Chemotherapy-driven evolution of the vascular secretome and its role in therapeutic resistance

项目总结 我们仍然无法开发出防止播散性乳腺肿瘤出现的选择性治疗方法 将细胞转化为致命转移需要新的方法。我们已经证明了播散性肿瘤细胞 (DCs)占据血管周围壁龛(PVN)，这个壁龛促进化疗耐药，并且 DTCs和PVN之间的靶向相互作用使DTCs对化疗增敏。翻译这个 乳腺癌临床前模型的方法防止了超过60%的高危小鼠的转移。 对其余小鼠的抗性机制(S)的质疑使我们考虑了动态反应 从血管壁龛到化疗。我们的初步数据表明，基因毒性物质会触发 将促生存因子分泌到PVN中，这是这种化疗相关的主要触发因素 血管分泌体是DNA损伤反应(DDR)。因此，在这里，我们的目标是针对目标(即， DDR)和血管进化的后果(即，化疗相关的血管分泌体)， 我们怀疑这会增加DTCs的治疗耐药性。我们将通过两个具体目标实现这一目标： 具体目的1.确定单个细胞外因子是否由血管内皮细胞通过 化疗可以保护DTC。我们已经定义了全球血管对DNA损伤剂的反应。Netrin-1 是这个分泌组的重要组成部分，具有已知的促进生存的功能。我们的数据显示远藤- 内皮来源的Netrin-1保护DCs免受化疗的影响。利用器官型、转基因和临床前模式 我们将确定：i)内皮细胞是否是化疗诱导的Netrin-1的相关来源 体内；ii)靶向Netrin-1作为佐剂是否使DCs对化疗敏感；iii)该Syner- 针对PVN中先前存在的保护因素；以及iv)这些方法的安全性。 特定目的2.确定血管内皮细胞DNA损伤驱动的信号通路，从而诱导 化疗相关的血管分泌体。我们的初步数据表明，基因毒性疗法会引起 一种来自静止内皮细胞的刻板的DDR，靶向这一反应的核子可使mA- 化疗相关的血管分泌体的优势。此方法可能是更可靠的替代方案 靶向单一的支持生存的因子，如Netrin-1。在这里，我们将识别和定位信号通路 将DDR连接到血管分泌组，并测量这种方法的有效性和毒性。 这项工作的意义和创新之处在于发现了化学保护的起源和产物 DTC利基市场中的因素。针对这两个目标将导致第一种方法专门针对DTC，影响 乳腺癌的存活率是积极和持久的。

PROJECT SUMMARY Our continued inability to develop selective therapies that prevent the emergence of disseminated breast tumor cells into lethal metastases necessitates new approaches. We have shown that disseminated tumor cells (DTCs) occupy the perivascular niche (PVN), that this niche promotes chemotherapeutic resistance, and that targeting interactions between DTCs and the PVN sensitizes DTCs to chemotherapy. Translating this approach to pre-clinical models of breast cancer prevented metastases in over 60% of at-risk mice. Questioning the mechanism(s) of resistance in the remainder of mice led us to consider the dynamic response of the vascular niche to chemotherapy. Our preliminary data indicate that genotoxic agents trigger the secretion of pro-survival factors into the PVN, and that the major trigger of this chemotherapy-associated vascular secretome is the DNA damage response (DDR). Therefore, here our goal is to target the cause (i.e., the DDR) and the consequence (i.e., the chemotherapy-associated vascular secretome) of vascular evolution, which we suspect promotes therapeutic resistance of DTCs. We will pursue this goal through 2 specific aims: Specific Aim 1. To determine whether individual extracellular factors elicited from vascular endothelium by chemotherapy protect DTCs. We have defined a global vascular response to DNA damaging agents. Netrin-1 is a prominent component of this secretome with documented pro-survival functions. Our data show that endo- thelial-derived Netrin-1 protects DTCs from chemotherapy. Using organotypic, transgenic and preclinical mod- els, we will determine: i) whether endothelial cells are the relevant source of chemotherapy-elicited Netrin-1 in vivo; ii) whether targeting Netrin-1 as an adjuvant sensitizes DTCs to chemotherapy; iii) whether this syner- gizes with targeting pre-existing protective factors in the PVN; and iv) the safety of these approaches. Specific Aim 2. To identify DNA damage driven signaling pathways in vascular endothelium that induce the chemotherapy-associated vascular secretome. Our preliminary data demonstrate that genotoxic therapy elicits a stereotypic DDR from quiescent endothelium, and that targeting a nucleator of this response mutes the ma- jority of the chemotherapy-associated vascular secretome. This approach may be a more robust alternative to targeting a single pro-survival factor such as Netrin-1. Here, we will identify and target the signaling pathway that connects DDR to the vascular secretome, and measure the efficacy and toxicity of this approach. The significance and innovation of this work lie in the discovery of origins and outputs of chemoprotective factors in the DTC niche. Targeting both will result in the first approach to specifically target DTCs, impacting breast cancer survival in a positive and lasting fashion.