Effect of quercetin on hoechst 33342 transport by purified and reconstituted P-glycoprotein
Effect of quercetin on hoechst 33342 transport by purified and reconstituted P-glycoprotein
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DOI：
10.1016/s0006-2952(96)00826-x
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发表时间：
1997-02-21
影响因子：
5.8
通讯作者：
Ling, V
中科院分区：
文献类型：
--
作者：
Shapiro, AB;Ling, V
P-糖蛋白引起的多药耐药严重阻碍了肿瘤化疗的成功。已知许多化合物可抑制P-糖蛋白的药物输出功能。由于通常使用的体内细胞系统的复杂性，理解这些化学增敏剂的作用机制变得困难。为了研究化疗增敏剂的直接作用，我们开发了一种系统，在该系统中，纯化和重组的P-糖蛋白将Hoechst 33342从脂膜转运到蛋白脂质体的水中，需要三磷酸腺苷的水解(Shapiro AB和Ling V，J Biol Chem 270：16167-16175,1995年)。在这里，我们使用这个系统来了解槲皮素对P-糖蛋白的影响，槲皮素是三种已被报道具有通过P-糖蛋白在体内刺激药物转运的独特性质的黄酮类化合物之一(Pang等人，癌症资源53：5977-5981,1993)。由于食物中含有丰富的类黄酮，了解它们对P-糖蛋白功能的影响是很重要的，因为这与癌症化疗有关。在我们的手中，根据流式细胞仪的测量，栎素抑制P-糖蛋白介导的Hoechst 33342的外流，并促进多药耐药的CH(R)C5细胞的积聚。在纯化的体系中，槲皮素至少部分地通过抑制转运所需的P-糖蛋白的ATPase活性来强烈地抑制P-糖蛋白对Hoechst 33342的转运。我们的结论是，以前报道的栎素对多药耐药细胞药物外排的刺激作用并不是对P-糖蛋白的直接作用。P-糖蛋白的ATPase结构域可能是新的化疗增敏剂的一个有吸引力的靶点。(C)1997年爱思唯尔科学公司。
Multidrug resistance due to P-glycoprotein is a serious impediment to successful chemotherapy of cancer. Numerous compounds are known that inhibit the drug-exporting function of P-glycoprotein. Understanding the mechanisms of action of these chemosensitizers is made difficult by the complexity of the in vivo cell systems usually employed. To examine the direct effects of chemosensitizers, we have developed a system in which purified and reconstituted P-glycoprotein transports Hoechst 33342 from the lipid membrane to the aqueous interior of proteoliposomes, requiring ATP hydrolysis (Shapiro AB and Ling V, J Biol Chem 270: 16167-16175, 1995). Here, we use this system to understand the effect on P-glycoprotein of quercetin, one of three flavonoids that have been reported to have the unique property of stimulating drug transport by P-glycoprotein in vivo (Phang et al., Cancer Res 53: 5977-5981, 1993). Since flavonoids are abundant in food, it is important to understand their effects on the function of P-glycoprotein because of the implications for cancer chemotherapy. In our hands, quercetin inhibited P-glycoprotein-mediated Hoechst 33342 efflux and enhanced accumulation, as measured by flow cytometry, by multidrug-resistant CH(R)C5 cells. In the purified system, quercetin strongly inhibited Hoechst 33342 transport by P-glycoprotein, at least in part by inhibiting the ATPase activity of P-glycoprotein required for transport. We conclude that the previously reported stimulatory effect of quercetin on drug efflux from multidrug-resistant cells is not a direct effect on P-glycoprotein. The ATPase domain of P-glycoprotein may be an attractive target for new chemosensitizing agents. (C) 1997 Elsevier Science Inc.