DT-diaphorase expression and tumor cell sensitivity to 17-allylamino,17-demethoxygeldanamycin, an inhibitor of heat shock protein 90
DT-diaphorase expression and tumor cell sensitivity to 17-allylamino,17-demethoxygeldanamycin, an inhibitor of heat shock protein 90
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DOI：
10.1093/jnci/91.22.1940
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发表时间：
1999-11-17
期刊：
影响因子：
--
通讯作者：
Workman, P
中科院分区：
文献类型：
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作者：
Kelland, LR;Sharp, SY;Workman, P
背景资料：据我们所知，17-烯丙基氨基，17-去甲氧基格尔德霉素（17-allylamino，17-demethoxygeldanamycin，17 AAG）是第一个进入癌症I期临床试验的热休克蛋白90（heat shock protein 90，Hsp 90）抑制剂。（一种帮助其他蛋白质避免产生非活性或聚集状态的错误折叠途径的蛋白质），导致重要致癌蛋白的耗尽，包括Raf-1和突变型p53（也称为TP 53）。鉴于其安莎霉素苯醌结构，我们质疑17 AAG的抗肿瘤活性是否受到编码醌代谢酶DT-心肌黄酶的NQO 1基因表达的影响。研究方法：通过在培养物中使用基于磺酰罗丹明B的细胞生长抑制测定和通过在裸鼠中抑制异种移植肿瘤生长来测定17 AAG和其它Hsp 90抑制剂的抗肿瘤活性。DT-心肌黄酶活性通过使用分光光度测定法测定，蛋白质表达通过Western免疫印迹法测定。结果如下：在两个独立的体外人肿瘤细胞组中，我们观察到DT-心肌黄酶表达水平与17 AAG的生长抑制之间存在正相关关系。稳定，高水平表达的活性NQO 1基因转染，到DT-心肌黄酶缺陷（NQO 1突变）BE人结肠癌细胞系导致17 AAG生长抑制活性增加32倍。在异种移植物中也证实了转染细胞系中对17 AAG的敏感性增加。Raf-1和突变型p53蛋白的耗竭程度证实了在具有高和低水平DT-黄递酶的细胞中维持Hsp 90抑制机制。17 AAG被证明是纯化的人DT-心肌黄酶的底物。结论：这些结果表明，抗肿瘤活性和可能的毒理学性质的17 AAG在人类中可能会受到影响的DT-心肌黄酶的表达。因此，建议在17 AAG临床试验中仔细监测NQO 1多态性和肿瘤DT-黄递酶活性水平。
Background: To our knowledge, 17-allylamino,17-demethoxygeldanamycin (17AAG) is the first inhibitor of heat shock protein 90 (Hsp90) to enter a phase I clinical trial in cancer, Inhibition of Hsp90, a chaperone protein (a protein that helps other proteins avoid misfolding pathways that produce inactive or aggregated states), leads to depletion of important oncogenic proteins, including Raf-1 and mutant p53 (also known as TP53), Given its ansamycin benzoquinone structure, we questioned whether the antitumor activity of 17AAG was affected by expression of the NQO1 gene, which encodes the quinone-metabolizing enzyme DT-diaphorase. Methods: The antitumor activity of 17AAG and other Hsp90 inhibitors was determined by use of a sulforhodamine B-based cell growth inhibition assay in culture and by the arrest of xenograft tumor growth in nude mice. DT-diaphorase activity was determined by use of a spectrophotometric assay, and protein expression was determined by means of western immunoblotting. Results: In two independent in vitro human tumor cell panels, we observed a positive relationship between DT-diaphorase expression level and growth inhibition by 17AAG. Stable, high-level expression of the active NQO1 gene transfected, into the DT-diaphorase-deficient (by NQO1 mutation) BE human colon carcinoma cell line resulted in a 32-fold increase in 17AAG growth-inhibition activity. Increased sensitivity to 17AAG in the transfected cell line was also confirmed in xenografts. The extent of depletion of Raf-1 and mutant p53 protein confirmed that the Hsp90 inhibition mechanism was maintained in cells with high and low levels of DT-diaphorase. 17AAG was shown to be a substrate for purified human DT-diaphorase. Conclusion: These results suggest that the antitumor activity and possibly the toxicologic properties of 17AAG in humans may be influenced by the expression of DT-diaphorase. Careful monitoring for NQO1 polymorphism and the level of tumor DT-diaphorase activity is therefore recommended in clinical trials with 17AAG.