Development of analysis for multidrug resistance protein 1 (MRP1) modulator

我们的研究目的是阐明肿瘤细胞抗癌药物耐药的机制，开发有效的耐药调节剂。多药耐药可通过多药耐药蛋白1(MRP1)的过度表达而介导。MRP作为跨膜外排泵，减少细胞内药物积聚，从而产生多药耐药。克服MRP1介导的多药耐药的方法之一是使用一种抑制剂来阻断MRP1的功能。这被称为MRP1调制器。到目前为止，已有几种MRP1调节剂进入研究和临床试验。近年来，白三烯受体拮抗剂(LTRA)被认为是MRP1的调节剂之一。我们研究了LTRA克服耐药的效果，并开发了原创的候选药物。在我们的研究期间，我们得到了以下结果：用两种方法建立了耐药癌细胞。细胞来源于Jurkat(人白血病细胞株)，通过长期接触阿霉素2个月以上，并转导MRP1cDNA.在耐药细胞中，MRP1的过度表达是由于扩增的MRP基因转录的MRPmRNA水平升高所致。在药物敏感的Jurkat细胞和过表达MRP的耐药细胞中检测LTRA在阿霉素存在或不存在的情况下的剂量-反应效应。LTRA逆转了Jurkat的抗性。荧光累积分析表明，预先孵育的抗性Jurkat的LTRA的荧光强度显著增加。我们通过细胞内谷胱甘肽含量的测定、ATPase活性的测定、细胞周期途径的分析，证明LTRA对MRP1的调控是科学的。这些结果是肿瘤学研究的重要发现。我们现在已经写好了报告。

Our purpose of research is to clarify the mechanism of anticancer drug resistanceby tumor cells and developing effective resistance modulators. Multidrug resistance can be mediated by overexpression of the multidrug resistance protein 1(MRP1). MRP function as transmembrane efflux pumps, which decrease intracellular drug accumulation, thereby conferring multidrug resistance. One of the ways to overcome MRP1 mediated multidrug resistance is to use an inhibitor to block the function of MRP1. This is called MRP1 modulator. To date, several MRP1 modulator have entered study and clinical trials. Recently, leukotriene receptor antagonist (LTRA) is thought to be one of the MRP1 modulator. We studied effect to overcome drug resistance by LTRA and have developed original candidate medications.In our study duration, we got results as below; The resistance cancer cells was established by two methods. The cells were selected from Jurkat (human leukemia cell line) by chronic exposure to doxorubicin over 2 months and transfection of MRP1cDNA. In the resistant cells, the overexpression of MRP1 resulted from an increased MRPmRNA level transcribed from amplified MRP gene. The dose-response effects of LTRA in the presence or absence of doxorubicin were examined in both drug-sensitive Jurkat and MRP-overexpressing resistant cells. LTRA reversed Jurkat resistance. The fluorescent accumulation analysis revealed a significant increase of fluorescence in resistant Jurkat pre-incubated LTRA. We demonstrated that LTRA modulate MRP1 scientifically by the measurement of intracellular glutathione, ATPase assay, analysis of cell-cycle pathway. The results were important findings for oncologic research. We have written the report now.