Introduction: Prostate cancer (PCa) development may be affected by the production and release of extracellular vesicles (EVs). The factors that regulate EV production and composition in PCa cells are not fully understood, and EV production in patients with PCa may be affected by fasting. Epidemiological studies have suggested that men drinking coffee have a lower risk of developing PCa. Bioactive compounds, such as caffeine may modulate cellular processes and signalling pathways, however, their effect on PCa development and EV production is unknown. In this study, we determined the effects of caffeine on EV production and composition in prostate cells and male subjects.
Methods: EVs were isolated by differential centrifugation of culture media from prostate cells treated with caffeine and from blood plasma from fasted, healthy participants taken prior to, 30 minutes after coffee consumption and 1.5 hours post meal consumption. All EVs were assessed for size and distribution by NTA, biomarker protein amounts were determined by Mass spectrometry and confirmed by Western blotting. Endosome/lysosome number were quantified by immunofluorescence in prostate cells.
Results: Caffeine affected the number and composition of EVs that were detected from successful isolation from a panel of prostate cells and plasma samples. Endosome/lysosome number were significantly affected by caffeine treatment in prostate cells.
Conclusion: This study suggests a potential role of coffee in PCa risk reduction, through the effects of caffeine affecting EV production through altered endosome/lysosome biogenesis. The accuracy of EV-based biomarkers may be affected in non-compliant PCa patients, requiring strict enforcement of fasting protocols.