Department of Orthopedic Surgery, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, P.R. China.
Department of Orthopedics, Wuhan Hospital No. 3 and Tongren Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China.
Mol Med Rep. 2017 Dec;16(6):8627-8634. doi: 10.3892/mmr.2017.7709. Epub 2017 Oct 4.
Tumorigenesis is a multistep process involving various cell growth‑associated factors. Accumulated evidence indicates that the disordered regulation of microRNAs (miRNAs) contributes to tumorigenesis. However, the detailed mechanism underlying the involvement of miRNAs in oncogenesis remains to be fully elucidated. In the present study, the repressed expression of microRNA (miR)‑494 was identified in 18 patients with osteosarcoma (OS) and OS cell lines, compared with corresponding controls. To determine whether deregulated miR‑494 exerts tumor‑suppressive effects in the development of OS, the effects of miR‑494 on cell proliferation and metastasis were evaluated. It was found that the restoration of miR‑494 in MG‑63 and U2OS cells led to inhibited cell proliferation and attenuated migratory propensity in vitro, determined through analysis using MTT, colony formation and Transwell assays. In addition, overexpression of miR‑494 markedly suppressed the tumor volume and weight in vivo. In accordance, the ectopic expression of miR‑494 induced cell cycle arrest at the G1/S phase in OS cells. Bioinformatics analysis and luciferase reporter assays were performed to investigate the potential regulatory role of miR‑494, the results of which indicated that miR‑494 directly targeted cyclin‑dependent kinase 6 (CDK6). Of note, the data obtained through reverse transcription‑quantitative polymerase chain reaction and western blot analyses suggested that the elevated expression of miR‑494 resulted in reduced mRNA and protein expression levels of CDK6. Taken together, these findings indicated that the miR‑494/CDK6 axis has a significant tumor‑suppressive effect on OS, and maybe a diagnostic and therapeutic target for the treatment of OS.
肿瘤发生是一个涉及多种细胞生长相关因子的多步骤过程。有大量证据表明，miRNAs（miRNA）的失调调节有助于肿瘤发生。然而，miRNA 参与致癌作用的详细机制仍有待充分阐明。在本研究中，与相应对照相比，在 18 名骨肉瘤（OS）患者和 OS 细胞系中发现 microRNA（miR）-494 的表达受到抑制。为了确定失调的 miR-494 是否对 OS 的发展具有肿瘤抑制作用，评估了 miR-494 对细胞增殖和转移的影响。结果发现，在 MG-63 和 U2OS 细胞中恢复 miR-494 导致体外细胞增殖受到抑制，迁移能力减弱，通过 MTT、集落形成和 Transwell 分析进行了评估。此外，miR-494 的过表达显著抑制了体内肿瘤体积和重量。相应地，miR-494 的异位表达导致 OS 细胞中的细胞周期停滞在 G1/S 期。进行了生物信息学分析和荧光素酶报告基因测定，以研究 miR-494 的潜在调节作用，结果表明 miR-494 直接靶向细胞周期蛋白依赖性激酶 6（CDK6）。值得注意的是，通过逆转录-定量聚合酶链反应和 Western blot 分析获得的数据表明，miR-494 的表达升高导致 CDK6 的 mRNA 和蛋白表达水平降低。综上所述，这些发现表明 miR-494/CDK6 轴对 OS 具有显著的肿瘤抑制作用，可能是 OS 治疗的诊断和治疗靶点。
