ZNF350 promoter methylation accelerates colon cancer cell migration
ZNF350 promoter methylation accelerates colon cancer cell migration
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DOI：
10.18632/oncotarget.26353
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发表时间：
2018-12
期刊：
影响因子：
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通讯作者：
Hiroki Tanaka;Y. Kuwano;Tatsuya Nishikawa;K. Rokutan;K. Nishida
中科院分区：
文献类型：
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作者：
Hiroki Tanaka;Y. Kuwano;Tatsuya Nishikawa;K. Rokutan;K. Nishida
在结直肠癌的扩展过程中，可能会发生转录和表观基因组状态的多样化。某些癌细胞失去其上皮特性，而获得间充质特性，称为上皮-间充质转化(EMT)，它们向非致瘤细胞外基质侵袭。在这项研究中，我们从一个结肠癌细胞系(HCT116)中分离出一个具有加速基线运动能力的亚群(MG细胞)和一个不活动的亚群(非MG细胞)。MG细胞的基因表达特征表明，该亚群可能是EMT杂交种。MG细胞在用甲基转移酶抑制剂5-氮杂胞苷处理后基本上失去了迁移特性，这表明DNA甲基化在这一过程中发挥了作用。用或不用5-氮胞苷处理的两种类型的细胞的全局转录组分析确定了640个基因，它们的表达可能是甲基化依赖的在MG细胞中下调。全球甲基化分析显示，在640个基因中，有35个基因在MG细胞中发生了超甲基化。其中，我们重点研究了抑癌基因ZNF350，它编码一个锌指和BRCA1相互作用的蛋白。值得注意的是，ZNF350基因敲除促进了非MG细胞的迁移，而在MG细胞中过表达ZNF350显著削弱了它们的迁移。最后，对ZNF350启动子的序列截短片段(-268~+49bp)进行了焦解序列分析和双荧光素酶分析，结果表明ZNF350启动子的基础活性可能与3个高甲基化位点有关。综上所述，我们的结果表明，ZNF350近端启动子的超甲基化可能是获得结肠癌细胞迁移能力增强的关键决定因素之一。
Diversification of transcriptomic and epigenomic states may occur during the expansion of colorectal cancers. Certain cancer cells lose their epithelial characters and gain mesenchymal properties, known as epithelial-mesenchymal transition (EMT), and they aggressively migrate into the non-tumorigenic extracellular matrix. In this study, we isolated a subpopulation with accelerated baseline motility (MG cells) and an immotile one (non-MG cells) from a colon cancer cell line (HCT116). Gene expression signatures of the MG cells indicated that this subpopulation was likely an EMT hybrid. The MG cells substantially lost their migratory properties after treatment with a methyltransferase inhibitor, 5-azacytidine, suggesting a role of DNA methylation in this process. Global transcriptome assays of both types of cells with or without 5-azacytidine treatment identified 640 genes, whose expression might be methylation-dependently down-regulated in the MG cells. Global methylation analysis revealed that 35 out of the 640 genes were hyper-methylated in the MG cells. Among them, we focused on the anti-oncogene ZNF350, which encodes a zinc-finger and BRCA1-interacting protein. Notably, ZNF350 knockdown accelerated migration of the non-MG cells, while overexpression of ZNF350 in the MG cells significantly impaired their migration. Finally, pyrosequence analysis together with dual luciferase assays of serially truncated fragments of the ZNF350 promoter (-268 to +49 bp) indicated that three hyper-methylated sites were possibly responsible for the basal promoter activity of ZNF350. Taken together, our results suggest that hyper-methylation of the ZNF350 proximal promoter may be one of the crucial determinants for acquiring increased migratory capabilities in colon cancer cells.