Hypermethylation of NAD(P)H: quinone oxidoreductase 1 (NQO1) gene in human hepatocellular carcinoma
Hypermethylation of NAD(P)H: quinone oxidoreductase 1 (NQO1) gene in human hepatocellular carcinoma
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DOI：
10.1016/j.jhep.2004.11.024
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发表时间：
2005-04-01
影响因子：
25.7
通讯作者：
Saisho, H
中科院分区：
文献类型：
--
作者：
Tada, M;Yokosuka, O;Saisho, H
背景/目的：NAD（P）H：醌氧化还原酶1（NQO 1）和谷胱甘肽S-转移酶P1（GSTP 1）属于11相外源性代谢酶。肝细胞癌（HCC）中通过CpG岛高甲基化导致的GST 1失活以前已有报道，但NQO 1在HCC中的参与尚不清楚。方法：采用逆转录聚合酶链反应（RT-PCR）、亚硫酸氢钠测序和甲基化特异性聚合酶链反应（MSP）检测NQO 1基因在人肝癌细胞和原发性肝癌组织中的转录水平和甲基化状态。结果：在Hep 3B和HuH 6细胞中，NQO 1基因转录水平下调，CpG岛DNA甲基化水平升高; 5-Aza-CdR处理后，NQO 1转录恢复，CpG岛DNA在这些细胞中被去甲基化。MSP分析显示，50.0%的HCC中存在NQO 1高甲基化。所有的肿瘤，表现出较少量的NQO 1 mRNA比相应的非肿瘤组织表现出NQO 1 hypermatilization.Conclusions：NQO 1转录可能是不适当的抑制启动子甲基化在一个子集的肝癌，以及GST 1基因。(C)2004年欧洲肝脏研究协会。Elsevier B. V.出版，保留所有权利。
Background/Aims: NAD(P)H: quinone oxydoreductase 1 (NQO1) and glutathione S-transferase P1 (GSTP1) belong to phase 11 xenobiotic-metabolizing enzymes. GSTP1 inactivation via CpG island hypermethylation in hepatocellular carcinoma (HCC) was previously reported, but the involvement of NQO1 in HCC is not well known. In this study, we assessed the transcription and status of methylation of NQO1 gene in human hepatoma cells and primary human HCC tissues.Methods: NQO1 transcription and DNA hypermethylation in hepatoma cells with or without 5-aza-deoxycytidine (5-Aza-CdR) treatment were investigated by reverse-transcription PCR (RT-PCR), sodium bisulfite sequencing and methylation-specific PCR (MSP). The methylation status of NQO1 and GSTP1, and NQO1 mRNA in 44 HCC cases was also analyzed by MSP and real-time PCR, respectively.Results: NQO1 transcription was down-regulated and the CpG island DNA was hypermethylated in Hep3B and HuH6 cells. After treatment with 5-Aza-CdR, NQO1 transcription was restored and CpG island DNA was demethylated in these cells. MSP analysis revealed that NQO1 hypermethylation occurred in 50.0% of HCC. All of the tumors that exhibited lesser amounts of NQO1 mRNA than corresponding non-tumorous tissues showed NQO1 hypermethylation.Conclusions: NQO1 transcription might be inappropriately suppressed by promoter hypermethylation in a subset of HCC, as well as GSTP1 gene. (C) 2004 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.