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

项目摘要 我们仍然无法开发出预防播散性乳腺肿瘤出现的选择性疗法， 细胞转化为致命的转移需要新的方法。我们已经证明了扩散的肿瘤细胞 （DTC）占据血管周围生态位（PVN），该生态位促进化疗抗性，并且 靶向DTC和PVN之间的相互作用使DTC对化疗敏感。翻译这 乳腺癌临床前模型的方法在超过60%的高危小鼠中预防了转移。 对剩余小鼠的抵抗机制的质疑使我们考虑了动态反应， 化疗的血管利基。我们的初步数据表明，遗传毒性剂触发 促生存因子分泌到PVN中，并且这种化疗相关的主要触发因素 血管分泌组是DNA损伤反应（DDR）。因此，我们的目标是针对原因（即， DDR）和结果（即，化疗相关的血管分泌物组）的血管演变， 我们怀疑其促进了DTC的治疗抗性。我们将通过两个具体目标来实现这一目标： 具体目标1。为了确定单个细胞外因子是否由血管内皮引起， 化疗可保护DTC。我们已经确定了一个全球性的血管反应的DNA损伤剂。Netrin-1 是该分泌蛋白质组的重要组成部分，具有记录的促生存功能。我们的数据显示内- 内皮衍生的Netrin-1保护DTC免受化疗。使用器官型，转基因和临床前模型- 因此，我们将确定：i）内皮细胞是否是化疗引起的Netrin-1的相关来源， 体内; ii）靶向Netrin-1作为佐剂是否使DTC对化疗敏感; iii）这种合成物是否 与靶向PVN中预先存在的保护因素有关;以及iv）这些方法的安全性。 具体目标2。为了确定血管内皮细胞中DNA损伤驱动的信号通路， 化疗相关的血管分泌蛋白。我们的初步数据表明，遗传毒性治疗 一个刻板的DDR从静止的内皮细胞，并以核因子的这种反应静音的主要- 大多数化疗相关的血管分泌物。这种方法可能是一个更强大的替代方案， 靶向单个促存活因子如Netrin-1。在这里，我们将识别和靶向信号通路 将DDR连接到血管分泌蛋白质组，并测量这种方法的有效性和毒性。 本工作的意义和创新之处在于发现了化学保护作用的来源和产物， DTC利基的因素。以两者为目标将产生专门针对DTC的第一种方法， 乳腺癌患者的生存率是积极和持久的。

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.