慢分割外照射对体外培养的小细胞肺癌细胞系放射敏感性的影响

Fractioned radiation exerts influence on the radio-sensitivity of NCI-H446 cell line

目的 观察外照射前后小细胞肺癌NCI H4 4 6细胞系放射敏感性的变化以及在外照射干扰下两组细胞生长和凋亡的特点。方法 采用GWGP80型远距离60 Co治疗机对进入指数生长期的NCI H4 4 6小细胞肺癌细胞系进行分次外照射 ,每次 2Gy ,总剂量为 5 0Gy。然后 ,对未进行过外照射的NCI H4 4 6细胞 (S cell)和已完成5 0Gy外照射的NCI H4 4 6细胞 (R cell)再给予不同剂量的外照射 ,1周后计算各自的集落形成率 (PE)和存活率(S) ;另外 ,对相同数量的S cell和R cell给予同一剂量的外照射 ,于照射后的不同时间点计算细胞总数和死亡细胞百分率。结果 S cell和R cell的集落形成率分别为 4 4 .6 7%和 13.11% ,两者相比具有非常显著性差异 (P <0 .0 1) ;在分别给予 2Gy和 4Gy的外照射后 ,R cell的存活率分别为 79.6 7%和 2 3.73% ,而S cell分别为 5 1.2 4 %和19.4 0 % ,两者分别相比均具有显著性差异 (P均 <0 .0 5 )。在外照射后的相同时间点 ,两组细胞的细胞总数和死亡细胞百分率相差不大 (P >0 .0 5 )。结论 经 5 0Gy的外照射后 ,NCI H4 4 6细胞的自然生存能力明显下降 ,同时 ,其放射敏感性也有所下降 ;两组细胞在外照射的干扰下 ,其生长和凋亡的速率较为接近。

Objective To observe the radio sensitivity of NCI H446 cells before and after the fractioned radiation treatment and the characteristics of growth and death of the two kinds of cells on the condition of radiation interference.Methods Exponentially growing NCI H446 cells were exposed to 50Gy radiation administered in 25 fractions,at 2Gy per fractions.We named the cells that were given 50Gy radiation as R cell and not given the same treatment as S cell.Firstly,the two kinds of cells were administered different doses(0,2,4,6,8,10Gy) of radiation treatment again.And then we calculated the plating efficiency(PE)and the survival rate(S) respectively one week after that treatment;Secondly,we gave the same dose of radiation treatment to the same amount of cells of the two kinds.At the different time points(2,4,6,8,10days),we calculated the total survival cells and the dead cells of them.Results The plating efficiencys of S cell and R cell were 44.67% and 13.11% respectively.The difference of them was very significant( P <0.01);After given 2Gy/4Gy radiation treatment,the survival rates of R cell were 79.67% and 23.73% respectively and that of S cell were 51.24 % and 19.40% separately. The difference of them was also statistically significant( P <0.05).At the same time after radiation,the total survival cells and death rates of the two cells were almost the same.The difference of them was not obvious( P >0.05).Conclusions After 50Gy radiation treatment, the plating efficiency of NCI H446 cells decreased,but the survival rate of it increased.On the condition of radiation interference,the velocity of the growth and death of two cell lines was approximately the same.