Downregulation of Epstein-Barr virus-encoded latent membrane protein-1 by arsenic trioxide in nasopharyngeal carcinoma cells
Downregulation of Epstein-Barr virus-encoded latent membrane protein-1 by arsenic trioxide in nasopharyngeal carcinoma cells
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DOI：
10.1177/030089160609200210
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发表时间：
2006-03-01
期刊：
影响因子：
1.9
通讯作者：
Wu, Mingyao
中科院分区：
文献类型：
--
作者：
Du, Caiwen;Wen, Bogui;Wu, Mingyao
目的和背景：研究表明，鼻咽癌（NPC）与EB病毒（EBV）有关，EB病毒编码的潜伏膜蛋白1（LMP 1）在NPC的发病机制中起重要作用。在临床前研究中，三氧化二砷（As（2）O（3））已被确定为一种有前途的治疗鼻咽癌的抗癌药物。方法：用3 μ mol/L的As_2O_3处理LMP_1阳性的鼻咽癌细胞株HNE 1-LMP_1 96小时，观察LMP_1的表达，并观察LMP_1的表达与As_2O_3浓度的关系。采用Western blot、共聚焦免疫荧光染色和半定量逆转录酶反应（RT-PCR）检测HNE 1-LMP 1细胞中LMP 1蛋白和mRNA的表达。光镜和TUNEL法检测细胞凋亡。还通过流式细胞术研究了细胞周期分布的改变。MTT法和集落形成实验检测细胞增殖情况。结果：3 μ mol/LAS 2 O3作用于鼻咽癌细胞后，LMP 1在蛋白和mRNA水平的表达均降低，LMP 1的mRNA水平下降。此剂量的As 2 O3可显著诱导HNE 1-LMP 1细胞凋亡和生长迟缓。此外，更多的HNE 1-LMP 1细胞被诱导至G 0/G1和G2/M期阻滞。结论：As_2O_3可抑制HNE 1和HNE 2细胞LMP 1的表达，并诱导细胞凋亡、细胞周期改变和生长迟缓。LMP 1阳性的鼻咽癌细胞对AS（2）O（3）的敏感性高于LMP 1阴性的鼻咽癌细胞。
Aims and background: It was documented that nasopharyngeal carcinoma (NPC) is associated with Epstein-Barr virus (EBV) and that EBV-encoded latent membrane protein-1 expression (LMP1) plays an important role in the pathogenesis of NPC. In preclinical studies, arsenic trioxide (AS(2)O(3)) has been identified as a promising anticancer agent for treatment of NPC. The purpose of this study is to investigate if this agent can inhibit the expression of LMP1 and therefore lead to growth inhibition of NPC cells in vitro.Methods: LMPl1positive NPC cells, HNE1-LMP1, were treated with 3 mu mol/L of As2O3 for 96 hours. The LMP1 protein expression and mRNA level in HNE1-LMP1 cells were determined by western blot, confocal immunofluorescence staining and semiquantitative reverse transcriptase reaction (RT-PCR). Apoptosis was determined by light microscopy and the TUNEL method. Alterations in the cell cycle distribution were also investigated by flow cytometry. MTT assay and colony formation assay were used to detect the proliferation of the cells. The LMP1-negative parental cell lines HNE1 and HNE2 were used as control in an attempt to elucidate the role of LMP1 in the anticancer effect of AS(2)O(3) on NPC cells.Results: The expression of LMP1 at the protein and mRNA level was reduced after exposure to 3 mu mol/L AS(2)O(3). This dose of As2O3 significantly induced apoptosis and growth retardation of HNE1-LMP1 cells. In addition, more HNEl-LMP1 cells were induced to G0/G1 and G2/M arrest. The same dose of As2O3 had a moderate effect on HNE1 and HNE2 cells.Conclusion: Arsenic trioxide can inhibit LMP1 expression and dictate apoptosis and alterations of cell cycle distribution as well as growth retardation. LMP1-positive NPC cells are more sensitive to AS(2)O(3) treatment than LMP1-negative NPC cells.