Project-1: Defining the mechanisms by which neurons promote breast cancer metastasis

项目摘要 肿瘤是癌细胞、浸润宿主细胞、分泌因子和细胞外基质的异质群体。 基质蛋白-共同构成肿瘤微环境。肿瘤微环境对肿瘤的发生 在支持肿瘤起始、存活、进展和转移中的作用。我们发现肿瘤 内皮细胞为癌细胞提供了“指导性”信号，从而驱动转移进展。我们找到了狭缝2 一种轴突导向分子，在转移性肿瘤的内皮细胞中被上调。内皮特异 Slit 2的缺失强烈抑制转移。在一个令人惊讶的发现中，我们发现内皮细胞-Slit 2缺失 还损害肿瘤神经支配。神经只是开始被认为是肿瘤间质中的关键角色， 最近的证据表明它们是胃癌和前列腺癌的肿瘤起始所必需的。在 乳腺癌，虽然有一些初步的证据表明，神经支配与肿瘤 侵袭性、转移的神经依赖性尚未被探索。在本项目中，我们将定义 研究原发性乳腺肿瘤间质内神经元的变化，并了解神经元如何调节转移。使用 差异转移潜能的等基因细胞系，逆行追踪和成像研究，我们将首先确定 调节乳腺癌转移的神经元亚群。我们将使用3D共培养系统， 去神经实验，以确定神经元在肿瘤侵袭，增殖，局部和全身的作用 传播、远缘播种和转移性生长。我们还将评估肿瘤神经支配在 乳腺癌的治疗耐药性。接下来，我们将使用无偏测序方法来定义肿瘤- 营养因子由神经元分泌并描绘癌细胞中的下游信号传导轴。最后我们将 描述内皮细胞在引导神经元进入转移性肿瘤中的作用，并确定是否有促血管生成的作用。 神经元的转移效应部分由免疫细胞介导。拟议的跨学科研究计划 结合了分子、遗传、生物化学、成像和计算方法， 乳腺癌转移进展的神经调节模型。总的来说，这些研究将定义 肿瘤内内皮细胞、神经元和免疫细胞之间的细胞和分子相互作用 微环境-我们提出的MetNet研究中心的首要目标。这些研究 具有巨大的影响潜力，因为它们可以确定干扰神经肿瘤的新治疗靶点， 驱动转移的信号轴。

Project Summary Tumors are a heterogenous population of cancer cells, infiltrating host cells, secreted factors and extracellular matrix proteins–together comprising the tumor microenvironment. The tumor microenvironment plays profound roles in supporting tumor initiation, survival, progression and metastasis. We have discovered that tumor endothelial cells provide an “instructive” signal to cancer cells that drives metastatic progression. We found Slit2, an axon guidance molecule, to be upregulated in endothelial cells within metastatic tumors. Endothelial-specific deletion of Slit2 strongly inhibited metastasis. In a surprising discovery, we found that endothelial-Slit2 deletion also impairs tumor innervation. Nerves are only starting to be recognized as key players within the tumor stroma, with recent evidence demonstrating their requirement for tumor initiation of gastric and prostate cancers. In breast cancer, although there is some preliminary evidence that innervation correlates with tumor aggressiveness, nerve dependence for metastasis has not been explored. In this Project, we will define the role of neurons within the stroma of primary breast tumors and understand how neurons regulate metastasis. Using isogenic cell lines of differential metastatic potential, retrograde tracing and imaging studies, we will first identify neuronal sub-populations that regulate breast cancer metastasis. We will use 3D co-culture systems and in vivo denervation experiments to identify the role of neurons in tumor invasion, proliferation, local and systemic dissemination, distant seeding, and metastatic outgrowth. We will also evaluate the role of tumor innervation in therapeutic resistance in breast cancer. Next, we will use unbiased sequencing approaches to define tumor- trophic factors secreted by neurons and delineate downstream signaling axes in cancer cells. Finally, we will characterize the role of endothelial cells in guiding neurons into metastatic tumors and determine if the pro- metastatic effects of neurons are partly mediated by immune cells. The proposed inter-disciplinary research plan combines molecular, genetic, biochemical, imaging and computational approaches to establish an integrated model for neural regulation of metastatic progression by breast cancer. Collectively, these studies will define the cellular and molecular interactions between endothelial cells, neurons, and immune cells within the tumor microenvironment–an overarching goal of our proposed MetNet research center. These studies have tremendous potential for impact as that they stand to identify novel therapeutic targets that perturb neural-tumoral signaling axes driving metastasis.