N cells treated with resveratrol for 24 hours but it increased dramatically after 48 hours of culture. Taken together, these results indicate that resveratrol may have not only preventive, but also therapeutic, properties against EBV-related malignancies.DiscussionResveratrol is a potent chemopreventive agent with in vivo and in vitro proved efficacy against a broad spectrum of malignant cells [10]. This report presents a comprehensive study of the anti-EBV activities of resveratrol. The data showed that resveratrol effectively interrupted the immortalization process associated with EBV infection in human B cells and consistently attenuated the proliferation of EBV-transformed B cells. Mechanistic studies showed that such an inhibitory effect of resveratrol on the EBV-Resveratrol Prevents EBV-Transformation of B Cellsassociated immortalization was mediated by inducing apoptosis in the EBV infected B cells. Resveratrol inhibited the expression of key EBV genes and blocked viral-induced cellular signals that are essential for the transformation, survival and proliferation of EBVinfected B cells thus; resulting in the apoptosis of the EBV-infected B cells. EBV uses various strategies to manipulate cellular signal of the host that promotes the survival and the indefinitely proliferation of the EBV-infected B cells. EBV expresses several viral genes during the immortalization process with growth-transforming activity. LMP1 is particularly Title Loaded From File important because it is a classic oncogenic protein [2] and is indispensable for the EBV-transformation of B cells [3]. Remarkably, resveratrol inhibited the expression of LMP1 gene in EBV-infected primary B cells and consistently down-regulated LMP1 at both the protein and transcriptional levels in EBV-immortalized LCLs. This finding are relevant for understanding the anti-EBV mechanism of resveratrol, since LMP1 functions as a homologue of 1531364 the constitutively active CD40 receptor and activates NFkB, AKT and STAT-3 [35?7], which are pathways involved in the regulation of apoptosis cell proliferation. Notably, the activation of these cascades, particularly NFkB and STAT-3, is necessary for the EBV-immortalization of B cells and is required for the proliferation of EBV-related malignancies [35,37]. Previous studies showed that resveratrol is an effective inhibitor of the NFkB and STAT-3 pathways, which represents an important mechanism mediating the antitumor properties of this polyphenol [10,11]. Therefore, it is conceivable that the effective inactivation of NFkB and STAT-3 signals by resveratrol in EBV-infected B cells, occurring as a Comparisons), total protein with dexamethasone treatment (2-way ANOVA). Count data was direct effect of the drug on these targets or as an indirect event associated with the downregulation of LMP1 induced by resveratrol, might account for the efficacy of this polyphenol preventing EBV-immortalization of B cells. LMP1-dependent activation of NFkB in EBV-infected host cells leads to the production of cytokines including IL-6, IL-8 and IL-10 that contributes to the survival and proliferation of the infected B cells [38]. The present study demonstrated that resveratrol suppressed the secretion of IL-6 and IL-10 in EBV-infected B cells and EBV-immortalized LCLs exposed to resveratrol secreted significant less IL-6, IL-10 and TNF-a than the untreated cells. These events, which appear to be a consequence of the NFkB inactivation induced by resveratrol, may further create a unique microenvironment that does not favor the immortalization and proliferation of the EBV-inf.N cells treated with resveratrol for 24 hours but it increased dramatically after 48 hours of culture. Taken together, these results indicate that resveratrol may have not only preventive, but also therapeutic, properties against EBV-related malignancies.DiscussionResveratrol is a potent chemopreventive agent with in vivo and in vitro proved efficacy against a broad spectrum of malignant cells [10]. This report presents a comprehensive study of the anti-EBV activities of resveratrol. The data showed that resveratrol effectively interrupted the immortalization process associated with EBV infection in human B cells and consistently attenuated the proliferation of EBV-transformed B cells. Mechanistic studies showed that such an inhibitory effect of resveratrol on the EBV-Resveratrol Prevents EBV-Transformation of B Cellsassociated immortalization was mediated by inducing apoptosis in the EBV infected B cells. Resveratrol inhibited the expression of key EBV genes and blocked viral-induced cellular signals that are essential for the transformation, survival and proliferation of EBVinfected B cells thus; resulting in the apoptosis of the EBV-infected B cells. EBV uses various strategies to manipulate cellular signal of the host that promotes the survival and the indefinitely proliferation of the EBV-infected B cells. EBV expresses several viral genes during the immortalization process with growth-transforming activity. LMP1 is particularly important because it is a classic oncogenic protein [2] and is indispensable for the EBV-transformation of B cells [3]. Remarkably, resveratrol inhibited the expression of LMP1 gene in EBV-infected primary B cells and consistently down-regulated LMP1 at both the protein and transcriptional levels in EBV-immortalized LCLs. This finding are relevant for understanding the anti-EBV mechanism of resveratrol, since LMP1 functions as a homologue of 1531364 the constitutively active CD40 receptor and activates NFkB, AKT and STAT-3 [35?7], which are pathways involved in the regulation of apoptosis cell proliferation. Notably, the activation of these cascades, particularly NFkB and STAT-3, is necessary for the EBV-immortalization of B cells and is required for the proliferation of EBV-related malignancies [35,37]. Previous studies showed that resveratrol is an effective inhibitor of the NFkB and STAT-3 pathways, which represents an important mechanism mediating the antitumor properties of this polyphenol [10,11]. Therefore, it is conceivable that the effective inactivation of NFkB and STAT-3 signals by resveratrol in EBV-infected B cells, occurring as a direct effect of the drug on these targets or as an indirect event associated with the downregulation of LMP1 induced by resveratrol, might account for the efficacy of this polyphenol preventing EBV-immortalization of B cells. LMP1-dependent activation of NFkB in EBV-infected host cells leads to the production of cytokines including IL-6, IL-8 and IL-10 that contributes to the survival and proliferation of the infected B cells [38]. The present study demonstrated that resveratrol suppressed the secretion of IL-6 and IL-10 in EBV-infected B cells and EBV-immortalized LCLs exposed to resveratrol secreted significant less IL-6, IL-10 and TNF-a than the untreated cells. These events, which appear to be a consequence of the NFkB inactivation induced by resveratrol, may further create a unique microenvironment that does not favor the immortalization and proliferation of the EBV-inf.