Institute of Experimental and Clinical Pharmacology (O.B., M.L., F.W., M.K., I.N., R.B., I.C.) and Institute for Experimental Cancer Research (C.R.), University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
Institute of Experimental and Clinical Pharmacology (O.B., M.L., F.W., M.K., I.N., R.B., I.C.) and Institute for Experimental Cancer Research (C.R.), University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
Mol Pharmacol. 2020 Feb;97(2):112-122. doi: 10.1124/mol.119.116590. Epub 2019 Nov 22.
ATP-binding cassette (ABC) transporters represent a large group of efflux pumps that are strongly involved in the pharmacokinetics of various drugs and nutrient distribution. It was recently shown that micro-RNAs (miRNAs) may significantly alter their expression as proven, e.g., for miR-379 and However, alternative mRNA polyadenylation may result in expression of 3'-untranslated regions (3'-UTRs) with varying lengths. Thus, length variants may result in presence or absence of miRNA binding sites for regulatory miRNAs with consequences on posttranscriptional control. In the present study, we report on 3'-UTR variants of , , and mRNA. Applying in vitro luciferase reporter gene assays, we show that expression of short 3'-UTR variants leads to a significant loss of miR-379/ interaction and subsequent upregulation of ABCC2 expression. Furthermore, we show that expression of 3'-UTR lengths varies significantly between human healthy tissues but is not directly correlated to the respective protein level in vivo. In conclusion, the presence of altered 3'-UTR lengths in ABC transporters could lead to functional consequences regarding posttranscriptional gene expression, potentially regulated by alternative polyadenylation. Hence, 3'-UTR length variability may be considered as a further mechanism contributing to variability of ABCC transporter expression and subsequent drug variation in drug response. SIGNIFICANCE STATEMENT: micro-RNA (miRNA) binding to 3'-untranslated region (3'-UTR) plays an important role in the control of ATP-binding cassette (ABC)-transporter mRNA degradation and translation into proteins. We disclosed various 3'-UTR length variants of ABCC1, C2, and C3 mRNA, with loss of mRNA seed regions partly leading to varying and tissue-dependent interaction with miRNAs, as proven by reporter gene assays. Alternative 3'-UTR lengths may contribute to variable ABCC transporter expression and potentially explains inconsistent findings in miRNA studies.
三磷酸腺苷结合盒（ABC）转运蛋白是一大类外排泵，它们在各种药物的药代动力学和营养物质分布中起着重要作用。最近的研究表明，微小 RNA（miRNA）可能会显著改变它们的表达，例如 miR-379 和 。然而，替代的 mRNA 多聚腺苷酸化可能导致具有不同长度的 3'-非翻译区（3'-UTR）的表达。因此，长度变异可能导致调节 miRNA 的 miRNA 结合位点的存在或缺失，从而对转录后调控产生影响。在本研究中，我们报告了 、 和 mRNA 的 3'-UTR 变异体。应用体外荧光素酶报告基因检测，我们表明短 3'-UTR 变异体的表达导致 miR-379/ 相互作用的显著丧失，并随后上调 ABCC2 的表达。此外，我们表明，人类健康组织之间 3'-UTR 长度的表达差异很大，但与体内相应的蛋白质水平没有直接相关性。总之，ABC 转运蛋白中存在改变的 3'-UTR 长度可能会导致潜在的转录后基因表达的功能后果，这可能受到替代多聚腺苷酸化的调节。因此，3'-UTR 长度的变异性可能被认为是 ABC 转运蛋白表达和随后药物反应中药物变异的另一种机制。
miRNA 与 3'-UTR 的结合在控制 ATP 结合盒（ABC）-转运蛋白 mRNA 降解和翻译为蛋白质方面起着重要作用。我们揭示了 ABCC1、C2 和 C3 mRNA 的各种 3'-UTR 长度变异体，部分由于报告基因检测证明 mRNA 种子区域的缺失导致与 miRNA 的相互作用发生变化且具有组织依赖性。替代的 3'-UTR 长度可能有助于 ABCC 转运蛋白表达的变化，并可能解释 miRNA 研究中的不一致发现。
