虎杖根部乙醇萃取物抑制 EB 病毒潛伏期膜蛋白質 1 的功能   全文下載

Inhibition of the Ethanolic Extract from Polygonum cuspidatum Root on the Functions of Epstein-Barr Virus Latent Membrane Protein 1

當 EB 病毒處於潛伏期時所表現的膜蛋白質 1（LMP1），它具有致癌特性，並且與許多惡性腫瘤有相關。本研究的目的是探討虎杖根部乙醇萃取物（PcE）如何抑制 EB 病毒潛伏期膜蛋白質 1 的功能。我們發現 EB 病毒陽性，B95-8 細胞，經由 PcE 處理會因為劑量增加及作用時間延長而導致細胞存活率下降。此外，也發現 PcE 能夠藉由抑制 Rta 的表現，進而有效抑制LMP1 基因，BNLF1 的轉錄及蛋白質的表現。由流式細胞儀分析結果也發現 B95-8 細胞經由 PcE 處理，會增加停滯在 sub-G1 期的細胞數，同時也發現細胞呈現細胞凋亡的特徵；也就是說 PcE 抑制 LMP1 表現及降低細胞核內 NF-kB 表現，進而促使 B95-8 細胞的凋亡。所以 PcE 有潛能被開發成為毒殺 EB 病毒腫瘤細胞的治療藥物。

Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1), which is expressed during viral latency, has oncogenic proper-ties that are associated with several malignant diseases. The purpose of this study is to examine how the ethanolic extract from Polygonum cuspidatum root (PcE) inhibits the functions of latent membrane protein 1. We found that the viability of EBV-positive cells, B95-8 cells decreased in a time- and dose-dependent manner after the cells were treated with PcE. Furthermore, PcE inhibited the transcription of the LMP1 gene, BNLF1. This was attributed to the inhibition of the expression of Rta, which are known to activate the transcription of BNLF1. Flow cytometry analysis showed that PcE caused an increase in the number of B95-8 cells that were arrested at the sub-G1 phase and displayed typical features of apoptosis. In other words, PcE promoted B95-8 cells apoptosis due to its ability to inhibit the expression of latent membrane protein 1 and deplete NF-κB in the nucleus. These results indicated that PcE may be a useful therapeutic drug to kill cells that are infected by EBV.