Department of General Surgery, Chen Xing Hai Hospital, Guangdong Medical College, Zhongshan 528415, China.
Cell Oncol (Dordr). 2011 Feb;34(1):33-44. doi: 10.1007/s13402-010-0003-7. Epub 2011 Jan 28.
The overexpression of ATP-binding cassette (ABC) transporters is one of the main causes of multi-drug resistance (MDR) which represents a major obstacle to the success of cancer chemotherapy. In this study, we examined the effect of BIBF 1120, an inhibitor of vascular endothelial growth factor receptors (VEGFRs), platelet-derived growth factor receptors (PDGFRs) and fibroblast growth factor receptors (FGFRs) tyrosine kinases, on the reversal of multidrug resistance in vitro.
The doxorubicin and rhodamine 123 retention assay was performed by flowcytometry. Western blot were employed to identify ABCB1 expression level and the effect of BIBF 1120 on the blockade of Akt and ERK1/2 phosphorylation. The expression of mdr1 mRNA was determined by RT-PCR analysis. The ATPase activity of ABCB1 was investigated using Pgp-Glo™ assay systems.
BIBF 1120 significantly enhanced the cytotoxicity of doxorubicin and paclitaxel and increased the accumulation of ABCB1 substrates in ABCB1-overexpressing cancer cells, whereas it had no effect on the parental cells. On the other hand, BIBF 1120 did not alter the cytotoxicity of non-ABCB1 substrates and was unable to reverse ABCC1 or ABCG2-mediated MDR. Furthermore, BIBF 1120 inhibited the ATPase activity of ABCB1 in a concentration-dependent manner. However, no detectable alteration on the expression level of mdr1 mRNA or ABCB1 protein was identified in ABCB1-overexpressing cancer cells by different treatments of BIBF 1120. Interestly, total and phosphorylated forms of AKT and ERK1/2 were not inhibited by BIBF 1120 at the reversal concentrations.
Our results suggest that BIBF 1120 is capable of overcoming ABCB1-mediated drug resistance by inhibiting ABCB1 function, which may have clinical significance for BIBF 1120 combinational treatment of certain resistant cancers.
三磷酸腺苷结合盒（ABC）转运蛋白的过度表达是多药耐药（MDR）的主要原因之一，这是癌症化疗成功的主要障碍。在这项研究中，我们研究了 BIBF 1120（一种血管内皮生长因子受体（VEGFRs）、血小板衍生生长因子受体（PDGFRs）和成纤维细胞生长因子受体（FGFRs）酪氨酸激酶抑制剂）对体外多药耐药逆转的影响。
采用流式细胞术进行阿霉素和罗丹明 123 保留试验。采用 Western blot 鉴定 ABCB1 表达水平及 BIBF 1120 对 Akt 和 ERK1/2 磷酸化阻断的影响。采用 RT-PCR 分析检测 mdr1 mRNA 的表达。采用 Pgp-GloTM 检测系统研究 ABCB1 的 ATP 酶活性。
BIBF 1120 显著增强阿霉素和紫杉醇的细胞毒性，增加 ABCB1 过表达癌细胞中 ABCB1 底物的积累，而对亲本细胞无影响。另一方面，BIBF 1120 不改变非 ABCB1 底物的细胞毒性，也不能逆转 ABCC1 或 ABCG2 介导的 MDR。此外，BIBF 1120 以浓度依赖的方式抑制 ABCB1 的 ATP 酶活性。然而，在 ABCB1 过表达癌细胞中，通过不同 BIBF 1120 处理未发现 mdr1 mRNA 或 ABCB1 蛋白表达水平的明显改变。有趣的是，在逆转浓度下，BIBF 1120 并未抑制 AKT 和 ERK1/2 的总形式和磷酸化形式。
我们的结果表明，BIBF 1120 能够通过抑制 ABCB1 功能克服 ABCB1 介导的药物耐药性，这可能对 BIBF 1120 联合治疗某些耐药性癌症具有临床意义。
