吞噬细胞运动蛋白1通过NF-κB/snail信号通路促进肺腺癌细胞A549的上皮-间质转化

ELMO1 Promotes EMT in Human Lung Adenocarcinoma A549 Cells via the NF-κB/snail Signaling Pathway

吞噬细胞运动蛋白1(engulfment and cell motility 1,ELMO1)在许多恶性肿瘤的侵袭转移中发挥重要作用,但其在肺腺癌侵袭转移中的研究相对较少。本研究旨在探讨ELMO1在肺腺癌上皮-间质转化(epithelial-mesenchymal transition,EMT)中的作用,为临床预防肺腺癌的侵袭和转移提供理论和实验依据。Western印迹结果显示,ELMO1在人正常肺上皮细胞BEAS-2B中的蛋白质表达水平低,而在人肺腺癌细胞A549中表达水平高。si ELMO1/A549细胞组中ELMO1的表达水平明显降低。用白细胞介素-8(interleukin-8,IL-8)刺激肺腺癌细胞A549 24 h后,趋化运动实验结果显示,IL-8浓度为100 ng/m L时为最适刺激浓度,此时肺腺癌细胞A549具有最强的趋化运动能力,增高或降低IL-8的浓度时细胞的趋化运动能力均下降。Transwell侵袭实验结果显示,用IL-8刺激24 h后,si ELMO1/A549细胞相比于Scr/A549细胞组的侵袭转移能力明显减弱。Western印迹结果显示,与未用IL-8刺激或用IL-8和抑制剂BAY11-7082同时刺激的相比,si ELMO1/A549细胞较Scr/ELMO1A549细胞组E-cadherin蛋白的表达上调,Vimentin蛋白的表达下调,p-IκBα、细胞核中snail的蛋白质表达水平均降低。综上所述,ELMO1可以通过NF-κB信号通路影响snail的转核,从而促进肺腺癌细胞A549的上皮-间质转化。

Engulfment and cell motility 1（ ELMO1） plays an important role in the invasion and metastasis of many malignant tumors. However,there are relatively few studies on the invasion and metastasis of lung adenocarcinoma. The purpose of this study was to investigate the role of ELMO1 in the epithelial-mesenchymal transition（ EMT） of lung adenocarcinoma and provide a theoretical and experimental basis for the prevention of invasion and metastasis of lung adenocarcinoma. The results of Western blotting showed that the protein level of ELMO1 in the normal lung epithelial cell line BEAS-2Bwas low,but it was high in the lung adenocarcinoma cell line A549. Using siRNA targeting ELMO1,the protein levels of ELMO1 in A549 cells were significantly decreased. The results of chemotaxis assays showed that A549 cells had the strongest chemotactic ability when stimulated with 100 ng/m L IL-8 for 24 hours. Above or below that concentration,the chemotactic ability of the cells would decrease. After stimulating with IL-8 for 24 hours,the Matrigel invasion assay showed that the invasion and metastasis ability of si ELMO1 treated A549 cells were significantly lower than control. Control or si ELMO1 treated A549 cells were mock incubated,or incubated with IL-8,or with IL-8 and the inhibitor BAY11-7082.Western blotting results showed that in the si ELMO1 treated cells,the protein levels of E-cadherin were up-regulated, vimentin were down-regulated, and both p-IκBα and nuclear snail decreased. In summary,ELMO1 may affect the nuclear translocation of snail through the NF-κB signaling pathway,thus promoting the EMT of A549 cells.