Exosomes are a type of extracellular vesicles (EVs) secreted by multiple mammalian cell types and involved in intercellular communication. Numerous studies have explored the diagnostic and therapeutic potential of exosomes. The key challenge is the lack of efficient and standard techniques for isolation and downstream analysis of nanovesicles. Conventional isolation methods, such as ultracentrifugation, precipitation, filtration, chromatography, and immune-affinity-based approaches, rely on specific physical properties or on surface biomarkers. However, any of the existing methods has its limitations. Various parameters, such as efficacy, specificity, labor input, cost and scalability, and standardization options, must be considered for the correct choice of appropriate approach. The isolation of exosomes from biological fluids is especially challenged by the complex nature and variability of these liquids. Here, we present a comparison of five protocols for exosome isolation from human plasma: two chemical affinity precipitation methods (lectin-based purification and SubX™ technology), immunoaffinity precipitation, and reference ultracentrifugation-based exosome isolation method in two modifications. An approach for the isolation of exosomes based on the phenomenon of binding and aggregation of these particles via clusters of outer membrane phosphate groups in the presence of SubX™ molecules has been put forward in the present study. The isolated EVs were characterized based upon size, quantity, and protein content.

Vesicular miRNA has emerged as a promising marker for various types of cancer, including prostate cancer (PC). In the advanced stage of PC, the cancer-cell-derived small extracellular vesicles (SEVs) may constitute a significant portion of circulating vesicles and may mediate a detectable change in the plasma vesicular miRNA profile. However, SEVs secreted by small tumor in the prostate gland constitute a tiny fraction of circulating vesicles and cause undetectable miRNA pattern changes. Thus, the isolation and miRNA profiling of a specific prostate-derived fraction of SEVs can improve the diagnostic potency of the methods based on vesicular miRNA analysis. Prostate-specific membrane antigen (PSMA) was selected as a marker of prostate-derived SEVs. Super-paramagnetic beads (SPMBs) were functionalized by PSMA-binding DNA aptamer (PSMA–Apt) via a click reaction. The efficacy of SPMB–PSMA–Apt complex formation and PSMA(+)SEVs capture were assayed by flow cytometry. miRNA was isolated from the total population of SEVs and PSMA(+)SEVs of PC patients (n = 55) and healthy donors (n = 30). Four PC-related miRNAs (miR-145, miR-451a, miR-143, and miR-221) were assayed by RT-PCR. The click chemistry allowed fixing DNA aptamers onto the surface of SPMB with an efficacy of up to 89.9%. The developed method more effectively isolates PSMA(+)SEVs than relevant antibody-based technology. The analysis of PC-related miRNA in the fraction of PSMA(+)SEVs was more sensitive and revealed distinct diagnostic potency (AUC: miR-145, 0.76; miR-221, 0.7; miR-451a, 0.65; and miR-141, 0.64) than analysis of the total SEV population. Thus, isolation of prostate-specific SEVs followed by analysis of vesicular miRNA might be a promising PC diagnosis method.

Endometriosis is a chronic disease characterized by the growth of endometrial tissue outside of the uterine cavity. Endometriosis affects up to 10% of women of reproductive age and has great social impact. The diagnostics of endometriosis are based on clinical appearance, ultrasound, and magnetic resonance imaging (MRI); however, a diagnosis is frequently hampered by the absence of objective criteria. Adenomyosis (AM) is a particular type of endometriosis wherein the spread of the ectopic endometrial gland is limited by the uterine myometrium. Alteration of the microRNA expression profile in the eutopic endometrium can be associated with AM, and may be assayed for diagnostic purposes. In the presented study, we aimed to explore the diagnostic potency of this approach. Eutopic endometrium specimens were collected from patients (n = 33) and healthy women (n = 30). The microRNA expression was profiled to select individual microRNAs with AM-associated expression alterations. A new method of two-tailed RT-qPCR microRNA analysis was applied to assay potential markers. The expression ratios of reciprocally dysregulated microRNAs were calculated, and the diagnostic potency of these parameters was evaluated by receiver operation curve (ROC) analysis. Mir-10b, miR-200c and miR-191 were significantly dysregulated in the eutopic endometrium of AM patients. The expression ratio of reciprocally dysregulated microRNAs allowed us to diagnose AM with a range of sensitivity from 65% to 74%, and of specificity from 72% to 86%. The analysis of microRNAs from the eutopic endometrium might present a promising low-invasive method of AM diagnostics.

Background: The current approaches to distinguish follicular adenomas (FA) and follicular thyroid cancer (FTC) at the pre-operative stage have low predictive value. Liquid biopsy-based analysis of circulating extracellular vesicles (EVs) presents a promising diagnostic method. However, the extreme heterogeneity of plasma EV population hampers the development of new diagnostic tests. We hypothesize that the isolation of EVs with thyroid-specific surface molecules followed by miRNA analysis, may have improved diagnostic potency. Methods: The total population of EVs was isolated from the plasma of patients with FA (n = 30) and FTC (n = 30). Thyroid peroxidase (TPO)-positive EVs were isolated from the total populations using immune-beads. The miRNA from the TPO(+)EVs obtained from the plasma of FA and FTC patients was assayed by RT-PCR. The diagnostic potency of the selected miRNAs was estimated by the receiver operating characteristic (ROC) analysis. Results: TPO(+)EVs can be efficiently isolated by immunobeads. The analysis of Let-7 family members in TPO(+)EVs allows one to distinguish FA and FTC with high accuracy (area under curve defined by ROC = 0.77–0.84). Conclusion: The isolation of TPO(+)EVs, followed by RT-qPCR analysis of Let-7 family members, may present a helpful approach to manage follicular nodules in the thyroid gland.

A liquid biopsy based on circulating small extracellular vesicles (SEVs) has not yet been used in routine clinical practice due to the lack of reliable analytic technologies. Recent studies have demonstrated the great diagnostic potential of nanozyme-based systems for the detection of SEV markers. Here, we hypothesize that CD30-positive Hodgkin and Reed–Sternberg (HRS) cells secrete CD30 + SEVs; therefore, the relative amount of circulating CD30 + SEVs might reflect classical forms of Hodgkin lymphoma (cHL) activity and can be measured by using a nanozyme-based technique. A AuNP aptasensor analytics system was created using aurum nanoparticles (AuNPs) with peroxidase activity. Sensing was mediated by competing properties of DNA aptamers to attach onto surface of AuNPs inhibiting their enzymatic activity and to bind specific markers on SEVs surface. An enzymatic activity of AuNPs was evaluated through the color reaction. The study included characterization of the components of the analytic system and its functionality using transmission and scanning electron microscopy, nanoparticle tracking analysis (NTA), dynamic light scattering (DLS), and spectrophotometry. AuNP aptasensor analytics were optimized to quantify plasma CD30 + SEVs. The developed method allowed us to differentiate healthy donors and cHL patients. The results of the CD30 + SEV quantification in the plasma of cHL patients were compared with the results of disease activity assessment by positron emission tomography/computed tomography (PET-CT) scanning, revealing a strong positive correlation. Moreover, two cycles of chemotherapy resulted in a statistically significant decrease in CD30 + SEVs in the plasma of cHL patients. The proposed AuNP aptasensor system presents a promising new approach for monitoring cHL patients and can be modified for the diagnostic testing of other diseases.

The quantification of the specific disease-associated populations of circulating extracellular membrane nanovesicles (ENVs) has opened up new opportunities for liquid biopsy in cancer and other chronic diseases. However, the sensitivity of such methods is mediated by an optimal combination of the isolation and labeling approaches, and is not yet sufficient for routine clinical application. The presented study aimed to develop, characterize, and explore a new approach to non-specific ENV staining, followed by size-exclusive chromatography (SEC), which allows us to increase the sensitivity of bead-assisted flow cytometry. Plasma from healthy donors was purified from large components, stained with lipophilic CM-Dil dye, and fractionated by means of SEC. The obtained fractions were analyzed in terms of particle size and concentration using NTA, as well as vesicular markers and plasma protein content via dot-blotting. We characterized the process of CM-Dil-stained plasma fractionation in detail and indicated the fractions with optimal characteristics. Finally, we explored the sensitivity of on-bead flow cytometry for the analysis of specific populations of plasma ENVs and demonstrated the advantages and limitations of the proposed technique.

Background. Heat stress (HS) induces the cellular secretion of heat shock proteins (HSP ) and extracellular nanovesicles (ENVs). The biological link between these phenomena is poorly understood. In the case of colorectal cancer (CRC) cells, the secretion of HSP s and ENV may be involved in the clinical response to intraperitoneal therapy of peritoneal carcinomatosis.Material and Methods. Established colon cancer cell lines COLO 320, HCT 116, HT29 and DLD 1 were used. ENVs were isolated from culture media by differential ultra-centrifugation and analyzed by dynamic light scattering, nanoparticle tracking analysis, atomic force microscopy and flow cytometry. Super-paramagnetic particles (SPMP ) covered by antibodies to the membrane form of Hsp70 were used for isolation and quantification of Hsp70(+) ENVs. Vesicular microRNA was assayed by RT-qPC R.Results. HS induces the secretion of ENVs by CRC cells, the resistance to HS correlates with the activity of HS-induced ENVs secretion. HS induces the secretion of a specific population of ENVs enriched by membrane form Hsp70 (mHsp70). The microRNA content of mHsp70(+) ENVs has qualitative and quantitative features. The concentration of miR-126-3p, -181-5p, -155-5p, -223 is increased in mHSP 70(+) ENVs secreted by three CRC cell lines.Conclusion. HS induces the secretion of mHSP 70(+) ENVs by CRC cells. This phenomenon may be involved in a clinical response to intraperitoneal chemo-hyperthermic perfusion therapy of peritoneal carcinomatosis.

Introduction. Testicular germ cell tumor is a relatively rare disease. Its high social significance is due to the fact that this pathology occurs in young patients. The standard schemes of polychemotherapy determine the potential possibility of effective treatment for most of the patients even with an advanced disease. Several circulating markers (alpha-fetoprotein, human chorionic gonadotropin and lactate dehydrogenase) are being used for therapy monitoring, but the low diagnostic specificity of these molecules determines the need to develop new approaches. Over the past years, circulating microRNA, for instance miR-371a-3p, appeared to be promising marker for testicular germ cell tumor monitoring. However, to develop and to implement in practice the microRNA-based diagnostic technologies, it’s necessarily to understand the features of the microRNA expression alterations specific for different histological types of testicular germ cell tumor.The study objective – to evaluate changes in the expression of several potential marker microRNA molecules (miR-302/ miR-367, miR-371/miR-373) in testicular germ cell tumor samples of various histological types.Materials and methods. Testicular germ cell tumor samples (n = 61), including seminomas, embryonic carcinomas, post-pubertal teratomas, yolk sac tumors, chorioncarcinomas, and corresponding normal tissue samples (n = 61) were included in the study. The analysis of selected miRNA expression was performed by reverse transcription and polymerase chain reaction.Results. We identified the changes in the expression profile of the miR-302/miR-367 cluster typical for semines, embryonic carcinomas, post-pubertal teratomas, yolk sac tumors and chorioncarcinomas, as well as changes in the expression profile of the miR-371/miR-373 cluster, universal for all histotypes except chorioncarcinomas. Inhibition of miR-10b and miR-145 expression in semines, embryonic carcinomas, and post-pubertal teratomas was demonstrated.Conclusion. Activation of miR-302b, miR-302d, miR-371a expression and inhibition of miR-10b, miR-145 expression in the tissue of the most common variants of testicular germ cell tumor is a characteristic feature of these tumors. The detected changes are significant and can lead to corresponding changes in the profile of circulating microRNAs.