miR-373 Negatively Regulates Methyl-CpG-Binding Domain Protein 2 (MBD2) in Hilar Cholangiocarcinoma
miR-373 Negatively Regulates Methyl-CpG-Binding Domain Protein 2 (MBD2) in Hilar Cholangiocarcinoma
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miR-373 负向调节肝门部胆管癌中的甲基 CpG 结合域蛋白 2 (MBD2)
DOI：
10.1007/s10620-010-1481-1
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发表时间：
2011-06-01
影响因子：
3.1
通讯作者：
Zou, Shengquan
中科院分区：
文献类型：
--
作者：
Chen, Yongjun;Luo, Jian;Zou, Shengquan
研究背景microRNAs（miRNAs）是一类非编码的单链RNA分子，在转录后水平调控基因表达。甲基化CpG结合域蛋白（Methyl-CpG-binding domain proteins，MBPs）是通过与甲基化基因启动子结合的转录抑制因子。最近的研究表明，miRNAs通过靶向DNA甲基转移酶（DNMTs）和/或MBPs对DNA甲基化的影响在多种人类肿瘤中起重要作用。MBD 1、MBD 2和Mecp 2的mRNA和蛋白分别通过QuantiTect®Primer Assays和Western blotting测定，RASSF 1A mRNA通过SYBR-Green实时PCR测定;结果miR-373在肝门部胆管癌中表达减少，与肝门部胆管癌细胞分化差、临床分期高、生存期短密切相关; MBD 2在QBC 939细胞中特异性过表达，且与miR-373相关，前体miR-373抑制MBD 2 -3′UTR构建体的荧光素酶活性，外源性miR-373抑制MBD 2的表达并增强RASSF 1A mRNA的表达;结论miR-373是MBD 2的负调控因子之一。在肝门部胆管癌中，miR-373的表达下调导致MBD 2的增加，这反过来又抑制了甲基化介导的基因，如RASSF 1A。
BackgroundmicroRNAs (miRNAs) are a class of non-coding, single-stranded RNA molecules that regulate gene expression at the posttranscriptional level. Methyl-CpG-binding domain proteins (MBPs) are transcription repressors through binding to methylated gene promoters. Recent studies have shown that the effect of miRNAs on DNA methylation by targeting DNA methyltransferase (DNMTs) and/or MBPs plays an important role in various human cancers.AimsThis study focuses on the regulation of MBPs by miR-373 and its downstream effect in hilar cholangiocarcinoma.MethodsmiR-373 was investigated by TaqMan miRNA Assay; mRNA and protein of MBD1, MBD2, and Mecp2 were determined by QuantiTect®Primer Assays and Western blotting, respectively; RASSF1A mRNA was measured by SYBR-Green real-time PCR; The targeting at MBD2-3′UTR by miR-373 was evaluated by dual-luciferase reporter gene assay.ResultsmiR-373 decreased and closely associated with poor cell differentiation, advanced clinical stage, and shorter survival in hilar cholangiocarcinoma; MBD2 exclusively over-expressed and reciprocally related to miR-373; precursor miR-373 inhibited the luciferase activity of MBD2-3′UTR construct; exogenous miR-373 suppressed the expression of MBD2 and enhanced RASSF1A mRNA in QBC939cells; anti-miR-373 inhibitor up-regulated the expression of MBD2 and reduced RASSF1A mRNA in HIBEpic cells.ConclusionsmiR-373 is one negative regulator of MBD2. In hilar cholangiocarcinoma, down-expression of miR-373 leads to increase of MBD2, which in turn suppresses the methylation-mediated gene such as RASSF1A.