Peroxiredoxin 1基因沉默对肝癌细胞HepG2和SMMC-7721放射增敏的研究  

Sensitizing hepatocellular carcinoma cells HepG2 and SMMC-7721 to ionizing radiation by peroxiredoxin 1 silencing

作　　者：高麦仓[1] 张龙[2] 张殿增[3] 张军[1] 

机构地区：[1]西安交通大学医学院第二附属医院消化科,陕西西安710004 [2]西安交通大学医学院第一附属医院肿瘤放疗科,陕西西安710061 [3]西安交通大学医学院实验中心,陕西西安710061

出　　处：《西安交通大学学报（医学版）》2011年第5期569-575,共7页Journal of Xi’an Jiaotong University（Medical Sciences）

摘　　要：目的探讨Peroxiredoxin（Prx）1基因的小分子干扰RNA（si RNA）对人肝癌细胞系HepG2和SMMC-7721的放射增敏作用及机制。方法通过逆转录PCR方法研究Prx家族（Prx1~6）在人肝癌细胞HepG2和SMMC-7721中的mRNA表达谱;使用si RNA敲低HepG2和SMMC-7721细胞高表达的Prx1亚型为Prx1 si RNA转染组,另设空白对照组、阴性对照组（Prx1si Neg）,分别经不同剂量X射线照射后,克隆形成法检测各组细胞的增殖情况,流式细胞仪测定细胞内活性氧水平、细胞周期及凋亡情况。结果 HepG2和SMMC-7721细胞均高表达Prx1、Prx3和Prx5。与对照组相比,两种细胞Prx1 si RNA转染组在8 Gy X线照射后其剂量生存曲线明显左移,照射12 h后细胞周期出现G2-M阻滞,24 h后细胞凋亡率及1 h后细胞内ROS水平明显升高（P〈0.05）。Prx1 si RNA转染组放射增敏比在1.38~1.45之间。结论小分子干扰RNA对人肝癌HepG2和SMMC-7721细胞有明显的放射增敏作用,其机制可能与细胞周期阻滞及细胞内活性氧水平升高有关。Objective To investigate the role of small interference RNA（siRNA） of peroxiredoxin（Prx） 1 in the radiosensitizing human hepatocellular carcinoma cells.Methods Prx mRNA expression profiles in human HepG2 and SMMC-7721 cells were determined by reverse transcription polymerase chain reaction.Prx1 was silenced by small interference RNA（siRNA） in HepG2 and SMMC-7721 cells.The two cell lines were divided into three groups（blank control group,negative control group and Prx1 siRNA transfected group）.The effects of Prx1 siRNA on proliferation of HepG2 and SMMC-7721 in the three groups were determined by colony-forming assay;the cell cycle,intracellular reactive oxygen species（ROS） and cell apoptosis were detected by flow cytometry.Results Prx1,Prx3 and Prx5 were highly expressed in HepG2 and SMMC-7721 cells.Prx1 siRNA transfected group exhibited a decreased proliferation following ionizing radiation（IR）,arrested G2-M checkpoint（12 hours after IR）,more cells blocked in G2 phase,a higher apoptosis rate（24 hours after IR） and increased intracellular ROS levels（1 hour after IR） compared to those in the control groups（P〈0.05）.The sensitization enhancement ratio of Prx1 siRNA transfected groups was between 1.38 and 1.45.Conclusion Silencing Prx1 sensitizes hepatocellular carcinoma cells to ionizing radiation in part through accumulation of intracellular reactive oxygen species and cell cycle arrest.

关 键 词：肝癌细胞 放射敏感性 PEROXIREDOXIN 1 RNA干扰 细胞内活性氧 细胞周期阻滞 放射增敏 

分 类 号：R735.7[医药卫生—肿瘤]