Pharmacological and biological evidence for differing mechanisms of doxorubicin resistance in two human tumor cell lines.
Pharmacological and biological evidence for differing mechanisms of doxorubicin resistance in two human tumor cell lines.
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发表时间：
1988-05
期刊：
影响因子：
11.2
通讯作者：
M. Slovak;G. Hoeltge;W. Dalton;J. Trent
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文献类型：
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作者：
M. Slovak;G. Hoeltge;W. Dalton;J. Trent
多柔比星耐药（DOXR）的细胞药理学通常与药物摄取减少、药物外排增强、对多种抗癌药物的交叉耐药性以及Mr 170，000细胞表面糖蛋白（称为P-糖蛋白）的过度产生有关。在这项研究中，两个新衍生的人DOXR亚系的药理学和遗传学特征进行了检查。这些DOXR亚系在持续增加DOX暴露后建立，直到开发出222倍抗性纤维肉瘤亚系（HT 1080/DR 4）和285倍抗性结肠腺癌亚系（LoVo/DR 5）。然而，三个主要的证据表明，尽管选择策略相似，但DOXR的机制在这两种细胞系之间显著不同。首先，使用对P-糖蛋白特异的C219抗体的蛋白质印迹法揭示了Mr 170，000细胞表面糖蛋白在LoVo DOXR细胞中的过表达，但在HT 1080 DOXR细胞中没有。其次，LoVo DOXR细胞对长春新碱、放线菌素D、秋水仙碱、依托泊苷和短杆菌肽D具有交叉耐药性，但对1-β-D-阿拉伯呋喃糖基胞嘧啶没有交叉耐药性。相反，HT 1080 DOXR细胞显示对长春新碱、放线菌素D、长春碱和依托泊苷的交叉耐药;然而，它们对短杆菌肽D没有交叉耐药，并且显示对1-β-D-阿拉伯呋喃糖基胞嘧啶的交叉耐药增加（约18倍）。第三，在LoVo DOXR细胞中，细胞内DOX积累（如在1小时时通过[14 C]DOX和高效液相色谱分析测量的）降低约2.7倍，在HT 1080/DR 4细胞中降低约2.0倍。然而，尽管在5微克/ml维拉帕米存在下的净蓄积研究将LoVo结肠腺癌细胞中的DOXR逆转至亲本值，但其仅最低限度地降低了HT 1080/DR 4细胞中的DOX抗性（12.6%）。DOXR亚系的[14 C]DOX外排模式相似，与其各自的亲本细胞系相比，1小时后DOX保留减少约50%。我们的研究结果表明，DOXR在LoVo/DR 5细胞中可能是由于P-糖蛋白的过度表达。相反，HT 1080/DR 4中的DOXR似乎是非P-糖蛋白介导的，并且可能与能够改变药物外排或差异药物结合的替代机制有关。
The cellular pharmacology of doxorubicin resistance (DOXR) has most commonly been associated with decreased drug uptake, enhanced drug efflux, cross-resistance to multiple anticancer agents, and the overproduction of a Mr 170,000 cell surface glycoprotein (termed P-glycoprotein). In this study, the pharmacological and genetic characteristics of two newly derived human DOXR sublines were examined. These DOXR sublines were established following continuously increasing DOX exposure until a 222-fold resistant fibrosarcoma subline (HT1080/DR4) and a 285-fold resistant colon adenocarcinoma subline (LoVo/DR5) were developed. However, three major lines of evidence suggest that despite the similar selection strategy, the mechanism of DOXR differs significantly between these two cell lines. First, Western blotting using the C219 antibody specific to P-glycoprotein revealed the overexpression of the Mr 170,000 cell surface glycoprotein in LoVo DOXR cells but not in HT1080 DOXR cells. Second, LoVo DOXR cells are cross-resistant to vincristine, actinomycin D, colchicine, etoposide, and gramicidin D, but not to 1-beta-D-arabinofuranosylcytosine. In contrast, HT1080 DOXR cells display cross-resistance to vincristine, actinomycin D, vinblastine, and etoposide; however, they are not cross-resistant to gramicidin D, and show an increased (approximately 18-fold) cross-resistance to 1-beta-D-arabinofuranosylcytosine. Third, intracellular DOX accumulation (as measured by [14C]DOX at 1-h and high-performance liquid chromatography analysis) was decreased approximately 2.7-fold in LoVo DOXR cells and approximately 2.0-fold in HT1080/DR4 cells. However, while net accumulation studies in the presence of 5 micrograms/ml verapamil reversed DOXR to parental values in LoVo colon adenocarcinoma cells, it only minimally decreased DOX resistance (12.6%) in HT1080/DR4 cells. Efflux patterns of [14C]DOX were similar for the DOXR sublines with an approximately 50% decrease in DOX retention after 1 h when compared to their respective parental cell lines. Our results suggest that DOXR in LoVo/DR5 cells may result from overexpression of P-glycoprotein. In contrast, DOXR in HT1080/DR4 appears to be non-P-glycoprotein mediated and may be related to an alternative mechanism capable of altering drug efflux or differential drug binding.