中文摘要：

目的探讨ATM基因表达沉默对肝癌细胞生长的影响。方法构建靶向人ATM基因的RNA干扰慢病毒载体L1、L2，包装成慢病毒；用含ATM特异性干扰片段的慢病毒感染HepG2细胞，RT-PCR鉴定干扰后ATM基因在细胞中的表达；MTT法检测ATM干扰后对细胞生长的影响。结果ATM的相对表达量阴性对照组与未感染病毒组表达水平接近；病毒感染的L1、L2组表达量低于未感染病毒组（P〈0．01）；L1、L2组与阴性对照组的表达水平均降低（P〈0．01）；两干扰组L1、L2组之间的表达量也有差异，L2组降低更为明显，且有统计学意义，L2组沉默效率更高，表达量仅为对照的15．52％，即干扰率为84．48％。MTT法检测结果示ATM基因表达沉默后感染和未感染的HepG2细胞增殖速度无明显改变。结论成功构建ATM基因siRNA慢病毒RNAi表达载体；ATM表达水平减低后，肝癌细胞体外生长无显著抑制。

英文摘要：

Objective To explore the effect of ATM gene silence on growth of HepG2 cells. Methods HepG2 ceils infected with lentiviral vector contain ATM gene. RT-PCR was used to identify ATM gene expression after RNA interference. Then, growth of HepG2 cells was detected by MTT way. Results The expression level of ATM gene was similar between the group not infected with virus and control group. The expression level of ATM gene was lower in L1 and L2 groups than in group not infected with virus （ P 〈 0.05 ） as well as in L2 group than in L1 group （ P 〈 0.05 ）. The efficiency of ATM gene silence was higher in L2 group than in control group, accounting for 84.48% and 15.52% , respectively. The results showed that no significant change occurred in growth of HepG2 cells infected or not infected with virus after ATM gene silence. Conclusion The RNAi expression vector of slow virus siRNA in the ATM gene can be constructed. Growth of HepG2 cells is not inhibited after ATM gene is silenced by RNAi.