Zhang Linlin, Yu Shuangquan
Respiratory Department, Shandong Chest Hospital, Jinan No. 5 People's Hospital, Jinan, Shandong 250000, P.R. China.
Department of General Surgery, Jinan No. 5 People's Hospital, Jinan, Shandong 250000, P.R. China.
Exp Ther Med. 2018 Nov;16(5):3987-3995. doi: 10.3892/etm.2018.6732. Epub 2018 Sep 12.
The aim of the present study was to investigate the expression of microRNA (miR)-520b in non-small cell lung cancer (NSCLC) and its biological functions. Reverse transcription-quantitative polymerase chain reaction was used to detect the expression of miR-520b in 52 cases of NSCLC tissues, and its associations with tumor clinical staging and lymph node metastasis were analyzed. miR-520b mimics was transfected into A549 and Calu-3 cells. Cell proliferation, cell cycle, and cell invasion and migration abilities were assessed via cell counting kit-8 assay, flow cytometry and Transwell chamber assay, respectively. Western blot analysis was performed to detected protein expression levels, and dual luciferase reporter assay was used to detect the gene interaction. miR-520b expression was significantly downregulated in NSCLC. The expression of miR-520b in tumor tissues at N1 stage was lower than that at the N0 stage. miR-520b expression was negatively associated with clinical TNM staging. Furthermore, miR-520b mimic transfection inhibited the proliferation and invasion and metastasis abilities of A549 and Calu-3 cells. The expression of Rab22A was downregulated in the miR-520b mimics-transfected cells, whereas E-cadherin expression was increased, and vimentin expression was downregulated. Dual luciferase reporter assay demonstrated that miR-520b directly targeted the expression of Rab22A. Furthermore, Rab22A reversal downregulated the inhibitory effect of miR-520b. miR-520b expression was downregulated in NSCLC, which was negatively correlated with lymph node metastasis and TNM staging. miR-520b targeted on Rab22A to work as a tumor suppressor, inhibiting tumor proliferation and metastasis.
本研究旨在探讨微小RNA（miR）-520b在非小细胞肺癌（NSCLC）中的表达及其生物学功能。采用逆转录-定量聚合酶链反应检测52例NSCLC组织中miR-520b的表达，并分析其与肿瘤临床分期及淋巴结转移的关系。将miR-520b模拟物转染至A549和Calu-3细胞中。分别通过细胞计数试剂盒-8法、流式细胞术和Transwell小室实验评估细胞增殖、细胞周期以及细胞侵袭和迁移能力。采用蛋白质印迹分析检测蛋白质表达水平，并用双荧光素酶报告基因检测法检测基因相互作用。miR-520b在NSCLC中表达明显下调。N1期肿瘤组织中miR-520b的表达低于N0期。miR-520b的表达与临床TNM分期呈负相关。此外，miR-520b模拟物转染抑制了A549和Calu-3细胞的增殖、侵袭和转移能力。在转染miR-520b模拟物的细胞中，Rab22A的表达下调，而E-钙黏蛋白表达增加，波形蛋白表达下调。双荧光素酶报告基因检测表明，miR-520b直接靶向Rab22A的表达。此外，Rab22A的逆转下调了miR-520b的抑制作用。miR-520b在NSCLC中表达下调，与淋巴结转移和TNM分期呈负相关。miR-520b靶向Rab22A发挥抑癌作用，抑制肿瘤增殖和转移。
