LAG-3 in Non-Small-cell Lung Cancer: Expression in Primary Tumors and Metastatic Lymph Nodes Is Associated With Improved Survival

PD-1 and LAG-3 positive T cells are related with the prognosis of patients with chronic kidney disease

OBJECTIVE

Our objective was to study the frequency of circulating LAG-3+ and PD-1+ T cells in chronic kidney disease (CKD) patients and their correlation with cytokines and patient prognosis.

METHODS

A total of 83 patients with CKD between June 2020 and June 2022 were enrolled. We measured serum levels of IL-6, CRP, IL-1β, and TNF-α by ELISA. The frequency of PD-1+ and LAG-3+ T cells was measured using flow cytometry. All patients were followed up for 1 year, and the occurrence of any of the following conditions during the follow-up period was considered as major adverse cardiac events (MACE) indicating poor prognosis.

RESULTS

The frequencies of LAG-3+PD-1+, LAG-3+ and PD-1+ cells were significantly increased in CKD group compared to healthy volunteers. Additionally, CKD patients had remarkably enhanced levels of cytokines. Compared to the non-MACE group, MACE group had significantly higher frequencies of LAG-3PD-1, LAG-3 and PD-1 expression on CD8 and CD4. Positive correlations were observed between IL-1β, IL-6 and frequencies of PD-1+LAG-3+. CD4+LAG-3+PD-1+ frequency displayed the highest diagnostic value for CKD patients with MACE. Moreover, CD8+LAG-3+, CD4+LAG-3+PD-1+, CD4+PD-1+, IL-1β and IL-6 were identified as risk factors for the occurrence of MACE in patients with CKD.

CONCLUSION

In summary, the present research showed that the frequencies of LAG-3+ and PD-1+ T cells were remarkably enhanced in CKD patients. These findings offer novel insights and potential therapeutic targets for the management of CKD.

Lymphocyte-activation gene 3 protein expression in tumor-infiltrating lymphocytes is associated with a poor prognosis of ovarian clear cell carcinoma

BACKGROUND

Histological analysis has revealed the need for new treatment techniques for epithelial ovarian cancer. Immune checkpoint inhibitors may be a new therapeutic strategy for ovarian clear cell carcinoma (OCCC). Lymphocyte-activation gene 3 (LAG-3), an immune checkpoint, is a poor prognostic factor and a new therapeutic target for several malignancies. In this study, we demonstrated the correlation between LAG-3 expression and the clinicopathological features of OCCC. We evaluated LAG-3 expression in tumor-infiltrating lymphocytes (TILs) via immunohistochemical analysis using tissue microarrays containing surgically resected specimens from 171 patients with OCCC.

RESULTS

The number of LAG-3-positive cases was 48 (28.1%), whereas the number of LAG-3-negative cases was 123 (71.9%). LAG-3 expression significantly increased in patients with advanced stages (P = 0.036) and recurrence (P = 0.012); however, its expression did not correlate with age (P = 0.613), residual tumor (P = 0.156), or death (P = 0.086). Using the Kaplan - Meier method, LAG-3 expression was found to be correlated with poor overall survival (P = 0.020) and progression-free survival (P = 0.019). Multivariate analysis revealed LAG-3 expression (hazard ratio [HR] = 1.86; 95% confidence interval [CI], 1.00 - 3.44, P = 0.049) and residual tumor (HR = 9.71; 95% CI, 5.13 - 18.52, P < 0.001) as independent prognostic factors.

CONCLUSION

Our study demonstrated that LAG-3 expression in patients with OCCC may be a useful biomarker for the prognosis of OCCC and could serve as a new therapeutic target.

Impact of microvessel patterns and immune status in NSCLC: a non-angiogenic vasculature is an independent negative prognostic factor in lung adenocarcinoma

Introduction

Non-small cell lung carcinomas (NSCLC) exhibit different microvessel patterns (MVPs). Basal (BA), diffuse (DA) and papillary (PA) patterns show signs of angiogenesis (new blood vessels), while an alveolar pattern indicates that tumors are co-opting existing normal vessels (non-angiogenic alveolar, NAA). NAA tumor growth is known to exist in NSCLC, but little is known about its prognostic impact in different histological subgroups, and about associations between MVPs and immune cell infiltration.

Methods

Detailed patterns of angiogenic and non-angiogenic tumor growth were evaluated by CD34 immunohistochemistry in whole tissue slides from 553 surgically treated patients with NSCLC stage I-IIIB disease. Associations with clinicopathological variables and markers related to tumor immunology-, angiogenesis- and hypoxia/metabolism were explored, and disease-specific survival (DSS) was analyzed according to histological subtypes.

Results

The predominant MVP was angiogenic in 82% of tumors: BA 40%, DA 34%, PA 8%, while a NAA pattern dominated in 18%. A contribution of the NAA pattern >5% (NAA+), i.e., either dominant or minority, was observed in 40.1% of tumors and was associated with poor disease-specific survival (DSS) (p=0.015). When stratified by histology, a significantly decreased DSS for NAA+ was found for adenocarcinomas (LUAD) only (p< 0.003). In multivariate analyses, LUAD NAA+ pattern was a significant independent prognostic factor; HR 2.37 (CI 95%, 1.50-3.73, p< 0.001). The immune cell density (CD3, CD4, CD8, CD45RO, CD204, PD1) added prognostic value in squamous cell carcinoma (LUSC) and LUAD with 0-5% NAA (NAA-), but not in LUAD NAA+. In correlation analyses, there were several significant associations between markers related to tumor metabolism (MCT1, MCT4, GLUT1) and different MVPs.

Conclusion

The NAA+ pattern is an independent poor prognostic factor in LUAD. In NAA+ tumors, several immunological markers add prognostic impact in LUSC but not in LUAD.

Recently approved and emerging monoclonal antibody immune checkpoint inhibitors for the treatment of advanced non-small cell lung cancer

INTRODUCTION

CTLA-4/PD-1/PD-L1- directed immune checkpoint inhibitors (ICIs) are one of the standard therapies for the treatment of advanced non-small cell lung cancer (NSCLC). However, some new classes of monoclonal antibodies are emerging as promising therapies for advanced NSCLC.

AREAS COVERED

Therefore, this paper aims to provide a comprehensive review of the recently approved as well as emerging monoclonal antibody immune checkpoint inhibitors for the treatment of advanced NSCLC.

EXPERT OPINION

Further and larger studies will be needed to explore the promising emerging data on new ICIs. Future phase III trials could allow us to properly assess the role of each immune checkpoints in the wider context of the tumor microenvironment and thus the best new ICIs to use, the best approach and the most effective subset of patients to select.

Clinicopathological significance and prognostic role of LAG3 + tumor-infiltrating lymphocytes in colorectal cancer; relationship with sidedness

BACKGROUND

It is well-documented that the interplay between tumor-infiltrating lymphocytes (TILs) and tumor cells is a major determining factor in cancer progression. CD45RO seems to be a reliable indicator for predicting prognosis and disease outcome, along with CD3 and CD8 markers. LAG-3 is another important marker that overexpresses on TILs in a variety of cancers and is associated with disease prognosis; however, its prognostic impact is controversial. Hence, in the present study, we aimed to investigate the presence of CD45RO + , LAG3 + , CD3 + , and CD8 + lymphocytes in CRC tumor tissues and their association with clinicopathological parameters of the disease as well as patients' survival, according to primary tumor locations.

METHODS

Expression of CD45RO, LAG3, CD3, and CD8 was immunohistochemically assessed in tissue sections of 136 patients with CRC. The percentages of TILs expressing these markers were then separately determined in both invasive margin (IM) and center of tumor (CT). Their associations with clinicopathological factors and patients' survival were analyzed in the entire cohort and the subgroups of patients with right- and left- rectum tumors.

RESULTS

Based on our observation, CD45RO + and CD3 + cells were the most frequent infiltrated lymphocytes in both CT and IM regions of colon tumor tissue. Whilst, LAG3 + lymphocytes were the least frequent subset in both areas. Statistical analysis indicated that the frequency of CD45RO + TILs was positively associated with advanced TNM stages (III/IV), in the entire cohort and right-sided tumors (P < 0.05). LAG3 + TILs in IM were also increased in tumor tissues with higher T-stages in the entire cohort (P = 0.027). In univariate analysis, high score of CD45RO + TILs in IM was associated with better overall survival in the entire cohort. High score of CD8 + and CD45RO + lymphocytes in IM were also associated with improved survival in patients with right-sided tumors.

CONCLUSIONS

Our findings generally suggest that the clinicopathological and prognostic significance of immune system-related markers such as CD45RO and LAG3 depends on the primary tumor sides. Our results collectively demonstrated that infiltration of CD45RO + lymphocytes in IM could be an independent prognostic factor in a site-dependent manner.

A more novel and robust gene signature predicts outcome in patients with esophageal squamous cell carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is a life-threatening thoracic tumor with a poor prognosis. The tumor microenvironment (TME) mainly comprises tumor cells and tumor-infiltrating immune cells mixed with stromal components. The latest research has displayed that tumor immune cell infiltration (ICI) is closely connected with the ESCC patients' clinical prognosis. This study was designed to construct a gene signature based on the ICI of ESCC to predict prognosis.

METHODS

Based on the selection criteria we set, the eligible ESCC cases from the GSE53625 and TCGA-ESCA datasets were chosen for the training cohort and the validation cohort, respectively. Unsupervised clustering detailed grouped ESCC cases of the training cohort based on the ICI profile. We determined the differential expression genes (DEGs) between the ICI clusters, and, subsequently, we adopted the univariate Cox analysis to recognize DEGs with prognostic potential. These screened DEGs underwent a Lasso regression, which then generated a gene signature. The harvested signature's predictive ability was further examined by the Kaplan-Meier analysis, Cox analysis, ROC, IAUC, and IBS. More importantly, we listed similar studies in the most recent year and compared theirs with ours. We performed the functional annotation, immune relevant signature correlation analysis, and immune infiltrating analysis to thoroughly understand the functional mechanism of the signature and the immune cells' roles in the gene signature's predicting capacity.

RESULTS

A sixteen-gene signature (ARSD, BCAT1, BIK, CLDN11, DLEU7-AS1, GGH, IGFBP2, LINC01037, LINC01446, LINC01497, M1AP, PCSK2, PCSK5, PPP2R2A, TIGD7, and TMSB4X) was generated from the Lasso model. We then confirmed the signature as having solid and stable prognostic capacity by several statistical methods. We revealed the superiority of our signature after comparing it to our predecessors, and the GSEA uncovered the specifically mechanism of action related to the gene signature. Two immune relevant signatures, including GZMA and LAG3 were identified associating with our signature. The immune-infiltrating analysis identified crucial roles of resting mast cells, which potentially support the sixteen-gene signature's prognosis ability.

CONCLUSIONS

We discovered a robust sixteen-gene signature that can accurately predict ESCC prognosis. The immune relevant signatures, GZMA and LAG3, and resting mast cells infiltrating were closely linked to the sixteen-gene signature's ability.

New Potential Immune Biomarkers in the Era of Precision Medicine: Lights and Shadows in Colorectal Cancer

Genetic alterations in CRC have shown a negative predictive and prognostic role in specific target therapies. The onset of immunotherapy has also undergone remarkable therapeutic innovation, although limited to a small subgroup of patients, the MSI-H/dMMR, which represents only 5% of CRC. Research is moving forward to identify whether other biomarkers can predict response to ICIs, despite various limitations regarding expression and identification methods. For this purpose, TMB, LAG3, and PD-L1 expression have been retrospectively evaluated in several solid tumors establishing the rationale to design clinical trials with concurrent inhibition of LAG3 and PD-1 results in a significant advantage in PFS and OS in advanced melanoma patients. Based on these data, there are clinical trials ongoing in the CRC as well. This review aims to highlight what is already known about genetic mutations and genomic alterations in CRC, their inhibition with targeted therapies and immune checkpoints inhibitors, and new findings useful to future treatment strategies.

The promising immune checkpoint LAG-3 in cancer immunotherapy: from basic research to clinical application

LAG-3, a type of immune checkpoint receptor protein belonging to the immunoglobulin superfamily, is confirmed to be expressed on activated immune cells, mainly including activated T cells. LAG-3 can negatively regulate the function of T cells, exerting important effects on maintaining the homeostasis of the immune system under normal physiological conditions and promoting tumor cells immune escape in the tumor microenvironment. Given its important biological roles, LAG-3 has been regarded as a promising target for cancer immunotherapy. To date, many LAG-3 inhibitors have been reported, which can be divided into monoclonal antibody, double antibody, and small molecule drug, some of which have entered the clinical research stage. LAG-3 inhibitors can negatively regulate and suppress T cell proliferation and activation through combination with MHC II ligand. Besides, LAG-3 inhibitors can also affect T cell function via binding to Galectin-3 and LSECtin. In addition, LAG-3 inhibitors can prevent the FGL1-LAG-3 interaction, thereby enhancing the human body’s antitumor immune effect. In this review, we will describe the function of LAG-3 and summarize the latest LAG-3 inhibitors in the clinic for cancer therapy.

Lag3: From Bench to Bedside

The introduction of immune checkpoint inhibitors represented a breakthrough treatment for metastatic melanoma, but the effect of these agents is not limited to a single cancer type. Promising results have been reported in various solid tumors, for example, lung cancer. The success of these drugs depends on the activation of tumor-infiltrating lymphocytes and primary and acquired resistance have been reported alongside a high rate of immune-related adverse events when agents targeting different immune checkpoints are given in combination. Numerous other targets have been investigated to overcome the resistance, improve the activity, and reduce the toxicity of checkpoint inhibitor therapy. Among these, the most promising is Lymphocyte-activation gene 3 (LAG-3), a transmembrane protein involved in cytokine release and inhibitory signaling in T cells. Preclinical data showed that LAG-3 is a negative regulator of both CD4⁺ T cell and CD8⁺ T cell and the activity on CD8⁺ T cell is independent of CD4⁺ activation. On the CD8⁺ T cell, LAG-3 activation abrogates the antigen presentation whereas on the CD4⁺ T cell, arrests the S phase of the cell cycle. The blockade of LAG-3 has been tested in several combination therapies, and recent clinical data showed a good safety profile and a synergistic effect with anti-PD-1, suggesting that this combination could become a standard treatment for metastatic melanoma. In this review, we report the available preclinical data and the new clinical data on LAG-3 blockade in different solid tumors, and we discuss LAG-3 as potential prognostic and predictive factor, together with possible future applications.

Lymphocyte-activation gene 3 in non-small-cell lung carcinomas: correlations with clinicopathologic features and prognostic significance

Lymphocyte-activation gene 3 (LAG-3) modulates the tumor microenvironment through immunosuppressive effects. Its associations with clinicopathologic parameters and prognostic significance in non-small-cell lung carcinomas remain unclear. We examined LAG-3 expression in 368 resected non-small-cell lung carcinomas (including 218 adenocarcinomas and 150 squamous-cell carcinomas) using tissue microarrays, with normalization to CD8⁺ T-cell count (LAG-3/CD8 index), and correlated LAG-3, CD8, and LAG-3/CD8 index with clinicopathologic features, molecular status, and survival. LAG-3 expression in the immune cells (ranged 0.35-540.1 cells/mm²) was identified in 92% of non-small-cell lung carcinomas. In adenocarcinomas and squamous-cell carcinomas, LAG-3 expression correlated with CD8⁺ T-cell count and PD-L1 expression. In adenocarcinomas, high LAG-3 expression (defined as >median) was additionally associated with smoking history, high T stage, aggressive pathologic features (solid-predominant histologic pattern, lymphovascular invasion, and nodal metastasis), and lack of EGFR mutation. In the entire resected tumor cohort and in adenocarcinomas, high LAG-3 and LAG-3/CD8 index were each associated with worse overall survival. In squamous-cell carcinomas, high CD8 was associated with better overall survival. In an exploratory analysis of pretreatment samples from advanced non-small-cell lung carcinoma patients treated with pembrolizumab, high CD8 was predictive of improved overall and progression-free survival, while high LAG-3, but not high LAG-3/CD8 index, was associated with improved progression-free survival. In conclusion, the clinicopathologic correlations and prognostic impact of LAG-3 in non-small-cell lung carcinoma are histotype-dependent, highlighting differences in the immune microenvironment between adenocarcinomas and squamous-cell carcinomas. The predictive impact of LAG-3 warrants further investigation.

The Immune Checkpoint Inhibitor LAG-3 and Its Ligand GAL-3 in Vulvar Squamous Neoplasia

Vulvar squamous cell carcinoma (vSCC), although rare, carries significant morbidity and a high rate of recurrence. Treatment options beyond surgical excision remain limited. Lymphocyte activation gene-3 (LAG-3) and its binding partner galectin-3 (GAL-3) are an immuno-inhibitory checkpoint pair that represent potential immunotherapy targets for the treatment of vSCC. This study examined the expression of LAG-3 and GAL-3 alongside programmed cell death ligand-1 expression in invasive SCC and vulvar intraepithelial neoplasia (VIN) by immunohistochemical analysis of formalin-fixed paraffin-embedded tissue. A total of 35 cases were selected for evaluation: 13 VIN3 [human papillomavirus (HPV)-associated VIN/usual-type VIN], 2 differentiated VIN (dVIN), 16 HPV-associated vSCC, and 4 dVIN-associated vSCC. LAG-3+ tumor-infiltrating lymphocytes were identified in 91% (32/35) of cases of vulvar squamous neoplasia. Tumor cells were positive for GAL-3 in 71% of the vulvar neoplasia cases. HPV-associated vSCC was more likely to demonstrate GAL-3 tumoral positivity when compared with dVIN-associated vSCC (24/29 vs. 1/6, P=0.004). We observed co-expression of all 3 immunomarkers in 40% (14/35) of cases evaluated. In light of these findings, use of immunomodulatory drugs that target the LAG-3/GAL-3 pathway may be potentially beneficial in vSCC and efficacy may be increased when combined with anti-programmed cell death ligand-1 therapy.

Update on lymphocyte-activation gene 3 (LAG-3) in cancers: from biological properties to clinical applications

Immunotherapy that targets checkpoints, especially programmed cell death protein 1 and programmed cell death ligand 1, has revolutionized cancer therapy regimens. The overall response rate to mono-immunotherapy, however, is limited, emphasizing the need to potentiate the efficacy of these regimens. The functions of immune cells are modulated by multiple stimulatory and inhibitory molecules, including lymphocyte activation gene 3 (LAG-3). LAG-3 is co-expressed together with other inhibitory checkpoints and plays key roles in immune suppression. Increasing evidence, particularly in the last 5 years, has shown the potential of LAG-3 blockade in anti-tumor immunity. This review provides an update on the biological properties and clinical applications of LAG-3 in cancers.

Diagnostic, Predictive, and Prognostic Biomarkers in Non-Small Cell Lung Cancer (NSCLC) Management

Lung cancer is the leading cause of cancer-related deaths worldwide. Despite growing efforts for its early detection by screening populations at risk, the majority of lung cancer patients are still diagnosed in an advanced stage. The management of lung cancer has dramatically improved in the last decade and is no longer based on the "one-fits-all" paradigm or the general histological classification of non-small cell versus small cell lung cancer. Emerging options of targeted therapies and immunotherapies have shifted the management of lung cancer to a more personalized treatment approach, significantly influencing the clinical course and outcome of the disease. Molecular biomarkers have emerged as valuable tools in the prognosis and prediction of therapy response. In this review, we discuss the relevant biomarkers used in the clinical management of lung tumors, from diagnosis to prognosis. We also discuss promising new biomarkers, focusing on non-small cell lung cancer as the most abundant type of lung cancer.

LAG-3 Expression Predicts Outcome in Stage II Colon Cancer

INTRODUCTION

LAG-3 is an inhibitory immune checkpoint molecule that suppresses T cell activation and inflammatory cytokine secretion. T cell density in the tumor microenvironment of colon cancer plays an important role in the host's immunosurveillance. We therefore hypothesized that LAG-3 expression on tumor-infiltrating lymphocytes (TILs) predicts outcome in patients with stage II colon cancer.

PATIENTS AND METHODS

Immunohistochemical staining for LAG-3 was performed on tissue microarrays (TMAs) of formalin-fixed paraffin-embedded tissue from 142 stage II colon cancer patients. LAG-3 expression was assessed in TILs within both the tumor front and tumor center and scored as either positive or negative. The primary endpoint was disease-free survival (DFS).

RESULTS

In patients diagnosed with stage II colon cancer, the presence of LAG-3 expression on TILs was significantly associated with better 5-year DFS (HR 0.34, 95% CI 0.14-0.80, p = 0.009). The effect on DFS was mainly due to LAG-3-positive TILs in the tumor front (HR 0.33, 95% CI 0.13-0.82, p = 0.012).

CONCLUSION

Assessment of LAG-3 might help to predict outcomes in patients with stage II colon cancer and potentially identify those patients who might benefit from adjuvant chemotherapy. Therefore, LAG-3 may serve as a prognostic biomarker in stage II colon cancer.

Clinical Research on the Mechanisms Underlying Immune Checkpoints and Tumor Metastasis

This study highlights aspects of the latest clinical research conducted on the relationship between immune checkpoints and tumor metastasis. The overview of each immune checkpoint is divided into the following three sections: 1) structure and expression; 2) immune mechanism related to tumor metastasis; and 3) clinical research related to tumor metastasis. This review expands on the immunological mechanisms of 17 immune checkpoints, including TIM-3, CD47, and OX-40L, that mediate tumor metastasis; evidence shows that most of these immune checkpoints are expressed on the surface of T cells, which mainly exert immunomodulatory effects. Additionally, we have summarized the roles of these immune checkpoints in the diagnosis and treatment of metastatic tumors, as these checkpoints are considered common predictors of metastasis in various cancers such as prostate cancer, non-Hodgkin lymphoma, and melanoma. Moreover, certain immune checkpoints can be used in synergy with PD-1 and CTLA-4, along with the implementation of combination therapies such as LIGHT-VTR and anti-PD-1 antibodies. Presently, most monoclonal antibodies generated against immune checkpoints are under investigation as part of ongoing preclinical or clinical trials conducted to evaluate their efficacy and safety to establish a better combination treatment strategy; however, no significant progress has been made regarding monoclonal antibody targeting of CD28, VISTA, or VTCN1. The application of immune checkpoint inhibitors in early stage tumors to prevent tumor metastasis warrants further evidence; the immune-related adverse events should be considered before combination therapy. This review aims to elucidate the mechanisms of immune checkpoint and the clinical progress on their use in metastatic tumors reported over the last 5 years, which may provide insights into the development of novel therapeutic strategies that will assist with the utilization of various immune checkpoint inhibitors.

Role of CD8+ T lymphocyte cells: Interplay with stromal cells in tumor microenvironment

CD8⁺ T lymphocytes are pivotal cells in the host response to antitumor immunity. Tumor-driven microenvironments provide the conditions necessary for regulating infiltrating CD8⁺ T cells in favor of tumor survival, including weakening CD8⁺ T cell activation, driving tumor cells to impair immune attack, and recruiting other cells to reprogram the immune milieu. Also in tumor microenvironment, stromal cells exert immunosuppressive skills to avoid CD8⁺ T cell cytotoxicity. In this review, we explore the universal function and fate decision of infiltrated CD8⁺ T cells and highlight their antitumor response within various stromal architectures in the process of confronting neoantigen-specific tumor cells. Thus, this review provides a foundation for the development of antitumor therapy based on CD8⁺ T lymphocyte manipulation.

Expression of the Immune Checkpoints LAG-3 and PD-L1 in High-grade Serous Ovarian Carcinoma: Relationship to Tumor-associated Lymphocytes and Germline BRCA Status

Ovarian high-grade serous carcinomas (HGSC) have shown lackluster responses to immunotherapies targeting the PD-1/PD-L1 axis, perhaps due to the coexistence of other mechanisms of immune evasion in this tumor type. Lymphocyte activation gene-3 (LAG-3) is another inhibitory immune checkpoint often expressed on tumor-associated lymphocytes which is targeted by drugs currently in clinical trials. Forty-eight HGSC with known germline BRCA mutation status were immunohistochemically stained for LAG-3, CD8, and FOXP3. Positive tumor-associated lymphocytes were enumerated and averaged over 10 high-power fields (HPF). PD-L1 immunostaining was also preformed and expression was evaluated on tumor cells and using the combined positive score (CPS). The average number of LAG-3-positve tumor-associated lymphocytes was 6/HPF (range: 0-25.6). Cytotoxic (CD8) T cells averaged 30/HPF (range: 0-168.9), and regulatory (FOXP3) cells averaged 6.6/HPF (range: 0-76.3). Tumoral PD-L1 expression of ≥1% was observed in 27% (13/48) of cases, with only 8% (4/48) showing >5% staining; 81% (39/48) cases had a CPS ≥1. LAG-3-positive lymphocytes and PD-L1 expression were positively correlated, even after controlling for the overall level of CD8 and FOX3P lymphocyte infiltration. Germline BRCA status was not significantly associated with LAG-3, CD8, FOXP3, or PD-L1 expression. These findings indicate that immunotherapies targeting LAG-3 may benefit some ovarian HGSC patients, particularly when used in conjunction with anti-PD-1/PD-L1 approaches. The typically limited expression of LAG-3 and PD-L1 suggests that immunotherapeutic response may be muted in most HGSC even with a combination approach.

Digitally quantified CD8+ cells: the best candidate marker for an immune cell score in non-small cell lung cancer?

The TNM classification is well established as a state-of-the-art prognostic and treatment-decision-making tool for non-small cell lung cancer (NSCLC) patients. However, incorporation of biological data may hone the TNM system. This article focuses on choosing and incorporating subsets of tissue-infiltrating lymphocyte (TIL), detected by specific immunohistochemistry and automatically quantified by open source software, into a TNM-Immune cell score (TNM-I) for NSCLC. We use common markers (CD3, CD4, CD8, CD20 and CD45RO) of TILs to identify TIL subsets in tissue micro-arrays comprising tumor tissue from 553 patients resected for primary NSCLC. The number of TILs is automatically quantified using open source software (QuPath). Their prognostic efficacy, alone and within a TNM-I model, is evaluated in all patients and histological subgroups. Compared with previous manual semi-quantitative scoring of TILs in the same cohort, the present digital quantification proved superior. As a proof-of-concept, we construct a TNM-I, using TNM categories and the CD8+ TIL density. The TNM-I is an independent prognosticator of favorable diagnosis in both the overall cohort and in the main histological subgroups. In conclusion, CD8+ TIL density is the most promising candidate marker for a TNM-I in NSCLC. The prognostic efficacy of the CD8+ TIL density is strongest in lung squamous cell carcinomas, whereas both CD8+ TILs and CD20+ TILs, or a combination of these, may be candidates for a TNM-I in lung adenocarcinoma. Furthermore, based on the presented results, digital quantification is the preferred method for scoring TILs in the future.

Understanding LAG-3 Signaling

Lymphocyte activation gene 3 (LAG-3) is a cell surface inhibitory receptor with multiple biological activities over T cell activation and effector functions. LAG-3 plays a regulatory role in immunity and emerged some time ago as an inhibitory immune checkpoint molecule comparable to PD-1 and CTLA-4 and a potential target for enhancing anti-cancer immune responses. LAG-3 is the third inhibitory receptor to be exploited in human anti-cancer immunotherapies, and it is considered a potential next-generation cancer immunotherapy target in human therapy, right next to PD-1 and CTLA-4. Unlike PD-1 and CTLA-4, the exact mechanisms of action of LAG-3 and its relationship with other immune checkpoint molecules remain poorly understood. This is partly caused by the presence of non-conventional signaling motifs in its intracellular domain that are different from other conventional immunoregulatory signaling motifs but with similar inhibitory activities. Here we summarize the current understanding of LAG-3 signaling and its role in LAG-3 functions, from its mechanisms of action to clinical applications.

Emerging immunotherapy targets in lung cancer

Immunotherapy has become the mainstay for lung cancer treatment, providing sustained therapeutic responses and improved prognosis compared with those obtained with surgery, chemotherapy, radiotherapy, and targeted therapy. It has the potential for anti-tumor treatment and killing tumor cells by activating human immunity and has moved the targets of anti-cancer therapy from malignant tumor cells to immune cell subsets. Two kinds of immune checkpoints, cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programmed death-1 (PD-1)/programmed death ligand 1 (PD-L1), are the main targets of current immunotherapy in lung cancer. Despite the successful outcomes achieved by immune checkpoint inhibitors, a small portion of lung cancer patients remain unresponsive to checkpoint immunotherapy or may ultimately become resistant to these agents as a result of the complex immune modulatory network in the tumor microenvironment. Therefore, it is imperative to exploit novel immunotherapy targets to further expand the proportion of patients benefiting from immunotherapy. This review summarizes the molecular features, biological function, and clinical significance of several novel checkpoints that have important roles in lung cancer immune responses beyond the CTLA-4 and PD-1/PD-L1 axes, including the markers of co-inhibitory and co-stimulatory T lymphocyte pathways and inhibitory markers of macrophages and natural killer cells.

LAG-3 is expressed on a majority of tumor infiltrating lymphocytes in pediatric Hodgkin lymphoma

LAG-3, through interaction with a variety of ligands, regulates T cell function via inhibition of T cell proliferation and activation. It has been demonstrated to be overexpressed on tumor infiltrating lymphocytes (TILs) of a variety of cancers with associated poor outcomes. The purpose of this study is to characterize the expression pattern and clinical significance of LAG-3 in pediatric Hodgkin lymphoma (HL). Patient tumor samples from Children's Oncology Group clinical trial AHOD0031 with matched patient outcome data were analyzed for the expression of LAG-3 and PD-L1 using immunohistochemistry. 73/115 patients (63%) demonstrated positive LAG-3 staining. No demographic or survival outcome data were significantly associated with LAG-3 expression. Interestingly, patients with the lowest density of expression were found to have the worst EFS, and those with highest density of expression demonstrated the best EFS. There was a positive statistically significant relationship between presence of LAG-3 and PD-L1 expression. This project is innovative in its characterization of LAG-3 as an immune checkpoint target in pediatric HL.

Interaction between Fibroblasts and Immune Cells Following DNA Damage Induced by Ionizing Radiation

Cancer-associated fibroblasts (CAF) form the basis of tumor microenvironment and possess immunomodulatory functions by interacting with other cells surrounding tumor, including T lymphocytes, macrophages, dendritic cells and natural killer cells. Ionizing radiation is a broadly-used method in radiotherapy to target tumors. In mammalian cells, ionizing radiation induces various types of DNA damages and DNA damage response. Being unspecific, radiotherapy affects all the cells in tumor microenvironment, including the tumor itself, CAFs and immune cells. CAFs are extremely radio-resistant and do not initiate apoptosis even at high doses of radiation. However, following radiation, CAFs become senescent and produce a distinct combination of immunoregulatory molecules. Radiosensitivity of immune cells varies depending on the cell type due to inefficient DNA repair in, for example, monocytes and granulocytes. In this minireview, we are summarizing recent findings on the interaction between CAF, ionizing radiation and immune cells in the tumor microenvironment.

Combined Immunoscore for Prognostic Stratification of Early Stage Non-Small-Cell Lung Cancer

Background

To date, no combined immunoscore has been evaluated for prognostic stratification of early stage non-small-cell lung cancer (NSCLC). The main goal of this study was to investigate the prognostic impact of programmed death ligand 1 (PD-L1) expression and different immune cell components (CD4+, CD8+ T-lymphocytes, and CD68+ macrophages) in early stage NSCLC patients, distinguishing peritumoral (PT) and intratumoral (IT) localizations. The secondary aim was to identify a combined immunoscore to optimize the prognostic stratification of NSCLC patients.

Methods

This retrospective study included surgical specimens from consecutive chemo-naive stage II-III radically resected NSCLC patients. Immunohistochemistry was carried out to evaluate PD-L1 expression and to quantify IT and PT CD4+, CD8+ T-lymphocytes, and CD68+ macrophages. The impact of a single marker and of a combination of multiple markers on overall survival (OS) was investigated.

Results

Seventy-nine patients were included in the study. PD-L1 expression was associated with worse prognosis (3 years OS: 58% in high- compared with 67% in low-expressing tumors), even though without statistical significance. When integrating PT CD8+, CD4+, and CD68 into a combined PT immunoscore, a significant prognostic stratification of patients was obtained and confirmed at multivariate analysis (3 years OS: 86% in patients with low PT immunoscore vs. 59% in patients with high PT immunoscore, p = 0.018). The integration of derived neutrophil/lymphocyte ratio (dNLR) with combined PT immunoscore improved prognostic stratification, with longer OS in patients with low PT immunoscore and low dNLR (p = 0.002).

Conclusion

The combined PT immunoscore (CD8+, CD4+, and CD68) integrated with dNLR may be a promising marker for the development of an integrated Tumor, Node, Metastasis (TNM) immunoscore.

Varied functions of immune checkpoints during cancer metastasis

Immune checkpoints comprise diverse receptors and ligands including costimulatory and inhibitory molecules, which play monumental roles in regulating the immune system. Immune checkpoints retain key potentials in maintaining the immune system homeostasis and hindering the malignancy development and autoimmunity. The expression of inhibitory immune checkpoints delineates an increase in a plethora of metastatic tumors and the inhibition of these immune checkpoints can be followed by promising results. On the other hand, the stimulation of costimulatory immune checkpoints can restrain the metastasis originating from diverse tumors. From the review above, key findings emerged regarding potential functions of inhibitory and costimulatory immune checkpoints targeting the metastatic cascade and point towards novel potential Achilles’ heels of cancer that might be exploited therapeutically in the future.

Progress of immune checkpoint LAG-3 in immunotherapy

Immune checkpoint inhibition has been shown to successfully reactivate T cell responses directed against tumor-associated antigens, resulting in significantly prolonged overall survival in patients with various types of solid tumors. Among them, cytotoxic T-lymphocyte protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) play key roles in tumor immune escape and are well-established targets of cancer immunotherapy. However, the low response rate PD-1 and CTLA-4 is a limitation and a challenge. Hence, studies have focused on investigating the tumor microenvironment for alternative therapeutic targets. Lymphocyte activation gene 3 protein (LAG-3) negatively regulates T lymphocytes by binding to the extracellular domain of the ligand, thus avoiding autoimmunity caused by T cell overactivation. LAG-3 is an important immune checkpoint in vivo and plays a balanced regulatory role in the human immune system. LAG-3 is now regarded as a new generation of immunotherapy targets. The present review describes the research progress of LAG-3 to provide reference for further investigation of LAG-3. The immune checkpoint of LAG-3 plays a crucial role in cancer development and may be used in future clinical practice of cancer therapy.

Expression and clinical significance of LAG-3, FGL1, PD-L1 and CD8+T cells in hepatocellular carcinoma using multiplex quantitative analysis

BACKGROUND

Fibrinogen-like protein 1 (FGL1)-Lymphocyte activating gene 3 (LAG-3) pathway is a promising immunotherapeutic target and has synergistic effect with programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1). However, the prognostic significance of FGL1-LAG-3 pathway and the correlation with PD-L1 in hepatocellular carcinoma (HCC) remain unknown.

METHODS

The levels of LAG-3, FGL1, PD-L1 and cytotoxic T (CD8⁺T) cells in 143 HCC patients were assessed by multiplex immunofluorescence. Associations between the marker's expression and clinical significances were studied.

RESULTS

We found FGL1 and LAG-3 densities were elevated while PD-L1 and CD8 were decreased in HCC tissues compared to adjacent normal liver tissues. High levels of FGL1 were strongly associated with high densities of LAG-3⁺cells but not PD-L1. CD8⁺ T cells densities had positive correlation with PD-L1 levels and negative association with FGL1 expression. Elevated densities of LAG-3⁺cells and low levels of CD8⁺ T cells were correlated with poor disease outcome. Moreover, LAG-3⁺cells deteriorated patient stratification based on the abundance of CD8⁺ T cells. Patients with positive PD-L1 expression on tumor cells (PD-L1 TC⁺) tended to have an improved survival than that with negative PD-L1 expression on tumor cells (PD-L1 TC^-). Furthermore, PD-L1 TC^- in combination with high densities of LAG-3⁺cells showed the worst prognosis, and PD-L1 TC⁺ patients with low densities of LAG-3⁺cells had the best prognosis.

CONCLUSIONS

LAG-3, FGL1, PD-L1 and CD8 have distinct tissue distribution and relationships with each other. High levels of LAG-3⁺cells and CD8⁺ T cells represent unfavorable and favorable prognostic biomarkers for HCC respectively.

A Review About Pembrolizumab in First-Line Treatment of Advanced NSCLC: Focus on KEYNOTE Studies

 Lung cancer is currently the malignant tumor with the highest incidence and mortality in the world, while non-small cell lung cancer (NSCLC) is the most common pathological type of lung caner. In the past few decades, the only treatment options available for advanced NSCLC patients have been targeted therapy or chemotherapy, but these therapies are inevitably tolerated by tumors.  The discovery of immune checkpints that mediate the immune escape of tumor cells have been promoting a series of immune checkpoint inhibitors to be used in cancer treatment and achieved great results. Among them, pembrolizumab is currently the only PD-1 inhibitor approved for first-line treatment of NSCLC, whether it is monotherapy or combination therapy, for creditable performance in KEYNOTE studies. In this review, we systematically integrate the latest series of clinical trial results, pharmacological mechanisms, adverse events (AEs) and predictive biomarkers in the first-line treatment of NSCLC. We hope pembrolizumab could become a better choice for more clinicians and benefit more patients with advanced NSCLC.

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.

In silico analysis of the immune microenvironment in bladder cancer

BACKGROUND

Infiltrating immune and stromal cells are vital components of the bladder cancer (BC) microenvironment, which can significantly affect BC progression and outcome. However, the contribution of each subset of tumour-infiltrating immune cells is unclear. The objective of this study was to perform cell phenotyping and transcriptional profiling of the tumour immune microenvironment and analyse the association of distinct cell subsets and genes with BC prognosis.

METHODS

Clinical data of 412 patients with BC and 433 transcription files for normal and cancer tissues were downloaded from The Cancer Genome Atlas. The CIBERSORT algorithm was used to determine the relative abundance of 22 immune cell types in each sample and the ESTIMATE algorithm was used to identify differentially expressed genes within the tumour microenvironment of BC, which were subjected to functional enrichment and protein-protein interaction (PPI) analyses. The association of cell subsets and differentially expressed genes with patient survival and clinical parameters was examined by Cox regression analysis and the Kaplan-Meier method.

RESULTS

Resting natural killer cells and activated memory CD4⁺ and CD8⁺ T cells were associated with favourable patient outcome, whereas resting memory CD4⁺ T cells were associated with poor outcome. Differential expression analysis revealed 1334 genes influencing both immune and stromal cell scores; of them, 97 were predictive of overall survival in patients with BC. Among the top 10 statistically significant hub genes in the PPI network, CXCL12, FN1, LCK, and CXCR4 were found to be associated with BC prognosis.

CONCLUSION

Tumour-infiltrating immune cells and cancer microenvironment-related genes can affect the outcomes of patients and are likely to be important determinants of both prognosis and response to immunotherapy in BC.

OX40 and LAG3 are associated with better prognosis in advanced gastric cancer patients treated with anti-programmed death-1 antibody

Background

Anti-PD-1 monoclonal antibody, nivolumab, has shown efficacy for advanced gastric cancer (AGC). However, the specific immune cell subsets predominantly activated during the period of anti-PD-1 therapy for AGC have not been clarified.

Methods

Peripheral blood of 30 AGC patients treated with nivolumab was prospectively obtained before the initial and second administrations and at the time of progressive disease (PD). The proportions of immune cell subsets and the serum concentrations of cytokines were systematically analysed by flow cytometry. Associations of subsets and serum cytokines with therapeutic effects were evaluated.

Results

After the initial administration, significant increases in activated central/effector memory, activated effector T cells, and activated T-helper 1 subsets were observed. At the time of PD, activated regulatory T cells, LAG3-positive CD4+/CD8+ T cells, and TIM3-positive CD4+/CD8+ T cells increased significantly. Significant positive correlations were shown between progression-free survival and proportions of LAG3-positive CD4+/CD8+ T cells and of OX40-positive CD4+/CD8+ T cells (log-rank p = 0.0008, 0.0003, 0.0035 and 0.0040).

Conclusions

Nivolumab therapy enhances activation of central/effector memory and effector subsets of CD4+/CD8+ T cells. The expression levels of LAG-3 and OX40 on T cells correlated with the efficacy of nivolumab therapy and could be reasonable biomarkers for anti-PD-1 therapy.

The New Immunotherapy Combinations in the Treatment of Advanced Non-Small Cell Lung Cancer: Reality and Perspectives

BACKGROUND

In the recent years, immunotherapeutics and specifically immunecheckpoints inhibitors have marked a significant shift in the diagnostic and therapeutic algorithm of Non-Small Cell Lung Cancer (NSCLC), allowing us to use immunotherapeutics alone or combined with chemotherapy for a great subset of patients. However, new interesting approaches are being presently investigated, markedly immunotherapy combinations, that is, the use of two or more immunotherapeutics combined.

METHODS

In particular, the combination of anti-PD-1 nivolumab and anti-CTLA-4 ipilimumab has already provided groundbreaking positive results in the advanced NSCLC and other combinations are currently under investigation.

RESULTS

Therefore, this paper aims to provide a comprehensive state-of-the-art review about immunotherapy combination, along with suggestions about future directions. A comprehensive literature search was carried out to identify eligible studies from MEDLINE/PubMed and ClinicalTrials.gov.

CONCLUSION

Nivolumab plus ipilimumab represent the most promising immunotherapy combination for the treatment of advanced NSCLC patients; safety, tolerability and efficacy of new immunotherapeutics (in monotherapy and in immunotherapy combinations) must be further assessed in future studies.

High CD3 and ICOS and low TIM-3 expression predict favourable survival in resected oesophageal squamous cell carcinoma

With the increasing oncological potential of immunotherapy, several immune checkpoint modulators are being investigated. The value of immune markers, including programmed cell death ligand-1, programmed cell death-1 (PD-1), inducible co-stimulator (ICOS), lymphocyte activation gene-3, T-cell immunoglobulin, and mucin-dominant containing-3 (TIM-3), is not well known. Using tissue microarrays of 396 patients who underwent surgery for oesophageal squamous cell carcinoma (ESCC), infiltrated T-cell subsets (CD3, CD8, and Foxp3) and checkpoint protein expression were scored. With a median follow-up of 24.8 months, CD3⁺ TIL subsets (50.0%) had longer median recurrence-free survival (RFS, 55.0 vs 21.4 months) and overall survival (OS, 77.7 vs 35.8 months). Patients with high ICOS expression (46.5%) had longer median RFS (53.9 vs 25.3 months) and OS (88.8 vs 36.9 months). For PD-1, RFS (hazard ratio [HR] 0.67) and OS (HR 0.66) were significantly longer in the high-expression group (45.2%). In the multivariate analysis, high TIM-3 expression (50.8%) had a significant relationship with shorter RFS (HR = 1.52) and OS (HR = 1.60). High CD3⁺ TIL and T-cell ICOS expression were associated with favourable prognosis, whereas high TIM-3 expression suggested a poor prognosis. Our findings may confer new insights to improve ESCC outcomes beyond the application of PD-1 blockade.

Data Mining of Prognostic Microenvironment-Related Genes in Clear Cell Renal Cell Carcinoma: A Study with TCGA Database

Clear cell renal cell carcinoma (ccRCC) is one of the most prevalent kidney malignancies. The tumor microenvironment (TME) is highly related to the oncogenesis, progress, and prognosis of ccRCC. The aim of this study was to infer the level of infiltrating stromal and immune cells and assess the prognostic value of them. The gene expression profile was obtained from TCGA and used for calculating the stromal and immune scores. Based on a cut-off value, patients were divided into low- and high-stromal/immune score groups. Survival analysis was performed to evaluate the prognostic value of stromal and immune scores. Moreover, differentially expressed genes (DEGs) that are highly related to TME were determined and applied for functional enrichment analysis and protein-protein interaction (PPI) network. The Kaplan-Meier plot demonstrated that patients with high-immune scores and stromal scores had poorer clinical outcome. In addition, a total of 89 DEGs were identified and mainly involved in 5 pathways. The top 5 degree genes were extracted from the PPI network; among them, IL10 and XCR1 were highly associated with prognosis of ccRCC. The results of the present study demonstrated that ESTIMATE algorithm-based stromal and immune scores may be a credible indicator of cancer prognosis and IL10 along with XCR1 may be a potential key regulator for the TME of ccRCC.

Prognostic Value of Lymphocyte-Activation Gene 3 (LAG3) in Cancer: A Meta-Analysis

Introduction: Therapeutic targeting of inhibitors of the immune response has reached the clinical setting. Inhibitors of the novel receptor LAG3, which negatively regulates T-cell activation, are under investigation. Here we explore the presence and prognostic role of LAG3 in cancer.

Methods: A systematic search of electronic databases identified publications exploring the effect of LAG3 on overall survival (OS) and (for early-stage cancers) disease-free survival (DFS). Hazard ratios (HR) were pooled in a meta-analysis using generic inverse-variance and random effect modeling. Subgroup analyses were conducted based on disease site and tumor type.

Results: Fifteen studies met the inclusion criteria. LAG3 was associated with better overall survival [HR 0.81, 95% confidence interval (CI) 0.66–0.99; P = 0.04], with subgroup analysis showing no significant differences between disease-site subgroups. The beneficial effect of LAG3 on OS was of greater magnitude in early-stage malignancies (HR 0.73, 95% CI 0.60–0.88) than in the metastatic setting (HR 1.20, 95% CI 0.70–2.05), but this difference was not statistically significant (subgroup difference p = 0.18). LAG3 did not have a significant association with DFS [HR 1.02, 95% confidence interval (CI) 0.77–1.37; P = 0.87], with subgroup analysis showing worse DFS in patients with lymphoma and improved DFS in those with breast cancer.

Conclusions: High expression of LAG3 is associated with favorable overall survival in several solid tumors. A trend toward an association in early-stage disease suggests the importance of immune surveillance in this setting.

Differential prognostic impact of platelet-derived growth factor receptor expression in NSCLC

Preclinical evidence suggests that stromal expression of platelet-derived growth factor receptors (PDGFRs) stimulates tumor development and diminishes intratumoral drug uptake. In non-small cell lung cancer (NSCLC), the clinical relevance of stromal PDGFR expression remains uncertain. Tumor specimens from 553 patients with primary operable stage I-IIIB NSCLC was obtained and tissue micro-arrays (TMA) were constructed (Norwegian cohort). Immunohistochemistry (IHC) was used to evaluate the expression of PDGFRα and -β in stromal cells and to explore their impact on patient survival. Results were validated in a non-related cohort consisting of TMAs of 367 stage I (A and B) NSCLC patients (Swedish cohort). High stromal PDGFRα expression was an independent predictor of increased survival in the overall populations and SCC (squamous cell carcinoma) subgroups of both investigated cohorts. PDGFRβ was an independent predictor of poor survival in the overall Norwegian cohort and an independent predictor of increased survival in the ADC (adenocarcinoma) subgroup of the Swedish cohort. Tumors displaying the combination PDGFRα-low/PDGFRβ-high exhibited inferior survival according to increasing stage in the Norwegian cohort. This study confirms that high stromal expression of PDGFRα is a predictor of increased survival in NSCLC. Further exploration of the prognostic impact of PDGFRβ and the relationship between PDGFRα and -β is warranted.

Immune checkpoints in the tumor microenvironment

Interactions between immune checkpoints (ICs) and their ligands negatively regulate T cell activation pathways involved in physiological immune responses against specific antigens. ICs and their ligands are frequently upregulated in the tumor microenvironment (TME) of various malignancies, and they represent significant barriers for induction of effective anti-tumor immune responses. Several IC inhibitors (ICIs) have been developed, with some currently in clinical trials and others have been approved for the treatment of different cancers. However, tumor cells are able to counteract the activity of ICIs and can commission additional inhibitory pathways via expression of other ICs/ligands within the TME. This review discusses the expression of various ICs/ligands in the TME and their impact on tumor immune evasion. Additionally, we discuss various regulatory mechanisms, including genetic and epigenetic, and other modulatory factors including hypoxia and the presence of immunosuppressive populations in the TME, which result in upregulation of ICs in various cancers. Moreover, we discuss the prognostic significance of ICs and their ligands, and the potential strategies to enhance treatment responses to ICIs. This review aims to advance our current knowledge on the role of ICs in the TME and the clinical benefits of targeting them.

Prognostic Value of Macrophage Phenotypes in Resectable Non-Small Cell Lung Cancer Assessed by Multiplex Immunohistochemistry

Macrophages are important inflammatory cells that regulate innate and adaptive immunity in cancer. Tumor-associated macrophages (TAMs) are thought to differentiate into two main phenotypes: proinflammatory M1 and protumorigenic M2. Currently, the prognostic impact of TAMs and their M1 and M2 phenotypes is unclear in non–small cell cancer (NSCLC). The present study was set up to evaluate an approach for identifying common M1 and M2 macrophage markers and explore their clinical significance in NSCLC. Using multiplex chromogenic immunohistochemistry, tissue microarrays of 553 primary tumors and 143 paired metastatic lymph nodes of NSCLC specimens were stained to detect various putative macrophage phenotypes: M1 (HLA-DR/CD68), M2 (CD163/CD68), M2 (CD204/CD68), and pan-macrophage (CD68/CK). Correlation analyses were performed to examine the relationship between TAMs and adaptive/innate immune infiltrates. HLA-DR⁺/CD68⁺M1 TAM level significantly decreased from pathological stage I to III. In a compartment-specific correlation analysis, moderate to strong correlations were observed between both TAM subsets (M1 and M2) with CD3-, CD8-, CD4-, and CD45RO-positive immune cells. Survival analyses, in both stromal and intratumoral compartments, revealed that high levels of HLA-DR⁺/CD68⁺M1 (stroma, hazard ratio [HR] = 0.73, P = .03; intratumor, HR = 0.7, P = .04), CD204⁺M2 (stroma, HR = 0.7, P = .02; intratumor, HR = 0.6, P = .004), and CD68 (stroma, HR = 0.69, P = .02; intratumor, HR = 0.73, P = .04) infiltration were independently associated with improved NSCLC-specific survival. In lymph nodes, the intratumoral level of HLA-DR⁺/CD68⁺M1 was an independent positive prognostic indicator (Cox model, HR = 0.38, P = .001). In conclusion, high levels of M1, CD204⁺M2, and CD68 macrophages are independent prognosticators of prolonged survival in NSCLC.

Prognostic Value of Lymphocyte Activation Gene-3 (LAG-3) Expression in Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is a malignant epithelial tumor with a high incidence in East Asia and the Middle East. The outcomes for ESCC patients are usually not optimal due to the recurrence and metastasis. This study is aim to examine the expression and the prognostic value of LAG-3 in ESCC. We applied immunohistochemistry analysis to examine the expression of LAG-3, CD4 and CD8 in 287 ESCC cohorts. Our study demonstrated that the decreased LAG-3 expression was significantly associated with CD4 tumor-infiltrated lymphocytes (TILs) (p=0.000), CD8 TILs (p=0.000), and the advanced clinical stages (p=0.041) by Chi-square analysis. Kaplan-Meier survival analysis revealed that higher LAG-3 expression were positively correlated with a better overall survival (OS) (p=0.010) and better progression free survival (PFS) (p=0.006), especially in the patients at stages T1-2 status (p=0.001, OS; p=0.001, PFS), N0 status (p=0.036, OS; p=0.050, PFS), and early stages (I-II) (p=0.006, OS; p=0.008, PFS). Both high of CD4 TIL /CD8 TIL ratio and LAG-3 expression were correlated with longer OS and PFS. Cox proportional hazards regression analysis showed that LAG-3 is an independent biomarker of survival (HR, 0.724; 95% CI 0.526-0.995; p = 0.047) (p=0.036). Taken together, we found that high expression of LAG-3 was correlated with an improved survival and LAG-3 is an independent predictor of survival, suggesting that LAG-3 may serve as a useful immune marker for the prognosis of ESCC.

Antitumor effects of the silencing of programmed cell death ligand 1 in colorectal cancer via immunoregulation

Activation of programmed cell death 1 (PD-1)/PD-ligand 1 (PD-L1) can promote immune suppression of the tumor microenvironment. However, the effects and mechanisms of PD-L1 silencing on colorectal cancer growth are largely unknown. In the present study, PD-L1 expression was compared in colorectal cancer and paracancerous tissues by immunofluorescence. A stable colorectal carcinoma cell line encoding PD-L1 short hairpin RNA (shRNA) was established. Thereafter, inoculated tumors were modeled in C57B/L6 mice. Experiments were divided into 3 groups: Control group, vector group, and PD-L1 silencing group (inoculated with the stable CT26 cell line encoding PD-L1 shRNA). Following decapitation of the mice, tumors were weighed and apoptosis of tumor cells was detected. The number and viability of cluster of differentiation (CD)4⁺ and CD8⁺ T cells were analyzed by flow cytometry and a cell counting kit assay, respectively. Compared with paracancerous tissue, colorectal cancer tissue extensively expressed PD-L1, RAC-α serine/threonine-protein kinase (AKT), and phosphatidylinositol 3-kinase (PI3K). Lymphocyte-activating gene 3 (LAG-3) expression was observed at the edge of tumor tissue, but rarely observed in paracancerous tissue. A stable CT26 cell line encoding PD-L1 shRNA was established, and lack of PD-L1 expression was confirmed by reverse transcription-polymerase chain reaction and western blotting. Compared with the control, the shPD-L1 group demonstrated reduced tumor growth, a high level of apoptosis in tumor cells, a low level of PI3K and AKT expression, and an increased number of cells and greater activity of CD4⁺ T and CD8⁺ T cells. Taken together, PD-L1 silencing promoted tumor cell apoptosis, at least in part, through the activation of CD4⁺ and CD8⁺ T cells.