Circulating exosomes potentiate tumor malignant properties in a mouse model of chronic sleep fragmentation

Extracellular vesicles and sleep deprivation

Sleep is vital in preserving mental and physical well-being by aiding bodily recovery, strengthening the immune system, and regulating hormones. It enhances memory, concentration, and mood regulation, reducing stress and anxiety. Sleep deprivation, a common phenomenon affecting approximately 20% of adults, decreases performance, alertness, and health integrity. Furthermore, it triggers physiological changes, including increased stress hormone levels, leading to various disorders such as hyperglycemia and hypertension. Recent research explores the role of extracellular vesicles (EVs) in sleep-related conditions. EVs, released by cells, play vital roles in intercellular communication and biomarker potential. Studies indicate that sleep deprivation influences EV release, impacting cancer progression, endothelial inflammation, and thrombosis risk. Understanding these mechanisms offers insights into therapeutic interventions. Thus, multidisciplinary approaches are crucial to unraveling the complex interactions between sleep, EVs, and health, providing direction for effective prevention and treatment approaches for sleep disorders and related conditions.

Exosomes regulate SIRT3-related autophagy by delivering miR-421 to regulate macrophage polarization and participate in OSA-related NAFLD

PURPOSE

To analyze the role of and mechanism underlying obstructive sleep apnea (OSA)-derived exosomes in inducing non-alcoholic fatty liver (NAFLD).

METHODS

The role of OSA-derived exosomes was analyzed in inducing hepatocyte fat accumulation in mice models both in vivo and in vitro.

RESULTS

OSA-derived exosomes caused fat accumulation and macrophage activation in the liver tissue. These exosomes promoted fat accumulation; steatosis was more noticeable in the presence of macrophages. Macrophages could internalize OSA-derived exosomes, which promoted macrophage polarization to the M1 type. Moreover, it inhibited sirtuin-3 (SIRT3)/AMP-activated protein kinase (AMPK) and autophagy and promoted the activation of nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasomes. The use of 3-methyladenine (3-MA) to inhibit autophagy blocked NLRP3 inflammasome activation and inhibited the M1 polarization of macrophages. miR-421 targeting inhibited SIRT3 protein expression in the macrophages. miR-421 was significantly increased in OSA-derived exosomes. Additionally, miR-421 levels were increased in OSA + NAFLD mice- and patient-derived exosomes. In the liver tissues of OSA and OSA + NAFLD mice, miR-421 displayed similar co-localization with the macrophages. Intermittent hypoxia-induced hepatocytes deliver miR-421 to the macrophages via exosomes to inhibit SIRT3, thereby participating in macrophage M1 polarization. After OSA and NAFLD modeling in miR-421-/- mice, liver steatosis and M1 polarization were significantly reduced. Additionally, in the case of miR-421 knockout, the inhibitory effects of OSA-derived exosomes on SIRT3 and autophagy were significantly alleviated. Furthermore, their effects on liver steatosis and macrophage M1 polarization were significantly reduced.

CONCLUSIONS

OSA promotes the delivery of miR-421 from the hepatocytes to macrophages. Additionally, it promotes M1 polarization by regulating the SIRT3/AMPK-autophagy pathway, thereby causing NAFLD.

Small Extracellular Vesicles Harboring PD-L1 in Obstructive Sleep Apnea

Obstructive sleep apnea syndrome (OSA) has been associated with increased cancer incidence and aggressiveness. One hypothesis to support this association is the implication of immune response, particularly the programmed cell death pathway, formed by the receptor PD-1 and its ligand PD-L1. Recent studies have shown dysregulation of this pathway in severe OSA patients. It has also been shown that small extracellular vesicles (sEVs) carrying PD-L1 induce lymphocyte dysfunction. Thus, the aim of our study was to analyze the expression of PD-L1 on sEVs of OSA patients and to evaluate the role of sEVs on lymphocyte activation and cytotoxicity. Circulating sEVs were isolated from OSA patients and the control group. Lymphocytes were isolated from the control group. Circulating sEVs were characterized by western blot, nanotracking analysis, and flow cytometry and were incubated with lymphocytes. Our results show no differences in the quantity and composition of sEVs in OSA patients and no significant effects of sEVs in OSA patients on lymphocyte activation and cytotoxicity. These results suggest that OSA does not modify PD-L1 expression on sEVs, which does not contribute to dysregulation of cytotoxic lymphocytes.

miRNAs as key modulators between normal cells and tumor microenvironment interactions

The tumor microenvironment (TME) is well-defined target for understanding tumor progression and various cell types. Major elements of the tumor microenvironment are the followings: endothelial cells, fibroblasts, signaling molecules, extracellular matrix, and infiltrating immune cells. MicroRNAs (miRNAs) are a group of small noncoding RNAs with major functions in the gene expression regulation at post-transcriptional level that have also appeared to exerts key functions in the cancer initiation/progression in diverse biological processes and the tumor microenvironment. This study summarized various roles of miRNAs in the complex interactions between the tumor and normal cells in their microenvironment.

Is obstructive sleep apnea a circadian rhythm disorder?

Obstructive sleep apnea is the most common sleep-related breathing disorder worldwide and remains underdiagnosed. Its multiple associated comorbidities contribute to a decreased quality of life and work performance as well as an increased risk of death. Standard treatment seems to have limited effects on cardiovascular and metabolic aspects of the disease, emphasising the need for early diagnosis and additional therapeutic approaches. Recent evidence suggests that the dysregulation of circadian rhythms, processes with endogenous rhythmicity that are adjusted to the environment through various cues, is involved in the pathogenesis of comorbidities. In patients with obstructive sleep apnea, altered circadian gene expression patterns have been demonstrated. Obstructive respiratory events may promote circadian dysregulation through the effects of sleep disturbance and intermittent hypoxia, with subsequent inflammation and disruption of neural and hormonal homeostasis. In this review, current knowledge on obstructive sleep apnea, circadian rhythm regulation, and circadian rhythm sleep disorders is summarised. Studies that connect obstructive sleep apnea to circadian rhythm abnormalities are critically evaluated. Furthermore, pathogenetic mechanisms that may underlie this association, most notably hypoxia signalling, are presented. A bidirectional relationship between obstructive sleep apnea and circadian rhythm dysregulation is proposed. Approaching obstructive sleep apnea as a circadian rhythm disorder may prove beneficial for the development of new, personalised diagnostic, therapeutic and prognostic tools. However, further studies are needed before the clinical approach to obstructive sleep apnea includes targeting the circadian system.

Potential Pathophysiological Pathways in the Complex Relationships between OSA and Cancer

Several epidemiological and clinical studies have suggested a relationship between obstructive sleep apnea (OSA) and a higher incidence or severity of cancer. This relationship appears to be dependent on a myriad of factors. These include non-modifiable factors, such as age and gender; and modifiable or preventable factors, such as specific comorbidities (especially obesity), the use of particular treatments, and, above all, the histological type or location of the cancer. Heterogeneity in the relationship between OSA and cancer is also related to the influences of intermittent hypoxemia (a hallmark feature of OSA), among others, on metabolism and the microenvironment of different types of tumoral cells. The hypoxia inducible transcription factor (HIF-1α), a molecule activated and expressed in situations of hypoxemia, seems to be key to enabling a variety of pathophysiological mechanisms that are becoming increasingly better recognized. These mechanisms appear to be operationally involved via alterations in different cellular functions (mainly involving the immune system) and molecular functions, and by inducing modifications in the microbiome. This, in turn, may individually or collectively increase the risk of cancer, which is then, further modulated by the genetic susceptibility of the individual. Here, we provide an updated and brief review of the different pathophysiological pathways that have been identified and could explain the relationship between OSA and cancer. We also identify future challenges that need to be overcome in this intriguing field of research.

Application of extracellular vesicles proteins in cancer diagnosis

Early tumor diagnosis is crucial for its treatment and reduction of death, with effective tumor biomarkers being important tools. Extracellular vesicles (EVs) are small vesicles secreted by cells with various biomolecules, including proteins, nucleic acids, and lipids. They harbor a double membrane structure. Previous studies on EVs in cancer diagnosis and therapy focused on miRNAs. Nonetheless, EVs contain proteins that represent physiological and pathological state of their parental cells. EVs proteins can reflect the pathological state of some diseases, which provides a basis for diagnosis and treatment. This study describes the role of EVs in cancer and summarizes the use of EVs proteins as diagnostic markers in different cancer types. Specifically, we discuss the potential and shortcomings of EVs as tumor biomarkers.

Cancer as a tool for preclinical psychoneuroimmunology

Cancer represents a novel homeostatic challenge to the host system. How the brain senses and responds to changes in peripheral physiology elicited by tumor growth is a largely untapped area of research. This is especially relevant given the widespread prevalence of systemic problems that people with various types of cancer experience. These include disruptions in sleep/wake cycles, cognitive function, depression, and changes in appetite/food intake, among others. Critically, many of these problems are evident prior to diagnosis, indicating that their etiology is potentially distinct from the effects of cancer treatment or the stress of a cancer diagnosis. Psychoneuroimmunology (PNI) is well equipped to tackle these types of problems, as it uses approaches from multiple disciplines to understand how specific stimuli (endogenous and environmental) are transduced into neural, endocrine, and immune signals that ultimately regulate health and behavior. In this article, I first provide a brief historical perspective of cancer and PNI, introduce the idea of cancer as a systemic homeostatic challenge, and provide examples from preclinical literature supporting this hypothesis. Given the rise of advanced tools in neuroscience (e.g., calcium imaging), we can now monitor and manipulate genetically defined neural circuits over the extended time scales necessary to disentangle distal communication between peripheral tumors and the brain.

Monocarboxylate Transporter-2 Expression Restricts Tumor Growth in a Murine Model of Lung Cancer: A Multi-Omic Analysis

Monocarboxylate transporter 2 (MCT2) is a major high-affinity pyruvate transporter encoded by the SLC16A7 gene, and is associated with glucose metabolism and cancer. Changes in the gut microbiota and host immune system are associated with many diseases, including cancer. Using conditionally expressed MCT2 in mice and the TC1 lung carcinoma model, we examined the effects of MCT2 on lung cancer tumor growth and local invasion, while also evaluating potential effects on fecal microbiome, plasma metabolome, and bulk RNA-sequencing of tumor macrophages. Conditional MCT2 mice were generated in our laboratory using MCT2^loxP mouse intercrossed with mCre-Tg mouse to generate MCT2^loxP/loxP; Cre⁺ mouse (MCT2 KO). Male MCT2 KO mice (8 weeks old) were treated with tamoxifen (0.18 mg/g BW) KO or vehicle (CO), and then injected with mouse lung carcinoma TC1 cells (10 × 10⁵/mouse) in the left flank. Body weight, tumor size and weight, and local tumor invasion were assessed. Fecal DNA samples were extracted using PowerFecal kits and bacterial 16S rRNA amplicons were also performed. Fecal and plasma samples were used for GC−MS Polar, as well as non-targeted UHPLC-MS/MS, and tumor-associated macrophages (TAMs) were subjected to bulk RNAseq. Tamoxifen-treated MCT2 KO mice showed significantly higher tumor weight and size, as well as evidence of local invasion beyond the capsule compared with the controls. PCoA and hierarchical clustering analyses of the fecal and plasma metabolomics, as well as microbiota, revealed a distinct separation between the two groups. KO TAMs showed distinct metabolic pathways including the Acetyl-coA metabolic process, activation of immune response, b-cell activation and differentiation, cAMP-mediated signaling, glucose and glutamate processes, and T-cell differentiation and response to oxidative stress. Multi-Omic approaches reveal a substantial role for MCT2 in the host response to TC1 lung carcinoma that may involve alterations in the gut and systemic metabolome, along with TAM-related metabolic pathway. These findings provide initial opportunities for potential delineation of oncometabolic immunomodulatory therapeutic approaches.

Heterogeneity of Melanoma Cell Responses to Sleep Apnea-Derived Plasma Exosomes and to Intermittent Hypoxia

Obstructive sleep apnea (OSA) is associated with increased cutaneous melanoma incidence and adverse outcomes. Exosomes are secreted by most cells, and play a role in OSA-associated tumor progression and metastasis. We aimed to study the effects of plasma exosomes from OSA patients before and after adherent treatment with continuous positive airway pressure (CPAP) on melanoma cells lines, and also to identify exosomal miRNAs from melanoma cells exposed to intermittent hypoxia (IH) or normoxia. Plasma-derived exosomes were isolated from moderate-to-severe OSA patients before (V1) and after (V2) adherent CPAP treatment for one year. Exosomes were co-incubated with three3 different melanoma cell lines (CRL 1424; CRL 1619; CRL 1675) that are characterized by genotypes involving different mutations in BRAF, STK11, CDKN2A, and PTEN genes to assess the effect of exosomes on cell proliferation and migration, as well as on pAMK activity in the presence or absence of a chemical activator. Subsequently, CRL-1424 and CRL-1675 cells were exposed to intermittent hypoxia (IH) and normoxia, and exosomal miRNAs were identified followed by GO and KEG pathways and gene networks. The exosomes from these IH-exposed melanoma cells were also administered to THP1 macrophages to examine changes in M1 and M2 polarity markers. Plasma exosomes from V1 increased CRL-1424 melanoma cell proliferation and migration compared to V2, but not the other two cell lines. Exposure to CRL-1424 exosomes reduced pAMPK/tAMPK in V1 compared to V2, and treatment with AMPK activator reversed the effects. Unique exosomal miRNAs profiles were identified for CRL-1424 and CRL-1675 in IH compared to normoxia, with six miRNAs being regulated and several KEGG pathways were identified. Two M1 markers (CXCL10 and IL6) were significantly increased in monocytes when treated with exosomes from IH-exposed CRL-1424 and CRL-1625 cells. Our findings suggest that exosomes from untreated OSA patients increase CRL-1424 melanoma malignant properties, an effect that is not observed in two other melanoma cell lines. Exosomal cargo from CRL-1424 cells showed a unique miRNA signature compared to CRL-1675 cells after IH exposures, suggesting that melanoma cells are differentially susceptible to IH, even if they retain similar effects on immune cell polarity. It is postulated that mutations in STK-11 gene encoding for the serine/threonine kinase family that acts as a tumor suppressor may underlie susceptibility to IH-induced metabolic dysfunction, as illustrated by CRL-1424 cells.

Interplay between Hypoxia and Extracellular Vesicles in Cancer and Inflammation

Simple Summary

Mounting evidence suggests a role for extracellular vesicles in cell-to-cell communication, in both physiological and pathological conditions. Moreover, the molecular content of vesicles can be exploited for diagnostic and therapeutic purposes. Inflamed tissues and tumors are often characterized by hypoxic areas, where oxygen levels drop dramatically. Several studies demonstrated that hypoxic stress affects the release of vesicles and their content. This review is intended to provide an exhaustive overview on the relationship between hypoxia and vesicles in inflammatory diseases and cancer.

Abstract

Hypoxia is a severe stress condition often observed in cancer and chronically inflamed cells and tissues. Extracellular vesicles play pivotal roles in these pathological processes and carry biomolecules that can be detected in many biofluids and may be exploited for diagnostic purposes. Several studies report the effects of hypoxia on extracellular vesicles’ release, molecular content, and biological functions in disease. This review summarizes the most recent findings in this field, highlighting the areas that warrant further investigation.

Associations of self-reported obstructive sleep apnea with total and site-specific cancer risk in older women: a prospective study

BACKGROUND AND OBJECTIVES

Chronic intermittent hypoxia resulting from obstructive sleep apnea (OSA) may activate multiple carcinogenic pathways and lead to cancer development.

METHODS

We prospectively examined the association between OSA and cancer risk among 65,330 women in the Nurses' Health Study who were free of cancer in 2008 (mean age: 73.3 years). Incident cancer diagnoses were collected until 2016 and confirmed by pathology reports. Clinically diagnosed OSA was self-reported in 2008 and updated in 2012. We used time-dependent Cox regression to estimate hazard ratios (HR) for the associations of OSA with total and site-specific cancer risk.

RESULTS

We documented 5,257 incident cancer diagnoses during follow-up. In the age-adjusted model, OSA was associated with a 15% (95% CI: 1.03, 1.29) increase in total cancer risk. The association became nonsignificant after adjustment for multiple cancer risk factors (HR: 1.08; 95% CI: 0.96, 1.21). When examining cancer risk by site, OSA was associated with significantly increased risk for lung (fully adjusted HR: 1.52; 95% CI: 1.07, 2.17), bladder (fully adjusted HR: 1.94; 95% CI: 1.12, 3.35), and thyroid cancer (fully adjusted HR: 2.06; 95% CI: 1.01, 4.22) and possibly increased risk for kidney cancer (fully adjusted HR: 1.59; 95% CI: 0.84, 3.01). When grouping cancer sites by risk factor profiles, OSA was positively associated with smoking-related cancers (fully adjusted HR: 1.37; 95% CI: 1.11, 1.67), and this association was stronger in never smokers than ever smokers.

CONCLUSION

While OSA was not independently associated with overall cancer risk in older women, significant associations were observed for smoking-related cancers, especially in nonsmokers.

The Mystery of Red Blood Cells Extracellular Vesicles in Sleep Apnea with Metabolic Dysfunction

Sleep is very important for overall health and quality of life, while sleep disorder has been associated with several human diseases, namely cardiovascular, metabolic, cognitive, and cancer-related alterations. Obstructive sleep apnea (OSA) is the most common respiratory sleep-disordered breathing, which is caused by the recurrent collapse of the upper airway during sleep. OSA has emerged as a major public health problem and increasing evidence suggests that untreated OSA can lead to the development of various diseases including neurodegenerative diseases. In addition, OSA may lead to decreased blood oxygenation and fragmentation of the sleep cycle. The formation of free radicals or reactive oxygen species (ROS) can emerge and react with nitric oxide (NO) to produce peroxynitrite, thereby diminishing the bioavailability of NO. Hypoxia, the hallmark of OSA, refers to a decline of tissue oxygen saturation and affects several types of cells, playing cell-to-cell communication a vital role in the outcome of this interplay. Red blood cells (RBCs) are considered transporters of oxygen and nutrients to the tissues, and these RBCs are important interorgan communication systems with additional functions, including participation in the control of systemic NO metabolism, redox regulation, blood rheology, and viscosity. RBCs have been shown to induce endothelial dysfunction and increase cardiac injury. The mechanistic links between changes of RBC functional properties and cardiovascular are largely unknown. Extracellular vesicles (EVs) are secreted by most cell types and released in biological fluids both under physiological and pathological conditions. EVs are involved in intercellular communication by transferring complex cargoes including proteins, lipids, and nucleic acids from donor cells to recipient cells. Advancing our knowledge about mechanisms of RBC-EVs formation and their pathophysiological relevance may help to shed light on circulating EVs and to translate their application to clinical practice. We will focus on the potential use of RBC-EVs as valuable diagnostic and prognostic biomarkers and state-specific cargoes, and possibilities as therapeutic vehicles for drug and gene delivery. The use of RBC-EVs as a precision medicine for the diagnosis and treatment of the patient with sleep disorder will improve the prognosis and the quality of life in patients with cardiovascular disease (CVD).

Tumor-derived exosomal miRNA-141 promote angiogenesis and malignant progression of lung cancer by targeting growth arrest-specific homeobox gene (GAX)

Previous researches have suggested that exosomal miRNA-141 has association with metastatic lung cancer, however, its role and regulatory mechanism require further study. In this study, exosomes were isolated from lung cancer patients and normal human serum and identified. We found that the expression of miRNA-141 was up-regulated in the lung cancer serum exosomes compared with the normal serum exosomes. When the exosomes were extracted for co-culture with HUVECs, they were absorbed and distributed around the nucleus by confocal microscopy. Moreover, exosomal miRNA-141 from A549 significantly not only promoted the migration and invasion of A549 but also increased the cell proliferation, tube formation of HUVECs. In order to reveal the mechanism of exosomal miRNA-141, bioinformatics analysis revealed that miRNA-141 targeted the binding of Growth arrest-specific homeobox gene (GAX) in the 3'UTR region, and confirmed by MS2-RIP assay and dual-luciferase assay. Exosome miRNA-141 could down-regulate the expression of GAX. Taken together, our results demonstrate that tumor-derived exosomal miRNA-141 promote angiogenesis and malignant progression of lung cancer by targeting GAX. It provides a new possibility for the treatment of lung cancer.

Circulating exosomes and gut microbiome induced insulin resistance in mice exposed to intermittent hypoxia: Effects of physical activity

Background

Gut microbiota (GM) contribute to obesity and insulin resistance (IR). Obstructive sleep apnea (OSA), characterized by intermittent hypoxia (IH), promotes IR and alters GM. Since circulating exosomes are implicated in IR, we examined the effects of IH and physical activity (PA) in mice on GM, colonic epithelium permeability, systemic IR, and plasma exosome cargo, and exosome effects on visceral white adipose tissues (vWAT) IR.

Methods

C57BL/6 mice were exposed to IH or room air (RA) for 6 weeks with and without PA (n = 12/group), and GM and systemic IR changes were assessed, as well as the effects of plasma exosomes on naïve adipocyte insulin sensitivity. Fecal microbiota transfers (FMT) were performed in naïve mice (n = 5/group), followed by fecal 16S rRNA sequencing, and systemic IR and exosome-induced effects on adipocyte insulin sensitivity were evaluated.

Findings

Principal coordinate analysis (PCoA) ordinates revealed B-diversity among IH and FMT recipients that accounted for 64% principal component 1 (PC1) and 12.5% (PC2) of total variance. Dominant microbiota families and genera in IH-exposed and FMT-treated were preserved, and IH-exposed GM and IH-FMT induced increased gut permeability. Plasma exosomes from IH-exposed and IH-FMT mice decreased pAKT/AKT responses to exogenous insulin in adipocytes vs. IH+PA or RA FMT-treated mice (p = 0.001).

Interpretation

IH exposures mimicking OSA induce changes in GM, increase gut permeability, and alter plasma exosome cargo, the latter inducing adipocyte dysfunction (increased IR). Furthermore, these alterations improved with PA. Thus, IH leads to perturbations of a singular GM-circulating exosome pathway that disrupts adipocyte homeostasis resulting in metabolic dysfunction, as reflected by IR.

Funding

This study was supported by grants from the National Institutes of Health grants HL130984 and HL140548 and University of Missouri Tier 2 grant. The study has not received any funding or grants from pharmaceutical or other industrial corporations.

The miRNA Content of Exosomes Released from the Glioma Microenvironment Can Affect Malignant Progression

Low-grade gliomas (LGG) are infiltrative primary brain tumors that in 70% of the cases undergo anaplastic transformation, deeply affecting prognosis. However, the timing of progression is heterogeneous. Recently, the tumor microenvironment (TME) has gained much attention either as prognostic factor or therapeutic target. Through the release of extracellular vesicles, the TME contributes to tumor progression by transferring bioactive molecules such as microRNA. The aim of the study was to take advantage of glioma-associated stem cells (GASC), an in vitro model of the glioma microenvironment endowed with a prognostic significance, and their released exosomes, to investigate the possible role of exosome miRNAs in favoring the anaplastic transformation of LGG. Therefore, by deep sequencing, we analyzed and compared the miRNA profile of GASC and exosomes obtained from LGG patients characterized by different prognosis. Results showed that exosomes presented a different signature, when compared to their cellular counterpart and that, although sharing several miRNAs, exosomes of patients with a bad prognosis, selectively expressed some miRNAs possibly responsible for the more aggressive phenotype. These findings get insights into the value of TME and exosomes as potential biomarkers for precision medicine approaches aimed at improving LGG prognostic stratification and therapeutic strategies.

Sleep Apnoea Adverse Effects on Cancer: True, False, or Too Many Confounders?

Obstructive sleep apnoea (OSA) is a prevalent disorder associated with increased cardiovascular, metabolic and neurocognitive morbidity. Recently, an increasing number of basic, clinical and epidemiological reports have suggested that OSA may also increase the risk of cancer, and adversely impact cancer progression and outcomes. This hypothesis is convincingly supported by biological evidence linking certain solid tumours and hypoxia, as well as by experimental studies involving cell and animal models testing the effects of intermittent hypoxia and sleep fragmentation that characterize OSA. However, the clinical and epidemiological studies do not conclusively confirm that OSA adversely affects cancer, even if they hold true for specific cancers such as melanoma. It is likely that the inconclusive studies reflect that they were not specifically designed to test the hypothesis or because of the heterogeneity of the relationship of OSA with different cancer types or even sub-types. This review critically focusses on the extant basic, clinical, and epidemiological evidence while formulating proposed directions on how the field may move forward.

Total Blood Exosomes in Breast Cancer: Potential Role in Crucial Steps of Tumorigenesis

Exosomes are crucial players in cell-to-cell communication and are involved in tumorigenesis. There are two fractions of blood circulating exosomes: free and cell-surface-associated. Here, we compared the effect of total blood exosomes (contain plasma exosomes and blood cell-surface-associated exosomes) and plasma exosomes from breast cancer patients (BCPs, n = 43) and healthy females (HFs, n = 35) on crucial steps of tumor progression. Exosomes were isolated by ultrafiltration, followed by ultracentrifugation, and characterized by cryo-electron microscopy (cryo-EM), nanoparticle tracking analysis, and flow cytometry. Cryo-EM revealed a wider spectrum of exosome morphology with lipid bilayers and vesicular internal structures in the HF total blood in comparison with plasma. No differences in the morphology of both exosomes fractions were detected in BCP blood. The plasma exosomes and total blood exosomes of BCPs had different expression levels of tumor-associated miR-92a and miR-25-3p, induced angiogenesis and epithelial-to-mesenchymal transition (EMT), and increased the number of migrating pseudo-normal breast cells and the total migration path length of cancer cells. The multidirectional effects of HF total blood exosomes on tumor dissemination were revealed; they suppress the angiogenesis and total migration path length of MCF10A, but stimulate EMT and increase the number of migrating MCF10A and the total path length of SKBR3 cells. In addition, HF plasma exosomes enhance the metastasis-promoting properties of SKBR3 cells and stimulate angiogenesis. Both cell-free and blood cell-surface-associated exosomes are involved in the crucial stages of carcinogenesis: the initiation of EMT and the stimulation of proliferation, cell migration, and angiogenesis. Thus, for the estimation of the diagnostic/prognostic significance of circulating exosomes in the blood of cancer patients more correctly, the total blood exosomes, which consist of plasma exosomes and blood cell-surface-associated exosomes should be used.

Obstructive sleep apnea and cancer: a complex relationship

PURPOSE OF REVIEW

Obstructive sleep apnea (OSA) has been recognized as a risk factor for cancer mainly through hypoxia, based on studies that did not distinguish among cancer types. The purpose of this review is to discuss the most recent data on epidemiology and pathophysiology of the OSA-cancer association.

RECENT FINDINGS

According to epidemiological studies, OSA may have different influences on each type of cancer, either increasing or decreasing its incidence and aggressiveness. Time spent with oxygen saturation below 90% appears the polysomnographic variable most strongly associated with unfavorable effects on cancer. Experimental studies support the role of hypoxia as an important risk factor for cancer growth and aggressiveness, especially when it shows an intermittent pattern. These effects are largely mediated by the hypoxia-inducible factor, which controls the synthesis of molecules with effects on inflammation, immune surveillance and cell proliferation. Sleep fragmentation participates in increasing cancer risk. Modulating effects of age remain controversial.

SUMMARY

Effects of OSA on cancer may largely vary among neoplastic diseases, both in their magnitude and direction. The worse risk associated with intermittent rather than persistent hypoxia, and the effects of OSA therapy on cancer natural history are still poorly known, and deserve new careful studies.

The Association of Sleep Disorders, Obesity and Sleep-Related Hypoxia with Cancer

BACKGROUND

Sleep disorders have emerged as potential cancer risk factors.

OBJECTIVE

This review discusses the relationships between sleep, obesity, and breathing disorders with concomitant risks of developing cancer.

RESULTS

Sleep disorders result in abnormal expression of clock genes, decreased immunity, and melatonin release disruption. Therefore, these disorders may contribute to cancer development. Moreover, in sleep breathing disorder, which is frequently experienced by obese persons, the sufferer experiences intermittent hypoxia that may stimulate cancer cell proliferation.

DISCUSSION

During short- or long- duration sleep, sleep-wake rhythm disruption may occur. Insomnia and obstructive sleep apnea increase cancer risks. In short sleepers, an increased risk of stomach cancer, esophageal squamous cell cancer, and breast cancer was observed. Among long sleepers (>9 hours), the risk of some hematologic malignancies is elevated.

CONCLUSION

Several factors including insomnia, circadian disruption, obesity, and intermittent hypoxia in obstructive sleep apnea are contributing risk factors for increased risk of several types of cancers. However, further studies are needed to determine the more significant of these risk factors and their interactions.

Role of Exosomes in Cancer-Related Cognitive Impairment

A decline in cognitive function following cancer treatment is one of the most commonly reported post-treatment symptoms among patients with cancer and those in remission, and include memory, processing speed, and executive function. A clear understanding of cognitive impairment as a result of cancer and its therapy can be obtained by delineating structural and functional changes using brain imaging studies and neurocognitive assessments. There is also a need to determine the underlying mechanisms and pathways that impact the brain and affect cognitive functioning in cancer survivors. Exosomes are small cell-derived vesicles formed by the inward budding of multivesicular bodies, and are released into the extracellular environment via an exocytic pathway. Growing evidence suggests that exosomes contribute to various physiological and pathological conditions, including neurological processes such as synaptic plasticity, neuronal stress response, cell-to-cell communication, and neurogenesis. In this review, we summarize the relationship between exosomes and cancer-related cognitive impairment. Unraveling exosomes’ actions and effects on the microenvironment of the brain, which impacts cognitive functioning, is critical for the development of exosome-based therapeutics for cancer-related cognitive impairment.

Tumor-associated exosomal miRNA biomarkers to differentiate metastatic vs. nonmetastatic non-small cell lung cancer

Background

Exosomal microRNAs (miRNAs) are proposed to be excellent candidate biomarkers for clinical applications. However, little is known about their potential value as diagnostic biomarkers for metastatic non-small cell lung cancer (NSCLC).

Methods

In this study, microarrays were used to determine distinct miRNA profiles of plasma exosomes in a discovery cohort of healthy donors, metastatic NSCLC and nonmetastatic NSCLC patients. Three potential candidate miRNAs were selected based on the differential expression profiles. The discovery set data were validated by quantitative real-time polymerase chain reaction using a validation cohort.

Results

NSCLC patients (n = 80) and healthy controls (n = 30) had different exosome-related miRNA profiles in plasma. Results demonstrated that the level of let-7f-5p was decreased in plasma exosomes of NSCLC patients (p < 0.0001). Further analysis of three differentially expressed miRNAs revealed that miR-320a, miR-622 and let-7f-5p levels could significantly segregate patients with metastatic NSCLC from patients with nonmetastatic NSCLC (p < 0.0001, p < 0.0001 and p = 0.023, respectively). In addition, the combination of let-7f-5p, CEA and Cyfra21-1 generated an area under the curve (AUC) of 0.981 for the diagnosis of NSCLC patients, and the combination of miR-320a, miR-622, CEA and Cyfra21-1 had an AUC of 0.900 for the diagnosis of patients with metastatic NSCLC.

Conclusions

This novel study demonstrated that plasma exosomal miRNAs are promising noninvasive diagnostic biomarkers for metastatic NSCLC.

Exosome-like Nanovectors for Drug Delivery in Cancer

Cancer treatment still represents a formidable challenge, despite substantial advancements in available therapies being made over the past decade. One major issue is poor therapeutic efficacy due to lack of specificity and low bioavailability. The progress of nanotechnology and the development of a variety of nanoplatforms have had a significant impact in improving the therapeutic outcome of chemotherapeutics. Nanoparticles can overcome various biological barriers and localize at tumor site, while simultaneously protecting a therapeutic cargo and increasing its circulation time. Despite this, due to their synthetic origin, nanoparticles are often detected by the immune system and preferentially sequestered by filtering organs. Exosomes have recently been investigated as suitable substitutes for the shortcomings of nanoparticles due to their biological compatibility and particularly small size (i.e., 30-150 nm). In addition, exosomes have been found to play important roles in cell communication, acting as natural carriers of biological cargoes throughout the body. This review aims to highlight the use of exosomes as drug delivery vehicles for cancer and showcases the various attempts used to exploit exosomes with a focus on the delivery of chemotherapeutics and nucleic acids.

Exosomal long noncoding RNA lnc-GNAQ-6:1 may serve as a diagnostic marker for gastric cancer

BACKGROUND

Gastric cancer (GC) is one of the most aggressive cancers, with limited early diagnostic measures. Tumor-originated exosomal molecules are regarded as suitable candidates for non-invasive diagnosis. This study aimed to investigate the capacity of exosomal long noncoding RNA lnc-GNAQ-6:1 as a biomarker for early diagnosis of GC.

METHODS

In this study, we collected sera from 43 patients with gastric cancer and 27 healthy subjects, then exosomes were isolated using commercial kits. Particle size analysis, Western bloting and protein-based exosomes quantification were conducted to identify the isolated exosomes and to evaluate its yield and purity. Expression levels of exosomal lnc-GNAQ-6:1 were detected by quantitative reverse transcription PCR (qRT-PCR). The serum concentrations of traditional biomarker (CA72-4, CEA, and CA19-9) were measured via a chemiluminescent detection system.The receiver operating characteristic curve (ROC) and area under curve (AUC) were used to estimate the diagnostic capacity. Furthermore, we analyzed the potential relationship between serum exosomal lnc-GNAQ-6:1 expression and clinicopathological parameters of gastric cancer.

RESULTS

The exosomes extracted in this study exhibited the typical exosome characteristics and purity. Patients with gastric cancer had the higher exosome yield than healthy volunteer. The results of qRT-PCR showed that compared with the healthy control, the expression of lnc-GNAQ-6:1 was significantly lower in the gastric cancer group. The area under the ROC curve is 0.732, which was higher than the diagnostic accuracy of CEA, CA 19-9 and CA72-4. However, the expression level of lnc-GNAQ-6:1 was not correlated with gender, age, tumor metastasis, serum carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and carbohydrate antigen 72-4(CA72-4).

CONCLUSIONS

Our data demonstrated that serum exosomal lnc-GNAQ-6:1 is lowly expressed in patient with gastric cancer and might be evaluated in larger studies as a new diagnostic marker for gastric cancer.

Obstructive sleep apnea severity and subsequent risk for cancer incidence

In vitro and animal models suggest that obstructive sleep apnea (OSA) increases cancer risk. However, the impact of OSA severity on cancer risk is poorly understood.

We conducted a case-cohort study (a variant of the case-control study design), nested in a cohort of patients with a clinical diagnosis of OSA. OSA patients diagnosed between 2005 and 2013 were linked to a population-based cancer registry to identify cancers diagnosed subsequent to OSA between 2005 and 2015. Medical records were reviewed for a representative sample of 1162 OSA patients from this cohort (including 24 with subsequent cancer), and for an additional 304 OSA patients diagnosed with cancer; information regarding OSA severity indicators, including apnea-hypopnea index (AHI) was abstracted from these records. Adjusted Cox proportional hazards regression were used to calculate hazard ratios (HR) and 95% confidence intervals (CI) for associations of OSA severity indicators on cancer incidence.

Compared with individuals in the lowest AHI category (5–14.9), indicating mild OSA, the adjusted HR (95% CI) for cancer incidence associated with having moderate (15–29.9) or severe (30+) OSA were 0.72 (0.40–1.29) and 0.87 (0.52–1.45) respectively. Associations with other severity indicators were not significantly associated with cancer. However, the proportion of patients with severe OSA (AHI ≥30) was consistently higher across numerous cancer sites relative to the subcohort, suggesting increased cancer risk relative to patients with less severe OSA.

The absence of significant associations with OSA severity measures suggest that the underlying mechanisms deserve further investigation.

Lung Injury and Loss of Regulatory T Cells Primes for Lung-Restricted Autoimmunity

Lung transplantation is a life-saving therapy for several end-stage lung diseases. However, lung allografts suffer from the lowest survival rate predominantly due to rejection. The pathogenesis of alloimmunity and its role in allograft rejection has been extensively studied and multiple approaches have been described to induce tolerance. However, in the context of lung transplantation, dysregulation of mechanisms, which maintain tolerance against self-antigens, can lead to lung-restricted autoimmunity, which has been recently identified to drive the immunopathogenesis of allograft rejection. Indeed, both preexisting as well as de novo lung-restricted autoimmunity can play a major role in the development of lung allograft rejection. The three most widely studied lung-restricted self-antigens include collagen type I, collagen type V, and k-alpha 1 tubulin. In this review, we discuss the role of lung-restricted autoimmunity in the development of both early as well as late lung allograft rejection and recent literature providing insight into the development of lung-restricted autoimmunity through the dysfunction of immune mechanisms which maintain peripheral tolerance.

Central regulation of breast cancer growth and metastasis

Cancer is a systemic disease. In order to fully understand it, we must take a holistic view on how cancer interacts with its host. The brain monitors and responds to natural and aberrant signals arriving from the periphery, particularly those of metabolic or immune origin. As has been well described, a hallmark of cancer is marked disruption of metabolic and inflammatory processes. Depending on the salience and timing of these inputs, the brain responds via neural and humoral routes to alter whole-body physiology. These responses have consequences for tumor growth and metastasis, directly influencing patient quality of life and subsequent mortality. Additionally, environmental inputs such as light, diet, and stress, can promote inappropriate neural activity that benefits cancer. Here, I discuss evidence for brain-tumor interactions, with special emphasis on subcortical neuromodulator neural populations, and potential ways of harnessing this cross-talk as a novel approach for cancer treatment.

Prostate cancer cells and exosomes in acidic condition show increased carbonic anhydrase IX expression and activity

Acidity and hypoxia are crucial phenotypes of tumour microenvironment both contributing to the selection of malignant cells under a micro evolutionistic pressure. During the tumour progression, nanovesicles, called exosomes and the metalloenzyme carbonic anhydrase IX (CA IX) affect the tumour growth and proliferation. Exosomes are released into the tumour microenvironment and spilt all over the body, while CA IX is a tumour-associated protein overexpressed in many different solid tumours. In the present study, to better understand the relationships between exosomes and CA IX, it has been used an in vitro cellular model of cells cultured in different pH conditions. The results showed that the acidic microenvironment induced upregulation of both expression and activity of CA IX in cancer cells and their exosomes, together with increasing the number of released exosomes. These data strongly support the importance of CA IX as a cancer biomarker and as a valuable target of new anticancer therapies.

Visible Light-Driven Self-Powered Device Based on a Straddling Nano-Heterojunction and Bio-Application for the Quantitation of Exosomal RNA

This paper reports the design and fabrication of a self-powered biosensing device based on TiO₂ nanosilks (NSs)@MoS₂ quantum dots (QDs) and demonstrates a bioapplication for the quantitative detection of exosomal RNA ( Homo sapiens HOXA distal transcript antisense RNA, HOTTIP). This self-powered device features enhanced power output compared to TiO₂ NSs alone. This is attributed to the formation of a heterojunction structure with suitable band offset derived from the hybridization between TiO₂ NSs and MoS₂ QDs, i.e., the straddling (Type I) band alignment. The sensitization effect and excellent visible light absorption provided by MoS₂ QDs can prolong interfacial carrier lifetime and improve energy conversion efficiency. This self-powered biosensing device has been successfully applied in quantitative HOTTIP detection through effective hybridization between a capture probe and HOTTIP. The successful capture of HOTTIP leads to a sequential decrease in power output, which is utilized for ultrasensitive quantitative HOTTIP detection, with a linear relationship of power output change versus the logarithm of HOTTIP concentration ranging from 5 fg/mL to 50 000 ng/mL and a detection limit as low as 5 fg/mL. This TiO₂ NSs@MoS₂ QDs-based nanomaterial has excellent potential for a superior self-powered device characterized by economical and portable self-powered biosensing. Moreover, this self-powered, visible-light-driven device shows promising applications for cancer biomarker quantitative detection.

Connexins and Atrial Fibrillation in Obstructive Sleep Apnea

PURPOSE OF THE REVIEW

To summarize the potential interactions between obstructive sleep apnea (OSA), atrial fibrillation (AF), and connexins.

RECENT FINDINGS

OSA is highly prevalent in patients with cardiovascular disease, and is associated with increased risk for end-organ substantial morbidities linked to autonomic nervous system imbalance, increased oxidative stress and inflammation, ultimately leading to reduced life expectancy. Epidemiological studies indicate that OSA is associated with increased incidence and progression of coronary heart disease, heart failure, stroke, as well as arrhythmias, particularly AF. Conversely, AF is very common among subjects referred for suspected OSA, and the prevalence of AF increases with OSA severity. The interrelationships between AF and OSA along with the well-known epidemiological links between these two conditions and obesity may reflect shared pathophysiological pathways, which may depend on the intercellular diffusion of signaling molecules into either the extracellular space or require cell-to-cell contact. Connexin signaling is accomplished via direct exchanges of cytosolic molecules between adjacent cells at gap membrane junctions for cell-to-cell coupling. The role of connexins in AF is now quite well established, but the impact of OSA on cardiac connexins has only recently begun to be investigated. Understanding the biology and regulatory mechanisms of connexins in OSA at the transcriptional, translational, and post-translational levels will undoubtedly require major efforts to decipher the breadth and complexity of connexin functions in OSA-induced AF.

SUMMARY

The risk of end-organ morbidities has initiated the search for circulating mechanistic biomarker signatures and the implementation of biomarker-based algorithms for precision-based diagnosis and risk assessment. Here we summarize recent findings in OSA as they relate to AF risk, and also review potential mechanisms linking OSA, AF and connexins.

Plasma exosomes stimulate breast cancer metastasis through surface interactions and activation of FAK signaling

PURPOSE

The interaction between malignant cells and surrounding healthy tissues is a critical factor in the metastatic progression of breast cancer (BC). Extracellular vesicles, especially exosomes, are known to be involved in inter-cellular communication during cancer progression. In the study presented herein, we aimed to evaluate the role of circulating plasma exosomes in the metastatic dissemination of BC and to investigate the underlying molecular mechanisms of this phenomenon.

METHODS

Exosomes isolated from plasma of healthy female donors were applied in various concentrations into the medium of MDA-MB-231 and MCF-7 cell lines. Motility and invasive properties of BC cells were examined by random migration and Transwell invasion assays, and the effect of plasma exosomes on the metastatic dissemination of BC cells was demonstrated in an in vivo zebrafish model. To reveal the molecular mechanism of interaction between plasma exosomes and BC cells, a comparison between un-treated and enzymatically modified exosomes was performed, followed by mass spectrometry, gene ontology, and pathway analysis.

RESULTS

Plasma exosomes stimulated the adhesive properties, two-dimensional random migration, and transwell invasion of BC cells in vitro as well as their in vivo metastatic dissemination in a dose-dependent manner. This stimulatory effect was mediated by interactions of surface exosome proteins with BC cells and consequent activation of focal adhesion kinase (FAK) signaling in the tumor cells.

CONCLUSIONS

Plasma exosomes have a potency to stimulate the metastasis-promoting properties of BC cells. This pro-metastatic property of normal plasma exosomes may have impact on the course of the disease and on its prognosis.

Exosome: a novel mediator in drug resistance of cancer cells

Exosomes are small membrane vesicles with a diameter of 40–100 nm, which are released into the intracellular environment. Exosomes could influence the genetic and epigenetic changes of receptor cells by promoting the horizontal transfer of various proteins or RNAs, especially miRNAs. Moreover, exosomes also play an important role in tumor microenvironment. Exosomes could promote the short- and long-distance exchanges of genetic information by acting as mediators of cell-to-cell communication. In addition, exosomes participate in drug resistance of tumor cells by genetic exchange between cells. It is reported that exosomes could be absorbed by recipient cells and transmit chemoresistance from drug-resistant tumor cells to sensitive ones. Then understanding the mechanisms of chemotherapy failure and controlling tumor progression effectively will be a major challenge for us. Therefore, in this review, we will briefly reveal the role of exosomes in drug resistance.

Sleep apnea and subsequent cancer incidence

PURPOSE

In vitro and animal models suggest that the physiological effects of sleep apnea could contribute to cancer risk, yet epidemiologic studies have been inconsistent.

METHODS

We identified a cohort of adults diagnosed with sleep apnea between 2005 and 2014 using regional administrative databases. Linking this cohort to a population-based cancer registry, we identified first incident cancers diagnosed after sleep apnea diagnosis through 2015. We calculated age-sex standardized cancer incidence ratios (SIRs) to compare the observed number of cancers among those with sleep apnea with expected population estimates over a comparable period.

RESULTS

Among 34,402 individuals with sleep apnea, 1,575 first incident cancers were diagnosed during follow-up (mean ± SD; 5.3 ± 2.0 years). Compared to the general population, cancer incidence (SIR 1.26, 95% CI 1.20-1.32) was elevated among sleep apnea patients. We observed significantly elevated incidence for kidney (SIR 2.24, 95% CI 1.82-2.72), melanoma (SIR 1.71, 95% CI 1.42-2.03), breast (SIR 1.43, 95% CI 1.76-2.00), and corpus uteri (SIR 2.80, 95% CI 2.24-2.47) while risk for lung (SIR 0.66, 95% CI 0.54-0.79) and colorectal cancer (SIR 0.71, 95% CI 0.56-0.89) was lower.

CONCLUSION

These findings suggest an elevated cancer burden, particularly at certain sites, among individuals with diagnosed sleep apnea. Results should be interpreted with caution due to unmeasured confounders (e.g., BMI, diabetes).

Sleep-disordered breathing, circulating exosomes, and insulin sensitivity in adipocytes

BACKGROUND

Sleep-disordered-breathing (SDB), which is characterized by chronic intermittent hypoxia (IH) and sleep fragmentation (SF), is a prevalent condition that promotes metabolic dysfunction, particularly among patients suffering from obstructive hypoventilation syndrome (OHS). Exosomes are generated ubiquitously, are readily present in the circulation, and their cargo may exert substantial functional cellular alterations in both physiological and pathological conditions. However, the effects of plasma exosomes on adipocyte metabolism in patients with OHS or in mice subjected to IH or SF mimicking SDB are unclear.

METHODS

Exosomes from fasting morning plasma samples from obese adults with polysomnographically-confirmed OSA before and after 3 months of adherent CPAP therapy were assayed. In addition, C57BL/6 mice were randomly assigned to (1) sleep control (SC), (2) sleep fragmentation (SF), and (3) intermittent hypoxia (HI) for 6 weeks, and plasma exosomes were isolated. Equivalent exosome amounts were added to differentiated adipocytes in culture, after which insulin sensitivity was assessed using 0 nM and 5 nM insulin-induced pAKT/AKT expression changes by western blotting.

RESULTS

When plasma exosomes were co-cultured and internalized by human naive adipocytes, significant reductions emerged in Akt phosphorylation responses to insulin when compared to exosomes obtained after 24 months of adherent CPAP treatment (n = 24; p < 0.001), while no such changes occur in untreated patients (n = 8). In addition, OHS exosomes induced significant increases in adipocyte lipolysis that were attenuated after CPAP, but did not alter pre-adipocyte differentiation. Similarly, exosomes from SF- and IH-exposed mice induced attenuated p-AKT/total AKT responses to exogenous insulin and increased glycerol content in naive murine adipocytes, without altering pre-adipocyte differentiation.

CONCLUSIONS

Using in vitro adipocyte-based functional reporter assays, alterations in plasma exosomal cargo occur in SDB, and appear to contribute to adipocyte metabolic dysfunction. Further exploration of exosomal miRNA signatures in either human subjects or animal models and their putative organ and cell targets appears warranted.

Effect of colorectal cancer-derived extracellular vesicles on the immunophenotype and cytokine secretion profile of monocytes and macrophages

Background

Macrophages are one of the most important players in the tumor microenvironment. The polarization status of tumor associated macrophages into a pro-inflammatory type M1 or anti-inflammatory type M2 may influence cancer progression and patient survival. Extracellular vesicles (EVs) are membrane-bound vesicles containing different biomolecules that are involved in cell to cell signal transfer. Accumulating evidence suggests that cancer-derived EVs are taken up by macrophages and modulate their phenotype and cytokine profile. However, the interactions of cancer-derived EVs with monocytes and macrophages at various differentiation and polarization states are poorly understood. In the current study, we have analyzed the uptake and functional effects of primary (SW480) and metastatic (SW620) isogenic colorectal cancer (CRC) cell line-derived EVs on monocytes (M), inactive macrophages (M0) and M1 and M2 polarized macrophages.

Methods

THP-1 monocytes were differentiated into M0 macrophages by addition of phorbol-12-myristate-13-acetate. Then M0 macrophages were further polarized into M1 and M2 macrophages in the presence of LPS, IFN- γ, IL-4, and IL-13 respectively. Internalization of SW480 and SW620-derived EVs was analyzed by flow cytometry and fluorescence microscopy. Changes in monocyte and macrophage immunophenotype and secretory profile upon EV exposure were analyzed by flow cytometry, quantitative PCR and Luminex assays.

Results

THP-1 monocytes and M0 macrophages efficiently take up SW480 and SW620-derived EVs, and our results indicate that dynamin-dependent endocytic pathways may be implicated. Interestingly, SW480 and SW620-derived EVs increased CD14 expression in M0 macrophages whereas SW480-derived EVs decreased HLA-DR expression in M1 and M2 polarized macrophages. Moreover, SW480-derived EVs significantly increased CXCL10 expression in monocytes and M0 macrophages. In contrast, SW620-derived EVs induced secretion of IL-6, CXCL10, IL-23 and IL-10 in M0 macrophages. However, addition of CRC cell line-derived EVs together with LPS, IFN- γ (M1) and IL-4, IL-13 (M2) stimuli during macrophage polarization had no additional effect on cytokine expression in M1 and M2 macrophages.

Conclusion

Our results suggest that CRC cell line-derived EVs are internalized and reprogram the immunophenotype and secretory profile in monocytes and inactive macrophages inducing mixed M1 and M2 cytokine response. Although CRC EVs decreased HLA-DR expression in M1, M2 polarized macrophages, their effect on the secretory profile of M1 and M2 polarized macrophages was negligible.

Electronic supplementary material

The online version of this article (10.1186/s12964-018-0229-y) contains supplementary material, which is available to authorized users.

Tumor-derived exosomes: Potential biomarker or therapeutic target in breast cancer?

Exosomes are released by normal and tumour cells, including those involved in breast cancer, and provide a means of intercellular communications. Exosomes with diameters ranging between 30-150 nm are involved in transferring biological information, via various lipids, proteins, different forms of RNAs, and DNA from one cell to another, and this can result in reprogramming of recipient cell functions. These vesicles are present in all body fluids, for example, blood plasma/serum, semen, saliva, cerebrospinal fluid, breast milk, and urine. It has been recently reported that these particles are involved in the development and progression of different tumor types, including breast cancer. Furthermore, it has been suggested that exosomes have the potential to be used as drug transporters, or as biomarkers. This review highlights the potential roles of exosomes in normal and breast cancer cells and their potential applications as biomarkers with special focus on their potential applications in treatment of breast cancer.

Exosomal long noncoding RNA CRNDE-h as a novel serum-based biomarker for diagnosis and prognosis of colorectal cancer

Cancer-secreted long non-coding RNAs (lncRNAs) are emerging mediators of cancer-host cross talk. The aim of our study was to illustrate the clinical significance of the lncRNA CRNDE-h in exosomes purified from the serum of patients with colorectal cancer (CRC). The study was divided into four parts: (1) The exosome isolated methods and lncRNA detected methods which accurately and reproducibly measure CRC-related exosomal CRNDE-h in serum were optimized in preliminary pilot stage; (2) The stability of exosomal CRNDE-h was evaluated systematically; (3) The origin of exosomal CRNDE-h was explorated in vitro and in vivo; (4) The diagnostic and prognostic value of exosomal CRNDE-h for CRC were validated in 468 patients. In pilot study, our results indicated that exosomal CRNDE-h was detectable and stable in serum of CRC patients, and derived from tumor cells. Then, the increased expression of exosomal CRNDE-h was successfully validated in 148 CRC patients when compared with colorectal benign disease patients and healthy donors. Exosomal CRNDE-h level significantly correlated with CRC regional lymph node metastasis (P = 0.019) and distant metastasis (P = 0.003). Moreover, at the cut-off value of 0.020 exosomal CRNDE-h level of serum, the area under ROC curve distinguishing CRC from colorectal benign disease patients and healthy donors was 0.892, with 70.3% sensitivity and 94.4% specificity, which was superior to carcinoembryogenic antigen. In addition, high exosomal CRNDE-h level has a lower overall survival rates than that for low groups (34.6% vs. 68.2%, P < 0.001). In conclusion, detection of lncRNA CRNDE-h in exosome shed a light on utilizing exosomal CRNDE-h as a noninvasive serum-based tumor marker for diagnosis and prognosis of CRC.

Plasma Exosomes and Improvements in Endothelial Function by Angiotensin 2 Type 1 Receptor or Cyclooxygenase 2 Blockade following Intermittent Hypoxia

Intermittent hypoxia (IH) is associated with increased endothelial dysfunction and cardiovascular disorders. Exosomes released in biological fluids may act as vehicles for propagating such damage, modifying the functional phenotype of endothelial cells. Drug interventions, however, may provide protection for the endothelium, in spite of exosomal activity. Using an experimental human model of IH, we investigated whether the beneficial effects of two drugs, celecoxib (CEL) and losartan (LOS), on IH-induced vascular dysfunction was mediated via exosomes or independent of IH-induced exosomal cargo alterations. We hypothesized that the beneficial effects of CEL and LOS on IH-induced vascular dysfunction would be mediated via modifications of exosomal properties by the drugs, rather than by direct effects of the drugs on the endothelium. Ten male volunteers were exposed to IH (single exposure of 6 h) while receiving LOS, CEL, or placebo (P) for 4 days before IH exposures, and plasma samples were obtained from which exosomes were isolated, and incubated with naïve human endothelial cell cultures either not treated or pretreated with LOS, CEL, or P. Functional reporter assays (monolayer impedance, monocyte adhesion, and eNOS phosphorylation) revealed that the degree of exosome-induced endothelial dysfunction was similar among IH-exposed subjects independent of drug treatment. However, pretreatment of naïve endothelial cells with LOS or CEL before addition of exosomes from IH-exposed subjects afforded significant protection. Thus, the cardiovascular protective impact of LOS and CEL appears to be mediated by their direct effects on endothelial cells, rather than via modulation of exosomal cargo.

Exosomes and Metabolic Function in Mice Exposed to Alternating Dark-Light Cycles Mimicking Night Shift Work Schedules

Sleep is an important modulator of metabolic function. Disruptions of sleep in circadian rhythm are common in modern societies and are associated with increased risk of developing cardiometabolic disorders. Exosomes are ubiquitous extracellular vesicles that may play a mechanistic role in metabolic derangements. We hypothesized that alternating dark-light cycles mimicking shift work in mice would alter fecal microbiota and colonic epithelium permeability and alter plasma exosome cargo and metabolic function. C57BL/6 mice were randomly assigned to (i) control day light (CL), or (ii) inverted dark-light every 2 weeks for 8 weeks (IN). Body weight, fat mass and HOMA-IR were measured, along with Tregs, metabolic, and resident macrophages in visceral white adipose tissue (vWAT). Fecal water samples were incubated with confluent colonic epithelium cell cultures in electric cell-substrate impedance sensing (ECIS) arrays, and plasma exosomes were added to differentiated adipocytes and insulin-induced pAKT/AKT expression changes were assessed by western blots. Mice exposed to IN showed elevated HOMA-IR, and their fecal samples showed altered microbiota which promote increased permeability of the colonic epithelial cell barrier. Plasma exosomes decreased pAKT/AKT responses to exogenous insulin compared to CL, and altered expression of circadian clock genes. Inflammatory macrophages (Ly-6c^high) were increased in IN-exposed vWAT, while Tregs were decreased. Thus, gut microbiota and the cargo of plasma exosomes are altered by periodic shifts in environmental lighting, and effectively alter metabolic function, possibly via induction of systemic inflammation and altered clock expression in target tissues. Further exploration of exosomal miRNA signatures in shift workers and their putative metabolic organ cell targets appears warranted.

Target of obstructive sleep apnea syndrome merge lung cancer: based on big data platform

Based on our hospital database, the incidence of lung cancer diagnoses was similar in obstructive sleep apnea Syndrome (OSAS) and hospital general population; among individual with a diagnosis of lung cancer, the presence of OSAS was associated with an increased risk for mortality. In the gene expression and network-level information, we revealed significant alterations of molecules related to HIF1 and metabolic pathways in the hypoxic-conditioned lung cancer cells. We also observed that GBE1 and HK2 are downstream of HIF1 pathway important in hypoxia-conditioned lung cancer cell. Furthermore, we used publicly available datasets to validate that the late-stage lung adenocarcinoma patients showed higher expression HK2 and GBE1 than early-stage ones. In terms of prognostic features, a survival analysis revealed that the high GBE1 and HK2 expression group exhibited poorer survival in lung adenocarcinoma patients. By analyzing and integrating multiple datasets, we identify molecular convergence between hypoxia and lung cancer that reflects their clinical profiles and reveals molecular pathways involved in hypoxic-induced lung cancer progression. In conclusion, we show that OSAS severity appears to increase the risk of lung cancer mortality.

Role of exosomal proteins in cancer diagnosis

Exosomes are emerging as a new type of cancer biomarkers. Exosome is a bilayered nano-sized vesicle secreted by various living cells in all body fluids. Based on the expanding albeit incomplete knowledge of their biogenesis, secretion by cells and cancer cell-specific molecular and genetic contents, exosomes are viewed as promising, clinically-relevant surrogates of cancer progression and response to therapy. Preliminary proteomic, genetic and functional profiling of cancer cell-derived or cancer plasma-derived exosomes confirms their unique characteristics. Alterations in protein or nucleic acid profiles of exosomes in plasma correlate with pathological processes of many diseases including cancer. However, previous studies on exosome application in cancer diagnosis and treatment mainly focussed on miRNAs. With the development of rapid large-scale production, purification, extraction and screening of exosomal contents, exosomal protein application can be explored for early stage cancer diagnosis, monitoring and prognosis evaluation. Here, we summarized the recent developments in application of exosomal proteins for cancer diagnosis.

Elevation of circulating microRNA levels in obese children compared to healthy controls

As childhood obesity increases, it is becoming important to understand the complications of obesity in children and develop novel biomarkers. Evidence indicates that microRNAs (miRNA) are dys-regulated in obesity and may serve as sensitive and specific circulating biomarkers. Non-alcoholic fatty liver disease (NAFLD) is a complication of obesity that ultimately requires a liver biopsy to determine disease severity. While studies have been conducted in adults, no study to date has examined circulating miRNAs in children with obesity and NAFLD. The goal of this study was to evaluate a panel of selected circulating miRNAs in obese children compared to healthy controls. We present here an analysis of a pre-selected panel of 20 candidate miRNAs in obese children compared to healthy controls. The miRNAs were chosen based on having been previously reported to be involved in NAFLD. We found that 16 out of 20 miRNAs tested were elevated at least twofold in children with obesity compared to controls. miR-122 and miR-199a showed the greatest increase in children with obesity versus controls. Both also had a high area under the curve when receiver-operator curves were plotted. Several circulating miRNAs correlated with body mass index (BMI) or serum transaminases. This study provides initial evidence that circulating miRNAs can be measured in the paediatric population and provides several diagnostic candidates increased in children with obesity that may be relevant to NAFLD.

Diagnostic potential of serum exosomal colorectal neoplasia differentially expressed long non-coding RNA (CRNDE-p) and microRNA-217 expression in colorectal carcinoma

In this study, we investigated the diagnostic potential of serum exosomal colorectal neoplasia differentially expressed (CRNDE-p) long coding RNA and microRNA-217 in colorectal carcinoma (CRC). We detected high CRNDE-p and low miR-217 levels in exosomes released by multiple CRC cell lines into culture media as well as in sera from CRC xenograft mice and CRC patients. Conversely, we observed lower CRNDE-p and higher miR-217 levels in serum exosomes from post-chemotherapy than from pre-chemotherapy patient samples. The area under curve (AUC) value for the serum exosomal CRNDE-p and miR-217 combination was higher than CRNDE-p or miR-217 alone. Moreover, high CRNDE-p and low miR-217 serum exosomal levels correlated with advanced clinical stages (III/IV), tumor classification (T3/T4), and lymph node or distant metastasis. Thus combined evaluation of serum exosomal CRNDE-p and miR-217 levels show diagnostic and prognostic potential for CRC patients.

Integrated stress response activation by sleep fragmentation during late gestation in mice leads to emergence of adverse metabolic phenotype in offspring

BACKGROUND

Late gestational sleep fragmentation (SF) is highly prevalent particularly in obese women, and induces metabolic dysfunction in adult offspring mice. SF induces activation of the integrated stress response (ISR), which might be involved in metabolic disorders. We hypothesized that adult offspring of double mutant mice (DM) involving the critical ISR genes CHOP and GADD34 would be protected from developing obesity and insulin resistance following SF.

METHODS

Time-pregnant CHOP/GADD34 DM and wild type (WT) mice were randomly assigned to sleep control (SC) or SF conditions during the last 5days of gestation. At 24-weeks of age, body weight, fat mass, and HOMA-IR were assessed in the offspring. Tregs lymphocytes, Lyc6c^high, M1 and M2 macrophages were examined in visceral white adipose tissues (vWAT) using flow cytometry. The effects of plasma exosomes on adipocyte cell line proliferation, differentiation and insulin sensitivity were also evaluated.

RESULTS

SF-WT male showed significant increases in body weight, vWAT mass and HOMA-IR compared to SC-WT mice, while SF had no effect in SF-DM mice. Inflammatory macrophages (Ly-6c^high) and the ratio of M1/M2 macrophages were increased while FoxP3+ Tregs counts were decreased in SF-WT but not in SF-DM mice. Exosomes from SF-WT, but not from the SF-DM offspring increased pre-adipocyte proliferation and differentiation, and decreased in vitro adipocyte insulin sensitivity.

CONCLUSION

Activation of the ISR during late gestation, as induced by late gestational SF, appears to underlie some of the transgenerational modifications in metabolic genes ultimately contributing to a metabolic syndrome phenotype in adult offspring.