骨肉瘤是儿童和青少年最常见的原发恶性骨肿瘤，早期转移仍是治疗骨肉瘤失败的主要原因，也是目前骨肉瘤治疗措施的主要研究方向。BMP信号通路是当前研究的热点，但在骨肉瘤中主要集中在依赖Smad的BMP信号通路，而对非依赖Smad的BMP信号通路的研究较少。本团队前期通过公共芯片数据库分析发现BMPR2的表达水平高的骨肉瘤患者预后较差，并且5年内易出现转移。而细胞学实验发现抑制BMPR2的表达可通过非依赖Smad的BMP通路抑制EMT的发生，并能抑制骨肉瘤细胞的侵袭迁移能力，但是具体机制尚未明确。而本项目拟从非依赖Smad的BMP信号通路入手，利用iTRAQ定量蛋白质组学高通量技术筛选BMPR2直接作用的靶蛋白及下游信号通路，通过细胞实验、动物实验和临床标本多重验证，得到BMPR2调控骨肉瘤侵袭转移的关键蛋白，从而为骨肉瘤的靶向治疗以及个体化治疗奠定基础。

Osteosarcoma, the most common primary malignant bone tumor in children and adolescents, is a highly metastatic tumor.Although BMP signaling pathway is a hotspot,the Smad-dependent signaling pathway in osteosarcoma draws most attention, and research about the role of Smad-independent pathway in osteosarcoma progression is rareness. Our previous studies found that osteosarcoma patients of high level of BMPR2 had poorer clinical prognosis and more tendence of metastasis in five years after dignosis. At the same time, we confirmed that inhibiting BMPR2 suppressed EMT, and inhibited the invasion and migration of osteosarcoma via Smad-independent pathway. However, the exactly mechanism is not clear. Based on the above results, the project intend to investigate Smad-independent signaling pathway in regulating migration and invasion of osteosarcoma. We will use iTRAQ-based quantitative proteomic analysis to screen and identify of target proteins and the signaling pathways from these proteins.Through in vitro and in vivo as well as clinical sample analysis, we expect to obtain the target proteins and corresponding signaling pathways which will benefit for osteosarcoma targeted therapy and individual therapy.