Epigenetic regulation affects N-myc downstream-regulated gene 1 expression indirectly in pancreatic cancer cells.
Epigenetic regulation affects N-myc downstream-regulated gene 1 expression indirectly in pancreatic cancer cells.
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DOI：
10.1097/mpa.0b013e3181c8b476
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发表时间：
2010-07
期刊：
影响因子：
2.9
通讯作者：
Eibl G
中科院分区：
文献类型：
--
作者：
Angst E;Dawson DW;Nguyen A;Park J;Go VL;Reber HA;Hines OJ;Eibl G
N-myc下游调节基因1（NDRG 1）在肿瘤的生长和转移过程中起重要作用，近年来成为肿瘤治疗的新靶点。NDRG 1表达缺失通常与胰腺癌（PaCa）患者的临床结局不良相关。由于NDRG 1基因具有一个大的启动子CpG岛，我们试图确定其抑制是否是表观遗传介导的PaCa细胞。PaCa细胞用DNA甲基转移酶抑制剂5-氮杂-2 '-脱氧胞苷（AZA）和组蛋白去乙酰化酶抑制剂曲古抑菌素A（TSA）处理。通过基因组亚硫酸氢盐测序和组合的亚硫酸氢盐限制性分析评估启动子甲基化。用AZA和TSA处理增强NDRG 1蛋白表达，暗示NDRG 1的表观遗传调节。然而，没有显着的NDRG 1启动子CpG岛的DNA甲基化，通过基因组亚硫酸氢盐测序的HPAF-II细胞。我们进一步证实了缺乏启动子甲基化在六个PaCa细胞系联合亚硫酸氢盐限制性分析。这些发现表明，NDRG 1基因在PaCa细胞系中通过DNA甲基化和组蛋白去乙酰化的药理学逆转的再激活通过间接机制发生。这可能是通过改变参与调节NDRG 1转录或NDRG 1蛋白在PaCa细胞中稳定性的基因的表达而发生的。
N-myc downstream regulated gene-1 (NDRG1), important in tumor growth and metastasis, has recently gained interest as a potential therapeutic target. Loss of NDRG1 expression is generally associated with poor clinical outcome in pancreatic cancer (PaCa) patients. As the NDRG1 gene possesses a large promoter CpG island, we sought to determine whether its repression is epigenetically mediated in PaCa cells. PaCa cells were treated with the DNA methyltransferase inhibitor 5-Aza-2’-deoxycytidine (AZA) and the histone deacetylase inhibitor Trichostatin A (TSA). Promoter methylation was assessed by genomic bisulfite sequencing, and by combined bisulfite restriction analyses. Treatment with AZA and TSA enhanced NDRG1 protein expression, implicating epigenetic regulation of NDRG1. However, there was no significant DNA methylation of the NDRG1 promoter CpG island, as determined by genomic bisulfite sequencing of HPAF-II cells. We further confirmed the lack of promoter methylation in six PaCa cell lines by combined bisulfite restriction analyses. These findings indicate that NDRG1 gene reactivation in PaCa cell lines by pharmacologic reversal of DNA methylation and histone deacetylation occurs via an indirect mechanism. This may occur via the altered expression of genes involved in the regulation of NDRG1 transcription or NDRG1 protein stability in PaCa cells.