微波及γ射线单独或联合辐射对人神经胶质瘤细胞HSP70表达的影响

Effects of Microwave Radiation Alone and Combined with γ-ray on HSP70 Expression in Glioma SHG44 Cells

[目的]探讨微波及γ射线单独或联合照射对人神经胶质瘤细胞(SHG44细胞)热休克蛋白70(HSP70)表达的影响。[方法]SHG44细胞按是否接受γ射线照射(5Gy)分为单独微波组(M组)和射线微波联合组(IM组);两组又均以接受微波强度不同(0、2、4、6mW/cm2)分为4个亚组,即M0、M2、M4、M6亚组和IM0、IM2、IM4、IM6亚组。用四甲基偶氮唑盐(MTT)法测定细胞存活率,用western blot和RT-PCR方法检测HSP70的表达。[结果]与M0组相比,M4、M6、IM6组的细胞存活率均明显下降(P<0.05或P<0.01),尤以IM6组下降为甚;且IM6组的细胞存活率也低于单独γ射线照射组(IM0组),P<0.01。与M0组相比,各剂量M组的HSP70表达差异无统计学意义;经γ射线照射后,即各IM组的HSP70表达较M0组均明显下降(P<0.01);而与IM0组相比,各IM组的HSP70表达差异无统计学意义(P>0.05)。[结论]本实验条件下,微波和γ射线单独或联合辐射均能降低细胞存活率;γ射线照射能抑制HSP70的表达,但微波不能引起HSP70表达的明显变化。

[ Objective ] To investigate the effects of microwave radiation alone and combined with γ-ray on heat shock protein 70 （ HSP70 ） expression in glioma SHG44 cells. [ Methods ] SHG44 cell cultures were divided into simple microwave groups （ M groups ） and microwave combined with y-ray groups （ IM groups ）. The two groups were further divided into four subgroups （ M0, M2, M4, M6 subgroups and IM0, IM2, IM4, IM6 subgroups ） according to different microwave power level（ 0, 2, 4, 6 mW/cm^2 ）. Cell viability was measured with MTT assay. The levels of HSP70 mRNA and HSPY0 protein were measured with RT-PCR and western blot methods respectively. [ Results ] Compared with M0 group, cell viability in M4, M6, IM6 groups decreased significantly（ P 〈 0.05 or P 〈 0.01 ）, and was especially much lower in IM6 group. The cell viability of IM6 group was lower than γ-ray alone group（ IM0 group ）, P 〈 0.01. Compared with the M0 group, the expressions of HSP70 in M groups did not change much, but after γ-ray irradiation, the expressions in IM groups were significantly decreased （ P 〈 0.01 ）. Compared with IM0 group, the expressions of HSP70 in other IM groups changed in a non-significant way（ P 〉 0.05 ）. [ Conclusion ] Under the experimental condition, the cell viability could be depressed by both microwave and γ-ray radiation, and the expression of HSP70 was inhibited only by γ-ray irradiation.