Epigenetic DNA methylation of antioxidative stress regulator NRF2 in human prostate cancer.
Epigenetic DNA methylation of antioxidative stress regulator NRF2 in human prostate cancer.
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DOI：
10.1158/1940-6207.capr-14-0127
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发表时间：
2014-12
期刊：
影响因子：
--
通讯作者：
Kong AN
中科院分区：
文献类型：
--
作者：
Khor TO;Fuentes F;Shu L;Paredes-Gonzalez X;Yang AY;Liu Y;Smiraglia DJ;Yegnasubramanian S;Nelson WG;Kong AN
NRF 2是人类前列腺癌（CaP）中许多关键抗氧化应激防御基因的主要调节因子，其表观遗传控制尚不清楚。我们之前的动物研究发现，在TRAMP小鼠中，在CaP进展期间，通过启动子CpG甲基化/组蛋白修饰降低Nrf 2表达。在这项研究中，我们评估了27个临床CaP样本和LNCaP细胞中的人NRF 2启动子的CpG甲基化，使用MAQMA分析和亚硫酸氢盐基因组DNA测序。应用免疫组织化学方法对前列腺癌组织芯片（TMA）中的正常前列腺组织和前列腺癌组织进行研究。在LNCaP细胞中进行使用特异性人NRF 2 DNA启动子片段的荧光素酶报告基因测定和针对组蛋白修饰蛋白的ChIP测定。NRF 2基因启动子区3个特异性CpG位点在临床CaP标本中发生高甲基化（BPH<ADT-RCaP<AS-CaP）。人CaP TMA中的NRF 2染色显示从正常组织到晚期CaP的阳性细胞的强度和百分比均呈下降趋势（Gleason评分为3-9）。在含有这三个CpG位点的LNCaP细胞中的报告基因测定显示NRF 2启动子的甲基化抑制转录活性。用5-aza/TSA处理的LNCaP细胞恢复了NRF 2和NRF 2下游靶基因的表达，降低了DNMT和HDAC蛋白的表达水平，并且ChIP测定显示RNA Pol II和H3 Ac增加，同时在人NRF 2启动子的CpG位点处H3 K9 me 3、MBD 2和MeCP 2减少。总之，这些研究结果表明，表观遗传修饰可能有助于调节NRF 2的转录活性，这可能是预防和治疗人类CaP的目标。
Epigenetic control of NRF2, a master regulator of many critical anti-oxidative stress defense genes in human prostate cancer (CaP) is unknown. Our previous animal study found decreased Nrf2 expression through promoter CpG methylation/histone modifications during CaP progression in TRAMP mice. In this study, we evaluated CpG methylation of human NRF2 promoter in 27 clinical CaP samples and in LNCaP cells using MAQMA analysis and bisulfite genomic DNA sequencing. Prostate cancer tissue microarray (TMA) containing normal and prostate cancer tissues were studied by immunohistochemistry. Luciferase reporter assay using specific human NRF2 DNA promoter segments and ChIP assay against histone modifying proteins were performed in LNCaP cells. Three specific CpG sites in the NRF2 promoter were found to be hypermethylated in clinical CaP samples (BPH<ADT-RCaP<AS-CaP). NRF2 staining in human CaP TMA showed a decreasing trend for both intensity and percentage of positive cells from normal tissues to advanced-stage CaP (Gleason score from 3–9). Reporter assays in the LNCaP cells containing these three CpG sites showed methylation inhibited transcriptional activity of the NRF2 promoter. LNCaP cells treated with 5-aza/TSA restored the expression of NRF2 and NRF2 downstream target genes, decreased expression levels of DNMT and HDAC proteins, and ChIP assays showed increased RNA Pol II and H3Ac with a concomitant decrease in H3K9me3, MBD2 and MeCP2 at CpG sites of human NRF2 promoter. Taken together, these findings suggest that epigenetic modification may contribute to the regulation of transcription activity of NRF2, which could be employed as prevention and treatment target of human CaP.
影响因子：
8.8
作者：
Berthon, P;Dimitrov, T;Stower, M;Cussenot, O;Maitland, N J
通讯作者：
Maitland, N J