The Biological Function and Therapeutic Potential of Exosomes in Cancer: Exosomes as Efficient Nanocommunicators for Cancer Therapy

Temozolomide and flavonoids against glioma: from absorption and metabolism to exosomal delivery

Patients with glioblastoma multiforme and anaplastic astrocytoma are treated with temozolomide. Although it has been demonstrated that temozolomide increases GBM patient survival, it has also been connected to negative immune-related adverse effects. Numerous research investigations have shown that flavonoids have strong antioxidant and chemo-preventive effects. Consequently, it might lessen chemotherapeutic medicines' side effects while also increasing therapeutic effectiveness. The need for creating innovative, secure, and efficient drug carriers for cancer therapy has increased over time. Recent research indicates that exosomes have enormous potential to serve as carriers and cutting-edge drug delivery systems to the target cell. In recent years, researchers have been paying considerable attention to exosomes because of their favorable biodistribution, biocompatibility, and low immunogenicity. In the present review, the mechanistic information of the anti-glioblastoma effects of temozolomide and flavonoids coupled with their exosomal delivery to the targeted cell has been discussed. In addition, we discuss the safety aspects of temozolomide and flavonoids against glioma. The in-depth information of temozolomide and flavonoids action via exosomal delivery can unravel novel strategies to target Glioma.

Application of single-cell sequencing to the research of tumor microenvironment

Single-cell sequencing is a technique for detecting and analyzing genomes, transcriptomes, and epigenomes at the single-cell level, which can detect cellular heterogeneity lost in conventional sequencing hybrid samples, and it has revolutionized our understanding of the genetic heterogeneity and complexity of tumor progression. Moreover, the tumor microenvironment (TME) plays a crucial role in the formation, development and response to treatment of tumors. The application of single-cell sequencing has ushered in a new age for the TME analysis, revealing not only the blueprint of the pan-cancer immune microenvironment, but also the heterogeneity and differentiation routes of immune cells, as well as predicting tumor prognosis. Thus, the combination of single-cell sequencing and the TME analysis provides a unique opportunity to unravel the molecular mechanisms underlying tumor development and progression. In this review, we summarize the recent advances in single-cell sequencing and the TME analysis, highlighting their potential applications in cancer research and clinical translation.

SCARA5 in bone marrow stromal cell-derived exosomes inhibits colorectal cancer progression by inactivating the PI3K/Akt pathway

Colorectal cancer (CRC) is the fourth most frequently diagnosed cancer worldwide. Bone marrow stromal cells (BMSCs) play an essential role in tumor development by secreting exosomes. Scavenger receptor class A member 5 (SCARA5) is a newly identified tumor suppressor. This study aimed to investigate the effects of BMSCs-derived exosomes (BMSCs-Exos) on CRC development and to explore their regulatory mechanisms. BMSCs-Exos showed an oval-shaped, bilayer membrane structure. BMSCs-Exos inhibited growth and motility of CRC cells, while BMSCs-Exos with SCARA5 knockdown significantly promoted cell proliferation and movement. Exosomal SCARA5 also effectively suppressed colorectal tumor growth in mouse xenografts. Further analysis revealed that exosomal SCARA5 inhibited the phosphorylation of protein kinase B and phosphoinositide 3-kinase in both CRC cells and tumors. In conclusion, SCARA5 in BMSCs-Exos inhibited CRC progression by inactivating PI3K/Akt, thus suggesting the potential clinical application of SCARA5-containing BMSCs-Exos for CRC treatment.

A tale of exosomes and their implication in cancer

Cancer is a cause of high deaths worldwide and also a huge burden for the health system. Cancer cells have unique properties such as a high rate of proliferation, self-renewal, metastasis, and treatment resistance, therefore, the development of novel diagnoses of cancers is a tedious task. Exosomes are secreted by virtually all cell types and have the ability to carry a multitude of biomolecules crucial for intercellular communication, hence, contributing a crucial part in the onset and spread of cancer. These exosomal components can be utilized in the development of markers for diagnostic and prognostic purposes for various cancers. This review emphasized primarily the following topics: exosomes structure and functions, isolation and characterization strategies of exosomes, the role of exosomal contents in cancer with a focus in particular on noncoding RNA and protein, exosomes, and the cancer microenvironment interactions, cancer stem cells, and tumor diagnosis and prognosis based on exosomes.

Exosomes as smart drug delivery vehicles for cancer immunotherapy

Exosomes (Exos) as drug delivery vehicles have been widely used for cancer immunotherapy owing to their good biocompatibility, low toxicity, and low immunogenicity. Some Exos-based cancer immunotherapy strategies such as tuning of immunosuppressive tumor microenvironment, immune checkpoint blockades, and cancer vaccines have also been investigated in recent years, which all showed excellent therapeutic effects for malignant tumor. Furthermore, some Exos-based drug delivery systems (DDSs) for cancer immunotherapy have also undergone clinic trails, indicating that Exos are a promising drug delivery carrier. In this review, in order to promote the development of Exos-based DDSs in cancer immunotherapy, the biogenesis and composition of Exos, and Exos as drug delivery vehicles for cancer immunotherapy are summarized. Meanwhile, their clinical translation and challenges are also discussed. We hope this review will provide a good guidance for Exos as drug delivery vehicles for cancer immunotherapy.

Mesenchymal stem cell-derived exosomes as a new therapeutic strategy in the brain tumors

Brain tumors are one of the most mortal cancers, leading to many deaths among kids and adults. Surgery, chemotherapy, and radiotherapy are available options for brain tumor treatment. However, these methods are not able to eradicate cancer cells. The blood-brain barrier (BBB) is one of the most important barriers to treat brain tumors that prevents adequate drug delivery to brain tissue. The connection between different brain parts is heterogeneous and causes many challenges in treatment. Mesenchymal stem cells (MSCs) migrate to brain tumor cells and have anti-tumor effects by delivering cytotoxic compounds. They contain very high regenerative properties, as well as support the immune system. MSCs-based therapy involves cell replacement and releases various vesicles, including exosomes. Exosomes receive more attention due to their excellent stability, less immunogenicity and toxicity compare to cells. Exosomes derived from MSCs can develop a powerful therapeutic strategy for different diseases and be a hopeful candidate for cell-based and cell-free regenerative medicine. These nanoparticles contain nucleic acid, proteins, lipids, microRNAs, and other biologically active substances. Many studies show that each microRNA can prevent angiogenesis, migration, and metastasis in glioblastoma. These exosomes can-act as a suitable nanoparticle carrier for therapeutic applications of brain tumors by passing through the BBB. In this review, we discuss potential applications of MSC and their produced exosomes in the treatment of brain tumors.

Current advances in the use of exosomes, liposomes, and bioengineered hybrid nanovesicles in cancer detection and therapy

Three major approaches of cancer therapy can be enunciated as delivery of biotherapeutics, tumor image analysis, and immunotherapy. Liposomes, artificial fat bubbles, are long known for their capacity to encapsulate a diverse range of bioactive molecules and release the payload in a sustained, stimuli-responsive manner. They have already been widely explored as a delivery vehicle for therapeutic drugs as well as imaging agents. They are also extensively being used in cancer immunotherapy. On the other hand, exosomes are naturally occurring nanosized extracellular vesicles that serve an important role in cell-cell communication. Importantly, the exosomes also have proven their capability to carry an array of active pharmaceuticals and diagnostic molecules to the tumor cells. Exosomes, being enriched with tumor antigens, have numerous immunomodulatory effects. Much to our intrigue, in recent times, efforts have been directed toward developing smart, bioengineered, exosome-liposome hybrid nanovesicles, which are augmented by the benefits of both vesicular systems. This review attempts to summarize the contemporary developments in the use of exosome and liposome toward cancer diagnosis, therapy, as a vehicle for drug delivery, diagnostic carrier for tumor imaging, and cancer immunotherapy. We shall also briefly reflect upon the recent advancements of the exosome-liposome hybrids in cancer therapy. Finally, we put forward future directions for the use of exosome/liposome and/or hybrid nanocarriers for accurate diagnosis and personalized therapies for cancers.

The roles of small extracellular vesicles as prognostic biomarkers and treatment approaches in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a particularly aggressive and invasive breast cancer subtype and is associated with poor clinical outcomes. Treatment approaches for TNBC remain limited partly due to the lack of expression of well-known molecular targets. Small extracellular vesicles (sEVs) carrying a variety of bioactive contents play an important role in intercellular communications. The biomolecules including nucleic acids, proteins, and metabolites can be transferred locally or systematically to recipient cells and regulate their biological states and are involved in physiological and pathological processes. Recently, despite the extensive attraction to the physiological functions of sEVs, few studies focus on the roles of sEVs in TNBC. In this review, we will summarize the involvement of sEVs in the tumor microenvironment of TNBC. Moreover, we will discuss the potential roles of sEVs as diagnostic markers and treatment therapy in this heterogeneous breast cancer subtype. We finally summarize the clinical application of sEVs in TNBC.

Exosome-Associated circRNAs as Key Regulators of EMT in Cancer

Epithelial-to-mesenchymal transition (EMT) is a dynamic program of cell plasticity aberrantly reactivated in cancer. The crosstalk between tumor cells and the tumoral microenvironment (TME) has a pivotal importance for the induction of the EMT and the progression toward a malignant phenotype. Notably, exosomes are key mediators of this crosstalk as vehicles of specific molecular signals that include the class of circular RNAs (circRNAs). This review specifically focuses on the role of exosome-associated circRNAs as key regulators of EMT in cancer. The relevance of these molecules in regulating the intercellular communication in TME and tumor progression is highlighted. Moreover, the here-presented evidence indicates that exosome-associated circRNA modulation should be taken in account for cancer diagnostic and therapeutic approaches.

Exosome-based drug delivery systems and their therapeutic applications

In the past few decades, scientists have actively worked on developing effective drug delivery systems (DDSs) as means to control life-threatening diseases and challenging illnesses.

Exosomes as A Next-Generation Diagnostic and Therapeutic Tool in Prostate Cancer

Extracellular vesicles (EVs) have brought great momentum to the non-invasive liquid biopsy procedure for the detection, characterization, and monitoring of cancer. Despite the common use of PSA (prostate-specific antigen) as a biomarker for prostate cancer, there is an unmet need for a more specific diagnostic tool to detect tumor progression and recurrence. Exosomes, which are EVs that are released from all cells, play a large role in physiology and pathology, including cancer. They are involved in intercellular communication, immune function, and they are present in every bodily fluid studied—making them an excellent window into how cells are operating. With liquid biopsy, EVs can be isolated and analyzed, enabling an insight into a potential therapeutic value, serving as a vehicle for drugs or nucleic acids that have anti-neoplastic effects. The current application of advanced technology also points to higher-sensitivity detection methods that are minimally invasive. In this review, we discuss the current understanding of the significance of exosomes in prostate cancer and the potential diagnostic value of these EVs in disease progression.

Plasma extracellular vesicles tau and β-amyloid as biomarkers of cognitive dysfunction of Parkinson's disease

The contribution of circulatory tau and β-amyloid in Parkinson's disease (PD), especially the cognitive function, remains inconclusive. Extracellular vesicles (EVs) cargo these proteins throughout the bloodstream after they are directly secreted from many cells, including neurons. The present study aims to investigate the role of the plasma EV-borne tau and β-amyloid as biomarkers for cognitive dysfunction in PD by investigating subjects with mild to moderate stage of PD (n = 116) and non-PD controls (n = 46). Plasma EVs were isolated, and immunomagnetic reduction-based immunoassay was used to assess the levels of α-synuclein, tau, and β-amyloid 1-42 (Aβ1-42) within the EVs. Artificial neural network (ANN) models were then applied to predict cognitive dysfunction. We observed no significant difference in plasma EV tau and Aβ1-42 between PD patients and controls. Plasma EV tau was significantly associated with cognitive function. Moreover, plasma EV tau and Aβ1-42 were significantly elevated in PD patients with cognitive impairment when compared to PD patients with optimal cognition. The ANN model used the plasma EV α-synuclein, tau, and Aβ1-42, as well as the patient's age and gender, as predicting factors. The model achieved an accuracy of 91.3% in identifying cognitive dysfunction in PD patients, and plasma EV tau and Aβ1-42 are the most valuable factors. In conclusion, plasma EV tau and Aβ1-42 are significant markers of cognitive function in PD patients. Combining with the plasma EV α-synuclein, age, and sex, plasma EV tau and Aβ1-42 can identify cognitive dysfunction in PD patients. This study corroborates the prognostic roles of plasma EV tau and Aβ1-42 in PD.

Extracellular Vesicles: Biology and Potentials in Cancer Therapeutics

Background [...].

Role of exosomal long non-coding RNAs in colorectal cancer

Exosomes are a class of small extracellular vesicles, 30-150 nm in diameter, that transfer biological information (e.g., DNA, RNA, and protein) via cell-to-cell communication. Exosomes play critical roles in the occurrence and development of human cancers, including colorectal cancer (CRC). Recent studies have shown that long non-coding RNAs (lncRNAs) can be encapsulated in exosomes, which transfer lncRNAs from secretory cells into recipient cells. This process affects the progression of CRC, since exosomal lncRNAs display special and extensive functions in CRC tumorigenesis, including malignant proliferation, metastasis, chemoresistance, and inflammatory response. Moreover, due to their specificity and sensitivity, exosomal lncRNAs are released into body fluids (e.g., urine, sputum, and plasma), which have the potential to be biomarkers of CRC tumorigenesis within screening efforts and medical and epidemiologic research. In this review, we aim to clarify the function and mechanism of exosomal lncRNAs in CRC tumorigenesis and provide a strategy for early diagnosis and medical treatment of this malignancy.

Nanomedicine-based strategies to target and modulate the tumor microenvironment

The interest in nanomedicine for cancer theranostics has grown significantly over the past few decades. However, these nanomedicines need to overcome several physiological barriers intrinsic to the tumor microenvironment (TME) before reaching their target. Intrinsic tumor genetic/phenotypic variations, along with intratumor heterogeneity, provide different cues to each cancer type, making each patient with cancer unique. This brings additional challenges in translating nanotechnology-based systems into clinically reliable therapies. To develop efficient therapeutic strategies, it is important to understand the dynamic interactions between TME players and the complex mechanisms involved, because they constitute invaluable targets to dismantle tumor progression. In this review, we discuss the latest nanotechnology-based strategies for cancer diagnosis and therapy as well as the potential targets for the design of future anticancer nanomedicines.

Plasma Extracellular Vesicle α-Synuclein Level in Patients with Parkinson's Disease

BACKGROUND

The most established pathognomonic protein of Parkinson's disease (PD), α-synuclein, is extensively investigated for disease diagnosis and prognosis; however, investigations into whether the free form of α-synuclein in the blood functions as a PD biomarker have not been fruitful. Extracellular vesicles (EVs) secreted from cells and present in blood transport molecules are novel platforms for biomarker identification. In blood EVs, α-synuclein originates predominantly from the brain without the interference of the blood-brain barrier. The present study investigated the role of plasma EV-borne α-synuclein as a biomarker of PD.

METHODS

Patients with mild to moderate stages of PD (n = 116) and individuals without PD (n = 46) were recruited to serve as the PD study group and the control group, respectively. Plasma EVs were isolated, and immunomagnetic reduction-based immunoassay was used to assess EV α-synuclein levels. Conventional statistical analysis was performed using SPSS 25.0, and p < 0.05 was considered significant.

RESULTS

Compared with controls, we observed significantly lower plasma EV α-synuclein levels in the patients with PD (PD: 56.0 ± 3.7 fg/mL vs. control: 74.5 ± 4.3 fg/mL, p = 0.009), and the significance remained after adjustment for age and sex. Plasma EV α-synuclein levels in the patients with PD did not correlate with age, disease duration, Part I and II scores of the Unified Parkinson's Disease Rating Scale (UPDRS), or the Mini-Mental State Examination scores. However, such levels were significantly correlated with UPDRS Part III score, which assesses motor dysfunction. Furthermore, the severity of akinetic-rigidity symptoms, but not tremor, was inversely associated with plasma EV α-synuclein level.

CONCLUSION

Plasma EV α-synuclein was significantly different between the control and PD group and was associated with akinetic-rigidity symptom severity in patients with PD. This study corroborates the possible diagnostic and subtyping roles of plasma EV α-synuclein in patients with PD, and it further provides a basis for this protein's clinical relevance and feasibility as a PD biomarker.

Exosomes: Isolation, characterization, and biomedical applications

Exosomes are nano-sized bioactive vesicles of 30-150 nm in diameter. They are secreted by exocytosis of nearly all type of cells in to the extracellular fluid. Thereby, they can be found in many biological fluids. Exosomes regulate intracellular communication between cells via delivery of their cargo which include lipids, proteins, and nucleic acid. Many desirable features of exosomes made them promising candidates in several therapeutic applications. In this review, we discuss the use of exosomes as diagnostic tools and their possible biomedical applications. Additionally, current techniques used for isolation, purification, and characterization of exosomes from both biological fluids and in vitro cell cultures were discussed.