The solvents cremophor EL and Tween 80 modulate daunorubicin resistance in the multidrug resistant Ehrlich ascites tumor.
The solvents cremophor EL and Tween 80 modulate daunorubicin resistance in the multidrug resistant Ehrlich ascites tumor.
复制标题
溶剂 Cremophor EL 和 Tween 80 可调节多重耐药艾氏腹水肿瘤中柔红霉素的耐药性。
作者：
E. Friche;P. B. Jensen;M. Sehested;Demant Ej;Nissen Nn
Cremophor EL（聚氧乙烯蓖麻油）和 Tween 80 分别用作环孢菌素 A 和 VP-16 的溶剂，被发现可以逆转多重耐药 (MDR) 表型。在柔红霉素 (DNR) 耐药性艾氏腹水肿瘤细胞 (EHR2/DNR+) 中，两种溶剂的百分比为 0.01% (v/v)，可将 DNR 积累增强至敏感水平。 Cremophor EL 和 Tween 80 不影响药物敏感细胞 (EHR2) 中的 DNR 积累。单独的环孢菌素 A 浓度可将 EHR2/DNR+ 细胞中的 DNR 积累增强至敏感水平，其浓度为 5 微克/mL，而溶解在 0.001% (v/v) Cremophor EL 中的 0.2 微克/mL 环孢菌素 A 则可将 DNR 积累增强至敏感水平，从而表明 Cremophor EL 和环孢菌素 A 之间存在协同作用。环孢菌素 A 对 EHR2/DNR+ 细胞中 DNR 积累的影响可忽略不计。药物敏感细胞。在克隆形成分析中，EHR2/DNR+ 细胞中 DNR 的 LD10 为 1 µM。将 1 microM DNR 与无毒量的 Cremophor EL（0.001% 和 0.002%，v/v）相结合可增强 DNR 的细胞毒性，并分别导致耐药细胞的细胞杀灭率达到 77% 和 86%。在无毒量下，CrEL 和 Tween 80 与维拉帕米浓度降低产生协同作用，导致 DNR 积累接近敏感水平。 EHR2/DNR+ 细胞质膜囊泡中 P 糖蛋白的叠氮平光亲和标记被 0.003% (v/v) Cremophor EL 或 Tween 80 分别抑制 100% 和 80%。这些数据得出这样的结论：无毒量的 CrEL 和 Tween 80 通过提高细胞内 DNR 水平来调节 DNR 抗性，因为它们具有与质膜 P-糖蛋白结合的能力。
Cremophor EL (polyoxyethylene castor oil) and Tween 80, used as solvents for cyclosporin A and VP-16, respectively, were found to reverse the multidrug resistant (MDR) phenotype. In daunorubicin (DNR) resistant Ehrlich ascites tumor cells (EHR2/DNR+), both solvents at percentages of 0.01% (v/v) enhanced DNR accumulation to sensitive levels. Cremophor EL and Tween 80 did not influence DNR accumulation in drug-sensitive cells (EHR2). The concentration of cyclosporin A alone that enhanced DNR accumulation in EHR2/DNR+ cells to sensitive levels was 5 micrograms/mL whereas 0.2 micrograms/mL of cyclosporin A dissolved in 0.001% (v/v) Cremophor EL enhanced DNR accumulation to sensitive levels, thus indicating synergy between Cremophor EL and cyclosporin A. Cyclosporin A had a negligible effect on DNR accumulation in the drug-sensitive cells. In clonogenic assays, the LD10 of DNR was 1 microM in EHR2/DNR+ cells. Combining 1 microM DNR with non-toxic amounts of Cremophor EL (0.001% and 0.002%, v/v) potentiated the cytotoxicity of DNR and resulted in a cell kill of 77% and 86%, respectively, in the resistant cells. In non-toxic amounts, CrEL and Tween 80 acted synergistically with reduced concentrations of verapamil, resulting in DNR accumulation approaching close to the sensitive level. Azidopine photoaffinity labeling of P-glycoprotein in plasma membrane vesicles from EHR2/DNR+ cells was inhibited 100% and 80%, by 0.003% (v/v) Cremophor EL or Tween 80, respectively. These data permit the conclusion that non-toxic amounts of CrEL and Tween 80 modulated DNR resistance by raising intracellular DNR levels, due to their abilities to bind to the plasma membrane P-glycoprotein.