黄曲霉毒素B1与DNA损伤修复关系的研究进展.doc

文档介绍：
黄曲霉毒素 B1 与 DNA 损伤修复关系的研究
进展#
杨雪娇,王守林**
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(南京医科大学公共卫生学院)
摘要:黄曲霉毒素 B1(Aflatoxin B1,AFB1)在体内能代谢生成 AFB1-8,9-epoxides,
AFB1-8,9-exo-epoxides 与 DNA 的鸟嘌呤残基反应后形成以 AFB1-N7-Gua 为主的 DNA 加合
物,AFB1-N7-Gua 加合物开环后可以形成 AFB1-FAPY 加合物,或者随加合物链的脱离形
成 AP 位点。在细菌、酵母和哺乳动物中,AFB1-N7-Gua 和 AFB1-FAPY 加合物主要由 NER
修复。虽然在哺乳动物中,AFB1-FAPY 加合物修复效率低于 AFB1-N7-Gua 加合物,但是
在细菌中,这两种加合物的修复效率接近,这说明细菌和哺乳动物的 DNA 损伤识别是有差
异的。此外,AFB1 诱导的 DNA 修复活性和修复调节是 AFB1 诱发癌变的主要易感因素。
关键词:黄曲霉毒素 B1;DNA 加合物;DNA 损伤;核酸切除修复
中图分类号:R114
Advances of the study on the relationship between aflatoxin
B1 and DNA damage repair
YANG Xuejiao, WANG Shoulin
(School of Public Health, Nanjing Medical University)
Abstract: Aflatoxin B1 (AFB1) may be metabolized in vivo to for its metabolite
AFB1-8,9-epoxides which subsequently generates DNA adducts such as AFB1-N7-Gua and
ultimately forms AFB1-FAPY adducts or separates from adducts chain to form AP sits. In bacteria,
yeast, or mammal, the adducts of AFB1-N7-Gua and AFB1-FAPY are repaired through nucleotide
excision repair (NER). Although the repair efficiency of AFB1-FAPY is lower than that of
AFB1-N7-Gua, they are very similar in bacteria, suggesting that there exists difference of the
DNA damage recognition between bacteria and mammal. In addition, AFB-induced DNA damage
activity and repair regulation are the susceptible factors in AFB1-induced carcinogenesis.
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