| Popis: |
Prostate cancer (PCa) is the most common cancer in men worldwide with higher prevalence in the developed countries. Current screening and diagnostic approaches cannot accurately detect PCa in the early stage and stratify the risk groups to guide clinicians for the best treatment option. Extracellular vesicles (EVs) secreted from all kinds of cells contain proteins, nucleic acids and metabolites and play an important role in intercellular communication. EVs hold promise for PCa early diagnosis and progression monitoring. The goals of my PhD study were to: 1) evaluate the EVs isolated from PCa cell lines with immunoaffinity and aldehyde magnetic beads capturing, and investigate the performance of self-conjugated ApoB beads for lipoprotein quantification; 2) investigate the characteristics of plasma-derived EVs with commercial isolation kits combined with magnetic beads for clinical assignment; 3) discover novel biomarkers in a panel of PCa cell lines, and then validate these identified potential markers in plasma and urine of PCa patients for predicting the presence of “clinically significant cancer” and the prognostic risk groups. My findings indicate that magnetic beads can pull down EVs easily and immunoaffinity beads approach, based on biochemical composition by using common EV markers, is obviously better than the aldehyde beads for EV isolation and quantification with flow cytometry. Furthermore, the study of combination of three commercial kits with magnetic beads capturing established a systematic assessment of the EV quality, demonstrating that beads combining with size exclusion chromatography are superior to that combining with precipitation kit for EV isolation. Moreover, my proteomics analysis of PCa cell lines identified a total of 20 new EV protein biomarkers such as Kindlin3, LAMB1, Histone H4 et al. These EV markers are associated with cancer invasion, migration, regulation, tumour microenvironment and metastasis. My validation results show the unique expression patterns of these markers, in EVs of plasma and urine samples from different stages of PCa patients, are promising and demonstrate the potential value for PCa diagnosis and prognosis. In summary, my PhD studies have established unique EV isolation methods for clinical EV application and discovered a panel of novel EV biomarkers for PCa diagnosis and stage stratification, holding promise for personalised medicine. |
