Cancers, Vol. 11, Pages 1795: Emodin Inhibits EBV Reactivation and Represses NPC Tumorigenesis

Cancers, Vol. 11, Pages 1795: Emodin Inhibits EBV Reactivation and Represses NPC Tumorigenesis Cancers doi: 10.3390/cancers11111795 Authors: Chung-Chun Wu Mei-Shu Chen Yu-Jhen Cheng Ying-Chieh Ko Su-Fang Lin Ing-Ming Chiu Jen-Yang Chen Nasopharyngeal carcinoma (NPC) is a unique malignancy derived from the epithelium of the nasopharynx. Despite great advances in the development of radiotherapy and chemotherapy, relapse and metastasis in NPC patients remain major causes of mortality. Evidence accumulated over recent years indicates that Epstein-Barr virus (EBV) lytic replication plays an important role in the pathogenesis of NPC and inhibition of EBV reactivation is now being considered as a goal for the therapy of EBV-associated cancers. With this in mind, a panel of dietary compounds was screened and emodin was found to have potential anti-EBV activity. Through Western blotting, immunofluorescence, and flow cytometric analysis, we show that emodin inhibits the expression of EBV lytic proteins and blocks virion production in EBV- positive epithelial cell lines. In investigating the underlying mechanism, reporter assays indicated that emodin represses Zta promoter (Zp) and Rta promoter (Rp) activities, triggered by various inducers. Mapping of the Zp construct reveals that the SP1 binding region is important for emodin-triggered repression and emodin is shown to be able to inhibit SP1 expression, suggesting that it likely inhibits EBV reactivation by suppres...
Source: Cancers - Category: Cancer & Oncology Authors: Tags: Article Source Type: research