Neddylation Inactivation Facilitates FOXO3a Nuclear Export to Suppress Estrogen Receptor Transcription and Improve Fulvestrant Sensitivity
Neddylation Inactivation Facilitates FOXO3a Nuclear Export to Suppress Estrogen Receptor Transcription and Improve Fulvestrant Sensitivity
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Neddylation 失活促进 FOXO3a 核输出抑制雌激素受体转录并提高氟维司群敏感性
DOI：
10.1158/1078-0432.ccr-18-2434
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发表时间：
2019-06-15
影响因子：
11.5
通讯作者：
Shao, Zhi-Ming
中科院分区：
文献类型：
--
作者：
Jia, Xiaoqing;Li, Chunjie;Shao, Zhi-Ming
目的：neddylation通路在乳腺肿瘤中的作用及其对雌激素受体（ER）表达的调控尚未见报道。本研究的目的是确定neddylation在乳腺癌和ER表达中的作用，并进一步探讨其潜在的机制。实验设计：nedd 8激活酶（NAE）和nedd 8，neddylation途径中的两个关键蛋白的表达模式，在人类乳腺标本进行了检查。在NAE抑制剂MLN 4924处理后，使用动物18 F-FES-PET/CT和免疫印迹法研究ER-α表达。染色质免疫沉淀试验、荧光素酶报告基因启动子试验和CRISPR-Cas9系统用于阐明MLN 4924调节ER-α的机制。使用ER阳性乳腺癌小鼠模型确定MLN 4924和氟维司群对肿瘤生长的协同作用。所有统计检验均为双侧检验。结果：NAE 1和nedd 8在ER阳性组中的表达均较高。NAE 1和nedd 8的高表达提示预后不良。重要的是，体外和体内MLN 4924处理后ER-α表达显著下调。从机制上讲，MLN 4924处理延迟了血清和糖皮质激素诱导的蛋白激酶（SGK）降解，诱导了Forkhead box O3 a（FOXO 3a）核输出，并降低了与ESR 1启动子的结合。重要的是，MLN 4924单独或与氟维司群协同作用可在体外和体内显著抑制ER阳性乳腺癌的生长。结论：我们的原理验证研究首次确定了乳腺肿瘤组织中neddylation的激活，揭示了一种新的ER-α调节机制，并进一步探索了通过neddylation失活组合提高氟维司群敏感性的有效方法。
Purpose: How the neddylation pathway functions in breast tumor and regulation of estrogen receptor (ER) expression is rarely reported. The purpose of this study was to identify the role of neddylation in breast cancer and ER expression, and further explore the underlying mechanisms. Experimental Design: Expression patterns of nedd8-activating enzyme (NAE) and nedd8, two key proteins in the neddylation pathway, were examined in human breast specimens. ER-α expression was investigated using animal 18F-FES-PET/CT and immunoblotting upon NAE inhibitor MLN4924 treatment. Chromatin immunoprecipitation assay, luciferase reporter promoter assay, and the CRISPR-Cas9 system were used to elucidate the mechanism of ER-α regulation by MLN4924. The ER-positive breast cancer mouse model was used to determine the synergetic effect of MLN4924 and fulvestrant on tumor growth. All statistical tests were two-sided. Results: Both NAE1 and nedd8 expressions were higher in the ER-positive subgroup. Higher expressions of NAE1 and nedd8 indicated poorer prognosis. Importantly, ER-α expression was significantly downregulated upon MLN4924 treatment in vitro and in vivo. Mechanistically, MLN4924 treatment delayed serum and glucocorticoid-induced protein kinase (SGK) degradation and induced Forkhead box O3a (FOXO3a) nuclear export as well as decreased binding to the ESR1 promoter. Importantly, MLN4924 single or synergized with fulvestrant significantly suppressed the growth of ER-positive breast cancer in vitro and in vivo. Conclusions: Our proof-of-principle study determines the activation of neddylation in breast tumor tissues for the first time and reveals a new ER-α regulatory mechanism, as well as further explores an effective approach to improve fulvestrant sensitivity through a neddylation inactivation combination.