中文摘要：

目的 探讨电离辐射联合自噬抑制剂、诱导剂和凋亡抑制剂对MCF7细胞自噬和凋亡的影响.方法 MCF7细胞经0 Gy、4 Gy、4 Gy ＋ rapamycin、4 Gy ＋ 3-MA、4 Gy ＋ z-VAD-fmk不同方法处理后,采用四甲基偶氮唑蓝（MTT）检测细胞的生长倍增时间;采用Western blot检测MCF7细胞经不同方法处理后自噬特异蛋白LC3和beclin1的表达,并比较蛋白表达量的差异;流式细胞仪（FCM）检测不同处理方法MCF7细胞凋亡百分率.结果 经4 Gy照射后,MCF7细胞生长倍增时间明显长于未经照射的细胞生长倍增时间（t=4.41,P〈0.05）;而4 Gy ＋ rapamycin处理后,明显长于单纯4 Gy照射组（t=4.35,P〈0.05）;经4 Gy ＋ 3-MA和4 Gy ＋ z-VAD-fmk处理后,均明显短于4 Gy＋rapamycin组（t=4.32,P〈0.05）.Western blot检测结果表明,Beclinl和LC3-Ⅱ蛋白表达4 Gy＋rapamycin组为最高,4 Gy＋3-MA组为最低,除4 Gy＋3-MA组与4 Gy＋z-VAD-fmk组比较差异无统计学意义外,其余各处理组问比较差异有统计学意义（t=3.91～4.78,P〈0.05）.结论 电离辐射联合自噬诱导剂可促进MCF7细胞凋亡;联合自噬抑制剂抑制自噬发生,进而延缓肿瘤细胞凋亡.

英文摘要：

Objective To detect the inhibiting effects of ionizing radiation combined with inhibitors or inducer of autophagy and apoptosis on MCF7 cell line,and to provide the evidence for human breast cancer therapy radiation.Methods MCF7 cells were exposed to X-rays and randomly divided into 4 groups,including 0 Gy,4 Gy,4 Gy＋rapamycin,4 Gy＋3-MA,and 4 Gy＋z-VAD-fmk groups,including 0 Gy,4 Gy,4 Gy＋rapamycin,4 Gy＋3-MA,and 4 Gy＋z-VAD-fmk groups,respectively.The growth doubling time was calculated by MTT method.The specific protein expressions of LC3 autophagy and beclinl were detected by using Western blot and the difference of Drotein contents was LC3 autophagy and beclinl were detected by using Western blot and the difference of Drotein contents was compared.The percentage of apoptosis of MCF7 cells was measured by flow cytometry （FCM）.Resuits The growth doubling time of MCF7 cells in 4 Gy group wag longer than that in O Gy group（t=4.41,P〈O.05）,but shorter than that in 4 Gy＋rapamycin group（t=4.35,P〈0.05）.Compared to 4 Gy＋rapamycin group,both of the growth doubling time in 4 Gy＋3-MA and 4 Gy＋z-VAD-fmk groups were shorter（t=4.32,P〈O.05）.The expressions of beclinl and LC3-Ⅱ proteins in 4 Gy＋rapamycin group were the highest,while those in 4 Gy＋3-MA group the lowest.Except for 4 Gy＋3-MA and 4 Gv＋z-VAD-fmk groups,there were significant differences among the other groups in two protein expressions（t=3.9 1-4.78,P〈0.05）.Conclusions Ionizing radiation could induce MCF7 cell autophagy,ptomote the apoptosis of tumor ceils in combination with autophagy inducer.Ionizing radiation combined with autophagy inhibitor might inhibit the development of autophagy,and delay the apoptosis of tumor cells.