Loss of NECL1, a Novel Tumor Suppressor, Can be Restored in Glioma by HDAC Inhibitor-Trichostatin A Through Sp1 Binding Site
Loss of NECL1, a Novel Tumor Suppressor, Can be Restored in Glioma by HDAC Inhibitor-Trichostatin A Through Sp1 Binding Site
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DOI：
10.1002/glia.20823
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发表时间：
2009-07-01
期刊：
影响因子：
6.2
通讯作者：
Peng, Xiaozhong
中科院分区：
文献类型：
--
作者：
Gao, Jing;Chen, Tao;Peng, Xiaozhong
Nectin-like molecule 1（NECL 1）/CADM 3/IGSF 4 B/TSLL 1/SynCAM 3是一种神经组织特异性免疫球蛋白样细胞-细胞粘附分子，在12种人脑胶质瘤细胞系中表达下调。我们发现NECL 1在6个胶质瘤细胞系和15个原发性胶质瘤组织中在RNA和蛋白水平均缺失表达。NECL 1的再表达。导入胶质瘤细胞系U251，可通过诱导细胞周期阻滞抑制细胞增殖。NECL 1在裸鼠体内也能抑制肿瘤的生长。为了进一步研究NECL 1在胶质瘤中沉默的机制，确定了NECL 1基因组序列中位于-271至+81的基本启动子区域。DNA亚硫酸氢盐测序法检测NECL 1启动子CpG岛甲基化状态，未发现CpG岛高甲基化位点;组蛋白去乙酰化酶（HDAC）活性在胶质瘤中高于正常脑组织，HDAC的合成酶曲古抑菌素A（TSA）可激活NECL 1在胶质瘤细胞中的表达。因此，神经胶质瘤中NECL 1的缺失至少部分是由组蛋白去乙酰化引起的。荧光素酶报告基因分析、染色质免疫沉淀和免疫共沉淀（co-IP）分析表明，Sp1通过与未经处理的胶质瘤细胞中的HDAC 1或TSA处理的细胞中的p300/CBP结合在此过程中发挥重要作用。我们的发现提示NECL 1在胶质瘤中可能是一种抑癌基因，其缺失可能是由组蛋白去乙酰化引起的。(C)2008 Wiley-Liss，Inc.
Nectin-like molecule 1 (NECL1)/CADM3/IGSF4B/TSLL1/SynCAM3 is a neural tissue-specific immunoglobulin-like cell-cell adhesion molecule downregulated at the mRNA level in 12 human glioma cell lines. Here we found that the expression of NECL1 was lost in six glioma cell lines and 15 primary glioma tissues at both RNA and protein levels. Re-expression of NECL1. into glioma cell line U251 would repress cell proliferation in vitro by inducing cell cycle arrest. And also NECL1 could decrease the growth rate of tumors in nude mice in vivo. To further investigate the mechanism why NECL1 was silenced in glioma, the basic promoter region located at -271 to +81 in NECL1 genomic sequence was determined. DNA bisulfite sequencing was performed to study the methylation status of CpG islands in NECL1 promoter; however, no hypermethylated CpG site was found. Additionally, the activity of histone deacetylase (HDACs) in glioma was higher than that in normal brain tissues, and the expression of NECL1 in glioma cell lines could be reactivated by HDACs inhibitor-Trichostatin A (TSA). So the loss of NECL1 in glioma was at least partly caused by histone deacetylation. Luciferase reporter assays, chromatin immunoprecipitation and co-immunoprecipitation (co-IP) assays indicated that Sp1 played an important role in this process by binding to either HDAC1 in untreated glioma cells or p300/CBP in TSA treated cells. Our finding suggests that NECL1 may act as a tumor suppressor in glioma and loss of it in glioma may be caused by histone deacetylation. (C) 2008 Wiley-Liss, Inc.