Inhibition of multidrug resistance by AdamantylGb3, a globotriaosylceramide analog
Inhibition of multidrug resistance by AdamantylGb3, a globotriaosylceramide analog
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DOI：
10.1074/jbc.m705473200
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发表时间：
2008-02-22
影响因子：
4.8
通讯作者：
Lingwood, Clifford
中科院分区：
文献类型：
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作者：
De Rosa, Maria Fabiana;Ackerley, Cameron;Lingwood, Clifford
多药耐药(MDR)通过ABC药物转运体(ABCB1)、P-糖蛋白(P-gp/mdr1)过表达，是肿瘤化疗的主要障碍。许多抑制剂逆转多药耐药，但像环孢菌素A(CsA)一样，有显著的毒性。MDR1也是一种转位酶，在高尔基体内翻转葡萄糖神经酰胺，促进中性鞘糖脂(GSL)的合成。我们观察到部分mdr1/球状三糖神经酰胺(GB(3))细胞表面共定位，GSL去除耗尽了细胞表面mdr1。因此，mdr1可能与GSLS相互作用。AdamantylGb(3)是一种水溶性的GB(3)模拟物，但不是其他GSL类似物，它逆转了MDR1-MDCK细胞的耐药性。CsA或adaGb(3)作用1h后，细胞表面mdr1表达上调，72h时，细胞表面mdr1表达消失。细胞内mdr1全程积聚，提示细胞膜mdr1转运存在长期缺陷。AdaGb(3)或CsA可迅速减少罗丹明123细胞外流。MDR1还介导胃肠上皮药物外流，限制口服生物利用度。在极化的人小肠C2BBe1细胞中，加入adaGb3或仅在顶端加入adaGb3后，长春花碱从尖到底的转运显著增加，与标准的MDR1抑制剂维拉帕米相当。突变体MDR1的二硫键交联显示adaGb3不与跨膜片段(TM)6和TM7表面近端螺旋之间的MDR1维拉帕米/环孢素结合位点结合，而是与TM6中心和TM7细胞外面更接近的位置结合，即靠近双层小叶界面。Vero毒素介导的GB(3)内吞作用也上调了总的MDR1，抑制了药物外排。因此，膜GB(3)和mdr1之间的功能相互作用提供了一种更基于生理的方法来调节mdr1以提高化疗药物的生物利用度。
Multidrug resistance (MDR) via the ABC drug transporter (ABCB1), P-glycoprotein (P-gp/MDR1) overexpression, is a major obstacle in cancer chemotherapy. Many inhibitors reverse MDR but, like cyclosporin A (CsA), have significant toxicities. MDR1 is also a translocase that flips glucosylceramide inside the Golgi to enhance neutral glycosphingolipid (GSL) synthesis. We observed partial MDR1/globotriaosylceramide (Gb(3)) cell surface co-localization, and GSL removal depleted cell surface MDR1. MDR1 may therefore interact with GSLs. AdamantylGb(3), a water-soluble Gb(3) mimic, but not other GSL analogs, reversed MDR1-MDCK cell drug resistance. Cell surface MDR1 was up-regulated 1 h after treatment with CsA or adaGb(3), but at 72 h, cell surface expression was lost. Intracellular MDR1 accumulated throughout, suggesting long term defects in plasma membrane MDR1 trafficking. AdaGb(3) or CsA rapidly reduced rhodamine 123 cellular efflux. MDR1 also mediates gastrointestinal epithelial drug efflux, restricting oral bioavailability. Vinblastine apical-to-basal transport in polarized human intestinal C2BBe1 cells was significantly increased when adaGb3 was added to both sides, or to the apical side only, comparable with verapamil, a standard MDR1 inhibitor. Disulfide cross-linking of mutant MDR1s showed no binding of adaGb3 to the MDR1 verapamil/cyclosporin-binding site between surface proximal helices of transmembrane segments (TM)6 and TM7, but rather to an adjacent site nearer the center of TM6 and the TM7 extracellular face, i.e. close to the bilayer leaflet interface. Verotoxin-mediated Gb(3) endocytosis also upregulated total MDR1 and inhibited drug efflux. Thus, a functional interplay between membrane Gb(3) and MDR1 provides a more physiologically based approach to MDR1 regulation to increase the bioavailability of chemotherapeutic drugs.