Introduction: Prostate cancer (PCa) is the most common malignant tumour and the second leading cause of death in men in Australia. The current diagnostic tools, such as prostate-specific antigen, magnetic resonance imaging and tissue biopsy , cannot accurately diagnose PCa. A major clinical challenge in PCa clinical management is posed by the inability of current diagnostic tests, to discern between indolent and aggressive diseases. Thus, there is an unmet need to develop novel approaches for more cost-effective and accurate biomarkers for PCa early diagnosis and treatment stratification to enable personalised medicine.
Aims: Our objective in this study was to isolate extracellular vesicles and particles (EVPs), including large extracellular vesicles, small extracellular vesicles, exomeres and supermeres, from a panel of PCa cell lines to identify different protein profiles using proteomic analysis for PCa diagnosis and progression risk stratification.
Methods: PCa cell lines including PC3, LNCaP and 22Rv1, as well as a normal prostate epithelial cell line RWPE-1 were cultured, and the supernatants were collected to isolate EVPs using ultracentrifugation. EVPs were then characterised by transmission electron microscopy, nanoparticle tracking analysis, Western blotting, atomic force microscopy, Zeta potential analyser and nano-flow cytometry.
Results: We have successfully established a reliable and reproducible method based on a series of gradient ultracentrifugation for isolating four different EVPs subpopulations from PCa cell lines . We used several methods to characterise EVPs including their morphology, size, classical EVPs protein biomarkers and some new physical parameters . Currently, the proteomic profiling of EVPs from PCa cell lines is in progress.
Conclusion: We have successfully established a method for isolating distinct EVP populations from PCa cells and comprehensively characterised their properties. Investigation of the protein profiles from EVPs is ongoing and holds promise for PCa early diagnosis and risk stratification.
Key words: Extracellular vesicles and particles, prostate cancer diagnosis, progression, stratification.