High Programmed Cell Death Ligand 1 Expression Research Articles

PD-L1 Expression Correlated with Clinicopathological Factors and Akt/Stat3 Pathway in Oral SCC.

Programmed cell death ligand 1 (PD-L1) is an immune checkpoint molecule that inhibits immune responses. The physiological and prognostic role of the PD-L1 signaling pathway in the oral maxillofacial region is unclear. This study aimed to investigate the role of PD-L1 in the progression of oral squamous cell carcinoma (OSCC). Furthermore, clinicopathological factors related to PD-L1 expression were examined in patients with OSCC through immunohistochemistry (IHC) of tissue sections and through an in vitro study in OSCC cells. The medical records, radiographic findings, and mortality referrals of 81 patients obtained from the National Statistical Office were reviewed. IHC was performed on tissue specimens of these patients to determine the expression levels of PD-L1, which showed significant statistical differences based on age, tumor size, TNM stage, cervical lymph node metastasis, and locoregional recurrence. Patients with a high PD-L1 expression had significantly poorer survival rates. Multivariate analysis using the Cox proportional model confirmed the high relative risk ratio for high PD-L1 expression, TNM stage, and neck node metastasis, all of which were significantly associated with a poor prognosis in patients with OSCC. The in vitro study showed that SAS and YD38 cells transfected with PD-L1 siRNA had significantly increased apoptosis, reduced proliferative capacity, and tumorigenicity.

Clinical efficacy of atezolizumab plus bevacizumab and chemotherapy in KRAS-mutated non-small cell lung cancer with STK11, KEAP1, or TP53 comutations: subgroup results from the phase III IMpower150 trial

BackgroundThe efficacy of atezolizumab (A) and/or bevacizumab (B) with carboplatin/paclitaxel (CP) chemotherapy was explored in the phase III, randomized IMpower150 study in patients with non-squamous non-small cell lung cancer (NSCLC)...

Prognostic Value of Programmed Death Ligand-1 Expression in Solid Tumors Irrespective of Immunotherapy Exposure: A Systematic Review and Meta-Analysis.

The programmed cell death-1/programmed cell death ligand-1 (PD-L1) pathway, which plays a crucial role in cancer immune surveillance, is the target of several approved immunotherapeutic agents and is used as a predictive biomarker in some solid tumors. However, its use as a prognostic marker (i.e., regardless of therapy used) is not established clearly with available data demonstrating inconsistent prognostic impact of PD-L1 expression in solid tumors. We conducted a systematic literature search of electronic databases and identified publications exploring the effect of PD-L1 expression on overall survival and/or disease-free survival. Hazard ratios were pooled in a meta-analysis using generic inverse-variance and random-effects modeling. We used the Deeks method to explore subgroup differences based on disease site, stage of disease, and method of PD-L1 quantification. One hundred and eighty-six studies met the inclusion criteria. Programmed cell death ligand-1 expression was associated with worse overall survival (hazard ratio 1.33, 95% confidence interval 1.26-1.39; p < 0.001). There was significant heterogeneity between disease sites (subgroup p = 0.002) with pancreatic, hepatocellular, and genitourinary cancers associated with the highest magnitude of adverse outcomes. Programmed cell death ligand-1 was also associated with worse overall disease-free survival (hazard ratio 1.19, 95% confidence interval 1.09-1.30; p < 0.001). Stage of disease did not significantly affect the results (subgroup p = 0.52), nor did the method of quantification via immunohistochemistry or messenger RNA (subgroup p = 0.70). High expression of PD-L1 is associated with worse survival in solid tumors albeit with significant heterogeneity among tumor types. The effect is consistent in early-stage and metastatic disease and is not sensitive to method of PD-L1 quantification. These data can provide additional information for the counseling of patients with cancer about prognosis.

Comprehensive genomic profiling and PD-L1 expression of primary lymphoepithelioma-like carcinoma of the stomach and parotid gland.

BackgroundTo investigate the comprehensive genomic profiling and programmed cell death ligand-1 (PD-L1) expression of primary lymphoepithelioma-like carcinoma (LELC) of different anatomical sites in the Chinese population and explore potential therapeutic strategies.MethodsCapture-based targeted sequencing was performed on tumor tissue samples collected from 35 patients with LELC. Tumor tissues were stained by immunohistochemistry (IHC) for PD-L1. The molecular features of LELC of the stomach/parotid gland and associations between somatic alterations and survival outcomes in LELC of the stomach were explored.ResultsAll patients with LELC of the stomach/parotid gland were microsatellite-stable with Epstein-Barr virus infection. A total of 215 somatic alterations spanning 126 genes were identified from 18 patients with LELC of the stomach. The most frequently mutated genes included PIK3CA, ARID1A, SMAD4, and KMT2D. In addition, 37 somatic alterations spanning 30 genes were identified from seven patients with LELC of the parotid gland. TP53, GNAS, and BCOR were the most frequently mutated genes. All cases of LELC of the stomach/parotid gland had a low tumor mutational burden (TMB) level, but a high PD-L1 expression level. Compared with LELC of the parotid gland, LELC of the stomach had a significantly higher TMB (1.0 vs. 5.0 mutations/Mb, P=0.0047) and a lower PD-L1 expression level (combined positive score: 90.0 vs. 47.5, P=0.0058). In addition, the presence of alterations in the p53 signaling pathway, homologous recombination pathway, and deoxyribonucleic acid (DNA) damage response pathway predicted unfavorable overall survival in patients with LELC of the stomach.ConclusionsThis study is the first to elucidate the comprehensive genomic profiling of LELC of the stomach in the Chinese population, and the first to demonstrate the molecular features of LELC of the parotid gland. The detection of high PD-L1 expression raises the potential of checkpoint immunotherapy for LELC of the stomach/parotid gland.KeywordsLymphoepithelioma-like carcinoma of the stomach (LELC of the stomach), lymphoepithelioma-like carcinoma of the parotid gland (LELC of the parotid gland), programmed cell death ligand-1 (PD-L1), genomic profiling, immunotherapy

The Importance of Exosomal PD-L1 in Cancer Progression and Its Potential as a Therapeutic Target.

Binding of programmed cell death ligand 1 (PD-L1) to its receptor programmed cell death protein 1 (PD-1) can lead to the inactivation of cytotoxic T lymphocytes, which is one of the mechanisms for immune escape of tumors. Immunotherapy based on this mechanism has been applied in clinic with some remaining issues such as drug resistance. Exosomal PD-L1 derived from tumor cells is considered to play a key role in mediating drug resistance. Here, the effects of various tumor-derived exosomes and tumor-derived exosomal PD-L1 on tumor progression are summarized and discussed. Researchers have found that high expression of exosomal PD-L1 can inhibit T cell activation in in vitro experiments, but the function of exosomal PD-L1 in vivo remains controversial. In addition, the circulating exosomal PD-L1 has high potential to act as an indicator to evaluate the clinical effect. Moreover, therapeutic strategy targeting exosomal PD-L1 is discussed, such as inhibiting the biogenesis or secretion of exosomes. Besides, some specific methods based on the strategy of inhibiting exosomes are concluded. Further study of exosomal PD-L1 may provide an effective and safe approach for tumor treatment, and targeting exosomal PD-L1 by inhibiting exosomes may be a potential method for tumor treatment.

The Prognostic Significance of PD1 and PDL1 Gene Expression in Lung Cancer: A Meta-Analysis.

BackgroundImmune checkpoint blockade therapy represents an extraordinary advance in lung cancer treatment. It is important to determine the expression of immune checkpoint genes, such as programmed cell death 1 (PD1) and programmed cell death-ligand 1 (PDL1), to develop immunotherapeutic strategies. The aim of this study was to explore the association between PD1 and PDL1 gene expression and prognoses and outcomes in lung cancer.MethodsThis meta-analysis analyzed 1,251 patients from eight different microarray gene expression datasets and were evaluated for their prognostic implications and verified using another independent research.ResultsThe mean expression levels of PDL1 in adenocarcinoma (AD) and squamous cell carcinoma (SC) were significantly higher in patients who died than in patients who did not. There was a trend toward incremental increases in PD1 and PDL1 expression significantly decreasing the risk of relapse and death among AD patients (HR = 0.69; 95% CI = 0.53 ~ 0.91; HR = 0.68; 95% CI = 0.54 ~ 0.84, respectively) and SC patients (HR = 0.53; 95% CI = 0.32 ~ 0.89; HR = 0.78; 95% CI = 0.57 ~ 1.00 respectively), as early-stage patients in this study were more likely to have high expression of both PD1 and PDL1 than late-stage patients (P-trend < 0.05). In contrast, late-stage SC patients expressing one or more of the genes at a high level had a significantly elevated risk of relapse (HR = 1.51; 95% CI = 1.07 ~ 2.11) and death (HR = 1.41; 95% CI = 1.08 ~ 1.84). This result was consistent with the validation data set.ConclusionThese findings indicate that high expression of PD1 and PDL1 is associated with superior outcome in early-stage lung cancer but an adverse outcome in late-stage lung cancer. The expression levels of PD1 and PDL1 individually or jointly are potential prognostic factors for predicting patient outcomes in lung cancer.

Expression of PD-L1 and BRCA1 in Triple-Negative Breast Cancer Patients and Relationship with Clinicopathological Characteristics.

Objective To study the expression of programmed cell death ligand-1 (PD-L1) and breast cancer susceptibility gene 1 (BRCA1) in triple-negative breast cancer (TNBC) patients and analyze their relationship with clinicopathological characteristics. Methods 76 TNBC tissues were collected as the research object, while 60 adjacent tissues were used as controls. All patients underwent surgical treatment, and the expression of PD-L1 and BRCA1 in cancer tissues and adjacent tissues was detected by immunohistochemistry. At the same time, the relationship between PD-L1, BRCA1, and clinicopathological characteristics of patients with TNBC (including patient age, menopausal status, tumor size, lymph node metastasis, histological grade, Ki-67 expression, and p53 expression) were analyzed by univariate and logistic multivariate analysis. Results The positive expression rate of PD-L1 in the TNBC group was 64.47%, which was higher than the control group by 41.67%. The positive expression rate of BRCA1 was 27.63%, which was lower than the control group by 48.33%. PD-L1 expression has no significant relationship with age, menopausal status, and p53 expression in TNBC patients. TNBC patients with tumors ≥2 cm, histological grade III, lymph node metastasis, and Ki-67 expression ≥20% had higher PD-L1 positive expression rates. The tumor size, Ki-67 expression, and PD-L1 expression of TNBC patients have independent effects. The expression of BRCA1 has no significant relationship with menopausal status, tumor size, Ki-67 expression, etc. TNBC patients with age <45 years, histological grade I or II, no lymph node metastasis, and high p53 expression positive rate had higher BRCA1 positive expression rate. The age of TNBC patients, p53 expression, and BRCA1 expression have independent effects. Conclusion In TNBC cancer tissues, there is a high expression of PD-L1 and low expression of BRAC1. The tumor size, Ki-67 expression, and PD-L1 expression of TNBC patients have independent effects. The age of TNBC patients, p53 expression, and BRCA1 expression have independent effects.

Differential expression of programmed cell death ligand 1 (PD-L1) and inflammatory cells in basal cell carcinoma subtypes.

Few studies have evaluated programmed cell death ligand (PD-L1) expression and lymphocytic infiltrates in Basal Cell Carcinoma (BCC). The objectives of this study are to assess PD-L1 expression and markers of local immune response in nodular, superficial, and morpheaform BCC, and compare it to normal, sun-exposed skin from the periphery of intradermal nevi. This was a retrospective study that included three histological subtypes of BCCs, and sun-exposed skin from the periphery of dermal nevi as quality controls. Tissue microarrays (TMA) were constructed with subsequent staining of H&E and immunohistochemistry (IHC) for CD4, CD8, FOXP3 and PD-L1. Non-automated quantification of the infiltrate in the intratumoral and stromal compartments on TMAs was performed. A total of 115 BCC (39 nodular, 39 morpheaform, and 37 superficial) and 41 sun-exposed skin samples were included (mean age 65.4years; 52.6% females). BCC showed higher expression of PD-L1 (5.4 vs 0.7%, p < 0.001), CD8 (29.8 vs 19.7%, p = 0.002), and FOXP3 (0.3 vs 0.06%, p = 0.022) compared to sun-exposed skin. There was a higher PD-L1 expression in nodular BCC compared with other subtypes. Low-risk BCC subtypes (superficial and nodular) exhibited more PD-L1 expression in intratumoral and stromal immune infiltrates as compared to high-risk BCC subtypes. As a limitation, no immune cells function was evaluatedin this study, only the presence/absence of T-lymphocyte sub-populations was recorded. Substantial differences in both PD-L1 expression and lymphocytic infiltrates were found amongst the histological subtypes of BCC and sun-exposed skin. Highest PD-L1 expression was found in nodular BCCs which suggests a potentially targetable strategy in the treatment of this most common BCCsubtype.

P16.05 Real World Data of First-Line Treatment With Pembrolizumab for Highly PD-L1-Expressing NSCLC

Programmed cell death-1 (PD-1) / programmed cell death-ligand 1 (PD-L1) inhibitors have shown efficacy for advanced non-small cell lung cancer (NSCLC) and are now standard therapies for patients with advanced-stage NSCLC. It is unknown whether pembrolizumab monotherapy (MONO) or pembrolizumab plus chemotherapy (COMB) should be selected for patients exhibiting high PD-L1 expression (tumour proportion score [TPS] of 50% or greater). However, there are few reports on the current status of first-line treatment with pembrolizumab for highly PD-L1 expressing NSCLC in clinical practice.

A highly specific aptamer probe targeting PD-L1 in tumor tissue sections: Mutation favors specificity

Although DNA aptamers can show comparable affinity to antibodies and have the advantage of having high batch-to-batch consistency, they often suffer from unsatisfied specificity for complex samples. The limited library size used for aptamer in vitro isolation (SELEX) has been recognized as one of the major reasons. Programmed cell death-ligand 1 (PD-L1) is both a key protein in cancer diagnostics and also immunotherapy. We report here a DNA aptamer that highly specifically binds PD-L1 expressed on the surface of various cancer cells and multiple types of tissue sections. The aptamers were selected from a DNA library containing a type II restriction endonuclease Alu I recognition site in the middle of the 40-nt random sequences, against recombinant PD-L1 rather than the whole cell or tissue section. The library enrichment was achieved by Alu I mediated-SELEX, named as REase-SELEX, in which Alu I cut off the non-binders at the recognition site and, more importantly, induced library mutations to substantially increase the library diversity. 8–60, a representative aptamer with high affinity (KD = 1.4 nM determined by SPR) successfully detected four types of cancer cells with PD-L1 expression levels from low to high by flow cytometry, normal human tonsil (gold standard for PD-L1 antibody evaluation), clinical non-small cell lung cancer (high PD-L1 expression level), and malignant melanoma (low PD-L1 expression level) tissue sections by fluorescence microscopy imaging, showing unprecedented high specificity. The results demonstrate that 8–60 is an advanced probe for PD-L1 cancer diagnostics and mutations in SELEX greatly favor aptamer specificity.

The Role of Oncogenes and Redox Signaling in the Regulation of PD-L1 in Cancer.

Simple SummaryPD-L1 is an important immune checkpoint molecule that is expressed in cancer tissues at various levels and plays a major role in tumor evasion from immune system. Therefore, understanding the mechanisms by which PD-L1 expression is regulated in tumor environment is important for the design of new therapeutic strategies to overcome tumor immune escape and improve the outcome of cancer treatment. Recent studies suggest that genetic, epigenetic, and transcriptional factors as well as posttranscriptional and posttranslational processes are crucial regulators of PD-L1 expression in tumor cells. This review focuses on two newly described regulations of PD-L1 mediated by oncogenes, and redox homeostasis. In this context, a recent research work describes the important role of oncogenic K-ras, growth factor receptors (FGFR1 and EGFR) and ROS in regulating PD-L1 expression in pancreatic cancer cells and aids significant new mechanistic insights in this important area.Tumor cells can evade the immune system via multiple mechanisms, including the dysregulation of the immune checkpoint signaling. These signaling molecules are important factors that can either stimulate or inhibit tumor immune response. Under normal physiological conditions, the interaction between programmed cell death ligand 1 (PD-L1) and its receptor, programmed cell death 1 (PD-1), negatively regulates T cell function. In cancer cells, high expression of PD-L1 plays a key role in cancer evasion of the immune surveillance and seems to be correlated with clinical response to immunotherapy. As such, it is important to understand various mechanisms by which PD-L1 is regulated. In this review article, we provide an up-to-date review of the different mechanisms that regulate PD-L1 expression in cancer. We will focus on the roles of oncogenic signals (c-Myc, EML4-ALK, K-ras and p53 mutants), growth factor receptors (EGFR and FGFR), and redox signaling in the regulation of PD-L1 expression and discuss their clinical relevance and therapeutic implications. These oncogenic signalings have common and distinct regulatory mechanisms and can also cooperatively control tumor PD-L1 expression. Finally, strategies to target PD-L1 expression in tumor microenvironment including combination therapies will be also discussed.

High PD-L1 Expression on Tumor Cells Indicates Worse Overall Survival in Advanced Oral Squamous Cell Carcinomas of the Tongue and the Floor of the Mouth but Not in Other Oral Compartments.

The markers of the tumor microenvironment (TME) are promising prognostic and predictive factors in oral squamous cell carcinoma (OSCC). The current study aims to analyze the immunohistochemical expression of programmed cell death-ligand 1 (PD-L1) and interleukin-33 (IL-33) in a cohort of 95 chemonaïve OSCCs. PD-L1 and IL-33 were assessed separately in tumor cells (TCs) and tumor-infiltrating lymphocytes (TILs). High PD-L1 expression in TILs was associated with better overall survival (OS) in univariate analysis. Tumors localized in the floor of the oral cavity and tongue tended to have a lower percentage of PD-L1-positive TCs when compared to other locations. PD-L1 expression on TCs had no prognostic significance when the whole cohort was analyzed. However, along with the T descriptor (TNM 8th), it was included in the multivariable model predicting death in carcinomas of the floor of the oral cavity and tongue (HR = 2.51, 95% CI = 1.97–5.28). In other locations, only nodal status was identified as an independent prognostic factor in multivariate analysis (HR = 0.24, 95% CI = 0.08–0.70). Expression of IL-33 had no impact on survival, but it was differently expressed in various locations. In conclusion, the prognostic significance of PD-L1 in oral cancer depends on the tumor site and type of cell expressing immune checkpoint receptor (TCs vs. TILs).

Role of Ezrin/Radixin/Moesin in the Surface Localization of Programmed Cell Death Ligand-1 in Human Colon Adenocarcinoma LS180 Cells.

Programmed cell death ligand-1 (PD-L1), an immune checkpoint protein highly expressed on the cell surface in various cancer cell types, binds to programmed cell death-1 (PD-1), leading to T-cell dysfunction and tumor survival. Despite clinical successes of PD-1/PD-L1 blockade therapies, patients with colorectal cancer (CRC) receive little benefit because most cases respond poorly. Because high PD-L1 expression is associated with immune evasion and poor prognosis in CRC patients, identifying potential modulators for the plasma membrane localization of PD-L1 may represent a novel therapeutic strategy for enhancing the efficacy of PD-1/PD-L1 blockade therapies. Here, we investigated whether PD-L1 expression in human colorectal adenocarcinoma cells (LS180) is affected by ezrin/radixin/moesin (ERM), functioning as scaffold proteins that crosslink plasma membrane proteins with the actin cytoskeleton. We observed colocalization of PD-L1 with all three ERM proteins in the plasma membrane and detected interactions involving PD-L1, the three ERM proteins, and the actin cytoskeleton. Furthermore, gene silencing of ezrin and radixin, but not of moesin, substantially decreased the expression of PD-L1 on the cell surface without affecting its mRNA level. Thus, in LS180 cells, ezrin and radixin may function as scaffold proteins mediating the plasma membrane localization of PD-L1, possibly by post-translational modification.

Genetic alternations and immune characteristics in patients with small cell lung cancer

Genetic alternations and immune characteristics in patients with small cell lung cancer

Prognostic role of programmed cell death ligand-1 expression in head and neck cancer treated with programmed cell death protein-1/programmed cell death ligand-1 inhibitors: A meta-analysis based on clinical trials.

The purpose of our meta-analysis is to clarify whether the biomarker of programmed cell death ligand-1 (PD-L1) could predict the treatment efficacy and prognosis of programmed cell death protein-1 (PD-1)/PD-L1 immune-checkpoint inhibitors (ICIs) in head and neck cancer (HNC) patients. We performed the article search in four main online databases. The search deadline was September 8, 2020. To elucidate whether a positive or negative PD-L1 expression correlates with different efficacy and prognosis of PD-1/PD-L1-related therapy in HNC, the relative risk (RR) and 95% confidence interval (95% CI) were pooled. Our meta-analysis assigned the overall survival (OS) at 6 and 12 months and the objective response rate (ORR) for the primary end points. The present meta-analysis included 11 relevant studies, which have 1663 HNC cases who received the treatment of PD-1/PD-L1 ICIs. The pooled results revealed that the high or positive expression of PD-L1 predicted better 6- and 12-month OS in head and neck squamous cell carcinoma (HNSCC) (RR 1.30, 95% CI: 1.02-1.65, P = 0.03; and RR 1.31, 95% CI: 1.05-1.62, P = 0.01). PD-L1 expressors were also relevant with higher ORR in HNC patients who had treatment of PD-1/PD-L1 inhibitors compared to PD-L1 nonexpressors (RR 1.84, 95% CI: 1.41-2.41, P < 0.00001). In summary, PD-L1-positive HNSCC patients portend favorable OS at 6 and 12 months from PD-1/PD-L1 ICIs. Increased ORR also favored to appear in PD-L1 expressors of HNC or recurrent/metastatic HNSCC who received PD-1/PD-L1 ICIs. Therefore, PD-L1 proved to be an appropriate biomarker to predict the clinical efficacy and prognosis of PD-1/PD-L1 ICIs in HNC.

Atezolizumab Monotherapy or Plus Chemotherapy in First-Line Treatment for Advanced Non-Small Cell Lung Cancer Patients: A Meta-Analysis.

BackgroundAtezolizumab plus chemotherapy has been recommended as a first-line treatment option for patients with advanced non-small cell lung carcinoma (NSCLC) irrespective of programmed cell death-ligand 1 (PD-L1) expression. Currently, little is known about the efficacy and treatment-related adverse effects (TRAEs) of subtracting chemotherapy from the combination for patients with high PD-L1 expression. Thus, we performed an indirect comparison between atezolizumab plus chemotherapy and atezolizumab alone.MethodsA total of five eligible randomized controlled trials (RCTs) were identified from PubMed, EMBASE, and Cochrane Central controlled trial registries, using keywords including atezolizumab, PD-1, PD-L1, NSCLC, and RCT. The clinical outcomes of objective response rate (ORR), progression-free survival (PFS), OS, and TRAEs were extracted and evaluated. Using indirect analysis, the efficacy and TRAEs were compared between arm A (atezolizumab plus chemotherapy) and arm C (atezolizumab), linked by arm B (chemotherapy).ResultsDirect comparison revealed that both atezolizumab plus chemotherapy (HR 0.65, P = 0.003) and atezolizumab alone (HR 0.59, P = 0.010) significantly improved OS compared with chemotherapy. More importantly, the indirect comparison showed that atezolizumab plus chemotherapy was not superior to atezolizumab regarding OS (RR 1.10, P =0.695) and ORR (RR 1.11, P = 0.645). However, patients who received atezolizumab combined with chemotherapy experienced more ≥ grade 3 TRAEs (RR 4.23, P<0.001) and TRAEs leading to drug discontinuation (RR 3.60, P<0.001) than those treated with atezolizumab monotherapy.ConclusionsAtezolizumab monotherapy might be a better treatment option for patients with advanced NSCLC and high PD-L1 expression than atezolizumab plus chemotherapy.

PD-L1 Expression and Tumor Infiltrating Lymphocytes in Neurofibromatosis Type 1-Related Benign Tumors and Malignant Peripheral Nerve Sheath Tumors: An Implication for Immune Checkpoint Inhibition Therapy

Neurofibromatosis type 1 (NF1) is an autosomal dominant inherited disorder. It can affect multiple systems of the body and cause severe disfigurement and discomfort in these patients. There are two types of neurofibromas, named cutaneous and plexiform neurofibromas. The latter type may transform into malignant peripheral nerve sheath tumors (MPNSTs). Surgical resection is difficult to perform owing to the complex tissue structure of neurofibromas; therefore, it is necessary to develop novel and effective therapies for the treatment of these tumors. Programmed cell death protein 1 (PD-1)/programmed cell death-ligand 1 (PD-L1)-related immune checkpoint inhibitors have been proven effective for various cancers, and the positive expression of PD-L1 and tumor-infiltrating lymphocytes (TILs) has been recognized as a biomarker for the response to immune checkpoint therapy. We conducted immunohistochemistry (IHC) staining to detect PD-L1 expression in plexiform neurofibroma and MPNST tissue samples. Reverse transcription-polymerase chain reaction (RT-PCR) and western blotting were performed to detect PD-L1 and PD-1 expression in MPNST cell lines. IHC staining was used to show immune cell infiltration in NF1 and MPNST tissues. IHC staining showed PD-L1 positive expression in neurofibromas and MPNST tumor tissues. In addition, qPCR and western blotting showed high expression of PD-L1 in MPNST tumor cells. IHC staining revealed that aberrant T lymphocytes infiltrated the plexiform neurofibroma and MPNST tumor tissues. These results indicate that immune checkpoint mechanisms may play a pivotal role in the development of NF1-related tumors, and immune checkpoint inhibitors may be effective for managing neurofibromas and MPNSTs. Combined therapy with other molecular agents may be explored in the future.

In-depth genomic characterization of programmed cell death ligand 1 (PD-L1) expression in Chinese lung adenocarcinoma patients.

e20500 Background: Immune checkpoint blockades have revolutionized anticancer treatments for lung cancers, and PD-L1 expression has been served as crucial predictive biomarkers for immunotherapies. However, PD-L1 expression has been found to be influenced by some extrinsic or intrinsic factors in vitro or to be associated with other biomarkers in vivo. Methods: An amount of tumor tissues was taken from a biopsy or surgery for PD-L1 expression assay and genomic profiling in Chinese lung adenocarcinoma patients using extend targeted sequencing panel. In-depth retrospective analyses of clinical features, gene alternations, singling pathways and immune signatures was conducted in negative group (TPS &lt; 1%), intermediate group (1% ≤ TPS &lt; 50%), and high group (TPS ≥ 50%). Clinical responses to selected mutation were also evaluated from public database such as TCGA and MSKCC. Results: A total of 248 Chinese patients with lung adenocarcinoma was retrospectively identified and included in this study, consisting of negative group (n = 124, 50%), intermediate group (n = 93, 38%), and high group (n = 38, 12%). High tumor mutation burden was significantly as associated with high PD-L1 expression. In addition, PD-L1 expression was highly related with gene alternations such as PRKDC, KMT2D, ERBB2 and SETD2. Moreover, signaling pathways of DDR, TP53, cell cycles and NOTCH also obviously related with PD-L1 expression. Besides, most of patients in high PD-L1 group were determined as high-grade immune subtypes (C2-C4), showing significant higher levels of IFN-gamma, CD8+ T-cells, NK cells, NK CD56 dim cells, Th1 cells, Th2 cells (P &lt; 0.0001). Moreover, the prognostic value of SETD2 mutation was slight positive with overall survival from MSKCC cohort (HR 1.92 [95%CI 0.90-4.10], P = 0.085), and the percentage of IFN-gamma was significantly higher in SETD2 mutant group than in wild-type subgroup ( P &lt; 0.01). Conclusions: This study illustrated in-depth genomic profiles and immune signatures of PD-L1 expression in Chinese lung adenocarcinoma patients, which might interpret more potential molecular mechanisms for anti-cancer immunotherapy in NSCLC. In addition, SETD2 may be potential biomarkers for predicting patients’ prognosis.

Clinicopathological and prognostic significance of programmed cell death ligand 1 expression in patients diagnosed with breast cancer: meta-analysis.

Uncertainty exists regarding the clinical relevance of programmed cell death ligand 1 (PD-L1) expression in breast cancer. A systematic review was performed in accordance with PRISMA guidelines. Observational studies that compared high versus low expression of PD-L1 on breast cancer cells were identified. Log hazard ratios (HRs) for disease-free and overall survival and their standard errors were calculated from Kaplan-Meier curves or Cox regression analyses, and pooled using the inverse-variance method. Dichotomous variables were pooled as odds ratios (ORs) using the Mantel-Haenszel method. Sixty-five studies with 19870 patients were included; 14 404 patients were classified as having low and 4975 high PD-L1 expression. High PD-L1 was associated with achieving a pathological complete response following neoadjuvant chemotherapy (OR 3.30, 95 per cent confidence interval 1.19 to 9.16; P < 0.01; I2 = 85 per cent). Low PD-L1 expression was associated with human epidermal growth factor receptor 2 (OR 3.98, 1.81 to 8.75; P < 0.001; I2 = 96 per cent) and luminal (OR 14.93, 6.46 to 34.51; P < 0.001; I2 = 99 per cent) breast cancer subtypes. Those with low PD-L1 had favourable overall survival rates (HR 1.30, 1.05 to 1.61; P = 0.02; I2 = 85 per cent). Breast cancers with high PD-L1 expression are associated with aggressive clinicopathological and immunohistochemical characteristics and are more likely to achieve a pathological complete response following neoadjuvant chemotherapy. These breast cancers are, however, associated with worse overall survival outcomes.

PD-L1 Expression Status Predicting Survival in Pulmonary Pleomorphic Carcinoma.

Pulmonary pleomorphic carcinoma (PPC) is a rare and aggressive tumor that is resistant to treatment. The expression and prognostic value of programmed cell death-ligand 1 (PD-L1) and its association with epithelial-mesenchymal transition (EMT) in PPC remains unclear. The expression of PD-L1 and EMT markers, such as E-cadherin, vimentin, zinc finger E-box-binding homeobox 1 (ZEB-1), and cellular mesenchymal-epithelial transition (c-Met) was evaluated by immuno - histochemistry in 16 patients with PPC who underwent surgical resection. The expression of PD-L1 varied between carcinomatous and sarcomatous areas. Positive correlations between PD-L1 and vimentin expression in carcinomatous areas (r=0.668, p=0.005) and PD-L1 and ZEB-1 expression in sarcomatous areas (r=0.562, p=0.023) were found. High PD-L1 and ZEB-1 expression in sarcomatous areas predicted poor survival (p=0.045 and p=0.012, respectively). PD-L1 expression associated with ZEB1 expression in the sarcomatoid component of patients with PPC may be useful for predicting patient prognosis.