Department of Microbiology, Immunology and Cancer Biology, University of Virginia, PO Box 800168, Charlottesville, VA, 22908, USA.
Neurosurgical Research, University Clinics Munich, Munich, Germany.
J Neurooncol. 2019 Oct;145(1):23-34. doi: 10.1007/s11060-019-03275-z. Epub 2019 Sep 3.
microRNAs are small noncoding RNAs that play important roles in cancer regulation. In this study, we investigated the expression, functional effects and mechanisms of action of microRNA-29a (miR-29a) in glioblastoma (GBM).
miR-29a expression levels in GBM cells, stem cells (GSCs) and human tumors as well as normal astrocytes and normal brain were measured by quantitative PCR. miR-29a targets were uncovered by target prediction algorithms, and verified by immunoblotting and 3' UTR reporter assays. The effects of miR-29a on cell proliferation, death, migration and invasion were assessed with cell counting, Annexin V-PE/7AAD flow cytometry, scratch assay and transwell assay, respectively. Orthotopic xenografts were used to determine the effects of miR-29a on tumor growth.
Mir-29a was downregulated in human GBM specimens, GSCs and GBM cell lines. Exogenous expression of miR-29a inhibited GSC and GBM cell growth and induced apoptosis. miR-29a also inhibited GBM cell migration and invasion. PDGFC and PDGFA were uncovered and validated as direct targets of miR-29a in GBM. miR-29a downregulated PDGFC and PDGFA expressions at the transcriptional and translational levels. PDGFC and PDGFA expressions in GBM tumors, GSCs, and GBM established cell lines were higher than in normal brain and human astrocytes. Mir-29a expression inhibited orthotopic GBM xenograft growth.
miR-29a is a tumor suppressor miRNA in GBM, where it inhibits cancer stem cells and tumor growth by regulating the PDGF pathway.
微小 RNA 是在癌症调控中发挥重要作用的小非编码 RNA。在这项研究中，我们研究了 microRNA-29a（miR-29a）在胶质母细胞瘤（GBM）中的表达、功能效应和作用机制。
通过定量 PCR 测量 GBM 细胞、干细胞（GSCs）和人肿瘤以及正常星形胶质细胞和正常脑内的 miR-29a 表达水平。通过靶标预测算法发现 miR-29a 的靶标，并通过免疫印迹和 3'UTR 报告基因检测进行验证。通过细胞计数、Annexin V-PE/7AAD 流式细胞术、划痕试验和 Transwell 试验分别评估 miR-29a 对细胞增殖、死亡、迁移和侵袭的影响。使用原位异种移植来确定 miR-29a 对肿瘤生长的影响。
miR-29a 在人 GBM 标本、GSCs 和 GBM 细胞系中下调。外源性表达 miR-29a 抑制 GSC 和 GBM 细胞生长并诱导细胞凋亡。miR-29a 还抑制 GBM 细胞迁移和侵袭。发现并验证 PDGFC 和 PDGFA 是 GBM 中 miR-29a 的直接靶标。miR-29a 在转录和翻译水平下调 PDGFC 和 PDGFA 的表达。GBM 肿瘤、GSCs 和 GBM 建立的细胞系中的 PDGFC 和 PDGFA 表达高于正常脑和人星形胶质细胞。miR-29a 的表达抑制了原位 GBM 异种移植的生长。
miR-29a 是 GBM 中的肿瘤抑制 miRNA，通过调节 PDGF 途径抑制癌症干细胞和肿瘤生长。
