Effect of MDR modulators verapamil and promethazine on gene expression levels of MDR1 and MRP1 in doxorubicin-resistant MCF-7 cells
Effect of MDR modulators verapamil and promethazine on gene expression levels of MDR1 and MRP1 in doxorubicin-resistant MCF-7 cells
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DOI：
10.1007/s00280-010-1385-y
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发表时间：
2011-04-01
影响因子：
3
通讯作者：
Gunduz, Ufuk
中科院分区：
文献类型：
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作者：
Donmez, Yaprak;Akhmetova, Laila;Gunduz, Ufuk
肿瘤化疗的主要问题之一是多药耐药(MDR)表型的形成。在MDR的众多机制中，一个突出的机制是膜转运蛋白的表达增加，其作用导致细胞内药物浓度降低和药物的细胞毒性。其中，MDR1基因编码的P-gp和MRP1基因编码的MRP1与MDR表型相关。化学调节剂可用于逆转多药耐药。这些化学物质既可以通过其底物类似物(如钙通道阻滞剂维拉帕米)调节MDR，也可与磷脂膜(如抗组胺药物异丙嗪)相互作用。为探讨维拉帕米和异丙嗪对乳腺癌耐药细胞株MCF-7中mdr1和MRP1基因表达水平及药物转运活性的影响，将耐药细胞株MCF-7/Dox分别与维拉帕米和异丙嗪共同孵育，提取总RNA。用mdr1、MRP1和-肌动蛋白基因的特异性引物进行实时定量聚合酶链式反应(QPCR)。激光共聚焦扫描显微镜观察阿霉素在细胞内的蓄积。结果显示，应用异丙嗪后，mdr1和mrp1的表达水平显著降低。研究还表明，维拉帕米处理细胞后，mdr1基因的表达水平显著降低。激光共聚焦扫描显微镜图像显示，维拉帕米作用于MCF-7/Dox细胞后，阿霉素在细胞内的蓄积增加。本研究从基因表达水平和转运活性水平探讨了维拉帕米和异丙嗪逆转多药耐药的效果。
One of the major problems of cancer chemotherapy is the development of multidrug resistance (MDR) phenotype. Among the numerous mechanisms of MDR, a prominent one is the increased expression of membrane transporter proteins, the action of which leads to decreased intracellular drug concentration and cytotoxicity of drugs. Among them, P-gp and MRP1, encoded by MDR1 and MRP1 genes, respectively, have been associated with MDR phenotype. Chemical modulators can be used to reverse MDR. These chemicals can either modulate MDR due to their substrate analogy (such as calcium channel blocker verapamil) or interact with phospholipid membranes (such as antihistaminic drug promethazine). This study focuses on the effect of verapamil and promethazine on the expression levels of MDR1 and MRP1 genes and the drug transport activity in doxorubicin-resistant MCF-7 breast carcinoma cell line.Doxorubicin-resistant MCF-7 (MCF-7/Dox) cells were incubated with either verapamil or promethazine, and total RNA was isolated. Real-time PCR (qPCR) was carried out by using specific primers for MDR1, MRP1, and -actin genes. Intracellular doxorubicin accumulation was also examined by confocal laser scanning microscopy in treated cells.Results demonstrated a significant decrease in both MDR1 and MRP1 expression levels after promethazine applications. It has also been shown that treatment of the cells with verapamil results in significant decrease in MDR1 mRNA levels. Confocal laser scanning microscopy images demonstrated that the intracellular accumulation of doxorubicin was increased after verapamil treatment in MCF-7/Dox cells.The present study gives an idea about the efficiency of verapamil and promethazine on MDR reversal both in gene expression and in transport activity levels.