Efficiency of P-glycoprotein-mediated exclusion of rhodamine dyes from multidrug-resistant cells is determined by their passive transmembrane movement rate
Efficiency of P-glycoprotein-mediated exclusion of rhodamine dyes from multidrug-resistant cells is determined by their passive transmembrane movement rate
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DOI：
10.1111/j.1432-1033.1997.00104.x
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发表时间：
1997-08-15
期刊：
影响因子：
--
通讯作者：
Assaraf, YG
中科院分区：
文献类型：
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作者：
Eytan, GD;Regev, R;Assaraf, YG
本研究的目的是研究多药耐药（MDR）型底物的被动跨膜运动速率与p -糖蛋白从MDR细胞中挤出它们的能力之间的关系。为此，研究了7种罗丹明染料在耐多药细胞中p糖蛋白介导的排斥作用、在野生型药物敏感细胞中的定位、对蛋白脂质体中重组p糖蛋白atp酶活性的刺激能力以及在人工脂质体中的跨膜运动速率。这些罗丹明染料均在野生型药敏细胞中积累，并主要定位于线粒体。所有测试的染料都是重组p糖蛋白和细胞p糖蛋白的底物，并在不同程度上从MDR细胞中排除。跨膜运动速率证明是决定p -糖蛋白介导的罗丹明染料从MDR细胞中排除效果的主要因素。因此，罗丹明B作为细胞p糖蛋白底物，对重组p糖蛋白表现出很高的亲和力，但却是最快的膜穿越染料。相比而言，四甲基罗斯胺是最佳的细胞MDR探针，对重组p -糖蛋白具有高亲和力，跨膜运动速度慢。因此，一种具有快速跨膜运动速率的抗癌药物有望克服耐多药现象。此外，广泛使用的MDR标记物罗丹明123与其他罗丹明染料（尤其是四甲基罗斯胺）相比，是一种较差的细胞MDR底物，而四甲基罗斯胺是一种较好的细胞MDR底物，用于功能性染料排斥研究。
The aim of the present study was to examine the relationship between the rate of the passive transmembrane movement of multidrug resistance (MDR)-type substrates and the ability of P-glycoprotein to extrude them from MDR cells. For this purpose, seven rhodamine dyes were examined for their P-glycoprotein-mediated exclusion from MDR cells, their localization in wild-type drug-sensitive cells, their capacity to stimulate the ATPase activity of P-glycoprotein reconstituted in proteoliposomes, and their transmembrane movement rate in artificial liposomes. All these rhodamine dyes were accumulated in wild-type drug-sensitive cells and were localized mainly in the mitochondria. All the dyes tested were substrates of reconstituted P-glycoprotein and cellular P-glycoprotein and were excluded to a variable degree from MDR cells. The transmembrane movement rate proved the major factor determining the efficacy of the P-glycoprotein-mediated exclusion of rhodamine dyes from MDR cells. Thus, rhodamine B, the poorest cellular P-glycoprotein substrate, exhibited a high affinity toward reconstituted P-glycoprotein, but was the fastest membrane-traversing dye. In contrast, tetramethylrosamine, the best cellular MDR probe, exhibited high affinity toward reconstituted P-glycoprotein and slow transmembrane movement rate. Therefore, an anticancer drug with a fast transmembrane movement rate is expected to overcome the MDR phenomenon. Furthermore, the widely used MDR marker, rhodamine 123, was a poor cellular MDR substrate compared with other rhodamine dyes, especially tetramethylrosamine, which was a superior cellular MDR substrate for functional dye-exclusion studies.