Multiple repair pathways mediate tolerance to chemotherapeutic cross-linking agents in vertebrate cells
Multiple repair pathways mediate tolerance to chemotherapeutic cross-linking agents in vertebrate cells
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DOI：
10.1158/0008-5472.can-05-1214
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发表时间：
2005-12-15
期刊：
影响因子：
11.2
通讯作者：
Sonoda, E
中科院分区：
文献类型：
--
作者：
Nojima, K;Hochegger, H;Sonoda, E
诱导 DNA 链间交联 (ICL) 的交联剂广泛用于抗癌化疗。酵母遗传学研究表明，核苷酸切除修复（NER）、依赖Rad6/Rad18的复制后修复、同源重组和细胞周期检查点途径参与ICL修复。为了研究脊椎动物 DNA 损伤反应途径对交联剂耐受性的影响，我们从鸡 DT40 细胞中制作了一组基因破坏的克隆，每个克隆都在特定的 DNA 修复或检查点途径中存在缺陷，并测量了对交联剂的敏感性，包括顺式二氨二氯铂 (II)（顺铂）、丝裂霉素 C 和美法仑。我们发现，存在跨损伤 DNA 合成 (TLS)、范可尼贫血互补组 (FANC) 或同源重组缺陷的细胞对所有交联剂均表现出明显的超敏反应，而 NER 似乎仅发挥次要作用。这种复制依赖性修复途径的作用与酵母中的情况明显不同，在酵母中，NER 似乎在处理 ICL 中发挥着主要作用。 Rev3（TLS 聚合酶 Pol zeta 的催化亚基）缺陷的细胞对顺铂表现出最高的敏感性，其次是 fanc-c。此外，上位性分析表明这两种突变体在相同的途径中发挥作用。我们的遗传综合研究揭示了 DNA 修复途径的关键作用，该途径在 ICL 处释放 DNA 复制阻断，从而提高细胞对交联剂的耐受性，并可直接用于设计有效的化疗。
Cross-linking agents that induce DNA interstrand cross-links (ICL) are widely used in anticancer chemotherapy. Yeast genetic studies show that nucleotide excision repair (NER), Rad6/Rad18-dependent postreplication repair, homologous recombination, and cell cycle checkpoint pathway are involved in ICL repair. To study the contribution of DNA damage response pathways in tolerance to cross-linking agents in vertebrates, we made a panel of gene-disrupted clones from chicken DT40 cells, each defective in a particular DNA repair or checkpoint pathway, and measured the sensitivities to cross-linking agents, including cis-diammine-dichloroplatinum (II) (cisplatin), mitomycin C, and melphalan. We found that cells harboring defects in translesion DNA synthesis (TLS), Fanconi anemia complementation groups (FANC), or homologous recombination displayed marked hypersensitivity to all the cross-linking agents, whereas NER seemed to play only a minor role. This effect of replication-dependent repair pathways is distinctively different from the situation in yeast, where NER seems to play a major role in dealing with ICL. Cells deficient in Rev3, the catalytic subunit of TLS polymerase Pol zeta, showed the highest sensitivity to cisplatin followed by fanc-c. Furthermore, epistasis analysis revealed that these two mutants work in the same pathway. Our genetic comprehensive study reveals a critical role for DNA repair pathways that release DNA replication block at ICLs in cellular tolerance to cross-linking agents and could be directly exploited in designing an effective chemotherapy.