Methylation-associated silencing of miR-638 promotes endometrial carcinoma progression by targeting MEF2C
Methylation-associated silencing of miR-638 promotes endometrial carcinoma progression by targeting MEF2C
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miR-638 甲基化相关沉默通过靶向 MEF2C 促进子宫内膜癌进展
DOI：
10.3892/ijmm.2020.4540
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发表时间：
2020-06-01
影响因子：
5.4
通讯作者：
Ren, Yulan
中科院分区：
文献类型：
--
作者：
Ni, Jianjiao;Liang, Shanhui;Ren, Yulan
启动子甲基化相关的癌症相关microRNA（miRNAs）沉默是各种类型人类癌症中肿瘤发生过程中常见的表观遗传机制。然而，这还没有在子宫内膜癌（EC）中得到全面的研究。在本研究中，使用由1，347种常见人类miRNA组成的miRNA微阵列来选择EC中高甲基化的潜在肿瘤抑制性miRNA。这导致了miR-638、miR-210和miR-3665的鉴定。通过亚硫酸氢盐测序聚合酶链反应检测miR-638的甲基化状态，并通过TaqMan miRNA分析测量miR-638的表达。构建了用过表达miR-638、其靶基因肌细胞增强因子2C（MEF 2C）或两者的载体转染的EC细胞系。设计了双荧光素酶报告基因测定、异种移植小鼠模型和拯救实验来研究miR-638及其靶基因MEF 2C。结果表明，在42例食管癌患者手术切除的癌组织中，miR-638基因启动子区高度甲基化，miR-638表达显著下调。此外，miR-638的低表达与晚期妇产科联合会分期显著相关，并被证明表明无病生存期较短。功能研究表明，miR-638在EC细胞系中的过表达抑制体外肿瘤进展和体内致瘤性。MEF 2C被证实是miR-638的直接靶点，并被证明介导miR-638在EC中的肿瘤抑制功能。
Promoter methylation-associated silencing of cancer-associated microRNAs (miRNAs) is a common epigenetic mechanism during tumorigenesis in various types of human cancer. However, this has not been comprehensively examined in endometrial carcinoma (EC). In the present study, an miRNA microarray consisting of 1,347 common human miRNAs was used to select potential tumor suppressive miRNAs that were hyper-methylated in EC. This led to the identification of miR-638, miR-210 and miR-3665. The methylation status of miR-638 was examined by bisulfite sequencing polymerase chain reaction and miR-638 expression was measured by TaqMan miRNA assays. EC cell lines transfected with vectors overexpressing miR-638, its target gene myocyte enhancer factor 2C (MEF2C) or both, were constructed. Dual-luciferase reporter assays, a xenograft mouse model and rescue experiments were designed to study miR-638 and its target gene MEF2C. The results indicated that the promoter region of miR-638 was highly methylated and the expression of miR-638 was significantly downregulated in cancerous tissues from 42 patients with EC who underwent surgical resection. Additionally, a low expression of miR-638 was significantly associated with advanced Federation of Gynecology and Obstetrics stage and was demonstrated to indicate shorter disease-free survival. Functional studies indicated that the overexpression of miR-638 in EC cell lines inhibited in vitro tumor progression and in vivo tumorigenicity. MEF2C was verified as a direct target of miR-638 and was demonstrated to mediate the tumor-suppressive function of miR-638 in EC.