Epidermal Growth Factor Receptor (EGFR) Pathway, Yes-Associated Protein (YAP) and the Regulation of Programmed Death-Ligand 1 (PD-L1) in Non-Small Cell Lung Cancer (NSCLC)

Choosing the optimal immunotherapeutic strategies for non-small cell lung cancer based on clinical factors

The treatment landscape of advanced non-small cell lung cancer (NSCLC) has changed dramatically since the emergence of immune checkpoint inhibitors (ICIs). Although some patients achieve long survival with relatively mild toxicities, not all patients experience such benefits from ICI treatment. There are several ways to use ICIs in NSCLC patients, including monotherapy, combination immunotherapy, and combination chemoimmunotherapy. Decision-making in the selection of an ICI treatment regimen for NSCLC is complicated partly because of the absence of head-to-head prospective comparisons. Programmed death-ligand 1 (PD-L1) expression is currently considered a standard biomarker for predicting the efficacy of ICIs, although some limitations exist. In addition to the PD-L1 tumor proportion score, many other clinical factors should also be considered to determine the optimal treatment strategy for each patient, including age, performance status, histological subtypes, comorbidities, status of oncogenic driver mutation, and metastatic sites. Nevertheless, evidence of the efficacy and safety of ICIs with some specific conditions of these factors is insufficient. Indeed, patients with poor performance status, oncogenic driver mutations, or interstitial lung disease have frequently been set as ineligible in randomized clinical trials of NSCLC. ICI use in these patients is controversial and remains to be discussed. It is important to select patients for whom ICIs can benefit the most from these populations. In this article, we review previous reports of clinical trials or experience in using ICIs in NSCLC, focusing on several clinical factors that are associated with treatment outcomes, and then discuss the optimal ICI treatment strategies for NSCLC.

Case Report: Good cardiac tolerance to Toripalimab in a CVD patient with oral melanoma

Primary oral melanoma is extremely rare, and the prognosis is very poor. With the development of immunotherapy, melanoma’s treatment landscape changed dramatically. Toripalimab, a recombinant programmed death receptor 1 (PD-1) monoclonal antibody, has been approved as second-line therapy for metastatic melanoma. However, the cardiac toxicity of Toripalimab is seldom reported. This article describes the application of Toripalimab on a patient who suffered from primary oral melanoma accompanied with arrhythmic mitral valve prolapse (AMVP).

Case Summary: A 55-year-old Chinese female was diagnosed with BRAF wild-type oral malignant melanoma by excisional biopsy and genetic test. The melanoma quickly progressed after complete tumor resection. Combined therapy after surgical resection was applied to control the progression of melanoma. Due to this patient’s basic cardiovascular situation, sacubitril–valsartan, spironolactone, and bisoprolol were used to maintain cardiac function. After five antitumor treatment courses, we re-evaluated the patient systemically from the symptom, physical examination, and auxiliary examination. The result showed that the patient who received Toripalimab combined with chemotherapy and radiotherapy did not present severe side effects on the cardiovascular system. The cardiac function remained well.

Conclusions: This case provided evidence of Toripalimab combined with chemotherapy on melanoma patients with complex cardiovascular diseases. Toripalimab demonstrated a manageable safety profile and durable clinical response. In addition, the standard CHF treatment plays a vital role in the protection of cardiac function. In a cancer patient with complex cardiovascular diseases, standard prophylactic CHF treatment should be applied at an early stage.

Clinical Efficacy of PD-1 Inhibitors Plus Split-Course Radiotherapy in the First-Line Treatment of Advanced Kidney Cancer: A Randomized Controlled Trial

Objective

To assess the clinical efficacy of programmed death 1 (PD-1) inhibitors plus split-course radiotherapy in the first-line treatment of advanced kidney cancer.

Methods

In this prospective, randomized, single-blinded, controlled trial, 44 patients with advanced kidney cancer initially treated in our hospital from January 2017 to December 2018 were recruited. They were concurrently and randomly assigned at a ratio of 1 : 1 to the control group and the study group, with 22 cases in each group. The control group received PD-1 inhibitor nivolumab combined with ipilimumab, and the study group received split-course radiotherapy plus. The primary endpoint is clinical efficacy, and the secondary endpoints are progression-free survival (PFS), overall survival (OS), and adverse events (AEs).

Results

Nivolumab plus split-course radiotherapy was associated with an objective remission rate (ORR) of 59.09% versus nivolumab alone with an ORR of 27.27%. The median PFS was 21.5 months (95% CI: 14.1—NA) after single nivolumab therapy and 28.1 months (95% CI: 24.5—NA) after nivolumab plus split-course radiotherapy, with an HR of 1.875 (95% CI: 0.877–4.011). The median OS was 27.1 months (95% CI: 20.7—NA) after single nivolumab therapy and not reached after nivolumab plus split-course radiotherapy and an HR of 2.56 (95% CI: 1.081–6.06). Nivolumab was associated with significantly better OS plus split-course radiotherapy versus nivolumab alone.

Conclusion

Nivolumab plus split-course radiotherapy in patients with advanced renal cell carcinoma significantly improves ORR and prolongs overall survival with a good safety profile.

The hypoxia-inducible factor 1 inhibitor LW6 mediates the HIF-1α/PD-L1 axis and suppresses tumor growth of hepatocellular carcinoma in vitro and in vivo

The low survival rate of hepatocellular carcinoma (HCC) remains a major challenge for clinicians and patients, and its progression may be related to hypoxia-inducible factor (HIF) and PD-L1. LW6 is a drug that inhibits hypoxia by reducing HIF-1α accumulation and gene transcriptional activity. However, its effect and regulatory mechanism in HCC remain to be revealed, especially under hypoxic conditions. The HIF-1α and PD-L1 expression in HCC specimens and paracarcinoma tissues was evaluated by a tissue microarray (TMA). The effects of LW6 were evaluated by cell viability, colony formation, and Transwell assays and xenografted nude mice. Cell cycle and apoptosis of HCC cells were detected by flow cytometry. The effects of LW6 on HIF-1α signaling and its targets PD-L1 and VEGF were evaluated through qRT-PCR, Western blots, Cell transfection, Transwell migration and invasion assays, immunohistochemistry, immunofluorescence and luciferase assays. In this study, we found that LW6 had antiproliferative effects on HCC and promoted HCC cell apoptosis, inhibited their migration and invasion, and affected their cell cycle. LW6 dramatically decreased HIF-1α expression through the VHL-dependent proteasome system pathway, inhibited HIF-1α transcriptional activation, and reduced PD-L1 expression by inhibiting EGFR pathway activation. These results suggest that LW6 can promote apoptosis of HCC cells by inhibiting HIF-1α, inhibit tumor angiogenesis, and downregulate the expression of PD-L1, which is an effective choice for the treatment of HCC. Moreover, inhibiting the hypoxic microenvironment combined with immunotherapy is expected to be a potentially effective strategy.

EGF Receptor Signaling Modulates YAP Activation and Promotes Experimental Proliferative Vitreoretinopathy

Purpose

Both epidermal growth factor receptor (EGFR) and the Yes-associated protein (YAP) signaling pathway are implicated in cell proliferation and differentiation. In this study, we explored whether the formation of proliferative vitreoretinopathy (PVR) depends on the interaction of the EGFR receptor and YAP pathway.

Methods

We studied the effects of EGFR and YAP activation on retinal fibrosis in a PVR mouse model as well as in knockout mice (conditional deletion of EGFR or YAP specifically in RPE cells). Reversal and knockdown experiments were performed to induce a model of ARPE-19 cells treated with TGF-β2 in vitro. The effect of EGFR/YAP signaling blockade on the PVR-induced cell cycle and TGF-β2-induced ARPE-19 cell activation was determined.

Results

The EGFR inhibitor erlotinib or conditional deletion of EGFR attenuated YAP activation and decreased the expression of YAP and its downstream target Cyr61 and of connective tissue growth factor in vivo and in vitro. EGFR-PI3K-PDK1 signaling induced by PVR promoted YAP activation and cell cycle progression. Furthermore, activated EGFR signaling bypassed RhoA to increase the protein levels of YAP, C-Myc, CyclinD1, and Bcl-xl.

Conclusions

Our work highlights that EGFR-PI3K-PDK1-dependent YAP activation plays a crucial role in the formation of PVR. Targeting EGFR and the YAP pathway provides promising therapeutic treatments for PVR.

Role of Yes-Associated Protein in Psoriasis and Skin Tumor Pathogenesis

Psoriasis and skin tumors (such as basal cell carcinoma, squamous cell carcinoma, and melanoma) are chronic diseases that endanger physical and mental health, and yet the causes are largely unknown and treatment options limited. The development of targeted drugs requires a better understanding of the exact pathogenesis of these diseases, and Yes-associated protein (YAP), a member of the Hippo signaling pathway, is believed to play an important role. Psoriasis and skin tumors are characterized by excessive cell proliferation, abnormal differentiation, vasodilation, and proliferation. Here, we review the literature related to YAP-associated disease mechanisms and discuss the latest research. YAP regulates cell apoptosis, proliferation, and differentiation; inhibits cell density and intercellular contacts and angiogenesis; and maintains the three-dimensional structure of the skin. These mechanisms may be associated with the occurrence and development of psoriasis and skin tumors. The results of recent studies have shown that YAP expression is increased in psoriasis and skin tumors. High expression of YAP in psoriasis and skin tumors may indicate its positive functions in skin inflammation and malignancies and may play an important role in disease pathogenesis. The study of new drugs targeting YAP can provide novel approaches for the treatment of skin diseases.

Discovery of Anilino-1,4-naphthoquinones as Potent EGFR Tyrosine Kinase Inhibitors: Synthesis, Biological Evaluation, and Comprehensive Molecular Modeling

Epidermal growth factor receptor (EGFR) has been recognized as one of the attractive targets for anticancer drug development. Herein, a set of anilino-1,4-naphthoquinone derivatives (3-18) was synthesized and investigated for their anticancer and EGFR inhibitory potentials. Among all tested compounds, three derivatives (3, 8, and 10) were selected for studying EGFR inhibitory activity (in vitro and in silico) due to their most potent cytotoxic activities against six tested cancer cell lines (i.e., HuCCA-1, HepG2, A549, MOLT-3, MDA-MB-231, and T47D; IC50 values = 1.75-27.91 μM), high selectivity index (>20), and good predicted drug-like properties. The experimental results showed that these three promising compounds are potent EGFR inhibitors with nanomolar IC50 values (3.96-18.64 nM). Interestingly, the most potent compound 3 bearing 4-methyl substituent on the phenyl ring displayed 4-fold higher potency than the known EGFR inhibitor, erlotinib. Molecular docking, molecular dynamics simulation, and MM/GBSA-based free energy calculation revealed that van der Waals force played a major role in the accommodations of compound 3 within the ATP-binding pocket of EGFR. Additionally, the 4-CH3 moiety of the compound was noted to be a key chemical feature contributing to the highly potent EGFR inhibitory activity via its formations of alkyl interactions with A743, K745, M766, and L788 residues as well as additional interactions with M766 and T790.

M6A regulator expression patterns predict the immune microenvironment and prognosis of non-small cell lung cancer

BACKGROUND

The m6A methylation modification is one of the most common mRNA modifications, and involved in a variety of biological processes, such as cell death, cancer stem cell formation and tumorigenesis. Increasing evidences have demonstrated that the expression patterns of m6A regulators are significantly correlated with PD-L1 level some solid tumors, but few study has explored the function of m6A regulators in the immune microenvironment and prognosis in non-small cell lung cancer (NSCLC).

METHODS

Survival analysis was independently conducted for 20 m6A regulators to explore their prognostic value in NSCLC, and then the prognostic risk model based on m6A regulator expression profiles is built to stratify NSCLC patients. Also, the correlation analysis between immune infiltrating cells and m6A regulators is used to reveal the impact of m6A on immune microenvironment of NSCLC. Furthermore, to explore the function of m6A as biomarker of anit-PD-L1 therapeutic effect, we explored the associations of tumor mutation burden (TMB) and PD-L1 levels to 20 m6A regulator expression patterns in NSCLC.

RESULTS

First, the expressions of 20 m6A regulators in NSCLC tissues were significantly increased compared to normal tissues. Survival analysis revealed that three genes, METTL3, HNRNPC and VIRMA, were markedly correlated to the prognosis of NSCLC patients. In particular, cox regression analysis verified that METTL3 could be used as an independent prognostic factor to predict the survival rate of NSCLC patients. Second, the risk prognostic model built on seven m6A regulators can effectively stratify NSCLC patients, and the low-risk subgroup had better prognosis compared to high-risk group. Finally, a few m6A regulators showed significant associations with immune microenvironment, as well as TMB and PD-L1 level, suggesting that the m6A RNA methylation is indicative of therapeutic effect of anti-PD-L1 treatment.

CONCLUSION

Our study identified some m6A regulatory factors as independent risk factors for the prognosis of NSCLC, and the expression patterns of m6A regulators are also correlated to the immune infiltration, as well as TMB and PD-L1 level in NSCLC. The m6A regulators could be used as biomarkers indicative of immunotherapy to NSCLC patients.

Regulation of Hippo signaling by metabolic pathways in cancer

Hippo signaling is known to maintain balance between cell proliferation and apoptosis via tight regulation of factors, such as metabolic cues, cell-cell contact, and mechanical cues. Cells directly recognize glucose, lipids, and other metabolic cues and integrate multiple signaling pathways, including Hippo signaling, to adjust their proliferation and apoptosis depending on nutrient conditions. Therefore, the dysregulation of the Hippo signaling pathway can promote tumor initiation and progression. Alteration in metabolic cues is considered a major factor affecting the risk of cancer formation and progression. It has recently been shown that the dysregulation of the Hippo signaling pathway, through diverse routes activated by metabolic cues, can lead to cancer with a poor prognosis. In addition, unique crosstalk between metabolic pathways and Hippo signaling pathways can inhibit the effect of anticancer drugs and promote drug resistance. In this review, we describe an integrated perspective of the relationship between the Hippo signaling pathway and metabolic signals in the context of cancer. We also characterize the mechanisms involved in changes in metabolism that are linked to the Hippo signaling pathway in the cancer microenvironment and propose several novel targets for anticancer drug treatment.

Efficacy of Camrelizumab in Advanced Non-Small-Cell Lung Cancer and Prognostic Analysis of Different PET/CT Features

Objective

To evaluate the efficacy of the PD-1 inhibitor camrelizumab plus chemotherapy in the first-line treatment of advanced non-small-cell lung cancer (NSCLC) and the prognostic differences of patients with different PET/CT features.

Methods

Between December 2018 and October 2020, 100 patients with NSCLC assessed for eligibility treated in our institution were recruited and randomly assigned (1 : 1) to receive either the TC regimen chemotherapy (control group) or the TC regimen chemotherapy plus camrelizumab (study group). The primary endpoints were clinical efficacy, progression-free survival (PFS), and overall survival (OS). A decrease of max standard uptake value (SUVmax) of >30% in primary lung cancer was considered as metabolic remission. The prognostic differences of the eligible patients with different PET/CT features were assessed. Survival data were analyzed using the Kaplan-Meier method to obtain the survival rate and calculate the median survival time.

Results

The metabolic remission rate and objective remission rate were significantly higher with chemotherapy plus camrelizumab versus chemotherapy alone. The study group had significantly higher CD3+ and CD4+ T-cell ratios and CD4+/CD8+ ratio and significantly lower CD8+ T-cell ratio than the control group after treatment. PFS (10 months versus 4 months) and OS (HR = 37.094, P ≤ 0.001) were better with camrelizumab plus chemotherapy versus stand-alone chemotherapy. The incidence of adverse events (AE) was similar between the two groups. The patients in the study group were stratified into metabolic remission and metabolic nonremission based on PET/CT results. Intersubgroup analysis showed significantly better PFS and OS in the metabolic remission group than in the nonmetabolic remission group.

Conclusion

The camrelizumab plus chemotherapy as a first-line treatment option for NSCLC significantly increases the survival benefit. Metabolic status shown by PET/CT correlates with long-term prognosis and demonstrates a great potential for early assessment of efficacy to support the choice of treatment regimens.

MicroRNA‑20a promotes non‑small cell lung cancer proliferation by upregulating PD‑L1 by targeting PTEN

Non-small cell lung cancer (NSCLC) remains one of the most common malignant tumors worldwide. The aim of the present study was to investigate the possibility of microRNA-20a (miR-20a) as a biomarker and therapeutic target for the diagnosis and treatment of NSCLC. Bioinformatics prediction, together with functional validation, confirmed miR-20a bound to programmed death ligand-1 (PD-L1) 3′-untranslated region to upregulate PD-L1 expression. Both miR-20a and PD-L1 could promote the proliferation of NSCLC cells. The expression level of PD-L1 was controlled by PTEN; however, further upstream regulation of PD-L1 expression was largely unknown. The present study showed that miR-20a could not restore the inhibition of PD-L1 expression levels by PTEN. Knockdown of PTEN expression upregulated the expression level of PD-L1 and promoted the proliferation of NSCLC cells. PTEN negatively regulated the Wnt/β-catenin signaling pathway by inhibiting β-catenin and Cyclin D1. Interestingly, PTEN could reverse miR-20a-mediated proliferation of NSCLC cells and the inhibitory effect was similar to that of XAV-939. miR-20a promotes the proliferation of NSCLC cells by inhibiting the expression level of PTEN and upregulating the expression level of PD-L1. It is suggested that miR-20a could be used as a biomarker and therapeutic target for the treatment of NSCLC.

Deep Learning to Predict EGFR Mutation and PD-L1 Expression Status in Non-Small-Cell Lung Cancer on Computed Tomography Images

OBJECTIVE

The detection of epidermal growth factor receptor (EGFR) mutation and programmed death ligand-1 (PD-L1) expression status is crucial to determine the treatment strategies for patients with non-small-cell lung cancer (NSCLC). Recently, the rapid development of radiomics including but not limited to deep learning techniques has indicated the potential role of medical images in the diagnosis and treatment of diseases.

METHODS

Eligible patients diagnosed/treated at the West China Hospital of Sichuan University from January 2013 to April 2019 were identified retrospectively. The preoperative CT images were obtained, as well as the gene status regarding EGFR mutation and PD-L1 expression. Tumor region of interest (ROI) was delineated manually by experienced respiratory specialists. We used 3D convolutional neural network (CNN) with ROI information as input to construct a classification model and established a prognostic model combining deep learning features and clinical features to stratify survival risk of lung cancer patients.

RESULTS

The whole cohort (N = 1262) was divided into a training set (N = 882, 70%), validation set (N = 125, 10%), and test set (N = 255, 20%). We used a 3D convolutional neural network (CNN) to construct a prediction model, with AUCs of 0.96 (95% CI: 0.94-0.98), 0.80 (95% CI: 0.72-0.88), and 0.73 (95% CI: 0.63-0.83) in the training, validation, and test cohorts, respectively. The combined prognostic model showed a good performance on survival prediction in NSCLC patients (C-index: 0.71).

CONCLUSION

In this study, a noninvasive and effective model was proposed to predict EGFR mutation and PD-L1 expression status as a clinical decision support tool. Additionally, the combination of deep learning features with clinical features demonstrated great stratification capabilities in the prognostic model. Our team would continue to explore the application of imaging markers for treatment selection of lung cancer patients.

R-2HG downregulates ERα to inhibit cholangiocarcinoma via the FTO/m6A-methylated ERα/miR16-5p/YAP1 signal pathway

Isocitrate dehydrogenase (IDH) mutations increase (R)-2-hydroxyglutarate (R-2HG) production; however, functional mechanisms of R-2HG in regulating cholangiocarcinoma (CCA) development remain to be further investigated. We first applied the CRISPR-Cas9 gene-editing system to create IDH1R132H-mutated CCA cells. Interestingly, our data showed that R-2HG could function through downregulating estrogen receptor alpha (ERα) and Yes-associated protein 1 (YAP1) pathways to decrease CCA growth. Detailed mechanistic studies revealed that R-2HG could target and degrade the fat mass and obesity-associated protein (FTO), the first identified mRNA demethylase. This reduced FTO can increase the N⁶-methyladenosine (m6A) to methylate the mRNA of ERα, and consequently decrease protein translation of the ERα. Further mechanistic studies revealed that ERα could transcriptionally suppress miR-16-5p expression, which could then increase YAP1 expression due to the reduced miR-16-5p binding to the 3′ UTR of YAP1. Furthermore, data from the pre-clinical animal model with implantation of IDH1R132H QBC939 cells demonstrated that R-2HG generated by the IDH1 mutation could downregulate ERα and YAP1 to suppress CCA tumor growth. Taken together, our new findings suggested that IDH1 mutation-induced R-2HG could suppress CCA growth via regulating the FTO/m6A-methylated ERα/miR16-5p/YAP1 signaling pathway. Upregulating R-2HG or downregulating the ERα signal by short hairpin RNA ERα (shERα) or antiestrogen could be effective strategies to inhibit CCA.

Trends in lung cancer incidence by age, sex and histology from 2012 to 2025 in Catalonia (Spain)

Lung cancer remains one the most common cancers in Europe and ranks first in terms of cancer mortality in both sexes. Incidence rates vary by region and depend above all on the prevalence of tobacco consumption. In this study we describe recent trends in lung cancer incidence by sex, age and histological type in Catalonia and project changes according to histology by 2025. Bayesian age-period-cohort models were used to predict trends in lung cancer incidence according to histological type from 2012 to 2025, using data from the population-based Catalan cancer registries. Data suggest a decrease in the absolute number of new cases in men under the age of 70 years and an increase in women aged 60 years or older. Adenocarcinoma was the most common type in both sexes, while squamous cell carcinoma and small cell carcinoma were decreasing significantly among men. In both sexes, the incident cases increased by 16% for patients over 70 years. Increases in adenocarcinoma and rising incidence in elderly patients suggest the need to prioritize strategies based on multidisciplinary teams, which should include geriatric specialists.

A Real-World Analysis of Patients with Untreated Metastatic Epidermal Growth Factor Receptor (EGFR)-Mutated Lung Adenocarcinoma Receiving First-Line Erlotinib and Bevacizumab Combination Therapy

INTRODUCTION

The clinical features of patients with metastatic epidermal growth factor receptor (EGFR)-mutated lung adenocarcinoma receiving first-line therapy based on erlotinib combined with bevacizumab are unclear. Here, we sought to analyze the clinical features of this patient group.

METHODS

Data were analyzed for the period from January 2015 to August 2019 for 49 patients with metastatic EGFR-mutated lung adenocarcinoma receiving first-line erlotinib-and-bevacizumab combination therapy from the Linkou and Kaohsiung Chang Gung Memorial Hospitals.

RESULTS

The combination of erlotinib and bevacizumab showed an 83.7% objective response rate and a 97.9% disease control rate. The median progression-free survival (PFS) and overall survival (OS) were 22.0 [95% CI (19.7-22.33)] and 47.6 [95% CI (38.87-56.37)] months, respectively, for all patients. The secondary EGFR-T790M mutation rate in the patients with acquired resistance to the combination was 72.4%. No predictive factor associated with the appearance of secondary EGFR-T790M mutations was found. The most frequent adverse event (AE) caused by the combination therapy was dermatitis (100%), and most of the AEs were manageable and grades 1 and 2.

CONCLUSION

Erlotinib combined with bevacizumab is an effective and safe therapy for untreated metastatic EGFR-mutated lung adenocarcinoma. The combination does not alter secondary EGFR-T790M mutations in patients with acquired resistance and is feasible in real-world clinical practice.

Comprehensive targeting of resistance to inhibition of RTK signaling pathways by using glucocorticoids

Inhibition of RTK pathways in cancer triggers an adaptive response that promotes therapeutic resistance. Because the adaptive response is multifaceted, the optimal approach to blunting it remains undetermined. TNF upregulation is a biologically significant response to EGFR inhibition in NSCLC. Here, we compared a specific TNF inhibitor (etanercept) to thalidomide and prednisone, two drugs that block TNF and also other inflammatory pathways. Prednisone is significantly more effective in suppressing EGFR inhibition-induced inflammatory signals. Remarkably, prednisone induces a shutdown of bypass RTK signaling and inhibits key resistance signals such as STAT3, YAP and TNF-NF-κB. Combined with EGFR inhibition, prednisone is significantly superior to etanercept or thalidomide in durably suppressing tumor growth in multiple mouse models, indicating that a broad suppression of adaptive signals is more effective than blocking a single component. We identify prednisone as a drug that can effectively inhibit adaptive resistance with acceptable toxicity in NSCLC and other cancers.

Cell Behavior of Non-Small Cell Lung Cancer Is at EGFR and MicroRNAs Hands

Lung cancer is a complex disease associated with gene mutations, particularly mutations of Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS) and epidermal growth factor receptor (EGFR). Non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) are the two major types of lung cancer. The former includes most lung cancers (85%) and are commonly associated with EGFR mutations. Several EGFR-tyrosine kinase inhibitors (EGFR-TKIs), including erlotinib, gefitinib, and osimertinib, are effective therapeutic agents in EGFR-mutated NSCLC. However, their effectiveness is limited by the development (acquired) or presence of intrinsic drug resistance. MicroRNAs (miRNAs) are key gene regulators that play a profound role in the development and outcomes for NSCLC via their role as oncogenes or oncosuppressors. The regulatory role of miRNA-dependent EGFR crosstalk depends on EGFR signaling pathway, including Rat Sarcoma/Rapidly Accelerated Fibrosarcoma/Mitogen-Activated Protein Kinase/Extracellular Signal-Regulated Kinase 1/2 (Ras/Raf/MEK/ERK1/2), Signal Transducer and Activator of Transcription (STAT), Nuclear Factor Kappa-Light-Chain-Enhancer of Activated B Cells (NF-kB), phosphoinositide 3-kinase/protein kinase B (PI3K/AKT), Janus kinase 1 (JAK1), and growth factor receptor-bound protein 2 (GRB2). Dysregulated expression of miRNAs affects sensitivity to treatment with EGFR-TKIs. Thus, abnormalities in miRNA-dependent EGFR crosstalk can be used as diagnostic and prognostic markers, as well as therapeutic targets in NSCLC. In this review, we present an overview of miRNA-dependent EGFR expression regulation, which modulates the behavior and progression of NSCLC.

Response with pembrolizumab in a patient with EGFR mutated non-small cell lung cancer harbouring insertion mutations in V834L and L858R

INTRODUCTION

Lung cancer is the leading cause of cancer-related deaths with non-small cell lung cancer (NSCLC) being the most common of them. About a third of NSCLC cases have an epidermal growth factor (EGFR) mutation, which is usually susceptible to tyrosine kinase inhibitors (TKIs). In rare cases where patients progress through TKI therapy, the use of immune checkpoint inhibitors (ICIs) remains controversial.

CASE REPORT

We describe a case of a patient with significant history of smoking and EGFR mutated programmed death ligand-1 (PD-L1) positive NSCLC who was initially treated with TKI therapy.

MANAGEMENT/OUTCOME

While patient progressed on TKI therapy, he was able to achieve a durable response with a single PD-L1 agent, pembrolizumab. Contrary to the available evidence, the presented EGFR mutant NSCLC responded to PD-L1 pathway inhibition.

DISCUSSION

From our observation Pembrolizumab could be promising in patients with rare EGFR mutations who do not respond to EGFR directed therapy. Our report provides supporting data for the use of immunotherapies in patients with EGFR mutated NSCLC.

Combination of immune check inhibitor and immunomodulatory arabinomannan extracted from Mycobacterium tuberculosis: A case report

The present study selected two patients with lung cancer and epidermal growth factor receptor (EGFR) mutations who were treated with a programmed cell death protein 1 (PD-1) antibody and an immunomodulatory arabinomannan extracted from Mycobacterium tuberculosis. In the first case, a 67-year-old female was diagnosed with lung adenocarcinoma with an EGFR mutation (exon 19 deletion) and Stage IVB disease. Initial treatment with an EGFR mutation-targeted tyrosine kinase inhibitor (TKI), erlotinib, demonstrated a partial response. After disease progression this was followed by carboplatin and pemetrexed with bevacizumab, and re-challenged by erlotinib plus bevacizumab; however, the tumor eventually progressed. Subsequently, the patient was treated with immunomodulatory arabinomannan for 3 months. Immediately after, she was treated with nivolumab and showed a partial response. In the second case, a 57-year-old male with a history of smoking was diagnosed with stage IVB pulmonary adenocarcinoma with an EGFR mutation (exon 19 deletion). He was treated with afatinib, followed by osimertinib when a T790M mutation was identified later. After disease progressed with TKIs, cisplatin plus pemetrexed and re-challenge with erlotinib plus bevacizumab were administered subsequently. Nivolumab was administered for recurrent disease. Although he experienced tumor remission, regrowth of the tumors was observed. Under continuing nivolumab, he was treated by palliative irradiation treatments to the right pelvic bone metastasis and left adrenal metastasis with immunomodulatory arabinomannan. A chest computed tomography scan showed a reduction in the sizes of the primary site and pulmonary metastases, with a decreasing trend of carcinoma embryonic antigen. Overall, these cases may indicate that the immune adjuvant actions of immunomodulatory arabinomannan extracted from Mycobacterium tuberculosis improves the effect of PD-1 antibody treatments.

Fibroblast growth factor 11 (FGF11) promotes non-small cell lung cancer (NSCLC) progression by regulating hypoxia signaling pathway

BACKGROUND

Accumulating evidence highlights the critical roles of fibroblast growth factors (FGFs) in regulating the progression of multiple human cancers, including non-small cell lung cancer (NSCLC). In this study, we investigated the role of FGF11 in the progression of NSCLC.

METHODS

Previously published transcriptomic data (GSE75037 and GSE81089) were used to compare FGF11 expression level between NSCLC tumor tissues and adjacent normal tissues. 100 cases of NSCLC tumor tissues and 30 cases of matched adjacent normal tissues were used to validate FGF11 expression at mRNA and protein level by qPCR and immunohistochemistry. Bioinformatics analysis and dual luciferase reporter analysis were performed to confirm the regulatory effect of miR-525-5p on FGF11 expression. CCK-8 assay and transwell migration assay were employed to examine cellular proliferation, migration and invasion. Gene set enrichment analysis (GSEA) was performed to identify the signaling pathway associated with FGF11 expression. Finally, the functional role of FGF11 in NSCLC tumor growth was evaluated by in vivo study.

RESULTS

FGF11 was upregulated in NSCLC tumor tissues and tumor cell lines. High FGF11 expression was associated with a poor prognosis in NSCLC patients. In vitro loss- and gain-of function experiments demonstrated that FGF11 knockdown inhibited, whereas FGF11 overexpression promoted the proliferation, migration and invasion of NSCLC cells. Dual luciferase reporter assay confirmed that FGF11 was downregulated by miR-525-5p, and the effect of FGF11 on cell proliferation, migration and invasion could be interfered by miR-525-5p. GSEA analysis further revealed that FGF11 expression was enriched with genes in hypoxia signaling pathway and the oncogenic function of FGF11 could be suppressed by knocking down HIF-1α in NSCLC cells. Moreover, FGF11 knockdown suppressed NSCLC tumor growth whereas FGF11 overexpression promoted tumor growth in vivo.

CONCLUSIONS

Our study showed that FGF11 functions as an oncogene in tumor NSCLC progression. miR-525-5p seems to negatively regulate FGF11 and the oncogenic role of FGF11 is dependent on the upregulation of HIF-1α. Our study suggests that targeting FGF11 and HIF-1α may serve as novel strategies for the treatment of NSCLC.

Current and Future Development in Lung Cancer Diagnosis

Lung cancer is the leading cause of cancer-related deaths in North America and other developed countries. One of the reasons lung cancer is at the top of the list is that it is often not diagnosed until the cancer is at an advanced stage. Thus, the earliest diagnosis of lung cancer is crucial, especially in screening high-risk populations, such as smokers, exposure to fumes, oil fields, toxic occupational places, etc. Based on the current knowledge, it looks that there is an urgent need to identify novel biomarkers. The current diagnosis of lung cancer includes different types of imaging complemented with pathological assessment of biopsies, but these techniques can still not detect early lung cancer developments. In this review, we described the advantages and disadvantages of current methods used in diagnosing lung cancer, and we provide an analysis of the potential use of body fluids as carriers of biomarkers as predictors of cancer development and progression.

Circular RNAs in Lung Cancer: Recent Advances and Future Perspectives

Globally, lung cancer is the most commonly diagnosed cancer and carries with it the greatest mortality rate, with 5-year survival rates varying from 4–17% depending on stage and geographical differences. For decades, researchers have studied disease mechanisms, occurrence rates and disease development, however, the mechanisms underlying disease progression are not yet fully elucidated, thus an increased understanding of disease pathogenesis is key to developing new strategies towards specific disease diagnoses and targeted treatments. Circular RNAs (circRNAs) are a class of non-coding RNA widely expressed in eukaryotic cells, and participate in various biological processes implicated in human disease. Recent studies have indicated that circRNAs both positively and negatively regulate lung cancer cell proliferation, migration, invasion and apoptosis. Additionally, circRNAs could be promising biomarkers and targets for lung cancer therapies. This review systematically highlights recent advances in circRNA regulatory roles in lung cancer, and sheds light on their use as potential biomarkers and treatment targets for this disease.

Membrane-Associated RING-CH 8 Functions as a Novel PD-L1 E3 Ligase to Mediate PD-L1 Degradation Induced by EGFR Inhibitors

Expression of programmed death-ligand 1 (PD-L1) on cancer cells is a critical mechanism contributing to immunosuppression and immune escape. PD-L1 expression may also affect therapeutic outcomes of epidermal growth factor receptor (EGFR)-targeted therapy (e.g., with osimertinib/AZD9291) against EGFR-mutant non-small cell lung cancers (NSCLC) and can even be altered during the treatment albeit with largely undefined mechanisms. This study primarily focuses on elucidating the mechanism by which osimertinib induces PD-L1 degradation in addition to validating osimertinib's effect on decreasing PD-L1 expression in EGFR-mutant NSCLC cells and tumors. Osimertinib and other EGFR inhibitors effectively decreased PD-L1 levels primarily in EGFR-mutant NSCLCs and xenografted tumors. Osimertinib not only decreased PD-L1 mRNA expression, but also prompted proteasomal degradation of PD-L1 protein, indicating both transcriptional and posttranslational mechanisms accounting for osimertinib-induced reduction of PD-L1. Knockdown of β-TrCP or inhibition of GSK3 failed to prevent PD-L1 reduction induced by osimertinib. Rather, knockdown of membrane-associated RING-CH 8 (MARCH8) that encodes a membrane-bound E3 ubiquitin ligase rescued osimertinib-induced PD-L1 reduction. Furthermore, manipulation of MARCH8 expression accordingly altered PD-L1 degradation rate. Critically, MARCH8 interacted with PD-L1 through its N-terminal region and also ubiquitinated PD-L1 in cells. Collectively, these results strongly suggest that MARCH8 is a previously undiscovered E3 ubiquitin ligase responsible for PD-L1 degradation including osimertinib-induced PD-L1 degradation, establishing a novel connection between MARCH8 and PD-L1 regulation. IMPLICATIONS: This study has demonstrated a previously undiscovered function of MARCH8 in mediating PD-L1 degradation induced by EGFR inhibitors in EGFR-mutant NSCLC cells, establishing a novel connection between MARCH8 and PD-L1 regulation.

Immunotherapy and Vaccination in Surgically Resectable Non-Small Cell Lung Cancer (NSCLC)

Early-stage NSCLC (stages I and II, and some IIIA diseases) accounts for approximately 30% of non-small cell lung cancer (NSCLC) cases, with surgery being its main treatment modality. The risk of disease recurrence and cancer-related death, however, remains high among NSCLC patients after complete surgical resection. In previous studies on the long-term follow-up of post-operative NSCLC, the results showed that the five-year survival rate was about 65% for stage IB and about 35% for stage IIIA diseases. Platinum-based chemotherapy with or without radiation therapy has been used as a neoadjuvant therapy or post-operative adjuvant therapy in NSCLC, but the improvement of survival is limited. Immune checkpoint inhibitors (ICIs) have effectively improved the 5-year survival of advanced NSCLC patients. Cancer vaccination has also been explored and used in the prevention of cancer or reducing disease recurrence in resected NSCLC. Here, we review studies that have focused on the use of immunotherapies (i.e., ICIs and vaccination) in surgically resectable NSCLC. We present the results of completed clinical trials that have used ICIs as neoadjuvant therapies in pre-operative NSCLC. Ongoing clinical trials investigating ICIs as neoadjuvant and adjuvant therapies are also summarized.

Targeting the miR-6734-3p/ZEB2 axis hampers development of non-small cell lung cancer (NSCLC) and increases susceptibility of cancer cells to cisplatin treatment

The unclear pathogenesis mechanisms and resistance of cancer cells to chemical drugs serious limits the development of effective treatment strategies for non-small cell lung cancer (NSCLC). In this study, we managed to investigate this issue, and identify potential cancer associated biomarkers for NSCLC diagnosis, prognosis and treatment. This study found that miR-6734-3p was downregulated in both NSCLC clinical specimens (tissues and serum) and cells, compared to the normal tissues and cells. Next, upregulation of miR-6734-3p inhibited cancer formation and progression in NSCLC cells in vitro and in vivo. Conversely, miR-6734-3p ablation had opposite effects and facilitated NSCLC development. In addition, miR-6734-3p bound to the 3ʹ untranslated region (3ʹUTR) of zinc finger E-box binding homeobox 2 (ZEB2) mRNA to suppress its expressions in NSCLC cells. Interestingly, the inhibiting effects of miR-6734-3p overexpression on NSCLC progression were abrogated by upregulating ZEB2. Furthermore, both upregulated miR-6734-3p and silencing of ZEB2 increased cisplatin-sensitivity in cisplatin-resistant NSCLC (CR-NSCLC) cells. Taken together, miR-6734-3p played an anti-tumor role to hinder cancer development and enhanced the cytotoxic effects of cisplatin treatment on NSCLC cells by downregulating ZEB2.

Ophiopogonin B induces reactive oxygen species‑dependent apoptosis through the Hippo pathway in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a common malignant tumor in South China and is characterized by a high death rate. Ophiopogonin B (OP‑B) is a bioactive component of Radix Ophiopogon japonicus, which is frequently used in traditional Chinese medicine to treat cancer. The present study aimed to examine the anti‑cancer properties of OP‑B on NPC cells. Cell viability and cell proliferation were measured using MTT and EdU assays. Flow cytometry was used to measure cell apoptosis, reactive oxygen species and mitochondrial membrane potential. Western blotting was used to investigate the expression of apoptosis and Hippo signaling pathway proteins. OP‑B inhibited the proliferation of NPC cells by inducing apoptosis and disturbing the mitochondrial integrity. OP‑B enhanced ROS accumulation. In addition, OP‑B promoted the expression of mammalian STE20‑like kinase 1, large tumor suppressor 1 and phosphorylated yes‑associated protein (YAP) and suppressed the expression of YAP and transcriptional enhanced associate domain in NPC cells. OP‑B increased the expression of forkhead box transcription factor O1 in the nuclear fraction. In conclusion, OP‑B has therapeutic potential and feasibility in the development of novel YAP inhibitors for NPC.

Overview of Ca2+ signaling in lung cancer progression and metastatic lung cancer with bone metastasis

Intracellular Ca²⁺ ions that are thought to be one of the most important second messengers for cellular signaling, have a substantial diversity of roles in regulating a plethora of fundamental cellular physiology such as gene expression, cell division, cell motility and apoptosis. It has been suggestive of the Ca²⁺ signaling-dependent cellular processes to be tightly regulated by the numerous types of Ca²⁺ channels, pumps, exchangers and sensing receptors. Consequently, dysregulated Ca²⁺ homeostasis leads to a series of events connected to elevated malignant phenotypes including uncontrolled proliferation, migration, invasion and metastasis, all of which are frequently observed in advanced stage lung cancer cells. The incidence of bone metastasis in patients with advanced stage lung cancer is estimated in a range of 30% to 40%, bringing about a significant negative impact on both morbidity and survival. This review dissects and summarizes the important roles of Ca²⁺ signaling transduction in contributing to lung cancer progression, and address the question: if and how Ca²⁺ signaling might have been engaged in metastatic lung cancer with bone metastasis, thereby potentially providing the multifaceted and promising solutions for therapeutic intervention.

Expression of miR-92a, miR-224 and miR-25 in non-small cell lung cancer and their correlation with clinical characteristics

OBJECTIVE

To analyze the correlation of the expression of microRNA-92a (miR-92a), microRNA-224 (miR-224), and microRNA-25 (miR-25) in non-small cell lung cancer with its clinical characteristics.

METHODS

This prospective study was performed in 125 non-small cell lung cancer patients admitted to our hospital between January 2019 and January 2020. All patients' cancer and adjacent tissue were collected and the expression of miR-92a, miR-224, and miR-25 were detected using real-time fluorescence quantitative RT-PCR. Data were analyzed using SPSS statistical software (version 20.0). Correlation analysis was conducted using Pearson correlation coefficient.

RESULTS

Compared with adjacent tissue, the relative expression of miR-92a, miR-224, and miR-25 in cancer tissue were increased (all P<0.001). There was no correlation between the expression of miR-92a, miR-224, and miR-25 and baseline data like gender, age, smoking history, and tumor size (all P>0.05). The relative expression of miR-92a, miR-224 and miR-25 in differentiated cancer patients were higher than those in highly and moderately differentiated cancer patients (all P<0.05). The relative expression of miR-92a, miR-224 and miR-25 in patients with lymph node metastasis (LNM) were increased when compared with those had no LNM (all P<0.001). Compared with stage I and II patients, the relative expression of miR-92a, miR-224 and miR-25 in stage III and IV patients were increased (all P<0.001). The relative expression of miR-92a, miR-224, and miR-25 were positively correlated to each other (all P<0.01).

CONCLUSION

miR-92a, miR-224, and miR-25 are overexpressed in non-small cell lung cancer and the expressions are related to the degree of differentiation, presence or absence of LNM, and TNM staging. In addition, the expression of miR-92a, miR-224 and miR-25 are positively correlated to each other. This suggests that miR-92a, miR-224, and miR-25 cooperatively participated in the occurrence and development of non-small cell lung cancer.

PD-L1 and CD47 co-expression predicts survival and enlightens future dual-targeting immunotherapy in non-small cell lung cancer

BACKGROUD

Recent studies have indicated that programmed cell death-ligand 1 (PD-L1) and cluster of differentiation 47 (CD47) play an essential role in tumor immune evasion and may serve as potential targets for combined immunotherapy. The aim of our study was to evaluate the PD-L1/CD47 expression status in lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD), and explore its survival impact and relevance with the immune microenvironment.

METHODS

The specimens from 190 LUSC and 240 LUAD patients who underwent intent-to-treat surgeries were retrospectively collected for immunohistochemistry assays of PD-L1, CD47, cluster of differentiation 8 (CD8), and cluster of differentiation 68 (CD68).

RESULTS

A total of 96 (22.3%) and 296 (68.8%) cases were positive for PD-L1 and CD47 expression, respectively, and 80 (18.6%) of them demonstrated the co-expression of PD-L1/CD47. The rate of PD-L1/CD47 co-expression was 23.7% in LUSC, significantly higher than the 14.6% in LUAD (p = 0.018). The median overall survival (OS) for all patients was 55.9 months (range 2.0-146.0 months). The univariate analysis showed that patients with positive CD47 expression (LUSC p = 0.003, LUAD p = 0.036) and PD-L1/CD47 co-expression (LUSC p = 0.023, LUAD p = 0.004) exhibited significantly worse prognosis. The multivariate analysis demonstrated that PD-L1/CD47 co-expression was an independent prognostic factor for OS (LUSC hazard ratio [HR] 1.922, 95% CI 1.245-2.969, p = 0.003; LUAD HR 1.549, 95% CI 1.015-2.364, p = 0.043). PD-L1/CD47 co-expression was associated with high CD8-positive T-lymphocyte density in LUSC (p = 0.004) and LUAD (p = 0.043), and with high CD68-positive macrophage density in LUSC (p = 0.026).

CONCLUSIONS

PD-L1/CD47 co-expression was an independent prognostic factor for LUSC and LUAD patients and may serve as a potential predictive biomarker for combined dual-targeting immunotherapy.

Prognostic value of CCR2 as an immune indicator in lung adenocarcinoma: A study based on tumor-infiltrating immune cell analysis

Background

Prognostic indicators in lung adenocarcinoma (LUAD) have been seeking under database analysis, and remarkable advance is on the way.

Methods

This study calculated the scores of stromal and immune components of the tumor microenvironment (TME) in 551 LUAD samples using the ESTIMATE algorithm on The Cancer Genome Atlas (TCGA) database. R package ''limma'' was used to selected differentially expressed genes (DEG). We have analyzed the DEGs by means of Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichments. The protein‐protein network, univariate Cox analysis, and Lasso regression analysis were performed to selected survival‐related genes. Gene Set Enrichment Analysis (GSEA) represented the enriched pathway of CC chemokine receptor 2 (CCR2). The ratios of immune cells in the TME of each LUAD sample were obtained using the R package "limma" and CIBERSORT algorithm in R 4.0.2.

Results

The ImmuneScore was positively correlated with prognosis regarding survival rate, T classification of TNM stages, and clinicopathological staging characteristics. GO and KEGG enrichments showed DEGs were associated with immune‐related activities. Three genes of LUAD were selected from the PPI network and Cox proportional hazards regression analysis. CCR2 was the most survival correlated gene by Lasso regression analysis. GSEA results showed that C2 kegg gene sets in the CCR2 high‐expression group were mainly enriched in the B cell or T cell receptor signaling pathway and natural killer cell‐mediated cytotoxicity. Correlation of CCR2 expression with prognosis was conducted, implicating a positive correlation with the prognosis of survival rate and M classification, negative correlation with the prognosis of T and N classifications. The correlation between CCR2 and tumor‐infiltrating immune cells (TICs) was analyzed, and 14 kinds of TICs were found closely correlated with CCR2 expression through difference analysis.

Conclusion

Therefore, CCR2 has prognostic value as an immune indicator in LUAD.

Immune Checkpoint Inhibitors in EGFR-Mutated NSCLC: Dusk or Dawn?

Although immune checkpoint inhibitors (ICIs) that target programmed cell death protein-1/programmed cell death ligand-1 axis have significantly shifted the treatment paradigm in advanced NSCLC, clinical benefits of these agents are limited in patients with EGFR-mutated NSCLC. Several predictive biomarkers (e.g., programmed cell death ligand-1 expression, tumor mutation burden), which have been validated in EGFR-wild type NSCLC, however, are not efficacious in EGFR-mutated tumors, suggesting the unique characteristics of tumor microenvironment of EGFR-mutated NSCLC. Here, we first summarized the clinical evidence on the efficacy of ICIs in patients with EGFR-mutated NSCLC. Then, the cancer immunogram features of EGFR-mutated NSCLC was depicted to visualize the state of cancer-immune system interactions, including tumor foreignness, tumor sensitivity to immune effectors, metabolism, general immune status, immune cell infiltration, cytokines, and soluble molecules. We further discussed the potential subpopulations with EGFR mutations that could benefit from ICI treatment. Lastly, we put forward future strategies to adequately maximize the efficacy of ICI treatment in patients with EGFR-mutated NSCLC in the upcoming era of combination immunotherapies.

NF2 and Canonical Hippo-YAP Pathway Define Distinct Tumor Subsets Characterized by Different Immune Deficiency and Treatment Implications in Human Pleural Mesothelioma

Simple Summary

It is a long-held notion that loss-of-function mutations in negative regulators of the Hippo-YAP pathway, such as NF2, LATS1/2, have a similar potential to promote nuclear YAP activity, which is thought to play an essential role in the pathogenesis of MPM. Whether loss-of-function in these individual regulators uniformly affects the Hippo-YAP activity and contributes to a similar disease phenotype has not yet been revealed in MPM. Surprisingly and interestingly, we found in this study that loss-of-function in the upstream regulator NF2 of the Hippo pathway is linked to the aberrant activation of Hippo-YAP-independent signaling. More importantly, our work showed NF2 loss-of-function and dysregulated Hippo-YAP pathway define distinct MPM subsets that differ in molecular features, therapeutic implications, patients’ prognosis, and in particular, infiltrative immune signatures. Our findings in this study may be instrumental for the precise management of immunotherapy and/or targeted therapy for MPM patients.

Abstract

(1) Inactivation of the tumor suppressor NF2 is believed to play a major role in the pathogenesis of malignant pleural mesothelioma (MPM) by deregulating the Hippo-YAP signaling pathway. However, NF2 has functions beyond regulation of the Hippo pathway, raising the possibility that NF2 contributes to MPM via Hippo-independent mechanisms. (2) We performed weighted gene co-expression analysis (WGCNA) in transcriptomic and proteomic datasets obtained from The Cancer Gene Atlas (TCGA) MPM cohort to identify clusters of co-expressed genes highly correlated with NF2 and phospho (p)-YAP protein, surrogate markers of active Hippo signaling and YAP inactivation. The potential targets are experimentally validated using a cell viability assay. (3) MPM tumors with NF2 loss-of-function are not associated with changes in p-YAP level nor YAP/TAZ activity score, but are characterized by a deficient B-cell receptor (BCR) signaling pathway. Conversely, MPM tumors with YAP activation display exhausted CD8 T-cell-mediated immunity together with significantly upregulated PD-L1, which is validated in an independent MPM cohort, suggesting a potential benefit of immune-checkpoint inhibitors (ICI) in this patient subset. In support of this, mutations in core Hippo signaling components including LATS2, but not NF2, are independently associated with better overall survival in response to ICI in patients. Additionally, based on cancer cell line models, we show that MPM cells with a high Hippo-YAP activity are particularly sensitive to inhibitors of BCR-ABL/SRC, stratifying a unique MPM patient subset that may benefit from BCR-ABL/SRC therapies. Furthermore, we observe that NF2 physically interacts with a considerable number of proteins that are not involved in the canonical Hippo-YAP pathway, providing a possible explanation for its Hippo-independent role in MPM. Finally, survival analyses show that YAP/TAZ scores together with p-YAP protein level, but not NF2, predict the prognosis of MPM patients. (4) NF2 loss-of-function and dysregulated Hippo-YAP pathway define distinct MPM subsets that differ in their molecular features and prognosis, which has important clinical implications for precision oncology in MPM patients.

EGFR mutation mediates resistance to EGFR tyrosine kinase inhibitors in NSCLC: From molecular mechanisms to clinical research

With the development of precision medicine, molecular targeted therapy has been widely used in the field of cancer, especially in non-small-cell lung cancer (NSCLC). Epidermal growth factor receptor (EGFR) is a well-recognized and effective target for NSCLC therapies, targeted EGFR therapy with EGFR-tyrosine kinase inhibitors (EGFR-TKIs) has achieved ideal clinical efficacy in recent years. Unfortunately, resistance to EGFR-TKIs inevitably occurs due to various mechanisms after a period of therapy. EGFR mutations, such as T790M and C797S, are the most common mechanism of EGFR-TKI resistance. Here, we discuss the mechanisms of EGFR-TKIs resistance induced by secondary EGFR mutations, highlight the development of targeted drugs to overcome EGFR mutation-mediated resistance, and predict the promising directions for development of novel candidates.

Afatinib Exerts Immunomodulatory Effects by Targeting the Pyrimidine Biosynthesis Enzyme CAD

Current clinical trials of combined EGFR-tyrosine kinase inhibitors (TKI) and immune checkpoint blockade (ICB) therapies show no additional effect. This raises questions regarding whether EGFR-TKIs attenuate ICB-enhanced CD8⁺ T lymphocyte function. Here we show that the EGFR-TKI afatinib suppresses CD8⁺ T lymphocyte proliferation, and we identify CAD, a key enzyme of de novo pyrimidine biosynthesis, to be a novel afatinib target. Afatinib reduced tumor-infiltrating lymphocyte numbers in Lewis lung carcinoma (LLC)-bearing mice. Early afatinib treatment inhibited CD8⁺ T lymphocyte proliferation in patients with non-small cell lung cancer, but their proliferation unexpectedly rebounded following long-term treatment. This suggests a transient immunomodulatory effect of afatinib on CD8⁺ T lymphocytes. Sequential treatment of afatinib with anti-PD1 immunotherapy substantially enhanced therapeutic efficacy in MC38 and LLC-bearing mice, while simultaneous combination therapy showed only marginal improvement over each single treatment. These results suggest that afatinib can suppress CD8⁺ T lymphocyte proliferation by targeting CAD, proposing a timing window for combined therapy that may prevent the dampening of ICB efficacy by EGFR-TKIs. SIGNIFICANCE: This study elucidates a mechanism of afatinib-mediated immunosuppression and provides new insights into treatment timing for combined targeted therapy and immunotherapy. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/12/3270/F1.large.jpg.

Efficacy of immune checkpoint inhibitors in the treatment of non-small cell lung cancer patients with different genes mutation: A meta-analysis

BACKGROUND

Latest clinical trials have proved the better overall survival (OS) for the use of immune checkpoint inhibitors verse chemotherapy in non-small cell lung cancer (NSCLC) patients. However, we still have no clear ideas of the factors which could affect the efficacy of immune checkpoint inhibitors. Cancer, essentially, is a disease related to genes mutation. Therefore, we conducted a systematic review and meta-analysis to compare efficacy of immune checkpoint inhibitors for NSCLC patients with different genes mutation.

METHODS

PubMed, EMBASE, Web of Science, and the Cochrane Library databases were searched for all clinical trials in NSCLC until December 16, 2019. The hazard ratio (HR) and 95% confidence intervals (CIs) of OS or progression-free survival (PFS) were used.

RESULTS

A total of 4453 patients from 7 randomized controlled trials (RCTs) were included. Immune checkpoint inhibitors significantly prolonged the OS (HR, 0.67; 95% CI, 0.60-0.67) in NSCLC patients having epidermal growth factor receptor (EGFR) wild-type versus chemotherapy. Meanwhile, they prolonged the OS (HR, 0.61; 95% CI, 0.39-0.94) in NSCLC patients with Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation. No matter PD-L1 tumor proportion scores were >1% or <1%, immune checkpoint inhibitors were more effective than chemotherapy (HR, 0.64; 95% CI, 0.55-0.75).

CONCLUSION

Immune checkpoint inhibitors are more efficacious than chemotherapy in NSCLC patients with EGFR wild-type, KRAS mutation, and any PD-L1 tumor proportion scores.

Relationship between PD-L1 expression and outcome in EGFR-mutant lung cancer patients treated with EGFR tyrosine kinase inhibitors

OBJECTIVES

Predictive biomarkers for poor response to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) is an area of ongoing research. This multicentre retrospective study sought to determine the impact of programmed death-ligand 1 (PD-L1) tumour proportional score (TPS) on outcome in EGFR TKI treated patients.

MATERIALS AND METHODS

Patients with Stage IIIB/IV lung adenocarcinoma harbouring a sensitising EGFR mutation treated with first-line TKI at five metropolitan hospitals were included. PD-L1 TPS was determined using the Ventana anti-PD-L1 (SP263) assay. High PD-L1 expression was defined as TPS ≥ 50 %. Determinants of progression and survival hazards were modelled using Cox regression.

RESULTS

A total of 186 patients were included. Mean age was 67 years, 66 % were female and 54 % were Asian. Patients with high PD-L1 expression (n = 23; 12 %) had significantly shorter progression free survival (6.6 vs 13.0 months, hazard ratio (HR) 2.6 95 % CI 1.6-4.2, p < 0.0001) and overall survival (11.5 vs 32.9 months, HR 3.3, 95 % CI 1.9-5.7, p < 0.0001) compared to patients with PD-L1 low/negative tumours. This remained significant in multivariate analyses. High PD-L1 in post-TKI progression biopsies was not associated with poorer survival.

CONCLUSION

In this large, real-world cohort of EGFR-mutant lung adenocarcinoma patients, high PD-L1 expression was associated with early resistance to 1st generation EGFR TKIs and shorter survival, regardless of ethnicity.

Activation of EGFR-Aurora A induces loss of primary cilia in oral squamous cell carcinoma

OBJECTIVE

Primary cilia, evolutionally conserved organelles involving multiple cell functions, are frequently lost in various cancers. However, little is known about the role of primary cilia in oral squamous cell carcinoma (OSCC).

METHODS

Immunofluorescence staining was applied to detect primary cilia in normal, oral leukoplakia (OLK) and OSCC tissues. Differentially expressed ciliary genes of OSCC were screened from the TCGA database. Immunohistochemical analysis was used for validating the correlation between the expression of interested proteins and primary cilia, and their regulatory effect on primary cilia was further proved in vitro and in vivo.

RESULTS

A significant decrease in cilia ratio was found in OLK, especially in OSCC. Multiple ciliary genes were abnormally expressed in OSCC and epidermal growth factor receptor (EGFR)-Aurora A signaling was chosen for further study. A parallel increase of EGFR-Aurora A was observed in OLK and OSCC tissues. Moreover, EGFR activation induced obvious cilia absorption by phosphorylating Aurora A. Besides, Aurora A silencing significantly restored ciliary expression and decreased tumor growth in vivo.

CONCLUSIONS

The abnormal activation of EGFR-Aurora A leads to the gradual loss of primary cilia in oral mucosa carcinogenesis. Primary cilia have the potential to be new biomarkers and therapeutic targets of oral cancer.

Gene expression in circulating tumor cells reveals a dynamic role of EMT and PD-L1 during osimertinib treatment in NSCLC patients

Liquid biopsy is a tool to unveil resistance mechanisms in NSCLC. We studied changes in gene expression in CTC-enriched fractions of EGFR-mutant NSCLC patients under osimertinib. Peripheral blood from 30 NSCLC patients before, after 1 cycle of osimertinib and at progression of disease (PD) was analyzed by size-based CTC enrichment combined with RT-qPCR for gene expression of epithelial (CK-8, CK-18, CK-19), mesenchymal/EMT (VIM, TWIST-1, AXL), stem cell (ALDH-1) markers, PD-L1 and PIM-1. CTCs were also analyzed by triple immunofluorescence for 45 identical blood samples. Epithelial and stem cell profile (p = 0.043) and mesenchymal/EMT and stem cell profile (p = 0.014) at PD were correlated. There was a strong positive correlation of VIM expression with PIM-1 expression at baseline and increased PD-L1 expression levels at PD. AXL overexpression varied among patients and high levels of PIM-1 transcripts were detected. PD-L1 expression was significantly increased at PD compared to baseline (p = 0.016). The high prevalence of VIM positive CTCs suggest a dynamic role of EMT during osimertinib treatment, while increased expression of PD-L1 at PD suggests a theoretical background for immunotherapy in EGFR-mutant NSCLC patients that develop resistance to osimertinib. This observation merits to be further evaluated in a prospective immunotherapy trial.

Epidermal growth factor receptor tyrosine kinase inhibitor remodels tumor microenvironment by upregulating LAG-3 in advanced non-small-cell lung cancer

INTRODUCTION

Previous clinical investigations have demonstrated that patients with non-small-cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutation have moderate responses to programmed cell death-1 and it's ligand-1 (PD-1/PD-L1) inhibitors, while some patients who failed EGFR-tyrosine kinase inhibitor (TKI) therapy could benefit from immunotherapy. As a result, we have explored alterations in the tumor immune microenvironment (TIME) before and after EGFR-TKI treatment to detect the chances and proper timing of immunotherapy among patients.

METHODS

We identified 16 paired tissue samples pre- and post-EGFR-TKI treatment. Sections 4 μm thick were utilized to evaluate CD8, PD-L1, PD-1, LAG-3, and TIM-3 expressions by multiplexed fluorescent immunohistochemical staining. Five to ten representative original multispectral images of each sample were employed in the analysis.

RESULTS

Patients with positive CD8 + T-cell infiltration accounted for 37.5 % at baseline. Positive expression of PD-L1, PD1, LAG-3, and TIM-3 cells were observed in seven (43.8 %), four (25 %), one (6.25 %) and five (31.25 %) of the patients, respectively. PD-1 expression and infiltration of CD8⁺PD-1⁺-exhausted T cells increased significantly in patients with EGFR L858R mutation compared to patients with EGFR 19DEL. Patients who acquired T790 M after TKI treatment had less infiltrations of CD8⁺PD-1⁺ T cells and CD8⁺TIM-3⁺ T cells in the TIME at baseline. Positive expression of checkpoint proteins-including PD-1, TIM-3, and LAG-3-significantly correlated with shorter progression-free survival. LAG-3 was significantly upregulated after TKI treatment (p = 0.003), while other checkpoint proteins remained stationary.

CONCLUSION

The present study is the first work to report LAG-3 upregulation after EGFR-TKI failure in advanced NSCLC, which proposed novel insights for rational use of LAG-3 inhibitors in advanced NSCLC patients with EGFR mutation.

Updated Insights on EGFR Signaling Pathways in Glioma

Nowadays, due to recent advances in molecular biology, the pathogenesis of glioblastoma is better understood. For the newly diagnosed, the current standard of care is represented by resection followed by radiotherapy and temozolomide administration, but because median overall survival remains poor, new diagnosis and treatment strategies are needed. Due to the quick progression, even with aggressive multimodal treatment, glioblastoma remains almost incurable. It is known that epidermal growth factor receptor (EGFR) amplification is a characteristic of the classical subtype of glioma. However, targeted therapies against this type of receptor have not yet shown a clear clinical benefit. Many factors contribute to resistance, such as ineffective blood-brain barrier penetration, heterogeneity, mutations, as well as compensatory signaling pathways. A better understanding of the EGFR signaling network, and its interrelations with other pathways, are essential to clarify the mechanisms of resistance and create better therapeutic agents.

Afatinib in EGFR TKI-naïve patients with locally advanced or metastatic EGFR mutation-positive non-small cell lung cancer: Interim analysis of a Phase 3b study

OBJECTIVES

Randomized controlled trials have demonstrated that afatinib is a suitable treatment option for patients with epidermal growth factor receptor mutation-positive (EGFRm +) non-small cell lung cancer (NSCLC). However, such studies often exclude patients treated in routine clinical practice. We report interim results from a Phase 3b, open-label, multicenter, single-arm, exploratory trial, in which afatinib was investigated in a real-world setting.

MATERIALS AND METHODS

Patients with EGFRm + tyrosine kinase inhibitor (TKI)-naïve NSCLC received afatinib 40 mg orally, once-daily, until disease progression, or voluntary withdrawal. Primary objective was safety.

RESULTS

Overall, 479 patients received afatinib: median age 65 years, 8 % of patients had an ECOG performance status ≥ 2, 17 % had brain metastases, and 13 % had tumors containing uncommon mutations only. All but one patient (99.8 %) had an adverse event (AE). Treatment-related AEs (TRAEs; any/grade ≥ 3) occurred in 97 %/44 % of patients; most common were diarrhea (87 %/16 %) and rash (51 %/11 %). AEs leading to afatinib dose-reduction were reported in 258 patients (54 %), and 37 patients (8 %) discontinued treatment due to a TRAE. Objective response rate was 45.5 %, median duration of response was 14.1 months (95 % CI: 12.2-16.4). Overall median time to symptomatic progression and progression-free survival were 14.9 months (95 % CI: 13.8-17.6) and 13.4 months (95 % CI: 11.8-14.5), respectively, in the overall population and 19.3 months (95 % CI: 15.6-21.8) and 15.9 months (95 % CI: 13.9-19.1) in patients with EGFR exon 19 deletions.

CONCLUSIONS

Afatinib administration in routine clinical practice was well tolerated with no new safety signals and demonstrated promising efficacy in patients with EGFRm + NSCLC. TRAEs were generally manageable with tolerability-guided dose reductions. Overall, these data independently support findings from randomized controlled trials of afatinib in EGFRm + NSCLC.

Mechanisms and Future of Non-Small Cell Lung Cancer Metastasis

Lung cancer, renowned for its fast progression and metastatic potency, is rising to become a leading cause of death globally. It has been long observed that lung cancer is particularly ept in spawning distant metastasis at its early stages, and it can readily colonize virtually any human organ. In recent years, cancer research has shed light on why lung cancer is endowed with its exceptional ability to metastasize. In this review, we will take a comprehensive look at the current research on lung cancer metastasis, including molecular pathways, anatomical features and genetic traits that make lung cancer intrinsically metastatic, as we go from lung cancer’s general metastatic potential to the particular metastasis mechanisms in multiple organs. We highly concerned about the advanced discovery and development of lung cancer metastasis, indicating the importance of lung cancer specific gene mutations, heterogeneity or biomarker discovery, and discussing potential opportunities and challenges. We will also introduce some current treatments that targets certain metastatic strategies of non-small cell lung cancer (NSCLC). Advances made in these regards could be critical to our current knowledge base of lung cancer metastasis.

The Combination of Afatinib and Bevacizumab in Untreated EGFR-Mutated Advanced Lung Adenocarcinoma: A Multicenter Observational Study

The efficacy of afatinib in combination with bevacizumab in untreated advanced epidermal growth factor receptor (EGFR)-mutated lung adenocarcinoma is currently unclear. We sought to investigate the efficacy of this combination through a multicenter observational analysis. Data for 57 patients with advanced EGFR-mutated lung adenocarcinoma who received afatinib combined with bevacizumab as first-line therapy at the Chang Gung Memorial Hospitals in Linkou and Kaohsiung and Taipei Tzu Chi Hospital from May 2015 to July 2019 were analyzed. The objective response rate and disease control rate of afatinib combined with bevacizumab therapy were 87.7% and 100%, respectively. In all patients, the median progression-free survival (PFS) and overall survival (OS) were 23.9 (95% confidence interval (CI) (17.56–29.17)) and 45.9 (95% CI (39.50–53.60)) months, respectively. No statistical significance between exon 19 deletion and L858R mutations was noted in PFS or OS. The most frequent adverse events (AEs) were diarrhea (98.2%) and dermatitis (96.5%), and most AEs were grade 2 or lower and manageable. The combination of afatinib and bevacizumab is an effective therapy for untreated advanced EGFR-mutated lung adenocarcinoma with acceptable safety. Future prospective studies focusing on this combination for untreated advanced EGFR-mutated lung adenocarcinoma are warranted.

Emerging role of tumor cell plasticity in modifying therapeutic response

Resistance to cancer therapy is a major barrier to cancer management. Conventional views have proposed that acquisition of resistance may result from genetic mutations. However, accumulating evidence implicates a key role of non-mutational resistance mechanisms underlying drug tolerance, the latter of which is the focus that will be discussed here. Such non-mutational processes are largely driven by tumor cell plasticity, which renders tumor cells insusceptible to the drug-targeted pathway, thereby facilitating the tumor cell survival and growth. The concept of tumor cell plasticity highlights the significance of re-activation of developmental programs that are closely correlated with epithelial-mesenchymal transition, acquisition properties of cancer stem cells, and trans-differentiation potential during drug exposure. From observations in various cancers, this concept provides an opportunity for investigating the nature of anticancer drug resistance. Over the years, our understanding of the emerging role of phenotype switching in modifying therapeutic response has considerably increased. This expanded knowledge of tumor cell plasticity contributes to developing novel therapeutic strategies or combination therapy regimens using available anticancer drugs, which are likely to improve patient outcomes in clinical practice.

PAQR3 Inhibits Non-small Cell Lung Cancer Growth by Regulating the NF-κB/p53/Bax Axis

Background

The expression of progestin and adipoQ receptor 3 (PAQR3) is generally downregulated in multiple tumors, which is associated with tumor progression and poor prognosis.

Methods

The clinical value of PAQR3 was analyzed using various databases and in 60 patients with non-small cell lung cancer (NSCLC). In addition, cell counting kit-8 (CCK-8), colony formation, and flow cytometry assays were used to evaluate the effect of PAQR3 on the growth of NSCLC cells in vitro. Gene set enrichment analysis (GSEA) was performed to investigate the possible mechanism through which PAQR3 is involved in the progression of lung cancer. Furthermore, western blotting was employed to verify the relevant mechanism.

Results

The expression of PAQR3 was decreased in 60 NSCLC patients and was related to the histological subtype, lymph node metastasis, tumor size, and diagnosis of NSCLC. Patients with lung adenocarcinoma with increased PAQR3 expression tended to have a better prognosis. Besides, PAQR3 inhibited proliferation, clone formation, and cycle transition in NSCLC cells, but induced apoptosis. The results of GSEA showed that PAQR3 regulated the progression of lung cancer by affecting cell cycle, DNA replication, and the p53 signaling pathway. We confirmed that PAQR3 overexpression inhibited the expression of NF-κB, while it increased the expression of p53, phospho-p53, and Bax. On the contrary, PAQR3 inhibition played an opposite role in these proteins.

Conclusion

PAQR3 inhibited the growth of NSCLC cells through the NF-κB/P53/Bax signaling pathway and might be a new target for diagnosis and treatment.

Spatial and Temporal Changes in PD-L1 Expression in Cancer: The Role of Genetic Drivers, Tumor Microenvironment and Resistance to Therapy

Immunotherapies blocking immune inhibitory receptors programmed cell death-1 (PD-1) and cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) on T-cells have dramatically improved patient outcomes in a range of advanced cancers. However, the lack of response, and the development of resistance remain major obstacles to long-term improvements in patient outcomes. There is significant interest in the clinical use of biomarkers to improve patient selection, and the expression of PD-1 ligand 1 (PD-L1) is often reported as a potential biomarker of response. However, accumulating evidence suggests that the predictive value of PD-L1 expression in tumor biopsies is relatively low due, in part, to its complex biology. In this review, we discuss the biological consequences of PD-L1 expression by various cell types within the tumor microenvironment, and the complex mechanisms that regulate PD-L1 expression at the genomic, transcriptomic and proteomic levels.

YAP‑mediated crosstalk between the Wnt and Hippo signaling pathways (Review)

Yes‑associated protein (YAP) acts as a transcriptional co‑activator in gene expression and cell proliferation control by binding to the transcriptional factor TEA domain (TEAD) of the Hippo signaling pathway in the nucleus, and also acts as a regulator by binding to another transcriptional co‑activator, β‑catenin of the Wnt signaling pathway. Whether YAP preferentially acts as a transcriptional co‑regulator of the activity of the Hippo signaling pathway or as a regulator in the Wnt signaling pathway depends on the cell type. Nuclear YAP upregulates the expression of β‑catenin, while cytoplasmic YAP has a negative effect on this expression. The present mini‑review focused on the important roles of YAP and further discussed the cross‑links between the Wnt and Hippo signaling pathways. The Wnt and Hippo signaling pathways are both related to the development of fibrosis or cancer. The current review discussed treatment approaches for these conditions based on the two pathways. YAP, the intersection of these two signaling pathways, has the potential to be developed as a novel treatment target, according to previous basic studies on fibroblasts and cancer cells.

Nitidine chloride possesses anticancer property in lung cancer cells through activating Hippo signaling pathway

Nitidine chloride (NC) has significant anti-tumor properties; however, the precise mechanism related to NC still needs further investigation. This study intends to investigate the anti-tumor functions and the feasible molecular basis of NC in NSCLC cells. Therefore, we determined the mechanism of NC-mediated anti-tumor function through various methods. Cell proliferation ability and migration and invasion were detected by CCK-8, colony formation assay and Transwell assay, respectively. Furthermore, flow cytometry was used to detect apoptosis, cell cycle and ROS. Moreover, protein expression level was measured by western blot. Our results showed that NC can inhibit the growth, motility of NSCLC cells, induce apoptosis and arrest cell cycle. Meanwhile, NC increased the level of ROS in NSCLC cells. Moreover, western blot data showed that NC suppressed the expression of Lats1, Mob1, and YAP, and enhanced the expression of p-Lats1, p-Mob1, p-YAP1 (ser127). Overall, our research reveals that NC exerts anticancer activity by activating and modulating the Hippo signaling pathway.

Water extract of sporoderm-broken spores of Ganoderma lucidum enhanced pd-l1 antibody efficiency through downregulation and relieved complications of pd-l1 monoclonal antibody

PURPOSE

Osteosarcoma is a malignant musculoskeletal tumor with early metastasis and a poor prognosis, especially in adolescents. Ganoderma lucidum (Leyss. Ex Fr.) Karst (G. lucidum), a traditional East Asian medicine, has been reported to play a critical role in antitumor and immunomodulatory activity. The aim of this study was to investigate the effects and molecular mechanisms of water extract of sporoderm-broken spores of G. lucidum (BSGWE) on osteosarcoma PD-L1 (programmed cell death-ligand 1) transcriptional regulation, efficacy enhancement, and side effect remission.

METHODS

The antitumor effects on cell proliferation of BSGWE in osteosarcoma cells were detected by apoptosis flow cytometry, and the migration ability of HOS and K7M2 cells were evaluated by cell scratch assay. Potential signaling regulation of PD-L1 was detected by western blotting. To confirm the signaling pathway of BSGWE-related PD-L1 downregulation, a pho-STAT3 turnover experiment was carried out. Colivelin was administered as a pho-STAT3 activator to rescue the BSGWE-induced PD-L1 inhibition. To further study in vivo signaling, in a Balb/c osteosarcoma allograft model, tumor volume was measured using an in vivo bioluminescence imaging system. The body weight curve and tumor volume curve were analyzed to reveal the remission effects of BSGWE on PD-L1 antibody-related body weight loss and its immunomodulatory effects on the osteosarcoma and spleen. The PD-L1 expression level and expression of related transcription-factor pho-STAT3 in tumor cells and spleens were assessed by IHC analysis.

RESULTS

BSGWE suppressed the proliferation and migration of osteosarcoma cells in vitro via induction of apoptosis. In addition, BSGWE downregulated PD-L1 expression and related STAT3 (signal transducers and activators of transcription) phosphorylation levels in a dose-dependent manner. Western blotting and qRT-PCR assay revealed that BSGWE downregulated PD-L1 expression by inhibiting STAT3 phosphorylation. A turnover experiment showed that colivelin administration could rescue PD-L1 inhibition via pho-STAT3 activation. BSGWE not only downregulated PD-L1 expression via the STAT3 pathway in an allograft Balb/c mouse model, but also relieved complications including weight loss and spleen atrophy in a mouse monoclonal antibody therapy model on the basis of its traditional advantages in immune enhancement.

CONCLUSION

BSGWE downregulated PD-L1 expression via pho-STAT3 inhibition of protein and RNA levels. BSGWE enhanced PD-L1 antibody efficacy via phosphorylated STAT3 downregulation in vitro and in vivo. BSGWE also relieved complications of weight loss and spleen atrophy in a murine allograft osteosarcoma immune checkpoint blockade therapy model.