Rajagopal Asha, Pant Alok C, Simon Sanford M, Chen Yu
Laboratory of Cellular Biophysics, The Rockefeller University, New York, New York 10021, USA.
Cancer Res. 2002 Jan 15;62(2):391-6.
The multidrug resistance protein 1 (MRP1) contributes cellular resistance to a wide array of physiological toxins and chemotherapeutic agents. Its in vivo activity has been studied primarily in cells that have been continuously drug selected, culture conditions that might confound the effects of MRP1 expression with the effects of a cell's detoxification machinery. Transient transfection with a MRP1-green fluorescent protein (EGFP) fusion protein allowed us to measure the activity of MRP1 in cells that had insufficient time to induce other chemoprotective proteins. Furthermore, separate transfections with MRP1-yellow fluorescent protein and a fluorescently tagged P-glycoprotein (MDR1-cyan fluorescent protein) permitted the drug-resistant properties of MRP1-expressing cells to be compared with those of MDR1-expressing cells. Our data showed that the expression of MRP1-EGFP results in significantly decreased cellular accumulation of tetramethylrhodamine ethyl ester (TMRE) and daunorubicin, mildly decreased cellular accumulation of mitoxantrone, and decreased nuclear accumulation of doxorubicin. Additionally, MRP1-EGFP expression protected cells from the microtubule depolymerization caused by vincristine and colchicine, but not by vinblastine.
多药耐药蛋白1（MRP1）赋予细胞对多种生理毒素和化疗药物的抗性。其体内活性主要在经过持续药物筛选的细胞中进行研究，而这种培养条件可能会使MRP1表达的影响与细胞解毒机制的影响相互混淆。用MRP1-绿色荧光蛋白（EGFP）融合蛋白进行瞬时转染，使我们能够在没有足够时间诱导其他化学保护蛋白的细胞中测量MRP1的活性。此外，分别用MRP1-黄色荧光蛋白和荧光标记的P-糖蛋白（MDR1-青色荧光蛋白）进行转染，可将表达MRP1的细胞的耐药特性与表达MDR1的细胞的耐药特性进行比较。我们的数据表明，MRP1-EGFP的表达导致四甲基罗丹明乙酯（TMRE）和柔红霉素在细胞内的积累显著减少，米托蒽醌在细胞内的积累略有减少，阿霉素在细胞核内的积累减少。此外，MRP1-EGFP的表达可保护细胞免受长春新碱和秋水仙碱引起的微管解聚，但不受长春碱的影响。
