THE ROLE OF HEF1 PROTEIN IN INVASION OF METASTATIC BREAST CANCER

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 这项建议的目的是确定前转移蛋白HEF1在乳腺癌转移到小鼠原位模型中的作用。异种移植模型的开发是合理的，因为我们需要确定HEF1影响的转移步骤，以开发针对HEF1通常过度表达的晚期乳腺癌患者的治疗策略。我们建立了几个高转移性乳腺癌细胞系，调控表达HEF1和针对HEF1的shRNA，以直接在小鼠肿瘤模型中测试其促进细胞迁移、侵袭和增殖的作用。随后，我们将确定HEF1下游靶点Aurora-A和HDAC6如何影响转移性乳腺癌细胞有丝分裂进程和侵袭的调节。在目标1中，我们将通过将HEF1操纵的肿瘤细胞注射到SCID小鼠的乳房脂肪垫中，在体内评估转移性乳腺癌细胞中HEF1缺失/或过表达的后果。我们将使用非侵入性多模式成像技术跟踪肿瘤生长、扩散和远处定植的步骤。在目标2中，我们将评估HEF1激活蛋白AURA和HDAC6在转移中的作用，并基于HEF1在肿瘤细胞中的表达来评估目前正在进行的转移性乳腺癌临床试验中的AURA和HDAC6抑制剂的疗效。这一分析将使我们能够确定HEF1表达在转移的每个阶段的影响，确定AURA和HDAC6在HEF1驱动的过程中的作用，并为未来的药物开发发展机制基础。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The goal of this proposal is to define the role of pro-metastatic protein HEF1 in breast cancer metastasis to mouse orthotopic models. Development of xenograft models is justified based on our need to identify the steps of metastasis affected by HEF1 to develop therapeutic strategies for advanced stage breast cancer patients where HEF1 is commonly overexpressed. We have established several highly metastatic breast cancer cell lines with regulated expression of HEF1 and shRNA against HEF1 to directly test its action in promoting cell migration, invasion and proliferation in mouse tumor models. Subsequently, we will define how HEF1 downstream targets, Aurora-A and HDAC6, affect the regulation of mitotic progression and invasion of metastatic breast cancer cells. In Aim 1, we will assess the consequences of HEF1 depletion/or overexpression in metastatic breast cancer cells in vivo, by injecting HEF1 -manipulated tumor cells into the mammary fat pads of SCID mice. We will follow tumor growth, dissemination, and distant sites colonization steps using non-invasive multimodal imaging techniques. In Aim 2 we will assess the role of HEF1 activated proteins AurA and HDAC6 in metastasis and evaluate efficacy of AurA and HDAC6 inhibitors currently in clinical trials for metastatic breast cancer treatment based on the expression of HEF1 in the tumor cells. This analysis will enable us to determine the impact of HEF1 expression at each stage of metastasis, define the role of AurA and HDAC6 in HEF1-driven processes, and develop the mechanistic rationale for future drug development.