Aberrant hypermethylation and reduced expression of disabled-2 promote the development of lung cancers
Aberrant hypermethylation and reduced expression of disabled-2 promote the development of lung cancers
复制标题
异常高甲基化和disabled-2表达减少促进肺癌的发展。
DOI：
10.3892/ijo.2013.2084
复制
发表时间：
2013-11-01
影响因子：
5.2
通讯作者：
Wang, En-Hua
中科院分区：
文献类型：
--
作者：
Xie, Xue-Mei;Zhang, Zi-Yin;Wang, En-Hua
Disabled-2（Dab 2）被认为是一种肿瘤抑制因子，在癌症中下调。我们检测了Dab 2的启动子甲基化状态和表达水平，并研究了它们在肺癌发生中的作用。采用甲基化特异性PCR方法检测100例肺癌组织中Dab 2基因的甲基化状态。用Western印迹分析确定Dab 2蛋白质的细胞质和细胞核表达。使用5-氮杂-2-脱氧胞苷（5-Aza-dC）对三种肺癌细胞系进行去甲基化处理。Dab 2基因转染可上调肺癌细胞中Dab 2的表达，siRNA可阻断Dab 2的表达。分别用3-（4，5-二甲基噻唑-2-基）-2，5-二苯基四氮唑溴化物（MTS）和Matrigel侵袭试验进行增殖和侵袭能力测试。肺癌组织中Dab 2基因甲基化率显著高于正常肺组织。Dab 2甲基化与肺癌细胞核和细胞质中Dab 2的表达降低、TNM分期和淋巴结转移有关。5-Aza-dC能消除Dab 2的甲基化，增强Dab 2的表达，抑制β-catenin的表达，抑制肺癌细胞的增殖和侵袭能力。上调Dab 2表达可降低β-catenin表达，降低肺癌细胞的增殖和侵袭能力。然而，Dab 2表达的中断诱导相反的结果。Dab 2甲基化在肺癌中是常见的，并且是导致Dab 2表达降低的最重要因素之一。Dab 2基因异常甲基化和表达降低促进肺癌的发生。
Disabled-2 (Dab2) is considered a tumor suppressor and is downregulated in cancers. We examined the promoter methylation status and expression levels of Dab2, and investigated their roles in the development of lung cancers. Methylation-specific PCR was employed to analyze the methylation status of Dab2 in 100 lung cancer tissues. The cytoplasmic and nuclear expression of the Dab2 protein was determined using western blot analysis. Demethylation treatment using 5-Aza-2-deoxycytidine (5-Aza-dC) was performed in three lung cancer cell lines. Dab2 expression was upregulated by Dab2 transfection or interrupted by Dab2 siRNA in lung cancer cells. Proliferative and invasive ability tests were performed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTS) and a Matrigel invasion assay, respectively. The methylation rate of Dab2 was significantly higher in lung cancer tissues compared to normal lung tissues. Dab2 methylation correlated with the reduced nuclear and cytoplasmic expression of Dab2, as well as the TNM stage and lymphatic metastasis of lung cancers. Treatment with 5-Aza-dC was able to eliminate the hypermethylation of Dab2, enhance Dab2 expression, and inhibit β-catenin expression, and the proliferative and invasive ability of lung cancer cells. Upregulation of Dab2 expression reduced β-catenin expression and proliferation and invasiveness of lung cancer cells. However, interruption of Dab2 expression induced the opposite results. Dab2 methylation is common in lung cancers, and is one of the most important factors responsible for the reduced expression of Dab2. Aberrant hypermethylation and reduced expression of Dab2 promote the development of lung cancers.