电离辐射致K562细胞旁效应的实验研究

Experimental study on bystander effects K562 cells induced by ionizing radiation

目的研究^60Coγ线不同剂量照射条件培养液（ICM）培养K562细胞后引发的旁效应。方法采用健康男性外周血自然杀伤（NK）细胞，观察不同剂量^60Coγ线照射的条件培养液培养后引发的K562细胞对NK细胞敏感性的改变，同时用流式细胞仪检测K562细胞的凋亡情况。结果照射组NK细胞活性显著增加，即受照肿瘤细胞的培养基显著影响了未受照肿瘤细胞的存活能力，从而NK细胞对未照射细胞的活性显著增加；其中，从0．5Gy起即出现显著升高，1．0Gy继续增加，2．0和5．0Gy出现波动，在8．5Gy达到最高。照射组K562细胞的凋亡率比对照组显著增加（P〈0．01），即受照肿瘤细胞的培养基显著影响了未受照肿瘤细胞的存活能力。在0．5Gy处，即出现非常明显的效应。结论对于K562细胞，ICM对细胞显示出明显损伤作用，NK细胞活性显著增加，凋亡率升高。提示存在培养基转移介导的电离辐射旁效应。

Objective To study the bystander effects and associated mechanisms through irradiated conditioned medium（ICM） . Methods Natural killer（NK） cells were obtained from peripheral blood samples. ICM irradiated with different doses of ^60Coγ-rays was used for culturing K562 cell strain. The degree of injury of K562 cells by activated NK cells was observed, as well as the apoptosis frequency of K562 cell was investigated. Results Severe injury was induced in K562 cells cultured in ICM than the control （sham-irradiated） as shown by increased sensitivity to NK cells （ P 〈 0.05） . The apoptosis frequency of K562 cell was increased significantly compared with the control cells （ P 〈 0.05 ） . Conclusions The bystander effect induced by irradiation is existent. ICM can trigger the bystander effect on K562 cell strains.