Stress-Induced Differential Survivin Release In Prostate Cancer Health Disparities

African-American men have the highest rate of prostate cancer (PCa) incidence in the U.S. In addition, their prostate cancer mortality rate is more than twice as high as the rate for white Americans. The causes of higher rates of prostate cancer among African-American males are largely unknown. Many studies are underway to unravel the impact of a wide variety of potential risk factors, including dietary and other lifestyle differences, occupational exposures, hormonal and genetic differences. Several lines of evidence suggest that one of the main events associated with the conversion to an aggressive phenotype is increased resistance to apoptosis (3) mainly due to upregulation of antiapoptotic genes, including Bcl-2, Bcl-XL, Mcl-1, and Survivin. Recently, we reported that Survivin is released in PCa sera and found to be in the exosomes. Therefore, we speculate that Survivin could be a potential target protein released differentially in prostate cancers in African American (AA) and Caucasian (CC) populations in response to stress. In this study, we have collected serum samples from prostate cancer patients of AA and CC, measured Survivin levels by ELISA. Exosome islation was perfomed by Exoquick approach and quantified by acetylcholinesterase activity assays. We have applied an in-vitro approach to compare the differences between cancer cell lines derived from AA (MDA-MB-PCa) and CC (PC3) patients in terms of stress and stress activated Survivin release by exosomes. Under oxidative stress and drug treatments, we have identified Survivin highly expressed in exosome derived from MDA-MB-PCa compared to PC3 cell lines. In addition, we found a relative overexpression of Survivin protein in AA-PCa compared to CC-PCa both in sera and exosomes. Based on our data, Survivin may be a key stress-induced protein in AA-PCa patients. It is possible that attempts to block Survivin release will not only interrupt the cancer proliferation and interfere with anti-apoptotic pathways, thus preventing cancer progression. Citation Format: Salma Khan, David Turay, Jessica Ms Jutzy, Jonathan R. Aspe, Tino W. Sanchez, Saeid Mirshahidi, Carlos A. Casiano, Nathan R. Wall. Stress-induced differential Survivin release in prostate cancer health disparities. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1118. doi:10.1158/1538-7445.AM2014-1118