低强度微波对γ射线致人早幼粒白血病HL-60细胞损伤的影响

Low Intensity Microwave Pre-exposure Alleviates Damages to HL-60 Cells Induced by γ-Rays

[目的]探讨低强度微波辐射对γ射线致人早幼粒白血病HL-60细胞的凋亡率、线粒体膜电位(mitochondrial membrane potential,MMP)和胞内游离Ca2+浓度改变的影响。[方法]将人早幼粒白血病HL-60细胞随机分为对照组、单纯微波组、单纯γ射线组和联合组(微波+γ射线)。单纯微波组和联合组给予12μW/cm2微波照射,每天1 h,连续辐照3 d;第4天给予单纯γ射线组和联合组8 Gyγ射线照射。用钙离子依赖性磷脂结合蛋白-异硫氰酸荧光素/碘化丙啶(Annexin V-FITC/PI)双标记法检测细胞凋亡率,流式细胞仪检测线粒体膜电位和胞内游离Ca2+浓度。[结果]与对照组相比,单纯γ射线组凋亡率明显增加(P<0.05);联合组凋亡率与单纯γ射线组相比显著降低(P<0.05)。与对照组相比,单纯γ射线组线粒体膜电位下降明显(P<0.05);联合组线粒体膜电位与单纯γ射线组相比显著升高(P<0.05)。与对照组相比,单纯γ射线组胞内游离Ca2+浓度明显升高(P<0.05);与单纯γ射线组相比,联合组胞内游离Ca2+浓度明显降低(P<0.05)。[结论]本实验条件下,8 Gyγ射线可以引起细胞凋亡率增加、线粒体膜电位下降和胞内游离Ca2+浓度增高,导致细胞损伤。预先900 MHz、12μW/cm2低强度微波照射能够显著减轻γ射线引起的细胞损伤,表现为细胞凋亡率减少、线粒体膜电位升高和细胞内游离Ca2+浓度降低。

[ Objective ] To explore the effects of pre-exposure to low intensity microwave on γ-rays induced changes of apoptosis rate, mitochondrial membrane potential （MMP） and intracellular Ca2＋ concentration in human promyelocytic leukemia cells （HL-60）. [ Methods]HL-60 cells were randomly divided into control group, microwave alone group, γ-rays alone group and combined exposure group. Microwave alone and combined exposure groups were exposed to 12 μW/cm2 microwaves, 1 hour a day, for 3 days. The combined exposure group and γ-rays alone group were subsequently exposed to 8 Gy 6yCoγ-rays on the 4th day. Apoptosis was detected with Annexin V-FITC/PI double labelling method. Ca2＋ concentration and MMP were detected with flow cytometry （FCM）. [ Results ] Compared with control group, apoptosis of γ-rays alone group significantly increased （P〈0.05）. Apoptosis rate of combined exposure group was statistically lower than that of γ-rays alone group （P〈 0.05）. Compared with control group, MMP of γ-rays alone group significantly decreased （P 〈 0.05）. MMP of combined exposure group was statistically higher than that of γ-rays alone group （P 〈 0.05）. Compared with control group, Ca2＋ concentration in γ-rays alone group significantly increased （P〈0.05）. Ca2＋ concentration in combined exposure group was statistically lower than that in γ-rays alone group （P〈0.05）. [ Conclusion ] Under this experimental condition, 8 Gy γ-rays increased apoptosis and Ca2＋ concentrations and decreased MMP in HL-60 cells. Pre-exposure with 900MHz, 12 μW/cm2 microwaves could significantly decrease the γ-rays damages to HL-60 cells, as evidenced by the decrease of apoptosis and Ca2＋ concentrations and the increase of MMP.