Exosome-mediated delivery of miR-204-5p inhibits tumor growth and chemoresistance

Harnessing tomato-derived small extracellular vesicles as drug delivery system for cancer therapy

AIM

This study aims to explore a sustainable and scalable approach using tomato fruit-derived sEVs (TsEVs) to deliver calcitriol for enhanced anticancer effects, addressing challenges of low yield and high costs associated with mammalian cell-derived sEVs.

METHODS

TsEVs were isolated by centrifugation and ultrafiltration and characterized using DLS, TEM, and biochemical assays. Calcitriol was loaded into TsEVs via loading methods, with efficiency measured by spectrophotometry and HPLC. HCT116 and HT29 colon cancer cells were treated with TsEV-calcitriol and assessed for viability, colony formation, migration, ROS levels, and apoptosis gene expression.

RESULTS

Isolated TsEVs ranged from 30-200 nm with a protein-to-lipid ratio of ∼1. Calcitriol encapsulation efficiencies were 15.4% (passive), 34.8% (freeze-thaw), and 47.3% (sonication). TsEV-calcitriol reduced HCT116 cell viability with IC50 values of 4.05 µg/ml (24 h) and 2.07 µg/ml (48 h). Clonogenic assays showed reduced colony formation and migration. Elevated ROS levels and increased Bax/Bcl-2 ratio were observed in treated HCT116 and HT29 colon cancer cells.

CONCLUSION

These findings highlight TsEVs as a promising alternative drug delivery platform to mammalian cell-derived sEV for enhancing the therapeutic efficiency of calcitriol and other anticancer agents.

Linc00239 Facilitates the Progress of Clear Cell Renal Cell Carcinoma via the miR-204-5p/RAB22A Axis

Long intergenic non-coding RNA 239 (Linc00239) acts as an oncogene in colorectal cancer (CRC), esophageal squamous cell carcinoma, and acute myeloid leukemia cells. However, its role and regulatory mechanisms in clear cell renal cell carcinoma (ccRCC) remain unknown. We used StarBase and The Cancer Genome Atlas databases to evaluate Linc00239 expression and its effect on ccRCC. Furthermore, the function of Linc00239 in ccRCC proliferation and metastasis was analyzed using Cell Counting Kit-8 and Transwell assays following Linc00239 knockdown. Subsequently, the Linc00239-miRNA-mRNA regulatory associations were selected based on miRanda, miTarbase, and previous references, and their expression levels and binding relationship were further validated using quantitative real-time polymerase chain reaction, western blotting and dual-luciferase reporter gene assay. Additionally, we transfected a miRNA inhibitor to evaluate whether the miR-204-5p/RAB22A (Ras-related proteins in brain 22a) axis was involved in Linc00239 function. Linc00239 was elevated in ccRCC and correlated with poor prognosis. Linc00239 knockdown inhibited ccRCC progression. Additionally, Linc00239 inhibition elevated miR-204-5p expression and repressed RAB22A levels. Moreover, miR-204-5p inhibitors attenuated this inhibitory effect on proliferation, migration, invasion, and RAB22A level when Linc00239 was knocked down. Linc00239 promotes ccRCC proliferation and metastasis by elevating RAB22A expression through the adsorption of miR-204-5p, which provides a clue for the diagnosis and treatment of ccRCC.

Macrophage exosomes mediate palmitic acid-induced metainflammation by transferring miR-3064-5p to target IκBα and activate NF-κB signaling

INTRODUCTION

High palmitic acid (PA) levels trigger metainflammation, facilitating the onset and progression of chronic metabolic diseases. Recently, exosomes were identified as new inflammation mediators. However, the mechanism by which macrophage exosomes mediate PA-induced inflammation remains unclear.

OBJECTIVES

To explore how PA induces metainflammation through macrophage exosomes.

METHODS

Exosomes secreted by RAW264.7 mouse macrophages stimulated with PA (ExosPA) or not (Exos) were prepared by ultracentrifugation. The differential miRNAs between ExosPA and Exos were identified by high-throughput sequencing, and their targeted mRNAs and proteins were bioinformatically analyzed and verified by qPCR and western blot. Mouse macrophages and metabolic cells (AML-12 hepatocytes, C2C12 myocytes or 3T3-L1 adipocytes) were treated with ExosPA or Exos. The verified miRNAs and its targeted molecules related to inflammation were analyzed in recipient cells. Furthers, exosomes were prepared from primary peritoneal macrophages isolated from AIN93G diet-fed (Control PM-Exos) or HPD-fed (PA PM-Exos) mice. Control or PA PM-Exos were then tail vein injected (30 μg) into mice (n = 10), once a week for 2 weeks. The verified miRNA and its targets in blood, blood exosomes, and metabolic tissues were detected. Finally, measured the levels of miRNA, inflammatory factors, and fatty acids in the blood of 20 obese/overweight individuals and 20 healthy individuals.

RESULTS

ExoPA activate NF-κB signaling and enhance inflammatory enzyme/cytokine production in macrophages and metabolic cells. ExoPA enrich miR-3064-5p and target to inhibit IκBα as verified by exosome inhibitors and miR-3064-5p mimics and inhibitors. HPD elevates exosomal miR-3064-5p, macrophage exosomal miR-3064-5p, and inflammatory cytokine levels in mice circulation. PA PM-Exos from HPD-fed mice triggered inflammation in the circulation and metabolic tissues/organs of chow diet-fed mice. Overweight/obese individuals exhibit increased levels of circulating palmitoleic acid, exosomal miR-3064-5p, and high-sensitivity C-reactive proteins.

CONCLUSIONS

Macrophage exosomes transferring miR-3064-5p to target IκBα and activate NF-κB signaling in metabolic cells is a mechanism of PA-induced metainflammation.

Apelin/APJ: Another Player in the Cancer Biology Network

The apelinergic system exerts multiple biological activities in human pathologies, including cancer. Overactivation of apelin/APJ, which has been detected in many malignant tumors, and the strong correlation with progression-free and overall survival, suggested the role of an oncogene for the apelin gene. Emerging evidence sheds new light on the effects of apelin on cellular functions and homeostasis in cancer cells and supports a direct role for this pathway on different hallmarks of cancer: "sustaining proliferative signaling", "resisting cell death", "activating invasion and metastasis", "inducing/accessing vasculature", "reprogramming cellular metabolism", "avoiding immune destruction" and "tumor-promoting inflammation", and "enabling replicative immortality". This article reviews the currently available literature on the intracellular processes regulated by apelin/APJ, focusing on those pathways correlated with tumor development and progression. Furthermore, the association between the activity of the apelinergic axis and the resistance of cancer cells to oncologic treatments (chemotherapy, immunotherapy, radiation) suggests apelin/APJ as a possible target to potentiate traditional therapies, as well as to develop diagnostic and prognostic applications. This issue will be also covered in the review.

Islet-derived exosomal miR-204 accelerates insulin resistance in skeletal muscle by suppressing sirtuin 1: An in vivo study in a mouse model of high-fat diet-induced obesity

AIMS

The interaction between pancreatic islets and skeletal muscle plays a pivotal role in the development of insulin resistance. The present study aimed to elucidate the impact of non-hormonal molecules from islets on the insulin sensitivity of skeletal muscle cells.

MATERIALS AND METHODS

We developed a mouse model of obesity through a high-fat diet, assessing glucose tolerance and conducting miRNA sequencing on skeletal muscle samples. An in vitro model was established by treating cells with palmitic acid, and exosomes in the supernatant were characterized using scanning electron microscopy and CD63 expression analysis. Intracellular miR-204-5p levels were quantified by RT-PCR.

RESULTS

Our in vivo model demonstrated a robust correlation between miR-204-5p level alterations and obesity-induced insulin resistance. Elevated fatty acid levels were observed to increase miR-204-5p in both skeletal muscle and islets. In cellular studies, palmitic acid increased miR-204-5p in MIN-6 islet β-cells but not in C2C12 skeletal muscle cells. Exosomes containing miR-204-5p, secreted by palmitic acid-treated MIN6 cells, were identified through morphological examination, immunoblotting for the exosomal marker CD63, and intraexosomal miR-204-5p level measurement. C2C12 cells were shown to uptake islet-derived miR-204-5p exosomes, as evidenced by the uptake of Exo-Red labeled exosomes. TargetScan analysis identified a highly conserved binding site for miR-204-5p in the 3' UTR of Sirt mRNA. Functional studies indicated that miR-204-5p overexpression reduced glucose consumption and uptake in C2C12 cells, decreased Sirt expression, and impaired insulin signaling, as evidenced by reduced Akt phosphorylation and membrane Glut4 levels.

CONCLUSIONS

Our findings reveal that miR-204-5p contributes to the development of insulin resistance in obesity and acts as a signaling molecule in the crosstalk between pancreatic islets and skeletal muscle.

Extracellular Vesicles as Mediators and Potential Targets in Combating Cancer Drug Resistance

Extracellular vesicles (EVs) are key mediators in the communication between cancer cells and their microenvironment, significantly influencing drug resistance. This review provides a comprehensive analysis of the roles of EVs in promoting drug resistance through mechanisms such as drug efflux, apoptosis resistance, autophagy imbalance, and tumor microenvironment modulation. Despite extensive research, details of EVs biogenesis, cargo selection, and specific pathways in EVs-mediated drug resistance are not fully understood. This review critically examines recent advancements, highlighting key studies that elucidate the molecular mechanisms of EVs functions. Additionally, innovative therapeutic strategies targeting EVs are explored, including inhibiting EVs biogenesis, engineering EVs for drug delivery, and identifying resistance-inhibiting molecules within EVs. By integrating insights from primary research and proposing new directions for future studies, this review aims to advance the understanding of EVs in cancer biology and foster effective interventions to mitigate drug resistance in cancer therapy.

Isolation and Comprehensive Analysis of Cochlear Tissue-Derived Small Extracellular Vesicles

Small extracellular vesicles (sEVs) act as a critical mediator in intercellular communication. Compared to sEVs derived from in vitro sources, tissue-derived sEVs can reflect the in vivo signals released from specific tissues more accurately. Currently, studies on the role of sEVs in the cochlea have relied on studying sEVs from in vitro sources. This study evaluates three cochlear tissue digestion and cochlear tissue-derived sEV (CDsEV) isolation methods, and first proposes that the optimal approach for isolating CDsEVs using collagenase D and DNase І combined with sucrose density gradient centrifugation. Furthermore, it comprehensively investigates CDsEV contents and cell origins. Small RNA sequencing and proteomics are performed to analyze the miRNAs and proteins of CDsEVs. The miRNAs and proteins of CDsEVs are crucial for maintaining normal auditory function. Among them, FGFR1 in CDsEVs may mediate the survival of cochlear hair cells via sEVs. Finally, the joint analysis of single CDsEV sequencing and single-cell RNA sequencing data is utilized to trace cellular origins of CDsEVs. The results show that different types of cochlear cells secrete different amounts of CDsEVs, with Kölliker's organ cells and supporting cells secrete the most. The findings are expected to enhance the understanding of CDsEVs in the cochlea.

Unraveling the ncRNA landscape that governs colorectal cancer: A roadmap to personalized therapeutics

Colorectal cancer (CRC) being one of the most common malignancies, has a significant death rate, especially when detected at an advanced stage. In most cases, the fundamental aetiology of CRC remains unclear despite the identification of several environmental and intrinsic risk factors. Numerous investigations, particularly in the last ten years, have indicated the involvement of epigenetic variables in this type of cancer. The development, progression, and metastasis of CRC are influenced by long non-coding RNAs (lncRNAs), which are significant players in the epigenetic pathways. LncRNAs are implicated in diverse pathological processes in CRC, such as liver metastasis, epithelial to mesenchymal transition (EMT), inflammation, and chemo-/radioresistance. It has recently been determined that CRC cells and tissues exhibit dysregulation of tens of oncogenic and tumor suppressor lncRNAs. Serum samples from CRC patients exhibit dysregulated expressions of several of these transcripts, offering a non-invasive method of detecting this kind of cancer. In this review, we outlined the typical paradigms of the deregulated lncRNA which exert significant role in the underlying molecular mechanisms of CRC initiation and progression. We comprehensively discuss the role of lncRNAs as innovative targets for CRC prognosis and treatment.

The effects of tumor-derived exosomes enriched with miRNA-211a on B16F10 cells

Introduction

Exosomes have emerged as a novel alternative delivery system for transporting small molecules. Tumor-derived exosomes (TEXs) possess anti-cancer properties and serve as natural carriers of microRNAs. Using this knowledge as a foundation, the current study evaluated the efficacy of delivering a miR-211 mimic via B16F10 cell-derived exosomes to block the growth and development of a melanoma cell line.

Material and methods

After exposing B16F10 cultured cells to serum-free media for 24 hours, we collected the supernatant. Subsequently, we purified the exosomes from the supernatant using a commercial kit. Scanning electron microscopy, transmission electron microscopy, dynamic light scattering, Western blot, and bicinchoninic acid protein assay were used to characterize exosomes. Following that, miR-211 mimic was loaded into exosomes (termed TEXomiR) via a modified calcium chloride procedure. The assessment of miR-211a loading efficiency into exosomes was conducted by analyzing its relative expression. MTT, annexin V/PI, and quantitative real-time polymerase chain reaction were used to measure the proliferation, apoptosis and relative expression of miR-211 target genes, respectively.

Results

Our study showed that the exosomes can deliver miR-211 mimic efficiently. The treatment of B16F10 cells with miR-211-enriched TEX downregulated miR-211 target genes, including brain-specific homeobox, vascular endothelial growth factor, and transforming growth factor-β receptor. The results indicated the antiproliferative effect of TEXomiR as time-dose-dependent. The flow cytometry evaluation showed that TEXomiR could induce the apoptosis of B16F10 cells.

Conclusions

Our data indicated that exosomes can be suitable carriers for miR-211 mimic. Moreover, TEXomiR via anti-cancer effects could inhibit the progression of melanoma cancer.

Exosome nanovesicles: biomarkers and new strategies for treatment of human diseases

Exosomes are nanoscale vesicles of cellular origin. One of the main characteristics of exosomes is their ability to carry a wide range of biomolecules from their parental cells, which are important mediators of intercellular communication and play an important role in physiological and pathological processes. Exosomes have the advantages of biocompatibility, low immunogenicity, and wide biodistribution. As researchers' understanding of exosomes has increased, various strategies have been proposed for their use in diagnosing and treating diseases. Here, we provide an overview of the biogenesis and composition of exosomes, describe the relationship between exosomes and disease progression, and focus on the use of exosomes as biomarkers for early screening, disease monitoring, and guiding therapy in refractory diseases such as tumors and neurodegenerative diseases. We also summarize the current applications of exosomes, especially engineered exosomes, for efficient drug delivery, targeted therapies, gene therapies, and immune vaccines. Finally, the current challenges and potential research directions for the clinical application of exosomes are also discussed. In conclusion, exosomes, as an emerging molecule that can be used in the diagnosis and treatment of diseases, combined with multidisciplinary innovative solutions, will play an important role in clinical applications.

Empowering Exosomes with Aptamers for Precision Theranostics

As information messengers for cell-to-cell communication, exosomes, typically small membrane vesicles (30-150 nm), play an imperative role in the physiological and pathological processes of living systems. Accumulating studies have demonstrated that exosomes are potential biological candidates for theranostics, including liquid biopsy-based diagnosis and drug delivery. However, their clinical applications are hindered by several issues, especially their unspecific detection and insufficient targeting ability. How to upgrade the accuracy of exosome-based theranostics is being widely explored. Aptamers, benefitting from their admirable characteristics, are used as excellent molecular recognition elements to empower exosomes for precision theranostics. With high affinity against targets and easy site-specific modification, aptamers can be incorporated with platforms for the specific detection of exosomes, thus providing opportunities for advancing disease diagnostics. Furthermore, aptamers can be tailored and functionalized on exosomes to enable targeted therapeutics. Herein, this review emphasizes the empowering of exosomes by aptamers for precision theranostics. A brief introduction of exosomes and aptamers is provided, followed by a discussion of recent progress in aptamer-based exosome detection for disease diagnosis, and the emerging applications of aptamer-functionalized exosomes for targeted therapeutics. Finally, current challenges and opportunities in this research field are presented.

Possible Involvement of Long Non-Coding RNAs GNAS-AS1 and MIR205HG in the Modulation of 5-Fluorouracil Chemosensitivity in Colon Cancer Cells through Increased Extracellular Release of Exosomes

A growing number of studies have suggested the involvement of long non-coding RNAs as the key players in not just the initiation and progression of the tumor microenvironment, but also in chemotherapy tolerance. In the present study, generated 5-FU-resistant SW480/DR cells were analyzed via cDNA microarray for its aberrant lncRNAs and mRNAs expression in comparison with the 5-FU-susceptible SW480/DS cells. Among the 126 lncRNAs described, lncRNAs GNAS-AS1, MIR205HG, and LOC102723721 have been identified to be significantly upregulated, while lncRNs lnc-RP11-597K23.2.1-2, LOC100507639, and CCDC144NL-AS1 have been found to be significantly downregulated. In the meantime, bioinformatic analysis through gene ontology studies of aberrantly expressed mRNAs revealed "regulated exocytosis", among others, as the biological process most impacted in SW480/DR cells. To investigate, exosome purification was then carried out and its characterization were validated via transmission electron microscopy and nanoparticle tracking analysis. Interestingly, it was determined that the 5-FU-resistant SW480/DR cells secretes significantly higher concentration of extracellular vesicles, particularly, exosomes when compared to the 5-FU-susceptible SW480/DS cells. Based on the lncRNA-mRNA interaction network analysis generated, lncRNA GNAS-AS1 and MIR205HG have been identified to be potentially involved in the incidence of 5-FU resistance in SW480 colon cancer cells through promoting increased release of exosomes into the intercellular matrix. Our study hopes not only to provide insights on the list of involved candidate lncRNAs, but also to elucidate the role exosomes play in the initiation and development of 5-FU chemotherapy resistance in colon cancer cells.

Exosomes in tumor-stroma crosstalk: Shaping the immune microenvironment in colorectal cancer

Colorectal cancer (CRC) is a multifaceted disease characterized by a complex interaction between tumor cells and the surrounding microenvironment. Within this intricate landscape, exosomes have emerged as pivotal players in the tumor-stroma crosstalk, influencing the immune microenvironment of CRC. These nano-sized vesicles, secreted by both tumoral and stromal cells, serve as molecular transporters, delivering a heterogeneous mix of biomolecules such as RNAs, proteins, and lipids. In the CRC context, exosomes exert dual roles: they promote tumor growth, metastasis, and immune escape by altering immune cell functions and activating oncogenic signaling pathways and offer potential as biomarkers for early CRC detection and treatment targets. This review delves into the multifunctional roles of exosomes in the CRC immune microenvironment, highlighting their potential implications for future therapeutic strategies and clinical outcomes.

Circular RNA in cervical cancer: Fundamental mechanism and clinical potential

CC (CC) remains a significant global health concern, imposing a substantial health burden on women worldwide due to its high incidence and mortality rates. To address this issue, there is a need for ongoing research to uncover the underlying molecular mechanisms of CC and to discover novel diagnostic and therapeutic strategies. Recent progress in non-coding RNAs (ncRNAs) has opened new avenues for investigation, and circular RNAs (circRNAs) have emerged as molecules with diverse roles in various cellular processes. These circRNAs are distinct in structure, forming a closed loop, setting them apart from their linear counterparts. They are intricately involved in regulating different aspects of cellular functions, particularly in cell growth and development. Remarkably, circRNAs can have varying functions, either promoting or inhibiting oncogenic processes, depending on the specific cellular context. Recent studies have identified abnormal circRNAs expression patterns associated with CC, indicating their significant involvement in disease development. The differing circRNAs profiles linked to CC present promising opportunities for early detection, precise prognosis evaluation, and personalized treatment strategies. In this comprehensive review, we embark on a detailed exploration of CC-related circRNAs, elucidating their distinct roles and providing insights into the intricate molecular mechanisms governing CC's onset and progression. A growing body of evidence strongly suggests that circRNAs can serve as valuable biomarkers for early CC detection and hold potential as therapeutic targets for intervention. By delving into the complex interplay between circRNAs and CC, we are paving the way for innovative, individualized approaches to combat this serious disease, with the goal of reducing its impact on women's health globally and improving patient outcomes. As our understanding of circRNAs in the context of CC continues to deepen, the outlook for breakthroughs in diagnosis and treatment becomes increasingly promising.

Chronological and reproductive aging-associated changes in resistance to oxidative stress in post-reproductive female mice

Effort toward reproduction is often thought to negatively influence health and survival. Reproduction has been shown to influence metabolism, but the pathways and mechanisms have yet to be thoroughly elucidated. In the current experiments, our aim was to dissect the role of young and old ovarian tissues in the response to oxidative stress, through changes in liver oxidative stress response proteins. Liver proteins were analyzed in control mice at 4, 13, and 27 months of age and compared to 23-month-old mice which received young ovarian tissue transplants (intact or follicle-depleted) at 13 months of age. In control mice, of the 29 oxidative stress response proteins measured, 31% of the proteins decreased, 52% increased, and 17% were unchanged from 13 to 27 months. The greatest changes were seen during the period of reproductive failure, from 4 to 13 months of age. In transplanted mice, far more proteins were decreased from 13 to 23 months (93% in follicle-containing young ovary recipients; 62% in follicle-depleted young ovary recipients). Neither transplant group reflected changes seen in control mice between 13 and 27 months. Estradiol levels in transplant recipient mice were not increased compared with age-matched control mice. The current results suggest the presence of a germ cell- and estradiol-independent ovarian influence on aging-associated changes in the response to oxidative stress, which is manifest differently in reproductive-aged adults and post-reproductive-aged mice. The results presented here separate chronological and ovarian aging and the influence of estradiol in the response to aging-associated oxidative stress and support a novel, estradiol-independent role for the ovary in female health and survival.

Reprogramming tumor-associated macrophages by a dually targeted milk exosome system as a potent monotherapy for cancer

Tumor-associated macrophages (TAMs) play a key role in inducing an immunosuppressive tumor microenvironment (TME) and cancer immune escape. We previously revealed that PDL1 (a key immune checkpoint) was upregulated in TAMs and induced M2 polarization, highlighting PDL1 in TAMs as a promising cancer therapeutic target. In this study, we developed an engineered milk exosome (mExo) system decorated with M2pep (an M2 macrophage binding peptide) and 7D12 (an anti-EGFR nanobody) (7D12-mExo-M2pep-siPDL1) to specifically deliver siPDL1 into M2 TAMs. A series of in vitro and in vivo assays showed that the dually targeted engineered mExos efficiently delivered siPDL1 into M2 TAMs and repolarized them into M1 macrophages, restoring CD8+ T cell immune activity and remodeling TME. Importantly, systemically administered 7D12-mExo-M2pep-siPDL1 showed efficient single-agent antitumor activity, resulting in nearly 90% tumor growth inhibition in a mouse model of orthotopic epidermal growth factor receptor (EGFR) cancer. Collectively, our study indicates that PDL1 is a promising target for TAM-based cancer immunotherapy, and our engineered mExo-based nanomedicine represents a novel tool for specifically targeting M2 TAMs, distinguishing this novel therapeutic method from other TAM-targeting therapies and highlighting its promising clinical potential.

Current Update of Research on Exosomes in Cancer

Exosomes are vesicles secreted by the plasma membrane of the cells delimited by a lipid bilayer membrane into the extracellular space of the cell. Their release is associated with the disposal mechanism to remove unwanted materials from the cells. Exosomes released from primary tumour sites migrate to other parts of the body to create a metastatic environment for spreading the tumour cells. We have reviewed that exosomes interfere with the tumour progression by (i) promoting angiogenesis, (ii) initiating metastasis, (iii) regulating tumour microenvironment (TME) and inflammation, (iv) modifying energy metabolism, and (v) transferring mutations. We have found that EVs play an important role in inducing tumour drug resistance against anticancer drugs. This review discusses the potential of exosomes to generate a significant therapeutic effect along with improved diagnosis, prognosis, insights on the various research conducted and their significant findings of our interest.

Exosomal non-coding RNAs: Blueprint in colorectal cancer metastasis and therapeutic targets

Colorectal cancer (CRC) is ranked as the world's third-most prevalent cancer, and metastatic CRC considerably increases cancer-related fatalities globally. A number of complex mechanisms that are strictly controlled at the molecular level are involved in metastasis, which is the primary reason for death in people with CRC. Recently, it has become clear that exosomes, which are small extracellular vesicles released by non-tumorous and tumorigenic cells, play a critical role as communication mediators among tumor microenvironment (TME). To facilitate communication between the TME and cancer cells, non-coding RNAs (ncRNAs) play a crucial role and are recognized as potent regulators of gene expression and cellular processes, such as metastasis and drug resistance. NcRNAs are now recognized as potent regulators of gene expression and many hallmarks of cancer, including metastasis. Exosomal ncRNAs, like miRNAs, circRNAs, and lncRNAs, have been demonstrated to influence a number of cellular mechanisms that contribute to CRC metastasis. However, the molecular mechanisms that link exosomal ncRNAs with CRC metastasis are not well understood. This review highlights the essential roles that exosomal ncRNAs play in the progression of CRC metastatic disease and explores the therapeutic choices that are open to patients who have CRC metastases. However, exosomal ncRNA treatment strategy development is still in its early phases; consequently, additional investigation is required to improve delivery methods and find novel therapeutic targets as well as confirm the effectiveness and safety of these therapies in preclinical and clinical contexts.

An off-the-shelf small extracellular vesicle nanomedicine for tumor targeting therapy

Small extracellular vesicles (sEVs) have shown excellent prospects as drug delivery systems for cancer therapy. However, the inherent non-targeting and short blood circulation characteristics severely restrict their practical applications as a delivery system. In addition, post-encapsulating drugs into sEVs also remains challenging. Here, we constructed an engineered cell line that secreted multifunctional sEVs (termed NBsEV204) with 7D12 (an anti-EGFR nanobody) and hCD47 decorations on their surface, as well as high levels of miR-204-5p encapsulation. NBsEV204 exhibited extended blood circulation and improved macrophage-mediated phagocytosis of tumor cells by blocking CD47 signaling. Importantly, NBsEV204 specifically targeted EGFR+ tumor cells and showed robust tumor-suppressive effects both in vitro and in vivo. Overall, this study provides a convenient and feasible method to produce off-the-shelf anticancer sEV nanomedicine, which exhibits tremendous potential for clinical translation.

Applications of engineered exosomes in drugging noncoding RNAs for cancer therapy

Noncoding RNAs (ncRNAs) are engaged in key cell biological and pathological events, and their expression alteration is connected to cancer progression both directly and indirectly. A huge number of studies have mentioned the significant role of ncRNAs in cancer prevention and therapy that make them an interesting subject for cancer therapy. However, there are several limitations, including delivery, uptake, and short half-life, in the application of ncRNAs in cancer treatment. Exosomes are introduced as promising options for the delivery of ncRNAs to the target cells. In this review, we will briefly discuss the application and barriers of ncRNAs. After that we will focus on exosome-based ncRNAs delivery and their advantages as well as the latest achievements in drugging ncRNAs with exosomes.

Exosomes as cutting-edge therapeutics in various biomedical applications: An update on engineering, delivery, and preclinical studies

Exosomes are cell-derived nanovesicles, circulating in different body fluids, and acting as an intercellular mechanism. They can be purified from culture media of different cell types and carry an enriched content of various protein and nucleic acid molecules originating from their parental cells. It was indicated that the exosomal cargo can mediate immune responses via many signaling pathways. Over recent years, the therapeutic effects of various exosome types were broadly investigated in many preclinical studies. Herein, we present an update on recent preclinical studies on exosomes as therapeutic and/or delivery agents for various applications. The exosome origin, structural modifications, natural or loaded active ingredients, size, and research outcomes were summarized for various diseases. Overall, the present article provides an overview of the latest exosome research interests and developments to clear the way for the clinical study design and application.

ELAVL4 promotes the tumorigenesis of small cell lung cancer by stabilizing LncRNA LYPLAL1-DT and enhancing profilin 2 activation

Small cell lung cancer (SCLC) is one of the most malignant tumors that has an extremely poor prognosis. RNA-binding protein (RBP) and long noncoding RNA (lncRNA) have been shown to be key regulators during tumorigenesis as well as lung tumor progression. However, the role of RBP ELAVL4 and lncRNA LYPLAL1-DT in SCLC remains unclear. In this study, we verified that lncRNA LYPLAL1-DT acts as an SCLC oncogenic lncRNA and was confirmed in vitro and in vivo. Mechanistically, LYPLAL1-DT negatively regulates the expression of miR-204-5p, leading to the upregulation of PFN2, thus, promoting SCLC cell proliferation, migration, and invasion. ELAVL4 has been shown to enhance the stability of LYPLAL1-DT and PFN2 mRNA. Our study reveals a regulatory pathway, where ELAVL4 stabilizes PFN2 and LYPLAL1-DT with the latter further increasing PFN2 expression by blocking the action of miR-204-5p. Upregulated PFN2 ultimately promotes tumorigenesis and invasion in SCLC. These findings provide novel prognostic indicators as well as promising new therapeutic targets for SCLC.

MiR-204-5p-targeted AP1S2 is necessary for papillary thyroid carcinoma

MiR-204-5p, as a tumour suppressor, has been found in several cancers. However, whether miR-204-5p is involved in papillary thyroid carcinoma (PTC) has not yet been investigated. In this study, we identified miR-204-5p as a down-regulated miRNA in PTC tissues, unveiling that the levels of miR-204-5p in serum of patients with PTC were linked to PTC risk, and that the expression in patients concomitant with both PTC and benign lesions was much lower than that in patients only with PTC. Furthermore, we documented that miR-204-5p inhibited proliferation, migration, invasion, and cell cycle progression and triggered apoptosis of PTC cells via cell biology experiments. Finally, we identified that AP1S2 was a target of miR-204-5p using RNA-seq, iTRAQ, and bioinformatics prediction. Overall, miR-204-5p functions as a suppressor for PTC pathogenesis via the miR-204-5p/AP1S2 axis.

Regulatory role of exosomes in colorectal cancer progression and potential as biomarkers

Colorectal cancer (CRC) remains an enormous challenge to human health worldwide. Unfortunately, the mechanism underlying CRC progression is not well understood. Mounting evidence has confirmed that exosomes play a vital role in CRC progression, which has attracted extensive attention among researchers. In addition to acting as messengers between CRC cells, exosomes also participate in the CRC immunomodulatory process and reshape immune function. As stable message carriers and liquid biopsy option under development, exosomes are promising biomarkers in the diagnosis or treatment of CRC. In this review we have described and analyzed the biogenesis and release of exosomes and current research on the role of exosomes in immune regulation and metastasis of CRC. Moreover, we have discussed candidate exosomal molecules as potential biomarkers to diagnose CRC, predict CRC progression, or determine CRC chemoresistance, and described the significance of exosomes in the immunotherapy of CRC. This review provides insight to further understand the role of exosomes in CRC progression and identify valuable biomarkers that facilitate the clinical management of CRC patients.

Progress of regulatory RNA in small extracellular vesicles in colorectal cancer

Colorectal cancer (CRC) is the second most common malignant tumor of the gastrointestinal tract with the second highest mortality rate and the third highest incidence rate. Early diagnosis and treatment are important measures to reduce CRC mortality. Small extracellular vesicles (sEVs) have emerged as key mediators that facilitate communication between tumor cells and various other cells, playing a significant role in the growth, invasion, and metastasis of cancer cells. Regulatory RNAs have been identified as potential biomarkers for early diagnosis and prognosis of CRC, serving as crucial factors in promoting CRC cell proliferation, invasion and metastasis, angiogenesis, drug resistance, and immune cell differentiation. This review provides a comprehensive summary of the vital role of sEVs as biomarkers in CRC diagnosis and their potential application in CRC treatment, highlighting their importance as a promising avenue for further research and clinical translation.

Recent Progress in Extracellular Vesicle-Based Carriers for Targeted Drug Delivery in Cancer Therapy

Extracellular vesicles (EVs) are small, membrane-based vesicles released by cells that play a critical role in various physiological and pathological processes. They act as vehicles for transporting a variety of endogenous cargo molecules, enabling intercellular communication. Due to their natural properties, EVs have emerged as a promising "cell-free therapy" strategy for treating various diseases, including cancer. They serve as excellent carriers for different therapeutics, including nucleic acids, proteins, small molecules, and other nanomaterials. Modifying or engineering EVs can improve the efficacy, targeting, specificity, and biocompatibility of EV-based therapeutics for cancer therapy. In this review, we comprehensively outline the biogenesis, isolation, and methodologies of EVs, as well as their biological functions. We then focus on specific applications of EVs as drug carriers in cancer therapy by citing prominent recent studies. Additionally, we discuss the opportunities and challenges for using EVs as pharmaceutical drug delivery vehicles. Ultimately, we aim to provide theoretical and technical support for the development of EV-based carriers for cancer treatment.

Identification of a Twelve-microRNA Signature with Prognostic Value in Stage II Microsatellite Stable Colon Cancer

We aimed to identify and validate a set of miRNAs that could serve as a prognostic signature useful to determine the recurrence risk for patients with COAD. Small RNAs from tumors of 100 stage II, untreated, MSS colon cancer patients were sequenced for the discovery step. For this purpose, we built an miRNA score using an elastic net Cox regression model based on the disease-free survival status. Patients were grouped into high or low recurrence risk categories based on the median value of the score. We then validated these results in an independent sample of stage II microsatellite stable tumor tissues, with a hazard ratio of 3.24, (CI_95% = 1.05-10.0) and a 10-year area under the receiver operating characteristic curve of 0.67. Functional analysis of the miRNAs present in the signature identified key pathways in cancer progression. In conclusion, the proposed signature of 12 miRNAs can contribute to improving the prediction of disease relapse in patients with stage II MSS colorectal cancer, and might be useful in deciding which patients may benefit from adjuvant chemotherapy.

Exosomes: Diagnostic and Therapeutic Implications in Cancer

Exosomes are a subset of extracellular vesicles produced by all cells, and they are present in various body fluids. Exosomes play crucial roles in tumor initiation/progression, immune suppression, immune surveillance, metabolic reprogramming, angiogenesis, and the polarization of macrophages. In this work, we summarize the mechanisms of exosome biogenesis and secretion. Since exosomes may be increased in the cancer cells and body fluids of cancer patients, exosomes and exosomal contents can be used as cancer diagnostic and prognostic markers. Exosomes contain proteins, lipids, and nucleic acids. These exosomal contents can be transferred into recipient cells. Therefore, this work details the roles of exosomes and exosomal contents in intercellular communications. Since exosomes mediate cellular interactions, exosomes can be targeted for developing anticancer therapy. This review summarizes current studies on the effects of exosomal inhibitors on cancer initiation and progression. Since exosomal contents can be transferred, exosomes can be modified to deliver molecular cargo such as anticancer drugs, small interfering RNAs (siRNAs), and micro RNAs (miRNAs). Thus, we also summarize recent advances in developing exosomes as drug delivery platforms. Exosomes display low toxicity, biodegradability, and efficient tissue targeting, which make them reliable delivery vehicles. We discuss the applications and challenges of exosomes as delivery vehicles in tumors, along with the clinical values of exosomes. In this review, we aim to highlight the biogenesis, functions, and diagnostic and therapeutic implications of exosomes in cancer.

The application of extracellular vesicles in colorectal cancer metastasis and drug resistance: recent advances and trends

Colorectal cancer (CRC) has high incidence and mortality rates and is one of the most common cancers of the digestive tract worldwide. Metastasis and drug resistance are the main causes of cancer treatment failure. Studies have recently suggested extracellular vesicles (EVs) as a novel mechanism for intercellular communication. They are vesicular particles, which are secreted and released into biological fluids, such as blood, urine, milk, etc., by a variety of cells and carry numerous biologically active molecules, including proteins, nucleic acids, lipids, metabolites, etc. EVs play a crucial part in the metastasis and drug resistance of CRC by delivering cargo to recipient cells and modulating their behavior. An in-depth exploration of EVs might facilitate a comprehensive understanding of the biological behavior of CRC metastasis and drug resistance, which might provide a basis for developing therapeutic strategies. Therefore, considering the specific biological properties of EVs, researchers have attempted to explore their potential as next-generation delivery systems. On the other hand, EVs have also been demonstrated as biomarkers for the prediction, diagnosis, and presumed prognosis of CRC. This review focuses on the role of EVs in regulating the metastasis and chemoresistance of CRC. Moreover, the clinical applications of EVs are also discussed.

The functional role of circular RNAs in the pathogenesis of retinoblastoma: a new potential biomarker and therapeutic target?

Retinoblastoma (RB) is a common cancer in infants and children. It is a curable disease; however, a delayed diagnosis or treatment makes the treatment difficult. Genetic mutations have a central role in the pathogenesis of RB. Genetic materials such as RNAs (coding and non-coding RNAs) are also involved in the progression of the tumor. Circular RNA (circRNA) is the most recently identified RNA and is involved in regulating gene expression mainly through "microRNA sponges". The dysregulation of circRNAs has been observed in several diseases and tumors. Also, various studies have shown that circRNAs expression is changed in RB tissues. Due to their role in the pathogenesis of the disease, circRNAs might be helpful as a diagnostic or prognostic biomarker in patients with RB. In addition, circRNAs could be a suitable therapeutic target to treat RB in a targeted therapy approach.

Extracellular Vesicles in Colorectal Cancer: From Tumor Growth and Metastasis to Biomarkers and Nanomedications

Colorectal cancer (CRC) is a leading public health concern due to its incidence and high mortality rates, highlighting the requirement of an early diagnosis. Evaluation of circulating extracellular vesicles (EVs) might constitute a noninvasive and reliable approach for CRC detection and for patient follow-up because EVs display the molecular features of the cells they originate. EVs are released by almost all cell types and are mainly categorized as exosomes originating from exocytosis of intraluminal vesicles from multivesicular bodies, ectosomes resulting from outward budding of the plasma membrane and apoptotic bodies' ensuing cell shrinkage. These vesicles play a critical role in intercellular communications during physiological and pathological processes. They facilitate CRC progression and premetastatic niche formation, and they enable transfer of chemotherapy resistance to sensitive cells through the local or remote delivery of their lipid, nucleic acid and protein content. On another note, their stability in the bloodstream, their permeation in tissues and their sheltering of packaged material make engineered EVs suitable vectors for efficient delivery of tracers and therapeutic agents for tumor imaging or treatment. Here, we focus on the physiopathological role of EVs in CRCs, their value in the diagnosis and prognosis and ongoing investigations into therapeutic approaches.

Identification of Hub Genes for Colorectal Cancer with Liver Metastasis Using miRNA-mRNA Network

Background

Liver metastasis is an important cause of death in patients with colorectal cancer (CRC). Increasing evidence indicates that microRNAs (miRNAs) are involved in the pathogenesis of colorectal cancer liver metastasis (CRLM). This study is aimed at exploring the potential miRNA-mRNA regulatory network.

Methods

From the GEO database, we downloaded the microarray datasets GSE56350 and GSE73178. GEO2R was used to conduct differentially expressed miRNAs (DEMs) between CRC and CRLM using the GEO2R tool. Then, GO and KEGG pathway analysis for differentially expressed genes (DEGs) performed via DAVID. A protein-protein interaction (PPI) network was constructed by the STRING and identified by Cytoscape. Hub genes were identified by miRNA-mRNA network. Finally, the expression of the hub gene expression was assessed in the GSE81558.

Results

The four DEMs (hsa-miR-204-5p, hsa-miR-122-5p, hsa-miR-95-3p, and hsa-miR-552-3p) were identified as common DEMs in GSE56350 and GSE73178 datasets. The SP1 was likely to adjust the upregulated DEMs; however, the YY1 could regulate both the upregulated and downregulated DEMs. A total of 3925 genes (3447 upregulated DEM genes and 478 downregulated DEM genes) were screened. These predicted genes were mainly linked to Platinum drug resistance, Cellular senescence, and ErbB signaling pathway. Through the gene network construction, most of the hub genes were found to be modulated by hsa-miR-204-5p, hsa-miR-122-5p, hsa-miR-95-3p, and hsa-miR-552-3p. Among the top 20 hub genes, the expression of CREB1, RHOA, and EGFR was significantly different in the GSE81558 dataset.

Conclusion

In this study, miRNA-mRNA networks in CRLM were screened between CRC patients and CRLM patients to provide a new method to predict for the pathogenesis and development of CRC.

MicroRNA-204-5p: A pivotal tumor suppressor

MicroRNAs (miRNAs) are a class of non-coding single-stranded RNA molecules with a length of approximately 18-25 nt nucleotides that regulate gene expression post-transcriptionally. MiR-204-5p originates from the sixth intron of the transient receptor potential cation channel subfamily M member 3 (TRPM3) gene. MiR-204-5p is frequently downregulated in various cancer types and is related to the clinicopathological characteristics and prognosis of cancer patients. So far, many studies have determined that miR-204-5p functions as a tumor suppressor for its extensive and powerful capacity to inhibit tumor proliferation, metastasis, autophagy, and chemoresistance in multiple cancer types. MiR-204-5p appears to be a promising prognostic biomarker and a therapeutic target for human cancers. This review summarized the latest advances on the role of miR-204-5p in human cancers.

Novel strategies to reverse chemoresistance in colorectal cancer

Colorectal cancer (CRC) is a common gastrointestinal malignancy with high morbidity and fatality. Chemotherapy, as traditional therapy for CRC, has exerted well antitumor effect and greatly improved the survival of CRC patients. Nevertheless, chemoresistance is one of the major problems during chemotherapy for CRC and significantly limits the efficacy of the treatment and influences the prognosis of patients. To overcome chemoresistance in CRC, many strategies are being investigated. Here, we review the common and novel measures to combat the resistance, including drug repurposing (nonsteroidal anti-inflammatory drugs, metformin, dichloroacetate, enalapril, ivermectin, bazedoxifene, melatonin, and S-adenosylmethionine), gene therapy (ribozymes, RNAi, CRISPR/Cas9, epigenetic therapy, antisense oligonucleotides, and noncoding RNAs), protein inhibitor (EFGR inhibitor, S1PR2 inhibitor, and DNA methyltransferase inhibitor), natural herbal compounds (polyphenols, terpenoids, quinones, alkaloids, and sterols), new drug delivery system (nanocarriers, liposomes, exosomes, and hydrogels), and combination therapy. These common or novel strategies for the reversal of chemoresistance promise to improve the treatment of CRC.

Exosome-encapsulated ncRNAs: Emerging yin and yang of tumor hallmarks

Tumorigenesis is a multifaceted process, where multiple physiological traits serving as cancer’s distinctive characteristics are acquired. “Hallmarks of cancer” is a set of cognitive abilities acquired by human cells that are pivotal to their tumor-forming potential. With limited or no protein-coding ability, non-coding RNAs (ncRNAs) interact with their target molecules and yield significant regulatory effects on several cell cycle processes. They play a “yin” and “yang” role, thereby functioning both as oncogenic and tumor suppressor and considered important in the management of various types of cancer entities. ncRNAs serve as important post-transcriptional and translational regulators of not only unrestricted expansion and metastasis of tumor cells but also of various biological processes, such as genomic mutation, DNA damage, immune escape, and metabolic disorder. Dynamical attributes such as increased proliferative signaling, migration, invasion, and epithelial–mesenchymal transition are considered to be significant determinants of tumor malignancy, metastatic dissemination, and therapeutic resistance. Furthermore, these biological attributes engage tumor cells with immune cells within the tumor microenvironment to promote tumor formation. We elaborate the interaction of ncRNAs with various factors in order to regulate cancer intra/intercellular signaling in a specific tumor microenvironment, which facilitates the cancer cells in acquiring malignant hallmarks. Exosomes represent a means of intercellular communication and participate in the maintenance of the tumor hallmarks, adding depth to the intricate, multifactorial character of malignant neoplasia. To summarize, ncRNAs have a profound impact on tumors, affecting their microcirculation, invasiveness, altered metabolism, microenvironment, and the capacity to modify the host immunological environment. Though the significance of ncRNAs in crosstalk between the tumor and its microenvironment is being extensively explored, we intend to review the hallmarks in the light of exosome-derived non-coding RNAs and their impact on the tumor microenvironment.

Exosomes and mimics as novel delivery platform for cancer therapy

Exosomes are nano-sized biological extracellular vesicles transmitting information between cells and constituting a new intercellular communication mode. Exosomes have many advantages as an ideal drug delivery nanocarrier, including good biocompatibility, permeability, low toxicity, and low immunogenicity. Recently, exosomes have been used to deliver chemotherapeutic agents, natural drugs, nucleic acid drugs, and other antitumor drugs to treat many types of tumors. Due to the limited production of exosomes, synthetic exosome-mimics have been developed as an ideal platform for drug delivery. This review summarizes recent advances in the application of exosomes and exosome-mimics delivering therapeutic drugs in treating cancers.

Exosomal miR92a Promotes Cytarabine Resistance in Myelodysplastic Syndromes by Activating Wnt/β-catenin Signal Pathway

Cytarabine (Ara-C) has been one of the frontline therapies for clonal hematopoietic stem cell disorders, such as myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML), but Ara-C resistance often occurs and leads to treatment failure. Exosomal microRNAs (miRNAs, miRs) as small noncoding RNA that play important roles in post-transcriptional gene regulation, can be delivered into recipient cells by exosomes and regulate target genes' expression. miR92a has been reported to be dysregulated in many cancers, including MDS and AML. However, the effects of exosomal miR92a in hematologic malignancies have not been fully investigated. In this study, qualitative analysis showed the significantly enhanced expression of exosomal miR92a in MDS/AML plasma. Subsequent functional assays indicated that exosomal miR92a can be transported and downregulate PTEN in recipient cells and, furthermore, activate the Wnt/β-catenin signaling pathway and interfere with the Ara-C resistance of receipt MDS/AML cells in vitro and in vivo. Altogether, our findings offer novel insights into plasma exosomal miR92a participating in Ara-C resistance in MDS/AML and we propose miR92a as a potential therapeutic target for MDS/AML.

Hyaluronic Acid-Coated Bovine Milk Exosomes for Achieving Tumor-Specific Intracellular Delivery of miRNA-204

Cell type-specific drug delivery is a straightforward strategy to achieve targeted cancer therapy and reduce side effects. Hyaluronic acid (HA), an U.S. Food and Drug Administration (FDA)-approved biocompatible carbohydrate polymer, has been extensively employed as a targeting ligand for a drug delivery system due to its natural ability to bind to tumor cells overexpressing cluster of differentiation 44 (CD44) receptors. Here, we report the preparation and antitumor efficacy of HA-coated bovine milk exosomes (HA-mExo) for tumor-specific delivery of microRNA-204-5p mimics (miR-204). The exosome-based delivery formulation was prepared with miR-204 encapsulated inside the lumen and HA displayed outside the membrane. The resultant formulation of HA-mExo-miR204 was able to specifically target CD44-positive cancer cells, with a concomitant increase in the intracellular uptake of miR-204. Compared to the uncoated mExo-miR204 formulation, HA-mExo-miR204 showed significantly increased antitumor efficacy both in vitro and in vivo. Importantly, HA-mExo-miR204 showed excellent biocompatibility and did not cause significant systemic toxicity. Given that both HA and bovine milk exosomes are low-cost and highly accessible biogenic materials with broad biomedical applications, HA-decorated bovine milk exosomes can be proven to be a practical drug delivery system of RNA drugs for targeted cancer therapy.

Extracellular vesicles and particles impact the systemic landscape of cancer

Intercellular cross talk between cancer cells and stromal and immune cells is essential for tumor progression and metastasis. Extracellular vesicles and particles (EVPs) are a heterogeneous class of secreted messengers that carry bioactive molecules and that have been shown to be crucial for this cell-cell communication. Here, we highlight the multifaceted roles of EVPs in cancer. Functionally, transfer of EVP cargo between cells influences tumor cell growth and invasion, alters immune cell composition and function, and contributes to stromal cell activation. These EVP-mediated changes impact local tumor progression, foster cultivation of pre-metastatic niches at distant organ-specific sites, and mediate systemic effects of cancer. Furthermore, we discuss how exploiting the highly selective enrichment of molecules within EVPs has profound implications for advancing diagnostic and prognostic biomarker development and for improving therapy delivery in cancer patients. Altogether, these investigations into the role of EVPs in cancer have led to discoveries that hold great promise for improving cancer patient care and outcome.

Exosomes carrying immune checkpoints, a promising therapeutic approach in cancer treatment

Exosomes are a subgroup of extracellular vesicles generated by distinct cells. Tumor-derived extracellular vesicles convey immunological checkpoint molecules. TEXs as critical mediators in tumor development, metastasis, and immune escape have recently become the focus of scientific research. Exosomes are involved in the regulation of the immune system. Exosomes interact with target cells in the tumor microenvironment, changing their function based on the cargo they contain. Exosomal immune checkpoints might be exploited to track tumor immune evasion, treatment response, and patient prognosis while enhancing tumor cell proliferation and spread. This review focuses on tumor-derived exosomes, their immunosuppressive effects in mice models, and their role in cancer immunotherapy. Exosomes are being studied as possible cancer vaccines, with numerous uses in tumor immunotherapy. Exosomes can carry chemotherapeutics, siRNA, and monoclonal antibodies. Exosomes produced by macrophages might be used to treat cancer. These and other clinical consequences provide new doors for cancer treatment.

Emerging Role of microRNA Dysregulation in Diagnosis and Prognosis of Extrahepatic Cholangiocarcinoma

Extrahepatic cholangiocarcinomas, also called bile duct carcinomas, represent a special entity in gastrointestinal tumors, and histological specimens of the tumors are often difficult to obtain. A special feature of these tumors is the strong neovascularization, which can often be seen in the endoluminal endoscopic procedure called cholangioscopy, performed alone or in combination with laserscanning techniques. The additional analysis of microRNA expression profiles associated with inflammation and neovascularization in bile duct tumors or just the bile duct fluid of these patients could be of enormous additional importance. In particular, the dysregulation of microRNA in these cholangiocarcinomas (CCA) was previously reported to affect epigenetics (reported for miR-148, miR-152), inflammation (determined for miR-200, miR-125, and miR-605), and chemoresistance (miR-200b, 204) in patients with cholangiocarcinoma. More importantly, in the context of malignant neovascularization, well-defined microRNAs including miR-141, miR-181, miR-191, and miR-200b have been found to be dysregulated in cholangiocarcinoma and have been associated with an increased proliferation and vascularization in CCA. Thus, a panel of these microRNA molecules together with the clinical aspects of these tumors might facilitate tumor diagnosis and early treatment. To our knowledge, this is the first review that outlines the unique potential of combining macroscopic findings from cholangioscopy with microRNA expression.

Chemokines in progression, chemoresistance, diagnosis, and prognosis of colorectal cancer

Plenty of factors affect the oncogenesis and progression of colorectal cancer in the tumor microenvironment, including various immune cells, stromal cells, cytokines, and other factors. Chemokine is a member of the cytokine superfamily. It is an indispensable component in the tumor microenvironment. Chemokines play an antitumor or pro-tumor role by recruitment or polarization of recruiting immune cells. Meanwhile, chemokines, as signal molecules, participate in the formation of a cross talk among signaling pathways and non-coding RNAs, which may be involved in promoting tumor progression. In addition, they also function in immune escape. Chemokines are related to drug resistance of tumor cells and may even provide reference for the diagnosis, therapy, and prognosis of patients with colorectal cancer.

Recent advances in exosome-mediated nucleic acid delivery for cancer therapy

Cancer is a leading public health problem worldwide. Its treatment remains a daunting challenge, although significant progress has been made in existing treatments in recent years. A large concern is the poor therapeutic effect due to lack of specificity and low bioavailability. Gene therapy has recently emerged as a powerful tool for cancer therapy. However, delivery methods limit its therapeutic effects. Exosomes, a subset of extracellular vesicles secreted by most cells, have the characteristics of good biocompatibility, low toxicity and immunogenicity, and great designability. In the past decades, as therapeutic carriers and diagnostic markers, they have caught extensive attention. This review introduced the characteristics of exosomes, and focused on their applications as delivery carriers in DNA, messenger RNA (mRNA), microRNA (miRNA), small interfering RNA (siRNA), circular RNA (circRNA) and other nucleic acids. Meanwhile, their application in cancer therapy and exosome-based clinical trials were presented and discussed. Through systematic summarization and analysis, the recent advances and current challenges of exosome-mediated nucleic acid delivery for cancer therapy are introduced, which will provide a theoretical basis for the development of nucleic acid drugs.

In vitro experimental study on the formation of microRNA-34a loaded exosomes and their inhibitory effect in oral squamous cell carcinoma

Studies have shown the inhibitory effect of microRNA-34a on proliferation, migration, and invasion of oral squamous cell carcinoma. However, the lack of a safe and effective delivery system limits the clinical application of microRNA-34a in oral cancer treatment. An exosome is a small extracellular vesicle that mediates intercellular communication by delivering proteins, nucleic acids, and other contents, and functions as a natural drug delivery carrier. Here, we aimed to explore whether exosomes could be used to load microRNA-34a via co-incubation and further used to treat OSCC. Ultracentrifugation was used to obtain exosomes derived from HEK293T cells and the extracted exosomes were analyzed via transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blotting. Subsequently, we loaded cholesterol-modified microRNA-34a into HEK293T cell exosomes by co-incubation. Then, PKH67 and Cy3 co-labeled exo-microRNA-34a were co-incubated with HN6 cells and exosome entry into the HN6 cells was observed using a confocal laser scanning microscope. The cell proliferation, migration, and invasion were assessed by CCK-8 and Transwell assay analysis. SATB2 expression in HN6 cells was analyzed via western blotting. In this study, cholesterol-modified microRNA-34a was loaded into exosomes of HEK293T cells by co-incubation. The microRNA-34a-loaded exosomes were secreted from HEK293T cells and were absorbed by HN6 oral squamous carcinoma cells. Further, microRNA-34a-loaded exosomes led to a significant inhibition of HN6 cell proliferation, migration, and invasion by down regulating SATB2 expression. These results report a new delivery method for microRNA-34a, providing a new approach for the treatment of oral cancer.

Emerging role of exosomes in the pathology of chronic obstructive pulmonary diseases; destructive and therapeutic properties

Chronic obstructive pulmonary disease (COPD) is known as the third leading cause of human death globally. Enhanced chronic inflammation and pathological remodeling are the main consequences of COPD, leading to decreased life span. Histological and molecular investigations revealed that prominent immune cell infiltration and release of several cytokines contribute to progressive chronic remodeling. Recent investigations have revealed that exosomes belonging to extracellular vesicles are involved in the pathogenesis of COPD. It has been elucidated that exosomes secreted from immune cells are eligible to carry numerous pro-inflammatory factors exacerbating the pathological conditions. Here, in this review article, we have summarized various and reliable information about the negative role of immune cell-derived exosomes in the remodeling of pulmonary tissue and airways destruction in COPD patients.

Early Salivary miRNA Expression in Extreme Low Gestational Age Newborns

Background: MicroRNAs (miRNA) are small non-coding RNAs that regulate gene expression playing a key role in organogenesis. MiRNAs are studied in tracheal aspirates (TA) of preterm infants. However; this is difficult to obtain in infants who are not intubated. This study examines early salivary miRNA expression as non-invasive early biomarkers in extremely low gestational age newborns (ELGANs). Methods: Saliva was collected using DNA-genotek swabs, miRNAs were analyzed using RNA seq and RT PCR arrays. Salivary miRNA expression was compared to TA using RNA seq at 3 days of age, and longitudinal changes at 28 days of age were analyzed using RT PCR arrays in ELGANs. Results: Approximately 822 ng of RNA was extracted from saliva of 7 ELGANs; Of the 757 miRNAs isolated, 161 miRNAs had significant correlation in saliva and TA at 3 days of age (r = 0.97). Longitudinal miRNA analysis showed 29 miRNAs downregulated and 394 miRNAs upregulated at 28 days compared to 3 days of age (adjusted p < 0.1). Bioinformatic analysis (Ingenuity Pathway Analysis) of differentially expressed miRNAs identified organismal injury and abnormalities and cellular development as the top physiological system development and cellular function. Conclusion: Salivary miRNA expression are source for early biomarkers of underlying pathophysiology in ELGANs.

Colorectal Cancer-Derived Small Extracellular Vesicles Promote Tumor Immune Evasion by Upregulating PD-L1 Expression in Tumor-Associated Macrophages

Tumor-associated macrophages (TAMs) are one of the most abundant cell types in colorectal cancer (CRC) tumor microenvironment (TME). Recent studies observed complicated "cross-talks" between cancer cells and macrophages in TME. However, the underlying mechanisms are still poorly elucidated. Here, PD-L1 levels are very low in CRC cells but highly abundant in TAMs, and a specific PD-L1+CD206+ macrophage subpopulation are identified, which is induced by tumor cells and associated with a poor prognosis. Mechanistic investigations reveal that CRC cells can secrete small extracellular vesicles (sEVs) taken up by macrophages that induce M2 like polarization and PD-L1 expression, resulting in increased PD-L1+CD206+ macrophage abundance and decreased T cell activity in CRC TME. sEV-derived miR-21-5p and miR-200a are identified as key signaling molecules mediating the regulatory effects of CRC on macrophages. Further studies reveal that CRC-derived miR-21-5p and miR-200a synergistically induces macrophage M2 like polarization and PD-L1 expression by regulating the PTEN/AKT and SCOS1/STAT1 pathways, resulting in decreased CD8+ T cell activity and increased tumor growth. This study suggests that inhibiting the secretion of specific sEV-miRNAs from CRC and targeting PD-L1 in TAMs may serve as novel methods for CRC treatment as well as a sensitization method for anti-PD-L1 therapy in CRC.

The Role of Exosomal Non-Coding RNAs in Colorectal Cancer Drug Resistance

BACKGROUND

Colorectal cancer (CRC) is one of the most common types of cancer diagnosed worldwide with high morbidity; drug resistance is often responsible for treatment failure in CRC. Non-coding RNAs (ncRNAs) play distinct regulatory roles in tumorigenesis, cancer progression and chemoresistance.

METHODS

A literature search was conducted in PubMed database in order to sum up and discuss the role of exosomal ncRNAs (ex-ncRNAs) in CRC drug resistance/response and their possible mechanisms.

RESULTS

Thirty-six (36) original research articles were identified; these included exosome or extracellular vesicle (EV)-containing microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs) and small-interfering (siRNAs). No studies were found for piwi-interacting RNAs.

CONCLUSIONS

Exosomal transfer of ncRNAs has been documented as a new mechanism of CRC drug resistance. Despite being in its infancy, it has emerged as a promising field for research in order to (i) discover novel biomarkers for therapy monitoring and/or (ii) reverse drug desensitization.

Exosomes as Drug Carriers in Anti-Cancer Therapy

Over the years, there has been a high demand for developing new safe and effective drug carriers for cancer therapy. Emerging studies have indicated that exosomes can serve as potent therapeutic carriers since they offer low immunogenicity, high stability, innate and acquired targetability, and the stimulation of anti-cancer immune responses. Yet, the development of exosome-based drug delivery systems remains challenging due to their heterogeneity, low yield, and limited drug loading efficiency. Herein, we summarized the current application of exosomes derived from different cells as drug carriers in anti-cancer therapy in vitro and in vivo. We also discussed the challenges and prospects of exosome-based drug delivery systems in cancer therapy.