目的 探讨自噬激活剂和自噬抑制剂分别对鼻咽癌细胞CNE2放疗敏感性的影响。方法 利用RNA干扰技术使atg5基因沉默,构建自噬抑制细胞模型后,与雷帕霉素、氯喹分别处理的两组细胞一起,每天以X射线5Gy照射细胞,连续8天观察各组细胞的生长状况,并设置对照组。以MTT法及克隆集落形成法检测其细胞活力,用流式细胞仪分析其细胞周期。结果 与对照组相比,其他三组细胞存活率、克隆形成率、照射后存活率均显著降低(P<0.05);细胞周期检测除对照组外其他三组细胞集中在G0/G1期,其他两个时期比G0/G1期相对较少。结论 自噬抑制剂与激活剂和atg5沉默均能为CNE2放疗增敏,然而自噬激活剂的增敏效果好于其他,为增敏放疗提供实验依据,开辟新的放疗增敏途径。

Objective This study aimed to investigate the autophagy activators and inhibitors effects in nasopharyngeal CNE2 cells radiotherapy sensitization. Methods Atg5 gene silencing by RNA interference technology, two groups of cell autophagy inhibition were built by rapamycin and chloroquine respectively. Then 5Gy x-ray irradiation of cells was taken every day, after 8 days in a row in each group of cell growth and setting a control group. The cell viability was clonaled colony formation by MTT method assay and cell cycle by flow cytometry analysis. Results The three cell group survival rate, colony-forming rate and survival after irradiation were significantly lower (P<0.05) than the control group. Detection of cell cycle in addition to control three other groups concentrated in the G0/G1 period.That of two other periods was relatively fewer than that of the G0/G1 period. Conclusion Autophagy inhibitors, activators and atg5 silence improved the radio-sensitization to CNE2. The autophagy activator group improving the sensitivity was better than the others.This study provided evidence to sensitive radiotherapy, explored a new promising radiosensitization ways.

目的 分析乳腺癌细胞中Snail与MTDH基因的作用,明确Snail是否通过结合于MTDH的启动子区域促进乳腺癌转移。方法 克隆、转染Snail基因至乳腺癌细胞,观察过表达Snail的乳腺癌细胞中MTDHmRNA及蛋白表达的变化;再使用免疫共沉淀法检测Snail与MTDH基因的共作用。结果 转染Snail基因进入乳腺癌MDA-MB-435细胞后,转染组、空白组和对照组中MTDHmRNA的表达水平分别为1.61±0.22、1.02±0.18、0.99±0.20,转染组高于空白组和对照组,差异有统计学意义(P<0.05),而后两组表达无差异(P>0.05);Westren blot检测结果显示,Snail可促进MTDH蛋白的表达;免疫共沉淀显示,Snail与MTDH在细胞内存在相互结合作用。结论 Snail在乳腺癌细胞中可通过结合于MTDH基因的启动子区域,促进MTDHmRNA转录及相关蛋白的表达,从而导致乳腺癌转移。

Objective To investigate the function of Snail to MTDH gene in breast cancer cells. Methods We observed the changement of MTDHmRNA and protein expression in breast cancer cell line MDA-MB-435 after transfected with Snail gene. Then, we used co-immunoprecipitation to determine the domain of Snail and MTDH binding in vitro. Results After transfected with Snail gene into MDA-MB-435 cell, the expression levels of MTDHmRNA in transfection group, blank group and control group were 1.61±0.22,1.02±0.18,0.99±0.20. The level of transfection group was significantly higher than the other groups(P< 0.05). Western blot showed that the expression of MTDH protein can be promoted by Snail. Co-immunoprecipitation showed that Snail and MTDH are binding interactions in breast cancer cell line MDA-MB-43. Conclusion Snail can promote transcription and expression of MTDH in breast cancer cells by binding to the promoter region of the MTDH gene resulting in metastasis of breast cancer.