Department of Neurosurgery, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan City People's Hospital, Guangdong Province, China.
Eur Rev Med Pharmacol Sci. 2020 May;24(10):5549-5557. doi: 10.26355/eurrev_202005_21340.
As the most common primary brain cancer in adults, glioblastoma shows an extremely poor prognosis. Glioblastoma-associated deaths account for approximately 3%-4% of all malignancy-associated deaths. Numerous microRNAs (miRNAs) play important roles in the occurrence and progression of solid tumors. Herein, identifying functional miRNAs and the central molecular mechanisms would provide novel proofs for the development of targeted cancer therapies. In this study, we described the role of miR-449b-5p in restraining ontogenesis and progression of glioblastoma.
Human glioblastoma tissues were provided by our hospital. Human U251 glioblastoma cells were infected with lentivirus induced miR-449b-5p mimics or miR-449b-5p siRNA. Real-time qPCR was carried out to determine miRNA expression. Tumor spheres formation, MTT assay, and BrdU cell proliferation assay were used to evaluate the growth ability of U251 cells. Western blot assay was performed to measure protein expression. ChIP was used to detect the capacity of β-catenin to recruit its downstream genes. Dual-Luciferase assay was conducted to detect the ability of miR-449b-5p to regulate the 3'UTR (untranslated regions) of WNT2B. TOP/FOP ratio was used to evaluate the activity of Wnt/β-catenin signaling pathway.
Down-regulation of miR-449b-5p expression was found in both human glioblastoma tissues and cell lines, which was negatively associated with the clinical stages. Up-regulation of miR-449b-5p inhibited tumor spheres formation, cell viability and proliferation ability of glioblastoma cells. The expression levels of WNT2B and nuclear β-catenin were negatively associated with miR-449b-5p levels in glioblastoma cells. MiR-449b-5p inhibited Wnt/β-catenin signaling by targeting WNT2B.
MiR-449b-5p acts as a tumor suppressor and retards the oncogenesis of glioblastoma, which is achieved via inactivation of Wnt/β-catenin signaling by directly targeting WNT2B.
作为成人中最常见的原发性脑癌，胶质母细胞瘤的预后极差。胶质母细胞瘤相关死亡约占所有恶性肿瘤相关死亡的 3%-4%。许多 microRNAs（miRNAs）在实体瘤的发生和发展中发挥重要作用。在此，确定功能性 miRNAs 及其中心分子机制将为靶向癌症治疗的发展提供新的证据。在这项研究中，我们描述了 miR-449b-5p 在抑制胶质母细胞瘤的发生和发展中的作用。
本研究中的人脑胶质母细胞瘤组织由我院提供。用人慢病毒诱导 miR-449b-5p 模拟物或 miR-449b-5p siRNA 感染人 U251 胶质母细胞瘤细胞。实时 qPCR 用于检测 miRNA 表达。肿瘤球形成、MTT 检测和 BrdU 细胞增殖检测用于评估 U251 细胞的生长能力。Western blot 检测用于测量蛋白表达。ChIP 用于检测β-catenin 募集其下游基因的能力。双荧光素酶报告基因检测用于检测 miR-449b-5p 调节 WNT2B 的 3'UTR（非翻译区）的能力。TOP/FOP 比值用于评估 Wnt/β-catenin 信号通路的活性。
下调 miR-449b-5p 在人脑胶质母细胞瘤组织和细胞系中均有表达，且与临床分期呈负相关。上调 miR-449b-5p 抑制了肿瘤球形成、细胞活力和增殖能力。在胶质母细胞瘤细胞中，WNT2B 和核 β-catenin 的表达水平与 miR-449b-5p 水平呈负相关。miR-449b-5p 通过靶向 WNT2B 抑制 Wnt/β-catenin 信号。
miR-449b-5p 作为一种肿瘤抑制因子，通过直接靶向 WNT2B 抑制 Wnt/β-catenin 信号，减缓胶质母细胞瘤的发生。
