Molecular Mimics of Classic P-Glycoprotein Inhibitors as Multidrug Resistance Suppressors and Their Synergistic Effect on Paclitaxel
作者:Moustafa E. El-Araby、Abdelsattar M. Omar、Maan T. Khayat、Hanan A. Assiri、Ahmed M. Al-Abd
DOI:10.1371/journal.pone.0168938
日期:——
P-glycoprotein (Pgp) is a membrane bound efflux pump spread in a variety of tumor cells and considered as a main component of multidrug resistance (MDR) to chemotherapies. In this work, three groups of compounds (imidazolone, oxazolone and vinyl dipeptide derivatives) were synthesized aiming to develop a molecular framework that effectively suppresses MDR. When tested for their influence on Pgp activity, four compounds coded Cur1-01, Cur1-12V, Curox-1 and Curox-3 significantly decreased remaining ATP concentration indicating Pgp substrate site blocking. On the other hand, Cur-3 and Cur-10 significantly increased remaining ATP concentration, which is indicative of Pgp ATPase inhibition. The cytotoxicity of synthesized compounds was examined against Pgp expressing/highly resistant colorectal cancer cell lines (LS-174T). Compounds Cur-1 and Cur-3 showed considerable cytotoxicity with IC50 values of 7.6 and 8.9 μM, respectively. Equitoxic combination (at IC50 concentrations) of PTX and Cur-3 greatly diminished resistant cell clone from 45.7% to 2.5%, albeit with some drop in potency from IC50 of 7.9 nM to IC50 of 23.8 nM. On the other hand, combination of PTX and the non-cytotoxic Cur1-12V (10 μM) significantly decreased the IC50 of PTX to 3.8 nM as well as the resistant fraction to 16.2%. The combination test was confirmed using the same protocol but on another resistant CRC cell line (HCT-116) as we obtained similar results. Both Cur-3 and Cur1-12V (10 μM) significantly increased the cellular entrapment of Pgp probe (doxorubicin) elevating its intracellular concentration from 1.9 pmole/cell to 3.0 and 2.9 pmole/cell, respectively.
P-糖蛋白(Pgp)是一种膜结合的排出泵,分布于各种肿瘤细胞中,被认为是化疗多药耐药性(MDR)的主要成分。在本研究中,合成了三组化合物(咪唑酮、噁唑酮和乙烯基二肽衍生物),旨在开发一种有效抑制MDR的分子框架。在测试它们对Pgp活性的影响时,编号为Cur1-01、Cur1-12V、Curox-1和Curox-3的四种化合物显著降低了剩余ATP浓度,表明Pgp底物结合位点被阻断。另一方面,Cur-3和Cur-10显著增加了剩余ATP浓度,这表明Pgp ATP酶受到抑制。针对表达Pgp/高度耐药的结直肠癌细胞系(LS-174T),检测了合成化合物的细胞毒性。化合物Cur-1和Cur-3显示出明显的细胞毒性,其IC50值分别为7.6和8.9 μM。等毒性组合(在IC50浓度下)的PTX和Cur-3将耐药细胞克隆从45.7%降低到2.5%,尽管其效力从IC50的7.9 nM降至23.8 nM。另一方面,PTX与非细胞毒性的Cur1-12V(10 μM)组合显著降低了PTX的IC50至3.8 nM以及耐药部分至16.2%。利用相同的协议,在另一种耐药的结直肠癌(CRC)细胞系(HCT-116)上确认了组合测试,我们获得了类似的结果。Cur-3和Cur1-12V(10 μM)显著增加了细胞内Pgp探针(多柔比星)的包裹量,使其细胞内浓度从1.9 pmole/cell分别增加到3.0和2.9 pmole/cell。