Inhibition of Epstein-Barr virus (EBV) reactivation by short interfering RNAs targeting p38 mitogen-activated protein kinase or c-myc in EBV-positive epithelial cells.
Latent Epstein-Barr virus (EBV) is reactivated by 12-O-tetradecanoylphorbol-13-acetate (TPA) in EBV-infected cells. In this study, we found that TPA up-regulated phosphorylation of p38, a mitogen-activated protein kinase, and activated c-myc mRNA in EBV-positive epithelial GT38 cells. The EBV immediate-early gene BZLF1 mRNA and its product ZEBRA protein were induced following TPA treatment. Protein kinase C inhibitors, 1-(5-isoquinolinesulphonyl)-2, 5-dimethylpiperazine (H7) and staurosporine, inhibited the induction of p38 phosphorylation and the activation of c-Myc by TPA. The p38 inhibitor SB203580 blocked both p38 phosphorylation and ZEBRA expression by TPA. Pretreatment of GT38 cells with the nitric oxide (NO) donor S-nitroso-N-acetylpenicillamine inhibited p38 phosphorylation and c-Myc activation by TPA, suggesting that NO may inhibit EBV reactivation via both p38 and c-Myc. By using short interfering RNA (siRNA) targeting either p38 or c-myc, we found that p38 or c-myc siRNA specifically inhibited expression of the respective gene and also suppressed the induction of ZEBRA and EBV early antigen. The interferon (IFN)-responsive gene expression tests ruled out the possibility that the antiviral effect of siRNA is dependent on IFN. Our present study demonstrates for the first time that either p38 or c-myc siRNA can efficiently inhibit TPA-induced EBV reactivation in GT38 cells, indicating that p38- and/or c-myc-associated signaling pathways may play critical roles in the disruption of EBV latency by TPA.
Division of Biosignaling, Department of Biomedical Sciences, School of Life Science, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan.
Xiangrong
X
Gao
Haoran
H
Wang
Takeshi
T
Sairenji
D002460:Cell Line; D004854:Herpesvirus 4, Human / Q000502:physiology*; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics; D010396:Penicillamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D010766:Phosphorylation; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D016271:Proto-Oncogene Proteins c-myc / Q000037:antagonists & inhibitors*; D034622:RNA Interference; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D015534:Trans-Activators / Q000235:genetics; D014764:Viral Proteins; D014775:Virus Activation; D048051:p38 Mitogen-Activated Protein Kinases
C068382:BRLF1 protein, Human herpesvirus 4; D017874:Immediate-Early Proteins; D016271:Proto-Oncogene Proteins c-myc; C110881:S-nitro-N-acetylpenicillamine; D015534:Trans-Activators; D014764:Viral Proteins; D011493:Protein Kinase C; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D010396:Penicillamine; D013755:Tetradecanoylphorbol Acetate