migration, and immune evasion. The EBV latency program is required for the immortalization of infected B cells and involves the expression of non-coding RNAs (ncRNAs), including viral microRNAs. These ncRNAs have different functions that contribute to virus persistence in the asymptomatic host and to the development of EBV-associated cancers. In this review, we discuss the function and potential clinical utility of EBV microRNAs and other ncRNAs in EBV-associated malignancies. This review is not intended to be comprehensive, but rather to provide examples of the importance of ncRNAs.

Regional Delivery of Anti-PD-1 Agent for Colorectal Liver Metastases Improves Therapeutic Index and Anti-Tumor Activity

Metastatic liver tumors have presented challenges with the use of checkpoint inhibitors (CPIs), with only limited success. We hypothesize that regional delivery (RD) of CPIs can improve activity in the liver and minimize systemic exposure, thereby reducing immune-related adverse events (irAE). Using a murine model of colorectal cancer liver metastases (LM), we confirmed high levels of PD-L1 expression on the tumor cells and liver myeloid-derived suppressor cells (L-MDSC). In vivo, we detected improved LM response at 3 mg/kg on PTD7 via portal vein (PV) regional delivery as compared to 3 mg/kg via tail vein (TV) systemic delivery (p = 0.04). The minimal effective dose at PTD7 was 5 mg/kg (p = 0.01) via TV and 0.3 mg/kg (p = 0.02) via PV. We detected 6.7-fold lower circulating CPI antibody levels in the serum using the 0.3 mg/kg PV treatment compared to the 5 mg/kg TV cohort (p < 0.001) without increased liver toxicity. Additionally, 3 mg/kg PV treatment resulted in increased tumor cell apoptotic signaling compared to 5 mg/kg TV (p < 0.05). Therefore, RD of an anti-PD-1 CPI therapy for CRCLM may improve the therapeutic index by reducing the total dose required and limiting the systemic exposure. These advantages could expand CPI indications for liver tumors.

CD11b+CTLA4+ myeloid cells are a key driver of tumor evasion in colorectal cancer

Background

Tumor metastasis is the major cause of death of colorectal cancer (CRC), and metastatic CRC remains incurable in many cases despite great advances in genetic and molecular profiling, and clinical development of numerous drugs, including immune checkpoint inhibitors. Thus, more effective treatments are urgently needed for the patients in clinical settings.

Methods

We used mouse CRC metastasis models that murine Colon26 cells were subcutaneously and intravenously implanted and attempted to elucidate the tumor biological and immunological mechanisms underlying cancer metastasis. Then, we evaluated in vivo antitumor efficacy induced by agents targeting the identified molecular mechanisms using the mouse models. We validated the clinical relevancy of the findings using peripheral blood mononuclear cells obtained from stage IV metastatic CRC patients.

Results

CD11b⁺CTLA4⁺ myeloid cells were systemically expanded in the metastatic settings and facilitated tumor progression and metastasis directly via generating lipid droplets in tumor cells and indirectly via inducing immune exhaustion. These events were mediated by IL1B produced via the CTLA4 signaling from the increased myeloid cells. Blocking CTLA4 and IL1B with the specific mAbs significantly suppressed tumor progression and metastasis in the mouse models resistant to anti-PD1 therapy, and the therapeutic efficacy was optimized by blocking cyclooxygenases with aspirin.

Conclusions

The CD11b⁺CTLA4⁺ cells are a key driver of tumor evasion, and targeting the CTLA4-IL1B axis could be a promising strategy for treating metastatic CRC. The triple combination regimen with anti-CTLA4/IL1B mAbs and aspirin may be useful in clinical settings.

Advances in the Pathogenesis of EBV-Associated Diffuse Large B Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin's lymphoma (NHL) in adults. Epstein-Barr virus (EBV) positive DLBCL of the elderly was defined by the World Health Organization (WHO) in 2008, it was restricted only to patients older than 50 years old, and it was attributed to immunesenescence associated with physiological aging. After the description of EBV-associated DLBCL in children and young adults, the WHO redefined the definition, leading to the substitution of the modifier "elderly" with "not otherwise specified" (EBV + DLBCL, NOS) in the updated classification, and it is no more considered provisional. The incidence of EBV + DLBCL, NOS varies around the world, in particular influenced by the percentage of EBV+ cells used as cut-off to define a case as EBV-associated. EBV has effect on the genetic composition of tumor cells, on survival, and at the recruitment of immune cells at the microenvironment. In this review, the role of EBV in the pathogenesis of DLBCL is discussed.

Design, Synthesis, and Evaluation of o-(Biphenyl-3-ylmethoxy)nitrophenyl Derivatives as PD-1/PD-L1 Inhibitors with Potent Anticancer Efficacy In Vivo

Two series of novel o-(biphenyl-3-ylmethoxy)nitrophenyl compounds (A1-31 and B1-17) were designed as programmed cell death protein 1 (PD-1)/PD-ligand 1 (PD-L1) inhibitors. All compounds showed significant inhibitory activity with IC₅₀ values ranging from 2.7 to 87.4 nM except compound A17, and compound B2 displayed the best activity. Further experiments showed that B2 bound to the PD-L1 protein without obvious toxicity in Lewis lung carcinoma (LLC) cells. Furthermore, B2 significantly promoted interferon-gamma secretion in a dose-dependent manner in vitro and in vivo. Especially, B2 exhibited potent in vivo anticancer efficacy in an LLC-bearing allograft mouse model at a low dose of 5 mg/kg, which was more active than BMS-1018 (tumor growth inhibition rate: 48.5% vs 17.8%). A panel of immunohistochemistry and flow cytometry assays demonstrated that B2 effectively counteracted PD-1-induced immunosuppression in the tumor microenvironment, thereby triggering antitumor immunity. These results indicate that B2 is a promising PD-1/PD-L1 inhibitor worthy of further development.

The Clinical Value of VDR and CTLA 4 in Evaluating the Prognosis of Invasive Duct Carcinoma of Egyptian Patients and their Benefit as a Target Therapy

OBJECTIVE

Breast cancer represents the second most common female malignancies worldwide  and  the most common in Egypt. The nuclear vitamin D receptor plays a role in the biology of cancer by affecting inflammatory microenvironment. The aim of this study is to evaluate the role of VDR and CTLA 4 in invasive duct carcinoma of Egyptian patients.

METHODS

This is a retrospective study that included 70 invasive duct carcinoma specimens retrieved from the archival material of Pathology Department, Faculty of medicine, Menoufia University, Egypt, spanning the period between January 2010 and December 2017. All cases were stained for VDR and CTLA 4 antibodies.

RESULTS

There is significant association between high VDR expression in tumor cells and parameters of good prognosis as low tumor stage (T1) and (N0) stage. On the other hand, there is significant association between low CTLA4 tumor expression and good prognostic parameters as low tumor stage (T1) and absent vascular invasion. Regarding lymphocyte expression, there is significant association between positive CTLA4 expression in lymphocytes and parameters of good prognosis as absent metastasis. High VDR tumor expression is the most independent prognostic factor on overall survival of breast carcinoma patients.

CONCLUSION

high VDR expression in tumor cells is associated with good prognostic parameters and is the most independent prognostic factor on overall survival  so it might be of benefit as a target therapy for Egyptian invasive duct carcinoma patients and VDR might augment the expression of CTLA-4, So tailored  immunotherapy might have an impact on invasive duct carcinoma patients.<br />.

Abnormal alternative splicing promotes tumor resistance in targeted therapy and immunotherapy

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Abnormal alternative splicing is involve in abnormal expression of genes in cancer.

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Abnormal alternative splicing events promote malignant progression of cancer.

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Abnormal alternative splicing develops tumor resistance to targeted therapy by changing the target point and signal transduction pathway.

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Abnormal alternative splicing develops tumor resistance to immunotherapy by changing cell surface antigens and protein structure.

Abnormally alternative splicing events are common hallmark of diverse types of cancers. Splicing variants with aberrant functions play an important role in cancer development. Most importantly, a growing body of evidence has supported that alternative splicing might play a significant role in the therapeutic resistance of tumors. Targeted therapy and immunotherapy are the future directions of tumor therapy; however, the loss of antigen targets on the tumor cells surface and alterations in drug efficacy have resulted in the failure of targeted therapy and immunotherapy. Interestingly, abnormal alternative splicing, as a strategy to regulate gene expression, is reportedly involved in the reprogramming of cell signaling pathways and epitopes on the tumor cell surface by changing splicing patterns of genes, thus rendering tumors resisted to targeted therapy and immunotherapy. Accordingly, increased knowledge regarding abnormal alternative splicing in tumors may help predict therapeutic resistance during targeted therapy and immunotherapy and lead to novel therapeutic approaches in cancer. Herein, we provide a brief synopsis of abnormal alternative splicing events in cancer progression and therapeutic resistance.

Expression of Immune Checkpoint Regulators, Cytotoxic T-Lymphocyte Antigen-4, and Programmed Death-Ligand 1 in Epstein-Barr Virus-associated Nasopharyngeal Carcinoma

BACKGROUND

Nasopharyngeal carcinoma (NPC) is the most common cancer arising from the nasopharynx with a poor prognosis. Targeting immune checkpoint is one of the new promising lines in cancer treatment. Cytotoxic T-lymphocyte antigen-4 (CTLA-4) and programmed death-ligand 1 (PD-L1) are immune checkpoints that regulate T-cell immune function.

AIM

This work aimed to assess the immunohistochemical expression of PD-L1 and CTLA-4 in NPC and their ability to predict survival and response therapy and to check their validity as immunotherapy targets. Twenty-six cases of NPC were studied by immunohistochemistry for PD-L1 and CTLA-4 and by nested polymerase chain reaction followed by DNA sequencing for the presence of EBNA-1 gene of Epstein-Barr virus (EBV). All investigated cases were diagnosed and treated in the Zagazig University Hospital in the period from August 2015 to July 2018. EBNA-1 gene was identified in 84.6% of the cases. Whereas the expression of PD-L1 was noted in 46.2% of all cases studied, 54.6% of EBV-associated NPCs were found to express PD-L1. There was a significant association between PD-L1 expression and the advanced stage of the tumor (P<0.001). CTLA-4 expression was observed in 88.4% of all NPC cases as cytoplasmic staining in both tumor cells and tumor-infiltrating lymphocytes. CTLA-4 expression in lymphocytes was associated with the presence of EBV. A significant association was detected between CTLA-4 and tumor-infiltrating lymphocyte expression on one side and the stage of the tumor on the other. High expression of CTLA-4 was significantly associated with disease progression and worse overall survival.

CONCLUSION

PD-L1 and CTLA-4 are adverse prognostic markers in NPC. The authors propose that targeted therapy against PD-L1 and CTLA-4 will be a hopeful therapy for cases of NPC with resistance to concurrent chemoradiation treatment in Egypt, especially EBV-associated cases.

Current and Future Therapeutic Targets: A Review on Treating Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) continues to be a global public health burden even after a tremendous development in its treatment. It is a heterogeneous cancer of upper aero-digestive tract. The contemporary strategy to treat cancer is the use of anticancer drugs against proteins possessing abnormal expression. Targeted chemotherapy was found successful in HNSCC, but, there is still a stagnant improvement in the survival rates and high recurrence rates due to undesirable chemotherapy reactions, non-specificity of drugs, resistance against drugs and drug toxicity on non-cancerous tissues and cells. Various extensive studies lead to the identification of drug targets capable to treat HNSCC effectively. The current review article gives an insight into these promising anticancer targets along with knowledge of drugs under various phases of development. In addition, new potential targets that are not yet explored against HNSCC are also described. We believe that exploring and developing drugs against these targets might prove beneficial in treating HNSCC.

Beyond T-Cells: Functional Characterization of CTLA-4 Expression in Immune and Non-Immune Cell Types

The immune response consists of a finely-tuned program, the activation of which must be coupled with inhibitory mechanisms whenever initiated. This ensures tight control of beneficial anti-pathogen and anti-tumor responses while preserving tissue integrity, promoting tissue repair, and safeguarding against autoimmunity. A cogent example of this binary response is in the mobilization of co-stimulatory and co-inhibitory signaling in regulating the strength and type of a T-cell response. Of particular importance is the costimulatory molecule CD28 which is countered by CTLA-4. While the role of CD28 in the immune response has been thoroughly elucidated, many aspects of CTLA-4 biology remain controversial. The expression of CD28 is largely constrained to constitutive expression in T-cells and as such, teasing out its function has been somewhat simplified by a limited and specific expression profile. The expression of CTLA-4, on the other hand, while reported predominantly in T-cells, has also been described on a diverse repertoire of cells within both lymphoid and myeloid lineages as well as on the surface of tumors. Nonetheless, the function of CTLA-4 has been mostly described within the context of T-cell biology. The focus on T-cell biology may be a direct result of the high degree of amino acid sequence homology and the co-expression pattern of CD28 and CTLA-4, which initially led to the discovery of CTLA-4 as a counter receptor to CD28 (for which a T-cell-activating role had already been described). Furthermore, observations of the outsized role of CTLA-4 in T_reg-mediated immune suppression and the striking phenotype of T-cell hyperproliferation and resultant disease in CTLA-4^−/− mice contribute to an appropriate T-cell-centric focus in the study of CTLA-4. Complete elucidation of CTLA-4 biology, however, may require a more nuanced understanding of its role in a context other than that of T-cells. This makes particular sense in light of the remarkable, yet limited utility of anti-CTLA-4 antibodies in the treatment of cancers and of CTLA-4-Ig in autoimmune disorders like rheumatoid arthritis. By fully deducing the biology of CTLA-4-regulated immune homeostasis, bottlenecks that hinder the widespread applicability of CTLA-4-based immunotherapies can be resolved.

Identification of a Novel Immune-Related Prognostic Biomarker and Small-Molecule Drugs in Clear Cell Renal Cell Carcinoma (ccRCC) by a Merged Microarray-Acquired Dataset and TCGA Database

Clear cell renal cell carcinoma (ccRCC) is one of the most common histological subtypes of renal cancer, with a poor prognosis. Our study aimed to identify a biomarker that is significantly associated with ccRCC prognosis and novel immunotherapeutic targets, as well as some novel molecular drugs for ccRCC. Based on the overlap of The Cancer Genome Atlas (TCGA)-Kidney Renal Clear Cell Carcinoma (KIRC) data and the ImmPort database, we obtained 1,292 immune-related genes (IRGs) and constructed a weighed co-expression network based on the IRGs. A total of 39 hub genes were screened out in three modules. CTLA4, which had the highest connectivity degree among the screened genes in a protein–protein interaction network (degree = 24), was selected. Internal validation based on the GEPIA database revealed that patients with a higher expression of CTLA4 had a significantly shorter overall survival time and disease-free survival time. Expression of CTLA4 was also closely correlated with local recurrence, pathologic stage, and immune infiltration level. External validation based on the Oncomine database and merged microarray-acquired dataset validated the mRNA expression level of hub genes. Gene-set enrichment analysis revealed that six KEGG signaling pathways, which were significantly associated with CTLA4, were enriched on immune-related pathways. Further analysis according to the TIMER database demonstrated that CTLA4 expression was positively related to dendritic cells (cor = 0.446, P = 1.32E-23) and negatively associated with tumor purity (cor = −0.267, P = 5.51E-09). Finally, we screened out 293 differentially expressed genes by integrating six datasets from the GEO database. The Connectivity Map (CMap) analysis revealed the strong potential of three small molecule drugs (monensin, quercetin, and fenbufen) for ccRCC treatment. In conclusion, CTLA4 was identified and validated in prognosis of ccRCC. CTLA4 may be a new prognostic biomarker and immunotherapeutic target for ccRCC. Monensin, quercetin, and fenbufen may be novel choices for ccRCC treatment.

Clinical burden of immune checkpoint inhibitor-induced pneumonitis

Immune checkpoint inhibitors (ICIs) have been a breakthrough in medical oncology. However, many patients experience a novel type of adverse drug reaction that has a unique clinical presentation, called immune-related adverse events (irAEs). A breakdown of self-tolerance and an exaggerated autoimmune reaction by the host are assumed to be the underlying mechanisms. Therefore, special attention to the optimal diagnosis and management is required. Among the various effects of irAE, pneumonitis has been recognized as an important manifestation because of its high morbidity and mortality. As the application of ICIs is expanding to a wider variety of tumor types, as well as its use with cytotoxic agents and radiation, clinicians are highly likely to encounter this complication. In this review, we will summarize the current understanding of the underlying mechanisms, incidence, risk factors, optimal diagnostic workup, and management of ICI-related pneumonitis (IRP). We will also review fundamental information on drug-induced lung toxicity in the oncology setting. In addition, research perspectives focused on better risk stratification and management to avoid serious complications in the future are presented.

News on immune checkpoint inhibitors as immunotherapy strategies in adult and pediatric solid tumors

Immune checkpoint inhibitors (ICIs) have shown unprecedented benefits in various adult cancers, and this success has prompted the exploration of ICI therapy even in childhood malignances. Although the use of ICIs as individual agents has achieved disappointing response rates, combinational therapies are likely to promise better results. However, only a subset of patients experienced prolonged clinical effects, thus suggesting the need to identify robust bio-markers that predict individual clinical response or resistance to ICI therapy as the main challenge. In this review, we focus on how the use of ICIs in adult cancers can be translated into pediatric malignances. We discuss the physiological mechanism of action of each IC, including PD-1, PD-L1 and CTLA-4 and the new emerging ones, LAG-3, TIM-3, TIGIT, B7-H3, BTLA and IDO-1, and evaluate their prognostic value in both adult and childhood tumors. Furthermore, we offer an overview of preclinical models and clinical trials currently under investigation to improve the effectiveness of cancer immunotherapies in these patients. Finally, we outline the main predictive factors that influence the efficacy of ICIs, in order to lay the basis for the development of a pan-cancer immunogenomic model, able to direct young patients towards more specific immunotherapy.

Prognostic impacts of tumoral expression and serum levels of PD-L1 and CTLA-4 in colorectal cancer patients

BACKGROUND

Programmed cell death ligand-1 (PD-L1) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) play a pivotal role in cancer immunotherapy. Each of these molecules has a membrane-bound receptor form (mPD-L1/mCTLA-4) and a soluble form (sPD-L1/sCTLA-4). However, these prognostic impacts in colorectal cancer (CRC) remain unclear.

METHODS

We immunohistochemically scored tumoral mPD-L1/mCTLA-4 expression and quantified preoperative circulating sPD-L1/sCTLA-4 levels using matched serum specimens from 131 patients with pStage I-III CRC. We also examined the association between these statuses and tumor infiltrating lymphocytes (TILs) in these patients.

RESULTS

Elevated levels of mPD-L1, mCTLA-4, sPD-L1 and sCTLA-4 were significantly correlated with poor overall survival (OS) and disease-free survival (DFS). Co-high expression of tumoral mPD-L1 and mCTLA-4 or co-elevated levels of serum sPD-L1 and sCTLA-4 were strongly correlated with poor OS and DFS. Multivariate analysis revealed that both statuses were negative independent prognostic factors for OS [hazard ratio (HR) 3.86, 95% confidence interval (95% CI) 1.71-8.51, p = 0.001; HR 5.72, 95% CI 1.87-14.54, p = 0.004, respectively] and DFS (HR 2.53, 95% CI 1.23-4.95, p = 0.01; HR 6.88, 95% CI 2.42-17.13, p = 0.0008, respectively). Although low expression of tumoral mCTLA-4 was significantly correlated with increased CD8(+) TILs, there was no correlation in any other combination.

CONCLUSIONS

We verified the prognostic impacts of mPD-L1, mCTLA-4, sPD-L1 and sCTLA-4 in pStage I-III CRC patients. Dual evaluation of immune checkpoint molecules in primary tissues or preoperative serum could identify a patient population with poor prognosis in these patients.

Novel Therapies Boosting T Cell Immunity in Epstein Barr Virus-Associated Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant tumour of the head and neck affecting localised regions of the world, with the highest rates described in Southeast Asia, Northern Africa, and Greenland. Its high morbidity rate is linked to both late-stage diagnosis and unresponsiveness to conventional anti-cancer treatments. Multiple aetiological factors have been described including environmental factors, genetics, and viral factors (Epstein Barr Virus, EBV), making NPC treatment that much more complex. The most common forms of NPCs are those that originate from the epithelial tissue lining the nasopharynx and are often linked to EBV infection. Indeed, they represent 75–95% of NPCs in the low-risk populations and almost 100% of NPCs in high-risk populations. Although conventional surgery has been improved with nasopharyngectomy’s being carried out using more sophisticated surgical equipment for better tumour resection, recent findings in the tumour microenvironment have led to novel treatment options including immunotherapies and photodynamic therapy, able to target the tumour and improve the immune system. This review provides an update on the disease’s aetiology and the future of NPC treatments with a focus on therapies activating T cell immunity.

The Resistance Mechanisms of Checkpoint Inhibitors in Solid Tumors

The emergence of cancer immunotherapy has already shown some remarkable results, having changed the treatment strategy in clinical practice for solid tumors. Despite these promising long-term responses, patients seem to lack the ability to respond to immune checkpoint inhibitors, thus demonstrating a primary resistance to immunotherapy. Moreover, a significant number of patients who initially respond to treatment eventually acquire resistance to immunotherapy. Both resistance mechanisms are a result of a complex interaction among different molecules, pathways, and cellular processes. Several resistance mechanisms, such as tumor microenvironment modification, autophagy, genetic and epigenetic alterations, tumor mutational burden, neo-antigens, and modulation of gut microbiota have already been identified, while more continue to be uncovered. In this review, we discuss the latest milestones in the field of immunotherapy, resistance mechanisms against this type of therapy as well as putative therapeutic strategies to overcome resistance in solid tumors.

Establishment and Characterization of Humanized Mouse NPC-PDX Model for Testing Immunotherapy

Immune checkpoint blockade (ICB) monotherapy shows early promise for the treatment of nasopharyngeal carcinoma (NPC) in patients. Nevertheless, limited representative NPC models hamper preclinical studies to evaluate the efficacy of novel ICB and combination regimens. In the present study, we engrafted NPC biopsies in non-obese diabetic-severe combined immunodeficiency interleukin-2 receptor gamma chain-null (NSG) mice and established humanized mouse NPC-patient-derived xenograft (NPC-PDX) model successfully. Epstein–Barr virus was detected in the NPC in both NSG and humanized mice as revealed by Epstein–Barr virus-encoded small RNA (EBER) in situ hybridization (ISH) and immunohistochemical (IHC) staining. In the NPC-bearing humanized mice, the percentage of tumor-infiltrating CD8⁺ cytotoxic T cells was lowered, and the T cells expressed higher levels of various inhibitory receptors, such as programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) than those in blood. The mice were then treated with nivolumab and ipilimumab, and the anti-tumor efficacy of combination immunotherapy was examined. In line with paired clinical data, the NPC-PDX did not respond to the treatment in terms of tumor burden, whilst an immunomodulatory response was elicited in the humanized mice. From our results, human proinflammatory cytokines, such as interferon-gamma (IFN-γ) and interleukin-6 (IL-6) were significantly upregulated in plasma. After treatment, there was a decrease in CD4/CD8 ratio in the NPC-PDX, which also simulated the modulation of intratumoral CD4/CD8 profile from the corresponding donor. In addition, tumor-infiltrating T cells were re-activated and secreted more IFN-γ towards ex vivo stimulation, suggesting that other factors, including soluble mediators and metabolic milieu in tumor microenvironment may counteract the effect of ICB treatment and contribute to the tumor progression in the mice. Taken together, we have established and characterized a novel humanized mouse NPC-PDX model, which plausibly serves as a robust platform to test for the efficacy of immunotherapy and may predict clinical outcomes in NPC patients.

The landscape of CD28, CD80, CD86, CTLA4, and ICOS DNA methylation in head and neck squamous cell carcinomas

CTLA-4 blocking therapeutic antibodies are currently under investigation in head and neck squamous cell carcinoma (HNSCC). A better understanding of the epigenetic regulation of the CD28 superfamily members CD28, CTLA-4, and ICOS and their B7 ligands, CD80 and CD86, could support the development of biomarkers for response prediction to anti-CTLA-4 immunotherapy. We investigated methylation of the encoding genes CD28, CTLA4, ICOS, CD80, and CD86 at single CpG resolution (51 CpG sites) in a cohort of HNSCC (N = 528) and normal adjacent tissue samples (N = 50) provided by The Cancer Genome Research Atlas, in isolated blood leukocytes from healthy individuals (N = 28), and HNSCC cell lines (N = 39). We analysed methylation levels with regard to mRNA expression, overall survival, mutational load, interferon-γ signature, and signatures of immune cell infiltrates. Depending on the location of the CpG sites (promoter, promoter flank, gene body, and intergenic sites), we found significant differences in methylation levels among isolated leukocytes, between leukocytes and HNSCC cell lines, and among HNSCCs. Methylation of all analysed genes correlated inversely or positively with mRNA expression, depending on the CpG site. CD28, CTLA4, and ICOS revealed almost identical correlation patterns. Furthermore, we found significant correlations with survival and features of response to immunotherapy, i.e. interferon-γ signature, signatures of tumour infiltrating immune cells, and mutational load. Our results suggest CD28, CTLA4, ICOS, CD80, and CD86 expression levels are epigenetically co-regulated by DNA methylation. This study provides rationale to test their DNA methylation as potential biomarker for prediction of response to CTLA-4 immune checkpoint inhibitors.

The yin and yang of co-inhibitory receptors: toward anti-tumor immunity without autoimmunity

Co-inhibitory receptors are important regulators of T-cell function that define the balance between tolerance and autoimmunity. The immune regulatory function of co-inhibitory receptors, including CTLA-4, PD-1, TIM-3, TIGIT, and LAG-3, was first discovered in the setting of autoimmune disease models, in which their blockade or deficiency resulted in induction or exacerbation of the disease. Later on, co-inhibitory receptors on lymphocytes have also been found to influence outcomes in tumor and chronic viral infection settings. These receptors suppress T-cell function in the tumor microenvironment (TME), thereby making the T cells dysfunctional. Based on this observation, blockade of co-inhibitory receptors (also known as checkpoint molecules) has emerged as a successful treatment option for a number of human cancers. However, severe autoimmune-like side effects limit the use of therapeutics that block individual or combinations of co-inhibitory receptors for cancer treatment. In this review we provide an overview of the role of co-inhibitory receptors in autoimmunity and anti-tumor immunity. We then discuss current approaches and future directions to leverage our knowledge of co-inhibitory receptors to target them in tumor immunity without inducing autoimmunity.

Tumor-infiltrating regulatory T cells, CD8/Treg ratio, and cancer stem cells are correlated with lymph node metastasis in patients with early breast cancer

BACKGROUND

Tumor-infiltrating lymphocytes are an important component of the tumor microenvironment (TME) in breast cancer. They have been linked with tumor pathogenesis in advanced stages. However, little is known about their contribution in early phases. In this study, we analyzed the infiltration of leukocytes and cancer stem cells (CSC) in tumors from patients with early breast cancer.

METHODS

Samples of blood and tumor tissue from 30 patients with breast cancer were collected, and the number of dendritic cells (DC), T cells, and CSC were analyzed by flow cytometry.

RESULTS

Tumor-infiltrating CD4 and CD8 T cells expressed higher levels of cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) compared with peripheral T cells. Regulatory T cells (Treg) were enriched in tumors and overexpressed glucocorticoid-induced TNFR-related protein and CTLA-4. Tumor Treg had a positive correlation with the amount of myeloid DC (mDC) and disease progression. The CD8/Treg ratio was associated with lymph node metastasis and tumor stages. The main subset of DC in early breast tumors was mDC, while plasmacytoid DC were almost absent. CSC were present in most tumors with higher frequencies in patients with lymph node metastasis. CSC were also associated with the amount of tumor-infiltrating Treg.

CONCLUSION

Early breast cancer has an inflammatory milieu characterized by mDC, Treg, and CSC infiltration. The frequencies of Treg, CSC and CD8/Treg ratio were associated with disease progression. The composition of leukocytes and the presence of CSC in early breast tumors should be considered for the development of new therapeutic approaches.

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.

The immune checkpoints CTLA-4 and PD-L1 in carcinomas of the uterine cervix

BACKGROUND

Evasion of immune control is a major feature of malignant tumors. This tumor aspect is poorly studied in cervical lesions.

AIM OF THE STUDY

To investigate the expression of PD-L1 and CTLA-4 in lesions of the uterine cervix.

MATERIAL AND METHODS

Sixty-three cervical lesions from 52 patients were immunohistochemically studied. The 63 lesions included 27 invasive adenocarcinomas, 19 squamous cell carcinomas (SCCs), 7 adenocarcinomas in situ, and 10 high-grade squamous intraepithelial lesions (CIN3).

RESULTS

CTLA-4 and PD-L1 tumor cell expression was found in 61.5 % and 26.9 % of the invasive cases, respectively. CTLA-4 tumor cell expression and PD-L1 tumor and immune cell expression were more often found in SCCs than in adenocarcinomas. CTLA-4 tumor cell expression was more often found in advanced FIGO tumors. PD-L1 and CTLA-4 immune cell expression was associated with lymph node metastasis. CTLA-4 expression did not affect survival. The prognosis was worse for PD-L1-expressing tumors.

CONCLUSION

CTLA-4 and PD-L1 are potential therapeutic targets in cervical cancer.

Prevalence of DLL3, CTLA-4 and MSTN Expression in Patients with Small Cell Lung Cancer

Introduction

Immune-based and antibody-drug conjugate therapies have shown promise in the treatment of patients with small cell lung cancer (SCLC). However, better predictive biomarkers are needed for selection of the appropriate SCLC patients for these advanced therapies and also for evaluation of the efficacy of these treatments.

Objective

The aim of this study was to examine the expression of delta-like protein 3 (DLL3), cytotoxic T lymphocyte-associated protein 4 (CTLA-4), and mesothelin (MSTN) in patients with SCLC and compare them with those patients’ clinical characteristics.

Methods

Immunohistochemical analyses of DLL3, CTLA-4 and MSTN expression were performed in 38 samples from patients with SCLC.

Results

We found that positive expression in patients of the biomarkers was as follows: for DLL3, 100% (38/38), for CTLA-4, 89.5% (36/38) and for MSTN 81.5% (31/38). The median survival time was 17.9 months in the DLL3 high expression group and 23 months in the DLL3 low expression group. Patients with a high expression of DLL3 showed a poorer prognosis than those with a low expression of DLL3 (HR=3.4; 95% CI, 1.34–8.6; p=0.01).

Conclusion

The expression of DLL3, CTLA-4 and MSTN was not correlated with patients’ age, sex, smoking status, stage, and tumor metastasis. The fact that there was a higher expression of DLL3, CTLA-4, and MSTN in SCLC suggested that these molecules could be used as predictive biomarkers for SCLC.

Evaluation of Laboratory Application of Camelid Sera Containing Heavy-Chain Polyclonal Antibody Against Recombinant Cytotoxic T-Lymphocyte-Associated Protein-4

Cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) is a critical negative immunomodulatory receptor that is normally expressed in activated T cells and noticeably, in many cancerous cells. Indeed, molecular detection of CTLA-4 protein is crucial in basic research. In this work, the extracellular domain of the human CTLA-4 (hCTLA-4) protein was cloned, expressed, and purified. Subsequently, this protein was used as an antigen for camel (Camelus dromedarius) immunization to obtain polyclonal camelid sera against this protein. Furthermore, we evaluated the benefits of applying camelid hyperimmune sera containing heavy-chain antibodies in different antibody-based techniques. Our results indicated that hCTLA-4 protein was successfully expressed in the prokaryotic system. The polyclonal antibody (pAb) that raised against recombinant hCTLA-4 protein was able to detect the CTLA-4 protein in antibody-based techniques, such as enzyme-linked immunosorbent assay, western blotting, flow cytometry and immunohistochemistry (IHC) staining. This study shows that, due to the advantages such as multi-epitope-binding ability, camelid pAbs are potent to efficiently apply for molecular detection of CTLA-4 receptors in fundamental antibody-based researches such as IHC.

The Common Costimulatory and Coinhibitory Signaling Molecules in Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinomas (HNSCCs) are closely linked with immunosuppression, accompanied by complex immune cell functional activities. The abnormal competition between costimulatory and coinhibitory signal molecules plays an important role in the malignant progression of HNSCC. This review will summarize the features of costimulatory molecules (including CD137, OX40 as well as CD40) and coinhibitory molecules (including CTLA-4, PD-1, LAG3, and TIM3), analyze the underlying mechanism behind these molecules' regulation of the progression of HNSCC, and introduce the clinic application. Vaccines, such as those targeting STING while working synergistically with monoclonal antibodies, are also discussed. A deep understanding of the tumor immune landscape will help find new and improved tumor immunotherapy for HNSCC.

Immunotherapeutic approaches in nasopharyngeal carcinoma

Introduction: Nasopharyngeal carcinoma (NPC) is endemic in Southern China and Southeast Asia. Epstein-Barr virus (EBV) represents a unique etiological culprit in the poorly differentiated nonkeratinizing and undifferentiated subtypes. EBV antigens are expressed on tumor cells albeit in a restricted manner. Treatment options for recurrent or metastatic disease are limited. Nevertheless, emerging data from immunotherapy studies in NPC have shed light into their potential antitumor efficacy. Areas covered: This article reviews existing clinical evidence for different immunotherapeutic approaches for NPC, including adoptive cellular therapy, therapeutic cancer vaccines, and immune checkpoint inhibitors. Expert opinion: There is a growing understanding on EBV virology and the immune evasion mechanisms in NPC. Immunotherapeutic strategies leveraging these properties have shown encouraging efficacy and safety results in early-phase clinical studies. Moving forward, areas to be addressed include appropriate patient selection, optimal incorporation into standard treatment paradigms, biomarker identification, as well as the development of scalable and reproducible immune product generation processes.