Small extracellular vesicles in cancer

Extracellular vesicles (EV) are lipid-bilayer enclosed vesicles in submicron size that are released from cells. A variety of molecules, including proteins, DNA fragments, RNAs, lipids, and metabolites can be selectively encapsulated into EVs and delivered to nearby and distant recipient cells. In tumors, through such intercellular communication, EVs can regulate initiation, growth, metastasis and invasion of tumors. Recent studies have found that EVs exhibit specific expression patterns which mimic the parental cell, providing a fingerprint for early cancer diagnosis and prognosis as well as monitoring responses to treatment. Accordingly, various EV isolation and detection technologies have been developed for research and diagnostic purposes. Moreover, natural and engineered EVs have also been used as drug delivery nanocarriers, cancer vaccines, cell surface modulators, therapeutic agents and therapeutic targets. Overall, EVs are under intense investigation as they hold promise for pathophysiological and translational discoveries. This comprehensive review examines the latest EV research trends over the last five years, encompassing their roles in cancer pathophysiology, diagnostics and therapeutics. This review aims to examine the full spectrum of tumor-EV studies and provide a comprehensive foundation to enhance the field. The topics which are discussed and scrutinized in this review encompass isolation techniques and how these issues need to be overcome for EV-based diagnostics, EVs and their roles in cancer biology, biomarkers for diagnosis and monitoring, EVs as vaccines, therapeutic targets, and EVs as drug delivery systems. We will also examine the challenges involved in EV research and promote a framework for catalyzing scientific discovery and innovation for tumor-EV-focused research.

Statin shapes inflamed tumor microenvironment and enhances immune checkpoint blockade in non-small cell lung cancer

Immune checkpoint blockade (ICB) therapy has achieved breakthroughs in the treatment of advanced non-small cell lung cancer (NSCLC). Nevertheless, the low response due to immuno-cold (i.e., tumors with limited tumor-infiltrating lymphocytes) tumor microenvironment (TME) largely limits the application of ICB therapy. Based on the glycolytic/cholesterol synthesis axis, a stratification framework for EGFR-WT NSCLC was developed to summarize the metabolic features of immuno-cold and immuno-hot tumors. The cholesterol subgroup displays the worst prognosis in immuno-cold NSCLC, with significant enrichment of the cholesterol gene signature, indicating that targeting cholesterol synthesis is essential for the therapy for immuno-cold NSCLC. Statin, the inhibitor for cholesterol synthesis, can suppress the aggressiveness of NSCLC in vitro and in vivo and can also drastically reverse the phenotype of immuno-cold to an inflamed phenotype in vivo. This change led to a higher response to ICB therapy. Moreover, both our in-house data and meta-analysis further support that statin can significantly enhance ICB efficacy. In terms of preliminary mechanisms, statin could transcriptionally inhibit PD-L1 expression and induce ferroptosis in NSCLC cells. Overall, we reveal the significance of cholesterol synthesis in NSCLC and demonstrate the improved therapeutic efficacy of ICB in combination with statin. These findings could provide a clinical insight to treat NSCLC patients with immuno-cold tumors.

The role of lipid metabolic reprogramming in tumor microenvironment

Metabolic reprogramming is one of the most important hallmarks of malignant tumors. Specifically, lipid metabolic reprogramming has marked impacts on cancer progression and therapeutic response by remodeling the tumor microenvironment (TME). In the past few decades, immunotherapy has revolutionized the treatment landscape for advanced cancers. Lipid metabolic reprogramming plays pivotal role in regulating the immune microenvironment and response to cancer immunotherapy. Here, we systematically reviewed the characteristics, mechanism, and role of lipid metabolic reprogramming in tumor and immune cells in the TME, appraised the effects of various cell death modes (specifically ferroptosis) on lipid metabolism, and summarized the antitumor therapies targeting lipid metabolism. Overall, lipid metabolic reprogramming has profound effects on cancer immunotherapy by regulating the immune microenvironment; therefore, targeting lipid metabolic reprogramming may lead to the development of innovative clinical applications including sensitizing immunotherapy.

Cell-derived nanovesicles prepared by membrane extrusion are good substitutes for natural extracellular vesicles

Extracellular vesicles (EV) as drug delivery nanocarriers are under intense investigation. Although clinical-grade EVs have been produced on a large-scale, low yield and high production costs of natural EVs (nEV) limit the relevant industrial translation. Recent studies show that mechanical extrusion of cells can generate nEV-like cell-derived nanovesicles (CNV) which can also be used as drug nanocarriers. Moreover, in comparison with nEVs, CNVs have similar physicochemical properties. Nevertheless, a comprehensive comparison of cargo between nEVs and CNVs has not been investigated yet. Therefore, the aim of this study is to profile and compare CNVs to nEVs. Our results show that no significant difference was found in size, morphology, and classical markers between nEVs and CNVs derived from MDA-MB-231 cells. Protein sequencing data reveals the similarity of membrane proteins between the two groups was ~71%, while it was ~21% when pertaining to total protein cargo. Notably, a high similarity of membrane proteins was also found between nEVs and CNVs derived from eight additional cancer cell lines. Moreover, analysis of the top 1000 small RNAs with RNA sequencing showed a ~65% similarity between the two groups. Altogether, we infer from the high similarity of membrane proteins and small RNA cargo that CNVs can be a good substitute for nEVs. In brief, our findings support previous studies with a notion that CNVs yield comparable performance with nEVs and could pave the way for clinical implementation of CNV-based therapeutics in the future.

MicroRNA-221-3p promotes pulmonary artery smooth muscle cells proliferation by targeting AXIN2 during pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a pathological condition characterized by excessive cell proliferation and migration of pulmonary arterial smooth muscle cells (PASMC). PAH pathogenesis shares similarities with cancers such as excessive cell proliferation and apoptosis resistance. A previous study by our group revealed that decreased expression of a tumor suppressor-AXIN2 (Axis inhibition protein 2) was responsible for enhanced PASMC proliferation and suppressed apoptosis. Nevertheless, the mechanisms that regulate the downregulation of AXIN2 in PAH remain elusive. Data from the present study demonstrated that miR-221-3p acts as an upstream regulator of AXIN2 and functions to induce PASMC proliferation. We first showed that miR-221-3p expression was elevated in lung tissue and PASMC of PAH patients as well as in animal models of PAH. Human PASMC were transfected with a miR-221-3p mimic and miR-221-3p inhibitor, respectively, and their effects on the proliferation and migration was assessed using BrdU incorporation, PCNA staining and wound healing assays. In addition, we investigated the molecular mechanism through which miR-221-3p contributes to cell proliferation in PASMC and identified AXIN2 as a direct target gene of miR-221-3p by dual luciferase reporter gene assays, qRT-qPCR and western blotting. Furthermore, we found that ectopic expression of AXIN2 or pharmacological inhibition of β-catenin by XAV-939 can attenuate the effect of miR-221-3p on cell proliferation in PASMC. Moreover, intravenous injection of miR-221-3p inhibitor attenuated the progression of SU5416-hypoxia-induced PAH in rats. The results of the present study identified a new regulatory axis in which miR-221-3p and AXIN2 regulate the proliferation of PASMC.

Bioinspired engineering of fusogen and targeting moiety equipped nanovesicles

Cell-derived small extracellular vesicles have been exploited as potent drug vehicles. However, significant challenges hamper their clinical translation, including inefficient cytosolic delivery, poor target-specificity, low yield, and inconsistency in production. Here, we report a bioinspired material, engineered fusogen and targeting moiety co-functionalized cell-derived nanovesicle (CNV) called eFT-CNV, as a drug vehicle. We show that universal eFT-CNVs can be produced by extrusion of genetically modified donor cells with high yield and consistency. We demonstrate that bioinspired eFT-CNVs can efficiently and selectively bind to targets and trigger membrane fusion, fulfilling endo-lysosomal escape and cytosolic drug delivery. We find that, compared to counterparts, eFT-CNVs significantly improve the treatment efficacy of drugs acting on cytosolic targets. We believe that our bioinspired eFT-CNVs will be promising and powerful tools for nanomedicine and precision medicine.

Engineered extracellular vesicles for concurrent Anti-PDL1 immunotherapy and chemotherapy

Immune checkpoint inhibitors (ICI) targeting PD-1/PD-L1 have been approved for the treatment of a variety of cancers. However, the efficacy of antibody-based ICIs could be further improved by mitigating anti-drug antibodies, proteolytic cleavage, and on-target off-tumor toxicity. One strategy for accomplishing this is through the use of extracellular vesicles (EVs), cell derived submicron vesicles with many unique properties. We constructed an engineered MDA-MB-231 cell line for harvesting EVs. This was accomplished by overexpressing a high-affinity variant human PD-1 protein (havPD-1), while simultaneously knocking out intrinsic PD-L1 and beta-2 microglobulin. The engineered havPD-1 EVs reduced PD-L1 overexpressing cancer cell proliferation and induced cellular apoptosis. Moreover, the EVs were shown to efficiently block PD-L1 mediated T cell suppression. Meanwhile antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity were not observed. The havPD-1 EVs treatment resulted in robust anti-tumor activity in both preventative co-implantation and therapeutic xenograft tumor models reconstituted with human T cells. The efficacy of the havPD-1 EVs was shown to be comparable to clinical anti-PD1 monoclonal antibodies. Additionally, loading the havPD-1 EVs with a potent PARP inhibitor was shown to further augment treatment efficacy. In brief, the engineered universal EVs harboring havPD-1 proteins can be used for cancer concurrent immunotherapy and chemotherapy.

Isolation of extracellular vesicles with multivalent aptamers

Extracellular vesicles (EVs) are lipid-enclosed submicron-sized vesicles that are secreted by all eukaryotic cells. EVs can selectively encapsulate tissue-specific small molecules from parent cells and efficiently deliver them to recipient cells. As signal mediators of intercellular communication, the molecules packaged in EVs play critical roles in the pathophysiology of diseases. In relevant clinical translation, EV contents have been used for cancer diagnosis and treatment monitoring. To further promote EV-based cancer liquid biopsy toward large-scale clinical implementation, the efficient and specific isolation of pure tumor-derived EVs from body fluids is a prerequisite. However, the existing EV isolation methods are unable to address certain technical challenges, such as lengthy procedures, low throughput, low specificity, heavy protein contamination, etc., and thus, new approaches for EV isolation are required. Here, we report a multivalent, long single-stranded aptamer with repeated units for EV enrichment and retrieval. After short incubation of biotin-labeled multivalent aptamers (MAs) with the samples, EVs can be quickly secured by MAs, anchored onto streptavidin-coated microspheres, and further retrieved via digestion of the DNA aptamer. Approximately 45% of EVs can be isolated from the spiked samples in 40 min with a depletion of 84.7% of albumin contamination. In addition, 93.1% of the isolated EVs can be retrieved via DNase-mediated aptamer degradation in 10 min for downstream molecular analyses. Our findings suggest that MAs can efficiently and specifically isolate EVs derived from malignant lymphocytes, and this simple method could facilitate the EV-centered study of acute lymphoblastic leukemia.

Conferring receptors on recipient cells with extracellular vesicles for targeted drug delivery

Triple negative breast cancer (TNBC) is a heterogeneous subset of breast cancer characterized by its lack of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2), which altogether prevents TNBC from being treated effectively. For many years, the treatment paradigms and overall survival of patients with TNBC have remained largely stagnant. Recent attempts to convert cold tumors to hot tumors by promoting antigen presentation have shown increased T cell infiltration and significantly induced immune responses for tumor killing. Inspired by this concept, the expression of specific targetable antigens on TNBC cells may further benefit relevant targeted drug delivery. In this study, we successfully conferred sufficient HER2 on the surface of TNBC MDA-MB-231 cells via simple EV-plasma membrane fusion with HER2+ extracellular vesicles (EV) derived from HER2 overexpressing BT-474 cells. Subsequently, anti-HER2 antibody conjugated paclitaxel-loaded liposomes were used for HER2-targeted drug delivery. Our findings demonstrated this HER2 grafting, in conjunction with targeted drug delivery, can improve the treatment efficacy in vitro and in vivo. This novel approach represents a facile method of altering cell membrane antigen presentation via convenient EVs uptake and may pave the way for the burgeoning wave of targeted therapy and/or immunotherapy.

Isolation and Retrieval of Extracellular Vesicles for Liquid Biopsy of Malignant Ground-Glass Opacity

Extracellular vesicles (EVs) are cell-released vesicles of submicrometer size. EVs contain a tissue-specific signature wherein a variety of proteins and nucleic acids are selectively packaged. Recent studies validate that EVs can be used for cancer diagnostics, staging, and treatment monitoring. EV-related clinical translation requires effective EV isolation as a prerequisite. However, lengthy procedures, low yield, low throughput, and high levels of contaminants disqualify the existing isolation approaches for large-scale clinical use. Hence, new approaches for rapid, efficient, and low-cost isolation of EVs in high purity for flexible analyses of the diverse contents in real-world clinical settings are highly desired yet are currently unavailable. Here, we report the effective use of heparin/polymer-coated microspheres (HPM) for EV isolation and retrieval. Approximately 81% of EVs can be isolated from plasma in 1 h with depletion of ∼99.5% plasma protein and nucleic acid contaminants, and 72% of isolated EVs can be retrieved with saline in 5 min for various cargo analyses. This approach was further validated with clinical samples derived from patients with malignant ground-glass opacity (GGO). In eight patients, the mutation concordance between EV DNA and tissue DNA is 39.8%. The prevalence and mutation count of EGFR, TP53, and NF1 are higher than those of other oncogenes and antioncogenes that are intensely associated with lung adenocarcinoma. Moreover, different mutation prevalence and patterns between smokers and nonsmokers can be observed. Our findings suggest that the combination of HPM assay and targeted sequencing of EV DNA could be translated in the differential diagnosis of malignant GGO with short turnaround time.

HLA class II molecule HLA-DRA identifies immuno-hot tumors and predicts the therapeutic response to anti-PD-1 immunotherapy in NSCLC

BACKGROUND

Immune checkpoint blockade (ICB) only works well for a certain subset of patients with non-small cell lung cancer (NSCLC). Therefore, biomarkers for patient stratification are desired, which can suggest the most beneficial treatment.

METHODS

In this study, three datasets (GSE126044, GSE135222, and GSE136961) of immunotherapy from the Gene Expression Omnibus (GEO) database were analyzed, and seven intersected candidates were extracted as potential biomarkers for ICB followed by validation with The Cancer Genome Atlas (TCGA) dataset and the in-house cohort data.

RESULTS

Among these candidates, we found that human leukocyte antigen-DR alpha (HLA-DRA) was downregulated in NSCLC tissues and both tumor and immune cells expressed HLA-DRA. In addition, HLA-DRA was associated with an inflamed tumor microenvironment (TME) and could predict the response to ICB in NSCLC. Moreover, we validated the predictive value of HLA-DRA in immunotherapy using an in-house cohort. Furthermore, HLA-DRA was related to the features of inflamed TME in not only NSCLC but also in most cancer types.

CONCLUSION

Overall, HLA-DRA could be a promising biomarker for guiding ICB in NSCLC.

α-Solanine reverses pulmonary vascular remodeling and vascular angiogenesis in experimental pulmonary artery hypertension

OBJECTIVE

Similar to cancer, pulmonary arterial hypertension (PAH) is characterized by vascular remodeling, which leads to obliteration of the small pulmonary arteriole, with marked proliferation of pulmonary artery smooth muscle cells (PASMC) and/or endothelial cells dysfunction. Aberrant expression of tumor suppressor genes is closely associated with susceptibility to PAH. We hypothesized that α-solanine, a glycoalkaloid found in members of the nightshade family known to have antitumor activity in different cancers, reverses experimental PAH by activating the tumor suppressor-axis inhibition protein 2 (AXIN2).

METHODS AND RESULTS

We investigated the effects of α-solanine on PASMC proliferation and apoptosis by using 5-ethynyl-2'-deoxyuridine proliferation assay, proliferating cell nuclear antigen and Ki67 staining, TUNEL and Anexine V assays. Scratch wound healing and tube formation assays were also used to study migration of endothelial cells. In vitro, we demonstrated, using cultured human PASMC from PAH patients, that α-solanine reversed dysfunctional AXIN2, β-catenin and bone morphogenetic protein receptor type-2 signaling, whereas restored [Ca]i, IL-6 and IL-8, contributing to the decrease of PAH-PASMC proliferation and resistance to apoptosis. Meanwhile, α-solanine inhibits proliferation, migration and tube formation of PAH-pulmonary artery endothelial cells by inhibiting Akt/GSK-3α activation. In vivo, α-solanine administration decreases distal pulmonary arteries remodeling, mean pulmonary arteries pressure and right ventricular hypertrophy in both monocrotaline-induced and Sugen/hypoxia-induced PAH in mice.

CONCLUSION

This study demonstrates that AXIN2/β-catenin axis and Akt pathway can be therapeutically targeted by α-solanine in PAH. α-Solanine could be used as a new therapeutic strategy for the treatment of PAH.

Initial experience of lung transplantation at a single center in China

OBJECTIVES

Lung transplantation (LT) remains the only available option for patients with end-stage lung disease. Until recently, 244 lung transplantations have been performed at approximate 20 institutes in China. The aim of this article was to present the initial experience of LT at a single center in China.

METHODS

We performed a retrospective review of the database from The Chinese Organ Transplantation Network between January 1978 and December 2010 with detailed records available at our center.

RESULTS

We performed 100 of 244 lung transplantions at the Wuxi Center, The remaining procedures were performed at other institutes. The overall survival rates for these patients at 1, 2, 3, and 5 years were 73.3%, 61.6%, 53.5%, and 40.7%, respectively. The indications for lung transplantation included idiopathic pulmonary fibrosis (n = 47), chronic obstructive pulmonary disease (n = 33), silicosis (n = 5), bronchiectasis (n = 5), and Eisenmenger's syndrome (n = 4). The procedure types consisted of single-lung transplantations (s; n = 72), and bilateral lung transplantations (s; n = 28). Cardiopulmonary bypass was required in 5 patients, whereas 56 required arteriovenous extracorporeal membrane oxygenation, including extended use in 3 before and 10 after LT. The main morbidities and complications after LT were sepsis (n = 11), primary graft dysfunction (PGD, n = 10), anastomotic stenosis (n = 10), acute rejection episodes (n = 25), and bronchiolitis obliterans syndrome (n = 15). In-hospital mortality was 18%, including sepsis (n = 10), PGD (n = 6), acute rejection episode (n = 1) and pulmonary infarction (n = 1). The mean survival time was 3.4 years.

CONCLUSIONS

In China, lung transplantation may offer a viable therapy for patients with various end-stage pulmonary conditions. The initiation of LT should focus on improving the survival rate by increased clinical practice.

High B7-H3 expression with low PD-L1 expression identifies armored-cold tumors in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is generally regarded as the most aggressive subtype among breast cancers, but exhibits higher chemotherapeutic and immunotherapeutic responses due to its unique immunogenicity. Thus, appropriate discrimination of subtypes is critical for guiding therapeutic options in clinical practice. In this research, using multiple in-house and public cohorts, we investigated the expression features and immuno-correlations of B7-H3 in breast cancer and checked the anti-tumor effect of the B7-H3 monoclonal antibody in a mouse model. We also developed a novel classifier combining B7-H3 and PD-L1 expression in TNBC. B7-H3 was revealed to be related to immuno-cold features and accumulated collagen in TNBC. In addition, targeting B7-H3 using the monoclonal antibody significantly suppressed mouse TNBC growth, reversed the armored-cold phenotype, and also boosted anti-PD-1 immunotherapy. In addition, patients with B7-H3 high and PD-L1 low expression showed the lowest anti-tumor immune infiltration, the highest collagen level, and the lowest therapeutic responses to multiple therapies, which mostly belong to armored-cold tumors. Overall, this research provides a novel subtyping strategy based on the combination of B7-H3/PD-L1 expression, which leads to a novel approach for the management of TNBC.

Axis inhibition protein 2 deficiency leads to hypoxic pulmonary hypertension through β-catenin signaling pathway

OBJECTIVE

Pulmonary arterial hypertension (PAH) is characterized by increased vascular tone, altered vasoreactivity and vascular remodeling induced by smooth muscle cell proliferation. Similarities exist between cancer and PAH. Aberrant expression of the tumor suppressor protein is closely associated with PAH. Here, we tested the hypothesis that a tumor suppressor-axis inhibition protein 2 (Axin2) deficiency leads to PAH.

METHODS AND RESULTS

We measured right ventricular systolic pressure in Axin2 knockout mice and assessed the expression of Axin2 in patients. We found that Axin2 expression level was decreased in both mice exposed to chronic hypoxia and patients with PAH in remodeled pulmonary arterioles. Axin2 knockout mice showed elevated mean right ventricular systolic pressure and enhanced contraction in response to phenylephrine. An increase in the cross-sectional area of the vessels was occupied by the vessel wall, indicating pulmonary vascular remodeling. Furthermore, knocking down Axin2 with small interfering RNA inhibited apoptosis of pulmonary arterial smooth muscle cells (PASMCs). This inhibition was significantly abolished by β-catenin inhibitors, indicating that Axin2 through β-catenin increased vascular wall by inhibiting the apoptosis of PASMCs. Importantly, overexpression of Axin2 attenuates the development of hypoxia-induced PAH in mice.

CONCLUSION

Taken together, our study, for the first time, established that Axin2 plays a key role in the progression of PAH. We identified Axin2 as a novel mediator of pulmonary vasoconstriction and PASMC growth in hypoxia-mediated PAH. Our results suggest that downregulation of Axin2 in the pulmonary vasculature may be an underlying mechanism in the development of hypoxia-induced PAH.

Protocol to identify novel immunotherapy biomarkers based on transcriptomic data in human cancers

Immune checkpoint inhibitors have transformed the management of advanced cancers, but biomarkers for the prediction of therapeutic responses have not been fully uncovered. Here, we provide a step-by-step approach for the identification of novel biomarkers from public transcriptomic datasets. We comprehensively summarize the available transcriptomic datasets containing immunotherapy information and describe the necessary procedures to evaluate the effectiveness of a novel immunotherapy biomarker, which may accelerate the identification of novel immunotherapy biomarkers. For complete details on the use and execution of this protocol, please refer to Mei et al.1.

SECTM1 is upregulated in immuno-hot tumors and predicts immunotherapeutic efficacy in multiple cancers

Immune checkpoint inhibitors (ICIs) have transformed the management of advanced cancers. However, many patients could not benefit from ICIs therapy, and thus several biomarkers for therapeutic prediction have been uncovered. In this research, more than ten public and in-house cohorts were used to explore the predictive value and immunological correlations of secreted and transmembrane 1 (SECTM1) in cancers. SECTM1 expression was enhanced in tumors from patients with well immunotherapeutic responses in multiple cancers. In addition, SECTM1 was immuno-correlated in pan-cancer and enhanced in immuno-hot tumors. In vitro assays revealed that SECTM1 was upregulated by the IFN-γ/STAT1 signaling. Moreover, analysis of in-house immunotherapy cohorts suggested both tumor-expressed and circulating SECTM1 are promising biomarkers to predict therapeutic responses. Overall, this study reveals that SECTM1 is a biomarker of benefit to ICIs in cancer patients. Further studies including large-scale patients are needed to establish its utilization as a biomarker of benefit to ICIs.

Untangling the web of intratumor microbiota in lung cancer

Microbes are pivotal in contemporary cancer research, influencing various biological behaviors in cancer. The previous notion that the lung was sterile has been destabilized by the discovery of microbiota in the lower airway and lung, even within tumor tissues. Advances of biotechnology enable the association between intratumor microbiota and lung cancer to be revealed. Nonetheless, the origin and tumorigenicity of intratumor microbiota in lung cancer still remain implicit. Additionally, accumulating evidence indicates that intratumor microbiota might serve as an emerging biomarker for cancer diagnosis, prognosis, and even a therapeutic target across multiple cancer types, including lung cancer. However, research on intratumor microbiota's role in lung cancer is still nascent and warrants more profound exploration. Herein, this paper provides an extensive review of recent advancements in the following fields, including 1) established and emerging biotechnologies utilized to study intratumor microbiota in lung cancer, 2) causation between intratumor microbiota and lung cancer from the perspectives of translocation, cancerogenesis and metastasis, 3) potential application of intratumor microbiota as a novel biomarker for lung cancer diagnosis and prognosis, and 4) promising lung cancer therapies via regulating intratumor microbiota. Moreover, this review addresses the limitations, challenges, and future prospects of studies focused on intratumor microbiota in lung cancer.

Epidermal Growth Factor Receptor Mutations in Resectable Non-Small Cell Lung Cancer Patients and their Potential Role in the Immune Landscape

BACKGROUND The epidermal growth factor receptor (EGFR) is a therapeutic target for non-small cell lung cancer (NSCLC), but knowledge on gene mutations that contribute to NSCLC development and persistence is lacking. In this study, we investigated genetic variations in EGFR and their association with the clinical and pathological factors of NSCLC. MATERIAL AND METHODS Clinical cases (331 patients) and The Cancer Genome Atlas (TCGA) cases (1040 patients) were selected and analyzed using the refractory mutation systems cBioPortal and the Tumor Immune Estimation Resource (TIMER). RESULTS EGFR mutation frequencies were 54.4% (180 of 331 patients) and 8.0% (83 of 1040 patients) in the clinical and TCGA cohorts, respectively. EGFR mutations were strongly associated with smoking and pathology (P≤0.05) in the clinical cohort, and with gender, smoking, and pathology (P=0.001, P<0.001, and P<0.001, respectively) in TCGA cohort. In cases of lung squamous carcinoma (LUSC), EGFR was overexpressed as a result of DNA amplification, but this amplified expression showed no association with the overall survival (OS) or progression-free survival of LUSC patients. EGFR gene alterations were, however, associated with worse OS in lung adenocarcinoma (LUAD) patients. Immune cell infiltrates from LUAD and LUSC tumors differed according to EGFR expression. EGFR mutations resulted in a decline of immune infiltration or a lack of infiltrating immune cells in the NSCLC microenvironment. CONCLUSIONS Mutational profiles of the EGFR in NSCLC patients provide useful information for the use of tyrosine kinase inhibitors for adjuvant or neoadjuvant therapy and immunotherapy.

Nur77 downregulation triggers pulmonary artery smooth muscle cell proliferation and migration in mice with hypoxic pulmonary hypertension via the Axin2-β-catenin signaling pathway

Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by remodeling of the pulmonary vasculature, including marked proliferation and reduced apoptosis of pulmonary artery smooth muscle cells (PASMCs). Members of the nuclear receptor 4A (NR4A) subfamily are involved in a variety of biological events, such as cell apoptosis, proliferation, inflammation, and metabolism. Activation of Nur77 (an orphan nuclear receptor that belongs to NR4A subfamily) has recently been reported to be as a beneficial agent in the treatment of cardiovascular and metabolic diseases. In the present study, we investigated the effects of NR4A on human PASMCs function in vitro and determined the underlying mechanisms. We found a robust expression of NR4A receptors in lung tissues of PAH patients and hypoxic mice but a highly significant downregulation within pulmonary arteries (PAs) as assessed by quantitative polymerase chain reaction, immunoblotting, and immunohistochemistry. In vitro, NR4A receptors were found significantly decreased in PASMCs derived from PAH patients. To explore the pathological effects of decreased Nur77 in PASMCs, PASMCs were transduced with siRNA against Nur77. The siRNA-mediated knockdown of Nur77 significantly augmented PASMCs proliferation and migration. In contrast, Nur77 overexpression prevented PASMCs from proliferation and migration. Mechanistically, overexpression of Axis inhibition protein 2 (Axin2) or inhibition of β-catenin signaling was shown to be responsible for Nur77 knockdown-induced proliferation of PASMCs. Following hypoxia-induced angiogenesis of the pulmonary artery in C57BL/6 mice, small-molecule Nur77 agonists-Octaketide Cytosporone B (Csn-B) can significantly decreased thickness of vascular wall and markedly attenuated the development of chronic hypoxia-induced PAH in vivo. Therefore, reconstitution of Nur77 levels represents a promising therapeutic option to prevent vascular remodeling processes.

Preoperative Clinical Characteristics Predict Recurrent Laryngeal Nerve Lymph Node Metastasis and Overall Survival in Esophageal Squamous Cell Carcinoma: A Retrospective Study With External Validation

BACKGROUND

Recurrent laryngeal nerve (RLN) lymph node metastasis (LNM) is not rare in patients with esophageal squamous cell carcinoma (ESCC). We aimed to develop and externally validate a preoperative nomogram using clinical characteristics to predict RLN LNM in patients with ESCC and evaluate its prognostic value.

METHODS

A total of 430 patients with ESCC who underwent esophagectomy with lymphadenectomy of RLN LNs at two centers between May 2015 and June 2019 were reviewed and divided into training (center 1, n = 283) and external validation cohorts (center 2, n = 147). Independent risk factors for RLN LNM were determined by multivariate logistic regression, and a nomogram was developed. The performance of the nomogram was assessed in terms of discrimination, calibration, clinical usefulness, and prognostic value. The nomogram was internally validated by the bootstrap method and externally validated by the external validation cohort.

RESULTS

Multivariate analysis indicated that clinical T stage (P <0.001), endoscopic tumor length (P = 0.003), bioptic tumor differentiation (P = 0.004), and preoperative carcinoembryonic antigen level (P = 0.001) were significantly associated with RLN LNM. The nomogram had good discrimination with the area under the curve of 0.770 and 0.832 after internal and external validations. The calibration curves and decision curve analysis confirmed the good calibration and clinical usefulness of this model. High-risk of RLN LNM predicted by the nomogram was associated with worse overall survival in the external validation cohort (P <0.001).

CONCLUSION

A nomogram developed by preoperative clinical characteristics demonstrated a good performance to predict RLN LNM and prognosis for patients with ESCC.

The roles of small extracellular vesicles in lung cancer: Molecular pathology, mechanisms, diagnostics, and therapeutics

Small extracellular vesicles (sEVs) are submicron-sized, lipid-bilayer-enclosed particles that are released from cells. A variety of tissue-specific molecules, including proteins, DNA fragments, RNA, lipids, and metabolites, can be selectively encapsulated into sEVs and delivered to nearby and distant recipient cells. Incontestable and growing evidence shows the important biological roles and the clinical relevance of sEVs in tumors. In particular, recent studies validate sEVs can be used for early tumor diagnostics, staging, and treatment monitoring. Moreover, sEVs have been used as drug delivery nanocarriers, cancer vaccines, and antigen conferrers. While still in its infancy, the field of sEV-based fundamental and translational studies has been rapidly advancing. This review comprehensively examines the latest sEV-related studies in lung cancers, encompassing extracellular vesicles and their roles in lung cancer pathophysiology, diagnostics, and therapeutics. The state-of-the-art technologies for sEV isolation, downstream molecular analyses, and sEV-based therapies indicate their potency as tools for understanding the pathology and promising clinical management of lung cancers.

Factors influencing the measurement of the secretion rate of extracellular vesicles

Extracellular vesicles (EVs) are cell-derived vesicles which encapsulate a variety of molecules. Numerous studies have demonstrated EVs as signaling mediators of intercellular communication and are heavily involved under physiological and pathological conditions. In translational medicine, EVs have been used for disease diagnosis and treatment monitoring. EVs as natural nanocarriers for drug delivery and therapeutic EVs are also under intense investigation. While still in its infancy, relevant EV studies have been growing. For EV-centered research to thrive, a few fundamental unanswered questions, such as EV biogenesis, EV secretion rate (SR), EV content sorting mechanisms, etc. require further investigation. In this study, we measured the SR of EVs derived from 6 cancerous cell lines. Several factors that may interfere with EV secretion, isolation, and storage were also investigated. Our results show that the SR of EVs derived from various cancer cells was significantly different, indicating a heterogeneous EV secretion behavior among cell types. Moreover, 5 different drugs that interfere with cellular metabolism significantly influenced EV release. In addition, we found that (1) more EVs can be harvested at 24 h compared to 48 h of serum-free cell culture with a similar degree of FBS contamination; (2) filtration of the cell culture supernatant with a 0.22 μm filter causes ∼70% loss of EVs; (3) the isolation efficiency of EVs with the prevalent ultracentrifugation is only ∼14%; (4) storage at 4 °C for 3 days causes ∼21% loss of EVs. Overall, our findings provide a guideline for proper EV collection and storage in laboratory settings.