HNRNPD靶向调控MAD2L2/ANGPTL4通路促进肺癌血管生成的分子机制研究

申请人前期研究发现，有丝分裂阻滞缺陷蛋白2（MAD2L2）表达异常和肿瘤发生密切相关，因此研究肿瘤中特异性的MAD2L2表达调控因子意义重大。预实验结果显示，MAD2L2在人肺癌中高表达，其通过泛素化降解血管生成素样蛋白4（ANGPTL4）促进肺癌血管生成。我们利用启动子探针垂钓技术，进一步发现异质核糖核蛋白D（HNRNPD）可结合到MAD2L2启动子区并调控其转录，但具体分子机制及临床意义，目前尚不清楚。本项目拟在肺癌细胞和移植瘤模型中敲除或过表达HNRNPD，探讨HNRNPD对MAD2L2转录、启动子活性、ANGPTL4泛素化的调控以及对肺癌血管生成的影响，揭示HNRNPD靶向调控MAD2L2/ANGPTL4通路在肺癌血管生成中的作用和分子机制；并结合临床样本，评估HNRNPD与肺癌血管生成及生存预后的关系，明确其临床意义。本项目将为确立新型的肺癌抗血管生成治疗靶点提供实验依据。

Our previous study has found that abnormal expression of mitotic arrest deficient 2-like protein 2 (MAD2L2) is closely related to tumorigenesis, so it is of great significance to study the tumor-specific factors that regulate MAD2L2 expression. The preliminary results showed that MAD2L2 was highly expressed in human lung cancer (LC), which promoted LC angiogenesis through ubiquitination and degradation of angiopoietin-like protein 4 (ANGPTL4). By using promoter probes and fishing techniques, we further found that heterogeneous nuclear ribonucleoprotein D (HNRNPD) bound to the MAD2L2 promoter region and regulated its transcription. However, so far it is unclear about its molecular mechanism and clinical implication. In this study, we will knockout and overexpress HNRNPD gene in human LC cells and xenograft models, and explore the effects of HNRNPD on MAD2L2 transcription, promoter activity, ANGPTL4 ubiquitination, and LC angiogenesis, thus revealing the role and molecular mechanism of HNRNPD targeted regulation of MAD2L2/ANGPTL4 pathway in LC angiogenesis. Moreover, we will use clinical specimens to evaluate the relationship of HNRNPD with LC angiogenesis and survival, thereby identifying its clinical significance. This project will provide experimental basis for the identification of new antiangiogenic therapeutic LC targets.