Jiang Liping, Cao Jun, An Yu, Geng Chengyan, Qu Shuxian, Jiang Lijie, Zhong Laifu
China-Japanese Joint Institute for Medical and Pharmaceutical Science, Dalian Medical University, 465 Zhongshan Road, Dalian 116027, Liaoning, China.
Toxicol In Vitro. 2007 Dec;21(8):1486-92. doi: 10.1016/j.tiv.2007.06.011. Epub 2007 Jul 4.
The recent finding that acrylamide (AA), a carcinogen in animal experiments and a probable human carcinogen, is formed in foods during cooking raises human health concerns. The relevance of dietary exposure for humans is still under debate. The purpose of the study was to evaluate the possible genotoxicity of acrylamide in human hepatoma G2 (HepG2) cells, a cell line of great relevance to detect genotoxic/antigenotoxic substances, using single cell gel electrophoresis (SCGE) assay and micronucleus test (MNT). In order to clarify the underlying mechanism(s) we evaluated the intracellular generation of reactive oxygen species (ROS) and the level of oxidative DNA damage by immunocytochemical analysis of 8-hydroxydeoxyguanosine (8-OHdG). The involvement of glutathione (GSH) in the AA-induced oxidative stress was examined through treatment with buthionine sulfoximine (BSO) to deplete GSH. The results indicate that AA caused DNA strand breaks and increase in frequency of MN in HepG2 cells in a dose-dependent manner. The possible mechanism underlies the increased levels of ROS, depletion of GSH and increase of 8-OHdG formation in HepG2 cells treated with AA. We conclude that AA exerts genotoxic effects in HepG2 cells, probably through oxidative DNA damage induced by intracellular ROS and depletion of GSH.
最近的研究发现,丙烯酰胺(AA)在动物实验中是一种致癌物,对人类可能也是致癌物,它在烹饪过程中会在食物中形成,这引发了人们对人类健康的担忧。饮食暴露对人类的相关性仍在争论中。本研究的目的是使用单细胞凝胶电泳(SCGE)分析和微核试验(MNT),评估丙烯酰胺对人肝癌G2(HepG2)细胞的潜在遗传毒性,HepG2细胞系对于检测遗传毒性/抗遗传毒性物质具有重要意义。为了阐明潜在机制,我们通过对8-羟基脱氧鸟苷(8-OHdG)进行免疫细胞化学分析,评估了细胞内活性氧(ROS)的产生和氧化性DNA损伤的水平。通过用丁硫氨酸亚砜胺(BSO)处理以耗尽谷胱甘肽(GSH),研究了GSH在AA诱导的氧化应激中的作用。结果表明,AA以剂量依赖性方式导致HepG2细胞中的DNA链断裂并增加微核频率。在用AA处理的HepG2细胞中,ROS水平升高、GSH耗竭和8-OHdG形成增加的潜在机制可能在此。我们得出结论,AA可能通过细胞内ROS诱导的氧化性DNA损伤和GSH耗竭,在HepG2细胞中发挥遗传毒性作用。