中文摘要：

目的利用基因芯片筛选榄香烯乳增加肺腺癌A549细胞放射敏感性的相关基因。方法MTT法检测榄香烯乳对A549细胞的生长抑制效应，求得IC50值；克隆形成实验检测榄香烯乳对肺腺癌A549细胞放射增敏作用；实验分为照射组及榄香烯乳联合照射组，寡核苷酸基因芯片筛选两组细胞的差异表达基因；RT—PCR法对差异表达基因进行验证。结果榄香烯乳对A549细胞24h的IC50值为120mg／L；10mg／L榄香烯乳对A549细胞有放射增敏作用，放射增敏比SERoo、SERDn。为1．54±0．20和1．43±0．15。基因芯片共检测出差异表达基因122个，上调基因89个，下调基因33个，其功能参与维持细胞结构、细胞代谢、增殖分化、信号传导、物质转运、细胞凋亡、DNA修复和免疫应答等。RT-PER结果：上调基因Egr-1及下调基因CyclinD1表达与基因芯片结果一致。结论榄香烯乳对肺腺癌A549细胞的放射增敏作用机制是多基因参与、协同作用的结果，对于新发现的差异基因的进一步研究，将有助于发现榄香烯乳对肺癌A549细胞放射增敏的新靶点。

英文摘要：

Objective To screen radiosensitizing-related genes mediated by elemene in lung adenocarcinoma A549 cells by using gene chip. Methods MTT test was used to calculate the IC50 of elemene. （1）The effect of radiosensitivity was detected by colony forming assay. A549 cells were divided into 2 groups： radiation group and radiation ＋ elemene group. Oligonucleotide chip was used to screen the gene expression changes of A549 cells from these 2 groups. The up-regulated gene Egr-1 and the down-regulated gene CyclinD1 were selected to undergo RT-PCR so as to confirm the reliability of the result. Results MTT test showed the elemene inhibited the proliferation of the A549 cells dose-dependently. The IC50value of elemene on the A549 cells was 120 mg/L. （2）10 mg/L elemene had radiosensiting effect on A549 cells. The values of SERD0and SERDqobtained from the survival curve were （1.54± 0. 20） and （1.43± 0. 15 ） respectively. Gene chip screened 122 differentially-expressed genes, including 89 up-regulated genes and 33 down-regulated genes. （3）These altered genes could be related to cell structure, substance metabolism, cell proliferation, cell differentiation, signal transduction, material transport, DNA repair, apoptosis, immune response and so forth. The RT-PCR results of Egr-1 and Cyclin D1 were consistent with the genen chip analysis. Conclusions The mechanism of elemene enhancing the radiosensitivity of lung adenocarcinoma A549 ceils is the result of participation and collaboration of multiple genes. Further study of the newly-discovered differentially-expressed gene helps find out new radiosensitizational targets of elemene.