Background

Osteosarcoma (OS) is one of the most commonly diagnosed malignant tumors that mainly affects children and adolescents. The underlying molecular mechanisms that are responsible for the initiation and development of OS are still not clear. Increasing evidence suggested the tumor suppressor role of microRNA-524-5p in a variety of cancers via targeting key pathways involved in tumorigenesis. The aim of this study was to characterize the function of miR-524-5p in OS.

Methods

A total 50 paired OS tissues and adjacent normal tissues were collected from OS patients. The expression of miR-524-5p in OS tissues and cells was detected by RT-qPCR. The CCK-8 assay, flow cytometry and transwell assay were applied to determine the proliferation and invasion abilities of OS cells. The targets of miR-524-5p were predicted using the miRDB dataset and confirmed by luciferase reporter assay and western blot analysis.

Results

The expression of miR-524-5p was decreased in OS tissues and cell lines. OS patients with lymph node metastasis harbored relative lower level of miR-524-5p. Overexpression of miR-524-5p in OS cells significantly suppressed the proliferation, drove cell cycle arrest and apoptosis. The mechanism investigation revealed that miR-524-5p bound the 3′-untranslated region (UTR) of Cyclin Dependent Kinase 6 (CDK6) and repressed the expression of CDK6 in OS cells. Overexpressed CDK6 was found in OS tissues, which was inversely correlated with that of miR-524-5p. Moreover, forced expression of CDK6 significantly reversed the anti-cancer effects of miR-524-5p on the proliferation, apoptosis and cell cycle arrest of OS cells.

Conclusions

Our results identified the tumor-suppressive role of miR-524-5p in OS via targeting CDK6, which may lead to the identification of novel therapeutic target for the treatment of OS.

中文翻译：

---

microRNA-524-5p通过靶向CDK6抑制增殖并诱导骨肉瘤细胞的细胞周期停滞。

背景

骨肉瘤（OS）是最常见的恶性肿瘤之一，主要影响儿童和青少年。尚不清楚导致OS发生和发展的潜在分子机制。越来越多的证据表明，通过靶向参与肿瘤发生的关键途径，microRNA-524-5p在多种癌症中的抑癌作用。这项研究的目的是表征miR-524-5p在OS中的功能。

方法

从OS患者中收集了总共50对配对的OS组织和相邻的正常组织。RT-qPCR检测miR-524-5p在OS组织和细胞中的表达。采用CCK-8法，流式细胞仪和transwell法测定OS细胞的增殖和侵袭能力。使用miRDB数据集预测了miR-524-5p的靶标，并通过荧光素酶报告基因分析和Western印迹分析进行了确认。

结果

miR-524-5p在OS组织和细胞系中的表达降低。淋巴结转移的OS患者的miR-524-5p水平相对较低。miR-524-5p在OS细胞中的过表达显着抑制了增殖，驱动了细胞周期停滞和凋亡。机制研究表明，miR-524-5p结合细胞周期蛋白依赖性激酶6（CDK6）的3'-非翻译区（UTR），并抑制OS细胞中CDK6的表达。在OS组织中发现过表达的CDK6，与miR-524-5p的表达负相关。此外，CDK6的强制表达显着逆转了miR-524-5p对OS细胞增殖，凋亡和细胞周期停滞的抗癌作用。

结论

我们的结果通过靶向CDK6鉴定了miR-524-5p在OS中的肿瘤抑制作用，这可能导致鉴定用于OS的新型治疗靶标。