Modification and uptake of a cisplatin carbonato complex by Jurkat cells
Modification and uptake of a cisplatin carbonato complex by Jurkat cells
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DOI：
10.1124/mol.106.023184
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发表时间：
2006-07-01
影响因子：
3.6
通讯作者：
Dabrowiak, James C.
中科院分区：
文献类型：
--
作者：
Centerwall, Corey R.;Tacka, Kirk A.;Dabrowiak, James C.
用H-1-N-15异核单量子相干核磁共振和电感耦合等离子体质谱研究了Jurkat细胞与顺铂顺铂[铂((NH3)-N-15)(2)Cl2](1)的相互作用。我们发现，Jurkat细胞在培养中迅速修饰单碳酸盐络合物顺-[铂((NH3)-N-15)(2)(CO3)Cl](-)(4)，这是一种在培养液中形成的顺铂物种，可能也在血液中形成。对4在不同数量的Jurkat细胞存在下的HSQC核磁共振峰强度的分析表明，每个细胞能够在类似于0.6h的时间内修饰0.0028 pmol的4。测量了细胞摄取的铂量、与细胞表面弱结合的铂量、保留在培养液中的铂量以及与基因组DNA结合的铂量作为接触不同浓度药物的时间的函数。结果表明，经细胞修饰后的4-甲基-4-羟基丁酸大部分以分子质量&3 kDa的形式留在培养液中，不被细胞摄取，HSQC-核磁共振无声。这些结果与迄今未见文献报道的细胞外解毒机制一致，在该机制中，细胞迅速修改存在于培养液中的4，因此它不能与细胞结合。由于在培养1h，-1.1+/-0.4muMh(-1)后，培养液中残留的未修饰4的量缓慢减少，细胞随后失去了修饰4的能力。这些观察结果对顺铂的作用机制有重要的意义。
The interactions of Jurkat cells with cisplatin, cis-[Pt((NH3)-N-15)(2)Cl-2](1), are studied using H-1-N-15 heteronuclear single quantum coherence (HSQC) NMR and inductively coupled plasma mass spectrometry. We show that Jurkat cells in culture rapidly modify the monocarbonato complex cis-[Pt((NH3)-N-15)(2)(CO3)Cl](-) (4), a cisplatin species that forms in culture media and probably also in blood. Analysis of the HSQC NMR peak intensity for 4 in the presence of different numbers of Jurkat cells reveals that each cell is capable of modifying 0.0028 pmol of 4 within similar to 0.6 h. The amounts of platinum taken up by the cell, weakly bound to the cell surface, remaining in the culture medium, and bound to genomic DNA were measured as functions of time of exposure to different concentrations of drug. The results show that most of the 4 that has been modified by the cells remains in the culture medium as a substance of molecular mass < 3 kDa, which is HSQC NMR silent, and is not taken up by the cell. These results are consistent with a hitherto undocumented extracellular detoxification mechanism in which the cells rapidly modify 4, which is present in the culture medium, so it cannot bind to the cell. Because there is only a slow decrease in the amount of unmodified 4 remaining in the culture medium after 1 h, -1.1 +/- 0.4 mu M h(-1), the cells subsequently lose their ability to modify 4. These observations have important implications for the mechanism of action of cisplatin.