Prometastatic Effects of Neoadjuvant Chemotherapy in Breast Cancer

项目概要 转移，即癌细胞从原发肿瘤扩散到继发部位，是导致癌症的主要原因 癌症相关死亡率。尽管化疗可以提高早期乳腺癌的总体生存率，但它并不能 为转移提供明确的治愈。矛盾的是，化疗会引起肿瘤的促转移变化 如果在术前（新辅助）环境中给予微环境。这些促转移的变化是 主要通过促血管生成 Tie2Hi 巨噬细胞浸润肿瘤启动，这是必不可少的 癌细胞浸润部位的组成部分称为肿瘤转移微环境（TMEM）。仅 表达 MenaINV 的侵袭性和迁移性癌细胞可以通过 TMEM 传播。在小鼠乳腺中 癌症和患者来源的异种移植物，新辅助化疗增加 (i) TMEM 组装，(ii) 表达 MenaINV 的癌细胞密度，(iii) 循环肿瘤细胞的数量，以及 (iv) 肺转移。 该提案将阐明化疗发挥这些促转移作用的分子机制 乳腺肿瘤微环境的变化，使预测生物标志物和靶向信号通路 可以识别“化疗引起的转移”。我们假设巨噬细胞被招募来 新辅助化疗后的肿瘤不仅通过以下方式使肿瘤细胞具有传播能力： 通过近分泌相互作用诱导 MenaINV 表达，同时也获得肿瘤启动能力 负责远处部位肿瘤生长的起始。在目标 1 中，我们将研究巨噬细胞癌是否 细胞相互作用是诱导 MenaINV 和 MenaINV 介导的促转移表型所必需的 新辅助化疗治疗。这将通过已建立的巨噬细胞耗竭来完成 体内研究，结合先进的显微镜。在目标 2 中，我们将研究乳腺肿瘤细胞是否 表达 MenaINV-Hi 也具有干细胞功能。表达荧光干细胞的 MDA-MB-231 细胞 报告基因（SORE6）将用于生成用于多光子活体成像显微镜和固定的异种移植物 组织多通道免疫荧光显微镜观察新辅助化疗对患者的影响 肿瘤细胞干性。目标 3 旨在解开导致上述现象的信号通路 促转移表型。针对相关的转基因和药理抑制小鼠模型 将开发近分泌途径以消除巨噬细胞-肿瘤细胞的相互作用，并研究是否 这些途径有助于化疗引起的转移。艾伯特的研究环境 爱因斯坦医学院为合作、科学讨论和研究提供了绝佳的机会 职业发展。拟议的研究和职业发展培训以及优秀的团队 高级显微镜专家 Condeelis 博士、医学科学家 Oktay 博士、医学先驱 Wakefield 博士 干细胞研究和巨噬细胞生物学领域的领导者理查德·斯坦利博士将确保我实现我的目标 在一所主要大学建立一个成功的、独立资助的实验室。

Project Summary Metastasis, the dissemination of cancer cells from the primary tumor to secondary sites, is the leading cause of cancer-related mortality. Although chemotherapy improves overall survival in early breast cancer, it does not provide definite cure for metastasis. Paradoxically, chemotherapy induces pro-metastatic changes in the tumor microenvironment if given in the pre-operative (neo-adjuvant) setting. These pro-metastatic changes are primarily initiated via infiltration of tumors by pro-angiogenic Tie2Hi macrophages, which are essential components of cancer cell intravasation sites called Tumor MicroEnvironment of Metastasis (TMEM). Only invasive and migratory cancer cell expressing MenaINV can disseminate via TMEM. In mouse mammary carcinoma and patient derived xenografts, neo-adjuvant chemotherapy increases (i) TMEM assembly, (ii) the density of cancer cells expressing MenaINV, (iii) the number of circulating tumor cells, and (iv) lung metastases. This proposal will elucidate molecular mechanisms by which chemotherapy exerts these pro-metastatic changes in the breast tumor microenviroment, so that predictive biomarkers and targetable signaling pathways of “chemotherapy-induced metastasis” can be identified. We hypothesize that macrophages recruited to tumors upon neo-adjuvant chemotherapy educate tumor cells not only to become dissemination-competent by inducing MenaINV expression through juxtacrine interactions, but also to obtain tumor-initiating capabilities responsible for tumor growth initiation at distant sites. In Aim 1, we will investigate whether macrophage-cancer cell interaction is required for induction of MenaINV and MenaINV-mediated pro-metastatic phenotypes upon treatment with neo-adjuvant chemotherapy. This will be accomplished using established macrophage depletion studies in vivo, coupled with advanced microscopy. In Aim 2, we will investigate whether breast tumor cells expressing MenaINV-Hi also harbor stem cell capabilities. MDA-MB-231 cells expressing a fluorescent stem cell reporter (SORE6) will be used to generate xenografts for multiphoton intravital imaging microscopy and fixed- tissue multichannel immune-fluorescent microscopy and study the effects of neo-adjuvant chemotherapy on tumor cell stemness. Aim 3 is designed to unravel the signaling pathways responsible for the aforementioned pro-metastatic phenotypes. Transgenic and pharmacological inhibition mouse models targeting the relevant juxtacrine pathways will be developed to eliminate macrophage-tumor cell interactions and study whether these pathways are instrumental in chemotherapy-induced metastasis. The research environment at the Albert Einstein College of Medicine offers outstanding opportunities for collaborations, scientific discussion and career development. The proposed studies and career development training coupled with an exceptional team of Dr. Condeelis, expert in advanced microscopy, Dr. Oktay, physician scientist, Dr. Wakefield a pioneer in stem cell research, and Dr. Richard Stanley, leader in macrophage biology, will ensure that I achieve my goal of establishing a successful, independently-funded lab at a major university.