The Dual Functions of Andrographolide in the Epstein朆arr Virus-Positive Head-and-Neck Cancer Cells The Inhibition of Lytic Reactivation of the Epstein朆arr Virus and the Induction of Cell Death

Abstract

Andrographolide a medicinal compound exhibits several pharmacological activities including antiviral and anticancer properties. Previously we reported that andrographolide inhibits Epstein朆arr virus (EBV) lytic reactivation which is associated with viral transmission and oncogenesis in epithelial cancers including head-and-neck cancer (HNC) cells. However the underlying mechanism through which andrographolide inhibits EBV lytic reactivation and affects HNC cells is poorly understood. Therefore we investigated these mechanisms using EBV-positive HNC cells and the molecular modeling and docking simulation of protein. Based on the results the expression of EBV lytic genes and viral production were significantly inhibited in andrographolide-treated EBV-positive HNC cells. Concurrently there was a reduction in transcription factors (TFs) myocyte enhancer factor-2D (MEF2D) specificity protein (SP) 1 and SP3 which was significantly associated with a combination of andrographolide and sodium butyrate (NaB) treatment. Surprisingly andrographolide treatment also significantly induced the expression of DNA Methyltransferase (DNMT) 1 DNMT3B and histone deacetylase (HDAC) 5 in EBV-positive cells. Molecular modeling and docking simulation suggested that HDAC5 could directly interact with MEF2D SP1 and SP3. In our in vitro study andrographolide exhibited a stronger cytotoxic effect on EBV-positive cells than EBV-negative cells by inducing cell death. Interestingly the proteome analysis revealed that the expression of RIPK1 RIPK3 and MLKL the key molecules for necroptosis was significantly greater in andrographolide-treated cells. Taken together it seems that andrographolide exhibits concurrent activities in HNC cells; it inhibits EBV lytic reactivation by interrupting the expression of TFs and induces cell death probably via necroptosis. ? 2023 by the authors.