Inhibition of RNA polymerase II transcription in human cell extracts by cisplatin DNA damage
Inhibition of RNA polymerase II transcription in human cell extracts by cisplatin DNA damage
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DOI：
10.1021/bi982685
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发表时间：
1999-05-11
期刊：
影响因子：
2.9
通讯作者：
Bohr, VA
中科院分区：
文献类型：
--
作者：
Cullinane, C;Mazur, SJ;Bohr, VA
抗癌药物顺铂会引起一系列 DNA 损伤。在人类细胞提取物中，在起始和延伸水平上研究了这种 DNA 损伤对 RNA 聚合酶 II (RNA pol II) 转录的影响。用增加浓度的顺铂处理含启动子的模板后，从腺病毒主要晚期启动子定向的RNA pol II转录受到抑制。此外，在外源质粒上存在越来越多的顺铂DNA损伤的情况下，来自未损伤的启动子片段的转录被耗尽，这表明这种损伤可能劫持转录起始的必需因子。使用位点特异性放置的顺铂加合物研究了顺铂损伤对 RNA pol II 延伸的影响。 GTG 加合物可有效阻断 RNA pol II 延伸，抑制聚合酶 80%。相比之下，RNA pol II 完全绕过了顺铂 GG 链内加合物。这些研究表明，用顺铂处理细胞后观察到的 RNA pol II 转录抑制可能反映了转录起始和延伸水平上 DNA 损伤的综合影响。
The anticancer drug cisplatin induces a spectrum of lesions in DNA. The effect of such DNA damage on transcription by RNA polymerase II (RNA pol II) in human cell extracts was investigated at the level of initiation and elongation. RNA pol II transcription directed from the adenovirus major late promoter was inhibited following treatment of the promoter-containing template with increasing concentrations of cisplatin. Furthermore, transcription from an undamaged promoter fragment was depleted in the presence of increasing amounts of cisplatin DNA damage on an exogenous plasmid, suggesting such damage may hijack an essential factor for transcription initiation. The effect of cisplatin damage on RNA pol II elongation was investigated using site-specifically-placed cisplatin adducts. The GTG adduct was an effective block to RNA pol II elongation, inhibiting the polymerase by 80%. In contrast, RNA pol II completely bypassed the cisplatin GG intrastrand adduct. These studies suggest that the inhibition of RNA pol II transcription observed following the treatment of cells with cisplatin is likely to reflect the combined effects of DNA damage at the level of both transcription initiation and elongation.