The role of HEF1/NEDD9 protein in proliferation and invasion of metastatic breast cancer

 描述(申请人提供)：HEF1/NEDD9是一种细胞质适配蛋白，是具有浸润性肿瘤特征的不同癌症预后不良的公认标志。我们先前已经报道，NEDD9调节有丝分裂激酶AURA/AURKA的稳定性和激活，导致多种细胞质底物的磷酸化，如参与迁移和侵袭的HDAC6、Src、CTTN、Arp/C和cofilin。我们的新发现表明，TNBCs中NEDD9表达的减少导致AURKA移位到细胞核。核AURKA的存在与转移定植的增加和对AURKA抑制剂的敏感性有关，但这种现象的分子机制及其在肿瘤进展和转移中的作用目前尚不清楚。有趣的是，NEDD9在HER2肿瘤中的缺失减少了转移，因此提示NEDD9在HER2 BCS中的不同作用。我们的新发现表明NEDD9是一种重要的增殖和敏感性调节因子 通过调节HER2的贩运/回收，HER2乳腺癌对赫赛汀的作用。本应用的目的是利用特征化的细胞系、患者来源的异种移植细胞和条件性NEDD9敲入小鼠模型，确定核AURKA在TN和HER2乳腺癌转移中的作用。我们的中心假设是，NEDD9需要AURKA滞留在细胞质中，以促进肿瘤细胞的迁移/侵袭，NEDD9的减少导致AURKA的核转位，从而促进TNBCs转移生态位中的细胞存活。此外，NEDD9在HER2 BCS中的上调将导致肿瘤发病率和疾病进展的增加。我们将通过执行以下目标来验证这一假说：目的1.确定NEDD9在AURKA细胞质/核转位中的作用以及核AURKA对转移的影响。我们的假设是，核AURKA通过失活TFEB和激活NUPR1和SOX2通路来促进存活和抗凋亡。目的2.利用转基因小鼠模型和患者来源的异种移植瘤，阐明NEDD9过表达促进HER2乳腺癌的作用和机制。我们的假设是，NEDD9的过表达增强了HER2驱动的肿瘤发生，并通过上调HER2蛋白和通过晚期内容体进行循环来赋予Herceptin抵抗。

 DESCRIPTION (provided by applicant): HEF1/NEDD9 is a cytoplasmic adaptor protein and a well-established marker of poor prognosis in different cancers with invasive tumor signature. We have previously reported that NEDD9 regulates stability and activation of mitotic kinase AurA/AURKA leading to phosphorylation of multiple cytoplasmic substrates, such as HDAC6, Src, CTTN, Arp/C and cofilin involved in migration and invasion. Our novel findings indicate that decrease in NEDD9 expression in TNBCs leads to translocation of AURKA to the nucleus. Presence of nuclear AURKA correlates with increase in metastatic colonization and sensitivity to AURKA inhibitors, but molecular mechanisms of this phenomenon and its role in tumor progression and metastasis is currently unknown. Interestingly, depletion of NEDD9 in HER2+ cancers decreases metastasis, thus suggesting differential role of NEDD9 in HER2+ BCs. Our novel findings indicate that NEDD9 emerges as a critical regulator of proliferation and sensitivity of HER2+ breast cancers to Herceptin via regulation of HER2 trafficking/recycling. The objective of this application is to determine the role of nuclear AURKA in metastasis in TN and HER2+ breast cancers using characterized cell lines, patient-derived xenografts and a conditional NEDD9 knock-in mouse model. Our central hypothesis is that NEDD9 is required for retention of AURKA in the cytoplasm to promote migration/invasion of tumor cells and a decrease in NEDD9 leads to nuclear translocation of AURKA, thus promoting cell survival in the metastatic niche of TNBCs. Furthermore, upregulation of NEDD9 in HER2+ BCs will lead to an increase in tumor incidence and disease progression. We will test this hypothesis by execution of the following aims: AIM 1. Determine the role of NEDD9 in AURKA cytoplasmic/nuclear translocation and the impact of nuclear AURKA on metastasis. Our hypothesis is that nuclear AURKA promotes survival and resistance to apoptosis, through the inactivation TFEB and activation of NUPR1 and Sox2 pathways. AIM 2. Elucidate the role and mechanisms by which overexpression of NEDD9 promotes HER2+ breast cancer using genetically modified mouse models and patient derived xenografts. Our hypothesis is that overexpression of NEDD9 heightens HER2-driven tumorigenesis and confers Herceptin resistance via upregulation of HER2 protein and recycling via late endosomes.