X射线诱导人外周血淋巴细胞GADD45和p21基因表达上调

应用实时荧光逆转录聚合酶链反应(RT-PCR)方法,定量分析不同剂量X射线体外照射对人外周血淋巴细胞GADD45和p21基因表达的影响,探讨了运用mRNA水平变化作为电离辐射生物剂量计的可能性。结果表明:经1、2、3、5Gy X射线照射后24h,GADD45和p21基因表达均明显上调。GADD45基因表达在1-5Gy照射剂量范围内呈指数相关。p21基因表达在1-3Gy照射剂量范围内呈线性剂量效应关系,但5.0Gy照射后,其表达不再继续增加。结果表明,X射线照射后人外周血淋巴细胞GADD45和p21基因的表达在一定剂量范围内呈剂量依赖性上调,GADD45更适合发展为核事故受照射人员的分子生物剂量计。

GADD45 and p21 gene expression up regulated by X-ray in human peripheral blood lymphocytes

SYBR real time RT-PCR method was applied to study the expression profiles of the Growth Arrest and DNA Damage gene 45(GADD45) and p21 induced by X-rays in human peripheral blood lymphocytes in vivo. Results show that GADD45 and p21 gene expressions in human PBLs at 24h after 1, 2, 3, 5Gy X-ray irradiation were increased significantly. A linear dose response relationship could be established for the GADD45 gene expression over the dose range from 1.0Gy to 5.0Gy and for the p21 gene expression over the dose range from 1.0Gy to 3.0Gy 24h after X-ray irradiation respectively. Results suggest that the relative level of the GADD45 and p21 gene expression in human PBLs is dose dependent under the experimental conditions, indicating that the GADD45 gene may serve as a potential biological dosimeter in future radiation accident dose assessment.