INTRODUCTION The orphan nuclear receptor 4A2 (NR4A2) has been extensively characterized in subcellular regions of the brain and is necessary for the function of dopaminergic neurons. The NR4A2 ligand, 1,1-bis (31-indoly1)-1-(p-chlorophenyl)methane (DIM-C-pPhCl) inhibits markers of neuroinflammation and degeneration in mouse models and in this study we investigated expression and function of NR4A2 in glioblastoma (GBM). METHODS Established and patient-derived cell lines were used as models and the expression and functions of NR4A2 were determined by western blots and NR4A2 gene silencing by antisense oligonucleotides respectively. Effects of NR4A2 knockdown and DIM-C-pPhCl on cell growth, induction of apoptosis (Annexin V Staining) and migration/invasion (Boyden chamber and spheroid invasion assay) and transactivation of NR4A2-regulated reporter genes were determined. Tumor growth was investigated in athymic nude mice bearing U87-MG cells as xenografts. RESULTS NR4A2 knockdown and DIM-C-pPhCl inhibited GBM cell and tumor growth, induced apoptosis and inhibited migration and invasion of GBM cells. DIM-C-pPhCl and related analogs also inhibited NR4A2-regulated transactivation (luciferase activity) confirming that DIM-C-pPhCl acts as an NR4A2 antagonist and blocks NR4A2-dependent pro-oncogenic responses in GBM. CONCLUSION We demonstrate for the first time that NR4A2 is pro-oncogenic in GBM and thus a potential druggable target for patients with tumors expressing this receptor. Moreover, our bis-indole-derived NR4A2 antagonists represent a novel class of anti-cancer agents with potential future clinical applications for treating GBM.

中文翻译：

---

核受体4A2（NR4A2）是胶质母细胞瘤的可治疗靶标。

引言孤儿核受体4A2（NR4A2）在大脑的亚细胞区域已得到广泛表征，对于多巴胺能神经元的功能是必不可少的。NR4A2配体1,1-双（31-吲哚1）-1-（对氯苯基）甲烷（DIM-C-pPhCl）抑制小鼠模型中神经炎症和变性的标志物，在这项研究中，我们研究了NR4A2的表达和功能在胶质母细胞瘤（GBM）中。方法以已建立的和患者来源的细胞系为模型，分别通过western blot和反义寡核苷酸检测NR4A2基因的表达和功能。NR4A2敲低和DIM-C-pPhCl对细胞生长的影响，确定了细胞凋亡的诱导（Annexin V染色）和迁移/侵袭（Boyden室和球体侵袭试验）以及NR4A2调节的报告基因的反式激活。在携带U87-MG细胞作为异种移植物的无胸腺裸鼠中研究了肿瘤的生长。结果NR4A2基因敲低和DIM-C-pPhCl抑制了GBM细胞和肿瘤的生长，诱导了细胞凋亡并抑制了GBM细胞的迁移和侵袭。DIM-C-pPhCl和相关类似物也抑制了NR4A2调节的反式激活（荧光素酶活性），从而确认DIM-C-pPhCl充当NR4A2拮抗剂并阻断GBM中依赖NR4A2的促癌反应。结论我们首次证明NR4A2在GBM中是促癌的，因此是表达该受体的肿瘤患者的潜在药物靶标。而且，