Gao Shun-Li, Wang Li-Zhong, Liu Hai-Ying, Liu Dan-Li, Xie Li-Ming, Zhang Zhi-Wei
Department of pediatrics, The First Affiliated Hospital, University of South China, Hengyang, China E-mail :
Asian Pac J Cancer Prev. 2014;15(11):4671-6. doi: 10.7314/apjcp.2014.15.11.4671.
MicroRNA-200a (miR-200a) has been reported to regulate tumour progression in several tumours but little is known about its role in neuroblastoma. Our aim was to investigate the potential role and mechanism of miR-200a in neuroblastomas.
Expression levels of miR-200a in tissues were determined using RT-PCR. The effect of miR-200a and shAP-2γ on cell viability was evaluated using MTS assays, and target protein expression was determined using Western blotting and RT-PCR. Luciferase reporter plasmids were constructed to confirm direct targeting. RESULTS were reported as mean±S.E.M and differences were tested for significance using the 2-tailed Students t-test.
We determined that miR-200a expression was significantly lower in neuroblastoma tumors than the adjacent non-cancer tissue. Over-expression of miR-200 are reduced cell viability in neuroblastoma cells and inhibited tumor growth in mouse xenografts. We identified AP-2γ as a novel target for miR-200a in neuroblastoma cells. Thus miR-200a targets the 3'UTR of AP-2γ and inhibits its mRNA and protein expression. Furthermore, our result showed that shRNA knockdown of AP-2γ in neuroblastoma cells results in significant inhibit of cell proliferation and tumor growth in vitro, supporting an oncogenic role of AP-2γ in neuroblastoma.
Our study revealed that miR-200a is a candidate tumor suppressor in neuroblastoma, through direct targeting of AP-2γ. These findings re-enforce the proposal of AP-2γ as a therapeutic target in neuroblastoma.
据报道,微小RNA-200a(miR-200a)可调节多种肿瘤的进展,但对其在神经母细胞瘤中的作用知之甚少。我们的目的是研究miR-200a在神经母细胞瘤中的潜在作用和机制。
采用逆转录聚合酶链反应(RT-PCR)测定组织中miR-200a的表达水平。使用MTS法评估miR-200a和短发夹RNA(shAP-2γ)对细胞活力的影响,并通过蛋白质免疫印迹法和RT-PCR测定靶蛋白表达。构建荧光素酶报告质粒以确认直接靶向作用。结果以平均值±标准误表示,差异采用双侧学生t检验进行显著性检验。
我们发现神经母细胞瘤肿瘤组织中miR-200a的表达明显低于相邻的非癌组织。miR-200a的过表达降低了神经母细胞瘤细胞的活力,并抑制了小鼠异种移植瘤的生长。我们确定AP-2γ是神经母细胞瘤细胞中miR-200a的一个新靶点。因此,miR-200a靶向AP-2γ的3'非翻译区(3'UTR),抑制其mRNA和蛋白质表达。此外,我们的结果表明,在神经母细胞瘤细胞中通过短发夹RNA敲低AP-2γ可显著抑制体外细胞增殖和肿瘤生长,这支持了AP-2γ在神经母细胞瘤中的致癌作用。
我们的研究表明,miR-200a通过直接靶向AP-2γ,是神经母细胞瘤中的一种候选肿瘤抑制因子。这些发现进一步支持了将AP-2γ作为神经母细胞瘤治疗靶点的提议。