Exosomal L1CAM Stimulates Glioblastoma Cell Motility, Proliferation, and Invasiveness

Current Understanding of the Exosomes and Their Associated Biomolecules in the Glioblastoma Biology, Clinical Treatment, and Diagnosis

Glioblastoma is the most common and aggressive brain tumor with a low survival rate. Due to its heterogeneous composition, high invasiveness, and frequent recurrence after surgery, treatment success has been limited. In addition, due to the brain's unique immune status and the suppressor tumor microenvironment (TME), glioblastoma treatment has faced more challenges. Exosomes play a critical role in cancer metastasis by regulating cell-cell interactions that promote tumor growth, angiogenesis, metastasis, treatment resistance, and immunological regulation in the tumor microenvironment. This review explores the pivotal role of exosomes in the development of glioblastoma, with a focus on their potential as non-invasive biomarkers for prognosis, early detection and real-time monitoring of disease progression. Notably, exosome-based drug delivery methods hold promise for overcoming the blood-brain barrier (BBB) and developing targeted therapies for glioblastoma. Despite challenges in clinical translation, the potential for personalized exosome = -054321`therapies and the capacity to enhance therapeutic responses in glioblastoma, present intriguing opportunities for improving patient outcomes. It seems that getting a good and current grasp of the role of exosomes in the fight against glioblastoma would properly serve the scientific community to further their understanding of the related potentials of these biological moieties.

Autoradiography of Intracerebral Tumours in the Chick Embryo Model: A Feasibility Study Using Different PET Tracers

PURPOSE

In addition to rodent models, the chick embryo model has gained attention for radiotracer evaluation. Previous studies have investigated tumours on the chorioallantoic membrane (CAM), but its value for radiotracer imaging of intracerebral tumours has yet to be demonstrated.

PROCEDURES

Human U87 glioblastoma cells and U87-IDH1 mutant glioma cells were implanted into the brains of chick embryos at developmental day 5. After 12-14 days of tumour growth, blood-brain-barrier integrity was evaluated in vivo using MRI contrast enhancement or ex vivo with Evans blue dye. The tracers O-(2-[18F]fluoroethyl)-L-tyrosine ([18F]FET) (n = 5), 3,4-dihydroxy-6-[18F]-fluoro-L-phenylalanine ([18F]FDOPA) (n = 3), or [68Ga] labelled quinoline-based small molecule fibroblast activation protein inhibitor ([68Ga]FAPI-46) (n = 4) were injected intravenously if solid tumours were detected with MRI. For time-activity curves for [18F]FET, additional micro PET (µPET) was performed. The chick embryos were sacrificed 60 min post-injection, and cryosections of the tumour-bearing brains were produced and evaluated with autoradiography and immunohistochemistry.

RESULTS

Intracerebral tumours were produced with a 100% success rate in viable chick embryos at the experimental endpoint. However, 52% of chick embryos (n = 85) did not survive the procedure to embryonic development day 20. For the evaluated radiotracers, the tumour-to-brain ratios (TBR) derived from ex vivo autoradiography, as well as the tracer kinetics derived from µPET for intracerebral chick embryo tumours, were comparable to those previously reported in rodents and patients: the TBRmean for [18F]FET was 1.69 ± 0.54 (n = 5), and 3.8 for one hypermetabolic tumour and < 2.0 for two isometabolic tumors using [18F]FDOPA, with a TBRmean of 1.92 ± 1,11 (n = 3). The TBRmean of [68Ga]FAPI-46 for intracerebral chick embryo tumours was 19.13 ± 0.64 (n = 4). An intact blood-tumour barrier was observed in one U87-MG tumour (n = 5).

CONCLUSIONS

Radiotracer imaging of intracerebral tumours in the chick embryo offers a fast model for the evaluation of radiotracer uptake, accumulation, and kinetics. Our results indicate a high comparability between intracerebral tumour imaging in chick embryos and xenograft rodent models or brain tumour patients.

Multiprobe Photoproximity Labeling of the EGFR Interactome in Glioblastoma Using Red-Light

Photocatalytic proximity labeling has emerged as a valuable technique for studying interactions between biomolecules in a cellular context, providing precise spatiotemporal control over protein labeling. One significant advantage of these methods is their modularity, allowing the use of a single photocatalyst with different reactive probes to expand interactome coverage and capture diverse protein interactions. Despite these advances, fewer methods have been developed using red-light excitation, limiting the use of photoproximity labeling in more complex media such as tissues and animal models. Herein, we develop a platform for proximity labeling under red-light excitation, utilizing a single catalyst and two distinct probe types. We first design a carbene based labeling system that utilizes sulfonium diazo probes. This system is successfully applied on A549 cells to capture the interactome of epidermal growth factor receptor (EGFR) using a Cetuximab-Chlorin e6 conjugate. Benchmarking against established techniques indicates that this approach performs comparably to leading carbene-based proximity labeling methods. Next, we leverage the strong singlet oxygen generation (SOG) ability of Chlorin e6 to establish an alternative labeling system using aniline and hydrazide probes. EGFR directed chemoproteomics experiments reveal significant overlap with the carbene system, with the carbene approach capturing a subset of interactions identified by the SOG system. Finally, we deploy our approach for the characterization of EGFR in resected human glioblastoma (GBM) tissue samples removed from distinct locations in the same tumor, representing the tumor's infiltrating edge and its viable center, identifying several GBM specific interacting proteins that may serve as a launch point for future therapeutic campaigns.

Unlocking the therapeutic potential of tumor-derived EVs in ischemia-reperfusion: a breakthrough perspective from glioma and stroke

Clinical studies have revealed a bidirectional relationship between glioma and ischemic stroke, with evidence of spatial overlap between the two conditions. This connection arises from significant similarities in their pathological processes, including the regulation of cellular metabolism, inflammation, coagulation, hypoxia, angiogenesis, and neural repair, all of which involve common biological factors. A significant shared feature of both diseases is the crucial role of extracellular vesicles (EVs) in mediating intercellular communication. Extracellular vesicles, with their characteristic bilayer structure, encapsulate proteins, lipids, and nucleic acids, shielding them from enzymatic degradation by ribonucleases, deoxyribonucleases, and proteases. This structural protection facilitates long-distance intercellular communication in multicellular organisms. In gliomas, EVs are pivotal in intracranial signaling and shaping the tumor microenvironment. Importantly, the cargos carried by glioma-derived EVs closely align with the biological factors involved in ischemic stroke, underscoring the substantial impact of glioma on stroke pathology, particularly through the crucial roles of EVs as key mediators in this interaction. This review explores the pathological interplay between glioma and ischemic stroke, addressing clinical manifestations and pathophysiological processes across the stages of hypoxia, stroke onset, progression, and recovery, with a particular focus on the crucial role of EVs and their cargos in these interactions.

QSOX1 Modulates Glioblastoma Cell Proliferation and Migration In Vitro and Invasion In Vivo

Background: Quiescin Sulfhydryl Oxidase 1 (QSOX1) is an enzyme that catalyzes the oxidation of free thiols to generate disulfide bonds in a variety of proteins, including the cell surface and extracellular matrix. QSOX1 has been reported to be upregulated in a number of cancers, and the overexpression of QSOX1 has been correlated with aggressive cancers and poor patient prognosis. Glioblastoma (GBM) brain cancer has been practically impossible to treat effectively, with cells that rapidly invade normal brain tissue and escape surgery and other treatment. Thus, there is a crucial need to understand the multiple mechanisms that facilitate GBM cell invasion and to determine if QSOX1 is involved. Methods and Results: Here, we investigated the function of QSOX1 in human glioblastoma cells using two cell lines derived from T98G cells, whose proliferation, motility, and invasiveness has been shown by us to be dependent on disulfide bond-containing adhesion and receptor proteins, such as L1CAM and the FGFR. We lentivirally introduced shRNA to attenuate the QSOX1 protein expression in one cell line, and a Western blot analysis confirmed the decreased QSOX1 expression. A DNA content/cell cycle analysis using flow cytometry revealed 27% fewer knockdown cells in the S-phase of the cell cycle, indicating a reduced proliferation. A cell motility analysis utilizing our highly quantitative SuperScratch time-lapse microscopy assay revealed that knockdown cells migrated more slowly, with a 45% decrease in migration velocity. Motility was partly rescued by the co-culture of knockdown cells with control cells, indicating a paracrine effect. Surprisingly, knockdown cells exhibited increased motility when assayed using a Transwell migration assay. Our novel chick embryo orthotopic xenograft model was used to assess the in vivo invasiveness of knockdown vs. control cells, and tumors developed from both cell types. However, fewer invasive knockdown cells were observed after about a week. Conclusions: Our results indicate that an experimental reduction in QSOX1 expression in GBM cells leads to decreased cell proliferation, altered in vitro migration, and decreased in vivo invasion.

The role and application of small extracellular vesicles in glioma

Small extracellular vesicles (sEVs) are cell-derived, nanometer-sized particles enclosed by a lipid bilayer. All kinds of biological molecules, including proteins, DNA fragments, RNA, lipids, and metabolites, can be selectively loaded into sEVs and transmitted to recipient cells that are near and distant. Growing shreds of evidence show the significant biological function and the clinical significance of sEVs in cancers. Numerous recent studies have validated that sEVs play an important role in tumor progression and can be utilized to diagnose, stage, grading, and monitor early tumors. In addition, sEVs have also served as drug delivery nanocarriers and cancer vaccines. Although it is still infancy, the field of basic and translational research based on sEVs has grown rapidly. In this review, we summarize the latest research on sEVs in gliomas, including their role in the malignant biological function of gliomas, and the potential of sEVs in non-invasive diagnostic and therapeutic approaches, i.e., as nanocarriers for drug or gene delivery and cancer vaccines.

From bench to bedside: The promising value of exosomes in precision medicine for CNS tumors

Exosomes are naturally present extracellular vesicles (EVs) released into the surrounding body fluids upon the fusion of polycystic and plasma membranes. They facilitate intercellular communication by transporting DNA, mRNA, microRNA, long non-coding RNA, circular RNA, proteins, lipids, and nucleic acids. They contribute to the onset and progression of Central Nervous System (CNS) tumors. In addition, they can be used as biomarkers of tumor proliferation, migration, and blood vessel formation, thereby affecting the Tumor Microenvironment (TME). This paper reviews the recent advancements in the diagnosis and treatment of exosomes in various CNS tumors, the promise and challenges of exosomes as natural carriers of CNS tumors, and the therapeutic prospects of exosomes in CNS tumors. Furthermore, we hope this research can contribute to the development of more targeted and effective treatments for central nervous system tumors.

Biological, diagnostic and therapeutic implications of exosomes in glioma

Despite therapeutic advances, overall survival in glioblastoma is dismal. To optimize progress, a more detailed understanding of glioma's molecular, cellular, and intercellular pathophysiology is needed. Recent investigation has revealed a vital role for exosomes in inter-cellular signaling, tumor cell support, and regulation of the tumor microenvironment. Exosomes carry miRNAs, lncRNAs, mRNAs, proteins, immune regulatory molecules, nucleic acids, and lipids; however, the composition of exosome cargo is variable depending on the cell of origin. Specific exosomal miRNA contents such as miR-21, miR-301a, miR-151a, miR-148a, and miR-5096 are altered in high-grade glioma. Unique proteomic, genomic, and miRNA signatures of tumor exosomes have been associated with disease pathobiology, temozolomide resistance, immunosuppression, and tumor proliferation. Exosomes hold promise for tissue diagnostic glioma diagnosis and monitoring response to therapy. This review summarizes the current understanding of exosomes, their crucial role in glioma pathology, and future directions for their use in diagnosis and treatment. METHODS: The MEDLINE/PubMed database was reviewed for papers written in English and publication dates of 1981-2023, using the search string "Exosome", "Extracellular vesicles", "Glioma", "Exosomes in glioma".

Drug target therapy and emerging clinical relevance of exosomes in meningeal tumors

Meningioma is the most common central nervous system (CNS) tumor. In recent decades, several efforts have been made to eradicate this disease. Surgery and radiotherapy remain the standard treatment options for these tumors. Drug therapy comes to play its role when both surgery and radiotherapy fail to treat the tumor. This mostly happens when the tumors are close to vital brain structures and are nonbenign. Although a wide variety of chemotherapeutic drugs and molecular targeted drugs such as tyrosine kinase inhibitors, alkylating agents, endocrine drugs, interferon, and targeted molecular pathway inhibitors have been studied, the roles of numerous drugs remain unexplored. Recent interest is growing toward studying and engineering exosomes for the treatment of different types of cancer including meningioma. The latest studies have shown the involvement of exosomes in the theragnostic of various cancers such as the lung and pancreas in the form of biomarkers, drug delivery vehicles, and vaccines. Proper attention to this new emerging technology can be a boon in finding the consistent treatment of meningioma.

Epigenetic Alteration of H3K27me3 as a Possible Oncogenic Mechanism of Central Neurocytoma

Central neurocytoma (CN) is a low-grade neuronal tumor that mainly arises from the lateral ventricle (LV). This tumor remains poorly understood in the sense that no driver gene aberrations have been identified thus far. We investigated immunomarkers in fetal and adult brains and 45 supratentorial periventricular tumors to characterize the biomarkers, cell of origin, and tumorigenesis of CN. All CNs occurred in the LV. A minority involved the third ventricle, but none involved the fourth ventricle. As expected, next-generation sequencing performed using a brain-tumor-targeted gene panel in 7 CNs and whole exome sequencing in 5 CNs showed no driver mutations. Immunohistochemically, CNs were robustly positive for FGFR3 (100%), SSTR2 (92%), TTF-1 (Nkx2.1) (88%), GLUT-1 (84%), and L1CAM (76%), in addition to the well-known markers of CN, synaptophysin (100%) and NeuN (96%). TTF-1 was also positive in subependymal giant cell astrocytomas (100%, 5/5) and the pituicyte tumor family, including pituicytoma and spindle cell oncocytoma (100%, 5/5). Interestingly, 1 case of LV subependymoma (20%, 1/5) was positive for TTF-1, but all LV ependymomas were negative (0/5 positive). Because TTF-1-positive cells were detected in the medial ganglionic eminence around the foramen of Monro of the fetal brain and in the subventricular zone of the LV of the adult brain, CN may arise from subventricular TTF-1-positive cells undergoing neuronal differentiation. H3K27me3 loss was observed in all CNs and one case (20%) of LV subependymoma, suggesting that chromatin remodeling complexes or epigenetic alterations may be involved in the tumorigenesis of all CNs and some ST-subependymomas. Further studies are required to determine the exact tumorigenic mechanism of CN.

Neuronally enriched microvesicle RNAs are differentially expressed in the serums of Parkinson's patients

Background

Circulating small RNAs (smRNAs) originate from diverse tissues and organs. Previous studies investigating smRNAs as potential biomarkers for Parkinson's disease (PD) have yielded inconsistent results. We investigated whether smRNA profiles from neuronally-enriched serum exosomes and microvesicles are altered in PD patients and discriminate PD subjects from controls.

Methods

Demographic, clinical, and serum samples were obtained from 60 PD subjects and 40 age- and sex-matched controls. Exosomes and microvesicles were extracted and isolated using a validated neuronal membrane marker (CD171). Sequencing and bioinformatics analyses were used to identify differentially expressed smRNAs in PD and control samples. SmRNAs also were tested for association with clinical metrics. Logistic regression and random forest classification models evaluated the discriminative value of the smRNAs.

Results

In serum CD171 enriched exosomes and microvesicles, a panel of 29 smRNAs was expressed differentially between PD and controls (false discovery rate (FDR) < 0.05). Among the smRNAs, 23 were upregulated and 6 were downregulated in PD patients. Pathway analysis revealed links to cellular proliferation regulation and signaling. Least absolute shrinkage and selection operator adjusted for the multicollinearity of these smRNAs and association tests to clinical parameters via linear regression did not yield significant results. Univariate logistic regression models showed that four smRNAs achieved an AUC ≥ 0.74 to discriminate PD subjects from controls. The random forest model had an AUC of 0.942 for the 29 smRNA panel.

Conclusion

CD171-enriched exosomes and microvesicles contain the differential expression of smRNAs between PD and controls. Future studies are warranted to follow up on the findings and understand the scientific and clinical relevance.

Exosomes as Novel Diagnostic Biomarkers and Therapeutic Tools in Gliomas

Exosomes constitute small extracellular vesicles that contain lipids, proteins, nucleic acids, and glycoconjugates from the secreted cells and are capable of transmitting signals between cells and coordinating cellular communication. By this means, they are ultimately involved in physiology and disease, including development, homeostasis, and immune system regulation, as well as contributing to tumor progression and neurodegenerative diseases pathology. Recent studies have shown that gliomas secrete a panel of exosomes which have been associated with cell invasion and migration, tumor immune tolerance, potential for malignant transformation, neovascularization, and resistance to treatment. Exosomes have therefore emerged as intercellular communicators, which mediate the tumor-microenvironment interactions and exosome-regulated glioma cell stemness and angiogenesis. They may induce tumor proliferation and malignancy in normal cells by carrying pro-migratory modulators from cancer cells as well as many different molecular cancer modifiers, such as oncogenic transcripts, miRNAs, mutant oncoproteins, etc., which promote the communication of cancer cells with the surrounding stromal cells and provide valuable information on the molecular profile of the existing tumor. Moreover, engineered exosomes can provide an alternative system for drug delivery and enable efficient treatment. In the present review, we discuss the latest findings regarding the role of exosomes in glioma pathogenesis, their utility in non-invasive diagnosis, and potential applications to treatment.

L1CAM expression in either metastatic brain lesion or peripheral blood is correlated with peripheral platelet count in patients with brain metastases from lung cancer

Background

Systemic immune-inflammation states across the heterogeneous population of brain metastases from lung cancer are very important, especially in the context of complex brain-immune bidirectional communication. Previous studies from our team and others have shown that the L1 cell adhesion molecule (L1CAM) is deeply involved in the aggressive phenotype, immunosuppressive tumor microenvironment (TME), and metastasis during multiple malignancies, which may lead to an unfavorable outcome. However, little is known about the relationship between the L1CAM expression and the systemic immune-inflammation macroenvironment beyond the TME in brain metastases from lung cancer.

Methods

Two cohorts of patients with brain metastases from lung cancer admitted to the National Cancer Center, Cancer Hospital of Chinese Academy of Medical Sciences, were studied in the present research. The L1CAM expression in cranial metastatic lesions by immunohistochemistry was explored in patients treated with neurosurgical resection, whereas the L1CAM expression in peripheral blood by ELISA was tested in patients treated with non-surgical antitumor management. Furthermore, based on peripheral blood cell counts in the CBC test, six systemic immune-inflammation biomarkers [neutrophil count, lymphocyte count, platelet count, systemic immune-inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio] were calculated. Then, the relationship between the L1CAM expression and these systemic immune-inflammation biomarkers was analyzed. In addition, these systemic immune-inflammation biomarkers were also used to compare the systemic immune-inflammation states in two cohorts of patients with brain metastases from lung cancer.

Results

Positive L1CAM expressions in the metastatic brain lesions were accompanied with significantly increased peripheral platelet counts in patients treated with neurosurgical tumor resection (P &lt; 0.05). Similarly, in patients treated with non-surgical antitumor management, L1CAM expressions in the peripheral blood were positively correlated with peripheral platelet counts (P &lt; 0.05). In addition, patients prepared for neurosurgical tumor resection were presented with poorer systemic immune-inflammation states in comparison with the one with non-surgical antitumor management, which was characterized by a significant increase in peripheral neutrophil counts (P &lt; 0.01), SII (P &lt; 0.05), and NLR (P &lt; 0.05) levels.

Conclusion

The L1CAM expression in either the metastatic brain lesion or peripheral blood is positively correlated with the peripheral platelet count in patients with brain metastases from lung cancer. In addition, brain metastases that are prepared for neurosurgical tumor resection show poor systemic immune-inflammation states.

Multiple roles of neuronal extracellular vesicles in neurological disorders

Neuropathy is a growing public health problem in the aging, adolescent, and sport-playing populations, and the number of individuals at risk of neuropathy is growing; its risks include aging, violence, and conflicts between players. The signal pathways underlying neuronal aging and damage remain incompletely understood and evidence-based treatment for patients with neuropathy is insufficiently delivered; these are two of the reasons that explain why neuropathy is still not completely curable and why the progression of the disease cannot be inhibited. Extracellular vesicles (EVs) shuttling is an important pathway in disease progression. Previous studies have focused on the EVs of cells that support and protect neurons, such as astrocytes and microglia. This review aims to address the role of neuronal EVs by delineating updated mechanisms of neuronal damage and summarizing recent findings on the function of neuronal EVs. Challenges and obstacles in isolating and analyzing neuronal EVs are discussed, with an emphasis on neuron as research object and modification of EVs on translational medicine.

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.

Exosome-based strategies for diagnosis and therapy of glioma cancer

Glioblastoma belongs to the most aggressive type of cancer with a low survival rate that is characterized by the ability in forming a highly immunosuppressive tumor microenvironment. Intercellular communication are created via exosomes in the tumor microenvironment through the transport of various biomolecules. They are primarily involved in tumor growth, differentiation, metastasis, and chemotherapy or radiation resistance. Recently several studies have highlighted the critical role of tumor-derived exosomes against immune cells. According to the structural and functional properties, exosomes could be essential instruments to gain a better molecular mechanism for tumor understanding. Additionally, they are qualified as diagnostic/prognostic markers and therapeutic tools for specific targeting of invasive tumor cells such as glioblastomas. Due to the strong dependency of exosome features on the original cells and their developmental status, it is essential to review their critical modulating molecules, clinical relevance to glioma, and associated signaling pathways. This review is a non-clinical study, as the possible role of exosomes and exosomal microRNAs in glioma cancer are reported. In addition, their content to overcome cancer resistance and their potential as diagnostic biomarkers are analyzed.

Glioma extracellular vesicles for precision medicine: prognostic and theragnostic application

EV produced by tumour cells carry a diverse population of proteins, lipids, DNA, and RNA molecules throughout the body and appear to play an important role in the overall development of the disease state, according to growing data. Gliomas account for a sizable fraction of all primary brain tumours and the vast majority of brain malignancies. Glioblastoma multiforme (GBM) is a kind of grade IV glioma that has a very dismal prognosis despite advancements in diagnostic methods and therapeutic options. The authors discuss advances in understanding the function of extracellular vesicles (EVs), in overall glioma growth, as well as how recent research is uncovering the utility of EVs in glioma diagnostics, prognostic and therapeutics approaches.

Tumor-Derived Exosomes Modulate Primary Site Tumor Metastasis

Tumor-derived exosomes (TDEs) are actively produced and released by tumor cells and carry messages from tumor cells to healthy cells or abnormal cells, and they participate in tumor metastasis. In this review, we explore the underlying mechanism of action of TDEs in tumor metastasis. TDEs transport tumor-derived proteins and non-coding RNA to tumor cells and promote migration. Transport to normal cells, such as vascular endothelial cells and immune cells, promotes angiogenesis, inhibits immune cell activation, and improves chances of tumor implantation. Thus, TDEs contribute to tumor metastasis. We summarize the function of TDEs and their components in tumor metastasis and illuminate shortcomings for advancing research on TDEs in tumor metastasis.

Antagonistic L1 Adhesion Molecule Mimetic Compounds Inhibit Glioblastoma Cell Migration In Vitro

Cell adhesion molecule L1 is a cell surface glycoprotein that promotes neuronal cell migration, fosters regeneration after spinal cord injury and ameliorates the consequences of neuronal degeneration in mouse and zebrafish models. Counter-indicative features of L1 were found in tumor progression: the more L1 is expressed, the more tumor cells migrate and increase their metastatic potential. L1′s metastatic potential is further evidenced by its promotion of epithelial–mesenchymal transition, endothelial cell transcytosis and resistance to chemo- and radiotherapy. These unfortunate features are indicated by observations that cells that normally do not express L1 are induced to express it when becoming malignant. With the aim to ameliorate the devastating functions of L1 in tumors, we designed an alternative approach to counteract tumor cell migration. Libraries of small organic compounds were screened using the ELISA competition approach similar to the one that we used for identifying L1 agonistic mimetics. Whereas in the former approach, a function-triggering monoclonal antibody was used for screening libraries, we here used the function-inhibiting monoclonal antibody 324 that reduces the migration of neurons. We now show that the L1 antagonistic mimetics anagrelide, 2-hydroxy-5-fluoropyrimidine and mestranol inhibit the migration of cultured tumor cells in an L1-dependent manner, raising hopes for therapy.

L1CAM-associated extracellular vesicles: A systematic review of nomenclature, sources, separation, and characterization

When released into biological fluids like blood or saliva, brain extracellular vesicles (EVs) might provide a window into otherwise inaccessible tissue, contributing useful biomarkers of neurodegenerative and other central nervous system (CNS) diseases. To enrich for brain EVs in the periphery, however, cell-specific EV surface markers are needed. The protein that has been used most frequently to obtain EVs of putative neuronal origin is the transmembrane L1 cell adhesion molecule (L1CAM/CD171). In this systematic review, we examine the existing literature on L1CAM and EVs, including investigations of both neurodegenerative disease and cancer through the lens of the minimal information for studies of EVs (MISEV), specifically in the domains of nomenclature usage, EV sources, and EV separation and characterization. Although numerous studies have reported L1CAM-associated biomarker signatures that correlate with disease, interpretation of these results is complicated since L1CAM expression is not restricted to neurons and is also upregulated during cancer progression. A recent study has suggested that L1CAM epitopes are present in biofluids mostly or entirely as cleaved, soluble protein. Our findings on practices and trends in L1CAM-mediated EV separation, enrichment, and characterization yield insights that may assist with interpreting results, evaluating rigor, and suggesting avenues for further exploration.

Structure and function of glycosphingolipids on small extracellular vesicles

Extracellular vesicles (EVs) are membrane-delineated particles secreted by most types of cells under both normal and pathophysiological conditions. EVs are believed to mediate intercellular communication by serving as carriers of different bioactive ingredients, including proteins, nucleic acids and lipids. Glycoconjugates are complex molecules consisting of covalently linked carbohydrate with proteins or lipids. These glycoconjugates play essential roles in the sorting of vesicular protein and the uptake of small extracellular vesicles (30–100 nm, sEVs) into recipient cells. Glycosphingolipids (GSLs), one subtype of glycolipids, which are ubiquitous membrane components in almost all living organisms, are also commonly distributed on sEVs. However, the study of functional roles of GSLs on sEVs are far behind than other functional cargos. The purpose of this review is to highlight the importance of GSLs on sEVs. Initially, we described classification and structure of GSLs. Then, we briefly introduced the essential functions of GSLs, which are able to interact with functional membrane proteins, such as growth factor receptors, integrins and tetraspanins, to modulate cell growth, adhesion and cell motility. In addition, we discussed analytical methods for studying GSLs on sEVs. Finally, we focused on the function of GSLs on sEVs, including regulating the aggregation of extracellular α-synuclein (α-syn) or extracellular amyloid-β (Aβ) and influencing tumor cell malignancy.

Tear proteomics reveals the molecular basis of the efficacy of human recombinant nerve growth factor treatment for Neurotrophic Keratopathy

Neurotrophic Keratopathy (NK), classified as an orphan disease (ORPHA137596), is a rare degenerative corneal disease characterized by epithelial instability and decreased corneal sensitivity caused by the damage to the corneal nerves. The administration of human recombinant nerve growth factor (rhNGF) eye drops, as a licensed-in-Europe specific medication for treatment of moderate and severe NK, has added promising perspectives to the management of this disorder by providing a valid alternative to the neurotization surgery. However, few studies have been conducted to the molecular mechanism underlying the response to the treatment. Here, we carried out tears proteomics to highlight the protein expression during pharmacological treatment of NK (Data are available via ProteomeXchange with identifier PXD025408).Our data emphasized a proteome modulation during rhNGF treatment related to an increase in DNA synthesis, an activation of both BDNF signal and IL6 receptor. Furthermore, the amount of neuronal Extracellular Vesicles EVs (CD171+) correlated with the EVs carrying IL6R (CD126+) together associated to the inflammatory EVs (CD45+) in tears. Such scenario determined drug response, confirmed by an in vivo confocal microscopy analysis, showing an increase in length, density and number of nerve fiber branches during treatment. In summary, rhNGF treatment seems to determine an inflammatory micro-environment, mediated by functionalized EVs, defining the drug response by stimulating protein synthesis and fiber regeneration.

Predicting Glioblastoma Cellular Motility from In Vivo MRI with a Radiomics Based Regression Model

Simple Summary

A diagnosis of glioblastoma carries a uniformly dismal prognosis. Contributing to this is the near certain chance of aggressive tumor spread and recurrence following treatment. Tumor cell motility may provide one way to characterize the tendencies of glioblastomas to spread and recur. We sought to develop a non-invasive technique for assessing tumor cell motility using quantitative features derived from in vivo preoperative magnetic resonance imaging. Our regression model accurately predicted tumor cell motility in a cohort of participants with preoperative imaging who also had mean cellular motility calculated for their resected tumor cells from time-lapse videos. This work establishes the feasibility of non-invasively characterizing the kinetic properties of tumors and could be used to select patients for motility-targeting precision therapies.

Abstract

Characterizing the motile properties of glioblastoma tumor cells could provide a useful way to predict the spread of tumors and to tailor the therapeutic approach. Radiomics has emerged as a diagnostic tool in the classification of tumor grade, stage, and prognosis. The purpose of this work is to examine the potential of radiomics to predict the motility of glioblastoma cells. Tissue specimens were obtained from 31 patients undergoing surgical resection of glioblastoma. Mean tumor cell motility was calculated from time-lapse videos of specimen cells. Manual segmentation was used to define the border of the enhancing tumor T1-weighted MR images, and 107 radiomics features were extracted from the normalized image volumes. Model parameter coefficients were estimated using the adaptive lasso technique validated with leave-one-out cross validation (LOOCV) and permutation tests. The R-squared value for the predictive model was 0.60 with p-values for each individual parameter estimate less than 0.0001. Permutation test models trained with scrambled motility failed to produce a model that out-performed the model trained on the true data. The results of this work suggest that it is possible for a quantitative MRI feature-based regression model to non-invasively predict the cellular motility of glioblastomas.

Transcription Factors Leading to High Expression of Neuropeptide L1CAM in Brain Metastases from Lung Adenocarcinoma and Clinical Prognostic Analysis

Background

There is a lack of understanding of the development of metastasis in lung adenocarcinoma (LUAD). This study is aimed at exploring the upstream regulatory transcription factors of L1 cell adhesion molecule (L1CAM) and to construct a prognostic model to predict the risk of brain metastasis in LUAD.

Methods

Differences in gene expression between LUAD and brain metastatic LUAD were analyzed using the Wilcoxon rank-sum test. The GRNdb (http://www.grndb.com) was used to reveal the upstream regulatory transcription factors of L1CAM in LUAD. Single-cell expression profile data (GSE131907) were obtained from the transcriptome data of 10 metastatic brain tissue samples. LUAD prognostic nomogram prediction models were constructed based on the identified significant transcription factors and L1CAM.

Results

Survival analysis suggested that high L1CAM expression was negatively significantly associated with overall survival, disease-specific survival, and prognosis in the progression-free interval (p < 0.05). The box plot indicates that high expression of L1CAM was associated with distant metastases in LUAD, while ROC curves suggested that high expression of L1CAM was associated with poor prognosis. FOSL2, HOXA9, IRF4, IKZF1, STAT1, FLI1, ETS1, E2F7, and ADARB1 are potential upstream transcriptional regulators of L1CAM. Single-cell data analysis revealed that the expression of L1CAM was found significantly and positively correlated with the expression of ETS1, FOSL2, and STAT1 in brain metastases. L1CAM, ETS1, FOSL2, and STAT1 were used to construct the LUAD prognostic nomogram prediction model, and the ROC curves suggest that the constructed nomogram possesses good predictive power.

Conclusion

By bioinformatics methods, ETS1, FOSL2, and STAT1 were identified as potential transcriptional regulators of L1CAM in this study. This will help to facilitate the early identification of patients at high risk of metastasis.

L1 cell adhesion molecule high expression is associated with poor prognosis in surgically resected brain metastases from lung adenocarcinoma

OBJECTIVES

Accurate prognosis assessment across the heterogeneous population of brain metastases is very important, which may facilitate clinical decision-making and appropriate stratification of future clinical trials. Previous studies have shown the L1 Cell Adhesion Molecule (L1CAM) is potentially involved in human malignancies of multiple different samples and unfavorable survival. However, no data of L1CAM are available for the brain metastases from lung adenocarcinoma, especially for the one with neurosurgical resection.

METHOD

The authors investigated the L1CAM expression in cranial metastatic lesions for patients with brain metastases from lung adenocarcinoma after neurosurgical resection using tissue microarrays that were obtained from the Department of Neurosurgery at the Cancer Hospital of the Chinese Academy of Medical Sciences. Furthermore, the relationship between L1CAM expression and clinic-pathological parameters, including overall survival time, was analyzed to assess the prognostic value of L1CAM.

RESULTS

L1CAM high expression was found in 62.30% of brain metastases from lung adenocarcinoma and significantly correlated with brain metastasis number (p = 0.028) and Lung-molGPA score (p = 0.042). Moreover, L1CAM expression was an independent predictor of survival for brain metastases after neurosurgical resection in a multivariate analysis. Patients with L1CAM high expression had unfavorable overall survival time (p = 0.016). In addition, the multivariate analysis also showed age and extracranial transfer were also the independent prognostic factors for this type of patient with brain metastases.

CONCLUSIONS

A subset of brain metastases from lung adenocarcinoma aberrantly expresses L1CAM. L1CAM is a novel independent prognostic factor for brain metastasis from lung adenocarcinoma after neurosurgical resection.

The impact of obesity on adipocyte-derived extracellular vesicles

Recently, the emerging roles of adipocyte-derived extracellular vesicles (EVs) linking obesity and its comorbidities have been recognized. In obese subjects, adipocytes are having hypertrophic growth and are under stressed. The dysfunction adipocytes dysregulate the assembly of the biological components in the EVs including exosomes. This article critically reviews the current findings on the impact of obesity on the exosomal cargo contents that induce the pathophysiological changes. Besides, this review also summarizes the understanding on how obesity affects the biogenesis of adipocyte-derived exosomes and the exosome secretion. Furthermore, the differences of the exosomal contents in different adipose depots, and the impact of obesity on the exosomes that are derived from the stromal vascular fraction such as the adipose tissue macrophages and adipocyte-derived stem cells will also be discussed. The current development and potential application of exosome-based therapy will be summarized. This review provides crucial information for the design of novel exosome-based therapy for the treatment of obesity and its comorbidities.

Extracellular vesicles derived from radioresistant oral squamous cell carcinoma cells contribute to the acquisition of radioresistance via the miR-503-3p-BAK axis

Despite advancements in treatments, oral squamous cell carcinoma (OSCC) has not significantly improved in prognosis or survival rate primarily due to the presence of treatment-resistant OSCC. The intercellular communication between tumour cells is a molecular mechanism involved in acquiring OSCC treatment resistance. Extracellular vesicles (EVs) and encapsulated miRNAs are important mediators of intercellular communication. Here, we focused on EVs released from clinically relevant radioresistant (CRR) OSCC cells. Additionally, we evaluated the correlation between miRNA expression in the serum samples of patients who showed resistance to radiotherapy and in EVs released from CRR OSCC cells. We found that EVs released from CRR OSCC cells conferred radioresistance to radiosensitive OSCC cells via miR-503-3p contained in EVs. This miR-503-3p inhibited BAK and impaired the caspase cascade to suppress radiation-induced apoptosis. Furthermore, OSCC cells with BAK knockdown had increased radioresistance. Additionally, the expression of circulating miR-503-3p in patients with OSCC was correlated with a poor treatment response and prognosis of radiotherapy. Our results provide new insights into the relationship between EVs and the radioresistance of OSCC and suggest that the miR-503-3p-BAK axis may be a therapeutic target and that circulating miR-503-3p is a useful prognostic biomarker in the radiotherapy of OSCC.

The Roles of Exosomes as Future Therapeutic Agents and Diagnostic Tools for Glioma

Glioma is a common type of tumor originating in the brain. Glioma develops in the gluey supporting cells (glial cells) that surround and support nerve cells. Exosomes are extracellular vesicles that contain microRNAs, messenger RNA, and proteins. Exosomes are the most prominent mediators of intercellular communication, regulating, instructing, and re-educating their surrounding milieu targeting different organs. As exosomes' diameter is in the nano range, the ability to cross the blood-brain barrier, a crucial obstacle in developing therapeutics against brain diseases, including glioma, makes the exosomes a potential candidate for delivering therapeutic agents for targeting malignant glioma. This review communicates the current knowledge of exosomes' significant roles that make them crucial future therapeutic agents and diagnostic tools for glioma.

Small Extracellular Vesicles: Functions and Potential Clinical Applications as Cancer Biomarkers

Cancer, as the second leading cause of death worldwide, is a major public health concern that imposes a heavy social and economic burden. Effective approaches for either diagnosis or therapy of most cancers are still lacking. Dynamic monitoring and personalized therapy are the main directions for cancer research. Cancer-derived extracellular vesicles (EVs) are potential disease biomarkers. Cancer EVs, including small EVs (sEVs), contain unique biomolecules (protein, nucleic acid, and lipids) at various stages of carcinogenesis. In this review, we discuss the biogenesis of sEVs, and their functions in cancer, revealing the potential applications of sEVs as cancer biomarkers.

Role of Exosomes in Brain Diseases

Exosomes are a subset of extracellular vesicles that act as messengers to facilitate communication between cells. Non-coding RNAs, proteins, lipids, and microRNAs are delivered by the exosomes to target molecules (such as proteins, mRNAs, or DNA) of host cells, thereby playing a key role in the maintenance of normal brain function. However, exosomes are also involved in the occurrence, prognosis, and clinical treatment of brain diseases, such as Alzheimer's disease, Parkinson's disease, stroke, and traumatic brain injury. In this review, we have summarized novel findings that elucidate the role of exosomes in the occurrence, prognosis, and treatment of brain diseases.

Serum-Derived Neuronal Exosomal miRNAs as Biomarkers of Acute Severe Stress

Stress is the physical and psychological tension felt by an individual while adapting to difficult situations. Stress is known to alter the expression of stress hormones and cause neuroinflammation in the brain. In this study, miRNAs in serum-derived neuronal exosomes (nEVs) were analyzed to determine whether differentially expressed miRNAs could be used as biomarkers of acute stress. Specifically, acute severe stress was induced in Sprague-Dawley rats via electric foot-shock treatment. In this acute severe-stress model, time-dependent changes in the expression levels of stress hormones and neuroinflammation-related markers were analyzed. In addition, nEVs were isolated from the serum of control mice and stressed mice at various time points to determine when brain damage was most prominent; this was found to be 7 days after foot shock. Next-generation sequencing was performed to compare neuronal exosomal miRNA at day 7 with the neuronal exosomal miRNA of the control group. From this analysis, 13 upregulated and 11 downregulated miRNAs were detected. These results show that specific miRNAs are differentially expressed in nEVs from an acute severe-stress animal model. Thus, this study provides novel insights into potential stress-related biomarkers.

The 3.0 Cell Communication: New Insights in the Usefulness of Tunneling Nanotubes for Glioblastoma Treatment

Simple Summary

Communication between cells helps tumors acquire resistance to chemotherapy and makes the struggle against cancer more challenging. Tunneling nanotubes (TNTs) are long channels able to connect both nearby and distant cells, contributing to a more malignant phenotype. This finding might be useful in designing novel strategies of drug delivery exploiting these systems of connection. This would be particularly important to reach tumor niches, where glioblastoma stem cells proliferate and provoke immune escape, thereby increasing metastatic potential and tumor recurrence a few months after surgical resection of the primary mass. Along with the direct inhibition of TNT formation, TNT analysis, and targeting strategies might be useful in providing innovative tools for the treatment of this tumor.

Abstract

Glioblastoma (GBM) is a particularly challenging brain tumor characterized by a heterogeneous, complex, and multicellular microenvironment, which represents a strategic network for treatment escape. Furthermore, the presence of GBM stem cells (GSCs) seems to contribute to GBM recurrence after surgery, and chemo- and/or radiotherapy. In this context, intercellular communication modalities play key roles in driving GBM therapy resistance. The presence of tunneling nanotubes (TNTs), long membranous open-ended channels connecting distant cells, has been observed in several types of cancer, where they emerge to steer a more malignant phenotype. Here, we discuss the current knowledge about the formation of TNTs between different cellular types in the GBM microenvironment and their potential role in tumor progression and recurrence. Particularly, we highlight two prospective strategies targeting TNTs as possible therapeutics: (i) the inhibition of TNT formation and (ii) a boost in drug delivery between cells through these channels. The latter may require future studies to design drug delivery systems that are exchangeable through TNTs, thus allowing for access to distant tumor niches that are involved in tumor immune escape, maintenance of GSC plasticity, and increases in metastatic potential.

Exosomal transfer of miR‑25‑3p promotes the proliferation and temozolomide resistance of glioblastoma cells by targeting FBXW7

Intrinsic or acquired resistance to temozolomide (TMZ) is a frequent occurrence in patients with glioblastoma (GBM). Accumulating evidence has indicated that the exosomal transfer of proteins and RNAs may confer TMZ resistance to recipient cells; however, the potential molecular mechanisms are not fully understood. Thus, the aim of the present study was to elucidate the possible role of exosomal microRNAs (miRNAs/miRs) in the acquired resistance to TMZ in GBM. A TMZ-resistant GBM cell line (A172R) was used, and exosomes derived from A172R cells were extracted. Exosomal miR-25-3p was identified as a miRNA associated with TMZ resistance. The potential functions of exosomal miR-25-3p were evaluated by reverse transcription-quantitative PCR, as well as cell viability, colony formation and soft agar assay, flow cytometry, western blot analysis, BrdU incorporation assay, tumor xenograft formation, luciferase reporter assay and RNA immunoprecipitation. It was found that A172R-derived exosomes promoted the proliferation and TMZ resistance of sensitive GBM cells. Moreover, miR-25-3p epxression was upregulated in the exosomes of A172R cells and in serum samples of patients with GBM treated with TMZ. The depletion of exosomal miR-25-3p partially abrogated the effects induced by the transfer of exosomes from A172R cells. By contrast, miR-25-3p overexpression facilitated the proliferation and TMZ resistance of sensitive GBM cells. F-box and WD repeat domain-containing-7 (FBXW7) was identified as a direct target of miR-25-3p. FBXW7 knockdown promoted the proliferation and TMZ resistance of GBM cells. Furthermore, the exosomal transfer of miR-25-3p promoted c-Myc and cyclin E expression by downregulating FBXW7. Our results provided a novel insight into exosomal microRNAs in acquired TMZ resistance of GBM cells. Besides, exosomal miR-25-3p might be a potential prognostic marker for GBM patients.

The Multifaceted Role of Extracellular Vesicles in Glioblastoma: microRNA Nanocarriers for Disease Progression and Gene Therapy

Glioblastoma (GB) is the most aggressive form of brain cancer in adults, characterized by poor survival rates and lack of effective therapies. MicroRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression post-transcriptionally through specific pairing with target messenger RNAs (mRNAs). Extracellular vesicles (EVs), a heterogeneous group of cell-derived vesicles, transport miRNAs, mRNAs and intracellular proteins, and have been shown to promote horizontal malignancy into adjacent tissue, as well as resistance to conventional therapies. Furthermore, GB-derived EVs have distinct miRNA contents and are able to penetrate the blood-brain barrier. Numerous studies have attempted to identify EV-associated miRNA biomarkers in serum/plasma and cerebrospinal fluid, but their collective findings fail to identify reliable biomarkers that can be applied in clinical settings. However, EVs carrying specific miRNAs or miRNA inhibitors have great potential as therapeutic nanotools in GB, and several studies have investigated this possibility on in vitro and in vivo models. In this review, we discuss the role of EVs and their miRNA content in GB progression and resistance to therapy, with emphasis on their potential as diagnostic, prognostic and disease monitoring biomarkers and as nanocarriers for gene therapy.

Tumor Vessels Fuel the Fire in Glioblastoma

Glioblastoma, a subset of aggressive brain tumors, deploy several means to increase blood vessel supply dedicated to the tumor mass. This includes typical program borrowed from embryonic development, such as vasculogenesis and sprouting angiogenesis, as well as unconventional processes, including co-option, vascular mimicry, and transdifferentiation, in which tumor cells are pro-actively engaged. However, these neo-generated vascular networks are morphologically and functionally abnormal, suggesting that the vascularization processes are rather inefficient in the tumor ecosystem. In this review, we reiterate the specificities of each neovascularization modality in glioblastoma, and, how they can be hampered mechanistically in the perspective of anti-cancer therapies.

Glioma-Derived Extracellular Vesicles - Far More Than Local Mediators

Extracellular vesicle (EV) secretion is a ubiquitous cellular process with both physiologic and pathologic consequences. EVs are small lipid bilayer vesicles that encompass both microvesicles and exosomes and which are secreted by virtually all cells including cancer cells. In this review, we will focus on the roles of EVs in mediating the crosstalk between glioblastoma (GBM) cells and innate and adaptive immune cells and the potential impact on glioma progression. Glioma-derived EVs contain many bioactive cargoes that can broaden and amplify glioma cell mediated immunosuppressive functions and thereby contribute to shaping the tumor microenvironment. We will discuss evidence demonstrating that the low oxygen (hypoxia) in the GBM microenvironment, in addition to cell-intrinsic effects, can affect intercellular communication through EV release, raising the possibility that properties of the tumor core can more widely impact the tumor microenvironment. Recent advances in glioma-derived EV research have shown their importance not only as message carriers, but also as mediators of immune escape, with the capacity to reprogram tumor infiltrating immune cells. Exploring EV function in cancer-immune crosstalk is therefore becoming an important research area, opening up opportunities to develop EV monitoring for mechanistic studies as well as novel diagnostic glioma biomarker applications. However, robust and reproducible EV analysis is not always routinely established, whether in research or in clinical settings. Taking into account the current state of the art in EV studies, we will discuss the challenges and opportunities for extending the many exciting findings in basic research to a better interpretation of glioma and its response to current and future immunotherapies.

Roles of exosomes in cancer chemotherapy resistance, progression, metastasis and immunity, and their clinical applications (Review)

Exosomes are a type of vesicle that are secreted by cells, with a diameter of 40-100 nm, and that appear as a cystic shape under an electron microscope. Exosome cargo includes a variety of biologically active substances such as non-coding RNA, lipids and small molecule proteins. Exosomes can be taken up by neighboring cells upon secretion or by distant cells within the circulatory system, affecting gene expression of the recipient cells. The present review discusses the formation and secretion of exosomes, and how they can remodel the tumor microenvironment, enhancing cancer cell chemotherapy resistance and tumor progression. Exosome-mediated induction of tumor metastasis is also highlighted. More importantly, the review discusses the manner in which exosomes can change the metabolism of cancer cells and the immune system, which may help to devise novel therapeutic approaches for cancer treatment. With the development of nanotechnology, exosomes can also be used as biomarkers and for the delivery of chemical drugs, serving as a tool to diagnose and treat cancer.

Exosomes and Their Role in Cancer Progression

Exosomes from extracellular vesicles can activate or inhibit various signaling pathways by transporting proteins, lipids, nucleic acids and other substances to recipient cells. In addition, exosomes are considered to be involved in the development and progression of tumors from different tissue sources in numerous ways, including remodeling of the tumor microenvironment, promoting angiogenesis, metastasis, and invasion, and regulating the immune escape of tumor cells. However, the precise molecular mechanisms by which exosomes participate in these different processes remains unclear. In this review, we describe the research progress of tumor cell-derived exosomes in cancer progression. We also discuss the prospects of the application of exosomes combined with nanoengineered chemotherapeutic drugs in the treatment of cancer.

Role of Tumor-Derived Extracellular Vesicles in Glioblastoma

Glioblastoma (GBM) is the most common primary central nervous system tumor and one of the most lethal cancers worldwide, with morbidity of 5.26 per 100,000 population per year. These tumors are often associated with poor prognosis and terrible quality of life. Extracellular vesicles (EVs) are membrane-bound nanoparticles secreted by cells and contain lipid, protein, DNA, mRNA, miRNA and other bioactive substances. EVs perform biological functions by binding or horizontal transfer of bioactive substances to target cell receptors. In recent years, EVs have been considered as possible targets for GBM therapy. A great many types of research demonstrated that EVs played a vital role in the GBM microenvironment, development, progression, angiogenesis, invasion, and even the diagnosis of GBM. Nevertheless, the exact molecular mechanisms and roles of EVs in these processes are unclear. It can provide the basis for GBM treatment in the future that clarifying the regulatory mechanism and related signal pathways of EVs derived from GBM and their clinical value in GBM diagnosis and treatment. In this paper, the research progress and clinical application prospects of GBM-derived EVs are reviewed and discussed.

Kinesin Family Member C1 Increases Temozolomide Resistance of Glioblastoma Through Promoting DNA Damage Repair

Glioblastoma (GBM) is one of the most frequent primary malignant brain tumors with a poor prognosis. Unfortunately, due to the intrinsic or acquired chemoresistance of GBM cells, it easily becomes refractory disease and tumors are easy to recur. Therefore, it is critical to elucidate the molecular mechanisms underlying the chemoresistance of GBM cells to discover more efficient therapeutic treatments. Kinesin family member C1 (KIFC1) is a normal nonessential kinesin motor that affects the progression of multiple types of cancers. However, whether KIFC1 have a function in GBM is still unexplored. Here we found that KIFC1 was upregulated in human temozolomide (TMZ)-resistant GBM tissues. KIFC1 silencing is sufficient to inhibit GBM cell proliferation and amplify TMZ-induced repression of cell proliferation. Mechanistically, KIFC1 silencing contributed to DNA damage, cell cycle arrest, and apoptosis through regulating Rad51, Akt, and DNA-PKcs phosphorylation. We also noticed that KIFC1 silencing also inhibited tumor formation and increased TMZ sensitivity through regulating Ki67, Rad51, γ-H2AX, and phosphorylation of AKT in vivo. Our findings therefore confirm the involvement of KIFC1 in GBM progression and provide a novel understanding of KIFC1-Akt axis in the sensitivity of GBM to chemotherapy.

Exosomes in Gliomas: Biogenesis, Isolation, and Preliminary Applications in Nanomedicine

Exosomes are phospholipid-based particles endogenously produced by both normal and tumor cells. Initially identified as a pathway for shuttling cellular waste, for a long time they were thought to act as “garbage bags”, and only in the past few years have they emerged as a promising drug delivery system. In this review, we provide an overview of the knowledge about exosome architecture and biogenesis and the recent progress in isolation methods. Furthermore, we describe the mechanisms involved in both extra- and intracellular communication with a focus on glioma brain tumors. Glioma is considered a rare disease and is the most prominent aggressive brain malignancy. How exosomes target glial tumoral cells in vivo remains largely unknown. However, they are able to influence numerous physio-pathological aspects. Here, we discuss the role they play in this heterogeneous and complex microenvironment and their potential applications.

Exosomal Secretion of Adipose Tissue during Various Physiological States

Exosomes are secreted extracellular vesicles containing a wide array of biologically active components. Recent studies have demonstrated that exosomes serve as an important vehicle for extracellular communication and exert systemic effects on the physiology of organisms. Adipose tissues (ATs) play a key role in balancing systemic energy homeostasis as a central hub for fatty acid metabolism. At the same time, proper endocrine function of ATs has also been shown to be crucial for regulating physiological and metabolic health. The endocrine function of ATs is partially mediated by AT-derived exosomes that regulate metabolic homeostasis, such as insulin signaling, lipolysis, and inflammation. During the pathogenesis of obesity, metabolic syndrome, and cancer, exosomes shed by the resident cells in ATs may also have a role in regulating the progression of these diseases along with associated pathologies. In this review, we summarize the contents of AT-derived exosomes and their effects on various cell populations along with possible underlying molecular mechanisms. We further discuss the potential applications of exosomes as a drug delivery tool and therapeutic target.

Genetic analysis of the molecular regulation of electric fields-guided glia migration

In a developing nervous system, endogenous electric field (EF) influence embryonic growth. We reported the EF-directed migration of both rat Schwann cells (SCs) and oligodendrocyte precursor cells (OPCs) and explored the molecular mechanism using RNA-sequencing assay. However, previous studies revealed the differentially expressed genes (DEGs) associated with EF-guided migration of SCs or OPCs alone. In this study, we performed joint differential expression analysis on the RNA-sequencing data from both cell types. We report a number of significantly enriched gene ontology (GO) terms that are related to the cytoskeleton, cell adhesion, and cell migration. Of the DEGs associated with these terms, nine up-regulated DEGs and 32 down-regulated DEGs showed the same direction of effect in both SCs and OPCs stimulated with EFs, while the remaining DEGs responded differently. Thus, our study reveals the similarities and differences in gene expression and cell migration regulation of different glial cell types in response to EF stimulation.

mTOR Modulates Intercellular Signals for Enlargement and Infiltration in Glioblastoma Multiforme

Simple Summary

Glioblastoma multiforme (GBM) is the most aggressive and lethal primary brain tumor. Emerging evidence indicate the multi-faceted role of extracellular vesicles (EVs) in GBM growth and proliferation. In fact, GBM-derived EVs can alter the phenotype of GBM-associated parenchymal cells; thus, promoting tumor growth, angiogenesis, and immune evasion. Remarkably, among several pathways that are frequently deregulated in GBM, mammalian Target of Rapamycin (mTOR) up-regulation, and subsequent autophagy (ATG) depression are considered hallmarks of GBM. In fact, mTOR-dependent ATG inhibition strongly correlates with the presence of EVs, which in turn promotes glioblastoma cancer stem cells (GSCs) self-renewal, proliferation, and infiltration. ATG and exosome release are reciprocally regulated. In detail, a failure in ATG enhances exosomal release. Therefore, strategies aimed at targeting on mTOR-dependent extracellular vesicles could be a promising approach for GBM prevention and treatment.

Abstract

Recently, exosomal release has been related to the acquisition of a malignant phenotype in glioblastoma cancer stem cells (GSCs). Remarkably, intriguing reports demonstrate that GSC-derived extracellular vesicles (EVs) contribute to glioblastoma multiforme (GBM) tumorigenesis via multiple pathways by regulating tumor growth, infiltration, and immune invasion. In fact, GSCs release tumor-promoting macrovesicles that can disseminate as paracrine factors to induce phenotypic alterations in glioma-associated parenchymal cells. In this way, GBM can actively recruit different stromal cells, which, in turn, may participate in tumor microenvironment (TME) remodeling and, thus, alter tumor progression. Vice versa, parenchymal cells can transfer their protein and genetic contents to GSCs by EVs; thus, promoting GSCs tumorigenicity. Moreover, GBM was shown to hijack EV-mediated cell-to-cell communication for self-maintenance. The present review examines the role of the mammalian Target of Rapamycin (mTOR) pathway in altering EVs/exosome-based cell-to-cell communication, thus modulating GBM infiltration and volume growth. In fact, exosomes have been implicated in GSC niche maintenance trough the modulation of GSCs stem cell-like properties, thus, affecting GBM infiltration and relapse. The present manuscript will focus on how EVs, and mostly exosomes, may act on GSCs and neighbor non tumorigenic stromal cells to modify their expression and translational profile, while making the TME surrounding the GSC niche more favorable for GBM growth and infiltration. Novel insights into the mTOR-dependent mechanisms regulating EV-mediated intercellular communication within GBM TME hold promising directions for future therapeutic applications.

Vesiclemia: counting on extracellular vesicles for glioblastoma patients

Although rare, glioblastoma is a devastating tumor of the central nervous system characterized by a poor survival and an extremely dark prognosis, making its diagnosis, treatment, and monitoring highly challenging. Numerous studies have highlighted extracellular vesicles (EVs) as key players of tumor growth, invasiveness, and resistance, as they carry oncogenic material. Moreover, EVs have been shown to communicate locally in a paracrine way but also at remote throughout the organism. Indeed, recent reports demonstrated the presence of brain tumor-derived EVs into body fluids such as plasma and cerebrospinal fluid. Fluid-associated EVs have indeed been suspected to reflect quantitative and qualitative information about the status and fate of the tumor and can potentially act as a resource for noninvasive biomarkers that might assist in diagnosis, treatment, and follow-up of glioblastoma patients. Here, we coined the name vesiclemia to define the concentration of plasmatic EVs, an intuitive term to be directly transposed in the clinical jargon.

The Involvement of Exosomes in Glioblastoma Development, Diagnosis, Prognosis, and Treatment

Brain tumours are a serious concern among both physicians and patients. The most feared brain tumour is glioblastoma (GBM) due to its heterogeneous histology, substantial invasive capacity, and rapid postsurgical recurrence. Even in cases of early management consisting of surgery, chemo-, and radiotherapy, the prognosis is still poor, with an extremely short survival period. Consequently, researchers are trying to better understand the underlying pathways involved in GBM development in order to establish a more personalised approach. The latest focus is on molecular characterisation of the tumour, including analysis of extracellular vesicles (EVs), nanostructures derived from both normal and pathological cells that have an important role in intercellular communication due to the various molecules they carry. There are two types of EV based on their biogenesis, but exosomes are of particular interest in GBM. Recent studies have demonstrated that GBM cells release numerous exosomes whose cargo provides them the capacity to facilitate tumour cell invasion and migration, to stimulate malignant transformation of previously normal cells, to increase immune tolerance towards the tumour, to induce resistance to chemotherapy, and to enhance the GBM vascular supply. As exosomes are specific to their parental cells, their isolation would allow a deeper perspective on GBM pathogenesis. A new era of molecular manipulation has emerged, and exosomes are rapidly proving their value not only as diagnostic and prognostic markers, but also as tools in therapies specifically targeting GBM cells. Nonetheless, further research will be required before exosomes could be used in clinical practice. This review aims to describe the structural and functional characteristics of exosomes and their involvement in GBM development, diagnosis, prognosis and treatment.

Role of exosomes in malignant glioma: microRNAs and proteins in pathogenesis and diagnosis

Malignant gliomas are the most common and deadly type of central nervous system tumors. Despite some advances in treatment, the mean survival time remains only about 1.25 years. Even after surgery, radiotherapy and chemotherapy, gliomas still have a poor prognosis. Exosomes are the most common type of extracellular vesicles with a size range of 30 to 100 nm, and can act as carriers of proteins, RNAs, and other bioactive molecules. Exosomes play a key role in tumorigenesis and resistance to chemotherapy or radiation. Recent evidence has shown that exosomal microRNAs (miRNAs) can be detected in the extracellular microenvironment, and can also be transferred from cell to cell via exosome secretion and uptake. Therefore, many recent studies have focused on exosomal miRNAs as important cellular regulators in various physiological and pathological conditions. A variety of exosomal miRNAs have been implicated in the initiation and progression of gliomas, by activating and/or inhibiting different signaling pathways. Exosomal miRNAs could be used as therapeutic agents to modulate different biological processes in gliomas. Exosomal miRNAs derived from mesenchymal stem cells could also be used for glioma treatment. The present review summarizes the exosomal miRNAs that have been implicated in the pathogenesis, diagnosis and treatment of gliomas. Moreover, exosomal proteins could also be involved in glioma pathogenesis. Exosomal miRNAs and proteins could also serve as non-invasive biomarkers for prognosis and disease monitoring. Video Abstract.

Bioinformatic analysis of the potential molecular mechanism of PAK7 expression in glioblastoma

The present study aimed to determine the potential molecular mechanisms underlying p21 (RAC1)-activated kinase 7 (PAK7) expression in glioblastoma (GBM) and evaluate candidate prognosis biomarkers for GBM. Gene expression data from patients with GBM, including 144 tumor samples and 5 normal brain samples, were downloaded. Long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) were explored via re-annotation. The differentially expressed genes (DEGs), including differentially expressed mRNAs and differentially expressed lncRNAs, were investigated and subjected to pathway analysis via gene set enrichment analysis. The miRNA-lncRNA-mRNA interaction [competing endogenous RNA (ceRNA)] network was investigated and survival analysis, including of overall survival (OS), was performed on lncRNAs/mRNAs to reveal prognostic markers for GBM. A total of 954 upregulated and 1,234 downregulated DEGs were investigated between GBM samples and control samples. These DEGs, including PAK7, were mainly enriched in pathways such as axon guidance. ceRNA network analysis revealed several outstanding ceRNA relationships, including miR-185-5p-LINC00599-PAK7. Moreover, paraneoplastic antigen Ma family member 5 (PNMA5) and somatostatin receptor 1 (SSTR1) were the two outstanding prognostic genes associated with OS. PAK7 may participate in the tumorigenesis of GBM by regulating axon guidance, and miR-185-5p may play an important role in GBM progression by sponging LINC00599 to prevent interactions with PAK7. PNMA5 and SSTR1 may serve as novel prognostic markers for GBM.

Extracellular Vesicles in Glioblastoma Tumor Microenvironment

Glioblastomas (GBM) are highly aggressive primary brain tumors. Complex and dynamic tumor microenvironment (TME) plays a crucial role in the sustained growth, proliferation, and invasion of GBM. Several means of intercellular communication have been documented between glioma cells and the TME, including growth factors, cytokines, chemokines as well as extracellular vesicles (EVs). EVs carry functional genomic and proteomic cargo from their parental cells and deliver that information to surrounding and distant recipient cells to modulate their behavior. EVs are emerging as crucial mediators of establishment and maintenance of the tumor by modulating the TME into a tumor promoting system. Herein we review recent literature in the context of GBM TME and the means by which EVs modulate tumor proliferation, reprogram metabolic activity, induce angiogenesis, escape immune surveillance, acquire drug resistance and undergo invasion. Understanding the multifaceted roles of EVs in the niche of GBM TME will provide invaluable insights into understanding the biology of GBM and provide functional insights into the dynamic EV-mediated intercellular communication during gliomagenesis, creating new opportunities for GBM diagnostics and therapeutics.

Extracellular Vesicle-Mediated Communication between the Glioblastoma and Its Microenvironment

The glioblastoma is the most malignant form of brain cancer. Glioblastoma cells use multiple ways of communication with the tumor microenvironment in order to tune it for their own benefit. Among these, extracellular vesicles have emerged as a focus of study in the last few years. Extracellular vesicles contain soluble proteins, DNA, mRNA and non-coding RNAs with which they can modulate the phenotypes of recipient cells. In this review we summarize recent findings on the extracellular vesicles-mediated bilateral communication established between glioblastoma cells and their tumor microenvironment, and the impact of this dialogue for tumor progression and recurrence.