Department of Thoracic & Cardiovascular Surgery, Lihuili Hospital, Ningbo Medical Center, Affiliated Hospital of Medical School, Ningbo University, Ningbo 315041, China.
J Zhejiang Univ Sci B. 2013 Jun;14(6):460-7. doi: 10.1631/jzus.B1200200.
Epithelial-mesenchymal transition (EMT) is believed to be the critical process in malignant tumor invasion and metastases, and has a great influence on improving the survival rate in non-small-cell lung cancer (NSCLC) patients. Recent studies suggested that eukaryotic initiation factor 5A-2 (eIF5A-2) might serve as an adverse prognostic marker of survival. We detected eIF5A-2 in NSCLC A549 cells, and found that the invasive capability correlates with the eIF5A-2 expression.
Transforming growth factor (TGF)-β1 was used to induce EMT in A549 cells. Western blotting, immunofluorescence, wound healing assay, and transwell-matrigel invasion chambers were used to identify phenotype changes. Western blotting was also used to observe changes of the expression of eIF5A-2. We down-regulated the eIF5A-2 expression using an eIF5A-2 siRNA and identified the phenotype changes by western blotting and immunofluorescence. We tested the change of migration and invasion capabilities of A549 cells by the wound healing assay and transwell-matrigel invasion chambers.
After stimulating with TGF-β1, almost all A549 cells changed to the mesenchymal phenotype and acquired more migration and invasion capabilities. These cells also had higher eIF5A-2 protein expression. Down-regulation of eIF5A-2 expression with eIF5A-2 siRNA transfection could change the cells from mesenchymal to epithelial phenotype and decrease tumor cell migration and invasive capabilities significantly.
The expression of eIF5A-2 was up-regulated following EMT phenotype changes in A549 cells, which correlated with enhanced tumor invasion and metastatic capabilities. Furthermore, in the A549 cell line, the process of EMT phenotype change could be reversed by eIF5A-2 siRNA, with a consequent weakening of both invasive and metastatic capabilities.
上皮-间充质转化（EMT）被认为是恶性肿瘤侵袭和转移的关键过程，对提高非小细胞肺癌（NSCLC）患者的生存率有很大影响。最近的研究表明，真核起始因子 5A-2（eIF5A-2）可能是生存的不良预后标志物。我们在 NSCLC A549 细胞中检测到 eIF5A-2，发现侵袭能力与 eIF5A-2 的表达相关。
用转化生长因子（TGF）-β1 诱导 A549 细胞发生 EMT。用 Western blot、免疫荧光、划痕愈合实验和 Transwell 小室侵袭实验来鉴定表型变化。Western blot 还用于观察 eIF5A-2 表达的变化。我们用 eIF5A-2 siRNA 下调 eIF5A-2 的表达，并用 Western blot 和免疫荧光鉴定表型变化。我们用划痕愈合实验和 Transwell 小室侵袭实验来检测 A549 细胞迁移和侵袭能力的变化。
用 TGF-β1 刺激后，A549 细胞几乎全部转变为间充质表型，获得了更强的迁移和侵袭能力。这些细胞的 eIF5A-2 蛋白表达也更高。用 eIF5A-2 siRNA 转染下调 eIF5A-2 表达后，细胞从间充质表型转变为上皮表型，肿瘤细胞迁移和侵袭能力显著下降。
在 A549 细胞中，EMT 表型改变后 eIF5A-2 的表达上调，与增强的肿瘤侵袭和转移能力相关。此外，在 A549 细胞系中，eIF5A-2 siRNA 可逆转 EMT 表型改变过程，导致侵袭和转移能力减弱。
