X射线对人外周全血细胞nm23-H1基因表达的影响

Changes of nm23-H1 gene expression in human peripheral blood cell after X-ray irradiation

目的应用实时荧光定量反转录PCR的方法，分析不同剂量X射线对人外周全血细胞nm23-H1基因表达的影响，探讨运用nm23．H1基因表达变化作为电离辐射生物剂量计的可行性。方法采用X射线照射人外周全血细胞，于不同剂量（0～5Gy）照射后不同时间点（0、6、12和24h）收集细胞提取总RNA，并反转录为eDNA，利用实时定量PCR检测不同剂量照射后nm23-H1基因表达变化，分析其剂量-效应关系及时间-效应变化。结果照后0h，各剂量组之间nm23-H1基因表达变化差异无统计学意义（F=0．478，P〉0．05），照后6h，在1～3Gy照射剂量范围内，nm23-H1基因表达水平随剂量增加有增高的趋势（F=15．064，P〈0．05），照后12h，在1—5Gy照射剂量范围内，nm23-H1基因表达水平随剂量增加而增高（F=3．435，P〈0．05）；照后24h，各剂量组之间差异无统计学意义（F=0．444，P〉0．05）。0、4和5Gy照射后，nm23-H1基因表达水平随时间的推移降低（F=8．636、4．112、5．411，P〈0．05）；1Gy照射后，不同时间点nm23-H1基因表达水平差异无统计学意义，仅12h的nm23-H1基因表达水平与0h的表达水平差异有统计学意义（t=-2．527，P〈0．05）；2和3Gy剂量照射后，nm23-H1基因表达水平均于24h时降至最低点（F=12．517、6．622，P〈0．05）。结论电离辐射可诱导人外周血nm23-H1基因的表达改变，该基因的表达变化具有作为电离辐射生物剂量计应用于核辐射事故早期生物剂量估算的潜能。

Objective To investigate the expression change of nm23-H1 gene in human peripheral blood cells exposed to ionizing irradiation, and explore the feasibility of nm23-H1 gene expression changes as a biodosimeter. Methods Human peripheral whole blood samples were collected from four healthy individuals, and exposed to X-rays with the doses between 0 and 5 Gy. The total mRNAs were isolated from the white-blood cells, and the changes of nm23-H1 gene mRNA expression postirradiation were detected by real-time RT-PCR at 0, 6, 12 and 24 h, respectively. Results The levels of nm23-H1 gene expression in human peripheral blood cells increased gradually with the doses from 1 to 3 Gy at 6 h （F=15.064, P〈0.05）, and from 1 to 5 Gy at 12 h （F =3.435, P〈0.05） after irradiation. However, gene expression levels at 0 and 24 h were not significantly different between various groups（ F = 0. 478,0. 444, P 〉 0.05）. The time-effect curve showed that the expression of nm23-Hi gene decreased with the doses of 0, 4 and 5 Gy after irradiation （F=8.636,4.112,5.411, P〈0.05）. Meanwhile, the expression of nm23-H1 gene showed the difference only at 12 h with 1 Gy irradiation（t = -2. 527, P 〈 0.05） and was the lowest at 24 h with 2 and 3 Gy irradiation （F = 12. 517,6. 622, P 〈 0.05）. Conclusions The expression change of nm23-H1 gene could he induced by X-ray in human peripheral blood cells, and might be a potential biodosimeter candidate applicable in early-response radiation accident victims.