Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Queens, NY 11439, USA.
Cancer Chemother Pharmacol. 2013 Jul;72(1):189-99. doi: 10.1007/s00280-013-2184-z. Epub 2013 May 15.
Specific tyrosine kinase inhibitors were recently reported to modulate the activity of ABC transporters, leading to an increase in the intracellular concentration of their substrate drugs. In this study, we determine whether PD173074, a specific fibroblast growth factor receptor (FGFR) inhibitor, could reverse ABC transporter-mediated multidrug resistance.
3-(4,5-Dimethylthiazol-yl)-2,5-diphenyllapatinibrazolium bromide assay was used to determine the effect of PD173074 on reversal of ABC transporter-mediated multidrug resistance (MDR). In addition, [³H]-paclitaxel accumulation/efflux assay, western blotting analysis, ATPase, and photoaffinity labeling assays were done to study the interaction of PD173074 on ABC transporters.
PD173074 significantly sensitized both ABCB1-transfected and drug-selected cell lines overexpressing this transporter to substrate anticancer drugs colchicine, paclitaxel, and vincristine. This effect of PD173074 is specific to ABCB1, as no significant interaction was detected with other ABC transporters such as ABCC1 and ABCG2. The observed reversal effect seems to be primarily due to the decreased active efflux of [³H]-paclitaxel in ABCB1 overexpressing cells observed in efflux assay. In addition, no significant change in the ABCB1 expression was observed when ABCB1 overexpressing cells were exposed to 5 μM PD173074 for up to 3 days, thereby further suggesting its role in modulating the function of the transporter. In addition, PD173074 stimulated the ATPase activity of ABCB1 in a concentration-dependent manner, indicating a direct interaction with the transporter. Interestingly, PD173074 did not inhibit photolabeling of ABCB1 with [¹²⁵I]-iodoarylazidoprazosin (IAAP), showing that it binds at a site different from that of IAAP in the drug-binding pocket.
Here, we report for the first time, PD173074, an inhibitor of the FGFR, to selectively reverse ABCB1 transporter-mediated MDR by directly blocking the efflux function of the transporter.
最近有报道称，特定的酪氨酸激酶抑制剂可调节 ABC 转运体的活性，导致其底物药物的细胞内浓度增加。在这项研究中，我们确定了 FGFR 抑制剂 PD173074 是否可以逆转 ABC 转运体介导的多药耐药性。
采用 3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐法测定 PD173074 对 ABC 转运体介导的多药耐药性（MDR）逆转的影响。此外，还进行了[³H]-紫杉醇积累/外排测定、western blot 分析、ATP 酶和光亲和标记测定，以研究 PD173074 与 ABC 转运体的相互作用。
PD173074 显著增加了 ABCB1 转染和药物选择的细胞系对其底物抗癌药物秋水仙碱、紫杉醇和长春新碱的敏感性。PD173074 的这种作用是特异性的，因为在其他 ABC 转运体（如 ABCC1 和 ABCG2）中没有检测到明显的相互作用。观察到的逆转作用似乎主要是由于在 ABCB1 过表达细胞中的[³H]-紫杉醇主动外排减少所致。此外，当 ABCB1 过表达细胞暴露于 5 μM PD173074 长达 3 天时，未观察到 ABCB1 表达的显著变化，从而进一步表明其在调节转运体功能中的作用。此外，PD173074 以浓度依赖的方式刺激 ABCB1 的 ATP 酶活性，表明与转运体直接相互作用。有趣的是，PD173074 不抑制 [¹²⁵I]-碘代芳基氮唑 prazosin（IAAP）与 ABCB1 的光标记，表明它结合在药物结合口袋中与 IAAP 不同的位点。
在这里，我们首次报道了 FGFR 抑制剂 PD173074 通过直接阻断转运体的外排功能选择性地逆转 ABCB1 转运体介导的 MDR。
