Ovarian cancer (OC) is one of the most common and fatal types of gynecological cancer. In the early phase of OC detection, the current treatment and diagnostic methods are not efficient and sensitive enough. Therefore, it is crucial to explore the mechanisms of OC metastasis and discover valuable factors for early diagnosis of female cancers and novel therapeutic strategies for metastasis. Exosomes are known to be involved in the development, migration, and invasion of cancer cells, and their cargo could be useful for the non-invasive biopsy development. CD151- and Tspan8-positive exosomes are known to support the degradation of the extracellular matrix, and are involved in stroma remodeling, angiogenesis and cell motility, as well as the association of miR-24 and miR-101 with these processes. The objective of this study was to explore the relationship of these components of exosomal cargo, in patients with OC, to clarify the clinical significance of these markers in liquid biopsies. The levels of tetraspanins Tspan8+ and CD151+ exosomes were significantly higher in plasma exosomes of OC patients compared with healthy females (HFs). The relative levels of miR-24 and miR-101 in plasma exosomes of HFs were significantly higher than in plasma exosomes of OC patients, while the levels of these microRNAs in exosomes from plasma and ascites of ill females showed no difference. Our study revealed a strong direct correlation between the change in the ascites exosomes CD151+Tspan8+ subpopulation level and the expression levels of the ascites (R = 0.81, p < 0.05) and plasma exosomal miR-24 (R = 0.74, p < 0.05) in OC patients, which confirms the assumption that exosomal cargo act synergistically to increase cellular motility, affecting cellular processes and signaling. Bioinformatics analysis confirmed the involvement of CD151 and Tspan8 tetraspanins and genes controlled by miR-24-3p and miR-101 in signaling pathways, which are crucial for carcinogenesis, demonstrating that these tetraspanins and microRNAs are potential biomarkers for OC screening, and predictors of poor clinicopathological behavior in tumors.

Ovarian cancer (OC) has the highest mortality rate among all gynecologic cancers and is characterized by early peritoneal spread. The growth and development of OC are associated with the formation of ascitic fluid, creating a unique tumor microenvironment. Understanding the mechanisms of tumor progression is crucial in identifying new diagnostic biomarkers and developing novel therapeutic strategies. Exosomes, lipid bilayer vesicles measuring 30–150 nm in size, are known to establish a crucial link between malignant cells and their microenvironment. Additionally, the confirmed involvement of exosomes in carcinogenesis enables them to mediate the invasion, migration, metastasis, and angiogenesis of tumor cells. Functionally active non-coding RNAs (such as microRNAs, long non-coding RNAs, circRNAs), proteins, and lipid rafts transported within exosomes can activate numerous signaling pathways and modify gene expression. This review aims to expand our understanding of the role of exosomes and their contents in OC carcinogenesis processes such as epithelial-mesenchymal transition (EMT), angiogenesis, vasculogenic mimicry, tumor cell proliferation, and peritoneal spread. It also discusses the potential for utilizing exosomal cargo to develop novel “liquid biopsy” biomarkers for early OC diagnosis.

Introduction. Ovarian cancer (OC) is one of the malignant neoplasms of the female reproductive system with a high mortality rate. Currently used tumor markers of this pathology do not have high sensitivity and specificity. In this regard, promising areas of molecular oncology are the study of the mechanisms of carcinogenesis of OC and the search for new biomarkers of liquid biopsy for early non-invasive diagnosis of neoplasms. It is known that tumor cells actively secrete exosomes into the extracellular space, which include biologically active molecules involved in carcinogenesis and claiming to be diagnostic markers. It was previously shown that microRNA-24 (miR-24) and microRNA-101 (miR-101) are transported as part of exosomes in OC and are involved in the degradation of the extracellular matrix, stromal remodeling, angiogenesis, and cancer cell motility.Aim. To evaluate the representation and diagnostic significance of miR-24 and miR-101 in plasma exosomes and ascitic fluid of OC patients.Materials and methods. The study included blood and ascitic fluid samples from OC patients (n = 20) and blood samples from healthy women (n = 19). The exosomal nature of the vesicles was confirmed by transmission electron microscopy, nanotracing analysis, and flow cytometry. After isolation of exosomal RNA, the relative level of miRNA was determined using reverse transcription and real-time polymerase chain reaction.Results. The highest concentration of exosomes was found in the ascitic fluid of OC patients, while the concentration of exosomes in the blood plasma of these patients was significantly higher than in healthy women. Relative levels of miR-24 and miR-101 in exosomes of blood plasma of healthy women were significantly higher than in exosomes of blood plasma and ascitic fluid of OC patients; at the same time, the levels of these miRNAs in exosomes of plasma and ascitic fluid of patients did not differ significantly.Conclusion. The results obtained confirm the promise of exosomal miR-101 and miR-24 for the diagnosis of OC by liquid biopsy.

Ovarian cancer (OC) remains the most lethal gynecological malignancy, mostly due to its frequent diagnosis at advanced stages, early peritoneal dissemination, ascites formation, and limited sensitivity of currently available approaches for early detection. Extracellular vesicles (EVs), particularly exosomes, mediate intercellular communication through the transfer of proteins, lipids, metabolites, and nucleic acids. In OC, EV-associated protein profiles reflect both tumor-cell-intrinsic programs and the complex interactions between malignant cells and the peritoneal microenvironment. This review summarizes current evidence regarding the involvement of exosomal proteins in OC progression, with particular emphasis on epithelial–mesenchymal transition, mesothelial reprogramming, extracellular matrix remodeling, angiogenesis, immune suppression, peritoneal dissemination, and platinum resistance. Mechanistic studies indicate that exosomal proteins, including CD44, the integrin α5β1/asparaginyl endopeptidase complex, annexin A2, low-density lipoprotein receptor-related protein 1, and programmed death-ligand 1, can directly contribute to metastatic niche formation and tumor progression. In parallel, proteomic studies of plasma-, serum-, ascites-, peritoneal-fluid-, and uterine-lavage-derived EVs have identified candidate liquid-biopsy biomarkers, including MUC1, EpCAM, FOLR1, integrins, complement- and coagulation-related proteins, and proteins associated with treatment resistance. To integrate the biological significance of proteins reported in OC-associated exosomes, we additionally performed protein–protein interaction and functional enrichment analyses. These analyses revealed interconnected protein groups associated with cell adhesion, oxidative stress adaptation, secretory remodeling, lipid metabolism, extracellular matrix organization, and inflammatory signaling. Taken together, the available evidence supports exosomal proteome profiling as a promising approach for investigating OC dissemination and developing minimally invasive diagnostic and prognostic tools. However, standardized EV isolation, quantitative proteomics, functional validation, and independent clinical cohorts remain essential for translation into clinical practice.