Michaelis Martin, Rothweiler Florian, Klassert Denise, von Deimling Andreas, Weber Kristoffer, Fehse Boris, Kammerer Bernd, Doerr Hans Wilhelm, Cinatl Jindrich
Institut für Medizinische Virologie, Klinikum der JW Goethe-Universität, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany.
Cancer Res. 2009 Jan 15;69(2):416-21. doi: 10.1158/0008-5472.CAN-08-1856.
Murine double minute 2 (MDM2) negatively regulates the activity of the tumor suppressor protein p53. Nutlin-3 is a MDM2 inhibitor under preclinical investigation as nongenotoxic activator of the p53 pathway for cancer therapy. Here, nutlin-3 was evaluated for its activity alone or in combination with established chemotherapeutic drugs for antitumor action in chemosensitive and chemoresistant neuroblastoma and rhabdomyosarcoma cell lines. Effects of nutlin-3 single treatment were much more pronounced in p53 wild-type cell lines (IC(50)s <3 micromol/L) than in p53-mutated cell lines (IC(50)s >17 micromol/L). In sharp contrast to the expectations, nutlin-3 concentrations that did not affect viability of p53-mutated cell lines strongly increased the efficacy of vincristine in p53-mutated, P-glycoprotein (P-gp)-overexpressing cell lines (decrease in IC(50)s 92- to 3,434-fold). Similar results were obtained for other P-gp substrates. Moreover, nutlin-3 reduced efflux of rhodamine 123 and other fluorescence dyes that are effluxed by P-gp. Investigation of Madin-Darby canine kidney (MDCK) II cells stably transfected with plasmids encoding for P-gp (MDCKII MDR1) or multidrug resistance protein 1 (MRP-1, MDCKII MRP1) revealed that nutlin-3 not only interferes with P-gp but also affects MRP-1-mediated efflux. Kinetic studies and investigation of P-gp-ATPase activity showed that nutlin-3 is likely to act as a P-gp transport substrate. Examination of the nutlin-3 enantiomers nutlin-3a and nutlin-3b revealed that, in contrast to MDM2-inhibitory activity that is limited to nutlin-3a, both enantiomers similarly interfere with P-gp-mediated drug efflux. In conclusion, nutlin-3-induced inhibition of P-gp and MRP-1 was discovered as a novel anticancer mechanism of the substance in this report.
小鼠双微体2（MDM2）负向调节肿瘤抑制蛋白p53的活性。Nutlin-3是一种正在临床前研究中的MDM2抑制剂，作为p53通路的非基因毒性激活剂用于癌症治疗。在此，评估了Nutlin-3单独使用或与已有的化疗药物联合使用对化疗敏感和化疗耐药的神经母细胞瘤及横纹肌肉瘤细胞系的抗肿瘤作用。Nutlin-3单药治疗对p53野生型细胞系（半数抑制浓度[IC(50)]<3 μmol/L）的作用比对p53突变细胞系（IC(50)>17 μmol/L）更为显著。与预期形成鲜明对比的是，不影响p53突变细胞系活力的Nutlin-3浓度显著提高了长春新碱对p53突变、P-糖蛋白（P-gp）过表达细胞系的疗效（IC(50)降低92至3434倍）。对其他P-gp底物也得到了类似结果。此外，Nutlin-3减少了罗丹明123及其他可被P-gp外排的荧光染料的外排。对稳定转染了编码P-gp（MDCKII MDR1）或多药耐药蛋白1（MRP-1，MDCKII MRP1）质粒的Madin-Darby犬肾（MDCK）II细胞的研究表明，Nutlin-3不仅干扰P-gp，还影响MRP-1介导的外排。动力学研究和对P-gp-ATP酶活性的研究表明，Nutlin-3可能作为P-gp转运底物发挥作用。对Nutlin-3对映体Nutlin-3a和Nutlin-3b的研究表明，与仅限于Nutlin-3a的MDM2抑制活性不同，两种对映体同样干扰P-gp介导的药物外排。总之，本报告发现Nutlin-3诱导的对P-gp和MRP-1的抑制是该物质一种新的抗癌机制。
