Overexpression of glutathione S-transferase π enhances the adduct formation of cisplatin with glutathione in human cancer cells
Overexpression of glutathione S-transferase π enhances the adduct formation of cisplatin with glutathione in human cancer cells
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DOI：
10.1080/10715769900301121
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发表时间：
1999-01-01
影响因子：
3.3
通讯作者：
Kondo, T
中科院分区：
文献类型：
--
作者：
Goto, S;Iida, T;Kondo, T
在本文中，我们提供了直接的证据，谷胱甘肽S-转移酶PI（GST PI）解毒顺铂（CDDP）。我们使用人结肠癌HCT 8细胞对CDDP敏感和耐药，顺铂-谷胱甘肽加合物（DDP-GSH）水平在耐药细胞中更高。在这些CDDP耐药细胞中存在GST pi mRNA的过表达。细胞与CDDP孵育后，DDP-GSH的形成依赖于CDDP的浓度和孵育时间。当细胞用GST pi抑制剂ethacrynic酸或酮洛芬预处理时，DDP-GSH的形成被消除。纯化的GST pi还在体外催化DDP-GSH的形成，对于CDDP具有0.23 mM的表观Km和4.9 nmol/min/mg蛋白质的表观V-max。GST pi产生的DDP-GSH的增加与孵育时间呈线性关系，最长可达3 h，最适pH为7.4。用含有GST π cDNA的表达载体pcDNA3.1（-）/Myc-His B在HCT 8细胞中构建GST π转染细胞系。将GST pi cDNA转染入HCT 8细胞中导致GST pi表达增加1.4倍，同时增加DDP-GSH的形成。这些结果表明，GST pi Flays在癌细胞中DDP-GSH的形成和对CDDP的抗性的获得中起作用。
In this paper, we provide direct evidence that glutathione S-transferase pi (GST pi) detoxifies cisplatin (CDDP). We used human colonic cancer HCT8 cells sensitive and resistant to CDDP, the level of cisplatin-glutathione adduct (DDP-GSH) being higher in the resistant cells. There was an overexpression of GST pi mRNA in these CDDP-resistant cells. Incubation of the cells with CDDP resulted in the formation of DDP-GSH dependent on the CDDP concentration and the incubation time. The formation of DDP-GSH was abolished when the cells were pre-treated with ethacrynic acid or ketoprofen, inhibitors of GST pi. Purified GST pi also catalyzed the formation of DDP-GSH in vitro, with an apparent K-m of 0.23 mM for CDDP and an apparent V-max of 4.9 nmol/min/mg protein. The increase in DDP-GSH produced by GST pi was linear with incubation time up to 3 h and optimal of pH 7.4. A GST ii transfectant cell line was constructed in HCT8 cells using a pcDNA3.1 (-)/Myc-His B with an expression vector containing cDNA for GST pi. Transfection of GST pi cDNA into HCT8 cells resulted in an increase in the expression of GST pi by 1.4-fold in parallel with an augmentation of the formation of DDP-GSH. These results suggest that GST pi Flays a role in the formation of DDP-GSH and the acquisition of resistance to CDDP in cancer cells.