microRNAs miR-27a and miR-27b directly regulate liver dihydropyrimidine dehydrogenase expression through two conserved binding sites.
microRNAs miR-27a and miR-27b directly regulate liver dihydropyrimidine dehydrogenase expression through two conserved binding sites.
复制标题
DOI：
10.1158/1535-7163.mct-13-0878
复制
发表时间：
2014-03
影响因子：
5.7
通讯作者：
Diasio RB
中科院分区：
文献类型：
--
作者：
Offer SM;Butterfield GL;Jerde CR;Fossum CC;Wegner NJ;Diasio RB
二氢嘧啶脱氢酶（DPD，由DPYD编码）是尿嘧啶分解代谢途径中的限速酶，在常用抗癌药物5-氟尿嘧啶（5-FU）的药代动力学中具有关键作用。无论是由于DPYD的表达不足还是有害变体，DPD的缺乏都与对5-FU的严重毒性反应有关。关于DPD在肝脏中表达的机制知之甚少。在这份报告中，我们发现在过表达高度同源的microRNA miR-27 a和miR-27 b的细胞中，DPYD mRNA上RNA诱导沉默复合物（RISC）蛋白的积累增加。这些microRNA显示通过DPYD中的两个保守识别位点抑制DPD表达。5-FU对过表达miR-27 a或miR-27 b的HCT 116细胞的IC 50为4.4 μM（均为），显著低于表达非靶向（scramble）对照microRNA的细胞（14.3 μM; P=3.3×10−5和P=1.5×10−7）。小鼠肝脏DPD酶活性与miR-27 a（R2=0.49，P=0.0012）和miR-27 b（R2=0.29，P=0.022）的表达水平呈负相关。hsa-mir-27 a发夹环区的一种常见变体（rs 895819）也显示与一组细胞系（P=0.029）和转基因过表达模型（P=0.0011）中miR-27 a表达升高相关。此外，在40名健康志愿者的队列中，rs 895819与DPD酶活性降低相关（P=0.028）。综上所述，这些结果表明，miR-27 a和miR-27 b表达可能是肝脏中DPD酶功能的非相关调节剂。此外，我们的数据表明rs 895819可能是5-FU敏感性的潜在风险等位基因。
Dihydropyrimidine dehydrogenase (DPD, encoded by DPYD) is the rate-limiting enzyme in the uracil catabolic pathway and has a pivotal role in the pharmacokinetics of the commonly prescribed anti-cancer drug 5-fluorouracil (5-FU). Deficiency of DPD, whether due to inadequate expression or deleterious variants in DPYD, has been linked to severe toxic responses to 5-FU. Little is known about the mechanisms governing DPD expression in the liver. In this report, we show increased accumulation of RNA induced silencing complex (RISC) proteins on DPYD mRNA in cells overexpressing the highly homologous microRNAs miR-27a and miR-27b. These microRNAs were shown to repress DPD expression through two conserved recognition sites in DPYD. The IC50 of 5-FU for HCT116 cells over-expressing miR-27a or miR-27b was 4.4 μM (both), significantly lower than that for cells expressing a non-targeting (scramble) control microRNA (14.3 μM; P=3.3×10−5 and P=1.5×10−7, respectively). Mouse liver DPD enzyme activity was inversely correlated with expression levels of miR-27a (R2=0.49, P=0.0012) and miR-27b (R2=0.29, P=0.022). A common variant in the hairpin loop region of hsa-mir-27a (rs895819) was also shown to be associated with elevated expression of the miR-27a in a panel of cell lines (P=0.029) and in a transgenic overexpression model (P=0.0011). Furthermore, rs895819 was associated with reduced DPD enzyme activity (P=0.028) in a cohort of 40 healthy volunteers. Taken together, these results suggest that miR-27a and miR-27b expression may be pharmacologically relevant modulators of DPD enzyme function in the liver. Furthermore, our data suggest that rs895819 may be a potential risk allele for 5-FU sensitivity.