X线电离辐射诱导人鼻咽癌CNE-2细胞发生上皮-间充质转化及其潜在机制

X-ray ionizing radiation induces epithelial-mesenchymal transition in human nasopharyngeal carcinoma CNE-2 cells

目的:探讨X线电离辐射诱导鼻咽癌CNE-2细胞发生上皮-间充质转化(epithelial-mesenchymal transition,EMT)及其可能的信号通路。方法:分别采用0 Gy、2 Gy、4 Gy和8 Gy的X线照射鼻咽癌CNE-2细胞,通过倒置显微镜观察照射24 h后细胞形态的改变;应用细胞划痕实验和Transwell实验观察细胞迁移和侵袭能力的变化;分别采用real-time PCR和Western blot法检测EMT相关蛋白E-钙黏蛋白(E-cadherin)、N-钙黏蛋白(N-cadherin)和波形蛋白(vimentin)mRNA及蛋白水平的变化,并采用Western blot法检测Akt和p-Akt蛋白水平的变化。结果:经X线照射后鼻咽癌CNE-2细胞呈典型的"鹅卵石"样或纺锤形,且伸出伪足,细胞间隙增大,细胞的侵袭和迁移能力增强(P<0.01);real-time PCR和Western blot法检测结果显示,与未照射组相比,各照射组细胞中E-cadherin mRNA和蛋白的表达水平均显著下调(P<0.01),而N-cadherin和vimentin mRNA和蛋白的表达水平明显上调(P<0.05);PI3K/Akt信号通路中p-Akt蛋白的水平显著升高(P<0.01),而Akt的表达无明显变化。结论:X线电离辐射能够诱导鼻咽癌CNE-2细胞发生EMT,其机制可能与PI3K/Akt信号通路的激活有关。

AIM： To investigate the effect of X-ray ionizing radiation on epithelial-mesenchymal transition（ EMT） in human nasopharyngeal carcinoma CNE-2 cells and its involved potential signaling pathway. METHODS： The nasopharyngeal carcinoma CNE-2 cells were irradiated with different doses（ 0 Gy,2 Gy,4 Gy and 8 Gy） of X-ray. The morphological changes of the cells were observed under inverted microscope after 24 h. The migration and invasion abilities were detected by wound healing and Transwell assays. The mRNA and protein levels of E-cadherin,N-cadherin and vimentin in nasopharyngeal carcinoma CNE-2 cells were determined by real-time PCR and Western blot,respectively. The protein levels of Akt and p-Akt were detected by Western blot. RESULTS： After X-ray irradiation,the CNE-2 cells exhibited typical ‘cobblestone＇or spindle-like shape,with extended pseudopodia and dilated intercellular space. The invasiveness and metastatic abilities of the CNE-2 cells were enhanced（ P〈0. 01）. The mRNA and protein expression levels of E-cadherin were significantly decreased（ P〈0. 01）,while the mRNA and protein expression levels of N-cadherin and vimentin were markedly increased after irradiation as compared with the control group（ no irradiation）（ P〈0. 05）. The protein level of p-Akt was significantly enhanced（ P〈0. 01）,while the protein level of Akt showed little change after irradiation.CONCLUSION： X-ray ionizing radiation induces EMT in nasopharyngeal carcinoma CNE-2 cells,which may be related to the activation of PI3 K/Akt signaling pathway.