^(60)Co γ射线诱导人淋巴细胞GDF15 mRNA表达水平的变化

Changes of GDF15 mRNA level in lymphoblastoid cells induced by ^(60)Co γ-rays

目的:研究电离辐射诱导正常人外周血永生化淋巴细胞株中生长分化因子15(GDF15)mRNA表达水平的变化,以期为采用基因表达指标估算电离辐射吸收剂量提供科学依据。方法:用60Coγ射线照射指数增长期的人淋巴细胞株,采用不同剂量(0～15Gy)照射,于照射后不同时间点(0～72h)收集细胞提取RNA,用实时荧光定量PCR测定GDF15 mRNA表达水平的变化。结果:除照射后12h外,其它各时间点淋巴细胞株中,照射后细胞GDF15 mRNA的表达水平均随照射剂量的增加而升高,至某一剂量达高峰后开始下降;照射后12h细胞GDF15基因表达水平在各照射剂量点均显著高于对照(0Gy)组,拟合剂量效应曲线为y=1.0469x+0.5278(R2=0.9457,P<0.05)。在不同时间点,各照射剂量组基因表达的变化规律不同。8Gy照射后,GDF15表达总体上调,照射后12h达最高。结论:电离辐射诱导的GDF15 mRNA表达水平升高与辐照剂量和时间有一定的关系。

OBJECTIVE：To investigate the changes of GDF15 mRNA expression in lymphoblastoid cells induced by ionizing radiation,in order to provide scientific evidence for gene expression as a biomarker in radiobiodosimetry. METHODS： Lymphoblastoid cells were irradiated by 60Co γ-rays with doses ranging from 0 to 15 Gy,and cultivated for different periods from 4 to 72 hours. The GDF15 mRNA levels in lymphoblastoid cells were analyzed with real-time PCR. RESULTS： After irradiation,the GDF15 mRNA level was enhanced gradually to peak at some dose,and then decreased in all time groups except the 12 h group. In the 12 h group,the GDF mRNA level increased significantly; the dose-effect fitted a linear model： y=1.046 9x＋0.527 8（R2=0.945 7,P0.05）. The changes of GDF15 mRNA levels varied at different time-points. After irradiation of 8 Gy,GDF15 mRNA level rose significantly and peaked at 12 h. CONCLUSION： The enhanced GDF15 mRNA level induced by ionizing radiation depended on the exposed dose and duration.