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目的:探讨哺乳动物细胞能否修复DNA链间交联(imerstrand crosslink,ICL)。方法:构建带有丝裂霉素(mito mycin C,MMC)交联的质粒pCMV-Luc／ICL,将该交联质粒转染无修复酶缺陷和有修复酶缺陷的哺乳动物细胞系,观察细胞对 MMC链间交联的修复能力。结果:(1)无酶缺陷的哺乳动物细胞对DNA的修复能力很强,即使缺乏同源序列,也能有效地去 除DNA链间交联;(2)修复过程需要许多酶类参与,其中与核苷酸切除修复(nucleotide excision repair,NER)相关的酶类起着 关键性作用,提示NER参与MMC链间交联的修复过程;(3)序列分析表明,非同源性重组修复为易错修复(error-prone re pair)。结论:哺乳动物细胞能有效地修复MMC诱导的DNA链间交联,核苷酸切除修复是重要的修复途径。
Objective: To investigate whether mammalian cells can repair imerstrand crosslinks (ICL). METHODS: Plasmid pCMV-Luc / ICL with the cross-linking of mitomycin C (MMC) was constructed. The cross-linked plasmid was transfected into mammalian cell lines without repair and repair defects. Ability to repair cross-links between MMC chains. Results: (1) Mammalian cells without enzyme deficiency had a strong ability to repair DNA, which could effectively remove the cross-links between DNA chains even in the absence of homologous sequences. (2) Many enzymes involved in the repair process. Among them, Enzymes related to nucleotide excision repair (NER) play a key role, suggesting that NER is involved in the repair process of cross-linking between MMC chains. (3) Sequence analysis shows that non-homologous recombination repair is error-prone Error-prone re pair CONCLUSION: Mammalian cells can effectively repair MMC-induced DNA cross-linking. Nucleotide excision repair is an important repair pathway.