China-Japan Union Hospital of Jilin University, Changchun City, Jilin Province, 130033, China.
Anticancer Agents Med Chem. 2020;20(10):1197-1208. doi: 10.2174/1871520620666200402074752.
Osteosarcoma (OS) is a prevalent primary bone malignancy and its distal metastasis remains the main cause of mortality in OS patients. MicroRNAs (miRNAs) play critical roles during cancer metastasis.
Thus, elucidating the role of miRNA dysregulation in OS metastasis may provide novel therapeutic targets.
The previous study found a low miR-134 expression level in the OS specimens compared with paracancer tissues. Overexpression of miR-134 stable cell lines was established. Cell viability assay, cell invasion and migration assay and apoptosis assay were performed to evaluate the role of miR-134 in OS in vitro.
We found that miR-134 overexpression inhibits cell proliferation, migration and invasion, and induces cell apoptosis in both MG63 and Saos-2 cell lines. Mechanistically, miR-134 targets the 3'-UTR of VEGFA and MYCN mRNA to silence its translation, which was confirmed by luciferase-reporter assay. The real-time PCR analysis illustrated that miR-134 overexpression decreases VEGFA and MYCN mRNA levels. Additionally, the overexpression of VEGFA or MYCN can partly attenuate the effects of miR-134 on OS cell migration and viability. Furthermore, the overexpression of miR-134 dramatically inhibits tumor growth in the human OS cell line xenograft mouse model in vivo. Moreover, bioinformatic and luciferase assays indicate that the expression of miR-134 is regulated by Interferon Regulatory Factor (IRF1), which binds to its promoter and activates miR-134 expression.
Our study demonstrates that IRF1 is a key player in the transcriptional control of miR-134, and it inhibits cell proliferation, invasion and migration in vitro and in vivo via targeting VEGFA and MYCN.
骨肉瘤（OS）是一种常见的原发性骨恶性肿瘤，其远端转移仍是 OS 患者死亡的主要原因。微小 RNA（miRNA）在癌症转移过程中发挥着关键作用。
因此，阐明 miRNA 失调在 OS 转移中的作用可能为新的治疗靶点提供依据。
先前的研究发现 OS 标本中的 miR-134 表达水平低于癌旁组织。建立了 miR-134 过表达稳定细胞系。通过细胞活力测定、细胞侵袭和迁移测定和细胞凋亡测定来评估 miR-134 在 OS 体外的作用。
我们发现 miR-134 过表达抑制 MG63 和 Saos-2 细胞系中的细胞增殖、迁移和侵袭，并诱导细胞凋亡。机制上，miR-134 靶向 VEGFA 和 MYCN mRNA 的 3'-UTR 以沉默其翻译，这通过荧光素酶报告基因测定得到证实。实时 PCR 分析表明 miR-134 过表达降低了 VEGFA 和 MYCN mRNA 水平。此外，VEGFA 或 MYCN 的过表达可以部分减弱 miR-134 对 OS 细胞迁移和活力的影响。此外，miR-134 的过表达在体内人骨肉瘤细胞系异种移植小鼠模型中显著抑制肿瘤生长。此外，生物信息学和荧光素酶测定表明，miR-134 的表达受干扰素调节因子（IRF1）调控，IRF1 结合其启动子并激活 miR-134 的表达。
我们的研究表明，IRF1 是 miR-134 转录调控的关键因子，它通过靶向 VEGFA 和 MYCN 在体外和体内抑制细胞增殖、侵袭和迁移。
