Small extracellular vesicles from malignant ascites of patients with advanced ovarian cancer provide insights into the dynamics of the extracellular matrix

Abstract

The exact role of malignant ascites in the development of intraperitoneal metastases remains unclear, and the mechanisms by which extracellular vesicles (EVs) promote tumor progression in the pre‐metastatic niche have not been fully discovered. In this study, we characterized ascites from high‐grade epithelial ovarian cancer patients. Small‐EVs (30–150 nm) were isolated from two sources—the bulk ascites and the ascitic fluid‐derived tumor cell cultures—and assessed with a combination of imaging, proteomic profiling, and protein expression analyses. In addition, Gene Ontology and pathway analysis were performed using different databases and bioinformatic tools. The results proved that the small‐EVs derived from the two sources exhibited significantly different stiffness and size distributions. The bulk ascitic fluid‐derived small‐EVs were predominantly involved in the complement and coagulation cascade. Small‐EVs derived from ascites cell cultures contained a robust proteomic profile of extracellular matrix remodeling regulators, and we observed an increase in transforming growth factor‐β‐I (TGFβI), plasminogen activator inhibitor 1 (PAI‐1), and fibronectin expression after neoadjuvant chemotherapy. When measured in the two sources, we demonstrated that fibronectin exhibited opposite expression patterns in small‐EVs in response to chemotherapy. These findings highlight the importance of an ascites cell isolation workflow in investigating the treatment‐induced cancer adaption processes.

Platelet Activation in Ovarian Cancer Ascites: Assessment of GPIIb/IIIa and PF4 in Small Extracellular Vesicles by Nano-Flow Cytometry Analysis

“…Enriched particles were found to have diameters between 40 and 900 nm. In all samples, particles above ~150 nm showed the characteristic nanomechanical behaviour of intact vesicles [ 27 , 30 , 35 ], which results in horizontally elongated clusters of objects having similar CAs (and thus, mechanical stiffnesses). EVs with D values above 150 nm tended to cluster around different CA values in samples from different patients; interestingly, EVs enriched from the same patient tended to maintain the same average CA value even when collected at successive time points.…”

“…Small-EVs from ascites were isolated as previously described [ 27 ], using Total Exosome Isolation Reagent (Invitrogen (Waltham, WA, USA), CN 4484453), following the protocol specified by the manufacturers. 1 mL of sample (ascites fluid) was centrifuged at 2000× g at room temperature to remove cells and debris.…”

Extracellular Vesicles-ceRNAs as Ovarian Cancer Biomarkers: Looking into circRNA-miRNA-mRNA Code

“…Generally, the exchange of molecular signals is an important feature in cell invasion and metastasis, and EVs play a crucial role in cell–cell communication; the pharmacological inhibition of EV uptake at metastatic sites or the decrease in EV release by cancer cells inhibits the PMNF [ 55 ]. EVs can be isolated from plasma [ 56 , 57 ], ascites [ 58 , 59 ], and urine [ 60 , 61 ] of patients with OC. EVs in these complex biofluids have a pivotal role in cancer progression, and their cargos may act as useful biomarkers for diagnosis, prognosis, therapy selection in different disease statuses, and monitoring response to therapies ( Figure 2 ).…”

Salivary Exosomes: From Waste to Promising Periodontitis Treatment

“…The detached blebs are called apoptotic bodies ( Rilla et al, 2019 ). Previous literature reported the detection of EVs from a variety of body fluids, e.g., bile ( Nakashiki et al, 2021 ), saliva ( Comfort et al, 2021 ), semen, blood ( Vojtech et al, 2019 ), breast milk ( Jiang et al, 2021 ), synovial fluid ( Mustonen et al, 2021 ), urine ( Blijdorp et al, 2021 ), and ascites ( Bortot et al, 2021 ). Generally, these EVs are composed of nucleic acids [e.g., microRNAs ( Nakashiki et al, 2021 )], proteins ( Bortot et al, 2021 ), lipids ( Skotland et al, 2020 ), and signaling molecules ( Vojtech et al, 2019 ).…”