PSC833, cyclosporine analogue, downregulates MDR1 expression by activating JNK/c-Jun/AP-1 and suppressing NF-κB
PSC833, cyclosporine analogue, downregulates MDR1 expression by activating JNK/c-Jun/AP-1 and suppressing NF-κB
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DOI：
10.1007/s00280-009-1121-7
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发表时间：
2010-05-01
影响因子：
3
通讯作者：
Choi, Cheol-Hee
中科院分区：
文献类型：
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作者：
Bark, H.;Choi, Cheol-Hee
多药耐药（MDR）是临床肿瘤化疗失败的主要原因之一。PSC833是一种非免疫抑制剂环孢素类似物，功能上抑制p糖蛋白（Pgp）， Pgp是MDR1基因的产物。我们研究了PSC833是否也可以改变MDR1的表达，如果是的话，有丝分裂原活化蛋白激酶（MAPKs）和核因子κ B （nf - κ B）途径参与了这一事件。采用MTT法和流式细胞术分别分析细胞毒性和细胞内药物蓄积。采用RT-PCR和Western blot法分析基因表达，电泳迁移转移法测定转录因子的dna结合活性。从SK-MES-1/WT细胞中选择的耐多柔比星肺癌细胞亚系（SK-MES-1/DX1000）上调了MDR1的表达，从而表现出MDR表型。PSC833使SK-MES-1/DX1000细胞对阿霉素增敏。PSC833 （5 μ M）也降低了SK-MES-1/DX1000细胞中荧光Pgp底物如罗丹明123和柔红霉素的细胞内积累。PSC833以时间和浓度依赖性的方式下调MDR1 mRNA和Pgp的表达。PSC833激活c-Jun nh2末端激酶(JNK)/c-Jun，增强AP-1 dna结合活性，但抑制NF-kappa B的核易位，这些都可以通过JNK抑制剂SP600125预处理来阻止。这些结果表明，PSC833不仅通过增强药物积累使sk - ms -1/DX1000细胞对阿霉素增敏，而且通过激活JNK/c-Jun/AP-1和抑制NF-kappa B下调MDR1的表达。
Multidrug resistance (MDR) is one of the major causes of clinical cancer chemotherapy failure. PSC833 is well known as a non-immunosuppressant cyclosporine analogue that functionally inhibits P-glycoprotein (Pgp), a product of the MDR1 gene. We investigated whether PSC833 could also alter MDR1 expression and, if so, which mitogen-activated protein kinases (MAPKs) and nuclear factor-kappaB (NF-kappa B) pathways were involved in this event.MTT assay and flow cytometry were used for the analysis of cytotoxicity and intracellular drug accumulation, respectively. RT-PCR and Western blot assays for analysis of gene expression and electrophoretic mobility shift assays for determination of DNA-binding activity of transcription factors were used.The doxorubicin-resistant lung cancer cell subline (SK-MES-1/DX1000), selected from SK-MES-1/WT cells, upregulated MDR1 expression, thereby showing MDR phenotypes. PSC833 sensitized SK-MES-1/DX1000 cells to doxorubicin. PSC833 (5 mu M) also decreased the intracellular accumulation of fluorescent Pgp substrates such as rhodamine 123 and daunorubicin in SK-MES-1/DX1000 cells. PSC833 downregulated MDR1 mRNA and Pgp expression in a time- and concentration-dependent manner. PSC833 activated c-Jun NH2-terminal kinase (JNK)/c-Jun and enhanced AP-1 DNA-binding activity, but suppressed nuclear translocation of NF-kappa B, all of which were prevented by pretreatment with a JNK inhibitor SP600125.These results indicate that PSC833 not only sensitizes SK-MES-1/DX1000 cells to doxorubicin by enhancing drug accumulation, but also downregulates MDR1 expression by activating JNK/c-Jun/AP-1 and suppressing NF-kappa B.