Exosomal miRNAs species in the blood of small cell and non-small cell lung cancer patients

Exosomal ncRNAs in liquid biopsies for lung cancer

Exosomal non-coding RNAs (ncRNAs) have become essential contributors to advancing and treating lung cancers (LCs). The development of liquid biopsies that utilize exosomal ncRNAs (exo-ncRNAs) offers an encouraging method for diagnosing, predicting, and treating LC. This thorough overview examines the dual function of exo-ncRNAs as both indicators for early diagnosis and avenues for LC treatment. Exosomes are tiny vesicles secreted by various cells, including cancerous cells, enabling connection between cells by delivering ncRNAs. These ncRNAs, which encompass circular RNAs, long ncRNAs, and microRNAs, participate in the modulation of gene expression and cellular functions. In LC, certain exo-ncRNAs are linked to tumour advancement, spread, and treatment resistance, positioning them as promising non-invasive indicators in liquid biopsies. Additionally, targeting these ncRNAs offers potential for innovative treatment approaches, whether by suppressing harmful ncRNAs or reinstating the activity of tumour-suppressing ones. This review emphasizes recent developments in the extraction and analysis of exo-ncRNAs, their practical applications in LC treatment, and the challenges and prospects for translating these discoveries into clinical usage. Through this detailed examination of the current state of the art, we aim to highlight the significant potential of exo-ncRNAs for LC diagnostics and treatments.

Extracellular Vesicle microRNA: A Promising Biomarker and Therapeutic Target for Respiratory Diseases

Respiratory diseases, including chronic obstructive pulmonary disease (COPD), asthma, lung cancer, and coronavirus pneumonia, present a major global health challenge. Current diagnostic and therapeutic options for these diseases are limited, necessitating the urgent development of novel biomarkers and therapeutic strategies. In recent years, microRNAs (miRNAs) within extracellular vesicles (EVs) have received considerable attention due to their crucial role in intercellular communication and disease progression. EVs are membrane-bound structures released by cells into the extracellular environment, encapsulating a variety of biomolecules such as DNA, RNA, lipids, and proteins. Specifically, miRNAs within EVs, known as EV-miRNAs, facilitate intercellular communication by regulating gene expression. The expression levels of these miRNAs can reflect distinct disease states and significantly influence immune cell function, chronic airway inflammation, airway remodeling, cell proliferation, angiogenesis, epithelial-mesenchymal transition, and other pathological processes. Consequently, EV-miRNAs have a profound impact on the onset, progression, and therapeutic responses of respiratory diseases, with great potential for disease management. Synthesizing the current understanding of EV-miRNAs in respiratory diseases such as COPD, asthma, lung cancer, and novel coronavirus pneumonia, this review aims to explore the potential of EV-miRNAs as biomarkers and therapeutic targets and examine their prospects in the diagnosis and treatment of these respiratory diseases.

Unraveling the Connection: Extracellular Vesicles and Non-Small Cell Lung Cancer

Extracellular vesicles (EVs) are nanoscale lipid bilayer vesicles released during cell activation, cellular damage, or apoptosis. They carry nucleic acids, proteins, and lipids facilitating intercellular communication and activate signaling pathways in target cells. In non-small cell lung cancer (NSCLC), EVs may contribute to tumor growth and metastasis by modulating immune responses, facilitating epithelial-mesenchymal transition, and promoting angiogenesis, while potentially contributing to resistance to chemotherapy drugs. EVs in liquid biopsies serve as non-invasive biomarkers for early cancer detection and diagnosis. Due to their small size, inherent molecular transport properties, and excellent biocompatibility, EVs also act as natural drug delivery vehicles in NSCLC therapy.

The diagnostic and prognostic value of exosomal microRNAs in lung cancer: a systematic review

BACKGROUND

Studies have shown that many exosomal microRNAs (miRNAs) can be used as non-invasive biomarkers of lung cancer, but their diagnostic and prognostic values need to be further clarified.

METHODS

We conducted a systematic literature search in Web of Science, PubMed, and ScienceDirect databases, obtained relevant articles and extracted data, and used statistical methods and statistical software to comprehensively evaluate the diagnostic and prognostic value of exosomal miRNAs in lung cancer.

REGISTRATION NUMBER

PROSPERO CRD42023447398.

RESULTS

In terms of diagnosis, two exosomal miRNAs (miR-486-5p and miR-451a) were reported with the highest frequency in lung cancer patients, both of which had good diagnostic value. Compared with the control group, the pooled sensitivities of miR-486-5p and miR-451a were 0.80 (95% CI: 0.73-0.86) and 0.76 (95% CI: 0.60-0.87), specificities: 0.93 (95% CI: 0.63-0.99) and 0.85 (95% CI: 0.72-0.92), and AUCs: 0.85 (95% CI: 0.81-0.88) and 0.88 (95% CI: 0.84-0.90), for the respective miRNAs. For prognosis, in lung cancer patients with abnormally expressed exosomal miRNAs, miR-1290 was associated with PFS outcome; miR-382, miR-1246, miR-23b-3p, miR-21-5p, and miR-10b-5p were associated with OS outcome; miR-21 and miR-4257 were associated with DFS outcome; miR-125a-3p and miR-625-5p were associated with PFS and OS outcomes; miR-216b and miR-451a were associated with OS and DFS outcomes.

CONCLUSIONS

Exosomal miRNAs are valuable biomarkers in lung cancer patients. Exosomal miR-486-5p and miR-451a can be used as new diagnostic biomarkers for lung cancer. Dysregulated exosomal miRNAs could serve as indicators of survival outcomes in lung cancer patients.

Circulating exosomal miRNAs as a promising diagnostic biomarker in cancer

Cancer belongs to multifactorial diseases characterized by uncontrolled growth and proliferation of abnormal cells. Breast cancer, non-small cell lung cancer, and colorectal cancer are the most frequently diagnosed malignancies with a high mortality rate. These carcinomas typically contain multiple genetically distinct subpopulations of tumor cells leading to tumor heterogeneity, which promotes the aggressiveness of the disease. Early diagnosis is necessary to increase patient progression-free survival. Particularly, miRNAs present in exosomes derived from tumors represent potential biomarkers suitable for early cancer diagnosis. Identification of miRNAs by liquid biopsy enables a personalized approach with the subsequent better clinical management of patients. This review article highlights the potential of circulating exosomal miRNAs in early breast, non-small cell lung, and colorectal cancer diagnosis.

Landscape of tumor and immune system cells-derived exosomes in lung cancer: mediators of antitumor immunity regulation

The immune system plays a critical role in cancer, including lung cancer, which is the leading cause of cancer-related deaths worldwide. Immunotherapy, particularly immune checkpoint blockade, has revolutionized the treatment of lung cancer, but a large subset of patients either do not respond or develop resistance. Exosomes, essential mediators of cell-to-cell communication, exert a profound influence on the tumor microenvironment and the interplay between cancer and the immune system. This review focuses on the role of tumor-derived exosomes and immune cells-derived exosomes in the crosstalk between these cell types, influencing the initiation and progression of lung cancer. Depending on their cell of origin and microenvironment, exosomes can contain immunosuppressive or immunostimulatory molecules that can either promote or inhibit tumor growth, thus playing a dual role in the disease. Furthermore, the use of exosomes in lung cancer immunotherapy is discussed. Their potential applications as cell-free vaccines and drug delivery systems make them an attractive option for lung cancer treatment. Additionally, exosomal proteins and RNAs emerge as promising biomarkers that could be employed for the prediction, diagnosis, prognosis and monitoring of the disease. In summary, this review assesses the relationship between exosomes, lung cancer, and the immune system, shedding light on their potential clinical applications and future perspectives.

Potential Avenues for Exosomal Isolation and Detection Methods to Enhance Small-Cell Lung Cancer Analysis

Around the world, lung cancer has long been the main factor in cancer-related deaths, with small-cell lung cancer (SCLC) being the deadliest form of lung cancer. Cancer cell-derived exosomes and exosomal miRNAs are considered promising biomarkers for diagnosing and prognosis of various diseases, including SCLC. Due to the rapidity of SCLC metastasis, early detection and diagnosis can offer better diagnosis and prognosis and therefore increase the patient's chances of survival. Over the past several years, many methodologies have been developed for analyzing non-SCLC-derived exosomes. However, minimal advances have been made in SCLC-derived exosome analysis methodologies. This Review discusses the epidemiology and prominent biomarkers of SCLC. Followed by a discussion about the effective strategies for isolating and detecting SCLC-derived exosomes and exosomal miRNA, highlighting the critical challenges and limitations of current methodologies. Finally, an overview is provided detailing future perspectives for exosome-based SCLC research.

Identifying cancer driver genes using a two-stage random walk with restart on a gene interaction network

Cancer development and progression are significantly influenced by cancer driver genes. Understanding cancer driver genes and their mechanisms of action is essential for developing effective cancer treatments. As a result, identifying driver genes is important for drug development, cancer diagnosis, and treatment. Here, we present an algorithm to discover driver genes based on the two-stage random walk with restart (RWR), and the modified method for calculating the transition probability matrix in random walk algorithm. First, we performed the first stage of RWR on the whole gene interaction network, in which we employ a new method for calculating the transition probability matrix and extracted the subnetwork based on nodes that had a high correlation with the seed nodes. The subnetwork was then applied to the second stage of RWR and the nodes were re-ranked in the subnetwork. Our approach outperformed existing methods in identifying driver genes. The outcome of the effect of three gene interaction networks, two rounds of random walk, and the seed nodes' sensitivity were all compared at the same time. In addition, we identified several potential driver genes, some of which are involved in driving cancer development. Overall, our method is efficient in various cancer types, significantly outperforms existing methods, and can identify possible driver genes.

Non-Coding RNAs in Airway Diseases: A Brief Overview of Recent Data

Inflammation of the human lung is mediated in response to different stimuli (e.g., physical, radioactive, infective, pro-allergenic, or toxic) such as cigarette smoke and environmental pollutants. These stimuli often promote an increase in different inflammatory activities in the airways, manifesting themselves as chronic diseases (e.g., allergic airway diseases, asthma chronic bronchitis/chronic obstructive pulmonary disease, or even lung cancer). Non-coding RNA (ncRNAs) are single-stranded RNA molecules of few nucleotides that regulate the gene expression involved in many cellular processes. ncRNA are molecules typically involved in the reduction of translation and stability of the genes of mRNAs s. They regulate many biological aspects such as cellular growth, proliferation, differentiation, regulation of cell cycle, aging, apoptosis, metabolism, and neuronal patterning, and influence a wide range of biologic processes essential for the maintenance of cellular homeostasis. The relevance of ncRNAs in the pathogenetic mechanisms of respiratory diseases has been widely established and in the last decade many papers were published. However, once their importance is established in pathogenetic mechanisms, it becomes important to further deepen the research in this direction. In this review we describe several of most recent knowledge concerning ncRNA (overall miRNAs) expression and activities in the lung.

[Research Progress on the Application of Liquid Biopsy in the Diagnosis and Treatment of Small Cell Lung Cancer]

Small cell lung cancer (SCLC) is a malignant tumor with strong invasiveness and high mortality. It has the characteristics of easy metastasis, fast growth, high degree of malignancy and strong invasiveness. The prognosis of patients is generally poor. The current clinical diagnosis of SCLC is mainly based on tissue biopsy, which is invasive, long cycle time and high cost. In recent years, liquid biopsy has been gradually applied because of its non-invasive, comprehensive and real-time characteristics that traditional tissue biopsy does not have. The main detection objects of liquid biopsy include circulating tumor DNA (ctDNA), circulating tumor cells (CTCs) and exosomes in peripheral blood. The application of liquid biopsy in the clinical treatment of SCLC will help clinicians to improve the detailed diagnosis of SCLC patients, as well as the timely control and response to the treatment response of patients.
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Haemolysis Detection in MicroRNA-Seq from Clinical Plasma Samples

The abundance of cell-free microRNA (miRNA) has been measured in blood plasma and proposed as a source of novel, minimally invasive biomarkers for several diseases. Despite improvements in quantification methods, there is no consensus regarding how haemolysis affects plasma miRNA content. We propose a method for haemolysis detection in miRNA high-throughput sequencing (HTS) data from libraries prepared using human plasma. To establish a miRNA haemolysis signature we tested differential miRNA abundance between plasma samples with known haemolysis status. Using these miRNAs with statistically significant higher abundance in our haemolysed group, we further refined the set to reveal high-confidence haemolysis association. Given our specific context, i.e., women of reproductive age, we also tested for significant differences between pregnant and non-pregnant groups. We report a novel 20-miRNA signature used to identify the presence of haemolysis in silico in HTS miRNA-sequencing data. Further, we validated the signature set using firstly an all-male cohort (prostate cancer) and secondly a mixed male and female cohort (radiographic knee osteoarthritis). Conclusion: Given the potential for haemolysis contamination, we recommend that assays for haemolysis detection become standard pre-analytical practice and provide here a simple method for haemolysis detection.

Characterization of the MicroRNA Cargo of Extracellular Vesicles Isolated from a Pulmonary Tumor-Draining Vein Identifies miR-203a-3p as a Relapse Biomarker for Resected Non-Small Cell Lung Cancer

In resected non-small cell lung cancer (NSCLC), post-surgical recurrence occurs in around 40% of patients, highlighting the necessity to identify relapse biomarkers. An analysis of the extracellular vesicle (EV) cargo from a pulmonary tumor-draining vein (TDV) can grant biomarker identification. We studied the pulmonary TDV EV-miRNAome to identify relapse biomarkers in a two-phase study (screening and validation). In the screening phase, a 17-miRNA relapse signature was identified in 18 selected patients by small RNAseq. The most expressed miRNA from the signature (EV-miR-203a-3p) was chosen for further validation. Pulmonary TDV EV-miR-203a-3p was studied by qRT-PCR in a validation cohort of 70 patients, where it was found to be upregulated in relapsed patients (p = 0.0194) and in patients with cancer spread to nearby lymph nodes (N+ patients) (p = 0.0396). The ROC curve analysis showed that TDV EV-miR-203a-3p was able to predict relapses with a sensitivity of 88% (AUC: 0.67; p = 0.022). Moreover, patients with high TDV EV-miR-203a-3p had a shorter time to relapse than patients with low levels (43.6 vs. 97.6 months; p = 0.00703). The multivariate analysis showed that EV-miR-203a-3p was an independent, predictive and prognostic post-surgical relapse biomarker. In conclusion, pulmonary TDV EV-miR-203a-3p is a promising new relapse biomarker for resected NSCLC patients.

High diagnostic value of miRNAs for NSCLC: quantitative analysis for both single and combined miRNAs in lung cancer

BACKGROUND

MicroRNAs (miRNAs) are good candidates as biomarkers for Lung cancer (LC). The aim of this article is to figure out the diagnostic value of both single and combined miRNAs in LC.

METHODS

Normative meta-analysis was conducted based on PRISMA. We assessed the diagnostic value by calculating the combined sensitivity (Sen), specificity (Spe), positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odds ratio (DOR) and the area under the curve (AUC) of single and combined miRNAs for LC and specific subgroups.

RESULTS

A total of 80 qualified studies with a total of 8971 patients and 10758 controls were included. In non-small cell lung carcinoma (NSCLC), we involved 20 single-miRNAs and found their Sen, Spe and AUC ranged from 0.52-0.81, 0.66-0.88, and 0.68-0.90, respectively, specially, miR-19 with the maximum Sen, miR-20 and miR-10 with the highest Spe as well as miR-17 with the maximum AUC. Additionally, we detected miR-21 with the maximum Sen of 0.74 [95%CI: 0.62-0.83], miR-146 with the maximum Spe and AUC of 0.93 [95%CI: 0.79-0.98] and 0.89 [95%CI: 0.86-0.92] for early-stage NSCLC. We also identified the diagnostic power of available panel (miR-210, miR-31 and miR-21) for NSCLC with satisfying Sen, Spe and AUC of 0.82 [95%CI: 0.78-0.84], 0.87 [95%CI: 0.84-0.89] and 0.91 [95%CI: 0.88-0.93], and furtherly constructed 2 models for better diagnosis.

CONCLUSIONS

We identified several single miRNAs and combined groups with high diagnostic power for NSCLC through pooled quantitative analysis, which shows that specific miRNAs are good biomarker candidates for NSCLC and further researches needed.

Formation, contents, functions of exosomes and their potential in lung cancer diagnostics and therapeutics

Lung cancer is the leading cause of cancer-related death worldwide due to diagnosis in the advanced stage and drug resistance in the subsequent treatments. Development of novel diagnostic and therapeutic methods is urged to improve the disease outcome. Exosomes are nano-sized vehicles which transport different types of biomolecules intercellularly, including DNA, RNA and proteins, and are implicated in cross-talk between cells and their surrounding microenvironment. Tumor-derived exosomes (TEXs) have been revealed to strongly influence the tumor microenvironment, antitumor immunoregulatory activities, tumor progression and metastasis. Potential of TEXs as biomarkers for lung cancer diagnosis, prognosis and treatment prediction is supported by numerous studies. Moreover, exosomes have been proposed to be promising drug carriers. Here, we review the mechanisms of exosomal formation and uptake, the functions of exosomes in carcinogenesis, and potential clinical utility of exosomes as biomarkers, tumor vaccine and drug delivery vehicles in the diagnosis and therapeutics of lung cancer.

Exosome-Derived microRNA: Efficacy in Cancer

Exosome-derived microRNA (miRNA) has been the focus of attention in recent years. Mainly, their role in the pathogenesis of different types of cancer has been extensively studied. The different types of exosomal miRNAs (exomiRs) act as either oncogenes or oncosupressors. They have potential prognostic and diagnostic efficacy in different types of cancer due to their high stability and easy detection in bodily fluids. This is especially true in lung cancer, colorectal cancer, ovarian cancer, and breast cancer. However, their efficacy as potential therapies has not been widely investigated. This review will discuss the structure and functions of exosomes and miRNA, as well as the role of exomiRs in the pathogenesis of different types of cancer through boosting growth, promoting progression, chemotherapy resistance, angiogenesis, metastasis, and immune system evasion. We will also discuss the application of exomiRs in diagnosing different types of cancer and their role in prognosis. Furthermore, we shed light on the challenges of developing therapeutic agents using miRNAs and how the carriage of therapeutic miRNA by exosomes can help solve these challenges. Finally, we examine recent studies exploring the potential of exomiRs in treating cancers such as neuroblastoma, glioblastoma, and melanoma.

Exosomal lncRNA SCIRT/miR-665 Transferring Promotes Lung Cancer Cell Metastasis through the Inhibition of HEYL

Lung cancer remains the leading cause of cancer-related death worldwide. Recently, extracellular vesicles such as exosomes have attracted considerable interest both as a source for theranostic biomarkers and an essential participant in lung cancer progression. However, how specific exosomal cargos, such as noncoding RNAs, are selectively packaged into exosomes and promote lung cancer progression remains unclear. In this study, we identified miR-665 as the most elevated exosomal miRNA from both non-small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC) patients. We further demonstrated that lncRNA SCIRT was also increased in cancer cell exosomes and may facilitate the exosomal loading of miR-665 with the help of hnRNPA1. As a consequence, exosomal miR-665 promoted lung cancer cell invasion and migration by targeting Notch downstream transcription factor HEYL. In addition, we found that miR-665 and SCIRT were significantly upregulated in tumor tissue and plasma of patients with lung cancer, and both of them showed increased expression in metastatic disease samples. Our findings suggest that the exosomal transferring of miR-665 and SCIRT is a functional and mechanism-driven pathway that contributes to cancer progression and, thus, may provide novel diagnostic and therapeutic targets for lung cancer.

Exosomal microRNAs in non-small cell lung cancer

Lung cancer is one of the highest incidence cancer types worldwide and one with the lowest 5-year survival rate of all cancer types. Despite recent insights into lung cancer pathobiology, including novel biomarker-targeted therapies and immunotherapies, most of lung patients are diagnosed at late stages with limited and ineffective treatments. Therefore, more approaches are needed to eradicate lung cancer. In the last years, small extracellular vesicles (EVs) secreted by tumor cells have been gaining relevance. These intercellular signal mediators, called exosomes, contain a huge range of biological elements, including lipids, nucleic acids and miRNAs, among others, that carry relevant information. The role of exosomes in cancer progression is dependent on cancer type, molecular characteristics and stage. MicroRNAs molecules are a big part of the content of exosomes cargo and probably the most studied ones. Due to the regulatory role in gene expression, miRNAs may provide information of the molecular characteristics of the tumor and be also able to reprogram distant target cells. Exosomal miRNAs can modulate different biological processes in cancer such as growth, progression, invasion, angiogenesis, metastasis and drug resistance; playing a critical role in modifying the microenvironment of non-small cell lung cancer (NSCLC). Therefore, they can act by regulating tumor resistance and also be useful to monitoring the response/relapse to targeted therapies. In this work, we summarize the relevant advances on the potential role of exosomal miRNAs in NSCLC pathobiogenesis, highlighting the clinical utility of exosomal microRNAs as biomarkers for the NSCLC diagnosis, prognosis, drug resistance and therapeutic strategies.

Role of microRNAs in regulating cell proliferation, metastasis and chemoresistance and their applications as cancer biomarkers in small cell lung cancer

Small cell lung cancer (SCLC), a smoking-related highly aggressive neuroendocrine cancer, is characterized by rapid cell proliferation, early metastatic dissemination, and early relapse due to chemoresistance to first-line platinum-doublet chemotherapy. Genomically, SCLC tumors show nearly universal loss of TP53 and RB1 tumor suppressor genes, while gene expression signature classifies them into 4 distinct subgroups based on the expression patterns of lineage transcription factors - ASCL1/ASH1, NEUROD1, YAP-1, and POU2F3. Due to the lack of targetable molecular alterations and clinically useful diagnostic, prognostic and predictive biomarker, there is insignificant progress in the therapeutic management of SCLC patients. Numerous studies have shown a significant involvement of non-coding RNAs in the regulation of cell proliferation, invasion and migration, apoptosis, metastasis, and chemoresistance in various human cancers. In this review, we comprehensively discuss the role of microRNAs (miRNAs) in regulating the aforementioned biological process in SCLC. For this, we searched the scientific literature and selected studies that have evaluated the role of miRNAs in the disease pathogenesis or as a cancer biomarker in SCLC. Our review suggests that several miRNAs are involved in the pathogenesis of SCLC mainly by regulating cell proliferation, metastasis, and chemoresistance. Few studies have also demonstrated the clinical utility of miRNAs in monitoring response to chemotherapy as well as in predicting survival outcomes. However, more in-depth mechanistic studies utilizing in vivo models and multicentric studies with larger patient cohorts are needed before the applications of miRNAs as therapeutic targets or as biomarkers are translated from the laboratory into clinics.

Serum Exosomes and Their miRNA Load-A Potential Biomarker of Lung Cancer

Early detection of lung cancer in screening programs is a rational way to reduce mortality associated with this malignancy. Low-dose computed tomography, a diagnostic tool used in lung cancer screening, generates a relatively large number of false-positive results, and its complementation with molecular biomarkers would greatly improve the effectiveness of such programs. Several biomarkers of lung cancer based on different components of blood, including miRNA signatures, were proposed. However, only a few of them have been positively validated in the context of early cancer detection yet, which imposes a constant need for new biomarker candidates. An emerging source of cancer biomarkers are exosomes and other types of extracellular vesicles circulating in body fluids. Hence, different molecular components of serum/plasma-derived exosomes were tested and showed different levels in lung cancer patients and healthy individuals. Several studies focused on the miRNA component of these vesicles. Proposed signatures of exosome miRNA had promising diagnostic value, though none of them have yet been clinically validated. These signatures involved a few dozen miRNA species overall, including a few species that recurred in different signatures. It is worth noting that all these miRNA species have cancer-related functions and have been associated with lung cancer progression. Moreover, a few of them, including known oncomirs miR-17, miR-19, miR-21, and miR-221, appeared in multiple miRNA signatures of lung cancer based on both the whole serum/plasma and serum/plasma-derived exosomes.

Extracellular Vesicle-Associated miRNAs as a Biomarker for Lung Cancer in Liquid Biopsy

Extracellular vesicles are cell-derived membranous vesicles that are secreted into biofluids. Emerging evidence suggests that EVs play an essential role in the pathogenesis of many diseases by transferring proteins, genetic material, and small signaling molecules between cells. Among these molecules, microRNAs (miRNAs), a type of small noncoding RNA, are one of the most important signals and are involved in various biological processes. Lung cancer is one of the leading causes of cancer-related deaths worldwide. Early diagnosis of lung cancer may help to reduce mortality and increase the 5 years survival rate and thereby reduce the associated socioeconomic burden. In the past, EV-miRNAs have been recognized as biomarkers of several cancers to assist in diagnosis or prognosis. In this review, we discuss recent findings and clinical practice for EV-miRNAs of lung cancer in several biofluids, including blood, bronchoalveolar lavage fluid (BALF), and pleural lavage.

Human umbilical vein endothelial cells-derived microRNA-203-containing extracellular vesicles alleviate non-small-cell lung cancer progression through modulating the DTL/p21 axis

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, and is characterized by extensive metastasis and poor prognosis. Extracellular vesicles (EVs) derived from endothelial cells carrying microRNAs (miRNAs/miRs) have diagnostic and therapeutic potential for NSCLC. We herein investigate the potential of EVs derived from human umbilical vein endothelial cells (HUVECs) to transfer miR-203 to affect the progression of NSCLC. miR-203 and p21 were poorly expressed while DTL was highly expressed both in NSCLC tissues and cell lines. We employed CCK-8 proliferation, colony formation, and Transwell migration and invasion assays to evaluate the effects of miR-203 on NSCLC cell behaviors using loss- and gain-function approaches. EVs were isolated from HUVECs and then co-cultured with the A549 cells transfected with mimic-NC or miR-203 inhibitor. miR-203 targeted DTL and downregulated its expression, subsequently leading to increased stability of p21 which is a tumor suppressor. EV-enriched miR-203 from HUVECs suppressed malignant phenotypes of NSCLC cells and delayed tumor growth. In conclusion, miR-203 from HUVEC-derived EVs exerts inhibitory effects on the progression of NSCLC by targeting DTL and promoting p21 protein stability.

Current Status and Future Perspectives of Liquid Biopsy in Small Cell Lung Cancer

Approximately 19% of all cancer-related deaths are due to lung cancer, which is the leading cause of mortality worldwide. Small cell lung cancer (SCLC) affects approximately 15% of patients diagnosed with lung cancer. SCLC is characterized by aggressiveness; the majority of SCLC patients present with metastatic disease, and less than 5% of patients are alive at 5 years. The gold standard of SCLC treatment is platinum and etoposide-based chemotherapy; however, its effects are short. In recent years, treatment for SCLC has changed; new drugs have been approved, and new biomarkers are needed for treatment selection. Liquid biopsy is a non-invasive, rapid, repeated and alternative tool to the traditional tumor biopsy that could allow the most personalized medicine into the management of SCLC patients. Circulating tumor cells (CTCs) and cell-free DNA (cfDNA) are the most commonly used liquid biopsy biomarkers. Some studies have reported the prognostic factors of CTCs and cfDNA in SCLC patients, independent of the stage. In this review, we summarize the recent SCLC studies of CTCs, cfDNA and other liquid biopsy biomarkers, and we discuss the future utility of liquid biopsy in the clinical management of SCLC.

Exosomal miRNAs as biomarkers for diagnostic and prognostic in lung cancer

More and more studies report that exosomes released by various cells can serve as a medium for information exchange between different cells. Through a deep understanding of the physical and chemical properties of exosomes, the researchers revealed a more precise molecular mechanism of its participation in the process of intercellular communication. In particular, microRNA (miRNA) is found inside exosomes, as well as long noncoding RNA (lncRNA). Extensive evidence indicates that exosomal miRNAs participates in the occurrence and development of lung cancer and plays a variety of roles. Therefore, the release of RNA‐containing exosomes in many different kinds of body fluids has caused widespread interest among researchers. In this review, we report evidence from human studies involving miRNAs and other ncRNAs in exosomes associated with lung cancer as diagnostic and prognostic markers. Currently, there is a small amount of evidence that exosomal miRNAs can be used as early diagnosis and prognostic markers for lung cancer, and their exact role in lung cancer patients still needs further study.

Plasma Next Generation Sequencing and Droplet Digital-qPCR-Based Quantification of Circulating Cell-Free RNA for Noninvasive Early Detection of Cancer

Early detection of cancer holds high promise for reducing cancer-related mortality. Detection of circulating tumor-specific nucleic acids holds promise, but sensitivity and specificity issues remain with current technology. We studied cell-free RNA (cfRNA) in patients with non-small cell lung cancer (NSCLC; n = 56 stage IV, n = 39 stages I-III), pancreatic cancer (PDAC, n = 20 stage III), malignant melanoma (MM, n = 12 stage III-IV), urothelial bladder cancer (UBC, n = 22 stage II and IV), and 65 healthy controls by means of next generation sequencing (NGS) and real-time droplet digital PCR (RT-ddPCR). We identified 192 overlapping upregulated transcripts in NSCLC and PDAC by NGS, more than 90% of which were noncoding. Previously reported transcripts (e.g., HOTAIRM1) were identified. Plasma cfRNA transcript levels of POU6F2-AS2 discriminated NSCLC from healthy donors (AUC = 0.82 and 0.76 for stages IV and I-III, respectively) and significantly associated (p = 0.017) with the established tumor marker Cyfra 21-1. cfRNA yield and POU6F2-AS transcript abundance discriminated PDAC patients from healthy donors (AUC = 1.0). POU6F2-AS2 transcript was significantly higher in MM (p = 0.044). In summary, our findings support further validation of cfRNA detection by RT-ddPCR as a biomarker for early detection of solid cancers.

miRNAs as Biomarkers in Disease: Latest Findings Regarding Their Role in Diagnosis and Prognosis

MicroRNAs (miRNAs) represent a class of small, non-coding RNAs with the main roles of regulating mRNA through its degradation and adjusting protein levels. In recent years, extraordinary progress has been made in terms of identifying the origin and exact functions of miRNA, focusing on their potential use in both the research and the clinical field. This review aims at improving the current understanding of these molecules and their applicability in the medical field. A thorough analysis of the literature consulting resources available in online databases such as NCBI, PubMed, Medline, ScienceDirect, and UpToDate was performed. There is promising evidence that in spite of the lack of standardized protocols regarding the use of miRNAs in current clinical practice, they constitute a reliable tool for future use. These molecules meet most of the required criteria for being an ideal biomarker, such as accessibility, high specificity, and sensitivity. Despite present limitations, miRNAs as biomarkers for various conditions remain an impressive research field. As current techniques evolve, we anticipate that miRNAs will become a routine approach in the development of personalized patient profiles, thus permitting more specific therapeutic interventions.

The roles of exosomal miRNAs and lncRNAs in lung diseases

An increasing number of studies have reported that exosomes released from various cells can serve as mediators of information exchange between different cells. With further exploration of exosome content, a more accurate molecular mechanism involved in the process of cell-to-cell communication has been revealed; specifically, microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) are shuttled by exosomes. In addition, exosomal miRNAs and lncRNAs may play vital roles in the pathogenesis of several respiratory diseases, such as chronic obstructive pulmonary disease (COPD), lung cancer, and asthma. Consequently, exosomal miRNAs and lncRNAs show promise as diagnostic biomarkers and therapeutic targets in several lung diseases. This review will summarize recent knowledge about the roles of exosomal miRNAs and lncRNAs in lung diseases, which has shed light on the discovery of novel diagnostic methods and treatments for these disorders. Because there is almost no published literature about exosomal lncRNAs in COPD, asthma, interstitial lung disease, or tuberculosis, we summarize the roles of exosomal lncRNAs only in lung cancer in the second section. This may inspire some new ideas for researchers who are interested in whether lncRNAs shuttled by exosomes may play roles in other lung diseases.

MicroRNA-204-5p: A novel candidate urinary biomarker of Xp11.2 translocation renal cell carcinoma

Xp11.2 translocation renal cell carcinoma (Xp11 tRCC) is a rare sporadic pediatric kidney cancer caused by constitutively active TFE3 fusion proteins. Tumors in patients with Xp11 tRCC tend to recur and undergo frequent metastasis, in part due to lack of methods available to detect early‐stage disease. Here we generated transgenic (Tg) mice overexpressing the human PRCC‐TFE3 fusion gene in renal tubular epithelial cells, as an Xp11 tRCC mouse model. At 20 weeks of age, mice showed no histological abnormalities in kidney but by 40 weeks showed Xp11 tRCC development and related morphological and histological changes. MicroRNA (miR)‐204‐5p levels in urinary exosomes of 40‐week‐old Tg mice showing tRCC were significantly elevated compared with levels in control mice. MicroRNA‐204‐5p expression also significantly increased in primary renal cell carcinoma cell lines established both from Tg mouse tumors and from tumor tissue from 2 Xp11 tRCC patients. All of these lines secreted miR‐204‐5p‐containing exosomes. Notably, we also observed increased miR‐204‐5p levels in urinary exosomes in 20‐week‐old renal PRCC‐TFE3 Tg mice prior to tRCC development, and those levels were equivalent to those in 40‐week‐old Tg mice, suggesting that miR‐204‐5p increases follow expression of constitutively active TFE3 fusion proteins in renal tubular epithelial cells prior to overt tRCC development. Finally, we confirmed that miR‐204‐5p expression significantly increases in noncancerous human kidney cells after overexpression of a PRCC‐TFE3 fusion gene. These findings suggest that miR‐204‐5p in urinary exosomes could be a useful biomarker for early diagnosis of patients with Xp11 tRCC.

Clinical significance of serum miR-25 in non-small-cell lung cancer

Background: MicroRNAs (miRNAs) are becoming recognized as novel diagnostic and prognostic biomarkers in several malignancies, including non-small-cell lung cancer (NSCLC). miR-25 is overexpressed in small cell lung cancer (SCLC) and NSCLC tissues, and high miR-25 expression is associated with poorer overall survival of women with lung ADC. We hypothesised links between serum miR-25 levels and clinicopathological characteristics, diagnosis and prognosis of NSCLC patients. Methods: Serum miR-25 was determined by real-time quantitative polymerase chain reaction in 128 NSCLC patients and 128 healthy controls, and links between miR-25 level and cliniopathological characteristics including diagnosis and prognosis were explored. Results: Median (IQR) serum miR-25 levels were significantly increased in NSCLC compared to healthy controls at 0.86 relative units (0.14-1.78) versus 0.23 (0.08-0.96) (P < 0.001). Using a cut-off of 0.67 units, miR-25 had a sensitivity of 76.4%, specificity of 84.6%, accuracy of 72.6%, positive predictive value of 92.8% and negative predictive value of 68.5% for the diagnosis of NSCLC. High serum miR-25 level was significantly associated with gender (P = 0.042), tumour stage (P = 0.014) and lymph node metastasis (P < 0.001). In multivariate analyses, miR-25 was an independent prognostic factor for overall survival and relapse-free survival. Conclusions: Serum levels of miR-25 could improve NSCLC screening, and be a useful diagnostic and prognostic marker of NSCLC.

Resectable lung lesions malignancy assessment and cancer detection by ultra-deep sequencing of targeted gene mutations in plasma cell-free DNA

Background

Early detection of lung cancer to allow curative treatment remains challenging. Cell-free circulating tumour (ct) DNA (ctDNA) analysis may aid in malignancy assessment and early cancer diagnosis of lung nodules found in screening imagery.

Methods

The multicentre clinical study enrolled 192 patients with operable occupying lung diseases. Plasma ctDNA, white cell count genomic DNA (gDNA) and tumour tissue gDNA of each patient were analysed by ultra-deep sequencing to an average of 35 000× of the coding regions of 65 lung cancer-related genes.

Results

The cohort consists of a quarter of benign lung diseases and three quarters of cancer patients with all histopathology subtypes. 64% of the cancer patients are at stage I. Gene mutations detection in tissue gDNA and plasma ctDNA results in a sensitivity of 91% and specificity of 88%. When ctDNA assay was used as the test, the sensitivity was 69% and specificity 96%. As for the lung cancer patients, the assay detected 63%, 83%, 94% and 100%, for stages I, II, III and IV, respectively. In a linear discriminant analysis, combination of ctDNA, patient age and a panel of serum biomarkers boosted the overall sensitivity to 80% at a specificity of 99%. 29 out of the 65 genes harboured mutations in the patients with lung cancer with the largest number found in TP53 (30% plasma and 62% tumour tissue samples) and EGFR (20% and 40%, respectively).

Conclusion

Plasma ctDNA was analysed in lung nodule assessment and early cancer detection, while an algorithm combining clinical information enhanced the test performance.

Trial registration number

NCT03081741.

The diagnostic accuracy of liquid exosomes for lung cancer detection: a meta-analysis

PURPOSE

Several studies have suggested that liquid exosomes can be used as biomarkers for the diagnosis of lung cancer (LC). The purpose of this meta-analysis was to investigate the comprehensive diagnostic value of liquid exosomes for LC.

MATERIALS AND METHODS

Relevant studies were searched from multiple electronic databases. The quality of the studies was assessed by the Quality Assessment of Diagnostic Accuracy Studies-2 criteria in RevMan 5.3 software. Stata 14.0 software and Meta-disc 1.4 software were used to synthesize the diagnostic parameters. Publication bias was judged according to the Deeks' funnel plot asymmetry test.

RESULTS

There were 13 eligible articles that comprised 1,338 LC patients and 1,075 paired controls for the meta-analysis. The pooled sensitivity (SEN), specificity (SPE), diagnostic likelihood ratio positive (DLR+), diagnostic likelihood ratio negative (DLR-), diagnostic OR (DOR), and area under the curve (AUC) of liquid exosomes in diagnosing LC were 0.82 (95% CI: 0.76-0.87), 0.84 (95% CI: 0.77-0.89), 5.27 (95% CI: 3.58-7.75), 0.21 (95% CI: 0.15-0.29), 25.14 (95% CI: 14.25-44.33), and 0.90 (95% CI: 0.87-0.92), respectively. Research based on serum, miRNA, the isolation kit method, one index in exosomes, patient sample size of 50 or greater, and control group size of 50 or greater obtained higher AUC values when the LC type was small cell lung cancer.

CONCLUSION

Liquid exosomes have shown potential as novel biomarkers that could facilitate LC diagnosis. Further prospective studies are still needed to confirm the diagnostic value of liquid exosomes.

Modeling small cell lung cancer (SCLC) biology through deterministic and stochastic mathematical models

Mathematical cancer models are immensely powerful tools that are based in part on the fractal nature of biological structures, such as the geometry of the lung. Cancers of the lung provide an opportune model to develop and apply algorithms that capture changes and disease phenotypes. We reviewed mathematical models that have been developed for biological sciences and applied them in the context of small cell lung cancer (SCLC) growth, mutational heterogeneity, and mechanisms of metastasis. The ultimate goal is to develop the stochastic and deterministic nature of this disease, to link this comprehensive set of tools back to its fractalness and to provide a platform for accurate biomarker development. These techniques may be particularly useful in the context of drug development research, such as combination with existing omics approaches. The integration of these tools will be important to further understand the biology of SCLC and ultimately develop novel therapeutics.