抑制PI3K/Akt提高药物对HeLa细胞放射增敏作用的研究  

On enhancing drugs effect on radiosensitivity of HeLa cells by inhibiting PI3K/Akt signal transduction

作　　者：夏曙[1] 于世英[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院肿瘤中心,武汉430030

出　　处：《中华放射肿瘤学杂志》2006年第5期419-422,共4页Chinese Journal of Radiation Oncology

摘　　要：目的通过研究抑制PI3K/Akt提高多烯紫杉醇和顺铂对HeLa细胞放射增敏作用,探讨PI3K/Akt在多烯紫杉醇和顺铂放射增敏中的机制。方法体外培养HeLa细胞,应用MTT测定多烯紫杉醇和顺铂对HeLa细胞半数抑制率(IC_(50))。应用药物(IC_(20))单独及联合LY294002作用24h后X线2、3、4、6、8Gy照射。计算细胞克隆存活分数,多靶单击模型拟合曲线并计算D_q、D_0、SF_2值和放射增敏比(SER)。应用western blot方法检测Akt和磷酸化Akt蛋白的表达。应用流式细胞仪检测细胞凋亡。结果多烯紫杉醇和顺铂能够明显提高放射引起的Akt磷酸化。多烯紫杉醇+LY294002+放射组、顺铂+LY294002+放射组SER(1．92、1．71)明显高于多烯紫杉醇+放射组、顺铂+放射组(1．41、1．37)。多烯紫杉醇+LY294002+放射组、顺铂+LY294002+放射组细胞凋亡率(12．5%、10．2%)明显高于多烯紫杉醇+放射组、顺铂+放射组(6．1%、5．1%)。结论PI3K/Akt信号转导途径的活化是多烯紫杉醇和顺铂对HeLa细胞放射增敏作用降低的重要原因,抑制PI3K/Akt能够提高多烯紫杉醇和顺铂对HeLa细胞的放射增敏作用。Objective To explore the mechanism of PI3K/Akt in radiosensitization of docetaxel and cisplatin by inhibiting PI3K/Akt pathway in HeLa cells. Methods To detect the 50% inhibition concentration（ IC50 ） of cisplatin and docetaxel in Hela cells by mono-nuclear cell direct cytotoxicity assay（MTT） in vitro. Using the IC20 of cisplatin and docetaxel in Hela cell or in association with LY294002 for 24 h, then, the cells were irradiated by X-ray with 2,3,4,6,8 Gy. The cell survival fraction was computed by clone formation. Cell survival curve was fitted by multitarget one-hit model, and Dq, Do , SF2 , sensitizing enhancing ratio（SER） was calculated. The expression of pAkt and total Akt by western blot were detected. Apoptosis was detected by flow cytometry. Results 1. Docetaxel and cisplatin improved the phosphorylation of Akt by irradiation obviously. 2. The SER of docetaxel ＋ LY294002 ＋ irradiation group （ 1.92 ） was higher than that of docetaxel ＋ irradition group（ 1.41 ）. The SER of cisplatin ＋ LY294002 ＋ irradition group（ 1.71 ） was higher than the cisplatin ＋ irradiation group（ 1.37 ）. 3. Apoptosis rate of docetaxel ＋ LY294002 ＋ irradiation and cisplatin ＋ LY294002 ＋ irradition groups（ 12.5% , 10.2% ） were higher than those of docetaxel ＋ irradition and cisplatin ＋ irradiation groups（6.1% ,5.1% ）. Conclusions PI3K/Akt signal transduction activation may be as an important reason of radiosensitization reduction of docetaxel and cisplatin in the HeLa cells. Our results show that inhibiting PI3K/Akt can improve the radiosensitization of docetaxel and cisplatin in the HeLa cells.

关 键 词：信号转导路径 药物 放射增敏 肿瘤细胞系 

分 类 号：R73-3[医药卫生—肿瘤]