PD-L1 In Tumor Microenvironment Research Articles

Fatty acids metabolism affects the therapeutic effect of anti-PD-1/PD-L1 in tumor immune microenvironment in clear cell renal cell carcinoma

BackgroundClear cell renal cell carcinoma (ccRCC) is a highly invasive and metastatic subtype of kidney malignancy and is correlated with metabolic reprogramming for adaptation to the tumor microenvironment comprising infiltrated immune cells and immunomodulatory molecules. The role of immune cells in the tumor microenvironment (TME) and their association with abnormal fatty acids metabolism in ccRCC remains poorly understood.MethodRNA-seq and clinical data of KIRC from The Cancer Genome Atlas (TCGA) and E-MTAB-1980 from the ArrayExpress dataset. The Nivolumab group and Everolimus group of the CheckMate 025 study, the Atezolizumab arm of IMmotion150 and the Atezolizumab plus Bevacizumab group of IMmotion151 cohort were obtained for subsequent analysis. After differential expression genes identification, the signature was constructed through univariate Cox proportional hazard regression and simultaneously the least absolute shrinkage and selection operator (Lasso) analysis and the predictive performance of our signature was assessed by using receiver operating characteristic (ROC), Kaplan–Meier (KM) survival analysis, nomogram, drug sensitivity analysis, immunotherapeutic effect analysis and enrichment analysis. Immunohistochemistry (IHC), qPCR and western blot were performed to measure related mRNA or protein expression. Biological features were evaluated by wound healing, cell migration and invasion assays and colony formation test and analyzed using coculture assay and flow cytometry.ResultsTwenty fatty acids metabolism-related mRNA signatures were constructed in TCGA and possessed a strong predictive performance demonstrated through time-dependent ROC and KM survival analysis. Notably, the high-risk group exhibited an impaired response to anti-PD-1/PD-L1 (Programmed death-1 receptor/Programmed death-1 receptor-ligand) therapy compared to the low-risk group. The overall levels of the immune score were higher in the high-risk group. Additionally, drug sensitivity analysis observed that the model could effectively predict efficacy and sensitivity to chemotherapy. Enrichment analysis revealed that the IL6-JAK-STAT3 signaling pathway was a major pathway. IL4I1 could promote ccRCC cells’ malignant features through JAK1/STAT3 signaling pathway and M2-like macrophage polarization.ConclusionThe study elucidates that targeting fatty acids metabolism can affect the therapeutic effect of PD-1/PD-L1 in TME and related signal pathways. The model can effectively predict the response to several treatment options, underscoring its potential clinical utility.

The E3 ubiquitin ligases regulate PD-1/PD-L1 protein levels in tumor microenvironment to improve immunotherapy.

The tumor microenvironment (TME) is the tumor surrounding environment, which is critical for tumor development and progression. TME is also involved in clinical intervention and treatment outcomes. Modulation of TME is useful for improving therapy strategies. PD-L1 protein on tumor cells interacts with PD-1 protein on T cells, contributing to T cell dysfunction and exhaustion, blockage of the immune response. Evidence has demonstrated that the expression of PD-1/PD-L1 is associated with clinical response to anti-PD-1/PD-L1 therapy in cancer patients. It is important to discuss the regulatory machinery how PD-1/PD-L1 protein is finely regulated in tumor cells. In recent years, studies have demonstrated that PD-1/PD-L1 expression was governed by various E3 ubiquitin ligases in TME, contributing to resistance of anti-PD-1/PD-L1 therapy in human cancers. In this review, we will discuss the role and molecular mechanisms of E3 ligases-mediated regulation of PD-1 and PD-L1 in TME. Moreover, we will describe how E3 ligases-involved PD-1/PD-L1 regulation alters anti-PD-1/PD-L1 efficacy. Altogether, targeting E3 ubiquitin ligases to control the PD-1/PD-L1 protein levels could be a potential strategy to potentiate immunotherapeutic effects in cancer patients.

Consistent expression of PD-L1 in tumor microenvironment with peripheral PD-1/PD-L1 in circulating T lymphocytes of operable breast cancer: a diagnostic test

BackgroundThe expression of PD-L1 in the immune microenvironment can guide the application of immunosuppressants. In order to monitor the immune status of the body, repeated biopsies have to be taken. Our research aims to find new and convenient means to evaluate this indicator.MethodsEighty-three cases of newly diagnosed operable breast cancer without receiving preoperative treatment, were recruited from Beijing Shijitan Hospital between November 2018 and November 2019. The expression of PD-1/PD-L1 on circulating T lymphocytes was detected by flow cytometry and the expression of PD-L1 on immune cells in tumor microenvironment was detected by immunohistochemistry.ResultsThe median percentage of positive PD-1 and PD-L1 expression on circulating T lymphocytes was 15.2% and 0.7%, respectively. The peripheral PD-1 had no relationship with clinicopathological characteristics, but the peripheral PD-L1 expression had a correlation with lymph node metastasis (p = 0.005) and Her-2 expression (p = 0.034) (p < 0.05). The positive rate of PD-L1 expression was 32.9% in tumor microenvironment. PD-L1 expression in tumor microenvironment had a significant correlation with PD-1/PD-L1 expression on circulating T lymphocytes, the correlation coefficients being 0.24 (p < 0.05) and 0.26 (p < 0.05), respectively. To predict the PD-L1 expression in tumor microenvironment, the area under the receiver operating characteristic curve was 0.65 and 0.66 for peripheral PD-1 and PD-L1, respectively. High level of peripheral PD-1/PD-L1 expression was associated with the odds ratios of 5.42 and 4.76 for positive PD-L1 expression in tumor microenvironment.ConclusionPeripheral PD-1/PD-L1 expression had a significant consistency with PD-L1 expression in tumor microenvironment and could act as an alternative choice of tissue detection, for the patients intolerable of biopsy.

PD-L1 in Combination with CD8+TIL and HIF-1α are Promising Prognosis Predictors of Head and Neck Squamous Cell Carcinoma.

ObjectiveThe aim of this study was to evaluate the prognosis effect of PD-L1 in combination with CD8+ tumor-infiltrating lymphocyte (TIL) or HIF-1α in head and neck squamous cell carcinoma (HNSCC).MethodsA total of 63 patients who underwent surgical resection were included in this study. The level of PD-L1, CD8+ TIL, and HIF-1α was determined by immunohistochemical analysis. The survival of patients was evaluated by Kaplan–Meier analysis. The prognostic power of these parameters was evaluated by C-index.ResultsWe observed that the survival of patients, who had a high level of PD-L1 in tumor cells, was significantly shorter than those who had a low level of PD-L1. However, the survival of patients who had a high level of PD-L1 in tumor microenvironment was significantly longer than patients with a low level of PD-L1 in tumor microenvironment. In addition, high level of CD8+ tumor-infiltrating lymphocyte or low level of HIF-1α level suggests a better prognosis. Moreover, we observed that PD-L1 in combination with CD8+ tumor-infiltrating lymphocyte and HIF-1α could significantly improve the prognostic effect of current TNM stage.ConclusionThe results of this study suggest that the level of PD-L1, CD8+TIL, and HIF-1α are useful prognostic biomarkers for patients with HNSCC. Incorporating these biomarkers into current TNM stage of HNSCC improve the discriminatory capability of TNM stage.

Prognostic Analysis of NSCLC Based on the Tumor-associated Macrophages, Tumor Neo-vessels and PD-L1 Expression in Tumor Microenvironment

背景与目的肿瘤微环境是肿瘤细胞赖以生存的复杂环境。其中肿瘤相关巨噬细胞（tumor-associated macrophages, TAMs）、肿瘤新生血管及程序性死亡受体1/程序性死亡受体-配体1（programmed cell death protein 1/programmed cell death ligand 1, PD-1/PD-L1）作为关键部分，在肿瘤发生、发展过程中起重要作用，影响患者预后。本研究旨在阐明TAMs、肿瘤新生血管和PD-L1的表达与非小细胞肺癌（non-small cell lung cancer, NSCLC）临床病理特征的相关性，并探讨它们对NSCLC预后的影响。方法收集92例NSCLC患者的临床病理资料及手术标本，采用免疫组化法检测癌组织和癌旁组织中TAMs、肿瘤新生血管和PD-L1的表达，采用配备有Olympus-DP72图像采集系统的Olympus-BX51正置显微镜进行拍照并用Image-pro Plus 6.0软件进行半定量分析。结果癌组织与癌旁组织中TAMs、肿瘤新生血管和PD-L1的表达差异无统计学意义（P > 0.05）。根据肿瘤微环境中各组分的定量表达，可将其分为低、中、高表达组。癌组织中TAMs的低、中和高密度组的中位总生存（overall survival, OS）分别是36个月（95%CI: 25.3-46.7）、26个月（95%CI: 12.2-39.8）和16个月（95%CI: 9.4-22.6），差异具有统计学意义（P=0.016）；肿瘤新生血管的低、中和高密度组的中位OS分别为30个月（95%CI: 22.5-37.5）、28个月（95%CI: 18.1-37.9）和25个月（95%CI: 14.6-35.4），差异无统计学意义（P=0.626）；PD-L1的低、中和高表达组的中位OS分别为35个月（95%CI: 29.4-40.6），28个月（95%CI: 13.6-42.4）和17个月（95%CI: 10.5-23.5），差异具有统计学意义（P=0.002）。联合低、中和高表达组的中位OS分别为36个月（95%CI: 30.6-41.4）、26个月（95%CI: 19.2-32.8）和9个月（95%CI: 4.4-13.6），差异具有统计学意义（P=0.001）。Cox回归分析结果显示，病理分型、TAMs和PD-L1均为肺癌患者的独立预后因素。结论肿瘤微环境关键成分PD-L1及TAMs的表达与NSCLC患者的预后密切相关。

PD-L1 in combination with CD8+TIL and HIF-1α are promising prognosis predictors of head and neck squamous cell carcinoma.

e18545 Background: Currently, the tumor/node/metastasis (TNM) staging is the most widely used Head and neck squamous cell carcinoma (HNSCC) staging system. However, this classification only provides limit information for the prognosis of HNSCC. Recently, some studies suggest that the level of PD-L1 in tumor cells (TC-PD-L1) or in tumor microenvironment cells (TMC-PD-L1) is a promising biomarker for the prognosis of HNSCC patients. Therefore, in this study, we evaluated the prognostic value of TC-PD-L1, TMC-PD-L1, CD8+ TIL, HIF-1α. In addition, we investigated if incorporated these biomarkers into TNM stage could improve the prognostic value of TNM stage. Methods: A total of 63 patients who underwent surgical resection. The level of PD-L1, CD8+ TIL and HIF-1α was determined by immunohistochemical analysis. The survival of patients was evaluated by Kaplan-Meier analysis and Cox proportional hazards model. The prognostic power of these parameters was evaluated by C-index. Results: We observed that the survival of patients, who had high level of PD-L1 in tumor cells, was significantly shorter than those who had low level of PD-L1. However, the survival of patients who had high level of PD-L1 in tumor microenvironment was significantly longer than patients with low level of PD-L1 in tumor microenvironment. In addition, high level of CD8+ tumor-infiltrating lymphocyte or low level of HIF-1α level suggests a better prognosis. Moreover, we observed that PD-L1 in combination with CD8+tumor-infiltrating lymphocyte and HIF-1α could significantly improve the prognostic effect of current TNM stage. Conclusions: The results of this study suggest that the level of PD-L1, CD8+TIL and HIF-1α is useful prognostic biomarkers for patients with HNSCC. Incorporated these biomarkers into current TNM stage of HNSCC improve the discriminatory capability of TNM stage.

Modulating the tumor immune microenvironment with sunitinib malate supports the rationale for combined treatment with immunotherapy

Small molecule inhibitors have proven useful in the treatment of a variety of tumors, but they are often limited by unsustainable benefits and confer resistance quickly. Immunotherapy can result in durable clinical responses, but activity only occurs in a minority of patients. The unfavorable tumor microenvironment (TME) is an important factor limiting immunotherapy. An appropriate understanding of how small molecule inhibitors modulate the TME may optimize the combination of targeted treatment and immunotherapy in managing tumors. In this study, we found that transient treatment with sunitinib malate inhibited the disorganized extension of tumor vessels, pericytes and collagen IV but increased the relative ratio of pericyte-wrapping blood vessels with alleviated hypoxia in tumors, which resulted from tumor vascular normalization. Sunitinib malate increased infiltration of CD8+ T cells and decreased regulatory T cells (Tregs), accompanied by inhibited expression of TGF-β1 and IL-10 and increased CCL-28, IFN-γ and IL-12, but no significant inhibition of myeloid-derived suppressor cells (MDSCs) was observed. In addition, sunitinib malate increased the levels of PD-1 and PD-L1 in TME, combined with anti-PD-1 therapy showed a significant reduction in tumor burden compared with either monotherapy, suggesting that anti-PD-1 therapy is reasonable after sunitinib malate treatment.

Roles of PD-1/PD-L1 Pathway: Signaling, Cancer, and Beyond.

Immunotherapies that target PD-1/PD-L1 axis have shown unprecedented success in a wide variety of human cancers. PD-1 is one of the key coinhibitory receptors expressed on T cells upon T cell activation. After engagement with its ligands, mainly PD-L1, PD-1 is activated and recruits the phosphatase SHP-2 in proximity to T cell receptor (TCR) and CD28 signaling. This event results in dephosphorylation and attenuation of key molecules in TCR and CD28 pathway, leading to inhibition of T cell proliferation, activation, cytokine production, altered metabolism and cytotoxic T lymphocytes (CTLs) killer functions, and eventual death of activated T cells. Bodies evolve coinhibitory pathways controlling T cell response magnitude and duration to limit tissue damage and maintain self-tolerance. However, tumor cells hijack these inhibitory pathways to escape host immune surveillance by overexpression of PD-L1. This provides the scientific rationale for clinical application of immune checkpoint inhibitors in oncology. The aberrantly high expression of PD-L1 in tumor microenvironment (TME) can be attributable to the "primary" activation of multiple oncogenic signaling and the "secondary" induction by inflammatory factors such as IFN-γ. Clinically, antibodies targeting PD-1/PD-L1 reinvigorate the "exhausted" T cells in TME and show remarkable objective response and durable remission with acceptable toxicity profile in large numbers of tumors such as melanoma, lymphoma, and mismatch-repair deficient tumors. Nevertheless, most patients are still refractory to anti-PD-1/PD-L1 therapy. Identifying the predictive biomarkers and design rational PD-1-based combination therapy become the priorities in cancer immunotherapy. PD-L1 expression, cytotoxic T lymphocytes infiltration, and tumor mutation burden (TMB) are generally considered as the most important factors affecting the effectiveness of PD-1/PD-L1 blockade. The revolution in cancer immunotherapy achieved by PD-1/PD-L1 blockade offers the paradigm for scientific translation from bench to bedside. The next decades will without doubt witness the renaissance of immunotherapy.

Abstract 4567: Immunoclassification of gastric cancer in the context of clinical outcome

Abstract Background: Gastric cancer (GC) plays a leading role in all cancer deaths especially in Eastern Asia. Current classifications including WHO, Lauren, and TCGA defined molecular classification have illuminated the clinicopathological characteristics or genetic profile of GC. However, these classifications were lack of association with clinical outcome and guidance for medication selection. Objective: We aimed to identify a new immunoclassification for GC to predict patient’s prognosis and provide evidence for choosing proper medication. Methods: Formalin-fixed and paraffin-embedded (FFPE) samples of GC were obtained along with the clinical outcome of the patient. Epstein-Barr virus (EBV) infection was measured by RT-PCR. Immune markers including CD3, CD8 and PD-L1 were measured by immunohistochemistry (IHC) at tumor infiltration area (TI) and invasive margin area (IM). The expression of PD-L1 in tumor microenvironment (TME) was assessed by immune reactive score (IRS) system. For immunoclassification, patients were classified into two subgroups: strong immunoreaction (SIR) and weak immunoreaction (WIR) defined by the number of CD8+ T cells and PD-L1 expression at TI. Results: EBV infection was associated with the number of CD3+T cells and PD-L1 expression in TME. EBV+ patients also showed a poor overall survival (OS) compared with EBV- patients. Importantly, WIR patients lived significantly shorter than SIR patients. Moreover, patients who were treated by taxanes in WIR group had a shorter OS compared with those not using taxanes. Conclusion: In this study, we suggest a new immunoclassification for gastric cancer which is associated with patients’ outcome and may provide a way to guide chemotherapy. Citation Format: Weili Wang, Ping Liao, Shangchen Xie, Dongya Shen, Chengfang Zhou, Howard Mcleod, Yijing He. Immunoclassification of gastric cancer in the context of clinical outcome [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4567. doi:10.1158/1538-7445.AM2017-4567