Investigation of expression regulatory mechanisms of drug transporters with its possible application for circumventing anticancer drug resistance

药物转运蛋白表达调控机制的研究及其在规避抗癌耐药性方面的可能应用

基本信息

批准号：
18590379
负责人：
IMAI Yasuo
金额：
$ 1.54万
依托单位：
Dokkyo Medical University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18590379/
关键词：
Cancer Chemotherapy

项目摘要

ABCG2/BCRP, a member of the ATP-binding cassette transporter G family, functions as an efflux pump that excludes such anticancer agents as mitoxantrone, SN-38 (an active metabolite of irinotecan), and topotecan, across cell membrane. Accordingly ABCG2 causes multidrug resistance when overexpressed in cancer cells. We have thus far clarified that estrogen markedly down-regulates ABCG2 expression in estrogen receptor-positive breast cancer cells in the post-transcriptional manner, but use of estrogen in the practical clinic seemed to be limited due to its original physiological function.We then transfected ABCG2 cDNA to breast cancer MCF-7 cells and gastric cancer MKN1 and NCI-N87 cells, which express endogenous ABCG2, in order to exploring small molecules that affects ABCG2 expression levels, and termed them MCF-7/ABCG2, MKN1/ABCG2, and NCI-N87/ABCG2 cells.Exogenous ABCG2 protein expression in MCF-7/ABCG2, MKN1/ABCG2, NCI-N87/ABCG2 cells was markedly repressed by p44/p42 mitogen-activat … More ed protein kinase (MAPK), PD98059 and U0126, in the dose-dependent manner. These compounds almost completely overcame mitoxantrone- or SN-38- resistance of MCF-7/ABCG2 and NCI-N87/ABCG2 cells. FACS analyses revealed that the reversal effects were due to increased intracellular uptake of anticancer agents. Quantitative RT-PCR analyses demonstrated that ABCG2 mRNA levels were not affected by the treatment with PD98059 or U0126. In addition, a half life of the ABCG2 protein was significantly short in the presence of PD98059 as compared with that in the control experiment.PD98059-mediated degradation of ABCG2 protein was not affected by MG132, an ubiquitin/endosome inhibitor, but was completely blocked by bafilomycin A1, an endosomal inhibitor. These data suggest that inhibition of p44/p42 MAPK pathway may accelerate endosomal degradation of ABCG2 protein and makes it possible to overcome ABCG2-mediated multidrug resistance. These data may also suggest that p44/p42 MAPK inhibitors may serve for establishment of safe and effective chemotherapeutic regimen. Less

ABCG2/BCRP是ATP结合盒转运蛋白G家族的成员，用作外排泵，排除了诸如Mitoxantrone，SN-38（Irinotecan的活性代谢物）和拓扑甘甘邦等抗癌剂，跨细胞膜。根据ABCG2在癌细胞中过表达时会引起多药耐药性。 We have thus far clarified that estrogen markedly down-regulates ABCG2 expression in estrogen receptor-positive breast cancer cells in the post-transcriptional manner, but use of estrogen in the practical clinic seemed to be limited due to its original physiological function.We then translated ABCG2 cDNA to breast cancer MCF-7 cells and gastric cancer MKN1 and NCI-N87 cells, which express endogenous ABCG2, in order to探索影响ABCG2表达水平的小分子，并将其称为MCF-7/ABCG2，MKN1/ABCG2和NCI-N87/ABCG2 CellS.Exenot ABCG2蛋白在MCF-7/ABCG2中的表达蛋白激酶（MAPK），PD98059和U0126，以剂量依赖性方式。这些化合物几乎完全克服了MCF-7/ABCG2和NCI-N87/ABCG2细胞的mitoxantrone-或Sn-38-抗性。 FACS分析表明，逆转效应是由于抗癌药的细胞内摄取增加所致。定量RT-PCR分析表明，ABCG2 mRNA水平不受PD98059或U0126处理的影响。此外，与对照实验相比，在存在PD98059的情况下，ABCG2蛋白的半衰期明显短。PD98059介导的ABCG2蛋白的降解不受MG132的影响，MG132不受泛素/内体抑制剂的影响，但由Bafiolcomycin a1 a1，Aneos An An An An An n obledior，但完全阻止了Bafafilsomiccin an n on on on onob。这些数据表明，抑制p44/p42 MAPK途径可能会加速ABCG2蛋白的内体降解，并使可以克服ABCG2介导的多药耐药性。这些数据还可能表明p44/p42 MAPK抑制剂可能有助于建立安全有效的化学治疗方案。较少的