The pH sensitive probe 5-(and-6)-carboxyl seminaphthorhodafluor is a substrate for the multidrug resistance-related protein MRP1
The pH sensitive probe 5-(and-6)-carboxyl seminaphthorhodafluor is a substrate for the multidrug resistance-related protein MRP1
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DOI：
10.1002/ijc.23892
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发表时间：
2009-01-01
影响因子：
6.4
通讯作者：
Jones, Arwyn T.
中科院分区：
文献类型：
--
作者：
Jin, Jing;Jones, Arwyn T.
细胞功能取决于细胞内pH值的严格调节，许多报告表明癌细胞的胞质溶胶和细胞器（例如溶酶体）中存在异常的pH值。5-（和-6）-羧基萘酚或（SNARF-1）是一种常用的pH敏感探针，本文用它测定HL-60白血病细胞和耐药细胞胞浆pH。过表达多药耐药相关蛋白1（MRP 1）的变体。与亲本细胞相比，抗性细胞积累的SNARF-1显著较少，但通过将细胞与特异性MRP 1抑制剂MK 571预孵育观察到接近对照水平的探针积累。暴露于阿霉素或柔红霉素后产生两种新的耐药细胞系，这些细胞分别上调MRP 1或P-糖蛋白表达。在这些细胞中的实验表明，减少SNARF-1积累是特异性的。MRP 1的过度表达，因为细胞上调P-糖蛋白积累控制水平的探针。使用已显示分别组成型表达MRP 1和P-糖蛋白的K562和KG 1a细胞获得SNARF-1是MRP 1底物的确认。总之，这些数据表明，SNARF-1是MRP 1的底物，而不是P-糖蛋白，因此可以用作探针来区分这2种外排蛋白的表达和活性。最后，我们证实了多柔比星而不是柔红霉素攻击的MRP 1过表达HL-60细胞具有升高的胞质pH。（C）2008 Wiley-Liss。Inc.
Cellular function is dependent on tight regulation of intracellular pH and numerous reports show cancer cells have abnormal pH values in the cytosol and organelles, such as lysosomes. 5-(and-6)-carboxyl seminaphthorhodafluor (SNARF-1) is a commonly used pH sensitive probe and was used here to determine cytosolic pH of HL-60 leukemia cells and a drug-resistant. variant overexpressing multidrug-resistance related protein 1 (MRP1). Resistant cells accumulated significantly less SNARF-1 compared to parental cells but near control levels of probe accumulation were observed by preincubating cells with the specific MRP1 inhibitor MK571. Two new drug-resistant cell lines were generated following exposure to doxorubicin or daunorubicin and these upregulated MRP1 or P-glycoprotein expression, respectively. Experiments in these cells showed that reduced SNARF-1 accumulation was specific. to MRP1 overexpression, as cells upregulating P-glycoprotein accumulated control levels of the probe. Confirmation that SNARF-1 is a MRP1 substrate was obtained using K562 and KG la cells that have been shown to, respectively, constitutively express MRP1 and P-glycoprotein. Together, the data suggest that SNARF-1 is a substrate for MRP1 but not P-glycoprotein, and could therefore be used as a probe to distinguish between expression and activity of these 2 efflux proteins. Finally, we confirm that doxorubicin but not daunorubicin challenged MRP1 overexpressing HL-60 cells have elevated cytosolic pH. (C) 2008 Wiley-Liss. Inc.