›› 2012, Vol. 24 ›› Issue (2): 81-85.doi: 10.3969/j.issn.1004-616x.2012.02.001

• 论著 •    下一篇

N-乙酰半胱氨酸对支气管上皮细胞辐射致癌模型DNA氧化损伤和存活率的影响

苟 巧,王春燕,佟 鹏,吕慧敏,齐雪,郝述霞,魏志权   

  1. ( 中国疾病预防控制中心辐射防护与核安全医学所,北京 100088 )
  • 收稿日期:2011-12-08 修回日期:2012-01-16 出版日期:2012-03-30 发布日期:2012-03-30
  • 通讯作者: 苟 巧

Effects of N-acetyl cysteine on the oxidative DNA damage and cell survival rate of malignant BERP35T-1 cells exposed to α-particles

GOU Qiao,WANG Chun-yan,TONG Peng,LU Hui-min,QI Xue-song,HAO Shu-xia,WEI Zhi-quan   

  1. (National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing 100088, China)
  • Received:2011-12-08 Revised:2012-01-16 Online:2012-03-30 Published:2012-03-30
  • Contact: GOU Qiao

摘要: 目的: 探讨N-乙酰半胱氨酸(N-acetyl cysteine, NAC)对人支气管上皮细胞辐射致癌模型BERP35T-1细胞 DNA氧化损伤和存活率的影响。方法:运用Western blot法检测人支气管上皮细胞BEP2D,RH22和BERP35T-1,以及用不同浓度NAC(0~2 mmol/L) 作用BERP35T-1 48 h后,细胞内DNA双链断裂产物γH2AX的表达水平变化;免疫细胞化学法检测1 mmol/L NAC作用BERP35T-1不同时间(0~48 h)后细胞内DNA氧化损伤产物8-OH-dG的表达水平;DCFH-DA荧光探针标记结合流式细胞仪检测1 mmol/L NAC作用 BERP35T-1 48 h后细胞内活性氧(active oxygen radicals, ROS)水平变化;二苯基溴化四氮唑蓝(MTT)法检测空白对照组、药物组(1 mmol/L NAC作用48 h)、照射组(2 Gyγ射线照射)和联合作用组(1 mmol/L NAC预处理48 h后+2 Gyγ射线照射)BERP35T-1细胞的存活率差异。结果:与BEP2D细胞相比,RH22和BERP35T-1细胞中γH2AX表达增强(P<0.01);BERP35T-1较RH22中γH2AX表达增强(P<0.01);1~2 mmol/L NAC作用BERP35T-1细胞48 h后,细胞中γH2AX的表达受到显著抑制(P<0.01);1 mmol/L NAC作用BERP35T-1细胞 24~48 h可显著下调细胞内8-OH-dG的表达(P<0.05或P<0.01);1 mmol/L NAC作用BERP35T-1细胞 48 h后,细胞内 ROS水平显著降低(P<0.05);药物组与空白对照组相比,BERP35T-1细胞存活率降低(P<0.01); 联合作用组与单纯照射组相比,BERP35T-1细胞存活率增高(P<0.05)。结论:抗氧化剂NAC可能通过提高恶性转化细胞BERP35T-1的抗氧化能力,降低细胞内ROS和DNA氧化损伤水平,促进基因组稳定性,部分逆转BERP35T-1细胞的恶性表型,并降低其辐射敏感性。

关键词: N-乙酰半胱氨酸, α粒子, 肺癌, 氧化损伤, 细胞存活率

Abstract: OBJECTIVE: To study the effects of N-acetyl cysteine (NAC) on the oxidative DNA damage and cell survival rate of malignant BERP35T-1 cells exposed to α-particles. METHODS:Western blot was used for the detection of protein expression of γH2AX in the human bronchial epithelial cell lines BEP2D,RH22 and BERP35T-1, and BERP35T-1 treated with 0-2 mmol/L NAC for 48 h. Immunocytochemistry was used to compare the different expression levels of 8-OH-dG in BERP35T-1 treated with 1 mmol/L NAC for 0-48 h. Using DCHF-DA, the generation of active oxygen radicals (ROS) in BERP35T-1 treated with 1 mmol/L NAC for 48 h was monitored by flow cytometry. MTT assay was used to examine the cell survival rate of BERP35T-1 cells treated with 1 mmol/L NAC for 48 h and/or 2 Gy γ-rays. RESULTS:Compared to BEP2D cells, increased level of γH2AX was detected in RH22 and BERP35T-1 cells (P<0.01). The protein expression of γH2AX in BERP35T-1 was higher than in RH22 cells (P<0.01). After treatment with 1-2 mmol/L NAC for 48 h, the expression level of γH2AX in BERP35T-1 was significantly decreased (P<0.01). Decreased expression of 8-OH-dG was seen in BERP35T-1 treated with 1 mmol/L NAC for 24-48 h (P<0.05 or P<0.01). After treatment by 1 mmol/L NAC for 48 h, the basal level of ROS in BERP35T-1 decreased (P<0.05). In addition,the cell survival rate of BERP35T-1 treated with NAC was reduced (P<0.01). Meanwhile, compared to BERP35T-1 treatment with γ-rays alone, increased cell survival rate was detected in BERP35T-1 when treated with γ-rays combined with NAC (P<0.05). CONCLUSION:NAC, as an antioxidant, could up-regulate the antioxidant ability of BERP35T-1, resulting in decreased ROS level and oxidative DNA damage and increased genomic stability to partially reverse the malignant phenotype of BERP35T-1,such as inhibiting the malignant proliferation,and reducing its radiosensitivity.

Key words: N-acetyl cysteine, α-particle, lung cancer, oxidative damage, cell survival rate