Sharp S Y, Smith V, Hobbs S, Kelland L R
CRC Centre for Cancer Therapeutics, The Institute of Cancer Research, Sutton, Surrey, UK.
Br J Cancer. 1998 Jul;78(2):175-80. doi: 10.1038/bjc.1998.461.
The level of expression of the multidrug resistance-associated protein (MRP1) in a panel of human ovarian carcinoma cell lines and their variants with acquired cisplatin resistance was determined using Western blotting. No overexpression of MRP1 was detected in any of the cell lines. In addition, we have transfected the MRP1 gene into an intrinsically cisplatin-resistant cell line SKOV3, previously shown to have elevated levels of glutathione (GSH). The MRP1-transfected line SKOV3-S2 was shown to be cross-resistant to doxorubicin, vincristine and etoposide but not to paclitaxel, vinblastine and platinum agents, such as cisplatin, JM216 [bis-acetato-ammine-dichloro-cyclohexylamine platinum (IV)] and AMD473 [cis-ammine dichloro (2-methyl-pyridine) platinum (II)]. No cross-resistance to any of the platinum agents was observed in a MRP1-overexpressing human lung cancer cell line with acquired doxorubicin resistance. Reduction of GSH levels (80-90%) by buthionine sulphoximine (BSO) produced significant potentiation in cisplatin sensitivity in the parental SKOV3, the vector-alone control SKOV3-puro and the MRP1-transfected line SKOV3-S2. The degree of sensitization was similar in all cell lines (1.6-fold). However, selective sensitization by BSO to vincristine was observed in the MRP1-transfected line (4.1-fold) but not in the vector control. No significant differences were observed in cisplatin accumulation in the SKOV3-puro and the SKOV3-S2 cells, although both these transfected lines accumulated significantly more than the parental line. Our results suggest that MRP1 does not play a significant role in platinum resistance in the human tumour cell lines investigated in this study.
使用蛋白质免疫印迹法测定了一组人卵巢癌细胞系及其获得性顺铂耐药变体中多药耐药相关蛋白（MRP1）的表达水平。在任何细胞系中均未检测到MRP1的过表达。此外，我们已将MRP1基因转染到一种内在顺铂耐药的细胞系SKOV3中，该细胞系先前已显示谷胱甘肽（GSH）水平升高。转染MRP1的细胞系SKOV3-S2对多柔比星、长春新碱和依托泊苷具有交叉耐药性，但对紫杉醇、长春碱和铂类药物如顺铂、JM216 [双乙酸-氨-二氯-环己胺铂（IV）]和AMD473 [顺-氨二氯（2-甲基吡啶）铂（II）]不具有交叉耐药性。在获得性多柔比星耐药的MRP1过表达人肺癌细胞系中未观察到对任何铂类药物的交叉耐药性。丁硫氨酸亚砜胺（BSO）使GSH水平降低（80 - 90%），在亲本SKOV3、仅载体对照SKOV3-puro和转染MRP1的细胞系SKOV3-S2中，顺铂敏感性显著增强。所有细胞系中的致敏程度相似（1.6倍）。然而，在转染MRP1的细胞系中观察到BSO对长春新碱的选择性致敏（4.1倍），而在载体对照中未观察到。尽管这两个转染细胞系的顺铂蓄积量均显著高于亲本细胞系，但SKOV3-puro和SKOV3-S2细胞中的顺铂蓄积量未观察到显著差异。我们的结果表明，在本研究中所研究的人肿瘤细胞系中，MRP1在铂耐药中不发挥重要作用。
