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

 描述（由申请人提供）：HEF 1/NEDD 9是一种细胞质衔接蛋白，是具有侵袭性肿瘤特征的不同癌症中预后不良的公认标志物。我们先前已经报道了NEDD 9调节有丝分裂激酶AurA/AURKA的稳定性和活化，导致多种细胞质底物的磷酸化，例如参与迁移和侵袭的HDAC 6、Src、CTTN、阿普/C和cofilin。我们的新发现表明，TNBC中NEDD 9表达的降低导致AURKA易位到细胞核。核AURKA的存在与转移性定殖的增加和对AURKA抑制剂的敏感性相关，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，HER 2+癌症中NEDD 9的消耗降低了转移，从而表明NEDD 9在HER 2 + BC中的不同作用。我们的新发现表明，NEDD 9是增殖和敏感性的关键调节因子 HER 2+乳腺癌通过调节HER 2运输/再循环对赫赛汀的作用。本申请的目的是使用表征的细胞系、患者来源的异种移植物和条件性NEDD 9敲入小鼠模型确定核AURKA在TN和HER 2+乳腺癌转移中的作用。我们的中心假设是NEDD 9是AURKA保留在细胞质中以促进肿瘤细胞迁移/侵袭所必需的，并且NEDD 9的减少导致AURKA的核易位，从而促进TNBC的转移性小生境中的细胞存活。此外，HER 2 + BC中NEDD 9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测试这一假设：AIM 1。确定NEDD 9在AURKA胞质/核易位中的作用以及核AURKA对转移的影响。我们的假设是，核AURKA通过灭活TFEB和激活NUPR 1和Sox 2途径促进存活和抗凋亡。AIM 2.使用基因修饰小鼠模型和患者来源的异种移植物阐明NEDD 9过表达促进HER 2+乳腺癌的作用和机制。我们的假设是，NEDD 9的过表达通过上调HER 2蛋白和通过晚期内体再循环来增强HER 2驱动的肿瘤发生并赋予赫赛汀抗性。

 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.