Pharmacological, molecular, and cytogenetic analysis of "atypical" multidrug-resistant human leukemic cells.
Pharmacological, molecular, and cytogenetic analysis of "atypical" multidrug-resistant human leukemic cells.
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DOI：
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发表时间：
1987-10
期刊：
影响因子：
11.2
通讯作者：
William T. Beck;M. Cirtain;M. Danks;Ronald L. Felsted;Ahmad R. Safa;J. S. Wolverton;D. Suttle;Jeffrey M. Trent
中科院分区：
文献类型：
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作者：
William T. Beck;M. Cirtain;M. Danks;Ronald L. Felsted;Ahmad R. Safa;J. S. Wolverton;D. Suttle;Jeffrey M. Trent
我们先前描述了对表鬼臼毒素替尼泊苷（M. K. Danks等人，癌症研究所，47：1297-1301，1987）。CEM/VLB 100是一种典型的多药耐药（MDR）细胞系，与之相比，CEM/VM-1细胞表现出“非典型”多药耐药（at-MDR），因为它们对多种天然产物抗肿瘤药物具有交叉耐药性，但不包括苦马豆生物碱，并且它们积累放射性标记的表鬼臼毒素的能力不受损害。在本研究中，我们已经扩展了我们对这种耐多药细胞系的表征。与CEM/VLB 100细胞相比，我们发现CEM/VM-1细胞对放线菌素D或秋水仙素没有交叉抗性。维拉帕米和氯喹可增强长春碱对CEM/VLB 100细胞的细胞毒性，但对CEM/VM-1细胞几乎没有这种作用。通过长春碱类似物N-（对叠氮基[3- 125 I]水杨基）-N '-β-氨基乙基长春地辛的光亲和标记，检查两种耐药亚系的膜囊泡中MDR相关质膜蛋白（P-糖蛋白、Mr 170，000蛋白或180，000糖蛋白）的过表达。在P-糖蛋白容易在CEM/VLB 100细胞膜中观察到的条件下，我们不能用这种光亲和探针观察CEM/VM-1膜中的MDR相关蛋白。此外，在来自at-MDR细胞的RNA的狭缝印迹分析中未观察到pMDR 1互补DNA的杂交，表明编码P-糖蛋白的mdr基因不像经典MDR细胞中的情况那样过表达。然而，细胞遗传学分析表明，CEM/VM-1细胞含有一个异常的带状区域染色体13 q上，这表明一个基因以外的mdr可能在这些细胞中扩增。因此，尽管这两种细胞系对表鬼臼毒素具有大致相同的耐药性，但我们的数据表明，导致at-MDR的机制与经典的P-糖蛋白相关MDR不同。
We previously described the cross-resistance patterns and cellular pharmacology of a human leukemic cell line, CEM/VM-1, selected for resistance to the epipodophyllotoxin teniposide (M. K. Danks et al., Cancer Res., 47: 1297-1301, 1987). Compared to CEM/VLB100, which is a well characterized "classic" multidrug-resistant (MDR) cell line, the CEM/VM-1 cells display "atypical" multidrug resistance (at-MDR) in that they are cross-resistant to a wide variety of natural product antitumor drugs, except the Vinca alkaloids, and they are not impaired in their ability to accumulate radiolabeled epipodophyllotoxin. We have extended our characterization of this at-MDR cell line in the present study. In comparison to CEM/VLB100 cells, we found that CEM/VM-1 cells are not cross-resistant to either actinomycin D or colchicine. Verapamil and chloroquine, which enhance the cytotoxicity of vinblastine in CEM/VLB100 cells, had little or no ability to do so in the CEM/VM-1 cells. Membrane vesicles of the two resistant sublines were examined for overexpression of the MDR-associated plasma membrane protein (P-glycoprotein, Mr 170,000 protein, or 180,000 glycoprotein) by photoaffinity labeling with the vinblastine analogue N-(p-azido[3-125I]salicyl)-N'-beta-aminoethylvindesine. We were unable to visualize the MDR-associated protein in the CEM/VM-1 membranes with this photoaffinity probe under conditions in which the P-glycoprotein was readily seen in the membranes of CEM/VLB100 cells. Furthermore, no hybridization of the pMDR1 complementary DNA was seen in slot-blot analyses of the RNA from at-MDR cells, indicating that the mdr gene coding for P-glycoprotein is not overexpressed as is the case in the classic MDR cells. However, cytogenetic analysis indicated that the CEM/VM-1 cells contained an abnormally banded region on chromosome 13q, suggesting that a gene other than mdr may be amplified in these cells. Thus, despite the two cell lines having approximately equal degrees of resistance to epipodophyllotoxins, our data indicate that the mechanism(s) responsible for at-MDR is different from that for classic, P-glycoprotein-associated MDR.