Exosomes are nano-membrane vesicles that various cell types secrete during physiological and pathophysiological conditions. By shuttling bioactive molecules such as nucleic acids, proteins, and lipids to target cells, exosomes serve as key regulators for multiple cellular processes, including cancer metastasis. Recently, microvesicles have emerged as a challenge in the treatment of prostate cancer (PCa), encountered either when the number of vesicles increases or when the vesicles move into circulation, potentially with an ability to induce drug resistance, angiogenesis, and metastasis. Notably, the exosomal cargo can induce the desmoplastic response of PCa-associated cells in a tumor microenvironment (TME) to promote PCa metastasis. However, the crosstalk between PCa-derived exosomes and the TME remains only partially understood. In this review, we provide new insights into the metabolic and molecular signatures of PCa-associated exosomes in reprogramming the TME, and the subsequent promotion of aggressive phenotypes of PCa cells. Elucidating the molecular mechanisms of TME reprogramming by exosomes draws more practical and universal conclusions for the development of new therapeutic interventions when considering TME in the treatment of PCa patients.

The utility of small extracellular vesicles (sEVs)-derived microRNAs (miRs) to segregate prostate cancer (PCa) patients according to tumor aggressiveness and ancestral background has not been fully investigated. Thus, we aimed to determine the diagnostic and prognostic utility of sEV-associated miRs in identifying aggressive PCa in African American (AA) and Caucasian (CA) men. Using a training cohort, miR profiling was performed on sEVs isolated from plasma of PCa patients. Top-ranked sEV-associated miRs were then validated in 150 plasma samples (75 AA and 75 CA) collected from two independent cohorts; NIH (n = 90) and Washington University (n = 60) cohorts. Receiver operating characteristic (ROC) curve, Kaplan–Meier and Cox proportional hazards regression were used to assess these miRs as clinical biomarkers. Among nine top-ranked sEV-associated miRs, miR-6068 and miR-1915-3p were enriched in sEVs collected from PCa patients compared to healthy volunteers. Moreover, miR-6716-5p and miR-3692-3p segregated AA from CA men and low from high Gleason score (GS), respectively. Upregulation of sEV-associated miR-1915-3p, miR-3692-3p and miR-5001-5p was associated with improved survival time, and only miR-1915-3p was associated with longer recurrence-free survival (RFS) as an independent prognostic marker. Taken together, we identified novel sEV-associated miRs that can differentiate PCa patients from normal, AA from CA and high from low GS and predicts RFS.

New antioxidant agents are urgently required to combat oxidative stress, which is linked to the emergence of serious diseases. In an effort to discover potent antioxidant agents, a novel series of 2-thiouracil-5-sulfonamides (4–9) were designed and synthesized. In line with this approach, our target new compounds were prepared from methyl ketone derivative 3, which was used as a blocking unit for further synthesis of a novel series of chalcone derivatives 4a–d, thiosemicarbazone derivatives 5a–d, pyridine derivatives 6a–d and 7a–d, bromo acetyl derivative 8, and thiazole derivatives 9a–d. All compounds were evaluated as antioxidants against 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide (H2O2), lipid peroxidation, and 15-lipoxygenase (15-LOX) inhibition activity. Compounds 5c, 6d, 7d, 9b, 9c, and 9d demonstrated significant RSA in all three techniques in comparison with ascorbic acid and 15-LOX inhibitory effectiveness using quercetin as a standard. Molecular docking of compound 9b endorsed its proper binding at the active site pocket of the human 15-LOX which explains its potent antioxidant activity in comparison with standard ascorbic acid.

Talin is a large cytoskeletal adaptor protein that is an important component of focal adhesion complexes of adherent cells. It was originally identifi ed as a component of focal adhesions and ruffl ing membranes of fi broblasts. It was the fi rst cytoplasmic protein partner of integrins to be identifi ed. Many studies proved that talin connects the intracellular actin cytoskeleton with the extracellular environment through interactions with integral membrane proteins in the dynamic focal adhesions. The modular structure of talin is responsible for its ability to serve as a linker protein. It was thought that animal cells contained only one talin. However, studies have been identifi ed a second talin (Talin-2) in vertebrates. Talin-1 levels are very low in brain and striated muscle, but high in kidney, liver, spleen, stomach, lung, and rat vascular smooth muscle cells. Talin-2 levels are high in brain and striated muscle. The variable expression of Talin-2 in these differentiated cells refl ects that these proteins have different roles, which would be refl ected in different properties of each protein. Moreover, Talins may be a good target for treatment of certain types of cancers. Talins levels are altered in various types of cancer indicating its possible use as cancer biomarker.

Talins were the fi rstly identifi ed cytoplasmic protein partners of integrins. Vertebrates have two talin genes, TLN1 and TLN2, which encode Talin-1 and Talin-2, respectively. Talin-1 is essential for cell adhesion and motility and is the primary talin component of focal adhesions. Many studies have demonstrated, involvement of talins in different mechanisms inside many body cells, induction of some diseases. Moreover, recent and ongoing research indicates the diagnostic and prognostic roles of talins in various clinical settings especially in critically ill patients. Additionally, talins may be a good target for treatment of certain types of diseases. Talins levels are altered in various physiological and pathological conditions indicating its importance and possible use as a biomarker or a tool for diagnosis or treatment. However, further research using talins in various clinical settings will prove its cost-effectiveness and clinical usefulness.

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.

Background: The morbidity and mortality rates of prostate cancer (PCa) in African American (AA) are 2-3 times higher than European American (EuA) men. The molecular mechanisms underlying the aggressiveness of PCa have not fully identified. Thus, our aim was to evaluate the diagnostic/prognostic utility of exosomal microRNAs (miRs) to classify PCa patients according their race and aggressive phenotype in AA patients. Their functional role in tumor aggressiveness was also determined. Methods: Exosomes were isolated from the conditioned media of AA and EuA PCa cell lines. The expression of miRs was validated in exosomes, free-circulating plasma, and FFPE tissue specimens of forty AA and EuA patients using quantitative real-time PCR analysis. The sensitivity and specificity of exosomal miRs to classify prostate cancer patients according their race and aggressiveness were assessed using receiver operating characteristic (ROC) curve analysis. To study the functional significance of exosomal miRs, cell proliferation, clonogenic, cell cycle and migration assays were performed in PCa cells transfected with miR-3128. Results: Differential expression of exosomal miR-3613-3p, miR-3218, miR-3679, and miR-3680 was demonstrated in the plasma of AA versus EuA of PCa patients. While exosomal miR-3613 and miR-3679 (p<0.05) were upregulated, free-circulating miRs downregulated (p<0.05) in the plasma of AA versus EuA patients. The accuracy of miR-3679 to discriminate AA from EuA was improved when combined with the other three miRs (AUC jumped from 0.717 to 0.897). Intriguingly, miR-3128 showed a dual role in AA versus EuA cells. Overexpression of miR-3128 increased the cell growth in AA cells while it did the opposite in EuA cells. These data were recapitulated by migration, cell cycle and clonogenic assays. Conclusion: Our findings underline the role of exosomal miRs in health disparity of PCa. The differential expression of miRs in AA men demonstrates their reliability as biomarkers and their potential role in promoting tumor aggressiveness in AA men. Citation Format: Hamdy E.A. Ali, Rofaida Gaballa, Andrew S. Sholl, Mohamed Gaballah, Juan J. Bustamante, Preeti Zanwar, Hamed I. Ali, Zakaria Y. Abd Elmageed. Exosomal microRNAs are associated with prostate cancer aggressiveness 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 B045.