骨肉瘤（OS）是最常见原发恶性骨肿瘤。m6A是目前恶性肿瘤研究热点。我们前期发现OS中m6A水平显著上调；其甲基化酶METTL14异常高表达，与预后负相关；功能实验证实该分子调控OS恶性进展。MeRIP-Seq联合RNA-Seq筛选并鉴定Hippo通路关键分子TAZ、SAV1、LATS1的m6A峰下调伴随蛋白表达改变；同时肿瘤细胞干性相关基因的表达显著变化；敲低METTL14证实OS细胞干性显著下调。目前METTL14通过Hippo通路调节OS细胞干性作用及机制尚未阐明。现拟在前期基础上用体内外模型验证METTL14通过Hippo通路对OS干性调控作用；应用m6A-qPCR、RIP-qPCR、核糖体印迹等研究METTL14-Hippo通路表观转录调控机制；结合病例资料分析METTL14及靶基因临床意义。本项目旨在研究METTL14在OS细胞干性调控中的作用及表观转录机制，探索OS新靶标。

Osteosarcoma (OS) is the most common primary malignant bone tumor. Recently, RNA m6A modification is currently a hot topic in malignant tumor research. In our previous work, we found that m6A in OS was up-regulated and changed with tumor stage. The m6A methylase METTL14 expression was abnormally overexpressed and negatively correlated with prognosis. Our functional experiments have confirmed it regulated the malignant progression in osteosarcoma. Through MeRIP-seq combined with RNA-seq, the m6A peaks of TAZ, SAV1, and LATS1, key molecules of Hippo pathway, were identified. Meanwhile, the expression of stemness related genes in OS cells was significantly changed. Furthermore knockdown of METTL14 confirmed that stemness characteristics of OS cells was significantly down-regulated. At present, the mechanism by which METTL14 regulates the stemness of OS cells and its epigenetic transcription through Hippo pathway remains unclear. On the basis of previous studies, we plan to use cells and animal models to validate the effect of METTL14 on stemness regulation through Hippo pathway in OS cells. Then we will use m6A-qPCR, CLIP-qPCR and polysome profiling to investigate the epigenetic transcription regulation mechanism of METTL14-m6A-Hippo pathway. Furthermore we will analyse the clinical significance of METTL14 and target gene according to clinical data. We aim to investigate the mechanisms and the role of METTL14 in the regulation of stemness on OS cells and the epitranscriptional mechanism, with the purpose to explore new molecular targets for osteosarcoma.