Neurotensin signaling stimulates glioblastoma cell proliferation by upregulating c-Myc and inhibiting miR-29b-1 and miR-129-3p
Neurotensin signaling stimulates glioblastoma cell proliferation by upregulating c-Myc and inhibiting miR-29b-1 and miR-129-3p
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神经降压素信号通过上调 c-Myc 并抑制 miR-29b-1 和 miR-129-3p 刺激胶质母细胞瘤细胞增殖。
DOI：
10.1093/neuonc/nov114
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发表时间：
2016-02-01
期刊：
影响因子：
15.9
通讯作者：
Yi, Liang
中科院分区：
文献类型：
--
作者：
Ouyang, Qing;Chen, Gang;Yi, Liang
神经降压素(NTS)及其主要受体NTSR1与肿瘤进展有关。NTS/NTSR1的异常表达有助于胶质母细胞瘤细胞的增殖，但其机制尚不完全清楚。采用基因芯片和实时荧光定量聚合酶链式反应鉴定NTS调控的微(Mi)RNA。通过荧光素酶活性测定和免疫印迹分析鉴定miRNAs的靶点。用染色质免疫沉淀法鉴定miR-29b-1和细胞周期蛋白依赖性激酶(CDK)4启动子上的c-Myc结合位点。用细胞计数试剂盒-8法和流式细胞仪检测细胞增殖。原位异种移植模型证实了NTS/NTSR1和miRNAs在胶质母细胞瘤体内生长中的作用。药物抑制或小干扰NTSR1治疗使胶质母细胞瘤细胞周期阻滞在G1期，同时CDK6、CDK4和c-Myc的表达减少。NTSR1基因敲除后，miR-29b-1和miR-129-3p的表达增加，从而导致CDK6的表达下降。NTS/NTSR1信号在U87细胞中激活转录因子c-Myc，导致CDK4表达增加，抑制miR-29b-1表达。NTSR1基因的敲除抑制了体内胶质母细胞瘤的生长，显著延长了荷瘤小鼠的生存时间，这种作用在很大程度上可以被抗癌药逆转。我们的研究发现了一种新的调控机制，NTS/NTSR1是miRNAs和c-Myc的上游信号通路，在胶质母细胞瘤的发展过程中。抑制NTSR1功能或上调miR-29b-1和miR-129-3p的表达会损害胶质瘤细胞的增殖。这些结果提示NTS/NTSR1/c-Myc/miRNA轴可能是胶质母细胞瘤治疗的潜在靶点。
Neurotensin (NTS) and its primary receptor NTSR1 are implicated in cancer progression. Aberrant expression of NTS/NTSR1 contributes to the proliferation of glioblastoma cells; however, the mechanism is not fully understood.Microarray and real-time PCR were performed to identify the NTS-regulated micro (mi)RNAs. The targets of the miRNAs were identified by luciferase assays and immunoblot analysis. The c-Myc binding sites in the miR-29b-1 and cyclin-dependent kinase (CDK)4 promoters were identified through chromatin immunoprecipitation assay. Cell proliferation was evaluated by Cell Counting Kit-8 assay and flow cytometry analysis. An orthotopic xenograft model demonstrated the role of NTS/NTSR1 and miRNAs in glioblastoma growth in vivo.Pharmacological inhibition or small interfering NTSR1 treatment blocked glioblastoma cell cycle progression in the G1 phase with a concomitantly decreased expression of CDK6, CDK4, and c-Myc. Knockdown of NTSR1 increased the expression of miR-29b-1 and miR-129-3p, which were responsible for the decreased CDK6 expression. NTS/NTSR1 signaling activated the transcription factor c-Myc in U87 cells, leading to increased CDK4 expression and repressed miR-29b-1 expression. Knockdown of NTSR1 decreased the glioblastoma growth in vivo and significantly prolonged the survival time of the tumor-bearing mice, an effect that can be largely reversed by antagomir.Our study showed a novel regulatory mechanism of NTS/NTSR1, an upstream signaling of miRNAs and c-Myc, in glioblastoma progression. The inhibition of the NTSR1 function or the upregulation of miR-29b-1 and miR-129-3p expression impaired glioma cell proliferation. These results suggested that the NTS/NTSR1/c-Myc/miRNA axis may be a potential therapeutic target for glioblastoma therapy.