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Immunotherapy has revolutionized cancer treatment, but the lack of a reliable predictive biomarker for treatment response remains a challenge. Alpha-1,6-Mannosylglycoprotein 6-β-N-Acetylglucosaminyltransferase 5 (MGAT5) is a key regulator of complex N-glycan synthesis, and its dysregulation is associated with cancer progression. The lectin Phaseolus vulgaris leukoagglutinin (PHA-L) specifically binds to mature MGAT5 products. Previous studies have indicated elevated PHA-L staining in head and neck squamous cell carcinoma (HNSCC), which implies increased activity of MGAT5. However, the specific role of MGAT5 in HNSCC remains unclear. In this study, we found significantly higher PHA-L staining and MGAT5 expression in HNSCC tumors compared to adjacent non-tumor tissues. Using a mass spectrometry (MS)-based glycoproteomic approach, we identified 163 potential protein substrates of MGAT5. Functional analysis revealed that protein substrates of MGAT5 regulated pathways related to T cell proliferation and activation. We further discovered that PD-L1 was among the protein substrates of MGAT5, and the expression of MGAT5 protected tumor cells from cytotoxic T lymphocyte (CTL) killing. Treatment of nivolumab alleviated the protective effects of MGAT5 on CTL activity. Consistently, patients with MGAT5-positive tumors showed improved responses to immunotherapy compared to those with MGAT5-negative tumors. Using purified PD-L1 from HNSCC cells and a glycoproteomic approach, we further deciphered that the N35 and N200 sites carry the majority of complex N-glycans on PD-L1. Our findings highlight the critical role of MGAT5-mediated branched N-glycans on PD-L1 in modulating the interaction with the immune checkpoint receptor PD-1. Consequently, we propose that MGAT5 could serve as a biomarker to predict patients' responses to anti-PD-1 therapy. Furthermore, targeting the branched N-glycans at N35 and N200 of PD-L1 may lead to the development of novel diagnostic and therapeutic approaches., (© 2024. The Author(s).)

Purpose: Tissue-based next-generation sequencing (NGS) analysis is highly recommended for patients with advanced/metastatic non-small cell lung cancer (NSCLC). We investigated a specific patient population with NSCLC that required tissue-based NGS analysis., Materials and Methods: We enrolled 500 patients with advanced/metastatic (1) epidermal growth factor receptor ( EGFR ) mutations or anaplastic large-cell lymphoma kinase ( ALK ) rearrangement-positive NSCLC who had failed at minimum one line of tyrosine kinase inhibitor (TKI) therapy, (2) EGFR-/ALK -negative nonsquamous, and (3) non- or light-smoker patients with squamous NSCLC who were treatment-naïve or had failed at maximum two lines of systemic treatment. These patients were divided into five cohorts. Comprehensive tissue-based NGS testing (ACTOnco+) was conducted., Results: Cohort 1: EGFR TKI-pretreated EGFR -mutated population (50.0%, n = 250), cohort 2: ALK inhibitor-pretreated ALK -positive population (1.6%, n = 8), cohort 3: treatment-naïve EGFR-/ALK -negative population (28.2%, n = 141), cohort 4: pretreated EGFR-/ALK -negative population (16.8%, n = 84), and cohort 5: squamous cell carcinoma (3.4%, n = 17). In cohort 1, 11.2% (28/250) of the patients had MET amplification, 32.4% (81/250) had been treated with osimertinib, and EGFR C797S was detected in 6.2% (5/81) of these patients. In cohort 2, resistance ALK mutation was detected in 37.5% (3/8) of the patients. In cohorts 3 and 4, targetable genetic alterations, including EGFR mutation (13.3%), ERBB2 mutation (9.3%), MET exon 14 skipping (5.3%), KRAS G12C mutation (4.4%), ROS1 fusion (2.7%), RET fusion (1.8%), and BRAF V600E mutation (1.3%), were detected. In cohort 5, MET exon 14 skipping was detected in 29.4% (5/17) of the patients., Conclusion: This multicenter registration study investigated tissue-based NGS for a specific patient population with NSCLC in Taiwan.

Introduction: In real-world practice, most non-small cell lung cancer (NSCLC) patients receiving combined immunochemotherapy are exposed to short-course corticosteroids following immune checkpoint inhibitor (ICI) infusion to prevent chemotherapy-related adverse events. However, whether this early short-course corticosteroid use prevents immune-related adverse events (irAEs) remains unknown., Methods: Between January 1st, 2015, and December 31st, 2020, NSCLC patients who received at least one cycle of ICI with or without chemotherapy were enrolled. Early short-course corticosteroids were defined as corticosteroids administered following ICI injection and before chemotherapy on the same day and no longer than 3 days afterward. The patients were categorized as either "corticosteroid group" or "non-corticosteroid group" depending on their exposure to early short-course corticosteroid. The frequencies of irAEs requiring systemic corticosteroid use and irAEs leading to ICI discontinuation were compared between the two groups, and exploratory survival analyses were performed., Results: Among 252 eligible patients, 137 patients were categorized as "corticosteroid group" and 115 patients as "non-corticosteroid group." The corticosteroid group enriched patients in the first-line setting (n = 75, 54.7%), compared to the non-corticosteroid group (n = 28, 24.3%). Thirty patients (21.9%) in the corticosteroid group and 35 patients (30.4%) in the non-corticosteroid group developed irAEs requiring systemic corticosteroid use (odds ratio [OR], 0.64; 95% confidence interval [CI], 0.35-1.18; p = 0.15). Eight patients (5.8%) in the corticosteroid group, as compared with 18 patients (15.7%) in the non-corticosteroid group, permanently discontinued ICI due to irAEs (OR, 0.34; 95% CI, 0.12-0.85; p = 0.013)., Conclusion: Early short-course corticosteroids following each ICI injection may reduce the rate of irAEs that lead to ICIs discontinuation, warranting further investigation of its prophylactic use to mitigate clinically significant irAEs., (© 2023 The Author(s). Published by S. Karger AG, Basel.)

Epidermal growth factor receptor ( EGFR ) T790M mutations drive resistance in 50% of patients with advanced non-small cell lung cancer (NSCLC) who progress on first/second generation (1G/2G) EGFR tyrosine kinase inhibitors (TKIs) and are sensitive to Osimertinib. Tissue sampling is the gold-standard modality of T790M testing, but it is invasive. We evaluated the efficacy of Osimertinib in patients with EGFR mutant NSCLC and T790M in circulating tumour DNA (ctDNA). PLASMA is a prospective, open-label, multicentre single-arm Phase II study. Patients with advanced NSCLC harbouring sensitizing EGFR and T790M mutations in plasma at progression from ≥one 1G/2G TKI were treated with 80 mg of Osimertinib daily until progression. The primary endpoint was the objective response rate (ORR); the secondary endpoints included progression-free survival (PFS), overall survival (OS), disease control rate (DCR) and toxicities. Plasma next-generation sequencing was performed to determine Osimertinib resistance mechanisms and assess serial ctDNA. A total of 110 patients from eight centres in five countries were enrolled from 2017 to 2019. The median follow-up duration was 2.64 (IQR 2.44-3.12) years. The ORR was 50.9% (95% CI 41.2-60.6) and the DCR was 84.5% (95% CI 76.4-90.7). Median PFS was 7.4 (95% CI 6.0-9.3) months; median OS was 1.63 (95% CI 1.35-2.16) years. Of all of the patients, 76% had treatment-related adverse events (TRAEs), most commonly paronychia (22.7%); 11% experienced ≥ Grade 3 TRAEs. The ctDNA baseline load and dynamics were prognostic. Osimertinib is active in NSCLC harbouring sensitizing EGFR and T790M mutations in ctDNA testing post 1G/2G TKIs.

Single-agent checkpoint inhibitor (CPI) activity in Epstein-Barr Virus (EBV) related nasopharyngeal carcinoma (NPC) is limited. Dual CPI shows increased activity in solid cancers. In this single-arm phase II trial (NCT03097939), 40 patients with recurrent/metastatic EBV-positive NPC who failed prior chemotherapy receive nivolumab 3 mg/kg every 2 weeks and ipilimumab 1 mg/kg every 6 weeks. Primary outcome of best overall response rate (BOR) and secondary outcomes (progression-free survival [PFS], clinical benefit rate, adverse events, duration of response, time to progression, overall survival [OS]) are reported. The BOR is 38% with median PFS and OS of 5.3 and 19.5 months, respectively. This regimen is well-tolerated and treatment-related adverse events requiring discontinuation are low. Biomarker analysis shows no correlation of outcomes to PD-L1 expression or tumor mutation burden. While the BOR does not meet pre-planned estimates, patients with low plasma EBV-DNA titre (<7800 IU/ml) trend to better response and PFS. Deep immunophenotyping of pre- and on-treatment tumor biopsies demonstrate early activation of the adaptive immune response, with T-cell cytotoxicity seen in responders prior to any clinically evident response. Immune-subpopulation profiling also identifies specific PD-1 and CTLA-4 expressing CD8 subpopulations that predict for response to combined immune checkpoint blockade in NPC., (© 2023. The Author(s).)

Objectives: The optimal duration of anti-PD-1 for cancer therapy has not been tested, especially when using combination therapy. Epidermal growth factor receptor (EGFR) pathway blocker was the top compound that enhanced T-cell killing of tumor cells in a high-throughput immune-oncology screen, possibly by stimulate the antigen presentation machinery and other mechanisms. We explored the effect of combination of EGFR inhibition with a short course of anti-PD-1 therapy in patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC)., Method: We analyzed the effect of a short course of anti-PD-1 with continuous afatinib on the survival of a real-world cohort of R/M HNSCC patients. Patient characteristics, treatments, efficacies, and toxicities were reviewed and recorded for analysis., Results: From November 2016 to May 2018, 51 consecutive patients received pembrolizumab and afatinib. The cutoff date was June 30, 2022. The most common toxicities (all grades) were diarrhea (62.7%), skin rash (43.1%), mucositis (31.4%), and paronychia (23.5%). The objective response rate was 54.9% (95% confidence interval [CI] 40.3-68.9%). Median progression-free survival was 5.9 months (95% CI: 4.4-7.6 months), and the median overall survival was 10.5 months (95% CI: 6.8-16.5 months). The 12-month, 24-month, 36-month, and 48-month survival rate was 47.0%, 22.5%, 17.7%, and 12.6% respectively., Conclusions: This retrospective study showed that short course pembrolizumab with afatinib therapy has acceptable efficacy in R/M HNSCC patients. The durable response and long-term survival rates were similar to prospective clinical trials. Short course anti-PD-1 therapy, especially in combination with EGFR blocker, is worth for further prospective study., (© 2022. The Author(s).)

Purpose: EGFR pathway inhibition may promote anti-programmed cell death protein 1 (PD-1) responses in preclinical models, but how EGFR inhibition affects tumor antigen presentation during anti-PD-1 monotherapy in humans remain unknown. We hypothesized that afatinib, an irreversible EGFR tyrosine kinase inhibitor, would improve outcomes in patients treated with pembrolizumab for recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) by promoting antigen presentation and immune activation in the tumor microenvironment., Patients and Methods: The ALPHA study (NCT03695510) was a single-arm, Phase II study with Simon's 2-stage design. Afatinib and pembrolizumab were administered to patients with platinum-refractory, recurrent, or metastatic HNSCC. The primary endpoint was the objective response rate (ORR). The study applied gene expression analysis using a NanoString PanCancer Immune Profiling Panel and next-generation sequencing using FoundationOne CDx., Results: From January 2019 to March 2020, the study enrolled 29 eligible patients. Common treatment-related adverse events were skin rash (75.9%), diarrhea (58.6%), and paronychia (44.8%). Twelve patients (41.4%) had an objective partial response to treatment. The median progression-free survival was 4.1 months, and the median overall survival was 8.9 months. In a paired tissue analysis, afatinib-pembrolizumab were found to upregulate genes involved in antigen presentation, immune activation, and natural killer cell-mediated cytotoxicity. Unaltered methylthioadenosine phosphorylase and EGFR amplification may predict the clinical response to the therapy., Conclusions: Afatinib may augment pembrolizumab therapy and improve the ORR in patients with HNSCC. Bioinformatics analysis suggested the enhancement of antigen presentation machinery in the tumor microenvironment., (©2022 The Authors; Published by the American Association for Cancer Research.)

Background/aim: Successful therapy of EGFR-mutant NSCLC remains a challenging task despite initial benefits with the usage of EGFR tyrosine kinase inhibitors. Cancer immunotherapy has shown promising results in certain tumors, but response rate in EGFR-mutant NCLC is low, because these tumors are thought to have weak immunogenicity., Materials and Methods: We used data from in vivo NSCLC databases as well as from in vitro cell culture experiments to investigate the regulation of CD73 by EGFR., Results: EGFR expression was correlated with CD73 expression in patients' datasets, with EGFR-mutant tumors showing higher expression than their EGFR wildtype counterparts. Treatment of EGFR-mutant NSCLC cell lines with EGFR TKI reduced expression of CD73 at both mRNA and protein level. Among EGFR downstream signaling pathways, the Ras-Raf-ERK pathway was involved in the regulation of CD73 expression directly via ERK1/2 without the engagement of RSKs or MSKs., Conclusion: The results of this study may provide novel therapeutic strategies for the treatment of oncogene-driven NSCLC., (Copyright © 2021 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Introduction: Recent advances in the detection of genomic DNA from plasma samples allow us to follow tumor DNA shedding in plasma during systemic treatment. Osimertinib is the standard of care for patients with NSCLC with acquired EGFR T790M mutations. We assessed changes in serial plasma cell-free circulating tumor DNA (ctDNA) genomic alterations to predict osimertinib efficacy., Methods: We prospectively collected plasma from patients having EGFR -mutated advanced NSCLC previously treated with EGFR tyrosine kinase inhibitor therapy and with acquired EGFR T790M mutation detected by standard methods. Plasma samples were collected before starting osimertinib treatment, 4 weeks after osimertinib treatment, and on progression. ctDNA was analyzed using the Guardant360 assay., Results: A total of 15 eligible patients received osimertinib. Before starting treatment, EGFR -activating mutations were detected in the ctDNA of all patients, and EGFR T790M was detected in 93% of the cases. Osimertinib treatment was associated with an objective response rate of 53% and a median progression-free survival of 7.3 months. A total of 12 of the 15 patients had undetectable plasma T790M and decreased activating mutation allelic frequency (AF) at week 4. None of the 12 patients had disease progression within 16 weeks. For the remaining three patients, with detectable plasma T790M (n = 2) or increased activating mutation AF (n = 1) at week 4, two had progressive disease within 16 weeks ( p  = 0.03)., Conclusions: In patients with EGFR -mutated advanced NSCLC, persistent EGFR T790M or increasing activating mutation AF as detected in ctDNA 4 weeks after the start of osimertinib treatment may predict disease progression within 16 weeks., (© 2020 The Authors.)

Background: Programmed death-ligand 1 (PD-L1) expression is associated with clinical outcomes of epidermal growth factor receptor (EGFR) mutant lung adenocarcinoma (ADC) treated with tyrosine kinase inhibitors (TKIs). However, whether PD-L1 expression plays a role in anaplastic lymphoma kinase (ALK)-positive lung ADC is unknown. We aimed to evaluate the impact of PD-L1 in patients with ALK-positive lung ADC receiving crizotinib., Materials and Methods: PD-L1 expression was identified by immunohistochemistry (IHC). Reverse transcriptase-polymerase chain reaction was used for ALK variant detection, and immunofluorescence-based multiplex staining was applied for exploring immune cells in tumor microenvironments., Results: A total of 78 patients with ALK-positive advanced ADC were enrolled in our study, of whom 52 received crizotinib. Compared with EGFR/ALK wild-type tumors, PD-L1 expression was lower in ALK-positive ADC. ALK fusion variants were identified in 32 patients, and those with variant 3 and 5 (short variants) had higher PD-L1 expression than those with other variants. The crizotinib objective response rate (ORR) and progression-free survival (PFS) was better in tumors with negative PD-L1 expression (ORR/PFS in PD-L1 0% vs. 1%-49% vs. 50%-100%: 60.7%/11.8 months vs. 38.5%/6.5 months vs. 36.4%/4.0 months, p = .007/.022). The multivariate Cox proportional hazards model revealed that PD-L1 0% (vs. ≥1%) was an independent factor for longer PFS (adjusted hazard ratio 0.322, 95% confidence interval 0.160-0.650, p = .002). Multiplex IHC in three cases showed a varied extent of immune cell infiltrations in tumors with different PD-L1 expression., Conclusion: Positive PD-L1 expression was associated with unfavorable clinical outcomes in patients with ALK-positive lung ADC receiving crizotinib., Implications for Practice: Not all lung adenocarcinoma with sensitizing driver mutations experienced durable responses to small-molecule tyrosine kinase inhibitors (TKIs). Similar to the negative impact of programmed death-ligand 1 (PD-L1) in epidermal growth factor receptor mutant tumors treated with TKIs, this study demonstrated that positive PD-L1 expression was also associated with worse response rate and shorter progression-free survival of anaplastic lymphoma kinase (ALK)-positive adenocarcinoma treated with crizotinib. Among different ALK fusion partners, tumors with short variants (V3 and V5) had higher PD-L1 compared with long variants (V1, V2, and V6). Testing PD-L1 before initiating crizotinib for ALK-positive lung cancer could be a simple method to provide important prognostic information., (© AlphaMed Press 2020.)

Introduction: Osimertinib is the current recommended treatment for EGFR T790M-positive NSCLC after EGFR tyrosine kinase inhibitor therapy. However, resistance to osimertinib therapy is inevitably acquired after a period of effective treatment. We had a patient with EGFR L858R/T790M-positive NSCLC who initially responded to osimertinib therapy but eventually experienced development of resistance. Plasma cell-free DNA analysis revealed the occurrence of exon 16-skipping HER2, which may have resulted in the erb-b2 receptor tyrosine kinase 2 gene (HER2) splice variant HER2D16. HER2D16 has never been reported in lung cancer, and HER2D16-driven signaling is known to be regulated by Src kinase in breast cancer. We investigated the role of HER2D16 as an osimertinib-resistant mechanism., Methods: We constructed and established H1975 cells stably expressing HER2D16. The dimeric formation of HER2D16 was tested by using nonreducing polyacrylamide gel electrophoresis. The effects of the study drugs on signaling transduction were examined by using Western blot. Synergistic effect was assessed by using the Chou-Talalay method., Results: We found that HER2D16 can form a homodimer in NSCLC cells. HER2D16-expressing H1975 cells were resistant to osimertinib treatment. We also found that mutant EGFR and HER2D16 cooperated to activate downstream signaling for osimertinib resistance. In addition, cotreatment with osimertinib and an Src kinase inhibitor failed to reverse resistance, indicating that HER2D16-driven signaling in NSCLC did not occur through a canonical pathway. Finally, we revealed that the combination of osimertinib with the pan-HER small-molecule inhibitor afatinib could synergistically repress cell growth and signaling in H1975-HER2D16 cells., Conclusion: HER2D16 can contribute to osimertinib resistance through an Src-independent pathway. HER2D16 should be included in the molecular diagnosis panel for lung cancer., (Copyright © 2019 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.)

Introduction: Besides being a predictive biomarker of response to immunotherapy in lung cancer in general, programmed death-ligand 1 (PD-L1) is not so well correlated with treatment outcomes of lung adenocarcinoma (ADC) harbouring epidermal growth factor receptor (EGFR) mutations, as reported studies are inconclusive and seldom addressed the issues of response to treatment and resistance. The primary objective is to evaluate the association of PD-L1 and EGFR tyrosine kinase inhibitor (TKI) efficacy, resistance, and relevant clinical outcomes. The secondary objective is to further explore the tumour microenvironments of EGFR mutant tumours with different PD-L1 expression., Methods and Materials: Using immunohistochemical (IHC) staining, we retrospectively tested PD-L1 expression (Dako 22C3) in the pre-treatment tumours from advanced EGFR mutant lung ADC patients, of whom all were treated with TKIs. Multiplex IHC assay was applied for exploring immune cells in tumour microenvironments., Results: A total of 153 Taiwanese patients were enrolled in our study, of whom a majority of cases were female (58.9%) and non-smokers (75.8%). The objective response rate (ORR) to EGFR TKI and progression-free survival (PFS) were better in patients with PD-L1 expression <50% (ORR/PFS in PD-L1 0% versus 1-49% versus ≥50%: 65.6%/12.5 months versus 56.4%/12.8 months versus 38.9%/5.9 months, P < 0.05). The multivariate analysis showed that PD-L1 <50% was an independent prognostic factor for longer PFS (hazard ratio (HR) 0.433, 95% confidence interval (CI) 0.250-0.751, P = 0.003). Furthermore, tumours with higher PD-L1 expression were less likely to develop a secondary T790M mutation (T790M+ in PD-L1 0% versus 1-49% versus ≥50%: 53.7% versus 35.7% versus 10%, P = 0.024). Multiplex IHC tests were applied in 15 cases and revealed a potential correlation between PD-L1, immune cells, and EGFR TKI responses., Conclusions: Lower pre-treatment PD-L1 is associated with better ORR, PFS, and higher frequency of T790M resistance in EGFR TKI-treated lung ADC patients., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the currently recommended treatment for advanced EGFR mutation-positive non-small cell lung cancer (NSCLC). Acquired resistance inevitably develops, with the EGFR T790M mutation comprising approximately 55% of the mechanisms of resistance following first- or second-generation EGFR-TKI therapy (e.g. gefitinib, erlotinib, afatinib, and dacomitinib). Patients without T790M are a heterogeneous group for whom platinum-based chemotherapy is currently recommended as a second-line treatment. In addition to secondary mutations in EGFR (e.g. T790M), the currently known resistance mechanisms can be classified into the following three categories: bypass pathways, downstream signaling pathways, and histologic transformations. Given the evolving knowledge and convenience of diagnosing acquired resistance mechanisms by next-generation sequencing and liquid biopsy, exploratory studies targeting these resistance mechanisms and incorporating immunotherapy into the treatment paradigm have become the mainstream of future development. This review focuses on acquired resistance mechanisms other than T790M that develop after first- or second-generation EGFR-TKI therapy. Exploratory second-line treatments targeting resistance mechanisms as well as combination immunotherapy and chemotherapy in ongoing clinical trials are reviewed here. We also highlight the recent development of next-generation sequencing and liquid biopsy in this field., Competing Interests: Conflict of interest statement: B-C Liao has received honoraria/speaker fees from AstraZeneca, Roche, Boehringer Ingelheim, Merck Sharp and Dohme, Merck Serono, and Chugai. J C-H Yang received honoraria for speeches or participated in compensated advisory boards of Boehringer Ingelheim, Eli Lilly, Bayer, Roche/Genentech/Chugai, Merck Sharp and Dohme, Merck Serono, Pfizer, Novartis, Celgene, Merrimack, Yuhan Pharmaceuticals, Bristol-Myers Squibb, Ono Pharmaceutical, Daiichi Sankyo, AstraZeneca, Takeda Oncology, Blueprint Medicines, and Hansoh Pharmaceuticals. No potential conflicts of interest were disclosed by the other authors., (© The Author(s), 2019.)

Introduction: Brain metastases (BMs) develop in up to 40% of patients with non-small cell lung cancer (NSCLC). In many recent practice-changing clinical trials, patients with BM were included; however, only few trials reported intracranial efficacies in either post hoc or pre-planned analysis. Clinically meaningful intracranial efficacy data of novel agents have not been completely disclosed., Areas Covered: The authors performed a systemic review of recent pharmaceutical clinical trials, mainly pivotal or practice-changing trials. Some of the prospective clinical trials focused on patients with NSCLC and BM. The authors collected and compared intracranial efficacy reports of chemotherapy, epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), ALK inhibitors, and immune checkpoint inhibitors., Expert Opinion: Many clinical trials, especially those on 'brain-active' EGFR-TKIs and ALK inhibitors, have robust reports of intracranial efficacies either as post hoc or pre-planned analysis. Physicians should interpret this data with caution and apply the results to patients accordingly. For the design of future clinical trials, enrolling patients with only BM, incorporating novel risk classifications, pre-planning intracranial efficacy endpoints, reporting prior local brain therapies, and applying novel response evaluation criteria are emerging trends in this area.

Background: Immunotherapy that targets programmed death protein-1 (PD-1) provides improved treatment efficacy and survival in patients with metastatic non-small cell lung cancer (NSCLC), especially those with high tumor expression of PD-L1. However, data on this treatment are mostly from clinical trials enrolling highly selected patients. The real-world experience of anti-PD-1 treatment and the usefulness of tumor PD-L1 expression in prediction of treatment response are largely unknown. Methods: We retrospectively reviewed patients with stage IIIB/ IV NSCLC who received monotherapy with nivolumab or pembrolizumab, and evaluated response using RECIST 1.1 criteria. Factors associated with treatment response, progression free survival (PFS), and overall survival (OS) were determined. Results: Seventy-four NSCLC patients out of 116 examined patients were included, most of whom had adenocarcinoma (48/74, 64.9%) and received immunotherapy as a third-line or subsequent treatment (51/74, 68.9%). The median PFS and OS were 1.8 and 7.9 months, respectively. The objective response rate was 32%, but only 47 of 74 patients were evaluable. Through multivariate analysis, epidermal growth factor receptor (EGFR) mutation was independently associated with a poor treatment response. Good performance status (ECOG≤1) and smoking were independently associated with better PFS and OS. Data on tumor PD-L1 expression were available in 43 patients (58%); higher PD-L1 expression correlated with better treatment response and longer PFS. Severe treatment-related adverse events were uncommon. Conclusion: The efficacy and safety of anti-PD-1 medications for advanced NSCLC were comparable in real-world and clinical settings, except in those with poor ECOG scores. Prediction of treatment response from tumor PD-L1 expression seemed practical., Competing Interests: Conflicts of Interest: Jin-Yuan Shih received speaking honoraria from AstraZeneca, Roche, Boehringer Ingelheim, Pfizer, Norvatis, Bristol-Myers Squibb, Merck Sharp & Dohme and Eli Lilly, and has been paid for a consulting or advisory role by AstraZeneca, Roche, Boehringer Ingelheim, Novartis, Merck Sharp & Dohme, AbbVie and Chugai Pharmaceutical. Other authors declared no conflicts of interest. James Chih-Hsin Yang is a member of the advisory committees and has received honoraria from AstraZeneca, Roche/Genentech, Boehringer Ingelheim, MSD, Merck Serono, Novartis, Pfizer, Clovis Oncology, Eli Lilly, Bayer, Celgene, Astellas, BMS, Ono Pharmaceutical, Yuhan Pharmaceutical, and Chugai Pharmaceutical.

Background/purpose: Research biopsies (RBs) are crucial for developing novel molecular targeted agents. However, the safety and diagnostic yields of RBs have not been investigated in EGFR mutation-positive non-small cell lung cancer (NSCLC) patients pretreated with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs)., Methods: We searched the medical records of NSCLC patients who participated in lung cancer clinical trials and underwent mandatory RBs between 2012 and 2014 at our institution. Only patients with EGFR mutation-positive NSCLC pretreated with at least 1 EGFR-TKI were enrolled., Results: Of 140 enrolled patients, 73 (52.1%) and 59 (42.1%) had exon 19 deletions and exon 21 L858R mutation, respectively. Before RBs, 108 (77.1%), 83 (59.3%), and 36 (25.7%) patients had been treated with gefitinib, erlotinib, and afatinib, respectively. Computed tomography-guided percutaneous core needle biopsy was the most frequently used modality among 181 RBs performed (50.8%), followed by ultrasonography-guided (32.0%) and endoscopic RBs (16.0%). The most common RB sites were the lung (69.6%), pleura (8.8%), and liver (6.1%). Pathologic examinations revealed malignant cells in most RB specimens (72.9%). Complications due to RBs included pneumothorax (11.6%), bleeding (6.1%), and infection (1.1%). Only 1 patient required chest tube placement for pneumothorax, and 2 patients underwent endotracheal intubation because of bleeding., Conclusion: RBs in this patient population were generally safe. Pneumothorax was the most frequent complication; bleeding, while infrequent, increased the risk of severe events. The diagnostic yields and complications of any particular modality should therefore be discussed with prospective clinical trial participants., (Copyright © 2017. Published by Elsevier B.V.)

Although current staging workups could differentiate most patients with operable from inoperable advanced gastric cancers, there are still some patients with low-volume peritoneal carcinomatosis, defined as only metastasis with multiple subcentimeter lesions in peritoneum, receiving unnecessary open-close procedures. The computed tomography (CT) of the patients with unresectable advanced gastric cancer harboring low-volume peritoneal carcinomatosis was retrospectively identified and then thoroughly reviewed by two independent radiologists unaware of the peritoneal carcinomatosis status. Of the 798 patients with newly diagnosed gastric cancer between January 2007 and December 2010, 52 patients harboring advanced gastric cancer with low-volume peritoneal carcinomatosis receiving surgery with curative intent were identified. Descriptive statistic was used for the radiologic characteristics. The most common radiologic characteristic of CT was omental fat stranding (57.7%), followed by omental clustered subcentimeter nodules (53.8%), distant enlarged lymph node (40.4%), distant grouping of small lymph nodes (36.5%), peritoneal nodules or thickening (34.6%), minimal loculated ascites (21.2%), intestinal wall thickening or irregularity (9.6%), and hydronephrosis or hydroureter without stone or urothelial lesion (5.8%). Comprehensively reviewing the radiologic characteristics of CT may identify the patients harboring advanced gastric cancer with low-volume peritoneal carcinomatosis.

The first-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), gefitinib and erlotinib, and the second-generation EGFR-TKI, afatinib, have all been approved as standard first-line treatments for advanced EGFR-mutant non-small cell lung cancer (NSCLC) based on superior progression-free survival results compared to platinum doublet chemotherapy regimens. Acquired resistance to an EGFR-TKI inevitably develops after a period of effective drug treatment. After tumor progression, many combination therapy regimens that include an EGFR-TKI, or EGFR-TKI monotherapy, have been tested in prospective trials with the aim of extending survival. Third-generation EGFR-TKIs such as osimertinib have been developed with the aim of overcoming the effects of EGFR T790M resistance mutation, which occurs in half of the patients with disease progression on EGFR-TKI therapy. Osimertinib has become the standard treatment in patients for whom tumor re-biopsy reveals an acquired EGFR T790M mutation following EGFR-TKI therapy. Other third-generation EGFR-TKIs, such as olmutinib, EGF816, and ASP8273, are still in the trial phase., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Afatinib, a second-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, has been approved worldwide as a first-line treatment for advanced non-small cell lung cancer (NSCLC) that harbors activating EGFR mutations. Here, we have reviewed the recent clinical developments in the treatment of lung cancer using afatinib. Emerging data have revealed the overall survival benefit of first-line afatinib therapy in patients with advanced EGFR del19 -positive NSCLC. Phase III studies of afatinib have shown the effectiveness of afatinib as a second-line treatment for advanced lung squamous cell carcinoma, as well as the benefit of continuing afatinib therapy in combination with cytotoxic chemotherapy for advanced NSCLC after the occurrence of disease progression in patients who are receiving afatinib monotherapy. Therapeutic benefits of afatinib have also been reported in studies of patients with central nervous system metastasis and patients with HER2 mutation. The utility of afatinib-based combination therapies is being investigated in ongoing research.

The first- and second-generation epidermal growth factor receptor tyrosine kinase inhibitors (1/2G EGFR-TKIs) gefitinib, erlotinib, and afatinib have all been approved as standard first-line treatments for advanced EGFR mutation-positive non-small cell lung cancer. The third-generation (3G) EGFR-TKIs have been developed to overcome the EGFR T790M mutation, which is the most common mechanism of acquired resistance to 1/2G EGFR-TKI treatment. This resistance mutation develops in half of the patients who respond to 1/2G EGFR-TKI therapy. The structures of the novel 3G EGFR-TKIs are different from those of 1/2G EGFR-TKIs. Particularly, 3G EGFR-TKIs have lower affinity to wild-type EGFR, and are therefore associated with lower rates of skin and gastrointestinal toxicities. However, many of the adverse events (AEs) that are observed in patients receiving 3G EGFR-TKIs have not been observed in patients receiving 1/2G EGFR-TKIs. Although preclinical studies have revealed many possible mechanisms for these AEs, the causes of some AEs remain unknown. Many mechanisms of resistance to 3G EGFR-TKI therapy have also been reported. Here, we have reviewed the recent clinical and preclinical developments related to novel 3G EGFR-TKIs, including osimertinib, rociletinib, olmutinib, EGF816, and ASP8273.

Aim: Cytotoxic chemotherapy is the standard first-line therapy for patients with advanced non-small cell lung cancer (NSCLC) without specific gene alterations. This study examined the prescription pattern and the survival outcome of cytotoxic chemotherapy regimens in daily practice in Taiwan., Methods: We established a population-based cohort of patients diagnosed with advanced NSCLC between 2005 and 2009 using the databases of Taiwan Cancer Registry and National Health Insurance in Taiwan. We then analyzed chemotherapy prescriptions and the survival outcomes of patients., Results: A total of 25,008 patients with advanced NSCLC were identified, 17,443 (70.0%) of which received first-line chemotherapy and were therefore included in this study. Among them, 11,551 (66.2%) patients had adenocarcinoma and 3,292 (18.9%) patients had squamous cell carcinoma (SCC). Approximately 70% of the patients were diagnosed with NSCLC in medical centers. Platinum-based doublet chemotherapy was administered to 66.9% of the patients. Among all chemotherapy regimens, platinum with gemcitabine (33.8%) was the most common, irrespective of geographic region. The second and third most common regimens were vinorelbine alone (13.0%) and platinum with docetaxel (11.6%). The prevalence of platinum-based doublet chemotherapy regimens decreased from 71.4% in 2005 to 64.1% in 2009. Among patients with adenocarcinoma histology, those who received platinum with pemetrexed had longer OS than did patients who received other platinum-based regimens (p < 0.001)., Conclusion: Our findings reaffirm that in real-world practice, treatment plans of advanced NSCLC should be drawn up according to histology type.

Background: Leptomeningeal carcinomatosis (LC) is a detrimental complication of patients with non-small-cell lung cancer (NSCLC). The effect of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) on the clinical outcome of these patients, particularly those with EGFR mutations, has not been studied yet., Methods: We searched the database for lung cancer patients diagnosed from 2003 to 2010 in one Asian medical center. NSCLC patients who also had LC diagnosed by either cytology or brain neuroimaging studies were identified. The treatments and clinical outcomes were reviewed., Results: Of 5526 lung cancer patients, we identified 212 (3.8%) NSCLC patients with LC. Most patients (88.7%) had adenocarcinoma histology, and 129 (60.9%) patients had been treated with at least one regimen of EGFR TKI before the diagnosis of LC. One hundred and twenty-four (58.5%) patients were treated with EGFR TKI, and 128 (60.4%) patients were treated with whole-brain radiation therapy (WBRT) after the diagnosis of LC. The median overall survival was 4.5 months (95% confidence interval, 3.5-7.3). Multivariate analysis suggested that EGFR TKI therapy, WBRT, and cytotoxic chemotherapy were independent predictors for longer survival. Mutational status of EGFR was evaluated in 101 patients, and 75 mutations (74.3%) were detected. Among the 75 patients with EGFR mutations, EGFR TKI therapy and cytotoxic chemotherapy after diagnosis of LC remained the independent factors predictive of extended survival in the multivariate analysis., Conclusions: Treatment of LC with EGFR TKI, cytotoxic chemotherapy, or WBRT in selected patients is associated with prolong survival period. These treatment options, especially EGFR TKIs, should be studied in patients with EGFR mutation-positive NSCLC and LC.

Rearrangements in anaplastic lymphoma kinase (ALK) gene and echinoderm microtubule-associated protein-like 4 (EML4) gene were first described in a small portion of patients with non-small cell lung cancer (NSCLC) in 2007. Fluorescence in situ hybridization is used as the diagnostic test for detecting an EML4-ALK rearrangement. Crizotinib, an ALK inhibitor, is effective in treating advanced ALK-positive NSCLC, and the US Food and Drug Administration approved it for treating ALK-positive NSCLC in 2011. Several mechanisms of acquired resistance to crizotinib have recently been reported. Second-generation ALK inhibitors were designed to overcome these resistance mechanisms. Two of them, ceritinib and alectinib, were approved in 2014 for advanced ALK-positive NSCLC in the US and Japan, respectively. Heat shock protein 90 (Hsp90) inhibitors also showed activity against ALK-positive NSCLC. Here we review the recent development of crizotinib, ceritinib, alectinib and other second-generation ALK inhibitors as well as Hsp90 inhibitors. We also discuss management strategies for advanced ALK-positive NSCLC.

Purpose of Review: The first-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), gefitinib and erlotinib, are effective as first-line treatment of advanced nonsmall cell lung cancer (NSCLC) harboring activating EGFR mutations (deletions in exon 19 and exon 21 L858R mutation). EGFR T790 M resistance mutation (EGFR T790 M) ultimately emerged in most of these patients. The second and third-generation EGFR-TKIs were designed to have more potent inhibition of EGFR and to overcome EGFR T790 M. This review describes the recent developments of these novel EGFR-TKIs., Recent Findings: The second-generation EGFR-TKIs, afatinib and dacomitinib, irreversibly bind to the tyrosine kinase of EGFR and other ErbB-family members. Afatinib has been approved as first-line treatment of advanced NSCLC harboring activating EGFR mutations. Dacomitinib is under development. Third-generation EGFR-TKIs, AZD9291, CO-1686, and HM61713, inhibit both EGFR activating and resistance mutations, while sparing wild-type EGFR. In early-phase studies, these drugs demonstrated promising response rates against tumors with acquired EGFR T790 M., Summary: Second-generation EGFR-TKI, afatinib, is available as first-line treatment of advanced NSCLC harboring activating EGFR mutations. Third-generation EGFR-TKIs are under development for tumors harboring acquired EGFR T790 M.

Background: Platinum-based chemotherapy is the standard first-line therapy for patients with advanced lung squamous cell carcinoma (SCC). We compared the effectiveness of first-line chemotherapy regimens., Methods: We searched the database of the Taiwan Cancer Registry for patients with newly diagnosed advanced lung SCC from 2004 to 2007. Medication prescription data were retrieved from the database of National Health Insurance, Taiwan. We identified patients who received standard first-line platinum-based chemotherapy, which was defined as chemotherapy with a platinum (P) compound (cisplatin or carboplatin) in addition to 1 of the 4 chemotherapy agents, including gemcitabine (G), docetaxel (D), paclitaxel (T), and vinorelbine (V). Deaths were identified by searching the National Death Registry. Overall survival (OS) was compared between patients who underwent different therapies., Results: In total, 2790 patients were identified; 983 patients (35.2%) received standard first-line chemotherapy with P and G (58.1%), D (14.5%), T (11.6%), or V (15.8%). Older patients (age ≥ 70 years) were less likely to receive P + D than P + G, P + T, or P + V (P = .018). Patients who received P + G, P + D, P + T, or P + V had similar OS (median, 8.9, 7.9, 9.5, and 8.2 months; P = .816). In multivariate analyses adjusting for age, sex, and stage, the first-line chemotherapy regimen was not a predictor for OS. With P + G as the reference group, the adjusted hazard ratios of P + D, P + T, and P + V were 1.03, 0.90, and 1.02, respectively (P = .710)., Conclusions: In patients with advanced lung SCC, various regimens did not have a significant effect on survival outcomes., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Recently, several types of foods and drinks, including coffee, cream, and cake, have been found to result in high methylglyoxal (MG) levels in the plasma, thus causing both nutritional and health concerns. MG can be metabolized by phase-II enzymes in liver through the positive regulation of nuclear factor-erythroid 2-related factor 2 (Nrf2). In this study, we investigated the ability of scopoletin (SP) to protect against MG-induced hyperglycemia and insulin resistance. Recently, SP was shown to be a peroxisome proliferator-activated receptor-γ activator to elevate insulin sensitivity. We investigated the effects of oral administration of SP on the metabolic, biochemical, and molecular abnormalities characteristic of type 2 diabetes in MG-treated Wistar rats to understand the potential mechanism of scopoletin for diabetes protection. Our results suggested that SP activated Nrf2 by Ser40 phosphorylation, resulting in the metabolism of MG into d-lactic acid and the inhibition of AGEs generation, which reduced the accumulation of AGEs in the livers of MG-induced rats. In this manner, SP improved the results of the oral glucose tolerance test and dyslipidemia. Moreover, SP also increased the plasma translocation of glucose transporter-2 and promoted Akt phosphorylation caused by insulin treatment in MG-treated FL83B hepatocytes. In contrast, SP effectively suppressed protein tyrosine phosphatase 1B (PTP1B) expression, thereby alleviating insulin resistance. These findings suggest that SP acts as an anti-glycation and anti-diabetic agent, and thus has therapeutic potential for the prevention of diabetes.

Gefitinib and erlotinib are small-molecule reversible tyrosine kinase inhibitors (TKIs) of epidermal growth factor receptor (EGFR). Objective responses have been observed frequently in patients with non-small cell lung cancer (NSCLC) harbouring activating EGFR mutations, the most common being deletions in exon 19 and the exon 21 L858R mutation. EGFR mutations are prevalent in female patients, those who have never smoked, those of Asian ethnicity and those who have adenocarcinoma histology. Given the efficacy of EGFR TKIs in advanced NSCLC in the salvage setting, and their favourable toxicity profile compared with conventional chemotherapy, there is considerable interest in evaluating their efficacy in the first-line treatment of advanced NSCLC. To date, there have been several phase II and phase III studies that have examined the efficacy of first-line single-agent EGFR TKIs in unselected, clinically selected or molecularly selected populations. Here we review and compare the differences in these phase III trials. Most phase III trials chose progression-free survival (PFS) rather than overall survival (OS) as their primary endpoint. PFS was prolonged but OS was not. The recent development of novel irreversible EGFR TKIs, such as afatinib and dacomitinib, is also reviewed.

Reversible protein glutathionylation is an important posttranslational modification that provides protection against oxidation. In endothelial cells (ECs), cinnamaldehyde is an electrophilic compound that can increase the intracellular glutathione (GSH) levels or reactive oxygen species (ROS) production depending on the treatment duration. ECs treated with GSH and H(2)O(2) show increased sulfhydryl modifications of the p65 subunit of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappaB), which are responsible for NF-kappaB inactivation, and also a block in TNF-alpha-induced p65 nuclear translocation and inter-cellular adhesion molecule-1 (ICAM-1) expression. In our current study, we find that cinnamaldehyde induces p65 glutathionylation and inhibits TNF-alpha-induced p65 nuclear translocation and ICAM-1 expression within 12 h of treatment. Our analyses also reveal that p65 glutathionylation is suppressed by a GSH synthesis inhibitor, buthionine sulfoximine (BSO), and we further observed that the inhibitory effects of p65 nuclear translocation and ICAM-1 expression are also suppressed by BSO. NF-E2-related factor-2 small interfering RNA (siRNA) molecules not only inhibit glutamate-cysteine ligase catalytic subunit (GCLC) and glutamate-cysteine ligase modifier subunit (GCLM) induction and increases in GSH but also abolish cinnamaldehyde-induced p65 glutathionylation and its inhibitory effects. The gene expression and activity of glutaredoxin-1 (Grx-1), which catalyzes the formation of protein-glutathione mixed disulfides (protein-SSG), were also found to be increased after cinnamaldehyde treatment. A knock down of endogenous Grx-1 by siRNA or pretreatment with an inhibitor of Grx-1 activity, CdCl(2), abolishes p65-SSG formation. In addition, Grx-1 siRNA blocks the inhibition of p65 nuclear translocation and ICAM-1 expression, suggesting that this enzyme is involved in the cinnamaldehyde-mediated NF-kappaB inhibition. Our current results thus indicate that the GSH/Grx-1-dependent glutathionylation of p65 is likely to be responsible for cinnamaldehyde-mediated NF-kappaB inactivation and for the enhanced inhibitory effects of cinnamaldehyde upon TNF-alpha-treated ECs.

The production of a low molecular weight xylanase by Aspergillus carneus M34 was investigated in solid-state fermentation using agricultural waste as the substrate. Experimental designs were practiced for optimisation of the medium composition. When agricultural wastes of coba husk and corn steep liquor were used in the ratio of 4.5:0.5, a 22.5% increase of xylanase activity was observed compared with the medium containing only coba husk. The incubation time for xylanase production can be reduced from 12 days to six days by increasing the inoculum size to 2 x 10(7) sporesmL(-1). The optimal media compositions were as follows by using statistical approach: coba husk/corn steep liquor (4.5/0.5); NH(4)NO(3), 32.4 gL(-1); CaCl(2), 1.34 gL(-1); MnSO(4).7H(2)O, 0.0124 gL(-1). Xylanase activity of 1721 Ug(-1) substrate was obtained by A. carneus M34 in a six-day period at 30 degrees C, which was a 227% increase compared with that obtained before applying the Plackett-Burman and response surface methodology experimental design., (Copyright 2009 Elsevier B.V. All rights reserved.)

Many polyphenols have been found to increase endothelial nitric oxide (NO) production. In our present study, we investigated the effects of 1-alpha-O-galloylpunicalagin upon endothelial nitric oxide synthase (eNOS) activity in endothelial cells (ECs). Both 1-alpha-O-galloylpunicalagin and punicalagin induced NO production in a dose-dependent manner in ECs. Despite having similar chemical structures, punicalagin induced lower levels of NO production than 1-alpha-O-galloylpunicalagin. After 1-alpha-O-galloylpunicalagin addition, a rise in the intracellular Ca(2+) concentration preceded NO production. The Ca(2+) ionophore A23187 stimulated eNOS phosphorylation and augmented NO production. Pretreatment with Ca(2+) chelators inhibited 1-alpha-O-galloylpunicalagin-induced eNOS phosphorylation and NO production. Treatment with 1-alpha-O-galloylpunicalagin did not alter the eNOS protein levels but, unlike punicalagin, induced a sustained activation of eNOS Ser(1179) phosphorylation. 1-alpha-O-galloylpunicalagin was also found to activate ERK1/2, JNK and Akt in ECs. Moreover, simultaneous treatment of these cells with specific phosphatidylinositol-3-kinase inhibitors significantly inhibited the observed increases in eNOS activity and phosphorylation levels. In contrast, the inhibition of (ERK)1/2, JNK and p38 had no influence on eNOS Ser(1179) phosphorylation. Our present results thus indicate that the 1-alpha-O-galloylpunicalagin-induced calcium-dependent activation of eNOS is primarily mediated via a phosphatidylinositol 3-kinase/Akt-dependent increase in eNOS activity, and occurs independently of the eNOS protein content.

The production of adhesion molecules and subsequent attachment of leukocytes to endothelial cells (ECs) are critical early events in atherogenesis. These adhesion molecules thus play an important role in the development of this disease. Recent studies have highlighted the chemoprotective and anti-inflammatory effects of cinnamaldehyde, a Cinnamomum cassia Presl-specific diterpene. In our current study, we have examined the effects of both cinnamaldehyde and extracts of C. cassia on cytokine-induced monocyte/human endothelial cell interactions. We find that these compounds inhibit the adhesion of TNFalpha-induced monocytes to endothelial cells and suppress the expression of the cell adhesion molecules, VCAM-1 and ICAM-1, at the transcriptional level. Moreover, in TNFalpha-treated ECs, the principal downstream signal of VCAM-1 and ICAM-1, NF-kappaB, was also found to be abolished in a time-dependent manner. Interestingly, cinnamaldehyde exerts its anti-inflammatory effects by blocking the degradation of the inhibitory protein IkappaB-alpha, but only in short term pretreatments, whereas it does so via the induction of Nrf2-related genes, including heme-oxygenase-1 (HO-1), over long term pretreatments. Treating ECs with zinc protoporphyrin, a HO-1 inhibitor, partially blocks the anti-inflammatory effects of cinnamaldehyde. Elevated HO-1 protein levels were associated with the inhibition of TNFalpha-induced ICAM-1 expression. In addition to HO-1, we also found that cinnamaldehyde can upregulate Nrf2 in nuclear extracts, and can increase ARE-luciferase activity and upregulate thioredoxin reductase-1, another Nrf2-related gene. Moreover, cinnamaldehyde exposure rapidly reduces the cellular GSH levels in ECs over short term treatments but increases these levels after 9 h exposure. Hence, our present findings indicate that cinnamaldehyde suppresses TNF-induced singling pathways via two distinct mechanisms that are activated by different pretreatment periods.

Substance P (SP), a neurotransmitter, may play an important role in neurogenic inflammation. Ginseng has been used extensively in traditional medicine; however, few studies were focused on their anti-allergic effect. Therefore, the effect and mechanism of ginsenoside Rb1 on the SP enhancement of allergic mediators were explored. In this study, SP and dinitrophenyl-bovine serum albumin (DNP-BSA) were used to activate rat basophilic leukemia (RBL)-2H3 cells. The cultured supernatants were assayed for histamine, leukotriene C(4)(LTC(4)) and interleulin-4 (IL-4) production. The mitogen-activated protein kinases (MAPKs) signaling pathway was determined by Western blotting analysis. We found that IgE/DNP-BSA, SP, ginsenoside Rb1, or MAPK specific inhibitors had no effect on cell viability and cytotoxicity. SP (30 microM) alone, did not induce histamine and LTC(4) release, but it enhanced allergen-induced histamine and LTC(4) release. In addition, SP significantly induced and enhanced allergen-activated IL-4. Ginsenoside Rb1 dose-dependently inhibited these effects. SP enhanced the allergen-activated ERK pathway in RBL-2H3 cells, and Rb1 effectively inhibited the ERK pathway activation. Although MAPK specific inhibitors suppressed LTC(4) and IL-4, only U0126 inhibited the SP enhanced histamine release. These results demonstrate that Rb1 dose-dependently inhibited SP enhanced allergen-induced mediator release and its mechanism was through the inhibition of the ERK pathway.