POLH mRNA作为辐射损伤分子生物标志物的可行性研究

Feasibility study on expression of POLH mRNA as a molecular biomarker for radiation injury

目的:研究受γ射线照射后人外周血中POLH mRNA的表达变化,为确立POLH mRNA作为新的辐射损伤分子生物标志物提供实验依据。方法:采取3名健康成人的外周血,利用^(60)Coγ放射源分别对其进行0.5、1、2、4、6、10 Gy照射,在照射后2、4、8、12和24 h收集各个剂量组受试者全血,提取总RNA,利用TaqMan探针实时定量PCR法,检测POLH mRNA的相对表达量。另收集30名不同年龄段(男女各占一半)的健康人外周血作为本底组,检测POLH mRNA在不同个体间的表达差异。结果:照射后2 h,仅10 Gy照射组POLH mRNA表达增加,其余各照射组无显著变化;照射后4、8、12和24 h,在0~2 Gy范围内,POLH mRNA表达量随照射剂量的增加而增加,呈现明显的剂量依赖效应,大于2 Gy照射后增加趋势接近饱和。照射后4~12 h随时间的增加表达量也不断增加,于12 h达到峰值。在对健康人群本底表达水平的分析中发现,POLH mRNA表达水平不受性别、年龄影响,在不同个体间相对均一,波动范围小。结论:POLH mRNA可由为辐射诱导表达,在一定时间和剂量范围内呈现明显的剂量依赖关系,且在不同个体之间本底表达水平相对均一,具备作为辐射损伤分子生物标志物的潜力。

OBJECTIVE：To explore the change in expression of POLH mRNA in human peripheral blood exposed to γ-ray and provide experimental evidence for POLH mRNA to be a new molecular biomarker for radiation injury.METHODS：After radiation with dose of 0,0.5,1,2,4,6,10 Gy by ^60Co γ-rays,total RNA was extracted from peripheral blood of three healthy adults at 0,2,4,8,12,24 h post-radiation.Expression level of POLH mRNA was measured by real-time quantitative PCR.30 healthy donors＇ peripheral blood were collected as the background group to measure the expression level of POLH mRNA in different individuals.RESULTS：The expression level of POLH mRNA increased in a dose-dependent manner within the range of 0-2 Gy at 4,8,12,and 24 h after radiation,with no significant change at 2 h post-radiation.Over 2 Gy,the expression level of POLH mRNA was close to saturation.It also showed that the expression level of POLH mRNA increased in a time-dependent manner within the range of 4-12 h postradiation,a maximum response was observed at 12 h.The basal level of POLH mRNA was not affected by age and gender.CONCLUSION：POLH mRNA was induced by radiation and increased in dose-dependent and time-dependent manners.The back ground level in healthy human peripheral blood was uniform.Our results suggested that POLH mRNA may be a useful radiation biomarker.