Hong Chao-qun, Ran Yong-gang, Chen Jiong-yu, Wu Xiao, You Yan-jie
Department of Tumor Research Lab, Cancer Hospital of Shantou University Medical College, China.
Zhonghua Bing Li Xue Za Zhi. 2010 Aug;39(8):532-6.
To investigate the role of methylation on E-cadherin inactivation in nasopharyngeal carcinoma (NPC) cell line HNE1 and CNE2, as well as evaluate the inhibitory effect of 5-aza-2'-deoxycytidine (5-Aza-dC) on cell abilities of proliferation and invasion.
The expression level of E-cadherin was measured by RT-PCR, Western blot and immunohistochemistry (polymer method), the methyaltion status was analyzed by methylation-specific PCR (MSP), and cell proliferation and invasion were examined by MTT and invasion assay, separately before and after treatment with demethylating agent 5-Aza-dC.
The expression level of E-cadherin was down-regulated compared with the normal tissue, simultaneously partially methylated in gene promoter. Treatment with 20 µmol/L 5-Aza-dC increased the expression of E-cadherin and reduced the methylation degree. Moreover, it also significantly suppressed cell growth (27.6% for HNE1 cells and 34.3% for CNE2 cells, P < 0.05) and invasiveness (37.2% for HNE1 cells and 29.7% for CNE2 cells, P < 0.05).
Aberrant methylation around gene promoter region may play an important part in down regulation of E-cadherin in NPC, suggesting a potential therapeutic strategy for demethylating agents such as 5-Aza-dC.
探讨甲基化在鼻咽癌（NPC）细胞系HNE1和CNE2中E-钙黏蛋白失活中的作用，并评估5-氮杂-2'-脱氧胞苷（5-Aza-dC）对细胞增殖和侵袭能力的抑制作用。
采用逆转录聚合酶链反应（RT-PCR）、蛋白质免疫印迹法和免疫组织化学（聚合物法）检测E-钙黏蛋白的表达水平，用甲基化特异性聚合酶链反应（MSP）分析甲基化状态，分别在使用去甲基化剂5-Aza-dC处理前后，通过MTT法和侵袭实验检测细胞增殖和侵袭情况。
与正常组织相比，E-钙黏蛋白的表达水平下调，同时其基因启动子部分甲基化。用20 μmol/L 5-Aza-dC处理后，E-钙黏蛋白的表达增加，甲基化程度降低。此外，它还显著抑制细胞生长（HNE1细胞为27.6%，CNE2细胞为34.3%，P < 0.05）和侵袭能力（HNE1细胞为37.2%，CNE2细胞为29.7%，P < 0.05）。
基因启动子区域周围的异常甲基化可能在鼻咽癌中E-钙黏蛋白的下调中起重要作用，提示5-Aza-dC等去甲基化剂具有潜在的治疗策略。
