Background/Objectives
Previously, it has been demonstrated that tumor-derived extracellular vesicles (T-EVs) can affect metastasis formation and immune responses, yet the specific molecular mechanisms affecting their protein packaging and functional impacts remain unclear. Thus, our study focuses on the influence of p53 on the molecular composition and functional activity of EVs, and their subsequent effects on immune cell profiles within the lung pre-metastatic niche (PMN) and the related metastasis formation.
Methods
T-EVs were isolated from B16V melanoma cell lines with different p53 status using differential ultracentrifugation (dUC), and characterized via various methods. To assess functional effects, two in-vivo experiments were conducted. First, to evaluate EV effects on pre-metastatic niche (PMN) formation, six intravenous (IV) EV injections were performed, followed by single-cell sequencing of the lungs. The second experiment investigated the impact of EVs on lung metastasis. Animals received three pre-treatment EV injections prior to IV injection of wild-type B16V cells. Subsequently, three additional EV injections were administered, and animals were dissected on day 35. Assessment was performed using immunohistochemistry and immunofluorescence staining.
Results
Our data demonstrated that EVs isolated from melanoma cells with different p53 status exhibited similar sizes and concentrations, but displayed significant differences in protein composition, including integrins (ITGs), macrophage migration inhibitory factor (MIF), and many other PMN-associated proteins. Preliminary in-vivo data demonstrate that EVs with different p53 status induce distinct effects on PMN formation and organotropism of metastases, and comprehensive data analysis is still ongoing.
Conclusion
p53 expression significantly influences the cargo composition of isolated EVs, with substantial effects on metastasis-associated profiles in the lung microenvironment. Further analyses are required to elucidate the specific molecular pathways involved. Additionally, the clinical relevance of identified EV-associated markers will be validated in patient samples, correlating molecular findings with clinical outcomes to explore potential diagnostic or therapeutic applications.
Keywords
Tumor-derived extracellular vesicles (T-EVs), p53 status, metastasis, pre-metastatic niche (PMN)
