Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine and Public Health, Flinders Medical Centre, Bedford Park, South Australia, Australia.
Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine and Public Health, Flinders Medical Centre, Bedford Park, South Australia, Australia
J Pharmacol Exp Ther. 2018 Apr;365(1):48-59. doi: 10.1124/jpet.117.245936. Epub 2018 Jan 24.
is an important androgen-metabolizing UDP-glucuronosyltransferase (UGT) and the mechanisms controlling its expression are of considerable interest. Recent studies showed that miR-376c regulates in prostate cancer cells via a canonical target site in the 3' untranslated region (). The also contains a canonical miR-331-5p target site; previous work indicated that deleting this site reduced, but did not abolish, the ability of miR-331-5p to repress a luciferase reporter carrying the We report here the discovery and characterization of a second, noncanonical miR-331-5p target site in the miR-331-5p-mediated repression of a reporter was partly inhibited by mutating either of the two miR-331-5p target sites separately, but completely abolished by mutating the two sites simultaneously, indicating that the two sites act cooperatively. miR-331-5p mimics significantly reduced both UGT2B15 mRNA levels and glucuronidation activity in prostate cancer cells, confirming that the native transcript is a miR-331-5p target. Transfection of either miR-331-5p or miR-376c mimics repressed the activity of the -reporter; however, cotransfection of both microRNAs (miRNAs) further reduced activity, indicating cooperative regulation by these two miRNAs. A significant negative correlation between miR-331 and UGT2B15 mRNA levels was observed in a tissue RNA panel, and analysis of The Cancer Genome Atlas (TCGA) hepatocellular carcinoma data set provided further evidence that miR-331 may play an important role in regulation of in vivo. There was no significant correlation between miR-331 and UGT2B15 mRNA levels in the TCGA prostate adenocarcinoma cohort, which may reflect the complexity of androgen-mediated regulation in determining levels in prostate cancer. Finally, we show that miR-331-5p does not regulate UGT2B17, providing the first evidence for a post-transcriptional mechanism that differentially regulates these two important androgen-metabolizing UGTs.
是一种重要的雄激素代谢 UDP-葡糖醛酸基转移酶（UGT），其表达的调控机制具有重要意义。最近的研究表明，miR-376c 通过 3'非翻译区（UTR）中的一个典型靶位点调控前列腺癌细胞中的 。 还包含一个典型的 miR-331-5p 靶位点；先前的工作表明，删除该位点降低了，但没有完全消除 miR-331-5p 抑制携带 的荧光素酶报告基因的能力。我们在这里报告了在 中发现和表征的第二个非典型 miR-331-5p 靶位点。miR-331-5p 介导的报告基因抑制部分被单独突变两个 miR-331-5p 靶位点中的一个所抑制，但同时突变两个靶位点则完全被抑制，表明这两个靶位点协同作用。miR-331-5p 模拟物显著降低了前列腺癌细胞中 UGT2B15 mRNA 水平和葡萄糖醛酸化活性，证实天然转录本是 miR-331-5p 的靶标。转染 miR-331-5p 或 miR-376c 模拟物均可抑制 -报告基因的活性；然而，这两种 miRNA 的共转染进一步降低了活性，表明这两种 miRNA 存在协同调控。组织 RNA 面板中观察到 miR-331 与 UGT2B15 mRNA 水平之间存在显著的负相关，对癌症基因组图谱（TCGA）肝细胞癌数据的分析进一步提供了证据，表明 miR-331 可能在体内调节 中发挥重要作用。在 TCGA 前列腺腺癌队列中，miR-331 与 UGT2B15 mRNA 水平之间没有显著相关性，这可能反映了雄激素介导的调节在确定前列腺癌中 水平方面的复杂性。最后，我们表明 miR-331-5p 不调节 UGT2B17，为差异化调节这两种重要的雄激素代谢 UGT 提供了第一个转录后机制的证据。
