Tian Qing-Qing, Xia Jing, Zhang Xin, Gao Bao-Qin, Wang Wei
Department of Pathology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China.
General Department of Houhu, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China.
Cancer Manag Res. 2020 Jul 14;12:5749-5758. doi: 10.2147/CMAR.S249686. eCollection 2020.
Mounting research has established the role of microRNAs (miRNAs) as oncogenes or anti-oncogenes (tumor suppressors) in the development and progression of several cancers. The purpose of our current study is to delineate the roles and functional mechanisms of miR-331-3p and MLLT10 in non-small cell lung cancer (NSCLC) tumorigenesis.
Quantitative reverse transcription-polymerase chain reaction (RT-qPCR) was employed to measure miR-331-3p expression levels in twenty-six matched tumor tissues and non-cancerous tissues collected from patients suffering from NSCLC, and from six NSCLC cell lines separately: A549, H1650, H292, H1299, H1944 and BEAS-2b. We employed the dual-luciferase activity assay to check whether the putative gene, MLLT10, was a downstream target of miR-331-3p in NSCLC pathogenesis and development. Western blot was conducted to analyze the protein expression levels of MLLT10 (AF10), E-cadherin, Vimentin, and GAPDH. CCK-8 assay, transwell migration assay, and transwell invasion assay were carried out to observe the functions of miR-331-3p and MLLT10 on NSCLC tumor cell proliferation, metastasis, and invasion, respectively. To identify whether the metastasis of NSCLC tumor cells was EMT-mediated, supplementary experiments involving E-cadherin and Vimentin were implemented.
miR-331-3p was downregulated in NSCLC, which promoted tumor cell proliferation, whereas the overexpression of miR-331-3p inhibited tumor cell proliferation. Being a direct target of miR-331-3p, MLLT10 was negatively modulated by miR-331-3p, which suppressed tumor cell proliferation, migration, and invasion in NSCLC. However, MLLT10 overexpression alleviated the above inhibitory effects. Furthermore, EMT-mediated metastasis was proved to be present in NSCLC.
miR-331-3p played a suppressor role in NSCLC tumor cell proliferation, EMT-mediated metastasis, and invasion by targeting MLLT10. Our findings highlighted that miR-331-3p/MLLT10 axis could be useful as a clinical diagnostic marker and therapeutic target in NSCLC patients.
越来越多的研究已证实微小RNA（miRNA）在多种癌症的发生和发展过程中作为癌基因或抑癌基因（肿瘤抑制因子）所起的作用。我们当前研究的目的是阐明miR-331-3p和MLLT10在非小细胞肺癌（NSCLC）肿瘤发生中的作用及功能机制。
采用定量逆转录聚合酶链反应（RT-qPCR）检测从NSCLC患者收集的26对匹配肿瘤组织和非癌组织以及6种NSCLC细胞系（分别为A549、H1650、H292、H1299、H1944和BEAS-2b）中miR-331-3p的表达水平。我们采用双荧光素酶活性测定法来检查假定基因MLLT10在NSCLC发病机制和发展过程中是否为miR-331-3p的下游靶点。进行蛋白质印迹法以分析MLLT10（AF10）、E-钙黏蛋白、波形蛋白和甘油醛-3-磷酸脱氢酶（GAPDH）的蛋白质表达水平。分别进行CCK-8测定、Transwell迁移测定和Transwell侵袭测定以观察miR-331-3p和MLLT10对NSCLC肿瘤细胞增殖、转移和侵袭的作用。为确定NSCLC肿瘤细胞的转移是否由上皮-间质转化（EMT）介导，实施了涉及E-钙黏蛋白和波形蛋白的补充实验。
miR-331-3p在NSCLC中表达下调，其促进肿瘤细胞增殖，而miR-331-3p的过表达抑制肿瘤细胞增殖。作为miR-331-3p的直接靶点，MLLT10受到miR-331-3p的负调控，miR-331-3p抑制NSCLC中的肿瘤细胞增殖、迁移和侵袭。然而，MLLT10的过表达减轻了上述抑制作用。此外，已证实在NSCLC中存在EMT介导的转移。
miR-331-3p通过靶向MLLT10在NSCLC肿瘤细胞增殖、EMT介导的转移和侵袭中发挥抑制作用。我们的研究结果突出表明，miR-331-3p/MLLT10轴可作为NSCLC患者的临床诊断标志物和治疗靶点。
