Reversal of multidrug resistance by small interfering RNA (siRNA) in doxorubicin-resistant MCF-7 breast cancer cells
Reversal of multidrug resistance by small interfering RNA (siRNA) in doxorubicin-resistant MCF-7 breast cancer cells
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DOI：
10.1016/j.biopha.2010.12.007
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发表时间：
2011-03-01
影响因子：
7.5
通讯作者：
Gunduz, Ufuk
中科院分区：
文献类型：
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作者：
Donmez, Yaprak;Gunduz, Ufuk
目的：抗癌药物耐药是肿瘤化疗的严重障碍。多药耐药（multidrug resistance，MDR）的一种常见形式是由跨膜转运蛋白P-糖蛋白（P-gp）和多药耐药相关蛋白1（multidrug resistance-associated protein-1，MRP 1）的过度表达引起的，它们分别由MDR 1和MRP 1基因编码。这些蛋白质通过其将药物泵出细胞的能力导致细胞内药物浓度降低和细胞毒性降低。乳腺癌耐药主要与P-gp/MDR 1的过度表达有关。虽然一些化学MDR调节剂旨在通过干扰P-gp的功能来克服MDR，但它们的毒性限制了它们在临床上的应用。因此，RNA干扰介导的序列特异性抑制P-gp/MDR 1 mRNA的表达可能是逆转MDR表型和提高化疗成功率的有效工具。本研究的目的是通过选择性下调P-gp/MDR 1 mRNA来使阿霉素耐药的乳腺癌细胞对抗癌药物阿霉素重新敏感。用共聚焦激光扫描显微镜研究MDR 1 siRNA处理后细胞内药物积聚和定位。XTT细胞增殖实验检测MDR 1基因沉默对阿霉素敏感性的影响。结果：筛选出的靶向MDR 1 mRNA的siRNA可使约90%的MDR 1基因沉默。而MDR 1下调后MRP 1 mRNA水平无明显变化。沉默P-gp编码的MDR 1基因导致几乎完全恢复细胞内阿霉素的积累和药物在细胞核中的重新定位。结论：筛选出的siRNA双链体能有效抑制MDR 1基因表达，恢复阿霉素的聚集和定位，增强耐药细胞的化疗敏感性，是一种理想的治疗药物。(C)2010年Elsevier Masson SAS。All rights reserved.
Purpose: Resistance to anticancer drugs is a serious obstacle to cancer chemotherapy. A common form of multidrug resistance (MDR) is caused by the overexpression of transmembrane transporter proteins P-glycoprotein (P-gp) and multidrug resistance-associated protein-1 (MRP1), encoded by MDR1 and MRP1 genes, respectively. These proteins lead to reduced intracellular drug concentration and decreased cytotoxicity by means of their ability to pump the drugs out of the cells. Breast cancer tumor resistance is mainly associated with overexpression of P-gp/MDR1. Although some chemical MDR modulators aim to overcome MDR by interfering functioning of P-gp, their toxicities limit their usage in clinics. Consequently, RNA interference mediated sequence specific inhibition of the expression of P-gp/MDR1 mRNA may be an efficient tool to reverse MDR phenotype and increase the success of chemotherapy. Aim of this study was resensitizing doxorubicin-resistant breast cancer cells to anticancer agent doxorubicin by selective downregulation of P-gp/MDR1 mRNA.Methods: The effect of the selected MDR1 siRNA, and MRP1 expression after MDR1 silencing was determined by qPCR analysis. Intracellular drug accumulation and localization was investigated by confocal laser scanning microscopy after treatment with MDR1 siRNA. XTT cell proliferation assay was performed to determine the effect of MDR1 silencing on doxorubicin sensitivity.Results: The results demonstrated that approximately 90% gene silencing occurred by the selected siRNA targeting MDR1 mRNA. However, the level of MRP1 mRNA did not change after MDR1 downregulation. Silencing of P-gp encoding MDR1 gene resulted in almost complete restoration of the intracellular doxorubicin accumulation and relocalization of the drug in the nuclei. Introduction of siRNA resulted in about 70% resensitization to doxorubicin.Conclusions: Selected siRNA duplex was shown to effectively inhibit MDR1 gene expression, restore doxorubicin accumulation and localization, and enhance chemosensitivity of resistant cells, which makes it a suitable candidate for therapeutic applications. (C) 2010 Elsevier Masson SAS. All rights reserved.