125Ⅰ粒子对体外培养的A549细胞系和人胚肺二倍体细胞系2BS细胞生长的影响及临床安全使用剂量评估

目的：观察不同剂量¹²⁵I粒子照射A549细胞系及人胚肺二倍体细胞系2BS后细胞计数的变化，探讨¹²⁵I粒子对此2种细胞生长的抑制作用，确定125I粒子治疗非小细胞肺癌的临床安全剂量。方法： 体外培养的A549细胞系及人胚肺二倍体细胞系2BS，分别置入低、中、高剂量(0.2、0.4和0.8 mCi）125I粒子，同时设立阴性对照组（无粒子）及空白组（空粒子），于照射后第2、4、6和8天收集细胞，通过细胞排染实验计数存活细胞，分别绘制细胞生长曲线并计算¹²⁵I粒子对2种细胞系的半数抑制浓度（IC₅₀）。 结果： 与空白组和对照组比较，低剂量组A549细胞增殖趋势未受明显影响（P＞0.05）；中、高剂量组A549细胞生长受到显著抑制，并呈时间依赖性，于第6天时最明显，与阴性对照组及空白组比较差异有统计学意义(P＜0. 05) ；125I粒子对A549细胞的IC50值约为0.4 mCi。各剂量组¹²⁵I粒子对2BS细胞生长的抑制作用比较差异无统计学意义（P＞0.05），¹²⁵I粒子对2BS细胞的IC50值约为1.65 mCi。 结论：放射性¹²⁵I粒子的活度为0.4 mCi时已对A549细胞具有明显的杀伤效应，0.8 mCi时杀伤效应更强。放射性125I粒子对2BS细胞的IC50值为1.65 mCi，故临床安全使用剂量应为0.4～0.8 mCi。

Effects of radioactive 125I seeds on A549 cell line and human embryonic lung diploid cell line 2BS cultivated in vitro and assessment of its clinical safety dose

Objective To observe the cell count changes of A549 cell line and human embryonic lung diploid cell line 2BS after irradiated by 125I seeds with different doses,and to study the growth inhibition of 125I on this two kinds of cell lines,and to determine its clinical safety dose in treatment of non-small cell lung.Methods 125I seeds with different doses(low dose:0.2 mCi,mediate dose:0.4 mCi,high dose:0.8 mCi)were chosen and put into A549 cells and human embryonic lung diploid cell line 2BS in vitro,the cells on the 2nd,4th,6th and 8th days after irradiation were collected,the alive cells were counted by cells dyeing experiments,then the growth curves were drawn,and the IC50 of the radioactive 125I seeds to both two cell lines were calculated.Results Compared with blank and control groups,the cell proliferation trend of A549 cells in low dose group was not significantly influenced(P>0.05),but the growth of A549 cells in mediate and high dose groups were inhibited in a time-dependent manner,there were significant differences(P<0.05),the most obvious change was on the 6th day.The IC50 of the radioactive 125I seeds to A549 cells was about 0.4 mCi.While the growth inhibition of 125I 2BS had no statistically significant differences between various dose groups(P>0.05),and the IC50 of the radioactive 125I seeds to 2BS cell line was about 1.65 mCi.Conclusion 0.4 mCi of radioactive 125I seeds has already had the obvious damage effect on A549 cells,0.8 mCi of radioactive 125I seeds has the stronger effect.The IC50 of the radioactive 125I seeds to 2BS cells is about 1.65 mCi,so the clinical safety dosage is 0.4-0.8 mCi.