中文摘要：

目的：研究电离辐射诱导人外周血永生化淋巴细胞株中线粒体COXⅡ基因表达水平的变化,以期为探索放射敏感生物标志物和解决放射生物学领域中快速剂量估算的难题提供科学依据。方法：采用不同剂量（0～15 Gy）~（60）Coγ射线照射指数生长期的人淋巴细胞株,于照射后不同时间点（0～72 h）收集细胞提取总RNA和总蛋白,分别用实时荧光定量PCR和Western blot方法测定COXⅡ基因表达水平的变化。结果：~（60）Coγ射线照射后的各个时间点上,COXⅡ基因在mRNA水平的变化无明显规律性。在蛋白水平上,与对照组相比,~（60）Coγ射线照射4和12 h后COXⅡ基因表达水平无显著变化（P〉0.05）,照射后24、48和72 h COXⅡ基因表达水平显著上调并且在不同范围内呈现良好的剂量-效应关系（P〈0.05）。对比相同照射时间点COXⅡ基因的mRNA和蛋白水平的表达水平变化发现,两者无必然一致的趋势,但照射后48和72 h,COXⅡ蛋白的表达水平与照射时间呈良好的线性关系。结论：~（60）Coγ射线照射后48和72 h,COXⅡ蛋白表达水平与照射时间呈良好的线性关系,可作为新的辐射损伤标志物进一步研究验证。

英文摘要：

OBJECTIVE：To investigate the changes of COXⅡgene 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 60Coγrays at doses of 0-15Gy,and then cultured for different periods of 0-72 h.The levels of COXⅡgene expression were measured by real-time PCR and Western blot.RESULTS：Real-time PCR results showed there were no significant changes in COXⅡgene expression at the transcriptional level after irradiation by 0-15 Gy 60Coγrays（P〉0.05）.While,at the translation level,COXⅡgene expression levels were significantly increased 24-72 h after being irradiated by 60Coγrays（P〈0.05）.In particular at two post-irradiation time-points,48 h and 72 h,COXⅡgene expression level correlated with radiation dose.The radiation-induced changes of COXⅡgene expression between the mRNA and protein levels in human lymphoblastoid cells were not identical.CONCLUSION：At the translation level,radiation could significantly increase COXⅡgene expression 24-72 h after irradiation in human lymphocytes,and showed good dose-response relationships at 48 h and 72 h.COXⅡhas the potential of becoming a sensitive biomarker and biodosimeter for radiation damage.