Chen L, Zhao Y, Halliday G C, Berry P, Rousseau R F, Middleton S A, Nichols G L, Del Bello F, Piergentili A, Newell D R, Lunec J, Tweddle D A
Newcastle Cancer Centre, Northern Institute for Cancer Research, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
Br J Cancer. 2014 Aug 12;111(4):716-25. doi: 10.1038/bjc.2014.325. Epub 2014 Jun 12.
A frequent mechanism of acquired multidrug resistance in human cancers is overexpression of ATP-binding cassette transporters such as the Multi-Drug Resistance Protein 1 (MDR-1). Nutlin-3, an MDM2-p53 antagonist, has previously been reported to be a competitive MDR-1 inhibitor.
This study assessed whether the structurally diverse MDM2-p53 antagonists, MI-63, NDD0005, and RG7388 are also able to modulate MDR-1 function, particularly in p53 mutant neuroblastoma cells, using XTT-based cell viability assays, western blotting, and liquid chromatography-mass spectrometry analysis.
Verapamil and the MDM2-p53 antagonists potentiated vincristine-mediated growth inhibition in a concentration-dependent manner when used in combination with high MDR-1-expressing p53 mutant neuroblastoma cell lines at concentrations that did not affect the viability of cells when given alone. Liquid chromatography-mass spectrometry analyses showed that verapamil, Nutlin-3, MI-63 and NDD0005, but not RG7388, led to increased intracellular levels of vincristine in high MDR-1-expressing cell lines.
These results show that in addition to Nutlin-3, other structurally unrelated MDM2-p53 antagonists can also act as MDR-1 inhibitors and reverse MDR-1-mediated multidrug resistance in neuroblastoma cell lines in a p53-independent manner. These findings are important for future clinical trial design with MDM2-p53 antagonists when used in combination with agents that are MDR-1 substrates.
人类癌症中获得性多药耐药的常见机制是ATP结合盒转运蛋白的过表达，如多药耐药蛋白1（MDR-1）。Nutlin-3是一种MDM2-p53拮抗剂，此前有报道称它是一种竞争性MDR-1抑制剂。
本研究使用基于XTT的细胞活力测定、蛋白质印迹法和液相色谱-质谱分析，评估结构多样的MDM2-p53拮抗剂MI-63、NDD0005和RG7388是否也能够调节MDR-1功能，特别是在p53突变的神经母细胞瘤细胞中。
维拉帕米和MDM2-p53拮抗剂与高表达MDR-1的p53突变神经母细胞瘤细胞系联合使用时，以浓度依赖性方式增强长春新碱介导的生长抑制作用，单独使用时的浓度不影响细胞活力。液相色谱-质谱分析表明，维拉帕米、Nutlin-3、MI-63和NDD0005，但不包括RG7388，导致高表达MDR-1的细胞系中长春新碱的细胞内水平升高。
这些结果表明，除了Nutlin-3之外，其他结构不相关的MDM2-p53拮抗剂也可以作为MDR-1抑制剂，并以不依赖p53的方式逆转神经母细胞瘤细胞系中MDR-1介导的多药耐药。这些发现对于未来将MDM2-p53拮抗剂与MDR-1底物药物联合使用的临床试验设计具有重要意义。
