Angiomotin p130通过泛素化途径介导HIF-1α降解调控三阴性乳腺癌血管生成拟态的作用机制研究

血管生成拟态(VM)是三阴性乳腺癌（TNBC）早期侵袭转移的关键步骤，然而调控机制不明确。我们前期研究发现血管抑素结合蛋白（Amot）p130在TNBC中低表达，过表达Amotp130能够抑制VM形成，并可能与HIF-1α的泛素化降解有关；同时发现Amotp130与泛素连接酶UBE3C存在相互作用，生信分析表明后者可与HIF-1α特异性结合。由此推测Amotp130可能通过UBE3C介导HIF-1α降解调控TNBC中VM形成。我们拟从临床病理、体外细胞、动物模型三个层面，应用临床病理数据与细胞分子生物学方法分析Amotp130、UBE3C、HIF-1α之间及其与VM的关系，探讨Amotp130通过泛素化途径介导HIF-1α降解调控TNBC中VM形成的机制，并应用动物实验在体内验证这一机制。本课题的顺利实施将有助于深入了解TNBC中VM的调控机制，为以VM为靶点的肿瘤分子靶向治疗提供新思路。

The formation of vasculogenic mimicry (VM) which is different from classic angiogenesis plays an important role in tumor’s blood and nutrition supplying, and closely related to the prognosis of breast cancer. Triple negative breast cancer (TNBC) as the most aggressive molecular classification of breast cancer has much closer relationship with VM. Studies have shown that VM is the pivotal step of metastasis and invasion in TNBC. However, the regulatory mechanism of VM formation and regulation in TNBC is still unclear. Amot p130 which is the subtype of vascular inhibition antibody binding protein (Angiomotin) is an important regulatory factor of angiogenesis. The relationship between Amot p130 and VM has not been reported by now. Our previous studies showed that the expression of Amot p130 was low in TNBC, and the up-regulation of Amot p130 could inhibit VM formation, so Amot p130 may be the important regulatory protein of VM, but the mechanism is not clear. HIF-1α (Hypoxia-inducible factors) is a key regulatory protein in VM formation. The expression of HIF-1α was inhibited in hypoxia while the Amot p130 was up-regulated. Our previous studies suggested that Amot p130 may be involved in the ubiquitination degradation of HIF-1α. Finally, we discovered a E3 ubiquitin-ligase enzymes UBE3C which may be related to Amot p130 and HIF-1α. Herein, we assume that the Amot p130 inhibit HIF-1α and regulate VM formation in TNBC via ubiquitination pathway. This project will be performed from three levels including clinicopathology, cells and animal models. We intend to analyze the relationship between Amotp130, UBE3C, HIF-1α and VM, to explore the mechanism of Amotp130 mediating the degradation of HIF-1α via ubiquitination pathway and regulating TNBC VM by clinicopathological data and cell molecular biological methods, and to verify this mechanism in vivo by animal experiments. The relationships between the expression of Amot p130, UBE3C, HIF-1α and VM formation, clinicopathologic characteristics, prognosis will be stressed in TNBC, and the mechanism of Amot p130 inhibiting VM formation will be proved, and the interaction between Amot p130, UBE3C and HIF-1α will be further analyzed. The project will help us know more information about the regulatory mechanisms and provide us new direction for finding new therapeutic targets in VM formation.