Hegedus C, Ozvegy-Laczka C, Apáti A, Magócsi M, Német K, Orfi L, Kéri G, Katona M, Takáts Z, Váradi A, Szakács G, Sarkadi B
Membrane Research Group of the Hungarian Academy of Sciences, National Blood Center and Semmelweis University, Budapest, Hungary.
Br J Pharmacol. 2009 Oct;158(4):1153-64. doi: 10.1111/j.1476-5381.2009.00383.x. Epub 2009 Sep 28.
ABC multidrug transporters (MDR-ABC proteins) cause multiple drug resistance in cancer and may be involved in the decreased anti-cancer efficiency and modified pharmacological properties of novel specifically targeted agents. It has been documented that ABCB1 and ABCG2 interact with several first-generation, small-molecule, tyrosine kinase inhibitors (TKIs), including the Bcr-Abl fusion kinase inhibitor imatinib, used for the treatment of chronic myeloid leukaemia. Here, we have investigated the specific interaction of these transporters with nilotinib, dasatinib and bosutinib, three clinically used, second-generation inhibitors of the Bcr-Abl tyrosine kinase activity.
MDR-ABC transporter function was screened in both membrane- and cell-based (K562 cells) systems. Cytotoxicity measurements in Bcr-Abl-positive model cells were coupled with direct determination of intracellular TKI concentrations by high-pressure liquid chromatography-mass spectrometry and analysis of the pattern of Bcr-Abl phosphorylation. Transporter function in membranes was assessed by ATPase activity.
Nilotinib and dasatinib were high-affinity substrates of ABCG2, and this protein mediated an effective resistance in cancer cells against these compounds. Nilotinib and dasatinib also interacted with ABCB1, but this transporter provided resistance only against dasatinib. Neither ABCB1 nor ABCG2 induced resistance to bosutinib. At relatively higher concentrations, however, each TKI inhibited both transporters.
A combination of in vitro assays may provide valuable preclinical information for the applicability of novel targeted anti-cancer TKIs, even in multidrug-resistant cancer. The pattern of MDR-ABC transporter-TKI interactions may also help to understand the general pharmacokinetics and toxicities of new TKIs.
ABC多药转运蛋白（MDR-ABC蛋白）导致癌症中的多药耐药，并且可能参与新型特异性靶向药物抗癌效率的降低和药理学特性的改变。已有文献记载，ABCB1和ABCG2与几种第一代小分子酪氨酸激酶抑制剂（TKIs）相互作用，包括用于治疗慢性髓性白血病的Bcr-Abl融合激酶抑制剂伊马替尼。在此，我们研究了这些转运蛋白与尼洛替尼、达沙替尼和博舒替尼这三种临床使用的第二代Bcr-Abl酪氨酸激酶活性抑制剂的特异性相互作用。
在基于膜和细胞（K562细胞）的系统中筛选MDR-ABC转运蛋白功能。在Bcr-Abl阳性模型细胞中进行细胞毒性测量，并通过高压液相色谱-质谱法直接测定细胞内TKI浓度以及分析Bcr-Abl磷酸化模式。通过ATP酶活性评估膜中的转运蛋白功能。
尼洛替尼和达沙替尼是ABCG2的高亲和力底物，并且该蛋白介导癌细胞对这些化合物的有效耐药。尼洛替尼和达沙替尼也与ABCB1相互作用，但该转运蛋白仅对达沙替尼产生耐药。ABCB1和ABCG2均未诱导对博舒替尼的耐药。然而，在相对较高浓度下，每种TKI均抑制这两种转运蛋白。
体外试验的组合可为新型靶向抗癌TKI的适用性提供有价值的临床前信息，即使在多药耐药癌症中也是如此。MDR-ABC转运蛋白与TKI相互作用的模式也可能有助于理解新TKI的一般药代动力学和毒性。
