OSR1通过YAP调控Hippo和Wnt信号通路抑制肺癌侵袭和转移的分子机制研究

Hippo信号通路以及Wnt信号通路在肺癌的侵袭和转移中发挥着重要的作用。我们前期发现OSR1能通过GSK3β抑制β-catenin的表达，下调Wnt信号通路的活性和肺癌的增殖及侵袭能力；还能激活Hippo信号通路，上调YAP的磷酸化水平；OSR1在YAP启动子区有潜在结合位点。我们推测：OSR1在转录以及蛋白水平通过YAP多层次调控Wnt和Hippo信号通路。结合课题组前期研究发现，本研究拟：①采用CHIP-seq和荧光素酶报告系统，并将IP与质谱联用，明确OSR1对YAP转录的调控作用、位点和相关转录因子；②采用IP结合基因转染敲除，明确OSR1、GSK3β、APC、YAP蛋白的相互作用和磷酸化调控关系，及对Wnt和Hippo通路活性和肺癌侵袭转移的影响；③通过肺癌组织和裸鼠移植瘤验证上述研究。本研究对阐明和拓展Wnt和Hippo通路调控机制，寻找肺癌防治的潜在靶点具有重要意义。

Hippo and Wnt signaling pathways play important roles in the proliferation and invasion of lung cancers. We previously found that OSR1 inhibited the expression of β-catenin through GSK3β, downregulated the activity of Wnt signaling pathway, and the proliferation and invasion of lung cancer cells; OSR1 could activate Hippo signaling pathway and enhance the phosphorylation level of YAP. Furthermore, there are potential binding sites of OSR1 on the promoters of YAP. So, we speculate that OSR1 can regulate Wnt and Hippo signaling pathways through YAP at both transcription and protein levels. In this study, we plan to: clarify the regulating mechanism of OSR1 on YAP transcription, and identify the binding sites and associated transcription factors using the CHIP-sequencing, luciferase reporter assay, IP and mass spectrometry methods; clarify the interaction and phosphorylating regulation among OSR1, GSK3β, APC and YAP, and their effects on the activities of Wnt and Hippo signaling pathways and the proliferation and invasion of lung cancers using IP, gene transfection and knockdown; confirm the regulating mechanism and effects of OSR1 in vivo using lung cancer tissue samples and xenograft model in nude mices. This study is of great significance to elucidate and expand the regulating mechanism of Wnt and Hippo signaling pathway, and to find potential targets for the prevention and treatment of lung cancers.