^(60)Co辐照肿瘤细胞对未照射细胞的旁观者效应及Trolox的干预作用

The Bystander Effects of ^(60)Co-γ Irradiated Osteogenic Sarcoma Cells on Nonirradiated Cells and the Intervention of Trolox

背景与目的:用经60Co-γ射线照射过的骨肉瘤U2OS细胞和未经照射的骨肉瘤U2OS细胞混合培养,在出现未受到照射肿瘤细胞的旁观者效应基础上,观察抗氧化剂Trolox的干预作用。材料与方法:骨肉瘤U2OS细胞分为对照组、照射组、效应组、干预组和Trolox阴性对照组,每组做5个平行样。照射组:U2OS细胞用3Gy剂量的60Co照射后继续培养;效应组:将照射过的细胞换液、继续培养1h后用胰酶消化分离并收获细胞,然后将照射与未照射细胞按1∶1的数量比混合培养;干预组:与效应组细胞的其它处理相同,仅在培养基中加入Trolox(终浓度10μg/ml)进行干预;Trolox阴性对照组:在未放射细胞的培养基中加人相同剂量Trolox。在上述各组培养的不同时段收集细胞,分别采用MTT法测定细胞的活性,计数法计算各组细胞克隆形成率和微核率,台盼蓝染色法测定各组存活细胞的百分率、化学荧光法测定各组细胞培养基中的MDA含量。结果:效应组与对照组相比,细胞的存活率下降(P<0.05),细胞的活性降低(P<0.05),细胞克隆形成率下降(P<0.05),细胞微核率和含量均明显的升高(P<0.05),培养基中的MDA含量明显增高(P<0.05)。经过Trolox干涉后,干预组细胞上述各项指标较效应组有明显的改善(P<0.05)。结论:Trolox作为一种抗氧化剂具有缓解60Co-γ射线照射所致旁观者效应的作用。

BACKGROUND AND AIM： Coculture of 60Co-γ irradiated and nonirradiated osteogenic sarcoma U20S cells was examined for the bystander effects and the interfering effects of Trolox. MATERIALS AND METHODS： groups with 5 samples each： control group, irradiated group, effect group and intervention group, the Trolox control group. In the irradiated group, U20S cells were treated with ~Co -7 at the dose of 3 Gy and then cultured. In the effect group, after the medium of the irradiated cells was changed, and kept for 1 h, cells with digested with trypsin and collected. After that, the irradiated and nonirradiated cells were co-cultured in the ratio of 1 ： 1. The intervention group was treated the same as the effect group except the addition of Tmlox （10 μg/ml final concentration） . At different time points, cells from the five groups were collected. The cell activity was determined by MTI＇; the colony formation efficiency and micronucleus frequency were assessed by counting method; the survival rates were estimated by Trypan Blue Staining; and the MDA content in the culture medium was determined by chemical fluorometric method. RESULTS： Compared with the control group, cells in the irradiated group exhibited decreased survival rate （P〈 0.05）, suppressed cell activity （P〈0.05）, decrease in colony formation efficiency （P〈0.05）, increase in micronucleus frequency （P〈0.05） and increase in MDA content in the culture medium（P 〈 0.05） With the intervention of Trolox, exhibitions of the above indexes were greatly improved. CONCLUSION： Trolox could suppress the bystander and other effects as an antioxidant.