Abstract 1457: Regulatory T cells and its impact on prostate cancer development and clearance

Abstract Prostate Cancer (PCa) is the most common non-skin malignancy and the most commonly diagnosed cancer in men in United States. The immunotherapeutic role of immune cells in regulation of PCa have been studied but still the specific roles of regulatory T cells needs further investigation. In this study, the role of immune cells, particularly the role of regulatory T cells, in tumor development and progression was analyzed using TRAMP (transgenic adenocarcinoma of mouse prostate) model system. TRAMP cells (TRAMP C1, C2 and C3) were used to induce tumor in C57/B6 mouse. Interestingly, the TRAMP-C3 is non-tumorigenic whileTRAMP-C1 and TRAMP-C2 are tumorigenic. Briefly, tumor induction studies were performed on different groups of mice. Mice were inoculated with these three cell lines, tumors were analyzed at different time points, and the percentage and absolute number of different immune cells (CD4, CD8, NK, NKT, Macrophages, regulatory T cells, and Dendritic cells) were analyzed. Our data demonstrated that the capacity of TRAMP-C1 and TRAMP-C2 cells to form tumors and the inability of TRAMP-C3 cells to induce tumors is mediated by number of regulatory T cells in the tumor microenvironment. Therefore, the data suggest an understanding of function and effect of regulatory T cells during tumor progression and clearance is needed to successfully develop a targeted therapy to modulate the number of immune cells in the tumor microenvironment. Citation Format: Sanjay Kumar, James Stokes III, Karyn Scissum Gunn, Udai Singh, Selvarangan Ponnazhagan, Manoj K. Mishra. Regulatory T cells and its impact on prostate cancer development and clearance. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1457.