Abstract：
Osteosarcoma (OS) is a malignant tumor that occurs in children and adolescents. Previous studies reported a low expression of miR-148b-3p in OS, but its biological function in OS remains obscure. This study aimed to explore the role of miR-148b-3p in OS progression. Herein, the expression of miR-148b-3p and son of sevenless homolog 1 (SOS1) both in OS tissues and cells were examined using quantitative real-time polymerase chain reaction and Western blotting assay. miR-148b-3p mimic or inhibitor, pcDH-SOS1 plasmid or si-SOS1 and agomir-miR-148b-3p were constructed for cell transfection. In vitro, the biological effect of miR-148b-3p was determined employing MTT, EdU, colony formation, flow cytometry, transwell and wound healing assay, separately. The target relationship between SOS1 3\'-untranslated region (3\'-UTR) and miR-148b-3p was analyzed using dual-luciferase reporter gene. In vivo, the inhibition of agomir-miR-148b-3p in mice was evaluated via a xenograft mouse model. miR-148b-3p was noticeably low-expressed in OS tissues and cells, and miR-148b-3p over-expression in OS cells suppressed the growth, migration and invasion, induced apoptosis. The effect of miR-148b-3p-inhibitor on cell biological behavior is opposite to that of miR-148b-3p over-expression. Conversely, The expression of SOS1 was significant higher in OS tissues and cells, miR-148b-3p targeted and was negatively associated with the expression level of SOS1. In addition, the anti-tumor effect of miR-148b-3p was reversed by SOS1. Importantly, we demonstrated that the tumor growth of stably over-expressed miR-148b-3p human MG-63 cells was obviously reduced in tumor-bearing mice. These data highlighted that miR-148b-3p might be as a promising therapeutic target for OS.
摘要：
骨肉瘤（OS）是一种发生在儿童和青少年中的恶性肿瘤。先前的研究报道了miR-148b-3p在OS中的低表达，但其在OS中的生物学功能仍不清楚。本研究旨在探讨miR-148b-3p在OS进展中的作用。在这里，使用定量实时聚合酶链反应和Western印迹法检测了OS组织和细胞中miR-148b-3p和无七同源物1(SOS1)的表达。miR-148b-3p模拟物或抑制剂，构建pcDH-SOS1质粒或si-SOS1和agomir-miR-148b-3p用于细胞转染。体外，用MTT法测定miR-148b-3p的生物学效应，EdU,菌落形成,流式细胞术,Transwell和伤口愈合试验，分开。使用双荧光素酶报告基因分析了SOS13'-非翻译区（3'-UTR）与miR-148b-3p之间的靶关系。在体内,通过异种移植小鼠模型评估了agomir-miR-148b-3p在小鼠中的抑制作用.miR-148b-3p在OS组织和细胞中显著低表达，miR-148b-3p在OS细胞中的过表达抑制了细胞的生长，移民和入侵，诱导细胞凋亡。miR-148b-3p抑制剂对细胞生物学行为的影响与miR-148b-3p过表达相反。相反，SOS1在OS组织和细胞中表达显著增高，miR-148b-3p靶向并与SOS1的表达水平呈负相关。此外,miR-148b-3p的抗肿瘤作用被SOS1逆转。重要的是,我们证明，稳定过表达的miR-148b-3p人MG-63细胞在荷瘤小鼠中的肿瘤生长明显减少。这些数据强调miR-148b-3p可能是OS的有希望的治疗靶标。
