Extracellular vesicles from biological fluids as potential biomarkers for prostate cancer

Abstract Purpose Despite the high incidence of false positives, prostate specific antigen (PSA) screening remains a widely used diagnostic test for prostate cancer, driving an urgent need for the discovery of better biomarkers for early prostate cancer detection. Extracellular vesicles (EV) secreted from cancer cells are present in various biological fluids, carrying distinctly different cellular components compared to normal cells, and have great potential to be used as a source of biomarkers. Methods EV from serum and urine of healthy men and prostate cancer patients were isolated, and characterised by transmission electron microscopy, particle size analysis, and western blot. Proteomic and cholesterol liquid chromatography-mass spectrometry (LC-MS) analyses were conducted. Results There was a successful enrichment of exosomes isolated from serum and urine. EV derived from biological fluids of prostate cancer patients had significant differences in composition when compared with those from healthy controls. Analysis of matched serum and urine samples from six prostate cancer patients revealed specific EV proteins common in both types of biological fluid for each patient. Conclusion Some of the EV proteins identified from our analyses have potential to be used as prostate cancer biomarkers, either to depict cancer progression or for disease diagnosis through non-invasive testing.