Regulation of exosomes released from normal ovarian epithelial cells and ovarian cancer cells

Harnessing exosomes as cancer biomarkers in clinical oncology

Exosomes are extracellular vesicles well known for facilitating cell-to-cell communication by distributing essential macromolecules like proteins, DNA, mRNA, lipids, and miRNA. These vesicles are abundant in fluids distributed throughout the body, including urine, blood, saliva, and even bile. They are important diagnostic tools for breast, lung, gastrointestinal cancers, etc. However, their application as cancer biomarkers has not yet been implemented in most parts of the world. In this review, we discuss how OMICs profiling of exosomes can be practiced by substituting traditional imaging or biopsy methods for cancer detection. Previous methods like extensive imaging and biopsy used for screening were expensive, mostly invasive, and could not easily provide early detection for various types of cancer. Exosomal biomarkers can be utilized for routine screening by simply collecting body fluids from the individual. We anticipate that the use of exosomes will be brought to light by the success of clinical trials investigating their potential to enhance cancer detection and treatment in the upcoming years.

Exosomes from porcine serum as endogenous additive maintain function of boar sperm during liquid preservation at 17 °C in vitro

The supplementation of sperm culture media with serum is quite common, and improves both sperm survival and motility. However, the link between serum and sperm remains poorly understood. The present study is the first investigation of the effects on sperm quality and function of endogenous porcine serum exosomes in medium used for culturing boar sperm. Scanning electron microscopy (SEM) confirmed that serum-derived exosomes from both castrated boars (cbsExos) and sows (ssExos) exhibited typical nanostructural morphology and expressed CD63, CD9, and Alix, as shown by Western blotting. At 17 °C, the progressive motility and membrane integrity of sperm were significantly increased after incubation of fresh boar semen for 7 days with cbsExos-4 (8 × 1010 particles/mL) or ssExos-16 (32 × 1010 particles/mL). Moreover, cbsExos-4 and ssExos-16 were found to be effective sperm additives, improving mitochondrial transmembrane potential (ΔΨm) and adenosine triphosphate (ATP) content, total antioxidant activity (T-AOC), superoxide dismutase (SOD) activity, and glutathione peroxidase (GPx) activity while reducing reactive oxygen species (ROS) levels, and malondialdehyde (MDA) content following preservation at 17 °C after a 5-day incubation. Both fluorescence and SEM showed that the serum exosomes bound directly to the sperm membrane, suggesting an interaction that could influence sperm-zona pellucida binding. Overall, this study provides new insights into the potential benefits of adding cbsExos and ssExos to enhance the quality of boar sperm during ambient temperature preservation, which may lead to advancements in sperm preservation strategies.

The current trend of exosome in epithelial ovarian cancer studies: A bibliometric review

Background: Epithelial ovarian cancer (EOC) is the most common type of ovarian cancer. About 90% of ovary tumors are epithelial. The current treatment for EOC involves surgical debulking of the tumors followed by a combination of chemotherapy. While most patients achieve complete remission, many EOCs will recur and develop chemoresistance. The cancer cells can adapt to several stress stimuli, becoming resistant. Therefore, new ways to fight resistant cells during the disease are being studied. Recently, exosomes, which reflect cell behavior in normal and pathological conditions such as epithelial ovarian cancer, are of academic interest as new biomarkers for diagnosis and therapy. Consequently, the current study aimed to investigate the research output of exosomes in EOC. Method: A bibliometric method was used for analyzing publications on exosome and epithelial ovarian cancer from the beginning to 15 October 2022 by searching keywords in Scopus, PubMed and Google scholar. Annual scientific publications, authors, citations, journals, co-authorships, and keywords co-occurrence were analyzed and plotted using Microsoft Office Excel and VOS viewer. 39 original journal articles and 3 reviews have been published since 2015 up to 15 October 2022. Results: The findings showed that China is the top country in research output, international collaborations, organization, author, and sponsorship. The top journals were the Journal of Ovarian Research, Oncotarget, and Tumor Biology, all in the United States. The top institution was Shanghai Jiao Tong University in China. The top author was Xipeng Wang. Co-occurrence analysis showed that academics' interest is toward:1) 1) Exosomes as prognostic biomarkers of EOC as well as their role in the proliferation and migration of cells. 2) The role of exosomes in metastasis through different mechanisms; 3) The role of exosomes in epithelial-mesenchymal transition of ovarian cancer cells; 4) The diagnostic role of EVs in EOC; and 5) Conferring chemoresistance in EOC through the exosomal transfer of miRNAs. Conclusion: Research on the exosome and EOC has an increasing trend, and China is much more involved than other countries in research, financial support, and international cooperation. These findings could aid researcher in understanding novel ideas and subjects interested by sponsors in this field.

Characterization of plasma exosomal microRNAs in responding to radiotherapy of human esophageal squamous cell carcinoma

Radiotherapy is one of the main treatment methods for esophageal squamous cell carcinoma (ESCC). Previous research has shown that plasma exosomal microRNAs (miRNAs) can predict therapeutic outcome. In the present study, to identify potential exosomal miRNAs that respond to radiotherapy, plasma exosomal miRNAs from ESCC patients undergoing radiotherapy were isolated and sequenced. Upregulated and downregulated miRNAs were detected from patients pre- and post-radiotherapy, and it was found that they play distinct roles in DNA damage process and endosomal mediated transport. Based on wound healing and Cell Counting Kit-8 assays in TE-1 human esophageal cancer cells, it was identified that representative miRNA miR-652 and miR-30a alter migration but not proliferation. The present findings identified differentially expressed miRNAs in responding to radiotherapy, and added a reference to explore non-invasive plasma biomarkers to evaluate therapeutic effects in ESCC.

The Emerging Roles of Extracellular Vesicles in Ovarian Cancer

Ovarian cancer (OC) is one of the deadliest gynecological malignancy. Epithelial ovarian cancer (EOC) is its most common form. OC has both, a poor prognosis and a high mortality rate due to the difficulties of early diagnosis, limitation of current treatment and resistance to chemotherapy. Extracellular vesicles (EVs) is a heterogeneous group of cell-derived submicron vesicles, which can be detected in body fluids, and it can be classified into three main types including exosomes, micro-vesicles, and apoptotic bodies. Cancer cells can produce more EVs than healthy cells. Moreover, the contents of these EVs have been found distinctive from each other. It has been considered that EVs shedding from tumor cells may be implicated in clinical applications, such as a tool for tumor diagnosis, prognosis and potential treatment of certain cancers. In this review, we provide a brief description of EVs. in diagnosis, prognosis, treatment, and drug-resistantance of OC. Cancer-related EVs show powerful influences on tumors by various biological mechanisms. However, the contents mentioned above remain in the laboratory stage and there is a lack of large-scale clinical trials, and the maturity of the purification and detection methods is a constraint. In addition, amplification of oncogenes on ecDNA is remarkably prevalent in cancer. It may be possible that ecDNA can be encapsulated in EVs and thus detected by us. In summary, much more research on EVs needs to be performed to reveal breakthroughs in OC and to accelerate the process of its application in clinic.

Extracellular vesicles in cancer diagnostics and therapeutics

Cancer promotion, development, and malignant transformation is greatly influenced by cell-to-cell interactions in a complex tissue microenvironment. Cancer and stromal cells secrete soluble factors, as well as deport membrane-encapsulated structures, which actively contribute and mediate cell-to-cell interaction within a tumor microenvironment (TME). These membrane structures are recognized as extracellular vesicles (EVs), which include exosomes and microvesicles. They can carry and transport regulatory molecules such as oncogenic proteins, coding and non-coding RNAs, DNA, and lipids between neighboring cells and to distant sites. EVs mediate crucial pathophysiological effects such as the formation of premetastatic niches and the progression of malignancies. There is compelling evidence that cancer cells exhibit a significant amount of EVs, which can be released into the surrounding body fluids, compared with nonmalignant cells. EVs therefore have the potential to be used as disease indicator for the diagnosis and prognosis of cancers, as well as for facilitating research into the underlying mechanism and biomolecular basis of these diseases. Because of their ability to transport substances, followed by their distinct immunogenicity and biocompatibility, EVs have been used to carry therapeutically-active molecules such as RNAs, proteins, short and long peptides, and various forms of drugs. In this paper, we summarize new advancement in the biogenesis and physiological roles of EVs, and underpin their functional impacts in the process of cancer growth and metastasis. We further highlight the therapeutic roles of EVs in the treatment, prevention, and diagnosis of human malignancies.

Polymer fraction including exosomes derived from Chinese hamster ovary cells promoted their growth during serum-free repeated batch culture

While continuous (perfusion) culture of mammalian cells might reduce the reactor size owing to the high cell density, there is the problem of higher medium cost; however, this problem is expected to be solved by the reuse of growth-promoting components in the culture supernatant. The polymer fraction (PF, 10 kDa-220 nm) collected from the supernatant of serum-free repeated-batch culture of Chinese hamster ovary (CHO) cells in not only adhesion but also suspension promoted the cell growth in respective serum-free cultures. PF contained CD81-positive exosomes and proteins, both of which were necessary for its growth-promoting activity. Consequently, the medium cost for the continuous (perfusion) serum-free suspension culture of CHO cells may be decreased by the repeated collection and addition of PF that contains exosomes and growth factor proteins.

Extracellular Vesicles in Cancer Detection: Hopes and Hypes

Early cancer diagnosis is critical for improving patient survival and mortality rates, but most diagnostics on solid tumors rely on imaging tests with limited sensitivity and specificity to identify potential cases, which are then confirmed by tissue biopsies. However, this process is usually not suitable for cancer screening or evaluation of tumor responses to treatment. Liquid biopsies have the potential to bridge this gap, but few such assays have been approved for cancer applications. Extracellular vesicles hold particular promise for liquid biopsy diagnostics but are currently limited by the lack of robust methods for isolation and analysis. New isolation and analysis techniques, however, show promise to improve the clinical utility of extracellular vesicle-based cancer diagnosis.

Defining lung cancer stem cells exosomal payload of miRNAs in clinical perspective

Since the first publication regarding the existence of stem cells in cancer [cancer stem cells (CSCs)] in 1994, many studies have been published providing in-depth information about their biology and function. This research has paved the way in terms of appreciating the role of CSCs in tumour aggressiveness, progression, recurrence and resistance to cancer therapy. Targeting CSCs for cancer therapy has still not progressed to a sufficient degree, particularly in terms of exploring the mechanism of dynamic interconversion between CSCs and non-CSCs. Besides the CSC scenario, the problem of cancer dissemination has been analyzed in-depth with the identification and isolation of microRNAs (miRs), which are now considered to be compelling molecular markers in the diagnosis and prognosis of tumours in general and specifically in patients with non-small cell lung cancer. Paracrine release of miRs via “exosomes” (small membrane vesicles (30-100 nm), the derivation of which lies in the luminal membranes of multi-vesicular bodies) released by fusion with the cell membrane is gaining popularity. Whether exosomes play a significant role in maintaining a dynamic equilibrium state between CSCs and non-CSCs and their mechanism of activity is as yet unknown. Future studies on CSC-related exosomes will provide new perspectives for precision-targeted treatment strategies.

MSC-derived exosomes attenuate cell death through suppressing AIF nucleus translocation and enhance cutaneous wound healing

Background

Skin wounding is very common and may be slow to heal. Increasing evidence shows that exosomes derived from mesenchymal stem cells (MSCs) dramatically enhance skin wound healing in a paracrine manner. However, the mechanism underlying this phenomenon has not yet been elucidated. Thus, the objective of the present study was to identify the signaling pathways and paracrine factors by which MSC-derived exosomes promote de novo skin tissue regeneration in response to wound healing.

Methods

In vitro and in vivo skin wound healing models were created by treating immortalized human keratinocytes (HaCaT) with hydrogen peroxide (H₂O₂) and excising full-thickness mouse skin, respectively. Exosomes were extracted from human umbilical cord Wharton’s jelly MSCs (hucMSC-Ex) by ultracentrifugation of cell culture supernatant.

Results

The hucMSC-Ex treatment significantly increased HaCaT cell proliferation and migration in a time- and dose-dependent manner, suppressed HaCaT apoptosis induced with H₂O₂ by inhibiting nuclear translocation of apoptosis-inducing factor (AIF) and upregulating poly ADP ribose polymerase 1 (PARP-1) and poly (ADP-ribose) (PAR). The animal experiments showed that relative to hucMSCs, hucMSC-Ex attenuated full-thickness skin wounding by enhancing epidermal re-epithelialization and dermal angiogenesis.

Conclusions

These findings indicated that direct administration of hucMSC-Ex may effectively treat cutaneous wounding and could be of great value in clinical settings.

Ovarian cancer circulating extracelluar vesicles promote coagulation and have a potential in diagnosis: an iTRAQ based proteomic analysis

Background

Circulating extracelluar vesicles (EVs) in epithelial ovarian cancer (EOC) patients emanate from multiple cells. These EVs are emerging as a new type of biomarker as they can be obtained by non-invasive approaches. The aim of this study was to investigate circulating EVs from EOC patients and healthy women to evaluate their biological function and potential as diagnostic biomarkers.

Methods

A quantitative proteomic analysis (iTRAQ) was applied and performed on 10 EOC patients with advanced stage (stage III–IV) and 10 controls. Twenty EOC patients and 20 controls were applied for validation. The candidate proteins were further validated in another 40-paired cohort to investigate their biomarker potential. Coagulation cascades activation was accessed by determining Factor X activity.

Results

Compared with controls, 200 proteins were upregulated and 208 proteins were downregulated in the EOC group. The most significantly involved pathway is complement and coagulation cascades. ApoE multiplexed with EpCAM, plg, serpinC1 and C1q provide optimal diagnostic information for EOC with AUC = 0.913 (95% confidence interval (CI) =0.848–0.957, p < 0.0001). Level of activated Factor X was significantly higher in EOC group than control (5.35 ± 0.14 vs. 3.69 ± 0.29, p < 0.0001).

Conclusions

Our study supports the concept of circulating EVs as a tool for non-invasive diagnosis of ovarian cancer. EVs also play pivotal roles in coagulation process, implying the inherent mechanism of generation of thrombus which often occurred in ovarian cancer patients at late stages.

The Role of Exo-miRNAs in Cancer: A Focus on Therapeutic and Diagnostic Applications

Exosomes are extracellular vesicles released into biological fluids where they act as carriers of various molecules, including proteins, lipids, and RNAs, between cells, modulating or perturbing specific physiological processes. Recently, it has been suggested that tumoral cells release excessive amounts of exosomes that, through their cargo, promote tumor progression, stimulating growth, angiogenesis, metastasis, insensitivity to chemotherapy, and immune evasion. Increasing evidence highlights exosomal microRNAs (exo-miRNAs) as important players in tumorigenesis. MicroRNA (miRNA) are a class of small non-coding RNA able to regulate gene expression, targeting multiple mRNAs and inducing translational repression and/or mRNA degradation. Exo-miRNAs are highly stable and easily detectable in biological fluids, and for these reasons, miRNAs are potential cancer biomarkers useful diagnostically and prognostically. Furthermore, since exosomes are natural delivery systems between cells, they can be appropriately modified to carry therapeutic miRNAs to specific recipient cells. Here we summarize the main functions of exo-miRNAs and their possible role for diagnostic and therapeutic applications.

Effects of exosomes on pre-metastatic niche formation in tumors

A pre-metastatic niche is a microenvironment prepared for the colonization of circulating tumor cells in specific organs. Exosomes are extracellular vesicles with a variety of biological functions. Exosomes play an irreplaceable role in the development of pre-metastatic niches, and mainly function as communication medium. In this review, we analyzed the effects of exosomes on pre-metastatic niches from various perspectives, including inflammation, immune response, angiogenesis, organotropism, matrix remodeling and biomarker expression. In particular, exosomes express programmed death ligand 1 (PD-L1) and cause the immune escape of tumor cells. The immunomodulatory effects of exosomes and their potential in liquid diagnosis have drawn our attention. The potential value of exosomes and pre-metastatic niches will be realized in the field of immunity therapy.

Endothelial colony-forming cell-derived exosomes restore blood-brain barrier continuity in mice subjected to traumatic brain injury

Traumatic brain injury (TBI) tends to cause disruption of the blood-brain barrier (BBB). Previous studies have shown that intravenously or intracerebroventricularly infused human umbilical cord blood-derived endothelial colony-forming cells (ECFCs) can home to injury sites and improve outcomes in mice subjected to experimental TBI. Several reports have demonstrated that these cells did not incorporate directly into newly formed vasculature but instead stimulated the proliferation and migration of tissue-resident endothelial cells (ECs) via paracrine mechanisms. In the present study, exosomes, which range from 30 to 150 nm in diameter, were isolated from ECFC-conditioned medium. The exosomes were labeled with PKH67 ex vivo, and we observed that they were taken up by ECs with high efficiency after 12 h of incubation. Pretreatment with ECFC-derived exosomes promoted the migration of ECs subjected to scratch injury, and incubating ECs exposed to hypoxia with ECFC-derived exosomes decreased PTEN expression, stimulated AKT phosphorylation and increased tight junction (TJ) protein expression in the cells. Furthermore, in vivo delivery of ECFC-derived exosomes into TBI mice also inhibited PTEN expression and increased AKT expression, changes accompanied by reductions in Evans blue (EB) dye extravasation, brain edema and TJ degradation. These data demonstrated that ECFC-derived exosomes have beneficial effects on BBB integrity in mice with TBI.

A comprehensive overview of exosomes in ovarian cancer: emerging biomarkers and therapeutic strategies

Exosomes are nanoparticles(40-100 nm) secreted by most cells in the body, which can be isolated from several types of extracellular fluids. It has been shown that exosomes play a key role in intercellular communication and in transportation of genetic information. Emerging evidence shows that exosomes are mediators of metastasis in tumour cells, stromal cells and the extracellular matrix component through the shuttling of cargo, such as proteins, lipids, RNAs, double-stranded DNAs, non-transcribed RNAs, and microRNAs. This phenomenon has been indicated in both tumourigenesis and drug resistance. In this review, we introduce new methods of exosome extraction, focusing on the emerging role of exosomes in ovarian cancer, and discuss their potential clinical applications.

Current Perspectives on In Vivo Noninvasive Tracking of Extracellular Vesicles with Molecular Imaging

Clinical and preclinical in vivo tracking of extracellular vesicles (EVs) are a crucial tool for the development and optimization of EV-based diagnosis and treatment. EVs have gained interest due to their unique properties that make them excellent candidates for biological applications. Noninvasive in vivo EV tracking has allowed marked progress towards elucidating the mechanisms and functions of EVs in real time in preclinical and clinical studies. In this review, we summarize several molecular imaging methods that deal with EVs derived from different cells, which have allowed investigations of EV biodistribution, as well as their tracking, delivery, and tumor targeting, to determine their physiological functions and to exploit imaging-derived information for EV-based theranostics.