Background: Although microRNA (miR) profiling has been widely used to predict clinical outcomes, differential miR expressions that can segregate prostate cancer (PCa) patients based on their races and tumor aggressiveness have not been fully investigated. We aimed to determine the diagnostic and prognostic abilities of exosomal miRs to identify the aggressive phenotypes of PCa in African American (AA) men.
Methods: Exosomes were isolated from blood of twenty AA and European Americans (EuA) PCa patients at low and high Gleason scores and their aged-matched healthy subjects (n=20) as well as AA and EuA normal and PCa cells. miR profiling was performed on PCa exosomes derived from blood and PCa cells. The expression level was correlated with clinical outcomes of PCa patients. The sensitivity and specificity of exosomal miRs were assessed using receiver operating characteristic (ROC) curve.
Results: Results from miR profiling showed a number of exosomal miRs that were able to differentiate normal from PCa, low from high Gleason scores and AA from EuA PCa patients. These dysregulated miRs were validated in another cohort of forty PCa patients in addition to a large panel of PCa cell lines. In the validation cohort, miR-5001, miR-3692 and miR-4529 were upregulated in the exosomes derived from blood of AA compared to EuA men. These miRs were correlated with age, T-stage, residual tumor, involvement of lymph nodes, Gleason score, and overall survival of AA patients. The combination of these miRs showed high discriminatory power (AUC=0.91) for segregation of PCa patients according to their clinical outcomes.
Conclusion: miR profiling identified a new set of miRs that can differentiate PCa specimens based on their race and Gleason score. The differential expression of these miRs demonstrates their potential role as biomarkers in the context of racial disparity. Further studies are warranted to determine their role in PCa at advanced stages.
Citation Format: Rofaida Gaballa, Mohamed Gaballah, Hamdy E.A. Ali, Andrew S. Sholl, Hamed I. Ali, Zakaria Y. Abd Elmageed. Exosomes-associated miR-5001, miR-3692 and miR-4529 are novel biomarkers for aggressive prostate cancer and associated with poor prognosis in African American patients [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C029.