Cellular Phototoxicity Evoked Through the Inhibition of Human ABC Transporter ABCG2 by Cyclin-dependent Kinase Inhibitors In vitro
Cellular Phototoxicity Evoked Through the Inhibition of Human ABC Transporter ABCG2 by Cyclin-dependent Kinase Inhibitors In vitro
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DOI：
10.1007/s11095-008-9738-5
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发表时间：
2009-02-01
影响因子：
3.7
通讯作者：
Ishikawa, Toshihisa
中科院分区：
文献类型：
--
作者：
An, Ran;Hagiya, Yuichiro;Ishikawa, Toshihisa
目的.人类ATP结合盒（ABC）转运蛋白ABCG 2的生理重要性已被公认为与卟啉介导的光敏性有关。由于药物或其遗传多态性抑制ABCG 2而导致的功能损害可能导致卟啉稳态的破坏，这反过来又导致细胞毒性。我们评估了ABCG 2功能的细胞周期蛋白依赖性激酶（CDK）抑制剂对光敏性的影响。为此，我们建立了新的方法，通过使用Flp-In-293细胞和质膜囊泡制备的Sf 9昆虫细胞的光敏性测定。使用新方法，我们随后测试了CDK抑制剂，即，purvalanol A、WHI-P180、bohemine、roscovitine和olomoucine。在测试的CDK抑制剂中，发现purvalanol A是ABCG 2介导的血卟啉转运的最有效的抑制剂（IC 50 =3.5 μ M）。在2.5 μ M的浓度下，它诱发了用脱镁叶绿酸a处理的表达ABCG 2的Flp-In-293细胞的光敏性。WHI-P180中度抑制ABCG 2功能，表现出弱的光毒性。相比之下，在我们的测定系统中，波希米亚碱、roscovitine和奥洛莫辛的光毒性最小。这表明，平面结构是一个重要的因素与ABCG 2的活性位点的相互作用。本研究为药物光毒性的体外研究提供了一种新的途径。
Purpose. The physiological importance of the human ATP-binding cassette (ABC) transporter ABCG2 has been recognized with regard to porphyrin-mediated photosensitivity. Functional impairment owing to inhibition of ABCG2 by drugs or its genetic polymorphisms may lead to the disruption of porphyrin homeostasis, which in turn causes cellular toxicity.Materials and Methods. We evaluated the impact on photosensitivity of the inhibition by cyclin-dependent kinase (CDK) inhibitors of ABCG2 function. For this purpose, we established new methods for photosensitivity assays by using Flp-In-293 cells and plasma membrane vesicles prepared from Sf9 insect cells. With the new methods, we subsequently tested CDK inhibitors, i.e., purvalanol A, WHI-P180, bohemine, roscovitine, and olomoucine.Results. Among CDK inhibitors tested, purvalanol A was found to be the most potent inhibitor (IC50=3.5 mu M) for ABCG2-mediated hematoporphyrin transport. At a concentration of 2.5 mu M, it evoked the photosensitivity of ABCG2-expressing Flp-In-293 cells treated with pheophorbide a. WHI-P180 moderately inhibited ABCG2 function, exhibiting weak phototoxicity. In contrast, the phototoxicity of bohemine, roscovitine, and olomoucine were minimal in our assay system.Conclusions. It is suggested that the planar structure is an important factor for interactions with the active site of ABCG2. The present study provides a new approach to studying drug-induced phototoxicity in vitro.