骨肉瘤（OS）是一种常见于20岁以下儿童和青少年的恶性骨肿瘤。microRNA（miRNA）失调是OS发生和进展的重要因素。 MicroRNA miR-744-5p 在多种肿瘤中异常表达。然而，其在OS中的作用和分子靶点仍不清楚。使用Gene Expression Omnibus数据集GSE65071分析了OS中差异表达的miRNA，并通过加权基因共表达网络分析鉴定了潜在的枢纽miRNA。采用实时定量PCR（qRT-PCR）检测OS细胞系中miR-744-5p的表达。进行体外实验，包括CCK-8测定、集落形成测定、流式细胞术凋亡测定和管形成测定，以探讨miR-744-5p对OS细胞生物学行为的影响。通过生物信息学预测miR-744-5p的下游靶基因，并通过双荧光素酶报告基因分析验证结合位点。低表达的miRNA miR-744-5p被确定为参与OS进展的枢纽miRNA通过生物信息分析。核因子 I X (NFIX) 被证实是 OS 中 miR-744-5p 的直接靶标。体外研究表明，miR-744-5p的过度表达可以抑制OS细胞的生长，而miR-744-5p的抑制则表现出相反的效果。还观察到，用 miR-744-5p 过表达的 OS 细胞的条件培养基处理会导致人脐静脉内皮细胞 (HUVEC) 的增殖和血管生成较差。此外，NFIX过表达恢复了miR-744-5p过表达对OS细胞生长和HUVEC血管生成的抑制作用。我们的结果表明，miR-744-5p是OS进展中潜在的肿瘤抑制miRNA，通过靶向NFIX来抑制OS细胞的生长。 HUVEC 中的 OS 细胞和血管生成。© 2024。作者。

Osteosarcoma (OS) is a malignant bone tumor that commonly occurs in children and adolescents under the age of 20. Dysregulation of microRNAs (miRNAs) is an important factor in the occurrence and progression of OS. MicroRNA miR-744-5p is aberrantly expressed in various tumors. However, its roles and molecular targets in OS remain unclear.Differentially expressed miRNAs in OS were analyzed using the Gene Expression Omnibus dataset GSE65071, and the potential hub miRNA was identified through weighted gene co-expression network analysis. Quantitative real-time PCR (qRT-PCR) was used to detect the expression of miR-744-5p in OS cell lines. In vitro experiments, including CCK-8 assays, colony formation assays, flow cytometry apoptosis assays, and tube formation assays, were performed to explore the effects of miR-744-5p on OS cell biological behaviors. The downstream target genes of miR-744-5p were predicted through bioinformatics, and the binding sites were validated by a dual-luciferase reporter assay.The lowly expressed miRNA, miR-744-5p, was identified as a hub miRNA involved in OS progression through bioinformatic analysis. Nuclear factor I X (NFIX) was confirmed as a direct target for miR-744-5p in OS. In vitro studies revealed that overexpression of miR-744-5p could restrain the growth of OS cells, whereas miR-744-5p inhibition showed the opposite effect. It was also observed that treatment with the conditioned medium from miR-744-5p-overexpressed OS cells led to poorer proliferation and angiogenesis in human umbilical vein endothelial cells (HUVECs). Furthermore, NFIX overexpression restored the suppression effects of miR-744-5p overexpression on OS cell growth and HUVECs angiogenesis.Our results indicated that miR-744-5p is a potential tumor-suppressive miRNA in OS progression by targeting NFIX to restrain the growth of OS cells and angiogenesis in HUVECs.© 2024. The Author(s).