含非甲基化二核苷酸的寡脱氧核苷酸7909对X射线诱导人肺腺癌A549细胞周期阻滞和凋亡的影响与ATM激酶的关系  

Role of ATM kinase in the effect of CpG ODN7909 on X-ray-induced GJM phase arrest and apoptosis in A549 cells

作　　者：刘小群[1] 乔田奎[1] 陈伟[1] 袁素娟[1] 

机构地区：[1]复旦大学附属金山医院肿瘤科,上海200540

出　　处：《中华放射医学与防护杂志》2012年第3期270-273,共4页Chinese Journal of Radiological Medicine and Protection

摘　　要：目的探讨含非甲基化二核苷酸的寡脱氧核苷酸（unmethylatedcytosine-phosphate．guanineoligodeo。ynucleotides，CpGODN）7909对X射线诱导人肺腺癌A549细胞周期阻滞和凋亡的影响及毛细血管扩张共济失调突变（ATM）激酶磷酸化在这一过程中的作用。方法人肺腺癌A549细胞用随机表法分为5组，对照组、CpG组、单纯照射组、CpG＋x射线组和ATMsiRNA＋CpG＋x射线组。采用集落形成法观察细胞存活率。流式细胞仪检测细胞周期和细胞凋亡。Westernblot检测ATM激酶及其下游底物周期检测点激酶2（checkpointkinase2，Chk2）和P53蛋白的表达。结果A549细胞经CpGODN7909预处理后，在x射线照射下生长缓慢，集落形成明显减少，与单纯照射组比较，差异有统计学意义（t=13．41，P〈0．05）；增强了X射线诱导的人肺腺癌A549细胞G2／M期阻滞和凋亡，与单纯照射组比较，差异有统计学意义（t=17．32和7．71，P〈0．05）；明显增加了X射线诱导的ATM、Chk2及P53蛋白磷酸化水平；小分子干扰RNA暂时性抑制ATM的表达后，CpGODN7909对x射线诱导G2／M期阻滞及凋亡的作用减弱，与CpG＋X射线组比较，差异有统计学意义（f=26．84和2．98，P〈0．05）。结论CpGODN7909在体外增强了X射线诱导的人肺腺癌A549细胞ATM激酶磷酸化，这一作用可能参与G2／M期阻滞和凋亡的调节。Objective To investigate the relationship between the effect of unmethylated cytosine- phosphate-guanine oligodeoxynucleotide （CpG ODN ）7909 on X-ray-induced G2/M phase arrest and apoptosis and the phosphorylation of ATM kinase. Methods Human lung adenocarcinoma A549 cells were randomly classified into five groups, control, CpG group, irradiation group, CpG ＋ irradiation group and ATM siRNA ＋ CpG ＋ irradiation group. Cell survival fraction was evaluated by clonogenic assay. Cell cycle and apoptosis were analyzed by flow cytomctry. The expressions of ATM, checkpoint kinase-2 （Chk2） and p53 were detected with Western blot. Results Compared to the situation under X-ray irradiation alone, decreased cell clonogenic survival, prolonged G2/M arrest, and increased cell apoptosis were observed after the combination treatment with CpG ODN7909 and X-rays （ t = 13.41,17.32 and 7.71, P 〈 0. 05 ）. Moreover, the phosphorylations on ATM, Chk2, and p53 were increased in the irradiated A549 cells that had been pre-treated with CpG ODN7909. After ATM siRNA interfering, abrogation of G2/M arrest, reduction of apoptosis, and decrease of Chk2 and p53 phosphorylation were found in A549 cells treated with CpG 0DN7909 and X-rays （ t = 26.84,2. 98,47.24 and 67.47, P 〈 0. 05）. Conclusions CpG 0DN7909 can enhance the X-ray-induced phosphorylation of ATM kinase in human lung adenoeareinoma cells in vitro, which might be involved in regulating G2/M phase arrest and apoptosis.

关 键 词：含非甲基化二核苷酸的寡脱氧核苷酸 X射线 毛细血管扩张共济失调突变激 酶 细胞周期 凋亡 

分 类 号：R734.2[医药卫生—肿瘤]