Du C W, Wen B G, Li D R, Peng X, Hong C Q, Chen J Y, Lin Z Z, Hong X, Lin Y C, Xie L X, Wu M Y, Zhang H
Laboratory of Cancer Research, Cancer Hospital, Shantou University Medical College, Guang Dong, PR, China.
Braz J Med Biol Res. 2006 May;39(5):677-85. doi: 10.1590/s0100-879x2006000500015. Epub 2006 Apr 20.
Nasopharyngeal carcinoma (NPC) is notorious for the metastases, which are in close association with Epstein-Barr virus-encoded latent membrane protein 1 (LMP1). Arsenic trioxide (As2O3) has been shown to induce apoptosis and differentiation in NPC xenografts. Then, can it repress the cancer cells' metastasis potential? To elucidate this issue, the present study was performed. LMP1-negative cell line HNE1 and LMP1-positive cell line HNE1-LMP1 were used as in vitro model. Cells (1 x 10(5)/mL) were cultured with or without 3 microM As2O3 for 48 h. Then the survival cells were collected to investigate their potential of colony formation, attachment, invasion, and migration. Both confocal immunofluorescence staining and Western blot were used to detect the changes of LMP1 expression. The changes of MMP-9 were examined by RT-PCR assay and Western blot. The results were as follow: i) the colony formation inhibition rate (75.41 +/- 3.9% in HNE1-LMP1 cells vs 37.89 +/- 4.9% in HNE1 cells), the rate of attachment (HNE1-LMP1 vs HNE1: 56.40 +/- 3.5 vs 65.87 +/- 5.9%), the invasion inhibitory rate (HNE1-LMP1 vs HNE1: 56.50 +/- 3.7 and 27.91 +/- 2.1%), and the migration inhibitory rate (HNE1-LMP1 vs HNE1: 48.70 +/- 3.9 vs 29.19 +/- 6.27%) were all significantly different between the two cell lines (P < 0.01). ii) LMP1 was down-regulated in As2O3-treated HNE1-LMP1 cells. iii) The reduction of MMP-9 was found in As2O3-treated groups, more evident in HNE1-LMP1 cells. Thus, we conclude that As2O3 can reduce metastasis potential of NPC cells, involving inhibition of MMP-9 expression. LMP1 were also reduced in this process and seemed to enhance anti-metastasis activity of As2O3.
鼻咽癌（NPC）因转移而臭名昭著，其转移与爱泼斯坦-巴尔病毒编码的潜伏膜蛋白1（LMP1）密切相关。三氧化二砷（As2O3）已被证明可诱导鼻咽癌异种移植瘤发生凋亡和分化。那么，它能否抑制癌细胞的转移潜能呢？为阐明这一问题，开展了本研究。将LMP1阴性细胞系HNE1和LMP1阳性细胞系HNE1-LMP1用作体外模型。细胞（1×10⁵/mL）在有或无3μM As2O3的条件下培养48小时。然后收集存活细胞，研究其集落形成、黏附、侵袭和迁移潜能。采用共聚焦免疫荧光染色和蛋白质印迹法检测LMP1表达的变化。通过逆转录聚合酶链反应（RT-PCR）分析和蛋白质印迹法检测基质金属蛋白酶-9（MMP-9）的变化。结果如下：i）两个细胞系之间的集落形成抑制率（HNE1-LMP1细胞中为75.41±3.9%，HNE1细胞中为37.89±4.9%）、黏附率（HNE1-LMP1与HNE1：56.40±3.5对65.87±5.9%）、侵袭抑制率（HNE1-LMP1与HNE1：56.50±3.7和27.91±2.1%）以及迁移抑制率（HNE1-LMP1与HNE1：48.70±3.9对29.19±6.27%）均有显著差异（P<0.01）。ii）在As2O3处理的HNE1-LMP1细胞中LMP1表达下调。iii）在As2O3处理组中发现MMP-9减少，在HNE1-LMP1细胞中更明显。因此，我们得出结论，As2O3可降低鼻咽癌细胞的转移潜能，这涉及对MMP-9表达的抑制。在此过程中LMP1也减少，且似乎增强了As2O3的抗转移活性。
