Characterizing the role of TAK1 in breast cancer metastasis

项目总结/摘要 大多数与癌症相关的死亡是由转移引起的，转移是一个复杂的过程，由肿瘤细胞的扩散引起。 肿瘤细胞进入循环，在那里它们被称为循环肿瘤细胞（CTC）。其中一个限制 预防或治疗转移的步骤是我们对肿瘤转移的生物学特性的认识不足。 CTC，即含有转移性前体的群体。我们之前开发了一种微流体装置 在人和小鼠中高效分离CTC。我们对胰腺CTC的分析工作 发现MAP 3 K7，也称为TGF-β激活的激酶（TAK 1），在促进 抗失巢凋亡-细胞外基质脱落诱导的细胞凋亡， 促进CTC在转运到远处的过程中存活。此外，我们最近的研究表明， 转移性乳腺癌患者的CTC中上皮-间质转化（EMT）的证据， 相关的信号通路，其中之一是众所周知的EMT诱导细胞因子- TGF-β。作为 TGF-β下游靶点TAK 1可能参与EMT过程，因此值得进一步研究。我 Oncomine数据库中的初步分析表明，乳腺癌中TAK 1的表达显著较高， 然而，相对于其他类型的癌症，TAK 1在乳腺癌中的作用还没有得到很好的研究。在 在初步实验中，我还发现悬浮培养的乳腺癌细胞对 TAK 1抑制。所有先前的工作导致假设TAK 1可能在促进细胞增殖中起重要作用。 乳腺癌转移胰腺癌在诊断时通常是转移性的，而乳腺癌在诊断时通常是转移性的。 癌症遵循更长的过程，其中防止血液传播转移的能力可能具有真实的 临床应用。因此，所提出的实验的总体目标是理解TAK 1信号传导 参与乳腺癌转移的途径，包括分析失巢凋亡抵抗，EMT， 及其在乳腺癌转移小鼠模型中的重要性。我将分析TAK 1在失巢凋亡中的作用 通过引入不同的TAK 1构建体， 激活TAK 1或消除TAK 1激酶功能。此外，我将研究TAK 1在 促进乳腺癌细胞的EMT。最后，我将评估抑制TAK 1的功能后果， 通过强力霉素诱导的对TK 1的抑制，在异种移植乳腺中的CTCs和转移瘤形成中 癌症转移小鼠模型。完成这些目标将有助于更好地理解这一重要的 激酶途径，并为预防乳腺癌靶向途径提供潜在的临床前数据 传播。拟议工作的总体职业发展目标是使我能够开始一个 富有成效的，独立的研究生涯，专注于了解乳腺癌的机制 转移 !

PROJECT SUMMARY/ABSTRACT Majority of cancer-related deaths are caused by metastasis, a complex process initiated by spreading of tumor cells into circulation, where they are referred to as circulating tumor cells (CTCs). One of the limiting steps towards preventing or treating metastasis is our insufficient knowledge of the biological properties of CTCs, the population that contains metastatic precursors. We have previously developed a microfluidic device to isolate CTCs with high efficiency in human and mice. Our work on analyzing pancreatic CTCs have identified that MAP3K7, also called TGF-¿ activated kinase (TAK1), plays an important role in promoting resistance to anoikis - apoptosis induced by detachment from the extracellular matrix, one of the features to facilitate CTCs to survive during transit to distant sites. In addition, our most recent research has demonstrated the evidence of epithelial-mesenchymal transition (EMT) in CTCs of metastatic breast cancer patients and associated signaling pathways, one of which is the well-known EMT inducing cytokine - TGF-¿. As a downstream target of TGF-¿, TAK1 may be involved in the EMT process thus warrant further investigation. My pilot analysis in Oncomine database indicated a significantly higher expression of TAK1 in breast cancers relative to other type of cancers, however, the role of TAK1 is not very well investigated in breast cancers. In preliminary experiments, I also found that breast cancer cells grown in suspension are exquisitely sensitive to TAK1 inhibition. All the prior work lead to the hypothesis that TAK1 may play an important role in promoting breast cancer metastasis. Whereas pancreatic cancer is often metastatic at the time of diagnosis, breast cancer follows a more prolonged course, where the ability to prevent blood borne metastasis may have real clinical application. Thus, the overall goal of the proposed experiments is to understand the TAK1 signaling pathways involved in breast cancer metastasis, including analyzing the features of anoikis resistance, EMT, and its importance in breast cancer metastatic mouse models. I will analyze the role of TAK1 on anoikis resistance in different subtypes of breast cancer cells by introducing different constructs of TAK1 that can either activate TAK1 or abolish TAK1 kinase function. In addition, I will examine the contribution of TAK1 in promoting EMT in breast cancer cells. Finally, I will evaluate the functional consequences of inhibiting TAK1, via a doxycycline-inducible suppression of TAK1, in CTCs and metastases formation in a xenograft breast cancer metastatic mouse model. Completing these goals will lead to a better understanding of this important kinase pathway and provide potential pre-clinical data on a targetable pathway for preventing breast cancer dissemination. The overall career development goal of the proposed work is to enable me to begin a productive, independent research career focusing on understanding the mechanisms of breast cancer metastasis. !