Human Immunodeficiency Virus Protease Inhibitors Interact with ATP Binding Cassette Transporter 4/Multidrug Resistance Protein 4: A Basis for Unanticipated Enhanced Cytotoxicity
Human Immunodeficiency Virus Protease Inhibitors Interact with ATP Binding Cassette Transporter 4/Multidrug Resistance Protein 4: A Basis for Unanticipated Enhanced Cytotoxicity
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DOI：
10.1124/mol.113.086967
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发表时间：
2013-09-01
影响因子：
3.6
通讯作者：
Schuetz, John D.
中科院分区：
文献类型：
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作者：
Fukuda, Yu;Takenaka, Kazumasa;Schuetz, John D.
人类免疫缺陷病毒（HIV）药物治疗，通过结合不同的药物类别，如核苷类似物和HIV蛋白酶抑制剂（PI），增加了HIV患者的预期寿命。因此，在这些患者中，非HIV相关癌症的增加产生了需要HIV和癌症化疗的患者队列。我们假设多药耐药蛋白4/ATP结合盒转运体4（MRP 4/ABCC 4），一种广泛表达的核苷类抗病毒药物以及癌症治疗药物的转运体，可能与PI相互作用。在评价的PI（奈非那韦、利托那韦、安普那韦、沙奎那韦和茚地那韦）中，只有奈非那韦既能有效刺激MRP 4 ATP酶活性，又能抑制底物刺激的ATP酶活性。Saos 2和人胚肾293细胞工程改造过表达MRP 4，然后用于评估运输和细胞毒性。MRP 4的表达减少了奈非那韦的细胞内积累，从而赋予奈非那韦细胞毒性的生存优势。奈非那韦阻断Mrp 4介导的输出，这与其增加表达MRP 4的细胞对甲氨蝶呤的敏感性的能力一致。相反，小鼠细胞中Abcc 4/Mrp 4的靶向失活特异性增强奈非那韦和9-（2-膦酰甲氧基乙基）腺嘌呤的细胞毒性。这些结果表明，奈非那韦既是MRP 4的抑制剂，也是其底物。由于奈非那韦是一种新的MRP 4/ABCC 4底物，我们建立了一个MRP 4/ABCC 4药效团模型，该模型表明奈非那韦与化疗底物如阿德福韦和甲氨蝶呤具有相同的结合位点。我们的研究首次揭示了奈非那韦，一种强效的细胞毒性PI，既是MRP 4的底物又是其抑制剂。这些发现表明，考虑到MRP 4/ABCC 4在出口核苷类抗逆转录病毒药物和癌症化疗药物中的作用，接受奈非那韦的HIV感染癌症患者可能会经历增强的抗肿瘤疗效和意外的不良毒性。
Human immunodeficiency virus (HIV) pharmacotherapy, by combining different drug classes such as nucleoside analogs and HIV protease inhibitors (PIs), has increased HIV-patient life expectancy. Consequently, among these patients, an increase in non-HIV-associated cancers has produced a patient cohort requiring both HIV and cancer chemotherapy. We hypothesized that multidrug resistance protein 4/ATP binding cassette transporter 4 (MRP4/ABCC4), a widely expressed transporter of nucleoside-based antiviral medications as well as cancer therapeutics might interact with PIs. Among the PIs evaluated (nelfinavir, ritonavir, amprenavir, saquinavir, and indinavir), only nelfinavir both effectively stimulated MRP4 ATPase activity and inhibited substrate-stimulated ATPase activity. Saos2 and human embryonic kidney 293 cells engineered to overexpress MRP4 were then used to assess transport and cytotoxicity. MRP4 expression reduced intracellular accumulation of nelfinavir and consequently conferred survival advantage to nelfinavir cytotoxicity. Nelfinavir blocked Mrp4-mediated export, which is consistent with its ability to increase the sensitivity of MRP4-expressing cells to methotrexate. In contrast, targeted inactivation of Abcc4/Mrp4 in mouse cells specifically enhanced nelfinavir and 9-(2-phosphonylmethoxyethyl) adenine cytotoxicity. These results suggest that nelfinavir is both an inhibitor and substrate of MRP4. Because nelfinavir is a new MRP4/ABCC4 substrate, we developed a MRP4/ABCC4 pharmacophore model, which showed that the nelfinavir binding site is shared with chemotherapeutic substrates such as adefovir and methotrexate. Our studies reveal, for the first time, that nelfinavir, a potent and cytotoxic PI, is both a substrate and inhibitor of MRP4. These findings suggest that HIV-infected cancer patients receiving nelfinavir might experience both enhanced antitumor efficacy and unexpected adverse toxicity given the role of MRP4/ABCC4 in exporting nucleoside-based antiretroviral medications and cancer chemotherapeutics.