Effect of 9-cis retinoic acid and all-trans retinoic acid in combination with verapamil on P-glycoprotein expression in L1210 cells
Effect of 9-cis retinoic acid and all-trans retinoic acid in combination with verapamil on P-glycoprotein expression in L1210 cells
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DOI：
10.4149/neo_2014_068
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发表时间：
2014-01-01
期刊：
影响因子：
3
通讯作者：
Sulova, Z.
中科院分区：
文献类型：
--
作者：
Breier, A.;Stetka, J.;Sulova, Z.
最常见的多药耐药（MDR）表型的发展与肿瘤细胞中p糖蛋白（P-gp）的大量过表达有关。在目前的研究中，我们使用了三种L1210细胞变体：S细胞亲代药物敏感细胞；R细胞-因长春新碱选择导致P-gp过表达的耐药细胞T细胞-由于稳定转染编码人全长P-gp的pHaMDRwt质粒而导致P-gp过表达的耐药细胞。几位作者描述了用全反式维甲酸（AtRA；视黄酸核受体配体，RARs）治疗后，在恶性细胞系中诱导P-gp的表达/活性。AtRA的一种异构体9-顺式维甲酸（9-cis retinoic acid）也存在，它是RARs和核类维甲酸X受体（RXRs）的配体。在之前的工作中，我们描述了维拉帕米和AtRA联合处理R细胞诱导P-gp表达/活性下调。在本研究中，我们研究了RARs和RXRs在S、R和T细胞中的表达，以及AtRA、9cRA和维拉帕米对R和T细胞中P-gp表达、细胞定位和外排活性的影响。我们发现P-gp在L1210细胞中的过表达与核受体亚群RARs和RXRs特异性转录的几个变化有关。我们还证明了AtRA、9cRA和维拉帕米治疗可诱导R和T细胞中P-gp表达的改变。特别是，维拉帕米和AtRA联合处理R细胞诱导P-gp含量/活性下调。相比之下，类似的T细胞处理诱导P-gp含量略有增加，但该蛋白的外排活性没有任何变化。这些发现表明，在RAR和RXR调控途径和p- gp介导的MDR之间可能发生主动串扰。
The development of the most common multidrug resistance (MDR) phenotype is associated with a massive overexpression of P-glycoprotein (P-gp) in neoplastic cells. In the current study, we used three L1210 cell variants: S cells parental drug-sensitive cells; R cells - drug-resistant cells with P-gp overexpression due to selection with vincristine; T cells - drug-resistant cells with P-gp overexpression due to stable transfection with the pHaMDRwt plasmid, which encodes human full-length P-gp. Several authors have described the induction of P-gp expression/activity in malignant cell lines after treatment with all-trans retinoic acid (AtRA; ligand of retinoic acid nuclear receptors, RARs). An isomer of AtRA also exists, 9-cis retinoic acid, which is a ligand of both RARs and nuclear retinoid X receptors (RXRs). In a previous work, we described that the combined treatment of R cells with verapamil and AtRA induces the downregulation of P-gp expression/activity. In the current study, we studied the expression of RARs and RXRs in S, R and T cells and the effects of treatment with AtRA, 9cRA and verapamil on P-gp expression, cellular localization and efflux activity in R and T cells. We found that the overexpression of P-gp in L1210 cells is associated with several changes in the specific transcription of both subgroups of nuclear receptors, RARs and RXRs. We also demonstrated that treatment with AtRA, 9cRA and verapamil induces alterations in P-gp expression in R and T cells. Particularly, combined treatment of R cells with verapamil and AtRA induced downregulation of P-gp content/activity. In contrast, similar treatment of T cells induced slight increase of P-gp content without any changes in efflux activity of this protein. These findings indicate that active crosstalk between the RAR and RXR regulatory pathways and P-gp-mediated MDR could take place.