摘要
目的研究重组人血管内皮抑制素(恩度)改善乏氧、增强肺腺癌细胞系A549的放射敏感性效果。方法①在常氧和乏氧培养下,以不同浓度的恩度与A549细胞分别处理不同的时间,用MTT法分别选择生长抑制率为20%的药物浓度(IC20);②将A549细胞分别在常氧和乏氧培养下分为对照组和恩度组,加药培养24 h后,分别给予高能X线0、2、4、6、8 Gy剂量照射。集落形成率实验检测各组在不同条件下的细胞存活分数,根据多靶单击模型拟合细胞存活曲线,求出各组的平均致死剂量(D0)、准域剂量(Dq)、外推数N、照射2 Gy时的细胞存活率(SF2)、放射增敏比(SER);③将A549细胞分别在常氧和乏氧培养下,分成对照组、单放组、恩度组和联合组。4组分别处理24 h后,通过流式细胞仪对各组凋亡细胞进行定量检测,得出各组的凋亡率。结果①恩度可以抑制常氧和乏氧培养下的A549细胞的生长,且呈时间-剂量依赖性,IC20分别是(330.34±4.18)mg/L和(437.23±3.32)mg/L;②在多靶单击模型中,在常氧下对照组和恩度组的D0值分别是1.36、1.30,Dq值分别是1.02、1.02;在乏氧培养下对照组和恩度组的D0值分别是1.70、1.39,Dq值分别是2.45、1.03。常氧和乏氧组恩度的SER分别为1.04和1.22;③在常氧培养下,对照组、单放组、恩度组和联合组的凋亡率分别为(15.91±0.57)%、(42.70±0.37)%、(19.90±0.48)%、(41.52±0.38)%,联合组和单放组比较,差异无统计学意义(F=1.22,P=0.479);在乏氧培养下4组的凋亡率分别为(16.72±0.67)%、(30.11±0.95)%、(26.71±0.62)%、(36.34±0.71)%,联合组和单放组比较,差异有统计学意义(F=3.34,P=0.036)。结论恩度在常氧培养下没有放射增敏作用,细胞凋亡率没有明显增加;而在乏氧培养下能提高A549的放射敏感性,而且细胞凋亡率明显增加。
Objective To observe the effects of recombinant human endostatin（endostar） on the radio-sensitivity of human pulmonary adenocarcinoma cell line A549.Methods ①A549 cells were incubated with endostar of various concentrations for different durations under normoxia and hypoxia.The IC20 of endostar was determined by MTT assay.②A549 cells were divided into the control group and the endostar group under normoxia and hypoxia.In the endostar group,A549 cells were incubated with endostar for 24 h,and then the two groups underwent high-energy X-ray irradiation with various doses of 0,2,4,6 and 8 Gy.The survival fraction of A549 cells in each group under different conditions was detected by clonogenic assay,and the mean lethal dose（D0）,quasi-threshold dose（Dq）,extrapolation number（N）,survival fraction at irradiation dose of 2 Gy（SF2） and sensitization enhancement ratio（SER） were calculated based on cell survival curves of single-hit multi-target（SHMT） models.③After being incubated for 24 h under normaxia and hypoxia,A549 cells were divided into the control group,radiotherapy only group,endostar group and combination group（endostar combined with radiotherapy）.The apoptotic A549 cells in each group were determined with flow cytometry.Results ①Endostatin can inhibit the growth of A549 cells under normoxic and hypoxic culture conditions,and showed time-and dose-dependence,with IC20 of（330.34±4.18） mg/L and（437.23±3.32） mg/L,respectively.②In SHMT models,the D0 and Dq values in the control and endostar groups were（1.36 and 1.30） vs（1.02 and 1.02） under normoxia and（1.70 and 1.39） vs（2.45 and 1.03） under hypoxia,respectively.SER was 1.04 under normoxia and 1.22 under hypoxia in the endostar group.③Under normoxia,the apoptosis rates in the control group,radiotherapy group,endostar group and combination group were（15.91±0.57）%,（42.70±0.37）%,（19.90±0.48）% and（41.52±0.38）%,respectively,and there was no significant difference（F=1.22,P=0.479） between combination and radiotherapy groups.Under hypoxia,the apoptosis rates in the four groups were（16.72±0.67）%,（30.11±0.95）%,（26.71±0.62）% and（36.34±0.71）%,respectively,and the difference between combination group and radiotherapy group was significant（F=3.34,P=0.036）.Conclusion Under normoxia,endostar has no radio-sensitizing effects without a significantly increased apoptosis rate.Under hypoxia,endostar can enhance the radio-sensitivity of A549 cells with a significantly increased apoptosis rate.
出处
《山东大学学报（医学版）》
CAS
北大核心
2011年第12期5-9,共5页
Journal of Shandong University:Health Sciences
基金
江苏省自然科学基金面上项目(bk2009167)
