Role of exosomal microRNAs in lung cancer biology and clinical applications

Exosomal LncRNAs and CircRNAs in lung cancer: Emerging regulators and potential therapeutic targets

Lung cancer remains one of the most prevalent and lethal malignancies globally, characterized by high incidence and mortality rates among all cancers. The delayed diagnosis of lung cancer at intermediate to advanced stages frequently leads to suboptimal treatment outcomes. To improve the management of this disease, it is imperative to identify new, highly sensitive prognostic and diagnostic biomarkers. Exosomes, extracellular vesicles with a lipid-bilayer structure and a size range of 30-150 nm, are pivotal in intercellular communication and play significant roles in lung cancer progression. Non-coding RNAs (ncRNAs), including long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), are highly prevalent within exosomes and play a crucial role in various pathophysiological processes mediated by these extracellular vesicles. Beyond their established functions in miRNA and protein sequestration, these ncRNAs are involved in regulating translation and interactions within exosomes. Numerous studies have highlighted the importance of exosomal lncRNAs and circRNAs in influencing epithelial-mesenchymal transition (EMT), angiogenesis, proliferation, invasion, migration, and metastasis in lung cancer. Due to their unique functional characteristics, these molecules are promising therapeutic targets and biomarkers for diagnosis and prognosis. This review provides a succinct summary of the formation of exosomal lncRNAs and circRNAs, clarifies their biological roles, and thoroughly explains the mechanisms by which they participate in the progression of lung cancer. Finally, we discuss the potential clinical applications and challenges associated with exosomal lncRNAs and circRNAs in lung cancer.

Cancer cell-derived exosomes promote NSCLC progression via the miR-199b-5p/HIF1AN axis

BACKGROUND

Exosomes are mediators of intercellular communication. Cancer cell-secreted exosomes allow exosome donor cells to promote cancer growth, as well as metastasis.

METHODS

Here, exosomes were isolated from the serum of non-small cell lung cancer (NSCLC) patients and characterized by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and western blot analysis. NSCLC cell proliferation and migration were assessed using CCK-8, 5-ethynyl-2'-deoxyuridine (EdU) and Transwell assays. H1299 tumor formation and pulmonary metastasis were examined in a xenograft model in nude mice.

RESULTS

We found that exosomes derived from NSCLC (NSCLC-Exos) promoted NSCLC cell migration and proliferation, and that NSCLC-Exo-mediated malignant progression of NSCLC was mediated by miR-199b-5p. Inhibition of miR-199b-5p decreased the effects of NSCLC-Exos on NSCLC malignant progression. HIF1AN was identified as a downstream target of miR-199b-5p. Furthermore, overexpression of HIF1AN reversed the effects of miR-199b-5p on NSCLC malignant progression.

CONCLUSION

In summary, our findings demonstrated that exosomal-specific miR-199b-5p promoted proliferation in distant or neighboring cells via the miR-199b-5p/HIF1AN axis, resulting in enhanced tumor growth.

Tumor-exosomal miR-205-5p as a diagnostic biomarker for colorectal cancer

BACKGROUND

Tumor-derived exosomal miRNAs play crucial roles in cancer diagnosis. Current studies aim to identify exosomal miRNAs associated with colorectal cancer (CRC) that are noninvasive, sensitive, and specific.

PATIENTS AND METHODS

Exosomes were extracted from CRC patients and healthy donors via ultracentrifugation, followed by verification via transmission electron microscopy (TEM), qNano, and Western blot analysis. The differential expression levels and clinical characteristics of miR-205-5p were analyzed in CRC via data from The Cancer Genome Atlas (TCGA). Real-time quantitative PCR was used to assess the expression levels of exosomal miRNAs in 157 primary CRC patients, 20 patients with benign diseases, and 135 healthy donors. Predictions regarding target genes were made to guide further exploration of the disease's etiopathogenesis through bioinformatics.

RESULTS

Compared with that in healthy donors, the expression of miR-205-5p in colorectal cancer (CRC) patients was significantly lower, as determined through analysis of the TCGA database. We conducted a prediction and analysis of the functional enrichment of downstream target genes regulated by miR-205-5p. A lower level of exosomal miR-205-5p in the serum of CRC patients than in that of healthy controls (p < 0.0001) and patients with benign disease (p < 0.0001) was observed. Furthermore, the expression levels of exosomal miR-205-5p were significantly lower in early-stage CRC patients than in the comparison groups (p<0.001 and p < 0.0001). Notably, the expression levels of exosomal miR-205-5p significantly increased postoperatively (p = 0.0053).

CONCLUSIONS

The present study demonstrated that serum exosomal miR-205-5p may be a diagnostic biomarker for CRC.

Current advance of nanotechnology in diagnosis and treatment for malignant tumors

Cancer remains a significant risk to human health. Nanomedicine is a new multidisciplinary field that is garnering a lot of interest and investigation. Nanomedicine shows great potential for cancer diagnosis and treatment. Specifically engineered nanoparticles can be employed as contrast agents in cancer diagnostics to enable high sensitivity and high-resolution tumor detection by imaging examinations. Novel approaches for tumor labeling and detection are also made possible by the use of nanoprobes and nanobiosensors. The achievement of targeted medication delivery in cancer therapy can be accomplished through the rational design and manufacture of nanodrug carriers. Nanoparticles have the capability to effectively transport medications or gene fragments to tumor tissues via passive or active targeting processes, thus enhancing treatment outcomes while minimizing harm to healthy tissues. Simultaneously, nanoparticles can be employed in the context of radiation sensitization and photothermal therapy to enhance the therapeutic efficacy of malignant tumors. This review presents a literature overview and summary of how nanotechnology is used in the diagnosis and treatment of malignant tumors. According to oncological diseases originating from different systems of the body and combining the pathophysiological features of cancers at different sites, we review the most recent developments in nanotechnology applications. Finally, we briefly discuss the prospects and challenges of nanotechnology in cancer.

Recent Technologies towards Diagnostic and Therapeutic Applications of Circulating Nucleic Acids in Colorectal Cancers

Liquid biopsy has emerged as a promising noninvasive approach for colorectal cancer (CRC) management. This review focuses on technologies detecting circulating nucleic acids, specifically circulating tumor DNA (ctDNA) and circulating RNA (cfRNA), as CRC biomarkers. Recent advancements in molecular technologies have enabled sensitive and specific detection of tumor-derived genetic material in bodily fluids. These include quantitative real-time PCR, digital PCR, next-generation sequencing (NGS), and emerging nanotechnology-based methods. For ctDNA analysis, techniques such as BEAMing and droplet digital PCR offer high sensitivity in detecting rare mutant alleles, while NGS approaches provide comprehensive genomic profiling. cfRNA detection primarily utilizes qRT-PCR arrays, microarray platforms, and RNA sequencing for profiling circulating microRNAs and discovering novel RNA biomarkers. These technologies show potential in early CRC detection, treatment response monitoring, minimal residual disease assessment, and tumor evolution tracking. However, challenges remain in standardizing procedures, optimizing detection limits, and establishing clinical utility across disease stages. This review summarizes current circulating nucleic acid detection technologies, their CRC applications, and discusses future directions for clinical implementation.

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.

MicroRNAs and the Mediterranean diet: a nutri-omics perspective for lung cancer

Lung cancer is the deadliest cancer type worldwide with ~ 1.8 million deaths per-year. Smoking accounts for ~ 85% of all cases, with a described joint effect with unhealthy diet in lung cancer risk increase. Public health policies to prevent carcinogens exposure, promote smoking cessation and advocacy for healthy nutrition, are therefore highly recommended. Here we have examined the benefits of the Mediterranean Diet (MedDiet) in protecting against some non-communicable diseases including lung cancer, highlighting the epidemiological and biomolecular aspects of MedDiet anti-inflammatory effect and its interaction with smoking habits closely linked to risk of lung cancer. Considering the high incidence and mortality rates of lung cancer, we discussed also about the global impact that a Planeterranean extension of the benefits of MedDiet could have on controlling lung cancer risk. We also debated the impact of personalized nutrition on lung cancer prevention, considering individual heterogeneity in response to diet plans as well as recent advancements on nutri-omics in lung cancer research, with a specific focus on the role of microRNAs (miRNAs) as a promising nutritional molecular hub for lung cancer prevention. We strongly believe that a deep understanding of the molecular link between food components and genetic/epigenetics factors can expand effective intervention strategies.

Non-coding RNAs and exosomal non-coding RNAs in lung cancer: insights into their functions

Lung cancer is the second most common form of cancer worldwide Research points to the pivotal role of non-coding RNAs (ncRNAs) in controlling and managing the pathology by controlling essential pathways. ncRNAs have all been identified as being either up- or downregulated among individuals suffering from lung cancer thus hinting that they may play a role in either promoting or suppressing the spread of the disease. Several ncRNAs could be effective non-invasive biomarkers to diagnose or even serve as effective treatment options for those with lung cancer, and several molecules have emerged as potential targets of interest. Given that ncRNAs are contained in exosomes and are implicated in the development and progression of the malady. Herein, we have summarized the role of ncRNAs in lung cancer. Moreover, we highlight the role of exosomal ncRNAs in lung cancer.

Red Blood Cell-Derived Exosomal Oncogenic MicroRNA Promote Cancer Development and Progression

The role of red blood cells (RBCs) in tumorigenesis is poorly understood. We previously identified RBC-microRNAs with aberrations linked to lung cancer, including miR-93-5p. Here we find that miR-93-5p levels are elevated in RBC-derived exosomes among lung cancer patients and are associated with their shorter survivals. RBC-derived miR-93-5p transfers to cancer cells primarily through the exosomal pathway. The transferred RBC-miR-93-5p can target PTEN in cancer cells, and hence increase cell proliferation, invasion, and migration. RBC-derived miR-93-5p accelerates, whereas targeting miR-93-5p diminishes tumor growth in xenograft models. These findings reveal a novel biological function of RBCs in tumorigenesis, where they facilitate cancer progression by transferring the oncomiR via exosomes, thereby offering new diagnostic and treatment strategies for lung cancer.

Advancements and trends in exosome research in lung cancer from a bibliometric analysis (2004-2023)

Background

Lung cancer, characterized by its high morbidity and lethality, necessitates thorough research to enhance our understanding of its pathogenesis and discover novel therapeutic approaches. Recent studies increasingly demonstrate that lung cancer cells can modulate the tumor microenvironment, promoting tumor growth, and metastasis through the release of exosomes. Exosomes are small vesicles secreted by cells and contain a variety of bioactive molecules such as proteins, nucleic acids, and metabolites. This paper presents a comprehensive review of exosome research in lung cancer and its progress through bibliometric analysis.

Methods

Publications related to exosomes in lung cancer patients were systematically searched on the Web of Science Core Collection (WoSCC) database. Bibliometric analysis was performed using VOSviwers, CiteSpace, and the R package "Bibliometrics". Publications were quantitatively analyzed using Microsoft Office Excel 2019. The language of publication was restricted to "English" and the search strategy employed TS=(exosomes or exosomes or exosomes) and TS=(lung cancer). The search period commenced on January 1, 2004, and concluded on November 12, 2023, at noon. The selected literature types included Articles and Reviews.

Results

The study encompassed 1699 papers from 521 journals across 71 countries and 2105 institutions. Analysis revealed a consistent upward trend in lung cancer exosome research over the years, with a notable surge in recent times. This surge indicates a growing interest and depth of inquiry into lung cancer exosomes. Major research institutions in China and the United States, including Nanjing Medical University, Shanghai Jiao Tong University, Chinese Academy Of Sciences, and Utmd Anderson Cancer Center, emerged as crucial research hubs. The annual publication count in this field witnessed a continuous rise, particularly in recent years. Key terms such as lung cancer, non-small cell lung cancer (NSCLC), microvesicles, intercellular communication, exosomal miRNAs, and oncology dominated the research landscape. Fields like cell biology, biochemistry, biotechnology, and oncology exhibited close relation with this research. Clotilde Théry emerged as the most cited author in the field, underlining her significant contributions. These results demonstrate the broad impact of exosome research in lung cancer, with key terms covering not only disease-specific aspects such as lung cancer and NSCLC but also basic biological concepts like microvesicles and intercellular communication. Explorations into exosomal microRNAs and oncology have opened new avenues for lung cancer exosome research. In summary, lung cancer exosome research is poised to continue receiving attention, potentially leading to breakthroughs in treatment and prevention.

Conclusion

Publications on lung cancer exosomes show a rising trend year by year, with China and the United States ranking first and second in terms of the number of publications. However, there is insufficient academic learning cooperation and exchanges between the two sides, and Chinese universities account for a large proportion of research institutions in this field. Jing Li is the most productive author, Clotilde Théry is the most co-cited author, and Cancers is the journal with the highest number of publications. The current focus in the field of lung cancer exosomes is on biomarkers, liquid biopsies, immunotherapy, and tumor microenvironment.

Exosomal microRNAs in regulation of tumor cells resistance to apoptosis

Exosomes are a type of extracellular vesicle that contains bioactive molecules that can be secreted by most cells. Nevertheless, the content of these cells differs depending on the cell from which they originate. The exosome plays a crucial role in modulating intercellular communication by conveying molecular messages to neighboring or distant cells. Cancer-derived exosomes can transfer several types of molecules into the tumor microenvironment, including high levels of microRNA (miRNA). These miRNAs significantly affect cell proliferation, angiogenesis, apoptosis resistance, metastasis, and immune evasion. Increasing evidence indicates that exosomal miRNAs (exomiRs) are crucial to regulating cancer resistance to apoptosis. In cancer cells, exomiRs orchestrate communication channels between them and their surrounding microenvironment, modulating gene expression and controlling apoptosis signaling pathways. This review presents an outline of present-day knowledge of the mechanisms that affect target cells and drive cancer resistance to apoptosis. Also, our study looks at the regulatory role of exomiRs in mediating intercellular communication between tumor cells and surrounding microenvironmental cells, specifically stromal and immune cells, to evade therapy-induced apoptosis.

Antitumor activity of bengamide ii in a panel of human and murine tumor cell lines: In vitro and in vivo determination of effectiveness against lung cancer

Lung cancer is the most commonly diagnosed cancer and the one that causes the most deaths worldwide, so there is a need for therapies that improve survival rates. Products derived from marine organisms are a source of novel and potent antitumor compounds, but they present the great obstacle of their obtaining from the natural environment and the problems associated with the synthesis and biological effects of chemical analogues. In this work, a Bengamide analogue (Bengamide II) was chemically synthesized and in vitro and in vivo studies were performed to determine its antitumor activity and mechanisms of action. It was shown to have potent antiproliferative activity in lung cancer lines in 2D and 3D models. In addition, Bengamide II-treated cells showed G2/M and G0/G1 cell cycle arrest, together with a decrease in the proliferation marker Ki67. As for the mechanism of action, the treatment was associated with increased LC3-II expression and production of acidic vesicles signaling autophagy. In addition, Bengamide II treatment was associated with caspase-3 activation and DNA fragmentation related to apoptosis. Furthermore, a reduction of VEGFA expression, related to angiogenesis, was also observed. In vivo studies showed that Bengamide II markedly reduced tumor volume and metastases increasing survival. Additionally, it revealed no systemic toxicity in in vivo models at the therapeutic doses used, which is essential for its future clinical use. Taken together, the chemically synthesized bengamide analogue Bengamide II, is a promising drug for lung cancer treatment showing relevant antitumor activity and significant safety.

Hairpin/DNA Ring Ternary Complex Initiated Rolling Circle Amplification for an Elevated Accuracy and Its Application in Analyzing Let-7a

Rolling circle amplification (RCA) is an attractive isothermal nucleic acid amplification approach and has been widely applied in constructing a variety of biosensors. However, the inevitable drawbacks of lacking enough selectivity greatly hindered further applications of RCA-based approaches. Here, we develop a novel RCA-based approach by integrating the specific target recognition capability of the hairpin/DNA ring ternary complex and multiple signal amplification and successfully applied it for let-7a detection. In this method, let-7a specifically unfolds the hairpin probe (Hp probe) in the ternary complex to induce target recycle and RCA- and DNAzyme-based signal generation. Based on this, the established approach exhibits a high selectivity to let-7a, and the response of the approach to one base pair mismatched sequences was 24.9%, indicating a significantly improved specificity. Meanwhile, the limit of detection is as low as 342 aM, which can meet the high requirement for a trace amount of miRNA detection. In all, we believe that the established approach can offer a new avenue for miRNA detection and post-tumor care.

Biological, pathological, and multifaceted therapeutic functions of exosomes to target cancer

Exosomes, small tiny vesicle contains a large number of intracellular particles that employ to cause various diseases and prevent several pathological events as well in the human body. It is considered a "double-edged sword", and depending on its biological source, the action of exosomes varies under physiological conditions. Also, the isolation and characterization of the exosomes should be performed accurately and the methodology also will vary depending on the exosome source. Moreover, the uptake of exosomes from the recipients' cells is a vital and initial step for all the physiological actions. There are different mechanisms present in the exosomes' cellular uptake to deliver their cargo to acceptor cells. Once the exosomal uptake takes place, it releases the intracellular particles that leads to activate the physiological response. Even though exosomes have lavish functions, there are some challenges associated with every step of their preparation to bring potential therapeutic efficacy. So, overcoming the pitfalls would give a desired quantity of exosomes with high purity.

Comparative analyses of salivary exosomal miRNAs for patients with or without lung cancer

Introduction: Lung cancer is the most frequent cause of cancer-related deaths worldwide. Exosomes are involved in different types of cancer, including lung cancer. Methods: We collected saliva from patients with (LC) or without (NC) lung cancer and successfully isolated salivary exosomes by ultracentrifugation. MiRNA sequencing was implemented for the exosome samples from NC and LC groups, dgeR was used to determine differentially expressed miRNAs (DE miRNAs), and quantitative real-time polymerase chain reaction (qPCR) was used to verify three differentially expressed microRNAs (miRNAs). Results: A total of 372 miRNAs were identified based on the sequencing results. Subsequently, 15 DE miRNAs were identified in LC vs. NC, including eight upregulated miRNAs and seven downregulated miRNAs. Some DE miRNAs were validated via qPCR. A total of 488 putative target genes of the upregulated DE miRNAs were found, and the functional analyses indicated that numerous target genes were enriched in the pathways associated with cancer. Discussion: This suggests that miRNAs of salivary exosomes might have the potential to be used as biomarkers for prediction and diagnosis of lung cancer.

Host and Pathogen-Directed Therapies against Microbial Infections Using Exosome- and Antimicrobial Peptide-derived Stem Cells with a Special look at Pulmonary Infections and Sepsis

Microbial diseases are a great threat to global health and cause considerable mortality and extensive economic losses each year. The medications for treating this group of diseases (antibiotics, antiviral, antifungal drugs, etc.) directly attack the pathogenic agents by recognizing the target molecules. However, it is necessary to note that excessive use of any of these drugs can lead to an increase in microbial resistance and infectious diseases. New therapeutic methods have been studied recently using emerging drugs such as mesenchymal stem cell-derived exosomes (MSC-Exos) and antimicrobial peptides (AMPs), which act based on two completely different strategies against pathogens including Host-Directed Therapy (HDT) and Pathogen-Directed Therapy (PDT), respectively. In the PDT approach, AMPs interact directly with pathogens to interrupt their intrusion, survival, and proliferation. These drugs interact directly with the cell membrane or intracellular components of pathogens and cause the death of pathogens or inhibit their replication. The mechanism of action of MSC-Exos in HDT is based on immunomodulation and regulation, promotion of tissue regeneration, and reduced host toxicity. This review studies the potential of mesenchymal stem cell-derived exosomes/ATPs therapeutic properties against microbial infectious diseases especially pulmonary infections and sepsis.

Plasma exosomal miR-1290 and miR-29c-3p as diagnostic biomarkers for lung cancer

Background

Enhancing the diagnostic efficacy of early-stage lung cancer is crucial for improving prognosis. The objective of this study was to ascertain dependable exosomal miRNAs as biomarkers for the diagnosis of lung cancer.

Methods

Exosomal miRNA candidates were identified through miRNA sequencing and subsequently validated in various case-control sets using real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR). The correlation between the expression of exosomal miRNAs and the clinicopathological features of lung cancer was investigated. To assess the diagnostic efficacy of exosomal miRNAs for lung cancer, the receiver operating characteristic (ROC) curve analysis was conducted. The optimal cutoff value of exosomal miRNAs was determined in the testing cohort and subsequently confirmed in the validation cohort.

Results

The results showed that the expression of exosomal miR-1290 was significantly elevated, while that of miR-29c-3p was significantly decreased in the plasma of lung cancer patients, especially in those with early-stage lung cancer, compared to individuals with benign lung conditions (P < 0.01). Exosomal miR-1290 and miR-29c-3p demonstrated superior diagnostic efficacy compared to conventional tumor biomarkers in distinguishing between lung cancer and benign lung diseases, as evidenced by their respective area under the curve (AUC) values of 0.934 and 0.868. Furthermore, exosomal miR-1290 and miR-29c-3p exhibited higher diagnostic efficiency in early-stage lung cancer than traditional tumor markers, with AUC values of 0.947 and 0.895, respectively. Notably, both exosomal miR-1290 and miR-29c-3p displayed substantial discriminatory capacity in distinguishing between non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), as indicated by their respective AUC values of 0.810 and 0.842.

Conclusions

The findings of this study provided evidence that exosomal miR-1290 and miR-29c-3p hold significant potential as biomarkers for the early detection of lung cancer, as well as for differentiating between NSCLC and SCLC.

Exosome nanovesicles as potential biomarkers and immune checkpoint signaling modulators in lung cancer microenvironment: recent advances and emerging concepts

Lung cancer remains the leading cause of cancer-related deaths globally, and the survival rate remains low despite advances in diagnosis and treatment. The progression of lung cancer is a multifaceted and dynamic phenomenon that encompasses interplays among cancerous cells and their microenvironment, which incorporates immune cells. Exosomes, which are small membrane-bound vesicles, are released by numerous cell types in normal and stressful situations to allow communication between cells. Tumor-derived exosomes (TEXs) possess diverse neo-antigens and cargoes such as proteins, RNA, and DNA and have a unique molecular makeup reflecting tumor genetic complexity. TEXs contain both immunosuppressive and immunostimulatory factors and may play a role in immunomodulation by influencing innate and adaptive immune components. Moreover, they transmit signals that contribute to the progression of lung cancer by promoting metastasis, epithelial-mesenchymal transition (EMT), angiogenesis, and immunosuppression. This makes them a valuable resource for investigating the immune environment of tumors, which could pave the way for the development of non-invasive biomarkers that could aid in the prognosis, diagnosis, and immunotherapy of lung cancer. While immune checkpoint inhibitor (ICI) immunotherapy has shown promising results in treating initial-stage cancers, most patients eventually develop adaptive resistance over time. Emerging evidence demonstrates that TEXs could serve as a prognostic biomarker for immunotherapeutic response and have a significant impact on both systemic immune suppression and tumor advancement. Therefore, understanding TEXs and their role in lung cancer tumorigenesis and their response to immunotherapies is an exciting research area and needs further investigation. This review highlights the role of TEXs as key contributors to the advancement of lung cancer and their clinical significance in lung immune-oncology, including their possible use as biomarkers for monitoring disease progression and prognosis, as well as emerging shreds of evidence regarding the possibility of using exosomes as targets to improve lung cancer therapy.

Differential Expression Profiles of Plasma Exosomal microRNAs in Rheumatoid Arthritis

Aim

Differential expression maps of microRNAs (miRNAs) are connected to the autoimmune diseases. This study sought to elucidate the expression maps of exosomal miRNA in plasma of rheumatoid arthritis (RA) patients and their potential clinical significance.

Methods

In the screening phase, small RNA sequencing was performed to characterize dysregulated exosome-derived miRNAs in the plasma samples from six patients with RA and six healthy patients. At the independent verification stage, the candidate plasma exosomal miRNAs were verified in 40 patients with RA and 32 healthy patients by using qRT-PCR. The correlation of miRNA levels and clinical characteristics was tested in patients with RA. The value of these miRNAs in diagnosing RA was assessed with the receiver operating characteristic curve.

Results

During the screening phase, 177 and 129 miRNAs were increased and decreased in RA patients and healthy controls, respectively. There were 10 candidate plasma exosomal miRNAs selected for the next identification. Compared with the healthy controls, eight plasma exosomal miRNAs (let-7a-5p, let-7b-5p, let-7d-5p, let-7f-5p, let-7g-5p, let-7i-5p, miR-128-3p, and miR-25-3p) were significantly elevated in RA patients, but miR-144-3p and miR-15a-5p expression exhibited no significant changes. The let-7a-5p and miR-25-3p levels were linked to the rheumatoid factor-positive phenotype in RA patients. For the eight miRNAs, the area under the subject work characteristic curve (AUC) is 0.641 to 0.843, and their combination had a high diagnostic accuracy for RA (AUC = 0.916).

Conclusion

Our study illustrates that novel exosomal miRNAs in the plasma may represent potential noninvasive biomarkers for RA.

Potential targets of natural medicines: preventing lung cancer pre-metastatic niche formation by regulating exosomes

Lung cancer is one of the most devastating diseases worldwide with high incidence and mortality, and the incidence continues to rise. Metastasis is the leading cause of death in lung cancer patients, yet the molecular effectors underlying tumor dissemination remain poorly defined. Research findings in recent years confirmed primed microenvironment of future metastatic sites, called the pre-metastatic niche, is a prerequisite for overt metastasis. Exosomes have recently emerged as important players in pre-metastatic niche formation. Natural medicines have traditionally been rich sources of drug discovery. Some of them exhibit favorable anti-lung cancer activity. The review focused on the latest advances in the regulation of the pre-metastatic niche formation in lung cancer by the contents of exosomes of representative natural medicines. Additionally, the mechanism of natural medicines was summarized in detail, which would provide new insights for anti-cancer new drug development.

Human umbilical cord mesenchymal stromal cell small extracellular vesicle transfer of microRNA-223-3p to lung epithelial cells attenuates inflammation in acute lung injury in mice

BACKGROUND

Acute lung injury (ALI), manifested as strong pulmonary inflammation and alveolar epithelial damage, is a life-threatening disease with high morbidity and mortality. Small extracellular vesicles (sEVs), secreted by multiple types of cells, are critical cellular communication mediators and can inhibit inflammation by transferring bioactive molecules, such as microRNAs (miRNAs). Thus, we hypothesized that sEVs derived from mesenchymal stromal cells (MSC sEVs) could transfer miRNAs to attenuate inflammation of lung epithelial cells during ALI.

METHODS

C57BL/6 male mice were intratracheally administered LPS (10 mg/kg). Six hours later, the mice were randomly administered with MSC sEVs (40 µg per mouse in 150 µl of saline), which were collected by ultracentrifugation. Control group received saline administration. After 48 h, the mice were sacrificed to evaluate pulmonary microvascular permeability and inflammatory responses. In vitro, A549 cells and primary human small airway epithelial cells (SAECs) were stimulated with LPS with or without MSC sEVs treatment.

RESULTS

In vitro, MSC sEVs could also inhibit the inflammation induced by LPS in A549 cells and SAECs (reducing TNF-α, IL-1β, IL-6 and MCP-1). Moreover, MSC sEV treatment improved the survival rate, alleviated pulmonary microvascular permeability, and inhibited proinflammatory responses (reducing TNF-α, IL-1β, IL-6 and JE-1) in ALI mice. Notably, miR-223-3p was found to be served as a critical mediator in MSC sEV-induced regulatory effects through inhibition of poly (adenosine diphosphate-ribose) polymerase-1 (PARP-1) in lung epithelial cells.

CONCLUSIONS

Overall, these findings suggest that MSC sEVs may offer a novel promising strategy for ALI.

MiR-22-3p suppresses NSCLC cell migration and EMT via targeting RAC1 expression

Previous studies have demonstrated the tumor-suppressive function of microRNA-22-3p (miR-22-3p) in several cancers, whereas the significance of miR-22-3p in non-small cell lung cancer (NSCLC) remains unclear. In this study, we explored the biological function and molecular mechanism of miR-22-3p in NSCLC cells. First, we assessed the expression of miR-22-3p in NSCLC tissues and cells based on RT-qPCR and TCGA database. Compared with normal lung tissues and cells, miR-22-3p expression was dramatically decreased in lung cancer tissues and cells. miR-22-3p expression was also correlated with lymph node metastasis and tumor size, but not TNM stages. We further explored the in vitro function of miR-22-3p on the migration and epithelial-mesenchymal transition (EMT) of NSCLC cells. The results showed that overexpression of miR-22-3p suppressed the migration and EMT of NSCLC cells, whereas silencing miR-22-3p showed the opposite effect. Luciferase assay demonstrated that RAS-related C3 botulinum toxin substrate 1 (RAC1) was the target gene for miR-22-3p. Mechanistically, we demonstrated that miR-22-3p suppressed the cell migration and EMT via downregulation of RAC1 because the inhibitory effect of miR-22-3p on cell migration and EMT of NSCLC cells was reversed by RAC1 overexpression. Based on these novel data, the miR-22-3p/RAC1 axis may be an alternative target in the therapeutic intervention of NSCLC.

Circulating exosomal microRNA-4497 as a potential biomarker for metastasis and prognosis in non-small-cell lung cancer

Circulating exosomal microRNAs (miRNAs) have shown great potential for the diagnosis, prognosis, and treatment monitoring of patients with non-small-cell lung cancer (NSCLC). Our main purpose was to determine the clinical value of serum exosomal miR-4497 as a new non-invasive biomarker for NSCLC. The exoRNeasy Kit (QIAGEN, Hilden, Germany) was used to isolate exosomes and exoRNA from the serum of 84 patients with NSCLC (NSCLC group), 30 patients with benign lung lesion (BLL group), and 47 healthy controls. Six serum exosomal miRNAs (Let-7b-5p, miR-122-5p, miR-155-5p, miR-223-3p, miR-320c, and miR-4497) were selected as candidate miRNAs and analyzed using real-time qPCR, among which miR-4497 displayed the most striking differences. Exosomal miR-4497 expressed significantly lower in NSCLC than in BLL patients and healthy controls (P < 0.001). Further investigation showed that miR-4497 was negatively correlated with the malignant characteristics of tumors (tumor size, tumor-node-metastasis [TNM] stage, and distant metastasis) and was an independent tumor suppressor (P < 0.05). According to receiver operating characteristic (ROC) analysis, exosomal miR-4497 independently exhibited excellent diagnostic efficacy, which could be improved by combining it with traditional markers (for identifying tumor size, the area under the curve [AUC] = 0.761; TNM stage, AUC = 0.878; distant metastasis, AUC = 0.895; all P < 0.001). Moreover, longitudinal analysis revealed that exosomal miR-4497 levels increased after chemoradiotherapy (P < 0.001). According to the survival analysis, poor overall survival (OS) and disease-free survival (DFS) were associated with low exosomal miR-4497 levels (P < 0.05). Moreover, exosomal miR-4497 was an independent protective factor affecting DFS (hazard ratio = 0.190, P = 0.009) in the Cox proportional hazards model. Therefore, serum exosomal miR-4497 can be used as a potential biomarker to identify NSCLC and healthy individuals or BLL patients for early screening or as a biomarker for staging and grading, prognosis, and monitoring recurrence, metastasis, and the therapeutic effects in patients with NSCLC.

Impact of exosome therapy on pancreatic cancer and its progression

Pancreatic cancer, one of the most aggressive tumors, has a dismal prognosis because of the low rates of early identification, fast progression, difficulties following surgery, and the ineffectiveness of current oncologic therapies. There are no imaging techniques or biomarkers that can accurately identify, categorize, or predict the biological behavior of this tumor. Exosomes are extracellular vesicles that play a crucial rule in the progression, metastasis, and chemoresistance of pancreatic cancer. They have been verified to be potential biomarkers for pancreatic cancer management. Studying the role of exosomes in pancreatic cancer is substantial. Exosomes are secreted by most eukaryotic cells and participated in intercellular communication. The components of exosomes, including proteins, DNA, mRNA, microRNA, long non-coding RNA, circular RNA, etc., play a crucial role in regulating tumor growth, metastasis, and angiogenesis in the process of cancer development, and can be used as a prognostic marker and/or grading basis for tumor patients. Hereby, in this concise review, we intend to summarize exosomes components and isolation, exosome secretion, function, importance of exosomes in the progression of pancreatic cancer and exosomal miRNAs as possible pancreatic cancer biomarkers. Finally, the application potential of exosomes in the treatment of pancreatic cancer, which provides theoretical supports for using exosomes to serve precise tumor treatment in the clinic, will be discussed.

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.

Identification of hsa-miR-619-5p and hsa-miR-4454 in plasma-derived exosomes as a potential biomarker for lung adenocarcinoma

Introduction: Lung cancer has long been at the forefront of all cancers in terms of incidence and mortality. Lung adenocarcinoma is the most common type of lung cancer, accounting for 40% of all lung cancer types. Exosomes can act as biomarkers of tumors and thus play an important role. Methods: In this article, high-throughput sequencing of miRNAs in plasma exosomes from lung adenocarcinoma patients and healthy individuals was performed to obtain 87 upregulated miRNAs, which were then combined with data from the GSE137140 database uploaded by others for screening. The database included 1566 preoperative lung cancer patients, 180 postoperative patients, and 1774 non-cancerous controls. We overlapped the miRNAs upregulated in the serum of lung cancer patients in the database relative to those of non-cancer controls and post-operative patients with the upregulated miRNAs obtained from our next-generation sequencing to obtain nine miRNAs. Two miRNAs that were not reported as tumor markers in lung cancer, hsa-miR-4454 and hsa-miR-619-5p, were selected from them and then validated by qRT-PCR, and further analysis of miRNAs was performed using bioinformatics. Results: Real-time quantitative PCR showed that the expression levels of hsa-miR-4454 and hsa-miR-619-5p in plasma exosomes of patients with lung adenocarcinoma were significantly up-regulated. The AUC values of hsa-miR-619-5p and hsa-miR-4454 were 0.906 and 0.975, respectively, both greater than 0.5, showing good performance. The target genes of miRNAs were screened by bioinformatics methods, and the regulatory network between miRNAs and lncRNAs and mRNAs was studied. Discussion: Our work demonstrated that hsa-miR-4454 and hsa-miR-619-5p have the potential to be used as biomarkers for the early diagnosis of lung adenocarcinoma.

Advances of exosomal miRNAs in the diagnosis and treatment of ovarian cancer

Ovarian cancer is a tumor with the highest fatalities among female malignant tumors. This disease has no typical symptoms in its early stage, and most of the patients are in an advanced stage when being treated. The treatment effect is poor and it is easy to develop chemotherapy resistance. Therefore, it is particularly urgent to clarify the pathogenesis of ovarian cancer, explore its early diagnosis of biomarkers, and discover new treatment methods. As a carrier of intercellular information and genetic material transfer, exosomes are widely distributed in body fluids (e.g. blood and urine), which are regarded as latent tumor markers and take effects on tumor occurrence and invasion. Several articles have recently signified that exosomal miRNAs are widely implicated in the formation of the ovarian cancer tumor microenvironment, disease initiation and progression, and the generation of chemotherapy resistance. This article reviews the research on exosomal miRNAs in ovarian cancer.

Bone mesenchymal stromal cell-derived small extracellular vesicles inhibit inflammation and ameliorate sepsis via delivery of microRNA-21a-5p

BACKGROUND AIMS

Sepsis is a potentially life-threatening disease that results from a severe systemic inflammatory response due to infection. Mesenchymal stromal cell-derived small extracellular vesicles (MSC sEVs) are able to transfer bioactive molecules and have been demonstrated to play an important role in the pathophysiological process of sepsis. Herein the authors aimed to investigate the potential role and downstream molecular mechanism of MSC sEVs in sepsis.

METHODS

MSC sEVs were acquired by ultracentrifugation and then injected into a cecal ligation and puncture mouse model. The efficacy of MSC sEVs in both in vitro and in vivo models of sepsis was evaluated.

RESULTS

MSC sEV therapy improved survival, reduced sepsis-induced inflammation, attenuated pulmonary capillary permeability and improved liver and kidney function in septic mice. In addition, the authors found that microRNA-21a-5p (miR-21a-5p) was highly enriched in MSC sEVs, could be transferred to recipient cells, inhibited inflammation and increased survival in septic mice. Furthermore, the authors demonstrated that MSC sEV miR-21a-5p suppressed inflammation by targeting toll-like receptor 4 and programmed cell death 4. The therapeutic efficacy of MSC sEVs was partially abrogated by transfection with miR-21a-5p inhibitors.

CONCLUSIONS

Collectively, the authors' data suggest that miR-21a-5p-bearing MSC sEVs may be a prospective and effective sepsis therapeutic strategy.

Cerebrospinal fluid exosomal microRNAs as biomarkers for diagnosing or monitoring the progression of non-small cell lung cancer with leptomeningeal metastases

Non-small-cell lung cancer (NSCLC) has a terrible consequence called leptomeningeal metastases (LM). It is crucial to look for novel biomarkers because none of the known biomarkers could effectively reflect the oncogenesis, progression and therapeutic responses of LM. Exosomal miRNAs from plasma have a critical function in lung cancer, according to growing data. However, unique biomarkers of cerebrospinal fluid (CSF) are more representative for patients with LM, which have not been reported. Here, we explore the possibility of using CSF-derived exosomal microRNAs as potential biomarkers for NSCLC-LM. Nine NSCLC-LM patients who received regular intrathecal chemotherapy with permetexed were divided into a partial response (PR) group and a progressive disease (PD) group. CSF samples were taken from all patients before and after intrathecal treatment and five non-cancerous controls. Using the size exclusion chromatography (SEC) method, the exosome microRNAs were isolated and profiled. Between LM patients and controls, 56 differentially expressed genes (DEGs) were found, of which three highly elevated diagnostic biomarkers (hsa-miR-183-5p, hsa-miR-96-5p and hsa-miR-182-5p) were ruled out. The two most significant DEGs between the untreated PR group and the PD group were determined to be upregulated hsa-miR-509-3p and downregulated hsa-miR-449a, and they may serve as potential indicators of intrathecal anti-pemetrexed treatment. Hsa-miR-1-3p increased gradually with the intrathecal chemotherapy in the PR group, which might offer a new approach to screen optimal patients and estimate the efficacy. This study revealed specific CSF exosomal miRNAs profile and dynamic changes of patients with NSCLC-LM for the first time and identified several potential exosomal miRNA biomarkers in diagnosis, drug resistance and prognosis.

Exosomal miR-133a-3p promotes the growth and metastasis of lung cancer cells following incomplete microwave ablation

PURPOSE

Exosomal miRNAs play key roles in various biological processes such as cell proliferation, angiogenesis, migration and invasion. We explored whether exosomal miRNAs can promote local recurrence (LR) of lung tumors following incomplete microwave ablation (MWA) therapy.

METHODS

Exosomal miRNA profiles before and after incomplete MWA in lung cancer (LC) patients with LR (n = 3) were sequenced and compared. The differentially expressed miRNAs of interest were validated in clinical samples (n = 10) and MWA-treated cells using RT-qPCR analysis. Target genes of the miRNAs were predicted and validated. The biological functions of miRNAs in proliferation, angiogenesis and metastasis of A549 cells were evaluated in vitro and in vivo.

RESULTS

A total of 270 miRNAs (243 upregulated and 27 downregulated) were differentially expressed after incomplete MWA in patients with local recurrence. Upregulation of miR-133a-3p after MWA was validated in the cells and clinical samples. Cell functional experiments suggested that miR-133a-3p overexpression derived from serum exosomes increased cell viability, migration and invasion ability, tube formation activity and proliferation of A549 cells. Sirtuin 1 (SIRT1) was identified as a target gene for miR-133a-3p. Moreover, miR-133a-3p delivered by exosomes significantly promoted tumor growth, paralleled by reduced SIRT1 expression in a subcutaneous tumorigenesis animal model and increased the number of lung nodules by tail vein metastasis in vivo.

CONCLUSION

Exosomal miR-133a-3p overexpression promoted tumor growth and metastasis following MWA and could be a promising biomarker for LC recurrence after incomplete MWA.

MicroRNAs Improve Cancer Treatment Outcomes Through Personalized Medicine

MicroRNAs (miRNAs) are short non-coding RNAs that repress or degrade mRNA targets to downregulate genes. In cancer occurrence, the expression of miRNAs is altered. Depending on the involvement of a certain miRNA in the pathogenetic growth of a tumor, It may be up or downregulated. The "oncogenic" action of miRNAs corresponds with upregulation, which leads to tumor proliferation and spread meanwhile the miRNAs that have been downregulated bring tumorsuppressive outcomes. Oncogenes and tumor suppressor genes are among the genes whose expression is under their control, demonstrating that classifying them solely as oncogenes or tumor suppressor genes alone is not only hindering but also incorrect. Apart from basic tumors, miRNAs may be found in nearly all human fluids and can be used for cancer diagnosis as well as clinical outcome prognostics and better response to treatment strategies. The overall variance of these tiny noncoding RNAs influences patient-specific pharmacokinetics and pharmacodynamics of anti-cancer medicines, driving a growing demand for personalized medicine. By now, microRNAs from tumor biopsies or blood are being widely investigated as substantial biomarkers for cancer in time diagnosis, prognosis, and, progression. With the rise of COVID-19, this paper also attempts to study recent research on miRNAs involved with deaths in lung cancer COVID patients. With the discovery of single nucleotide polymorphisms, personalized treatment via microRNAs has lately become a reality. The present review article describes the highlights of recent knowledge of miRNAs in various cancers, with a focus on miRNA translational applications as innovative potential diagnostic and prognostic indicators that expand person-to-person therapy options.

The landscape of exosomal non-coding RNAs in breast cancer drug resistance, focusing on underlying molecular mechanisms

Breast cancer (BC) is the most common malignancy among women worldwide. Like many other cancers, BC therapy is challenging and sometimes frustrating. In spite of the various therapeutic modalities applied to treat the cancer, drug resistance, also known as, chemoresistance, is very common in almost all BCs. Undesirably, a breast tumor might be resistant to different curative approaches (e.g., chemo- and immunotherapy) at the same period of time. Exosomes, as double membrane-bound extracellular vesicles 1) secreted from different cell species, can considerably transfer cell products and components through the bloodstream. In this context, non-coding RNAs (ncRNAs), including miRNAs, long ncRNAs (lncRNAs), and circular RNAs (circRNAs), are a chief group of exosomal constituents with amazing abilities to regulate the underlying pathogenic mechanisms of BC, such as cell proliferation, angiogenesis, invasion, metastasis, migration, and particularly drug resistance. Thereby, exosomal ncRNAs can be considered potential mediators of BC progression and drug resistance. Moreover, as the corresponding exosomal ncRNAs circulate in the bloodstream and are found in different body fluids, they can serve as foremost prognostic/diagnostic biomarkers. The current study aims to comprehensively review the most recent findings on BC-related molecular mechanisms and signaling pathways affected by exosomal miRNAs, lncRNAs, and circRNAs, with a focus on drug resistance. Also, the potential of the same exosomal ncRNAs in the diagnosis and prognosis of BC will be discussed in detail.

Exosomes in sarcoma: Prospects for clinical applications

Sarcoma is a group of rare and heterogeneous mesenchymal tumors, prone to late diagnosis and poor prognosis. Exosomes are cell-derived small extracellular vesicles found in most body fluids and contain nucleic acids, proteins, lipids, and other molecules. Qualitative and quantitative changes of exosomes and the contents are associated with sarcoma progression, exhibiting their potential as biomarkers. Exosomes possess the capacity of evading immune responses, bioactivity for trafficking, tumor tropism, and lesion residence. Thus, exosomes could be engineered as tumor-specific vehicles in drugs and RNA delivery systems. Exosomes might also serve as therapeutic targets in targeted therapy and immunotherapy and be involved in chemotherapy resistance. Here, we provide a comprehensive summary of exosome applications in liquid biopsy-based diagnosis and explore their implications in the delivery system, targeted therapy, and chemotherapy resistance of sarcoma. Moreover, challenges in exosome clinical applications are raised and some future research directions are proposed.

The Implication of Liquid Biopsy in the Non-small Cell Lung Cancer: Potential and Expectation

Nowadays, lung cancer has remained the most lethal cancer, despite great advances in diagnosis and treatment. However, a large proportion of patients were diagnosed with locally advanced or metastatic disease and have poor prognosis. Immunotherapy and targeted drugs have greatly improved the survival and prognosis of patients with advanced lung cancer. However, how to identify the optimal patients to accept those therapies and how to monitor therapeutic efficacy are still in dispute. In the past few decades, tissue biopsy, including percutaneous fine needle biopsy and surgical excision, has still been the gold standard for examining the gene mutation such as EGFR, ALK, ROS, and PD-1/PD/L1, which can indicate the follow-up treatment. Nevertheless, the biopsy techniques mentioned above were invasive and unrepeatable, which were not suitable for advanced patients. Liquid biopsy, accounting for heterogeneity compared with tissue biopsy, is an alternative technique for monitoring the mutation, and a large quantity of research has demonstrated its feasibility to detect the circulating tumor cell, cell-free DNA, circulating tumor DNA, and extracellular vesicles from peripheral venous blood. The proposal of the concept of precision medicine brings a novel medical model developed with the rapid progress of genome sequencing technology and the cross-application of bioinformation, which was based on personalized medicine. The emerging method of liquid biopsy might contribute to promoting the development of precision medicine. In this review, we intend to describe the liquid biopsy in non-small cell lung cancer in detail in the aspect of screening, diagnosis, monitoring, treatment, and drug resistance.

Drug Resistance: The Role of Exosomal miRNA in the Microenvironment of Hematopoietic Tumors

Extracellular vesicles (EVs), including exosomes, have an important role thanks to their ability to communicate and exchange information between tumor cells and the tumor microenvironment (TME), and have also been associated with communicating anti-cancer drug resistance (DR). The increase in proliferation of cancer cells alters oxygen levels, which causes hypoxia and results in a release of exosomes by the cancer cells. In this review, the results of studies examining the role of exosomal miRNA in DR, and their mechanism, are discussed in detail in hematological tumors: leukemia, lymphoma, and multiple myeloma. In conclusion, we underline the exosome's function as a possible drug delivery vehicle by understanding its cargo. Engineered exosomes can be used to be more specific for personalized therapy.

Updated review of advances in microRNAs and complex diseases: experimental results, databases, webservers and data fusion

MicroRNAs (miRNAs) are gene regulators involved in the pathogenesis of complex diseases such as cancers, and thus serve as potential diagnostic markers and therapeutic targets. The prerequisite for designing effective miRNA therapies is accurate discovery of miRNA-disease associations (MDAs), which has attracted substantial research interests during the last 15 years, as reflected by more than 55 000 related entries available on PubMed. Abundant experimental data gathered from the wealth of literature could effectively support the development of computational models for predicting novel associations. In 2017, Chen et al. published the first-ever comprehensive review on MDA prediction, presenting various relevant databases, 20 representative computational models, and suggestions for building more powerful ones. In the current review, as the continuation of the previous study, we revisit miRNA biogenesis, detection techniques and functions; summarize recent experimental findings related to common miRNA-associated diseases; introduce recent updates of miRNA-relevant databases and novel database releases since 2017, present mainstream webservers and new webserver releases since 2017 and finally elaborate on how fusion of diverse data sources has contributed to accurate MDA prediction.

Microbiome dysbiosis and epigenetic modulations in lung cancer: From pathogenesis to therapy

The lung microbiome plays an essential role in maintaining healthy lung function, including host immune homeostasis. Lung microbial dysbiosis or disruption of the gut-lung axis can contribute to lung carcinogenesis by causing DNA damage, inducing genomic instability, or altering the host's susceptibility to carcinogenic insults. Thus far, most studies have reported the association of microbial composition in lung cancer. Mechanistic studies describing host-microbe interactions in promoting lung carcinogenesis are limited. Considering cancer as a multifaceted disease where epigenetic dysregulation plays a critical role, epigenetic modifying potentials of microbial metabolites and toxins and their roles in lung tumorigenesis are not well studied. The current review explains microbial dysbiosis and epigenetic aberrations in lung cancer and potential therapeutic opportunities.

The emerging role of circular RNAs in drug resistance of non-small cell lung cancer

Due to the characteristics of aggressiveness and high risk of postoperative recurrence, non-small cell lung cancer (NSCLC) is a serious hazard to human health, accounting for 85% of all lung cancer cases. Drug therapies, including chemotherapy, targeted therapy and immunotherapy, are effective treatments for NSCLC in clinics. However, most patients ultimately develop drug resistance, which is also the leading cause of treatment failure in cancer. To date, the mechanisms of drug resistance have yet to be fully elucidated, thus original strategies are developed to overcome this issue. Emerging studies have illustrated that circular RNAs (circRNAs) participate in the generation of therapeutic resistance in NSCLC. CircRNAs mediate the modulations of immune cells, cytokines, autophagy, ferroptosis and metabolism in the tumor microenvironment (TME), which play essential roles in the generation of drug resistance of NSCLC. More importantly, circRNAs function as miRNAs sponges to affect specific signaling pathways, directly leading to the generation of drug resistance. Consequently, this review highlights the mechanisms underlying the relationship between circRNAs and drug resistance in NSCLC. Additionally, several therapeutic drugs associated with circRNAs are summarized, aiming to provide references for circRNAs serving as potential therapeutic targets in overcoming drug resistance in NSCLC.

miR-137 represses migration and cell motility by targeting COX-2 in non-small cell lung cancer

BACKGROUND

Lung cancer is a common malignant tumor, with, non-small cell lung cancer (NSCLC) accounting for about 80-85% of cases. This study investigated the expression of miR-137 in NSCLC tissues and cells and its effects on the migration and invasion of NSCLC cells and related mechanisms.

METHODS

We collected the neoplastic and paracancerous tissues of NSCLC patients, detected the expression of miR-137 in NSCLC tissues and cell lines by real-time quantitative polymerase chain reaction (RT-qPCR), and analyzed the correlation between miR-137 expression and the clinicopathological features and survival of NSCLC. Following transfection with miR-137 mimic or inhibitor in NSCLC cell lines (A549 or H1299) to upregulate or downregulate the expression of miR-137, transwell assay was employed to detect the effects of miR-137 on migration or invasion. Online software was employed to predict and analyze the target gene of miR-137, and luciferase reporter gene system was adopted to validate it. The effects of miR-137 on the expressions of COX-2 and Epithelial-Mesenchymal Transition (EMT) related proteins were investigated by Western blot.

RESULTS

Compared to paracancerous tissues and BEAS-2B cells, the expressions of miR-137 in NSCLC tissues, A549 and H1299 cells were dramatically down-regulated (P<0.01). After transfection with miR-137 mimic or inhibitor in A549 and H1299 cells, the miR-137 expressions were markedly up-regulated or down-regulated (P<0.01), respectively. The number of migrating or invading cells was observably decreased or increased (P<0.01) after transfected with mimic or inhibitor, respectively, while relative luciferase activity was evidently decreased in cells co-transfected with miR-137 mimic and wild type recombined vector of 3'UTR of COX-2. While the expressions of COX-2 and E-cadherin were both substantially reduced in A549 cells treated with miR-137 mimic, that of vimentin was substantially raised. The expression of miR-137 correlated with smoking history, lymph node metastasis, and TNM clinical stage, and patients with high miR-137 expression had apparent longer survival.

CONCLUSIONS

The expression of miR-137 was significantly down-regulated in NSCLC tissues and cells, and correlated with NSCLC progress. miR-137 suppressed the migration and invasion of NSCLC cells through regulating EMT relative proteins by targeting COX-2. miR-137 is expected to become a novel biomarker and therapeutic target of NSCLC.

All-trans retinoic acid-mediated miR-30a up-regulation suppresses autophagy and sensitizes gastric cancer cells to cisplatin

AIMS

The potential of all-trans retinoic acid (ATRA) in regulating some microRNAs (miRNAs) involved in multiple cancer-related pathways, including resistance to chemotherapeutics, may be a valuable idea for overcoming the CDDP resistance of GC cells.

MAIN METHODS

Treatment of gastric AGS and MKN-45 cells with CDDP enriched the CDDP surviving cells (CDDP-SCs). The abilities of chemoresistance to CDDP drug, migration, either apoptosis or cell cycle distribution, spheroid body formation and changes at miRNA and protein levels were evaluated in vitro by MTT assay, colony formation assay, flow cytometry, tumor spheres culture, qRT-PCR and western blot assay in CDDP-SCs and ATRA-treated CDDP-SCs cells, respectively.

KEY FINDINGS

CDDP-based chemotherapy significantly reduced microRNA-30a (miR-30a) levels in GC cells. We also observed elevated autophagy activity in cancer cells that possess stem cell-like properties with overexpressed specific stem cell markers. Our extended study suggested that the reduction of miR-30a by CDDP treatment, is the possible underlying mechanism of enhanced autophagic activity, as demonstrated by enhancing autophagy-related protein beclin 1 and LC3-II/LC-I ratio. The addition of ATRA in the culture medium of GC cells increased the expression of miR-30a, and disturbed characteristic CSC-like properties. Additional studies revealed that the increased expression of miR-30a declined the expression level of its target gene, beclin 1, and beclin 1-mediated autophagy. This leads to promoted CDDP-induced GC cell apoptosis and G2/M cell cycle arrest.

SIGNIFICANCE

Overall, miR-30a/autophagy signaling has a critical role in regulating the chemoresistance of GC cells that ATRA could modulate.

Circular RNA_0120376 regulates microRNA-148b-3 and centrosomal protein 55 to promote non-small cell lung cancer development

Circular RNAs (circRNAs) are non-coding RNAs with covalent closed-loop structures that are vital in regulating diverse pathological processes. This work is aimed to investigate the role of circ_0120376 in non-small cell lung cancer (NSCLC). Circ_0120376, microRNA (miR)-148b-3p, and centrosomal protein 55 (CEP55) mRNA expression in NSCLC tissues and cells were determined using qRT-PCR. The influences of circ_0120376 and miR-148b-3p on the proliferation of NSCLC cell lines were analyzed by CCK-8 and colony formation assays. Apoptosis was analyzed by flow cytometry. Cell migration and invasion were analyzed using the Transwell experiment. Binding relationships between circ_0120376 and miR-148b-3p and between miR-148b-3p and CEP55 3'UTR were investigated using the dual-luciferase reporter experiment and the RIP experiment. Western blot was conducted to analyze the regulatory effect of circ_0120376 and miR-148b-3p on CEP55 expression. We found that circ_0120376 was markedly overexpressed in NSCLC, and its overexpression was positively associated with increased T stage and lymph node metastasis of the patients. Functional experiments unveiled that circ_0120376 enhanced the proliferation, migration and invasion of NSCLC cells and impeded apoptosis, while knocking down circ_0120376 remarkably suppressed the malignant features of NSCLC cells mentioned above. Circ_0120376 could adsorb miR-148b-3p to reduce miR-148b-3p expression, and circ_0120376 could increase CEP55 expression via adsorbing miR-148b-3p. In summary, circ_0120376 contributes to the malignancy of NSCLC cells through a ceRNA mechanism via regulating miR-148b-3p/CEP55 axis. Circ_0120376 is likely to be a potential diagnostic biomarker and therapeutic target for NSCLC.

Exosomes derived from the blood of patients with sepsis regulate apoptosis and aerobic glycolysis in human myocardial cells via the hsa‑miR‑1262/SLC2A1 signaling pathway

Myocardial injury occurs in the majority of patients with sepsis and is associated with early mortality. MicroRNAs (miRs) transported by exosomes have been implicated in numerous diseases, such as tumors, acute myocardial infarction and cardiovascular disease. Human serum albumin (hsa)‑miR‑1262 has been shown to serve a role in sepsis; however, its role in exosomes isolated from patients with sepsis and septic myocardial injury remains unclear. In the present study, serum exosomes were isolated via ultracentrifugation. Solute carrier family 2 member 1 (SLC2A1), an essential mediator in energy metabolism, was silenced and overexpressed in the human myocardial AC16 cell line using lentiviral plasmids containing either SLC2A1‑targeting short interfering RNAs or SLC2A1 cDNA, respectively. Cell apoptosis was analyzed using flow cytometry, and the extracellular acidification rate and oxygen consumption rate of AC16 cells were determined using an XFe24 Extracellular Flux Analyzer. Furthermore, the dual‑luciferase reporter assay was used to evaluate the interaction between hsa‑miR‑1262 and SLC2A1. Finally, reverse transcription‑quantitative PCR and western blotting were used to evaluate gene and protein expression levels, respectively. Exosomes isolated from the blood of patients with sepsis (Sepsis‑exo) markedly reduced aerobic glycolysis activity, but significantly promoted the apoptosis of human AC16 cells in a time‑dependent manner. Moreover, Sepsis‑exo significantly increased hsa‑miR‑1262 expression levels, but significantly decreased SLC2A1 mRNA expression levels in a time‑dependent manner. Bioinformatics analysis indicated that hsa‑miR‑1262 bound to the 3' untranslated region of SLC2A1 to negatively regulate its expression. The silencing of SLC2A1 promoted apoptosis and suppressed glycolysis in AC16 cells, whereas SLC2A1 overexpression resulted in the opposite effects. Therefore, the present study demonstrated that exosomes derived from patients with sepsis may inhibit glycolysis and promote the apoptosis of human myocardial cells through exosomal hsa‑miR‑1262 via its target SLC2A1. These findings highlighted the importance of the hsa‑miR‑1262/SLC2A1 signaling pathway in septic myocardial injury and provided novel insights into therapeutic strategies for septic myocardial depression.

Exosomal Proteins and Lipids as Potential Biomarkers for Lung Cancer Diagnosis, Prognosis, and Treatment

Simple Summary

Exosomes (or extracellular vesicles) are known to mediate intercellular communication and to transmit molecular signals between cells. Molecules carried by exosomes have their own molecular roles in affecting surrounding and distant environment, as well as recipient cells. Molecular components of exosomes can be used as cancer biomarkers for diagnosis and prognosis, being promising therapeutic targets for the interruption of cellular signals. Therefore, the understanding of the molecular compositions and their functional indications of exosomes has the potential to help doctors to diagnose and monitor diseases and to allow researchers to design and develop potential targeted therapies. This review aims to provide a comprehensive protein and lipid characterization of lung cancer exosomes and to explore their molecular functions and mechanisms regulating physiological and pathological processes. This organization offers informative insight for lung cancer diagnosis and treatment.

Abstract

Exosomes participate in cell–cell communication by transferring molecular components between cells. Previous studies have shown that exosomal molecules derived from cancer cells and liquid biopsies can serve as biomarkers for cancer diagnosis and prognosis. The exploration of the molecules transferred by lung cancer-derived exosomes can advance the understanding of exosome-mediated signaling pathways and mechanisms. However, the molecular characterization and functional indications of exosomal proteins and lipids have not been comprehensively organized. This review thoroughly collected data concerning exosomal proteins and lipids from various lung cancer samples, including cancer cell lines and cancer patients. As potential diagnostic and prognostic biomarkers, exosomal proteins and lipids are available for clinical use in lung cancer. Potential therapeutic targets are mentioned for the future development of lung cancer therapy. Molecular functions implying their possible roles in exosome-mediated signaling are also discussed. Finally, we emphasized the importance and value of lung cancer stem cell-derived exosomes in lung cancer therapy. In summary, this review presents a comprehensive description of the protein and lipid composition and function of lung cancer-derived exosomes for lung cancer diagnosis, prognosis, and treatment.

The role of Exosomal miRNAs in cancer

Exosomal miRNAs have attracted much attention due to their critical role in regulating genes and the altered expression of miRNAs in virtually all cancers affecting humans (Sun et al. in Mol Cancer 17(1):14, 2018). Exosomal miRNAs modulate processes that interfere with cancer immunity and microenvironment, and are significantly involved in tumor growth, invasion, metastasis, angiogenesis and drug resistance. Fully investigating the detailed mechanism of miRNAs in the occurrence and development of various cancers could help not only in the treatment of cancers but also in the prevention of malignant diseases. The current review highlighted recently published advances regarding cancer-derived exosomes, e.g., sorting and delivery mechanisms for RNAs. Exosomal miRNAs that modulate cancer cell-to-cell communication, impacting tumor growth, angiogenesis, metastasis and multiple biological features, were discussed. Finally, the potential role of exosomal miRNAs as diagnostic and prognostic molecular markers was summarized, as well as their usefulness in detecting cancer resistance to therapeutic agents.

Exosomal miR-338-3p suppresses non-small-cell lung cancer cells metastasis by inhibiting CHL1 through the MAPK signaling pathway

Globally, lung cancer remains one of the most prevalent malignant cancers. However, molecular mechanisms and functions involved in its pathogenesis have not been clearly elucidated. This study aimed to evaluate the specific regulatory mechanisms of exosomal miR-338-3p/CHL1/MAPK signaling pathway axis in non-small-cell lung cancer. Western blotting and qRT-PCR (reverse transcription-polymerase chain reaction) were used to determine the expression levels of CHL1 and exosomal miR-338-3p in NSCLC (non-small-cell lung cancer). The CHL1 gene was upregulated and downregulated to evaluate its functions in NSCLC progression. In vitro MTS and apoptotic assays were used to investigate the functions of CHL1 and exosomal miR-338-3p in NSCLC progression. The high-throughput sequencing was used to explore differently expressed exosomal miRNAs. The biological relationships between MAPK signaling pathway and CHL1 and exosomal miR-338-3p in NSCLC were predicted through bioinformatics analyses and verified by western blotting. Elevated CHL1 levels were observed in NSCLC tissues and cells. Upregulated CHL1 expression enhanced NSCLC cells’ progression by promoting tumor cells proliferation while suppressing their apoptosis. Conversely, the downregulation of the CHL1 gene inhibited NSCLC cells’ growth and promoted tumor cells’ apoptotic rate. Additionally, CHL1 activated the MAPK signaling pathway. Besides, we confirmed that miR-338-3p directly sponged with CHL1 to mediate tumor cells progression. Moreover, exosomal miR-338-3p serum levels in NSCLC patients were found to be low. BEAS-2B cells can transfer exosomal miR-338-3p to A549 cells and SK-MES-1 cells. In addition, elevated exosomal miR-338-3p levels significantly inhibited tumor cells proliferation and promoted their apoptosis by suppressing activation of the MAPK signaling pathway. Exosomal miR-338-3p suppresses tumor cells' metastasis by downregulating the expression of CHL1 through MAPK signaling pathway inactivation.

Identification of cell cycle as the critical pathway modulated by exosome-derived microRNAs in gallbladder carcinoma

Gallbladder cancer (GBC), the most common malignancy in the biliary tract, is highly lethal malignant due to seldomly specific symptoms in the early stage of GBC. This study aimed to identify exosome-derived miRNAs mediated competing endogenous RNAs (ceRNA) participant in GBC tumorigenesis. A total of 159 differentially expressed miRNAs (DEMs) was identified as exosome-derived miRNAs, contains 34 upregulated exo-DEMs and 125 downregulated exo-DEMs based on the expression profiles in GBC clinical samples downloaded from the Gene Expression Omnibus database with the R package. Among them, 2 up-regulated exo-DEMs, hsa-miR-125a-3p and hsa-miR-4647, and 5 down-regulated exo-DEMs, including hsa-miR-29c-5p, hsa-miR-145a-5p, hsa-miR-192-5p, hsa-miR-194-5p, and hsa-miR-338-3p, were associated with the survival of GBC patients. Results of the gene set enrichment analysis showed that the cell cycle-related pathways were activated in GBC tumor tissues, mainly including cell cycle, M phase, and cell cycle checkpoints. Furthermore, the dysregulated ceRNA network was constructed based on the lncRNA-miRNA-mRNA interactions using miRDB, TargetScan, miRTarBase, miRcode, and starBase v2.0., consisting of 27 lncRNAs, 6 prognostic exo-DEMs, and 176 mRNAs. Together with prognostic exo-DEMs, the STEAP3-AS1/hsa-miR-192-5p/MAD2L1 axis was identified, suggesting lncRNA STEAP3-AS1, might as a sponge of exosome-derived hsa-miR-192-5p, modulates cell cycle progression via affecting MAD2L1 expression in GBC tumorigenesis. In addition, the biological functions of genes in the ceRNA network were also annotated by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. Our study promotes exploration of the molecular mechanisms associated with tumorigenesis and provide potential targets for GBC diagnosis and treatment.

Extracellular Vesicles in Lung Cancer: Prospects for Diagnostic and Therapeutic Applications

Extracellular vesicles (EVs) are nano-sized lipid-bound particles containing proteins, nucleic acids and metabolites released by cells. They have been identified in body fluids including blood, saliva, sputum and pleural effusions. In tumors, EVs derived from cancer and immune cells mediate intercellular communication and exchange, and can affect immunomodulatory functions. In the context of lung cancer, emerging evidence implicates EV involvement during various stages of tumor development and progression, including angiogenesis, epithelial to mesenchymal transformation, immune system suppression, metastasis and drug resistance. Additionally, tumor-derived EVs (TDEs) have potential as a liquid biopsy source and as a means of therapeutic targeting, and there is considerable interest in developing clinical applications for EVs in these contexts. In this review, we consider the biogenesis, components, biological functions and isolation methods of EVs, and the implications for their clinical utility for diagnostic and therapeutic applications in lung cancer.