Extracellular Vesicles and Resistance to Anticancer Drugs: A Tumor Skeleton Key for Unhinging Chemotherapies

Exploratory Analysis of Molecular Subtypes in Early-Stage Osteosarcoma: Identifying Resistance and Optimizing Therapy

Background: Osteosarcoma (OS) is a highly aggressive bone malignancy with limited treatment options and poor prognosis. This exploratory study aimed to identify molecular subtypes of early-stage, treatment-naive OS to guide precise therapeutic strategies. Methods: We analyzed RNA-seq data obtained from tumor tissues from 102 OS patients using a non-negative matrix factorization algorithm (NMF) to classify the tumors into three subtypes: S1, S2, and S3. Differential gene expression was evaluated using DESeq2, followed by functional enrichment analysis with clusterProfiler and CancerHallmarks. The tumor microenvironment was assessed through ESTIMATE and CIBERSORT, and drug sensitivity was predicted using OncoPredict. SAOS-2 and MG63 cells, representing the S1 subtype, were used in the viability essays to determine the effect of hesperidin, a natural phenolic compound noted for its anti-cancer potential, alone and in combination with doxorubicin and 5-fluorouracil. Results: This study revealed three OS subtypes: S1 was enriched in cell cycle regulation, vesicular transport, and RNA metabolism while S2 and S3 were enriched in pathways related to extracellular matrix organization and protein translation, respectively. S1 displayed high tumor purity, significant chemoresistance, and overexpression of KIF20 A, correlating with poor prognosis. AURKB, a hesperidin target, was implicated in S1 pathogenesis. In vitro, hesperidin significantly reduced the viability of SAOS-2 and MG63 cells and enhanced doxorubicin efficacy. Conclusions: Our findings support the molecular subclassification of OS, emphasizing subtype-specific mechanisms of tumor progression and chemoresistance, with hesperidin offering potential as a therapeutic adjunct for high-risk OS patients.

SLC35A2-mediated bisected GlcNAc-modified extracellular vesicles enhance immune regulation in breast cancer lung metastasis

This study investigates the role of SLC35A2-mediated bisected GlcNAc-modified small extracellular vesicles (sEVs) in breast cancer (BC) lung metastasis. By modulating B3GALT1 expression, these sEVs regulate the pre-metastatic immune microenvironment, enhancing CD8+ T cell infiltration and reducing immune evasion. The use of β-peptide-loaded sEVs further amplifies anti-metastatic effects, as demonstrated in vivo mouse models and molecular analyses. These findings underscore the therapeutic potential of glycosylation-modified sEVs in enhancing immune responses and controlling BC metastasis.

Unraveling exosome-mediated cancer therapy resistance: pathways and therapeutic challenges

Extracellular vesicles (EVs) have emerged as key cell-to-cell communication mediators and play significant roles in both physiological and pathological processes. In EVs, exosomes represent a distinct subpopulation of EVs that have been found to be involved in cancer initiation and therapeutic resistance. Exosomes transfer a diverse spectrum of molecular cargos that have significant effects on the tumor microenvironment (TME), thereby enabling cancer initiation, metastasis, and therapeutic resistance. Exosomes have recently been of interest in cancer therapy due to their role as important mediators of treatment resistance. The exosomal molecular content-proteins, miRNAs, and lncRNAs-allows exosomes to perform functions including drug efflux and detoxification, cell death pathway modulation, induction of epithelial-to-mesenchymal transition (EMT), and suppression of the immune system. In addition to facilitating immune and stromal cell interactions, exosomes cause extracellular matrix remodeling and induce tumor heterogeneity, making it more difficult to respond to therapy. This review covers intricate roles of exosomes in cancer therapy resistance with regard to their biogenesis, molecular content, and functional impact in the TME. Along with this, we also discuss new therapeutic strategies to overcome exosome-mediated resistance including utilizing exosome inhibitors, designed exosome therapy, and combination with conventional therapies. While exosomes hold promise in prediction and diagnosis through their biomarker function, their heterogeneous origins and cryptic functions make it difficult to target interventions. This review emphasizes that research on exosome-mediated pathways is urgently required to develop new therapeutic strategies that can improve cancer treatment outcomes.

Exploring the role of vault complex in the nervous system: a literature review

Vault RNAs (vtRNAs) are a novel group of non-coding RNAs that are involved in various signaling mechanisms. vtRNAs are joined by three proteins major vault protein (MVP), vault poly (ADP-ribose) polymerase (VPARP), and telomerase-associated protein 1 (TEP1) to form the vault complex. In humans, only four vtRNA including vtRNA 1-1, vtRNA 1-2, vtRNA 1-3, vtRNA 2-1) have been discovered. In nerve cells, vtRNA is involved in synapse formation through MAPK signaling. vtRNA travels to the distal area of neurites as a key unit in the vault complex. Moreover, tRNA is detached from the vault complex in the neurite via a mitotic kinase Aurora-A-reliant MVP phosphorylation. Several molecules contribute to the formation of vtRNAs. For instance, SRSF2 and NSUN2 and their attachment to vtRNA1-1 determines the production of small-vtRNAs. Through the same factors, vtRNAs could play a role in neurodevelopmental deficits. Addition the role of vtRNA expression and vault proteins has been recently studied in neurodegenerative disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS) as well as brain cancers. While the mechanisms of vtRNA involvement in neurological disorders is not well-demonstrated, we believe this could be related to the impact of vtRNA regulation in autophagy, immunoregulation, RNA stability, cellular stress, apoptosis, and regulation of other epigenetic pathways. The present review captures the state-of-the-art regarding the role of vtRNAs in neurodevelopment, normal nervous system function, and neurological disorders.

Exosomes: from basic research to clinical diagnostic and therapeutic applications in cancer

Cancer continues to pose a global threat despite potent anticancer drugs, often accompanied by undesired side effects. To enhance patient outcomes, sophisticated multifunctional approaches are imperative. Small extracellular vesicles (EVs), a diverse family of naturally occurring vesicles derived from cells, offer advantages over synthetic carriers. Among the EVs, the exosomes are facilitating intercellular communication with minimal toxicity, high biocompatibility, and low immunogenicity. Their tissue-specific targeting ability, mediated by surface molecules, enables precise transport of biomolecules to cancer cells. Here, we explore the potential of exosomes as innovative therapeutic agents, including cancer vaccines, and their clinical relevance as biomarkers for clinical diagnosis. We highlight the cargo possibilities, including nucleic acids and drugs, which make them a good delivery system for targeted cancer treatment and contrast agents for disease monitoring. Other general aspects, sources, and the methodology associated with therapeutic cancer applications are also reviewed. Additionally, the challenges associated with translating exosome-based therapies into clinical practice are discussed, together with the future prospects for this innovative approach.

Extracellular vesicle-mediated chemoresistance in breast cancer: focus on miRNA cargo

The role of extracellular vesicles (EVs) in mediating chemoresistance has gained significant attention due to their ability to transfer bioactive molecules between drug-resistant and drug-sensitive cells. In particular, they have been demonstrated to play an active part in breast cancer chemoresistance by the horizontal transfer of genetic and protein material. This review highlights the role of EVs, particularly their miRNA cargo, in driving drug resistance in breast cancer. EVs derived from chemoresistant cells carry miRNAs and lncRNAs, which are known to modulate gene networks involved in cell proliferation and survival. These cargo molecules suppress apoptosis by targeting pro-apoptotic genes like PTEN and BIM, promote epithelial-mesenchymal transition (EMT) through the regulation of pathways such as TGF-β and Wnt/b-catenin, and contribute to tumor growth and resistance by enhancing angiogenesis and modulating the tumor microenvironment. Beyond RNA-mediated effects, EVs also transfer functional proteins, including P-glycoprotein and Hsp70, which impact cellular metabolism and survival pathways. Our findings underscore the significance of EVs in breast cancer chemoresistance, suggesting their potential involvement as possible prognostic factors to predict therapy response and as therapeutic targets in combination with usual therapy.

Mechanisms of extracellular vesicle uptake and implications for the design of cancer therapeutics

The translation of pre-clinical anti-cancer therapies to regulatory approval has been promising, but slower than hoped. While innovative and effective treatments continue to achieve or seek approval, setbacks are often attributed to a lack of efficacy, failure to achieve clinical endpoints, and dose-limiting toxicities. Successful efforts have been characterized by the development of therapeutics designed to specifically deliver optimal and effective dosing to tumour cells while minimizing off-target toxicity. Much effort has been devoted to the rational design and application of synthetic nanoparticles to serve as targeted therapeutic delivery vehicles. Several challenges to the successful application of this modality as delivery vehicles include the induction of a protracted immune response that results in their rapid systemic clearance, manufacturing cost, lack of stability, and their biocompatibility. Extracellular vesicles (EVs) are a heterogeneous class of endogenous biologically produced lipid bilayer nanoparticles that mediate intercellular communication by carrying bioactive macromolecules capable of modifying cellular phenotypes to local and distant cells. By genetic, chemical, or metabolic methods, extracellular vesicles (EVs) can be engineered to display targeting moieties on their surface while transporting specific cargo to modulate pathological processes following uptake by target cell populations. This review will survey the types of EVs, their composition and cargoes, strategies employed to increase their targeting, uptake, and cargo release, and their potential as targeted anti-cancer therapeutic delivery vehicles.

Tackling Anticancer Drug Resistance and Endosomal Escape in Aggressive Brain Tumors Using Bioelectronics

Resistance mechanisms in brain tumors, such as medulloblastoma and glioblastoma, frequently involve the entrapment of chemotherapeutic agents within endosomes and the extracellular expulsion of drugs. These barriers to effective treatment are exacerbated in nanotechnology-based drug delivery systems, where therapeutic nanoparticles often remain confined within endosomes, thus diminishing their therapeutic efficacy. Addressing this challenge necessitates the development of novel strategies to enhance the efficiency of cancer therapies. This study tests the hypothesis that external electrical stimuli can modulate intracellular trafficking of chemotherapeutic drugs in common malignant brain tumors in children (medulloblastoma) and adults (glioblastoma) by using gold nanoparticles (GNPs). In our experiments, alternating current (AC) stimulation ranging from 1 kHz to 5 MHz and at a strength of 1 V/cm significantly reduced cell viability in drug-resistant medulloblastoma and enhanced delivery of GNPs in glioblastoma. Low-frequency AC resulted in a 50% increase in apoptosis compared to controls and an 8-fold increase in cell death in cisplatin-resistant medulloblastoma cells, accompanied by a substantial reduction in EC50 from 2.5 to 0.3 μM. Similarly, vincristine-resistant cells demonstrated a 4-fold enhancement in drug sensitivity. Furthermore, high-frequency AC facilitated a significant increase from 20 to 75% in the endosomal escape of GNPs in glioblastoma cells. These findings underscore the potential of AC to selectively disrupt cancer cell resistance mechanisms and bolster the efficacy of nanoparticle-based therapies. The results indicate the effectiveness of AC stimulation in circumventing the limitations inherent in current nanotechnology-based drug delivery systems but also illustrates its transformative potential for treating aggressive, drug-resistant brain tumors.

Harmonising cellular conversations: decoding the vital roles of extracellular vesicles in respiratory system intercellular communications

Extracellular vesicles (EVs) released by various cells play crucial roles in intercellular communication within the respiratory system. This review explores the historical context and significance of research into extracellular vesicles. Categorised into exosomes (sized 30-150 nm), microvesicles (sized 50-1000 nm) and apoptotic bodies (sized 500-2000nm), based on their generation mechanisms, extracellular vesicles carry diverse cargoes of biomolecules, including proteins, lipids and nucleic acids. Respiratory ailments are the primary contributors to both mortality and morbidity across various populations globally, significantly impacting public health. Recent studies have underscored the pivotal role of extracellular vesicles, particularly their cargo content, in mediating intercellular communication between lung cells in respiratory diseases. This comprehensive review provides insights into extracellular vesicle mechanisms and emphasises their significance in major respiratory conditions, including acute lung injury, COPD, pulmonary hypertension, pulmonary fibrosis, asthma and lung cancer.

Extracellular Vesicles in Ovarian Cancer: From Chemoresistance Mediators to Therapeutic Vectors

Ovarian cancer (OC) remains the deadliest gynecological malignancy, with alarming projections indicating a 42% increase in new cases and a 51% rise in mortality by 2040. This review explores the challenges in OC treatment, focusing on chemoresistance mechanisms and the potential of extracellular vesicles (EVs) as drug delivery agents. Despite advancements in treatment strategies, including cytoreductive surgery, platinum-based chemotherapy, and targeted therapies, the high recurrence rate underscores the need for innovative approaches. Key resistance mechanisms include drug efflux, apoptosis disruption, enhanced DNA repair, cancer stem cells, immune evasion, and the complex tumor microenvironment. Cancer-associated fibroblasts and extracellular vesicles play crucial roles in modulating the tumor microenvironment and facilitating chemoresistance. EVs, naturally occurring nanovesicles, emerge as promising drug carriers due to their low toxicity, high biocompatibility, and inherent targeting capabilities. They have shown potential in delivering chemotherapeutics like doxorubicin, cisplatin, and paclitaxel, as well as natural compounds such as curcumin and berry anthocyanidins, enhancing therapeutic efficacy while reducing systemic toxicity in OC models. However, challenges such as low production yields, heterogeneity, rapid clearance, and inefficient drug loading methods need to be addressed for clinical application. Ongoing research aims to optimize EV production, loading efficiency, and targeting, paving the way for novel and more effective therapeutic strategies in OC treatment. Overcoming these obstacles is crucial to unlocking the full potential of EV-based therapies and improving outcomes for OC patients.

Tumor-Derived Small Extracellular Vesicles Involved in Breast Cancer Progression and Drug Resistance

Breast cancer is one of the most serious and terrifying threats to the health of women. Recent studies have demonstrated that interaction among cancer cells themselves and those with other cells, including immune cells, in a tumor microenvironment potentially and intrinsically regulate and determine cancer progression and metastasis. Small extracellular vesicles (sEVs), a type of lipid-bilayer particles derived from cells, with a size of less than 200 nm, are recognized as one form of important mediators in cell-to-cell communication. sEVs can transport a variety of bioactive substances, including proteins, RNAs, and lipids. Accumulating evidence has revealed that sEVs play a crucial role in cancer development and progression, with a significant impact on proliferation, invasion, and metastasis. In addition, sEVs systematically coordinate physiological and pathological processes, such as coagulation, vascular leakage, and stromal cell reprogramming, to bring about premetastatic niche formation and to determine metastatic organ tropism. There are a variety of oncogenic factors in tumor-derived sEVs that mediate cellular communication between local stromal cells and distal microenvironment, both of which are important in cancer progression and metastasis. Tumor-derived sEVs contain substances that are similar to parental tumor cells, and as such, sEVs could be biomarkers in cancer progression and potential therapeutic targets, particularly for predicting and preventing future metastatic development. Here, we review the mechanisms underlying the regulation by tumor-derived sEVs on cancer development and progression, including proliferation, metastasis, drug resistance, and immunosuppression, which coordinately shape the pro-metastatic microenvironment. In addition, we describe the application of sEVs to the development of cancer biomarkers and potential therapeutic modalities and discuss how they can be engineered and translated into clinical practice.

Regulation of Extracellular Vesicle-Mediated Immune Responses against Antigen-Specific Presentation

Extracellular vesicles (EVs) produced by various immune cells, including B and T cells, macrophages, dendritic cells (DCs), natural killer (NK) cells, and mast cells, mediate intercellular communication and have attracted much attention owing to the novel delivery system of molecules in vivo. DCs are among the most active exosome-secreting cells of the immune system. EVs produced by cancer cells contain cancer antigens; therefore, the development of vaccine therapy that does not require the identification of cancer antigens using cancer-cell-derived EVs may have significant clinical implications. In this review, we summarise the molecular mechanisms underlying EV-based immune responses and their therapeutic effects on tumour vaccination.