Prometastatic Effects of Neoadjuvant Chemotherapy in Breast Cancer

项目摘要 转移，即癌细胞从原发肿瘤扩散到继发部位，是导致 癌症相关死亡率。虽然化疗提高了早期乳腺癌的总体存活率，但它并不能 为转移提供确切的治疗方法。矛盾的是，化疗会导致肿瘤的转移性改变 如果在术前(新辅助)环境中给予微环境。这些有利于转移的变化是 主要是通过促血管生成的Tie2Hi巨噬细胞侵袭肿瘤而启动的，这是必不可少的 癌细胞内渗部位的成分称为肿瘤转移微环境(TMEM)。仅限 表达MenaINV的侵袭性和迁移性癌细胞可通过TMEM扩散。在小鼠的乳房 肿瘤和患者来源的异种移植，新辅助化疗增加(I)TMEM组装，(Ii) 表达MenaINV的癌细胞密度，(Iii)循环中肿瘤细胞的数量，以及(Iv)肺转移。 这项建议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，从而预测生物标记物和靶向信号通路 可以确定“化疗引起的转移”的可能性。我们假设巨噬细胞招募到 基于新辅助化疗的肿瘤不仅通过以下途径培养肿瘤细胞变得具有扩散能力 通过旁分泌相互作用诱导MenaINV的表达，但也获得启动肿瘤的能力 负责远距离部位的肿瘤生长。在目标1中，我们将研究巨噬细胞癌 MenaINV和MenaINV介导的前转移表型的诱导需要细胞相互作用 采用新辅助化疗治疗。这将通过已建立的巨噬细胞耗竭来实现 活体研究，加上先进的显微镜。在目标2中，我们将研究乳腺肿瘤细胞 表达MenaINV-Hi还具有干细胞能力。表达荧光干细胞的MDA-MB-231细胞 报告(SORE6)将用于产生用于多光子活体成像显微镜的异种移植物，并固定- 组织多道免疫荧光显微镜观察及新辅助化疗对肿瘤细胞的影响 肿瘤细胞干性。AIM 3旨在解开导致上述疾病的信号通路 支持转移的表型。靶向相关基因的转基因和药物抑制小鼠模型 将开发旁分泌途径来消除巨噬细胞-肿瘤细胞的相互作用，并研究是否 这些途径在化疗诱导的转移中起着重要作用。艾伯特大学的研究环境 爱因斯坦医学院为合作、科学讨论和 职业发展。拟议的学习和职业发展培训加上一支出色的团队 康迪利斯博士是高级显微镜专家，奥克泰博士是内科科学家，韦克菲尔德博士是 干细胞研究，以及巨噬细胞生物学的领导者理查德·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.