Exosomes and extracellular vesicles: Rethinking the essential values in cancer biology

Exosomal miRNA-21 from Toxoplasma gondii-infected microglial cells induces the growth of U87 glioma cells by inhibiting tumor suppressor genes

Toxoplasma gondii is an intracellular protozoan parasite that can modulate the microenvironment of infected hosts and is known to be associated with the incidence of brain tumor growth. In this study, we suggested that the exosomal microRNA-21 derived from Toxoplasma infection would contribute to the growth of brain tumors. Exosomes of BV2 microglial cells infected with Toxoplasma were characterized and confirmed internalization to U87 glioma cells. Exosomal miRNA expression profiles were analyzed using microRNA array and miR-21A-5p associated with Toxoplasma and tumor sorted. We also examined the mRNA level of tumor-associated genes in U87 glioma cells by changing the level of miR-21 within exosomes and the effects of exosomes on the proliferation of human U87 glioma cells. Expression of miRNA-21 was increased and anti-tumorigenic genes (FoxO1, PTEN, and PDCD4) were decreased in exosomes within T. gondii-infected U87 glioma cells. Toxoplasma-infected BV2-derived exosomes induced proliferation of U87 glioma cells. The exosomes induced the growth of U87 cells in a mouse tumor model. We suggest that the increased exosomal miR-21 from Toxoplasma-infected BV2 microglial cells may play an important role as a cell growth promotor of U87 glioma cells through a down-regulation of anti-tumorigenic genes.

Microfluidics-Based Urine Biopsy for Cancer Diagnosis: Recent Advances and Future Trends

Urine biopsy, allowing for the detection, analysis and monitoring of numerous cancer-associated urinary biomarkers to provide insights into cancer occurrence, progression and metastasis, has emerged as an attractive liquid biopsy strategy with enormous advantages over traditional tissue biopsy, such as noninvasiveness, large sample volume, and simple sampling operation. Microfluidics enables precise manipulation of fluids in a tiny chip and exhibits outstanding performance in urine biopsy owing to its minimization, low cost, high integration, high throughput and low sample consumption. Herein, we review recent advances in microfluidic techniques employed in urine biopsy for cancer detection. After briefly summarizing the major urinary biomarkers used for cancer diagnosis, we provide an overview of the typical microfluidic techniques utilized to develop urine biopsy devices. Some prospects along with the major challenges to be addressed for the future of microfluidic-based urine biopsy are also discussed.

Interleukin-4 Receptor Targeting Peptide Decorated Extracellular Vesicles as a Platform for In Vivo Drug Delivery to Thyroid Cancer

Mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) have been demonstrated to deliver therapeutic drugs in preclinical studies. However, their use is limited, as they lack the ability to specifically deliver drugs to tumor tissues in vivo. In the present study, we propose the use of a targeting peptide, IL-4R-binding peptide (IL4RPep-1), to specifically deliver intravenously (i.v.) infused EVs to thyroid tumors. In vivo, a xenograft tumor model was treated with either the control peptide (NSSSVDK) or IL4RPep-1-Flamma; mice were fluorescently imaged (FLI) using an in vivo imaging system at 0–3 h post-treatment. EVs (labeled with DiD dye) were conjugated with IL4RPep-1 through a DOPE-NHS linker and administered to mice intravenously. FLI was performed 0–24 h post-injection, and the animals were sacrificed for further experiments. The morphology and size of EVs, the presence of EV markers such as CD63 and ALIX, and the absence of the markers GM130 and Cyto-C were confirmed. In vivo, FLI indicated an accumulation of i.v. injected IL4RPep-1-Flamma at the tumor site 90 min post-injection. No accumulation of NSSSVDK-Flamma was detected. In vivo, IL4RPep-1-EVs targeted the Cal-62 tumor 2 h post-injection. NSSSVDK-EVs were not even detected in the tumor 24 h post-injection. The quantification of FLI showed a significant accumulation of MSC-EVs in the tumor 2 h, 3 h, and 24 h post-injection. Furthermore, ex vivo imaging and an IF analysis confirmed the in vivo findings. Our results demonstrate the use of the IL4RPep-1 peptide as a targeting moiety of EVs for IL-4R-expressing anaplastic thyroid tumors.

Application of Perinatal Derivatives on Oncological Preclinical Models: A Review of Animal Studies

The increasing cancer incidence has certified oncological management as one of the most critical challenges for the coming decades. New anticancer strategies are still needed, despite the significant advances brought to the forefront in the last decades. The most recent, promising therapeutic approaches have benefitted from the application of human perinatal derivatives (PnD), biological mediators with proven benefits in several fields beyond oncology. To elucidate preclinical results and clinic outcomes achieved in the oncological field, we present a narrative review of the studies resorting to animal models to assess specific outcomes of PnD products. Recent preclinical evidence points to promising anticancer effects offered by PnD mediators isolated from the placenta, amniotic membrane, amniotic fluid, and umbilical cord. Described effects include tumorigenesis prevention, uncontrolled growth or regrowth inhibition, tumor homing ability, and adequate cell-based delivery capacity. Furthermore, PnD treatments have been described as supportive of chemotherapy and radiological therapies, particularly when resistance has been reported. However, opposite effects of PnD products have also been observed, offering support and trophic effect to malignant cells. Such paradoxical and dichotomous roles need to be intensively investigated. Current hypotheses identify as explanatory some critical factors, such as the type of the PnD biological products used or the manufacturing procedure to prepare the tissue/cellular treatment, the experimental design (including human-relevant animal models), and intrinsic pathophysiological characteristics. The effective and safe translation of PnD treatments to clinical practice relies on the collaborative efforts of all researchers working with human-relevant oncological preclinical models. However, it requires proper guidelines and consensus compiled by experts and health workers who accurately describe the methodology of tissue collection, PnD isolation, manufacturing, preservation, and delivery to the final user.

Identification of RNA Markers in Red Blood Cells for Doping Control in Autologous Blood Transfusion

The World Anti-Doping Agency (WADA) has prohibited the use of autologous blood transfusion (ABT) as a doping method by athletes. It is difficult to detect this doping method in laboratory tests, and a robust testing method has not yet been established. We conducted an animal experiment and used total RNA sequencing (RNA-Seq) to identify novel RNA markers to detect ABT doping within red blood cells (RBCs) as a pilot study before human trials. This study used whole blood samples from Wistar rats. The whole blood samples were mixed with a citrate–phosphate–dextrose solution with adenine (CPDA) and then stored in a refrigerator at 4 °C for 0 (control), 10, or 20 days. After each storage period, total RNA-Seq and bioinformatics were performed following RNA extraction and the purification of the RBCs. In the results, clear patterns of expression fluctuations were observed depending on the storage period, and it was found that there were large numbers of genes whose expression decreased in the 10- and 20-day periods compared to the control. Moreover, additional bioinformatic analysis identified three significant genes whose expression levels were drastically decreased according to the storage period. These results provide novel insights that may allow future studies to develop a testing method for ABT doping.

Construction of a miRNA-mRNA Network Related to Exosomes in Colon Cancer

Background

The competing endogenous RNA (CeRNA) network plays important roles in the occurrence and development of colon cancer. This research is aimed at constructing a miRNA-mRNA network associated with exosomes in colon cancer.

Methods

We explored the GEO database and then analyzed the RNAs of 722 samples to obtain differentially expressed miRNAs (DEMs) and mRNAs (DEGs) alongside the progress of colon cancer. Next, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of DEM target genes and DEGs were performed. In addition, a miRNA-mRNA network related to exosomes in colon cancer was constructed based on DEMs and DEGs. Finally, the expression of miRNA and mRNA in the network was verified by GEPIA2 on the base of TCGA database.

Results

Through our analysis, 19 DEMs (17 up and 2 down) and 1672 DEGs (954 up and 718 down) were screened. The GO and KEGG results show that these DEGs were mainly enriched in ribonucleoprotein complex biogenesis, noncoding RNA metabolic process, cell-substrate junction, cadherin binding, transcription coregulator activity, and regulation of the human T-cell leukemia virus 1 infection-related pathway. Besides, a miRNA-mRNA network, including 4 miRNAs (hsa-miR-623, hsa-miR-320c, hsa-miR-486-5p, and hsa-miR-1290) and 7 mRNAs (GNAI1, CADM1, PGRMC2, etc.), was constructed. Three of these seven mRNAs were downregulated in colon cancer. Ultimately, the GNAI1, CADM1, and PGRMC2 expression levels were verified by TCGA database.

Conclusions

This study reveals the network relationship between colon cancer exosome-derived miRNA and targeted mRNA. It deepens our understanding of new molecular mechanisms and pathways that may play a role in the occurrence and metastasis of colon cancer.

The Effect of Hypoxia-Induced Exosomes on Anti-Tumor Immunity and Its Implication for Immunotherapy

Hypoxia is a critical feature of solid tumors and is considered to be a key factor in promoting tumorigenesis and progression. Beyond inducing metabolic reprogramming of tumor cells to adapt to the hypoxia tumor microenvironment (TME), hypoxia can also promote tumor growth by affecting the secretion of exosomes. Exosomes are nano-sized (30-150 nm in diameter) extracellular vesicles that can carry numerous substances including lipids, proteins, nucleic acids, and metabolites. Notably, hypoxia-induced exosomes alterations not only exist in tumor cells, but also in various TME cells including stromal cells and immune cells. Besides promoting tumor invasion, angiogenesis, and drug resistance, the secretion of these altered exosomes has recently been found to negatively regulate anti-tumor immune responses. In this review, we focus on the hypoxia-induced changes in exosome secretion and found it can contributes to immune evasion and cancer progression by recruiting protumor immune cells into TME, as well as inhibiting antitumor immune cells. Next, we also describe the recent advances of exosomes in immunotherapy and future direction. In conclusion, ongoing discoveries in this field have brought new insights into hypoxia exosome-led immunosuppression, enabling the development of exosome-based therapeutics and elucidating their potential in immunotherapy.

Advances of exosomes in periodontitis treatment

Periodontitis is an inflammatory disease initiated by dysbiosis of the local microbial community. Periodontitis can result in destruction of tooth-supporting tissue; however, overactivation of the host immune response is the main reason for alveolar bone loss. Periodontal tissue cells, immune cells, and even further activated osteoclasts and neutrophils play pro-inflammatory or anti-inflammatory roles. Traditional therapies for periodontitis are effective in reducing the microbial quantities and improving the clinical symptoms of periodontitis. However, these methods are non-selective, and it is still challenging to achieve an ideal treatment effect in clinics using the currently available treatments and approaches. Exosomes have shown promising potential in various preclinical and clinical studies, including in the diagnosis and treatment of periodontitis. Exos can be secreted by almost all types of cells, containing specific substances of cells: RNA, free fatty acids, proteins, surface receptors and cytokines. Exos act as local and systemic intercellular communication medium, play significant roles in various biological functions, and regulate physiological and pathological processes in numerous diseases. Exos-based periodontitis diagnosis and treatment strategies have been reported to obtain the potential to overcome the drawbacks of traditional therapies. This review focuses on the accumulating evidence from the last 5 years, indicating the therapeutic potential of the Exos in preclinical and clinical studies of periodontitis. Recent advances on Exos-based periodontitis diagnosis and treatment strategies, existing challenges, and prospect are summarized as guidance to improve the effectiveness of Exos on periodontitis in clinics.

MALDI-TOF/MS Analysis of Extracellular Vesicles Released by Cancer Cells

The direct shedding of extracellular vesicles (EVs) from the plasma membrane is a recognized fundamental method for the intercellular transfer of properties in both physiological and pathological conditions. EVs are classified according to origin, biogenesis, size, content, surface markers, and/or functional properties, and contain various bioactive molecules depending on the physiological state and the type of the cells of origin including lipids, nucleic acids, and proteins. The presence of tumor-derived EVs in body fluids such as blood, ascites, urine, and saliva, together with the important role played in the tumor microenvironment where they intervene at different levels from oncogenesis to metastasis, make EVs a priority target for cancer studies. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) can play a leading role in the analysis and characterization of EVs and their load due to its intrinsic advantages such as high throughput, low sample consumption, speed, the cost-effectiveness of the analysis, and the ease of use. This work reviews the main MALDI-TOF applications for the analysis and characterization of extracellular vesicles in the tumor field.

Macrophage-Derived Extracellular Vesicles: A Promising Tool for Personalized Cancer Therapy

The incidence of cancer is increasing dramatically, affecting all ages of the population and reaching an ever higher worldwide mortality rate. The lack of therapies' efficacy is due to several factors such as a delay in diagnosis, tumor regrowth after surgical resection and the occurrence of multidrug resistance (MDR). Tumor-associated immune cells and the tumor microenvironment (TME) deeply affect the tumor's progression, leading to several physicochemical changes compared to physiological conditions. In this scenario, macrophages play a crucial role, participating both in tumor suppression or progression based on the polarization of onco-suppressive M1 or pro-oncogenic M2 phenotypes. Moreover, much evidence supports the pivotal role of macrophage-derived extracellular vesicles (EVs) as mediators in TME, because of their ability to shuttle the cell-cell and organ-cell communications, by delivering nucleic acids and proteins. EVs are lipid-based nanosystems with a broad size range distribution, which reflect a similar composition of native parent cells, thus providing a natural selectivity towards target sites. In this review, we discuss the impact of macrophage-derived EVs in the cancer's fate as well as their potential implications for the development of personalized anticancer nanomedicine.

Extracellular Vesicles as Novel Drug-Delivery Systems through Intracellular Communications

Since it has been reported that extracellular vesicles (EVs) carry cargo using cell-to-cell comminication according to various in vivo situations, they are exprected to be applied as new drug-delivery systems (DDSs). In addition, non-coding RNAs, such as microRNAs (miRNAs), have attracted much attention as potential biomarkers in the encapsulated extracellular-vesicle (EV) form. EVs are bilayer-based lipids with heterogeneous populations of varying sizes and compositions. The EV-mediated transport of contents, which includes proteins, lipids, and nucleic acids, has attracted attention as a DDS through intracellular communication. Many reports have been made on the development of methods for introducing molecules into EVs and efficient methods for introducing them into target vesicles. In this review, we outline the possible molecular mechanisms by which miRNAs in exosomes participate in the post-transcriptional regulation of signaling pathways via cell–cell communication as novel DDSs, especially small EVs.

A targeted siRNA-loaded PDL1-exosome and functional evaluation against lung cancer

BACKGROUND

As an endocytic nanosicle involved in intercellular communication, an exosome can efficiently deliver drugs from one cell to another and deliver therapeutic short interfering RNA (siRNA) to target cells. This is conducive to gene therapy for cancers. In this study, an exosome was used as the siRNA-loaded substrate to prepare a targeted siRNA-loaded PD-L1 exosome and evaluate its function against lung cancer.

METHODS

The optimal preparation process and binding ratio of the targeted nanovesicle/siRNA complex was determined by detecting the particle size, potential, and other physical parameters in combination with cell binding and uptake capacity of exosome complexes. The biological cell behavior of targeted exosome nanosicles was evaluated through cytotoxicity, apoptosis, and the cell uptake capacity.

RESULTS

A targeted exosome nanovesicle capable of loading siRNA and characterized with low toxicity, high loading rate, and the ability to be used for targeted tumor cell gene therapy was constructed.

CONCLUSION

The PD-L1 targeting exosome can be used as an efficient siRNA delivery carrier, which is an efficient and safe nanocarrier for tumor targeted gene therapy.

Current insights on extracellular vesicle-mediated glioblastoma progression: Implications in drug resistance and epithelial-mesenchymal transition

BACKGROUND

Glioblastoma multiforme (GBM) is one of the most fatal tumors of the central nervous system with high rate of disease progression, diagnosis, prognosis and low survival rate. Therapeutic approaches that relied on surgical resection and chemotherapy have been unable to curb the disease progression and subsequently leading to increase in incidences of GBM reoccurrence.

SCOPE OF THE REVIEW

In the recent times, membrane-bound extracellular vesicles (EVs) have been observed as one of the key reasons for the uncontrolled growth of GBM. EVs are shown to have the potential to contribute to the disease progression via mediating drug resistance and epithelial-mesenchymal transition. The GBM-derived EVs (GDEVs) with its cargo contents act as the biological trojan horse and lead to disease progression after being received by the recipient target cells. This review article highlights the biophysical, biochemical properties of EVs, its cargo contents and its potential role in the growth and progression of GBM by altering tumour microenvironment.

MAJOR CONCLUSIONS

EVs are being explored for serving as novel disease biomarkers in a variety of cancer types such as adenocarcinoma, pancreatic cancer, color rectal cancer, gliomas and glioblastomas. Improvement in the EV isolation protocols, polymer-based separation techniques and transcriptomics, have made EVs a key diagnostic marker to unravel the progression and early GBM diagnosis. GDEVs role in tumour progression is under extensive investigations.

GENERAL SIGNIFICANCE

Attempts have been also made to discuss and compare the usage of EVs as potential therapeutic targets versus existing therapies targeting drug resistance and EMT.

Oncogenic Role of Exosomal Circular and Long Noncoding RNAs in Gastrointestinal Cancers

Circular RNAs (circRNAs) and long noncoding RNAs (lncRNAs) are differentially expressed in gastrointestinal cancers. These noncoding RNAs (ncRNAs) regulate a variety of cellular activities by physically interacting with microRNAs and proteins and altering their activity. It has also been suggested that exosomes encapsulate circRNAs and lncRNAs in cancer cells. Exosomes are then discharged into the extracellular environment, where they are taken up by other cells. As a result, exosomal ncRNA cargo is critical for cell-cell communication within the cancer microenvironment. Exosomal ncRNAs can regulate a range of events, such as angiogenesis, metastasis, immune evasion, drug resistance, and epithelial-to-mesenchymal transition. To set the groundwork for developing novel therapeutic strategies against gastrointestinal malignancies, a thorough understanding of circRNAs and lncRNAs is required. In this review, we discuss the function and intrinsic features of oncogenic circRNAs and lncRNAs that are enriched within exosomes.

Cell secretomes for wound healing and tissue regeneration: Next generation acellular based tissue engineered products

Wound represents a significant socioeconomic burden for both affected individuals and as a whole healthcare system. Accordingly, stem cells have garnered attention due to their differentiation capacity and ability to aid tissue regeneration by releasing biologically active molecules, found in the cells' cultivated medium which known as conditioned medium (CM) or secretomes. This acellular approach provides a huge advantage over conventional treatment options, which are mainly used cellular treatment at wound closure. Interestingly, the secretomes contained the cell-secreted proteins such as growth factors, cytokines, chemokines, extracellular matrix (ECM), and small molecules including metabolites, microvesicles, and exosomes. This review aims to provide a general view on secretomes and how it is proven to have great potential in accelerating wound healing. Utilizing the use of secretomes with its secreted proteins and suitable biomaterials for fabrications of acellular skin substitutes can be promising in treating skin loss and accelerate the healing process.

Mesenchymal stem cell-derived extracellular vesicles prevent the development of osteoarthritis via the circHIPK3/miR-124-3p/MYH9 axis

Background

Extracellular vesicles (EVs) secreted by mesenchymal stem cells (MSCs) may play a vital role in a variety of biological processes, including cartilage regeneration. However, few studies reported their potential in the development of osteoarthritis (OA) previously. In this study, we explored the biological roles and underlying mechanism of MSCs-EVs in OA.

Results

Co-culture experiments revealed that MSCs-EVs could promote the expression of collagen type II alpha 1 chain (COL2A1), SRY-box transcription factor 9 (SOX9) and Aggrecan while negatively regulate the expression of chondrocyte hypertrophy markers matrix metallopeptidase 13 (MMP-13) and RUNX family transcription factor 2 (Runx2) in mouse chondrocytes in the OA model. Besides, the results of cell experiments indicated that MSCs-EVs could notably weaken the suppression of chondrocyte proliferation, migration and the promotion of chondrocyte apoptosis via interleukin1β (IL-1β) induction. In addition, MSCs-circHIPK3-EVs (EVs derived from MSCs overexpressing circHIPK3) considerably improved IL-1β-induced chondrocyte injury. Mechanistically, we elucidated that circHIPK3 could directly bind to miR-124-3p and subsequently elevate the expression of the target gene MYH9.

Conclusion

The findings in our study demonstrated that EVs-circHIPK3 participated in MSCs-EVs-mediated chondrocyte proliferation and migration induction and in chondrocyte apoptosis inhibition via the miR-124-3p/MYH9 axis. This offers a promising novel cell-free therapy for treating OA.

Graphic abstract