Arrest of replication forks by drug-stabilized topoisomerase I-DNA cleavable complexes as a mechanism of cell killing by camptothecin

Y. H. Hsiang, M. G. Lihou, Leroy-Fong Liu

研究成果: 雜誌貢獻文章

980 引文 斯高帕斯(Scopus)

摘要

Camptothecin, which induces an unusual type of DNA damage by trapping cellular topoisomerase I on chromosomal DNA in the form of drug-enzyme-DNA cleavable complexes, inhibits DNA synthesis and specifically kills S-phase cells. Cotreatment of L1210 cells with aphidicolin, which is an inhibitor of replicative DNA polymerases, completely abolished camptothecin cytotoxicity, suggesting the involvement of DNA replication in camptothecin cytotoxicity. In order to study the role of DNA replication in drug action, a cell-free SV40 DNA replication system was used in the present study. Camptothecin inhibited SV40 DNA replication in this cell-free system only in the presence of topoisomerase I. Addition of excess purified calf thymus DNA topoisomerase I to this extract system in the presence of camptothecin resulted in severe inhibition of SV40 DNA replication and the accumulation of linearized replication products, which contained covalently bound DNA topoisomerase I. We propose that the collision between moving replication forks and camptothecin-stabilized topoisomerase I-DNA cleavable complexes results in fork arrest and possibly fork breakage, which are lethal to proliferating cells.

原文英語
頁(從 - 到)5077-5082
頁數6
期刊Cancer Research
49
發行號18
出版狀態已發佈 - 1989
對外發佈Yes

ASJC Scopus subject areas

  • Cancer Research
  • Oncology

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