Exosome Analysis in Tumor-Draining Pulmonary Vein Identifies NSCLC Patients with Higher Risk of Relapse after Curative Surgery

Abstract

Since tumor-draining pulmonary vein blood (PV) is enriched in tumor-secreted products, we hypothesized that it would also be enriched in tumor-derived exosomes, which would be important in the metastasis process. We characterized exosomes from PV of 61 resected non-small cell lung cancer (NSCLC) patients to evaluate its potential as relapse biomarkers. Exosomes were characterized using transmission electron microscopy, western blot and nanoparticle tracking analysis and we examined time to relapse (TTR) and overall survival (OS). Differences between PV and peripheral vein were found. PV was enriched in smaller exosomes than the paired peripheral vein (p = 0.01). Moreover, PV exosome size mode was able to identify relapsed patients (Area under the curve [AUC] = 0.781; 95%CI: 0.6641–0.8978), in whom exosome size was smaller (<112 nm; p < 0.001). The combination of PV exosome size and N (lymph node involvement) showed an AUC of 0.89 (95%CI: 0.80–0.97). Moreover, smaller PV exosome size was associated with shorter TTR (28.3 months vs. not reached, p < 0.001) and OS (43.9 months vs. not reached, p = 0.009). Multivariate analyses identified PV exosome size and stage as independent prognostic markers for TTR and OS. PV exosome size is a promising relapse biomarker after surgery that can add valuable information to clinical variables.

Liquid Biopsy in Non-Small Cell Lung Cancer: Highlights and Challenges

“…In a recent study, by screening the pulmonary vein-derived exosomes in a cohort of 72 resected NSCLC patients, Navarro and colleagues showed that exosome size (cut-off: 112 nm) was able to discriminate relapsed patients with a higher accuracy than clinical data (stage and lymph node involvement). In the multivariate analysis, exosome size resulted an independent risk factor for both time to relapse (HR: 6.66; 95% CI, 2.06-21.51; p = 0.001) and OS (HR: 4.55; 95% CI, 1.43-14.49; p = 0.010) [78]. Whatever their dimension, exosomes have an active role in the process of carcinogenesis, progression, and metastasis of several tumors, including NSCLC, which is exerted by transferring their cargo.…”

Extracellular Vesicles in Liquid Biopsies: Potential for Disease Diagnosis

“…For example, in melanoma patients, lymphatic exudate contains more cancer-derived EVs than plasma, and lymph vessels were shown to be the major route of EV transport from tumors into the circulation [ 192 , 193 ]. In lung cancer, tumor-draining pulmonary venous blood contains more cancer-derived EVs than peripheral blood [ 194 ]. Further studies are needed to develop standard protocols for sampling different biofluids and isolating EVs from them, as well as for establishing the diagnostic accuracy of those EVs.…”

Platelet-derived vesicles: diagnostic and predictive value in cardiovascular diseases

“…Thus, the balance between pro-coagulant and anti-coagulant properties of the platelet-derived vesicles plays an important role in supporting of hemostasis [24,25] . Intriguingly, there is evidence that the platelet-derived vesicles are cargo for several molecules, including chromatin, hormones, proteins, which mediate cell-to-cell cooperation, immune reaction, inflammatory response, and reparation [18][19][20][21][22] . It has been found that the main fraction of miRNA is localized in the platelet-derived vesicles, which protect miRNA from degradation in the circulation.…”

“…The populations of the Figure 1. The proportions and functions of several types of extracellular vesicles in circulation [20][21][22][23] . APC: antigen presenting cells platelet-derived EVs may distinguish each other in not just their size and immune phenotype, but yet they can have a difference in a density (utilized as sucrose density gradient in ultracentrifugation), proteomic and lipidomic profiles [40] .…”

“…In fact, the EVs are able to mediate the exchange of appropriate information between various cells. Finally, the EVs were found witnesses and biomarkers of several diseases, such as CV, autoimmune, infective, metabolic, renal, rheumatic, neurological, ocular diseases and malignancy [20][21][22][23] .…”