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目的探讨生长抑制和DNA损伤诱导基因45A(GADD45A)与转移抑制基因23-H1(NM23-H1)作为X射线电离辐射生物剂量计的可行性。方法采用0、1、2、3、4、5 Gy剂量(设为相应的剂量组)X射线离体照射周围血样本,分别于照射后0、6、12、24 h时间点收集细胞,采用实时定量聚合酶链式反应法检测GADD45A和NM23-H1的相对表达水平,采用两因素重复测量资料的方差分析、多元线性回归与曲线拟合分析分析2者表达情况以及单独和联合应用预测照射剂量的结果。结果不同剂量组间、不同时间点间GADD45A相对表达水平分别比较,差异均有统计学意义(P<0.01);剂量与时间之间存在交互作用(P<0.01)。不同时间点间NM23-H1相对表达水平比较,差异有统计学意义(P<0.01);不同剂量组间NM23-H1相对表达水平比较,差异无统计学意义(P>0.05);剂量与时间之间不存在交互作用(P>0.05)。照射后12和24 h,采用GADD45A相对表达水平预测照射剂量的回归模型决定系数(分别为0.198,0.393)与联合以GADD45A和NM23-H1相对表达水平预测的回归模型决定系数(分别为0.144,0.347)相近。结论电离辐射可诱导人周围血GADD45A和NM23-H1表达的改变;GADD45A和NM23-H1组合检测作为电离辐射生物剂量计的应用尚有待进一步研究。
Objective To investigate the feasibility of growth inhibition and DNA damage induced gene 45A (GADD45A) and metastasis suppressor gene 23-H1 (NM23-H1) as biological dosimeters for X-ray ionizing radiation. Methods Peripheral blood samples were irradiated with x-rays at doses of 0, 1, 2, 3, 4 and 5 Gy (set as the corresponding dose group). Cells were harvested at 0, 6, 12 and 24 h after irradiation, The relative expression levels of GADD45A and NM23-H1 were detected by real-time quantitative polymerase chain reaction. The variance analysis of two-factor repeated measurement data, multivariate linear regression and curve fitting analysis were used to analyze the expression of both and the prediction of irradiation dose alone and in combination the result of. Results The relative expression levels of GADD45A at different time points were significantly different between different dose groups (P <0.01). There was interaction between dose and time (P <0.01). The relative expression levels of NM23-H1 at different time points had statistical significance (P <0.01). There was no significant difference in the relative expression levels of NM23-H1 among different dosage groups (P> 0.05) There was no interaction between the two groups (P> 0.05). At 12 and 24 h after irradiation, the regression coefficients of the regression models determined by the relative expression levels of GADD45A (0.198, 0.393, respectively) and those determined by the relative expression levels of GADD45A and NM23-H1 were 0.144 and 0.347 )similar. Conclusion Ionizing radiation can induce changes of GADD45A and NM23-H1 expression in human peripheral blood. The combination of GADD45A and NM23-H1 as biological dosimeters for ionizing radiation remains to be further studied.