X线照射后鼻咽癌细胞自噬与转移关系及机制初探

A preliminary study of the relationship between autophagy and metastasis of nasopharyngeal carcinoma cells after X-ray irradiation

目的 研究X线照射后鼻咽癌高低转移潜能的细胞系5-8F和6-10B自噬与转移的关系及机制初探.方法 以鼻咽癌细胞SUNE1的高转移潜能亚株5-8F和低转移潜能亚株6-10B作为研究对象,应用4 Gy X线照射细胞,5-8F应用20μmol/L的Rapamycin（自噬诱导剂）,6-10B应用10μmol/L的LY294002（自噬抑制剂）.对经X射线照射及药物处理后的鼻咽癌细胞采用qRT-PCR、蛋白印迹法、Transwell实验、激光共聚焦、透射电镜等方法检测其自噬和转移能力.结果 经X线照射后高转移细胞5-8F自噬水平比低转移细胞6-10B低.X线照射5-8F细胞后应用Rapamycin后自噬水平增高、转移能力降低,而6-10B细胞照射后应用LY294002,自噬水平降低、转移能力增高.结论高转移能力的鼻咽癌细胞5-8F的自噬水平比低移能力细胞6-10B低.抑制鼻咽癌细胞自噬能增强其转移能力,促进鼻咽癌细胞自噬可以降低其转移能力,并且与PI3K/AKT/mTOR通路有关.

Objective To investigate the relationship between autophagy and metastasis of nasopharyngeal cancer （ NPC） cell lines 5-8F and 6-10B after X-ray irradiation and the related mechanism. Methods Two substrains, 5-8F and 6-10B, of the NPC cell line SUNE1, with high and low metastatic potentials, respectively, were used in our study. After 4 Gy X-ray irradiation, 5-8F cells were treated with rapamycin （ 20 μmol/L） to induce autophagy and 6-10B cells were treated with LY294002（ 10μmol/L） to inhibit autophagy. The autophagy and metastatic activity of NPC cells were determined using qRT-PCR, Western blot, Transwell assay, laser confocal microscopy, and transmission electron microscopy. Results 5-8F cells showed a lower level of autophagy than 6-10B cells after X-ray irradiation. Rapamycin increased the autophagy and inhibited the metastasis of 5-8F cells after irradiation, while LY294002 inhibited the autophagy and increased the metastasis of 6-10B cells. Conclusions NPC 5-8F cells, which have a high metastatic potential, have a lower level of autophagy than 6-10B cells, which have a low metastatic potential. Autophagic inhibition could increase the metastatic activity of NPC cells, while autophagic activation could reduce their metastatic activity. Mechanistic analysis indicates that the PI3K/AKT/mTOR pathway is involved in this process.