Shahraki Omolbanin, Edraki Najmeh, Khoshneviszadeh Mehdi, Zargari Farshid, Ranjbar Sara, Saso Luciano, Firuzi Omidreza, Miri Ramin
Medicinal and Natural Products Chemistry Research Center; Department of Medicinal Chemistry, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran.
Medicinal and Natural Products Chemistry Research Center.
Drug Des Devel Ther. 2017 Feb 14;11:407-418. doi: 10.2147/DDDT.S119995. eCollection 2017.
Overexpression of the efflux pump P-glycoprotein (P-gp) is one of the important mechanisms of multidrug resistance (MDR) in many tumor cells. In this study, 26 novel 5-oxo-hexahydroquinoline derivatives containing different nitrophenyl moieties at C and various carboxamide substituents at C were designed, synthesized and evaluated for their ability to inhibit P-gp by measuring the amount of rhodamine 123 (Rh123) accumulation in uterine sarcoma cells that overexpress P-gp (MES-SA/Dx5) using flow cytometry. The effect of compounds with highest MDR reversal activities was further evaluated by measuring the alterations of MES-SA/Dx5 cells' sensitivity to doxorubicin (DXR) using MTT assay. The results of both biological assays indicated that compounds bearing 2-nitrophenyl at C position and compounds with 4-chlorophenyl carboxamide at C demonstrated the highest activities in resistant cells, while they were devoid of any effect in parental nonresistant MES-SA cells. One of the active derivatives, , significantly increased intracellular Rh123 at 100 µM, and it also significantly reduced the IC of DXR by 70.1% and 88.7% at 10 and 25 µM, respectively, in MES-SA/Dx5 cells. The toxicity of synthesized compounds against HEK293 as a noncancer cell line was also investigated. All tested derivatives except for compound showed no cytotoxicity. A molecular dynamics simulation study was also performed to investigate the possible binding site of in complex with human P-gp, which showed that this compound formed 11 average H-bonds with Ser909, Thr911, Arg547, Arg543 and Ser474 residues of P-gp. A good agreement was found between the results of the computational and experimental studies. The findings of this study show that some 5-oxo-hexahydroquinoline derivatives could serve as promising candidates for the discovery of new agents for P-gp-mediated MDR reversal.
外排泵P-糖蛋白（P-gp）的过表达是许多肿瘤细胞多药耐药（MDR）的重要机制之一。在本研究中，设计、合成了26种新型的5-氧代六氢喹啉衍生物，这些衍生物在C位含有不同的硝基苯基部分，在C位含有各种羧酰胺取代基，并通过使用流式细胞术测量过表达P-gp的子宫肉瘤细胞（MES-SA/Dx5）中罗丹明123（Rh123）的积累量，来评估它们抑制P-gp的能力。通过使用MTT法测量MES-SA/Dx5细胞对阿霉素（DXR）敏感性的变化，进一步评估了具有最高MDR逆转活性的化合物的效果。两种生物学试验的结果均表明，在C位带有2-硝基苯基的化合物以及在C位带有4-氯苯基羧酰胺的化合物在耐药细胞中表现出最高活性，而它们对亲本非耐药MES-SA细胞没有任何影响。其中一种活性衍生物，在100μM时显著增加细胞内Rh123，并且在MES-SA/Dx5细胞中，在10μM和25μM时，它还分别使DXR的IC显著降低70.1%和88.7%。还研究了合成化合物对作为非癌细胞系的HEK293的毒性。除化合物外，所有测试衍生物均无细胞毒性。还进行了分子动力学模拟研究，以研究与人类P-gp复合时的可能结合位点，结果表明该化合物与P-gp的Ser909、Thr911、Arg547、Arg543和Ser474残基形成了11个平均氢键。计算研究和实验研究的结果之间发现了良好的一致性。本研究结果表明，一些5-氧代六氢喹啉衍生物有望成为发现P-gp介导的MDR逆转新药物的候选物。
