Essential role of PKCδ in histone deacetylase inhibitor-induced Epstein-Barr virus reactivation in nasopharyngeal carcinoma cells

Histone deactylase inhibitors (HDACi) are common chemotherapeutic agents that stimulate Epstein-Barr virus (EBV) reactivation; the detailed mechanism remains obscure. In this study, it is demonstrated that PKCδ is required for induction of the EBV lytic cycle by HDACi. Inhibition of PKCδ abrogates HDACi-mediated transcriptional activation of the Zta promoter and downstream lytic gene expression. Nuclear translocation of PKCδ is observed following HDACi stimulation and its overexpression leads to progression of the EBV lytic cycle. Our study suggests that PKCδ is a crucial mediator of EBV reactivation and provides a novel insight to study the regulation of the EBV lytic cycle.