Reversal of resistance by GF120918 in cell lines expressing the ABC half-transporter, MXR
Reversal of resistance by GF120918 in cell lines expressing the ABC half-transporter, MXR
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DOI：
10.1016/s0304-3835(99)00182-2
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发表时间：
1999-11-15
期刊：
影响因子：
9.7
通讯作者：
Bates, SE
中科院分区：
文献类型：
--
作者：
de Bruin, M;Miyake, K;Bates, SE
ABC转运蛋白家族中新发现的几个成员的出现使得能够抑制不止一种转运蛋白的拮抗剂的开发成为必要。我们通过细胞毒性试验、罗丹明和钙黄绿素外排试验以及共聚焦显微镜在表达不同多药耐药转运体的细胞系中评估了化学增敏剂GF120918作为多特异性拮抗剂的能力。在1 mU M的细胞毒性实验中，GF120918对表达P-糖蛋白(Pgp)的亚系S1-B1-20和表达新发现的米托蒽醌转运体MXR的亚系S1-M1-80均有增敏作用，而GF120918对MRP高表达的MCF-7 VP-16细胞对依托泊苷的增敏作用不明显。在HOW细胞术实验中，当GF120918浓度低至25-50 nM时，细胞的罗丹明123外排减少，而250 nM的GF120918则完全抑制罗丹明外流。完全抑制耐药细胞罗丹明的外排需要10微米。通过共聚焦显微镜观察细胞内的米托蒽酮积聚证实，当与GF120918一起孵育时，S1-B1-20和S1-M1-80细胞中的米托蒽酮水平高于单独与米托蒽醌孵育时的水平。因此，GF120918似乎符合多特异性阻滞剂的范例，并能够通过新发现的米托蒽酮转运体阻断罗丹明和米托蒽醌的外流。应继续对该化合物进行进一步研究，以确定其临床应用的可行性。(C)1999爱思唯尔爱尔兰科学有限公司。保留所有权利。
The emergence of several newly identified members of the ABC transporter family has necessitated the development of antagonists that are able to inhibit more than one transporter. We assessed the ability of the chemosensitizer GF120918 to function as a multispecific antagonist using cytotoxicity assays, rhodamine and calcein efflux assays, and confocal microscopy in cell lines expressing different multidrug resistance transporters. At a concentration of 1 mu M in cytotoxicity assays, GF120918 was able to sensitize both S1-B1-20, a subline expressing P-glycoprotein (Pgp), and S1-M1-80, a subline expressing a newly identified mitoxantrone transporter, MXR, GF120918 was ineffective in sensitizing MRP-overexpressing MCF-7 VP-16 cells to etoposide as determined by cytotoxicity studies. In how cytometry experiments, rhodamine 123 efflux in S1-B1-20 cells was decreased at GF120918 concentrations as low as 25-50 nM, with 250 nM giving complete inhibition of rhodamine efflux. Complete inhibition of rhodamine efflux in mitoxantrone-resistant S1-M1-80 cells required 10 mu M. Examination of intracellular mitoxantrone accumulation by confocal microscopy confirmed higher levels of mitoxantrone in S1-B1-20 and S1-M1-80 cells when incubated in the presence of GF120918 than when incubated with mitoxantrone alone. Thus, GF120918 appears to fit the paradigm of a multispecific blocker and is able to block rhodamine and mitoxantrone efflux by the newly identified mitoxantrone transporter. Further studies of this compound should be pursued to determine its feasibility for use in the clinic. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.