Ichibangase Y, Yamamoto M, Yasuda M, Houki N, Nobunaga M
Department of Clinical Immunology, Medical Institute of Bioregulation, Kyushu University, Beppu City, Oita, Japan.
Clin Rheumatol. 1998;17(3):214-8. doi: 10.1007/BF01451050.
The expression of metallothionein, an intracellular heavy-metal-binding protein, and p-glycoprotein, an energy-dependent drug efflux pump, was examined to study the mechanism of cell resistance to gold sodium thiomalate (GST). THP-1, one of the monocyte-derived cell lines, was cultured for 6 months and resistance to 25 microg/ml of GST (GST-resistant cells) was thus induced. The GST-resistant cells were then cultured with bucillamine to examine the presence of cross-resistance. The intracellular GST concentration was examined by flameless atomic absorption spectroscopy. The cell viability was determined by the uptake of 3-4,5 dimethylthiazole-2,5 diphenyl tetrazolium bromide (MTT). The expression of p-glycoprotein was detected by Western blotting using monoclonal anti-p-glycoprotein antibody. The expression of metallothionein was detected using the indirect immunofluorescence technique. GST-resistant cells did not show any cross-resistance to bucillamine. The rate of cytoplasmic GST accumulation decreased in the GST-resistant cells, while the rate of GST efflux also decreased. The expression of p-glycoprotein in the GST-resistant cells was not significantly different from that in the cells not treated with GST. On the other hand, the GST-resistant cells showed a higher expression of metallothionein than cells not treated with GST. These findings suggest that the induced resistance to GST might partly be due to an induction of metallothionein.
为研究细胞对硫代苹果酸金钠（GST）耐药的机制，检测了细胞内重金属结合蛋白金属硫蛋白和能量依赖性药物外排泵P -糖蛋白的表达。单核细胞衍生细胞系之一的THP - 1细胞培养6个月，从而诱导出对25μg/ml GST的耐药性（GST耐药细胞）。然后用布西拉明培养GST耐药细胞，检测交叉耐药性的存在。通过无火焰原子吸收光谱法检测细胞内GST浓度。通过3 -（4,5 -二甲基噻唑-2）- 2,5 -二苯基四氮唑溴盐（MTT）摄取法测定细胞活力。使用单克隆抗P -糖蛋白抗体通过蛋白质免疫印迹法检测P -糖蛋白的表达。使用间接免疫荧光技术检测金属硫蛋白的表达。GST耐药细胞对布西拉明未表现出任何交叉耐药性。GST耐药细胞中细胞质GST积累率降低，而GST外排率也降低。GST耐药细胞中P -糖蛋白的表达与未用GST处理的细胞相比无显著差异。另一方面，GST耐药细胞中金属硫蛋白的表达高于未用GST处理的细胞。这些发现表明，诱导产生的对GST的耐药性可能部分归因于金属硫蛋白的诱导。
