Dietary Glycation Products Regulate Immune Homeostasis: Early Glycation Products Promote Prostate Cancer Cell Proliferation through Modulating Macrophages

cope : Well-controlled glycation (generally limited to the early stages) has been proposed as a strategy to improve the physiochemical properties of dietary proteins, but the functional studies of glycation products were mostly on advanced glycation end-products (AGEs) rather than early glycation products (EGPs). Since cytokines are important modulators of various biological processes, this study aimed to determine whether EGPs and AGEs affected immune homeostasis differentially and did so through modulating macrophage-derived factors. Methods and results : Two systems (glycine-glucose and whey protein isolate (WPI)-glucose) were established to generate glycation products. They were applied to human macrophages (PMA-differentiated U937 cells), and cell viability and cytokine production were measured. Furthermore, EGPs, AGEs and their conditioned medium (CM) from macrophages were applied to human prostate cancer (PCa) cells with different etiology (LNCaP and PC-3) and murine PCa cells (TRAMP-C2) to determine their direct and indirect effects on PCa cell proliferation. EGPs enhanced the production of anti-inflammatory and immunosuppressive cytokines, and this enhancement was associated with increased PCa cell proliferation. In contrast, AGEs inhibited macrophages to secret cytokines, but increased PCa cell proliferation directly. Conclusions : Our data suggest that EGPs promote the prostate tumor proliferation indirectly through modulating macrophages, while AGEs have a direct effect. This article is protected by copyright. All rights reserved