He Qianting, Zhou Xiaofeng, Li Su, Jin Yi, Chen Zhujian, Chen Dan, Cai Yuchen, Liu Zhonghua, Zhao Tingting, Wang Anxun
Department of Oral and Maxillofacial Surgery, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong 510080, China.
Biochim Biophys Acta. 2013 Nov;1830(11):5258-66. doi: 10.1016/j.bbagen.2013.07.028. Epub 2013 Aug 2.
To date microRNAs and their contribution to the onset and propagation of salivary adenoid cystic carcinoma (SACC) are limited. The objective of this study was to identify miR-181a and its mechanism in the metastasis of SACC.
At first microarray and quantitative RT-PCR were used to investigate microRNA profiles and miR-181a in paired SACC cell lines with different metastatic potential. Then the effect of miR-181a on metastatic potential of SACC was investigated. MiR-181a target genes and Snai2 promoter activity were investigated using luciferase reporter gene assays. Western blot was used to detect MAPK-Snai2 pathway-related protein level.
A panel of deregulated microRNAs (including miR-181a) was identified in paired of SACC cell lines. Functional analysis indicated that miR-181a inhibited SACC cell migration, invasion and proliferation in vitro, and it suppressed tumor growth and lung metastasis in vivo. Direct targeting of miR-181a to MAP2K1, MAPK1 and Snai2 was confirmed by luciferase reporter gene assays. MiR-181a mimic inhibited the expression of MAP2K1, MAPK1 and Snai2 in SACC cells. MAP2K1 or MAPK1 siRNA suppressed Snai2 gene promoter activity and reduced Snai2 expression and the metastatic potential of SACC cells.
Our results indicate that miR-181a plays an important role in the metastasis of SACC, and may serve as a novel therapeutic target for SACC. MiR-181a regulates the MAPK-Snai2 pathway both through direct cis-regulatory mechanism and through indirect trans-regulatory mechanism.
To our knowledge, this is the first study revealing that miR-181a deregulation mediated the metastasis of SACC by regulating MAPK-Snai2 pathway.
迄今为止，微小RNA及其在涎腺腺样囊性癌（SACC）发生和发展中的作用尚不清楚。本研究旨在鉴定miR-181a及其在SACC转移中的机制。
首先，利用基因芯片和定量逆转录-聚合酶链反应（qRT-PCR）检测具有不同转移潜能的配对SACC细胞系中的微小RNA谱和miR-181a。然后研究miR-181a对SACC转移潜能的影响。采用荧光素酶报告基因实验检测miR-181a的靶基因和Snai2启动子活性。蛋白质免疫印迹法检测丝裂原活化蛋白激酶（MAPK）-Snai2信号通路相关蛋白水平。
在配对的SACC细胞系中鉴定出一组失调的微小RNA（包括miR-181a）。功能分析表明，miR-181a在体外抑制SACC细胞的迁移、侵袭和增殖，并在体内抑制肿瘤生长和肺转移。荧光素酶报告基因实验证实miR-181a直接靶向丝裂原活化蛋白激酶激酶1（MAP2K1）、丝裂原活化蛋白激酶1（MAPK1）和Snai2。miR-181a模拟物抑制SACC细胞中MAP2K1、MAPK1和Snai2的表达。MAP2K1或MAPK1小干扰RNA（siRNA）抑制Snai2基因启动子活性，降低Snai2表达和SACC细胞的转移潜能。
我们的结果表明，miR-181a在SACC转移中起重要作用，可能成为SACC的一个新的治疗靶点。miR-181a通过直接顺式调控机制和间接反式调控机制调节MAPK-Snai2信号通路。
据我们所知，这是第一项揭示miR-181a失调通过调节MAPK-Snai2信号通路介导SACC转移的研究。
