^60Coγ射线照射后人正常肝细胞子代的基因差异表达

Differential expression profile in the progeny of normal human liver cells irradiated by γ-rays

目的探讨经不同剂量^60Coγ射线照射人正常肝细胞后克隆子代基因表达图谱变化，并对部分差异表达基因进行验证。方法人正常肝细胞7702分别经2、4和6Gy^60Coγ射线照射后，存活细胞克隆继续传代培养至15代，提取细胞总RNA，采用Illumina人全基因组基因芯片分析基因表达情况，并筛选出差异表达基因。用实时荧光定量PCR技术验证差异基因HAVGR2、RAN的表达。结果与对照组相比，2Gy照射后子代细胞差异表达显著的基因有262个；4Gy照射组有2746个差异表达基因；6Gy照射组有3406个差异表达基因；3个剂量组的共同差异表达基因有71个，其中上调基因35个，下调基因36个。这些基因的功能涉及细胞周期、细胞骨架和运动、细胞凋亡、DNA结合、细胞信号转导、代谢、DNA复制和修复等。其中，RAN、CDTl、RAD51APl等基因在受照肝细胞子代中均显示出特征性的差异表达，RT—PCR检测结果与基因芯片结果一致。结论电离辐射可诱发7702细胞子代中一系列基因表达的改变，提示基因组不稳定性涉及复杂的调控机制。

Objective To investigate the differential expression profile in the progeny of human liver ceils surviving from ionizing radiation. Methods Complemental DNA gene chip was used to measure the transcriptional profile in progeny of HL-7702 cells exposed to 0, 2, 4, and 6 Gy of ^60Coγ-rays, and the differentially expressed genes HAVCR2 and RAN were further identified by real-time PCR. Results The transcription level of 262 genes, 2746 genes and 3406 genes changed in the progeny of survival cells at 2, 4 and 6 Gy, respectively. A total of 71 common differentially expressed genes were screened, most of which were associated with transduetion, cell cycle regulation, cellular immunity, cytoskeleton and movement, cell replication and repair mechanism. Conclusions Ionizing radiation could induce the expression changes of many genes, which might reveal the molecular mechanisms of gene expression in radiation induced genomie instability.