中文摘要：

目的 研究自噬在照射致人食管鳞癌Eca-109细胞死亡过程中的作用.方法 选用食管鳞癌Eca-109细胞,分为对照组、5 mmol/L给药组、10 mmol/L给药组、单纯照射组、照射＋5 mmol/L组、照射＋10 mmol/L组,共6组.采用Western blot检测不同处理组自噬标志物LC3B表达水平;GFP-LC3转染食管鳞癌Eca-109细胞后监测自噬体数量变化;MTT法检测不同处理组细胞活力;荧光染料Hoechst 33342观察不同处理组细胞凋亡的形态学变化;流式细胞术检测不同处理组细胞周期和细胞凋亡;克隆形成实验检测食管鳞癌Eca-109细胞不同处理组放射敏感性.结果 Western blot显示,照射后自噬水平升高,自噬抑制后LC3BⅡ和LC3BⅡ/LC3B Ⅰ比值明显下降（F=25.64,P＜0.05）;GFP-LC3转染食管鳞癌Eca-109细胞后,可见照射后自噬体荧光斑点明显增多,自噬抑制后自噬体明显减少（F=127.36,P＜0.05）;抑制自噬协同照射后细胞活力明显低于单纯照射组（F=129.54,P＜0.05）;抑制自噬后也增加了照射诱导的凋亡率和G2/M期阻滞细胞比;线性二次模型拟合剂量存活曲线显示,抑制自噬能增加食管鳞癌Eca-109细胞的放射敏感性.结论 抑制自噬能提高食管鳞癌Eca-109细胞的放射敏感性,协同杀伤肿瘤细胞,提示抑制自噬或可用于辅助食管鳞癌的放射治疗.

英文摘要：

Objective To investigate the role of autophagy in radiation-induced death process of human esophageal squamous carcinoma Eca-109 cells.Methods Esophageal carcinoma cell line Eca-109 was divided into 6 groups of control,5 mmol/L 3-Methyladenine treatment,10 mmol/L treatment,6 Gy irradiation,irradiation ＋ 5 mmol/L drug,and irradiation ＋ 10 mmol/L drug.Some cells were transferred with GFP-LC3 plasmid and the changes of autophagosome were obserred.After each treatment,the expression of autophagy marker LC3B was measured by Western Blot,cell viability was detected by MTT,morphological characteristics of apoptosis cells were stained with a fluorescein of Hoechst 33342 and the percentage of apoptotic cells and cell cycle distribution were measured by flow cytometry.Clonogenic survival were used to evaluate the cell radiosensitivity.Results Autophagy level was increased after radiation,and the LC3B Ⅱ expression and LC3B Ⅱ/LC3B Ⅰ ratio were significantly decreased by autophagy inhibitor 3-Methyladenine （F =25.64,P 〈 0.05）.The number of autophagosome fluorescent foci were significantly increased in the GFP-LC3 transfected cells after radiation,but reduced by 3-Methyladenine （F =127.36,P 〈 0.05）.Compared with radiation alone group,autophagy inhibition combined with radiation significantly decreased cell viability （F =129.54,P 〈 0.05） and colony formation,increased apoptosis and the percentage of G2/M-phase cells.Conclusions 3-Methyladenine enhances the radiosensitivity of esophageal squamous carcinoma Eca-109 cells,suggesting that inhibition of autophagy could be used as an adjuvant treatment of radiotherapy in esophageal squamous carcinoma.